[PATCH v3 0/5] drm/sitronix/st7571-i2c: Add support for the ST7567 Controller

[PATCH v3 0/5] drm/sitronix/st7571-i2c: Add support for the ST7567 Controller

[Javier Martinez Canillas]

This patch-series adds support for the Sitronix ST7567 Controller, which is a
monochrome Dot Matrix LCD Controller that has SPI, I2C and parallel interfaces.

The st7571-i2c driver only has support for I2C so displays using other transport
interfaces are currently not supported.

The DRM_FORMAT_R1 pixel format and data commands are the same than what is used
by the ST7571 controller, so only is needed a different callback that implements
the expected initialization sequence for the ST7567 chip and a different callback
to parse the sub-set of DT properties needed by the ST7567.

Patches #1 and #2 are some trivial cleanups for the driver.

Patch #3 is a preparatory change that adds the level of indirection for the DT
parsing logic.

Patch #4 adds a Device Tree binding schema for the ST7567 Controller.

Patch #5 finally extends the st7571-i2c driver to also support the ST7567 device.

Changes in v3:
- Fix reset typo in commit message (Marcus Folkesson).
- Explicitly set ST7571_SET_REVERSE(0) instead of relying on defaults.

Changes in v2:
- Use a different parse DT function (Thomas Zimmermann).

Javier Martinez Canillas (5):
  drm/sitronix/st7571-i2c: Fix encoder callbacks function names
  drm/sitronix/st7571-i2c: Log probe deferral cause for GPIO get failure
  drm/sitronix/st7571-i2c: Add an indirection level to parse DT
  dt-bindings: display: Add Sitronix ST7567 LCD Controller
  drm/sitronix/st7571-i2c: Add support for the ST7567 Controller

 .../bindings/display/sitronix,st7567.yaml     | 63 ++++++++++++
 MAINTAINERS                                   |  1 +
 drivers/gpu/drm/sitronix/st7571-i2c.c         | 95 +++++++++++++++++--
 3 files changed, 151 insertions(+), 8 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/display/sitronix,st7567.yaml

-- 
2.49.0

base-commit: d5ca45b508916144d1e8be1102bedab405c1f6fb
branch: drm-st7567-v3

[PATCH v3 1/5] drm/sitronix/st7571-i2c: Fix encoder callbacks function names

[Javier Martinez Canillas]

It seems the driver took some inspiration from ssd130x and some of the
functions (encoder callbacks) were not renamed to use a st7571_ prefix.

Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Marcus Folkesson <marcus.folkesson@gmail.com>
---

(no changes since v1)

 drivers/gpu/drm/sitronix/st7571-i2c.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/sitronix/st7571-i2c.c b/drivers/gpu/drm/sitronix/st7571-i2c.c
index eec846892962..634b426e2874 100644
--- a/drivers/gpu/drm/sitronix/st7571-i2c.c
+++ b/drivers/gpu/drm/sitronix/st7571-i2c.c
@@ -550,8 +550,8 @@ static const struct drm_crtc_funcs st7571_crtc_funcs = {
  * Encoder
  */
 
-static void ssd130x_encoder_atomic_enable(struct drm_encoder *encoder,
-					  struct drm_atomic_state *state)
+static void st7571_encoder_atomic_enable(struct drm_encoder *encoder,
+					 struct drm_atomic_state *state)
 {
 	struct drm_device *drm = encoder->dev;
 	struct st7571_device *st7571 = drm_to_st7571(drm);
@@ -565,8 +565,8 @@ static void ssd130x_encoder_atomic_enable(struct drm_encoder *encoder,
 	st7571_send_command_list(st7571, &command, 1);
 }
 
-static void ssd130x_encoder_atomic_disable(struct drm_encoder *encoder,
-					   struct drm_atomic_state *state)
+static void st7571_encoder_atomic_disable(struct drm_encoder *encoder,
+					  struct drm_atomic_state *state)
 {
 	struct drm_device *drm = encoder->dev;
 	struct st7571_device *st7571 = drm_to_st7571(drm);
@@ -581,8 +581,8 @@ static const struct drm_encoder_funcs st7571_encoder_funcs = {
 };
 
 static const struct drm_encoder_helper_funcs st7571_encoder_helper_funcs = {
-	.atomic_enable = ssd130x_encoder_atomic_enable,
-	.atomic_disable = ssd130x_encoder_atomic_disable,
+	.atomic_enable = st7571_encoder_atomic_enable,
+	.atomic_disable = st7571_encoder_atomic_disable,
 };
 
 /*
-- 
2.49.0

[PATCH v3 2/5] drm/sitronix/st7571-i2c: Log probe deferral cause for GPIO get failure

[Javier Martinez Canillas]

The driver already uses the dev_err_probe() helper (that only prints error
messages for the -EPROBE_DEFER case) when fails to get any other resource.

