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