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 #include <linux/property.h>
14 
15 /**
16  * struct altr_a10sr_gpio - Altera Max5 GPIO device private data structure
17  * @gp:   : instance of the gpio_chip
18  * @regmap: the regmap from the parent device.
19  */
20 struct altr_a10sr_gpio {
21 	struct gpio_chip gp;
22 	struct regmap *regmap;
23 };
24 
25 static int altr_a10sr_gpio_get(struct gpio_chip *chip, unsigned int offset)
26 {
27 	struct altr_a10sr_gpio *gpio = gpiochip_get_data(chip);
28 	int ret, val;
29 
30 	ret = regmap_read(gpio->regmap, ALTR_A10SR_PBDSW_REG, &val);
31 	if (ret < 0)
32 		return ret;
33 
34 	return !!(val & BIT(offset - ALTR_A10SR_LED_VALID_SHIFT));
35 }
36 
37 static void altr_a10sr_gpio_set(struct gpio_chip *chip, unsigned int offset,
38 				int value)
39 {
40 	struct altr_a10sr_gpio *gpio = gpiochip_get_data(chip);
41 
42 	regmap_update_bits(gpio->regmap, ALTR_A10SR_LED_REG,
43 			   BIT(ALTR_A10SR_LED_VALID_SHIFT + offset),
44 			   value ? BIT(ALTR_A10SR_LED_VALID_SHIFT + offset)
45 			   : 0);
46 }
47 
48 static int altr_a10sr_gpio_direction_input(struct gpio_chip *gc,
49 					   unsigned int nr)
50 {
51 	if (nr < (ALTR_A10SR_IN_VALID_RANGE_LO - ALTR_A10SR_LED_VALID_SHIFT))
52 		return -EINVAL;
53 
54 	return 0;
55 }
56 
57 static int altr_a10sr_gpio_direction_output(struct gpio_chip *gc,
58 					    unsigned int nr, int value)
59 {
60 	if (nr > (ALTR_A10SR_OUT_VALID_RANGE_HI - ALTR_A10SR_LED_VALID_SHIFT))
61 		return -EINVAL;
62 
63 	altr_a10sr_gpio_set(gc, nr, value);
64 	return 0;
65 }
66 
67 static const struct gpio_chip altr_a10sr_gc = {
68 	.label = "altr_a10sr_gpio",
69 	.owner = THIS_MODULE,
70 	.get = altr_a10sr_gpio_get,
71 	.set = altr_a10sr_gpio_set,
72 	.direction_input = altr_a10sr_gpio_direction_input,
73 	.direction_output = altr_a10sr_gpio_direction_output,
74 	.can_sleep = true,
75 	.ngpio = 12,
76 	.base = -1,
77 };
78 
79 static int altr_a10sr_gpio_probe(struct platform_device *pdev)
80 {
81 	struct altr_a10sr_gpio *gpio;
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.fwnode = dev_fwnode(&pdev->dev);
93 
94 	return devm_gpiochip_add_data(&pdev->dev, &gpio->gp, gpio);
95 }
96 
97 static const struct of_device_id altr_a10sr_gpio_of_match[] = {
98 	{ .compatible = "altr,a10sr-gpio" },
99 	{ },
100 };
101 MODULE_DEVICE_TABLE(of, altr_a10sr_gpio_of_match);
102 
103 static struct platform_driver altr_a10sr_gpio_driver = {
104 	.probe = altr_a10sr_gpio_probe,
105 	.driver = {
106 		.name	= "altr_a10sr_gpio",
107 		.of_match_table = of_match_ptr(altr_a10sr_gpio_of_match),
108 	},
109 };
110 module_platform_driver(altr_a10sr_gpio_driver);
111 
112 MODULE_LICENSE("GPL v2");
113 MODULE_AUTHOR("Thor Thayer <tthayer@opensource.altera.com>");
114 MODULE_DESCRIPTION("Altera Arria10 System Resource Chip GPIO");
115