mfd: twl-core: regulator configuration for twl6030 V1V8, V2V1 SMPS
[linux-2.6.git] / drivers / mfd / stmpe-spi.c
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
19 static 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
27 static 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
35 static 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
49 static 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
63 static 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
77 static 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
85 static int __devinit
86 stmpe_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
104 static 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
111 static 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 };
120 MODULE_DEVICE_TABLE(spi, stmpe_id);
121
122 static 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
136 static int __init stmpe_init(void)
137 {
138         return spi_register_driver(&stmpe_spi_driver);
139 }
140 subsys_initcall(stmpe_init);
141
142 static void __exit stmpe_exit(void)
143 {
144         spi_unregister_driver(&stmpe_spi_driver);
145 }
146 module_exit(stmpe_exit);
147
148 MODULE_LICENSE("GPL v2");
149 MODULE_DESCRIPTION("STMPE MFD SPI Interface Driver");
150 MODULE_AUTHOR("Viresh Kumar <viresh.kumar@st.com>");