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/mod_devicetable.h>
13 #include <linux/module.h>
14 #include <linux/property.h>
15 
16 /**
17  * struct altr_a10sr_gpio - Altera Max5 GPIO device private data structure
18  * @gp:   : instance of the gpio_chip
19  * @regmap: the regmap from the parent device.
20  */
21 struct altr_a10sr_gpio {
22 	struct gpio_chip gp;
23 	struct regmap *regmap;
24 };
25 
26 static int altr_a10sr_gpio_get(struct gpio_chip *chip, unsigned int offset)
27 {
28 	struct altr_a10sr_gpio *gpio = gpiochip_get_data(chip);
29 	int ret, val;
30 
31 	ret = regmap_read(gpio->regmap, ALTR_A10SR_PBDSW_REG, &val);
32 	if (ret < 0)
33 		return ret;
34 
35 	return !!(val & BIT(offset - ALTR_A10SR_LED_VALID_SHIFT));
36 }
37 
38 static void altr_a10sr_gpio_set(struct gpio_chip *chip, unsigned int offset,
39 				int value)
40 {
41 	struct altr_a10sr_gpio *gpio = gpiochip_get_data(chip);
42 
43 	regmap_update_bits(gpio->regmap, ALTR_A10SR_LED_REG,
44 			   BIT(ALTR_A10SR_LED_VALID_SHIFT + offset),
45 			   value ? BIT(ALTR_A10SR_LED_VALID_SHIFT + offset)
46 			   : 0);
47 }
48 
49 static int altr_a10sr_gpio_direction_input(struct gpio_chip *gc,
50 					   unsigned int nr)
51 {
52 	if (nr < (ALTR_A10SR_IN_VALID_RANGE_LO - ALTR_A10SR_LED_VALID_SHIFT))
53 		return -EINVAL;
54 
55 	return 0;
56 }
57 
58 static int altr_a10sr_gpio_direction_output(struct gpio_chip *gc,
59 					    unsigned int nr, int value)
60 {
61 	if (nr > (ALTR_A10SR_OUT_VALID_RANGE_HI - ALTR_A10SR_LED_VALID_SHIFT))
62 		return -EINVAL;
63 
64 	altr_a10sr_gpio_set(gc, nr, value);
65 	return 0;
66 }
67 
68 static const struct gpio_chip altr_a10sr_gc = {
69 	.label = "altr_a10sr_gpio",
70 	.owner = THIS_MODULE,
71 	.get = altr_a10sr_gpio_get,
72 	.set = altr_a10sr_gpio_set,
73 	.direction_input = altr_a10sr_gpio_direction_input,
74 	.direction_output = altr_a10sr_gpio_direction_output,
75 	.can_sleep = true,
76 	.ngpio = 12,
77 	.base = -1,
78 };
79 
80 static int altr_a10sr_gpio_probe(struct platform_device *pdev)
81 {
82 	struct altr_a10sr_gpio *gpio;
83 	struct altr_a10sr *a10sr = dev_get_drvdata(pdev->dev.parent);
84 
85 	gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
86 	if (!gpio)
87 		return -ENOMEM;
88 
89 	gpio->regmap = a10sr->regmap;
90 
91 	gpio->gp = altr_a10sr_gc;
92 	gpio->gp.parent = pdev->dev.parent;
93 	gpio->gp.fwnode = dev_fwnode(&pdev->dev);
94 
95 	return devm_gpiochip_add_data(&pdev->dev, &gpio->gp, gpio);
96 }
97 
98 static const struct of_device_id altr_a10sr_gpio_of_match[] = {
99 	{ .compatible = "altr,a10sr-gpio" },
100 	{ },
101 };
102 MODULE_DEVICE_TABLE(of, altr_a10sr_gpio_of_match);
103 
104 static struct platform_driver altr_a10sr_gpio_driver = {
105 	.probe = altr_a10sr_gpio_probe,
106 	.driver = {
107 		.name	= "altr_a10sr_gpio",
108 		.of_match_table = altr_a10sr_gpio_of_match,
109 	},
110 };
111 module_platform_driver(altr_a10sr_gpio_driver);
112 
113 MODULE_LICENSE("GPL v2");
114 MODULE_AUTHOR("Thor Thayer <tthayer@opensource.altera.com>");
115 MODULE_DESCRIPTION("Altera Arria10 System Resource Chip GPIO");
116