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(dev: 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 return GPIO_LINE_DIRECTION_OUT;
38}
39
40static int twl6040gpo_direction_out(struct gpio_chip *chip, unsigned offset,
41 int value)
42{
43 /* This only drives GPOs, and can't change direction */
44 return 0;
45}
46
47static void twl6040gpo_set(struct gpio_chip *chip, unsigned offset, int value)
48{
49 struct twl6040 *twl6040 = dev_get_drvdata(dev: chip->parent->parent);
50 int ret;
51 u8 gpoctl;
52
53 ret = twl6040_reg_read(twl6040, TWL6040_REG_GPOCTL);
54 if (ret < 0)
55 return;
56
57 if (value)
58 gpoctl = ret | BIT(offset);
59 else
60 gpoctl = ret & ~BIT(offset);
61
62 twl6040_reg_write(twl6040, TWL6040_REG_GPOCTL, val: gpoctl);
63}
64
65static struct gpio_chip twl6040gpo_chip = {
66 .label = "twl6040",
67 .owner = THIS_MODULE,
68 .get = twl6040gpo_get,
69 .direction_output = twl6040gpo_direction_out,
70 .get_direction = twl6040gpo_get_direction,
71 .set = twl6040gpo_set,
72 .can_sleep = true,
73};
74
75/*----------------------------------------------------------------------*/
76
77static int gpo_twl6040_probe(struct platform_device *pdev)
78{
79 struct device *twl6040_core_dev = pdev->dev.parent;
80 struct twl6040 *twl6040 = dev_get_drvdata(dev: twl6040_core_dev);
81 int ret;
82
83 device_set_node(dev: &pdev->dev, dev_fwnode(pdev->dev.parent));
84
85 twl6040gpo_chip.base = -1;
86
87 if (twl6040_get_revid(twl6040) < TWL6041_REV_ES2_0)
88 twl6040gpo_chip.ngpio = 3; /* twl6040 have 3 GPO */
89 else
90 twl6040gpo_chip.ngpio = 1; /* twl6041 have 1 GPO */
91
92 twl6040gpo_chip.parent = &pdev->dev;
93
94 ret = devm_gpiochip_add_data(&pdev->dev, &twl6040gpo_chip, NULL);
95 if (ret < 0) {
96 dev_err(&pdev->dev, "could not register gpiochip, %d\n", ret);
97 twl6040gpo_chip.ngpio = 0;
98 }
99
100 return ret;
101}
102
103/* Note: this hardware lives inside an I2C-based multi-function device. */
104MODULE_ALIAS("platform:twl6040-gpo");
105
106static struct platform_driver gpo_twl6040_driver = {
107 .driver = {
108 .name = "twl6040-gpo",
109 },
110 .probe = gpo_twl6040_probe,
111};
112
113module_platform_driver(gpo_twl6040_driver);
114
115MODULE_AUTHOR("Texas Instruments, Inc.");
116MODULE_DESCRIPTION("GPO interface for TWL6040");
117MODULE_LICENSE("GPL");
118

source code of linux/drivers/gpio/gpio-twl6040.c