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	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(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, 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(twl6040_core_dev);
81	int ret;
82
83	device_set_node(&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