1 /* drivers/video/backlight/rk29_backlight.c
3 * Copyright (C) 2009-2011 Rockchip Corporation.
5 * This software is licensed under the terms of the GNU General Public
6 * License version 2, as published by the Free Software Foundation, and
7 * may be copied, distributed, and modified under those terms.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
16 #include <linux/init.h>
17 #include <linux/module.h>
18 #include <linux/kernel.h>
19 #include <linux/err.h>
20 #include <linux/delay.h>
21 #include <linux/platform_device.h>
22 #include <linux/backlight.h>
24 #include <linux/clk.h>
26 #include <linux/earlysuspend.h>
28 #include <mach/board.h>
30 #include "rk2818_backlight.h"
36 #define DBG(x...) printk(KERN_INFO x)
41 #if defined(CONFIG_ARCH_RK30) || defined(CONFIG_ARCH_RK31)
42 #define write_pwm_reg(id, addr, val) __raw_writel(val, addr+(RK30_PWM01_BASE+(id>>1)*0x20000)+id*0x10)
43 #define read_pwm_reg(id, addr) __raw_readl(addr+(RK30_PWM01_BASE+(id>>1)*0x20000+id*0x10))
45 #elif defined(CONFIG_ARCH_RK2928)
46 #define write_pwm_reg(id, addr, val) __raw_writel(val, addr+(RK2928_PWM_BASE+id*0x10))
47 #define read_pwm_reg(id, addr) __raw_readl(addr+(RK2928_PWM_BASE+id*0x10))
49 #elif defined(CONFIG_ARCH_RK29)
50 #define write_pwm_reg(id, addr, val) __raw_writel(val, addr+(RK29_PWM_BASE+id*0x10))
51 #define read_pwm_reg(id, addr) __raw_readl(addr+(RK29_PWM_BASE+id*0x10))
54 static struct clk *pwm_clk;
55 static struct backlight_device *rk29_bl;
56 static int suspend_flag = 0;
59 int convertint(char s[])
63 for (i = 0; s[i] >= '0' && s[i] <= '9'; ++i)
65 n = 10 * n + (s[i] - '0');
70 static ssize_t backlight_write(struct device *dev,
71 struct device_attribute *attr, char *buf)
74 struct rk29_bl_info *rk29_bl_info = bl_get_data(rk29_bl);
77 number = convertint(buf);
79 rk29_bl_info->min_brightness=number;
84 static ssize_t backlight_read(struct device *dev,
85 struct device_attribute *attr, char *buf)
87 struct rk29_bl_info *rk29_bl_info = bl_get_data(rk29_bl);
89 DBG("rk29_bl_info->min_brightness=%d\n",rk29_bl_info->min_brightness);
91 static DEVICE_ATTR(rk29backlight, 0660, backlight_read, backlight_write);
93 static int rk29_bl_update_status(struct backlight_device *bl)
96 struct rk29_bl_info *rk29_bl_info = bl_get_data(bl);
97 u32 id = rk29_bl_info->pwm_id;
98 u32 ref = rk29_bl_info->bl_ref;
103 if (bl->props.brightness < rk29_bl_info->min_brightness) /*avoid can't view screen when close backlight*/
104 bl->props.brightness = rk29_bl_info->min_brightness;
106 div_total = read_pwm_reg(id, PWM_REG_LRC);
108 divh = div_total*(bl->props.brightness)/BL_STEP;
110 divh = div_total*(BL_STEP-bl->props.brightness)/BL_STEP;
112 write_pwm_reg(id, PWM_REG_HRC, divh);
114 DBG(">>>%s-->%d brightness = %d, div_total = %d, divh = %d\n",__FUNCTION__,__LINE__,bl->props.brightness, div_total, divh);
118 static int rk29_bl_get_brightness(struct backlight_device *bl)
121 struct rk29_bl_info *rk29_bl_info = bl_get_data(bl);
122 u32 id = rk29_bl_info->pwm_id;
123 u32 ref = rk29_bl_info->bl_ref;
125 div_total = read_pwm_reg(id, PWM_REG_LRC);
126 divh = read_pwm_reg(id, PWM_REG_HRC);
132 return BL_STEP*divh/div_total;
134 return BL_STEP-(BL_STEP*divh/div_total);
138 static struct backlight_ops rk29_bl_ops = {
139 .update_status = rk29_bl_update_status,
140 .get_brightness = rk29_bl_get_brightness,
143 static void rk29_backlight_work_func(struct work_struct *work)
146 rk29_bl_update_status(rk29_bl);
148 static DECLARE_DELAYED_WORK(rk29_backlight_work, rk29_backlight_work_func);
150 #ifdef CONFIG_HAS_EARLYSUSPEND
151 static void rk29_bl_suspend(struct early_suspend *h)
153 struct rk29_bl_info *rk29_bl_info = bl_get_data(rk29_bl);
154 int brightness = rk29_bl->props.brightness;
156 cancel_delayed_work_sync(&rk29_backlight_work);
158 if (rk29_bl->props.brightness) {
159 rk29_bl->props.brightness = 0;
160 rk29_bl_update_status(rk29_bl);
161 rk29_bl->props.brightness = brightness;
165 clk_disable(pwm_clk);
166 if (rk29_bl_info->pwm_suspend)
167 rk29_bl_info->pwm_suspend();
173 static void rk29_bl_resume(struct early_suspend *h)
