summaryrefslogtreecommitdiffstats
path: root/drivers/video/backlight/tps65217_bl.c
blob: 380917c862769524c56687c0e5bf86c8fc339914 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
/*
 * tps65217_bl.c
 *
 * TPS65217 backlight driver
 *
 * Copyright (C) 2012 Matthias Kaehlcke
 * Author: Matthias Kaehlcke <matthias@kaehlcke.net>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation version 2.
 *
 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
 * kind, whether express or implied; without even the implied warranty
 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/kernel.h>
#include <linux/backlight.h>
#include <linux/err.h>
#include <linux/fb.h>
#include <linux/mfd/tps65217.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>

struct tps65217_bl {
	struct tps65217 *tps;
	struct device *dev;
	struct backlight_device *bl;
	bool is_enabled;
};

static int tps65217_bl_enable(struct tps65217_bl *tps65217_bl)
{
	int rc;

	rc = tps65217_set_bits(tps65217_bl->tps, TPS65217_REG_WLEDCTRL1,
			TPS65217_WLEDCTRL1_ISINK_ENABLE,
			TPS65217_WLEDCTRL1_ISINK_ENABLE, TPS65217_PROTECT_NONE);
	if (rc) {
		dev_err(tps65217_bl->dev,
			"failed to enable backlight: %d\n", rc);
		return rc;
	}

	tps65217_bl->is_enabled = true;

	dev_dbg(tps65217_bl->dev, "backlight enabled\n");

	return 0;
}

static int tps65217_bl_disable(struct tps65217_bl *tps65217_bl)
{
	int rc;

	rc = tps65217_clear_bits(tps65217_bl->tps,
				TPS65217_REG_WLEDCTRL1,
				TPS65217_WLEDCTRL1_ISINK_ENABLE,
				TPS65217_PROTECT_NONE);
	if (rc) {
		dev_err(tps65217_bl->dev,
			"failed to disable backlight: %d\n", rc);
		return rc;
	}

	tps65217_bl->is_enabled = false;

	dev_dbg(tps65217_bl->dev, "backlight disabled\n");

	return 0;
}

static int tps65217_bl_update_status(struct backlight_device *bl)
{
	struct tps65217_bl *tps65217_bl = bl_get_data(bl);
	int rc;
	int brightness = bl->props.brightness;

	if (bl->props.state & BL_CORE_SUSPENDED)
		brightness = 0;

	if ((bl->props.power != FB_BLANK_UNBLANK) ||
		(bl->props.fb_blank != FB_BLANK_UNBLANK))
		/* framebuffer in low power mode or blanking active */
		brightness = 0;

	if (brightness > 0) {
		rc = tps65217_reg_write(tps65217_bl->tps,
					TPS65217_REG_WLEDCTRL2,
					brightness - 1,
					TPS65217_PROTECT_NONE);
		if (rc) {
			dev_err(tps65217_bl->dev,
				"failed to set brightness level: %d\n", rc);
			return rc;
		}

		dev_dbg(tps65217_bl->dev, "brightness set to %d\n", brightness);

		if (!tps65217_bl->is_enabled)
			rc = tps65217_bl_enable(tps65217_bl);
	} else {
		rc = tps65217_bl_disable(tps65217_bl);
	}

	return rc;
}

static const struct backlight_ops tps65217_bl_ops = {
	.options	= BL_CORE_SUSPENDRESUME,
	.update_status	= tps65217_bl_update_status,
};

static int tps65217_bl_hw_init(struct tps65217_bl *tps65217_bl,
			struct tps65217_bl_pdata *pdata)
{
	int rc;

	rc = tps65217_bl_disable(tps65217_bl);
	if (rc)
		return rc;

	switch (pdata->isel) {
	case TPS65217_BL_ISET1:
		/* select ISET_1 current level */
		rc = tps65217_clear_bits(tps65217_bl->tps,
					TPS65217_REG_WLEDCTRL1,
					TPS65217_WLEDCTRL1_ISEL,
					TPS65217_PROTECT_NONE);
		if (rc) {
			dev_err(tps65217_bl->dev,
				"failed to select ISET1 current level: %d)\n",
				rc);
			return rc;
		}

		dev_dbg(tps65217_bl->dev, "selected ISET1 current level\n");

		break;

	case TPS65217_BL_ISET2:
		/* select ISET2 current level */
		rc = tps65217_set_bits(tps65217_bl->tps, TPS65217_REG_WLEDCTRL1,
				TPS65217_WLEDCTRL1_ISEL,
				TPS65217_WLEDCTRL1_ISEL, TPS65217_PROTECT_NONE);
		if (rc) {
			dev_err(tps65217_bl->dev,
				"failed to select ISET2 current level: %d\n",
				rc);
			return rc;
		}

		dev_dbg(tps65217_bl->dev, "selected ISET2 current level\n");

		break;

	default:
		dev_err(tps65217_bl->dev,
			"invalid value for current level: %d\n", pdata->isel);
		return -EINVAL;
	}

