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
wm831x_isink_enable(struct regulator_dev * rdev)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
wm831x_isink_disable(struct regulator_dev * rdev)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
wm831x_isink_is_enabled(struct regulator_dev * rdev)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
wm831x_isink_set_current(struct regulator_dev * rdev,int min_uA,int max_uA)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
wm831x_isink_get_current(struct regulator_dev * rdev)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
wm831x_isink_irq(int irq,void * data)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
wm831x_isink_probe(struct platform_device * pdev)151 static __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 = devm_kzalloc(&pdev->dev, sizeof(struct wm831x_isink),
166 GFP_KERNEL);
167 if (isink == NULL) {
168 dev_err(&pdev->dev, "Unable to allocate private data\n");
169 return -ENOMEM;
170 }
171
172 isink->wm831x = wm831x;
173
174 res = platform_get_resource(pdev, IORESOURCE_IO, 0);
175 if (res == NULL) {
176 dev_err(&pdev->dev, "No I/O resource\n");
177 ret = -EINVAL;
178 goto err;
179 }
180 isink->reg = res->start;
181
182 /* For current parts this is correct; probably need to revisit
183 * in future.
184 */
185 snprintf(isink->name, sizeof(isink->name), "ISINK%d", id + 1);
186 isink->desc.name = isink->name;
187 isink->desc.id = id;
188 isink->desc.ops = &wm831x_isink_ops;
189 isink->desc.type = REGULATOR_CURRENT;
190 isink->desc.owner = THIS_MODULE;
191
192 isink->regulator = regulator_register(&isink->desc, &pdev->dev,
193 pdata->isink[id], isink, NULL);
194 if (IS_ERR(isink->regulator)) {
195 ret = PTR_ERR(isink->regulator);
196 dev_err(wm831x->dev, "Failed to register ISINK%d: %d\n",
197 id + 1, ret);
198 goto err;
199 }
200
201 irq = platform_get_irq(pdev, 0);
202 ret = request_threaded_irq(irq, NULL, wm831x_isink_irq,
203 IRQF_TRIGGER_RISING, isink->name, 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
214 err_regulator:
215 regulator_unregister(isink->regulator);
216 err:
217 return ret;
218 }
219
wm831x_isink_remove(struct platform_device * pdev)220 static __devexit int wm831x_isink_remove(struct platform_device *pdev)
221 {
222 struct wm831x_isink *isink = platform_get_drvdata(pdev);
223
224 platform_set_drvdata(pdev, NULL);
225
226 free_irq(platform_get_irq(pdev, 0), isink);
227
228 regulator_unregister(isink->regulator);
229
230 return 0;
231 }
232
233 static struct platform_driver wm831x_isink_driver = {
234 .probe = wm831x_isink_probe,
235 .remove = __devexit_p(wm831x_isink_remove),
236 .driver = {
237 .name = "wm831x-isink",
238 .owner = THIS_MODULE,
239 },
240 };
241
wm831x_isink_init(void)242 static int __init wm831x_isink_init(void)
243 {
244 int ret;
245 ret = platform_driver_register(&wm831x_isink_driver);
246 if (ret != 0)
247 pr_err("Failed to register WM831x ISINK driver: %d\n", ret);
248
249 return ret;
250 }
251 subsys_initcall(wm831x_isink_init);
252
wm831x_isink_exit(void)253 static void __exit wm831x_isink_exit(void)
254 {
255 platform_driver_unregister(&wm831x_isink_driver);
256 }
257 module_exit(wm831x_isink_exit);
258
259 /* Module information */
260 MODULE_AUTHOR("Mark Brown");
261 MODULE_DESCRIPTION("WM831x current sink driver");
262 MODULE_LICENSE("GPL");
263 MODULE_ALIAS("platform:wm831x-isink");
264