drivers/gpio/gpio-twl6040.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Access to GPOs on TWL6040 chip
   4  *
   5  * Copyright (C) 2012 Texas Instruments, Inc.
   6  *
   7  * Authors:
   8  *      Sergio Aguirre <saaguirre@ti.com>
   9  *      Peter Ujfalusi <peter.ujfalusi@ti.com>
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/init.h>
  14 #include <linux/kthread.h>
  15 #include <linux/irq.h>
  16 #include <linux/gpio/driver.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/bitops.h>
  19 #include <linux/of.h>
  20
  21 #include <linux/mfd/twl6040.h>
  22
  23 static int twl6040gpo_get(struct gpio_chip *chip, unsigned offset)
  24 {
  25         struct twl6040 *twl6040 = dev_get_drvdata(chip->parent->parent);
  26         int ret = 0;
  27
  28         ret = twl6040_reg_read(twl6040, TWL6040_REG_GPOCTL);
  29         if (ret < 0)
  30                 return ret;
  31
  32         return !!(ret & BIT(offset));
  33 }
  34
  35 static int twl6040gpo_get_direction(struct gpio_chip *chip, unsigned offset)
  36 {
  37         /* This means "out" */
  38         return 0;
  39 }
  40
  41 static int twl6040gpo_direction_out(struct gpio_chip *chip, unsigned offset,
  42                                     int value)
  43 {
  44         /* This only drives GPOs, and can't change direction */
  45         return 0;
  46 }
  47
  48 static void twl6040gpo_set(struct gpio_chip *chip, unsigned offset, int value)
  49 {
  50         struct twl6040 *twl6040 = dev_get_drvdata(chip->parent->parent);
  51         int ret;
  52         u8 gpoctl;
  53
  54         ret = twl6040_reg_read(twl6040, TWL6040_REG_GPOCTL);
  55         if (ret < 0)
  56                 return;
  57
  58         if (value)
  59                 gpoctl = ret | BIT(offset);
  60         else
  61                 gpoctl = ret & ~BIT(offset);
  62
  63         twl6040_reg_write(twl6040, TWL6040_REG_GPOCTL, gpoctl);
  64 }
  65
  66 static struct gpio_chip twl6040gpo_chip = {
  67         .label                  = "twl6040",
  68         .owner                  = THIS_MODULE,
  69         .get                    = twl6040gpo_get,
  70         .direction_output       = twl6040gpo_direction_out,
  71         .get_direction          = twl6040gpo_get_direction,
  72         .set                    = twl6040gpo_set,
  73         .can_sleep              = true,
  74 };
  75
  76 /*----------------------------------------------------------------------*/
  77
  78 static int gpo_twl6040_probe(struct platform_device *pdev)
  79 {
  80         struct device *twl6040_core_dev = pdev->dev.parent;
  81         struct twl6040 *twl6040 = dev_get_drvdata(twl6040_core_dev);
  82         int ret;
  83
  84         twl6040gpo_chip.base = -1;
  85
  86         if (twl6040_get_revid(twl6040) < TWL6041_REV_ES2_0)
  87                 twl6040gpo_chip.ngpio = 3; /* twl6040 have 3 GPO */
  88         else
  89                 twl6040gpo_chip.ngpio = 1; /* twl6041 have 1 GPO */
  90
  91         twl6040gpo_chip.parent = &pdev->dev;
  92 #ifdef CONFIG_OF_GPIO
  93         twl6040gpo_chip.of_node = twl6040_core_dev->of_node;
  94 #endif
  95
  96         ret = devm_gpiochip_add_data(&pdev->dev, &twl6040gpo_chip, NULL);
  97         if (ret < 0) {
  98                 dev_err(&pdev->dev, "could not register gpiochip, %d\n", ret);
  99                 twl6040gpo_chip.ngpio = 0;
 100         }
 101
 102         return ret;
 103 }
 104
 105 /* Note:  this hardware lives inside an I2C-based multi-function device. */
 106 MODULE_ALIAS("platform:twl6040-gpo");
 107
 108 static struct platform_driver gpo_twl6040_driver = {
 109         .driver = {
 110                 .name   = "twl6040-gpo",
 111         },
 112         .probe          = gpo_twl6040_probe,
 113 };
 114
 115 module_platform_driver(gpo_twl6040_driver);
 116
 117 MODULE_AUTHOR("Texas Instruments, Inc.");
 118 MODULE_DESCRIPTION("GPO interface for TWL6040");
 119 MODULE_LICENSE("GPL");