1df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann/* 2df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * I2C bus driver for the Cadence I2C controller. 3df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * 4df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * Copyright (C) 2009 - 2014 Xilinx, Inc. 5df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * 6df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * This program is free software; you can redistribute it 7df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * and/or modify it under the terms of the GNU General Public 8df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * License as published by the Free Software Foundation; 9df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * either version 2 of the License, or (at your option) any 10df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * later version. 11df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann */ 12df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 13df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#include <linux/clk.h> 14df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#include <linux/delay.h> 15df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#include <linux/i2c.h> 16df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#include <linux/interrupt.h> 17df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#include <linux/io.h> 18df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#include <linux/module.h> 19df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#include <linux/platform_device.h> 20df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 21df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann/* Register offsets for the I2C device. */ 22df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#define CDNS_I2C_CR_OFFSET 0x00 /* Control Register, RW */ 23df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#define CDNS_I2C_SR_OFFSET 0x04 /* Status Register, RO */ 24df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#define CDNS_I2C_ADDR_OFFSET 0x08 /* I2C Address Register, RW */ 25df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#define CDNS_I2C_DATA_OFFSET 0x0C /* I2C Data Register, RW */ 26df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#define CDNS_I2C_ISR_OFFSET 0x10 /* IRQ Status Register, RW */ 27df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#define CDNS_I2C_XFER_SIZE_OFFSET 0x14 /* Transfer Size Register, RW */ 28df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#define CDNS_I2C_TIME_OUT_OFFSET 0x1C /* Time Out Register, RW */ 29df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#define CDNS_I2C_IER_OFFSET 0x24 /* IRQ Enable Register, WO */ 30df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#define CDNS_I2C_IDR_OFFSET 0x28 /* IRQ Disable Register, WO */ 31df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 32df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann/* Control Register Bit mask definitions */ 33df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#define CDNS_I2C_CR_HOLD BIT(4) /* Hold Bus bit */ 34df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#define CDNS_I2C_CR_ACK_EN BIT(3) 35df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#define CDNS_I2C_CR_NEA BIT(2) 36df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#define CDNS_I2C_CR_MS BIT(1) 37df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann/* Read or Write Master transfer 0 = Transmitter, 1 = Receiver */ 38df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#define CDNS_I2C_CR_RW BIT(0) 39df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann/* 1 = Auto init FIFO to zeroes */ 40df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#define CDNS_I2C_CR_CLR_FIFO BIT(6) 41df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#define CDNS_I2C_CR_DIVA_SHIFT 14 42df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#define CDNS_I2C_CR_DIVA_MASK (3 << CDNS_I2C_CR_DIVA_SHIFT) 43df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#define CDNS_I2C_CR_DIVB_SHIFT 8 44df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#define CDNS_I2C_CR_DIVB_MASK (0x3f << CDNS_I2C_CR_DIVB_SHIFT) 45df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 46df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann/* Status Register Bit mask definitions */ 47df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#define CDNS_I2C_SR_BA BIT(8) 48df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#define CDNS_I2C_SR_RXDV BIT(5) 49df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 50df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann/* 51df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * I2C Address Register Bit mask definitions 52df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * Normal addressing mode uses [6:0] bits. Extended addressing mode uses [9:0] 53df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * bits. A write access to this register always initiates a transfer if the I2C 54df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * is in master mode. 55df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann */ 56df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#define CDNS_I2C_ADDR_MASK 0x000003FF /* I2C Address Mask */ 57df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 58df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann/* 59df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * I2C Interrupt Registers Bit mask definitions 60df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * All the four interrupt registers (Status/Mask/Enable/Disable) have the same 61df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * bit definitions. 62df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann */ 63df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#define CDNS_I2C_IXR_ARB_LOST BIT(9) 64df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#define CDNS_I2C_IXR_RX_UNF BIT(7) 65df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#define CDNS_I2C_IXR_TX_OVF BIT(6) 66df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#define CDNS_I2C_IXR_RX_OVF BIT(5) 67df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#define CDNS_I2C_IXR_SLV_RDY BIT(4) 68df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#define CDNS_I2C_IXR_TO BIT(3) 69df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#define CDNS_I2C_IXR_NACK BIT(2) 70df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#define CDNS_I2C_IXR_DATA BIT(1) 71df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#define CDNS_I2C_IXR_COMP BIT(0) 72df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 73df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#define CDNS_I2C_IXR_ALL_INTR_MASK (CDNS_I2C_IXR_ARB_LOST | \ 74df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann CDNS_I2C_IXR_RX_UNF | \ 75df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann CDNS_I2C_IXR_TX_OVF | \ 76df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann CDNS_I2C_IXR_RX_OVF | \ 77df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann CDNS_I2C_IXR_SLV_RDY | \ 78df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann CDNS_I2C_IXR_TO | \ 79df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann CDNS_I2C_IXR_NACK | \ 80df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann CDNS_I2C_IXR_DATA | \ 81df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann CDNS_I2C_IXR_COMP) 82df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 83df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#define CDNS_I2C_IXR_ERR_INTR_MASK (CDNS_I2C_IXR_ARB_LOST | \ 84df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann CDNS_I2C_IXR_RX_UNF | \ 85df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann CDNS_I2C_IXR_TX_OVF | \ 86df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann CDNS_I2C_IXR_RX_OVF | \ 87df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann CDNS_I2C_IXR_NACK) 88df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 89df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#define CDNS_I2C_ENABLED_INTR_MASK (CDNS_I2C_IXR_ARB_LOST | \ 90df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann CDNS_I2C_IXR_RX_UNF | \ 91df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann CDNS_I2C_IXR_TX_OVF | \ 92df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann CDNS_I2C_IXR_RX_OVF | \ 93df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann CDNS_I2C_IXR_NACK | \ 94df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann CDNS_I2C_IXR_DATA | \ 95df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann CDNS_I2C_IXR_COMP) 96df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 97df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#define CDNS_I2C_TIMEOUT msecs_to_jiffies(1000) 98df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 99df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#define CDNS_I2C_FIFO_DEPTH 16 100df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann/* FIFO depth at which the DATA interrupt occurs */ 101df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#define CDNS_I2C_DATA_INTR_DEPTH (CDNS_I2C_FIFO_DEPTH - 2) 102df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#define CDNS_I2C_MAX_TRANSFER_SIZE 255 103df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann/* Transfer size in multiples of data interrupt depth */ 104df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#define CDNS_I2C_TRANSFER_SIZE (CDNS_I2C_MAX_TRANSFER_SIZE - 3) 105df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 106df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#define DRIVER_NAME "cdns-i2c" 107df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 108df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#define CDNS_I2C_SPEED_MAX 400000 109df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#define CDNS_I2C_SPEED_DEFAULT 100000 110df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 