drivers/gpio/gpio-altera-a10sr.c

   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/module.h>
  13
  14 /**
  15  * struct altr_a10sr_gpio - Altera Max5 GPIO device private data structure
  16  * @gp:   : instance of the gpio_chip
  17  * @regmap: the regmap from the parent device.
  18  */
  19 struct altr_a10sr_gpio {
  20         struct gpio_chip gp;
  21         struct regmap *regmap;
  22 };
  23
  24 static int altr_a10sr_gpio_get(struct gpio_chip *chip, unsigned int offset)
  25 {
  26         struct altr_a10sr_gpio *gpio = gpiochip_get_data(chip);
  27         int ret, val;
  28
  29         ret = regmap_read(gpio->regmap, ALTR_A10SR_PBDSW_REG, &val);
  30         if (ret < 0)
  31                 return ret;
  32
  33         return !!(val & BIT(offset - ALTR_A10SR_LED_VALID_SHIFT));
  34 }
  35
  36 static void altr_a10sr_gpio_set(struct gpio_chip *chip, unsigned int offset,
  37                                 int value)
  38 {
  39         struct altr_a10sr_gpio *gpio = gpiochip_get_data(chip);
  40
  41         regmap_update_bits(gpio->regmap, ALTR_A10SR_LED_REG,
  42                            BIT(ALTR_A10SR_LED_VALID_SHIFT + offset),
  43                            value ? BIT(ALTR_A10SR_LED_VALID_SHIFT + offset)
  44                            : 0);
  45 }
  46
  47 static int altr_a10sr_gpio_direction_input(struct gpio_chip *gc,
  48                                            unsigned int nr)
  49 {
  50         if (nr < (ALTR_A10SR_IN_VALID_RANGE_LO - ALTR_A10SR_LED_VALID_SHIFT))
  51                 return -EINVAL;
  52
  53         return 0;
  54 }
  55
  56 static int altr_a10sr_gpio_direction_output(struct gpio_chip *gc,
  57                                             unsigned int nr, int value)
  58 {
  59         if (nr > (ALTR_A10SR_OUT_VALID_RANGE_HI - ALTR_A10SR_LED_VALID_SHIFT))
  60                 return -EINVAL;
  61
  62         altr_a10sr_gpio_set(gc, nr, value);
  63         return 0;
  64 }
  65
  66 static const struct gpio_chip altr_a10sr_gc = {
  67         .label = "altr_a10sr_gpio",
  68         .owner = THIS_MODULE,
  69         .get = altr_a10sr_gpio_get,
  70         .set = altr_a10sr_gpio_set,
  71         .direction_input = altr_a10sr_gpio_direction_input,
  72         .direction_output = altr_a10sr_gpio_direction_output,
  73         .can_sleep = true,
  74         .ngpio = 12,
  75         .base = -1,
  76 };
  77
  78 static int altr_a10sr_gpio_probe(struct platform_device *pdev)
  79 {
  80         struct altr_a10sr_gpio *gpio;
  81         int ret;
  82         struct altr_a10sr *a10sr = dev_get_drvdata(pdev->dev.parent);
  83
  84         gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
  85         if (!gpio)
  86                 return -ENOMEM;
  87
  88         gpio->regmap = a10sr->regmap;
  89
  90         gpio->gp = altr_a10sr_gc;
  91         gpio->gp.parent = pdev->dev.parent;
  92         gpio->gp.of_node = pdev->dev.of_node;
  93
  94         ret = devm_gpiochip_add_data(&pdev->dev, &gpio->gp, gpio);
  95         if (ret < 0) {
  96                 dev_err(&pdev->dev, "Could not register gpiochip, %d\n", ret);
  97                 return ret;
  98         }
  99
 100         platform_set_drvdata(pdev, gpio);
 101
 102         return 0;
 103 }
 104
 105 static const struct of_device_id altr_a10sr_gpio_of_match[] = {
 106         { .compatible = "altr,a10sr-gpio" },
 107         { },
 108 };
 109 MODULE_DEVICE_TABLE(of, altr_a10sr_gpio_of_match);
 110
 111 static struct platform_driver altr_a10sr_gpio_driver = {
 112         .probe = altr_a10sr_gpio_probe,
 113         .driver = {
 114                 .name   = "altr_a10sr_gpio",
 115                 .of_match_table = of_match_ptr(altr_a10sr_gpio_of_match),
 116         },
 117 };
 118 module_platform_driver(altr_a10sr_gpio_driver);
 119
 120 MODULE_LICENSE("GPL v2");
 121 MODULE_AUTHOR("Thor Thayer <tthayer@opensource.altera.com>");
 122 MODULE_DESCRIPTION("Altera Arria10 System Resource Chip GPIO");