From 0dac6ecdc056b83ac66e5b5c923fb73268f4332d Mon Sep 17 00:00:00 2001 From: Ben Dooks Date: Tue, 16 Jun 2009 15:34:34 -0700 Subject: [PATCH] s3c-fb: CPUFREQ frequency scaling support Add support for CPU frequency scaling in the S3C24XX video driver. Signed-off-by: Simtec Linux Team Signed-off-by: Ben Dooks Cc: Dave Jones Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/video/s3c2410fb.c | 67 +++++++++++++++++++++++++++++++++++++-- drivers/video/s3c2410fb.h | 5 +++ 2 files changed, 70 insertions(+), 2 deletions(-) diff --git a/drivers/video/s3c2410fb.c b/drivers/video/s3c2410fb.c index b0b4513ba53..7da0027e240 100644 --- a/drivers/video/s3c2410fb.c +++ b/drivers/video/s3c2410fb.c @@ -24,6 +24,7 @@ #include #include #include +#include #include #include @@ -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); diff --git a/drivers/video/s3c2410fb.h b/drivers/video/s3c2410fb.h index 9a6ba3e9d1b..47a17bd2301 100644 --- a/drivers/video/s3c2410fb.h +++ b/drivers/video/s3c2410fb.h @@ -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]; -- 2.41.0