1/* 2 * wm8994-gpio.c -- gpiolib support for Wolfson WM8994 3 * 4 * Copyright 2009 Wolfson Microelectronics PLC. 5 * 6 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com> 7 * 8 * This program is free software; you can redistribute it and/or modify it 9 * under the terms of the GNU General Public License as published by the 10 * Free Software Foundation; either version 2 of the License, or (at your 11 * option) any later version. 12 * 13 */ 14 15#include <linux/kernel.h> 16#include <linux/slab.h> 17#include <linux/module.h> 18#include <linux/gpio.h> 19#include <linux/mfd/core.h> 20#include <linux/platform_device.h> 21#include <linux/seq_file.h> 22 23#include <linux/mfd/wm8994/core.h> 24#include <linux/mfd/wm8994/pdata.h> 25#include <linux/mfd/wm8994/gpio.h> 26#include <linux/mfd/wm8994/registers.h> 27 28struct wm8994_gpio { 29 struct wm8994 *wm8994; 30 struct gpio_chip gpio_chip; 31}; 32 33static inline struct wm8994_gpio *to_wm8994_gpio(struct gpio_chip *chip) 34{ 35 return container_of(chip, struct wm8994_gpio, gpio_chip); 36} 37 38static int wm8994_gpio_direction_in(struct gpio_chip *chip, unsigned offset) 39{ 40 struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip); 41 struct wm8994 *wm8994 = wm8994_gpio->wm8994; 42 43 return wm8994_set_bits(wm8994, WM8994_GPIO_1 + offset, 44 WM8994_GPN_DIR, WM8994_GPN_DIR); 45} 46 47static int wm8994_gpio_get(struct gpio_chip *chip, unsigned offset) 48{ 49 struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip); 50 struct wm8994 *wm8994 = wm8994_gpio->wm8994; 51 int ret; 52 53 ret = wm8994_reg_read(wm8994, WM8994_GPIO_1 + offset); 54 if (ret < 0) 55 return ret; 56 57 if (ret & WM8994_GPN_LVL) 58 return 1; 59 else 60 return 0; 61} 62 63static int wm8994_gpio_direction_out(struct gpio_chip *chip, 64 unsigned offset, int value) 65{ 66 struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip); 67 struct wm8994 *wm8994 = wm8994_gpio->wm8994; 68 69 return wm8994_set_bits(wm8994, WM8994_GPIO_1 + offset, 70 WM8994_GPN_DIR, 0); 71} 72 73static void wm8994_gpio_set(struct gpio_chip *chip, unsigned offset, int value) 74{ 75 struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip); 76 struct wm8994 *wm8994 = wm8994_gpio->wm8994; 77 78 if (value) 79 value = WM8994_GPN_LVL; 80 81 wm8994_set_bits(wm8994, WM8994_GPIO_1 + offset, WM8994_GPN_LVL, value); 82} 83 84static int wm8994_gpio_to_irq(struct gpio_chip *chip, unsigned offset) 85{ 86 struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip); 87 struct wm8994 *wm8994 = wm8994_gpio->wm8994; 88 89 if (!wm8994->irq_base) 90 return -EINVAL; 91 92 return wm8994->irq_base + offset; 93} 94 95 96#ifdef CONFIG_DEBUG_FS 97static void wm8994_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip) 98{ 99 struct wm8994_gpio *wm8994_gpio = to_wm8994_gpio(chip); 100 struct wm8994 *wm8994 = wm8994_gpio->wm8994; 101 int i; 102 103 for (i = 0; i < chip->ngpio; i++) { 104 int gpio = i + chip->base; 105 int reg; 106 const char *label; 107 108 /* We report the GPIO even if it's not requested since 109 * we're also reporting things like alternate 110 * functions which apply even when the GPIO is not in 111 * use as a GPIO. 112 */ 113 label = gpiochip_is_requested(chip, i); 114 if (!label) 115 label = "Unrequested"; 116 117 seq_printf(s, " gpio-%-3d (%-20.20s) ", gpio, label); 118 119 reg = wm8994_reg_read(wm8994, WM8994_GPIO_1 + i); 120 if (reg < 0) { 121 dev_err(wm8994->dev, 122 "GPIO control %d read failed: %d\n", 123 gpio, reg); 124 seq_printf(s, "\n"); 125 continue; 126 } 127 128 /* No decode yet; note that GPIO2 is special */ 129 seq_printf(s, "(%x)\n", reg); 130 } 131} 132#else 133#define wm8994_gpio_dbg_show NULL 134#endif 135 136static struct gpio_chip template_chip = { 137 .label = "wm8994", 138 .owner = THIS_MODULE, 139 .direction_input = wm8994_gpio_direction_in, 140 .get = wm8994_gpio_get, 141 .direction_output = wm8994_gpio_direction_out, 142 .set = wm8994_gpio_set, 143 .dbg_show = wm8994_gpio_dbg_show, 144 .can_sleep = 1, 145}; 146 147static int __devinit wm8994_gpio_probe(struct platform_device *pdev) 148{ 149 struct wm8994 *wm8994 = dev_get_drvdata(pdev->dev.parent); 150 struct wm8994_pdata *pdata = wm8994->dev->platform_data; 151 struct wm8994_gpio *wm8994_gpio; 152 int ret; 153 154 wm8994_gpio = kzalloc(sizeof(*wm8994_gpio), GFP_KERNEL); 155 if (wm8994_gpio == NULL) 156 return -ENOMEM; 157 158 wm8994_gpio->wm8994 = wm8994; 159 wm8994_gpio->gpio_chip = template_chip; 160 wm8994_gpio->gpio_chip.ngpio = WM8994_GPIO_MAX; 161 wm8994_gpio->gpio_chip.dev = &pdev->dev; 162 if (pdata && pdata->gpio_base) 163 wm8994_gpio->gpio_chip.base = pdata->gpio_base; 164 else 165 wm8994_gpio->gpio_chip.base = -1; 166 167 ret = gpiochip_add(&wm8994_gpio->gpio_chip); 168 if (ret < 0) { 169 dev_err(&pdev->dev, "Could not register gpiochip, %d\n", 170 ret); 171 goto err; 172 } 173 174 platform_set_drvdata(pdev, wm8994_gpio); 175 176 return ret; 177 178err: 179 kfree(wm8994_gpio); 180 return ret; 181} 182 183static int __devexit wm8994_gpio_remove(struct platform_device *pdev) 184{ 185 struct wm8994_gpio *wm8994_gpio = platform_get_drvdata(pdev); 186 int ret; 187 188 ret = gpiochip_remove(&wm8994_gpio->gpio_chip); 189 if (ret == 0) 190 kfree(wm8994_gpio); 191 192 return ret; 193} 194 195static struct platform_driver wm8994_gpio_driver = { 196 .driver.name = "wm8994-gpio", 197 .driver.owner = THIS_MODULE, 198 .probe = wm8994_gpio_probe, 199 .remove = __devexit_p(wm8994_gpio_remove), 200}; 201 202static int __init wm8994_gpio_init(void) 203{ 204 return platform_driver_register(&wm8994_gpio_driver); 205} 206subsys_initcall(wm8994_gpio_init); 207 208static void __exit wm8994_gpio_exit(void) 209{ 210 platform_driver_unregister(&wm8994_gpio_driver); 211} 212module_exit(wm8994_gpio_exit); 213 214MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>"); 215MODULE_DESCRIPTION("GPIO interface for WM8994"); 216MODULE_LICENSE("GPL"); 217MODULE_ALIAS("platform:wm8994-gpio"); 218