1 /* 2 * gpiolib support for Wolfson WM831x PMICs 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/wm831x/core.h> 24 #include <linux/mfd/wm831x/pdata.h> 25 #include <linux/mfd/wm831x/gpio.h> 26 #include <linux/mfd/wm831x/irq.h> 27 28 struct wm831x_gpio { 29 struct wm831x *wm831x; 30 struct gpio_chip gpio_chip; 31 }; 32 33 static int wm831x_gpio_direction_in(struct gpio_chip *chip, unsigned offset) 34 { 35 struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip); 36 struct wm831x *wm831x = wm831x_gpio->wm831x; 37 int val = WM831X_GPN_DIR; 38 39 if (wm831x->has_gpio_ena) 40 val |= WM831X_GPN_TRI; 41 42 return wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + offset, 43 WM831X_GPN_DIR | WM831X_GPN_TRI | 44 WM831X_GPN_FN_MASK, val); 45 } 46 47 static int wm831x_gpio_get(struct gpio_chip *chip, unsigned offset) 48 { 49 struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip); 50 struct wm831x *wm831x = wm831x_gpio->wm831x; 51 int ret; 52 53 ret = wm831x_reg_read(wm831x, WM831X_GPIO_LEVEL); 54 if (ret < 0) 55 return ret; 56 57 if (ret & 1 << offset) 58 return 1; 59 else 60 return 0; 61 } 62 63 static void wm831x_gpio_set(struct gpio_chip *chip, unsigned offset, int value) 64 { 65 struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip); 66 struct wm831x *wm831x = wm831x_gpio->wm831x; 67 68 wm831x_set_bits(wm831x, WM831X_GPIO_LEVEL, 1 << offset, 69 value << offset); 70 } 71 72 static int wm831x_gpio_direction_out(struct gpio_chip *chip, 73 unsigned offset, int value) 74 { 75 struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip); 76 struct wm831x *wm831x = wm831x_gpio->wm831x; 77 int val = 0; 78 int ret; 79 80 if (wm831x->has_gpio_ena) 81 val |= WM831X_GPN_TRI; 82 83 ret = wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + offset, 84 WM831X_GPN_DIR | WM831X_GPN_TRI | 85 WM831X_GPN_FN_MASK, val); 86 if (ret < 0) 87 return ret; 88 89 /* Can only set GPIO state once it's in output mode */ 90 wm831x_gpio_set(chip, offset, value); 91 92 return 0; 93 } 94 95 static int wm831x_gpio_to_irq(struct gpio_chip *chip, unsigned offset) 96 { 97 struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip); 98 struct wm831x *wm831x = wm831x_gpio->wm831x; 99 100 return irq_create_mapping(wm831x->irq_domain, 101 WM831X_IRQ_GPIO_1 + offset); 102 } 103 104 static int wm831x_gpio_set_debounce(struct wm831x *wm831x, unsigned offset, 105 unsigned debounce) 106 { 107 int reg = WM831X_GPIO1_CONTROL + offset; 108 int ret, fn; 109 110 ret = wm831x_reg_read(wm831x, reg); 111 if (ret < 0) 112 return ret; 113 114 switch (ret & WM831X_GPN_FN_MASK) { 115 case 0: 116 case 1: 117 break; 118 default: 119 /* Not in GPIO mode */ 120 return -EBUSY; 121 } 122 123 if (debounce >= 32 && debounce <= 64) 124 fn = 0; 125 else if (debounce >= 4000 && debounce <= 8000) 126 fn = 1; 127 else 128 return -EINVAL; 129 130 return wm831x_set_bits(wm831x, reg, WM831X_GPN_FN_MASK, fn); 131 } 132 133 static int wm831x_set_config(struct gpio_chip *chip, unsigned int offset, 134 unsigned long config) 135 { 136 struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip); 137 struct wm831x *wm831x = wm831x_gpio->wm831x; 138 int reg = WM831X_GPIO1_CONTROL + offset; 139 140 switch (pinconf_to_config_param(config)) { 141 case PIN_CONFIG_DRIVE_OPEN_DRAIN: 142 return wm831x_set_bits(wm831x, reg, 143 WM831X_GPN_OD_MASK, WM831X_GPN_OD); 144 case PIN_CONFIG_DRIVE_PUSH_PULL: 145 return wm831x_set_bits(wm831x, reg, 146 WM831X_GPN_OD_MASK, 0); 147 case PIN_CONFIG_INPUT_DEBOUNCE: 148 return wm831x_gpio_set_debounce(wm831x, offset, 149 pinconf_to_config_argument(config)); 150 default: 151 break; 152 } 153 154 return -ENOTSUPP; 155 } 156 157 #ifdef CONFIG_DEBUG_FS 158 static void wm831x_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip) 159 { 160 struct wm831x_gpio *wm831x_gpio = gpiochip_get_data(chip); 161 struct wm831x *wm831x = wm831x_gpio->wm831x; 162 int i, tristated; 163 164 for (i = 0; i < chip->ngpio; i++) { 165 