diff mbox

[v2,3/3] drm/panel: Add support for otm8009a panel driver

Message ID 1499677333-10571-4-git-send-email-philippe.cornu@st.com (mailing list archive)
State New, archived
Headers show

Commit Message

Philippe CORNU July 10, 2017, 9:02 a.m. UTC
This patch adds Orise Tech otm8009a 3.97" 480x800 TFT LCD
panel driver (MIPI-DSI video mode). The panel backlight is
managed through the DSI link. This panel driver is used in
several STM32 boards.

Signed-off-by: Philippe CORNU <philippe.cornu@st.com>
---
 drivers/gpu/drm/panel/Kconfig                    |   9 +
 drivers/gpu/drm/panel/Makefile                   |   1 +
 drivers/gpu/drm/panel/panel-orisetech-otm8009a.c | 489 +++++++++++++++++++++++
 3 files changed, 499 insertions(+)
 create mode 100755 drivers/gpu/drm/panel/panel-orisetech-otm8009a.c

Comments

Andrzej Hajda July 12, 2017, 2:12 p.m. UTC | #1
On 10.07.2017 11:02, Philippe CORNU wrote:
> This patch adds Orise Tech otm8009a 3.97" 480x800 TFT LCD
> panel driver (MIPI-DSI video mode). The panel backlight is
> managed through the DSI link. This panel driver is used in
> several STM32 boards.
>
> Signed-off-by: Philippe CORNU <philippe.cornu@st.com>
> ---
>  drivers/gpu/drm/panel/Kconfig                    |   9 +
>  drivers/gpu/drm/panel/Makefile                   |   1 +
>  drivers/gpu/drm/panel/panel-orisetech-otm8009a.c | 489 +++++++++++++++++++++++
>  3 files changed, 499 insertions(+)
>  create mode 100755 drivers/gpu/drm/panel/panel-orisetech-otm8009a.c
>
> diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
> index d84a031..c1c9291 100644
> --- a/drivers/gpu/drm/panel/Kconfig
> +++ b/drivers/gpu/drm/panel/Kconfig
> @@ -117,4 +117,13 @@ config DRM_PANEL_SITRONIX_ST7789V
>  	  Say Y here if you want to enable support for the Sitronix
>  	  ST7789V controller for 240x320 LCD panels
>  
> +config DRM_PANEL_ORISETECH_OTM8009A
> +	tristate "Orise Tech otm8009a 480p dsi 2dl video mode panel"
> +	depends on OF
> +	depends on DRM_MIPI_DSI
> +	depends on BACKLIGHT_CLASS_DEVICE
> +	help
> +	  Say Y here if you want to enable support for Orise Tech OTM8009A
> +	  480x800 DSI panel
> +
>  endmenu
> diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
> index 9f6610d..ac798f3 100644
> --- a/drivers/gpu/drm/panel/Makefile
> +++ b/drivers/gpu/drm/panel/Makefile
> @@ -10,3 +10,4 @@ obj-$(CONFIG_DRM_PANEL_SAMSUNG_S6E8AA0) += panel-samsung-s6e8aa0.o
>  obj-$(CONFIG_DRM_PANEL_SHARP_LQ101R1SX01) += panel-sharp-lq101r1sx01.o
>  obj-$(CONFIG_DRM_PANEL_SHARP_LS043T1LE01) += panel-sharp-ls043t1le01.o
>  obj-$(CONFIG_DRM_PANEL_SITRONIX_ST7789V) += panel-sitronix-st7789v.o
> +obj-$(CONFIG_DRM_PANEL_ORISETECH_OTM8009A) += panel-orisetech-otm8009a.o
> \ No newline at end of file

Alphabetical order and new line at EOF.

> diff --git a/drivers/gpu/drm/panel/panel-orisetech-otm8009a.c b/drivers/gpu/drm/panel/panel-orisetech-otm8009a.c
> new file mode 100755
> index 0000000..2a3ce47
> --- /dev/null
> +++ b/drivers/gpu/drm/panel/panel-orisetech-otm8009a.c
> @@ -0,0 +1,489 @@
> +/*
> + * Copyright (C) STMicroelectronics SA 2017
> + *
> + * Authors: Philippe Cornu <philippe.cornu@st.com>
> + *          Yannick Fertre <yannick.fertre@st.com>
> + *
> + * License terms:  GNU General Public License (GPL), version 2
> + */
> +#include <drm/drmP.h>
> +#include <drm/drm_mipi_dsi.h>
> +#include <drm/drm_panel.h>
> +#include <linux/backlight.h>
> +#include <linux/gpio/consumer.h>
> +#include <video/mipi_display.h>
> +
> +#define DRV_NAME "orisetech_otm8009a"
> +
> +#define OTM8009A_BACKLIGHT_DEFAULT	240
> +#define OTM8009A_BACKLIGHT_MAX		255
> +
> +/* Manufacturer Command Set */
> +#define MCS_ADRSFT	0x0000	/* Address Shift Function */
> +#define MCS_PANSET	0xB3A6	/* Panel Type Setting */
> +#define MCS_SD_CTRL	0xC0A2	/* Source Driver Timing Setting */
> +#define MCS_P_DRV_M	0xC0B4	/* Panel Driving Mode */
> +#define MCS_OSC_ADJ	0xC181	/* Oscillator Adjustment for Idle/Normal mode */
> +#define MCS_RGB_VID_SET	0xC1A1	/* RGB Video Mode Setting */
> +#define MCS_SD_PCH_CTRL	0xC480	/* Source Driver Precharge Control */
> +#define MCS_NO_DOC1	0xC48A	/* Command not documented */
> +#define MCS_PWR_CTRL1	0xC580	/* Power Control Setting 1 */
> +#define MCS_PWR_CTRL2	0xC590	/* Power Control Setting 2 for Normal Mode */
> +#define MCS_PWR_CTRL4	0xC5B0	/* Power Control Setting 4 for DC Voltage */
> +#define MCS_PANCTRLSET1	0xCB80	/* Panel Control Setting 1 */
> +#define MCS_PANCTRLSET2	0xCB90	/* Panel Control Setting 2 */
> +#define MCS_PANCTRLSET3	0xCBA0	/* Panel Control Setting 3 */
> +#define MCS_PANCTRLSET4	0xCBB0	/* Panel Control Setting 4 */
> +#define MCS_PANCTRLSET5	0xCBC0	/* Panel Control Setting 5 */
> +#define MCS_PANCTRLSET6	0xCBD0	/* Panel Control Setting 6 */
> +#define MCS_PANCTRLSET7	0xCBE0	/* Panel Control Setting 7 */
> +#define MCS_PANCTRLSET8	0xCBF0	/* Panel Control Setting 8 */
> +#define MCS_PANU2D1	0xCC80	/* Panel U2D Setting 1 */
> +#define MCS_PANU2D2	0xCC90	/* Panel U2D Setting 2 */
> +#define MCS_PANU2D3	0xCCA0	/* Panel U2D Setting 3 */
> +#define MCS_PAND2U1	0xCCB0	/* Panel D2U Setting 1 */
> +#define MCS_PAND2U2	0xCCC0	/* Panel D2U Setting 2 */
> +#define MCS_PAND2U3	0xCCD0	/* Panel D2U Setting 3 */
> +#define MCS_GOAVST	0xCE80	/* GOA VST Setting */
> +#define MCS_GOACLKA1	0xCEA0	/* GOA CLKA1 Setting */
> +#define MCS_GOACLKA3	0xCEB0	/* GOA CLKA3 Setting */
> +#define MCS_GOAECLK	0xCFC0	/* GOA ECLK Setting */
> +#define MCS_NO_DOC2	0xCFD0	/* Command not documented */
> +#define MCS_GVDDSET	0xD800	/* GVDD/NGVDD */
> +#define MCS_VCOMDC	0xD900	/* VCOM Voltage Setting */
> +#define MCS_GMCT2_2P	0xE100	/* Gamma Correction 2.2+ Setting */
> +#define MCS_GMCT2_2N	0xE200	/* Gamma Correction 2.2- Setting */
> +#define MCS_NO_DOC3	0xF5B6	/* Command not documented */
> +#define MCS_CMD2_ENA1	0xFF00	/* Enable Access Command2 "CMD2" */
> +#define MCS_CMD2_ENA2	0xFF80	/* Enable Access Orise Command2 */
> +
> +struct otm8009a {
> +	struct device *dev;
> +	struct drm_panel panel;
> +	struct backlight_device *bl_dev;
> +	struct gpio_desc *reset_gpio;
> +	bool prepared;
> +	bool enabled;
> +};
> +
> +static const struct drm_display_mode default_mode = {
> +	.clock = 32729,
> +	.hdisplay = 480,
> +	.hsync_start = 480 + 120,
> +	.hsync_end = 480 + 120 + 63,
> +	.htotal = 480 + 120 + 63 + 120,
> +	.vdisplay = 800,
> +	.vsync_start = 800 + 12,
> +	.vsync_end = 800 + 12 + 12,
> +	.vtotal = 800 + 12 + 12 + 12,
> +	.vrefresh = 50,
> +	.flags = 0,
> +	.width_mm = 52,
> +	.height_mm = 86,
> +};
> +
> +static inline struct otm8009a *panel_to_otm8009a(struct drm_panel *panel)
> +{
> +	return container_of(panel, struct otm8009a, panel);
> +}
> +
> +static void otm8009a_dcs_write_buf(struct otm8009a *ctx, const void *data,
> +				   size_t len)
> +{
> +	struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
> +
> +	if (mipi_dsi_dcs_write_buffer(dsi, data, len) < 0)
> +		DRM_WARN("mipi dsi dcs write buffer failed\n");
> +}
> +
> +#define dcs_write_seq(ctx, seq...)			\
> +({							\
> +	static const u8 d[] = { seq };			\
> +	otm8009a_dcs_write_buf(ctx, d, ARRAY_SIZE(d));	\
> +})
> +
> +#define dcs_write_cmd_at(ctx, cmd, seq...)		\
> +({							\
> +	dcs_write_seq(ctx, MCS_ADRSFT, (cmd) & 0xFF);	\
> +	dcs_write_seq(ctx, (cmd) >> 8, seq);		\
> +})

This approach looks better than my proposition, for sure it is more
consistent with documentation.

