Re: [PATCH v2 2/2] drm/panel: add panel driver for Leadtek LTK050H3146W

8 Apr 2020

Goodmorning Heiko.
Thanks for the v2 of this driver.
checkpatch, using --strict, complains about indent.
I have also noted some of them below.
A few comments in the following.
Sam
On Wed, Apr 08, 2020 at 01:23:51AM +0200, Heiko Stuebner wrote:
...
From: Heiko Stuebner heiko.stuebner@theobroma-systems.com
The LTK050H3146W is 5.0" 720x1280 DSI display. There are two variants
with essentially the same name, LTK050H3146W and LTK050H3146W-A2.
They differ in their init sequence and mode details.
changes in v2:

add display variants

Signed-off-by: Heiko Stuebner heiko.stuebner@theobroma-systems.com
drivers/gpu/drm/panel/Kconfig                 |  11 +
 drivers/gpu/drm/panel/Makefile                |   1 +
 .../drm/panel/panel-leadtek-ltk050h3146w.c    | 697 ++++++++++++++++++
 3 files changed, 709 insertions(+)
 create mode 100644 drivers/gpu/drm/panel/panel-leadtek-ltk050h3146w.c

diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
index a1723c1b5fbf..d56258b9fcaf 100644
--- a/drivers/gpu/drm/panel/Kconfig
+++ b/drivers/gpu/drm/panel/Kconfig
@@ -137,6 +137,17 @@ config DRM_PANEL_KINGDISPLAY_KD097D04
     24 bit RGB per pixel. It provides a MIPI DSI interface to
     the host and has a built-in LED backlight.
+config DRM_PANEL_LEADTEK_LTK050H3146W

tristate "Leadtek LTK050H3146W 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 Leadtek LTK050H3146W


 TFT-LCD modules. The panel has a 720x1280 resolution and uses


 24 bit RGB per pixel. It provides a MIPI DSI interface to


 the host and has a built-in LED backlight.




config DRM_PANEL_LEADTEK_LTK500HD1829
   tristate "Leadtek LTK500HD1829 panel"
   depends on OF
diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
index 96a883cd6630..2335a1e32ae0 100644
--- a/drivers/gpu/drm/panel/Makefile
+++ b/drivers/gpu/drm/panel/Makefile
@@ -12,6 +12,7 @@ obj-$(CONFIG_DRM_PANEL_ILITEK_ILI9881C) += panel-ilitek-ili9881c.o
 obj-$(CONFIG_DRM_PANEL_INNOLUX_P079ZCA) += panel-innolux-p079zca.o
 obj-$(CONFIG_DRM_PANEL_JDI_LT070ME05000) += panel-jdi-lt070me05000.o
 obj-$(CONFIG_DRM_PANEL_KINGDISPLAY_KD097D04) += panel-kingdisplay-kd097d04.o
+obj-$(CONFIG_DRM_PANEL_LEADTEK_LTK050H3146W) += panel-leadtek-ltk050h3146w.o
 obj-$(CONFIG_DRM_PANEL_LEADTEK_LTK500HD1829) += panel-leadtek-ltk500hd1829.o
 obj-$(CONFIG_DRM_PANEL_LG_LB035Q02) += panel-lg-lb035q02.o
 obj-$(CONFIG_DRM_PANEL_LG_LG4573) += panel-lg-lg4573.o
diff --git a/drivers/gpu/drm/panel/panel-leadtek-ltk050h3146w.c b/drivers/gpu/drm/panel/panel-leadtek-ltk050h3146w.c
new file mode 100644
index 000000000000..43fbedf01b85
--- /dev/null
+++ b/drivers/gpu/drm/panel/panel-leadtek-ltk050h3146w.c
@@ -0,0 +1,697 @@
+// SPDX-License-Identifier: GPL-2.0
+/*


Copyright (C) 2020 Theobroma Systems Design und Consulting GmbH


*/


+#include <drm/drm_mipi_dsi.h>
+#include <drm/drm_modes.h>
+#include <drm/drm_panel.h>
+#include <drm/drm_print.h>



