[PATCH 1/3] drm/dsi: Add support for Turn on/Shutdown peripheral packets

[PATCH 1/3] drm/dsi: Add support for Turn on/Shutdown peripheral packets

[bjorn]

From: Werner Johansson <werner.johansson@sonymobile.com>

The MIPI_DSI_TURN_ON_PERIPHERAL and MIPI_DSI_SHUTDOWN_PERIPHERAL
packets are required for some panels, one example being the
Panasonic VVX10F034N00 panel.

Signed-off-by: Werner Johansson <werner.johansson@sonymobile.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
---
 drivers/gpu/drm/drm_mipi_dsi.c | 47 ++++++++++++++++++++++++++++++++++++++++++
 include/drm/drm_mipi_dsi.h     |  3 +++
 2 files changed, 50 insertions(+)

diff --git a/drivers/gpu/drm/drm_mipi_dsi.c b/drivers/gpu/drm/drm_mipi_dsi.c
index 2d5ca8ee..13b4a9c 100644
--- a/drivers/gpu/drm/drm_mipi_dsi.c
+++ b/drivers/gpu/drm/drm_mipi_dsi.c
@@ -862,6 +862,53 @@ int mipi_dsi_dcs_set_pixel_format(struct mipi_dsi_device *dsi, u8 format)
 }
 EXPORT_SYMBOL(mipi_dsi_dcs_set_pixel_format);
 
+/**
+ * mipi_dsi_raw_short_write() - Sends a data-less short DSI packet
+ * @dsi: DSI peripheral device
+ * @type: Data Type of packet to send
+ *
+ * Return: 0 on success or a negative error code on failure.
+ */
+static ssize_t mipi_dsi_raw_short_write(struct mipi_dsi_device *dsi, u8 type)
+{
+	u8 dummy[2] = { 0, 0 };
+	struct mipi_dsi_msg msg = {
+		.channel = dsi->channel,
+		.tx_buf = dummy,
+		.tx_len = sizeof(dummy),
+		.type = type
+	};
+
+	if (mipi_dsi_packet_format_is_short(type))
+		return mipi_dsi_device_transfer(dsi, &msg);
+	else
+		return -1;
+}
+
+/**
+ * mipi_dsi_turn_on_peripheral() - Sends Turn On Peripheral DSI command
+ * @dsi: DSI peripheral device
+ *
+ * Return: 0 on success or a negative error code on failure.
+ */
+ssize_t mipi_dsi_turn_on_peripheral(struct mipi_dsi_device *dsi)
+{
+	return mipi_dsi_raw_short_write(dsi, MIPI_DSI_TURN_ON_PERIPHERAL);
+}
+EXPORT_SYMBOL(mipi_dsi_turn_on_peripheral);
+
+/**
+ * mipi_dsi_shutdown_peripheral() - Sends Shutdown Peripheral DSI command
+ * @dsi: DSI peripheral device
+ *
+ * Return: 0 on success or a negative error code on failure.
+ */
+ssize_t mipi_dsi_shutdown_peripheral(struct mipi_dsi_device *dsi)
+{
+	return mipi_dsi_raw_short_write(dsi, MIPI_DSI_SHUTDOWN_PERIPHERAL);
+}
+EXPORT_SYMBOL(mipi_dsi_shutdown_peripheral);
+
 static int mipi_dsi_drv_probe(struct device *dev)
 {
 	struct mipi_dsi_driver *drv = to_mipi_dsi_driver(dev->driver);
diff --git a/include/drm/drm_mipi_dsi.h b/include/drm/drm_mipi_dsi.h
index f1d8d0d..2e0f057 100644
--- a/include/drm/drm_mipi_dsi.h
+++ b/include/drm/drm_mipi_dsi.h
@@ -215,6 +215,9 @@ int mipi_dsi_dcs_set_tear_on(struct mipi_dsi_device *dsi,
 			     enum mipi_dsi_dcs_tear_mode mode);
 int mipi_dsi_dcs_set_pixel_format(struct mipi_dsi_device *dsi, u8 format);
 
+ssize_t mipi_dsi_turn_on_peripheral(struct mipi_dsi_device *dsi);
+ssize_t mipi_dsi_shutdown_peripheral(struct mipi_dsi_device *dsi);
+
 /**
  * struct mipi_dsi_driver - DSI driver
  * @driver: device driver model driver
-- 
2.3.2 (Apple Git-55)

[PATCH 2/3] panel/panasonic-vvx10f034n00: Add DT bindings

[bjorn]

From: Werner Johansson <werner.johansson@sonymobile.com>

This patch adds bindings for the Panasonic VVX10F034N00
WUXGA panel.

