diff mbox

[2/2] drm/panel: Add driver for sitronix ST7789V panel

Message ID 8194211279dd2d1b1c2e88a3c17d154c356bbbc7.1486115846.git-series.maxime.ripard@free-electrons.com (mailing list archive)
State New, archived
Headers show

Commit Message

Maxime Ripard Feb. 3, 2017, 9:59 a.m. UTC 
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 drivers/gpu/drm/panel/Kconfig                  |   4 +-
 drivers/gpu/drm/panel/Makefile                 |   1 +-
 drivers/gpu/drm/panel/panel-sitronix-st7789v.c | 435 ++++++++++++++++++-
 3 files changed, 440 insertions(+), 0 deletions(-)
 create mode 100644 drivers/gpu/drm/panel/panel-sitronix-st7789v.c

Comments

Noralf Trønnes Feb. 3, 2017, 6:53 p.m. UTC | #1 
Den 03.02.2017 10.59, skrev Maxime Ripard:
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> ---
>   drivers/gpu/drm/panel/Kconfig                  |   4 +-
>   drivers/gpu/drm/panel/Makefile                 |   1 +-
>   drivers/gpu/drm/panel/panel-sitronix-st7789v.c | 435 ++++++++++++++++++-
>   3 files changed, 440 insertions(+), 0 deletions(-)
>   create mode 100644 drivers/gpu/drm/panel/panel-sitronix-st7789v.c
>
> diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
> index 62aba976e744..d07b996a07b8 100644
> --- a/drivers/gpu/drm/panel/Kconfig
> +++ b/drivers/gpu/drm/panel/Kconfig
> @@ -81,4 +81,8 @@ config DRM_PANEL_SHARP_LS043T1LE01
>   	  Say Y here if you want to enable support for Sharp LS043T1LE01 qHD
>   	  (540x960) DSI panel as found on the Qualcomm APQ8074 Dragonboard
>   
> +config DRM_PANEL_SITRONIX_ST7789V
> +	tristate "Sitronx ST7789V panel"
> +	depends on OF && SPI
> +
>   endmenu
> diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
> index a5c7ec0236e0..41b245d39984 100644
> --- a/drivers/gpu/drm/panel/Makefile
> +++ b/drivers/gpu/drm/panel/Makefile
> @@ -6,3 +6,4 @@ obj-$(CONFIG_DRM_PANEL_SAMSUNG_LD9040) += panel-samsung-ld9040.o
>   obj-$(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
> diff --git a/drivers/gpu/drm/panel/panel-sitronix-st7789v.c b/drivers/gpu/drm/panel/panel-sitronix-st7789v.c
> new file mode 100644
> index 000000000000..aab817b55aa6
> --- /dev/null
> +++ b/drivers/gpu/drm/panel/panel-sitronix-st7789v.c
> @@ -0,0 +1,435 @@
> +/*
> + * Copyright (C) 2017 Free Electrons
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License version
> + * 2 as published by the Free Software Foundation.
> + */
> +
> +#include <drm/drmP.h>
> +#include <drm/drm_panel.h>
> +
> +#include <linux/gpio/consumer.h>
> +#include <linux/spi/spi.h>
> +
> +#define ST7789V_SLPIN_CMD		0x10
> +
> +#define ST7789V_SLPOUT_CMD		0x11
> +
> +#define ST7789V_INVON_CMD		0x21
> +
> +#define ST7789V_DISPOFF_CMD		0x28
> +
> +#define ST7789V_DISPON_CMD		0x29
> +
> +#define ST7789V_MADCTL_CMD		0x36
> +
> +#define ST7789V_COLMOD_CMD		0x3a

You can use these from include/video/mipi_display.h:

         MIPI_DCS_ENTER_SLEEP_MODE       = 0x10,
         MIPI_DCS_EXIT_SLEEP_MODE        = 0x11,
         MIPI_DCS_ENTER_INVERT_MODE      = 0x21,
         MIPI_DCS_SET_DISPLAY_OFF        = 0x28,
         MIPI_DCS_SET_DISPLAY_ON         = 0x29,
         MIPI_DCS_SET_ADDRESS_MODE       = 0x36,
         MIPI_DCS_SET_PIXEL_FORMAT       = 0x3A,


Noralf.

