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eebfdc17 MK |
1 | /* |
2 | * tps65217_bl.c | |
3 | * | |
4 | * TPS65217 backlight driver | |
5 | * | |
6 | * Copyright (C) 2012 Matthias Kaehlcke | |
7 | * Author: Matthias Kaehlcke <matthias@kaehlcke.net> | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or | |
10 | * modify it under the terms of the GNU General Public License as | |
11 | * published by the Free Software Foundation version 2. | |
12 | * | |
13 | * This program is distributed "as is" WITHOUT ANY WARRANTY of any | |
14 | * kind, whether express or implied; without even the implied warranty | |
15 | * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | * GNU General Public License for more details. | |
17 | */ | |
18 | ||
19 | #include <linux/kernel.h> | |
20 | #include <linux/backlight.h> | |
21 | #include <linux/err.h> | |
22 | #include <linux/fb.h> | |
23 | #include <linux/mfd/tps65217.h> | |
24 | #include <linux/module.h> | |
25 | #include <linux/platform_device.h> | |
26 | #include <linux/slab.h> | |
27 | ||
28 | struct tps65217_bl { | |
29 | struct tps65217 *tps; | |
30 | struct device *dev; | |
31 | struct backlight_device *bl; | |
32 | bool is_enabled; | |
33 | }; | |
34 | ||
35 | static int tps65217_bl_enable(struct tps65217_bl *tps65217_bl) | |
36 | { | |
37 | int rc; | |
38 | ||
39 | rc = tps65217_set_bits(tps65217_bl->tps, TPS65217_REG_WLEDCTRL1, | |
40 | TPS65217_WLEDCTRL1_ISINK_ENABLE, | |
41 | TPS65217_WLEDCTRL1_ISINK_ENABLE, TPS65217_PROTECT_NONE); | |
42 | if (rc) { | |
43 | dev_err(tps65217_bl->dev, | |
44 | "failed to enable backlight: %d\n", rc); | |
45 | return rc; | |
46 | } | |
47 | ||
48 | tps65217_bl->is_enabled = true; | |
49 | ||
50 | dev_dbg(tps65217_bl->dev, "backlight enabled\n"); | |
51 | ||
52 | return 0; | |
53 | } | |
54 | ||
55 | static int tps65217_bl_disable(struct tps65217_bl *tps65217_bl) | |
56 | { | |
57 | int rc; | |
58 | ||
59 | rc = tps65217_clear_bits(tps65217_bl->tps, | |
60 | TPS65217_REG_WLEDCTRL1, | |
61 | TPS65217_WLEDCTRL1_ISINK_ENABLE, | |
62 | TPS65217_PROTECT_NONE); | |
63 | if (rc) { | |
64 | dev_err(tps65217_bl->dev, | |
65 | "failed to disable backlight: %d\n", rc); | |
66 | return rc; | |
67 | } | |
68 | ||
69 | tps65217_bl->is_enabled = false; | |
70 | ||
71 | dev_dbg(tps65217_bl->dev, "backlight disabled\n"); | |
72 | ||
73 | return 0; | |
74 | } | |
75 | ||
76 | static int tps65217_bl_update_status(struct backlight_device *bl) | |
77 | { | |
78 | struct tps65217_bl *tps65217_bl = bl_get_data(bl); | |
79 | int rc; | |
80 | int brightness = bl->props.brightness; | |
81 | ||
82 | if (bl->props.state & BL_CORE_SUSPENDED) | |
83 | brightness = 0; | |
84 | ||
85 | if ((bl->props.power != FB_BLANK_UNBLANK) || | |
86 | (bl->props.fb_blank != FB_BLANK_UNBLANK)) | |
87 | /* framebuffer in low power mode or blanking active */ | |
88 | brightness = 0; | |
89 | ||
90 | if (brightness > 0) { | |
91 | rc = tps65217_reg_write(tps65217_bl->tps, | |
92 | TPS65217_REG_WLEDCTRL2, | |
93 | brightness - 1, | |
94 | TPS65217_PROTECT_NONE); | |
95 | if (rc) { | |
96 | dev_err(tps65217_bl->dev, | |
97 | "failed to set brightness level: %d\n", rc); | |
98 | return rc; | |
99 | } | |
100 | ||
101 | dev_dbg(tps65217_bl->dev, "brightness set to %d\n", brightness); | |
102 | ||
103 | if (!tps65217_bl->is_enabled) | |
104 | rc = tps65217_bl_enable(tps65217_bl); | |
105 | } else { | |
106 | rc = tps65217_bl_disable(tps65217_bl); | |
107 | } | |
108 | ||
109 | return rc; | |
110 | } | |
111 | ||
112 | static int tps65217_bl_get_brightness(struct backlight_device *bl) | |
113 | { | |
114 | return bl->props.brightness; | |
115 | } | |
116 | ||
