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