1 // SPDX-License-Identifier: GPL-2.0+ 2 // 3 // wm831x-isink.c -- Current sink driver for the WM831x series 4 // 5 // Copyright 2009 Wolfson Microelectronics PLC. 6 // 7 // Author: Mark Brown <broonie@opensource.wolfsonmicro.com> 8 9 #include <linux/module.h> 10 #include <linux/moduleparam.h> 11 #include <linux/init.h> 12 #include <linux/bitops.h> 13 #include <linux/err.h> 14 #include <linux/i2c.h> 15 #include <linux/platform_device.h> 16 #include <linux/regulator/driver.h> 17 #include <linux/slab.h> 18 19 #include <linux/mfd/wm831x/core.h> 20 #include <linux/mfd/wm831x/regulator.h> 21 #include <linux/mfd/wm831x/pdata.h> 22 23 #define WM831X_ISINK_MAX_NAME 7 24 25 struct wm831x_isink { 26 char name[WM831X_ISINK_MAX_NAME]; 27 struct regulator_desc desc; 28 int reg; 29 struct wm831x *wm831x; 30 struct regulator_dev *regulator; 31 }; 32 33 static int wm831x_isink_enable(struct regulator_dev *rdev) 34 { 35 struct wm831x_isink *isink = rdev_get_drvdata(rdev); 36 struct wm831x *wm831x = isink->wm831x; 37 int ret; 38 39 /* We have a two stage enable: first start the ISINK... */ 40 ret = wm831x_set_bits(wm831x, isink->reg, WM831X_CS1_ENA, 41 WM831X_CS1_ENA); 42 if (ret != 0) 43 return ret; 44 45 /* ...then enable drive */ 46 ret = wm831x_set_bits(wm831x, isink->reg, WM831X_CS1_DRIVE, 47 WM831X_CS1_DRIVE); 48 if (ret != 0) 49 wm831x_set_bits(wm831x, isink->reg, WM831X_CS1_ENA, 0); 50 51 return ret; 52 53 } 54 55 static int wm831x_isink_disable(struct regulator_dev *rdev) 56 { 57 struct wm831x_isink *isink = rdev_get_drvdata(rdev); 58 struct wm831x *wm831x = isink->wm831x; 59 int ret; 60 61 ret = wm831x_set_bits(wm831x, isink->reg, WM831X_CS1_DRIVE, 0); 62 if (ret < 0) 63 return ret; 64 65 ret = wm831x_set_bits(wm831x, isink->reg, WM831X_CS1_ENA, 0); 66 if (ret < 0) 67 return ret; 68 69 return ret; 70 71 } 72 73 static int wm831x_isink_is_enabled(struct regulator_dev *rdev) 74 { 75 struct wm831x_isink *isink = rdev_get_drvdata(rdev); 76 struct wm831x *wm831x = isink->wm831x; 77 int ret; 78 79 ret = wm831x_reg_read(wm831x, isink->reg); 80 if (ret < 0) 81 return ret; 82 83 if ((ret & (WM831X_CS1_ENA | WM831X_CS1_DRIVE)) == 84 (WM831X_CS1_ENA | WM831X_CS1_DRIVE)) 85 return 1; 86 else 87 return 0; 88 } 89 90 static const struct regulator_ops wm831x_isink_ops = { 91 .is_enabled = wm831x_isink_is_enabled, 92 .enable = wm831x_isink_enable, 93 .disable = wm831x_isink_disable, 94 .set_current_limit = regulator_set_current_limit_regmap, 95 .get_current_limit = regulator_get_current_limit_regmap, 96 }; 97 98 static irqreturn_t wm831x_isink_irq(int irq, void *data) 99 { 100 struct wm831x_isink *isink = data; 101 102 regulator_notifier_call_chain(isink->regulator, 103 REGULATOR_EVENT_OVER_CURRENT, 104 NULL); 105 106 return IRQ_HANDLED; 107 } 108 109 110 static int wm831x_isink_probe(struct platform_device *pdev) 111 { 112 struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent); 113 