int gpio = i + chip->base; 166 int reg; 167 const char *label, *pull, *powerdomain; 168 169 /* We report the GPIO even if it's not requested since 170 * we're also reporting things like alternate 171 * functions which apply even when the GPIO is not in 172 * use as a GPIO. 173 */ 174 label = gpiochip_is_requested(chip, i); 175 if (!label) 176 label = "Unrequested"; 177 178 seq_printf(s, " gpio-%-3d (%-20.20s) ", gpio, label); 179 180 reg = wm831x_reg_read(wm831x, WM831X_GPIO1_CONTROL + i); 181 if (reg < 0) { 182 dev_err(wm831x->dev, 183 "GPIO control %d read failed: %d\n", 184 gpio, reg); 185 seq_printf(s, "\n"); 186 continue; 187 } 188 189 switch (reg & WM831X_GPN_PULL_MASK) { 190 case WM831X_GPIO_PULL_NONE: 191 pull = "nopull"; 192 break; 193 case WM831X_GPIO_PULL_DOWN: 194 pull = "pulldown"; 195 break; 196 case WM831X_GPIO_PULL_UP: 197 pull = "pullup"; 198 break; 199 default: 200 pull = "INVALID PULL"; 201 break; 202 } 203 204 switch (i + 1) { 205 case 1 ... 3: 206 case 7 ... 9: 207 if (reg & WM831X_GPN_PWR_DOM) 208 powerdomain = "VPMIC"; 209 else 210 powerdomain = "DBVDD"; 211 break; 212 213 case 4 ... 6: 214 case 10 ... 12: 215 if (reg & WM831X_GPN_PWR_DOM) 216 powerdomain = "SYSVDD"; 217 else 218 powerdomain = "DBVDD"; 219 break; 220 221 case 13 ... 16: 222 powerdomain = "TPVDD"; 223 break; 224 225 default: 226 BUG(); 227 break; 228 } 229 230 tristated = reg & WM831X_GPN_TRI; 231 if (wm831x->has_gpio_ena) 232 tristated = !tristated; 233 234 seq_printf(s, " %s %s %s %s%s\n" 235 " %s%s (0x%4x)\n", 236 reg & WM831X_GPN_DIR ? "in" : "out", 237 wm831x_gpio_get(chip, i) ? "high" : "low", 238 pull, 239 powerdomain, 240 reg & WM831X_GPN_POL ? "" : " inverted", 241 reg & WM831X_GPN_OD ? "open-drain" : "push-pull", 242 tristated ? " tristated" : "", 243 reg); 244 } 245 } 246 #else 247 #define wm831x_gpio_dbg_show NULL 248 #endif 249 250 static const struct gpio_chip template_chip = { 251 .label = "wm831x", 252 .owner = THIS_MODULE, 253 .direction_input = wm831x_gpio_direction_in, 254 .get = wm831x_gpio_get, 255 .direction_output = wm831x_gpio_direction_out, 256 .set = wm831x_gpio_set, 257 .to_irq = wm831x_gpio_to_irq, 258 .set_config = wm831x_set_config, 259 .dbg_show = wm831x_gpio_dbg_show, 260 .can_sleep = true, 261 }; 262 263 static int wm831x_gpio_probe(struct platform_device *pdev) 264 { 265 struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent); 266 struct wm831x_pdata *pdata = &wm831x->pdata; 267 struct wm831x_gpio *wm831x_gpio; 268 int ret; 269 270 wm831x_gpio = devm_kzalloc(&pdev->dev, sizeof(*wm831x_gpio), 271 GFP_KERNEL); 272 if (wm831x_gpio == NULL) 273 return -ENOMEM; 274 275 wm831x_gpio->wm831x = wm831x; 276 wm831x_gpio->gpio_chip = template_chip; 277 wm831x_gpio->gpio_chip.ngpio = wm831x->num_gpio; 278 wm831x_gpio->gpio_chip.parent = &pdev->dev; 279 if (pdata && pdata->gpio_base) 280 wm831x_gpio->gpio_chip.base = pdata->gpio_base; 281 else 282 wm831x_gpio->gpio_chip.base = -1; 283 #ifdef CONFIG_OF_GPIO 284 wm831x_gpio->gpio_chip.of_node = wm831x->dev->of_node; 285 #endif 286 287 ret = devm_gpiochip_add_data(&pdev->dev, &wm831x_gpio->gpio_chip, 288 wm831x_gpio); 289 if (ret < 0) { 290 dev_err(&pdev->dev, "Could not register gpiochip, %d\n", ret); 291 return ret; 292 } 293 294 platform_set_drvdata(pdev, wm831x_gpio); 295 296 return ret; 297 } 298 299 static struct platform_driver wm831x_gpio_driver = { 300 .driver.name = "wm831x-gpio", 301 .probe = wm831x_gpio_probe, 302 }; 303 304 static int __init wm831x_gpio_init(void) 305 { 306 return platform_driver_register(&wm831x_gpio_driver); 307 } 308 subsys_initcall(wm831x_gpio_init); 309 310 static void __exit wm831x_gpio_exit(void) 311 { 312 platform_driver_unregister(&wm831x_gpio_driver); 313 } 314 module_exit(wm831x_gpio_exit); 315 316 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>"); 317 MODULE_DESCRIPTION("GPIO interface for WM831x PMICs"); 318 MODULE_LICENSE("GPL"); 319 MODULE_ALIAS("platform:wm831x-gpio"); 320