drm/panel: Support Rocktech jh057n00900 DSI panel

v4 fixes up the DT binding example and uses a wider cc list since I failed to extend that when touching more files.

The panel is a 5.5" 720x1440 TFT LCD MIPI DSI panel with built in touchscreen and backlight as found in the Librem 5 devkit.

These patches are against linux next as of 2019-03-22. v3 got acked by Sam Ravnborg:

https://lists.freedesktop.org/archives/dri-devel/2019-March/209326.html

Changes from v4
* As per review comments from Fabio Estevam
* Add missing unit name in dt binding docs

Changes from v3
* Forward to next-20190322
* Add MAINTAINERS entry

Changes from v2
* As per review comments from Sam Ravnborg
* Lowercase sentinel
* Drop '_panel' postfix
* DRM_DEV_ logging instead of plain DRM_
* Add Reviewed-by:
* Add "panel-rocktech-" to the driver name following the pattern from other drm panel drivers.

Changes from v1
* As per review comments from Sam Ravnborg
* Make SPDX-License-Identifier match MODULE_LICENSE
* Sort include files alphabetically
* Drop drmP.h and use individual includes
* Drop superfuous 'x' in mode printout on error path
* Allpixelson_set: Add proper space around '*'
* Drop superfluous put_device(&ctx->backlight->dev);
* Add /* Sentinel */ in jh057n_of_match
* Drop jh057n->enabled
* Drop drm_display_info_set_bus_formats
* Kconfig: Depend on BACKLIGHT_CLASS_DEVICE which somehow got lost
* Move jh057n_enable close to jh057n_disable

Guido Günther (3):
dt-bindings: Add vendor prefix for ROCKTECH DISPLAYS LIMITED
dt-bindings: Add Rocktech jh057n00900 panel bindings drm/panel: Add Rocktech jh057n00900 panel driver

 .../display/panel/rocktech,jh057n00900.txt    |  18 +
 .../devicetree/bindings/vendor-prefixes.txt   |   1 +
 MAINTAINERS                                   |   6 +
 drivers/gpu/drm/panel/Kconfig                 |  13 +
 drivers/gpu/drm/panel/Makefile                |   1 +
 .../drm/panel/panel-rocktech-jh057n00900.c    | 386 ++++++++++++++++++
 6 files changed, 425 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/display/panel/rocktech,jh057n00900.txt
 create mode 100644 drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c

Quoted 2 lines · Guido Günther

v4 fixes up the DT binding example and uses a wider cc list since I failed to extend that when touching more files.

Applied, thanks.

checkpatch does complain about the dsi_generic_write_seq() macro definition, because it uses flow control statements, but there are already similar macros in other drivers, so I let this slide. We may want to eventually come up with something better and then replace these macros for the other drivers as well.

Quoted 3 lines · Thierry Reding

Quoted 2 lines · Guido Günther

v4 fixes up the DT binding example and uses a wider cc list since I failed to extend that when touching more files.

[]

Quoted 7 lines

Applied, thanks.

checkpatch does complain about the dsi_generic_write_seq() macro definition, because it uses flow control statements, but there are already similar macros in other drivers, so I let this slide. We may want to eventually come up with something better and then replace these macros for the other drivers as well.

Dunno about the other drivers, but the mechanism isn't particularly nice as it separates the init identifier from the data being written.

It might be better to use something like a struct for each command and a for loop for each block of commands.

Also the 0xBF value used in one of the init sequence writes does not have an identifier #define in the 'Manufacturer specific Commands send via DSI' block which is odd.

---
 drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c | 210 +++++++++++++--------
 1 file changed, 136 insertions(+), 74 deletions(-)

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c +103 -21

index 158a6d548068..7862863db5f7 100644
@@ -20,27 +20,6 @@
 
 #define DRV_NAME "panel-rocktech-jh057n00900"
 
-/* Manufacturer specific Commands send via DSI */
-#define ST7703_CMD_ALL_PIXEL_OFF 0x22
-#define ST7703_CMD_ALL_PIXEL_ON	 0x23
-#define ST7703_CMD_SETDISP	 0xB2
-#define ST7703_CMD_SETRGBIF	 0xB3
-#define ST7703_CMD_SETCYC	 0xB4
-#define ST7703_CMD_SETBGP	 0xB5
-#define ST7703_CMD_SETVCOM	 0xB6
-#define ST7703_CMD_SETOTP	 0xB7
-#define ST7703_CMD_SETPOWER_EXT	 0xB8
-#define ST7703_CMD_SETEXTC	 0xB9
-#define ST7703_CMD_SETMIPI	 0xBA
-#define ST7703_CMD_SETVDC	 0xBC
-#define ST7703_CMD_SETSCR	 0xC0
-#define ST7703_CMD_SETPOWER	 0xC1
-#define ST7703_CMD_SETPANEL	 0xCC
-#define ST7703_CMD_SETGAMMA	 0xE0
-#define ST7703_CMD_SETEQ	 0xE3
-#define ST7703_CMD_SETGIP1	 0xE9
-#define ST7703_CMD_SETGIP2	 0xEA
-
 struct jh057n {
 	struct device *dev;
 	struct drm_panel panel;

