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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 = backlight_get_brightness(bl);
81
82 if (brightness > 0) {
83 rc = tps65217_reg_write(tps65217_bl->tps,
84 TPS65217_REG_WLEDCTRL2,
85 brightness - 1,
86 TPS65217_PROTECT_NONE);
87 if (rc) {
88 dev_err(tps65217_bl->dev,
89 "failed to set brightness level: %d\n", rc);
90 return rc;
91 }
92
93 dev_dbg(tps65217_bl->dev, "brightness set to %d\n", brightness);
94
95 if (!tps65217_bl->is_enabled)
96 rc = tps65217_bl_enable(tps65217_bl);
97 } else {
98 rc = tps65217_bl_disable(tps65217_bl);
99 }
100
101 return rc;
102}
103
104static const struct backlight_ops tps65217_bl_ops = {
105 .options = BL_CORE_SUSPENDRESUME,
106 .update_status = tps65217_bl_update_status,
107};
108
109static int tps65217_bl_hw_init(struct tps65217_bl *tps65217_bl,
110 struct tps65217_bl_pdata *pdata)
111{
112 int rc;
113
114 rc = tps65217_bl_disable(tps65217_bl);
115 if (rc)
116 return rc;
117
118 switch (pdata->isel) {
119 case TPS65217_BL_ISET1:
120
121 rc = tps65217_clear_bits(tps65217_bl->tps,
122 TPS65217_REG_WLEDCTRL1,
123 TPS65217_WLEDCTRL1_ISEL,
124 TPS65217_PROTECT_NONE);
125 if (rc) {
126 dev_err(tps65217_bl->dev,
127 "failed to select ISET1 current level: %d)\n",
128 rc);
129 return rc;
130 }
131
132 dev_dbg(tps65217_bl->dev, "selected ISET1 current level\n");
133
134 break;
135
136 case TPS65217_BL_ISET2:
137
138 rc = tps65217_set_bits(tps65217_bl->tps, TPS65217_REG_WLEDCTRL1,
139 TPS65217_WLEDCTRL1_ISEL,
140 TPS65217_WLEDCTRL1_ISEL, TPS65217_PROTECT_NONE);
141 if (rc) {
142 dev_err(tps65217_bl->dev,
143 "failed to select ISET2 current level: %d\n",
144 rc);
145 return rc;
146 }
147
148 dev_dbg(tps65217_bl->dev, "selected ISET2 current level\n");
149
150 break;
151
152 default:
153 dev_err(tps65217_bl->dev,
154 "invalid value for current level: %d\n", pdata->isel);
155 return -EINVAL;
156 }
157
158
159 rc = tps65217_set_bits(tps65217_bl->tps,
160 TPS65217_REG_WLEDCTRL1,
161 TPS65217_WLEDCTRL1_FDIM_MASK,
162 pdata->fdim,
163 TPS65217_PROTECT_NONE);
164 if (rc) {
165 dev_err(tps65217_bl->dev,
166 "failed to select PWM dimming frequency: %d\n",
167 rc);
168 return rc;
169 }
170
171 return 0;
172}
173
174#ifdef CONFIG_OF
175static struct tps65217_bl_pdata *
176tps65217_bl_parse_dt(struct platform_device *pdev)
177{
178 struct tps65217 *tps = dev_get_drvdata(pdev->dev.parent);
179 struct device_node *node;
180 struct tps65217_bl_pdata *pdata, *err;
181 u32 val;
182
183 node = of_get_child_by_name(tps->dev->of_node, "backlight");
184 if (!node)
185 return ERR_PTR(-ENODEV);
186
187 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
188 if (!pdata) {
189 err = ERR_PTR(-ENOMEM);
190 goto err;
191 }
192
193 pdata->isel = TPS65217_BL_ISET1;
194 if (!of_property_read_u32(node, "isel", &val)) {
195 if (val < TPS65217_BL_ISET1 ||
196 val > TPS65217_BL_ISET2) {
197 dev_err(&pdev->dev,
198 "invalid 'isel' value in the device tree\n");
199 err = ERR_PTR(-EINVAL);
200 goto err;
201 }
202
