[PATCH v3 2/2] drm/panel: Add driver for sitronix ST7789V LCD controller

[Maxime Ripard <maxime.ripard@free-electrons.com>]

The Sitronix ST7789v controller is used to drive 240x320 LCD panels through
various interfaces, including SPI and RGB/Parallel.

The current driver is configuring it for the latter. Support for tinyDRM
can always be added later.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 drivers/gpu/drm/panel/Kconfig                  |   7 +-
 drivers/gpu/drm/panel/Makefile                 |   1 +-
 drivers/gpu/drm/panel/panel-sitronix-st7789v.c | 449 ++++++++++++++++++-
 3 files changed, 457 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..eb42dc37e979 100644
--- a/drivers/gpu/drm/panel/Kconfig
+++ b/drivers/gpu/drm/panel/Kconfig
@@ -81,4 +81,11 @@ 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 "Sitronix ST7789V panel"
+	depends on OF && SPI
+	help
+	  Say Y here if you want to enable support for the Sitronix
+	  ST7789V controller for 240x320 LCD panels
+
 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..358c64ef1922
--- /dev/null
+++ b/drivers/gpu/drm/panel/panel-sitronix-st7789v.c
@@ -0,0 +1,449 @@
+/*
+ * 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 <linux/gpio/consumer.h>
+#include <linux/regulator/consumer.h>
+#include <linux/spi/spi.h>
+
+#include <drm/drmP.h>
+#include <drm/drm_panel.h>
+
+#include <video/mipi_display.h>
+
+#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)
+
+#define ST7789V_TEST(val, func)			\
+	do {					\
+		if ((val = (func)))		\
+			return val;		\
+	} while (0)
+
+struct st7789v {
+	struct drm_panel panel;
+	struct spi_device *spi;
+	struct gpio_desc *reset;
+	struct backlight_device *backlight;
+	struct regulator *power;
+};
+
+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, enum st7789v_prefix 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 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;
+}
+
+static int st7789v_prepare(struct drm_panel *panel)
+{
+	struct st7789v *ctx = panel_to_st7789v(panel);
+	int ret;
+
+	ret = regulator_enable(ctx->power);
+	if (ret)
+		return ret;
+
+	gpiod_set_value(ctx->reset, 1);
+	msleep(30);
+	gpiod_set_value(ctx->reset, 0);
+	msleep(120);
+
+	ST7789V_TEST(ret, st7789v_write_command(ctx, MIPI_DCS_EXIT_SLEEP_MODE));
+
+	/* We need to wait 120ms after a sleep out command */
+	msleep(120);
+
+	ST7789V_TEST(ret, st7789v_write_command(ctx,
+						MIPI_DCS_SET_ADDRESS_MODE));
+	ST7789V_TEST(ret, st7789v_write_data(ctx, 0));
+
+	ST7789V_TEST(ret, st7789v_write_command(ctx,
+						MIPI_DCS_SET_PIXEL_FORMAT));
+	ST7789V_TEST(ret, st7789v_write_data(ctx,
+					     (MIPI_DCS_PIXEL_FMT_18BIT << 4) |
+					     (MIPI_DCS_PIXEL_FMT_18BIT)));
+
+	ST7789V_TEST(ret, st7789v_write_command(ctx, ST7789V_PORCTRL_CMD));
