1/* 2 * Core driver for STw4810/STw4811 3 * 4 * Copyright (C) 2013 ST-Ericsson SA 5 * Written on behalf of Linaro for ST-Ericsson 6 * 7 * Author: Linus Walleij <linus.walleij@linaro.org> 8 * 9 * License terms: GNU General Public License (GPL) version 2 10 */ 11 12#include <linux/err.h> 13#include <linux/i2c.h> 14#include <linux/init.h> 15#include <linux/mfd/core.h> 16#include <linux/mfd/stw481x.h> 17#include <linux/module.h> 18#include <linux/regmap.h> 19#include <linux/spinlock.h> 20#include <linux/slab.h> 21 22/* 23 * This driver can only access the non-USB portions of STw4811, the register 24 * range 0x00-0x10 dealing with USB is bound to the two special I2C pins used 25 * for USB control. 26 */ 27 28/* Registers inside the power control address space */ 29#define STW_PC_VCORE_SEL 0x05U 30#define STW_PC_VAUX_SEL 0x06U 31#define STW_PC_VPLL_SEL 0x07U 32 33/** 34 * stw481x_get_pctl_reg() - get a power control register 35 * @stw481x: handle to the stw481x chip 36 * @reg: power control register to fetch 37 * 38 * The power control registers is a set of one-time-programmable registers 39 * in its own register space, accessed by writing addess bits to these 40 * two registers: bits 7,6,5 of PCTL_REG_LO corresponds to the 3 LSBs of 41 * the address and bits 8,9 of PCTL_REG_HI corresponds to the 2 MSBs of 42 * the address, forming an address space of 5 bits, i.e. 32 registers 43 * 0x00 ... 0x1f can be obtained. 44 */ 45static int stw481x_get_pctl_reg(struct stw481x *stw481x, u8 reg) 46{ 47 u8 msb = (reg >> 3) & 0x03; 48 u8 lsb = (reg << 5) & 0xe0; 49 unsigned int val; 50 u8 vrfy; 51 int ret; 52 53 ret = regmap_write(stw481x->map, STW_PCTL_REG_HI, msb); 54 if (ret) 55 return ret; 56 ret = regmap_write(stw481x->map, STW_PCTL_REG_LO, lsb); 57 if (ret) 58 return ret; 59 ret = regmap_read(stw481x->map, STW_PCTL_REG_HI, &val); 60 if (ret) 61 return ret; 62 vrfy = (val & 0x03) << 3; 63 ret = regmap_read(stw481x->map, STW_PCTL_REG_LO, &val); 64 if (ret) 65 return ret; 66 vrfy |= ((val >> 5) & 0x07); 67 if (vrfy != reg) 68 return -EIO; 69 return (val >> 1) & 0x0f; 70} 71 72static int stw481x_startup(struct stw481x *stw481x) 73{ 74 /* Voltages multiplied by 100 */ 75 u8 vcore_val[] = { 100, 105, 110, 115, 120, 122, 124, 126, 128, 76 130, 132, 134, 136, 138, 140, 145 }; 77 u8 vpll_val[] = { 105, 120, 130, 180 }; 78 u8 vaux_val[] = { 15, 18, 25, 28 }; 79 u8 vcore; 80 u8 vcore_slp; 81 u8 vpll; 82 u8 vaux; 83 bool vaux_en; 84 bool it_warn; 85 int ret; 86 unsigned int val; 87 88 ret = regmap_read(stw481x->map, STW_CONF1, &val); 89 if (ret) 90 return ret; 91 vaux_en = !!(val & STW_CONF1_PDN_VAUX); 92 it_warn = !!(val & STW_CONF1_IT_WARN); 93 94 dev_info(&stw481x->client->dev, "voltages %s\n", 95 (val & STW_CONF1_V_MONITORING) ? "OK" : "LOW"); 96 dev_info(&stw481x->client->dev, "MMC level shifter %s\n", 97 (val & STW_CONF1_MMC_LS_STATUS) ? "high impedance" : "ON"); 98 dev_info(&stw481x->client->dev, "VMMC: %s\n", 99 (val & STW_CONF1_PDN_VMMC) ? "ON" : "disabled"); 100 101 dev_info(&stw481x->client->dev, "STw481x power control registers:\n"); 102 103 ret = stw481x_get_pctl_reg(stw481x, STW_PC_VCORE_SEL); 104 if (ret < 0) 105 return ret; 106 vcore = ret & 0x0f; 107 108 ret = stw481x_get_pctl_reg(stw481x, STW_PC_VAUX_SEL); 109 if (ret < 0) 110 return ret; 111 vaux = (ret >> 2) & 3; 112 vpll = (ret >> 4) & 1; /* Save bit 4 */ 113 114 ret = stw481x_get_pctl_reg(stw481x, STW_PC_VPLL_SEL); 115 if (ret < 0) 116 return ret; 117 vpll |= (ret >> 1) & 2; 118 119 dev_info(&stw481x->client->dev, "VCORE: %u.%uV %s\n", 120 vcore_val[vcore] / 100, vcore_val[vcore] % 100, 121 (ret & 4) ? "ON" : "OFF"); 122 123 dev_info(&stw481x->client->dev, "VPLL: %u.