video: tegra: Move to using simple-panel and pwm-backlight

We have standard drivers for panels and backlights which can do most of the
work for us. Move the tegra20 LCD driver over to use those instead of custom
code.

This patch includes device tree changes for the nvidia boards. I have only
been able to test seaboard. If this patch is applied, these boards will
also need to be synced with the kernel, and updated to use display-timings:

   - colibri
   - medcom-wide
   - paz00
   - tec

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>

1 files changed, 49 insertions, 263 deletions

diff --git a/drivers/video/tegra.c b/drivers/video/tegra.c
index c01809e89e..5c48c3b964 100644
--- a/drivers/video/tegra.c
+++ b/drivers/video/tegra.c
@@ -6,6 +6,7 @@
 #include <common.h>
 #include <dm.h>
 #include <fdtdec.h>
+#include <panel.h>
 #include <pwm.h>
 #include <video.h>
 #include <asm/system.h>
@@ -21,28 +22,6 @@
 
 DECLARE_GLOBAL_DATA_PTR;
 
-/* These are the stages we go throuh in enabling the LCD */
-enum stage_t {
-	STAGE_START,
-	STAGE_PANEL_VDD,
-	STAGE_LVDS,
-	STAGE_BACKLIGHT_VDD,
-	STAGE_PWM,
-	STAGE_BACKLIGHT_EN,
-	STAGE_DONE,
-};
-
-#define FDT_LCD_TIMINGS	4
-
-enum {
-	FDT_LCD_TIMING_REF_TO_SYNC,
-	FDT_LCD_TIMING_SYNC_WIDTH,
-	FDT_LCD_TIMING_BACK_PORCH,
-	FDT_LCD_TIMING_FRONT_PORCH,
-
-	FDT_LCD_TIMING_COUNT,
-};
-
 enum lcd_cache_t {
 	FDT_LCD_CACHE_OFF		= 0,
 	FDT_LCD_CACHE_WRITE_THROUGH	= 1 << 0,
@@ -54,37 +33,15 @@ enum lcd_cache_t {
 
 /* Information about the display controller */
 struct tegra_lcd_priv {
-	enum stage_t stage;	/* Current stage we are at */
-	unsigned long timer_next; /* Time we can move onto next stage */
 	int width;			/* width in pixels */
 	int height;			/* height in pixels */
-
-	/*
-	 * log2 of number of bpp, in general, unless it bpp is 24 in which
-	 * case this field holds 24 also! This is a U-Boot thing.
-	 */
-	int log2_bpp;
+	enum video_log2_bpp log2_bpp;	/* colour depth */
+	struct display_timing timing;
+	struct udevice *panel;
 	struct disp_ctlr *disp;		/* Display controller to use */
 	fdt_addr_t frame_buffer;	/* Address of frame buffer */
 	unsigned pixel_clock;		/* Pixel clock in Hz */
-	uint horiz_timing[FDT_LCD_TIMING_COUNT];	/* Horizontal timing */
-	uint vert_timing[FDT_LCD_TIMING_COUNT];		/* Vertical timing */
-	struct udevice *pwm;
-	int pwm_channel;		/* PWM channel to use for backlight */
 	enum lcd_cache_t cache_type;
-
-	struct gpio_desc backlight_en;	/* GPIO for backlight enable */
-	struct gpio_desc lvds_shutdown;	/* GPIO for lvds shutdown */
-	struct gpio_desc backlight_vdd;	/* GPIO for backlight vdd */
-	struct gpio_desc panel_vdd;	/* GPIO for panel vdd */
-	/*
-	 * Panel required timings
-	 * Timing 1: delay between panel_vdd-rise and data-rise
-	 * Timing 2: delay between data-rise and backlight_vdd-rise
-	 * Timing 3: delay between backlight_vdd and pwm-rise
-	 * Timing 4: delay between pwm-rise and backlight_en-rise
-	 */
-	uint panel_timings[FDT_LCD_TIMINGS];
 };
 
 enum {
@@ -150,26 +107,23 @@ static void update_window(struct dc_ctlr *dc, struct disp_ctl_win *win)
 	writel(val, &dc->cmd.state_ctrl);
 }
 
