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
altr_a10sr_gpio_get(struct gpio_chip * chip,unsigned int offset)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
altr_a10sr_gpio_set(struct gpio_chip * chip,unsigned int offset,int value)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
altr_a10sr_gpio_direction_input(struct gpio_chip * gc,unsigned int nr)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
altr_a10sr_gpio_direction_output(struct gpio_chip * gc,unsigned int nr,int value)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
altr_a10sr_gpio_probe(struct platform_device * pdev)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