[PATCH 2/2] drm/mcde: Support DPI output

Sam Ravnborg sam at ravnborg.org
Mon Nov 23 22:12:00 UTC 2020


Hi Linus.

On Thu, Nov 12, 2020 at 03:29:25PM +0100, Linus Walleij wrote:
> This implements support for DPI output using the port node
> in the device tree to connect a DPI LCD display to the
> MCDE. The block also supports TV-out but we leave that
> for another day when we have a hardware using it.
> 
> We implement parsing and handling of the "port" node,
> and follow that to the DPI endpoint.
> 
> The clock divider used by the MCDE to divide down the
> "lcdclk" (this has been designed for TV-like frequencies)
> is represented by an ordinary clock provider internally
> in the MCDE. This idea was inspired by the PL111 solution
> by Eric Anholt: the divider also works very similar to
> the Pl111 clock divider.
> 
> We take care to clear up some errors regarding the number
> of available formatters and their type. We have 6 DSI
> formatters and 2 DPI formatters.
> 
> Tested on the Samsung GT-I9070 Janice mobile phone.
> 
> Cc: Stephan Gerhold <stephan at gerhold.net>
> Cc: phone-devel at vger.kernel.org
> Cc: upstreaming at lists.sr.ht
> Signed-off-by: Linus Walleij <linus.walleij at linaro.org>
> ---
>  drivers/gpu/drm/mcde/Kconfig             |   1 +
>  drivers/gpu/drm/mcde/Makefile            |   2 +-
>  drivers/gpu/drm/mcde/mcde_clk_div.c      | 192 ++++++++++++++
>  drivers/gpu/drm/mcde/mcde_display.c      | 304 ++++++++++++++++++++---
>  drivers/gpu/drm/mcde/mcde_display_regs.h |  87 +++++++
>  drivers/gpu/drm/mcde/mcde_drm.h          |  10 +
>  drivers/gpu/drm/mcde/mcde_drv.c          |  46 +++-
>  7 files changed, 595 insertions(+), 47 deletions(-)
>  create mode 100644 drivers/gpu/drm/mcde/mcde_clk_div.c
> 
> diff --git a/drivers/gpu/drm/mcde/Kconfig b/drivers/gpu/drm/mcde/Kconfig
> index b3990126562c..71c689b573c9 100644
> --- a/drivers/gpu/drm/mcde/Kconfig
> +++ b/drivers/gpu/drm/mcde/Kconfig
> @@ -4,6 +4,7 @@ config DRM_MCDE
>  	depends on CMA
>  	depends on ARM || COMPILE_TEST
>  	depends on OF
> +	depends on COMMON_CLK
>  	select MFD_SYSCON
>  	select DRM_MIPI_DSI
>  	select DRM_BRIDGE
> diff --git a/drivers/gpu/drm/mcde/Makefile b/drivers/gpu/drm/mcde/Makefile
> index fe28f4e0fe46..15d9c89a3273 100644
> --- a/drivers/gpu/drm/mcde/Makefile
> +++ b/drivers/gpu/drm/mcde/Makefile
> @@ -1,3 +1,3 @@
> -mcde_drm-y +=	mcde_drv.o mcde_dsi.o mcde_display.o
> +mcde_drm-y +=	mcde_drv.o mcde_dsi.o mcde_clk_div.o mcde_display.o
>  
>  obj-$(CONFIG_DRM_MCDE) += mcde_drm.o
> diff --git a/drivers/gpu/drm/mcde/mcde_clk_div.c b/drivers/gpu/drm/mcde/mcde_clk_div.c
> new file mode 100644
> index 000000000000..038821d2ef80
> --- /dev/null
> +++ b/drivers/gpu/drm/mcde/mcde_clk_div.c
> @@ -0,0 +1,192 @@
> +// SPDX-License-Identifier: GPL-2.0
> +#include <linux/clk-provider.h>
> +#include <linux/regulator/consumer.h>
> +
> +#include "mcde_drm.h"
> +#include "mcde_display_regs.h"
> +
> +/* The MCDE internal clock dividers for FIFO A and B */
> +struct mcde_clk_div {
> +	struct clk_hw hw;
> +	struct mcde *mcde;
> +	u32 cr;
> +	u32 cr_div;
> +};
> +
> +static int mcde_clk_div_enable(struct clk_hw *hw)
> +{
> +	struct mcde_clk_div *cdiv = container_of(hw, struct mcde_clk_div, hw);
> +	struct mcde *mcde = cdiv->mcde;
> +	u32 val;
> +
> +	spin_lock(&mcde->fifo_crx1_lock);
> +	val = readl(mcde->regs + cdiv->cr);
> +	/*
> +	 * Select the PLL72 (LCD) clock as parent
> +	 * FIXME: implement other parents.
