1/*
2 * ST Microelectronics MFD: stmpe's spi client specific driver
3 *
4 * Copyright (C) ST Microelectronics SA 2011
5 *
6 * License Terms: GNU General Public License, version 2
7 * Author: Viresh Kumar <viresh.kumar@st.com> for ST Microelectronics
8 */
9
10#include <linux/spi/spi.h>
11#include <linux/interrupt.h>
12#include <linux/kernel.h>
13#include <linux/module.h>
14#include <linux/types.h>
15#include "stmpe.h"
16
17#define READ_CMD	(1 << 7)
18
19static int spi_reg_read(struct stmpe *stmpe, u8 reg)
20{
21	struct spi_device *spi = stmpe->client;
22	int status = spi_w8r16(spi, reg | READ_CMD);
23
24	return (status < 0) ? status : status >> 8;
25}
26
27static int spi_reg_write(struct stmpe *stmpe, u8 reg, u8 val)
28{
29	struct spi_device *spi = stmpe->client;
30	u16 cmd = (val << 8) | reg;
31
32	return spi_write(spi, (const u8 *)&cmd, 2);
33}
34
35static int spi_block_read(struct stmpe *stmpe, u8 reg, u8 length, u8 *values)
36{
37	int ret, i;
38
39	for (i = 0; i < length; i++) {
40		ret = spi_reg_read(stmpe, reg + i);
41		if (ret < 0)
42			return ret;
43		*(values + i) = ret;
44	}
45
46	return 0;
47}
48
49static int spi_block_write(struct stmpe *stmpe, u8 reg, u8 length,
50		const u8 *values)
51{
52	int ret = 0, i;
53
54	for (i = length; i > 0; i--, reg++) {
55		ret = spi_reg_write(stmpe, reg, *(values + i - 1));
56		if (ret < 0)
57			return ret;
58	}
59
60	return ret;
61}
62
63static void spi_init(struct stmpe *stmpe)
64{
65	struct spi_device *spi = stmpe->client;
66
67	spi->bits_per_word = 8;
68
69	/* This register is only present for stmpe811 */
70	if (stmpe->variant->id_val == 0x0811)
71		spi_reg_write(stmpe, STMPE811_REG_SPI_CFG, spi->mode);
72
73	if (spi_setup(spi) < 0)
74		dev_dbg(&spi->dev, "spi_setup failed\n");
75}
76
77static struct stmpe_client_info spi_ci = {
78	.read_byte = spi_reg_read,
79	.write_byte = spi_reg_write,
80	.read_block = spi_block_read,
81	.write_block = spi_block_write,
82	.init = spi_init,
83};
84
85static int __devinit
86stmpe_spi_probe(struct spi_device *spi)
87{
88	const struct spi_device_id *id = spi_get_device_id(spi);
89
90	/* don't exceed max specified rate - 1MHz - Limitation of STMPE */
91	if (spi->max_speed_hz > 1000000) {
92		dev_dbg(&spi->dev, "f(sample) %d KHz?\n",
93				(spi->max_speed_hz/1000));
94		return -EINVAL;
95	}
96
97	spi_ci.irq = spi->irq;
98	spi_ci.client = spi;
99	spi_ci.dev = &spi->dev;
100
101	return stmpe_probe(&spi_ci, id->driver_data);
102}
103
104static int __devexit stmpe_spi_remove(struct spi_device *spi)
105{
106	struct stmpe *stmpe = dev_get_drvdata(&spi->dev);
107
108	return stmpe_remove(stmpe);
109}
110
111static const struct spi_device_id stmpe_spi_id[] = {
112	{ "stmpe610", STMPE610 },
113	{ "stmpe801", STMPE801 },
114	{ "stmpe811", STMPE811 },
115	{ "stmpe1601", STMPE1601 },
116	{ "stmpe2401", STMPE2401 },
117	{ "stmpe2403", STMPE2403 },
118	{ }
119};
120MODULE_DEVICE_TABLE(spi, stmpe_id);
121
122static struct spi_driver stmpe_spi_driver = {
123	.driver = {
124		.name	= "stmpe-spi",
125		.bus	= &spi_bus_type,
126		.owner	= THIS_MODULE,
127#ifdef CONFIG_PM
128		.pm	= &stmpe_dev_pm_ops,
129#endif
130	},
131	.probe		= stmpe_spi_probe,
132	.remove		= __devexit_p(stmpe_spi_remove),
133	.id_table	= stmpe_spi_id,
134};
135
136static int __init stmpe_init(void)
137{
138	return spi_register_driver(&stmpe_spi_driver);
139}
140subsys_initcall(stmpe_init);
141
142static void __exit stmpe_exit(void)
143{
144	spi_unregister_driver(&stmpe_spi_driver);
145}
146module_exit(stmpe_exit);
147
148MODULE_LICENSE("GPL v2");
149MODULE_DESCRIPTION("STMPE MFD SPI Interface Driver");
150MODULE_AUTHOR("Viresh Kumar <viresh.kumar@st.com>");
151