tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Copyright 2009-2010 Pengutronix
3 * Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>
4 *
5 * loosely based on an earlier driver that has
6 * Copyright 2009 Pengutronix, Sascha Hauer <s.hauer@pengutronix.de>
7 *
8 * This program is free software; you can redistribute it and/or modify it under
9 * the terms of the GNU General Public License version 2 as published by the
10 * Free Software Foundation.
11 */
12
13#include <linux/slab.h>
14#include <linux/module.h>
15#include <linux/platform_device.h>
16#include <linux/mutex.h>
17#include <linux/interrupt.h>
18#include <linux/mfd/core.h>
19#include <linux/mfd/mc13xxx.h>
20#include <linux/of.h>
21#include <linux/of_device.h>
22#include <linux/of_gpio.h>
23#include <linux/err.h>
24#include <linux/spi/spi.h>
25
26#include "mc13xxx.h"
27
28static const struct spi_device_id mc13xxx_device_id[] = {
29 {
30 .name = "mc13783",
31 .driver_data = MC13XXX_ID_MC13783,
32 }, {
33 .name = "mc13892",
34 .driver_data = MC13XXX_ID_MC13892,
35 }, {
36 /* sentinel */
37 }
38};
39MODULE_DEVICE_TABLE(spi, mc13xxx_device_id);
40
41static const struct of_device_id mc13xxx_dt_ids[] = {
42 { .compatible = "fsl,mc13783", .data = (void *) MC13XXX_ID_MC13783, },
43 { .compatible = "fsl,mc13892", .data = (void *) MC13XXX_ID_MC13892, },
44 { /* sentinel */ }
45};
46MODULE_DEVICE_TABLE(of, mc13xxx_dt_ids);
47
48static struct regmap_config mc13xxx_regmap_spi_config = {
49 .reg_bits = 7,
50 .pad_bits = 1,
51 .val_bits = 24,
52 .write_flag_mask = 0x80,
53
54 .max_register = MC13XXX_NUMREGS,
55
56 .cache_type = REGCACHE_NONE,
57 .use_single_rw = 1,
58};
59
60static int mc13xxx_spi_read(void *context, const void *reg, size_t reg_size,
61 void *val, size_t val_size)
62{
63 unsigned char w[4] = { *((unsigned char *) reg), 0, 0, 0};
64 unsigned char r[4];
65 unsigned char *p = val;
66 struct device *dev = context;
67 struct spi_device *spi = to_spi_device(dev);
68 struct spi_transfer t = {
69 .tx_buf = w,
70 .rx_buf = r,
71 .len = 4,
72 };
73
74 struct spi_message m;
75 int ret;
76
77 if (val_size != 3 || reg_size != 1)
78 return -ENOTSUPP;
79
80 spi_message_init(&m);
81 spi_message_add_tail(&t, &m);
82 ret = spi_sync(spi, &m);
83
84 memcpy(p, &r[1], 3);
85
86 return ret;
87}
88
89static int mc13xxx_spi_write(void *context, const void *data, size_t count)
90{
91 struct device *dev = context;
92 struct spi_device *spi = to_spi_device(dev);
93
94 if (count != 4)
95 return -ENOTSUPP;
96
97 return spi_write(spi, data, count);
98}
99
100/*
101 * We cannot use regmap-spi generic bus implementation here.
102 * The MC13783 chip will get corrupted if CS signal is deasserted
103 * and on i.Mx31 SoC (the target SoC for MC13783 PMIC) the SPI controller
104 * has the following errata (DSPhl22960):
105 * "The CSPI negates SS when the FIFO becomes empty with
106 * SSCTL= 0. Software cannot guarantee that the FIFO will not
107 * drain because of higher priority interrupts and the
108 * non-realtime characteristics of the operating system. As a
109 * result, the SS will negate before all of the data has been
110 * transferred to/from the peripheral."
111 * We workaround this by accessing the SPI controller with a
112 * single transfert.
113 */
114
115static struct regmap_bus regmap_mc13xxx_bus = {
116 .write = mc13xxx_spi_write,
117 .read = mc13xxx_spi_read,
118};
119
120static int mc13xxx_spi_probe(struct spi_device *spi)
121{
122 struct mc13xxx *mc13xxx;
123 struct mc13xxx_platform_data *pdata = dev_get_platdata(&spi->dev);
124 int ret;
125
126 mc13xxx = devm_kzalloc(&spi->dev, sizeof(*mc13xxx), GFP_KERNEL);
127 if (!mc13xxx)
128 return -ENOMEM;
129
130 dev_set_drvdata(&spi->dev, mc13xxx);
131 spi->mode = SPI_MODE_0 | SPI_CS_HIGH;
132
133 mc13xxx->dev = &spi->dev;
134 mutex_init(&mc13xxx->lock);
135
136 mc13xxx->regmap = devm_regmap_init(&spi->dev, ®map_mc13xxx_bus,
137 &spi->dev,
138 &mc13xxx_regmap_spi_config);
139 if (IS_ERR(mc13xxx->regmap)) {
140 ret = PTR_ERR(mc13xxx->regmap);
141 dev_err(mc13xxx->dev, "Failed to initialize register map: %d\n",
142 ret);
143 dev_set_drvdata(&spi->dev, NULL);
144 return ret;
145 }
146
147 ret = mc13xxx_common_init(mc13xxx, pdata, spi->irq);
148
149 if (ret) {
150 dev_set_drvdata(&spi->dev, NULL);
151 } else {
152 const struct spi_device_id *devid =
153 spi_get_device_id(spi);
154 if (!devid || devid->driver_data != mc13xxx->ictype)
155 dev_warn(mc13xxx->dev,
156 "device id doesn't match auto detection!\n");
157 }
158
159 return ret;
160}
161
162static int __devexit mc13xxx_spi_remove(struct spi_device *spi)
163{
164 struct mc13xxx *mc13xxx = dev_get_drvdata(&spi->dev);
165
166 mc13xxx_common_cleanup(mc13xxx);
167
168 return 0;
169}
170
171static struct spi_driver mc13xxx_spi_driver = {
172 .id_table = mc13xxx_device_id,
173 .driver = {
174 .name = "mc13xxx",
175 .owner = THIS_MODULE,
176 .of_match_table = mc13xxx_dt_ids,
177 },
178 .probe = mc13xxx_spi_probe,
179 .remove = __devexit_p(mc13xxx_spi_remove),
180};
181
182static int __init mc13xxx_init(void)
183{
184 return spi_register_driver(&mc13xxx_spi_driver);
185}
186subsys_initcall(mc13xxx_init);
187
188static void __exit mc13xxx_exit(void)
189{
190 spi_unregister_driver(&mc13xxx_spi_driver);
191}
192module_exit(mc13xxx_exit);
193
194MODULE_DESCRIPTION("Core driver for Freescale MC13XXX PMIC");
195MODULE_AUTHOR("Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>");
196MODULE_LICENSE("GPL v2");