> +	 */
> +	val &= ~MCDE_CRX1_CLKSEL_MASK;
> +	val |= MCDE_CRX1_CLKSEL_CLKPLL72 << MCDE_CRX1_CLKSEL_SHIFT;
> +	/* Internal clock */
> +	val |= MCDE_CRA1_CLKTYPE_TVXCLKSEL1;
> +
> +	/* Clear then set the divider */
> +	val &= ~(MCDE_CRX1_BCD | MCDE_CRX1_PCD_MASK);
> +	val |= cdiv->cr_div;
> +
> +	writel(val, mcde->regs + cdiv->cr);
> +	spin_unlock(&mcde->fifo_crx1_lock);
> +
> +	return 0;
> +}
> +
> +static int mcde_clk_div_choose_div(struct clk_hw *hw, unsigned long rate,
> +				   unsigned long *prate, bool set_parent)
> +{
> +	int best_div = 1, div;
> +	struct clk_hw *parent = clk_hw_get_parent(hw);
> +	unsigned long best_prate = 0;
> +	unsigned long best_diff = ~0ul;
> +	int max_div = (1 << MCDE_CRX1_PCD_BITS) - 1;
> +
> +	for (div = 1; div < max_div; div++) {
> +		unsigned long this_prate, div_rate, diff;
> +
> +		if (set_parent)
> +			this_prate = clk_hw_round_rate(parent, rate * div);
> +		else
> +			this_prate = *prate;
> +		div_rate = DIV_ROUND_UP_ULL(this_prate, div);
> +		diff = abs(rate - div_rate);
> +
> +		if (diff < best_diff) {
> +			best_div = div;
> +			best_diff = diff;
> +			best_prate = this_prate;
> +		}
> +	}
> +
> +	*prate = best_prate;
> +	return best_div;
> +}
> +
> +static long mcde_clk_div_round_rate(struct clk_hw *hw, unsigned long rate,
> +				     unsigned long *prate)
> +{
> +	int div = mcde_clk_div_choose_div(hw, rate, prate, true);
> +
> +	return DIV_ROUND_UP_ULL(*prate, div);
> +}
> +
> +static unsigned long mcde_clk_div_recalc_rate(struct clk_hw *hw,
> +					       unsigned long prate)
> +{
> +	struct mcde_clk_div *cdiv = container_of(hw, struct mcde_clk_div, hw);
> +	struct mcde *mcde = cdiv->mcde;
> +	u32 cr;
> +	int div;
> +
> +	/*
> +	 * If the MCDE is not powered we can't access registers.
> +	 * It will come up with 0 in the divider register bits, which
> +	 * means "divide by 2".
> +	 */
> +	if (!regulator_is_enabled(mcde->epod))
> +		return DIV_ROUND_UP_ULL(prate, 2);
> +
> +	cr = readl(mcde->regs + cdiv->cr);
> +	if (cr & MCDE_CRX1_BCD)
> +		return prate;
> +
> +	/* 0 in the PCD means "divide by 2", 1 means "divide by 3" etc */
> +	div = cr & MCDE_CRX1_PCD_MASK;
> +	div += 2;
> +
> +	return DIV_ROUND_UP_ULL(prate, div);
> +}
> +
> +static int mcde_clk_div_set_rate(struct clk_hw *hw, unsigned long rate,
> +				  unsigned long prate)
> +{
> +	struct mcde_clk_div *cdiv = container_of(hw, struct mcde_clk_div, hw);
> +	int div = mcde_clk_div_choose_div(hw, rate, &prate, false);
> +	u32 cr = 0;
> +
> +	/*
> +	 * We cache the CR bits to set the divide in the state so that
> +	 * we can call this before we can even write to the hardware.
> +	 */
> +	if (div == 1) {
> +		/* Bypass clock divider */
> +		cr |= MCDE_CRX1_BCD;
> +	} else {
> +		div -= 2;
> +		cr |= div & MCDE_CRX1_PCD_MASK;
> +	}
> +	cdiv->cr_div = cr;
> +
> +	return 0;
> +}
> +
> +static const struct clk_ops mcde_clk_div_ops = {
> +	.enable = mcde_clk_div_enable,
> +	.recalc_rate = mcde_clk_div_recalc_rate,
> +	.round_rate = mcde_clk_div_round_rate,
> +	.set_rate = mcde_clk_div_set_rate,
> +};
> +
> +int mcde_init_clock_divider(struct mcde *mcde)
> +{
> +	struct device *dev = mcde->dev;
> +	struct mcde_clk_div *fifoa;
> +	struct mcde_clk_div *fifob;
> +	const char *parent_name;
> +	struct clk_init_data fifoa_init = {
const?

> +		.name = "fifoa",
> +		.ops = &mcde_clk_div_ops,
> +		.parent_names = &parent_name,
> +		.num_parents = 1,
> +		.flags = CLK_SET_RATE_PARENT,
> +	};
> +	struct clk_init_data fifob_init = {
const?

> +		.name = "fifob",
> +		.ops = &mcde_clk_div_ops,
> +		.parent_names = &parent_name,
> +		.num_parents = 1,
> +		.flags = CLK_SET_RATE_PARENT,
> +	};
> +	int ret;
> +
> +	spin_lock_init(&mcde->fifo_crx1_lock);
> +	parent_name = __clk_get_name(mcde->lcd_clk);
> +
> +	/* Allocate 2 clocks */
> +	fifoa = devm_kzalloc(dev, sizeof(*fifoa), GFP_KERNEL);
> +	if (!fifoa)
> +		return -ENOMEM;
> +	fifob = devm_kzalloc(dev, sizeof(*fifob), GFP_KERNEL);
> +	if (!fifob)
> +		return -ENOMEM;
> +
> +	fifoa->mcde = mcde;
> +	fifoa->cr = MCDE_CRA1;
> +	fifoa->hw.init = &fifoa_init;
> +	ret = devm_clk_hw_register(dev, &fifoa->hw);
> +	if (ret) {
> +		dev_err(dev, "error registering FIFO A clock divider\n");
> +		return ret;
> +	}
> +	mcde->fifoa_clk = fifoa->hw.clk;
> +
> +	fifob->mcde = mcde;
> +	fifob->cr = MCDE_CRB1;
> +	fifob->hw.init = &fifob_init;
> +	ret = devm_clk_hw_register(dev, &fifob->hw);
> +	if (ret) {
> +		dev_err(dev, "error registering FIFO B clock divider\n");
> +		return ret;
> +	}
> +	mcde->fifob_clk = fifob->hw.clk;
> +
> +	return 0;
> +}
> diff --git a/drivers/gpu/drm/mcde/mcde_display.c b/drivers/gpu/drm/mcde/mcde_display.c
> index 66a07e340f8a..14c76d3a8e5a 100644
> --- a/drivers/gpu/drm/mcde/mcde_display.c
> +++ b/drivers/gpu/drm/mcde/mcde_display.c
> @@ -8,6 +8,7 @@
>  #include <linux/delay.h>
>  #include <linux/dma-buf.h>
>  #include <linux/regulator/consumer.h>
> +#include <linux/media-bus-format.h>
>  
>  #include <drm/drm_device.h>
>  #include <drm/drm_fb_cma_helper.h>
> @@ -16,6 +17,7 @@
>  #include <drm/drm_gem_framebuffer_helper.h>
>  #include <drm/drm_mipi_dsi.h>
>  #include <drm/drm_simple_kms_helper.h>
> +#include <drm/drm_bridge.h>
>  #include <drm/drm_vblank.h>
>  #include <video/mipi_display.h>
>  
> @@ -57,10 +59,15 @@ enum mcde_overlay {
>  	MCDE_OVERLAY_5,
>  };
>  
> -enum mcde_dsi_formatter {
> +enum mcde_formatter {
>  	MCDE_DSI_FORMATTER_0 = 0,
>  	MCDE_DSI_FORMATTER_1,
>  	MCDE_DSI_FORMATTER_2,
> +	MCDE_DSI_FORMATTER_3,
> +	MCDE_DSI_FORMATTER_4,
> +	MCDE_DSI_FORMATTER_5,
> +	MCDE_DPI_FORMATTER_0,
> +	MCDE_DPI_FORMATTER_1,
>  };
>  
>  void mcde_display_irq(struct mcde *mcde)
> @@ -81,7 +88,7 @@ void mcde_display_irq(struct mcde *mcde)
>  	 *
>  	 * TODO: Currently only one DSI link is supported.