> +
> +static int otm8009a_init_sequence(struct otm8009a *ctx)
> +{
> +	struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
> +	int ret;
> +
> +	/* Enter CMD2 */
> +	dcs_write_cmd_at(ctx, MCS_CMD2_ENA1, 0x80, 0x09, 0x01);
> +
> +	/* Enter Orise Command2 */
> +	dcs_write_cmd_at(ctx, MCS_CMD2_ENA2, 0x80, 0x09);
> +
> +	dcs_write_cmd_at(ctx, MCS_SD_PCH_CTRL, 0x30);
> +	mdelay(10);
> +
> +	dcs_write_cmd_at(ctx, MCS_NO_DOC1, 0x40);
> +	mdelay(10);
> +
> +	dcs_write_cmd_at(ctx, MCS_PWR_CTRL4 + 1, 0xA9);
> +	dcs_write_cmd_at(ctx, MCS_PWR_CTRL2 + 1, 0x34);
> +	dcs_write_cmd_at(ctx, MCS_P_DRV_M, 0x50);
> +	dcs_write_cmd_at(ctx, MCS_VCOMDC, 0x4E);
> +	dcs_write_cmd_at(ctx, MCS_OSC_ADJ, 0x66); /* 65Hz */
> +	dcs_write_cmd_at(ctx, MCS_RGB_VID_SET, 0x08);
> +	dcs_write_cmd_at(ctx, MCS_PWR_CTRL2 + 2, 0x01);
> +	dcs_write_cmd_at(ctx, MCS_PWR_CTRL2 + 5, 0x34);
> +	dcs_write_cmd_at(ctx, MCS_PWR_CTRL2 + 4, 0x33);
> +	dcs_write_cmd_at(ctx, MCS_GVDDSET, 0x79, 0x79);
> +	dcs_write_cmd_at(ctx, MCS_SD_CTRL + 1, 0x1B);
> +	dcs_write_cmd_at(ctx, MCS_PWR_CTRL1 + 2, 0x83);
> +	dcs_write_cmd_at(ctx, MCS_SD_PCH_CTRL + 1, 0x83);
> +	dcs_write_cmd_at(ctx, MCS_RGB_VID_SET, 0x0E); /* FIXME before 0x08! */

Quite cryptic comment, either remove, either make it readable.

> +	dcs_write_cmd_at(ctx, MCS_PANSET, 0x00, 0x01);
> +
> +	dcs_write_cmd_at(ctx, MCS_GOAVST, 0x85, 0x01, 0x00, 0x84, 0x01, 0x00);
> +	dcs_write_cmd_at(ctx, MCS_GOACLKA1, 0x18, 0x04, 0x03, 0x39, 0x00, 0x00,
> +			 0x00, 0x18, 0x03, 0x03, 0x3A, 0x00, 0x00, 0x00);
> +	dcs_write_cmd_at(ctx, MCS_GOACLKA3, 0x18, 0x02, 0x03, 0x3B, 0x00, 0x00,
> +			 0x00, 0x18, 0x01, 0x03, 0x3C, 0x00, 0x00, 0x00);
> +	dcs_write_cmd_at(ctx, MCS_GOAECLK, 0x01, 0x01, 0x20, 0x20, 0x00, 0x00,
> +			 0x01, 0x02, 0x00, 0x00);
> +
> +	dcs_write_cmd_at(ctx, MCS_NO_DOC2, 0x00);
> +
> +	dcs_write_cmd_at(ctx, MCS_PANCTRLSET1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0);
> +	dcs_write_cmd_at(ctx, MCS_PANCTRLSET2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
> +			 0, 0, 0, 0, 0);
> +	dcs_write_cmd_at(ctx, MCS_PANCTRLSET3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
> +			 0, 0, 0, 0, 0);
> +	dcs_write_cmd_at(ctx, MCS_PANCTRLSET4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0);
> +	dcs_write_cmd_at(ctx, MCS_PANCTRLSET5, 0, 4, 4, 4, 4, 4, 0, 0, 0, 0,
> +			 0, 0, 0, 0, 0);
> +	dcs_write_cmd_at(ctx, MCS_PANCTRLSET6, 0, 0, 0, 0, 0, 0, 4, 4, 4, 4,
> +			 4, 0, 0, 0, 0);
> +	dcs_write_cmd_at(ctx, MCS_PANCTRLSET7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0);
> +	dcs_write_cmd_at(ctx, MCS_PANCTRLSET8, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
> +			 0xFF, 0xFF, 0xFF, 0xFF, 0xFF);
> +
> +	dcs_write_cmd_at(ctx, MCS_PANU2D1, 0x00, 0x26, 0x09, 0x0B, 0x01, 0x25,
> +			 0x00, 0x00, 0x00, 0x00);
> +	dcs_write_cmd_at(ctx, MCS_PANU2D2, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
> +			 0x00, 0x00, 0x00, 0x00, 0x00, 0x26, 0x0A, 0x0C, 0x02);
> +	dcs_write_cmd_at(ctx, MCS_PANU2D3, 0x25, 0x00, 0x00, 0x00, 0x00, 0x00,
> +			 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00);
> +	dcs_write_cmd_at(ctx, MCS_PAND2U1, 0x00, 0x25, 0x0C, 0x0A, 0x02, 0x26,
> +			 0x00, 0x00, 0x00, 0x00);
> +	dcs_write_cmd_at(ctx, MCS_PAND2U2, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
> +			 0x00, 0x00, 0x00, 0x00, 0x00, 0x25, 0x0B, 0x09, 0x01);
> +	dcs_write_cmd_at(ctx, MCS_PAND2U3, 0x26, 0x00, 0x00, 0x00, 0x00, 0x00,
> +			 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00);
> +
> +	dcs_write_cmd_at(ctx, MCS_PWR_CTRL1 + 1, 0x66);
> +
> +	dcs_write_cmd_at(ctx, MCS_NO_DOC3, 0x06);
> +
> +	dcs_write_cmd_at(ctx, MCS_GMCT2_2P, 0x00, 0x09, 0x0F, 0x0E, 0x07, 0x10,
> +			 0x0B, 0x0A, 0x04, 0x07, 0x0B, 0x08, 0x0F, 0x10, 0x0A,
> +			 0x01);
> +	dcs_write_cmd_at(ctx, MCS_GMCT2_2N, 0x00, 0x09, 0x0F, 0x0E, 0x07, 0x10,
> +			 0x0B, 0x0A, 0x04, 0x07, 0x0B, 0x08, 0x0F, 0x10, 0x0A,
> +			 0x01);
> +
> +	/* Exit CMD2 */
> +	dcs_write_cmd_at(ctx, MCS_CMD2_ENA1, 0xFF, 0xFF, 0xFF);
> +
> +	ret = mipi_dsi_dcs_nop(dsi);
> +	if (ret)
> +		return ret;
> +
> +	ret = mipi_dsi_dcs_exit_sleep_mode(dsi);
> +	if (ret)
> +		return ret;
> +
> +	/* Wait for sleep out exit */
> +	mdelay(120);
> +
> +	/* Default portrait 480x800 rgb24 */
> +	dcs_write_seq(ctx, MIPI_DCS_SET_ADDRESS_MODE, 0x00);
> +
> +	ret = mipi_dsi_dcs_set_column_address(dsi, 0,
> +					      default_mode.hdisplay - 1);
> +	if (ret)
> +		return ret;
> +
> +	ret = mipi_dsi_dcs_set_page_address(dsi, 0, default_mode.vdisplay - 1);
> +	if (ret)
> +		return ret;
> +
> +	/* See otm8009a driver documentation for pixel format descriptions */
> +	ret = mipi_dsi_dcs_set_pixel_format(dsi, MIPI_DCS_PIXEL_FMT_24BIT |
> +					    MIPI_DCS_PIXEL_FMT_24BIT << 4);
> +	if (ret)
> +		return ret;
> +
> +	/* Disable CABC feature */
> +	dcs_write_seq(ctx, MIPI_DCS_WRITE_POWER_SAVE, 0x00);
> +
> +	ret = mipi_dsi_dcs_set_display_on(dsi);
> +	if (ret)
> +		return ret;
> +
> +	ret = mipi_dsi_dcs_nop(dsi);
> +	if (ret)
> +		return ret;
> +
> +	/* Send Command GRAM memory write (no parameters) */
> +	dcs_write_seq(ctx, MIPI_DCS_WRITE_MEMORY_START);
> +
> +	return 0;
> +}
> +
> +static int otm8009a_disable(struct drm_panel *panel)
> +{
> +	struct otm8009a *ctx = panel_to_otm8009a(panel);
> +	struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
> +	int ret;
> +
> +	if (!ctx->enabled)
> +		return 0; /* This is not an issue so we return 0 here */
> +
> +	/* Power off the backlight. Note: end-user still controls brightness */
> +	ctx->bl_dev->props.power = FB_BLANK_POWERDOWN;
> +	ret = backlight_update_status(ctx->bl_dev);
> +	if (ret)
> +		return ret;
> +
> +	ret = mipi_dsi_dcs_set_display_off(dsi);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = mipi_dsi_dcs_enter_sleep_mode(dsi);
> +	if (ret < 0)
> +		return ret;
> +
> +	msleep(120);
> +
> +	ctx->enabled = false;
> +
> +	return 0;
> +}
> +
> +static int otm8009a_unprepare(struct drm_panel *panel)
> +{
> +	struct otm8009a *ctx = panel_to_otm8009a(panel);
> +
> +	if (!ctx->prepared)
> +		return 0;
> +
> +	if (ctx->reset_gpio) {
> +		gpiod_set_value_cansleep(ctx->reset_gpio, 1);
> +		msleep(20);
> +	}
> +
> +	ctx->prepared = false;
> +
> +	return 0;
> +}
> +
> +static int otm8009a_prepare(struct drm_panel *panel)
> +{
> +	struct otm8009a *ctx = panel_to_otm8009a(panel);
> +	int ret;
> +
> +	if (ctx->prepared)
> +		return 0;
> +
> +	if (ctx->reset_gpio) {
> +		gpiod_set_value_cansleep(ctx->reset_gpio, 0);
> +		gpiod_set_value_cansleep(ctx->reset_gpio, 1);
> +		msleep(20);
> +		gpiod_set_value_cansleep(ctx->reset_gpio, 0);
> +		msleep(100);
> +	}
> +
> +	ret = otm8009a_init_sequence(ctx);
> +	if (ret)
> +		return ret;
> +
> +	ctx->prepared = true;
> +
> +	/* Power on the backlight. Note: end-user still controls brightness */
> +	ctx->bl_dev->props.power = FB_BLANK_UNBLANK;
> +	backlight_update_status(ctx->bl_dev);
> +
> +	return 0;
> +}
> +
> +static int otm8009a_enable(struct drm_panel *panel)
> +{
> +	struct otm8009a *ctx = panel_to_otm8009a(panel);
> +
> +	ctx->enabled = true;
> +
> +	return 0;
> +}

I am not sure about it, but I guess unblanking should be performed in
_enable callback. Otherwise you risk seeing garbage at panel start - it
starts displaying uninitialized data.
Usually sequence looks like:
A. Power on DSI host
B. Initialize panel (prepare callback)
C. Start video transmission from the host to the panel
D. wait about 120ms, then unblank panel (enable callback)

Of course this is only my experience, maybe your panel is different.

