The wm8505fb driver requires a clock to work properly. Without a clock,
the driver can only initialize the display resolution that was set in
uboot.
This patch updates the driver to get and use a clock, and updates
the devicetree documentation to indicate the requirement for a clock.
Signed-off-by: Tony Prisk <li...@prisktech.co.nz>
---
.../devicetree/bindings/video/wm,wm8505-fb.txt | 4 ++-
drivers/video/wm8505fb.c | 30 +++++++++++++++++---
2 files changed, 29 insertions(+), 5 deletions(-)
diff --git a/Documentation/devicetree/bindings/video/wm,wm8505-fb.txt
b/Documentation/devicetree/bindings/video/wm,wm8505-fb.txt
index 0bcadb2..601416c 100644
--- a/Documentation/devicetree/bindings/video/wm,wm8505-fb.txt
+++ b/Documentation/devicetree/bindings/video/wm,wm8505-fb.txt
@@ -5,6 +5,7 @@ Required properties:
- compatible : "wm,wm8505-fb"
- reg : Should contain 1 register ranges(address and length)
- bits-per-pixel : bit depth of framebuffer (16 or 32)
+- clocks : phandle to DVO clock
Required subnodes:
- display-timings: see display-timing.txt for information
@@ -15,11 +16,12 @@ Example:
compatible = "wm,wm8505-fb";
reg = <0xd8051700 0x200>;
bits-per-pixel = <16>;
+ clocks = <&clkdvo>;
display-timings {
native-mode = <&timing0>;
timing0: 800x480 {
- clock-frequency = <0>; /* unused but required */
+ clock-frequency = <30000000>;
hactive = <800>;
vactive = <480>;
hfront-porch = <40>;
diff --git a/drivers/video/wm8505fb.c b/drivers/video/wm8505fb.c
index 167a9e2..f8bffc2 100644
--- a/drivers/video/wm8505fb.c
+++ b/drivers/video/wm8505fb.c
@@ -14,6 +14,7 @@
* GNU General Public License for more details.
*/
+#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/fb.h>
@@ -130,9 +131,11 @@
#define to_wm8505fb_info(__info) container_of(__info, \
struct wm8505fb_info, fb)
struct wm8505fb_info {
- struct fb_info fb;
- void __iomem *regbase;
- unsigned int contrast;
+ struct fb_info fb;
+ void __iomem *regbase;
+ unsigned int contrast;
+ struct device *dev;
+ struct clk *clk_dvo;
};
@@ -210,6 +213,13 @@ static int wm8505fb_set_par(struct fb_info *info)
if (!fbi)
return -EINVAL;
+ if (info->var.pixclock == 0) {
+ dev_err(fbi->dev, "requested pixclock = 0\n");
+ return -EINVAL;
+ }
+
+ clk_set_rate(fbi->clk_dvo, PICOS2KHZ(info->var.pixclock)*1000);
+
if (info->var.bits_per_pixel == 32) {
info->var.red.offset = 16;
info->var.red.length = 8;
@@ -369,6 +379,8 @@ static int wm8505fb_probe(struct platform_device *pdev)
return -ENOMEM;
}
+ fbi->dev = &pdev->dev;
+
strcpy(fbi->fb.fix.id, DRIVER_NAME);
fbi->fb.fix.type = FB_TYPE_PACKED_PIXELS;
@@ -408,6 +420,14 @@ static int wm8505fb_probe(struct platform_device *pdev)
if (ret)
return ret;
+ fbi->clk_dvo = of_clk_get(pdev->dev.of_node, 0);
+ if (IS_ERR(fbi->clk_dvo)) {
+ dev_err(&pdev->dev, "Error retrieving clock\n");
+ return PTR_ERR(fbi->clk_dvo);
+ }
+
+ clk_prepare_enable(fbi->clk_dvo);
+
fb_videomode_to_var(&fbi->fb.var, &mode);
fbi->fb.var.nonstd = 0;
@@ -421,7 +441,7 @@ static int wm8505fb_probe(struct platform_device *pdev)
fb_mem_virt = dmam_alloc_coherent(&pdev->dev, fb_mem_len, &fb_mem_phys,
GFP_KERNEL);
if (!fb_mem_virt) {
- pr_err("%s: Failed to allocate framebuffer\n", __func__);
+ dev_err(&pdev->dev, "Failed to allocate framebuffer\n");
return -ENOMEM;
}
@@ -480,6 +500,8 @@ static int wm8505fb_remove(struct platform_device *pdev)
unregister_framebuffer(&fbi->fb);
+ clk_disable_unprepare(fbi->clk_dvo);
+
writel(0, fbi->regbase);
if (fbi->fb.cmap.len)
--
1.7.9.5
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