>  	 */
> -	if (mcde_dsi_irq(mcde->mdsi)) {
> +	if (!mcde->dpi_output && mcde_dsi_irq(mcde->mdsi)) {
>  		u32 val;
>  
>  		/*
> @@ -556,6 +563,7 @@ static void mcde_configure_channel(struct mcde *mcde, enum mcde_channel ch,
>  			<< MCDE_CHNLXSYNCHMOD_OUT_SYNCH_SRC_SHIFT;
>  		break;
>  	case MCDE_VIDEO_FORMATTER_FLOW:
> +	case MCDE_DPI_FORMATTER_FLOW:
>  		val = MCDE_CHNLXSYNCHMOD_SRC_SYNCH_HARDWARE
>  			<< MCDE_CHNLXSYNCHMOD_SRC_SYNCH_SHIFT;
>  		val |= MCDE_CHNLXSYNCHMOD_OUT_SYNCH_SRC_FORMATTER
> @@ -594,10 +602,35 @@ static void mcde_configure_channel(struct mcde *mcde, enum mcde_channel ch,
>  		       mcde->regs + mux);
>  		break;
>  	}
> +
> +	/*
> +	 * If using DPI configure the sync event.
> +	 * TODO: this is for LCD only, it does not cover TV out.
> +	 */
> +	if (mcde->dpi_output) {
> +		u32 stripwidth;
> +
> +		stripwidth = 0xF000 / (mode->vdisplay * 4);
> +		dev_info(mcde->dev, "stripwidth: %d\n", stripwidth);
> +
> +		val = MCDE_SYNCHCONF_HWREQVEVENT_ACTIVE_VIDEO |
> +			(mode->hdisplay - 1 - stripwidth) << MCDE_SYNCHCONF_HWREQVCNT_SHIFT |
> +			MCDE_SYNCHCONF_SWINTVEVENT_ACTIVE_VIDEO |
> +			(mode->hdisplay - 1 - stripwidth) << MCDE_SYNCHCONF_SWINTVCNT_SHIFT;
> +
> +		switch (fifo) {
> +		case MCDE_FIFO_A:
> +			writel(val, mcde->regs + MCDE_SYNCHCONFA);
> +			break;
> +		case MCDE_FIFO_B:
> +			writel(val, mcde->regs + MCDE_SYNCHCONFB);
> +			break;
> +		}
> +	}
>  }
>  
>  static void mcde_configure_fifo(struct mcde *mcde, enum mcde_fifo fifo,
> -				enum mcde_dsi_formatter fmt,
> +				enum mcde_formatter fmt,
>  				int fifo_wtrmrk)
>  {
>  	u32 val;
> @@ -618,12 +651,49 @@ static void mcde_configure_fifo(struct mcde *mcde, enum mcde_fifo fifo,
>  	}
>  
>  	val = fifo_wtrmrk << MCDE_CTRLX_FIFOWTRMRK_SHIFT;
> -	/* We only support DSI formatting for now */
> -	val |= MCDE_CTRLX_FORMTYPE_DSI <<
> -		MCDE_CTRLX_FORMTYPE_SHIFT;
>  
> -	/* Select the formatter to use for this FIFO */
> -	val |= fmt << MCDE_CTRLX_FORMID_SHIFT;
> +	/*
> +	 * Select the formatter to use for this FIFO
> +	 *
> +	 * The register definitions imply that different IDs should be used
> +	 * by the DSI formatters depending on if they are in VID or CMD
> +	 * mode, and the manual says they are dedicated but identical.
> +	 * The vendor code uses them as it seems fit.
