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Commit 0dac6ecd authored by Ben Dooks's avatar Ben Dooks Committed by Linus Torvalds
Browse files

s3c-fb: CPUFREQ frequency scaling support 



Add support for CPU frequency scaling in the S3C24XX video driver.

Signed-off-by: default avatarSimtec Linux Team <linux@simtec.co.uk>
Signed-off-by: default avatarBen Dooks <ben@simtec.co.uk>
Cc: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent ddc518d9

drivers/video/s3c2410fb.c

+65 −2
Original line number Diff line number Diff line
@@ -24,6 +24,7 @@ 
#include <linux/interrupt.h>

#include <linux/platform_device.h>

#include <linux/clk.h>

#include <linux/cpufreq.h>



#include <asm/io.h>

#include <asm/div64.h>
@@ -89,7 +90,7 @@ static void s3c2410fb_set_lcdaddr(struct fb_info *info) 
static unsigned int s3c2410fb_calc_pixclk(struct s3c2410fb_info *fbi,

					  unsigned long pixclk)

{

	unsigned long clk = clk_get_rate(fbi->clk);

	unsigned long clk = fbi->clk_rate;

	unsigned long long div;



	/* pixclk is in picoseconds, our clock is in Hz
@@ -758,6 +759,57 @@ static irqreturn_t s3c2410fb_irq(int irq, void *dev_id) 
	return IRQ_HANDLED;

}



#ifdef CONFIG_CPU_FREQ



static int s3c2410fb_cpufreq_transition(struct notifier_block *nb,

					unsigned long val, void *data)

{

	struct cpufreq_freqs *freqs = data;

	struct s3c2410fb_info *info;

	struct fb_info *fbinfo;

	long delta_f;



	info = container_of(nb, struct s3c2410fb_info, freq_transition);

	fbinfo = platform_get_drvdata(to_platform_device(info->dev));



	/* work out change, <0 for speed-up */

	delta_f = info->clk_rate - clk_get_rate(info->clk);



	if ((val == CPUFREQ_POSTCHANGE && delta_f > 0) ||

	    (val == CPUFREQ_PRECHANGE && delta_f < 0)) {

		info->clk_rate = clk_get_rate(info->clk);

		s3c2410fb_activate_var(fbinfo);

	}



	return 0;

}



static inline int s3c2410fb_cpufreq_register(struct s3c2410fb_info *info)

{

	info->freq_transition.notifier_call = s3c2410fb_cpufreq_transition;



	return cpufreq_register_notifier(&info->freq_transition,

					 CPUFREQ_TRANSITION_NOTIFIER);

}



static inline void s3c2410fb_cpufreq_deregister(struct s3c2410fb_info *info)

{

	cpufreq_unregister_notifier(&info->freq_transition,

				    CPUFREQ_TRANSITION_NOTIFIER);

}



#else

static inline int s3c2410fb_cpufreq_register(struct s3c2410fb_info *info)

{

	return 0;

}



static inline void s3c2410fb_cpufreq_deregister(struct s3c2410fb_info *info)

{

}

#endif





static char driver_name[] = "s3c2410fb";



static int __init s3c24xxfb_probe(struct platform_device *pdev,
@@ -875,6 +927,8 @@ static int __init s3c24xxfb_probe(struct platform_device *pdev, 


	msleep(1);



	info->clk_rate = clk_get_rate(info->clk);



	/* find maximum required memory size for display */

	for (i = 0; i < mach_info->num_displays; i++) {

		unsigned long smem_len = mach_info->displays[i].xres;
@@ -904,11 +958,17 @@ static int __init s3c24xxfb_probe(struct platform_device *pdev, 


	s3c2410fb_check_var(&fbinfo->var, fbinfo);



	ret = s3c2410fb_cpufreq_register(info);

	if (ret < 0) {

		dev_err(&pdev->dev, "Failed to register cpufreq\n");

		goto free_video_memory;

	}



	ret = register_framebuffer(fbinfo);

	if (ret < 0) {

		printk(KERN_ERR "Failed to register framebuffer device: %d\n",

			ret);

		goto free_video_memory;

		goto free_cpufreq;

	}



	/* create device files */
@@ -922,6 +982,8 @@ static int __init s3c24xxfb_probe(struct platform_device *pdev, 


	return 0;



 free_cpufreq:

	s3c2410fb_cpufreq_deregister(info);

free_video_memory:

	s3c2410fb_unmap_video_memory(fbinfo);

release_clock:
@@ -961,6 +1023,7 @@ static int s3c2410fb_remove(struct platform_device *pdev) 
	int irq;



	unregister_framebuffer(fbinfo);

	s3c2410fb_cpufreq_deregister(info);



	s3c2410fb_lcd_enable(info, 0);

	msleep(1);

drivers/video/s3c2410fb.h

+5 −0
Original line number Diff line number Diff line
@@ -29,8 +29,13 @@ struct s3c2410fb_info { 
	enum s3c_drv_type	drv_type;

	struct s3c2410fb_hw	regs;



	unsigned long		clk_rate;

	unsigned int		palette_ready;



#ifdef CONFIG_CPU_FREQ

	struct notifier_block	freq_transition;

#endif



	/* keep these registers in case we need to re-write palette */

	u32			palette_buffer[256];

	u32			pseudo_pal[16];