drivers/gpio/gpio-palmas.c

   1 /*
   2  * TI Palma series PMIC's GPIO driver.
   3  *
   4  * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
   5  *
   6  * Author: Laxman Dewangan <ldewangan@nvidia.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify it
   9  * under the terms and conditions of the GNU General Public License,
  10  * version 2, as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope it will be useful, but WITHOUT
  13  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  15  * more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #include <linux/gpio.h>
  22 #include <linux/kernel.h>
  23 #include <linux/module.h>
  24 #include <linux/mfd/palmas.h>
  25 #include <linux/of.h>
  26 #include <linux/of_device.h>
  27 #include <linux/platform_device.h>
  28
  29 struct palmas_gpio {
  30         struct gpio_chip gpio_chip;
  31         struct palmas *palmas;
  32 };
  33
  34 static inline struct palmas_gpio *to_palmas_gpio(struct gpio_chip *chip)
  35 {
  36         return container_of(chip, struct palmas_gpio, gpio_chip);
  37 }
  38
  39 static int palmas_gpio_get(struct gpio_chip *gc, unsigned offset)
  40 {
  41         struct palmas_gpio *pg = to_palmas_gpio(gc);
  42         struct palmas *palmas = pg->palmas;
  43         unsigned int val;
  44         int ret;
  45
  46         ret = palmas_read(palmas, PALMAS_GPIO_BASE, PALMAS_GPIO_DATA_IN, &val);
  47         if (ret < 0) {
  48                 dev_err(gc->dev, "GPIO_DATA_IN read failed, err = %d\n", ret);
  49                 return ret;
  50         }
  51         return !!(val & BIT(offset));
  52 }
  53
  54 static void palmas_gpio_set(struct gpio_chip *gc, unsigned offset,
  55                         int value)
  56 {
  57         struct palmas_gpio *pg = to_palmas_gpio(gc);
  58         struct palmas *palmas = pg->palmas;
  59         int ret;
  60
  61         if (value)
  62                 ret = palmas_write(palmas, PALMAS_GPIO_BASE,
  63                                 PALMAS_GPIO_SET_DATA_OUT, BIT(offset));
  64         else
  65                 ret = palmas_write(palmas, PALMAS_GPIO_BASE,
  66                                 PALMAS_GPIO_CLEAR_DATA_OUT, BIT(offset));
  67         if (ret < 0)
  68                 dev_err(gc->dev, "%s write failed, err = %d\n",
  69                         (value) ? "GPIO_SET_DATA_OUT" : "GPIO_CLEAR_DATA_OUT",
  70                         ret);
  71 }
  72
  73 static int palmas_gpio_output(struct gpio_chip *gc, unsigned offset,
  74                                 int value)
  75 {
  76         struct palmas_gpio *pg = to_palmas_gpio(gc);
  77         struct palmas *palmas = pg->palmas;
  78         int ret;
  79
  80         /* Set the initial value */
  81         palmas_gpio_set(gc, offset, value);
  82
  83         ret = palmas_update_bits(palmas, PALMAS_GPIO_BASE,
  84                 PALMAS_GPIO_DATA_DIR, BIT(offset), BIT(offset));
  85         if (ret < 0)
  86                 dev_err(gc->dev, "GPIO_DATA_DIR write failed, err = %d\n", ret);
  87         return ret;
  88 }
  89
  90 static int palmas_gpio_input(struct gpio_chip *gc, unsigned offset)
  91 {
  92         struct palmas_gpio *pg = to_palmas_gpio(gc);
  93         struct palmas *palmas = pg->palmas;
  94         int ret;
  95
  96         ret = palmas_update_bits(palmas, PALMAS_GPIO_BASE,
  97                 PALMAS_GPIO_DATA_DIR, BIT(offset), 0);
