Re: [PATCH 2/2] drm/panel: add visionox vtdr6130 DSI panel driver

From: Neil Armstrong
Date: Wed Jan 04 2023 - 03:54:19 EST


Hi Sam,

On 03/01/2023 19:15, Sam Ravnborg wrote:
Hi Neil,

On Tue, Jan 03, 2023 at 03:22:28PM +0100, Neil Armstrong wrote:
Add support for the 1080x2400 Visionox VTDR6130 AMOLED DSI panel
found on the Qualcomm SM8550 MTP board.

By default the the panel is configured to work with DSI compressed
streams, but can work in uncompressed video mode since 1080x2400 in
RGB888 fits in the 4 DSI lanes bandwidth.

While display compression is preferred for performance and power
reasons, let's start with the uncompressed video mode support and
add the DSC support later on.

Signed-off-by: Neil Armstrong <neil.armstrong@xxxxxxxxxx>

a few comments in the following.

Sam

---
drivers/gpu/drm/panel/Kconfig | 8 +
drivers/gpu/drm/panel/Makefile | 1 +
drivers/gpu/drm/panel/panel-visionox-vtdr6130.c | 366 ++++++++++++++++++++++++
3 files changed, 375 insertions(+)

diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
index 737edcdf9eef..fd1d7e6f536b 100644
--- a/drivers/gpu/drm/panel/Kconfig
+++ b/drivers/gpu/drm/panel/Kconfig
@@ -717,6 +717,14 @@ config DRM_PANEL_VISIONOX_RM69299
Say Y here if you want to enable support for Visionox
RM69299 DSI Video Mode panel.
+config DRM_PANEL_VISIONOX_VTDR6130
+ tristate "Visionox VTDR6130"
+ depends on OF
+ depends on DRM_MIPI_DSI
+ help
+ Say Y here if you want to enable support for Visionox
+ VTDR6130 1080x2400 AMOLED DSI panel.
+
config DRM_PANEL_WIDECHIPS_WS2401
tristate "Widechips WS2401 DPI panel driver"
depends on SPI && GPIOLIB
diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
index f8f9d9f6a307..1966404fcf7a 100644
--- a/drivers/gpu/drm/panel/Makefile
+++ b/drivers/gpu/drm/panel/Makefile
@@ -73,5 +73,6 @@ obj-$(CONFIG_DRM_PANEL_TPO_TD043MTEA1) += panel-tpo-td043mtea1.o
obj-$(CONFIG_DRM_PANEL_TPO_TPG110) += panel-tpo-tpg110.o
obj-$(CONFIG_DRM_PANEL_TRULY_NT35597_WQXGA) += panel-truly-nt35597.o
obj-$(CONFIG_DRM_PANEL_VISIONOX_RM69299) += panel-visionox-rm69299.o
+obj-$(CONFIG_DRM_PANEL_VISIONOX_VTDR6130) += panel-visionox-vtdr6130.o
obj-$(CONFIG_DRM_PANEL_WIDECHIPS_WS2401) += panel-widechips-ws2401.o
obj-$(CONFIG_DRM_PANEL_XINPENG_XPP055C272) += panel-xinpeng-xpp055c272.o
diff --git a/drivers/gpu/drm/panel/panel-visionox-vtdr6130.c b/drivers/gpu/drm/panel/panel-visionox-vtdr6130.c
new file mode 100644
index 000000000000..94ad2a32efc9
--- /dev/null
+++ b/drivers/gpu/drm/panel/panel-visionox-vtdr6130.c
@@ -0,0 +1,366 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (c) 2023, Linaro Limited
+
+#include <linux/backlight.h>
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <linux/of.h>
+
+#include <drm/drm_mipi_dsi.h>
+#include <drm/drm_modes.h>
+#include <drm/drm_panel.h>
+#include <drm/display/drm_dsc.h>
+#include <linux/regulator/consumer.h>
Keep linux includes in one block.