> +#define ST7789V_COLMOD_RGB_FMT_18BITS		(6 << 4)
> +#define ST7789V_COLMOD_CTRL_FMT_18BITS		(6 << 0)
> +
> +#define ST7789V_RAMCTRL_CMD		0xb0
> +#define ST7789V_RAMCTRL_RM_RGB			BIT(4)
> +#define ST7789V_RAMCTRL_DM_RGB			BIT(0)
> +#define ST7789V_RAMCTRL_MAGIC			(3 << 6)
> +#define ST7789V_RAMCTRL_EPF(n)			(((n) & 3) << 4)
> +
> +#define ST7789V_RGBCTRL_CMD		0xb1
> +#define ST7789V_RGBCTRL_WO			BIT(7)
> +#define ST7789V_RGBCTRL_RCM(n)			(((n) & 3) << 5)
> +#define ST7789V_RGBCTRL_VSYNC_HIGH		BIT(3)
> +#define ST7789V_RGBCTRL_HSYNC_HIGH		BIT(2)
> +#define ST7789V_RGBCTRL_PCLK_HIGH		BIT(1)
> +#define ST7789V_RGBCTRL_VBP(n)			((n) & 0x7f)
> +#define ST7789V_RGBCTRL_HBP(n)			((n) & 0x1f)
> +
> +#define ST7789V_PORCTRL_CMD		0xb2
> +#define ST7789V_PORCTRL_IDLE_BP(n)		(((n) & 0xf) << 4)
> +#define ST7789V_PORCTRL_IDLE_FP(n)		((n) & 0xf)
> +#define ST7789V_PORCTRL_PARTIAL_BP(n)		(((n) & 0xf) << 4)
> +#define ST7789V_PORCTRL_PARTIAL_FP(n)		((n) & 0xf)
> +
> +#define ST7789V_GCTRL_CMD		0xb7
> +#define ST7789V_GCTRL_VGHS(n)			(((n) & 7) << 4)
> +#define ST7789V_GCTRL_VGLS(n)			((n) & 7)
> +
> +#define ST7789V_VCOMS_CMD		0xbb
> +
> +#define ST7789V_LCMCTRL_CMD		0xc0
> +#define ST7789V_LCMCTRL_XBGR			BIT(5)
> +#define ST7789V_LCMCTRL_XMX			BIT(3)
> +#define ST7789V_LCMCTRL_XMH			BIT(2)
> +
> +#define ST7789V_VDVVRHEN_CMD		0xc2
> +#define ST7789V_VDVVRHEN_CMDEN			BIT(0)
> +
> +#define ST7789V_VRHS_CMD		0xc3
> +
> +#define ST7789V_VDVS_CMD		0xc4
> +
> +#define ST7789V_FRCTRL2_CMD		0xc6
> +
> +#define ST7789V_PWCTRL1_CMD		0xd0
> +#define ST7789V_PWCTRL1_MAGIC			0xa4
> +#define ST7789V_PWCTRL1_AVDD(n)			(((n) & 3) << 6)
> +#define ST7789V_PWCTRL1_AVCL(n)			(((n) & 3) << 4)
> +#define ST7789V_PWCTRL1_VDS(n)			((n) & 3)
> +
> +#define ST7789V_PVGAMCTRL_CMD		0xe0
> +#define ST7789V_PVGAMCTRL_JP0(n)		(((n) & 3) << 4)
> +#define ST7789V_PVGAMCTRL_JP1(n)		(((n) & 3) << 4)
> +#define ST7789V_PVGAMCTRL_VP0(n)		((n) & 0xf)
> +#define ST7789V_PVGAMCTRL_VP1(n)		((n) & 0x3f)
> +#define ST7789V_PVGAMCTRL_VP2(n)		((n) & 0x3f)
> +#define ST7789V_PVGAMCTRL_VP4(n)		((n) & 0x1f)
> +#define ST7789V_PVGAMCTRL_VP6(n)		((n) & 0x1f)
> +#define ST7789V_PVGAMCTRL_VP13(n)		((n) & 0xf)
> +#define ST7789V_PVGAMCTRL_VP20(n)		((n) & 0x7f)
> +#define ST7789V_PVGAMCTRL_VP27(n)		((n) & 7)
> +#define ST7789V_PVGAMCTRL_VP36(n)		(((n) & 7) << 4)
> +#define ST7789V_PVGAMCTRL_VP43(n)		((n) & 0x7f)
> +#define ST7789V_PVGAMCTRL_VP50(n)		((n) & 0xf)
> +#define ST7789V_PVGAMCTRL_VP57(n)		((n) & 0x1f)
> +#define ST7789V_PVGAMCTRL_VP59(n)		((n) & 0x1f)
> +#define ST7789V_PVGAMCTRL_VP61(n)		((n) & 0x3f)
> +#define ST7789V_PVGAMCTRL_VP62(n)		((n) & 0x3f)
> +#define ST7789V_PVGAMCTRL_VP63(n)		(((n) & 0xf) << 4)
> +
> +#define ST7789V_NVGAMCTRL_CMD		0xe1
> +#define ST7789V_NVGAMCTRL_JN0(n)		(((n) & 3) << 4)
> +#define ST7789V_NVGAMCTRL_JN1(n)		(((n) & 3) << 4)
> +#define ST7789V_NVGAMCTRL_VN0(n)		((n) & 0xf)
> +#define ST7789V_NVGAMCTRL_VN1(n)		((n) & 0x3f)
> +#define ST7789V_NVGAMCTRL_VN2(n)		((n) & 0x3f)
> +#define ST7789V_NVGAMCTRL_VN4(n)		((n) & 0x1f)
> +#define ST7789V_NVGAMCTRL_VN6(n)		((n) & 0x1f)
> +#define ST7789V_NVGAMCTRL_VN13(n)		((n) & 0xf)
> +#define ST7789V_NVGAMCTRL_VN20(n)		((n) & 0x7f)
> +#define ST7789V_NVGAMCTRL_VN27(n)		((n) & 7)
> +#define ST7789V_NVGAMCTRL_VN36(n)		(((n) & 7) << 4)
> +#define ST7789V_NVGAMCTRL_VN43(n)		((n) & 0x7f)
> +#define ST7789V_NVGAMCTRL_VN50(n)		((n) & 0xf)
> +#define ST7789V_NVGAMCTRL_VN57(n)		((n) & 0x1f)
> +#define ST7789V_NVGAMCTRL_VN59(n)		((n) & 0x1f)
> +#define ST7789V_NVGAMCTRL_VN61(n)		((n) & 0x3f)
> +#define ST7789V_NVGAMCTRL_VN62(n)		((n) & 0x3f)
> +#define ST7789V_NVGAMCTRL_VN63(n)		(((n) & 0xf) << 4)
> +
> +struct st7789v {
> +	struct drm_panel panel;
> +	struct spi_device *spi;
> +	struct gpio_desc *reset;
> +	struct backlight_device *backlight;
> +};
> +
> +enum st7789v_prefix {
> +	ST7789V_COMMAND = 0,
> +	ST7789V_DATA = 1,
> +};
> +
> +static inline struct st7789v *panel_to_st7789v(struct drm_panel *panel)
> +{
> +	return container_of(panel, struct st7789v, panel);
> +}
> +
> +static int st7789v_spi_write(struct st7789v *ctx, u8 prefix, u8 data)
> +{
> +	struct spi_transfer xfer = { };
> +	struct spi_message msg;
> +	u16 txbuf = ((prefix & 1) << 8) | data;
> +
> +	spi_message_init(&msg);
> +
> +	xfer.tx_buf = &txbuf;
> +	xfer.bits_per_word = 9;
> +	xfer.len = sizeof(txbuf);
> +
> +	spi_message_add_tail(&xfer, &msg);
> +	return spi_sync(ctx->spi, &msg);
> +}
> +
> +static int st7789v_write_command(struct st7789v *ctx, u8 cmd)
> +{
> +	return st7789v_spi_write(ctx, ST7789V_COMMAND, cmd);
> +}
> +
> +static int st7789v_write_data(struct st7789v *ctx, u8 cmd)
> +{
> +	return st7789v_spi_write(ctx, ST7789V_DATA, cmd);
> +}
> +
> +static int st7789v_write_command_data(struct st7789v *ctx, u8 cmd,
> +				      unsigned long n_data, ...)
> +{
> +	va_list ap;
> +	int i;
> +
> +	st7789v_write_command(ctx, cmd);
> +
> +	va_start(ap, n_data);
> +	for (i = 0; i < n_data; i++)
> +		st7789v_write_data(ctx, va_arg(ap, int));
> +	va_end(ap);
> +
> +	return 0;
> +}
> +
> +static const struct drm_display_mode default_mode = {
> +	.clock = 7000,
> +	.hdisplay = 240,
> +	.hsync_start = 240 + 38,
> +	.hsync_end = 240 + 38 + 10,
> +	.htotal = 240 + 38 + 10 + 10,
> +	.vdisplay = 320,
> +	.vsync_start = 320 + 8,
> +	.vsync_end = 320 + 8 + 4,
> +	.vtotal = 320 + 8 + 4 + 4,
> +	.vrefresh = 60,
> +};
> +
> +static int st7789v_get_modes(struct drm_panel *panel)
> +{
> +	struct drm_connector *connector = panel->connector;
> +	struct drm_display_mode *mode;
> +
> +	mode = drm_mode_duplicate(panel->drm, &default_mode);
> +	if (!mode) {
> +		dev_err(panel->drm->dev, "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(connector, mode);
> +
> +	panel->connector->display_info.width_mm = 61;
> +	panel->connector->display_info.height_mm = 103;
> +
> +	return 1;
> +}
> +
> +#define NUMARGS(...)  (sizeof((int[]){__VA_ARGS__}) / sizeof(int))
> +#define st7789v_send(ctx, cmd, ...)					\
> +	st7789v_write_command_data(ctx, cmd, NUMARGS(__VA_ARGS__),	\
> +				   ##__VA_ARGS__)
> +
> +static int st7789v_prepare(struct drm_panel *panel)
> +{
> +	struct st7789v *ctx = panel_to_st7789v(panel);
> +
> +	gpiod_set_value(ctx->reset, 1);
> +	msleep(30);
> +	gpiod_set_value(ctx->reset, 0);
> +	msleep(120);
> +
> +	st7789v_send(ctx, ST7789V_SLPOUT_CMD);
> +
> +	/* We need to wait 120ms after a sleep out command */
> +	msleep(120);
> +
> +	st7789v_send(ctx, ST7789V_MADCTL_CMD, 0);
> +
> +	st7789v_send(ctx, ST7789V_COLMOD_CMD,
> +		     ST7789V_COLMOD_CTRL_FMT_18BITS |
> +		     ST7789V_COLMOD_RGB_FMT_18BITS);
> +
> +	st7789v_send(ctx, ST7789V_PORCTRL_CMD,
> +		     0xc,		/* Backporch, normal mode*/
> +		     0xc,		/* Frontporch, normal mode */
> +		     0,			/* Disable separate porch control */
> +		     ST7789V_PORCTRL_IDLE_BP(3) |
> +		     ST7789V_PORCTRL_IDLE_FP(3),
> +		     ST7789V_PORCTRL_PARTIAL_BP(3) |
> +		     ST7789V_PORCTRL_PARTIAL_FP(3));
> +
> +	st7789v_send(ctx, ST7789V_GCTRL_CMD,
> +		     ST7789V_GCTRL_VGLS(5) | ST7789V_GCTRL_VGHS(3));
> +
> +	st7789v_send(ctx, ST7789V_VCOMS_CMD, 0x2b);
> +
> +	st7789v_send(ctx, ST7789V_LCMCTRL_CMD, ST7789V_LCMCTRL_XMH |
> +		     ST7789V_LCMCTRL_XMX | ST7789V_LCMCTRL_XBGR);
> +
> +	st7789v_send(ctx, ST7789V_VDVVRHEN_CMD, ST7789V_VDVVRHEN_CMDEN);
> +
> +	st7789v_send(ctx, ST7789V_VRHS_CMD, 0xf);
> +
> +	st7789v_send(ctx, ST7789V_VDVS_CMD, 0x20);
> +
> +	st7789v_send(ctx, ST7789V_FRCTRL2_CMD, 0xf);
> +
> +	st7789v_send(ctx, ST7789V_PWCTRL1_CMD, ST7789V_PWCTRL1_MAGIC,
> +		     ST7789V_PWCTRL1_AVDD(2) | ST7789V_PWCTRL1_AVCL(2) |
> +		     ST7789V_PWCTRL1_VDS(1));
> +
> +	st7789v_send(ctx, ST7789V_PVGAMCTRL_CMD,
> +		     ST7789V_PVGAMCTRL_VP63(0xd),
> +		     ST7789V_PVGAMCTRL_VP1(0xca),
> +		     ST7789V_PVGAMCTRL_VP2(0xe),
> +		     ST7789V_PVGAMCTRL_VP4(8),
> +		     ST7789V_PVGAMCTRL_VP6(9),
> +		     ST7789V_PVGAMCTRL_VP13(7),
> +		     ST7789V_PVGAMCTRL_VP20(0x2d),
> +		     ST7789V_PVGAMCTRL_VP27(0xb) | ST7789V_PVGAMCTRL_VP36(3),
> +		     ST7789V_PVGAMCTRL_VP43(0x3d),
> +		     ST7789V_PVGAMCTRL_JP1(3) | ST7789V_PVGAMCTRL_VP50(4),
> +		     ST7789V_PVGAMCTRL_VP57(0xa),
> +		     ST7789V_PVGAMCTRL_VP59(0xa),
> +		     ST7789V_PVGAMCTRL_VP61(0x1b),
> +		     ST7789V_PVGAMCTRL_VP62(0x28));
> +
> +	st7789v_send(ctx, ST7789V_NVGAMCTRL_CMD,
> +		     ST7789V_NVGAMCTRL_VN63(0xd),
> +		     ST7789V_NVGAMCTRL_VN1(0xca),
> +		     ST7789V_NVGAMCTRL_VN2(0xf),
> +		     ST7789V_NVGAMCTRL_VN4(8),
> +		     ST7789V_NVGAMCTRL_VN6(8),
> +		     ST7789V_NVGAMCTRL_VN13(7),
> +		     ST7789V_NVGAMCTRL_VN20(0x2e),
> +		     ST7789V_NVGAMCTRL_VN27(0xc) | ST7789V_NVGAMCTRL_VN36(5),
> +		     ST7789V_NVGAMCTRL_VN43(0x40),
> +		     ST7789V_NVGAMCTRL_JN1(3) | ST7789V_NVGAMCTRL_VN50(4),
> +		     ST7789V_NVGAMCTRL_VN57(9),
> +		     ST7789V_NVGAMCTRL_VN59(0xb),
> +		     ST7789V_NVGAMCTRL_VN61(0x1b),
> +		     ST7789V_NVGAMCTRL_VN62(0x28));
> +
> +	st7789v_send(ctx, ST7789V_INVON_CMD);
> +
> +	st7789v_send(ctx, ST7789V_RAMCTRL_CMD,
> +		     ST7789V_RAMCTRL_DM_RGB | ST7789V_RAMCTRL_RM_RGB,
> +		     ST7789V_RAMCTRL_EPF(3) | ST7789V_RAMCTRL_MAGIC);
> +
> +	st7789v_send(ctx, ST7789V_RGBCTRL_CMD,
> +		     ST7789V_RGBCTRL_WO | ST7789V_RGBCTRL_RCM(2) |
> +		     ST7789V_RGBCTRL_VSYNC_HIGH | ST7789V_RGBCTRL_HSYNC_HIGH |
> +		     ST7789V_RGBCTRL_PCLK_HIGH,
> +		     ST7789V_RGBCTRL_VBP(8), ST7789V_RGBCTRL_HBP(20));
> +
> +	return 0;
> +}
> +
> +static int st7789v_enable(struct drm_panel *panel)
> +{
> +	struct st7789v *ctx = panel_to_st7789v(panel);
> +
> +	if (ctx->backlight) {
> +		ctx->backlight->props.state &= ~BL_CORE_FBBLANK;
> +		ctx->backlight->props.power = FB_BLANK_UNBLANK;
> +		backlight_update_status(ctx->backlight);
> +	}
> +
> +	return st7789v_send(ctx, ST7789V_DISPON_CMD);
> +}
> +
> +static int st7789v_disable(struct drm_panel *panel)
> +{
> +	struct st7789v *ctx = panel_to_st7789v(panel);
> +
> +	st7789v_send(ctx, ST7789V_DISPOFF_CMD);
> +
> +	if (ctx->backlight) {
> +		ctx->backlight->props.power = FB_BLANK_POWERDOWN;
> +		ctx->backlight->props.state |= BL_CORE_FBBLANK;
> +		backlight_update_status(ctx->backlight);
> +	}
> +
> +	return 0;
> +}
> +
> +static int st7789v_unprepare(struct drm_panel *panel)
> +{
> +	struct st7789v *ctx = panel_to_st7789v(panel);
> +
> +	st7789v_send(ctx, ST7789V_SLPIN_CMD);
> +
> +	return 0;
> +}
> +
> +static const struct drm_panel_funcs st7789v_drm_funcs = {
> +	.disable	= st7789v_disable,
> +	.enable		= st7789v_enable,
> +	.get_modes	= st7789v_get_modes,
> +	.prepare	= st7789v_prepare,
> +	.unprepare	= st7789v_unprepare,
> +};
> +
> +static int st7789v_probe(struct spi_device *spi)
> +{
> +	struct device_node *backlight;
> +	struct st7789v *ctx;
> +	int ret;
> +
> +	ctx = devm_kzalloc(&spi->dev, sizeof(*ctx), GFP_KERNEL);
> +	if (!ctx)
> +		return -ENOMEM;
> +
> +	spi_set_drvdata(spi, ctx);
> +	ctx->spi = spi;
> +
> +	ctx->panel.dev = &spi->dev;
> +	ctx->panel.funcs = &st7789v_drm_funcs;
> +
> +	ctx->reset = devm_gpiod_get(&spi->dev, "reset", GPIOD_OUT_LOW);
> +	if (IS_ERR(ctx->reset)) {
> +		dev_err(&spi->dev, "Couldn't get our reset line\n");
> +		return PTR_ERR(ctx->reset);
> +	}
> +
> +	backlight = of_parse_phandle(spi->dev.of_node, "backlight", 0);
> +	if (backlight) {
> +		ctx->backlight = of_find_backlight_by_node(backlight);
> +		of_node_put(backlight);
> +
> +		if (!ctx->backlight)
> +			return -EPROBE_DEFER;
> +	}
> +
> +	ret = drm_panel_add(&ctx->panel);
> +	if (ret < 0)
> +		goto err_free_backlight;
> +
> +	return 0;
> +
> +err_free_backlight:
> +	if (ctx->backlight)
> +		put_device(&ctx->backlight->dev);
> +
> +	return ret;
> +}
> +
> +static int st7789v_remove(struct spi_device *spi)
> +{
> +	struct st7789v *ctx = spi_get_drvdata(spi);
> +
> +	drm_panel_detach(&ctx->panel);
> +	drm_panel_remove(&ctx->panel);
> +
> +	if (ctx->backlight)
> +		put_device(&ctx->backlight->dev);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id st7789v_of_match[] = {
> +	{ .compatible = "sitronix,st7789v" },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(of, st7789v_of_match);
> +
> +static struct spi_driver st7789v_driver = {
> +	.probe = st7789v_probe,
> +	.remove = st7789v_remove,
> +	.driver = {
> +		.name = "st7789v",
> +		.of_match_table = st7789v_of_match,
> +	},
> +};
> +module_spi_driver(st7789v_driver);
> +
> +MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
> +MODULE_DESCRIPTION("Sitronix st7789v LCD Driver");
> +MODULE_LICENSE("GPL v2");
Maxime Ripard Feb. 6, 2017, 10:50 a.m. UTC | #2 
Hi Noralf,

