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 int wm831x_isink_probe(struct platform_device *pdev)
152{
153	struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
154	struct wm831x_pdata *pdata = dev_get_platdata(wm831x->dev);
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)
169		return -ENOMEM;
170
171	isink->wm831x = wm831x;
172
173	res = platform_get_resource(pdev, IORESOURCE_REG, 0);
174	if (res == NULL) {
175		dev_err(&pdev->dev, "No REG 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	config.dev = pdev->dev.parent;
192	config.init_data = pdata->isink[id];
193	config.driver_data = isink;
194
195	isink->regulator = devm_regulator_register(&pdev->dev, &isink->desc,
196						   &config);
197	if (IS_ERR(isink->regulator)) {
198		ret = PTR_ERR(isink->regulator);
199		dev_err(wm831x->dev, "Failed to register ISINK%d: %d\n",
200			id + 1, ret);
201		goto err;
202	}
203
204	irq = wm831x_irq(wm831x, platform_get_irq(pdev, 0));
205	ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
206					wm831x_isink_irq,
207					IRQF_TRIGGER_RISING | IRQF_ONESHOT,
208					isink->name,
209					isink);
210	if (ret != 0) {
211		dev_err(&pdev->dev, "Failed to request ISINK IRQ %d: %d\n",
212			irq, ret);
213		goto err;
214	}
215
216	platform_set_drvdata(pdev, isink);
217
218	return 0;
219
220err:
221	return ret;
222}
223
224static struct platform_driver wm831x_isink_driver = {
225	.probe = wm831x_isink_probe,
226	.driver		= {
227		.name	= "wm831x-isink",
228	},
229};
230
231static int __init wm831x_isink_init(void)
232{
233	int ret;
234	ret = platform_driver_register(&wm831x_isink_driver);
235	if (ret != 0)
236		pr_err("Failed to register WM831x ISINK driver: %d\n", ret);
237
238	return ret;
239}
240subsys_initcall(wm831x_isink_init);
241
242static void __exit wm831x_isink_exit(void)
243{
244	platform_driver_unregister(&wm831x_isink_driver);
245}
246module_exit(wm831x_isink_exit);
247
248/* Module information */
249MODULE_AUTHOR("Mark Brown");
250MODULE_DESCRIPTION("WM831x current sink driver");
251MODULE_LICENSE("GPL");
252MODULE_ALIAS("platform:wm831x-isink");
253