Beside above comments:
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>

 --
Regards
Andrzej


> +
> +static int otm8009a_get_modes(struct drm_panel *panel)
> +{
> +	struct drm_display_mode *mode;
> +
> +	mode = drm_mode_duplicate(panel->drm, &default_mode);
> +	if (!mode) {
> +		DRM_ERROR("failed to add mode %ux%ux@%u\n",
> +			  default_mode.hdisplay, default_mode.vdisplay,
> +			  default_mode.vrefresh);
> +		return -ENOMEM;
> +	}
> +
> +	drm_mode_set_name(mode);
> +
> +	mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
> +	drm_mode_probed_add(panel->connector, mode);
> +
> +	panel->connector->display_info.width_mm = mode->width_mm;
> +	panel->connector->display_info.height_mm = mode->height_mm;
> +
> +	return 1;
> +}
> +
> +static const struct drm_panel_funcs otm8009a_drm_funcs = {
> +	.disable   = otm8009a_disable,
> +	.unprepare = otm8009a_unprepare,
> +	.prepare   = otm8009a_prepare,
> +	.enable    = otm8009a_enable,
> +	.get_modes = otm8009a_get_modes,
> +};
> +
> +/*
> + * DSI-BASED BACKLIGHT
> + */
> +
> +static int otm8009a_backlight_update_status(struct backlight_device *bd)
> +{
> +	struct otm8009a *ctx = bl_get_data(bd);
> +	u8 data[2];
> +
> +	if (!ctx->prepared) {
> +		DRM_DEBUG("lcd not ready yet for setting its backlight!\n");
> +		return -ENXIO;
> +	}
> +
> +	if (bd->props.power <= FB_BLANK_NORMAL) {
> +		/* Power on the backlight with the requested brightness
> +		 * Note We can not use mipi_dsi_dcs_set_display_brightness()
> +		 * as otm8009a driver support only 8-bit brightness (1 param).
> +		 */
> +		data[0] = MIPI_DCS_SET_DISPLAY_BRIGHTNESS;
> +		data[1] = bd->props.brightness;
> +		otm8009a_dcs_write_buf(ctx, data, ARRAY_SIZE(data));
> +
> +		/* set Brightness Control & Backlight on */
> +		data[1] = 0x24;
> +
> +	} else {
> +		/* Power off the backlight: set Brightness Control & Bl off */
> +		data[1] = 0;
> +	}
> +
> +	/* Update Brightness Control & Backlight */
> +	data[0] = MIPI_DCS_WRITE_CONTROL_DISPLAY;
> +	otm8009a_dcs_write_buf(ctx, data, ARRAY_SIZE(data));
> +
> +	return 0;
> +}
> +
> +static const struct backlight_ops otm8009a_backlight_ops = {
> +	.update_status = otm8009a_backlight_update_status,
> +};
> +
> +static int otm8009a_probe(struct mipi_dsi_device *dsi)
> +{
> +	struct device *dev = &dsi->dev;
> +	struct otm8009a *ctx;
> +	int ret;
> +
> +	ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
> +	if (!ctx)
> +		return -ENOMEM;
> +
> +	ctx->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
> +	if (IS_ERR(ctx->reset_gpio)) {
> +		dev_err(dev, "cannot get reset-gpio\n");
> +		return PTR_ERR(ctx->reset_gpio);
> +	}
> +
> +	mipi_dsi_set_drvdata(dsi, ctx);
> +
> +	ctx->dev = dev;
> +
> +	dsi->lanes = 2;
> +	dsi->format = MIPI_DSI_FMT_RGB888;
> +	dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_BURST |
> +			  MIPI_DSI_MODE_LPM;
> +
> +	drm_panel_init(&ctx->panel);
> +	ctx->panel.dev = dev;
> +	ctx->panel.funcs = &otm8009a_drm_funcs;
> +
> +	ctx->bl_dev = backlight_device_register(DRV_NAME "_backlight", dev, ctx,
> +						&otm8009a_backlight_ops, NULL);
> +	if (IS_ERR(ctx->bl_dev)) {
> +		dev_err(dev, "failed to register backlight device\n");
> +		return PTR_ERR(ctx->bl_dev);
> +	}
> +
> +	ctx->bl_dev->props.max_brightness = OTM8009A_BACKLIGHT_MAX;
> +	ctx->bl_dev->props.brightness = OTM8009A_BACKLIGHT_DEFAULT;
> +	ctx->bl_dev->props.power = FB_BLANK_POWERDOWN;
> +	ctx->bl_dev->props.type = BACKLIGHT_RAW;
> +
> +	drm_panel_add(&ctx->panel);
> +
> +	ret = mipi_dsi_attach(dsi);
> +	if (ret < 0) {
> +		dev_err(dev, "mipi_dsi_attach failed. Is host ready?\n");
> +		drm_panel_remove(&ctx->panel);
> +		backlight_device_unregister(ctx->bl_dev);
> +		return ret;
> +	}
> +
> +	DRM_INFO(DRV_NAME "_panel %ux%u@%u %ubpp dsi %udl - ready\n",
> +		 default_mode.hdisplay, default_mode.vdisplay,
> +		 default_mode.vrefresh,
> +		 mipi_dsi_pixel_format_to_bpp(dsi->format), dsi->lanes);
> +
> +	return 0;
> +}
> +
> +static int otm8009a_remove(struct mipi_dsi_device *dsi)
> +{
> +	struct otm8009a *ctx = mipi_dsi_get_drvdata(dsi);
> +
> +	mipi_dsi_detach(dsi);
> +	drm_panel_remove(&ctx->panel);
> +
> +	backlight_device_unregister(ctx->bl_dev);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id orisetech_otm8009a_of_match[] = {
> +	{ .compatible = "orisetech,otm8009a" },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(of, orisetech_otm8009a_of_match);
> +
> +static struct mipi_dsi_driver orisetech_otm8009a_driver = {
> +	.probe  = otm8009a_probe,
> +	.remove = otm8009a_remove,
> +	.driver = {
> +		.name = DRV_NAME "_panel",
> +		.of_match_table = orisetech_otm8009a_of_match,
> +	},
> +};
> +module_mipi_dsi_driver(orisetech_otm8009a_driver);
> +
> +MODULE_AUTHOR("Philippe Cornu <philippe.cornu@st.com>");
> +MODULE_AUTHOR("Yannick Fertre <yannick.fertre@st.com>");
> +MODULE_DESCRIPTION("DRM driver for Orise Tech OTM8009A MIPI DSI panel");
> +MODULE_LICENSE("GPL v2");
Philippe CORNU July 17, 2017, 1:28 p.m. UTC | #2
On 07/12/2017 04:12 PM, Andrzej Hajda wrote:
> On 10.07.2017 11:02, Philippe CORNU wrote:
>> This patch adds Orise Tech otm8009a 3.97" 480x800 TFT LCD
>> panel driver (MIPI-DSI video mode). The panel backlight is
>> managed through the DSI link. This panel driver is used in
>> several STM32 boards.
>>
>> Signed-off-by: Philippe CORNU <philippe.cornu@st.com>
>> ---
>>   drivers/gpu/drm/panel/Kconfig                    |   9 +
>>   drivers/gpu/drm/panel/Makefile                   |   1 +
>>   drivers/gpu/drm/panel/panel-orisetech-otm8009a.c | 489 +++++++++++++++++++++++
>>   3 files changed, 499 insertions(+)
>>   create mode 100755 drivers/gpu/drm/panel/panel-orisetech-otm8009a.c
>>
>> diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
>> index d84a031..c1c9291 100644
>> --- a/drivers/gpu/drm/panel/Kconfig
>> +++ b/drivers/gpu/drm/panel/Kconfig
>> @@ -117,4 +117,13 @@ config DRM_PANEL_SITRONIX_ST7789V
>>   	  Say Y here if you want to enable support for the Sitronix
>>   	  ST7789V controller for 240x320 LCD panels
>>   
>> +config DRM_PANEL_ORISETECH_OTM8009A
>> +	tristate "Orise Tech otm8009a 480p dsi 2dl video mode panel"
>> +	depends on OF
>> +	depends on DRM_MIPI_DSI
>> +	depends on BACKLIGHT_CLASS_DEVICE
>> +	help
>> +	  Say Y here if you want to enable support for Orise Tech OTM8009A
>> +	  480x800 DSI panel
>> +
>>   endmenu
>> diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
>> index 9f6610d..ac798f3 100644
>> --- a/drivers/gpu/drm/panel/Makefile
>> +++ b/drivers/gpu/drm/panel/Makefile
>> @@ -10,3 +10,4 @@ obj-$(CONFIG_DRM_PANEL_SAMSUNG_S6E8AA0) += panel-samsung-s6e8aa0.o
>>   obj-$(CONFIG_DRM_PANEL_SHARP_LQ101R1SX01) += panel-sharp-lq101r1sx01.o
>>   obj-$(CONFIG_DRM_PANEL_SHARP_LS043T1LE01) += panel-sharp-ls043t1le01.o
>>   obj-$(CONFIG_DRM_PANEL_SITRONIX_ST7789V) += panel-sitronix-st7789v.o
>> +obj-$(CONFIG_DRM_PANEL_ORISETECH_OTM8009A) += panel-orisetech-otm8009a.o
>> \ No newline at end of file
> 
> Alphabetical order and new line at EOF.
> 

Dear Andrzej,
Many thanks for your code review.
Makefile & Kconfig are now fixed in v3 following your comments.