On Fri, Feb 03, 2017 at 07:53:58PM +0100, Noralf Trønnes wrote:
> 
> Den 03.02.2017 10.59, skrev Maxime Ripard:
> > Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> > ---
> >   drivers/gpu/drm/panel/Kconfig                  |   4 +-
> >   drivers/gpu/drm/panel/Makefile                 |   1 +-
> >   drivers/gpu/drm/panel/panel-sitronix-st7789v.c | 435 ++++++++++++++++++-
> >   3 files changed, 440 insertions(+), 0 deletions(-)
> >   create mode 100644 drivers/gpu/drm/panel/panel-sitronix-st7789v.c
> > 
> > diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
> > index 62aba976e744..d07b996a07b8 100644
> > --- a/drivers/gpu/drm/panel/Kconfig
> > +++ b/drivers/gpu/drm/panel/Kconfig
> > @@ -81,4 +81,8 @@ config DRM_PANEL_SHARP_LS043T1LE01
> >   	  Say Y here if you want to enable support for Sharp LS043T1LE01 qHD
> >   	  (540x960) DSI panel as found on the Qualcomm APQ8074 Dragonboard
> > +config DRM_PANEL_SITRONIX_ST7789V
> > +	tristate "Sitronx ST7789V panel"
> > +	depends on OF && SPI
> > +
> >   endmenu
> > diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
> > index a5c7ec0236e0..41b245d39984 100644
> > --- a/drivers/gpu/drm/panel/Makefile
> > +++ b/drivers/gpu/drm/panel/Makefile
> > @@ -6,3 +6,4 @@ obj-$(CONFIG_DRM_PANEL_SAMSUNG_LD9040) += panel-samsung-ld9040.o
> >   obj-$(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
> > diff --git a/drivers/gpu/drm/panel/panel-sitronix-st7789v.c b/drivers/gpu/drm/panel/panel-sitronix-st7789v.c
> > new file mode 100644
> > index 000000000000..aab817b55aa6
> > --- /dev/null
> > +++ b/drivers/gpu/drm/panel/panel-sitronix-st7789v.c
> > @@ -0,0 +1,435 @@
> > +/*
> > + * Copyright (C) 2017 Free Electrons
> > + *
> > + * This program is free software; you can redistribute it and/or
> > + * modify it under the terms of the GNU General Public License version
> > + * 2 as published by the Free Software Foundation.
> > + */
> > +
> > +#include <drm/drmP.h>
> > +#include <drm/drm_panel.h>
> > +
> > +#include <linux/gpio/consumer.h>
> > +#include <linux/spi/spi.h>
> > +
> > +#define ST7789V_SLPIN_CMD		0x10
> > +
> > +#define ST7789V_SLPOUT_CMD		0x11
> > +
> > +#define ST7789V_INVON_CMD		0x21
> > +
> > +#define ST7789V_DISPOFF_CMD		0x28
> > +
> > +#define ST7789V_DISPON_CMD		0x29
> > +
> > +#define ST7789V_MADCTL_CMD		0x36
> > +
> > +#define ST7789V_COLMOD_CMD		0x3a
> 
> You can use these from include/video/mipi_display.h:
> 
>         MIPI_DCS_ENTER_SLEEP_MODE       = 0x10,
>         MIPI_DCS_EXIT_SLEEP_MODE        = 0x11,
>         MIPI_DCS_ENTER_INVERT_MODE      = 0x21,
>         MIPI_DCS_SET_DISPLAY_OFF        = 0x28,
>         MIPI_DCS_SET_DISPLAY_ON         = 0x29,
>         MIPI_DCS_SET_ADDRESS_MODE       = 0x36,
>         MIPI_DCS_SET_PIXEL_FORMAT       = 0x3A,

I don't know, that controller cannot do MIPI DSI at all, and we would
have to define all the other commands anyway.