203 pdata->isel = val;
204 }
205
206 pdata->fdim = TPS65217_BL_FDIM_200HZ;
207 if (!of_property_read_u32(node, "fdim", &val)) {
208 switch (val) {
209 case 100:
210 pdata->fdim = TPS65217_BL_FDIM_100HZ;
211 break;
212
213 case 200:
214 pdata->fdim = TPS65217_BL_FDIM_200HZ;
215 break;
216
217 case 500:
218 pdata->fdim = TPS65217_BL_FDIM_500HZ;
219 break;
220
221 case 1000:
222 pdata->fdim = TPS65217_BL_FDIM_1000HZ;
223 break;
224
225 default:
226 dev_err(&pdev->dev,
227 "invalid 'fdim' value in the device tree\n");
228 err = ERR_PTR(-EINVAL);
229 goto err;
230 }
231 }
232
233 if (!of_property_read_u32(node, "default-brightness", &val)) {
234 if (val > 100) {
235 dev_err(&pdev->dev,
236 "invalid 'default-brightness' value in the device tree\n");
237 err = ERR_PTR(-EINVAL);
238 goto err;
239 }
240
241 pdata->dft_brightness = val;
242 }
243
244 of_node_put(node);
245
246 return pdata;
247
248err:
249 of_node_put(node);
250
251 return err;
252}
253#else
254static struct tps65217_bl_pdata *
255tps65217_bl_parse_dt(struct platform_device *pdev)
256{
257 return NULL;
258}
259#endif
260
261static int tps65217_bl_probe(struct platform_device *pdev)
262{
263 int rc;
264 struct tps65217 *tps = dev_get_drvdata(pdev->dev.parent);
265 struct tps65217_bl *tps65217_bl;
266 struct tps65217_bl_pdata *pdata;
267 struct backlight_properties bl_props;
268
269 pdata = tps65217_bl_parse_dt(pdev);
270 if (IS_ERR(pdata))
271 return PTR_ERR(pdata);
272
273 tps65217_bl = devm_kzalloc(&pdev->dev, sizeof(*tps65217_bl),
274 GFP_KERNEL);
275 if (tps65217_bl == NULL)
276 return -ENOMEM;
277
278 tps65217_bl->tps = tps;
279 tps65217_bl->dev = &pdev->dev;
280 tps65217_bl->is_enabled = false;
281
282 rc = tps65217_bl_hw_init(tps65217_bl, pdata);
283 if (rc)
284 return rc;
285
286 memset(&bl_props, 0, sizeof(struct backlight_properties));
287 bl_props.type = BACKLIGHT_RAW;
288 bl_props.max_brightness = 100;
289
290 tps65217_bl->bl = devm_backlight_device_register(&pdev->dev, pdev->name,
291 tps65217_bl->dev, tps65217_bl,
292 &tps65217_bl_ops, &bl_props);
293 if (IS_ERR(tps65217_bl->bl)) {
294 dev_err(tps65217_bl->dev,
295 "registration of backlight device failed: %d\n", rc);
296 return PTR_ERR(tps65217_bl->bl);
297 }
298
299 tps65217_bl->bl->props.brightness = pdata->dft_brightness;
300 backlight_update_status(tps65217_bl->bl);
301 platform_set_drvdata(pdev, tps65217_bl);
302
303 return 0;
304}
305
306#ifdef CONFIG_OF
307static const struct of_device_id tps65217_bl_of_match[] = {
308 { .compatible = "ti,tps65217-bl", },
309 { },
310};
311MODULE_DEVICE_TABLE(of, tps65217_bl_of_match);
312#endif
313
314static struct platform_driver tps65217_bl_driver = {
315 .probe = tps65217_bl_probe,
316 .driver = {
317 .name = "tps65217-bl",
318 .of_match_table = of_match_ptr(tps65217_bl_of_match),
319 },
320};
321
322module_platform_driver(tps65217_bl_driver);
323
324MODULE_DESCRIPTION("TPS65217 Backlight driver");
325MODULE_LICENSE("GPL v2");
326MODULE_AUTHOR("Matthias Kaehlcke <matthias@kaehlcke.net>");
327
