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 30 struct 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 38 static 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 60 static 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 78 static 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 95 static 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 } 113 114 static 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 } 130 131 static 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 }; 138 139 static 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 } 149 150 151 static 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 regulator_config config = { }; 158 struct resource *res; 159 int ret, irq; 160 161 dev_dbg(&pdev->dev, "Probing ISINK%d\n", id + 1); 162 163 if (pdata == NULL || pdata->isink[id] == NULL) 164 return -ENODEV; 165 166 isink = devm_kzalloc(&pdev->dev, sizeof(struct wm831x_isink), 167 GFP_KERNEL); 168 if (isink == NULL) { 169 dev_err(&pdev->dev, "Unable to allocate private data\n"); 170 return -ENOMEM; 171 } 172 173 isink->wm831x = wm831x; 174 175 res = platform_get_resource(pdev, IORESOURCE_REG, 0); 176 if (res == NULL) { 177 dev_err(&pdev->dev, "No REG resource\n"); 178 ret = -EINVAL; 179 goto err; 180 } 181 isink->reg = res->start; 182 183 /* For current parts this is correct; probably need to revisit 184 * in future. 185 */ 186 snprintf(isink->name, sizeof(isink->name), "ISINK%d", id + 1); 187 isink->desc.name = isink->name; 188 isink->desc.id = id; 189 isink->desc.ops = &wm831x_isink_ops; 190 isink->desc.type = REGULATOR_CURRENT; 191 isink->desc.owner = THIS_MODULE; 192 193 config.dev = pdev->dev.parent; 194 config.init_data = pdata->isink[id]; 195 config.driver_data = isink; 196 197 isink->regulator = regulator_register(&isink->desc, &config); 198 if (IS_ERR(isink->regulator)) { 199 ret = PTR_ERR(isink->regulator); 200 dev_err(wm831x->dev, "Failed to register ISINK%d: %d\n", 201 id + 1, ret); 202 goto err; 203 } 204 205 irq = wm831x_irq(wm831x, platform_get_irq(pdev, 0)); 206 ret = request_threaded_irq(irq, NULL, wm831x_isink_irq, 207 IRQF_TRIGGER_RISING, isink->name, isink); 208 if (ret != 0) { 209 dev_err(&pdev->dev, "Failed to request ISINK IRQ %d: %d\n", 210 irq, ret); 211 goto err_regulator; 212 } 213 214 platform_set_drvdata(pdev, isink); 215 216 return 0; 217 218 err_regulator: 219 regulator_unregister(isink->regulator); 220 err: 221 return ret; 222 } 223 224 static int wm831x_isink_remove(struct platform_device *pdev) 225 { 226 struct wm831x_isink *isink = platform_get_drvdata(pdev); 227 228 platform_set_drvdata(pdev, NULL); 229 230 free_irq(wm831x_irq(isink->wm831x, platform_get_irq(pdev, 0)), isink); 231 232 regulator_unregister(isink->regulator); 233 234 return 0; 235 } 236 237 static struct platform_driver wm831x_isink_driver = { 238 .probe = wm831x_isink_probe, 239 .remove = wm831x_isink_remove, 240 .driver = { 241 .name = "wm831x-isink", 242 .owner = THIS_MODULE, 243 }, 244 }; 245 246 static int __init wm831x_isink_init(void) 247 { 248 int ret; 249 ret = platform_driver_register(&wm831x_isink_driver); 250 if (ret != 0) 251 pr_err("Failed to register WM831x ISINK driver: %d\n", ret); 252 253 return ret; 254 } 255 subsys_initcall(wm831x_isink_init); 256 257 static void __exit wm831x_isink_exit(void) 258 { 259 platform_driver_unregister(&wm831x_isink_driver); 260 } 261 module_exit(wm831x_isink_exit); 262 263 /* Module information */ 264 MODULE_AUTHOR("Mark Brown"); 265 MODULE_DESCRIPTION("WM831x current sink driver"); 266 MODULE_LICENSE("GPL"); 267 MODULE_ALIAS("platform:wm831x-isink"); 268