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 int tps65217_bl_get_brightness(struct backlight_device *bl)
114 return bl->props.brightness;
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
123 static int tps65217_bl_hw_init(struct tps65217_bl *tps65217_bl,
124 struct tps65217_bl_pdata *pdata)
128 rc = tps65217_bl_disable(tps65217_bl);
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);
140 dev_err(tps65217_bl->dev,
141 "failed to select ISET1 current level: %d)\n",
146 dev_dbg(tps65217_bl->dev, "selected ISET1 current level\n");
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);
156 dev_err(tps65217_bl->dev,
157 "failed to select ISET2 current level: %d\n",
162 dev_dbg(tps65217_bl->dev, "selected ISET2 current level\n");
167 dev_err(tps65217_bl->dev,
168 "invalid value for current level: %d\n", pdata->isel);
172 /* set PWM frequency */
173 rc = tps65217_set_bits(tps65217_bl->tps,
174 TPS65217_REG_WLEDCTRL1,
175 TPS65217_WLEDCTRL1_FDIM_MASK,
177 TPS65217_PROTECT_NONE);
179 dev_err(tps65217_bl->dev,
180 "failed to select PWM dimming frequency: %d\n",
189 static struct tps65217_bl_pdata *
190 tps65217_bl_parse_dt(struct platform_device *pdev)
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;
197 node = of_find_node_by_name(node, "backlight");
199 return ERR_PTR(-ENODEV);
201 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
203 dev_err(&pdev->dev, "failed to allocate platform data\n");
204 err = ERR_PTR(-ENOMEM);
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) {
213 "invalid 'isel' value in the device tree\n");
214 err = ERR_PTR(-EINVAL);
221 pdata->fdim = TPS65217_BL_FDIM_200HZ;
222 if (!of_property_read_u32(node, "fdim", &val)) {
225 pdata->fdim = TPS65217_BL_FDIM_100HZ;
229 pdata->fdim = TPS65217_BL_FDIM_200HZ;
233 pdata->fdim = TPS65217_BL_FDIM_500HZ;
237 pdata->fdim = TPS65217_BL_FDIM_1000HZ;
242 "invalid 'fdim' value in the device tree\n");
243 err = ERR_PTR(-EINVAL);
258 static struct tps65217_bl_pdata *
259 tps65217_bl_parse_dt(struct platform_device *pdev)
265 static int tps65217_bl_probe(struct platform_device *pdev)
268 struct tps65217 *tps = dev_get_drvdata(pdev->dev.parent);
269 struct tps65217_bl *tps65217_bl;
270 struct tps65217_bl_pdata *pdata;
271 struct backlight_properties bl_props;
273 if (tps->dev->of_node) {
274 pdata = tps65217_bl_parse_dt(pdev);
276 return PTR_ERR(pdata);
278 if (!pdev->dev.platform_data) {
279 dev_err(&pdev->dev, "no platform data provided\n");
283 pdata = pdev->dev.platform_data;
286 tps65217_bl = devm_kzalloc(&pdev->dev, sizeof(*tps65217_bl),
288 if (tps65217_bl == NULL) {
289 dev_err(&pdev->dev, "allocation of struct tps65217_bl failed\n");
293 tps65217_bl->tps = tps;
294 tps65217_bl->dev = &pdev->dev;
295 tps65217_bl->is_enabled = false;
297 rc = tps65217_bl_hw_init(tps65217_bl, pdata);
301 memset(&bl_props, 0, sizeof(struct backlight_properties));
302 bl_props.type = BACKLIGHT_RAW;
303 bl_props.max_brightness = 100;
305 tps65217_bl->bl = backlight_device_register(pdev->name,
306 tps65217_bl->dev, tps65217_bl,
307 &tps65217_bl_ops, &bl_props);
308 if (IS_ERR(tps65217_bl->bl)) {
309 dev_err(tps65217_bl->dev,
310 "registration of backlight device failed: %d\n", rc);
311 return PTR_ERR(tps65217_bl->bl);
314 tps65217_bl->bl->props.brightness = 0;
315 platform_set_drvdata(pdev, tps65217_bl);
320 static int tps65217_bl_remove(struct platform_device *pdev)
322 struct tps65217_bl *tps65217_bl = platform_get_drvdata(pdev);
324 backlight_device_unregister(tps65217_bl->bl);
329 static struct platform_driver tps65217_bl_driver = {
330 .probe = tps65217_bl_probe,
331 .remove = tps65217_bl_remove,
333 .owner = THIS_MODULE,
334 .name = "tps65217-bl",
338 module_platform_driver(tps65217_bl_driver);
340 MODULE_DESCRIPTION("TPS65217 Backlight driver");
341 MODULE_LICENSE("GPL v2");
342 MODULE_AUTHOR("Matthias Kaehlcke <matthias@kaehlcke.net>");