[PATCH 2/2] video: mxsfb: manage LCD_RESET signal according to reset-active property

From: Mans Rullgard
Date: Tue Dec 15 2015 - 12:25:39 EST


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 <mans@xxxxxxxxx>
---
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

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/