diff options
Diffstat (limited to 'drivers/video/fbdev/amba-clcd.c')
| -rw-r--r-- | drivers/video/fbdev/amba-clcd.c | 27 |
1 files changed, 19 insertions, 8 deletions
diff --git a/drivers/video/fbdev/amba-clcd.c b/drivers/video/fbdev/amba-clcd.c index beadd3edaa17..6ad23bd3523a 100644 --- a/drivers/video/fbdev/amba-clcd.c +++ b/drivers/video/fbdev/amba-clcd.c @@ -24,6 +24,7 @@ #include <linux/list.h> #include <linux/amba/bus.h> #include <linux/amba/clcd.h> +#include <linux/bitops.h> #include <linux/clk.h> #include <linux/hardirq.h> #include <linux/dma-mapping.h> @@ -638,9 +639,7 @@ static int clcdfb_of_init_tft_panel(struct clcd_fb *fb, u32 r0, u32 g0, u32 b0) if (g0 != panels[i].g0) continue; if (r0 == panels[i].r0 && b0 == panels[i].b0) - fb->panel->caps = panels[i].caps & CLCD_CAP_RGB; - if (r0 == panels[i].b0 && b0 == panels[i].r0) - fb->panel->caps = panels[i].caps & CLCD_CAP_BGR; + fb->panel->caps = panels[i].caps; } return fb->panel->caps ? 0 : -EINVAL; @@ -650,6 +649,7 @@ static int clcdfb_of_init_display(struct clcd_fb *fb) { struct device_node *endpoint; int err; + unsigned int bpp; u32 max_bandwidth; u32 tft_r0b0g0[3]; @@ -667,11 +667,22 @@ static int clcdfb_of_init_display(struct clcd_fb *fb) err = of_property_read_u32(fb->dev->dev.of_node, "max-memory-bandwidth", &max_bandwidth); - if (!err) - fb->panel->bpp = 8 * max_bandwidth / (fb->panel->mode.xres * - fb->panel->mode.yres * fb->panel->mode.refresh); - else - fb->panel->bpp = 32; + if (!err) { + /* + * max_bandwidth is in bytes per second and pixclock in + * pico-seconds, so the maximum allowed bits per pixel is + * 8 * max_bandwidth / (PICOS2KHZ(pixclock) * 1000) + * Rearrange this calculation to avoid overflow and then ensure + * result is a valid format. + */ + bpp = max_bandwidth / (1000 / 8) + / PICOS2KHZ(fb->panel->mode.pixclock); + bpp = rounddown_pow_of_two(bpp); + if (bpp > 32) + bpp = 32; + } else + bpp = 32; + fb->panel->bpp = bpp; #ifdef CONFIG_CPU_BIG_ENDIAN fb->panel->cntl |= CNTL_BEBO; |