Commit 5fbc0dbb authored by Brigham Campbell's avatar Brigham Campbell Committed by Douglas Anderson
Browse files

drm/panel: novatek-nt35560: Clean up driver 



Update driver to use the "multi" variants of MIPI functions which
facilitate improved error handling and cleaner driver code.

Remove information from a comment which was made obsolete by commit
994ea402 ("drm/panel: Rename Sony ACX424 to Novatek NT35560"), which
determined that this driver supports the Novatek NT35560 panel
controller.

Reviewed-by: default avatarDouglas Anderson <dianders@chromium.org>
Signed-off-by: default avatarBrigham Campbell <me@brighamcampbell.com>
Signed-off-by: default avatarDouglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20250731032343.1258366-4-me@brighamcampbell.com
parent ffc23a20

drivers/gpu/drm/panel/panel-novatek-nt35560.c

+60 −138
Original line number Diff line number Diff line
@@ -148,24 +148,20 @@ static inline struct nt35560 *panel_to_nt35560(struct drm_panel *panel) 
static int nt35560_set_brightness(struct backlight_device *bl)

{

	struct nt35560 *nt = bl_get_data(bl);

	struct mipi_dsi_device *dsi = to_mipi_dsi_device(nt->dev);

	int period_ns = 1023;

	struct mipi_dsi_multi_context dsi_ctx = {

		.dsi = to_mipi_dsi_device(nt->dev)

	};

	int duty_ns = bl->props.brightness;

	int period_ns = 1023;

	u8 pwm_ratio;

	u8 pwm_div;

	u8 par;

	int ret;



	if (backlight_is_blank(bl)) {

		/* Disable backlight */

		par = 0x00;

		ret = mipi_dsi_dcs_write(dsi, MIPI_DCS_WRITE_CONTROL_DISPLAY,

					 &par, 1);

		if (ret < 0) {

			dev_err(nt->dev, "failed to disable display backlight (%d)\n", ret);

			return ret;

		}

		return 0;

		mipi_dsi_dcs_write_seq_multi(&dsi_ctx,

					     MIPI_DCS_WRITE_CONTROL_DISPLAY,

					     0x00);

		return dsi_ctx.accum_err;

	}



	/* Calculate the PWM duty cycle in n/256's */
@@ -176,12 +172,6 @@ static int nt35560_set_brightness(struct backlight_device *bl) 


	/* Set up PWM dutycycle ONE byte (differs from the standard) */

	dev_dbg(nt->dev, "calculated duty cycle %02x\n", pwm_ratio);

	ret = mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_DISPLAY_BRIGHTNESS,

				 &pwm_ratio, 1);

	if (ret < 0) {

		dev_err(nt->dev, "failed to set display PWM ratio (%d)\n", ret);

		return ret;

	}



	/*

	 * Sequence to write PWMDIV:
@@ -192,46 +182,23 @@ static int nt35560_set_brightness(struct backlight_device *bl) 
	 *	0x22		PWMDIV

	 *	0x7F		0xAA   CMD2 page 1 lock

	 */

	par = 0xaa;

	ret = mipi_dsi_dcs_write(dsi, 0xf3, &par, 1);

	if (ret < 0) {

		dev_err(nt->dev, "failed to unlock CMD 2 (%d)\n", ret);

		return ret;

	}

	par = 0x01;

	ret = mipi_dsi_dcs_write(dsi, 0x00, &par, 1);

	if (ret < 0) {

		dev_err(nt->dev, "failed to enter page 1 (%d)\n", ret);

		return ret;

	}

	par = 0x01;

	ret = mipi_dsi_dcs_write(dsi, 0x7d, &par, 1);

	if (ret < 0) {

		dev_err(nt->dev, "failed to disable MTP reload (%d)\n", ret);

		return ret;

	}

	ret = mipi_dsi_dcs_write(dsi, 0x22, &pwm_div, 1);

	if (ret < 0) {

		dev_err(nt->dev, "failed to set PWM divisor (%d)\n", ret);

		return ret;

	}

	par = 0xaa;

	ret = mipi_dsi_dcs_write(dsi, 0x7f, &par, 1);

	if (ret < 0) {

		dev_err(nt->dev, "failed to lock CMD 2 (%d)\n", ret);

		return ret;