Also do the same when it fails to obtain the reset GPIO.

Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Marcus Folkesson <marcus.folkesson@gmail.com>
---

Changes in v3:
- Fix reset typo in commit message (Marcus Folkesson).

 drivers/gpu/drm/sitronix/st7571-i2c.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/sitronix/st7571-i2c.c b/drivers/gpu/drm/sitronix/st7571-i2c.c
index 634b426e2874..fd9d6c701cc4 100644
--- a/drivers/gpu/drm/sitronix/st7571-i2c.c
+++ b/drivers/gpu/drm/sitronix/st7571-i2c.c
@@ -804,7 +804,9 @@ static int st7571_parse_dt(struct st7571_device *st7571)
 
 	st7571->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
 	if (IS_ERR(st7571->reset))
-		return PTR_ERR(st7571->reset);
+		return dev_err_probe(dev, PTR_ERR(st7571->reset),
+				     "Failed to get reset gpio\n");
+
 
 	return 0;
 }
-- 
2.49.0

[PATCH v3 3/5] drm/sitronix/st7571-i2c: Add an indirection level to parse DT

[Javier Martinez Canillas]

Other Sitronix display controllers might need a different parsing DT
logic, so lets add a .parse_dt callback to struct st7571_panel_data.

Suggested-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Marcus Folkesson <marcus.folkesson@gmail.com>
---

(no changes since v1)

 drivers/gpu/drm/sitronix/st7571-i2c.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/sitronix/st7571-i2c.c b/drivers/gpu/drm/sitronix/st7571-i2c.c
index fd9d6c701cc4..f9c4fedb3cca 100644
--- a/drivers/gpu/drm/sitronix/st7571-i2c.c
+++ b/drivers/gpu/drm/sitronix/st7571-i2c.c
@@ -92,6 +92,7 @@ struct st7571_panel_constraints {
 
 struct st7571_panel_data {
 	int (*init)(struct st7571_device *st7571);
+	int (*parse_dt)(struct st7571_device *st7571);
 	struct st7571_panel_constraints constraints;
 };
 
@@ -881,7 +882,7 @@ static int st7571_probe(struct i2c_client *client)
 	i2c_set_clientdata(client, st7571);
 	st7571->pdata = device_get_match_data(&client->dev);
 
-	ret = st7571_parse_dt(st7571);
+	ret = st7571->pdata->parse_dt(st7571);
 	if (ret)
 		return ret;
 
@@ -964,6 +965,7 @@ static void st7571_remove(struct i2c_client *client)
 
 struct st7571_panel_data st7571_config = {
 	.init = st7571_lcd_init,
+	.parse_dt = st7571_parse_dt,
 	.constraints = {
 		.min_nlines = 1,
 		.max_nlines = 128,
-- 
2.49.0

[PATCH v3 4/5] dt-bindings: display: Add Sitronix ST7567 LCD Controller

[Javier Martinez Canillas]

Sitronix ST7567 is a monochrome Dot Matrix LCD Controller.

Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Reviewed-by: Marcus Folkesson <marcus.folkesson@gmail.com>
---

(no changes since v1)

 .../bindings/display/sitronix,st7567.yaml     | 63 +++++++++++++++++++
 MAINTAINERS                                   |  1 +
 2 files changed, 64 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/display/sitronix,st7567.yaml

