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/mod_devicetable.h>
12#include <linux/module.h>
13#include <linux/platform_device.h>
14#include <linux/interrupt.h>
15#include <linux/mfd/core.h>
16#include <linux/mfd/mc13xxx.h>
17#include <linux/err.h>
18#include <linux/spi/spi.h>
19
20#include "mc13xxx.h"
21
22static const struct spi_device_id mc13xxx_device_id[] = {
23 {
24 .name = "mc13783",
25 .driver_data = (kernel_ulong_t)&mc13xxx_variant_mc13783,
26 }, {
27 .name = "mc13892",
28 .driver_data = (kernel_ulong_t)&mc13xxx_variant_mc13892,
29 }, {
30 .name = "mc34708",
31 .driver_data = (kernel_ulong_t)&mc13xxx_variant_mc34708,
32 }, {
33 /* sentinel */
34 }
35};
36MODULE_DEVICE_TABLE(spi, mc13xxx_device_id);
37
38static const struct of_device_id mc13xxx_dt_ids[] = {
39 { .compatible = "fsl,mc13783", .data = &mc13xxx_variant_mc13783, },
40 { .compatible = "fsl,mc13892", .data = &mc13xxx_variant_mc13892, },
41 { .compatible = "fsl,mc34708", .data = &mc13xxx_variant_mc34708, },
42 { /* sentinel */ }
43};
44MODULE_DEVICE_TABLE(of, mc13xxx_dt_ids);
45
46static const struct regmap_config mc13xxx_regmap_spi_config = {
47 .reg_bits = 7,
48 .pad_bits = 1,
49 .val_bits = 24,
50 .write_flag_mask = 0x80,
51
52 .max_register = MC13XXX_NUMREGS,
53
54 .cache_type = REGCACHE_NONE,
55 .use_single_read = true,
56 .use_single_write = true,
57};
58
59static int mc13xxx_spi_read(void *context, const void *reg, size_t reg_size,
60 void *val, size_t val_size)
61{
62 unsigned char w[4] = { *((unsigned char *) reg), 0, 0, 0};
63 unsigned char r[4];
64 unsigned char *p = val;
65 struct device *dev = context;
66 struct spi_device *spi = to_spi_device(dev);
67 struct spi_transfer t = {
68 .tx_buf = w,
69 .rx_buf = r,
70 .len = 4,
71 };
72
73 struct spi_message m;
74 int ret;
75
76 if (val_size != 3 || reg_size != 1)
77 return -ENOTSUPP;
78
79 spi_message_init(m: &m);
80 spi_message_add_tail(t: &t, m: &m);
81 ret = spi_sync(spi, message: &m);
82
83 memcpy(p, &r[1], 3);
84
85 return ret;
86}
87
88static int mc13xxx_spi_write(void *context, const void *data, size_t count)
89{
90 struct device *dev = context;
91 struct spi_device *spi = to_spi_device(dev);
92 const char *reg = data;
93
94 if (count != 4)
95 return -ENOTSUPP;
96
97 /* include errata fix for spi audio problems */
98 if (*reg == MC13783_AUDIO_CODEC || *reg == MC13783_AUDIO_DAC)
99 spi_write(spi, buf: data, len: count);
100
101 return spi_write(spi, buf: data, len: count);
102}
103
104/*
105 * We cannot use regmap-spi generic bus implementation here.
106 * The MC13783 chip will get corrupted if CS signal is deasserted
107 * and on i.Mx31 SoC (the target SoC for MC13783 PMIC) the SPI controller
108 * has the following errata (DSPhl22960):
109 * "The CSPI negates SS when the FIFO becomes empty with
110 * SSCTL= 0. Software cannot guarantee that the FIFO will not
111 * drain because of higher priority interrupts and the
112 * non-realtime characteristics of the operating system. As a
113 * result, the SS will negate before all of the data has been
114 * transferred to/from the peripheral."
115 * We workaround this by accessing the SPI controller with a
116 * single transfer.
117 */
118
119static struct regmap_bus regmap_mc13xxx_bus = {
120 .write = mc13xxx_spi_write,
121 .read = mc13xxx_spi_read,
122};
123
124static int mc13xxx_spi_probe(struct spi_device *spi)
125{
126 struct mc13xxx *mc13xxx;
127 int ret;
128
129 mc13xxx = devm_kzalloc(dev: &spi->dev, size: sizeof(*mc13xxx), GFP_KERNEL);
130 if (!mc13xxx)
131 return -ENOMEM;
132
133 dev_set_drvdata(dev: &spi->dev, data: mc13xxx);
134
135 spi->mode = SPI_MODE_0 | SPI_CS_HIGH;
136
137 mc13xxx->irq = spi->irq;
138
139 spi->max_speed_hz = spi->max_speed_hz ? : 26000000;
140 ret = spi_setup(spi);
141 if (ret)
142 return ret;
143
144 mc13xxx->regmap = devm_regmap_init(&spi->dev, &regmap_mc13xxx_bus,
145 &spi->dev,
146 &mc13xxx_regmap_spi_config);
147 if (IS_ERR(ptr: mc13xxx->regmap)) {
148 ret = PTR_ERR(ptr: mc13xxx->regmap);
149 dev_err(&spi->dev, "Failed to initialize regmap: %d\n", ret);
150 return ret;
151 }
152
153 mc13xxx->variant = spi_get_device_match_data(sdev: spi);
154
155 return mc13xxx_common_init(dev: &spi->dev);
156}
157
158static void mc13xxx_spi_remove(struct spi_device *spi)
159{
160 mc13xxx_common_exit(dev: &spi->dev);
161}
162
163static struct spi_driver mc13xxx_spi_driver = {
164 .id_table = mc13xxx_device_id,
165 .driver = {
166 .name = "mc13xxx",
167 .of_match_table = mc13xxx_dt_ids,
168 },
169 .probe = mc13xxx_spi_probe,
170 .remove = mc13xxx_spi_remove,
171};
172
173static int __init mc13xxx_init(void)
174{
175 return spi_register_driver(&mc13xxx_spi_driver);
176}
177subsys_initcall(mc13xxx_init);
178
179static void __exit mc13xxx_exit(void)
180{
181 spi_unregister_driver(sdrv: &mc13xxx_spi_driver);
182}
183module_exit(mc13xxx_exit);
184
185MODULE_DESCRIPTION("Core driver for Freescale MC13XXX PMIC");
186MODULE_AUTHOR("Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>");
187MODULE_LICENSE("GPL v2");
188

source code of linux/drivers/mfd/mc13xxx-spi.c