+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/media-bus-format.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/regulator/consumer.h>



+#include <video/display_timing.h>
+#include <video/mipi_display.h>



Sorted within each block - good.
The typical pattern is:
#include <linux/*>
#include <video/*>
#include <drm/*>
Following the above pattern is not a hard rule.
...
+struct ltk050h3146w_cmd {

char cmd;
char data;

+};



+struct ltk050h3146w;
+struct ltk050h3146w_desc {

const struct drm_display_mode *mode;
int (*init)(struct ltk050h3146w *ctx);

+};



+struct ltk050h3146w {

struct device *dev;
struct drm_panel panel;
struct gpio_desc *reset_gpio;
struct regulator *vci;
struct regulator *iovcc;
const struct ltk050h3146w_desc *panel_desc;
bool prepared;

+};



+static const struct ltk050h3146w_cmd page1_cmds[] = {

{ 0x22, 0x0A }, /* BGR SS GS */
{ 0x31, 0x00 }, /* column inversion */
{ 0x53, 0xA2 }, /* VCOM1 */
{ 0x55, 0xA2 }, /* VCOM2 */
{ 0x50, 0x81 }, /* VREG1OUT=5V */
{ 0x51, 0x85 }, /* VREG2OUT=-5V */
{ 0x62, 0x0D }, /* EQT Time setting */

+/*


For whatever reason the vendor init selected page 1 here _again_



Is this supposed to be page 2?


*/

...
...
+static inline
+struct ltk050h3146w *panel_to_ltk050h3146w(struct drm_panel *panel)
+{

return container_of(panel, struct ltk050h3146w, panel);

+}



+#define dsi_dcs_write_seq(dsi, cmd, seq...) do {			\

static const u8 d[] = { seq };				\


int ret;						\


ret = mipi_dsi_dcs_write(dsi, cmd, d, ARRAY_SIZE(d));	\


if (ret < 0)						\


	return ret;					\


} while (0)


+static int ltk050h3146w_init_sequence(struct ltk050h3146w *ctx)
+{

struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
struct device *dev = ctx->dev;
int ret;

/*
* Init sequence was supplied by the panel vendor without much


* documentation.


*/


dsi_dcs_write_seq(dsi, 0xdf, 0x93, 0x65, 0xf8);
dsi_dcs_write_seq(dsi, 0xb0, 0x01, 0x03, 0x02, 0x00, 0x64, 0x06,
	      0x01);



Fix indent. 0x01 must be alinged right after the opening '('
Same comments goes for many other cases below.
...

dsi_dcs_write_seq(dsi, 0xb2, 0x00, 0xb5);
dsi_dcs_write_seq(dsi, 0xb3, 0x00, 0xb5);
dsi_dcs_write_seq(dsi, 0xb7, 0x00, 0xbf, 0x00, 0x00, 0xbf, 0x00);

dsi_dcs_write_seq(dsi, 0xb9, 0x00, 0xc4, 0x23, 0x07);
dsi_dcs_write_seq(dsi, 0xbb, 0x02, 0x01, 0x24, 0x00, 0x28, 0x0f,
	      0x28, 0x04, 0xcc, 0xcc, 0xcc);


dsi_dcs_write_seq(dsi, 0xbc, 0x0f, 0x04);
dsi_dcs_write_seq(dsi, 0xbe, 0x1e, 0xf2);
dsi_dcs_write_seq(dsi, 0xc0, 0x26, 0x03);
dsi_dcs_write_seq(dsi, 0xc1, 0x00, 0x12);
dsi_dcs_write_seq(dsi, 0xc3, 0x04, 0x02, 0x02, 0x76, 0x01, 0x80,
	      0x80);


dsi_dcs_write_seq(dsi, 0xc4, 0x24, 0x80, 0xb4, 0x81, 0x12, 0x0f,
	      0x16, 0x00, 0x00);


dsi_dcs_write_seq(dsi, 0xc8, 0x7f, 0x72, 0x67, 0x5d, 0x5d, 0x50,
	      0x56, 0x41, 0x59, 0x57, 0x55, 0x70, 0x5b, 0x5f,