diff --git a/Documentation/devicetree/bindings/display/sitronix,st7567.yaml b/Documentation/devicetree/bindings/display/sitronix,st7567.yaml
new file mode 100644
index 000000000000..e8a5b8ad18fe
--- /dev/null
+++ b/Documentation/devicetree/bindings/display/sitronix,st7567.yaml
@@ -0,0 +1,63 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/display/sitronix,st7567.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Sitronix ST7567 Display Controller
+
+maintainers:
+  - Javier Martinez Canillas <javierm@redhat.com>
+
+description:
+  Sitronix ST7567 is a driver and controller for monochrome
+  dot matrix LCD panels.
+
+allOf:
+  - $ref: panel/panel-common.yaml#
+
+properties:
+  compatible:
+    const: sitronix,st7567
+
+  reg:
+    maxItems: 1
+
+  width-mm: true
+  height-mm: true
+  panel-timing: true
+
+required:
+  - compatible
+  - reg
+  - width-mm
+  - height-mm
+  - panel-timing
+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        display@3f {
+            compatible = "sitronix,st7567";
+            reg = <0x3f>;
+            width-mm = <37>;
+            height-mm = <27>;
+
+            panel-timing {
+                hactive = <128>;
+                vactive = <64>;
+                hback-porch = <0>;
+                vback-porch = <0>;
+                clock-frequency = <0>;
+                hfront-porch = <0>;
+                hsync-len = <0>;
+                vfront-porch = <0>;
+                vsync-len = <0>;
+            };
+          };
+     };
diff --git a/MAINTAINERS b/MAINTAINERS
index ee2ef9d9db2a..d97e091b1742 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7835,6 +7835,7 @@ F:	drivers/gpu/drm/sitronix/st7586.c
 DRM DRIVER FOR SITRONIX ST7571 PANELS
 M:	Marcus Folkesson <marcus.folkesson@gmail.com>
 S:	Maintained
+F:	Documentation/devicetree/bindings/display/sitronix,st7567.yaml
 F:	Documentation/devicetree/bindings/display/sitronix,st7571.yaml
 F:	drivers/gpu/drm/sitronix/st7571-i2c.c
 
-- 
2.49.0

[PATCH v3 5/5] drm/sitronix/st7571-i2c: Add support for the ST7567 Controller

[Javier Martinez Canillas]

The Sitronix ST7567 is a monochrome Dot Matrix LCD Controller that has SPI,
I2C and parallel interfaces. The st7571-i2c driver only has support for I2C
so displays using other transport interfaces are currently not supported.

The DRM_FORMAT_R1 pixel format and data commands are the same than what
is used by the ST7571 controller, so only is needed a different callback
that implements the expected initialization sequence for the ST7567 chip.

Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
---

Changes in v3:
- Explicitly set ST7571_SET_REVERSE(0) instead of relying on defaults.

Changes in v2:
- Use a different parse DT function (Thomas Zimmermann).

 drivers/gpu/drm/sitronix/st7571-i2c.c | 75 +++++++++++++++++++++++++++
 1 file changed, 75 insertions(+)

diff --git a/drivers/gpu/drm/sitronix/st7571-i2c.c b/drivers/gpu/drm/sitronix/st7571-i2c.c
index f9c4fedb3cca..453eb7e045e5 100644
--- a/drivers/gpu/drm/sitronix/st7571-i2c.c
+++ b/drivers/gpu/drm/sitronix/st7571-i2c.c
@@ -68,6 +68,9 @@
 #define ST7571_SET_COLOR_MODE(c)		(0x10 | FIELD_PREP(GENMASK(0, 0), (c)))
 #define ST7571_COMMAND_SET_NORMAL		(0x00)
 
+/* ST7567 commands */
+#define ST7567_SET_LCD_BIAS(m) (0xa2 | FIELD_PREP(GENMASK(0, 0), (m)))
+
 #define ST7571_PAGE_HEIGHT 8
 
 #define DRIVER_NAME "st7571"
@@ -774,6 +777,32 @@ static int st7571_validate_parameters(struct st7571_device *st7571)
 	return 0;
 }
 
+static int st7567_parse_dt(struct st7571_device *st7567)
+{
+	struct device *dev = &st7567->client->dev;
+	struct device_node *np = dev->of_node;
+	struct display_timing dt;
+	int ret;
+
+	ret = of_get_display_timing(np, "panel-timing", &dt);
+	if (ret) {
+		dev_err(dev, "Failed to get display timing from DT\n");
+		return ret;
+	}
+
+	of_property_read_u32(np, "width-mm", &st7567->width_mm);
+	of_property_read_u32(np, "height-mm", &st7567->height_mm);
+
+	st7567->pformat = &st7571_monochrome;
+	st7567->bpp = 1;
+
+	st7567->startline = dt.vfront_porch.typ;
+	st7567->nlines = dt.vactive.typ;
+	st7567->ncols = dt.hactive.typ;
+
+	return 0;
+}
+
 static int st7571_parse_dt(struct st7571_device *st7571)
 {
 	struct device *dev = &st7571->client->dev;
@@ -819,6 +848,38 @@ static void st7571_reset(struct st7571_device *st7571)
 	gpiod_set_value_cansleep(st7571->reset, 0);
 }
 