Maxime
Noralf Trønnes Feb. 6, 2017, 12:13 p.m. UTC | #3 
Den 06.02.2017 11.50, skrev Maxime Ripard:
> Hi Noralf,
>
> On Fri, Feb 03, 2017 at 07:53:58PM +0100, Noralf Trønnes wrote:
>> Den 03.02.2017 10.59, skrev Maxime Ripard:
>>> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
>>> ---
>>>    drivers/gpu/drm/panel/Kconfig                  |   4 +-
>>>    drivers/gpu/drm/panel/Makefile                 |   1 +-
>>>    drivers/gpu/drm/panel/panel-sitronix-st7789v.c | 435 ++++++++++++++++++-
>>>    3 files changed, 440 insertions(+), 0 deletions(-)
>>>    create mode 100644 drivers/gpu/drm/panel/panel-sitronix-st7789v.c
>>>
>>> diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
>>> index 62aba976e744..d07b996a07b8 100644
>>> --- a/drivers/gpu/drm/panel/Kconfig
>>> +++ b/drivers/gpu/drm/panel/Kconfig
>>> @@ -81,4 +81,8 @@ config DRM_PANEL_SHARP_LS043T1LE01
>>>    	  Say Y here if you want to enable support for Sharp LS043T1LE01 qHD
>>>    	  (540x960) DSI panel as found on the Qualcomm APQ8074 Dragonboard
>>> +config DRM_PANEL_SITRONIX_ST7789V
>>> +	tristate "Sitronx ST7789V panel"
>>> +	depends on OF && SPI
>>> +
>>>    endmenu
>>> diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
>>> index a5c7ec0236e0..41b245d39984 100644
>>> --- a/drivers/gpu/drm/panel/Makefile
>>> +++ b/drivers/gpu/drm/panel/Makefile
>>> @@ -6,3 +6,4 @@ obj-$(CONFIG_DRM_PANEL_SAMSUNG_LD9040) += panel-samsung-ld9040.o
>>>    obj-$(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
>>> diff --git a/drivers/gpu/drm/panel/panel-sitronix-st7789v.c b/drivers/gpu/drm/panel/panel-sitronix-st7789v.c
>>> new file mode 100644
>>> index 000000000000..aab817b55aa6
>>> --- /dev/null
>>> +++ b/drivers/gpu/drm/panel/panel-sitronix-st7789v.c
>>> @@ -0,0 +1,435 @@
>>> +/*
>>> + * Copyright (C) 2017 Free Electrons
>>> + *
>>> + * This program is free software; you can redistribute it and/or
>>> + * modify it under the terms of the GNU General Public License version
>>> + * 2 as published by the Free Software Foundation.
>>> + */
>>> +
>>> +#include <drm/drmP.h>
>>> +#include <drm/drm_panel.h>
>>> +
>>> +#include <linux/gpio/consumer.h>
>>> +#include <linux/spi/spi.h>
>>> +
>>> +#define ST7789V_SLPIN_CMD		0x10
>>> +
>>> +#define ST7789V_SLPOUT_CMD		0x11
>>> +
>>> +#define ST7789V_INVON_CMD		0x21
>>> +
>>> +#define ST7789V_DISPOFF_CMD		0x28
>>> +
>>> +#define ST7789V_DISPON_CMD		0x29
>>> +
>>> +#define ST7789V_MADCTL_CMD		0x36
>>> +
>>> +#define ST7789V_COLMOD_CMD		0x3a
>> You can use these from include/video/mipi_display.h:
>>
>>          MIPI_DCS_ENTER_SLEEP_MODE       = 0x10,
>>          MIPI_DCS_EXIT_SLEEP_MODE        = 0x11,
>>          MIPI_DCS_ENTER_INVERT_MODE      = 0x21,
>>          MIPI_DCS_SET_DISPLAY_OFF        = 0x28,
>>          MIPI_DCS_SET_DISPLAY_ON         = 0x29,
>>          MIPI_DCS_SET_ADDRESS_MODE       = 0x36,
>>          MIPI_DCS_SET_PIXEL_FORMAT       = 0x3A,
> I don't know, that controller cannot do MIPI DSI at all, and we would
> have to define all the other commands anyway.

MIPI DCS commands can be sent over both Display Serial Interface (DSI)
and in your case Display Bus Interface (DBI) (not quite sure if the
Control Interface can be outside of DBI). So Display Command Set (DCS)
is not specific to the interface, but to the controller.

It's up to you if you want to use them though.


Noralf.
Thierry Reding Feb. 6, 2017, 12:25 p.m. UTC | #4 
On Mon, Feb 06, 2017 at 01:13:19PM +0100, Noralf Trønnes wrote:
> 
> Den 06.02.2017 11.50, skrev Maxime Ripard:
> > Hi Noralf,
> > 
> > On Fri, Feb 03, 2017 at 07:53:58PM +0100, Noralf Trønnes wrote:
> > > Den 03.02.2017 10.59, skrev Maxime Ripard:
> > > > Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> > > > ---
> > > >    drivers/gpu/drm/panel/Kconfig                  |   4 +-
> > > >    drivers/gpu/drm/panel/Makefile                 |   1 +-
> > > >    drivers/gpu/drm/panel/panel-sitronix-st7789v.c | 435 ++++++++++++++++++-
> > > >    3 files changed, 440 insertions(+), 0 deletions(-)
> > > >    create mode 100644 drivers/gpu/drm/panel/panel-sitronix-st7789v.c
> > > > 
> > > > diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
> > > > index 62aba976e744..d07b996a07b8 100644
> > > > --- a/drivers/gpu/drm/panel/Kconfig
> > > > +++ b/drivers/gpu/drm/panel/Kconfig
> > > > @@ -81,4 +81,8 @@ config DRM_PANEL_SHARP_LS043T1LE01
> > > >    	  Say Y here if you want to enable support for Sharp LS043T1LE01 qHD
> > > >    	  (540x960) DSI panel as found on the Qualcomm APQ8074 Dragonboard
> > > > +config DRM_PANEL_SITRONIX_ST7789V
> > > > +	tristate "Sitronx ST7789V panel"
> > > > +	depends on OF && SPI
> > > > +
> > > >    endmenu
> > > > diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
> > > > index a5c7ec0236e0..41b245d39984 100644
> > > > --- a/drivers/gpu/drm/panel/Makefile
> > > > +++ b/drivers/gpu/drm/panel/Makefile
> > > > @@ -6,3 +6,4 @@ obj-$(CONFIG_DRM_PANEL_SAMSUNG_LD9040) += panel-samsung-ld9040.o
> > > >    obj-$(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
> > > > diff --git a/drivers/gpu/drm/panel/panel-sitronix-st7789v.c b/drivers/gpu/drm/panel/panel-sitronix-st7789v.c
> > > > new file mode 100644
> > > > index 000000000000..aab817b55aa6
> > > > --- /dev/null
> > > > +++ b/drivers/gpu/drm/panel/panel-sitronix-st7789v.c
> > > > @@ -0,0 +1,435 @@
> > > > +/*
> > > > + * Copyright (C) 2017 Free Electrons
> > > > + *
> > > > + * This program is free software; you can redistribute it and/or
> > > > + * modify it under the terms of the GNU General Public License version
> > > > + * 2 as published by the Free Software Foundation.
> > > > + */
> > > > +
> > > > +#include <drm/drmP.h>
> > > > +#include <drm/drm_panel.h>
> > > > +
> > > > +#include <linux/gpio/consumer.h>
> > > > +#include <linux/spi/spi.h>
> > > > +
> > > > +#define ST7789V_SLPIN_CMD		0x10
> > > > +
> > > > +#define ST7789V_SLPOUT_CMD		0x11
> > > > +
> > > > +#define ST7789V_INVON_CMD		0x21
> > > > +
> > > > +#define ST7789V_DISPOFF_CMD		0x28
> > > > +
> > > > +#define ST7789V_DISPON_CMD		0x29
> > > > +
> > > > +#define ST7789V_MADCTL_CMD		0x36
> > > > +
> > > > +#define ST7789V_COLMOD_CMD		0x3a
> > > You can use these from include/video/mipi_display.h:
> > > 
> > >          MIPI_DCS_ENTER_SLEEP_MODE       = 0x10,
> > >          MIPI_DCS_EXIT_SLEEP_MODE        = 0x11,
> > >          MIPI_DCS_ENTER_INVERT_MODE      = 0x21,
> > >          MIPI_DCS_SET_DISPLAY_OFF        = 0x28,
> > >          MIPI_DCS_SET_DISPLAY_ON         = 0x29,
> > >          MIPI_DCS_SET_ADDRESS_MODE       = 0x36,
> > >          MIPI_DCS_SET_PIXEL_FORMAT       = 0x3A,
> > I don't know, that controller cannot do MIPI DSI at all, and we would
> > have to define all the other commands anyway.
> 
> MIPI DCS commands can be sent over both Display Serial Interface (DSI)
> and in your case Display Bus Interface (DBI) (not quite sure if the
> Control Interface can be outside of DBI). So Display Command Set (DCS)
> is not specific to the interface, but to the controller.
> 
> It's up to you if you want to use them though.