-static void write_pair(struct tegra_lcd_priv *priv, int item, u32 *reg)
-{
-	writel(priv->horiz_timing[item] |
-			(priv->vert_timing[item] << 16), reg);
-}
-
 static int update_display_mode(struct dc_disp_reg *disp,
 			       struct tegra_lcd_priv *priv)
 {
+	struct display_timing *dt = &priv->timing;
 	unsigned long val;
 	unsigned long rate;
 	unsigned long div;
 
 	writel(0x0, &disp->disp_timing_opt);
-	write_pair(priv, FDT_LCD_TIMING_REF_TO_SYNC, &disp->ref_to_sync);
-	write_pair(priv, FDT_LCD_TIMING_SYNC_WIDTH, &disp->sync_width);
-	write_pair(priv, FDT_LCD_TIMING_BACK_PORCH, &disp->back_porch);
-	write_pair(priv, FDT_LCD_TIMING_FRONT_PORCH, &disp->front_porch);
 
-	writel(priv->width | (priv->height << 16), &disp->disp_active);
+	writel(1 | 1 << 16, &disp->ref_to_sync);
+	writel(dt->hsync_len.typ | dt->vsync_len.typ << 16, &disp->sync_width);
+	writel(dt->hback_porch.typ | dt->vback_porch.typ << 16,
+	       &disp->back_porch);
+	writel((dt->hfront_porch.typ - 1) | (dt->vfront_porch.typ - 1) << 16,
+	       &disp->front_porch);
+	writel(dt->hactive.typ | (dt->vactive.typ << 16), &disp->disp_active);
 
 	val = DE_SELECT_ACTIVE << DE_SELECT_SHIFT;
 	val |= DE_CONTROL_NORMAL << DE_CONTROL_SHIFT;
@@ -287,12 +241,11 @@ static int setup_window(struct disp_ctl_win *win,
 	win->stride = priv->width * (1 << priv->log2_bpp) / 8;
 	debug("%s: depth = %d\n", __func__, priv->log2_bpp);
 	switch (priv->log2_bpp) {
-	case 5:
-	case 24:
+	case VIDEO_BPP32:
 		win->fmt = COLOR_DEPTH_R8G8B8A8;
 		win->bpp = 32;
 		break;
-	case 4:
+	case VIDEO_BPP16:
 		win->fmt = COLOR_DEPTH_B5G6R5;
 		win->bpp = 16;
 		break;
@@ -305,18 +258,6 @@ static int setup_window(struct disp_ctl_win *win,
 	return 0;
 }
 
-static void debug_timing(const char *name, unsigned int timing[])
-{
-#ifdef DEBUG
-	int i;
-
-	debug("%s timing: ", name);
-	for (i = 0; i < FDT_LCD_TIMING_COUNT; i++)
-		debug("%d ", timing[i]);
-	debug("\n");
-#endif
-}
-
 /**
  * Register a new display based on device tree configuration.
  *
@@ -363,112 +304,6 @@ static int tegra_display_probe(const void *blob, struct tegra_lcd_priv *priv,
 	return 0;
 }
 
