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
altr_a10sr_gpio_get(struct gpio_chip * chip,unsigned int offset)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
altr_a10sr_gpio_set(struct gpio_chip * chip,unsigned int offset,int value)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
altr_a10sr_gpio_direction_input(struct gpio_chip * gc,unsigned int nr)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
altr_a10sr_gpio_direction_output(struct gpio_chip * gc,unsigned int nr,int value)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
altr_a10sr_gpio_probe(struct platform_device * pdev)78 static 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
105 static const struct of_device_id altr_a10sr_gpio_of_match[] = {
106 { .compatible = "altr,a10sr-gpio" },
107 { },
108 };
109 MODULE_DEVICE_TABLE(of, altr_a10sr_gpio_of_match);
110
111 static 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 };
118 module_platform_driver(altr_a10sr_gpio_driver);
119
120 MODULE_LICENSE("GPL v2");
121 MODULE_AUTHOR("Thor Thayer <tthayer@opensource.altera.com>");
122 MODULE_DESCRIPTION("Altera Arria10 System Resource Chip GPIO");
123