2012-02-09 06:41:21

by Manjunathappa, Prakash

Subject: [PATCH v2] video:da8xx-fb: calculate pixel clock period for the panel

Patch calculates pixel clock period in pico seconds and updates
the same in variable screen information structure. fbset utility
uses this information.

Signed-off-by: Manjunathappa, Prakash <[email protected]>
---
Since v1:
Fixed the spelling mistake.

drivers/video/da8xx-fb.c | 19 ++++++++++++++++++-
1 files changed, 18 insertions(+), 1 deletions(-)

diff --git a/drivers/video/da8xx-fb.c b/drivers/video/da8xx-fb.c
index f360d62..882dd67 100644
--- a/drivers/video/da8xx-fb.c
+++ b/drivers/video/da8xx-fb.c
@@ -32,6 +32,7 @@
#include <linux/console.h>
#include <linux/slab.h>
#include <video/da8xx-fb.h>
+#include <asm/div64.h>

#define DRIVER_NAME "da8xx_lcdc"

@@ -174,7 +175,6 @@ static struct fb_var_screeninfo da8xx_fb_var __devinitdata = {
.activate = 0,
.height = -1,
.width = -1,
- .pixclock = 46666, /* 46us - AUO display */
.accel_flags = 0,
.left_margin = LEFT_MARGIN,
.right_margin = RIGHT_MARGIN,
@@ -1048,6 +1048,22 @@ static struct fb_ops da8xx_fb_ops = {
.fb_blank = cfb_blank,
};

+/* Calculate and return pixel clock period in pico seconds */
+static unsigned int da8xxfb_pixel_clk_period(struct da8xx_fb_par *par)
+{
+ unsigned int lcd_clk, div;
+ unsigned int configured_pix_clk;
+ unsigned long long pix_clk_period_picosec = 1000000000000ULL;
+
+ lcd_clk = clk_get_rate(par->lcdc_clk);
+ div = lcd_clk / par->pxl_clk;
+ configured_pix_clk = (lcd_clk / div);
+
+ do_div(pix_clk_period_picosec, configured_pix_clk);
+
+ return pix_clk_period_picosec;
+}
+
static int __devinit fb_probe(struct platform_device *device)
{
struct da8xx_lcdc_platform_data *fb_pdata =
@@ -1209,6 +1225,7 @@ static int __devinit fb_probe(struct platform_device *device)

da8xx_fb_var.hsync_len = lcdc_info->hsw;
da8xx_fb_var.vsync_len = lcdc_info->vsw;
+ da8xx_fb_var.pixclock = da8xxfb_pixel_clk_period(par);

/* Initialize fbinfo */
da8xx_fb_info->flags = FBINFO_FLAG_DEFAULT;
--
1.7.1

2012-02-13 21:28:23

by Florian Tobias Schandinat

Subject: Re: [PATCH v2] video:da8xx-fb: calculate pixel clock period for the panel

On 02/09/2012 06:24 AM, Manjunathappa, Prakash wrote:
> Patch calculates pixel clock period in pico seconds and updates
> the same in variable screen information structure. fbset utility
> uses this information.
>
> Signed-off-by: Manjunathappa, Prakash <[email protected]>

Applied.


Thanks,

Florian Tobias Schandinat

> ---
> Since v1:
> Fixed the spelling mistake.
>
> drivers/video/da8xx-fb.c | 19 ++++++++++++++++++-
> 1 files changed, 18 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/video/da8xx-fb.c b/drivers/video/da8xx-fb.c
> index f360d62..882dd67 100644
> --- a/drivers/video/da8xx-fb.c
> +++ b/drivers/video/da8xx-fb.c
> @@ -32,6 +32,7 @@
> #include <linux/console.h>
> #include <linux/slab.h>
> #include <video/da8xx-fb.h>
> +#include <asm/div64.h>
>
> #define DRIVER_NAME "da8xx_lcdc"
>
> @@ -174,7 +175,6 @@ static struct fb_var_screeninfo da8xx_fb_var __devinitdata = {
> .activate = 0,
> .height = -1,
> .width = -1,
> - .pixclock = 46666, /* 46us - AUO display */
> .accel_flags = 0,
> .left_margin = LEFT_MARGIN,
> .right_margin = RIGHT_MARGIN,
> @@ -1048,6 +1048,22 @@ static struct fb_ops da8xx_fb_ops = {
> .fb_blank = cfb_blank,
> };
>
> +/* Calculate and return pixel clock period in pico seconds */
> +static unsigned int da8xxfb_pixel_clk_period(struct da8xx_fb_par *par)
> +{
> + unsigned int lcd_clk, div;
> + unsigned int configured_pix_clk;
> + unsigned long long pix_clk_period_picosec = 1000000000000ULL;
> +
> + lcd_clk = clk_get_rate(par->lcdc_clk);
> + div = lcd_clk / par->pxl_clk;
> + configured_pix_clk = (lcd_clk / div);
> +
> + do_div(pix_clk_period_picosec, configured_pix_clk);
> +
> + return pix_clk_period_picosec;
> +}
> +
> static int __devinit fb_probe(struct platform_device *device)
> {
> struct da8xx_lcdc_platform_data *fb_pdata =
> @@ -1209,6 +1225,7 @@ static int __devinit fb_probe(struct platform_device *device)
>
> da8xx_fb_var.hsync_len = lcdc_info->hsw;
> da8xx_fb_var.vsync_len = lcdc_info->vsw;
> + da8xx_fb_var.pixclock = da8xxfb_pixel_clk_period(par);
>
> /* Initialize fbinfo */
> da8xx_fb_info->flags = FBINFO_FLAG_DEFAULT;