sm501fb: control panel pin usage with platform data flags

PATCH Superseded Magnus Damm 2 participants 3 messages Dec 28, 2007 – Jan 10, 2008 Framebuffer layer

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Magnus Damm

author

2007-12-28 05:53 UTC #0 lore raw

PATCH 1/1 sm501fb: control panel pin usage with platform data flags

sm501fb: control panel pin usage with platform data flags

This patch makes it possible to control panel pins usage with flags passed from the platform data. Without this patch the sm501fb driver always controls the VBIASEN and FPEN pins. The polarity and use of these pins are very platform specific, so this patch introduces the flags SM501FB_FLAG_PANEL_USE_VBIASEN and SM501FB_FLAG_PANEL_USE_FPEN which enable the use of these pins.

This patch is needed to support the a Sharp LQ104V1DG21 lcd panel on SuperH platforms such as R2D-1 and R2D-PLUS boards. Letting the sm501fb driver control the FPEN and VBIASEN pins like today just results in lcd panel flicker.

Signed-off-by Magnus Damm <[email protected]>

---

Applies to 2.6.24-rc6.

 drivers/video/sm501fb.c |   41 +++++++++++++++++++++++++----------------
 include/linux/sm501.h   |    2 ++
 2 files changed, 27 insertions(+), 16 deletions(-)

drivers/video/sm501fb.c +25 ~~-16~~

@@ -639,6 +639,7 @@ static void sm501fb_panel_power(struct s
 {
 	unsigned long control;
 	void __iomem *ctrl_reg = fbi->regs + SM501_DC_PANEL_CONTROL;
+	struct sm501_platdata_fbsub *pd = fbi->pdata->fb_pnl;
 
 	control = readl(ctrl_reg);

@@ -655,26 +656,34 @@ static void sm501fb_panel_power(struct s
 		sm501fb_sync_regs(fbi);
 		mdelay(10);
 
-		control |= SM501_DC_PANEL_CONTROL_BIAS;	/* VBIASEN */
-		writel(control, ctrl_reg);
-		sm501fb_sync_regs(fbi);
-		mdelay(10);
-
-		control |= SM501_DC_PANEL_CONTROL_FPEN;
-		writel(control, ctrl_reg);
+		if (pd->flags & SM501FB_FLAG_PANEL_USE_VBIASEN) {
+			control |= SM501_DC_PANEL_CONTROL_BIAS;	/* VBIASEN */
+			writel(control, ctrl_reg);
+			sm501fb_sync_regs(fbi);
+			mdelay(10);
+		}
 
+		if (pd->flags & SM501FB_FLAG_PANEL_USE_FPEN) {
+			control |= SM501_DC_PANEL_CONTROL_FPEN;
+			writel(control, ctrl_reg);
+			sm501fb_sync_regs(fbi);
+			mdelay(10);
+		}
 	} else if (!to && (control & SM501_DC_PANEL_CONTROL_VDD) != 0) {
 		/* disable panel power */
+		if (pd->flags & SM501FB_FLAG_PANEL_USE_FPEN) {
+			control &= ~SM501_DC_PANEL_CONTROL_FPEN;
+			writel(control, ctrl_reg);
+			sm501fb_sync_regs(fbi);
+			mdelay(10);
+		}
 
-		control &= ~SM501_DC_PANEL_CONTROL_FPEN;
-		writel(control, ctrl_reg);
-		sm501fb_sync_regs(fbi);
-		mdelay(10);
-
-		control &= ~SM501_DC_PANEL_CONTROL_BIAS;
-		writel(control, ctrl_reg);
-		sm501fb_sync_regs(fbi);
-		mdelay(10);
+		if (pd->flags & SM501FB_FLAG_PANEL_USE_VBIASEN) {
+			control &= ~SM501_DC_PANEL_CONTROL_BIAS;
+			writel(control, ctrl_reg);
+			sm501fb_sync_regs(fbi);
+			mdelay(10);
+		}
 
 		control &= ~SM501_DC_PANEL_CONTROL_DATA;
 		writel(control, ctrl_reg);

include/linux/sm501.h +2 -0

@@ -70,6 +70,8 @@ extern unsigned long sm501_gpio_get(stru
 #define SM501FB_FLAG_DISABLE_AT_EXIT	(1<<1)
 #define SM501FB_FLAG_USE_HWCURSOR	(1<<2)
 #define SM501FB_FLAG_USE_HWACCEL	(1<<3)
+#define SM501FB_FLAG_PANEL_USE_FPEN	(1<<4)
+#define SM501FB_FLAG_PANEL_USE_VBIASEN	(1<<5)
 
 struct sm501_platdata_fbsub {
 	struct fb_videomode	*def_mode;