117 | static const struct backlight_ops tps65217_bl_ops = { | |
118 | .options = BL_CORE_SUSPENDRESUME, | |
119 | .update_status = tps65217_bl_update_status, | |
120 | .get_brightness = tps65217_bl_get_brightness | |
121 | }; | |
122 | ||
123 | static int tps65217_bl_hw_init(struct tps65217_bl *tps65217_bl, | |
124 | struct tps65217_bl_pdata *pdata) | |
125 | { | |
126 | int rc; | |
127 | ||
128 | rc = tps65217_bl_disable(tps65217_bl); | |
129 | if (rc) | |
130 | return rc; | |
131 | ||
132 | switch (pdata->isel) { | |
133 | case TPS65217_BL_ISET1: | |
134 | /* select ISET_1 current level */ | |
135 | rc = tps65217_clear_bits(tps65217_bl->tps, | |
136 | TPS65217_REG_WLEDCTRL1, | |
137 | TPS65217_WLEDCTRL1_ISEL, | |
138 | TPS65217_PROTECT_NONE); | |
139 | if (rc) { | |
140 | dev_err(tps65217_bl->dev, | |
141 | "failed to select ISET1 current level: %d)\n", | |
142 | rc); | |
143 | return rc; | |
144 | } | |
145 | ||
146 | dev_dbg(tps65217_bl->dev, "selected ISET1 current level\n"); | |
147 | ||
148 | break; | |
149 | ||
150 | case TPS65217_BL_ISET2: | |
151 | /* select ISET2 current level */ | |
152 | rc = tps65217_set_bits(tps65217_bl->tps, TPS65217_REG_WLEDCTRL1, | |
153 | TPS65217_WLEDCTRL1_ISEL, | |
154 | TPS65217_WLEDCTRL1_ISEL, TPS65217_PROTECT_NONE); | |
155 | if (rc) { | |
156 | dev_err(tps65217_bl->dev, | |
157 | "failed to select ISET2 current level: %d\n", | |
158 | rc); | |
159 | return rc; | |
160 | } | |
161 | ||
162 | dev_dbg(tps65217_bl->dev, "selected ISET2 current level\n"); | |
163 | ||
164 | break; | |
165 | ||
166 | default: | |
167 | dev_err(tps65217_bl->dev, | |
168 | "invalid value for current level: %d\n", pdata->isel); | |
169 | return -EINVAL; | |
170 | } | |
171 | ||
172 | /* set PWM frequency */ | |
173 | rc = tps65217_set_bits(tps65217_bl->tps, | |
174 | TPS65217_REG_WLEDCTRL1, | |
175 | TPS65217_WLEDCTRL1_FDIM_MASK, | |
176 | pdata->fdim, | |
177 | TPS65217_PROTECT_NONE); | |
178 | if (rc) { | |
179 | dev_err(tps65217_bl->dev, | |
180 | "failed to select PWM dimming frequency: %d\n", | |
181 | rc); | |
182 | return rc; | |
183 | } | |
184 | ||
185 | return 0; | |
186 | } | |
187 | ||
188 | #ifdef CONFIG_OF | |
189 | static struct tps65217_bl_pdata * | |
190 | tps65217_bl_parse_dt(struct platform_device *pdev) | |
191 | { | |
192 | struct tps65217 *tps = dev_get_drvdata(pdev->dev.parent); | |
193 | struct device_node *node = of_node_get(tps->dev->of_node); | |
194 | struct tps65217_bl_pdata *pdata, *err; | |
195 | u32 val; | |
196 | ||
197 | node = of_find_node_by_name(node, "backlight"); | |
198 | if (!node) | |
199 | return ERR_PTR(-ENODEV); | |
200 | ||
201 | pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL); | |
202 | if (!pdata) { | |
203 | dev_err(&pdev->dev, "failed to allocate platform data\n"); | |
204 | err = ERR_PTR(-ENOMEM); | |
205 | goto err; | |
206 | } | |
207 | ||
208 | pdata->isel = TPS65217_BL_ISET1; | |
209 | if (!of_property_read_u32(node, "isel", &val)) { | |
210 | if (val < TPS65217_BL_ISET1 || | |
211 | val > TPS65217_BL_ISET2) { | |
212 | dev_err(&pdev->dev, | |
213 | "invalid 'isel' value in the device tree\n"); | |
214 | err = ERR_PTR(-EINVAL); | |
215 | goto err; | |
216 | } | |
217 | ||
218 | pdata->isel = val; | |
219 | } | |
220 | ||
221 | pdata->fdim = TPS65217_BL_FDIM_200HZ; | |
222 | if (!of_property_read_u32(node, "fdim", &val)) { | |
223 | switch (val) { | |
224 | case 100: | |
225 | pdata->fdim = TPS65217_BL_FDIM_100HZ; | |
226 | break; | |
227 | ||
228 | case 200: | |
229 | pdata->fdim = TPS65217_BL_FDIM_200HZ; | |
230 | break; | |
231 | ||
232 | case 500: | |
233 | pdata->fdim = TPS65217_BL_FDIM_500HZ; | |
234 | break; | |
235 | ||
236 | case 1000: | |
237 | pdata->fdim = TPS65217_BL_FDIM_1000HZ; | |