	      0x4f, 0x47, 0x38, 0x23, 0x08, 0x7f, 0x72, 0x67,


	      0x5d, 0x5d, 0x50, 0x56, 0x41, 0x59, 0x57, 0x55,


	      0x70, 0x5b, 0x5f, 0x4f, 0x47, 0x38, 0x23, 0x08);


dsi_dcs_write_seq(dsi, 0xd0, 0x1e, 0x1f, 0x57, 0x58, 0x48, 0x4a,
	      0x44, 0x46, 0x40, 0x1f, 0x42, 0x1f, 0x1f, 0x1f,


	      0x1f, 0x1f, 0x1f, 0x1f, 0x1f, 0x1f, 0x1f, 0x1f);


dsi_dcs_write_seq(dsi, 0xd1, 0x1e, 0x1f, 0x57, 0x58, 0x49, 0x4b,
	      0x45, 0x47, 0x41, 0x1f, 0x43, 0x1f, 0x1f, 0x1f,


	      0x1f, 0x1f, 0x1f, 0x1f, 0x1f, 0x1f, 0x1f, 0x1f);


dsi_dcs_write_seq(dsi, 0xd2, 0x1f, 0x1e, 0x17, 0x18, 0x07, 0x05,
	      0x0b, 0x09, 0x03, 0x1f, 0x01, 0x1f, 0x1f, 0x1f,


	      0x1f, 0x1f, 0x1f, 0x1f, 0x1f, 0x1f, 0x1f, 0x1f);


dsi_dcs_write_seq(dsi, 0xd3, 0x1f, 0x1e, 0x17, 0x18, 0x06, 0x04,
	      0x0a, 0x08, 0x02, 0x1f, 0x00, 0x1f, 0x1f, 0x1f,


	      0x1f, 0x1f, 0x1f, 0x1f, 0x1f, 0x1f, 0x1f, 0x1f);


dsi_dcs_write_seq(dsi, 0xd4, 0x00, 0x00, 0x00, 0x0c, 0x06, 0x20,
	      0x01, 0x02, 0x00, 0x60, 0x15, 0xb0, 0x30, 0x03,


	      0x04, 0x00, 0x60, 0x72, 0x0a, 0x00, 0x60, 0x08);


dsi_dcs_write_seq(dsi, 0xd5, 0x00, 0x06, 0x06, 0x00, 0x30, 0x00,
	      0x00, 0x00, 0x00, 0x00, 0xbc, 0x50, 0x00, 0x05,


	      0x21, 0x00, 0x60);


dsi_dcs_write_seq(dsi, 0xdd, 0x2c, 0xa3, 0x00);
dsi_dcs_write_seq(dsi, 0xde, 0x02);
dsi_dcs_write_seq(dsi, 0xb2, 0x32, 0x1c);
dsi_dcs_write_seq(dsi, 0xb7, 0x3b, 0x70, 0x00, 0x04);
dsi_dcs_write_seq(dsi, 0xc1, 0x11);
dsi_dcs_write_seq(dsi, 0xbb, 0x21, 0x22, 0x23, 0x24, 0x36, 0x37);
dsi_dcs_write_seq(dsi, 0xc2, 0x20, 0x38, 0x1e, 0x84);
dsi_dcs_write_seq(dsi, 0xde, 0x00);

ret = mipi_dsi_dcs_set_tear_on(dsi, 1);
if (ret < 0) {
DRM_DEV_ERROR(ctx->dev, "failed to set tear on: %d\n",


	      ret);


return ret;


}

msleep(60);

DRM_DEV_DEBUG_DRIVER(dev, "Panel init sequence done\n");

Looks like a debug artifact that can be dropped in the upstream driver.
...

return 0;

+}



+static const struct drm_display_mode ltk050h3146w_mode = {

.hdisplay	= 720,
.hsync_start	= 720 + 42,
.hsync_end	= 720 + 42 + 8,
.htotal		= 720 + 42 + 8 + 42,
.vdisplay	= 1280,
.vsync_start	= 1280 + 12,
.vsync_end	= 1280 + 12 + 4,
.vtotal		= 1280 + 12 + 4 + 18,
.vrefresh	= 60,

vrefresh is soon gone. Drop it here.
...

