s3c-fb: CPUFREQ frequency scaling support
Add support for CPU frequency scaling in the S3C24XX video driver.
Signed-off-by: Simtec Linux Team <linux@simtec.co.uk>
Signed-off-by: Ben Dooks <ben@simtec.co.uk>
Cc: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/video/s3c2410fb.c b/drivers/video/s3c2410fb.c
index b0b4513..7da0027 100644
--- a/drivers/video/s3c2410fb.c
+++ b/drivers/video/s3c2410fb.c
@@ -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 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 @@
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 @@
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 @@
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 @@
return 0;
+ free_cpufreq:
+ s3c2410fb_cpufreq_deregister(info);
free_video_memory:
s3c2410fb_unmap_video_memory(fbinfo);
release_clock:
@@ -961,6 +1023,7 @@
int irq;
unregister_framebuffer(fbinfo);
+ s3c2410fb_cpufreq_deregister(info);
s3c2410fb_lcd_enable(info, 0);
msleep(1);