@@ -51,75 +30,153 @@ struct jh057n {
 	struct dentry *debugfs;
 };
 
+struct st7703_cmd {
+	const size_t	size;
+	const u8	data[];
+};
+
+#define st7703_cmd_data(cmd, ...)					\
+	.size = 1 + (sizeof((u8[]){__VA_ARGS__})/sizeof(u8)),		\
+	.data = {cmd, __VA_ARGS__}
+
+/* Manufacturer specific Commands send via DSI */
+static const struct st7703_cmd ST7703_CMD_ALL_PIXEL_OFF = {
+	st7703_cmd_data(0x22)
+};
+static const struct st7703_cmd ST7703_CMD_ALL_PIXEL_ON = {
+	st7703_cmd_data(0x23)
+};
+static const struct st7703_cmd ST7703_CMD_SETDISP = {
+	st7703_cmd_data(0xB2,
+			0xF0, 0x12, 0x30)
+};
+static const struct st7703_cmd ST7703_CMD_SETRGBIF = {
+	st7703_cmd_data(0xB3,
+			0x10, 0x10, 0x05, 0x05, 0x03, 0xFF, 0x00, 0x00,
+			0x00, 0x00)
+};
+static const struct st7703_cmd ST7703_CMD_SETCYC = {
+	st7703_cmd_data(0xB4,
+			0x80)
+};
+static const struct st7703_cmd ST7703_CMD_SETBGP = {
+	st7703_cmd_data(0xB5,
+			0x08, 0x08)
+};
+static const struct st7703_cmd ST7703_CMD_SETVCOM = {
+	st7703_cmd_data(0xB6,
+			0x3F, 0x3F)
+};
+static const struct st7703_cmd ST7703_CMD_SETOTP = {
+	st7703_cmd_data(0xB7)
+};
+static const struct st7703_cmd ST7703_CMD_SETPOWER_EXT = {
+	st7703_cmd_data(0xB8)
+};
+static const struct st7703_cmd ST7703_CMD_SETEXTC = {
+	st7703_cmd_data(0xB9,
+			0xF1, 0x12, 0x83)
+};
+static const struct st7703_cmd ST7703_CMD_SETMIPI = {
+	st7703_cmd_data(0xBA)
+};
+static const struct st7703_cmd ST7703_CMD_SETVDC = {
+	st7703_cmd_data(0xBC,
+			0x4E)
+};
+static const struct st7703_cmd ST7703_CMD_SETSCR = {
+	st7703_cmd_data(0xC0,
+			0x73, 0x73, 0x50, 0x50, 0x00, 0x00, 0x08, 0x70,
+			0x00)
+};
+static const struct st7703_cmd ST7703_CMD_SETPOWER = {
+	st7703_cmd_data(0xC1)
+};
+static const struct st7703_cmd ST7703_CMD_SETPANEL = {
+	st7703_cmd_data(0xCC,
+			0x0B)
+};
+static const struct st7703_cmd ST7703_CMD_SETGAMMA = {
+	st7703_cmd_data(0xE0,
+			0x00, 0x09, 0x0E, 0x29, 0x2D, 0x3C, 0x41, 0x37,
+			0x07, 0x0B, 0x0D, 0x10, 0x11, 0x0F, 0x10, 0x11,
+			0x18, 0x00, 0x09, 0x0E, 0x29, 0x2D, 0x3C, 0x41,
+			0x37, 0x07, 0x0B, 0x0D, 0x10, 0x11, 0x0F, 0x10,
+			0x11, 0x18)
+};
+static const struct st7703_cmd ST7703_CMD_SETEQ = {
+	st7703_cmd_data(0xE3,
+			0x07, 0x07, 0x0B, 0x0B, 0x03, 0x0B, 0x00, 0x00,
+			0x00, 0x00, 0xFF, 0x00, 0xC0, 0x10)
+};
+static const struct st7703_cmd ST7703_CMD_SETGIP1 = {
+	st7703_cmd_data(0xE9,
+			0x82, 0x10, 0x06, 0x05, 0x9E, 0x0A, 0xA5, 0x12,
+			0x31, 0x23, 0x37, 0x83, 0x04, 0xBC, 0x27, 0x38,
+			0x0C, 0x00, 0x03, 0x00, 0x00, 0x00, 0x0C, 0x00,
+			0x03, 0x00, 0x00, 0x00, 0x75, 0x75, 0x31, 0x88,
+			0x88, 0x88, 0x88, 0x88, 0x88, 0x13, 0x88, 0x64,
+			0x64, 0x20, 0x88, 0x88, 0x88, 0x88, 0x88, 0x88,
+			0x02, 0x88, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00)
+};
+
+static const struct st7703_cmd ST7703_CMD_SETGIP2 = {
+	st7703_cmd_data(0xEA,
+			0x02, 0x21, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+			0x00, 0x00, 0x00, 0x00, 0x02, 0x46, 0x02, 0x88,
+			0x88, 0x88, 0x88, 0x88, 0x88, 0x64, 0x88, 0x13,
+			0x57, 0x13, 0x88, 0x88, 0x88, 0x88, 0x88, 0x88,
+			0x75, 0x88, 0x23, 0x14, 0x00, 0x00, 0x02, 0x00,
+			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+			0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x30, 0x0A,
+			0xA5, 0x00, 0x00, 0x00, 0x00)
+};
+
 static inline struct jh057n *panel_to_jh057n(struct drm_panel *panel)
 {