>> diff --git a/drivers/gpu/drm/panel/panel-orisetech-otm8009a.c b/drivers/gpu/drm/panel/panel-orisetech-otm8009a.c
>> new file mode 100755
>> index 0000000..2a3ce47
>> --- /dev/null
>> +++ b/drivers/gpu/drm/panel/panel-orisetech-otm8009a.c
>> @@ -0,0 +1,489 @@
>> +/*
>> + * Copyright (C) STMicroelectronics SA 2017
>> + *
>> + * Authors: Philippe Cornu <philippe.cornu@st.com>
>> + *          Yannick Fertre <yannick.fertre@st.com>
>> + *
>> + * License terms:  GNU General Public License (GPL), version 2
>> + */
>> +#include <drm/drmP.h>
>> +#include <drm/drm_mipi_dsi.h>
>> +#include <drm/drm_panel.h>
>> +#include <linux/backlight.h>
>> +#include <linux/gpio/consumer.h>
>> +#include <video/mipi_display.h>
>> +
>> +#define DRV_NAME "orisetech_otm8009a"
>> +
>> +#define OTM8009A_BACKLIGHT_DEFAULT	240
>> +#define OTM8009A_BACKLIGHT_MAX		255
>> +
>> +/* Manufacturer Command Set */
>> +#define MCS_ADRSFT	0x0000	/* Address Shift Function */
>> +#define MCS_PANSET	0xB3A6	/* Panel Type Setting */
>> +#define MCS_SD_CTRL	0xC0A2	/* Source Driver Timing Setting */
>> +#define MCS_P_DRV_M	0xC0B4	/* Panel Driving Mode */
>> +#define MCS_OSC_ADJ	0xC181	/* Oscillator Adjustment for Idle/Normal mode */
>> +#define MCS_RGB_VID_SET	0xC1A1	/* RGB Video Mode Setting */
>> +#define MCS_SD_PCH_CTRL	0xC480	/* Source Driver Precharge Control */
>> +#define MCS_NO_DOC1	0xC48A	/* Command not documented */
>> +#define MCS_PWR_CTRL1	0xC580	/* Power Control Setting 1 */
>> +#define MCS_PWR_CTRL2	0xC590	/* Power Control Setting 2 for Normal Mode */
>> +#define MCS_PWR_CTRL4	0xC5B0	/* Power Control Setting 4 for DC Voltage */
>> +#define MCS_PANCTRLSET1	0xCB80	/* Panel Control Setting 1 */
>> +#define MCS_PANCTRLSET2	0xCB90	/* Panel Control Setting 2 */
>> +#define MCS_PANCTRLSET3	0xCBA0	/* Panel Control Setting 3 */
>> +#define MCS_PANCTRLSET4	0xCBB0	/* Panel Control Setting 4 */
>> +#define MCS_PANCTRLSET5	0xCBC0	/* Panel Control Setting 5 */
>> +#define MCS_PANCTRLSET6	0xCBD0	/* Panel Control Setting 6 */
>> +#define MCS_PANCTRLSET7	0xCBE0	/* Panel Control Setting 7 */
>> +#define MCS_PANCTRLSET8	0xCBF0	/* Panel Control Setting 8 */
>> +#define MCS_PANU2D1	0xCC80	/* Panel U2D Setting 1 */
>> +#define MCS_PANU2D2	0xCC90	/* Panel U2D Setting 2 */
>> +#define MCS_PANU2D3	0xCCA0	/* Panel U2D Setting 3 */
>> +#define MCS_PAND2U1	0xCCB0	/* Panel D2U Setting 1 */
>> +#define MCS_PAND2U2	0xCCC0	/* Panel D2U Setting 2 */
>> +#define MCS_PAND2U3	0xCCD0	/* Panel D2U Setting 3 */
>> +#define MCS_GOAVST	0xCE80	/* GOA VST Setting */
>> +#define MCS_GOACLKA1	0xCEA0	/* GOA CLKA1 Setting */
>> +#define MCS_GOACLKA3	0xCEB0	/* GOA CLKA3 Setting */
>> +#define MCS_GOAECLK	0xCFC0	/* GOA ECLK Setting */
>> +#define MCS_NO_DOC2	0xCFD0	/* Command not documented */
>> +#define MCS_GVDDSET	0xD800	/* GVDD/NGVDD */
>> +#define MCS_VCOMDC	0xD900	/* VCOM Voltage Setting */
>> +#define MCS_GMCT2_2P	0xE100	/* Gamma Correction 2.2+ Setting */
>> +#define MCS_GMCT2_2N	0xE200	/* Gamma Correction 2.2- Setting */
>> +#define MCS_NO_DOC3	0xF5B6	/* Command not documented */
>> +#define MCS_CMD2_ENA1	0xFF00	/* Enable Access Command2 "CMD2" */
>> +#define MCS_CMD2_ENA2	0xFF80	/* Enable Access Orise Command2 */
>> +
>> +struct otm8009a {
>> +	struct device *dev;
>> +	struct drm_panel panel;
>> +	struct backlight_device *bl_dev;
>> +	struct gpio_desc *reset_gpio;
>> +	bool prepared;
>> +	bool enabled;
>> +};
>> +
>> +static const struct drm_display_mode default_mode = {
>> +	.clock = 32729,
>> +	.hdisplay = 480,
>> +	.hsync_start = 480 + 120,
>> +	.hsync_end = 480 + 120 + 63,
>> +	.htotal = 480 + 120 + 63 + 120,
>> +	.vdisplay = 800,
>> +	.vsync_start = 800 + 12,
>> +	.vsync_end = 800 + 12 + 12,
>> +	.vtotal = 800 + 12 + 12 + 12,
>> +	.vrefresh = 50,
>> +	.flags = 0,
>> +	.width_mm = 52,
>> +	.height_mm = 86,
>> +};
>> +
>> +static inline struct otm8009a *panel_to_otm8009a(struct drm_panel *panel)
>> +{
>> +	return container_of(panel, struct otm8009a, panel);
>> +}
>> +
>> +static void otm8009a_dcs_write_buf(struct otm8009a *ctx, const void *data,
>> +				   size_t len)
>> +{
>> +	struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
>> +
>> +	if (mipi_dsi_dcs_write_buffer(dsi, data, len) < 0)
>> +		DRM_WARN("mipi dsi dcs write buffer failed\n");
>> +}
>> +
>> +#define dcs_write_seq(ctx, seq...)			\
>> +({							\
>> +	static const u8 d[] = { seq };			\
>> +	otm8009a_dcs_write_buf(ctx, d, ARRAY_SIZE(d));	\
>> +})
>> +
>> +#define dcs_write_cmd_at(ctx, cmd, seq...)		\
>> +({							\
>> +	dcs_write_seq(ctx, MCS_ADRSFT, (cmd) & 0xFF);	\
>> +	dcs_write_seq(ctx, (cmd) >> 8, seq);		\
>> +})
> 
> This approach looks better than my proposition, for sure it is more
> consistent with documentation.
> 
Thank you for your good initial proposition helping me a lot to improve 
all this : )

>> +
>> +static int otm8009a_init_sequence(struct otm8009a *ctx)
>> +{
>> +	struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
>> +	int ret;
>> +
>> +	/* Enter CMD2 */
>> +	dcs_write_cmd_at(ctx, MCS_CMD2_ENA1, 0x80, 0x09, 0x01);
>> +
>> +	/* Enter Orise Command2 */
>> +	dcs_write_cmd_at(ctx, MCS_CMD2_ENA2, 0x80, 0x09);
>> +
>> +	dcs_write_cmd_at(ctx, MCS_SD_PCH_CTRL, 0x30);
>> +	mdelay(10);
>> +
>> +	dcs_write_cmd_at(ctx, MCS_NO_DOC1, 0x40);
>> +	mdelay(10);
>> +
>> +	dcs_write_cmd_at(ctx, MCS_PWR_CTRL4 + 1, 0xA9);
>> +	dcs_write_cmd_at(ctx, MCS_PWR_CTRL2 + 1, 0x34);
>> +	dcs_write_cmd_at(ctx, MCS_P_DRV_M, 0x50);
>> +	dcs_write_cmd_at(ctx, MCS_VCOMDC, 0x4E);
>> +	dcs_write_cmd_at(ctx, MCS_OSC_ADJ, 0x66); /* 65Hz */
>> +	dcs_write_cmd_at(ctx, MCS_RGB_VID_SET, 0x08);
>> +	dcs_write_cmd_at(ctx, MCS_PWR_CTRL2 + 2, 0x01);
>> +	dcs_write_cmd_at(ctx, MCS_PWR_CTRL2 + 5, 0x34);
>> +	dcs_write_cmd_at(ctx, MCS_PWR_CTRL2 + 4, 0x33);
>> +	dcs_write_cmd_at(ctx, MCS_GVDDSET, 0x79, 0x79);
>> +	dcs_write_cmd_at(ctx, MCS_SD_CTRL + 1, 0x1B);
>> +	dcs_write_cmd_at(ctx, MCS_PWR_CTRL1 + 2, 0x83);
>> +	dcs_write_cmd_at(ctx, MCS_SD_PCH_CTRL + 1, 0x83);
>> +	dcs_write_cmd_at(ctx, MCS_RGB_VID_SET, 0x0E); /* FIXME before 0x08! */
> 
> Quite cryptic comment, either remove, either make it readable.
> 
fixed in v3, thanks.

