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  */
19 struct altr_a10sr_gpio {
20 	struct gpio_chip gp;
21 	struct regmap *regmap;
22 };
23 
24 static 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 
36 static 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 
47 static 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 
56 static 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 
66 static 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 
78 static int altr_a10sr_gpio_probe(struct platform_device *pdev)
79 {
80 	struct altr_a10sr_gpio *gpio;
81 	struct altr_a10sr *a10sr = dev_get_drvdata(pdev->dev.parent);
82 
83 	gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
84 	if (!gpio)
85 		return -ENOMEM;
86 
87 	gpio->regmap = a10sr->regmap;
88 
89 	gpio->gp = altr_a10sr_gc;
90 	gpio->gp.parent = pdev->dev.parent;
91 	gpio->gp.of_node = pdev->dev.of_node;
92 
93 	return devm_gpiochip_add_data(&pdev->dev, &gpio->gp, gpio);
94 }
95 
96 static const struct of_device_id altr_a10sr_gpio_of_match[] = {
97 	{ .compatible = "altr,a10sr-gpio" },
98 	{ },
99 };
100 MODULE_DEVICE_TABLE(of, altr_a10sr_gpio_of_match);
101 
102 static struct platform_driver altr_a10sr_gpio_driver = {
103 	.probe = altr_a10sr_gpio_probe,
104 	.driver = {
105 		.name	= "altr_a10sr_gpio",
106 		.of_match_table = of_match_ptr(altr_a10sr_gpio_of_match),
107 	},
108 };
109 module_platform_driver(altr_a10sr_gpio_driver);
110 
111 MODULE_LICENSE("GPL v2");
112 MODULE_AUTHOR("Thor Thayer <tthayer@opensource.altera.com>");
113 MODULE_DESCRIPTION("Altera Arria10 System Resource Chip GPIO");
114