Hi Joe.

Thanks for your patch.

Quoted 3 lines

---
 drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c | 210 +++++++++++++--------
 1 file changed, 136 insertions(+), 74 deletions(-)

Hmmm, add more lines than it deletes.

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c struct jh057n { · line 65

Quoted 7 lines

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c +0 -7

-#define dsi_generic_write_seq(dsi, seq...) do {				\
-		static const u8 d[] = { seq };				\
-		int ret;						\
-		ret = mipi_dsi_generic_write(dsi, d, ARRAY_SIZE(d));	\
-		if (ret < 0)						\
-			return ret;					\
-	} while (0)

The above macro was the one triggering this patch. And frankly it looks nice and simple.

The old code is IMO more readable.
- We have all the commands listed in the order they are used and in a rahter compatch format.

- It is obvious when we need delays.

- We have traditional #defines for the constants we know

This is all to some extent bikeshedding,

but I suggest
to keep the current code.
It is simple and it is tested.

Thanks for trying to come up with a better solution.

Quoted 3 lines · Thierry Reding

Quoted 2 lines · Guido Günther

v4 fixes up the DT binding example and uses a wider cc list since I failed to extend that when touching more files.

[]

Quoted 7 lines

Applied, thanks.

checkpatch does complain about the dsi_generic_write_seq() macro definition, because it uses flow control statements, but there are already similar macros in other drivers, so I let this slide. We may want to eventually come up with something better and then replace these macros for the other drivers as well.

Dunno about the other drivers, but the mechanism isn't particularly nice as it separates the init identifier from the data being written.

It might be better to use something like a struct for each command and a for loop for each block of commands.

Also the 0xBF value used in one of the init sequence writes does not have an identifier #define in the 'Manufacturer specific Commands send via DSI' block which is odd.

These were missing '\n' terminations, add them.

Signed-off-by Joe Perches <[email protected]>

---
 drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c +8 -8

index 158a6d548068..d88ea8da2ec2 100644
@@ -123,7 +123,7 @@ static int jh057n_init_sequence(struct jh057n *ctx)
 
 	ret = mipi_dsi_dcs_exit_sleep_mode(dsi);
 	if (ret < 0) {
-		DRM_DEV_ERROR(dev, "Failed to exit sleep mode");
+		DRM_DEV_ERROR(dev, "Failed to exit sleep mode\n");
 		return ret;
 	}
 	/* Panel is operational 120 msec after reset */

@@ -132,7 +132,7 @@ static int jh057n_init_sequence(struct jh057n *ctx)
 	if (ret)
 		return ret;
 
-	DRM_DEV_DEBUG_DRIVER(dev, "Panel init sequence done");
+	DRM_DEV_DEBUG_DRIVER(dev, "Panel init sequence done\n");
 	return 0;
 }
 

@@ -172,7 +172,7 @@ static int jh057n_prepare(struct drm_panel *panel)
 	if (ctx->prepared)
 		return 0;
 
