1 /*
2  *  Copyright Intel Corporation (C) 2014-2016. All Rights Reserved
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms and conditions of the GNU General Public License,
6  * version 2, as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope it will be useful, but WITHOUT
9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
11  * more details.
12  *
13  * You should have received a copy of the GNU General Public License along with
14  * this program.  If not, see <http://www.gnu.org/licenses/>.
15  *
16  * GPIO driver for  Altera Arria10 MAX5 System Resource Chip
17  *
18  * Adapted from gpio-tps65910.c
19  */
20 
21 #include <linux/gpio/driver.h>
22 #include <linux/mfd/altera-a10sr.h>
23 #include <linux/module.h>
24 
25 /**
26  * struct altr_a10sr_gpio - Altera Max5 GPIO device private data structure
27  * @gp:   : instance of the gpio_chip
28  * @regmap: the regmap from the parent device.
29  */
30 struct altr_a10sr_gpio {
31 	struct gpio_chip gp;
32 	struct regmap *regmap;
33 };
34 
35 static int altr_a10sr_gpio_get(struct gpio_chip *chip, unsigned int offset)
36 {
37 	struct altr_a10sr_gpio *gpio = gpiochip_get_data(chip);
38 	int ret, val;
39 
40 	ret = regmap_read(gpio->regmap, ALTR_A10SR_PBDSW_REG, &val);
41 	if (ret < 0)
42 		return ret;
43 
44 	return !!(val & BIT(offset - ALTR_A10SR_LED_VALID_SHIFT));
45 }
46 
47 static void altr_a10sr_gpio_set(struct gpio_chip *chip, unsigned int offset,
48 				int value)
49 {
50 	struct altr_a10sr_gpio *gpio = gpiochip_get_data(chip);
51 
52 	regmap_update_bits(gpio->regmap, ALTR_A10SR_LED_REG,
53 			   BIT(ALTR_A10SR_LED_VALID_SHIFT + offset),
54 			   value ? BIT(ALTR_A10SR_LED_VALID_SHIFT + offset)
55 			   : 0);
56 }
57 
58 static int altr_a10sr_gpio_direction_input(struct gpio_chip *gc,
59 					   unsigned int nr)
60 {
61 	if (nr >= (ALTR_A10SR_IN_VALID_RANGE_LO - ALTR_A10SR_LED_VALID_SHIFT))
62 		return 0;
63 	return -EINVAL;
64 }
65 
66 static int altr_a10sr_gpio_direction_output(struct gpio_chip *gc,
67 					    unsigned int nr, int value)
68 {
69 	if (nr <= (ALTR_A10SR_OUT_VALID_RANGE_HI - ALTR_A10SR_LED_VALID_SHIFT))
70 		return 0;
71 	return -EINVAL;
72 }
73 
74 static const struct gpio_chip altr_a10sr_gc = {
75 	.label = "altr_a10sr_gpio",
76 	.owner = THIS_MODULE,
77 	.get = altr_a10sr_gpio_get,
78 	.set = altr_a10sr_gpio_set,
79 	.direction_input = altr_a10sr_gpio_direction_input,
80 	.direction_output = altr_a10sr_gpio_direction_output,
81 	.can_sleep = true,
82 	.ngpio = 12,
83 	.base = -1,
84 };
85 
86 static int altr_a10sr_gpio_probe(struct platform_device *pdev)
87 {
88 	struct altr_a10sr_gpio *gpio;
89 	int ret;
90 	struct altr_a10sr *a10sr = dev_get_drvdata(pdev->dev.parent);
91 
92 	gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
93 	if (!gpio)
94 		return -ENOMEM;
95 
96 	gpio->regmap = a10sr->regmap;
97 
98 	gpio->gp = altr_a10sr_gc;
99 	gpio->gp.parent = pdev->dev.parent;
100 	gpio->gp.of_node = pdev->dev.of_node;
101 
102 	ret = devm_gpiochip_add_data(&pdev->dev, &gpio->gp, gpio);
103 	if (ret < 0) {
104 		dev_err(&pdev->dev, "Could not register gpiochip, %d\n", ret);
105 		return ret;
106 	}
107 
108 	platform_set_drvdata(pdev, gpio);
109 
110 	return 0;
111 }
112 
113 static const struct of_device_id altr_a10sr_gpio_of_match[] = {
114 	{ .compatible = "altr,a10sr-gpio" },
115 	{ },
116 };
117 MODULE_DEVICE_TABLE(of, altr_a10sr_gpio_of_match);
118 
119 static struct platform_driver altr_a10sr_gpio_driver = {
120 	.probe = altr_a10sr_gpio_probe,
121 	.driver = {
122 		.name	= "altr_a10sr_gpio",
123 		.of_match_table = of_match_ptr(altr_a10sr_gpio_of_match),
124 	},
125 };
126 module_platform_driver(altr_a10sr_gpio_driver);
127 
128 MODULE_LICENSE("GPL v2");
129 MODULE_AUTHOR("Thor Thayer <tthayer@opensource.altera.com>");
130 MODULE_DESCRIPTION("Altera Arria10 System Resource Chip GPIO");
131