>> +	dcs_write_cmd_at(ctx, MCS_PANSET, 0x00, 0x01);
>> +
>> +	dcs_write_cmd_at(ctx, MCS_GOAVST, 0x85, 0x01, 0x00, 0x84, 0x01, 0x00);
>> +	dcs_write_cmd_at(ctx, MCS_GOACLKA1, 0x18, 0x04, 0x03, 0x39, 0x00, 0x00,
>> +			 0x00, 0x18, 0x03, 0x03, 0x3A, 0x00, 0x00, 0x00);
>> +	dcs_write_cmd_at(ctx, MCS_GOACLKA3, 0x18, 0x02, 0x03, 0x3B, 0x00, 0x00,
>> +			 0x00, 0x18, 0x01, 0x03, 0x3C, 0x00, 0x00, 0x00);
>> +	dcs_write_cmd_at(ctx, MCS_GOAECLK, 0x01, 0x01, 0x20, 0x20, 0x00, 0x00,
>> +			 0x01, 0x02, 0x00, 0x00);
>> +
>> +	dcs_write_cmd_at(ctx, MCS_NO_DOC2, 0x00);
>> +
>> +	dcs_write_cmd_at(ctx, MCS_PANCTRLSET1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0);
>> +	dcs_write_cmd_at(ctx, MCS_PANCTRLSET2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
>> +			 0, 0, 0, 0, 0);
>> +	dcs_write_cmd_at(ctx, MCS_PANCTRLSET3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
>> +			 0, 0, 0, 0, 0);
>> +	dcs_write_cmd_at(ctx, MCS_PANCTRLSET4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0);
>> +	dcs_write_cmd_at(ctx, MCS_PANCTRLSET5, 0, 4, 4, 4, 4, 4, 0, 0, 0, 0,
>> +			 0, 0, 0, 0, 0);
>> +	dcs_write_cmd_at(ctx, MCS_PANCTRLSET6, 0, 0, 0, 0, 0, 0, 4, 4, 4, 4,
>> +			 4, 0, 0, 0, 0);
>> +	dcs_write_cmd_at(ctx, MCS_PANCTRLSET7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0);
>> +	dcs_write_cmd_at(ctx, MCS_PANCTRLSET8, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
>> +			 0xFF, 0xFF, 0xFF, 0xFF, 0xFF);
>> +
>> +	dcs_write_cmd_at(ctx, MCS_PANU2D1, 0x00, 0x26, 0x09, 0x0B, 0x01, 0x25,
>> +			 0x00, 0x00, 0x00, 0x00);
>> +	dcs_write_cmd_at(ctx, MCS_PANU2D2, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
>> +			 0x00, 0x00, 0x00, 0x00, 0x00, 0x26, 0x0A, 0x0C, 0x02);
>> +	dcs_write_cmd_at(ctx, MCS_PANU2D3, 0x25, 0x00, 0x00, 0x00, 0x00, 0x00,
>> +			 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00);
>> +	dcs_write_cmd_at(ctx, MCS_PAND2U1, 0x00, 0x25, 0x0C, 0x0A, 0x02, 0x26,
>> +			 0x00, 0x00, 0x00, 0x00);
>> +	dcs_write_cmd_at(ctx, MCS_PAND2U2, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
>> +			 0x00, 0x00, 0x00, 0x00, 0x00, 0x25, 0x0B, 0x09, 0x01);
>> +	dcs_write_cmd_at(ctx, MCS_PAND2U3, 0x26, 0x00, 0x00, 0x00, 0x00, 0x00,
>> +			 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00);
>> +
>> +	dcs_write_cmd_at(ctx, MCS_PWR_CTRL1 + 1, 0x66);
>> +
>> +	dcs_write_cmd_at(ctx, MCS_NO_DOC3, 0x06);
>> +
>> +	dcs_write_cmd_at(ctx, MCS_GMCT2_2P, 0x00, 0x09, 0x0F, 0x0E, 0x07, 0x10,
>> +			 0x0B, 0x0A, 0x04, 0x07, 0x0B, 0x08, 0x0F, 0x10, 0x0A,
>> +			 0x01);
>> +	dcs_write_cmd_at(ctx, MCS_GMCT2_2N, 0x00, 0x09, 0x0F, 0x0E, 0x07, 0x10,
>> +			 0x0B, 0x0A, 0x04, 0x07, 0x0B, 0x08, 0x0F, 0x10, 0x0A,
>> +			 0x01);
>> +
>> +	/* Exit CMD2 */
>> +	dcs_write_cmd_at(ctx, MCS_CMD2_ENA1, 0xFF, 0xFF, 0xFF);
>> +
>> +	ret = mipi_dsi_dcs_nop(dsi);
>> +	if (ret)
>> +		return ret;
>> +
>> +	ret = mipi_dsi_dcs_exit_sleep_mode(dsi);
>> +	if (ret)
>> +		return ret;
>> +
>> +	/* Wait for sleep out exit */
>> +	mdelay(120);
>> +
>> +	/* Default portrait 480x800 rgb24 */
>> +	dcs_write_seq(ctx, MIPI_DCS_SET_ADDRESS_MODE, 0x00);
>> +
>> +	ret = mipi_dsi_dcs_set_column_address(dsi, 0,
>> +					      default_mode.hdisplay - 1);
>> +	if (ret)
>> +		return ret;
>> +
>> +	ret = mipi_dsi_dcs_set_page_address(dsi, 0, default_mode.vdisplay - 1);
>> +	if (ret)
>> +		return ret;
>> +
>> +	/* See otm8009a driver documentation for pixel format descriptions */
>> +	ret = mipi_dsi_dcs_set_pixel_format(dsi, MIPI_DCS_PIXEL_FMT_24BIT |
>> +					    MIPI_DCS_PIXEL_FMT_24BIT << 4);
>> +	if (ret)
>> +		return ret;
>> +
>> +	/* Disable CABC feature */
>> +	dcs_write_seq(ctx, MIPI_DCS_WRITE_POWER_SAVE, 0x00);
>> +
>> +	ret = mipi_dsi_dcs_set_display_on(dsi);
>> +	if (ret)
>> +		return ret;
>> +
>> +	ret = mipi_dsi_dcs_nop(dsi);
>> +	if (ret)
>> +		return ret;
>> +
>> +	/* Send Command GRAM memory write (no parameters) */
>> +	dcs_write_seq(ctx, MIPI_DCS_WRITE_MEMORY_START);
>> +
>> +	return 0;
>> +}
>> +
>> +static int otm8009a_disable(struct drm_panel *panel)
>> +{
>> +	struct otm8009a *ctx = panel_to_otm8009a(panel);
>> +	struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
>> +	int ret;
>> +
>> +	if (!ctx->enabled)
>> +		return 0; /* This is not an issue so we return 0 here */
>> +
>> +	/* Power off the backlight. Note: end-user still controls brightness */
>> +	ctx->bl_dev->props.power = FB_BLANK_POWERDOWN;
>> +	ret = backlight_update_status(ctx->bl_dev);
>> +	if (ret)
>> +		return ret;
>> +
>> +	ret = mipi_dsi_dcs_set_display_off(dsi);
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	ret = mipi_dsi_dcs_enter_sleep_mode(dsi);
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	msleep(120);
>> +
>> +	ctx->enabled = false;
>> +
>> +	return 0;
>> +}
>> +
>> +static int otm8009a_unprepare(struct drm_panel *panel)
>> +{
>> +	struct otm8009a *ctx = panel_to_otm8009a(panel);
>> +
>> +	if (!ctx->prepared)
>> +		return 0;
>> +
>> +	if (ctx->reset_gpio) {
>> +		gpiod_set_value_cansleep(ctx->reset_gpio, 1);
>> +		msleep(20);
>> +	}
>> +
>> +	ctx->prepared = false;
>> +
>> +	return 0;
>> +}
>> +
>> +static int otm8009a_prepare(struct drm_panel *panel)
>> +{
>> +	struct otm8009a *ctx = panel_to_otm8009a(panel);
>> +	int ret;
>> +
>> +	if (ctx->prepared)
>> +		return 0;
>> +
>> +	if (ctx->reset_gpio) {
>> +		gpiod_set_value_cansleep(ctx->reset_gpio, 0);
>> +		gpiod_set_value_cansleep(ctx->reset_gpio, 1);
>> +		msleep(20);
>> +		gpiod_set_value_cansleep(ctx->reset_gpio, 0);
>> +		msleep(100);
>> +	}
>> +
>> +	ret = otm8009a_init_sequence(ctx);
>> +	if (ret)
>> +		return ret;
>> +
>> +	ctx->prepared = true;
>> +
>> +	/* Power on the backlight. Note: end-user still controls brightness */
>> +	ctx->bl_dev->props.power = FB_BLANK_UNBLANK;
>> +	backlight_update_status(ctx->bl_dev);
>> +
>> +	return 0;
>> +}
>> +
>> +static int otm8009a_enable(struct drm_panel *panel)
>> +{
>> +	struct otm8009a *ctx = panel_to_otm8009a(panel);
>> +
>> +	ctx->enabled = true;
>> +
>> +	return 0;
>> +}
> 
> I am not sure about it, but I guess unblanking should be performed in
> _enable callback. Otherwise you risk seeing garbage at panel start - it
> starts displaying uninitialized data.
> Usually sequence looks like:
> A. Power on DSI host
> B. Initialize panel (prepare callback)
> C. Start video transmission from the host to the panel
> D. wait about 120ms, then unblank panel (enable callback)
> 
> Of course this is only my experience, maybe your panel is different.

This otm8009a panel does not really like receiving dsi commands during 
the video mode blankings, that is why I have an _enable() function with 
no dcs command call. Maybe it could be improved in the future, by 
adjusting timings for instance, helping the panel to support dcs 
commands during video mode blankings. For the moment, I prefer the *safe 
approach* ie. no dsi command during video mode blankings (excepted 
backlight updates).