+	ST7789V_TEST(ret, st7789v_write_data(ctx, 0xc));
+	ST7789V_TEST(ret, st7789v_write_data(ctx, 0xc));
+	ST7789V_TEST(ret, st7789v_write_data(ctx, 0));
+	ST7789V_TEST(ret, st7789v_write_data(ctx, ST7789V_PORCTRL_IDLE_BP(3) |
+					     ST7789V_PORCTRL_IDLE_FP(3)));
+	ST7789V_TEST(ret, st7789v_write_data(ctx,
+					     ST7789V_PORCTRL_PARTIAL_BP(3) |
+					     ST7789V_PORCTRL_PARTIAL_FP(3)));
+
+	ST7789V_TEST(ret, st7789v_write_command(ctx, ST7789V_GCTRL_CMD));
+	ST7789V_TEST(ret, st7789v_write_data(ctx, ST7789V_GCTRL_VGLS(5) |
+					     ST7789V_GCTRL_VGHS(3)));
+
+	ST7789V_TEST(ret, st7789v_write_command(ctx, ST7789V_VCOMS_CMD));
+	ST7789V_TEST(ret, st7789v_write_data(ctx, 0x2b));
+
+	ST7789V_TEST(ret, st7789v_write_command(ctx, ST7789V_LCMCTRL_CMD));
+	ST7789V_TEST(ret, st7789v_write_data(ctx, ST7789V_LCMCTRL_XMH |
+					     ST7789V_LCMCTRL_XMX |
+					     ST7789V_LCMCTRL_XBGR));
+
+	ST7789V_TEST(ret, st7789v_write_command(ctx, ST7789V_VDVVRHEN_CMD));
+	ST7789V_TEST(ret, st7789v_write_data(ctx, ST7789V_VDVVRHEN_CMDEN));
+
+	ST7789V_TEST(ret, st7789v_write_command(ctx, ST7789V_VRHS_CMD));
+	ST7789V_TEST(ret, st7789v_write_data(ctx, 0xf));
+
+	ST7789V_TEST(ret, st7789v_write_command(ctx, ST7789V_VDVS_CMD));
+	ST7789V_TEST(ret, st7789v_write_data(ctx, 0x20));
+
+	ST7789V_TEST(ret, st7789v_write_command(ctx, ST7789V_FRCTRL2_CMD));
+	ST7789V_TEST(ret, st7789v_write_data(ctx, 0xf));
+
+	ST7789V_TEST(ret, st7789v_write_command(ctx, ST7789V_PWCTRL1_CMD));
+	ST7789V_TEST(ret, st7789v_write_data(ctx, ST7789V_PWCTRL1_MAGIC));
+	ST7789V_TEST(ret, st7789v_write_data(ctx, ST7789V_PWCTRL1_AVDD(2) |
+					     ST7789V_PWCTRL1_AVCL(2) |
+					     ST7789V_PWCTRL1_VDS(1)));
+
+	ST7789V_TEST(ret, st7789v_write_command(ctx, ST7789V_PVGAMCTRL_CMD));
+	ST7789V_TEST(ret, st7789v_write_data(ctx, ST7789V_PVGAMCTRL_VP63(0xd)));
+	ST7789V_TEST(ret, st7789v_write_data(ctx, ST7789V_PVGAMCTRL_VP1(0xca)));
+	ST7789V_TEST(ret, st7789v_write_data(ctx, ST7789V_PVGAMCTRL_VP2(0xe)));
+	ST7789V_TEST(ret, st7789v_write_data(ctx, ST7789V_PVGAMCTRL_VP4(8)));
+	ST7789V_TEST(ret, st7789v_write_data(ctx, ST7789V_PVGAMCTRL_VP6(9)));
+	ST7789V_TEST(ret, st7789v_write_data(ctx, ST7789V_PVGAMCTRL_VP13(7)));
+	ST7789V_TEST(ret, st7789v_write_data(ctx, ST7789V_PVGAMCTRL_VP20(0x2d)));
+	ST7789V_TEST(ret, st7789v_write_data(ctx, ST7789V_PVGAMCTRL_VP27(0xb) |
+					     ST7789V_PVGAMCTRL_VP36(3)));
+	ST7789V_TEST(ret, st7789v_write_data(ctx, ST7789V_PVGAMCTRL_VP43(0x3d)));
+	ST7789V_TEST(ret, st7789v_write_data(ctx, ST7789V_PVGAMCTRL_JP1(3) |
+					     ST7789V_PVGAMCTRL_VP50(4)));
+	ST7789V_TEST(ret, st7789v_write_data(ctx, ST7789V_PVGAMCTRL_VP57(0xa)));
+	ST7789V_TEST(ret, st7789v_write_data(ctx, ST7789V_PVGAMCTRL_VP59(0xa)));
+	ST7789V_TEST(ret, st7789v_write_data(ctx, ST7789V_PVGAMCTRL_VP61(0x1b)));
