tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Access to GPOs on TWL6040 chip
4 *
5 * Copyright (C) 2012 Texas Instruments, Inc.
6 *
7 * Authors:
8 * Sergio Aguirre <saaguirre@ti.com>
9 * Peter Ujfalusi <peter.ujfalusi@ti.com>
10 */
11
12#include <linux/module.h>
13#include <linux/init.h>
14#include <linux/kthread.h>
15#include <linux/irq.h>
16#include <linux/gpio/driver.h>
17#include <linux/platform_device.h>
18#include <linux/bitops.h>
19#include <linux/of.h>
20
21#include <linux/mfd/twl6040.h>
22
23static int twl6040gpo_get(struct gpio_chip *chip, unsigned offset)
24{
25 struct twl6040 *twl6040 = dev_get_drvdata(chip->parent->parent);
26 int ret = 0;
27
28 ret = twl6040_reg_read(twl6040, TWL6040_REG_GPOCTL);
29 if (ret < 0)
30 return ret;
31
32 return !!(ret & BIT(offset));
33}
34
35static int twl6040gpo_get_direction(struct gpio_chip *chip, unsigned offset)
36{
37 /* This means "out" */
38 return 0;
39}
40
41static int twl6040gpo_direction_out(struct gpio_chip *chip, unsigned offset,
42 int value)
43{
44 /* This only drives GPOs, and can't change direction */
45 return 0;
46}
47
48static void twl6040gpo_set(struct gpio_chip *chip, unsigned offset, int value)
49{
50 struct twl6040 *twl6040 = dev_get_drvdata(chip->parent->parent);
51 int ret;
52 u8 gpoctl;
53
54 ret = twl6040_reg_read(twl6040, TWL6040_REG_GPOCTL);
55 if (ret < 0)
56 return;
57
58 if (value)
59 gpoctl = ret | BIT(offset);
60 else
61 gpoctl = ret & ~BIT(offset);
62
63 twl6040_reg_write(twl6040, TWL6040_REG_GPOCTL, gpoctl);
64}
65
66static struct gpio_chip twl6040gpo_chip = {
67 .label = "twl6040",
68 .owner = THIS_MODULE,
69 .get = twl6040gpo_get,
70 .direction_output = twl6040gpo_direction_out,
71 .get_direction = twl6040gpo_get_direction,
72 .set = twl6040gpo_set,
73 .can_sleep = true,
74};
75
76/*----------------------------------------------------------------------*/
77
78static int gpo_twl6040_probe(struct platform_device *pdev)
79{
80 struct device *twl6040_core_dev = pdev->dev.parent;
81 struct twl6040 *twl6040 = dev_get_drvdata(twl6040_core_dev);
82 int ret;
83
84 twl6040gpo_chip.base = -1;
85
86 if (twl6040_get_revid(twl6040) < TWL6041_REV_ES2_0)
87 twl6040gpo_chip.ngpio = 3; /* twl6040 have 3 GPO */
88 else
89 twl6040gpo_chip.ngpio = 1; /* twl6041 have 1 GPO */
90
91 twl6040gpo_chip.parent = &pdev->dev;
92#ifdef CONFIG_OF_GPIO
93 twl6040gpo_chip.of_node = twl6040_core_dev->of_node;
94#endif
95
96 ret = devm_gpiochip_add_data(&pdev->dev, &twl6040gpo_chip, NULL);
97 if (ret < 0) {
98 dev_err(&pdev->dev, "could not register gpiochip, %d\n", ret);
99 twl6040gpo_chip.ngpio = 0;
100 }
101
102 return ret;
103}
104
105/* Note: this hardware lives inside an I2C-based multi-function device. */
106MODULE_ALIAS("platform:twl6040-gpo");
107
108static struct platform_driver gpo_twl6040_driver = {
109 .driver = {
110 .name = "twl6040-gpo",
111 },
112 .probe = gpo_twl6040_probe,
113};
114
115module_platform_driver(gpo_twl6040_driver);
116
117MODULE_AUTHOR("Texas Instruments, Inc.");
118MODULE_DESCRIPTION("GPO interface for TWL6040");
119MODULE_LICENSE("GPL");