Some boards connect the LCD_RESET pin to a reset input on the
display panel. On these boards, this pin must be set to the
proper level for the display to function.
This adds an optional "reset-active" property to the "display"
subnode such that devicetrees can specify the desired polarity
of the LCD_RESET pin.
Signed-off-by: Mans Rullgard <[email protected]>
---
Documentation/devicetree/bindings/display/mxsfb.txt | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/Documentation/devicetree/bindings/display/mxsfb.txt b/Documentation/devicetree/bindings/display/mxsfb.txt
index 96ec517..cb7212a 100644
--- a/Documentation/devicetree/bindings/display/mxsfb.txt
+++ b/Documentation/devicetree/bindings/display/mxsfb.txt
@@ -13,6 +13,11 @@ Required properties:
- bits-per-pixel : <16> for RGB565, <32> for RGB888/666.
- bus-width : number of data lines. Could be <8>, <16>, <18> or <24>.
+Optional properties:
+- reset-active : <0>: reset pin is active low
+ <1>: reset pin is active high
+ omitted: reset pin not used
+
Required sub-node:
- display-timings : Refer to binding doc display-timing.txt for details.
--
2.6.3
Activate/deactivate the LCD_RESET signal as specified by the
reset-active DT property when the controller is disabled/enabled.
If the property is missing, leave the signal unchanged.
Signed-off-by: Mans Rullgard <[email protected]>
---
drivers/video/fbdev/mxsfb.c | 28 +++++++++++++++++++++++++---
1 file changed, 25 insertions(+), 3 deletions(-)
diff --git a/drivers/video/fbdev/mxsfb.c b/drivers/video/fbdev/mxsfb.c
index 4e6608c..0200a0f 100644
--- a/drivers/video/fbdev/mxsfb.c
+++ b/drivers/video/fbdev/mxsfb.c
@@ -99,6 +99,7 @@
#define CTRL1_FIFO_CLEAR (1 << 21)
#define CTRL1_SET_BYTE_PACKAGING(x) (((x) & 0xf) << 16)
#define CTRL1_GET_BYTE_PACKAGING(x) (((x) >> 16) & 0xf)
+#define CTRL1_RESET (1 << 0)
#define TRANSFER_COUNT_SET_VCOUNT(x) (((x) & 0xffff) << 16)
#define TRANSFER_COUNT_GET_VCOUNT(x) (((x) >> 16) & 0xffff)
@@ -152,6 +153,9 @@
#define MXSFB_SYNC_DATA_ENABLE_HIGH_ACT (1 << 6)
#define MXSFB_SYNC_DOTCLK_FALLING_ACT (1 << 7) /* negtive edge sampling */
+#define MXSFB_RESET_LOW 1
+#define MXSFB_RESET_HIGH 2
+
enum mxsfb_devtype {
MXSFB_V3,
MXSFB_V4,
@@ -181,6 +185,7 @@ struct mxsfb_info {
unsigned dotclk_delay;
const struct mxsfb_devdata *devdata;
u32 sync;
+ u32 reset;
struct regulator *reg_lcd;
};
@@ -362,6 +367,11 @@ static void mxsfb_enable_controller(struct fb_info *fb_info)
writel(CTRL_RUN, host->base + LCDC_CTRL + REG_SET);
+ if (host->reset == MXSFB_RESET_HIGH)
+ writel(CTRL1_RESET, host->base + LCDC_CTRL1 + REG_CLR);
+ else if (host->reset == MXSFB_RESET_LOW)
+ writel(CTRL1_RESET, host->base + LCDC_CTRL1 + REG_SET);
+
host->enabled = 1;
}
@@ -388,6 +398,11 @@ static void mxsfb_disable_controller(struct fb_info *fb_info)
loop--;
}
+ if (host->reset == MXSFB_RESET_HIGH)
+ writel(CTRL1_RESET, host->base + LCDC_CTRL1 + REG_SET);
+ else if (host->reset == MXSFB_RESET_LOW)
+ writel(CTRL1_RESET, host->base + LCDC_CTRL1 + REG_CLR);
+
reg = readl(host->base + LCDC_VDCTRL4);
writel(reg & ~VDCTRL4_SYNC_SIGNALS_ON, host->base + LCDC_VDCTRL4);
@@ -410,7 +425,7 @@ static void mxsfb_disable_controller(struct fb_info *fb_info)
static int mxsfb_set_par(struct fb_info *fb_info)
{
struct mxsfb_info *host = to_imxfb_host(fb_info);
- u32 ctrl, vdctrl0, vdctrl4;
+ u32 ctrl, ctrl1, vdctrl0, vdctrl4;
int line_size, fb_size;
int reenable = 0;
@@ -439,12 +454,13 @@ static int mxsfb_set_par(struct fb_info *fb_info)
ctrl = CTRL_BYPASS_COUNT | CTRL_MASTER |
CTRL_SET_BUS_WIDTH(host->ld_intf_width);
+ ctrl1 = readl(host->base + LCDC_CTRL1) & CTRL1_RESET;
switch (fb_info->var.bits_per_pixel) {
case 16:
dev_dbg(&host->pdev->dev, "Setting up RGB565 mode\n");
ctrl |= CTRL_SET_WORD_LENGTH(0);
- writel(CTRL1_SET_BYTE_PACKAGING(0xf), host->base + LCDC_CTRL1);
+ ctrl1 |= CTRL1_SET_BYTE_PACKAGING(0xf);
break;
case 32:
dev_dbg(&host->pdev->dev, "Setting up RGB888/666 mode\n");
@@ -462,7 +478,7 @@ static int mxsfb_set_par(struct fb_info *fb_info)
break;
}
/* do not use packed pixels = one pixel per word instead */
- writel(CTRL1_SET_BYTE_PACKAGING(0x7), host->base + LCDC_CTRL1);
+ ctrl1 |= CTRL1_SET_BYTE_PACKAGING(0x7);
break;
default:
mxsfb_disable_axi_clk(host);
@@ -472,6 +488,7 @@ static int mxsfb_set_par(struct fb_info *fb_info)
}
writel(ctrl, host->base + LCDC_CTRL);
+ writel(ctrl1, host->base + LCDC_CTRL1);
writel(TRANSFER_COUNT_SET_VCOUNT(fb_info->var.yres) |
TRANSFER_COUNT_SET_HCOUNT(fb_info->var.xres),
@@ -736,6 +753,7 @@ static int mxsfb_init_fbinfo_dt(struct mxsfb_info *host,
struct device_node *display_np;
struct videomode vm;
u32 width;
+ u32 reset;
int ret;
display_np = of_parse_phandle(np, "display", 0);
@@ -776,6 +794,10 @@ static int mxsfb_init_fbinfo_dt(struct mxsfb_info *host,
goto put_display_node;
}
+ ret = of_property_read_u32(display_np, "reset-active", &reset);
+ if (!ret)
+ host->reset = reset ? MXSFB_RESET_HIGH : MXSFB_RESET_LOW;
+
ret = of_get_videomode(display_np, &vm, OF_USE_NATIVE_MODE);
if (ret) {
dev_err(dev, "failed to get videomode from DT\n");
--
2.6.3
On Tue, Dec 15, 2015 at 05:24:56PM +0000, Mans Rullgard wrote:
> Some boards connect the LCD_RESET pin to a reset input on the
> display panel. On these boards, this pin must be set to the
> proper level for the display to function.
>
> This adds an optional "reset-active" property to the "display"
> subnode such that devicetrees can specify the desired polarity
> of the LCD_RESET pin.
>
> Signed-off-by: Mans Rullgard <[email protected]>
Acked-by: Rob Herring <[email protected]>