1/* 2 * wm831x-isink.c -- Current sink driver for the WM831x series 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#include <linux/module.h> 15#include <linux/moduleparam.h> 16#include <linux/init.h> 17#include <linux/bitops.h> 18#include <linux/err.h> 19#include <linux/i2c.h> 20#include <linux/platform_device.h> 21#include <linux/regulator/driver.h> 22#include <linux/slab.h> 23 24#include <linux/mfd/wm831x/core.h> 25#include <linux/mfd/wm831x/regulator.h> 26#include <linux/mfd/wm831x/pdata.h> 27 28#define WM831X_ISINK_MAX_NAME 7 29 30struct wm831x_isink { 31 char name[WM831X_ISINK_MAX_NAME]; 32 struct regulator_desc desc; 33 int reg; 34 struct wm831x *wm831x; 35 struct regulator_dev *regulator; 36}; 37 38static int wm831x_isink_enable(struct regulator_dev *rdev) 39{ 40 struct wm831x_isink *isink = rdev_get_drvdata(rdev); 41 struct wm831x *wm831x = isink->wm831x; 42 int ret; 43 44 /* We have a two stage enable: first start the ISINK... */ 45 ret = wm831x_set_bits(wm831x, isink->reg, WM831X_CS1_ENA, 46 WM831X_CS1_ENA); 47 if (ret != 0) 48 return ret; 49 50 /* ...then enable drive */ 51 ret = wm831x_set_bits(wm831x, isink->reg, WM831X_CS1_DRIVE, 52 WM831X_CS1_DRIVE); 53 if (ret != 0) 54 wm831x_set_bits(wm831x, isink->reg, WM831X_CS1_ENA, 0); 55 56 return ret; 57 58} 59 60static int wm831x_isink_disable(struct regulator_dev *rdev) 61{ 62 struct wm831x_isink *isink = rdev_get_drvdata(rdev); 63 struct wm831x *wm831x = isink->wm831x; 64 int ret; 65 66 ret = wm831x_set_bits(wm831x, isink->reg, WM831X_CS1_DRIVE, 0); 67 if (ret < 0) 68 return ret; 69 70 ret = wm831x_set_bits(wm831x, isink->reg, WM831X_CS1_ENA, 0); 71 if (ret < 0) 72 return ret; 73 74 return ret; 75 76} 77 78static int wm831x_isink_is_enabled(struct regulator_dev *rdev) 79{ 80 struct wm831x_isink *isink = rdev_get_drvdata(rdev); 81 struct wm831x *wm831x = isink->wm831x; 82 int ret; 83 84 ret = wm831x_reg_read(wm831x, isink->reg); 85 if (ret < 0) 86 return ret; 87 88 if ((ret & (WM831X_CS1_ENA | WM831X_CS1_DRIVE)) == 89 (WM831X_CS1_ENA | WM831X_CS1_DRIVE)) 90 return 1; 91 else 92 return 0; 93} 94 95static int wm831x_isink_set_current(struct regulator_dev *rdev, 96 int min_uA, int max_uA) 97{ 98 struct wm831x_isink *isink = rdev_get_drvdata(rdev); 99 struct wm831x *wm831x = isink->wm831x; 100 int ret, i; 101 102 for (i = 0; i < ARRAY_SIZE(wm831x_isinkv_values); i++) { 103 int val = wm831x_isinkv_values[i]; 104 if (min_uA >= val && val <= max_uA) { 105 ret = wm831x_set_bits(wm831x, isink->reg, 106 WM831X_CS1_ISEL_MASK, i); 107 return ret; 108 } 109 } 110 111 return -EINVAL; 112} 113 114static int wm831x_isink_get_current(struct regulator_dev *rdev) 115{ 116 struct wm831x_isink *isink = rdev_get_drvdata(rdev); 117 struct wm831x *wm831x = isink->wm831x; 118 int ret; 119 120 ret = wm831x_reg_read(wm831x, isink->reg); 121 if (ret < 0) 122 return ret; 123 124 ret &= WM831X_CS1_ISEL_MASK; 125 if (ret > WM831X_ISINK_MAX_ISEL) 126 ret = WM831X_ISINK_MAX_ISEL; 127 128 return wm831x_isinkv_values[ret]; 129} 130 131static struct regulator_ops wm831x_isink_ops = { 132 .is_enabled = wm831x_isink_is_enabled, 133 .enable = wm831x_isink_enable, 134 .disable = wm831x_isink_disable, 135 .set_current_limit = wm831x_isink_set_current, 136 .get_current_limit = wm831x_isink_get_current, 137}; 138 139static irqreturn_t wm831x_isink_irq(int irq, void *data) 