111df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#define CDNS_I2C_DIVA_MAX 4 112df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#define CDNS_I2C_DIVB_MAX 64 113df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 114681d15a0f527af7ab3a783e1037de86fbcb136acVishnu Motghare#define CDNS_I2C_TIMEOUT_MAX 0xFF 115681d15a0f527af7ab3a783e1037de86fbcb136acVishnu Motghare 116df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#define cdns_i2c_readreg(offset) readl_relaxed(id->membase + offset) 117df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#define cdns_i2c_writereg(val, offset) writel_relaxed(val, id->membase + offset) 118df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 119df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann/** 120df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * struct cdns_i2c - I2C device private data structure 121df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * @membase: Base address of the I2C device 122df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * @adap: I2C adapter instance 123df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * @p_msg: Message pointer 124df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * @err_status: Error status in Interrupt Status Register 125df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * @xfer_done: Transfer complete status 126df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * @p_send_buf: Pointer to transmit buffer 127df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * @p_recv_buf: Pointer to receive buffer 128df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * @suspended: Flag holding the device's PM status 129df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * @send_count: Number of bytes still expected to send 130df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * @recv_count: Number of bytes still expected to receive 131df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * @irq: IRQ number 132df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * @input_clk: Input clock to I2C controller 133df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * @i2c_clk: Maximum I2C clock speed 134df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * @bus_hold_flag: Flag used in repeated start for clearing HOLD bit 135df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * @clk: Pointer to struct clk 136df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * @clk_rate_change_nb: Notifier block for clock rate changes 137df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann */ 138df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmannstruct cdns_i2c { 139df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann void __iomem *membase; 140df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann struct i2c_adapter adap; 141df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann struct i2c_msg *p_msg; 142df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann int err_status; 143df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann struct completion xfer_done; 144df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann unsigned char *p_send_buf; 145df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann unsigned char *p_recv_buf; 146df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann u8 suspended; 147df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann unsigned int send_count; 148df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann unsigned int recv_count; 149df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann int irq; 150df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann unsigned long input_clk; 151df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann unsigned int i2c_clk; 152df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann unsigned int bus_hold_flag; 153df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann struct clk *clk; 154df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann struct notifier_block clk_rate_change_nb; 155df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann}; 156df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 157df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann#define to_cdns_i2c(_nb) container_of(_nb, struct cdns_i2c, \ 158df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann clk_rate_change_nb) 159df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 160df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann/** 161df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * cdns_i2c_clear_bus_hold() - Clear bus hold bit 162df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * @id: Pointer to driver data struct 163df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * 164df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * Helper to clear the controller's bus hold bit. 165df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann */ 166df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmannstatic void cdns_i2c_clear_bus_hold(struct cdns_i2c *id) 167df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann{ 168df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann u32 reg = cdns_i2c_readreg(CDNS_I2C_CR_OFFSET); 169df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (reg & CDNS_I2C_CR_HOLD) 170df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann cdns_i2c_writereg(reg & ~CDNS_I2C_CR_HOLD, CDNS_I2C_CR_OFFSET); 171df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann} 172df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 173df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann/** 174df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * cdns_i2c_isr - Interrupt handler for the I2C device 175df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * @irq: irq number for the I2C device 176df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * @ptr: void pointer to cdns_i2c structure 177df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * 178df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * This function handles the data interrupt, transfer complete interrupt and 179df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * the error interrupts of the I2C device. 180df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * 181df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * Return: IRQ_HANDLED always 182df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann */ 183df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmannstatic irqreturn_t cdns_i2c_isr(int irq, void *ptr) 184df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann{ 185df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann unsigned int isr_status, avail_bytes; 186df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann unsigned int bytes_to_recv, bytes_to_send; 187df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann struct cdns_i2c *id = ptr; 188df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann /* Signal completion only after everything is updated */ 189df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann int done_flag = 0; 190df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann irqreturn_t status = IRQ_NONE; 191df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 192df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann isr_status = cdns_i2c_readreg(CDNS_I2C_ISR_OFFSET); 193df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 194df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann /* Handling nack and arbitration lost interrupt */ 195df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (isr_status & (CDNS_I2C_IXR_NACK | CDNS_I2C_IXR_ARB_LOST)) { 196df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann done_flag = 1; 197df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann status = IRQ_HANDLED; 198df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann } 199df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 200df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann /* Handling Data interrupt */ 201df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if ((isr_status & CDNS_I2C_IXR_DATA) && 202df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann (id->recv_count >= CDNS_I2C_DATA_INTR_DEPTH)) { 203df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann /* Always read data interrupt threshold bytes */ 204df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann bytes_to_recv = CDNS_I2C_DATA_INTR_DEPTH; 205df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann id->recv_count -= CDNS_I2C_DATA_INTR_DEPTH; 206df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann avail_bytes = cdns_i2c_readreg(CDNS_I2C_XFER_SIZE_OFFSET); 207df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 208df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann /* 209df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * if the tranfer size register value is zero, then 210df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * check for the remaining bytes and update the 211df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * transfer size register. 