.clock		= 64018,
.width_mm	= 62,
.height_mm	= 110,

+};



+static const struct ltk050h3146w_desc ltk050h3146w_data = {

.mode = &ltk050h3146w_mode,
.init = ltk050h3146w_init_sequence,

+};



+static int ltk050h3146w_a2_select_page(struct ltk050h3146w *ctx, int page)
+{

struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
u8 d[3] = { 0x98, 0x81, page };

return mipi_dsi_dcs_write(dsi, 0xff, d, ARRAY_SIZE(d));

+}



+static int ltk050h3146w_a2_write_page(struct ltk050h3146w *ctx, int page,

		   const struct ltk050h3146w_cmd *cmds, int num)



Fix indent.
...
+{

struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
int i, ret;

ret = ltk050h3146w_a2_select_page(ctx, page);
if (ret < 0) {
DRM_DEV_ERROR(ctx->dev, "failed to select page %d: %d\n",


	      page, ret);


return ret;


}

for (i = 0; i < num; i++) {
ret = mipi_dsi_generic_write(dsi, &cmds[i],


			     sizeof(struct ltk050h3146w_cmd));


if (ret < 0) {


	DRM_DEV_ERROR(ctx->dev,


		      "failed to write page %d init cmds: %d\n",


		       page, ret);


	return ret;


}


}

return 0;

+}



+static int ltk050h3146w_a2_init_sequence(struct ltk050h3146w *ctx)
+{

struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
struct device *dev = ctx->dev;
int ret;

/*
* Init sequence was supplied by the panel vendor without much


* documentation.


*/


ret = ltk050h3146w_a2_write_page(ctx, 3, page3_cmds,
			      ARRAY_SIZE(page3_cmds));



Fix indent.
...

if (ret < 0)
return ret;



ret = ltk050h3146w_a2_write_page(ctx, 4, page4_cmds,
			      ARRAY_SIZE(page4_cmds));


if (ret < 0)
return ret;



ret = ltk050h3146w_a2_write_page(ctx, 1, page1_cmds,
			      ARRAY_SIZE(page1_cmds));


if (ret < 0)
return ret;



ret = ltk050h3146w_a2_select_page(ctx, 0);
if (ret < 0) {
DRM_DEV_ERROR(ctx->dev, "failed to select page 0: %d\n", ret);


return ret;


}

/* vendor code called this without param, where there should be one */
ret = mipi_dsi_dcs_set_tear_on(dsi, 0);
if (ret < 0) {
DRM_DEV_ERROR(ctx->dev, "failed to set tear on: %d\n",


	      ret);


return ret;


}

msleep(60);

DRM_DEV_DEBUG_DRIVER(dev, "Panel init sequence done\n");

Debug artifact?
...

return 0;

+}



+static const struct drm_display_mode ltk050h3146w_a2_mode = {

.hdisplay	= 720,
.hsync_start	= 720 + 42,
.hsync_end	= 720 + 42 + 10,
.htotal		= 720 + 42 + 10 + 60,
.vdisplay	= 1280,
.vsync_start	= 1280 + 18,
.vsync_end	= 1280 + 18 + 4,
.vtotal		= 1280 + 18 + 4 + 12,
.vrefresh	= 60,
.clock		= 65595,
.width_mm	= 62,
.height_mm	= 110,

+};



+static const struct ltk050h3146w_desc ltk050h3146w_a2_data = {

.mode = &ltk050h3146w_a2_mode,
.init = ltk050h3146w_a2_init_sequence,

+};



