Commit 91867ac7 authored by Linus Walleij's avatar Linus Walleij
Browse files

drm/panel: s6e63m0: Add reading functionality 



This adds code to send read commands to read a single
byte from the display, in order to perform MTP ID
look-up of the mounted panel on the s6e63m0 controller.
This is needed for proper biasing on the DSI variants.

Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Tested-by: default avatarStephan Gerhold <stephan@gerhold.net>
Cc: Paweł Chmiel <pawel.mikolaj.chmiel@gmail.com>
Acked-by: default avatarPaul Cercueil <paul@crapouillou.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20200809215104.1830206-4-linus.walleij@linaro.org
parent 435e06c0

drivers/gpu/drm/panel/panel-samsung-s6e63m0-dsi.c

+18 −1
Original line number Diff line number Diff line
@@ -16,6 +16,22 @@ 
#define MCS_GLOBAL_PARAM	0xb0

#define S6E63M0_DSI_MAX_CHUNK	15 /* CMD + 15 bytes max */



static int s6e63m0_dsi_dcs_read(struct device *dev, const u8 cmd, u8 *data)

{

	struct mipi_dsi_device *dsi = to_mipi_dsi_device(dev);

	int ret;



	ret = mipi_dsi_dcs_read(dsi, cmd, data, 1);

	if (ret < 0) {

		DRM_DEV_ERROR(dev, "could not read DCS CMD %02x\n", cmd);

		return ret;

	}



	DRM_DEV_INFO(dev, "DSI read CMD %02x = %02x\n", cmd, *data);



	return 0;

}



static int s6e63m0_dsi_dcs_write(struct device *dev, const u8 *data, size_t len)

{

	struct mipi_dsi_device *dsi = to_mipi_dsi_device(dev);
@@ -90,7 +106,8 @@ static int s6e63m0_dsi_probe(struct mipi_dsi_device *dsi) 
		MIPI_DSI_MODE_EOT_PACKET |

		MIPI_DSI_MODE_VIDEO_BURST;



	ret = s6e63m0_probe(dev, s6e63m0_dsi_dcs_write, true);

	ret = s6e63m0_probe(dev, s6e63m0_dsi_dcs_read, s6e63m0_dsi_dcs_write,

			    true);

	if (ret)

		return ret;

drivers/gpu/drm/panel/panel-samsung-s6e63m0-spi.c

+13 −1
Original line number Diff line number Diff line
@@ -11,6 +11,17 @@ 


#define DATA_MASK	0x100



static int s6e63m0_spi_dcs_read(struct device *dev, const u8 cmd, u8 *data)

{

	/*

	 * FIXME: implement reading DCS commands over SPI so we can

	 * properly identify which physical panel is connected.

	 */

	*data = 0;



	return 0;

}



static int s6e63m0_spi_write_word(struct device *dev, u16 data)

{

	struct spi_device *spi = to_spi_device(dev);
@@ -60,7 +71,8 @@ static int s6e63m0_spi_probe(struct spi_device *spi) 
		DRM_DEV_ERROR(dev, "spi setup failed.\n");

		return ret;

	}

	return s6e63m0_probe(dev, s6e63m0_spi_dcs_write, false);

	return s6e63m0_probe(dev, s6e63m0_spi_dcs_read, s6e63m0_spi_dcs_write,

			     false);

}



static int s6e63m0_spi_remove(struct spi_device *spi)

drivers/gpu/drm/panel/panel-samsung-s6e63m0.c

+11 −0
Original line number Diff line number Diff line
@@ -86,6 +86,7 @@ static u8 const s6e63m0_gamma_22[NUM_GAMMA_LEVELS][GAMMA_TABLE_COUNT] = { 


struct s6e63m0 {

	struct device *dev;

	int (*dcs_read)(struct device *dev, const u8 cmd, u8 *val);

	int (*dcs_write)(struct device *dev, const u8 *data, size_t len);

	struct drm_panel panel;

	struct backlight_device *bl_dev;
@@ -134,6 +135,14 @@ static int s6e63m0_clear_error(struct s6e63m0 *ctx) 
	return ret;

}



static void s6e63m0_dcs_read(struct s6e63m0 *ctx, const u8 cmd, u8 *data)

{

	if (ctx->error < 0)

		return;



	ctx->error = ctx->dcs_read(ctx->dev, cmd, data);

}



static void s6e63m0_dcs_write(struct s6e63m0 *ctx, const u8 *data, size_t len)

{

	if (ctx->error < 0 || len == 0)
@@ -400,6 +409,7 @@ static int s6e63m0_backlight_register(struct s6e63m0 *ctx) 
}



int s6e63m0_probe(struct device *dev,

		  int (*dcs_read)(struct device *dev, const u8 cmd, u8 *val),

		  int (*dcs_write)(struct device *dev, const u8 *data, size_t len),

		  bool dsi_mode)

{
@@ -410,6 +420,7 @@ int s6e63m0_probe(struct device *dev, 
	if (!ctx)

		return -ENOMEM;



	ctx->dcs_read = dcs_read;

	ctx->dcs_write = dcs_write;

	dev_set_drvdata(dev, ctx);

drivers/gpu/drm/panel/panel-samsung-s6e63m0.h

+1 −0
Original line number Diff line number Diff line
@@ -4,6 +4,7 @@ 
#define _PANEL_SAMSUNG_S6E63M0_H



int s6e63m0_probe(struct device *dev,

		  int (*dcs_read)(struct device *dev, const u8 cmd, u8 *val),

		  int (*dcs_write)(struct device *dev, const u8 *data,

				   size_t len),

		  bool dsi_mode);