238 | break; | |
239 | ||
240 | default: | |
241 | dev_err(&pdev->dev, | |
242 | "invalid 'fdim' value in the device tree\n"); | |
243 | err = ERR_PTR(-EINVAL); | |
244 | goto err; | |
245 | } | |
246 | } | |
247 | ||
4d22f8c3 MU |
248 | if (!of_property_read_u32(node, "default-brightness", &val)) { |
249 | if (val < 0 || | |
250 | val > 100) { | |
251 | dev_err(&pdev->dev, | |
252 | "invalid 'default-brightness' value in the device tree\n"); | |
253 | err = ERR_PTR(-EINVAL); | |
254 | goto err; | |
255 | } | |
256 | ||
257 | pdata->dft_brightness = val; | |
258 | } | |
259 | ||
eebfdc17 MK |
260 | of_node_put(node); |
261 | ||
262 | return pdata; | |
263 | ||
264 | err: | |
265 | of_node_put(node); | |
266 | ||
267 | return err; | |
268 | } | |
269 | #else | |
270 | static struct tps65217_bl_pdata * | |
271 | tps65217_bl_parse_dt(struct platform_device *pdev) | |
272 | { | |
273 | return NULL; | |
274 | } | |
275 | #endif | |
276 | ||
277 | static int tps65217_bl_probe(struct platform_device *pdev) | |
278 | { | |
279 | int rc; | |
280 | struct tps65217 *tps = dev_get_drvdata(pdev->dev.parent); | |
281 | struct tps65217_bl *tps65217_bl; | |
282 | struct tps65217_bl_pdata *pdata; | |
283 | struct backlight_properties bl_props; | |
284 | ||
285 | if (tps->dev->of_node) { | |
286 | pdata = tps65217_bl_parse_dt(pdev); | |
287 | if (IS_ERR(pdata)) | |
288 | return PTR_ERR(pdata); | |
289 | } else { | |
290 | if (!pdev->dev.platform_data) { | |
291 | dev_err(&pdev->dev, "no platform data provided\n"); | |
292 | return -EINVAL; | |
293 | } | |
294 | ||
295 | pdata = pdev->dev.platform_data; | |
296 | } | |
297 | ||
298 | tps65217_bl = devm_kzalloc(&pdev->dev, sizeof(*tps65217_bl), | |
299 | GFP_KERNEL); | |
300 | if (tps65217_bl == NULL) { | |
301 | dev_err(&pdev->dev, "allocation of struct tps65217_bl failed\n"); | |
302 | return -ENOMEM; | |
303 | } | |
304 | ||
305 | tps65217_bl->tps = tps; | |
306 | tps65217_bl->dev = &pdev->dev; | |
307 | tps65217_bl->is_enabled = false; | |
308 | ||
309 | rc = tps65217_bl_hw_init(tps65217_bl, pdata); | |
310 | if (rc) | |
311 | return rc; | |
312 | ||
313 | memset(&bl_props, 0, sizeof(struct backlight_properties)); | |
314 | bl_props.type = BACKLIGHT_RAW; | |
315 | bl_props.max_brightness = 100; | |
316 | ||
317 | tps65217_bl->bl = backlight_device_register(pdev->name, | |
318 | tps65217_bl->dev, tps65217_bl, | |
319 | &tps65217_bl_ops, &bl_props); | |
320 | if (IS_ERR(tps65217_bl->bl)) { | |
321 | dev_err(tps65217_bl->dev, | |
322 | "registration of backlight device failed: %d\n", rc); | |
323 | return PTR_ERR(tps65217_bl->bl); | |
324 | } | |
325 | ||
4d22f8c3 MU |
326 | tps65217_bl->bl->props.brightness = pdata->dft_brightness; |
327 | backlight_update_status(tps65217_bl->bl); | |
c6bed9de | 328 | platform_set_drvdata(pdev, tps65217_bl); |
eebfdc17 MK |
329 | |
330 | return 0; | |
331 | } | |
332 | ||
333 | static int tps65217_bl_remove(struct platform_device *pdev) | |
334 | { | |
335 | struct tps65217_bl *tps65217_bl = platform_get_drvdata(pdev); | |
336 | ||
337 | backlight_device_unregister(tps65217_bl->bl); | |
338 | ||
339 | return 0; | |
340 | } | |
341 | ||
342 | static struct platform_driver tps65217_bl_driver = { | |
343 | .probe = tps65217_bl_probe, | |
344 | .remove = tps65217_bl_remove, | |
345 | .driver = { | |
346 | .owner = THIS_MODULE, | |
347 | .name = "tps65217-bl", | |
348 | }, | |
349 | }; | |
350 | ||
c6bed9de | 351 | module_platform_driver(tps65217_bl_driver); |
eebfdc17 MK |
352 | |
353 | MODULE_DESCRIPTION("TPS65217 Backlight driver"); | |
354 | MODULE_LICENSE("GPL v2"); | |
355 | MODULE_AUTHOR("Matthias Kaehlcke <matthias@kaehlcke.net>"); |