Signed-off-by: Werner Johansson <werner.johansson@sonymobile.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
---
 .../bindings/panel/panasonic,vvx10f034n00.txt        | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/panel/panasonic,vvx10f034n00.txt

diff --git a/Documentation/devicetree/bindings/panel/panasonic,vvx10f034n00.txt b/Documentation/devicetree/bindings/panel/panasonic,vvx10f034n00.txt
new file mode 100644
index 0000000..37dedf6
--- /dev/null
+++ b/Documentation/devicetree/bindings/panel/panasonic,vvx10f034n00.txt
@@ -0,0 +1,20 @@
+Panasonic 10" WUXGA TFT LCD panel
+
+Required properties:
+- compatible: should be "panasonic,vvx10f034n00"
+- reg: DSI virtual channel of the peripheral
+- power-supply: phandle of the regulator that provides the supply voltage
+
+Optional properties:
+- backlight: phandle of the backlight device attached to the panel
+
+Example:
+
+	mdss_dsi@fd922800 {
+		panel@0 {
+			compatible = "panasonic,vvx10f034n00";
+			reg = <0>;
+			power-supply = <&vreg_vsp>;
+			backlight = <&lp8566_wled>;
+		};
+	};
-- 
2.3.2 (Apple Git-55)

Re: [PATCH 2/3] panel/panasonic-vvx10f034n00: Add DT bindings

[Rob Herring]

On Fri, Oct 30, 2015 at 7:38 PM,  <bjorn@kryo.se> wrote:
> From: Werner Johansson <werner.johansson@sonymobile.com>
>
> This patch adds bindings for the Panasonic VVX10F034N00
> WUXGA panel.
>
> Signed-off-by: Werner Johansson <werner.johansson@sonymobile.com>
> Signed-off-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>

Acked-by: Rob Herring <robh@kernel.org>

> ---
>  .../bindings/panel/panasonic,vvx10f034n00.txt        | 20 ++++++++++++++++++++
>  1 file changed, 20 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/panel/panasonic,vvx10f034n00.txt
>
> diff --git a/Documentation/devicetree/bindings/panel/panasonic,vvx10f034n00.txt b/Documentation/devicetree/bindings/panel/panasonic,vvx10f034n00.txt
> new file mode 100644
> index 0000000..37dedf6
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/panel/panasonic,vvx10f034n00.txt
> @@ -0,0 +1,20 @@
> +Panasonic 10" WUXGA TFT LCD panel
> +
> +Required properties:
> +- compatible: should be "panasonic,vvx10f034n00"
> +- reg: DSI virtual channel of the peripheral
> +- power-supply: phandle of the regulator that provides the supply voltage
> +
> +Optional properties:
> +- backlight: phandle of the backlight device attached to the panel
> +
> +Example:
> +
> +       mdss_dsi@fd922800 {
> +               panel@0 {
> +                       compatible = "panasonic,vvx10f034n00";
> +                       reg = <0>;
> +                       power-supply = <&vreg_vsp>;
> +                       backlight = <&lp8566_wled>;
> +               };
> +       };
> --
> 2.3.2 (Apple Git-55)
>

Re: [PATCH 2/3] panel/panasonic-vvx10f034n00: Add DT bindings

[Thierry Reding]

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On Fri, Oct 30, 2015 at 05:38:27PM -0700, bjorn@kryo.se wrote:
> From: Werner Johansson <werner.johansson@sonymobile.com>
> 
> This patch adds bindings for the Panasonic VVX10F034N00
> WUXGA panel.
> 
> Signed-off-by: Werner Johansson <werner.johansson@sonymobile.com>
> Signed-off-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
> ---
>  .../bindings/panel/panasonic,vvx10f034n00.txt        | 20 ++++++++++++++++++++
>  1 file changed, 20 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/panel/panasonic,vvx10f034n00.txt

Applied, thanks.

Thierry

[-- Attachment #2: signature.asc --]
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[PATCH 3/3] drm/panel: Add Panasonic VVX10F034N00 MIPI DSI panel

[bjorn]

From: Werner Johansson <werner.johansson@sonymobile.com>

This adds support for the Panasonic panel found in some Xperia Z2
tablets.

Signed-off-by: Werner Johansson <werner.johansson@sonymobile.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
---
 drivers/gpu/drm/panel/Kconfig                      |  10 +
 drivers/gpu/drm/panel/Makefile                     |   1 +
 .../gpu/drm/panel/panel-panasonic-vvx10f034n00.c   | 334 +++++++++++++++++++++
 3 files changed, 345 insertions(+)
 create mode 100644 drivers/gpu/drm/panel/panel-panasonic-vvx10f034n00.c

diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
index 7d4704b..77a20d6 100644
--- a/drivers/gpu/drm/panel/Kconfig
+++ b/drivers/gpu/drm/panel/Kconfig
@@ -51,4 +51,14 @@ config DRM_PANEL_SHARP_LQ101R1SX01
 	  To compile this driver as a module, choose M here: the module
 	  will be called panel-sharp-lq101r1sx01.
 