> +	 */
> +	switch (fmt) {
> +	case MCDE_DSI_FORMATTER_0:
> +		val |= MCDE_CTRLX_FORMTYPE_DSI << MCDE_CTRLX_FORMTYPE_SHIFT;
> +		val |= MCDE_CTRLX_FORMID_DSI0VID << MCDE_CTRLX_FORMID_SHIFT;
> +		break;
> +	case MCDE_DSI_FORMATTER_1:
> +		val |= MCDE_CTRLX_FORMTYPE_DSI << MCDE_CTRLX_FORMTYPE_SHIFT;
> +		val |= MCDE_CTRLX_FORMID_DSI0CMD << MCDE_CTRLX_FORMID_SHIFT;
> +		break;
> +	case MCDE_DSI_FORMATTER_2:
> +		val |= MCDE_CTRLX_FORMTYPE_DSI << MCDE_CTRLX_FORMTYPE_SHIFT;
> +		val |= MCDE_CTRLX_FORMID_DSI1VID << MCDE_CTRLX_FORMID_SHIFT;
> +		break;
> +	case MCDE_DSI_FORMATTER_3:
> +		val |= MCDE_CTRLX_FORMTYPE_DSI << MCDE_CTRLX_FORMTYPE_SHIFT;
> +		val |= MCDE_CTRLX_FORMID_DSI1CMD << MCDE_CTRLX_FORMID_SHIFT;
> +		break;
> +	case MCDE_DSI_FORMATTER_4:
> +		val |= MCDE_CTRLX_FORMTYPE_DSI << MCDE_CTRLX_FORMTYPE_SHIFT;
> +		val |= MCDE_CTRLX_FORMID_DSI2VID << MCDE_CTRLX_FORMID_SHIFT;
> +		break;
> +	case MCDE_DSI_FORMATTER_5:
> +		val |= MCDE_CTRLX_FORMTYPE_DSI << MCDE_CTRLX_FORMTYPE_SHIFT;
> +		val |= MCDE_CTRLX_FORMID_DSI2CMD << MCDE_CTRLX_FORMID_SHIFT;
> +		break;
> +	case MCDE_DPI_FORMATTER_0:
> +		val |= MCDE_CTRLX_FORMTYPE_DPITV << MCDE_CTRLX_FORMTYPE_SHIFT;
> +		val |= MCDE_CTRLX_FORMID_DPIA << MCDE_CTRLX_FORMID_SHIFT;
> +		break;
> +	case MCDE_DPI_FORMATTER_1:
> +		val |= MCDE_CTRLX_FORMTYPE_DPITV << MCDE_CTRLX_FORMTYPE_SHIFT;
> +		val |= MCDE_CTRLX_FORMID_DPIB << MCDE_CTRLX_FORMID_SHIFT;
> +		break;
> +	}
>  	writel(val, mcde->regs + ctrl);
>  
>  	/* Blend source with Alpha 0xff on FIFO */
> @@ -631,17 +701,54 @@ static void mcde_configure_fifo(struct mcde *mcde, enum mcde_fifo fifo,
>  		0xff << MCDE_CRX0_ALPHABLEND_SHIFT;
>  	writel(val, mcde->regs + cr0);
>  
> -	/* Set-up from mcde_fmtr_dsi.c, fmtr_dsi_enable_video() */
> -
> -	/* Use the MCDE clock for this FIFO */
> -	val = MCDE_CRX1_CLKSEL_MCDECLK << MCDE_CRX1_CLKSEL_SHIFT;
> +	spin_lock(&mcde->fifo_crx1_lock);
> +	val = readl(mcde->regs + cr1);
> +	/*
> +	 * Set-up from mcde_fmtr_dsi.c, fmtr_dsi_enable_video()
> +	 * FIXME: a different clock needs to be selected for TV out.
> +	 */
> +	if (mcde->dpi_output) {
> +		struct drm_connector *connector = drm_panel_bridge_connector(mcde->bridge);
> +		u32 bus_format;
> +
> +		/* Assume RGB888 24 bit if we have no further info */
> +		if (!connector->display_info.num_bus_formats) {
> +			dev_info(mcde->dev, "panel does not specify bus format, assume RGB888\n");
> +			bus_format = MEDIA_BUS_FMT_RGB888_1X24;
> +		} else {
> +			bus_format = connector->display_info.bus_formats[0];
> +		}
>  
> -	/* TODO: when adding DPI support add OUTBPP etc here */
> +		/*
> +		 * Set up the CDWIN and OUTBPP for the LCD
> +		 *
> +		 * FIXME: fill this in if you know the correspondance between the MIPI
> +		 * DPI specification and the media bus formats.
> +		 */
> +		val &= ~MCDE_CRX1_CDWIN_MASK;
> +		val &= ~MCDE_CRX1_OUTBPP_MASK;
> +		switch (bus_format) {
> +		case MEDIA_BUS_FMT_RGB888_1X24:
> +			val |= MCDE_CRX1_CDWIN_24BPP << MCDE_CRX1_CDWIN_SHIFT;
> +			val |= MCDE_CRX1_OUTBPP_24BPP << MCDE_CRX1_OUTBPP_SHIFT;
> +			break;
> +		default:
> +			dev_err(mcde->dev, "unknown bus format, assume RGB888\n");
> +			val |= MCDE_CRX1_CDWIN_24BPP << MCDE_CRX1_CDWIN_SHIFT;
> +			val |= MCDE_CRX1_OUTBPP_24BPP << MCDE_CRX1_OUTBPP_SHIFT;
> +			break;
> +		}
> +	} else {
> +		/* Use the MCDE clock for DSI */
> +		val &= ~MCDE_CRX1_CLKSEL_MASK;
> +		val = MCDE_CRX1_CLKSEL_MCDECLK << MCDE_CRX1_CLKSEL_SHIFT;
> +	}
>  	writel(val, mcde->regs + cr1);
> +	spin_unlock(&mcde->fifo_crx1_lock);
>  };
>  
>  static void mcde_configure_dsi_formatter(struct mcde *mcde,
> -					 enum mcde_dsi_formatter fmt,
> +					 enum mcde_formatter fmt,
>  					 u32 formatter_frame,
>  					 int pkt_size)
>  {
> @@ -681,6 +788,9 @@ static void mcde_configure_dsi_formatter(struct mcde *mcde,
>  		delay0 = MCDE_DSIVID2DELAY0;
>  		delay1 = MCDE_DSIVID2DELAY1;
>  		break;
> +	default:
> +		dev_err(mcde->dev, "tried to configure a non-DSI formatter as DSI\n");
> +		return;
>  	}
>  
>  	/*
> @@ -860,6 +970,103 @@ static int mcde_dsi_get_pkt_div(int ppl, int fifo_size)
>  	return 1;
>  }
>  
> +static void mcde_setup_dpi(struct mcde *mcde, const struct drm_display_mode *mode,
> +			   int *fifo_wtrmrk_lvl)
> +{
> +	struct drm_connector *connector = drm_panel_bridge_connector(mcde->bridge);
> +	u32 hsw, hfp, hbp;
> +	u32 vsw, vfp, vbp;
> +	u32 val;
> +
> +	/* FIXME: we only support LCD, implement TV out */
> +	hsw = mode->hsync_end - mode->hsync_start;
> +	hfp = mode->hsync_start - mode->hdisplay;
> +	hbp = mode->htotal - mode->hsync_end;
> +	vsw = mode->vsync_end - mode->vsync_start;
> +	vfp = mode->vsync_start - mode->vdisplay;
> +	vbp = mode->vtotal - mode->vsync_end;
> +
> +	dev_info(mcde->dev, "output on DPI LCD from channel A\n");
> +	/* Display actual values */
> +	dev_info(mcde->dev, "HSW: %d, HFP: %d, HBP: %d, VSW: %d, VFP: %d, VBP: %d\n",
> +		 hsw, hfp, hbp, vsw, vfp, vbp);
> +
> +	/*
> +	 * The pixel fetcher is 128 64-bit words deep = 1024 bytes.
