atmel_lcdfb: new alternate pixel clock formula
Nicolas Ferre [Wed, 11 Nov 2009 22:26:35 +0000 (14:26 -0800)]
at91sam9g45 non ES lots have an alternate pixel clock calculation formula.
Introduce this one with condition on the cpu_is_xxxxx() macros.

Newer 9g45 SOC will not have good pixel clock calculation without this
fix.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Krzysztof Helt <krzysztof.h1@wp.pl>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/video/atmel_lcdfb.c

index 2830ffd..d5e8010 100644 (file)
@@ -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));
        }