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);
80	spi_message_add_tail(&t, &m);
81	ret = spi_sync(spi, &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, data, count);
100
101	return spi_write(spi, data, 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(&spi->dev, sizeof(*mc13xxx), GFP_KERNEL);
130	if (!mc13xxx)
131		return -ENOMEM;
132
133	dev_set_drvdata(&spi->dev, 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(mc13xxx->regmap)) {
148		ret = PTR_ERR(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(spi);
154
155	return mc13xxx_common_init(&spi->dev);
156}
157
158static void mc13xxx_spi_remove(struct spi_device *spi)
159{
160	mc13xxx_common_exit(&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(&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