	}

	mipi_dsi_dcs_write_var_seq_multi(&dsi_ctx,

					 MIPI_DCS_SET_DISPLAY_BRIGHTNESS,

					 pwm_ratio);



	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xf3, 0xaa);

	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x00, 0x01);

	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x7d, 0x01);



	mipi_dsi_dcs_write_var_seq_multi(&dsi_ctx, 0x22, pwm_div);



	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x7f, 0xaa);



	/* Enable backlight */

	par = 0x24;

	ret = mipi_dsi_dcs_write(dsi, MIPI_DCS_WRITE_CONTROL_DISPLAY,

				 &par, 1);

	if (ret < 0) {

		dev_err(nt->dev, "failed to enable display backlight (%d)\n", ret);

		return ret;

	}

	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, MIPI_DCS_WRITE_CONTROL_DISPLAY,

				     0x24);



	return 0;

	return dsi_ctx.accum_err;

}



static const struct backlight_ops nt35560_bl_ops = {
@@ -244,32 +211,23 @@ static const struct backlight_properties nt35560_bl_props = { 
	.max_brightness = 1023,

};



static int nt35560_read_id(struct nt35560 *nt)

static void nt35560_read_id(struct mipi_dsi_multi_context *dsi_ctx)

{

	struct mipi_dsi_device *dsi = to_mipi_dsi_device(nt->dev);

	struct device dev = dsi_ctx->dsi->dev;

	u8 vendor, version, panel;

	u16 val;

	int ret;



	ret = mipi_dsi_dcs_read(dsi, NT35560_DCS_READ_ID1, &vendor, 1);

	if (ret < 0) {

		dev_err(nt->dev, "could not vendor ID byte\n");

		return ret;

	}

	ret = mipi_dsi_dcs_read(dsi, NT35560_DCS_READ_ID2, &version, 1);

	if (ret < 0) {

		dev_err(nt->dev, "could not read device version byte\n");

		return ret;

	}

	ret = mipi_dsi_dcs_read(dsi, NT35560_DCS_READ_ID3, &panel, 1);

	if (ret < 0) {

		dev_err(nt->dev, "could not read panel ID byte\n");

		return ret;

	}

	mipi_dsi_dcs_read_multi(dsi_ctx, NT35560_DCS_READ_ID1, &vendor, 1);

	mipi_dsi_dcs_read_multi(dsi_ctx, NT35560_DCS_READ_ID2, &version, 1);

	mipi_dsi_dcs_read_multi(dsi_ctx, NT35560_DCS_READ_ID3, &panel, 1);



	if (dsi_ctx->accum_err < 0)

		return;



	if (vendor == 0x00) {

		dev_err(nt->dev, "device vendor ID is zero\n");

		return -ENODEV;

		dev_err(&dev, "device vendor ID is zero\n");

		dsi_ctx->accum_err = -ENODEV;

		return;

	}



	val = (vendor << 8) | panel;
@@ -278,16 +236,16 @@ static int nt35560_read_id(struct nt35560 *nt) 
	case DISPLAY_SONY_ACX424AKP_ID2:

	case DISPLAY_SONY_ACX424AKP_ID3:

	case DISPLAY_SONY_ACX424AKP_ID4:

		dev_info(nt->dev, "MTP vendor: %02x, version: %02x, panel: %02x\n",

		dev_info(&dev,

			 "MTP vendor: %02x, version: %02x, panel: %02x\n",

			 vendor, version, panel);

		break;

	default:

		dev_info(nt->dev, "unknown vendor: %02x, version: %02x, panel: %02x\n",

		dev_info(&dev,

			 "unknown vendor: %02x, version: %02x, panel: %02x\n",

			 vendor, version, panel);

		break;

	}



	return 0;

}



static int nt35560_power_on(struct nt35560 *nt)
@@ -322,92 +280,56 @@ static void nt35560_power_off(struct nt35560 *nt) 
static int nt35560_prepare(struct drm_panel *panel)

{

	struct nt35560 *nt = panel_to_nt35560(panel);

	struct mipi_dsi_device *dsi = to_mipi_dsi_device(nt->dev);

	const u8 mddi = 3;

	struct mipi_dsi_multi_context dsi_ctx = {

		.dsi = to_mipi_dsi_device(nt->dev)