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Magnus Damm

author

2007-12-28 05:57 UTC #1 lore raw

PATCH 1/1 sm501fb: clear framebuffer memory and palette

sm501fb: clear framebuffer memory and palette

Avoid displaying garbage on unused framebuffers. For most users a single framebuffer is used together with fbcon. sm501fb supports two framebuffers where one often is assigned to fbcon and the other one is left unused during the boot.

The problem here is that framebuffers not in use by fbcon happen to display garbage. This can easily be solved by making sure that framebuffer memory and palette ram are cleared.

The problem can be observed by using looking at the panel output (fb1) after booting the kernel with fbcon on crt (fb0). This is the default configuration. It's also possible to watch the garbage on the crt framebuffer by passing "fbcon=map:1" on the kernel cmdline. This will assign fbcon to the panel (fb1) and leave the crt (fb0) unused.

Signed-off-by Magnus Damm <[email protected]>

---

Applies to 2.6.24-rc6.

 drivers/video/sm501fb.c |    8 ++++++++
 1 file changed, 8 insertions(+)

drivers/video/sm501fb.c +8 -0

@@ -1264,6 +1264,7 @@ static int sm501fb_start(struct sm501fb_
 {
 	struct resource	*res;
 	struct device *dev;
+	int k;
 	int ret;
 
 	info->dev = dev = &pdev->dev;

@@ -1325,6 +1326,13 @@ static int sm501fb_start(struct sm501fb_
 
 	info->fbmem_len = (res->end - res->start)+1;
 
+	/* clear framebuffer memory - avoids garbage data on unused fb */
+	memset(info->fbmem, 0, info->fbmem_len);
+
+	/* clear palette ram - undefined at power on */
+	for (k = 0; k < (256 * 3); k++)
+		writel(0, info->regs + SM501_DC_PANEL_PALETTE + (k * 4));
+
 	/* enable display controller */
 	sm501_unit_power(dev->parent, SM501_GATE_DISPLAY, 1);

Paul Mundt

2008-01-10 02:53 UTC #2 lore raw

Quoted 13 lines · Magnus Damm

sm501fb: control panel pin usage with platform data flags
This patch makes it possible to control panel pins usage with flags passed from the platform data. Without this patch the sm501fb driver always controls the VBIASEN and FPEN pins. The polarity and use of these pins are very platform specific, so this patch introduces the flags SM501FB_FLAG_PANEL_USE_VBIASEN and SM501FB_FLAG_PANEL_USE_FPEN which enable the use of these pins.
This patch is needed to support the a Sharp LQ104V1DG21 lcd panel on SuperH platforms such as R2D-1 and R2D-PLUS boards. Letting the sm501fb driver control the FPEN and VBIASEN pins like today just results in lcd panel flicker.
Signed-off-by Magnus Damm <[email protected]>

Quoted 11 lines · Magnus Damm

sm501fb: clear framebuffer memory and palette
Avoid displaying garbage on unused framebuffers. For most users a single framebuffer is used together with fbcon. sm501fb supports two framebuffers where one often is assigned to fbcon and the other one is left unused during the boot.
The problem here is that framebuffers not in use by fbcon happen to display garbage. This can easily be solved by making sure that framebuffer memory and palette ram are cleared.

Quoted 7 lines

The problem can be observed by using looking at the panel output (fb1) after booting the kernel with fbcon on crt (fb0). This is the default configuration. It's also possible to watch the garbage on the crt framebuffer by passing "fbcon=map:1" on the kernel cmdline. This will assign fbcon to the panel (fb1) and leave the crt (fb0) unused.
Signed-off-by Magnus Damm <[email protected]>

There hasn't been any updates or objections to these, and we do still need them. Andrew, can you roll these in to -mm?

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