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 = bl->props.brightness;
82 if (bl->props.state & BL_CORE_SUSPENDED)
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 */
91 rc = tps65217_reg_write(tps65217_bl->tps,
92 TPS65217_REG_WLEDCTRL2,
94 TPS65217_PROTECT_NONE);
96 dev_err(tps65217_bl->dev,
97 "failed to set brightness level: %d\n", rc);
101 dev_dbg(tps65217_bl->dev, "brightness set to %d\n", brightness);
103 if (!tps65217_bl->is_enabled)
104 rc = tps65217_bl_enable(tps65217_bl);
106 rc = tps65217_bl_disable(tps65217_bl);
112 static const struct backlight_ops tps65217_bl_ops = {
113 .options = BL_CORE_SUSPENDRESUME,
114 .update_status = tps65217_bl_update_status,
117 static int tps65217_bl_hw_init(struct tps65217_bl *tps65217_bl,
118 struct tps65217_bl_pdata *pdata)
122 rc = tps65217_bl_disable(tps65217_bl);
126 switch (pdata->isel) {
127 case TPS65217_BL_ISET1:
128 /* select ISET_1 current level */
129 rc = tps65217_clear_bits(tps65217_bl->tps,
130 TPS65217_REG_WLEDCTRL1,
131 TPS65217_WLEDCTRL1_ISEL,
132 TPS65217_PROTECT_NONE);
134 dev_err(tps65217_bl->dev,
135 "failed to select ISET1 current level: %d)\n",
140 dev_dbg(tps65217_bl->dev, "selected ISET1 current level\n");
144 case TPS65217_BL_ISET2:
145 /* select ISET2 current level */
146 rc = tps65217_set_bits(tps65217_bl->tps, TPS65217_REG_WLEDCTRL1,
147 TPS65217_WLEDCTRL1_ISEL,
148 TPS65217_WLEDCTRL1_ISEL, TPS65217_PROTECT_NONE);
150 dev_err(tps65217_bl->dev,
151 "failed to select ISET2 current level: %d\n",
156 dev_dbg(tps65217_bl->dev, "selected ISET2 current level\n");
161 dev_err(tps65217_bl->dev,
162 "invalid value for current level: %d\n", pdata->isel);
166 /* set PWM frequency */
167 rc = tps65217_set_bits(tps65217_bl->tps,
168 TPS65217_REG_WLEDCTRL1,
169 TPS65217_WLEDCTRL1_FDIM_MASK,
171 TPS65217_PROTECT_NONE);
173 dev_err(tps65217_bl->dev,
174 "failed to select PWM dimming frequency: %d\n",
183 static struct tps65217_bl_pdata *
184 tps65217_bl_parse_dt(struct platform_device *pdev)
186 struct tps65217 *tps = dev_get_drvdata(pdev->dev.parent);
187 struct device_node *node;
188 struct tps65217_bl_pdata *pdata, *err;
191 node = of_get_child_by_name(tps->dev->of_node, "backlight");
193 return ERR_PTR(-ENODEV);
195 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
197 err = ERR_PTR(-ENOMEM);
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) {
206 "invalid 'isel' value in the device tree\n");
207 err = ERR_PTR(-EINVAL);
214 pdata->fdim = TPS65217_BL_FDIM_200HZ;
215 if (!of_property_read_u32(node, "fdim", &val)) {
218 pdata->fdim = TPS65217_BL_FDIM_100HZ;
222 pdata->fdim = TPS65217_BL_FDIM_200HZ;
226 pdata->fdim = TPS65217_BL_FDIM_500HZ;
230 pdata->fdim = TPS65217_BL_FDIM_1000HZ;
235 "invalid 'fdim' value in the device tree\n");
236 err = ERR_PTR(-EINVAL);
241 if (!of_property_read_u32(node, "default-brightness", &val)) {
245 "invalid 'default-brightness' value in the device tree\n");
246 err = ERR_PTR(-EINVAL);
250 pdata->dft_brightness = val;
263 static struct tps65217_bl_pdata *
264 tps65217_bl_parse_dt(struct platform_device *pdev)
270 static int tps65217_bl_probe(struct platform_device *pdev)
273 struct tps65217 *tps = dev_get_drvdata(pdev->dev.parent);
274 struct tps65217_bl *tps65217_bl;
275 struct tps65217_bl_pdata *pdata;
276 struct backlight_properties bl_props;
278 if (tps->dev->of_node) {
279 pdata = tps65217_bl_parse_dt(pdev);
281 return PTR_ERR(pdata);
283 pdata = dev_get_platdata(&pdev->dev);
285 dev_err(&pdev->dev, "no platform data provided\n");
290 tps65217_bl = devm_kzalloc(&pdev->dev, sizeof(*tps65217_bl),
292 if (tps65217_bl == NULL)
295 tps65217_bl->tps = tps;
296 tps65217_bl->dev = &pdev->dev;
297 tps65217_bl->is_enabled = false;
299 rc = tps65217_bl_hw_init(tps65217_bl, pdata);
303 memset(&bl_props, 0, sizeof(struct backlight_properties));
304 bl_props.type = BACKLIGHT_RAW;
305 bl_props.max_brightness = 100;
307 tps65217_bl->bl = devm_backlight_device_register(&pdev->dev, pdev->name,
308 tps65217_bl->dev, tps65217_bl,
309 &tps65217_bl_ops, &bl_props);
310 if (IS_ERR(tps65217_bl->bl)) {
311 dev_err(tps65217_bl->dev,
312 "registration of backlight device failed: %d\n", rc);
313 return PTR_ERR(tps65217_bl->bl);
316 tps65217_bl->bl->props.brightness = pdata->dft_brightness;
317 backlight_update_status(tps65217_bl->bl);
318 platform_set_drvdata(pdev, tps65217_bl);
323 static struct platform_driver tps65217_bl_driver = {
324 .probe = tps65217_bl_probe,
326 .name = "tps65217-bl",
330 module_platform_driver(tps65217_bl_driver);
332 MODULE_DESCRIPTION("TPS65217 Backlight driver");
333 MODULE_LICENSE("GPL v2");
334 MODULE_AUTHOR("Matthias Kaehlcke <matthias@kaehlcke.net>");