+static int ltk050h3146w_unprepare(struct drm_panel *panel)
+{

struct ltk050h3146w *ctx = panel_to_ltk050h3146w(panel);
struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
int ret;

if (!ctx->prepared)
return 0;



ret = mipi_dsi_dcs_set_display_off(dsi);
if (ret < 0) {
DRM_DEV_ERROR(ctx->dev, "failed to set display off: %d\n",


	      ret);


return ret;


}

mipi_dsi_dcs_enter_sleep_mode(dsi);
if (ret < 0) {
DRM_DEV_ERROR(ctx->dev, "failed to enter sleep mode: %d\n",


	      ret);


return ret;


}

regulator_disable(ctx->iovcc);
regulator_disable(ctx->vci);

ctx->prepared = false;

return 0;

+}



+static int ltk050h3146w_prepare(struct drm_panel *panel)
+{

struct ltk050h3146w *ctx = panel_to_ltk050h3146w(panel);
struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
int ret;

if (ctx->prepared)
return 0;



DRM_DEV_DEBUG_DRIVER(ctx->dev, "Resetting the panel\n");
ret = regulator_enable(ctx->vci);
if (ret < 0) {
DRM_DEV_ERROR(ctx->dev,


	      "Failed to enable vci supply: %d\n", ret);


return ret;


}
ret = regulator_enable(ctx->iovcc);
if (ret < 0) {
DRM_DEV_ERROR(ctx->dev,


	      "Failed to enable iovcc supply: %d\n", ret);


goto disable_vci;


}

gpiod_set_value_cansleep(ctx->reset_gpio, 1);
usleep_range(5000, 6000);
gpiod_set_value_cansleep(ctx->reset_gpio, 0);
msleep(20);


+//	ret = ltk050h3146w_a2_init_sequence(ctx);
Please fix - this looks like something replaced by the following line.
...

ret = ctx->panel_desc->init(ctx);
if (ret < 0) {
DRM_DEV_ERROR(ctx->dev, "Panel init sequence failed: %d\n",


	      ret);


goto disable_iovcc;


}

ret = mipi_dsi_dcs_exit_sleep_mode(dsi);
if (ret < 0) {
DRM_DEV_ERROR(ctx->dev, "Failed to exit sleep mode: %d\n", ret);


goto disable_iovcc;


}

/* T9: 120ms */
msleep(120);

ret = mipi_dsi_dcs_set_display_on(dsi);
if (ret < 0) {
DRM_DEV_ERROR(ctx->dev, "Failed to set display on: %d\n", ret);


goto disable_iovcc;


}

msleep(50);

ctx->prepared = true;

return 0;


+disable_iovcc:

regulator_disable(ctx->iovcc);

+disable_vci:

regulator_disable(ctx->vci);
return ret;

+}



+static int ltk050h3146w_get_modes(struct drm_panel *panel,

		struct drm_connector *connector)



+{

struct ltk050h3146w *ctx = panel_to_ltk050h3146w(panel);
struct drm_display_mode *mode;

mode = drm_mode_duplicate(connector->dev, ctx->panel_desc->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;
drm_mode_probed_add(connector, mode);

return 1;

+}



+static const struct drm_panel_funcs ltk050h3146w_funcs = {

.unprepare	= ltk050h3146w_unprepare,
.prepare	= ltk050h3146w_prepare,
.get_modes	= ltk050h3146w_get_modes,

+};



+static int ltk050h3146w_probe(struct mipi_dsi_device *dsi)
+{

struct device *dev = &dsi->dev;
struct ltk050h3146w *ctx;
int ret;

ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
if (!ctx)
return -ENOMEM;



ctx->panel_desc = of_device_get_match_data(dev);
if (!ctx->panel_desc)
return -EINVAL;



ctx->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
if (IS_ERR(ctx->reset_gpio)) {
DRM_DEV_ERROR(dev, "cannot get reset gpio\n");


return PTR_ERR(ctx->reset_gpio);


