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/of_gpio.h>
19 #include <linux/err.h>
20 #include <linux/spi/spi.h>
21
22 #include "mc13xxx.h"
23
24 static const struct spi_device_id mc13xxx_device_id[] = {
25 {
26 .name = "mc13783",
27 .driver_data = (kernel_ulong_t)&mc13xxx_variant_mc13783,
28 }, {
29 .name = "mc13892",
30 .driver_data = (kernel_ulong_t)&mc13xxx_variant_mc13892,
31 }, {
32 .name = "mc34708",
33 .driver_data = (kernel_ulong_t)&mc13xxx_variant_mc34708,
34 }, {
35 /* sentinel */
36 }
37 };
38 MODULE_DEVICE_TABLE(spi, mc13xxx_device_id);
39
40 static const struct of_device_id mc13xxx_dt_ids[] = {
41 { .compatible = "fsl,mc13783", .data = &mc13xxx_variant_mc13783, },
42 { .compatible = "fsl,mc13892", .data = &mc13xxx_variant_mc13892, },
43 { .compatible = "fsl,mc34708", .data = &mc13xxx_variant_mc34708, },
44 { /* sentinel */ }
45 };
46 MODULE_DEVICE_TABLE(of, mc13xxx_dt_ids);
47
48 static const 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_read = true,
58 .use_single_write = true,
59 };
60
mc13xxx_spi_read(void * context,const void * reg,size_t reg_size,void * val,size_t val_size)61 static int mc13xxx_spi_read(void *context, const void *reg, size_t reg_size,
62 void *val, size_t val_size)
63 {
64 unsigned char w[4] = { *((unsigned char *) reg), 0, 0, 0};
65 unsigned char r[4];
66 unsigned char *p = val;
67 struct device *dev = context;
68 struct spi_device *spi = to_spi_device(dev);
69 struct spi_transfer t = {
70 .tx_buf = w,
71 .rx_buf = r,
72 .len = 4,
73 };
74
75 struct spi_message m;
76 int ret;
77
78 if (val_size != 3 || reg_size != 1)
79 return -ENOTSUPP;
80
81 spi_message_init(&m);
82 spi_message_add_tail(&t, &m);
83 ret = spi_sync(spi, &m);
84
85 memcpy(p, &r[1], 3);
86
87 return ret;
88 }
89
mc13xxx_spi_write(void * context,const void * data,size_t count)90 static int mc13xxx_spi_write(void *context, const void *data, size_t count)
91 {
92 struct device *dev = context;
93 struct spi_device *spi = to_spi_device(dev);
94 const char *reg = data;
95
96 if (count != 4)
97 return -ENOTSUPP;
98
99 /* include errata fix for spi audio problems */
100 if (*reg == MC13783_AUDIO_CODEC || *reg == MC13783_AUDIO_DAC)
101 spi_write(spi, data, count);
102
103 return spi_write(spi, data, count);
104 }
105
106 /*
107 * We cannot use regmap-spi generic bus implementation here.
108 * The MC13783 chip will get corrupted if CS signal is deasserted
109 * and on i.Mx31 SoC (the target SoC for MC13783 PMIC) the SPI controller
110 * has the following errata (DSPhl22960):
111 * "The CSPI negates SS when the FIFO becomes empty with
112 * SSCTL= 0. Software cannot guarantee that the FIFO will not
113 * drain because of higher priority interrupts and the
114 * non-realtime characteristics of the operating system. As a
115 * result, the SS will negate before all of the data has been
116 * transferred to/from the peripheral."
117 * We workaround this by accessing the SPI controller with a
118 * single transfert.
119 */
120
121 static struct regmap_bus regmap_mc13xxx_bus = {
122 .write = mc13xxx_spi_write,
123 .read = mc13xxx_spi_read,
124 };
125
mc13xxx_spi_probe(struct spi_device * spi)126 static int mc13xxx_spi_probe(struct spi_device *spi)
127 {
128 struct mc13xxx *mc13xxx;
129 int ret;
130
131 mc13xxx = devm_kzalloc(&spi->dev, sizeof(*mc13xxx), GFP_KERNEL);
132 if (!mc13xxx)
133 return -ENOMEM;
134
135 dev_set_drvdata(&spi->dev, mc13xxx);
136
137 spi->mode = SPI_MODE_0 | SPI_CS_HIGH;
138
139 mc13xxx->irq = spi->irq;
140
141 spi->max_speed_hz = spi->max_speed_hz ? : 26000000;
142 ret = spi_setup(spi);
143 if (ret)
144 return ret;
145
146 mc13xxx->regmap = devm_regmap_init(&spi->dev, ®map_mc13xxx_bus,
147 &spi->dev,
148 &mc13xxx_regmap_spi_config);
149 if (IS_ERR(mc13xxx->regmap)) {
150 ret = PTR_ERR(mc13xxx->regmap);
151 dev_err(&spi->dev, "Failed to initialize regmap: %d\n", ret);
152 return ret;
153 }
154
155 if (spi->dev.of_node) {
156 const struct of_device_id *of_id =
157 of_match_device(mc13xxx_dt_ids, &spi->dev);
158
159 mc13xxx->variant = of_id->data;
160 } else {
161 const struct spi_device_id *id_entry = spi_get_device_id(spi);
162
163 mc13xxx->variant = (void *)id_entry->driver_data;
164 }
165
166 return mc13xxx_common_init(&spi->dev);
167 }
168
mc13xxx_spi_remove(struct spi_device * spi)169 static int mc13xxx_spi_remove(struct spi_device *spi)
170 {
171 return mc13xxx_common_exit(&spi->dev);
172 }
173
174 static struct spi_driver mc13xxx_spi_driver = {
175 .id_table = mc13xxx_device_id,
176 .driver = {
177 .name = "mc13xxx",
178 .of_match_table = mc13xxx_dt_ids,
179 },
180 .probe = mc13xxx_spi_probe,
181 .remove = mc13xxx_spi_remove,
182 };
183
mc13xxx_init(void)184 static int __init mc13xxx_init(void)
185 {
186 return spi_register_driver(&mc13xxx_spi_driver);
187 }
188 subsys_initcall(mc13xxx_init);
189
mc13xxx_exit(void)190 static void __exit mc13xxx_exit(void)
191 {
192 spi_unregister_driver(&mc13xxx_spi_driver);
193 }
194 module_exit(mc13xxx_exit);
195
196 MODULE_DESCRIPTION("Core driver for Freescale MC13XXX PMIC");
197 MODULE_AUTHOR("Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>");
198 MODULE_LICENSE("GPL v2");
199