%uV %s\n", 124 vpll_val[vpll] / 100, vpll_val[vpll] % 100, 125 (ret & 0x10) ? "ON" : "OFF"); 126 127 dev_info(&stw481x->client->dev, "VAUX: %u.%uV %s\n", 128 vaux_val[vaux] / 10, vaux_val[vaux] % 10, 129 vaux_en ? "ON" : "OFF"); 130 131 ret = regmap_read(stw481x->map, STW_CONF2, &val); 132 if (ret) 133 return ret; 134 135 dev_info(&stw481x->client->dev, "TWARN: %s threshold, %s\n", 136 it_warn ? "below" : "above", 137 (val & STW_CONF2_MASK_TWARN) ? 138 "enabled" : "mask through VDDOK"); 139 dev_info(&stw481x->client->dev, "VMMC: %s\n", 140 (val & STW_CONF2_VMMC_EXT) ? "internal" : "external"); 141 dev_info(&stw481x->client->dev, "IT WAKE UP: %s\n", 142 (val & STW_CONF2_MASK_IT_WAKE_UP) ? "enabled" : "masked"); 143 dev_info(&stw481x->client->dev, "GPO1: %s\n", 144 (val & STW_CONF2_GPO1) ? "low" : "high impedance"); 145 dev_info(&stw481x->client->dev, "GPO2: %s\n", 146 (val & STW_CONF2_GPO2) ? "low" : "high impedance"); 147 148 ret = regmap_read(stw481x->map, STW_VCORE_SLEEP, &val); 149 if (ret) 150 return ret; 151 vcore_slp = val & 0x0f; 152 dev_info(&stw481x->client->dev, "VCORE SLEEP: %u.%uV\n", 153 vcore_val[vcore_slp] / 100, vcore_val[vcore_slp] % 100); 154 155 return 0; 156} 157 158/* 159 * MFD cells - we have one cell which is selected operation 160 * mode, and we always have a GPIO cell. 161 */ 162static struct mfd_cell stw481x_cells[] = { 163 { 164 .of_compatible = "st,stw481x-vmmc", 165 .name = "stw481x-vmmc-regulator", 166 .id = -1, 167 }, 168}; 169 170static const struct regmap_config stw481x_regmap_config = { 171 .reg_bits = 8, 172 .val_bits = 8, 173}; 174 175static int stw481x_probe(struct i2c_client *client, 176 const struct i2c_device_id *id) 177{ 178 struct stw481x *stw481x; 179 int ret; 180 int i; 181 182 stw481x = devm_kzalloc(&client->dev, sizeof(*stw481x), GFP_KERNEL); 183 if (!stw481x) 184 return -ENOMEM; 185 186 i2c_set_clientdata(client, stw481x); 187 stw481x->client = client; 188 stw481x->map = devm_regmap_init_i2c(client, &stw481x_regmap_config); 189 if (IS_ERR(stw481x->map)) { 190 ret = PTR_ERR(stw481x->map); 191 dev_err(&client->dev, "Failed to allocate register map: %d\n", 192 ret); 193 return ret; 194 } 195 196 ret = stw481x_startup(stw481x); 197 if (ret) { 198 dev_err(&client->dev, "chip initialization failed\n"); 199 return ret; 200 } 201 202 /* Set up and register the platform devices. */ 203 for (i = 0; i < ARRAY_SIZE(stw481x_cells); i++) { 204 /* One state holder for all drivers, this is simple */ 205 stw481x_cells[i].platform_data = stw481x; 206 stw481x_cells[i].pdata_size = sizeof(*stw481x); 207 } 208 209 ret = mfd_add_devices(&client->dev, 0, stw481x_cells, 210 ARRAY_SIZE(stw481x_cells), NULL, 0, NULL); 211 if (ret) 212 return ret; 213 214 dev_info(&client->dev, "initialized STw481x device\n"); 215 216 return ret; 217} 218 219static int stw481x_remove(struct i2c_client *client) 220{ 221 mfd_remove_devices(&client->dev); 222 return 0; 223} 224 225/* 226 * This ID table is completely unused, as this is a pure 227 * device-tree probed driver, but it has to be here due to 228 * the structure of the I2C core. 229 */ 230static const struct i2c_device_id stw481x_id[] = { 231 { "stw481x", 0 }, 232 { }, 233}; 234 235static const struct of_device_id stw481x_match[] = { 236 { .compatible = "st,stw4810", }, 237 { .compatible = "st,stw4811", }, 238 { }, 239}; 240MODULE_DEVICE_TABLE(of, stw481x_match); 241 242static struct i2c_driver stw481x_driver = { 243 .driver = { 244 .name = "stw481x", 245 .of_match_table = stw481x_match, 246 }, 247 .probe = stw481x_probe, 248 .remove = stw481x_remove, 249 .id_table = stw481x_id, 250}; 251 252module_i2c_driver(stw481x_driver); 253 254MODULE_AUTHOR("Linus Walleij"); 255MODULE_DESCRIPTION("STw481x PMIC driver"); 256MODULE_LICENSE("GPL v2"); 257