}

ctx->vci = devm_regulator_get(dev, "vci");
if (IS_ERR(ctx->vci)) {
ret = PTR_ERR(ctx->vci);


if (ret != -EPROBE_DEFER)


	DRM_DEV_ERROR(dev,


		      "Failed to request vci regulator: %d\n",


		      ret);


return ret;


}

ctx->iovcc = devm_regulator_get(dev, "iovcc");
if (IS_ERR(ctx->iovcc)) {
ret = PTR_ERR(ctx->iovcc);


if (ret != -EPROBE_DEFER)


	DRM_DEV_ERROR(dev,


		      "Failed to request iovcc regulator: %d\n",


		      ret);


return ret;


}

mipi_dsi_set_drvdata(dsi, ctx);

ctx->dev = dev;

dsi->lanes = 4;
dsi->format = MIPI_DSI_FMT_RGB888;
dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_BURST |
	  MIPI_DSI_MODE_LPM | MIPI_DSI_MODE_EOT_PACKET;



drm_panel_init(&ctx->panel, &dsi->dev, &ltk050h3146w_funcs,
       DRM_MODE_CONNECTOR_DSI);



ret = drm_panel_of_backlight(&ctx->panel);
if (ret)
return ret;



drm_panel_add(&ctx->panel);

ret = mipi_dsi_attach(dsi);
if (ret < 0) {
DRM_DEV_ERROR(dev, "mipi_dsi_attach failed: %d\n", ret);


drm_panel_remove(&ctx->panel);


return ret;


}

return 0;

+}



+static void ltk050h3146w_shutdown(struct mipi_dsi_device *dsi)
+{

struct ltk050h3146w *ctx = mipi_dsi_get_drvdata(dsi);
int ret;

ret = drm_panel_unprepare(&ctx->panel);
if (ret < 0)
DRM_DEV_ERROR(&dsi->dev, "Failed to unprepare panel: %d\n",


	      ret);



ret = drm_panel_disable(&ctx->panel);
if (ret < 0)
DRM_DEV_ERROR(&dsi->dev, "Failed to disable panel: %d\n",


	      ret);



+}



+static int ltk050h3146w_remove(struct mipi_dsi_device *dsi)
+{

struct ltk050h3146w *ctx = mipi_dsi_get_drvdata(dsi);
int ret;

ltk050h3146w_shutdown(dsi);

ret = mipi_dsi_detach(dsi);
if (ret < 0)
DRM_DEV_ERROR(&dsi->dev, "Failed to detach from DSI host: %d\n",


	      ret);



drm_panel_remove(&ctx->panel);

return 0;

+}



+static const struct of_device_id ltk050h3146w_of_match[] = {

{
.compatible = "leadtek,ltk050h3146w",


.data = &ltk050h3146w_data,


},
{
.compatible = "leadtek,ltk050h3146w-a2",


.data = &ltk050h3146w_a2_data,


},
{ /* sentinel */ }

+};
+MODULE_DEVICE_TABLE(of, ltk050h3146w_of_match);



+static struct mipi_dsi_driver ltk050h3146w_driver = {

.driver = {
.name = "panel-leadtek-ltk050h3146w",


.of_match_table = ltk050h3146w_of_match,


},
.probe	= ltk050h3146w_probe,
.remove = ltk050h3146w_remove,
.shutdown = ltk050h3146w_shutdown,

+};
+module_mipi_dsi_driver(ltk050h3146w_driver);



+MODULE_AUTHOR("Heiko Stuebner heiko.stuebner@theobroma-systems.com");
+MODULE_DESCRIPTION("DRM driver for Leadtek LTK050H3146W MIPI DSI panel");
+MODULE_LICENSE("GPL v2");
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Re: [PATCH v2 2/2] drm/panel: add panel driver for Leadtek LTK050H3146W

Signed-off-by: Heiko Stuebner heiko.stuebner@theobroma-systems.com

+MODULE_LICENSE("GPL v2");