	/* set PWM frequency */
	rc = tps65217_set_bits(tps65217_bl->tps,
			TPS65217_REG_WLEDCTRL1,
			TPS65217_WLEDCTRL1_FDIM_MASK,
			pdata->fdim,
			TPS65217_PROTECT_NONE);
	if (rc) {
		dev_err(tps65217_bl->dev,
			"failed to select PWM dimming frequency: %d\n",
			rc);
		return rc;
	}

	return 0;
}

#ifdef CONFIG_OF
static struct tps65217_bl_pdata *
tps65217_bl_parse_dt(struct platform_device *pdev)
{
	struct tps65217 *tps = dev_get_drvdata(pdev->dev.parent);
	struct device_node *node = of_node_get(tps->dev->of_node);
	struct tps65217_bl_pdata *pdata, *err;
	u32 val;

	node = of_find_node_by_name(node, "backlight");
	if (!node)
		return ERR_PTR(-ENODEV);

	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
	if (!pdata) {
		err = ERR_PTR(-ENOMEM);
		goto err;
	}

	pdata->isel = TPS65217_BL_ISET1;
	if (!of_property_read_u32(node, "isel", &val)) {
		if (val < TPS65217_BL_ISET1 ||
			val > TPS65217_BL_ISET2) {
			dev_err(&pdev->dev,
				"invalid 'isel' value in the device tree\n");
			err = ERR_PTR(-EINVAL);
			goto err;
		}

		pdata->isel = val;
	}

	pdata->fdim = TPS65217_BL_FDIM_200HZ;
	if (!of_property_read_u32(node, "fdim", &val)) {
		switch (val) {
		case 100:
			pdata->fdim = TPS65217_BL_FDIM_100HZ;
			break;

		case 200:
			pdata->fdim = TPS65217_BL_FDIM_200HZ;
			break;

		case 500:
			pdata->fdim = TPS65217_BL_FDIM_500HZ;
			break;

		case 1000:
			pdata->fdim = TPS65217_BL_FDIM_1000HZ;
			break;

		default:
			dev_err(&pdev->dev,
				"invalid 'fdim' value in the device tree\n");
			err = ERR_PTR(-EINVAL);
			goto err;
		}
	}

	if (!of_property_read_u32(node, "default-brightness", &val)) {
		if (val > 100) {
			dev_err(&pdev->dev,
				"invalid 'default-brightness' value in the device tree\n");
			err = ERR_PTR(-EINVAL);
			goto err;
		}

		pdata->dft_brightness = val;
	}

	of_node_put(node);

	return pdata;

err:
	of_node_put(node);

	return err;
}
#else
static struct tps65217_bl_pdata *
tps65217_bl_parse_dt(struct platform_device *pdev)
{
	return NULL;
}
#endif

static int tps65217_bl_probe(struct platform_device *pdev)
{
	int rc;
	struct tps65217 *tps = dev_get_drvdata(pdev->dev.parent);
	struct tps65217_bl *tps65217_bl;
	struct tps65217_bl_pdata *pdata;
	struct backlight_properties bl_props;

	pdata = tps65217_bl_parse_dt(pdev);
	if (IS_ERR(pdata))
		return PTR_ERR(pdata);

	tps65217_bl = devm_kzalloc(&pdev->dev, sizeof(*tps65217_bl),
				GFP_KERNEL);
	if (tps65217_bl == NULL)
		return -ENOMEM;

	tps65217_bl->tps = tps;
	tps65217_bl->dev = &pdev->dev;
	tps65217_bl->is_enabled = false;

	rc = tps65217_bl_hw_init(tps65217_bl, pdata);
	if (rc)
		return rc;

	memset(&bl_props, 0, sizeof(struct backlight_properties));
	bl_props.type = BACKLIGHT_RAW;
	bl_props.max_brightness = 100;

	tps65217_bl->bl = devm_backlight_device_register(&pdev->dev, pdev->name,
						tps65217_bl->dev, tps65217_bl,
						&tps65217_bl_ops, &bl_props);
	if (IS_ERR(tps65217_bl->bl)) {
		dev_err(tps65217_bl->dev,
			"registration of backlight device failed: %d\n", rc);
		return PTR_ERR(tps65217_bl->bl);
	}

	tps65217_bl->bl->props.brightness = pdata->dft_brightness;
	backlight_update_status(tps65217_bl->bl);
	platform_set_drvdata(pdev, tps65217_bl);

	return 0;
}

#ifdef CONFIG_OF
static const struct of_device_id tps65217_bl_of_match[] = {
	{ .compatible = "ti,tps65217-bl", },
	{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, tps65217_bl_of_match);
#endif

static struct platform_driver tps65217_bl_driver = {
	.probe		= tps65217_bl_probe,
	.driver		= {
		.name	= "tps65217-bl",
		.of_match_table = of_match_ptr(tps65217_bl_of_match),
	},
};

module_platform_driver(tps65217_bl_driver);

MODULE_DESCRIPTION("TPS65217 Backlight driver");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Matthias Kaehlcke <matthias@kaehlcke.net>");