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
25struct 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
33static 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
55static 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
73static 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
90static 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
98static 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
110static 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
184err:
185	return ret;
186}
187
188static 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
196static 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}
205subsys_initcall(wm831x_isink_init);
206
207static void __exit wm831x_isink_exit(void)
208{
209	platform_driver_unregister(&wm831x_isink_driver);
210}
211module_exit(wm831x_isink_exit);
212
213/* Module information */
214MODULE_AUTHOR("Mark Brown");
215MODULE_DESCRIPTION("WM831x current sink driver");
216MODULE_LICENSE("GPL");
217MODULE_ALIAS("platform:wm831x-isink");
218