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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
28struct tps65217_bl {
29 struct tps65217 *tps;
30 struct device *dev;
31 struct backlight_device *bl;
32 bool is_enabled;
33};
34
35static 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
55static 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
76static 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
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
112static const struct backlight_ops tps65217_bl_ops = {
113 .options = BL_CORE_SUSPENDRESUME,
114 .update_status = tps65217_bl_update_status,
115};
116
117static int tps65217_bl_hw_init(struct tps65217_bl *tps65217_bl,
118 struct tps65217_bl_pdata *pdata)
119{
120 int rc;
121
122 rc = tps65217_bl_disable(tps65217_bl);
123 if (rc)
124 return rc;
125
126 switch (pdata->isel) {
127 case TPS65217_BL_ISET1:
128
129 rc = tps65217_clear_bits(tps65217_bl->tps,
130 TPS65217_REG_WLEDCTRL1,
131 TPS65217_WLEDCTRL1_ISEL,
132 TPS65217_PROTECT_NONE);
133 if (rc) {
134 dev_err(tps65217_bl->dev,
135 "failed to select ISET1 current level: %d)\n",
136 rc);
137 return rc;
138 }
139
140 dev_dbg(tps65217_bl->dev, "selected ISET1 current level\n");
141
142 break;
143
144 case TPS65217_BL_ISET2:
145
146 rc = tps65217_set_bits(tps65217_bl->tps, TPS65217_REG_WLEDCTRL1,
147 TPS65217_WLEDCTRL1_ISEL,
148 TPS65217_WLEDCTRL1_ISEL, TPS65217_PROTECT_NONE);
149 if (rc) {
150 dev_err(tps65217_bl->dev,
151 "failed to select ISET2 current level: %d\n",
152 rc);
153 return rc;
154 }
155
156 dev_dbg(tps65217_bl->dev, "selected ISET2 current level\n");
157
158 break;
159
160 default:
161 dev_err(tps65217_bl->dev,
162 "invalid value for current level: %d\n", pdata->isel);
163 return -EINVAL;
164 }
165
166
167 rc = tps65217_set_bits(tps65217_bl->tps,
168 TPS65217_REG_WLEDCTRL1,
169 TPS65217_WLEDCTRL1_FDIM_MASK,
170 pdata->fdim,
171 TPS65217_PROTECT_NONE);
172 if (rc) {
173 dev_err(tps65217_bl->dev,
174 "failed to select PWM dimming frequency: %d\n",
175 rc);
176 return rc;
177 }
178
179 return 0;
180}
181
182#ifdef CONFIG_OF
183static struct tps65217_bl_pdata *
184tps65217_bl_parse_dt(struct platform_device *pdev)
185{
186 struct tps65217 *tps = dev_get_drvdata(pdev->dev.parent);
187 struct device_node *node;
188 struct tps65217_bl_pdata *pdata, *err;
189 u32 val;
190
191 node = of_get_child_by_name(tps->dev->of_node, "backlight");
192 if (!node)
193 return ERR_PTR(-ENODEV);
194
195 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
196 if (!pdata) {
197 err = ERR_PTR(-ENOMEM);
198 goto err;
199 }
200
201 pdata->isel = TPS65217_BL_ISET1;
202 if (!of_property_read_u32(node, "isel", &val)) {
203 if (val < TPS65217_BL_ISET1 ||
204 val > TPS65217_BL_ISET2) {
205 dev_err(&pdev->dev,
206 "invalid 'isel' value in the device tree\n");
207 err = ERR_PTR(-EINVAL);
208 goto err;
209 }
210
211 pdata->isel = val;
212 }
213
214 pdata->fdim = TPS65217_BL_FDIM_200HZ;
215 if (!of_property_read_u32(node, "fdim", &val)) {
216 switch (val) {
217 case 100:
218 pdata->fdim = TPS65217_BL_FDIM_100HZ;
219 break;
220
221 case 200:
222 pdata->fdim = TPS65217_BL_FDIM_200HZ;
223 break;
224
225 case 500:
226 pdata->fdim = TPS65217_BL_FDIM_500HZ;
227 break;
228
229 case 1000:
230 pdata->fdim = TPS65217_BL_FDIM_1000HZ;
231 break;
232
233 default:
234 dev_err(&pdev->dev,
235 "invalid 'fdim' value in the device tree\n");
236 err = ERR_PTR(-EINVAL);
237 goto err;
238 }
239 }
240
241 if (!of_property_read_u32(node, "default-brightness", &val)) {
242 if (val > 100) {
243 dev_err(&pdev->dev,
244 "invalid 'default-brightness' value in the device tree\n");
245 err = ERR_PTR(-EINVAL);
246 goto err;
247 }
248
249 pdata->dft_brightness = val;
250 }
251
252 of_node_put(node);
253
254 return pdata;
255
256err:
257 of_node_put(node);
258
259 return err;
260}
261#else
262static struct tps65217_bl_pdata *
263tps65217_bl_parse_dt(struct platform_device *pdev)
264{
265 return NULL;
266}
267#endif
268
269static int tps65217_bl_probe(struct platform_device *pdev)
270{
271 int rc;
272 struct tps65217 *tps = dev_get_drvdata(pdev->dev.parent);
273 struct tps65217_bl *tps65217_bl;
274 struct tps65217_bl_pdata *pdata;
275 struct backlight_properties bl_props;
276
277 pdata = tps65217_bl_parse_dt(pdev);
278 if (IS_ERR(pdata))
279 return PTR_ERR(pdata);
280
281 tps65217_bl = devm_kzalloc(&pdev->dev, sizeof(*tps65217_bl),
282 GFP_KERNEL);
283 if (tps65217_bl == NULL)
284 return -ENOMEM;
285
286 tps65217_bl->tps = tps;
287 tps65217_bl->dev = &pdev->dev;
288 tps65217_bl->is_enabled = false;
289
290 rc = tps65217_bl_hw_init(tps65217_bl, pdata);
291 if (rc)
292 return rc;
293
294 memset(&bl_props, 0, sizeof(struct backlight_properties));
295 bl_props.type = BACKLIGHT_RAW;
296 bl_props.max_brightness = 100;
297
298 tps65217_bl->bl = devm_backlight_device_register(&pdev->dev, pdev->name,
299 tps65217_bl->dev, tps65217_bl,
300 &tps65217_bl_ops, &bl_props);
301 if (IS_ERR(tps65217_bl->bl)) {
302 dev_err(tps65217_bl->dev,
303 "registration of backlight device failed: %d\n", rc);
304 return PTR_ERR(tps65217_bl->bl);
305 }
306
307 tps65217_bl->bl->props.brightness = pdata->dft_brightness;
308 backlight_update_status(tps65217_bl->bl);
309 platform_set_drvdata(pdev, tps65217_bl);
310
311 return 0;
312}
313
314#ifdef CONFIG_OF
315static const struct of_device_id tps65217_bl_of_match[] = {
316 { .compatible = "ti,tps65217-bl", },
317 { },
318};
319MODULE_DEVICE_TABLE(of, tps65217_bl_of_match);
320#endif
321
322static struct platform_driver tps65217_bl_driver = {
323 .probe = tps65217_bl_probe,
324 .driver = {
325 .name = "tps65217-bl",
326 .of_match_table = of_match_ptr(tps65217_bl_of_match),
327 },
328};
329
330module_platform_driver(tps65217_bl_driver);
331
332MODULE_DESCRIPTION("TPS65217 Backlight driver");
333MODULE_LICENSE("GPL v2");
334MODULE_AUTHOR("Matthias Kaehlcke <matthias@kaehlcke.net>");
335