> 
> Beside above comments:
> Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
> 
>   --
> Regards
> Andrzej
> 
> 

Many thanks,
Philippe
>> +
>> +static int otm8009a_get_modes(struct drm_panel *panel)
>> +{
>> +	struct drm_display_mode *mode;
>> +
>> +	mode = drm_mode_duplicate(panel->drm, &default_mode);
>> +	if (!mode) {
>> +		DRM_ERROR("failed to add mode %ux%ux@%u\n",
>> +			  default_mode.hdisplay, default_mode.vdisplay,
>> +			  default_mode.vrefresh);
>> +		return -ENOMEM;
>> +	}
>> +
>> +	drm_mode_set_name(mode);
>> +
>> +	mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
>> +	drm_mode_probed_add(panel->connector, mode);
>> +
>> +	panel->connector->display_info.width_mm = mode->width_mm;
>> +	panel->connector->display_info.height_mm = mode->height_mm;
>> +
>> +	return 1;
>> +}
>> +
>> +static const struct drm_panel_funcs otm8009a_drm_funcs = {
>> +	.disable   = otm8009a_disable,
>> +	.unprepare = otm8009a_unprepare,
>> +	.prepare   = otm8009a_prepare,
>> +	.enable    = otm8009a_enable,
>> +	.get_modes = otm8009a_get_modes,
>> +};
>> +
>> +/*
>> + * DSI-BASED BACKLIGHT
>> + */
>> +
>> +static int otm8009a_backlight_update_status(struct backlight_device *bd)
>> +{
>> +	struct otm8009a *ctx = bl_get_data(bd);
>> +	u8 data[2];
>> +
>> +	if (!ctx->prepared) {
>> +		DRM_DEBUG("lcd not ready yet for setting its backlight!\n");
>> +		return -ENXIO;
>> +	}
>> +
>> +	if (bd->props.power <= FB_BLANK_NORMAL) {
>> +		/* Power on the backlight with the requested brightness
>> +		 * Note We can not use mipi_dsi_dcs_set_display_brightness()
>> +		 * as otm8009a driver support only 8-bit brightness (1 param).
>> +		 */
>> +		data[0] = MIPI_DCS_SET_DISPLAY_BRIGHTNESS;
>> +		data[1] = bd->props.brightness;
>> +		otm8009a_dcs_write_buf(ctx, data, ARRAY_SIZE(data));
>> +
>> +		/* set Brightness Control & Backlight on */
>> +		data[1] = 0x24;
>> +
>> +	} else {
>> +		/* Power off the backlight: set Brightness Control & Bl off */
>> +		data[1] = 0;
>> +	}
>> +
>> +	/* Update Brightness Control & Backlight */
>> +	data[0] = MIPI_DCS_WRITE_CONTROL_DISPLAY;
>> +	otm8009a_dcs_write_buf(ctx, data, ARRAY_SIZE(data));
>> +
>> +	return 0;
>> +}
>> +
>> +static const struct backlight_ops otm8009a_backlight_ops = {
>> +	.update_status = otm8009a_backlight_update_status,
>> +};
>> +
>> +static int otm8009a_probe(struct mipi_dsi_device *dsi)
>> +{
>> +	struct device *dev = &dsi->dev;
>> +	struct otm8009a *ctx;
>> +	int ret;
>> +
>> +	ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
>> +	if (!ctx)
>> +		return -ENOMEM;
>> +
>> +	ctx->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
>> +	if (IS_ERR(ctx->reset_gpio)) {
>> +		dev_err(dev, "cannot get reset-gpio\n");
>> +		return PTR_ERR(ctx->reset_gpio);
>> +	}
>> +
>> +	mipi_dsi_set_drvdata(dsi, ctx);
>> +
>> +	ctx->dev = dev;
>> +
>> +	dsi->lanes = 2;
>> +	dsi->format = MIPI_DSI_FMT_RGB888;
>> +	dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_BURST |
>> +			  MIPI_DSI_MODE_LPM;
>> +
>> +	drm_panel_init(&ctx->panel);
>> +	ctx->panel.dev = dev;
>> +	ctx->panel.funcs = &otm8009a_drm_funcs;
>> +
>> +	ctx->bl_dev = backlight_device_register(DRV_NAME "_backlight", dev, ctx,
>> +						&otm8009a_backlight_ops, NULL);
>> +	if (IS_ERR(ctx->bl_dev)) {
>> +		dev_err(dev, "failed to register backlight device\n");
>> +		return PTR_ERR(ctx->bl_dev);
>> +	}
>> +
>> +	ctx->bl_dev->props.max_brightness = OTM8009A_BACKLIGHT_MAX;
>> +	ctx->bl_dev->props.brightness = OTM8009A_BACKLIGHT_DEFAULT;
>> +	ctx->bl_dev->props.power = FB_BLANK_POWERDOWN;
>> +	ctx->bl_dev->props.type = BACKLIGHT_RAW;
>> +
>> +	drm_panel_add(&ctx->panel);
>> +
>> +	ret = mipi_dsi_attach(dsi);
>> +	if (ret < 0) {
>> +		dev_err(dev, "mipi_dsi_attach failed. Is host ready?\n");
>> +		drm_panel_remove(&ctx->panel);
>> +		backlight_device_unregister(ctx->bl_dev);
>> +		return ret;
>> +	}
>> +
>> +	DRM_INFO(DRV_NAME "_panel %ux%u@%u %ubpp dsi %udl - ready\n",
>> +		 default_mode.hdisplay, default_mode.vdisplay,
>> +		 default_mode.vrefresh,
>> +		 mipi_dsi_pixel_format_to_bpp(dsi->format), dsi->lanes);
>> +
>> +	return 0;
>> +}
>> +
>> +static int otm8009a_remove(struct mipi_dsi_device *dsi)
>> +{
>> +	struct otm8009a *ctx = mipi_dsi_get_drvdata(dsi);
>> +
>> +	mipi_dsi_detach(dsi);
>> +	drm_panel_remove(&ctx->panel);
>> +
>> +	backlight_device_unregister(ctx->bl_dev);
>> +
>> +	return 0;
>> +}
>> +
>> +static const struct of_device_id orisetech_otm8009a_of_match[] = {
>> +	{ .compatible = "orisetech,otm8009a" },
>> +	{ }
>> +};
>> +MODULE_DEVICE_TABLE(of, orisetech_otm8009a_of_match);
>> +
>> +static struct mipi_dsi_driver orisetech_otm8009a_driver = {
>> +	.probe  = otm8009a_probe,
>> +	.remove = otm8009a_remove,
>> +	.driver = {
>> +		.name = DRV_NAME "_panel",
>> +		.of_match_table = orisetech_otm8009a_of_match,
>> +	},
>> +};
>> +module_mipi_dsi_driver(orisetech_otm8009a_driver);
>> +
>> +MODULE_AUTHOR("Philippe Cornu <philippe.cornu@st.com>");
>> +MODULE_AUTHOR("Yannick Fertre <yannick.fertre@st.com>");
>> +MODULE_DESCRIPTION("DRM driver for Orise Tech OTM8009A MIPI DSI panel");
>> +MODULE_LICENSE("GPL v2");
> 
>
diff mbox

Patch

diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
index d84a031..c1c9291 100644
--- a/drivers/gpu/drm/panel/Kconfig
+++ b/drivers/gpu/drm/panel/Kconfig
@@ -117,4 +117,13 @@  config DRM_PANEL_SITRONIX_ST7789V
 	  Say Y here if you want to enable support for the Sitronix
 	  ST7789V controller for 240x320 LCD panels
 
