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 */
 30struct altr_a10sr_gpio {
 31	struct gpio_chip gp;
 32	struct regmap *regmap;
 33};
 34
 35static 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
 47static 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
 58static 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
 66static 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
 74static 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
 86static 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
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
113static const struct of_device_id altr_a10sr_gpio_of_match[] = {
114	{ .compatible = "altr,a10sr-gpio" },
115	{ },
116};
117MODULE_DEVICE_TABLE(of, altr_a10sr_gpio_of_match);
118
119static 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};
126module_platform_driver(altr_a10sr_gpio_driver);
127
128MODULE_LICENSE("GPL v2");
129MODULE_AUTHOR("Thor Thayer <tthayer@opensource.altera.com>");
130MODULE_DESCRIPTION("Altera Arria10 System Resource Chip GPIO");