182c29810SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only
2c103de24SGrant Likely /*
3c103de24SGrant Likely * MC33880 high-side/low-side switch GPIO driver
4c103de24SGrant Likely * Copyright (c) 2009 Intel Corporation
5c103de24SGrant Likely */
6c103de24SGrant Likely
7c103de24SGrant Likely /* Supports:
8c103de24SGrant Likely * Freescale MC33880 high-side/low-side switch
9c103de24SGrant Likely */
10c103de24SGrant Likely
11c103de24SGrant Likely #include <linux/init.h>
12c103de24SGrant Likely #include <linux/mutex.h>
13c103de24SGrant Likely #include <linux/spi/spi.h>
14c103de24SGrant Likely #include <linux/spi/mc33880.h>
1503a3f19cSLinus Walleij #include <linux/gpio/driver.h>
16c103de24SGrant Likely #include <linux/slab.h>
17bb207ef1SPaul Gortmaker #include <linux/module.h>
18c103de24SGrant Likely
19c103de24SGrant Likely #define DRIVER_NAME "mc33880"
20c103de24SGrant Likely
21c103de24SGrant Likely /*
22c103de24SGrant Likely * Pin configurations, see MAX7301 datasheet page 6
23c103de24SGrant Likely */
24c103de24SGrant Likely #define PIN_CONFIG_MASK 0x03
25c103de24SGrant Likely #define PIN_CONFIG_IN_PULLUP 0x03
26c103de24SGrant Likely #define PIN_CONFIG_IN_WO_PULLUP 0x02
27c103de24SGrant Likely #define PIN_CONFIG_OUT 0x01
28c103de24SGrant Likely
29c103de24SGrant Likely #define PIN_NUMBER 8
30c103de24SGrant Likely
31c103de24SGrant Likely
32c103de24SGrant Likely /*
33c103de24SGrant Likely * Some registers must be read back to modify.
34c103de24SGrant Likely * To save time we cache them here in memory
35c103de24SGrant Likely */
36c103de24SGrant Likely struct mc33880 {
37c103de24SGrant Likely struct mutex lock; /* protect from simultaneous accesses */
38c103de24SGrant Likely u8 port_config;
39c103de24SGrant Likely struct gpio_chip chip;
40c103de24SGrant Likely struct spi_device *spi;
41c103de24SGrant Likely };
42c103de24SGrant Likely
mc33880_write_config(struct mc33880 * mc)43c103de24SGrant Likely static int mc33880_write_config(struct mc33880 *mc)
44c103de24SGrant Likely {
45c103de24SGrant Likely return spi_write(mc->spi, &mc->port_config, sizeof(mc->port_config));
46c103de24SGrant Likely }
47c103de24SGrant Likely
48c103de24SGrant Likely
__mc33880_set(struct mc33880 * mc,unsigned offset,int value)49c103de24SGrant Likely static int __mc33880_set(struct mc33880 *mc, unsigned offset, int value)
50c103de24SGrant Likely {
51c103de24SGrant Likely if (value)
52c103de24SGrant Likely mc->port_config |= 1 << offset;
53c103de24SGrant Likely else
54c103de24SGrant Likely mc->port_config &= ~(1 << offset);
55c103de24SGrant Likely
56c103de24SGrant Likely return mc33880_write_config(mc);
57c103de24SGrant Likely }
58c103de24SGrant Likely
59c103de24SGrant Likely
mc33880_set(struct gpio_chip * chip,unsigned offset,int value)60c103de24SGrant Likely static void mc33880_set(struct gpio_chip *chip, unsigned offset, int value)
61c103de24SGrant Likely {
62609f9692SLinus Walleij struct mc33880 *mc = gpiochip_get_data(chip);
63c103de24SGrant Likely
64c103de24SGrant Likely mutex_lock(&mc->lock);
65c103de24SGrant Likely
66c103de24SGrant Likely __mc33880_set(mc, offset, value);
67c103de24SGrant Likely
68c103de24SGrant Likely mutex_unlock(&mc->lock);
69c103de24SGrant Likely }
70c103de24SGrant Likely
mc33880_probe(struct spi_device * spi)713836309dSBill Pemberton static int mc33880_probe(struct spi_device *spi)
72c103de24SGrant Likely {
73c103de24SGrant Likely struct mc33880 *mc;
74c103de24SGrant Likely struct mc33880_platform_data *pdata;
75c103de24SGrant Likely int ret;
76c103de24SGrant Likely
77e56aee18SJingoo Han pdata = dev_get_platdata(&spi->dev);
78c103de24SGrant Likely if (!pdata || !pdata->base) {
79c103de24SGrant Likely dev_dbg(&spi->dev, "incorrect or missing platform data\n");
80c103de24SGrant Likely return -EINVAL;
81c103de24SGrant Likely }
82c103de24SGrant Likely
83c103de24SGrant Likely /*
84c103de24SGrant Likely * bits_per_word cannot be configured in platform data
85c103de24SGrant Likely */