175 struct rk29_bl_info *rk29_bl_info = bl_get_data(rk29_bl);
176 DBG("%s : %s\n", __FILE__, __FUNCTION__);
178 if (rk29_bl_info->pwm_resume)
179 rk29_bl_info->pwm_resume();
183 schedule_delayed_work(&rk29_backlight_work, msecs_to_jiffies(rk29_bl_info->delay_ms));
186 static struct early_suspend bl_early_suspend = {
187 .suspend = rk29_bl_suspend,
188 .resume = rk29_bl_resume,
189 .level = EARLY_SUSPEND_LEVEL_BLANK_SCREEN - 1,
192 void rk29_backlight_set(bool on)
194 printk("%s: set %d\n", __func__, on);
196 rk29_bl_resume(NULL);
198 rk29_bl_suspend(NULL);
201 EXPORT_SYMBOL(rk29_backlight_set);
204 static int rk29_backlight_probe(struct platform_device *pdev)
207 struct rk29_bl_info *rk29_bl_info = pdev->dev.platform_data;
208 u32 id = rk29_bl_info->pwm_id;
210 unsigned long pwm_clk_rate;
211 struct backlight_properties props;
214 printk(KERN_CRIT "%s: backlight device register has existed \n",
219 if (!rk29_bl_info->delay_ms)
220 rk29_bl_info->delay_ms = 100;
222 if (rk29_bl_info->min_brightness < 0 || rk29_bl_info->min_brightness > BL_STEP)
223 rk29_bl_info->min_brightness = 52;
225 if (rk29_bl_info && rk29_bl_info->io_init) {
226 rk29_bl_info->io_init();
229 memset(&props, 0, sizeof(struct backlight_properties));
230 props.type = BACKLIGHT_RAW;
231 props.max_brightness = BL_STEP;
232 rk29_bl = backlight_device_register("rk28_bl", &pdev->dev, rk29_bl_info, &rk29_bl_ops, &props);
234 printk(KERN_CRIT "%s: backlight device register error\n",
239 #if defined(CONFIG_ARCH_RK29)
240 pwm_clk = clk_get(NULL, "pwm");
241 #elif defined(CONFIG_ARCH_RK30) || defined(CONFIG_ARCH_RK31) || defined(CONFIG_ARCH_RK2928)
242 if (id == 0 || id == 1)
243 pwm_clk = clk_get(NULL, "pwm01");
244 else if (id == 2 || id == 3)
245 pwm_clk = clk_get(NULL, "pwm23");
247 if (IS_ERR(pwm_clk) || !pwm_clk) {
248 printk(KERN_ERR "failed to get pwm clock source\n");
251 pwm_clk_rate = clk_get_rate(pwm_clk);
252 div_total = pwm_clk_rate / PWM_APB_PRE_DIV;
254 div_total >>= (1 + (PWM_DIV >> 9));
255 div_total = (div_total) ? div_total : 1;
257 if(rk29_bl_info->bl_ref) {
264 write_pwm_reg(id, PWM_REG_CTRL, PWM_DIV|PWM_RESET);
265 write_pwm_reg(id, PWM_REG_LRC, div_total);
266 write_pwm_reg(id, PWM_REG_HRC, divh);
267 write_pwm_reg(id, PWM_REG_CNTR, 0x0);
268 write_pwm_reg(id, PWM_REG_CTRL, PWM_DIV|PWM_ENABLE|PWM_TIME_EN);
270 rk29_bl->props.power = FB_BLANK_UNBLANK;
271 rk29_bl->props.fb_blank = FB_BLANK_UNBLANK;
272 rk29_bl->props.brightness = BL_STEP / 2;
274 schedule_delayed_work(&rk29_backlight_work, msecs_to_jiffies(rk29_bl_info->delay_ms));
275 ret = device_create_file(&pdev->dev,&dev_attr_rk29backlight);
278 dev_err(&pdev->dev, "failed to create sysfs file\n");
281 register_early_suspend(&bl_early_suspend);
283 printk("RK29 Backlight Driver Initialized.\n");
287 static int rk29_backlight_remove(struct platform_device *pdev)
289 struct rk29_bl_info *rk29_bl_info = pdev->dev.platform_data;
292 backlight_device_unregister(rk29_bl);
293 unregister_early_suspend(&bl_early_suspend);
294 clk_disable(pwm_clk);
296 if (rk29_bl_info && rk29_bl_info->io_deinit) {
297 rk29_bl_info->io_deinit();
301 DBG(KERN_CRIT "%s: no backlight device has registered\n",
307 static void rk29_backlight_shutdown(struct platform_device *pdev)
309 struct rk29_bl_info *rk29_bl_info = pdev->dev.platform_data;
311 unregister_early_suspend(&bl_early_suspend);
313 rk29_bl->props.brightness >>= 1;
314 rk29_bl_update_status(rk29_bl);
317 rk29_bl->props.brightness >>= 1;
318 rk29_bl_update_status(rk29_bl);
321 rk29_bl->props.brightness = 0;
322 rk29_bl_update_status(rk29_bl);
324 if (rk29_bl_info && rk29_bl_info->io_deinit)
325 rk29_bl_info->io_deinit();
328 static struct platform_driver rk29_backlight_driver = {
329 .probe = rk29_backlight_probe,
330 .remove = rk29_backlight_remove,
332 .name = "rk29_backlight",
333 .owner = THIS_MODULE,
335 .shutdown = rk29_backlight_shutdown,
338 static int __init rk29_backlight_init(void)
340 platform_driver_register(&rk29_backlight_driver);
343 fs_initcall_sync(rk29_backlight_init);