212df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann */ 213df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (!avail_bytes) { 214df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (id->recv_count > CDNS_I2C_TRANSFER_SIZE) 215df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann cdns_i2c_writereg(CDNS_I2C_TRANSFER_SIZE, 216df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann CDNS_I2C_XFER_SIZE_OFFSET); 217df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann else 218df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann cdns_i2c_writereg(id->recv_count, 219df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann CDNS_I2C_XFER_SIZE_OFFSET); 220df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann } 221df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 222df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann /* Process the data received */ 223df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann while (bytes_to_recv--) 224df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann *(id->p_recv_buf)++ = 225df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann cdns_i2c_readreg(CDNS_I2C_DATA_OFFSET); 226df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 227df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (!id->bus_hold_flag && 228df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann (id->recv_count <= CDNS_I2C_FIFO_DEPTH)) 229df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann cdns_i2c_clear_bus_hold(id); 230df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 231df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann status = IRQ_HANDLED; 232df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann } 233df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 234df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann /* Handling Transfer Complete interrupt */ 235df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (isr_status & CDNS_I2C_IXR_COMP) { 236df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (!id->p_recv_buf) { 237df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann /* 238df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * If the device is sending data If there is further 239df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * data to be sent. Calculate the available space 240df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * in FIFO and fill the FIFO with that many bytes. 241df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann */ 242df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (id->send_count) { 243df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann avail_bytes = CDNS_I2C_FIFO_DEPTH - 244df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann cdns_i2c_readreg(CDNS_I2C_XFER_SIZE_OFFSET); 245df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (id->send_count > avail_bytes) 246df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann bytes_to_send = avail_bytes; 247df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann else 248df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann bytes_to_send = id->send_count; 249df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 250df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann while (bytes_to_send--) { 251df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann cdns_i2c_writereg( 252df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann (*(id->p_send_buf)++), 253df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann CDNS_I2C_DATA_OFFSET); 254df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann id->send_count--; 255df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann } 256df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann } else { 257df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann /* 258df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * Signal the completion of transaction and 259df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * clear the hold bus bit if there are no 260df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * further messages to be processed. 261df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann */ 262df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann done_flag = 1; 263df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann } 264df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (!id->send_count && !id->bus_hold_flag) 265df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann cdns_i2c_clear_bus_hold(id); 266df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann } else { 267df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (!id->bus_hold_flag) 268df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann cdns_i2c_clear_bus_hold(id); 269df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann /* 270df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * If the device is receiving data, then signal 271df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * the completion of transaction and read the data 272df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * present in the FIFO. Signal the completion of 273df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * transaction. 274df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann */ 275df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann while (cdns_i2c_readreg(CDNS_I2C_SR_OFFSET) & 276df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann CDNS_I2C_SR_RXDV) { 277df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann *(id->p_recv_buf)++ = 278df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann cdns_i2c_readreg(CDNS_I2C_DATA_OFFSET); 279df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann id->recv_count--; 280df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann } 281df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann done_flag = 1; 282df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann } 283df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 284df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann status = IRQ_HANDLED; 285df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann } 286df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 287df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann /* Update the status for errors */ 288df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann id->err_status = isr_status & CDNS_I2C_IXR_ERR_INTR_MASK; 289df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (id->err_status) 290df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann status = IRQ_HANDLED; 291df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 292df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann cdns_i2c_writereg(isr_status, CDNS_I2C_ISR_OFFSET); 293df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 294df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (done_flag) 295df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann complete(&id->xfer_done); 296df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 297df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann return status; 298df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann} 299df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 300df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann/** 301df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * cdns_i2c_mrecv - Prepare and start a master receive operation 302df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * @id: pointer to the i2c device structure 303df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann */ 304df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmannstatic void cdns_i2c_mrecv(struct cdns_i2c *id) 305df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann{ 306df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann unsigned int ctrl_reg; 307df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann unsigned int isr_status; 308df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 309df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann id->p_recv_buf = id->p_msg->buf; 310df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann id->recv_count = id->p_msg->len; 311df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 312df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann /* Put the controller in master receive mode and clear the FIFO */ 313df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann ctrl_reg = cdns_i2c_readreg(CDNS_I2C_CR_OFFSET); 314df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann ctrl_reg |= CDNS_I2C_CR_RW | CDNS_I2C_CR_CLR_FIFO; 315df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 316df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (id->p_msg->flags & I2C_M_RECV_LEN) 317df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann id->recv_count = I2C_SMBUS_BLOCK_MAX + 1; 318df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 319df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann /* 320df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * Check for the message size against FIFO depth and set the 321df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * 'hold bus' bit if it is greater than FIFO depth. 322df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann */ 323df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (id->recv_count > CDNS_I2C_FIFO_DEPTH) 324df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann ctrl_reg |= CDNS_I2C_CR_HOLD; 325df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 326df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann cdns_i2c_writereg(ctrl_reg, CDNS_I2C_CR_OFFSET); 327df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 328df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann /* Clear the interrupts in interrupt status register */ 329df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann isr_status = cdns_i2c_readreg(CDNS_I2C_ISR_OFFSET); 330df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann cdns_i2c_writereg(isr_status, CDNS_I2C_ISR_OFFSET); 331df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 332df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann /* 333df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * The no. of bytes to receive is checked against the limit of 334df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * max transfer size. Set transfer size register with no of bytes 335df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * receive if it is less than transfer size and transfer size if 336df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * it is more. Enable the interrupts. 