I think it makes sense to unify as much as possible to make it easier to
spot similarities between controllers. Also, we've already got these
definitions in one place, no use in duplicating them. They are obviously
used for the same purposes.

Thierry
Thierry Reding Feb. 6, 2017, 1:26 p.m. UTC | #5 
On Fri, Feb 03, 2017 at 10:59:06AM +0100, Maxime Ripard wrote:
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> ---
>  drivers/gpu/drm/panel/Kconfig                  |   4 +-
>  drivers/gpu/drm/panel/Makefile                 |   1 +-
>  drivers/gpu/drm/panel/panel-sitronix-st7789v.c | 435 ++++++++++++++++++-
>  3 files changed, 440 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/gpu/drm/panel/panel-sitronix-st7789v.c
> 
> diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
> index 62aba976e744..d07b996a07b8 100644
> --- a/drivers/gpu/drm/panel/Kconfig
> +++ b/drivers/gpu/drm/panel/Kconfig
> @@ -81,4 +81,8 @@ config DRM_PANEL_SHARP_LS043T1LE01
>  	  Say Y here if you want to enable support for Sharp LS043T1LE01 qHD
>  	  (540x960) DSI panel as found on the Qualcomm APQ8074 Dragonboard
>  
> +config DRM_PANEL_SITRONIX_ST7789V
> +	tristate "Sitronx ST7789V panel"

"Sitronix"

> +	depends on OF && SPI
> +

Maybe be more verbose here about what kind of panel it is, and what
resolution it provides.

>  endmenu
> diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
> index a5c7ec0236e0..41b245d39984 100644
> --- a/drivers/gpu/drm/panel/Makefile
> +++ b/drivers/gpu/drm/panel/Makefile
> @@ -6,3 +6,4 @@ obj-$(CONFIG_DRM_PANEL_SAMSUNG_LD9040) += panel-samsung-ld9040.o
>  obj-$(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
> diff --git a/drivers/gpu/drm/panel/panel-sitronix-st7789v.c b/drivers/gpu/drm/panel/panel-sitronix-st7789v.c
> new file mode 100644
> index 000000000000..aab817b55aa6
> --- /dev/null
> +++ b/drivers/gpu/drm/panel/panel-sitronix-st7789v.c
> @@ -0,0 +1,435 @@
> +/*
> + * Copyright (C) 2017 Free Electrons
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License version
> + * 2 as published by the Free Software Foundation.
> + */
> +
> +#include <drm/drmP.h>
> +#include <drm/drm_panel.h>
> +
> +#include <linux/gpio/consumer.h>
> +#include <linux/spi/spi.h>

I prefer linux/* headers to go first.

> +
> +#define ST7789V_SLPIN_CMD		0x10
> +
> +#define ST7789V_SLPOUT_CMD		0x11
> +
> +#define ST7789V_INVON_CMD		0x21
> +
> +#define ST7789V_DISPOFF_CMD		0x28
> +
> +#define ST7789V_DISPON_CMD		0x29
> +
> +#define ST7789V_MADCTL_CMD		0x36
> +
> +#define ST7789V_COLMOD_CMD		0x3a
> +#define ST7789V_COLMOD_RGB_FMT_18BITS		(6 << 4)
> +#define ST7789V_COLMOD_CTRL_FMT_18BITS		(6 << 0)

MIPI_DCS_PIXEL_FMT_18BIT?

[...]
> +struct st7789v {
> +	struct drm_panel panel;
> +	struct spi_device *spi;
> +	struct gpio_desc *reset;
> +	struct backlight_device *backlight;
> +};
> +
> +enum st7789v_prefix {
> +	ST7789V_COMMAND = 0,
> +	ST7789V_DATA = 1,
> +};
> +
> +static inline struct st7789v *panel_to_st7789v(struct drm_panel *panel)
> +{
> +	return container_of(panel, struct st7789v, panel);
> +}
> +
> +static int st7789v_spi_write(struct st7789v *ctx, u8 prefix, u8 data)

Why aren't you using the proper type here for prefix?

> +{
> +	struct spi_transfer xfer = { };
> +	struct spi_message msg;
> +	u16 txbuf = ((prefix & 1) << 8) | data;
> +
> +	spi_message_init(&msg);
> +
> +	xfer.tx_buf = &txbuf;
> +	xfer.bits_per_word = 9;
> +	xfer.len = sizeof(txbuf);
> +
> +	spi_message_add_tail(&xfer, &msg);
> +	return spi_sync(ctx->spi, &msg);
> +}
> +
> +static int st7789v_write_command(struct st7789v *ctx, u8 cmd)
> +{
> +	return st7789v_spi_write(ctx, ST7789V_COMMAND, cmd);
> +}
> +
> +static int st7789v_write_data(struct st7789v *ctx, u8 cmd)
> +{
> +	return st7789v_spi_write(ctx, ST7789V_DATA, cmd);
> +}
> +
> +static int st7789v_write_command_data(struct st7789v *ctx, u8 cmd,
> +				      unsigned long n_data, ...)
> +{
> +	va_list ap;
> +	int i;
> +
> +	st7789v_write_command(ctx, cmd);
> +
> +	va_start(ap, n_data);
> +	for (i = 0; i < n_data; i++)
> +		st7789v_write_data(ctx, va_arg(ap, int));
> +	va_end(ap);
> +
> +	return 0;
> +}

Please propagate error codes from st7789v_write_{command,data}(). And
you should abort early on errors.

> +#define NUMARGS(...)  (sizeof((int[]){__VA_ARGS__}) / sizeof(int))
> +#define st7789v_send(ctx, cmd, ...)					\
> +	st7789v_write_command_data(ctx, cmd, NUMARGS(__VA_ARGS__),	\
> +				   ##__VA_ARGS__)

How is this going to work if any of the arguments happens to not be an
int? What if you have something like this:

	u8 value = 0x2;

	st7789v_write_command_data(ctx, cmd, 0x1, value, 0x3);

? Wouldn't that invalidly read "value" as int and wrongly increment the
ap by three bytes too many?