Ack


+
+struct visionox_vtdr6130 {
+ struct drm_panel panel;
+ struct mipi_dsi_device *dsi;
+ struct gpio_desc *reset_gpio;
+ struct regulator_bulk_data supplies[3];
+ bool prepared;
+};
+
+static inline struct visionox_vtdr6130 *to_visionox_vtdr6130(struct drm_panel *panel)
+{
+ return container_of(panel, struct visionox_vtdr6130, panel);
+}
+
+static inline int visionox_vtdr6130_dsi_write(struct mipi_dsi_device *dsi, const void *seq,
+ size_t len)
+{
+ return mipi_dsi_dcs_write_buffer(dsi, seq, len);
+}
+
+#define dsi_dcs_write_seq(dsi, seq...) \
+ { \
+ const u8 d[] = { seq }; \
+ visionox_vtdr6130_dsi_write(dsi, d, ARRAY_SIZE(d)); \
+ }
Please use mipi_dsi_dcs_write_seq()
No need to add your own macros here.

This will also add a little bit of error reporting that is missing here.

OK, should I add a check and return in the macro in case of error ?
Checkpatch emits some warning when this is done.



+
+static void visionox_vtdr6130_reset(struct visionox_vtdr6130 *ctx)
+{
+ gpiod_set_value_cansleep(ctx->reset_gpio, 0);
+ usleep_range(10000, 11000);
+ gpiod_set_value_cansleep(ctx->reset_gpio, 1);
+ usleep_range(10000, 11000);
+ gpiod_set_value_cansleep(ctx->reset_gpio, 0);
+ usleep_range(10000, 11000);
+}
I have seen this pattern before - and I am still confused if the HW
really requires the 0 => 1 => 0 sequence.
I would expect writing 1 - wait and then writing 0 would do it.

It's what downstream code uses and recommend all over the place, if it's an issue
I can try to remove the first set_value


+
+static int visionox_vtdr6130_on(struct visionox_vtdr6130 *ctx)
+{
+ struct mipi_dsi_device *dsi = ctx->dsi;
+ struct device *dev = &dsi->dev;
+ int ret;
+
+ dsi->mode_flags |= MIPI_DSI_MODE_LPM;
+
+ dsi_dcs_write_seq(dsi, 0x03, 0x01);
MIPI_DSI_GENERIC_SHORT_WRITE_0_PARAM?

+ dsi_dcs_write_seq(dsi, 0x35, 0x00);
MIPI_DCS_SET_TEAR_ON?
+ dsi_dcs_write_seq(dsi, 0x53, 0x20);
MIPI_DCS_WRITE_CONTROL_DISPLAY?

etc - use the MIPI_DCS commands, not just hex-values

Ack, will clean this.


