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 	},
193 };
194 
195 static int __init wm831x_isink_init(void)
196 {
197 	int ret;
198 	ret = platform_driver_register(&wm831x_isink_driver);
199 	if (ret != 0)
200 		pr_err("Failed to register WM831x ISINK driver: %d\n", ret);
201 
202 	return ret;
203 }
204 subsys_initcall(wm831x_isink_init);
205 
206 static void __exit wm831x_isink_exit(void)
207 {
208 	platform_driver_unregister(&wm831x_isink_driver);
209 }
210 module_exit(wm831x_isink_exit);
211 
212 /* Module information */
213 MODULE_AUTHOR("Mark Brown");
214 MODULE_DESCRIPTION("WM831x current sink driver");
215 MODULE_LICENSE("GPL");
216 MODULE_ALIAS("platform:wm831x-isink");
217