-	DRM_DEV_DEBUG_DRIVER(ctx->dev, "Resetting the panel.");
+	DRM_DEV_DEBUG_DRIVER(ctx->dev, "Resetting the panel\n");
 	gpiod_set_value_cansleep(ctx->reset_gpio, 1);
 	usleep_range(20, 40);
 	gpiod_set_value_cansleep(ctx->reset_gpio, 0);

@@ -180,7 +180,8 @@ static int jh057n_prepare(struct drm_panel *panel)
 
 	ret = jh057n_init_sequence(ctx);
 	if (ret < 0) {
-		DRM_DEV_ERROR(ctx->dev, "Panel init sequence failed: %d", ret);
+		DRM_DEV_ERROR(ctx->dev, "Panel init sequence failed: %d\n",
+			      ret);
 		return ret;
 	}
 

@@ -212,7 +213,7 @@ static int jh057n_get_modes(struct drm_panel *panel)
 
 	mode = drm_mode_duplicate(panel->drm, &default_mode);
 	if (!mode) {
-		DRM_DEV_ERROR(ctx->dev, "Failed to add mode %ux%u@%u",
+		DRM_DEV_ERROR(ctx->dev, "Failed to add mode %ux%u@%u\n",
 			      default_mode.hdisplay, default_mode.vdisplay,
 			      default_mode.vrefresh);
 		return -ENOMEM;

@@ -241,7 +242,7 @@ static int allpixelson_set(void *data, u64 val)
 	struct jh057n *ctx = data;
 	struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
 
-	DRM_DEV_DEBUG_DRIVER(ctx->dev, "Setting all pixels on");
+	DRM_DEV_DEBUG_DRIVER(ctx->dev, "Setting all pixels on\n");
 	dsi_generic_write_seq(dsi, ST7703_CMD_ALL_PIXEL_ON);
 	msleep(val * 1000);
 	/* Reset the panel to get video back */

@@ -290,7 +291,7 @@ static int jh057n_probe(struct mipi_dsi_device *dsi)
 
 	ctx->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
 	if (IS_ERR(ctx->reset_gpio)) {
-		DRM_DEV_ERROR(dev, "cannot get reset gpio");
+		DRM_DEV_ERROR(dev, "cannot get reset gpio\n");
 		return PTR_ERR(ctx->reset_gpio);
 	}
 

@@ -315,12 +316,12 @@ static int jh057n_probe(struct mipi_dsi_device *dsi)
 
 	ret = mipi_dsi_attach(dsi);
 	if (ret < 0) {
-		DRM_DEV_ERROR(dev, "mipi_dsi_attach failed. Is host ready?");

Hi Joe,

P.S.: The cc: list is huge, is there a reason for going way past what get_maintainers puts out for this patch?

Hi Joe,

Quoted 85 lines · Joe Perches

These were missing '\n' terminations, add them.

Signed-off-by Joe Perches <[email protected]>

---
 drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c +9 -8

index 158a6d548068..d88ea8da2ec2 100644
@@ -123,7 +123,7 @@ static int jh057n_init_sequence(struct jh057n *ctx)
 
 	ret = mipi_dsi_dcs_exit_sleep_mode(dsi);
 	if (ret < 0) {
-		DRM_DEV_ERROR(dev, "Failed to exit sleep mode");
+		DRM_DEV_ERROR(dev, "Failed to exit sleep mode\n");
 		return ret;
 	}
 	/* Panel is operational 120 msec after reset */

@@ -132,7 +132,7 @@ static int jh057n_init_sequence(struct jh057n *ctx)
 	if (ret)
 		return ret;
 
-	DRM_DEV_DEBUG_DRIVER(dev, "Panel init sequence done");
+	DRM_DEV_DEBUG_DRIVER(dev, "Panel init sequence done\n");
 	return 0;
 }
 

@@ -172,7 +172,7 @@ static int jh057n_prepare(struct drm_panel *panel)
 	if (ctx->prepared)
 		return 0;
 
-	DRM_DEV_DEBUG_DRIVER(ctx->dev, "Resetting the panel.");
+	DRM_DEV_DEBUG_DRIVER(ctx->dev, "Resetting the panel\n");
 	gpiod_set_value_cansleep(ctx->reset_gpio, 1);
 	usleep_range(20, 40);
 	gpiod_set_value_cansleep(ctx->reset_gpio, 0);

@@ -180,7 +180,8 @@ static int jh057n_prepare(struct drm_panel *panel)
 
 	ret = jh057n_init_sequence(ctx);
 	if (ret < 0) {
-		DRM_DEV_ERROR(ctx->dev, "Panel init sequence failed: %d", ret);
+		DRM_DEV_ERROR(ctx->dev, "Panel init sequence failed: %d\n",
+			      ret);
 		return ret;
 	}
 