+ dsi_dcs_write_seq(dsi, 0x51, 0x00, 0x00);
+ dsi_dcs_write_seq(dsi, 0x59, 0x09);
+ dsi_dcs_write_seq(dsi, 0x6c, 0x01);
+ dsi_dcs_write_seq(dsi, 0x6d, 0x00);
+ dsi_dcs_write_seq(dsi, 0x6f, 0x01);
+ dsi_dcs_write_seq(dsi, 0x70,
+ 0x12, 0x00, 0x00, 0xab, 0x30, 0x80, 0x09, 0x60, 0x04,
+ 0x38, 0x00, 0x28, 0x02, 0x1c, 0x02, 0x1c, 0x02, 0x00,
+ 0x02, 0x0e, 0x00, 0x20, 0x03, 0xdd, 0x00, 0x07, 0x00,
+ 0x0c, 0x02, 0x77, 0x02, 0x8b, 0x18, 0x00, 0x10, 0xf0,
+ 0x07, 0x10, 0x20, 0x00, 0x06, 0x0f, 0x0f, 0x33, 0x0e,
+ 0x1c, 0x2a, 0x38, 0x46, 0x54, 0x62, 0x69, 0x70, 0x77,
+ 0x79, 0x7b, 0x7d, 0x7e, 0x02, 0x02, 0x22, 0x00, 0x2a,
+ 0x40, 0x2a, 0xbe, 0x3a, 0xfc, 0x3a, 0xfa, 0x3a, 0xf8,
+ 0x3b, 0x38, 0x3b, 0x78, 0x3b, 0xb6, 0x4b, 0xb6, 0x4b,
+ 0xf4, 0x4b, 0xf4, 0x6c, 0x34, 0x84, 0x74, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x00);
+ dsi_dcs_write_seq(dsi, 0xf0, 0xaa, 0x10);
+ dsi_dcs_write_seq(dsi, 0xb1,
+ 0x01, 0x38, 0x00, 0x14, 0x00, 0x1c, 0x00, 0x01, 0x66,
+ 0x00, 0x14, 0x00, 0x14, 0x00, 0x01, 0x66, 0x00, 0x14,
+ 0x05, 0xcc, 0x00);
+ dsi_dcs_write_seq(dsi, 0xf0, 0xaa, 0x13);
+ dsi_dcs_write_seq(dsi, 0xce,
+ 0x09, 0x11, 0x09, 0x11, 0x08, 0xc1, 0x07, 0xfa, 0x05,
+ 0xa4, 0x00, 0x3c, 0x00, 0x34, 0x00, 0x24, 0x00, 0x0c,
+ 0x00, 0x0c, 0x04, 0x00, 0x35);
+ dsi_dcs_write_seq(dsi, 0xf0, 0xaa, 0x14);
+ dsi_dcs_write_seq(dsi, 0xb2, 0x03, 0x33);
+ dsi_dcs_write_seq(dsi, 0xb4,
+ 0x00, 0x33, 0x00, 0x00, 0x00, 0x3e, 0x00, 0x00, 0x00,
+ 0x3e, 0x00, 0x00);
+ dsi_dcs_write_seq(dsi, 0xb5,
+ 0x00, 0x09, 0x09, 0x09, 0x09, 0x09, 0x09, 0x06, 0x01);
+ dsi_dcs_write_seq(dsi, 0xb9, 0x00, 0x00, 0x08, 0x09, 0x09, 0x09);
+ dsi_dcs_write_seq(dsi, 0xbc,
+ 0x10, 0x00, 0x00, 0x06, 0x11, 0x09, 0x3b, 0x09, 0x47,
+ 0x09, 0x47, 0x00);
+ dsi_dcs_write_seq(dsi, 0xbe,
+ 0x10, 0x10, 0x00, 0x08, 0x22, 0x09, 0x19, 0x09, 0x25,
+ 0x09, 0x25, 0x00);
+ dsi_dcs_write_seq(dsi, 0xff, 0x5a, 0x80);
+ dsi_dcs_write_seq(dsi, 0x65, 0x14);
+ dsi_dcs_write_seq(dsi, 0xfa, 0x08, 0x08, 0x08);
+ dsi_dcs_write_seq(dsi, 0xff, 0x5a, 0x81);
+ dsi_dcs_write_seq(dsi, 0x65, 0x05);
+ dsi_dcs_write_seq(dsi, 0xf3, 0x0f);
+ dsi_dcs_write_seq(dsi, 0xf0, 0xaa, 0x00);
+ dsi_dcs_write_seq(dsi, 0xff, 0x5a, 0x82);
+ dsi_dcs_write_seq(dsi, 0xf9, 0x00);
+ dsi_dcs_write_seq(dsi, 0xff, 0x51, 0x83);
+ dsi_dcs_write_seq(dsi, 0x65, 0x04);
+ dsi_dcs_write_seq(dsi, 0xf8, 0x00);
+ dsi_dcs_write_seq(dsi, 0xff, 0x5a, 0x00);
+ dsi_dcs_write_seq(dsi, 0x65, 0x01);
+ dsi_dcs_write_seq(dsi, 0xf4, 0x9a);
+ dsi_dcs_write_seq(dsi, 0xff, 0x5a, 0x00);
+
+ ret = mipi_dsi_dcs_exit_sleep_mode(dsi);
+ if (ret < 0) {
+ dev_err(dev, "Failed to exit sleep mode: %d\n", ret);
+ return ret;
+ }
+ msleep(120);
+
+ ret = mipi_dsi_dcs_set_display_on(dsi);
+ if (ret < 0) {
+ dev_err(dev, "Failed to set display on: %d\n", ret);
+ return ret;
+ }
+ msleep(20);
+
+ return 0;
+}
+
+static int visionox_vtdr6130_off(struct visionox_vtdr6130 *ctx)
+{
+ struct mipi_dsi_device *dsi = ctx->dsi;
+ struct device *dev = &dsi->dev;
+ int ret;
+
+ dsi->mode_flags &= ~MIPI_DSI_MODE_LPM;
+
+ ret = mipi_dsi_dcs_set_display_off(dsi);
+ if (ret < 0) {
+ dev_err(dev, "Failed to set display off: %d\n", ret);
+ return ret;
+ }
+ msleep(20);
+
+ ret = mipi_dsi_dcs_enter_sleep_mode(dsi);
+ if (ret < 0) {
+ dev_err(dev, "Failed to enter sleep mode: %d\n", ret);
+ return ret;
+ }
+ msleep(120);
+
+ return 0;
+}
+
+static int visionox_vtdr6130_prepare(struct drm_panel *panel)
+{
+ struct visionox_vtdr6130 *ctx = to_visionox_vtdr6130(panel);
+ struct device *dev = &ctx->dsi->dev;
+ int ret;
+
+ if (ctx->prepared)
+ return 0;
+
+ ret = regulator_bulk_enable(ARRAY_SIZE(ctx->supplies),
+ ctx->supplies);
+ if (ret < 0)
+ return ret;
+
+ visionox_vtdr6130_reset(ctx);
+
+ ret = visionox_vtdr6130_on(ctx);
+ if (ret < 0) {
+ dev_err(dev, "Failed to initialize panel: %d\n", ret);
+ gpiod_set_value_cansleep(ctx->reset_gpio, 1);
+ regulator_bulk_disable(ARRAY_SIZE(ctx->supplies), ctx->supplies);
+ return ret;
+ }
+
+ /* Explicitly disable DSC since compression is on by default on the panel */
+ mipi_dsi_compression_mode(ctx->dsi, false);
+
+ ctx->prepared = true;
+ return 0;
+}
+
+static int visionox_vtdr6130_unprepare(struct drm_panel *panel)
+{
+ struct visionox_vtdr6130 *ctx = to_visionox_vtdr6130(panel);
+ struct device *dev = &ctx->dsi->dev;
+ int ret;
+
+ if (!ctx->prepared)
+ return 0;
+
+ ret = visionox_vtdr6130_off(ctx);
+ if (ret < 0)
+ dev_err(dev, "Failed to un-initialize panel: %d\n", ret);
+
+ gpiod_set_value_cansleep(ctx->reset_gpio, 1);
+
+ regulator_bulk_disable(ARRAY_SIZE(ctx->supplies), ctx->supplies);
+
+ ctx->prepared = false;
+ return 0;
+}
+
+static const struct drm_display_mode visionox_vtdr6130_mode = {
+ .clock = (1080 + 20 + 2 + 20) * (2400 + 20 + 2 + 18) * 144 / 1000,
+ .hdisplay = 1080,
+ .hsync_start = 1080 + 20,
+ .hsync_end = 1080 + 20 + 2,
+ .htotal = 1080 + 20 + 2 + 20,
+ .vdisplay = 2400,
+ .vsync_start = 2400 + 20,
+ .vsync_end = 2400 + 20 + 2,
+ .vtotal = 2400 + 20 + 2 + 18,
+ .width_mm = 0,
+ .height_mm = 0,
Here height/width are set to 0.

