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/of.h>
  19
  20 #include <linux/mfd/twl6040.h>
  21
  22 static int twl6040gpo_get(struct gpio_chip *chip, unsigned offset)
  23 {
  24         struct twl6040 *twl6040 = dev_get_drvdata(chip->parent->parent);
  25         int ret = 0;
  26
  27         ret = twl6040_reg_read(twl6040, TWL6040_REG_GPOCTL);
  28         if (ret < 0)
  29                 return ret;
  30
  31         return (ret >> offset) & 1;
  32 }
  33
  34 static int twl6040gpo_direction_out(struct gpio_chip *chip, unsigned offset,
  35                                     int value)
  36 {
  37         /* This only drives GPOs, and can't change direction */
  38         return 0;
  39 }
  40
  41 static void twl6040gpo_set(struct gpio_chip *chip, unsigned offset, int value)
  42 {
  43         struct twl6040 *twl6040 = dev_get_drvdata(chip->parent->parent);
  44         int ret;
  45         u8 gpoctl;
  46
  47         ret = twl6040_reg_read(twl6040, TWL6040_REG_GPOCTL);
  48         if (ret < 0)
  49                 return;
  50
  51         if (value)
  52                 gpoctl = ret | (1 << offset);
  53         else
  54                 gpoctl = ret & ~(1 << offset);
  55
  56         twl6040_reg_write(twl6040, TWL6040_REG_GPOCTL, gpoctl);
  57 }
  58
  59 static struct gpio_chip twl6040gpo_chip = {
  60         .label                  = "twl6040",
  61         .owner                  = THIS_MODULE,
  62         .get                    = twl6040gpo_get,
  63         .direction_output       = twl6040gpo_direction_out,
  64         .set                    = twl6040gpo_set,
  65         .can_sleep              = true,
  66 };
  67
  68 /*----------------------------------------------------------------------*/
  69
  70 static int gpo_twl6040_probe(struct platform_device *pdev)
  71 {
  72         struct device *twl6040_core_dev = pdev->dev.parent;
  73         struct twl6040 *twl6040 = dev_get_drvdata(twl6040_core_dev);
  74         int ret;
  75
  76         twl6040gpo_chip.base = -1;
  77
  78         if (twl6040_get_revid(twl6040) < TWL6041_REV_ES2_0)
  79                 twl6040gpo_chip.ngpio = 3; /* twl6040 have 3 GPO */
  80         else
  81                 twl6040gpo_chip.ngpio = 1; /* twl6041 have 1 GPO */
  82
  83         twl6040gpo_chip.parent = &pdev->dev;
  84 #ifdef CONFIG_OF_GPIO
  85         twl6040gpo_chip.of_node = twl6040_core_dev->of_node;
  86 #endif
  87
  88         ret = devm_gpiochip_add_data(&pdev->dev, &twl6040gpo_chip, NULL);
  89         if (ret < 0) {
  90                 dev_err(&pdev->dev, "could not register gpiochip, %d\n", ret);
  91                 twl6040gpo_chip.ngpio = 0;
  92         }
  93
  94         return ret;
  95 }
  96
  97 /* Note:  this hardware lives inside an I2C-based multi-function device. */
  98 MODULE_ALIAS("platform:twl6040-gpo");
  99
 100 static struct platform_driver gpo_twl6040_driver = {
 101         .driver = {
 102                 .name   = "twl6040-gpo",
 103         },
 104         .probe          = gpo_twl6040_probe,
 105 };
 106
 107 module_platform_driver(gpo_twl6040_driver);
 108
 109 MODULE_AUTHOR("Texas Instruments, Inc.");
 110 MODULE_DESCRIPTION("GPO interface for TWL6040");
 111 MODULE_LICENSE("GPL");