1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 *  Copyright Intel Corporation (C) 2014-2016. All Rights Reserved
4 *
5 * GPIO driver for  Altera Arria10 MAX5 System Resource Chip
6 *
7 * Adapted from gpio-tps65910.c
8 */
9
10#include <linux/gpio/driver.h>
11#include <linux/mfd/altera-a10sr.h>
12#include <linux/module.h>
13
14/**
15 * struct altr_a10sr_gpio - Altera Max5 GPIO device private data structure
16 * @gp:   : instance of the gpio_chip
17 * @regmap: the regmap from the parent device.
18 */
19struct altr_a10sr_gpio {
20	struct gpio_chip gp;
21	struct regmap *regmap;
22};
23
24static int altr_a10sr_gpio_get(struct gpio_chip *chip, unsigned int offset)
25{
26	struct altr_a10sr_gpio *gpio = gpiochip_get_data(chip);
27	int ret, val;
28
29	ret = regmap_read(gpio->regmap, ALTR_A10SR_PBDSW_REG, &val);
30	if (ret < 0)
31		return ret;
32
33	return !!(val & BIT(offset - ALTR_A10SR_LED_VALID_SHIFT));
34}
35
36static void altr_a10sr_gpio_set(struct gpio_chip *chip, unsigned int offset,
37				int value)
38{
39	struct altr_a10sr_gpio *gpio = gpiochip_get_data(chip);
40
41	regmap_update_bits(gpio->regmap, ALTR_A10SR_LED_REG,
42			   BIT(ALTR_A10SR_LED_VALID_SHIFT + offset),
43			   value ? BIT(ALTR_A10SR_LED_VALID_SHIFT + offset)
44			   : 0);
45}
46
47static int altr_a10sr_gpio_direction_input(struct gpio_chip *gc,
48					   unsigned int nr)
49{
50	if (nr < (ALTR_A10SR_IN_VALID_RANGE_LO - ALTR_A10SR_LED_VALID_SHIFT))
51		return -EINVAL;
52
53	return 0;
54}
55
56static int altr_a10sr_gpio_direction_output(struct gpio_chip *gc,
57					    unsigned int nr, int value)
58{
59	if (nr > (ALTR_A10SR_OUT_VALID_RANGE_HI - ALTR_A10SR_LED_VALID_SHIFT))
60		return -EINVAL;
61
62	altr_a10sr_gpio_set(gc, nr, value);
63	return 0;
64}
65
66static const struct gpio_chip altr_a10sr_gc = {
67	.label = "altr_a10sr_gpio",
68	.owner = THIS_MODULE,
69	.get = altr_a10sr_gpio_get,
70	.set = altr_a10sr_gpio_set,
71	.direction_input = altr_a10sr_gpio_direction_input,
72	.direction_output = altr_a10sr_gpio_direction_output,
73	.can_sleep = true,
74	.ngpio = 12,
75	.base = -1,
76};
77
78static int altr_a10sr_gpio_probe(struct platform_device *pdev)
79{
80	struct altr_a10sr_gpio *gpio;
81	int ret;
82	struct altr_a10sr *a10sr = dev_get_drvdata(pdev->dev.parent);
83
84	gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
85	if (!gpio)
86		return -ENOMEM;
87
88	gpio->regmap = a10sr->regmap;
89
90	gpio->gp = altr_a10sr_gc;
91	gpio->gp.parent = pdev->dev.parent;
92	gpio->gp.of_node = pdev->dev.of_node;
93
94	ret = devm_gpiochip_add_data(&pdev->dev, &gpio->gp, gpio);
95	if (ret < 0) {
96		dev_err(&pdev->dev, "Could not register gpiochip, %d\n", ret);
97		return ret;
98	}
99
100	platform_set_drvdata(pdev, gpio);
101
102	return 0;
103}
104
105static const struct of_device_id altr_a10sr_gpio_of_match[] = {
106	{ .compatible = "altr,a10sr-gpio" },
107	{ },
108};
109MODULE_DEVICE_TABLE(of, altr_a10sr_gpio_of_match);
110
111static struct platform_driver altr_a10sr_gpio_driver = {
112	.probe = altr_a10sr_gpio_probe,
113	.driver = {
114		.name	= "altr_a10sr_gpio",
115		.of_match_table = of_match_ptr(altr_a10sr_gpio_of_match),
116	},
117};
118module_platform_driver(altr_a10sr_gpio_driver);
119
120MODULE_LICENSE("GPL v2");
121MODULE_AUTHOR("Thor Thayer <tthayer@opensource.altera.com>");
122MODULE_DESCRIPTION("Altera Arria10 System Resource Chip GPIO");
123