Oops, I forgot to fix those

+};
+
+static int visionox_vtdr6130_get_modes(struct drm_panel *panel,
+ struct drm_connector *connector)
+{
+ struct drm_display_mode *mode;
+
+ mode = drm_mode_duplicate(connector->dev, &visionox_vtdr6130_mode);
+ if (!mode)
+ return -ENOMEM;
+
+ drm_mode_set_name(mode);
+
+ mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
+ connector->display_info.width_mm = mode->width_mm;
+ connector->display_info.height_mm = mode->height_mm;
Here they are used.
This looks wrong.

+ drm_mode_probed_add(connector, mode);
+
+ return 1;
+}
+
+static const struct drm_panel_funcs visionox_vtdr6130_panel_funcs = {
+ .prepare = visionox_vtdr6130_prepare,
+ .unprepare = visionox_vtdr6130_unprepare,
+ .get_modes = visionox_vtdr6130_get_modes,
+};
+
+static int visionox_vtdr6130_bl_update_status(struct backlight_device *bl)
+{
+ struct mipi_dsi_device *dsi = bl_get_data(bl);
+ u16 brightness = backlight_get_brightness(bl);
backlight_get_brightness() return an int, so maybe use an int here.
+ int ret;
+
+ ret = mipi_dsi_dcs_set_display_brightness(dsi, cpu_to_le16(brightness));
mipi_dsi_dcs_set_display_brightness() take u16 as brightness - so this
will do an implicit conversion.