+config DRM_PANEL_ORISETECH_OTM8009A
+	tristate "Orise Tech otm8009a 480p dsi 2dl video mode panel"
+	depends on OF
+	depends on DRM_MIPI_DSI
+	depends on BACKLIGHT_CLASS_DEVICE
+	help
+	  Say Y here if you want to enable support for Orise Tech OTM8009A
+	  480x800 DSI panel
+
 endmenu
diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
index 9f6610d..ac798f3 100644
--- a/drivers/gpu/drm/panel/Makefile
+++ b/drivers/gpu/drm/panel/Makefile
@@ -10,3 +10,4 @@  obj-$(CONFIG_DRM_PANEL_SAMSUNG_S6E8AA0) += panel-samsung-s6e8aa0.o
 obj-$(CONFIG_DRM_PANEL_SHARP_LQ101R1SX01) += panel-sharp-lq101r1sx01.o
 obj-$(CONFIG_DRM_PANEL_SHARP_LS043T1LE01) += panel-sharp-ls043t1le01.o
 obj-$(CONFIG_DRM_PANEL_SITRONIX_ST7789V) += panel-sitronix-st7789v.o
+obj-$(CONFIG_DRM_PANEL_ORISETECH_OTM8009A) += panel-orisetech-otm8009a.o
\ No newline at end of file
diff --git a/drivers/gpu/drm/panel/panel-orisetech-otm8009a.c b/drivers/gpu/drm/panel/panel-orisetech-otm8009a.c
new file mode 100755
index 0000000..2a3ce47
--- /dev/null
+++ b/drivers/gpu/drm/panel/panel-orisetech-otm8009a.c
@@ -0,0 +1,489 @@ 
+/*
+ * Copyright (C) STMicroelectronics SA 2017
+ *
+ * Authors: Philippe Cornu <philippe.cornu@st.com>
+ *          Yannick Fertre <yannick.fertre@st.com>
+ *
+ * License terms:  GNU General Public License (GPL), version 2
+ */
+#include <drm/drmP.h>
+#include <drm/drm_mipi_dsi.h>
+#include <drm/drm_panel.h>
+#include <linux/backlight.h>
+#include <linux/gpio/consumer.h>
+#include <video/mipi_display.h>
+
+#define DRV_NAME "orisetech_otm8009a"
+
+#define OTM8009A_BACKLIGHT_DEFAULT	240
+#define OTM8009A_BACKLIGHT_MAX		255
+
+/* Manufacturer Command Set */
+#define MCS_ADRSFT	0x0000	/* Address Shift Function */
+#define MCS_PANSET	0xB3A6	/* Panel Type Setting */
+#define MCS_SD_CTRL	0xC0A2	/* Source Driver Timing Setting */
+#define MCS_P_DRV_M	0xC0B4	/* Panel Driving Mode */
+#define MCS_OSC_ADJ	0xC181	/* Oscillator Adjustment for Idle/Normal mode */
+#define MCS_RGB_VID_SET	0xC1A1	/* RGB Video Mode Setting */
+#define MCS_SD_PCH_CTRL	0xC480	/* Source Driver Precharge Control */
+#define MCS_NO_DOC1	0xC48A	/* Command not documented */
+#define MCS_PWR_CTRL1	0xC580	/* Power Control Setting 1 */
+#define MCS_PWR_CTRL2	0xC590	/* Power Control Setting 2 for Normal Mode */
+#define MCS_PWR_CTRL4	0xC5B0	/* Power Control Setting 4 for DC Voltage */
+#define MCS_PANCTRLSET1	0xCB80	/* Panel Control Setting 1 */
+#define MCS_PANCTRLSET2	0xCB90	/* Panel Control Setting 2 */
+#define MCS_PANCTRLSET3	0xCBA0	/* Panel Control Setting 3 */
+#define MCS_PANCTRLSET4	0xCBB0	/* Panel Control Setting 4 */
+#define MCS_PANCTRLSET5	0xCBC0	/* Panel Control Setting 5 */
+#define MCS_PANCTRLSET6	0xCBD0	/* Panel Control Setting 6 */
+#define MCS_PANCTRLSET7	0xCBE0	/* Panel Control Setting 7 */
+#define MCS_PANCTRLSET8	0xCBF0	/* Panel Control Setting 8 */
+#define MCS_PANU2D1	0xCC80	/* Panel U2D Setting 1 */
+#define MCS_PANU2D2	0xCC90	/* Panel U2D Setting 2 */
+#define MCS_PANU2D3	0xCCA0	/* Panel U2D Setting 3 */
+#define MCS_PAND2U1	0xCCB0	/* Panel D2U Setting 1 */
+#define MCS_PAND2U2	0xCCC0	/* Panel D2U Setting 2 */
+#define MCS_PAND2U3	0xCCD0	/* Panel D2U Setting 3 */
+#define MCS_GOAVST	0xCE80	/* GOA VST Setting */
+#define MCS_GOACLKA1	0xCEA0	/* GOA CLKA1 Setting */
+#define MCS_GOACLKA3	0xCEB0	/* GOA CLKA3 Setting */
+#define MCS_GOAECLK	0xCFC0	/* GOA ECLK Setting */
+#define MCS_NO_DOC2	0xCFD0	/* Command not documented */
+#define MCS_GVDDSET	0xD800	/* GVDD/NGVDD */
+#define MCS_VCOMDC	0xD900	/* VCOM Voltage Setting */
+#define MCS_GMCT2_2P	0xE100	/* Gamma Correction 2.2+ Setting */
+#define MCS_GMCT2_2N	0xE200	/* Gamma Correction 2.2- Setting */
+#define MCS_NO_DOC3	0xF5B6	/* Command not documented */
+#define MCS_CMD2_ENA1	0xFF00	/* Enable Access Command2 "CMD2" */
+#define MCS_CMD2_ENA2	0xFF80	/* Enable Access Orise Command2 */
+
+struct otm8009a {
+	struct device *dev;
+	struct drm_panel panel;
+	struct backlight_device *bl_dev;
+	struct gpio_desc *reset_gpio;
+	bool prepared;
+	bool enabled;
+};
+
+static const struct drm_display_mode default_mode = {
+	.clock = 32729,
+	.hdisplay = 480,
+	.hsync_start = 480 + 120,
+	.hsync_end = 480 + 120 + 63,
+	.htotal = 480 + 120 + 63 + 120,
+	.vdisplay = 800,
+	.vsync_start = 800 + 12,
+	.vsync_end = 800 + 12 + 12,
+	.vtotal = 800 + 12 + 12 + 12,
+	.vrefresh = 50,
+	.flags = 0,
+	.width_mm = 52,
+	.height_mm = 86,
+};
+
+static inline struct otm8009a *panel_to_otm8009a(struct drm_panel *panel)
+{
+	return container_of(panel, struct otm8009a, panel);
+}
+
+static void otm8009a_dcs_write_buf(struct otm8009a *ctx, const void *data,
+				   size_t len)
+{
+	struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
+
+	if (mipi_dsi_dcs_write_buffer(dsi, data, len) < 0)
+		DRM_WARN("mipi dsi dcs write buffer failed\n");
+}
+
+#define dcs_write_seq(ctx, seq...)			\
+({							\
+	static const u8 d[] = { seq };			\
+	otm8009a_dcs_write_buf(ctx, d, ARRAY_SIZE(d));	\
+})
+
+#define dcs_write_cmd_at(ctx, cmd, seq...)		\
+({							\
+	dcs_write_seq(ctx, MCS_ADRSFT, (cmd) & 0xFF);	\
+	dcs_write_seq(ctx, (cmd) >> 8, seq);		\
+})
+
+static int otm8009a_init_sequence(struct otm8009a *ctx)
+{
+	struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
+	int ret;
+
+	/* Enter CMD2 */
+	dcs_write_cmd_at(ctx, MCS_CMD2_ENA1, 0x80, 0x09, 0x01);
+
+	/* Enter Orise Command2 */
+	dcs_write_cmd_at(ctx, MCS_CMD2_ENA2, 0x80, 0x09);
+
+	dcs_write_cmd_at(ctx, MCS_SD_PCH_CTRL, 0x30);
+	mdelay(10);
+
+	dcs_write_cmd_at(ctx, MCS_NO_DOC1, 0x40);
+	mdelay(10);
+
+	dcs_write_cmd_at(ctx, MCS_PWR_CTRL4 + 1, 0xA9);
+	dcs_write_cmd_at(ctx, MCS_PWR_CTRL2 + 1, 0x34);
+	dcs_write_cmd_at(ctx, MCS_P_DRV_M, 0x50);
+	dcs_write_cmd_at(ctx, MCS_VCOMDC, 0x4E);
+	dcs_write_cmd_at(ctx, MCS_OSC_ADJ, 0x66); /* 65Hz */
+	dcs_write_cmd_at(ctx, MCS_RGB_VID_SET, 0x08);
+	dcs_write_cmd_at(ctx, MCS_PWR_CTRL2 + 2, 0x01);
+	dcs_write_cmd_at(ctx, MCS_PWR_CTRL2 + 5, 0x34);
+	dcs_write_cmd_at(ctx, MCS_PWR_CTRL2 + 4, 0x33);
+	dcs_write_cmd_at(ctx, MCS_GVDDSET, 0x79, 0x79);
+	dcs_write_cmd_at(ctx, MCS_SD_CTRL + 1, 0x1B);
+	dcs_write_cmd_at(ctx, MCS_PWR_CTRL1 + 2, 0x83);
+	dcs_write_cmd_at(ctx, MCS_SD_PCH_CTRL + 1, 0x83);
+	dcs_write_cmd_at(ctx, MCS_RGB_VID_SET, 0x0E); /* FIXME before 0x08! */
+	dcs_write_cmd_at(ctx, MCS_PANSET, 0x00, 0x01);
+
+	dcs_write_cmd_at(ctx, MCS_GOAVST, 0x85, 0x01, 0x00, 0x84, 0x01, 0x00);
+	dcs_write_cmd_at(ctx, MCS_GOACLKA1, 0x18, 0x04, 0x03, 0x39, 0x00, 0x00,
+			 0x00, 0x18, 0x03, 0x03, 0x3A, 0x00, 0x00, 0x00);
+	dcs_write_cmd_at(ctx, MCS_GOACLKA3, 0x18, 0x02, 0x03, 0x3B, 0x00, 0x00,
+			 0x00, 0x18, 0x01, 0x03, 0x3C, 0x00, 0x00, 0x00);
+	dcs_write_cmd_at(ctx, MCS_GOAECLK, 0x01, 0x01, 0x20, 0x20, 0x00, 0x00,
+			 0x01, 0x02, 0x00, 0x00);
+
+	dcs_write_cmd_at(ctx, MCS_NO_DOC2, 0x00);
+
+	dcs_write_cmd_at(ctx, MCS_PANCTRLSET1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0);
+	dcs_write_cmd_at(ctx, MCS_PANCTRLSET2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+			 0, 0, 0, 0, 0);
+	dcs_write_cmd_at(ctx, MCS_PANCTRLSET3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+			 0, 0, 0, 0, 0);
+	dcs_write_cmd_at(ctx, MCS_PANCTRLSET4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0);
+	dcs_write_cmd_at(ctx, MCS_PANCTRLSET5, 0, 4, 4, 4, 4, 4, 0, 0, 0, 0,
+			 0, 0, 0, 0, 0);
+	dcs_write_cmd_at(ctx, MCS_PANCTRLSET6, 0, 0, 0, 0, 0, 0, 4, 4, 4, 4,
+			 4, 0, 0, 0, 0);
+	dcs_write_cmd_at(ctx, MCS_PANCTRLSET7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0);
+	dcs_write_cmd_at(ctx, MCS_PANCTRLSET8, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
+			 0xFF, 0xFF, 0xFF, 0xFF, 0xFF);
+
+	dcs_write_cmd_at(ctx, MCS_PANU2D1, 0x00, 0x26, 0x09, 0x0B, 0x01, 0x25,
+			 0x00, 0x00, 0x00, 0x00);
+	dcs_write_cmd_at(ctx, MCS_PANU2D2, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+			 0x00, 0x00, 0x00, 0x00, 0x00, 0x26, 0x0A, 0x0C, 0x02);
+	dcs_write_cmd_at(ctx, MCS_PANU2D3, 0x25, 0x00, 0x00, 0x00, 0x00, 0x00,
+			 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00);
+	dcs_write_cmd_at(ctx, MCS_PAND2U1, 0x00, 0x25, 0x0C, 0x0A, 0x02, 0x26,