337df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann */ 338df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (id->recv_count > CDNS_I2C_TRANSFER_SIZE) 339df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann cdns_i2c_writereg(CDNS_I2C_TRANSFER_SIZE, 340df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann CDNS_I2C_XFER_SIZE_OFFSET); 341df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann else 342df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann cdns_i2c_writereg(id->recv_count, CDNS_I2C_XFER_SIZE_OFFSET); 343df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann /* Clear the bus hold flag if bytes to receive is less than FIFO size */ 344df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (!id->bus_hold_flag && 345df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann ((id->p_msg->flags & I2C_M_RECV_LEN) != I2C_M_RECV_LEN) && 346df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann (id->recv_count <= CDNS_I2C_FIFO_DEPTH)) 347df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann cdns_i2c_clear_bus_hold(id); 348df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann /* Set the slave address in address register - triggers operation */ 349df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann cdns_i2c_writereg(id->p_msg->addr & CDNS_I2C_ADDR_MASK, 350df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann CDNS_I2C_ADDR_OFFSET); 351df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann cdns_i2c_writereg(CDNS_I2C_ENABLED_INTR_MASK, CDNS_I2C_IER_OFFSET); 352df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann} 353df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 354df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann/** 355df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * cdns_i2c_msend - Prepare and start a master send operation 356df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * @id: pointer to the i2c device 357df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann */ 358df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmannstatic void cdns_i2c_msend(struct cdns_i2c *id) 359df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann{ 360df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann unsigned int avail_bytes; 361df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann unsigned int bytes_to_send; 362df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann unsigned int ctrl_reg; 363df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann unsigned int isr_status; 364df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 365df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann id->p_recv_buf = NULL; 366df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann id->p_send_buf = id->p_msg->buf; 367df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann id->send_count = id->p_msg->len; 368df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 369df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann /* Set the controller in Master transmit mode and clear the FIFO. */ 370df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann ctrl_reg = cdns_i2c_readreg(CDNS_I2C_CR_OFFSET); 371df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann ctrl_reg &= ~CDNS_I2C_CR_RW; 372df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann ctrl_reg |= CDNS_I2C_CR_CLR_FIFO; 373df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 374df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann /* 375df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * Check for the message size against FIFO depth and set the 376df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * 'hold bus' bit if it is greater than FIFO depth. 377df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann */ 378df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (id->send_count > CDNS_I2C_FIFO_DEPTH) 379df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann ctrl_reg |= CDNS_I2C_CR_HOLD; 380df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann cdns_i2c_writereg(ctrl_reg, CDNS_I2C_CR_OFFSET); 381df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 382df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann /* Clear the interrupts in interrupt status register. */ 383df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann isr_status = cdns_i2c_readreg(CDNS_I2C_ISR_OFFSET); 384df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann cdns_i2c_writereg(isr_status, CDNS_I2C_ISR_OFFSET); 385df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 386df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann /* 387df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * Calculate the space available in FIFO. Check the message length 388df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * against the space available, and fill the FIFO accordingly. 389df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * Enable the interrupts. 390df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann */ 391df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann avail_bytes = CDNS_I2C_FIFO_DEPTH - 392df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann cdns_i2c_readreg(CDNS_I2C_XFER_SIZE_OFFSET); 393df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 394df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (id->send_count > avail_bytes) 395df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann bytes_to_send = avail_bytes; 396df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann else 397df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann bytes_to_send = id->send_count; 398df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 399df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann while (bytes_to_send--) { 400df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann cdns_i2c_writereg((*(id->p_send_buf)++), CDNS_I2C_DATA_OFFSET); 401df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann id->send_count--; 402df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann } 403df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 404df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann /* 405df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * Clear the bus hold flag if there is no more data 406df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * and if it is the last message. 407df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann */ 408df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (!id->bus_hold_flag && !id->send_count) 409df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann cdns_i2c_clear_bus_hold(id); 410df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann /* Set the slave address in address register - triggers operation. */ 411df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann cdns_i2c_writereg(id->p_msg->addr & CDNS_I2C_ADDR_MASK, 412df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann CDNS_I2C_ADDR_OFFSET); 413df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 414df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann cdns_i2c_writereg(CDNS_I2C_ENABLED_INTR_MASK, CDNS_I2C_IER_OFFSET); 415df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann} 416df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 417df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann/** 418df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * cdns_i2c_master_reset - Reset the interface 419df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * @adap: pointer to the i2c adapter driver instance 420df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * 421df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * This function cleanup the fifos, clear the hold bit and status 422df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * and disable the interrupts. 423df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann */ 424df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmannstatic void cdns_i2c_master_reset(struct i2c_adapter *adap) 425df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann{ 426df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann struct cdns_i2c *id = adap->algo_data; 427df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann u32 regval; 428df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 429df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann /* Disable the interrupts */ 430df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann cdns_i2c_writereg(CDNS_I2C_IXR_ALL_INTR_MASK, CDNS_I2C_IDR_OFFSET); 431df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann /* Clear the hold bit and fifos */ 432df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann regval = cdns_i2c_readreg(CDNS_I2C_CR_OFFSET); 433df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann regval &= ~CDNS_I2C_CR_HOLD; 434df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann regval |= CDNS_I2C_CR_CLR_FIFO; 435df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann cdns_i2c_writereg(regval, CDNS_I2C_CR_OFFSET); 436df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann /* Update the transfercount register to zero */ 437df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann cdns_i2c_writereg(0, CDNS_I2C_XFER_SIZE_OFFSET); 438df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann /* Clear the interupt status register */ 439df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann regval = cdns_i2c_readreg(CDNS_I2C_ISR_OFFSET); 440df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann cdns_i2c_writereg(regval, CDNS_I2C_ISR_OFFSET); 441df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann /* Clear the status register */ 442df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann regval = cdns_i2c_readreg(CDNS_I2C_SR_OFFSET); 443df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann cdns_i2c_writereg(regval, CDNS_I2C_SR_OFFSET); 444df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann} 445df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 446df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmannstatic int cdns_i2c_process_msg(struct cdns_i2c *id, struct i2c_msg *msg, 447df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann struct i2c_adapter *adap) 448df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann{ 449df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann int ret; 450df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann u32 reg; 451df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 452df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann id->p_msg = msg; 453df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann id->err_status = 0; 454df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann reinit_completion(&id->xfer_done); 455df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 456df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann /* Check for the TEN Bit mode on each msg */ 457df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann reg = cdns_i2c_readreg(CDNS_I2C_CR_OFFSET); 458df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (msg->flags & I2C_M_TEN) { 459df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (reg & CDNS_I2C_CR_NEA) 460df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann cdns_i2c_writereg(reg & ~CDNS_I2C_CR_NEA, 461df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann CDNS_I2C_CR_OFFSET); 462df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann } else { 463df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (!(reg & CDNS_I2C_CR_NEA)) 464df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann cdns_i2c_writereg(reg | CDNS_I2C_CR_NEA, 465df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann CDNS_I2C_CR_OFFSET); 466df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann } 467df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 468df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann /* Check for the R/W flag on each msg */ 469df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (msg->flags & I2C_M_RD) 470df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann cdns_i2c_mrecv(id); 471df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann else 472df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann cdns_i2c_msend(id); 473df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 474df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann /* Wait for the signal of completion */ 475df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann ret = wait_for_completion_timeout(&id->xfer_done, adap->timeout); 476df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (!ret) { 477df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann cdns_i2c_master_reset(adap); 478df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann dev_err(id->adap.dev.parent, 479df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann "timeout waiting on completion\n"); 480df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann return -ETIMEDOUT; 481df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann } 482df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 483df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann cdns_i2c_writereg(CDNS_I2C_IXR_ALL_INTR_MASK, 484df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann CDNS_I2C_IDR_OFFSET); 485df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 486df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann /* If it is bus arbitration error, try again */ 487df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (id->err_status & CDNS_I2C_IXR_ARB_LOST) 488df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann return -EAGAIN; 489df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 490df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann return 0; 491df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann} 492df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 493df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann/** 494df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * cdns_i2c_master_xfer - The main i2c transfer function 495df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * @adap: pointer to the i2c adapter driver instance 496df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * @msgs: pointer to the i2c message structure 497df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * @num: the number of messages to transfer 498df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * 499df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * Initiates the send/recv activity based on the transfer message received. 500df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * 501df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * Return: number of msgs processed on success, negative error otherwise 502df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann */ 503df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmannstatic int cdns_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, 504df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann int num) 505df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann{ 506df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann int ret, count; 507df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann u32 reg; 508df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann struct cdns_i2c *id = adap->algo_data; 509df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 510df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann /* Check if the bus is free */ 511df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (cdns_i2c_readreg(CDNS_I2C_SR_OFFSET) & CDNS_I2C_SR_BA) 512df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann return -EAGAIN; 513df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 514df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann /* 515df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * Set the flag to one when multiple messages are to be 516df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * processed with a repeated start. 517df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann */ 518df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (num > 1) { 519df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann id->bus_hold_flag = 1; 520df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann reg = cdns_i2c_readreg(CDNS_I2C_CR_OFFSET); 521df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann reg |= CDNS_I2C_CR_HOLD; 522df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann cdns_i2c_writereg(reg, CDNS_I2C_CR_OFFSET); 523df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann } else { 524df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann id->bus_hold_flag = 0; 525df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann } 526df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 527df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann /* Process the msg one by one */ 528df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann for (count = 0; count < num; count++, msgs++) { 529df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (count == (num - 1)) 530df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann id->bus_hold_flag = 0; 531df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 532df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann ret = cdns_i2c_process_msg(id, msgs, adap); 533df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (ret) 534df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann return ret; 535df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 536df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann /* Report the other error interrupts to application */ 537df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (id->err_status) { 538df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann cdns_i2c_master_reset(adap); 539df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 540df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (id->err_status & CDNS_I2C_IXR_NACK) 541df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann return -ENXIO; 542df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 543df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann return -EIO; 544df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann } 545df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann } 546df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 547df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann return num; 548df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann} 549df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 550df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann/** 551df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * cdns_i2c_func - Returns the supported features of the I2C driver 552df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * @adap: pointer to the i2c adapter structure 553df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * 554df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * Return: 32 bit value, each bit corresponding to a feature 555df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann */ 556df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmannstatic u32 cdns_i2c_func(struct i2c_adapter *adap) 557df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann{ 558df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | 559df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK) | 560df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann I2C_FUNC_SMBUS_BLOCK_DATA; 561df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann} 562df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 563df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmannstatic const struct i2c_algorithm cdns_i2c_algo = { 564df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann .master_xfer = cdns_i2c_master_xfer, 565df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann .functionality = cdns_i2c_func, 566df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann}; 567df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 568df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann/** 569df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * cdns_i2c_calc_divs - Calculate clock dividers 570df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * @f: I2C clock frequency 571df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * @input_clk: Input clock frequency 572df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * @a: First divider (return value) 573df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * @b: Second divider (return value) 574df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * 575df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * f is used as input and output variable. As input it is used as target I2C 576df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * frequency. On function exit f holds the actually resulting I2C frequency. 