+	ST7789V_TEST(ret, st7789v_write_data(ctx, ST7789V_PVGAMCTRL_VP62(0x28)));
+
+	ST7789V_TEST(ret, st7789v_write_command(ctx, ST7789V_NVGAMCTRL_CMD));
+	ST7789V_TEST(ret, st7789v_write_data(ctx, ST7789V_NVGAMCTRL_VN63(0xd)));
+	ST7789V_TEST(ret, st7789v_write_data(ctx, ST7789V_NVGAMCTRL_VN1(0xca)));
+	ST7789V_TEST(ret, st7789v_write_data(ctx, ST7789V_NVGAMCTRL_VN2(0xf)));
+	ST7789V_TEST(ret, st7789v_write_data(ctx, ST7789V_NVGAMCTRL_VN4(8)));
+	ST7789V_TEST(ret, st7789v_write_data(ctx, ST7789V_NVGAMCTRL_VN6(8)));
+	ST7789V_TEST(ret, st7789v_write_data(ctx, ST7789V_NVGAMCTRL_VN13(7)));
+	ST7789V_TEST(ret, st7789v_write_data(ctx, ST7789V_NVGAMCTRL_VN20(0x2e)));
+	ST7789V_TEST(ret, st7789v_write_data(ctx, ST7789V_NVGAMCTRL_VN27(0xc) |
+					     ST7789V_NVGAMCTRL_VN36(5)));
+	ST7789V_TEST(ret, st7789v_write_data(ctx, ST7789V_NVGAMCTRL_VN43(0x40)));
+	ST7789V_TEST(ret, st7789v_write_data(ctx, ST7789V_NVGAMCTRL_JN1(3) |
+					     ST7789V_NVGAMCTRL_VN50(4)));
+	ST7789V_TEST(ret, st7789v_write_data(ctx, ST7789V_NVGAMCTRL_VN57(9)));
+	ST7789V_TEST(ret, st7789v_write_data(ctx, ST7789V_NVGAMCTRL_VN59(0xb)));
+	ST7789V_TEST(ret, st7789v_write_data(ctx, ST7789V_NVGAMCTRL_VN61(0x1b)));
+	ST7789V_TEST(ret, st7789v_write_data(ctx, ST7789V_NVGAMCTRL_VN62(0x28)));
+
+	ST7789V_TEST(ret, st7789v_write_command(ctx, MIPI_DCS_ENTER_INVERT_MODE));
+
+	ST7789V_TEST(ret, st7789v_write_command(ctx, ST7789V_RAMCTRL_CMD));
+	ST7789V_TEST(ret, st7789v_write_data(ctx, ST7789V_RAMCTRL_DM_RGB |
+					     ST7789V_RAMCTRL_RM_RGB));
+	ST7789V_TEST(ret, st7789v_write_data(ctx, ST7789V_RAMCTRL_EPF(3) |
+					     ST7789V_RAMCTRL_MAGIC));
+
+	ST7789V_TEST(ret, st7789v_write_command(ctx, ST7789V_RGBCTRL_CMD));
+	ST7789V_TEST(ret, st7789v_write_data(ctx, ST7789V_RGBCTRL_WO |
+					     ST7789V_RGBCTRL_RCM(2) |
+					     ST7789V_RGBCTRL_VSYNC_HIGH |
+					     ST7789V_RGBCTRL_HSYNC_HIGH |
+					     ST7789V_RGBCTRL_PCLK_HIGH));
+	ST7789V_TEST(ret, st7789v_write_data(ctx, ST7789V_RGBCTRL_VBP(8)));
+	ST7789V_TEST(ret, st7789v_write_data(ctx, 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_write_command(ctx, MIPI_DCS_SET_DISPLAY_ON);
+}
+
+static int st7789v_disable(struct drm_panel *panel)
+{
+	struct st7789v *ctx = panel_to_st7789v(panel);
+	int ret;
+
+	ST7789V_TEST(ret, st7789v_write_command(ctx, MIPI_DCS_SET_DISPLAY_OFF));
+
+	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);
+	int ret;
+
+	ST7789V_TEST(ret, st7789v_write_command(ctx, MIPI_DCS_ENTER_SLEEP_MODE));
+
+	regulator_disable(ctx->power);
+
+	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->power = devm_regulator_get(&spi->dev, "power");
+	if (IS_ERR(ctx->power))
+		return PTR_ERR(ctx->power);
+
+	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");
-- 
git-series 0.8.11