11f67b599SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only
2e789995dSViresh Kumar /*
3e789995dSViresh Kumar * ST Microelectronics MFD: stmpe's spi client specific driver
4e789995dSViresh Kumar *
5e789995dSViresh Kumar * Copyright (C) ST Microelectronics SA 2011
6e789995dSViresh Kumar *
7da89947bSViresh Kumar * Author: Viresh Kumar <vireshk@kernel.org> for ST Microelectronics
8e789995dSViresh Kumar */
9e789995dSViresh Kumar
10e789995dSViresh Kumar #include <linux/spi/spi.h>
11e789995dSViresh Kumar #include <linux/interrupt.h>
12e789995dSViresh Kumar #include <linux/kernel.h>
13e789995dSViresh Kumar #include <linux/module.h>
141e955becSJavier Martinez Canillas #include <linux/of.h>
15e789995dSViresh Kumar #include <linux/types.h>
16e789995dSViresh Kumar #include "stmpe.h"
17e789995dSViresh Kumar
18e789995dSViresh Kumar #define READ_CMD (1 << 7)
19e789995dSViresh Kumar
spi_reg_read(struct stmpe * stmpe,u8 reg)20e789995dSViresh Kumar static int spi_reg_read(struct stmpe *stmpe, u8 reg)
21e789995dSViresh Kumar {
22e789995dSViresh Kumar struct spi_device *spi = stmpe->client;
23e789995dSViresh Kumar int status = spi_w8r16(spi, reg | READ_CMD);
24e789995dSViresh Kumar
25e789995dSViresh Kumar return (status < 0) ? status : status >> 8;
26e789995dSViresh Kumar }
27e789995dSViresh Kumar
spi_reg_write(struct stmpe * stmpe,u8 reg,u8 val)28e789995dSViresh Kumar static int spi_reg_write(struct stmpe *stmpe, u8 reg, u8 val)
29e789995dSViresh Kumar {
30e789995dSViresh Kumar struct spi_device *spi = stmpe->client;
31e789995dSViresh Kumar u16 cmd = (val << 8) | reg;
32e789995dSViresh Kumar
33e789995dSViresh Kumar return spi_write(spi, (const u8 *)&cmd, 2);
34e789995dSViresh Kumar }
35e789995dSViresh Kumar
spi_block_read(struct stmpe * stmpe,u8 reg,u8 length,u8 * values)36e789995dSViresh Kumar static int spi_block_read(struct stmpe *stmpe, u8 reg, u8 length, u8 *values)
37e789995dSViresh Kumar {
38e789995dSViresh Kumar int ret, i;
39e789995dSViresh Kumar
40e789995dSViresh Kumar for (i = 0; i < length; i++) {
41e789995dSViresh Kumar ret = spi_reg_read(stmpe, reg + i);
42e789995dSViresh Kumar if (ret < 0)
43e789995dSViresh Kumar return ret;
44e789995dSViresh Kumar *(values + i) = ret;
45e789995dSViresh Kumar }
46e789995dSViresh Kumar
47e789995dSViresh Kumar return 0;
48e789995dSViresh Kumar }
49e789995dSViresh Kumar
spi_block_write(struct stmpe * stmpe,u8 reg,u8 length,const u8 * values)50e789995dSViresh Kumar static int spi_block_write(struct stmpe *stmpe, u8 reg, u8 length,
51e789995dSViresh Kumar const u8 *values)
52e789995dSViresh Kumar {
53e789995dSViresh Kumar int ret = 0, i;
54e789995dSViresh Kumar
55e789995dSViresh Kumar for (i = length; i > 0; i--, reg++) {
56e789995dSViresh Kumar ret = spi_reg_write(stmpe, reg, *(values + i - 1));
57e789995dSViresh Kumar if (ret < 0)
58e789995dSViresh Kumar return ret;
59e789995dSViresh Kumar }
60e789995dSViresh Kumar
61e789995dSViresh Kumar return ret;
62e789995dSViresh Kumar }
63e789995dSViresh Kumar
spi_init(struct stmpe * stmpe)64e789995dSViresh Kumar static void spi_init(struct stmpe *stmpe)
65e789995dSViresh Kumar {
66e789995dSViresh Kumar struct spi_device *spi = stmpe->client;
67e789995dSViresh Kumar
68e789995dSViresh Kumar spi->bits_per_word = 8;
69e789995dSViresh Kumar
70e789995dSViresh Kumar /* This register is only present for stmpe811 */
71e789995dSViresh Kumar if (stmpe->variant->id_val == 0x0811)
72e789995dSViresh Kumar spi_reg_write(stmpe, STMPE811_REG_SPI_CFG, spi->mode);
73e789995dSViresh Kumar
74e789995dSViresh Kumar if (spi_setup(spi) < 0)
75e789995dSViresh Kumar dev_dbg(&spi->dev, "spi_setup failed\n");
76e789995dSViresh Kumar }
77e789995dSViresh Kumar
78e789995dSViresh Kumar static struct stmpe_client_info spi_ci = {
79e789995dSViresh Kumar .read_byte = spi_reg_read,
80e789995dSViresh Kumar .write_byte = spi_reg_write,
81e789995dSViresh Kumar .read_block = spi_block_read,