I know, but the panel needs an inversed value, so perhaps I should directly
call mipi_dsi_dcs_write_buffer() here instead of needing a double
inversion.


Thanks for the review,
Neil


The mipi_dsi_dcs_set_display_brightness() do the necessary conversion,
so cpu_to_le16() is not needed.

+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
+
+static const struct backlight_ops visionox_vtdr6130_bl_ops = {
+ .update_status = visionox_vtdr6130_bl_update_status,
+};
+
+static struct backlight_device *
+visionox_vtdr6130_create_backlight(struct mipi_dsi_device *dsi)
+{
+ struct device *dev = &dsi->dev;
+ const struct backlight_properties props = {
+ .type = BACKLIGHT_RAW,
+ .brightness = 4095,
+ .max_brightness = 4095,
+ };
+
+ return devm_backlight_device_register(dev, dev_name(dev), dev, dsi,
+ &visionox_vtdr6130_bl_ops, &props);
+}
+
+static int visionox_vtdr6130_probe(struct mipi_dsi_device *dsi)
+{
+ struct device *dev = &dsi->dev;
+ struct visionox_vtdr6130 *ctx;
+ int ret;
+
+ ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
+ if (!ctx)
+ return -ENOMEM;
+
+ ctx->supplies[0].supply = "vddio";
+ ctx->supplies[1].supply = "vci";
+ ctx->supplies[2].supply = "vdd";
+
+ ret = devm_regulator_bulk_get(&dsi->dev, ARRAY_SIZE(ctx->supplies),
+ ctx->supplies);
+ if (ret < 0)
+ return ret;
+
+ ctx->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
+ if (IS_ERR(ctx->reset_gpio))
+ return dev_err_probe(dev, PTR_ERR(ctx->reset_gpio),
+ "Failed to get reset-gpios\n");
+
+ ctx->dsi = dsi;
+ mipi_dsi_set_drvdata(dsi, ctx);
+
+ dsi->lanes = 4;
+ dsi->format = MIPI_DSI_FMT_RGB888;
+ dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_NO_EOT_PACKET |
+ MIPI_DSI_CLOCK_NON_CONTINUOUS;
+
+ drm_panel_init(&ctx->panel, dev, &visionox_vtdr6130_panel_funcs,
+ DRM_MODE_CONNECTOR_DSI);
+
+ ctx->panel.backlight = visionox_vtdr6130_create_backlight(dsi);
+ if (IS_ERR(ctx->panel.backlight))
+ return dev_err_probe(dev, PTR_ERR(ctx->panel.backlight),
+ "Failed to create backlight\n");
+
+ drm_panel_add(&ctx->panel);
+
+ ret = mipi_dsi_attach(dsi);
+ if (ret < 0) {
+ dev_err(dev, "Failed to attach to DSI host: %d\n", ret);
+ drm_panel_remove(&ctx->panel);
+ return ret;
+ }
+
+ return 0;
+}
+
+static void visionox_vtdr6130_remove(struct mipi_dsi_device *dsi)
+{
+ struct visionox_vtdr6130 *ctx = mipi_dsi_get_drvdata(dsi);
+ int ret;
+
+ ret = mipi_dsi_detach(dsi);
+ if (ret < 0)
+ dev_err(&dsi->dev, "Failed to detach from DSI host: %d\n", ret);
+
+ drm_panel_remove(&ctx->panel);
+}
+
+static const struct of_device_id visionox_vtdr6130_of_match[] = {
+ { .compatible = "visionox,vtdr6130" },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, visionox_vtdr6130_of_match);
+
+static struct mipi_dsi_driver visionox_vtdr6130_driver = {
+ .probe = visionox_vtdr6130_probe,
+ .remove = visionox_vtdr6130_remove,
+ .driver = {
+ .name = "panel-visionox-vtdr6130",
+ .of_match_table = visionox_vtdr6130_of_match,
+ },
+};
+module_mipi_dsi_driver(visionox_vtdr6130_driver);
+
+MODULE_AUTHOR("Neil Armstron <neil.armstrong@xxxxxxxxxx>");
+MODULE_DESCRIPTION("Panel driver for the visionox VTDR6130 AMOLED DSI panel");
+MODULE_LICENSE("GPL");

--
2.34.1