	};

	int ret;



	ret = nt35560_power_on(nt);

	if (ret)

		return ret;



	ret = nt35560_read_id(nt);

	if (ret) {

		dev_err(nt->dev, "failed to read panel ID (%d)\n", ret);

		goto err_power_off;

	}

	nt35560_read_id(&dsi_ctx);



	/* Enabe tearing mode: send TE (tearing effect) at VBLANK */

	ret = mipi_dsi_dcs_set_tear_on(dsi,

	/* Enable tearing mode: send TE (tearing effect) at VBLANK */

	mipi_dsi_dcs_set_tear_on_multi(&dsi_ctx,

				       MIPI_DSI_DCS_TEAR_MODE_VBLANK);

	if (ret) {

		dev_err(nt->dev, "failed to enable vblank TE (%d)\n", ret);

		goto err_power_off;

	}



	/*

	 * Set MDDI

	 *

	 * This presumably deactivates the Qualcomm MDDI interface and

	 * selects DSI, similar code is found in other drivers such as the

	 * Sharp LS043T1LE01 which makes us suspect that this panel may be

	 * using a Novatek NT35565 or similar display driver chip that shares

	 * this command. Due to the lack of documentation we cannot know for

	 * sure.

	 * Sharp LS043T1LE01.

	 */

	ret = mipi_dsi_dcs_write(dsi, NT35560_DCS_SET_MDDI,

				 &mddi, sizeof(mddi));

	if (ret < 0) {

		dev_err(nt->dev, "failed to set MDDI (%d)\n", ret);

		goto err_power_off;

	}

	mipi_dsi_dcs_write_seq_multi(&dsi_ctx, NT35560_DCS_SET_MDDI, 3);



	/* Exit sleep mode */

	ret = mipi_dsi_dcs_exit_sleep_mode(dsi);

	if (ret) {

		dev_err(nt->dev, "failed to exit sleep mode (%d)\n", ret);

		goto err_power_off;

	}

	msleep(140);

	mipi_dsi_dcs_exit_sleep_mode_multi(&dsi_ctx);

	mipi_dsi_msleep(&dsi_ctx, 140);



	ret = mipi_dsi_dcs_set_display_on(dsi);

	if (ret) {

		dev_err(nt->dev, "failed to turn display on (%d)\n", ret);

		goto err_power_off;

	}

	mipi_dsi_dcs_set_display_on_multi(&dsi_ctx);

	if (nt->video_mode) {

		/* In video mode turn peripheral on */

		ret = mipi_dsi_turn_on_peripheral(dsi);

		if (ret) {

			dev_err(nt->dev, "failed to turn on peripheral\n");

			goto err_power_off;

		mipi_dsi_turn_on_peripheral_multi(&dsi_ctx);

	}

	}



	return 0;



err_power_off:

	if (dsi_ctx.accum_err < 0)

		nt35560_power_off(nt);

	return ret;

	return dsi_ctx.accum_err;

}



static int nt35560_unprepare(struct drm_panel *panel)

{

	struct nt35560 *nt = panel_to_nt35560(panel);

	struct mipi_dsi_device *dsi = to_mipi_dsi_device(nt->dev);

	int ret;

	struct mipi_dsi_multi_context dsi_ctx = {

		.dsi = to_mipi_dsi_device(nt->dev)

	};



	ret = mipi_dsi_dcs_set_display_off(dsi);

	if (ret) {

		dev_err(nt->dev, "failed to turn display off (%d)\n", ret);

		return ret;

	}

	mipi_dsi_dcs_set_display_off_multi(&dsi_ctx);

	mipi_dsi_dcs_enter_sleep_mode_multi(&dsi_ctx);



	if (dsi_ctx.accum_err < 0)

		return dsi_ctx.accum_err;



	/* Enter sleep mode */

	ret = mipi_dsi_dcs_enter_sleep_mode(dsi);

	if (ret) {

		dev_err(nt->dev, "failed to enter sleep mode (%d)\n", ret);

		return ret;

	}

	msleep(85);



	nt35560_power_off(nt);