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         return GPIO_LINE_DIRECTION_OUT;
  38 }
  39
  40 static int twl6040gpo_direction_out(struct gpio_chip *chip, unsigned offset,
  41                                     int value)
  42 {
  43         /* This only drives GPOs, and can't change direction */
  44         return 0;
  45 }
  46
  47 static void twl6040gpo_set(struct gpio_chip *chip, unsigned offset, int value)
  48 {
  49         struct twl6040 *twl6040 = dev_get_drvdata(chip->parent->parent);
  50         int ret;
  51         u8 gpoctl;
  52
  53         ret = twl6040_reg_read(twl6040, TWL6040_REG_GPOCTL);
  54         if (ret < 0)
  55                 return;
  56
  57         if (value)
  58                 gpoctl = ret | BIT(offset);
  59         else
  60                 gpoctl = ret & ~BIT(offset);
  61
  62         twl6040_reg_write(twl6040, TWL6040_REG_GPOCTL, gpoctl);
  63 }
  64
  65 static struct gpio_chip twl6040gpo_chip = {
  66         .label                  = "twl6040",
  67         .owner                  = THIS_MODULE,
  68         .get                    = twl6040gpo_get,
  69         .direction_output       = twl6040gpo_direction_out,
  70         .get_direction          = twl6040gpo_get_direction,
  71         .set                    = twl6040gpo_set,
  72         .can_sleep              = true,
  73 };
  74
  75 /*----------------------------------------------------------------------*/
  76
  77 static int gpo_twl6040_probe(struct platform_device *pdev)
  78 {
  79         struct device *twl6040_core_dev = pdev->dev.parent;
  80         struct twl6040 *twl6040 = dev_get_drvdata(twl6040_core_dev);
  81         int ret;
  82
  83         twl6040gpo_chip.base = -1;
  84
  85         if (twl6040_get_revid(twl6040) < TWL6041_REV_ES2_0)
  86                 twl6040gpo_chip.ngpio = 3; /* twl6040 have 3 GPO */
  87         else
  88                 twl6040gpo_chip.ngpio = 1; /* twl6041 have 1 GPO */
  89
  90         twl6040gpo_chip.parent = &pdev->dev;
  91 #ifdef CONFIG_OF_GPIO
  92         twl6040gpo_chip.of_node = twl6040_core_dev->of_node;
  93 #endif
  94
  95         ret = devm_gpiochip_add_data(&pdev->dev, &twl6040gpo_chip, NULL);
  96         if (ret < 0) {
  97                 dev_err(&pdev->dev, "could not register gpiochip, %d\n", ret);
  98                 twl6040gpo_chip.ngpio = 0;
  99         }
 100
 101         return ret;
 102 }
 103
 104 /* Note:  this hardware lives inside an I2C-based multi-function device. */
 105 MODULE_ALIAS("platform:twl6040-gpo");
 106
 107 static struct platform_driver gpo_twl6040_driver = {
 108         .driver = {
 109                 .name   = "twl6040-gpo",
 110         },
 111         .probe          = gpo_twl6040_probe,
 112 };
 113
 114 module_platform_driver(gpo_twl6040_driver);
 115
 116 MODULE_AUTHOR("Texas Instruments, Inc.");
 117 MODULE_DESCRIPTION("GPO interface for TWL6040");
 118 MODULE_LICENSE("GPL");