aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/mfd/stmpe-spi.c
blob: 7351734f759385e372d89fd95bbf0dbd3eb7e2e0 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
// SPDX-License-Identifier: GPL-2.0-only
/*
 * ST Microelectronics MFD: stmpe's spi client specific driver
 *
 * Copyright (C) ST Microelectronics SA 2011
 *
 * Author: Viresh Kumar <vireshk@kernel.org> for ST Microelectronics
 */

#include <linux/spi/spi.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/types.h>
#include "stmpe.h"

#define READ_CMD	(1 << 7)

static int spi_reg_read(struct stmpe *stmpe, u8 reg)
{
	struct spi_device *spi = stmpe->client;
	int status = spi_w8r16(spi, reg | READ_CMD);

	return (status < 0) ? status : status >> 8;
}

static int spi_reg_write(struct stmpe *stmpe, u8 reg, u8 val)
{
	struct spi_device *spi = stmpe->client;
	u16 cmd = (val << 8) | reg;

	return spi_write(spi, (const u8 *)&cmd, 2);
}

static int spi_block_read(struct stmpe *stmpe, u8 reg, u8 length, u8 *values)
{
	int ret, i;

	for (i = 0; i < length; i++) {
		ret = spi_reg_read(stmpe, reg + i);
		if (ret < 0)
			return ret;
		*(values + i) = ret;
	}

	return 0;
}

static int spi_block_write(struct stmpe *stmpe, u8 reg, u8 length,
		const u8 *values)
{
	int ret = 0, i;

	for (i = length; i > 0; i--, reg++) {
		ret = spi_reg_write(stmpe, reg, *(values + i - 1));
		if (ret < 0)
			return ret;
	}

	return ret;
}

static void spi_init(struct stmpe *stmpe)
{
	struct spi_device *spi = stmpe->client;

	spi->bits_per_word = 8;

	/* This register is only present for stmpe811 */
	if (stmpe->variant->id_val == 0x0811)
		spi_reg_write(stmpe, STMPE811_REG_SPI_CFG, spi->mode);

	if (spi_setup(spi) < 0)
		dev_dbg(&spi->dev, "spi_setup failed\n");
}

static struct stmpe_client_info spi_ci = {
	.read_byte = spi_reg_read,
	.write_byte = spi_reg_write,
	.read_block = spi_block_read,
	.write_block = spi_block_write,
	.init = spi_init,
};

static int
stmpe_spi_probe(struct spi_device *spi)
{
	const struct spi_device_id *id = spi_get_device_id(spi);

	/* don't exceed max specified rate - 1MHz - Limitation of STMPE */
	if (spi->max_speed_hz > 1000000) {
		dev_dbg(&spi->dev, "f(sample) %d KHz?\n",
				(spi->max_speed_hz/1000));
		return -EINVAL;
	}

	spi_ci.irq = spi->irq;
	spi_ci.client = spi;
	spi_ci.dev = &spi->dev;

	return stmpe_probe(&spi_ci, id->driver_data);
}

static int stmpe_spi_remove(struct spi_device *spi)
{
	struct stmpe *stmpe = spi_get_drvdata(spi);

	return stmpe_remove(stmpe);
}

static const struct of_device_id stmpe_spi_of_match[] = {
	{ .compatible = "st,stmpe610", },
	{ .compatible = "st,stmpe801", },
	{ .compatible = "st,stmpe811", },
	{ .compatible = "st,stmpe1601", },
	{ .compatible = "st,stmpe2401", },
	{ .compatible = "st,stmpe2403", },
	{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, stmpe_spi_of_match);

static const struct spi_device_id stmpe_spi_id[] = {
	{ "stmpe610", STMPE610 },
	{ "stmpe801", STMPE801 },
	{ "stmpe811", STMPE811 },
	{ "stmpe1601", STMPE1601 },
	{ "stmpe2401", STMPE2401 },
	{ "stmpe2403", STMPE2403 },
	{ }
};
MODULE_DEVICE_TABLE(spi, stmpe_id);

static struct spi_driver stmpe_spi_driver = {
	.driver = {
		.name	= "stmpe-spi",
		.of_match_table = of_match_ptr(stmpe_spi_of_match),
#ifdef CONFIG_PM
		.pm	= &stmpe_dev_pm_ops,
#endif
	},
	.probe		= stmpe_spi_probe,
	.remove		= stmpe_spi_remove,
	.id_table	= stmpe_spi_id,
};

static int __init stmpe_init(void)
{
	return spi_register_driver(&stmpe_spi_driver);
}
subsys_initcall(stmpe_init);

static void __exit stmpe_exit(void)
{
	spi_unregister_driver(&stmpe_spi_driver);
}
module_exit(stmpe_exit);

MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("STMPE MFD SPI Interface Driver");
MODULE_AUTHOR("Viresh Kumar <vireshk@kernel.org>");