> +static int st7789v_prepare(struct drm_panel *panel)
> +{
> +	struct st7789v *ctx = panel_to_st7789v(panel);
> +
> +	gpiod_set_value(ctx->reset, 1);
> +	msleep(30);
> +	gpiod_set_value(ctx->reset, 0);
> +	msleep(120);
> +
> +	st7789v_send(ctx, ST7789V_SLPOUT_CMD);
> +
> +	/* We need to wait 120ms after a sleep out command */
> +	msleep(120);
> +
> +	st7789v_send(ctx, ST7789V_MADCTL_CMD, 0);
> +
> +	st7789v_send(ctx, ST7789V_COLMOD_CMD,
> +		     ST7789V_COLMOD_CTRL_FMT_18BITS |
> +		     ST7789V_COLMOD_RGB_FMT_18BITS);
> +
> +	st7789v_send(ctx, ST7789V_PORCTRL_CMD,
> +		     0xc,		/* Backporch, normal mode*/
> +		     0xc,		/* Frontporch, normal mode */
> +		     0,			/* Disable separate porch control */
> +		     ST7789V_PORCTRL_IDLE_BP(3) |
> +		     ST7789V_PORCTRL_IDLE_FP(3),
> +		     ST7789V_PORCTRL_PARTIAL_BP(3) |
> +		     ST7789V_PORCTRL_PARTIAL_FP(3));
> +
> +	st7789v_send(ctx, ST7789V_GCTRL_CMD,
> +		     ST7789V_GCTRL_VGLS(5) | ST7789V_GCTRL_VGHS(3));
> +
> +	st7789v_send(ctx, ST7789V_VCOMS_CMD, 0x2b);
> +
> +	st7789v_send(ctx, ST7789V_LCMCTRL_CMD, ST7789V_LCMCTRL_XMH |
> +		     ST7789V_LCMCTRL_XMX | ST7789V_LCMCTRL_XBGR);
> +
> +	st7789v_send(ctx, ST7789V_VDVVRHEN_CMD, ST7789V_VDVVRHEN_CMDEN);
> +
> +	st7789v_send(ctx, ST7789V_VRHS_CMD, 0xf);
> +
> +	st7789v_send(ctx, ST7789V_VDVS_CMD, 0x20);
> +
> +	st7789v_send(ctx, ST7789V_FRCTRL2_CMD, 0xf);
> +
> +	st7789v_send(ctx, ST7789V_PWCTRL1_CMD, ST7789V_PWCTRL1_MAGIC,
> +		     ST7789V_PWCTRL1_AVDD(2) | ST7789V_PWCTRL1_AVCL(2) |
> +		     ST7789V_PWCTRL1_VDS(1));
> +
> +	st7789v_send(ctx, ST7789V_PVGAMCTRL_CMD,
> +		     ST7789V_PVGAMCTRL_VP63(0xd),
> +		     ST7789V_PVGAMCTRL_VP1(0xca),
> +		     ST7789V_PVGAMCTRL_VP2(0xe),
> +		     ST7789V_PVGAMCTRL_VP4(8),
> +		     ST7789V_PVGAMCTRL_VP6(9),
> +		     ST7789V_PVGAMCTRL_VP13(7),
> +		     ST7789V_PVGAMCTRL_VP20(0x2d),
> +		     ST7789V_PVGAMCTRL_VP27(0xb) | ST7789V_PVGAMCTRL_VP36(3),
> +		     ST7789V_PVGAMCTRL_VP43(0x3d),
> +		     ST7789V_PVGAMCTRL_JP1(3) | ST7789V_PVGAMCTRL_VP50(4),
> +		     ST7789V_PVGAMCTRL_VP57(0xa),
> +		     ST7789V_PVGAMCTRL_VP59(0xa),
> +		     ST7789V_PVGAMCTRL_VP61(0x1b),
> +		     ST7789V_PVGAMCTRL_VP62(0x28));
> +
> +	st7789v_send(ctx, ST7789V_NVGAMCTRL_CMD,
> +		     ST7789V_NVGAMCTRL_VN63(0xd),
> +		     ST7789V_NVGAMCTRL_VN1(0xca),
> +		     ST7789V_NVGAMCTRL_VN2(0xf),
> +		     ST7789V_NVGAMCTRL_VN4(8),
> +		     ST7789V_NVGAMCTRL_VN6(8),
> +		     ST7789V_NVGAMCTRL_VN13(7),
> +		     ST7789V_NVGAMCTRL_VN20(0x2e),
> +		     ST7789V_NVGAMCTRL_VN27(0xc) | ST7789V_NVGAMCTRL_VN36(5),
> +		     ST7789V_NVGAMCTRL_VN43(0x40),
> +		     ST7789V_NVGAMCTRL_JN1(3) | ST7789V_NVGAMCTRL_VN50(4),
> +		     ST7789V_NVGAMCTRL_VN57(9),
> +		     ST7789V_NVGAMCTRL_VN59(0xb),
> +		     ST7789V_NVGAMCTRL_VN61(0x1b),
> +		     ST7789V_NVGAMCTRL_VN62(0x28));
> +
> +	st7789v_send(ctx, ST7789V_INVON_CMD);
> +
> +	st7789v_send(ctx, ST7789V_RAMCTRL_CMD,
> +		     ST7789V_RAMCTRL_DM_RGB | ST7789V_RAMCTRL_RM_RGB,
> +		     ST7789V_RAMCTRL_EPF(3) | ST7789V_RAMCTRL_MAGIC);
> +
> +	st7789v_send(ctx, ST7789V_RGBCTRL_CMD,
> +		     ST7789V_RGBCTRL_WO | ST7789V_RGBCTRL_RCM(2) |
> +		     ST7789V_RGBCTRL_VSYNC_HIGH | ST7789V_RGBCTRL_HSYNC_HIGH |
> +		     ST7789V_RGBCTRL_PCLK_HIGH,
> +		     ST7789V_RGBCTRL_VBP(8), ST7789V_RGBCTRL_HBP(20));
> +
> +	return 0;
> +}

Please check for errors in all of the above.

> +static int st7789v_probe(struct spi_device *spi)
> +{
> +	struct device_node *backlight;
> +	struct st7789v *ctx;
> +	int ret;
> +
> +	ctx = devm_kzalloc(&spi->dev, sizeof(*ctx), GFP_KERNEL);
> +	if (!ctx)
> +		return -ENOMEM;
> +
> +	spi_set_drvdata(spi, ctx);
> +	ctx->spi = spi;
> +
> +	ctx->panel.dev = &spi->dev;
> +	ctx->panel.funcs = &st7789v_drm_funcs;
> +
> +	ctx->reset = devm_gpiod_get(&spi->dev, "reset", GPIOD_OUT_LOW);
> +	if (IS_ERR(ctx->reset)) {
> +		dev_err(&spi->dev, "Couldn't get our reset line\n");
> +		return PTR_ERR(ctx->reset);
> +	}
> +
> +	backlight = of_parse_phandle(spi->dev.of_node, "backlight", 0);
> +	if (backlight) {
> +		ctx->backlight = of_find_backlight_by_node(backlight);
> +		of_node_put(backlight);
> +
> +		if (!ctx->backlight)
> +			return -EPROBE_DEFER;
> +	}

This could make use of one of the helpers that Noralf had sent earlier
for TinyDRM. That is, if it weren't specific to TinyDRM.

Thierry
Maxime Ripard Feb. 7, 2017, 3:53 p.m. UTC | #6 
On Mon, Feb 06, 2017 at 02:26:20PM +0100, Thierry Reding wrote:
> > +#define NUMARGS(...)  (sizeof((int[]){__VA_ARGS__}) / sizeof(int))
> > +#define st7789v_send(ctx, cmd, ...)					\
> > +	st7789v_write_command_data(ctx, cmd, NUMARGS(__VA_ARGS__),	\
> > +				   ##__VA_ARGS__)
> 
> How is this going to work if any of the arguments happens to not be an
> int? What if you have something like this:
> 
> 	u8 value = 0x2;
> 
> 	st7789v_write_command_data(ctx, cmd, 0x1, value, 0x3);
> 
> ? Wouldn't that invalidly read "value" as int and wrongly increment the
> ap by three bytes too many?


Hmmm, it might be. I'll remove it, and take all your other changes
into account.

Thanks!
Maxime
diff mbox

Patch

diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
index 62aba976e744..d07b996a07b8 100644
--- a/drivers/gpu/drm/panel/Kconfig
+++ b/drivers/gpu/drm/panel/Kconfig
@@ -81,4 +81,8 @@  config DRM_PANEL_SHARP_LS043T1LE01
 	  Say Y here if you want to enable support for Sharp LS043T1LE01 qHD
 	  (540x960) DSI panel as found on the Qualcomm APQ8074 Dragonboard
 