@@ -212,7 +213,7 @@ static int jh057n_get_modes(struct drm_panel *panel)
 
 	mode = drm_mode_duplicate(panel->drm, &default_mode);
 	if (!mode) {
-		DRM_DEV_ERROR(ctx->dev, "Failed to add mode %ux%u@%u",
+		DRM_DEV_ERROR(ctx->dev, "Failed to add mode %ux%u@%u\n",
 			      default_mode.hdisplay, default_mode.vdisplay,
 			      default_mode.vrefresh);
 		return -ENOMEM;

@@ -241,7 +242,7 @@ static int allpixelson_set(void *data, u64 val)
 	struct jh057n *ctx = data;
 	struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
 
-	DRM_DEV_DEBUG_DRIVER(ctx->dev, "Setting all pixels on");
+	DRM_DEV_DEBUG_DRIVER(ctx->dev, "Setting all pixels on\n");
 	dsi_generic_write_seq(dsi, ST7703_CMD_ALL_PIXEL_ON);
 	msleep(val * 1000);
 	/* Reset the panel to get video back */

@@ -290,7 +291,7 @@ static int jh057n_probe(struct mipi_dsi_device *dsi)
 
 	ctx->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
 	if (IS_ERR(ctx->reset_gpio)) {
-		DRM_DEV_ERROR(dev, "cannot get reset gpio");
+		DRM_DEV_ERROR(dev, "cannot get reset gpio\n");
 		return PTR_ERR(ctx->reset_gpio);
 	}
 

@@ -315,12 +316,12 @@ static int jh057n_probe(struct mipi_dsi_device *dsi)
 
 	ret = mipi_dsi_attach(dsi);
 	if (ret < 0) {
-		DRM_DEV_ERROR(dev, "mipi_dsi_attach failed. Is host ready?");
+		DRM_DEV_ERROR(dev, "mipi_dsi_attach failed. Is host ready?\n");
 		drm_panel_remove(&ctx->panel);
 		return ret;
 	}
 

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c static int jh057n_probe(struct mipi_dsi_device *dsi) · line 327

Quoted 6 lines

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c +1 -1

-	DRM_DEV_INFO(dev, "%ux%u@%u %ubpp dsi %udl - ready",
+	DRM_DEV_INFO(dev, "%ux%u@%u %ubpp dsi %udl - ready\n",
 		     default_mode.hdisplay, default_mode.vdisplay,
 		     default_mode.vrefresh,
 		     mipi_dsi_pixel_format_to_bpp(dsi->format), dsi->lanes);

Reviewed-by Guido Günther <[email protected]>

These were missing '\n' terminations, add them.

Signed-off-by Joe Perches <[email protected]>

---
 drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c +0 -0

index 158a6d548068..d88ea8da2ec2 100644

Hi Joe.

Quoted 13 lines · Joe Perches

These were missing '\n' terminations, add them.

Signed-off-by Joe Perches <[email protected]>

---
 drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c +0 -0

index 158a6d548068..d88ea8da2ec2 100644
@@ -123,7 +123,7 @@ static int jh057n_init_sequence(struct jh057n *ctx)
 

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c static int jh057n_init_sequence(struct jh057n *ctx) · line 126

Quoted 4 lines

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c +1 -1

 	ret = mipi_dsi_dcs_exit_sleep_mode(dsi);
 	if (ret < 0) {
-		DRM_DEV_ERROR(dev, "Failed to exit sleep mode");
+		DRM_DEV_ERROR(dev, "Failed to exit sleep mode\n");

I was under the impression that newlines was optional these days. Should we always use them with logging?

I did not find any obvious clues in linux/printk.h

Quoted 8 lines

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c static int jh057n_init_sequence(struct jh057n *ctx) · line 126

Quoted 5 lines

drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c +1 -1

 	ret = mipi_dsi_dcs_exit_sleep_mode(dsi);
 	if (ret < 0) {
-		DRM_DEV_ERROR(dev, "Failed to exit sleep mode");
+		DRM_DEV_ERROR(dev, "Failed to exit sleep mode\n");

I was under the impression that newlines was optional these days. Should we always use them with logging?

Yes.

The general problem is KERN_CONT/pr_cont uses where interleaving is still possible from multiple threads.

Quoted 1 line

I did not find any obvious clues in linux/printk.h

I'll see about adding something one day to the Documentation. Likely in coding-style.rst.

These were missing '\n' terminations, add them.

Signed-off-by Joe Perches <[email protected]>

---
 drivers/gpu/drm/panel/panel-rocktech-jh057n00900.c | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)