+			 0x00, 0x00, 0x00, 0x00);
+	dcs_write_cmd_at(ctx, MCS_PAND2U2, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+			 0x00, 0x00, 0x00, 0x00, 0x00, 0x25, 0x0B, 0x09, 0x01);
+	dcs_write_cmd_at(ctx, MCS_PAND2U3, 0x26, 0x00, 0x00, 0x00, 0x00, 0x00,
+			 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00);
+
+	dcs_write_cmd_at(ctx, MCS_PWR_CTRL1 + 1, 0x66);
+
+	dcs_write_cmd_at(ctx, MCS_NO_DOC3, 0x06);
+
+	dcs_write_cmd_at(ctx, MCS_GMCT2_2P, 0x00, 0x09, 0x0F, 0x0E, 0x07, 0x10,
+			 0x0B, 0x0A, 0x04, 0x07, 0x0B, 0x08, 0x0F, 0x10, 0x0A,
+			 0x01);
+	dcs_write_cmd_at(ctx, MCS_GMCT2_2N, 0x00, 0x09, 0x0F, 0x0E, 0x07, 0x10,
+			 0x0B, 0x0A, 0x04, 0x07, 0x0B, 0x08, 0x0F, 0x10, 0x0A,
+			 0x01);
+
+	/* Exit CMD2 */
+	dcs_write_cmd_at(ctx, MCS_CMD2_ENA1, 0xFF, 0xFF, 0xFF);
+
+	ret = mipi_dsi_dcs_nop(dsi);
+	if (ret)
+		return ret;
+
+	ret = mipi_dsi_dcs_exit_sleep_mode(dsi);
+	if (ret)
+		return ret;
+
+	/* Wait for sleep out exit */
+	mdelay(120);
+
+	/* Default portrait 480x800 rgb24 */
+	dcs_write_seq(ctx, MIPI_DCS_SET_ADDRESS_MODE, 0x00);
+
+	ret = mipi_dsi_dcs_set_column_address(dsi, 0,
+					      default_mode.hdisplay - 1);
+	if (ret)
+		return ret;
+
+	ret = mipi_dsi_dcs_set_page_address(dsi, 0, default_mode.vdisplay - 1);
+	if (ret)
+		return ret;
+
+	/* See otm8009a driver documentation for pixel format descriptions */
+	ret = mipi_dsi_dcs_set_pixel_format(dsi, MIPI_DCS_PIXEL_FMT_24BIT |
+					    MIPI_DCS_PIXEL_FMT_24BIT << 4);
+	if (ret)
+		return ret;
+
+	/* Disable CABC feature */
+	dcs_write_seq(ctx, MIPI_DCS_WRITE_POWER_SAVE, 0x00);
+
+	ret = mipi_dsi_dcs_set_display_on(dsi);
+	if (ret)
+		return ret;
+
+	ret = mipi_dsi_dcs_nop(dsi);
+	if (ret)
+		return ret;
+
+	/* Send Command GRAM memory write (no parameters) */
+	dcs_write_seq(ctx, MIPI_DCS_WRITE_MEMORY_START);
+
+	return 0;
+}
+
+static int otm8009a_disable(struct drm_panel *panel)
+{
+	struct otm8009a *ctx = panel_to_otm8009a(panel);
+	struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
+	int ret;
+
+	if (!ctx->enabled)
+		return 0; /* This is not an issue so we return 0 here */
+
+	/* Power off the backlight. Note: end-user still controls brightness */
+	ctx->bl_dev->props.power = FB_BLANK_POWERDOWN;
+	ret = backlight_update_status(ctx->bl_dev);
+	if (ret)
+		return ret;
+
+	ret = mipi_dsi_dcs_set_display_off(dsi);
+	if (ret < 0)
+		return ret;
+
+	ret = mipi_dsi_dcs_enter_sleep_mode(dsi);
+	if (ret < 0)
+		return ret;
+
+	msleep(120);
+
+	ctx->enabled = false;
+
+	return 0;
+}
+
+static int otm8009a_unprepare(struct drm_panel *panel)
+{
+	struct otm8009a *ctx = panel_to_otm8009a(panel);
+
+	if (!ctx->prepared)
+		return 0;
+
+	if (ctx->reset_gpio) {
+		gpiod_set_value_cansleep(ctx->reset_gpio, 1);
+		msleep(20);
+	}
+
+	ctx->prepared = false;
+
+	return 0;
+}
+
+static int otm8009a_prepare(struct drm_panel *panel)
+{
+	struct otm8009a *ctx = panel_to_otm8009a(panel);
+	int ret;
+
+	if (ctx->prepared)
+		return 0;
+
+	if (ctx->reset_gpio) {
+		gpiod_set_value_cansleep(ctx->reset_gpio, 0);
+		gpiod_set_value_cansleep(ctx->reset_gpio, 1);
+		msleep(20);
+		gpiod_set_value_cansleep(ctx->reset_gpio, 0);
+		msleep(100);
+	}
+
+	ret = otm8009a_init_sequence(ctx);
+	if (ret)
+		return ret;
+
+	ctx->prepared = true;
+
+	/* Power on the backlight. Note: end-user still controls brightness */
+	ctx->bl_dev->props.power = FB_BLANK_UNBLANK;
+	backlight_update_status(ctx->bl_dev);
+
+	return 0;
+}
+
+static int otm8009a_enable(struct drm_panel *panel)
+{
+	struct otm8009a *ctx = panel_to_otm8009a(panel);
+
+	ctx->enabled = true;
+
+	return 0;
+}
+
+static int otm8009a_get_modes(struct drm_panel *panel)
+{
+	struct drm_display_mode *mode;
+
+	mode = drm_mode_duplicate(panel->drm, &default_mode);
+	if (!mode) {
+		DRM_ERROR("failed to add mode %ux%ux@%u\n",
+			  default_mode.hdisplay, default_mode.vdisplay,
+			  default_mode.vrefresh);
+		return -ENOMEM;
+	}
+
+	drm_mode_set_name(mode);
+
+	mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
+	drm_mode_probed_add(panel->connector, mode);
+
+	panel->connector->display_info.width_mm = mode->width_mm;
+	panel->connector->display_info.height_mm = mode->height_mm;
+
+	return 1;
+}
+
+static const struct drm_panel_funcs otm8009a_drm_funcs = {
+	.disable   = otm8009a_disable,
+	.unprepare = otm8009a_unprepare,
+	.prepare   = otm8009a_prepare,
+	.enable    = otm8009a_enable,
+	.get_modes = otm8009a_get_modes,
+};
+
+/*
+ * DSI-BASED BACKLIGHT
+ */
+
+static int otm8009a_backlight_update_status(struct backlight_device *bd)
+{
+	struct otm8009a *ctx = bl_get_data(bd);
+	u8 data[2];
+
+	if (!ctx->prepared) {
+		DRM_DEBUG("lcd not ready yet for setting its backlight!\n");
+		return -ENXIO;
+	}
+
+	if (bd->props.power <= FB_BLANK_NORMAL) {
+		/* Power on the backlight with the requested brightness
+		 * Note We can not use mipi_dsi_dcs_set_display_brightness()
+		 * as otm8009a driver support only 8-bit brightness (1 param).
+		 */
+		data[0] = MIPI_DCS_SET_DISPLAY_BRIGHTNESS;
+		data[1] = bd->props.brightness;
+		otm8009a_dcs_write_buf(ctx, data, ARRAY_SIZE(data));
+
+		/* set Brightness Control & Backlight on */
+		data[1] = 0x24;
+
+	} else {
+		/* Power off the backlight: set Brightness Control & Bl off */
+		data[1] = 0;
+	}
+
+	/* Update Brightness Control & Backlight */
+	data[0] = MIPI_DCS_WRITE_CONTROL_DISPLAY;
+	otm8009a_dcs_write_buf(ctx, data, ARRAY_SIZE(data));
+
+	return 0;
+}
+
+static const struct backlight_ops otm8009a_backlight_ops = {
+	.update_status = otm8009a_backlight_update_status,
+};
+
+static int otm8009a_probe(struct mipi_dsi_device *dsi)
+{
+	struct device *dev = &dsi->dev;
+	struct otm8009a *ctx;
+	int ret;
+
+	ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+
+	ctx->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
+	if (IS_ERR(ctx->reset_gpio)) {
+		dev_err(dev, "cannot get reset-gpio\n");
+		return PTR_ERR(ctx->reset_gpio);
+	}
+
+	mipi_dsi_set_drvdata(dsi, ctx);
+
+	ctx->dev = dev;
+
+	dsi->lanes = 2;
+	dsi->format = MIPI_DSI_FMT_RGB888;
+	dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_BURST |
+			  MIPI_DSI_MODE_LPM;
+
+	drm_panel_init(&ctx->panel);
+	ctx->panel.dev = dev;
+	ctx->panel.funcs = &otm8009a_drm_funcs;
+
+	ctx->bl_dev = backlight_device_register(DRV_NAME "_backlight", dev, ctx,
+						&otm8009a_backlight_ops, NULL);
+	if (IS_ERR(ctx->bl_dev)) {
+		dev_err(dev, "failed to register backlight device\n");
+		return PTR_ERR(ctx->bl_dev);
+	}
+
+	ctx->bl_dev->props.max_brightness = OTM8009A_BACKLIGHT_MAX;
+	ctx->bl_dev->props.brightness = OTM8009A_BACKLIGHT_DEFAULT;
+	ctx->bl_dev->props.power = FB_BLANK_POWERDOWN;
+	ctx->bl_dev->props.type = BACKLIGHT_RAW;
+
+	drm_panel_add(&ctx->panel);
+
+	ret = mipi_dsi_attach(dsi);
+	if (ret < 0) {
+		dev_err(dev, "mipi_dsi_attach failed. Is host ready?\n");
+		drm_panel_remove(&ctx->panel);
+		backlight_device_unregister(ctx->bl_dev);
+		return ret;
+	}
+
+	DRM_INFO(DRV_NAME "_panel %ux%u@%u %ubpp dsi %udl - ready\n",
+		 default_mode.hdisplay, default_mode.vdisplay,
+		 default_mode.vrefresh,
+		 mipi_dsi_pixel_format_to_bpp(dsi->format), dsi->lanes);
+
+	return 0;
+}
+
+static int otm8009a_remove(struct mipi_dsi_device *dsi)
+{
+	struct otm8009a *ctx = mipi_dsi_get_drvdata(dsi);
+
+	mipi_dsi_detach(dsi);
+	drm_panel_remove(&ctx->panel);
+
+	backlight_device_unregister(ctx->bl_dev);
+
+	return 0;
+}
+
+static const struct of_device_id orisetech_otm8009a_of_match[] = {
+	{ .compatible = "orisetech,otm8009a" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, orisetech_otm8009a_of_match);
+
+static struct mipi_dsi_driver orisetech_otm8009a_driver = {
+	.probe  = otm8009a_probe,
+	.remove = otm8009a_remove,
+	.driver = {
+		.name = DRV_NAME "_panel",
+		.of_match_table = orisetech_otm8009a_of_match,
+	},
+};
+module_mipi_dsi_driver(orisetech_otm8009a_driver);
+
+MODULE_AUTHOR("Philippe Cornu <philippe.cornu@st.com>");
+MODULE_AUTHOR("Yannick Fertre <yannick.fertre@st.com>");
+MODULE_DESCRIPTION("DRM driver for Orise Tech OTM8009A MIPI DSI panel");
+MODULE_LICENSE("GPL v2");