imxfb: add clock support
v2: Added change from Martin Fuzzey: pixclock should be in pico seconds
instead of MHz.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
diff --git a/drivers/video/imxfb.c b/drivers/video/imxfb.c
index bd1cb75..8f7a2b2 100644
--- a/drivers/video/imxfb.c
+++ b/drivers/video/imxfb.c
@@ -26,9 +26,11 @@
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/cpufreq.h>
+#include <linux/clk.h>
#include <linux/platform_device.h>
#include <linux/dma-mapping.h>
#include <linux/io.h>
+#include <linux/math64.h>
#include <mach/imxfb.h>
@@ -141,6 +143,7 @@
struct imxfb_info {
struct platform_device *pdev;
void __iomem *regs;
+ struct clk *clk;
u_int max_bpp;
u_int max_xres;
@@ -403,6 +406,8 @@
writel(RMCR_LCDC_EN, fbi->regs + LCDC_RMCR);
+ clk_enable(fbi->clk);
+
if (fbi->backlight_power)
fbi->backlight_power(1);
if (fbi->lcd_power)
@@ -418,6 +423,8 @@
if (fbi->lcd_power)
fbi->lcd_power(0);
+ clk_disable(fbi->clk);
+
writel(0, fbi->regs + LCDC_RMCR);
}
@@ -461,6 +468,9 @@
static int imxfb_activate_var(struct fb_var_screeninfo *var, struct fb_info *info)
{
struct imxfb_info *fbi = info->par;
+ unsigned int pcr, lcd_clk;
+ unsigned long long tmp;
+
pr_debug("var: xres=%d hslen=%d lm=%d rm=%d\n",
var->xres, var->hsync_len,
var->left_margin, var->right_margin);
@@ -507,7 +517,23 @@
writel(SIZE_XMAX(var->xres) | SIZE_YMAX(var->yres),
fbi->regs + LCDC_SIZE);
- writel(fbi->pcr, fbi->regs + LCDC_PCR);
+
+ lcd_clk = clk_get_rate(fbi->clk);
+ tmp = var->pixclock * (unsigned long long)lcd_clk;
+ do_div(tmp, 1000000);
+ if (do_div(tmp, 1000000) > 500000)
+ tmp++;
+ pcr = (unsigned int)tmp;
+ if (--pcr > 0x3F) {
+ pcr = 0x3F;
+ printk(KERN_WARNING "Must limit pixel clock to %uHz\n",
+ lcd_clk / pcr);
+ }
+
+ /* add sync polarities */
+ pcr |= fbi->pcr & ~0x3F;
+
+ writel(pcr, fbi->regs + LCDC_PCR);
writel(fbi->pwmr, fbi->regs + LCDC_PWMR);
writel(fbi->lscr1, fbi->regs + LCDC_LSCR1);
writel(fbi->dmacr, fbi->regs + LCDC_DMACR);
@@ -649,6 +675,13 @@
goto failed_req;
}
+ fbi->clk = clk_get(&pdev->dev, NULL);
+ if (IS_ERR(fbi->clk)) {
+ ret = PTR_ERR(fbi->clk);;
+ dev_err(&pdev->dev, "unable to get clock: %d\n", ret);
+ goto failed_getclock;
+ }
+
fbi->regs = ioremap(res->start, resource_size(res));
if (fbi->regs == NULL) {
printk(KERN_ERR"Cannot map frame buffer registers\n");
@@ -717,6 +750,8 @@
dma_free_writecombine(&pdev->dev,fbi->map_size,fbi->map_cpu,
fbi->map_dma);
failed_map:
+ clk_put(fbi->clk);
+failed_getclock:
iounmap(fbi->regs);
failed_ioremap:
release_mem_region(res->start, res->end - res->start);
@@ -751,6 +786,9 @@
iounmap(fbi->regs);
release_mem_region(res->start, res->end - res->start + 1);
+ clk_disable(fbi->clk);
+ clk_put(fbi->clk);
+
platform_set_drvdata(pdev, NULL);
return 0;