+static int st7567_lcd_init(struct st7571_device *st7567)
+{
+	/*
+	 * Most of the initialization sequence is taken directly from the
+	 * referential initial code in the ST7567 datasheet.
+	 */
+	u8 commands[] = {
+		ST7571_DISPLAY_OFF,
+
+		ST7567_SET_LCD_BIAS(1),
+
+		ST7571_SET_SEG_SCAN_DIR(0),
+		ST7571_SET_COM_SCAN_DIR(1),
+
+		ST7571_SET_REGULATOR_REG(4),
+		ST7571_SET_CONTRAST_MSB,
+		ST7571_SET_CONTRAST_LSB(0x20),
+
+		ST7571_SET_START_LINE_MSB,
+		ST7571_SET_START_LINE_LSB(st7567->startline),
+
+		ST7571_SET_POWER(0x4),	/* Power Control, VC: ON, VR: OFF, VF: OFF */
+		ST7571_SET_POWER(0x6),	/* Power Control, VC: ON, VR: ON, VF: OFF */
+		ST7571_SET_POWER(0x7),	/* Power Control, VC: ON, VR: ON, VF: ON */
+
+		ST7571_SET_REVERSE(0),
+		ST7571_SET_ENTIRE_DISPLAY_ON(0),
+	};
+
+	return st7571_send_command_list(st7567, commands, ARRAY_SIZE(commands));
+}
+
 static int st7571_lcd_init(struct st7571_device *st7571)
 {
 	/*
@@ -963,6 +1024,18 @@ static void st7571_remove(struct i2c_client *client)
 	drm_dev_unplug(&st7571->dev);
 }
 
+struct st7571_panel_data st7567_config = {
+	.init = st7567_lcd_init,
+	.parse_dt = st7567_parse_dt,
+	.constraints = {
+		.min_nlines = 1,
+		.max_nlines = 64,
+		.min_ncols = 128,
+		.max_ncols = 128,
+		.support_grayscale = false,
+	},
+};
+
 struct st7571_panel_data st7571_config = {
 	.init = st7571_lcd_init,
 	.parse_dt = st7571_parse_dt,
@@ -976,12 +1049,14 @@ struct st7571_panel_data st7571_config = {
 };
 
 static const struct of_device_id st7571_of_match[] = {
+	{ .compatible = "sitronix,st7567", .data = &st7567_config },
 	{ .compatible = "sitronix,st7571", .data = &st7571_config },
 	{},
 };
 MODULE_DEVICE_TABLE(of, st7571_of_match);
 
 static const struct i2c_device_id st7571_id[] = {
+	{ "st7567", 0 },
 	{ "st7571", 0 },
 	{ }
 };
-- 
2.49.0

Re: [PATCH v3 0/5] drm/sitronix/st7571-i2c: Add support for the ST7567 Controller

[Javier Martinez Canillas]

Javier Martinez Canillas <javierm@redhat.com> writes:

> This patch-series adds support for the Sitronix ST7567 Controller, which is a
> monochrome Dot Matrix LCD Controller that has SPI, I2C and parallel interfaces.
>
> The st7571-i2c driver only has support for I2C so displays using other transport
> interfaces are currently not supported.
>
> The DRM_FORMAT_R1 pixel format and data commands are the same than what is used
> by the ST7571 controller, so only is needed a different callback that implements
> the expected initialization sequence for the ST7567 chip and a different callback
> to parse the sub-set of DT properties needed by the ST7567.
>
> Patches #1 and #2 are some trivial cleanups for the driver.
>
> Patch #3 is a preparatory change that adds the level of indirection for the DT
> parsing logic.
>
> Patch #4 adds a Device Tree binding schema for the ST7567 Controller.
>
> Patch #5 finally extends the st7571-i2c driver to also support the ST7567 device.
>
> Changes in v3:
> - Fix reset typo in commit message (Marcus Folkesson).
> - Explicitly set ST7571_SET_REVERSE(0) instead of relying on defaults.
>
> Changes in v2:
> - Use a different parse DT function (Thomas Zimmermann).
>
> Javier Martinez Canillas (5):
>   drm/sitronix/st7571-i2c: Fix encoder callbacks function names
>   drm/sitronix/st7571-i2c: Log probe deferral cause for GPIO get failure
>   drm/sitronix/st7571-i2c: Add an indirection level to parse DT
>   dt-bindings: display: Add Sitronix ST7567 LCD Controller
>   drm/sitronix/st7571-i2c: Add support for the ST7567 Controller
>

Pushed to drm-misc (drm-misc-next). Thanks!

-- 
Best regards,

Javier Martinez Canillas
Core Platforms
Red Hat