+config DRM_PANEL_SITRONIX_ST7789V
+	tristate "Sitronx ST7789V panel"
+	depends on OF && SPI
+
 endmenu
diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
index a5c7ec0236e0..41b245d39984 100644
--- a/drivers/gpu/drm/panel/Makefile
+++ b/drivers/gpu/drm/panel/Makefile
@@ -6,3 +6,4 @@  obj-$(CONFIG_DRM_PANEL_SAMSUNG_LD9040) += panel-samsung-ld9040.o
 obj-$(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
diff --git a/drivers/gpu/drm/panel/panel-sitronix-st7789v.c b/drivers/gpu/drm/panel/panel-sitronix-st7789v.c
new file mode 100644
index 000000000000..aab817b55aa6
--- /dev/null
+++ b/drivers/gpu/drm/panel/panel-sitronix-st7789v.c
@@ -0,0 +1,435 @@ 
+/*
+ * Copyright (C) 2017 Free Electrons
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ */
+
+#include <drm/drmP.h>
+#include <drm/drm_panel.h>
+
+#include <linux/gpio/consumer.h>
+#include <linux/spi/spi.h>
+
+#define ST7789V_SLPIN_CMD		0x10
+
+#define ST7789V_SLPOUT_CMD		0x11
+
+#define ST7789V_INVON_CMD		0x21
+
+#define ST7789V_DISPOFF_CMD		0x28
+
+#define ST7789V_DISPON_CMD		0x29
+
+#define ST7789V_MADCTL_CMD		0x36
+
+#define ST7789V_COLMOD_CMD		0x3a
+#define ST7789V_COLMOD_RGB_FMT_18BITS		(6 << 4)
+#define ST7789V_COLMOD_CTRL_FMT_18BITS		(6 << 0)
+
+#define ST7789V_RAMCTRL_CMD		0xb0
+#define ST7789V_RAMCTRL_RM_RGB			BIT(4)
+#define ST7789V_RAMCTRL_DM_RGB			BIT(0)
+#define ST7789V_RAMCTRL_MAGIC			(3 << 6)
+#define ST7789V_RAMCTRL_EPF(n)			(((n) & 3) << 4)
+
+#define ST7789V_RGBCTRL_CMD		0xb1
+#define ST7789V_RGBCTRL_WO			BIT(7)
+#define ST7789V_RGBCTRL_RCM(n)			(((n) & 3) << 5)
+#define ST7789V_RGBCTRL_VSYNC_HIGH		BIT(3)
+#define ST7789V_RGBCTRL_HSYNC_HIGH		BIT(2)
+#define ST7789V_RGBCTRL_PCLK_HIGH		BIT(1)
+#define ST7789V_RGBCTRL_VBP(n)			((n) & 0x7f)
+#define ST7789V_RGBCTRL_HBP(n)			((n) & 0x1f)
+
+#define ST7789V_PORCTRL_CMD		0xb2
+#define ST7789V_PORCTRL_IDLE_BP(n)		(((n) & 0xf) << 4)
+#define ST7789V_PORCTRL_IDLE_FP(n)		((n) & 0xf)
+#define ST7789V_PORCTRL_PARTIAL_BP(n)		(((n) & 0xf) << 4)
+#define ST7789V_PORCTRL_PARTIAL_FP(n)		((n) & 0xf)
+
+#define ST7789V_GCTRL_CMD		0xb7
+#define ST7789V_GCTRL_VGHS(n)			(((n) & 7) << 4)
+#define ST7789V_GCTRL_VGLS(n)			((n) & 7)
+
+#define ST7789V_VCOMS_CMD		0xbb
+
+#define ST7789V_LCMCTRL_CMD		0xc0
+#define ST7789V_LCMCTRL_XBGR			BIT(5)
+#define ST7789V_LCMCTRL_XMX			BIT(3)
+#define ST7789V_LCMCTRL_XMH			BIT(2)
+
+#define ST7789V_VDVVRHEN_CMD		0xc2
+#define ST7789V_VDVVRHEN_CMDEN			BIT(0)
+
+#define ST7789V_VRHS_CMD		0xc3
+
+#define ST7789V_VDVS_CMD		0xc4
+
+#define ST7789V_FRCTRL2_CMD		0xc6
+
+#define ST7789V_PWCTRL1_CMD		0xd0
+#define ST7789V_PWCTRL1_MAGIC			0xa4
+#define ST7789V_PWCTRL1_AVDD(n)			(((n) & 3) << 6)
+#define ST7789V_PWCTRL1_AVCL(n)			(((n) & 3) << 4)
+#define ST7789V_PWCTRL1_VDS(n)			((n) & 3)
+
+#define ST7789V_PVGAMCTRL_CMD		0xe0
+#define ST7789V_PVGAMCTRL_JP0(n)		(((n) & 3) << 4)
+#define ST7789V_PVGAMCTRL_JP1(n)		(((n) & 3) << 4)
+#define ST7789V_PVGAMCTRL_VP0(n)		((n) & 0xf)
+#define ST7789V_PVGAMCTRL_VP1(n)		((n) & 0x3f)
+#define ST7789V_PVGAMCTRL_VP2(n)		((n) & 0x3f)
+#define ST7789V_PVGAMCTRL_VP4(n)		((n) & 0x1f)
+#define ST7789V_PVGAMCTRL_VP6(n)		((n) & 0x1f)
+#define ST7789V_PVGAMCTRL_VP13(n)		((n) & 0xf)
+#define ST7789V_PVGAMCTRL_VP20(n)		((n) & 0x7f)
+#define ST7789V_PVGAMCTRL_VP27(n)		((n) & 7)
+#define ST7789V_PVGAMCTRL_VP36(n)		(((n) & 7) << 4)
+#define ST7789V_PVGAMCTRL_VP43(n)		((n) & 0x7f)
+#define ST7789V_PVGAMCTRL_VP50(n)		((n) & 0xf)
+#define ST7789V_PVGAMCTRL_VP57(n)		((n) & 0x1f)
+#define ST7789V_PVGAMCTRL_VP59(n)		((n) & 0x1f)
+#define ST7789V_PVGAMCTRL_VP61(n)		((n) & 0x3f)
+#define ST7789V_PVGAMCTRL_VP62(n)		((n) & 0x3f)
+#define ST7789V_PVGAMCTRL_VP63(n)		(((n) & 0xf) << 4)
+
+#define ST7789V_NVGAMCTRL_CMD		0xe1
+#define ST7789V_NVGAMCTRL_JN0(n)		(((n) & 3) << 4)
+#define ST7789V_NVGAMCTRL_JN1(n)		(((n) & 3) << 4)
+#define ST7789V_NVGAMCTRL_VN0(n)		((n) & 0xf)
+#define ST7789V_NVGAMCTRL_VN1(n)		((n) & 0x3f)
+#define ST7789V_NVGAMCTRL_VN2(n)		((n) & 0x3f)
+#define ST7789V_NVGAMCTRL_VN4(n)		((n) & 0x1f)
+#define ST7789V_NVGAMCTRL_VN6(n)		((n) & 0x1f)
+#define ST7789V_NVGAMCTRL_VN13(n)		((n) & 0xf)
+#define ST7789V_NVGAMCTRL_VN20(n)		((n) & 0x7f)
+#define ST7789V_NVGAMCTRL_VN27(n)		((n) & 7)
+#define ST7789V_NVGAMCTRL_VN36(n)		(((n) & 7) << 4)
+#define ST7789V_NVGAMCTRL_VN43(n)		((n) & 0x7f)
+#define ST7789V_NVGAMCTRL_VN50(n)		((n) & 0xf)
+#define ST7789V_NVGAMCTRL_VN57(n)		((n) & 0x1f)
+#define ST7789V_NVGAMCTRL_VN59(n)		((n) & 0x1f)
+#define ST7789V_NVGAMCTRL_VN61(n)		((n) & 0x3f)
+#define ST7789V_NVGAMCTRL_VN62(n)		((n) & 0x3f)
+#define ST7789V_NVGAMCTRL_VN63(n)		(((n) & 0xf) << 4)
+
+struct st7789v {
+	struct drm_panel panel;
+	struct spi_device *spi;
+	struct gpio_desc *reset;
+	struct backlight_device *backlight;
+};
+
+enum st7789v_prefix {
+	ST7789V_COMMAND = 0,
+	ST7789V_DATA = 1,
+};
+
+static inline struct st7789v *panel_to_st7789v(struct drm_panel *panel)
+{
+	return container_of(panel, struct st7789v, panel);
+}
+
+static int st7789v_spi_write(struct st7789v *ctx, u8 prefix, u8 data)
+{
+	struct spi_transfer xfer = { };
+	struct spi_message msg;
+	u16 txbuf = ((prefix & 1) << 8) | data;
+
+	spi_message_init(&msg);
+
+	xfer.tx_buf = &txbuf;
+	xfer.bits_per_word = 9;
+	xfer.len = sizeof(txbuf);
+
+	spi_message_add_tail(&xfer, &msg);
+	return spi_sync(ctx->spi, &msg);
+}
+
+static int st7789v_write_command(struct st7789v *ctx, u8 cmd)
+{
+	return st7789v_spi_write(ctx, ST7789V_COMMAND, cmd);
+}
+
+static int st7789v_write_data(struct st7789v *ctx, u8 cmd)
+{
+	return st7789v_spi_write(ctx, ST7789V_DATA, cmd);
+}
+
+static int st7789v_write_command_data(struct st7789v *ctx, u8 cmd,
+				      unsigned long n_data, ...)
+{
+	va_list ap;
+	int i;
+
+	st7789v_write_command(ctx, cmd);
+
+	va_start(ap, n_data);
+	for (i = 0; i < n_data; i++)
+		st7789v_write_data(ctx, va_arg(ap, int));
+	va_end(ap);
+
+	return 0;
+}
+
+static const struct drm_display_mode default_mode = {
+	.clock = 7000,
+	.hdisplay = 240,
+	.hsync_start = 240 + 38,
+	.hsync_end = 240 + 38 + 10,
+	.htotal = 240 + 38 + 10 + 10,
+	.vdisplay = 320,
+	.vsync_start = 320 + 8,
+	.vsync_end = 320 + 8 + 4,
+	.vtotal = 320 + 8 + 4 + 4,
+	.vrefresh = 60,
+};
+
+static int st7789v_get_modes(struct drm_panel *panel)
+{
+	struct drm_connector *connector = panel->connector;
+	struct drm_display_mode *mode;
+
+	mode = drm_mode_duplicate(panel->drm, &default_mode);