-/**
- * Handle the next stage of device init
- */
-static int handle_stage(const void *blob, struct tegra_lcd_priv *priv)
-{
-	debug("%s: stage %d\n", __func__, priv->stage);
-
-	/* do the things for this stage */
-	switch (priv->stage) {
-	case STAGE_START:
-		/*
-		 * It is possible that the FDT has requested that the LCD be
-		 * disabled. We currently don't support this. It would require
-		 * changes to U-Boot LCD subsystem to have LCD support
-		 * compiled in but not used. An easier option might be to
-		 * still have a frame buffer, but leave the backlight off and
-		 * remove all mention of lcd in the stdout environment
-		 * variable.
-		 */
-
-		funcmux_select(PERIPH_ID_DISP1, FUNCMUX_DEFAULT);
-		break;
-	case STAGE_PANEL_VDD:
-		if (dm_gpio_is_valid(&priv->panel_vdd))
-			dm_gpio_set_value(&priv->panel_vdd, 1);
-		break;
-	case STAGE_LVDS:
-		if (dm_gpio_is_valid(&priv->lvds_shutdown))
-			dm_gpio_set_value(&priv->lvds_shutdown, 1);
-		break;
-	case STAGE_BACKLIGHT_VDD:
-		if (dm_gpio_is_valid(&priv->backlight_vdd))
-			dm_gpio_set_value(&priv->backlight_vdd, 1);
-		break;
-	case STAGE_PWM:
-		/* Enable PWM at 15/16 high, 32768 Hz with divider 1 */
-		pinmux_set_func(PMUX_PINGRP_GPU, PMUX_FUNC_PWM);
-		pinmux_tristate_disable(PMUX_PINGRP_GPU);
-
-		pwm_set_config(priv->pwm, priv->pwm_channel, 0xdf, 0xff);
-		pwm_set_enable(priv->pwm, priv->pwm_channel, true);
-		break;
-	case STAGE_BACKLIGHT_EN:
-		if (dm_gpio_is_valid(&priv->backlight_en))
-			dm_gpio_set_value(&priv->backlight_en, 1);
-		break;
-	case STAGE_DONE:
-		break;
-	}
-
-	/* set up timer for next stage */
-	priv->timer_next = timer_get_us();
-	if (priv->stage < FDT_LCD_TIMINGS)
-		priv->timer_next += priv->panel_timings[priv->stage] * 1000;
-
-	/* move to next stage */
-	priv->stage++;
-	return 0;
-}
-
-/**
- * Perform the next stage of the LCD init if it is time to do so.
- *
- * LCD init can be time-consuming because of the number of delays we need
- * while waiting for the backlight power supply, etc. This function can
- * be called at various times during U-Boot operation to advance the
- * initialization of the LCD to the next stage if sufficient time has
- * passed since the last stage. It keeps track of what stage it is up to
- * and the time that it is permitted to move to the next stage.
- *
- * The final call should have wait=1 to complete the init.
- *
- * @param blob	fdt blob containing LCD information
- * @param wait	1 to wait until all init is complete, and then return
- *		0 to return immediately, potentially doing nothing if it is
- *		not yet time for the next init.
- */
-static int tegra_lcd_check_next_stage(const void *blob,
-				      struct tegra_lcd_priv *priv, int wait)
-{
-	if (priv->stage == STAGE_DONE)
-		return 0;
-
-	do {
-		/* wait if we need to */
-		debug("%s: stage %d\n", __func__, priv->stage);
-		if (priv->stage != STAGE_START) {
-			int delay = priv->timer_next - timer_get_us();
-
-			if (delay > 0) {
-				if (wait)
-					udelay(delay);
-				else
-					return 0;
-			}
-		}
-
-		if (handle_stage(blob, priv))
-			return -1;
-	} while (wait && priv->stage != STAGE_DONE);
-	if (priv->stage == STAGE_DONE)
-		debug("%s: LCD init complete\n", __func__);
-
-	return 0;
-}
-
 static int tegra_lcd_probe(struct udevice *dev)
 {
 	struct video_uc_platdata *plat = dev_get_uclass_platdata(dev);
@@ -476,14 +311,23 @@ static int tegra_lcd_probe(struct udevice *dev)
 	struct tegra_lcd_priv *priv = dev_get_priv(dev);
 	const void *blob = gd->fdt_blob;
 	int type = DCACHE_OFF;
+	int ret;
 
