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/mod_devicetable.h>
  13 #include <linux/module.h>
  14 #include <linux/property.h>
  15
  16 /**
  17  * struct altr_a10sr_gpio - Altera Max5 GPIO device private data structure
  18  * @gp:   : instance of the gpio_chip
  19  * @regmap: the regmap from the parent device.
  20  */
  21 struct altr_a10sr_gpio {
  22         struct gpio_chip gp;
  23         struct regmap *regmap;
  24 };
  25
  26 static int altr_a10sr_gpio_get(struct gpio_chip *chip, unsigned int offset)
  27 {
  28         struct altr_a10sr_gpio *gpio = gpiochip_get_data(chip);
  29         int ret, val;
  30
  31         ret = regmap_read(gpio->regmap, ALTR_A10SR_PBDSW_REG, &val);
  32         if (ret < 0)
  33                 return ret;
  34
  35         return !!(val & BIT(offset - ALTR_A10SR_LED_VALID_SHIFT));
  36 }
  37
  38 static void altr_a10sr_gpio_set(struct gpio_chip *chip, unsigned int offset,
  39                                 int value)
  40 {
  41         struct altr_a10sr_gpio *gpio = gpiochip_get_data(chip);
  42
  43         regmap_update_bits(gpio->regmap, ALTR_A10SR_LED_REG,
  44                            BIT(ALTR_A10SR_LED_VALID_SHIFT + offset),
  45                            value ? BIT(ALTR_A10SR_LED_VALID_SHIFT + offset)
  46                            : 0);
  47 }
  48
  49 static int altr_a10sr_gpio_direction_input(struct gpio_chip *gc,
  50                                            unsigned int nr)
  51 {
  52         if (nr < (ALTR_A10SR_IN_VALID_RANGE_LO - ALTR_A10SR_LED_VALID_SHIFT))
  53                 return -EINVAL;
  54
  55         return 0;
  56 }
  57
  58 static int altr_a10sr_gpio_direction_output(struct gpio_chip *gc,
  59                                             unsigned int nr, int value)
  60 {
  61         if (nr > (ALTR_A10SR_OUT_VALID_RANGE_HI - ALTR_A10SR_LED_VALID_SHIFT))
  62                 return -EINVAL;
  63
  64         altr_a10sr_gpio_set(gc, nr, value);
  65         return 0;
  66 }
  67
  68 static const struct gpio_chip altr_a10sr_gc = {
  69         .label = "altr_a10sr_gpio",
  70         .owner = THIS_MODULE,
  71         .get = altr_a10sr_gpio_get,
  72         .set = altr_a10sr_gpio_set,
  73         .direction_input = altr_a10sr_gpio_direction_input,
  74         .direction_output = altr_a10sr_gpio_direction_output,
  75         .can_sleep = true,
  76         .ngpio = 12,
  77         .base = -1,
  78 };
  79
  80 static int altr_a10sr_gpio_probe(struct platform_device *pdev)
  81 {
  82         struct altr_a10sr_gpio *gpio;
  83         struct altr_a10sr *a10sr = dev_get_drvdata(pdev->dev.parent);
  84
  85         gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
  86         if (!gpio)
  87                 return -ENOMEM;
  88
  89         gpio->regmap = a10sr->regmap;
  90
  91         gpio->gp = altr_a10sr_gc;
  92         gpio->gp.parent = pdev->dev.parent;
  93         gpio->gp.fwnode = dev_fwnode(&pdev->dev);
  94
  95         return devm_gpiochip_add_data(&pdev->dev, &gpio->gp, gpio);
  96 }
  97
  98 static const struct of_device_id altr_a10sr_gpio_of_match[] = {
  99         { .compatible = "altr,a10sr-gpio" },
 100         { },
 101 };
 102 MODULE_DEVICE_TABLE(of, altr_a10sr_gpio_of_match);
 103
 104 static struct platform_driver altr_a10sr_gpio_driver = {
 105         .probe = altr_a10sr_gpio_probe,
 106         .driver = {
 107                 .name   = "altr_a10sr_gpio",
 108                 .of_match_table = altr_a10sr_gpio_of_match,
 109         },
 110 };
 111 module_platform_driver(altr_a10sr_gpio_driver);
 112
 113 MODULE_LICENSE("GPL v2");
 114 MODULE_AUTHOR("Thor Thayer <tthayer@opensource.altera.com>");
 115 MODULE_DESCRIPTION("Altera Arria10 System Resource Chip GPIO");