+	if (!mode) {
+		dev_err(panel->drm->dev, "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(connector, mode);
+
+	panel->connector->display_info.width_mm = 61;
+	panel->connector->display_info.height_mm = 103;
+
+	return 1;
+}
+
+#define NUMARGS(...)  (sizeof((int[]){__VA_ARGS__}) / sizeof(int))
+#define st7789v_send(ctx, cmd, ...)					\
+	st7789v_write_command_data(ctx, cmd, NUMARGS(__VA_ARGS__),	\
+				   ##__VA_ARGS__)
+
+static int st7789v_prepare(struct drm_panel *panel)
+{
+	struct st7789v *ctx = panel_to_st7789v(panel);
+
+	gpiod_set_value(ctx->reset, 1);
+	msleep(30);
+	gpiod_set_value(ctx->reset, 0);
+	msleep(120);
+
+	st7789v_send(ctx, ST7789V_SLPOUT_CMD);
+
+	/* We need to wait 120ms after a sleep out command */
+	msleep(120);
+
+	st7789v_send(ctx, ST7789V_MADCTL_CMD, 0);
+
+	st7789v_send(ctx, ST7789V_COLMOD_CMD,
+		     ST7789V_COLMOD_CTRL_FMT_18BITS |
+		     ST7789V_COLMOD_RGB_FMT_18BITS);
+
+	st7789v_send(ctx, ST7789V_PORCTRL_CMD,
+		     0xc,		/* Backporch, normal mode*/
+		     0xc,		/* Frontporch, normal mode */
+		     0,			/* Disable separate porch control */
+		     ST7789V_PORCTRL_IDLE_BP(3) |
+		     ST7789V_PORCTRL_IDLE_FP(3),
+		     ST7789V_PORCTRL_PARTIAL_BP(3) |
+		     ST7789V_PORCTRL_PARTIAL_FP(3));
+
+	st7789v_send(ctx, ST7789V_GCTRL_CMD,
+		     ST7789V_GCTRL_VGLS(5) | ST7789V_GCTRL_VGHS(3));
+
+	st7789v_send(ctx, ST7789V_VCOMS_CMD, 0x2b);
+
+	st7789v_send(ctx, ST7789V_LCMCTRL_CMD, ST7789V_LCMCTRL_XMH |
+		     ST7789V_LCMCTRL_XMX | ST7789V_LCMCTRL_XBGR);
+
+	st7789v_send(ctx, ST7789V_VDVVRHEN_CMD, ST7789V_VDVVRHEN_CMDEN);
+
+	st7789v_send(ctx, ST7789V_VRHS_CMD, 0xf);
+
+	st7789v_send(ctx, ST7789V_VDVS_CMD, 0x20);
+
+	st7789v_send(ctx, ST7789V_FRCTRL2_CMD, 0xf);
+
+	st7789v_send(ctx, ST7789V_PWCTRL1_CMD, ST7789V_PWCTRL1_MAGIC,
+		     ST7789V_PWCTRL1_AVDD(2) | ST7789V_PWCTRL1_AVCL(2) |
+		     ST7789V_PWCTRL1_VDS(1));
+
+	st7789v_send(ctx, ST7789V_PVGAMCTRL_CMD,
+		     ST7789V_PVGAMCTRL_VP63(0xd),
+		     ST7789V_PVGAMCTRL_VP1(0xca),
+		     ST7789V_PVGAMCTRL_VP2(0xe),
+		     ST7789V_PVGAMCTRL_VP4(8),
+		     ST7789V_PVGAMCTRL_VP6(9),
+		     ST7789V_PVGAMCTRL_VP13(7),
+		     ST7789V_PVGAMCTRL_VP20(0x2d),
+		     ST7789V_PVGAMCTRL_VP27(0xb) | ST7789V_PVGAMCTRL_VP36(3),
+		     ST7789V_PVGAMCTRL_VP43(0x3d),
+		     ST7789V_PVGAMCTRL_JP1(3) | ST7789V_PVGAMCTRL_VP50(4),
+		     ST7789V_PVGAMCTRL_VP57(0xa),
+		     ST7789V_PVGAMCTRL_VP59(0xa),
+		     ST7789V_PVGAMCTRL_VP61(0x1b),
+		     ST7789V_PVGAMCTRL_VP62(0x28));
+
+	st7789v_send(ctx, ST7789V_NVGAMCTRL_CMD,
+		     ST7789V_NVGAMCTRL_VN63(0xd),
+		     ST7789V_NVGAMCTRL_VN1(0xca),
+		     ST7789V_NVGAMCTRL_VN2(0xf),
+		     ST7789V_NVGAMCTRL_VN4(8),
+		     ST7789V_NVGAMCTRL_VN6(8),
+		     ST7789V_NVGAMCTRL_VN13(7),
+		     ST7789V_NVGAMCTRL_VN20(0x2e),
+		     ST7789V_NVGAMCTRL_VN27(0xc) | ST7789V_NVGAMCTRL_VN36(5),
+		     ST7789V_NVGAMCTRL_VN43(0x40),
+		     ST7789V_NVGAMCTRL_JN1(3) | ST7789V_NVGAMCTRL_VN50(4),
+		     ST7789V_NVGAMCTRL_VN57(9),
+		     ST7789V_NVGAMCTRL_VN59(0xb),
+		     ST7789V_NVGAMCTRL_VN61(0x1b),
+		     ST7789V_NVGAMCTRL_VN62(0x28));
+
+	st7789v_send(ctx, ST7789V_INVON_CMD);
+
+	st7789v_send(ctx, ST7789V_RAMCTRL_CMD,
+		     ST7789V_RAMCTRL_DM_RGB | ST7789V_RAMCTRL_RM_RGB,
+		     ST7789V_RAMCTRL_EPF(3) | ST7789V_RAMCTRL_MAGIC);
+
+	st7789v_send(ctx, ST7789V_RGBCTRL_CMD,
+		     ST7789V_RGBCTRL_WO | ST7789V_RGBCTRL_RCM(2) |
+		     ST7789V_RGBCTRL_VSYNC_HIGH | ST7789V_RGBCTRL_HSYNC_HIGH |
+		     ST7789V_RGBCTRL_PCLK_HIGH,
+		     ST7789V_RGBCTRL_VBP(8), ST7789V_RGBCTRL_HBP(20));
+
+	return 0;
+}
+
+static int st7789v_enable(struct drm_panel *panel)
+{
+	struct st7789v *ctx = panel_to_st7789v(panel);
+
+	if (ctx->backlight) {
+		ctx->backlight->props.state &= ~BL_CORE_FBBLANK;
+		ctx->backlight->props.power = FB_BLANK_UNBLANK;
+		backlight_update_status(ctx->backlight);
+	}
+
+	return st7789v_send(ctx, ST7789V_DISPON_CMD);
+}
+
+static int st7789v_disable(struct drm_panel *panel)
+{
+	struct st7789v *ctx = panel_to_st7789v(panel);
+
+	st7789v_send(ctx, ST7789V_DISPOFF_CMD);
+
+	if (ctx->backlight) {
+		ctx->backlight->props.power = FB_BLANK_POWERDOWN;
+		ctx->backlight->props.state |= BL_CORE_FBBLANK;
+		backlight_update_status(ctx->backlight);
+	}
+
+	return 0;
+}
+
+static int st7789v_unprepare(struct drm_panel *panel)
+{
+	struct st7789v *ctx = panel_to_st7789v(panel);
+
+	st7789v_send(ctx, ST7789V_SLPIN_CMD);
+
+	return 0;
+}
+
+static const struct drm_panel_funcs st7789v_drm_funcs = {
+	.disable	= st7789v_disable,
+	.enable		= st7789v_enable,
+	.get_modes	= st7789v_get_modes,
+	.prepare	= st7789v_prepare,
+	.unprepare	= st7789v_unprepare,
+};
+
+static int st7789v_probe(struct spi_device *spi)
+{
+	struct device_node *backlight;
+	struct st7789v *ctx;
+	int ret;
+
+	ctx = devm_kzalloc(&spi->dev, sizeof(*ctx), GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+
+	spi_set_drvdata(spi, ctx);
+	ctx->spi = spi;
+
+	ctx->panel.dev = &spi->dev;
+	ctx->panel.funcs = &st7789v_drm_funcs;
+
+	ctx->reset = devm_gpiod_get(&spi->dev, "reset", GPIOD_OUT_LOW);
+	if (IS_ERR(ctx->reset)) {
+		dev_err(&spi->dev, "Couldn't get our reset line\n");
+		return PTR_ERR(ctx->reset);
+	}
+
+	backlight = of_parse_phandle(spi->dev.of_node, "backlight", 0);
+	if (backlight) {
+		ctx->backlight = of_find_backlight_by_node(backlight);
+		of_node_put(backlight);
+
+		if (!ctx->backlight)
+			return -EPROBE_DEFER;
+	}
+
+	ret = drm_panel_add(&ctx->panel);
+	if (ret < 0)
+		goto err_free_backlight;
+
+	return 0;
+
+err_free_backlight:
+	if (ctx->backlight)
+		put_device(&ctx->backlight->dev);
+
+	return ret;
+}
+
+static int st7789v_remove(struct spi_device *spi)
+{
+	struct st7789v *ctx = spi_get_drvdata(spi);
+
+	drm_panel_detach(&ctx->panel);
+	drm_panel_remove(&ctx->panel);
+
+	if (ctx->backlight)
+		put_device(&ctx->backlight->dev);
+
+	return 0;
+}
+
+static const struct of_device_id st7789v_of_match[] = {
+	{ .compatible = "sitronix,st7789v" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, st7789v_of_match);
+
+static struct spi_driver st7789v_driver = {
+	.probe = st7789v_probe,
+	.remove = st7789v_remove,
+	.driver = {
+		.name = "st7789v",
+		.of_match_table = st7789v_of_match,
+	},
+};
+module_spi_driver(st7789v_driver);
+
+MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
+MODULE_DESCRIPTION("Sitronix st7789v LCD Driver");
+MODULE_LICENSE("GPL v2");