  98         if (ret < 0)
  99                 dev_err(gc->dev, "GPIO_DATA_DIR write failed, err = %d\n", ret);
 100         return ret;
 101 }
 102
 103 static int palmas_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
 104 {
 105         struct palmas_gpio *pg = to_palmas_gpio(gc);
 106         struct palmas *palmas = pg->palmas;
 107
 108         return palmas_irq_get_virq(palmas, PALMAS_GPIO_0_IRQ + offset);
 109 }
 110
 111 static int palmas_gpio_probe(struct platform_device *pdev)
 112 {
 113         struct palmas *palmas = dev_get_drvdata(pdev->dev.parent);
 114         struct palmas_platform_data *palmas_pdata;
 115         struct palmas_gpio *palmas_gpio;
 116         int ret;
 117
 118         palmas_gpio = devm_kzalloc(&pdev->dev,
 119                                 sizeof(*palmas_gpio), GFP_KERNEL);
 120         if (!palmas_gpio) {
 121                 dev_err(&pdev->dev, "Could not allocate palmas_gpio\n");
 122                 return -ENOMEM;
 123         }
 124
 125         palmas_gpio->palmas = palmas;
 126         palmas_gpio->gpio_chip.owner = THIS_MODULE;
 127         palmas_gpio->gpio_chip.label = dev_name(&pdev->dev);
 128         palmas_gpio->gpio_chip.ngpio = 8;
 129         palmas_gpio->gpio_chip.can_sleep = 1;
 130         palmas_gpio->gpio_chip.direction_input = palmas_gpio_input;
 131         palmas_gpio->gpio_chip.direction_output = palmas_gpio_output;
 132         palmas_gpio->gpio_chip.to_irq = palmas_gpio_to_irq;
 133         palmas_gpio->gpio_chip.set      = palmas_gpio_set;
 134         palmas_gpio->gpio_chip.get      = palmas_gpio_get;
 135         palmas_gpio->gpio_chip.dev = &pdev->dev;
 136 #ifdef CONFIG_OF_GPIO
 137         palmas_gpio->gpio_chip.of_node = palmas->dev->of_node;
 138 #endif
 139         palmas_pdata = dev_get_platdata(palmas->dev);
 140         if (palmas_pdata && palmas_pdata->gpio_base)
 141                 palmas_gpio->gpio_chip.base = palmas_pdata->gpio_base;
 142         else
 143                 palmas_gpio->gpio_chip.base = -1;
 144
 145         ret = gpiochip_add(&palmas_gpio->gpio_chip);
 146         if (ret < 0) {
 147                 dev_err(&pdev->dev, "Could not register gpiochip, %d\n", ret);
 148                 return ret;
 149         }
 150
 151         platform_set_drvdata(pdev, palmas_gpio);
 152         return ret;
 153 }
 154
 155 static int palmas_gpio_remove(struct platform_device *pdev)
 156 {
 157         struct palmas_gpio *palmas_gpio = platform_get_drvdata(pdev);
 158
 159         return gpiochip_remove(&palmas_gpio->gpio_chip);
 160 }
 161
 162 static struct platform_driver palmas_gpio_driver = {
 163         .driver.name    = "palmas-gpio",
 164         .driver.owner   = THIS_MODULE,
 165         .probe          = palmas_gpio_probe,
 166         .remove         = palmas_gpio_remove,
 167 };
 168
 169 static int __init palmas_gpio_init(void)
 170 {
 171         return platform_driver_register(&palmas_gpio_driver);
 172 }
 173 subsys_initcall(palmas_gpio_init);
 174
 175 static void __exit palmas_gpio_exit(void)
 176 {
 177         platform_driver_unregister(&palmas_gpio_driver);
 178 }
 179 module_exit(palmas_gpio_exit);
 180
 181 MODULE_ALIAS("platform:palmas-gpio");
 182 MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
 183 MODULE_DESCRIPTION("GPIO driver for TI Palmas series PMICs");
 184 MODULE_LICENSE("GPL v2");