577df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * 578df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * Return: 0 on success, negative errno otherwise. 579df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann */ 580df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmannstatic int cdns_i2c_calc_divs(unsigned long *f, unsigned long input_clk, 581df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann unsigned int *a, unsigned int *b) 582df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann{ 583df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann unsigned long fscl = *f, best_fscl = *f, actual_fscl, temp; 584df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann unsigned int div_a, div_b, calc_div_a = 0, calc_div_b = 0; 585df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann unsigned int last_error, current_error; 586df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 587df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann /* calculate (divisor_a+1) x (divisor_b+1) */ 588df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann temp = input_clk / (22 * fscl); 589df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 590df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann /* 591df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * If the calculated value is negative or 0, the fscl input is out of 592df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * range. Return error. 593df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann */ 594df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (!temp || (temp > (CDNS_I2C_DIVA_MAX * CDNS_I2C_DIVB_MAX))) 595df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann return -EINVAL; 596df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 597df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann last_error = -1; 598df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann for (div_a = 0; div_a < CDNS_I2C_DIVA_MAX; div_a++) { 599df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann div_b = DIV_ROUND_UP(input_clk, 22 * fscl * (div_a + 1)); 600df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 601df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if ((div_b < 1) || (div_b > CDNS_I2C_DIVB_MAX)) 602df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann continue; 603df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann div_b--; 604df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 605df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann actual_fscl = input_clk / (22 * (div_a + 1) * (div_b + 1)); 606df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 607df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (actual_fscl > fscl) 608df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann continue; 609df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 610df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann current_error = ((actual_fscl > fscl) ? (actual_fscl - fscl) : 611df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann (fscl - actual_fscl)); 612df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 613df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (last_error > current_error) { 614df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann calc_div_a = div_a; 615df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann calc_div_b = div_b; 616df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann best_fscl = actual_fscl; 617df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann last_error = current_error; 618df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann } 619df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann } 620df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 621df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann *a = calc_div_a; 622df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann *b = calc_div_b; 623df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann *f = best_fscl; 624df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 625df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann return 0; 626df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann} 627df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 628df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann/** 629df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * cdns_i2c_setclk - This function sets the serial clock rate for the I2C device 630df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * @clk_in: I2C clock input frequency in Hz 631df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * @id: Pointer to the I2C device structure 632df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * 633df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * The device must be idle rather than busy transferring data before setting 634df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * these device options. 635df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * The data rate is set by values in the control register. 636df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * The formula for determining the correct register values is 637df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * Fscl = Fpclk/(22 x (divisor_a+1) x (divisor_b+1)) 638df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * See the hardware data sheet for a full explanation of setting the serial 639df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * clock rate. The clock can not be faster than the input clock divide by 22. 640df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * The two most common clock rates are 100KHz and 400KHz. 641df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * 642df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * Return: 0 on success, negative error otherwise 643df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann */ 644df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmannstatic int cdns_i2c_setclk(unsigned long clk_in, struct cdns_i2c *id) 645df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann{ 646df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann unsigned int div_a, div_b; 647df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann unsigned int ctrl_reg; 648df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann int ret = 0; 649df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann unsigned long fscl = id->i2c_clk; 650df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 651df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann ret = cdns_i2c_calc_divs(&fscl, clk_in, &div_a, &div_b); 652df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (ret) 653df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann return ret; 654df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 655df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann ctrl_reg = cdns_i2c_readreg(CDNS_I2C_CR_OFFSET); 656df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann ctrl_reg &= ~(CDNS_I2C_CR_DIVA_MASK | CDNS_I2C_CR_DIVB_MASK); 657df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann ctrl_reg |= ((div_a << CDNS_I2C_CR_DIVA_SHIFT) | 658df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann (div_b << CDNS_I2C_CR_DIVB_SHIFT)); 659df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann cdns_i2c_writereg(ctrl_reg, CDNS_I2C_CR_OFFSET); 660df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 661df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann return 0; 662df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann} 663df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 664df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann/** 665df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * cdns_i2c_clk_notifier_cb - Clock rate change callback 666df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * @nb: Pointer to notifier block 667df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * @event: Notification reason 668df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * @data: Pointer to notification data object 669df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * 670df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * This function is called when the cdns_i2c input clock frequency changes. 671df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * The callback checks whether a valid bus frequency can be generated after the 672df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * change. If so, the change is acknowledged, otherwise the change is aborted. 673df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * New dividers are written to the HW in the pre- or post change notification 674df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * depending on the scaling direction. 675df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * 676df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * Return: NOTIFY_STOP if the rate change should be aborted, NOTIFY_OK 677df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * to acknowedge the change, NOTIFY_DONE if the notification is 678df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * considered irrelevant. 