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
23static 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};
37MODULE_DEVICE_TABLE(spi, mc13xxx_device_id);
38
39static 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};
45MODULE_DEVICE_TABLE(of, mc13xxx_dt_ids);
46
47static 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
60static 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
89static 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
120static struct regmap_bus regmap_mc13xxx_bus = {
121	.write = mc13xxx_spi_write,
122	.read = mc13xxx_spi_read,
123};
124
125static 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, &regmap_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
168static void mc13xxx_spi_remove(struct spi_device *spi)
169{
170	mc13xxx_common_exit(&spi->dev);
171}
172
173static 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
183static int __init mc13xxx_init(void)
184{
185	return spi_register_driver(&mc13xxx_spi_driver);
186}
187subsys_initcall(mc13xxx_init);
188
189static void __exit mc13xxx_exit(void)
190{
191	spi_unregister_driver(&mc13xxx_spi_driver);
192}
193module_exit(mc13xxx_exit);
194
195MODULE_DESCRIPTION("Core driver for Freescale MC13XXX PMIC");
196MODULE_AUTHOR("Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>");
197MODULE_LICENSE("GPL v2");
198