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 <vireshk@kernel.org> 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/of.h>
15#include <linux/types.h>
16#include "stmpe.h"
17
18#define READ_CMD (1 << 7)
19
20static int spi_reg_read(struct stmpe *stmpe, u8 reg)
21{
22 struct spi_device *spi = stmpe->client;
23 int status = spi_w8r16(spi, reg | READ_CMD);
24
25 return (status < 0) ? status : status >> 8;
26}
27
28static int spi_reg_write(struct stmpe *stmpe, u8 reg, u8 val)
29{
30 struct spi_device *spi = stmpe->client;
31 u16 cmd = (val << 8) | reg;
32
33 return spi_write(spi, (const u8 *)&cmd, 2);
34}
35
36static int spi_block_read(struct stmpe *stmpe, u8 reg, u8 length, u8 *values)
37{
38 int ret, i;
39
40 for (i = 0; i < length; i++) {
41 ret = spi_reg_read(stmpe, reg + i);
42 if (ret < 0)
43 return ret;
44 *(values + i) = ret;
45 }
46
47 return 0;
48}
49
50static int spi_block_write(struct stmpe *stmpe, u8 reg, u8 length,
51 const u8 *values)
52{
53 int ret = 0, i;
54
55 for (i = length; i > 0; i--, reg++) {
56 ret = spi_reg_write(stmpe, reg, *(values + i - 1));
57 if (ret < 0)
58 return ret;
59 }
60
61 return ret;
62}
63
64static void spi_init(struct stmpe *stmpe)
65{
66 struct spi_device *spi = stmpe->client;
67
68 spi->bits_per_word = 8;
69
70 /* This register is only present for stmpe811 */
71 if (stmpe->variant->id_val == 0x0811)
72 spi_reg_write(stmpe, STMPE811_REG_SPI_CFG, spi->mode);
73
74 if (spi_setup(spi) < 0)
75 dev_dbg(&spi->dev, "spi_setup failed\n");
76}
77
78static struct stmpe_client_info spi_ci = {
79 .read_byte = spi_reg_read,
80 .write_byte = spi_reg_write,
81 .read_block = spi_block_read,
82 .write_block = spi_block_write,
83 .init = spi_init,
84};
85
86static int
87stmpe_spi_probe(struct spi_device *spi)
88{
89 const struct spi_device_id *id = spi_get_device_id(spi);
90
91 /* don't exceed max specified rate - 1MHz - Limitation of STMPE */
92 if (spi->max_speed_hz > 1000000) {
93 dev_dbg(&spi->dev, "f(sample) %d KHz?\n",
94 (spi->max_speed_hz/1000));
95 return -EINVAL;
96 }
97
98 spi_ci.irq = spi->irq;
99 spi_ci.client = spi;
100 spi_ci.dev = &spi->dev;
101
102 return stmpe_probe(&spi_ci, id->driver_data);
103}
104
105static int stmpe_spi_remove(struct spi_device *spi)
106{
107 struct stmpe *stmpe = spi_get_drvdata(spi);
108
109 return stmpe_remove(stmpe);
110}
111
112static const struct of_device_id stmpe_spi_of_match[] = {
113 { .compatible = "st,stmpe610", },
114 { .compatible = "st,stmpe801", },
115 { .compatible = "st,stmpe811", },
116 { .compatible = "st,stmpe1601", },
117 { .compatible = "st,stmpe2401", },
118 { .compatible = "st,stmpe2403", },
119 { /* sentinel */ },
120};
121MODULE_DEVICE_TABLE(of, stmpe_spi_of_match);
122
123static const struct spi_device_id stmpe_spi_id[] = {
124 { "stmpe610", STMPE610 },
125 { "stmpe801", STMPE801 },
126 { "stmpe811", STMPE811 },
127 { "stmpe1601", STMPE1601 },
128 { "stmpe2401", STMPE2401 },
129 { "stmpe2403", STMPE2403 },
130 { }
131};
132MODULE_DEVICE_TABLE(spi, stmpe_id);
133
134static struct spi_driver stmpe_spi_driver = {
135 .driver = {
136 .name = "stmpe-spi",
137 .of_match_table = of_match_ptr(stmpe_spi_of_match),
138#ifdef CONFIG_PM
139 .pm = &stmpe_dev_pm_ops,
140#endif
141 },
142 .probe = stmpe_spi_probe,
143 .remove = stmpe_spi_remove,
144 .id_table = stmpe_spi_id,
145};
146
147static int __init stmpe_init(void)
148{
149 return spi_register_driver(&stmpe_spi_driver);
150}
151subsys_initcall(stmpe_init);
152
153static void __exit stmpe_exit(void)
154{
155 spi_unregister_driver(&stmpe_spi_driver);
156}
157module_exit(stmpe_exit);
158
159MODULE_LICENSE("GPL v2");
160MODULE_DESCRIPTION("STMPE MFD SPI Interface Driver");
161MODULE_AUTHOR("Viresh Kumar <vireshk@kernel.org>");
162