drivers/gpio/gpio-altera-a10sr.c

   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                 altr_a10sr_gpio_set(gc, nr, value);
  71                 return 0;
  72         }
  73         return -EINVAL;
  74 }
  75
  76 static const struct gpio_chip altr_a10sr_gc = {
  77         .label = "altr_a10sr_gpio",
  78         .owner = THIS_MODULE,
  79         .get = altr_a10sr_gpio_get,
  80         .set = altr_a10sr_gpio_set,
  81         .direction_input = altr_a10sr_gpio_direction_input,
  82         .direction_output = altr_a10sr_gpio_direction_output,
  83         .can_sleep = true,
  84         .ngpio = 12,
  85         .base = -1,
  86 };
  87
  88 static int altr_a10sr_gpio_probe(struct platform_device *pdev)
  89 {
  90         struct altr_a10sr_gpio *gpio;
  91         int ret;
  92         struct altr_a10sr *a10sr = dev_get_drvdata(pdev->dev.parent);
  93
  94         gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
  95         if (!gpio)
  96                 return -ENOMEM;
  97
  98         gpio->regmap = a10sr->regmap;
  99
 100         gpio->gp = altr_a10sr_gc;
 101         gpio->gp.parent = pdev->dev.parent;
 102         gpio->gp.of_node = pdev->dev.of_node;
 103
 104         ret = devm_gpiochip_add_data(&pdev->dev, &gpio->gp, gpio);
 105         if (ret < 0) {
 106                 dev_err(&pdev->dev, "Could not register gpiochip, %d\n", ret);
 107                 return ret;
 108         }
 109
 110         platform_set_drvdata(pdev, gpio);
 111
 112         return 0;
 113 }
 114
 115 static const struct of_device_id altr_a10sr_gpio_of_match[] = {
 116         { .compatible = "altr,a10sr-gpio" },
 117         { },
 118 };
 119 MODULE_DEVICE_TABLE(of, altr_a10sr_gpio_of_match);
 120
 121 static struct platform_driver altr_a10sr_gpio_driver = {
 122         .probe = altr_a10sr_gpio_probe,
 123         .driver = {
 124                 .name   = "altr_a10sr_gpio",
 125                 .of_match_table = of_match_ptr(altr_a10sr_gpio_of_match),
 126         },
 127 };
 128 module_platform_driver(altr_a10sr_gpio_driver);
 129
 130 MODULE_LICENSE("GPL v2");
 131 MODULE_AUTHOR("Thor Thayer <tthayer@opensource.altera.com>");
 132 MODULE_DESCRIPTION("Altera Arria10 System Resource Chip GPIO");