2 * Copyright 2009-2010 Pengutronix
3 * Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>
5 * loosely based on an earlier driver that has
6 * Copyright 2009 Pengutronix, Sascha Hauer <s.hauer@pengutronix.de>
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.
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>
21 #include <linux/of_device.h>
22 #include <linux/of_gpio.h>
23 #include <linux/err.h>
24 #include <linux/spi/spi.h>
28 static const struct spi_device_id mc13xxx_device_id[] = {
31 .driver_data = (kernel_ulong_t)&mc13xxx_variant_mc13783,
34 .driver_data = (kernel_ulong_t)&mc13xxx_variant_mc13892,
37 .driver_data = (kernel_ulong_t)&mc13xxx_variant_mc34708,
42 MODULE_DEVICE_TABLE(spi, mc13xxx_device_id);
44 static const struct of_device_id mc13xxx_dt_ids[] = {
45 { .compatible = "fsl,mc13783", .data = &mc13xxx_variant_mc13783, },
46 { .compatible = "fsl,mc13892", .data = &mc13xxx_variant_mc13892, },
47 { .compatible = "fsl,mc34708", .data = &mc13xxx_variant_mc34708, },
50 MODULE_DEVICE_TABLE(of, mc13xxx_dt_ids);
52 static struct regmap_config mc13xxx_regmap_spi_config = {
56 .write_flag_mask = 0x80,
58 .max_register = MC13XXX_NUMREGS,
60 .cache_type = REGCACHE_NONE,
64 static int mc13xxx_spi_read(void *context, const void *reg, size_t reg_size,
65 void *val, size_t val_size)
67 unsigned char w[4] = { *((unsigned char *) reg), 0, 0, 0};
69 unsigned char *p = val;
70 struct device *dev = context;
71 struct spi_device *spi = to_spi_device(dev);
72 struct spi_transfer t = {
81 if (val_size != 3 || reg_size != 1)
85 spi_message_add_tail(&t, &m);
86 ret = spi_sync(spi, &m);
93 static int mc13xxx_spi_write(void *context, const void *data, size_t count)
95 struct device *dev = context;
96 struct spi_device *spi = to_spi_device(dev);
97 const char *reg = data;
102 /* include errata fix for spi audio problems */
103 if (*reg == MC13783_AUDIO_CODEC || *reg == MC13783_AUDIO_DAC)
104 spi_write(spi, data, count);
106 return spi_write(spi, data, count);
110 * We cannot use regmap-spi generic bus implementation here.
111 * The MC13783 chip will get corrupted if CS signal is deasserted
112 * and on i.Mx31 SoC (the target SoC for MC13783 PMIC) the SPI controller
113 * has the following errata (DSPhl22960):
114 * "The CSPI negates SS when the FIFO becomes empty with
115 * SSCTL= 0. Software cannot guarantee that the FIFO will not
116 * drain because of higher priority interrupts and the
117 * non-realtime characteristics of the operating system. As a
118 * result, the SS will negate before all of the data has been
119 * transferred to/from the peripheral."
120 * We workaround this by accessing the SPI controller with a
124 static struct regmap_bus regmap_mc13xxx_bus = {
125 .write = mc13xxx_spi_write,
126 .read = mc13xxx_spi_read,
129 static int mc13xxx_spi_probe(struct spi_device *spi)
131 struct mc13xxx *mc13xxx;
132 struct mc13xxx_platform_data *pdata = dev_get_platdata(&spi->dev);
135 mc13xxx = devm_kzalloc(&spi->dev, sizeof(*mc13xxx), GFP_KERNEL);
139 spi_set_drvdata(spi, mc13xxx);
140 spi->mode = SPI_MODE_0 | SPI_CS_HIGH;
142 mc13xxx->dev = &spi->dev;
143 mutex_init(&mc13xxx->lock);
145 mc13xxx->regmap = devm_regmap_init(&spi->dev, ®map_mc13xxx_bus,
147 &mc13xxx_regmap_spi_config);
148 if (IS_ERR(mc13xxx->regmap)) {
149 ret = PTR_ERR(mc13xxx->regmap);
150 dev_err(mc13xxx->dev, "Failed to initialize register map: %d\n",
152 spi_set_drvdata(spi, NULL);
156 if (spi->dev.of_node) {
157 const struct of_device_id *of_id =
158 of_match_device(mc13xxx_dt_ids, &spi->dev);
160 mc13xxx->variant = of_id->data;
162 const struct spi_device_id *id_entry = spi_get_device_id(spi);
164 mc13xxx->variant = (void *)id_entry->driver_data;
167 return mc13xxx_common_init(mc13xxx, pdata, spi->irq);
170 static int mc13xxx_spi_remove(struct spi_device *spi)
172 struct mc13xxx *mc13xxx = spi_get_drvdata(spi);
174 mc13xxx_common_cleanup(mc13xxx);
179 static struct spi_driver mc13xxx_spi_driver = {
180 .id_table = mc13xxx_device_id,
183 .owner = THIS_MODULE,
184 .of_match_table = mc13xxx_dt_ids,
186 .probe = mc13xxx_spi_probe,
187 .remove = mc13xxx_spi_remove,
190 static int __init mc13xxx_init(void)
192 return spi_register_driver(&mc13xxx_spi_driver);
194 subsys_initcall(mc13xxx_init);
196 static void __exit mc13xxx_exit(void)
198 spi_unregister_driver(&mc13xxx_spi_driver);
200 module_exit(mc13xxx_exit);
202 MODULE_DESCRIPTION("Core driver for Freescale MC13XXX PMIC");
203 MODULE_AUTHOR("Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>");
204 MODULE_LICENSE("GPL v2");