> +	 * One overlay of 32bpp (4 cpp) assumed, fetch 160 pixels.
> +	 * 160 * 4 = 640 bytes.
> +	 */
> +	*fifo_wtrmrk_lvl = 640;
> +
> +	/* Set up the main control, watermark level at 7 */
> +	val = 7 << MCDE_CONF0_IFIFOCTRLWTRMRKLVL_SHIFT;
> +
> +	/*
> +	 * This sets up the internal silicon muxing of the DPI
> +	 * lines. This is how the silicon connects out to the
> +	 * external pins, then the pins need to be further
> +	 * configured into "alternate functions" using pin control
> +	 * to actually get the signals out.
> +	 *
> +	 * FIXME: this is hardcoded to the only setting found in
> +	 * the wild. If we need to use different settings for
> +	 * different DPI displays, make this parameterizable from
> +	 * the device tree.
> +	 */
> +	/* 24 bits DPI: connect Ch A LSB to D[0:7] */
> +	val |= 0 << MCDE_CONF0_OUTMUX0_SHIFT;
> +	/* 24 bits DPI: connect Ch A MID to D[8:15] */
> +	val |= 1 << MCDE_CONF0_OUTMUX1_SHIFT;
> +	/* Don't care about this muxing */
> +	val |= 0 << MCDE_CONF0_OUTMUX2_SHIFT;
> +	/* Don't care about this muxing */
> +	val |= 0 << MCDE_CONF0_OUTMUX3_SHIFT;
> +	/* 24 bits DPI: connect Ch A MSB to D[32:39] */
> +	val |= 2 << MCDE_CONF0_OUTMUX4_SHIFT;
> +	/* Syncmux bits zero: DPI channel A */
> +	writel(val, mcde->regs + MCDE_CONF0);
> +
> +	/* This hammers us into LCD mode */
> +	writel(0, mcde->regs + MCDE_TVCRA);
> +
> +	/* Front porch and sync width */
> +	val = (vsw << MCDE_TVBL1_BEL1_SHIFT);
> +	val |= (vfp << MCDE_TVBL1_BSL1_SHIFT);
> +	writel(val, mcde->regs + MCDE_TVBL1A);
> +	/* The vendor driver sets the same value into TVBL2A */
> +	writel(val, mcde->regs + MCDE_TVBL2A);
> +
> +	/* Vertical back porch */
> +	val = (vbp << MCDE_TVDVO_DVO1_SHIFT);
> +	/* The vendor drivers sets the same value into TVDVOA */
> +	val |= (vbp << MCDE_TVDVO_DVO2_SHIFT);
> +	writel(val, mcde->regs + MCDE_TVDVOA);
> +
> +	/* Horizontal back porch, as 0 = 1 cycle we need to subtract 1 */
> +	writel((hbp - 1), mcde->regs + MCDE_TVTIM1A);
> +
> +	/* Horizongal sync width and horizonal front porch, 0 = 1 cycle */
> +	val = ((hsw - 1) << MCDE_TVLBALW_LBW_SHIFT);
> +	val |= ((hfp - 1) << MCDE_TVLBALW_ALW_SHIFT);
> +	writel(val, mcde->regs + MCDE_TVLBALWA);
> +
> +	/* Blank some TV registers we don't use */
> +	writel(0, mcde->regs + MCDE_TVISLA);
> +	writel(0, mcde->regs + MCDE_TVBLUA);
> +
> +	/* Set up sync inversion etc */
> +	val = 0;
> +	if (mode->flags & DRM_MODE_FLAG_NHSYNC)
> +		val |= MCDE_LCDTIM1B_IHS;
> +	if (mode->flags & DRM_MODE_FLAG_NVSYNC)
> +		val |= MCDE_LCDTIM1B_IVS;
> +	if (connector->display_info.bus_flags & DRM_BUS_FLAG_DE_LOW)
> +		val |= MCDE_LCDTIM1B_IOE;
> +	if (connector->display_info.bus_flags & DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE)
> +		val |= MCDE_LCDTIM1B_IPC;
> +	writel(val, mcde->regs + MCDE_LCDTIM1A);
> +}
> +
>  static void mcde_setup_dsi(struct mcde *mcde, const struct drm_display_mode *mode,
>  			   int cpp, int *fifo_wtrmrk_lvl, int *dsi_formatter_frame,
>  			   int *dsi_pkt_size)
> @@ -977,8 +1184,11 @@ static void mcde_display_enable(struct drm_simple_display_pipe *pipe,
>  	writel(0, mcde->regs + MCDE_IMSCERR);
>  	writel(0xFFFFFFFF, mcde->regs + MCDE_RISERR);
>  
> -	mcde_setup_dsi(mcde, mode, cpp, &fifo_wtrmrk,
> -		       &dsi_formatter_frame, &dsi_pkt_size);
> +	if (mcde->dpi_output)
> +		mcde_setup_dpi(mcde, mode, &fifo_wtrmrk);
> +	else
> +		mcde_setup_dsi(mcde, mode, cpp, &fifo_wtrmrk,
> +			       &dsi_formatter_frame, &dsi_pkt_size);
>  
>  	mcde->stride = mode->hdisplay * cpp;
>  	dev_dbg(drm->dev, "Overlay line stride: %u bytes\n",
> @@ -1010,29 +1220,47 @@ static void mcde_display_enable(struct drm_simple_display_pipe *pipe,
>  	 */
>  	mcde_configure_channel(mcde, MCDE_CHANNEL_0, MCDE_FIFO_A, mode);
>  
> -	/* Configure FIFO A to use DSI formatter 0 */
> -	mcde_configure_fifo(mcde, MCDE_FIFO_A, MCDE_DSI_FORMATTER_0,
> -			    fifo_wtrmrk);
> +	if (mcde->dpi_output) {
> +		unsigned long lcd_freq;
> +