struct wm831x_pdata *pdata = dev_get_platdata(wm831x->dev); 114 struct wm831x_isink *isink; 115 int id = pdev->id % ARRAY_SIZE(pdata->isink); 116 struct regulator_config config = { }; 117 struct resource *res; 118 int ret, irq; 119 120 dev_dbg(&pdev->dev, "Probing ISINK%d\n", id + 1); 121 122 if (pdata == NULL || pdata->isink[id] == NULL) 123 return -ENODEV; 124 125 isink = devm_kzalloc(&pdev->dev, sizeof(struct wm831x_isink), 126 GFP_KERNEL); 127 if (!isink) 128 return -ENOMEM; 129 130 isink->wm831x = wm831x; 131 132 res = platform_get_resource(pdev, IORESOURCE_REG, 0); 133 if (res == NULL) { 134 dev_err(&pdev->dev, "No REG resource\n"); 135 ret = -EINVAL; 136 goto err; 137 } 138 isink->reg = res->start; 139 140 /* For current parts this is correct; probably need to revisit 141 * in future. 142 */ 143 snprintf(isink->name, sizeof(isink->name), "ISINK%d", id + 1); 144 isink->desc.name = isink->name; 145 isink->desc.id = id; 146 isink->desc.ops = &wm831x_isink_ops; 147 isink->desc.type = REGULATOR_CURRENT; 148 isink->desc.owner = THIS_MODULE; 149 isink->desc.curr_table = wm831x_isinkv_values; 150 isink->desc.n_current_limits = ARRAY_SIZE(wm831x_isinkv_values); 151 isink->desc.csel_reg = isink->reg; 152 isink->desc.csel_mask = WM831X_CS1_ISEL_MASK; 153 154 config.dev = pdev->dev.parent; 155 config.init_data = pdata->isink[id]; 156 config.driver_data = isink; 157 config.regmap = wm831x->regmap; 158 159 isink->regulator = devm_regulator_register(&pdev->dev, &isink->desc, 160 &config); 161 if (IS_ERR(isink->regulator)) { 162 ret = PTR_ERR(isink->regulator); 163 dev_err(wm831x->dev, "Failed to register ISINK%d: %d\n", 164 id + 1, ret); 165 goto err; 166 } 167 168 irq = wm831x_irq(wm831x, platform_get_irq(pdev, 0)); 169 ret = devm_request_threaded_irq(&pdev->dev, irq, NULL, 170 wm831x_isink_irq, 171 IRQF_TRIGGER_RISING | IRQF_ONESHOT, 172 isink->name, 173 isink); 174 if (ret != 0) { 175 dev_err(&pdev->dev, "Failed to request ISINK IRQ %d: %d\n", 176 irq, ret); 177 goto err; 178 } 179 180 platform_set_drvdata(pdev, isink); 181 182 return 0; 183 184 err: 185 return ret; 186 } 187 188 static struct platform_driver wm831x_isink_driver = { 189 .probe = wm831x_isink_probe, 190 .driver = { 191 .name = "wm831x-isink", 192 .probe_type = PROBE_PREFER_ASYNCHRONOUS, 193 }, 194 }; 195 196 static int __init wm831x_isink_init(void) 197 { 198 int ret; 199 ret = platform_driver_register(&wm831x_isink_driver); 200 if (ret != 0) 201 pr_err("Failed to register WM831x ISINK driver: %d\n", ret); 202 203 return ret; 204 } 205 subsys_initcall(wm831x_isink_init); 206 207 static void __exit wm831x_isink_exit(void) 208 { 209 platform_driver_unregister(&wm831x_isink_driver); 210 } 211 module_exit(wm831x_isink_exit); 212 213 /* Module information */ 214 MODULE_AUTHOR("Mark Brown"); 215 MODULE_DESCRIPTION("WM831x current sink driver"); 216 MODULE_LICENSE("GPL"); 217 MODULE_ALIAS("platform:wm831x-isink"); 218