[PATCH] atmel_lcdfb: New alternate pixel clock formula

From: Nicolas Ferre
Date: Wed Nov 04 2009 - 05:26:20 EST


at91sam9g45 non ES lots have an alternate pixel clock
calculation formula. Introduce this one with condition
on the cpu_is_xxxxx() macros.

Signed-off-by: Nicolas Ferre <nicolas.ferre@xxxxxxxxx>
---
Newer 9g45 SOC will not have good pixel clock calculation without
this fix.
Can we schedule this fix for .32-final ?

It depends on the newly merged macros in this patch:
"at91: at91sam9g45 family: identify several chip versions"
d8951adeba05719b9efd7ce875a3294ffdbb37ea

drivers/video/atmel_lcdfb.c | 11 ++++++++---
1 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/video/atmel_lcdfb.c b/drivers/video/atmel_lcdfb.c
index 2830ffd..d5e8010 100644
--- a/drivers/video/atmel_lcdfb.c
+++ b/drivers/video/atmel_lcdfb.c
@@ -484,6 +484,7 @@ static int atmel_lcdfb_set_par(struct fb_info *info)
unsigned long value;
unsigned long clk_value_khz;
unsigned long bits_per_line;
+ unsigned long pix_factor = 2;

might_sleep();

@@ -516,20 +517,24 @@ static int atmel_lcdfb_set_par(struct fb_info *info)
/* Now, the LCDC core... */

/* Set pixel clock */
+ if (cpu_is_at91sam9g45() && !cpu_is_at91sam9g45es())
+ pix_factor = 1;
+
clk_value_khz = clk_get_rate(sinfo->lcdc_clk) / 1000;

value = DIV_ROUND_UP(clk_value_khz, PICOS2KHZ(info->var.pixclock));

- if (value < 2) {
+ if (value < pix_factor) {
dev_notice(info->device, "Bypassing pixel clock divider\n");
lcdc_writel(sinfo, ATMEL_LCDC_LCDCON1, ATMEL_LCDC_BYPASS);
} else {
- value = (value / 2) - 1;
+ value = (value / pix_factor) - 1;
dev_dbg(info->device, " * programming CLKVAL = 0x%08lx\n",
value);
lcdc_writel(sinfo, ATMEL_LCDC_LCDCON1,
value << ATMEL_LCDC_CLKVAL_OFFSET);
- info->var.pixclock = KHZ2PICOS(clk_value_khz / (2 * (value + 1)));
+ info->var.pixclock =
+ KHZ2PICOS(clk_value_khz / (pix_factor * (value + 1)));
dev_dbg(info->device, " updated pixclk: %lu KHz\n",
PICOS2KHZ(info->var.pixclock));
}
--
1.5.6.5

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