 	/* Initialize the Tegra display controller */
+	funcmux_select(PERIPH_ID_DISP1, FUNCMUX_DEFAULT);
 	if (tegra_display_probe(blob, priv, (void *)plat->base)) {
 		printf("%s: Failed to probe display driver\n", __func__);
 		return -1;
 	}
 
-	tegra_lcd_check_next_stage(blob, priv, 1);
+	pinmux_set_func(PMUX_PINGRP_GPU, PMUX_FUNC_PWM);
+	pinmux_tristate_disable(PMUX_PINGRP_GPU);
+
+	ret = panel_enable_backlight(priv->panel);
+	if (ret) {
+		debug("%s: Cannot enable backlight, ret=%d\n", __func__, ret);
+		return ret;
+	}
 
 	/* Set up the LCD caching as requested */
 	if (priv->cache_type & FDT_LCD_CACHE_WRITE_THROUGH)
@@ -507,13 +351,11 @@ static int tegra_lcd_probe(struct udevice *dev)
 static int tegra_lcd_ofdata_to_platdata(struct udevice *dev)
 {
 	struct tegra_lcd_priv *priv = dev_get_priv(dev);
-	struct fdtdec_phandle_args args;
 	const void *blob = gd->fdt_blob;
+	struct display_timing *timing;
 	int node = dev->of_offset;
-	int front, back, ref;
 	int panel_node;
 	int rgb;
-	int bpp, bit;
 	int ret;
 
 	priv->disp = (struct disp_ctlr *)dev_get_addr(dev);
@@ -523,96 +365,40 @@ static int tegra_lcd_ofdata_to_platdata(struct udevice *dev)
 	}
 
 	rgb = fdt_subnode_offset(blob, node, "rgb");
-
-	panel_node = fdtdec_lookup_phandle(blob, rgb, "nvidia,panel");
-	if (panel_node < 0) {
-		debug("%s: Cannot find panel information\n", __func__);
+	if (rgb < 0) {
+		debug("%s: Cannot find rgb subnode for '%s' (ret=%d)\n",
+		      __func__, dev->name, rgb);
 		return -EINVAL;
 	}
 
-	priv->width = fdtdec_get_int(blob, panel_node, "xres", -1);
-	priv->height = fdtdec_get_int(blob, panel_node, "yres", -1);
-	priv->pixel_clock = fdtdec_get_int(blob, panel_node, "clock", 0);
-	if (!priv->pixel_clock || priv->width == -1 || priv->height == -1) {
-		debug("%s: Pixel parameters missing\n", __func__);
-		return -EINVAL;
-	}
-
-	back = fdtdec_get_int(blob, panel_node, "left-margin", -1);
-	front = fdtdec_get_int(blob, panel_node, "right-margin", -1);
-	ref = fdtdec_get_int(blob, panel_node, "hsync-len", -1);
-	if ((back | front | ref) == -1) {
-		debug("%s: Horizontal parameters missing\n", __func__);
-		return -EINVAL;
-	}
-
-	/* Use a ref-to-sync of 1 always, and take this from the front porch */
-	priv->horiz_timing[FDT_LCD_TIMING_REF_TO_SYNC] = 1;
-	priv->horiz_timing[FDT_LCD_TIMING_SYNC_WIDTH] = ref;
-	priv->horiz_timing[FDT_LCD_TIMING_BACK_PORCH] = back;
-	priv->horiz_timing[FDT_LCD_TIMING_FRONT_PORCH] = front -
-		priv->horiz_timing[FDT_LCD_TIMING_REF_TO_SYNC];
-	debug_timing("horiz", priv->horiz_timing);
-
-	back = fdtdec_get_int(blob, panel_node, "upper-margin", -1);
-	front = fdtdec_get_int(blob, panel_node, "lower-margin", -1);
-	ref = fdtdec_get_int(blob, panel_node, "vsync-len", -1);
-	if ((back | front | ref) == -1) {
-		debug("%s: Vertical parameters missing\n", __func__);
-		return -EINVAL;
-	}
-
-	priv->vert_timing[FDT_LCD_TIMING_REF_TO_SYNC] = 1;
-	priv->vert_timing[FDT_LCD_TIMING_SYNC_WIDTH] = ref;
-	priv->vert_timing[FDT_LCD_TIMING_BACK_PORCH] = back;
-	priv->vert_timing[FDT_LCD_TIMING_FRONT_PORCH] = front -
-		priv->vert_timing[FDT_LCD_TIMING_REF_TO_SYNC];
-	debug_timing("vert", priv->vert_timing);
-
-	bpp = fdtdec_get_int(blob, panel_node, "nvidia,bits-per-pixel", -1);
-	bit = ffs(bpp) - 1;
-	if (bpp == (1 << bit))
-		priv->log2_bpp = bit;
-	else
-		priv->log2_bpp = bpp;
-	if (bpp == -1) {
-		debug("%s: Pixel bpp parameters missing\n", __func__);
+	ret = fdtdec_decode_display_timing(blob, rgb, 0, &priv->timing);
+	if (ret) {
+		debug("%s: Cannot read display timing for '%s' (ret=%d)\n",
+		      __func__, dev->name, ret);
 		return -EINVAL;
 	}
+	timing = &priv->timing;
+	priv->width = timing->hactive.typ;
+	priv->height = timing->vactive.typ;
+	priv->pixel_clock = timing->pixelclock.typ;
+	priv->log2_bpp = VIDEO_BPP16;
 