140{ 141 struct wm831x_isink *isink = data; 142 143 regulator_notifier_call_chain(isink->regulator, 144 REGULATOR_EVENT_OVER_CURRENT, 145 NULL); 146 147 return IRQ_HANDLED; 148} 149 150 151static __devinit int wm831x_isink_probe(struct platform_device *pdev) 152{ 153 struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent); 154 struct wm831x_pdata *pdata = wm831x->dev->platform_data; 155 struct wm831x_isink *isink; 156 int id = pdev->id % ARRAY_SIZE(pdata->isink); 157 struct resource *res; 158 int ret, irq; 159 160 dev_dbg(&pdev->dev, "Probing ISINK%d\n", id + 1); 161 162 if (pdata == NULL || pdata->isink[id] == NULL) 163 return -ENODEV; 164 165 isink = kzalloc(sizeof(struct wm831x_isink), GFP_KERNEL); 166 if (isink == NULL) { 167 dev_err(&pdev->dev, "Unable to allocate private data\n"); 168 return -ENOMEM; 169 } 170 171 isink->wm831x = wm831x; 172 173 res = platform_get_resource(pdev, IORESOURCE_IO, 0); 174 if (res == NULL) { 175 dev_err(&pdev->dev, "No I/O resource\n"); 176 ret = -EINVAL; 177 goto err; 178 } 179 isink->reg = res->start; 180 181 /* For current parts this is correct; probably need to revisit 182 * in future. 183 */ 184 snprintf(isink->name, sizeof(isink->name), "ISINK%d", id + 1); 185 isink->desc.name = isink->name; 186 isink->desc.id = id; 187 isink->desc.ops = &wm831x_isink_ops; 188 isink->desc.type = REGULATOR_CURRENT; 189 isink->desc.owner = THIS_MODULE; 190 191 isink->regulator = regulator_register(&isink->desc, &pdev->dev, 192 pdata->isink[id], isink); 193 if (IS_ERR(isink->regulator)) { 194 ret = PTR_ERR(isink->regulator); 195 dev_err(wm831x->dev, "Failed to register ISINK%d: %d\n", 196 id + 1, ret); 197 goto err; 198 } 199 200 irq = platform_get_irq(pdev, 0); 201 ret = wm831x_request_irq(wm831x, irq, wm831x_isink_irq, 202 IRQF_TRIGGER_RISING, isink->name, 203 isink); 204 if (ret != 0) { 205 dev_err(&pdev->dev, "Failed to request ISINK IRQ %d: %d\n", 206 irq, ret); 207 goto err_regulator; 208 } 209 210 platform_set_drvdata(pdev, isink); 211 212 return 0; 213 214err_regulator: 215 regulator_unregister(isink->regulator); 216err: 217 kfree(isink); 218 return ret; 219} 220 221static __devexit int wm831x_isink_remove(struct platform_device *pdev) 222{ 223 struct wm831x_isink *isink = platform_get_drvdata(pdev); 224 struct wm831x *wm831x = isink->wm831x; 225 226 platform_set_drvdata(pdev, NULL); 227 228 wm831x_free_irq(wm831x, platform_get_irq(pdev, 0), isink); 229 230 regulator_unregister(isink->regulator); 231 kfree(isink); 232 233 return 0; 234} 235 236static struct platform_driver wm831x_isink_driver = { 237 .probe = wm831x_isink_probe, 238 .remove = __devexit_p(wm831x_isink_remove), 239 .driver = { 240 .name = "wm831x-isink", 241 .owner = THIS_MODULE, 242 }, 243}; 244 245static int __init wm831x_isink_init(void) 246{ 247 int ret; 248 ret = platform_driver_register(&wm831x_isink_driver); 249 if (ret != 0) 250 pr_err("Failed to register WM831x ISINK driver: %d\n", ret); 251 252 return ret; 253} 254subsys_initcall(wm831x_isink_init); 255 256static void __exit wm831x_isink_exit(void) 257{ 258 platform_driver_unregister(&wm831x_isink_driver); 259} 260module_exit(wm831x_isink_exit); 261 262/* Module information */ 263MODULE_AUTHOR("Mark Brown"); 264MODULE_DESCRIPTION("WM831x current sink driver"); 265MODULE_LICENSE("GPL"); 266MODULE_ALIAS("platform:wm831x-isink"); 267