82e789995dSViresh Kumar .write_block = spi_block_write,
83e789995dSViresh Kumar .init = spi_init,
84e789995dSViresh Kumar };
85e789995dSViresh Kumar
86f791be49SBill Pemberton static int
stmpe_spi_probe(struct spi_device * spi)87e789995dSViresh Kumar stmpe_spi_probe(struct spi_device *spi)
88e789995dSViresh Kumar {
89e789995dSViresh Kumar const struct spi_device_id *id = spi_get_device_id(spi);
90e789995dSViresh Kumar
91e789995dSViresh Kumar /* don't exceed max specified rate - 1MHz - Limitation of STMPE */
92e789995dSViresh Kumar if (spi->max_speed_hz > 1000000) {
93e789995dSViresh Kumar dev_dbg(&spi->dev, "f(sample) %d KHz?\n",
94e789995dSViresh Kumar (spi->max_speed_hz/1000));
95e789995dSViresh Kumar return -EINVAL;
96e789995dSViresh Kumar }
97e789995dSViresh Kumar
98e789995dSViresh Kumar spi_ci.irq = spi->irq;
99e789995dSViresh Kumar spi_ci.client = spi;
100e789995dSViresh Kumar spi_ci.dev = &spi->dev;
101e789995dSViresh Kumar
102e789995dSViresh Kumar return stmpe_probe(&spi_ci, id->driver_data);
103e789995dSViresh Kumar }
104e789995dSViresh Kumar
stmpe_spi_remove(struct spi_device * spi)105a0386bbaSUwe Kleine-König static void stmpe_spi_remove(struct spi_device *spi)
106e789995dSViresh Kumar {
107e65ad41eSJingoo Han struct stmpe *stmpe = spi_get_drvdata(spi);
108e789995dSViresh Kumar
109356bbabaSUwe Kleine-König stmpe_remove(stmpe);
110e789995dSViresh Kumar }
111e789995dSViresh Kumar
1121e955becSJavier Martinez Canillas static const struct of_device_id stmpe_spi_of_match[] = {
1131e955becSJavier Martinez Canillas { .compatible = "st,stmpe610", },
1141e955becSJavier Martinez Canillas { .compatible = "st,stmpe801", },
1151e955becSJavier Martinez Canillas { .compatible = "st,stmpe811", },
1161e955becSJavier Martinez Canillas { .compatible = "st,stmpe1601", },
1171e955becSJavier Martinez Canillas { .compatible = "st,stmpe2401", },
1181e955becSJavier Martinez Canillas { .compatible = "st,stmpe2403", },
1191e955becSJavier Martinez Canillas { /* sentinel */ },
1201e955becSJavier Martinez Canillas };
1211e955becSJavier Martinez Canillas MODULE_DEVICE_TABLE(of, stmpe_spi_of_match);
1221e955becSJavier Martinez Canillas
123e789995dSViresh Kumar static const struct spi_device_id stmpe_spi_id[] = {
1241cda2394SViresh Kumar { "stmpe610", STMPE610 },
1257f7f4ea1SViresh Kumar { "stmpe801", STMPE801 },
126e789995dSViresh Kumar { "stmpe811", STMPE811 },
127e789995dSViresh Kumar { "stmpe1601", STMPE1601 },
128e789995dSViresh Kumar { "stmpe2401", STMPE2401 },
129e789995dSViresh Kumar { "stmpe2403", STMPE2403 },
130e789995dSViresh Kumar { }
131e789995dSViresh Kumar };
132e789995dSViresh Kumar MODULE_DEVICE_TABLE(spi, stmpe_id);
133e789995dSViresh Kumar
134e789995dSViresh Kumar static struct spi_driver stmpe_spi_driver = {
135e789995dSViresh Kumar .driver = {
136e789995dSViresh Kumar .name = "stmpe-spi",
1371e955becSJavier Martinez Canillas .of_match_table = of_match_ptr(stmpe_spi_of_match),
138*f7f292feSPaul Cercueil .pm = pm_sleep_ptr(&stmpe_dev_pm_ops),
139e789995dSViresh Kumar },
140e789995dSViresh Kumar .probe = stmpe_spi_probe,
14184449216SBill Pemberton .remove = stmpe_spi_remove,
142e789995dSViresh Kumar .id_table = stmpe_spi_id,
143e789995dSViresh Kumar };
144e789995dSViresh Kumar
stmpe_init(void)145e789995dSViresh Kumar static int __init stmpe_init(void)
146e789995dSViresh Kumar {
147e789995dSViresh Kumar return spi_register_driver(&stmpe_spi_driver);
148e789995dSViresh Kumar }
149e789995dSViresh Kumar subsys_initcall(stmpe_init);
150e789995dSViresh Kumar
stmpe_exit(void)151e789995dSViresh Kumar static void __exit stmpe_exit(void)
152e789995dSViresh Kumar {
153e789995dSViresh Kumar spi_unregister_driver(&stmpe_spi_driver);
154e789995dSViresh Kumar }
155e789995dSViresh Kumar module_exit(stmpe_exit);
156e789995dSViresh Kumar
157e789995dSViresh Kumar MODULE_DESCRIPTION("STMPE MFD SPI Interface Driver");
158da89947bSViresh Kumar MODULE_AUTHOR("Viresh Kumar <vireshk@kernel.org>");
159