drivers/gpio/gpio-tps6586x.c

   1 /*
   2  * TI TPS6586x GPIO driver
   3  *
   4  * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
   5  * Author: Laxman dewangan <ldewangan@nvidia.com>
   6  *
   7  * Based on tps6586x.c
   8  * Copyright (c) 2010 CompuLab Ltd.
   9  * Mike Rapoport <mike@compulab.co.il>
  10  *
  11  * This program is free software; you can redistribute it and/or modify it
  12  * under the terms and conditions of the GNU General Public License,
  13  * version 2, as published by the Free Software Foundation.
  14  *
  15  * This program is distributed in the hope it will be useful, but WITHOUT
  16  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  17  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  18  * more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  22  */
  23
  24 #include <linux/errno.h>
  25 #include <linux/gpio.h>
  26 #include <linux/kernel.h>
  27 #include <linux/init.h>
  28 #include <linux/mfd/tps6586x.h>
  29 #include <linux/of_device.h>
  30 #include <linux/platform_device.h>
  31
  32 /* GPIO control registers */
  33 #define TPS6586X_GPIOSET1       0x5d
  34 #define TPS6586X_GPIOSET2       0x5e
  35
  36 struct tps6586x_gpio {
  37         struct gpio_chip gpio_chip;
  38         struct device *parent;
  39 };
  40
  41 static int tps6586x_gpio_get(struct gpio_chip *gc, unsigned offset)
  42 {
  43         struct tps6586x_gpio *tps6586x_gpio = gpiochip_get_data(gc);
  44         uint8_t val;
  45         int ret;
  46
  47         ret = tps6586x_read(tps6586x_gpio->parent, TPS6586X_GPIOSET2, &val);
  48         if (ret)
  49                 return ret;
  50
  51         return !!(val & (1 << offset));
  52 }
  53
  54 static void tps6586x_gpio_set(struct gpio_chip *gc, unsigned offset,
  55                               int value)
  56 {
  57         struct tps6586x_gpio *tps6586x_gpio = gpiochip_get_data(gc);
  58
  59         tps6586x_update(tps6586x_gpio->parent, TPS6586X_GPIOSET2,
  60                         value << offset, 1 << offset);
  61 }
  62
  63 static int tps6586x_gpio_output(struct gpio_chip *gc, unsigned offset,
  64                                 int value)
  65 {
  66         struct tps6586x_gpio *tps6586x_gpio = gpiochip_get_data(gc);
  67         uint8_t val, mask;
  68
  69         tps6586x_gpio_set(gc, offset, value);
  70
  71         val = 0x1 << (offset * 2);
  72         mask = 0x3 << (offset * 2);
  73
  74         return tps6586x_update(tps6586x_gpio->parent, TPS6586X_GPIOSET1,
  75                                 val, mask);
  76 }
  77
  78 static int tps6586x_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
  79 {
  80         struct tps6586x_gpio *tps6586x_gpio = gpiochip_get_data(gc);
  81
  82         return tps6586x_irq_get_virq(tps6586x_gpio->parent,
  83                                 TPS6586X_INT_PLDO_0 + offset);
  84 }
  85
  86 static int tps6586x_gpio_probe(struct platform_device *pdev)
  87 {
  88         struct tps6586x_platform_data *pdata;
  89         struct tps6586x_gpio *tps6586x_gpio;
  90         int ret;
  91
  92         pdata = dev_get_platdata(pdev->dev.parent);
  93         tps6586x_gpio = devm_kzalloc(&pdev->dev,
  94                                 sizeof(*tps6586x_gpio), GFP_KERNEL);
  95         if (!tps6586x_gpio)
  96                 return -ENOMEM;
  97
  98         tps6586x_gpio->parent = pdev->dev.parent;
  99
 100         tps6586x_gpio->gpio_chip.owner = THIS_MODULE;
 101         tps6586x_gpio->gpio_chip.label = pdev->name;
 102         tps6586x_gpio->gpio_chip.parent = &pdev->dev;
 103         tps6586x_gpio->gpio_chip.ngpio = 4;
 104         tps6586x_gpio->gpio_chip.can_sleep = true;
 105
 106         /* FIXME: add handling of GPIOs as dedicated inputs */
 107         tps6586x_gpio->gpio_chip.direction_output = tps6586x_gpio_output;
 108         tps6586x_gpio->gpio_chip.set    = tps6586x_gpio_set;
 109         tps6586x_gpio->gpio_chip.get    = tps6586x_gpio_get;
 110         tps6586x_gpio->gpio_chip.to_irq = tps6586x_gpio_to_irq;
 111
 112 #ifdef CONFIG_OF_GPIO
 113         tps6586x_gpio->gpio_chip.of_node = pdev->dev.parent->of_node;
 114 #endif
 115         if (pdata && pdata->gpio_base)
 116                 tps6586x_gpio->gpio_chip.base = pdata->gpio_base;
 117         else
 118                 tps6586x_gpio->gpio_chip.base = -1;
 119
 120         ret = devm_gpiochip_add_data(&pdev->dev, &tps6586x_gpio->gpio_chip,
 121                                      tps6586x_gpio);
 122         if (ret < 0) {
 123                 dev_err(&pdev->dev, "Could not register gpiochip, %d\n", ret);
 124                 return ret;
 125         }
 126
 127         platform_set_drvdata(pdev, tps6586x_gpio);
 128
 129         return ret;
 130 }
 131
 132 static struct platform_driver tps6586x_gpio_driver = {
 133         .driver.name    = "tps6586x-gpio",
 134         .driver.owner   = THIS_MODULE,
 135         .probe          = tps6586x_gpio_probe,
 136 };
 137
 138 static int __init tps6586x_gpio_init(void)
 139 {
 140         return platform_driver_register(&tps6586x_gpio_driver);
 141 }
 142 subsys_initcall(tps6586x_gpio_init);