86c103de24SGrant Likely spi->bits_per_word = 8;
87c103de24SGrant Likely
88c103de24SGrant Likely ret = spi_setup(spi);
89c103de24SGrant Likely if (ret < 0)
90c103de24SGrant Likely return ret;
91c103de24SGrant Likely
92632d8e55SJingoo Han mc = devm_kzalloc(&spi->dev, sizeof(struct mc33880), GFP_KERNEL);
93c103de24SGrant Likely if (!mc)
94c103de24SGrant Likely return -ENOMEM;
95c103de24SGrant Likely
96c103de24SGrant Likely mutex_init(&mc->lock);
97c103de24SGrant Likely
98493294d4SJingoo Han spi_set_drvdata(spi, mc);
99c103de24SGrant Likely
100c103de24SGrant Likely mc->spi = spi;
101c103de24SGrant Likely
102c103de24SGrant Likely mc->chip.label = DRIVER_NAME,
103c103de24SGrant Likely mc->chip.set = mc33880_set;
104c103de24SGrant Likely mc->chip.base = pdata->base;
105c103de24SGrant Likely mc->chip.ngpio = PIN_NUMBER;
1069fb1f39eSLinus Walleij mc->chip.can_sleep = true;
10758383c78SLinus Walleij mc->chip.parent = &spi->dev;
108c103de24SGrant Likely mc->chip.owner = THIS_MODULE;
109c103de24SGrant Likely
110c103de24SGrant Likely mc->port_config = 0x00;
111c103de24SGrant Likely /* write twice, because during initialisation the first setting
112c103de24SGrant Likely * is just for testing SPI communication, and the second is the
113c103de24SGrant Likely * "real" configuration
114c103de24SGrant Likely */
115c103de24SGrant Likely ret = mc33880_write_config(mc);
116c103de24SGrant Likely mc->port_config = 0x00;
117c103de24SGrant Likely if (!ret)
118c103de24SGrant Likely ret = mc33880_write_config(mc);
119c103de24SGrant Likely
120c103de24SGrant Likely if (ret) {
12130db2bd1SJingoo Han dev_err(&spi->dev, "Failed writing to " DRIVER_NAME ": %d\n",
12230db2bd1SJingoo Han ret);
123c103de24SGrant Likely goto exit_destroy;
124c103de24SGrant Likely }
125c103de24SGrant Likely
126609f9692SLinus Walleij ret = gpiochip_add_data(&mc->chip, mc);
127c103de24SGrant Likely if (ret)
128c103de24SGrant Likely goto exit_destroy;
129c103de24SGrant Likely
130c103de24SGrant Likely return ret;
131c103de24SGrant Likely
132c103de24SGrant Likely exit_destroy:
133c103de24SGrant Likely mutex_destroy(&mc->lock);
134c103de24SGrant Likely return ret;
135c103de24SGrant Likely }
136c103de24SGrant Likely
mc33880_remove(struct spi_device * spi)137*a0386bbaSUwe Kleine-König static void mc33880_remove(struct spi_device *spi)
138c103de24SGrant Likely {
139c103de24SGrant Likely struct mc33880 *mc;
140c103de24SGrant Likely
141493294d4SJingoo Han mc = spi_get_drvdata(spi);
142c103de24SGrant Likely
1439f5132aeSabdoulaye berthe gpiochip_remove(&mc->chip);
144c103de24SGrant Likely mutex_destroy(&mc->lock);
145c103de24SGrant Likely }
146c103de24SGrant Likely
147c103de24SGrant Likely static struct spi_driver mc33880_driver = {
148c103de24SGrant Likely .driver = {
149c103de24SGrant Likely .name = DRIVER_NAME,
150c103de24SGrant Likely },
151c103de24SGrant Likely .probe = mc33880_probe,
1528283c4ffSBill Pemberton .remove = mc33880_remove,
153c103de24SGrant Likely };
154c103de24SGrant Likely
mc33880_init(void)155c103de24SGrant Likely static int __init mc33880_init(void)
156c103de24SGrant Likely {
157c103de24SGrant Likely return spi_register_driver(&mc33880_driver);
158c103de24SGrant Likely }
159c103de24SGrant Likely /* register after spi postcore initcall and before
160c103de24SGrant Likely * subsys initcalls that may rely on these GPIOs
161c103de24SGrant Likely */
162c103de24SGrant Likely subsys_initcall(mc33880_init);
163c103de24SGrant Likely
mc33880_exit(void)164c103de24SGrant Likely static void __exit mc33880_exit(void)
165c103de24SGrant Likely {
166c103de24SGrant Likely spi_unregister_driver(&mc33880_driver);
167c103de24SGrant Likely }
168c103de24SGrant Likely module_exit(mc33880_exit);
169c103de24SGrant Likely
170c103de24SGrant Likely MODULE_AUTHOR("Mocean Laboratories <info@mocean-labs.com>");
171c103de24SGrant Likely MODULE_LICENSE("GPL v2");
172c103de24SGrant Likely
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