> +		/* Configure FIFO A to use DPI formatter 0 */
> +		mcde_configure_fifo(mcde, MCDE_FIFO_A, MCDE_DPI_FORMATTER_0,
> +				    fifo_wtrmrk);
> +
> +		/* Set up and enable the LCD clock */
> +		lcd_freq = clk_round_rate(mcde->fifoa_clk, mode->clock * 1000);
> +		ret = clk_set_rate(mcde->fifoa_clk, lcd_freq);
> +		if (ret)
> +			dev_err(mcde->dev, "failed to set LCD clock rate %lu Hz\n",
> +				lcd_freq);
> +		ret = clk_prepare_enable(mcde->fifoa_clk);
> +		if (ret) {
> +			dev_err(mcde->dev, "failed to enable FIFO A DPI clock\n");
> +			return;
> +		}
> +		dev_info(mcde->dev, "LCD FIFO A clk rate %lu Hz\n",
> +			 clk_get_rate(mcde->fifoa_clk));
> +	} else {
> +		/* Configure FIFO A to use DSI formatter 0 */
> +		mcde_configure_fifo(mcde, MCDE_FIFO_A, MCDE_DSI_FORMATTER_0,
> +				    fifo_wtrmrk);
>  
> -	/*
> -	 * This brings up the DSI bridge which is tightly connected
> -	 * to the MCDE DSI formatter.
> -	 *
> -	 * FIXME: if we want to use another formatter, such as DPI,
> -	 * we need to be more elaborate here and select the appropriate
> -	 * bridge.
> -	 */
> -	mcde_dsi_enable(mcde->bridge);
> +		/*
> +		 * This brings up the DSI bridge which is tightly connected
> +		 * to the MCDE DSI formatter.
> +		 */
> +		mcde_dsi_enable(mcde->bridge);
>  
> -	/* Configure the DSI formatter 0 for the DSI panel output */
> -	mcde_configure_dsi_formatter(mcde, MCDE_DSI_FORMATTER_0,
> -				     dsi_formatter_frame, dsi_pkt_size);
> +		/* Configure the DSI formatter 0 for the DSI panel output */
> +		mcde_configure_dsi_formatter(mcde, MCDE_DSI_FORMATTER_0,
> +					     dsi_formatter_frame, dsi_pkt_size);
> +	}
>  
>  	switch (mcde->flow_mode) {
>  	case MCDE_COMMAND_TE_FLOW:
>  	case MCDE_COMMAND_BTA_TE_FLOW:
>  	case MCDE_VIDEO_TE_FLOW:
> -		/* We are using TE in some comination */
> +		/* We are using TE in some combination */
>  		if (mode->flags & DRM_MODE_FLAG_NVSYNC)
>  			val = MCDE_VSCRC_VSPOL;
>  		else
> @@ -1084,8 +1312,12 @@ static void mcde_display_disable(struct drm_simple_display_pipe *pipe)
>  	/* Disable FIFO A flow */
>  	mcde_disable_fifo(mcde, MCDE_FIFO_A, true);
>  
> -	/* This disables the DSI bridge */
> -	mcde_dsi_disable(mcde->bridge);
> +	if (mcde->dpi_output) {
> +		clk_disable_unprepare(mcde->fifoa_clk);
> +	} else {
> +		/* This disables the DSI bridge */
> +		mcde_dsi_disable(mcde->bridge);
> +	}
>  
>  	event = crtc->state->event;
>  	if (event) {
> @@ -1276,6 +1508,10 @@ int mcde_display_init(struct drm_device *drm)
>  		DRM_FORMAT_YUV422,
>  	};
>  
> +	ret = mcde_init_clock_divider(mcde);
> +	if (ret)
> +		return ret;
> +
>  	ret = drm_simple_display_pipe_init(drm, &mcde->pipe,
>  					   &mcde_display_funcs,
>  					   formats, ARRAY_SIZE(formats),
> diff --git a/drivers/gpu/drm/mcde/mcde_display_regs.h b/drivers/gpu/drm/mcde/mcde_display_regs.h
> index d3ac7ef5ff9a..ae76da8a2138 100644
> --- a/drivers/gpu/drm/mcde/mcde_display_regs.h
> +++ b/drivers/gpu/drm/mcde/mcde_display_regs.h
> @@ -215,6 +215,80 @@
>  #define MCDE_OVLXCOMP_Z_SHIFT 27
>  #define MCDE_OVLXCOMP_Z_MASK 0x78000000
>  
> +/* DPI/TV configuration registers, channel A and B */
> +#define MCDE_TVCRA 0x00000838
> +#define MCDE_TVCRB 0x00000A38
> +#define MCDE_TVCR_MOD_TV BIT(0) /* 0 = LCD mode */
> +#define MCDE_TVCR_INTEREN BIT(1)
> +#define MCDE_TVCR_IFIELD BIT(2)
> +#define MCDE_TVCR_TVMODE_SDTV_656P (0 << 3)
> +#define MCDE_TVCR_TVMODE_SDTV_656P_LE (3 << 3)
> +#define MCDE_TVCR_TVMODE_SDTV_656P_BE (4 << 3)
> +#define MCDE_TVCR_SDTVMODE_Y0CBY1CR (0 << 6)
> +#define MCDE_TVCR_SDTVMODE_CBY0CRY1 (1 << 6)
> +#define MCDE_TVCR_AVRGEN BIT(8)
> +#define MCDE_TVCR_CKINV BIT(9)
> +
> +/* TV blanking control register 1, channel A and B */
> +#define MCDE_TVBL1A 0x0000083C
> +#define MCDE_TVBL1B 0x00000A3C
> +#define MCDE_TVBL1_BEL1_SHIFT 0 /* VFP vertical front porch 11 bits */
> +#define MCDE_TVBL1_BSL1_SHIFT 16 /* VSW vertical sync pulse width 11 bits */
> +
> +/* Pixel processing TV start line, channel A and B */