-	if (fdtdec_parse_phandle_with_args(blob, panel_node, "nvidia,pwm",
-					   "#pwm-cells", 0, 0, &args)) {
-		debug("%s: Unable to decode PWM\n", __func__);
+	/*
+	 * Sadly the panel phandle is in an rgb subnode so we cannot use
+	 * uclass_get_device_by_phandle().
+	 */
+	panel_node = fdtdec_lookup_phandle(blob, rgb, "nvidia,panel");
+	if (panel_node < 0) {
+		debug("%s: Cannot find panel information\n", __func__);
 		return -EINVAL;
 	}
-
-	ret = uclass_get_device_by_of_offset(UCLASS_PWM, args.node, &priv->pwm);
+	ret = uclass_get_device_by_of_offset(UCLASS_PANEL, panel_node,
+					     &priv->panel);
 	if (ret) {
-		debug("%s: Unable to find PWM\n", __func__);
-		return -EINVAL;
+		debug("%s: Cannot find panel for '%s' (ret=%d)\n", __func__,
+		      dev->name, ret);
+		return ret;
 	}
-	priv->pwm_channel = args.args[0];
-
-	priv->cache_type = fdtdec_get_int(blob, panel_node, "nvidia,cache-type",
-					  FDT_LCD_CACHE_WRITE_BACK_FLUSH);
-
-	/* These GPIOs are all optional */
-	gpio_request_by_name_nodev(blob, panel_node,
-				   "nvidia,backlight-enable-gpios", 0,
-				   &priv->backlight_en, GPIOD_IS_OUT);
-	gpio_request_by_name_nodev(blob, panel_node,
-				   "nvidia,lvds-shutdown-gpios", 0,
-				   &priv->lvds_shutdown, GPIOD_IS_OUT);
-	gpio_request_by_name_nodev(blob, panel_node,
-				   "nvidia,backlight-vdd-gpios", 0,
-				   &priv->backlight_vdd, GPIOD_IS_OUT);
-	gpio_request_by_name_nodev(blob, panel_node,
-				   "nvidia,panel-vdd-gpios", 0,
-				   &priv->panel_vdd, GPIOD_IS_OUT);
-
-	if (fdtdec_get_int_array(blob, panel_node, "nvidia,panel-timings",
-				 priv->panel_timings, FDT_LCD_TIMINGS))
-		return -EINVAL;
 
 	return 0;
 }