4 * TPS65217 backlight driver
6 * Copyright (C) 2012 Matthias Kaehlcke
7 * Author: Matthias Kaehlcke <matthias@kaehlcke.net>
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.
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.
19 #include <linux/kernel.h>
20 #include <linux/backlight.h>
21 #include <linux/err.h>
23 #include <linux/mfd/tps65217.h>
24 #include <linux/module.h>
25 #include <linux/platform_device.h>
26 #include <linux/slab.h>
31 struct backlight_device *bl;
35 static int tps65217_bl_enable(struct tps65217_bl *tps65217_bl)
39 rc = tps65217_set_bits(tps65217_bl->tps, TPS65217_REG_WLEDCTRL1,
40 TPS65217_WLEDCTRL1_ISINK_ENABLE,
41 TPS65217_WLEDCTRL1_ISINK_ENABLE, TPS65217_PROTECT_NONE);
43 dev_err(tps65217_bl->dev,
44 "failed to enable backlight: %d\n", rc);
48 tps65217_bl->is_enabled = true;
50 dev_dbg(tps65217_bl->dev, "backlight enabled\n");
55 static int tps65217_bl_disable(struct tps65217_bl *tps65217_bl)
59 rc = tps65217_clear_bits(tps65217_bl->tps,
60 TPS65217_REG_WLEDCTRL1,
61 TPS65217_WLEDCTRL1_ISINK_ENABLE,
62 TPS65217_PROTECT_NONE);
64 dev_err(tps65217_bl->dev,
65 "failed to disable backlight: %d\n", rc);
69 tps65217_bl->is_enabled = false;
71 dev_dbg(tps65217_bl->dev, "backlight disabled\n");
76 static int tps65217_bl_update_status(struct backlight_device *bl)
78 struct tps65217_bl *tps65217_bl = bl_get_data(bl);
80 int brightness = backlight_get_brightness(bl);
83 rc = tps65217_reg_write(tps65217_bl->tps,
84 TPS65217_REG_WLEDCTRL2,
86 TPS65217_PROTECT_NONE);
88 dev_err(tps65217_bl->dev,
89 "failed to set brightness level: %d\n", rc);
93 dev_dbg(tps65217_bl->dev, "brightness set to %d\n", brightness);
95 if (!tps65217_bl->is_enabled)
96 rc = tps65217_bl_enable(tps65217_bl);
98 rc = tps65217_bl_disable(tps65217_bl);
104 static const struct backlight_ops tps65217_bl_ops = {
105 .options = BL_CORE_SUSPENDRESUME,
106 .update_status = tps65217_bl_update_status,
109 static int tps65217_bl_hw_init(struct tps65217_bl *tps65217_bl,
110 struct tps65217_bl_pdata *pdata)
114 rc = tps65217_bl_disable(tps65217_bl);
118 switch (pdata->isel) {
119 case TPS65217_BL_ISET1:
120 /* select ISET_1 current level */
121 rc = tps65217_clear_bits(tps65217_bl->tps,
122 TPS65217_REG_WLEDCTRL1,
123 TPS65217_WLEDCTRL1_ISEL,
124 TPS65217_PROTECT_NONE);
126 dev_err(tps65217_bl->dev,
127 "failed to select ISET1 current level: %d)\n",
132 dev_dbg(tps65217_bl->dev, "selected ISET1 current level\n");
136 case TPS65217_BL_ISET2:
137 /* select ISET2 current level */
138 rc = tps65217_set_bits(tps65217_bl->tps, TPS65217_REG_WLEDCTRL1,
139 TPS65217_WLEDCTRL1_ISEL,
140 TPS65217_WLEDCTRL1_ISEL, TPS65217_PROTECT_NONE);
142 dev_err(tps65217_bl->dev,
143 "failed to select ISET2 current level: %d\n",
148 dev_dbg(tps65217_bl->dev, "selected ISET2 current level\n");
153 dev_err(tps65217_bl->dev,
154 "invalid value for current level: %d\n", pdata->isel);
158 /* set PWM frequency */
159 rc = tps65217_set_bits(tps65217_bl->tps,
160 TPS65217_REG_WLEDCTRL1,
161 TPS65217_WLEDCTRL1_FDIM_MASK,
163 TPS65217_PROTECT_NONE);
165 dev_err(tps65217_bl->dev,
166 "failed to select PWM dimming frequency: %d\n",
175 static struct tps65217_bl_pdata *
176 tps65217_bl_parse_dt(struct platform_device *pdev)
178 struct tps65217 *tps = dev_get_drvdata(pdev->dev.parent);
179 struct device_node *node;
180 struct tps65217_bl_pdata *pdata, *err;
183 node = of_get_child_by_name(tps->dev->of_node, "backlight");
185 return ERR_PTR(-ENODEV);
187 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
189 err = ERR_PTR(-ENOMEM);
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) {
198 "invalid 'isel' value in the device tree\n");
199 err = ERR_PTR(-EINVAL);
206 pdata->fdim = TPS65217_BL_FDIM_200HZ;
207 if (!of_property_read_u32(node, "fdim", &val)) {
210 pdata->fdim = TPS65217_BL_FDIM_100HZ;
214 pdata->fdim = TPS65217_BL_FDIM_200HZ;
218 pdata->fdim = TPS65217_BL_FDIM_500HZ;
222 pdata->fdim = TPS65217_BL_FDIM_1000HZ;
227 "invalid 'fdim' value in the device tree\n");
228 err = ERR_PTR(-EINVAL);
233 if (!of_property_read_u32(node, "default-brightness", &val)) {
236 "invalid 'default-brightness' value in the device tree\n");
237 err = ERR_PTR(-EINVAL);
241 pdata->dft_brightness = val;
254 static struct tps65217_bl_pdata *
255 tps65217_bl_parse_dt(struct platform_device *pdev)
261 static int tps65217_bl_probe(struct platform_device *pdev)
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;
269 pdata = tps65217_bl_parse_dt(pdev);
271 return PTR_ERR(pdata);
273 tps65217_bl = devm_kzalloc(&pdev->dev, sizeof(*tps65217_bl),
275 if (tps65217_bl == NULL)
278 tps65217_bl->tps = tps;
279 tps65217_bl->dev = &pdev->dev;
280 tps65217_bl->is_enabled = false;
282 rc = tps65217_bl_hw_init(tps65217_bl, pdata);
286 memset(&bl_props, 0, sizeof(struct backlight_properties));
287 bl_props.type = BACKLIGHT_RAW;
288 bl_props.max_brightness = 100;
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);
299 tps65217_bl->bl->props.brightness = pdata->dft_brightness;
300 backlight_update_status(tps65217_bl->bl);
301 platform_set_drvdata(pdev, tps65217_bl);
307 static const struct of_device_id tps65217_bl_of_match[] = {
308 { .compatible = "ti,tps65217-bl", },
311 MODULE_DEVICE_TABLE(of, tps65217_bl_of_match);
314 static struct platform_driver tps65217_bl_driver = {
315 .probe = tps65217_bl_probe,
317 .name = "tps65217-bl",
318 .of_match_table = of_match_ptr(tps65217_bl_of_match),
322 module_platform_driver(tps65217_bl_driver);
324 MODULE_DESCRIPTION("TPS65217 Backlight driver");
325 MODULE_LICENSE("GPL v2");
326 MODULE_AUTHOR("Matthias Kaehlcke <matthias@kaehlcke.net>");