> +#define MCDE_TVISLA 0x00000840
> +#define MCDE_TVISLB 0x00000A40
> +#define MCDE_TVISL_FSL1_SHIFT 0 /* Field 1 identification start line 11 bits */
> +#define MCDE_TVISL_FSL2_SHIFT 16 /* Field 2 identification start line 11 bits */
> +
> +/* Pixel processing TV DVO offset */
> +#define MCDE_TVDVOA 0x00000844
> +#define MCDE_TVDVOB 0x00000A44
> +#define MCDE_TVDVO_DVO1_SHIFT 0 /* VBP vertical back porch 0 = 0 */
> +#define MCDE_TVDVO_DVO2_SHIFT 16
> +
> +/*
> + * Pixel processing TV Timing 1
> + * HBP horizontal back porch 11 bits horizontal offset
> + * 0 = 1 pixel HBP, 255 = 256 pixels, so actual value - 1
> + */
> +#define MCDE_TVTIM1A 0x0000084C
> +#define MCDE_TVTIM1B 0x00000A4C
> +
> +/* Pixel processing TV LBALW */
> +/* 0 = 1 clock cycle, 255 = 256 clock cycles */
> +#define MCDE_TVLBALWA 0x00000850
> +#define MCDE_TVLBALWB 0x00000A50
> +#define MCDE_TVLBALW_LBW_SHIFT 0 /* HSW horizonal sync width, line blanking width 11 bits */
> +#define MCDE_TVLBALW_ALW_SHIFT 16 /* HFP horizontal front porch, active line width 11 bits */
> +
> +/* TV blanking control register 1, channel A and B */
> +#define MCDE_TVBL2A 0x00000854
> +#define MCDE_TVBL2B 0x00000A54
> +#define MCDE_TVBL2_BEL2_SHIFT 0 /* Field 2 blanking end line 11 bits */
> +#define MCDE_TVBL2_BSL2_SHIFT 16 /* Field 2 blanking start line 11 bits */
> +
> +/* Pixel processing TV background */
> +#define MCDE_TVBLUA 0x00000858
> +#define MCDE_TVBLUB 0x00000A58
> +#define MCDE_TVBLU_TVBLU_SHIFT 0 /* 8 bits luminance */
> +#define MCDE_TVBLU_TVBCB_SHIFT 8 /* 8 bits Cb chrominance */
> +#define MCDE_TVBLU_TVBCR_SHIFT 16 /* 8 bits Cr chrominance */
> +
> +/* Pixel processing LCD timing 1 */
> +#define MCDE_LCDTIM1A 0x00000860
> +#define MCDE_LCDTIM1B 0x00000A60
> +/* inverted vertical sync pulse for HRTFT 0 = active low, 1 active high */
> +#define MCDE_LCDTIM1B_IVP BIT(19)
> +/* inverted vertical sync, 0 = active high (the normal), 1 = active low */
> +#define MCDE_LCDTIM1B_IVS BIT(20)
> +/* inverted horizontal sync, 0 = active high (the normal), 1 = active low */
> +#define MCDE_LCDTIM1B_IHS BIT(21)
> +/* inverted panel clock 0 = rising edge data out, 1 = falling edge data out */
> +#define MCDE_LCDTIM1B_IPC BIT(22)
> +/* invert output enable 0 = active high, 1 = active low */
> +#define MCDE_LCDTIM1B_IOE BIT(23)
> +
>  #define MCDE_CRC 0x00000C00
>  #define MCDE_CRC_C1EN BIT(2)
>  #define MCDE_CRC_C2EN BIT(3)
> @@ -360,6 +434,7 @@
>  #define MCDE_CRB1 0x00000A04
>  #define MCDE_CRX1_PCD_SHIFT 0
>  #define MCDE_CRX1_PCD_MASK 0x000003FF
> +#define MCDE_CRX1_PCD_BITS 10
>  #define MCDE_CRX1_CLKSEL_SHIFT 10
>  #define MCDE_CRX1_CLKSEL_MASK 0x00001C00
>  #define MCDE_CRX1_CLKSEL_CLKPLL72 0
> @@ -421,8 +496,20 @@
>  #define MCDE_ROTACONF 0x0000087C
>  #define MCDE_ROTBCONF 0x00000A7C
>  
> +/* Synchronization event configuration */
>  #define MCDE_SYNCHCONFA 0x00000880
>  #define MCDE_SYNCHCONFB 0x00000A80
> +#define MCDE_SYNCHCONF_HWREQVEVENT_SHIFT 0
> +#define MCDE_SYNCHCONF_HWREQVEVENT_VSYNC (0 << 0)
> +#define MCDE_SYNCHCONF_HWREQVEVENT_BACK_PORCH (1 << 0)
> +#define MCDE_SYNCHCONF_HWREQVEVENT_ACTIVE_VIDEO (2 << 0)
> +#define MCDE_SYNCHCONF_HWREQVEVENT_FRONT_PORCH (3 << 0)
> +#define MCDE_SYNCHCONF_HWREQVCNT_SHIFT 2 /* 14 bits */
> +#define MCDE_SYNCHCONF_SWINTVEVENT_VSYNC (0 << 16)
> +#define MCDE_SYNCHCONF_SWINTVEVENT_BACK_PORCH (1 << 16)
> +#define MCDE_SYNCHCONF_SWINTVEVENT_ACTIVE_VIDEO (2 << 16)
> +#define MCDE_SYNCHCONF_SWINTVEVENT_FRONT_PORCH (3 << 16)
> +#define MCDE_SYNCHCONF_SWINTVCNT_SHIFT 18 /* 14 bits */
>  
>  /* Channel A+B control registers */
>  #define MCDE_CTRLA 0x00000884
> diff --git a/drivers/gpu/drm/mcde/mcde_drm.h b/drivers/gpu/drm/mcde/mcde_drm.h
> index 8253e2f9993e..ecb70b4b737c 100644
> --- a/drivers/gpu/drm/mcde/mcde_drm.h
> +++ b/drivers/gpu/drm/mcde/mcde_drm.h
> @@ -62,6 +62,8 @@ enum mcde_flow_mode {
>  	MCDE_VIDEO_TE_FLOW,
>  	/* Video mode with the formatter itself as sync source */