679df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann */ 680df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmannstatic int cdns_i2c_clk_notifier_cb(struct notifier_block *nb, unsigned long 681df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann event, void *data) 682df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann{ 683df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann struct clk_notifier_data *ndata = data; 684df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann struct cdns_i2c *id = to_cdns_i2c(nb); 685df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 686df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (id->suspended) 687df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann return NOTIFY_OK; 688df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 689df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann switch (event) { 690df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann case PRE_RATE_CHANGE: 691df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann { 692df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann unsigned long input_clk = ndata->new_rate; 693df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann unsigned long fscl = id->i2c_clk; 694df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann unsigned int div_a, div_b; 695df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann int ret; 696df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 697df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann ret = cdns_i2c_calc_divs(&fscl, input_clk, &div_a, &div_b); 698df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (ret) { 699df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann dev_warn(id->adap.dev.parent, 700df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann "clock rate change rejected\n"); 701df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann return NOTIFY_STOP; 702df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann } 703df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 704df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann /* scale up */ 705df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (ndata->new_rate > ndata->old_rate) 706df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann cdns_i2c_setclk(ndata->new_rate, id); 707df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 708df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann return NOTIFY_OK; 709df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann } 710df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann case POST_RATE_CHANGE: 711df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann id->input_clk = ndata->new_rate; 712df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann /* scale down */ 713df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (ndata->new_rate < ndata->old_rate) 714df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann cdns_i2c_setclk(ndata->new_rate, id); 715df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann return NOTIFY_OK; 716df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann case ABORT_RATE_CHANGE: 717df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann /* scale up */ 718df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (ndata->new_rate > ndata->old_rate) 719df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann cdns_i2c_setclk(ndata->old_rate, id); 720df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann return NOTIFY_OK; 721df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann default: 722df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann return NOTIFY_DONE; 723df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann } 724df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann} 725df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 726df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann/** 727df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * cdns_i2c_suspend - Suspend method for the driver 728df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * @_dev: Address of the platform_device structure 729df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * 730df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * Put the driver into low power mode. 731df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * 732df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * Return: 0 always 733df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann */ 734df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmannstatic int __maybe_unused cdns_i2c_suspend(struct device *_dev) 735df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann{ 736df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann struct platform_device *pdev = container_of(_dev, 737df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann struct platform_device, dev); 738df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann struct cdns_i2c *xi2c = platform_get_drvdata(pdev); 739df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 740df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann clk_disable(xi2c->clk); 741df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann xi2c->suspended = 1; 742df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 743df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann return 0; 744df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann} 745df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 746df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann/** 747df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * cdns_i2c_resume - Resume from suspend 748df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * @_dev: Address of the platform_device structure 749df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * 750df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * Resume operation after suspend. 751df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * 752df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * Return: 0 on success and error value on error 753df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann */ 754df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmannstatic int __maybe_unused cdns_i2c_resume(struct device *_dev) 755df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann{ 756df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann struct platform_device *pdev = container_of(_dev, 757df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann struct platform_device, dev); 758df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann struct cdns_i2c *xi2c = platform_get_drvdata(pdev); 759df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann int ret; 760df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 761df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann ret = clk_enable(xi2c->clk); 762df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (ret) { 763df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann dev_err(_dev, "Cannot enable clock.\n"); 764df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann return ret; 765df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann } 766df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 767df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann xi2c->suspended = 0; 768df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 769df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann return 0; 770df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann} 771df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 772df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmannstatic SIMPLE_DEV_PM_OPS(cdns_i2c_dev_pm_ops, cdns_i2c_suspend, 773df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann cdns_i2c_resume); 774df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 775df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann/** 776df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * cdns_i2c_probe - Platform registration call 777df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * @pdev: Handle to the platform device structure 778df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * 779df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * This function does all the memory allocation and registration for the i2c 780df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * device. User can modify the address mode to 10 bit address mode using the 781df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * ioctl call with option I2C_TENBIT. 782df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * 783df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * Return: 0 on success, negative error otherwise 784df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann */ 785df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmannstatic int cdns_i2c_probe(struct platform_device *pdev) 786df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann{ 787df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann struct resource *r_mem; 788df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann struct cdns_i2c *id; 789df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann int ret; 790df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 791df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann id = devm_kzalloc(&pdev->dev, sizeof(*id), GFP_KERNEL); 792df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (!id) 793df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann return -ENOMEM; 794df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 795df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann platform_set_drvdata(pdev, id); 796df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 797df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann r_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 798df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann id->membase = devm_ioremap_resource(&pdev->dev, r_mem); 799df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (IS_ERR(id->membase)) 800df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann return PTR_ERR(id->membase); 801df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 802df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann id->irq = platform_get_irq(pdev, 0); 803df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 804df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann id->adap.dev.of_node = pdev->dev.of_node; 805df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann id->adap.algo = &cdns_i2c_algo; 806df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann id->adap.timeout = CDNS_I2C_TIMEOUT; 807df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann id->adap.retries = 3; /* Default retry value. */ 808df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann id->adap.algo_data = id; 809df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann id->adap.dev.parent = &pdev->dev; 810df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann init_completion(&id->xfer_done); 811df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann snprintf(id->adap.name, sizeof(id->adap.name), 812df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann "Cadence I2C at %08lx", (unsigned long)r_mem->start); 813df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 814df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann id->clk = devm_clk_get(&pdev->dev, NULL); 815df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (IS_ERR(id->clk)) { 816df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann dev_err(&pdev->dev, "input clock not found.