1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright 2009-2010 Pengutronix
4 * Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>
5 *
6 * loosely based on an earlier driver that has
7 * Copyright 2009 Pengutronix, Sascha Hauer <s.hauer@pengutronix.de>
8 */
9
10 #include <linux/slab.h>
11 #include <linux/module.h>
12 #include <linux/platform_device.h>
13 #include <linux/interrupt.h>
14 #include <linux/mfd/core.h>
15 #include <linux/mfd/mc13xxx.h>
16 #include <linux/of.h>
17 #include <linux/of_device.h>
18 #include <linux/err.h>
19 #include <linux/spi/spi.h>
20
21 #include "mc13xxx.h"
22
23 static const struct spi_device_id mc13xxx_device_id[] = {
24 {
25 .name = "mc13783",
26 .driver_data = (kernel_ulong_t)&mc13xxx_variant_mc13783,
27 }, {
28 .name = "mc13892",
29 .driver_data = (kernel_ulong_t)&mc13xxx_variant_mc13892,
30 }, {
31 .name = "mc34708",
32 .driver_data = (kernel_ulong_t)&mc13xxx_variant_mc34708,
33 }, {
34 /* sentinel */
35 }
36 };
37 MODULE_DEVICE_TABLE(spi, mc13xxx_device_id);
38
39 static const struct of_device_id mc13xxx_dt_ids[] = {
40 { .compatible = "fsl,mc13783", .data = &mc13xxx_variant_mc13783, },
41 { .compatible = "fsl,mc13892", .data = &mc13xxx_variant_mc13892, },
42 { .compatible = "fsl,mc34708", .data = &mc13xxx_variant_mc34708, },
43 { /* sentinel */ }
44 };
45 MODULE_DEVICE_TABLE(of, mc13xxx_dt_ids);
46
47 static const struct regmap_config mc13xxx_regmap_spi_config = {
48 .reg_bits = 7,
49 .pad_bits = 1,
50 .val_bits = 24,
51 .write_flag_mask = 0x80,
52
53 .max_register = MC13XXX_NUMREGS,
54
55 .cache_type = REGCACHE_NONE,
56 .use_single_read = true,
57 .use_single_write = true,
58 };
59
mc13xxx_spi_read(void * context,const void * reg,size_t reg_size,void * val,size_t val_size)60 static 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
mc13xxx_spi_write(void * context,const void * data,size_t count)89 static 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 const char *reg = data;
94
95 if (count != 4)
96 return -ENOTSUPP;
97
98 /* include errata fix for spi audio problems */
99 if (*reg == MC13783_AUDIO_CODEC || *reg == MC13783_AUDIO_DAC)
100 spi_write(spi, data, count);
101
102 return spi_write(spi, data, count);
103 }
104
105 /*
106 * We cannot use regmap-spi generic bus implementation here.
107 * The MC13783 chip will get corrupted if CS signal is deasserted
108 * and on i.Mx31 SoC (the target SoC for MC13783 PMIC) the SPI controller
109 * has the following errata (DSPhl22960):
110 * "The CSPI negates SS when the FIFO becomes empty with
111 * SSCTL= 0. Software cannot guarantee that the FIFO will not
112 * drain because of higher priority interrupts and the
113 * non-realtime characteristics of the operating system. As a
114 * result, the SS will negate before all of the data has been
115 * transferred to/from the peripheral."
116 * We workaround this by accessing the SPI controller with a
117 * single transfer.
118 */
119
120 static struct regmap_bus regmap_mc13xxx_bus = {
121 .write = mc13xxx_spi_write,
122 .read = mc13xxx_spi_read,
123 };
124
mc13xxx_spi_probe(struct spi_device * spi)125 static int mc13xxx_spi_probe(struct spi_device *spi)
126 {
127 struct mc13xxx *mc13xxx;
128 int ret;
129
130 mc13xxx = devm_kzalloc(&spi->dev, sizeof(*mc13xxx), GFP_KERNEL);
131 if (!mc13xxx)
132 return -ENOMEM;
133
134 dev_set_drvdata(&spi->dev, mc13xxx);
135
136 spi->mode = SPI_MODE_0 | SPI_CS_HIGH;
137
138 mc13xxx->irq = spi->irq;
139
140 spi->max_speed_hz = spi->max_speed_hz ? : 26000000;
141 ret = spi_setup(spi);
142 if (ret)
143 return ret;
144
145 mc13xxx->regmap = devm_regmap_init(&spi->dev, ®map_mc13xxx_bus,
146 &spi->dev,
147 &mc13xxx_regmap_spi_config);
148 if (IS_ERR(mc13xxx->regmap)) {
149 ret = PTR_ERR(mc13xxx->regmap);
150 dev_err(&spi->dev, "Failed to initialize regmap: %d\n", ret);
151 return ret;
152 }
153
154 if (spi->dev.of_node) {
155 const struct of_device_id *of_id =
156 of_match_device(mc13xxx_dt_ids, &spi->dev);
157
158 mc13xxx->variant = of_id->data;
159 } else {
160 const struct spi_device_id *id_entry = spi_get_device_id(spi);
161
162 mc13xxx->variant = (void *)id_entry->driver_data;
163 }
164
165 return mc13xxx_common_init(&spi->dev);
166 }
167
mc13xxx_spi_remove(struct spi_device * spi)168 static void mc13xxx_spi_remove(struct spi_device *spi)
169 {
170 mc13xxx_common_exit(&spi->dev);
171 }
172
173 static struct spi_driver mc13xxx_spi_driver = {
174 .id_table = mc13xxx_device_id,
175 .driver = {
176 .name = "mc13xxx",
177 .of_match_table = mc13xxx_dt_ids,
178 },
179 .probe = mc13xxx_spi_probe,
180 .remove = mc13xxx_spi_remove,
181 };
182
mc13xxx_init(void)183 static int __init mc13xxx_init(void)
184 {
185 return spi_register_driver(&mc13xxx_spi_driver);
186 }
187 subsys_initcall(mc13xxx_init);
188
mc13xxx_exit(void)189 static void __exit mc13xxx_exit(void)
190 {
191 spi_unregister_driver(&mc13xxx_spi_driver);
192 }
193 module_exit(mc13xxx_exit);
194
195 MODULE_DESCRIPTION("Core driver for Freescale MC13XXX PMIC");
196 MODULE_AUTHOR("Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>");
197 MODULE_LICENSE("GPL v2");
198