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/module.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 inline struct tps6586x_gpio *to_tps6586x_gpio(struct gpio_chip *chip)
  42 {
  43         return container_of(chip, struct tps6586x_gpio, gpio_chip);
  44 }
  45
  46 static int tps6586x_gpio_get(struct gpio_chip *gc, unsigned offset)
  47 {
  48         struct tps6586x_gpio *tps6586x_gpio = to_tps6586x_gpio(gc);
  49         uint8_t val;
  50         int ret;
  51
  52         ret = tps6586x_read(tps6586x_gpio->parent, TPS6586X_GPIOSET2, &val);
  53         if (ret)
  54                 return ret;
  55
  56         return !!(val & (1 << offset));
  57 }
  58
  59 static void tps6586x_gpio_set(struct gpio_chip *gc, unsigned offset,
  60                               int value)
  61 {
  62         struct tps6586x_gpio *tps6586x_gpio = to_tps6586x_gpio(gc);
  63
  64         tps6586x_update(tps6586x_gpio->parent, TPS6586X_GPIOSET2,
  65                         value << offset, 1 << offset);
  66 }
  67
  68 static int tps6586x_gpio_output(struct gpio_chip *gc, unsigned offset,
  69                                 int value)
  70 {
  71         struct tps6586x_gpio *tps6586x_gpio = to_tps6586x_gpio(gc);
  72         uint8_t val, mask;
  73
  74         tps6586x_gpio_set(gc, offset, value);
  75
  76         val = 0x1 << (offset * 2);
  77         mask = 0x3 << (offset * 2);
  78
  79         return tps6586x_update(tps6586x_gpio->parent, TPS6586X_GPIOSET1,
  80                                 val, mask);
  81 }
  82
  83 static int __devinit tps6586x_gpio_probe(struct platform_device *pdev)
  84 {
  85         struct tps6586x_platform_data *pdata;
  86         struct tps6586x_gpio *tps6586x_gpio;
  87         int ret;
  88
  89         pdata = dev_get_platdata(pdev->dev.parent);
  90         tps6586x_gpio = devm_kzalloc(&pdev->dev,
  91                                 sizeof(*tps6586x_gpio), GFP_KERNEL);
  92         if (!tps6586x_gpio) {
  93                 dev_err(&pdev->dev, "Could not allocate tps6586x_gpio\n");
  94                 return -ENOMEM;
  95         }
  96
  97         tps6586x_gpio->parent = pdev->dev.parent;
  98
  99         tps6586x_gpio->gpio_chip.owner = THIS_MODULE;
 100         tps6586x_gpio->gpio_chip.label = pdev->name;
 101         tps6586x_gpio->gpio_chip.dev = &pdev->dev;
 102         tps6586x_gpio->gpio_chip.ngpio = 4;
 103         tps6586x_gpio->gpio_chip.can_sleep = 1;
 104
 105         /* FIXME: add handling of GPIOs as dedicated inputs */
 106         tps6586x_gpio->gpio_chip.direction_output = tps6586x_gpio_output;
 107         tps6586x_gpio->gpio_chip.set    = tps6586x_gpio_set;
 108         tps6586x_gpio->gpio_chip.get    = tps6586x_gpio_get;
 109
 110 #ifdef CONFIG_OF_GPIO
 111         tps6586x_gpio->gpio_chip.of_node = pdev->dev.parent->of_node;
 112 #endif
 113         if (pdata && pdata->gpio_base)
 114                 tps6586x_gpio->gpio_chip.base = pdata->gpio_base;
 115         else
 116                 tps6586x_gpio->gpio_chip.base = -1;
 117
 118         ret = gpiochip_add(&tps6586x_gpio->gpio_chip);
 119         if (ret < 0) {
 120                 dev_err(&pdev->dev, "Could not register gpiochip, %d\n", ret);
 121                 return ret;
 122         }
 123
 124         platform_set_drvdata(pdev, tps6586x_gpio);
 125
 126         return ret;
 127 }
 128
 129 static int __devexit tps6586x_gpio_remove(struct platform_device *pdev)
 130 {
 131         struct tps6586x_gpio *tps6586x_gpio = platform_get_drvdata(pdev);
 132
 133         return gpiochip_remove(&tps6586x_gpio->gpio_chip);
 134 }
 135
 136 static struct platform_driver tps6586x_gpio_driver = {
 137         .driver.name    = "tps6586x-gpio",
 138         .driver.owner   = THIS_MODULE,
 139         .probe          = tps6586x_gpio_probe,
 140         .remove         = __devexit_p(tps6586x_gpio_remove),
 141 };
 142
 143 static int __init tps6586x_gpio_init(void)
 144 {
 145         return platform_driver_register(&tps6586x_gpio_driver);
 146 }
 147 subsys_initcall(tps6586x_gpio_init);
 148
 149 static void __exit tps6586x_gpio_exit(void)
 150 {
 151         platform_driver_unregister(&tps6586x_gpio_driver);
 152 }
 153 module_exit(tps6586x_gpio_exit);
 154
 155 MODULE_ALIAS("platform:tps6586x-gpio");
 156 MODULE_DESCRIPTION("GPIO interface for TPS6586X PMIC");
 157 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
 158 MODULE_LICENSE("GPL");