\n"); 817df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann return PTR_ERR(id->clk); 818df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann } 819df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann ret = clk_prepare_enable(id->clk); 820df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (ret) { 821df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann dev_err(&pdev->dev, "Unable to enable clock.\n"); 822df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann return ret; 823df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann } 824df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann id->clk_rate_change_nb.notifier_call = cdns_i2c_clk_notifier_cb; 825df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (clk_notifier_register(id->clk, &id->clk_rate_change_nb)) 826df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann dev_warn(&pdev->dev, "Unable to register clock notifier.\n"); 827df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann id->input_clk = clk_get_rate(id->clk); 828df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 829df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann ret = of_property_read_u32(pdev->dev.of_node, "clock-frequency", 830df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann &id->i2c_clk); 831df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (ret || (id->i2c_clk > CDNS_I2C_SPEED_MAX)) 832df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann id->i2c_clk = CDNS_I2C_SPEED_DEFAULT; 833df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 834df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann cdns_i2c_writereg(CDNS_I2C_CR_ACK_EN | CDNS_I2C_CR_NEA | CDNS_I2C_CR_MS, 835df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann CDNS_I2C_CR_OFFSET); 836df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 837df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann ret = cdns_i2c_setclk(id->input_clk, id); 838df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (ret) { 839df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann dev_err(&pdev->dev, "invalid SCL clock: %u Hz\n", id->i2c_clk); 840df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann ret = -EINVAL; 841df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann goto err_clk_dis; 842df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann } 843df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 844df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann ret = devm_request_irq(&pdev->dev, id->irq, cdns_i2c_isr, 0, 845df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann DRIVER_NAME, id); 846df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (ret) { 847df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann dev_err(&pdev->dev, "cannot get irq %d\n", id->irq); 848df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann goto err_clk_dis; 849df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann } 850df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 851df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann ret = i2c_add_adapter(&id->adap); 852df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann if (ret < 0) { 853df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann dev_err(&pdev->dev, "reg adap failed: %d\n", ret); 854df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann goto err_clk_dis; 855df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann } 856df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 857681d15a0f527af7ab3a783e1037de86fbcb136acVishnu Motghare /* 858681d15a0f527af7ab3a783e1037de86fbcb136acVishnu Motghare * Cadence I2C controller has a bug wherein it generates 859681d15a0f527af7ab3a783e1037de86fbcb136acVishnu Motghare * invalid read transaction after HW timeout in master receiver mode. 860681d15a0f527af7ab3a783e1037de86fbcb136acVishnu Motghare * HW timeout is not used by this driver and the interrupt is disabled. 861681d15a0f527af7ab3a783e1037de86fbcb136acVishnu Motghare * But the feature itself cannot be disabled. Hence maximum value 862681d15a0f527af7ab3a783e1037de86fbcb136acVishnu Motghare * is written to this register to reduce the chances of error. 863681d15a0f527af7ab3a783e1037de86fbcb136acVishnu Motghare */ 864681d15a0f527af7ab3a783e1037de86fbcb136acVishnu Motghare cdns_i2c_writereg(CDNS_I2C_TIMEOUT_MAX, CDNS_I2C_TIME_OUT_OFFSET); 865681d15a0f527af7ab3a783e1037de86fbcb136acVishnu Motghare 866df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann dev_info(&pdev->dev, "%u kHz mmio %08lx irq %d\n", 867df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann id->i2c_clk / 1000, (unsigned long)r_mem->start, id->irq); 868df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 869df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann return 0; 870df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 871df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmannerr_clk_dis: 872df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann clk_disable_unprepare(id->clk); 873df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann return ret; 874df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann} 875df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 876df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann/** 877df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * cdns_i2c_remove - Unregister the device after releasing the resources 878df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * @pdev: Handle to the platform device structure 879df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * 880df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * This function frees all the resources allocated to the device. 881df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * 882df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann * Return: 0 always 883df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann */ 884df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmannstatic int cdns_i2c_remove(struct platform_device *pdev) 885df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann{ 886df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann struct cdns_i2c *id = platform_get_drvdata(pdev); 887df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 888df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann i2c_del_adapter(&id->adap); 889df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann clk_notifier_unregister(id->clk, &id->clk_rate_change_nb); 890df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann clk_disable_unprepare(id->clk); 891df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 892df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann return 0; 893df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann} 894df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 895df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmannstatic const struct of_device_id cdns_i2c_of_match[] = { 896df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann { .compatible = "cdns,i2c-r1p10", }, 897df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann { /* end of table */ } 898df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann}; 899df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren BrinkmannMODULE_DEVICE_TABLE(of, cdns_i2c_of_match); 900df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 901df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmannstatic struct platform_driver cdns_i2c_drv = { 902df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann .driver = { 903df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann .name = DRIVER_NAME, 904df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann .owner = THIS_MODULE, 905df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann .of_match_table = cdns_i2c_of_match, 906df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann .pm = &cdns_i2c_dev_pm_ops, 907df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann }, 908df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann .probe = cdns_i2c_probe, 909df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann .remove = cdns_i2c_remove, 910df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann}; 911df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 912df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmannmodule_platform_driver(cdns_i2c_drv); 913df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren Brinkmann 914df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren BrinkmannMODULE_AUTHOR("Xilinx Inc."); 915df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren BrinkmannMODULE_DESCRIPTION("Cadence I2C bus driver"); 916df8eb5691c48d3b03b918bdf065caa59c4281cdcSoren BrinkmannMODULE_LICENSE("GPL"); 917