>  	MCDE_VIDEO_FORMATTER_FLOW,
> +	/* DPI video with the formatter itsels as sync source */
> +	MCDE_DPI_FORMATTER_FLOW,
>  };
>  
>  struct mcde {
> @@ -72,6 +74,7 @@ struct mcde {
>  	struct drm_connector *connector;
>  	struct drm_simple_display_pipe pipe;
>  	struct mipi_dsi_device *mdsi;
> +	bool dpi_output;
>  	s16 stride;
>  	enum mcde_flow_mode flow_mode;
>  	unsigned int flow_active;
> @@ -82,6 +85,11 @@ struct mcde {
>  	struct clk *mcde_clk;
>  	struct clk *lcd_clk;
>  	struct clk *hdmi_clk;
> +	/* Handles to the clock dividers for FIFO A and B */
> +	struct clk *fifoa_clk;
> +	struct clk *fifob_clk;
> +	/* Locks the MCDE FIFO control register A and B */
> +	spinlock_t fifo_crx1_lock;
>  
>  	struct regulator *epod;
>  	struct regulator *vana;
> @@ -105,4 +113,6 @@ void mcde_display_irq(struct mcde *mcde);
>  void mcde_display_disable_irqs(struct mcde *mcde);
>  int mcde_display_init(struct drm_device *drm);
>  
> +int mcde_init_clock_divider(struct mcde *mcde);
> +
>  #endif /* _MCDE_DRM_H_ */
> diff --git a/drivers/gpu/drm/mcde/mcde_drv.c b/drivers/gpu/drm/mcde/mcde_drv.c
> index 92f8bd907193..c890ce24a513 100644
> --- a/drivers/gpu/drm/mcde/mcde_drv.c
> +++ b/drivers/gpu/drm/mcde/mcde_drv.c
> @@ -22,13 +22,13 @@
>   * The hardware has four display pipes, and the layout is a little
>   * bit like this::
>   *
> - *   Memory     -> Overlay -> Channel -> FIFO -> 5 formatters -> DSI/DPI
> - *   External      0..5       0..3       A,B,    3 x DSI         bridge
> + *   Memory     -> Overlay -> Channel -> FIFO -> 8 formatters -> DSI/DPI
> + *   External      0..5       0..3       A,B,    6 x DSI         bridge
>   *   source 0..9                         C0,C1   2 x DPI
>   *
>   * FIFOs A and B are for LCD and HDMI while FIFO CO/C1 are for
>   * panels with embedded buffer.
> - * 3 of the formatters are for DSI.
> + * 6 of the formatters are for DSI, 3 pairs for VID/CMD respectively.
>   * 2 of the formatters are for DPI.
>   *
>   * Behind the formatters are the DSI or DPI ports that route to
> @@ -130,9 +130,37 @@ static int mcde_modeset_init(struct drm_device *drm)
>  	struct mcde *mcde = to_mcde(drm);
>  	int ret;
>  
> +	/*
> +	 * If no other bridge was found, check if we have a DPI panel or
> +	 * any other bridge connected directly to the MCDE DPI output.
> +	 * If a DSI bridge is found, DSI will take precedence.
> +	 *
> +	 * TODO: more elaborate bridge selection if we have more than one
> +	 * thing attached to the system.
> +	 */
>  	if (!mcde->bridge) {
> -		dev_err(drm->dev, "no display output bridge yet\n");
> -		return -EPROBE_DEFER;
> +		struct drm_panel *panel;
> +		struct drm_bridge *bridge;
> +
> +		ret = drm_of_find_panel_or_bridge(drm->dev->of_node,
> +						  0, 0, &panel, &bridge);
> +		if (ret) {
> +			dev_err(drm->dev,
> +				"Could not locate any output bridge or panel\n");
> +			return ret;
> +		}
> +		if (panel) {
> +			bridge = drm_panel_bridge_add_typed(panel,
> +					DRM_MODE_CONNECTOR_DPI);
> +			if (IS_ERR(bridge)) {
> +				dev_err(drm->dev,
> +					"Could not connect panel bridge\n");
> +				return PTR_ERR(bridge);
> +			}
> +		}
> +		mcde->dpi_output = true;
> +		mcde->bridge = bridge;
> +		mcde->flow_mode = MCDE_DPI_FORMATTER_FLOW;
>  	}
>  
>  	mode_config = &drm->mode_config;
> @@ -156,13 +184,7 @@ static int mcde_modeset_init(struct drm_device *drm)
>  		return ret;
>  	}
>  
> -	/*
> -	 * Attach the DSI bridge
> -	 *
> -	 * TODO: when adding support for the DPI bridge or several DSI bridges,
> -	 * we selectively connect the bridge(s) here instead of this simple
> -	 * attachment.
> -	 */
> +	/* Attach the bridge. */
>  	ret = drm_simple_display_pipe_attach_bridge(&mcde->pipe,
>  						    mcde->bridge);
>  	if (ret) {

Patch looks good - but it was more a visual check as a lot of the code
is HW dependent.

Acked-by: Sam Ravnborg <sam at ravnborg.org>



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