+config DRM_PANEL_PANASONIC_VVX10F034N00
+	tristate "Panasonic VVX10F034N00 1920x1200 video mode 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 Panasonic VVX10F034N00
+	  WUXGA (1920x1200) Novatek NT1397-based DSI panel as found in some
+	  Xperia Z2 tablets
+
 endmenu
diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
index d0f016d..a2ca8ff 100644
--- a/drivers/gpu/drm/panel/Makefile
+++ b/drivers/gpu/drm/panel/Makefile
@@ -3,3 +3,4 @@ obj-$(CONFIG_DRM_PANEL_LG_LG4573) += panel-lg-lg4573.o
 obj-$(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_PANASONIC_VVX10F034N00) += panel-panasonic-vvx10f034n00.o
diff --git a/drivers/gpu/drm/panel/panel-panasonic-vvx10f034n00.c b/drivers/gpu/drm/panel/panel-panasonic-vvx10f034n00.c
new file mode 100644
index 0000000..7f915f7
--- /dev/null
+++ b/drivers/gpu/drm/panel/panel-panasonic-vvx10f034n00.c
@@ -0,0 +1,334 @@
+/*
+ * Copyright (C) 2015 Red Hat
+ * Copyright (C) 2015 Sony Mobile Communications Inc.
+ * Author: Werner Johansson <werner.johansson@sonymobile.com>
+ *
+ * Based on AUO panel driver by Rob Clark <robdclark@gmail.com>
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/backlight.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/regulator/consumer.h>
+
+#include <drm/drmP.h>
+#include <drm/drm_crtc.h>
+#include <drm/drm_mipi_dsi.h>
+#include <drm/drm_panel.h>
+
+#include <video/mipi_display.h>
+
+/*
+ * When power is turned off to this panel a minimum off time of 500ms has to be
+ * observed before powering back on as there's no external reset pin. Keep
+ * track of earliest wakeup time and delay subsequent prepare call accordingly
+ */
+#define MIN_POFF_MS (500)
+
+struct wuxga_nt_panel {
+	struct drm_panel base;
+	struct mipi_dsi_device *dsi;
+
+	struct backlight_device *backlight;
+	struct regulator *supply;
+
+	bool prepared;
+	bool enabled;
+
+	ktime_t earliest_wake;
+
+	const struct drm_display_mode *mode;
+};
+
+static inline struct wuxga_nt_panel *to_wuxga_nt_panel(struct drm_panel *panel)
+{
+	return container_of(panel, struct wuxga_nt_panel, base);
+}
+
+static int wuxga_nt_panel_on(struct wuxga_nt_panel *wuxga_nt)
+{
+	struct mipi_dsi_device *dsi = wuxga_nt->dsi;
+	int ret;
+
+	ret = mipi_dsi_turn_on_peripheral(dsi);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static int wuxga_nt_panel_disable(struct drm_panel *panel)
+{
+	struct wuxga_nt_panel *wuxga_nt = to_wuxga_nt_panel(panel);
+
+	if (!wuxga_nt->enabled)
+		return 0;
+
+	mipi_dsi_shutdown_peripheral(wuxga_nt->dsi);
+
+	if (wuxga_nt->backlight) {
+		wuxga_nt->backlight->props.power = FB_BLANK_POWERDOWN;
+		wuxga_nt->backlight->props.state |= BL_CORE_FBBLANK;
+		backlight_update_status(wuxga_nt->backlight);
+	}
+
+	wuxga_nt->enabled = false;
+
+	return 0;
+}
+
+static int wuxga_nt_panel_unprepare(struct drm_panel *panel)
+{
+	struct wuxga_nt_panel *wuxga_nt = to_wuxga_nt_panel(panel);
+
+	if (!wuxga_nt->prepared)
+		return 0;
+
+	regulator_disable(wuxga_nt->supply);
+	wuxga_nt->earliest_wake = ktime_add_ms(ktime_get_real(), MIN_POFF_MS);
+	wuxga_nt->prepared = false;
+
+	return 0;
+}
+
+static int wuxga_nt_panel_prepare(struct drm_panel *panel)
+{
+	struct wuxga_nt_panel *wuxga_nt = to_wuxga_nt_panel(panel);
+	int ret;
+	s64 enablewait;
+
+	if (wuxga_nt->prepared)
+		return 0;
+
+	/*
+	 * If the user re-enabled the panel before the required off-time then
+	 * we need to wait the remaining period before re-enabling regulator
+	 */
+	enablewait = ktime_ms_delta(wuxga_nt->earliest_wake, ktime_get_real());
+
+	/* Sanity check, this should never happen */
+	if (enablewait > MIN_POFF_MS)
+		enablewait = MIN_POFF_MS;
+
+	if (enablewait > 0)
+		msleep(enablewait);
+
+	ret = regulator_enable(wuxga_nt->supply);
+	if (ret < 0)
+		return ret;
+
+	/*
+	 * A minimum delay of 250ms is required after power-up until commands
+	 * can be sent
+	 */
+	msleep(250);
+
+	ret = wuxga_nt_panel_on(wuxga_nt);
+	if (ret < 0) {
+		dev_err(panel->dev, "failed to set panel on: %d\n", ret);
+		goto poweroff;
+	}
+
+	wuxga_nt->prepared = true;
+
+	return 0;
+
+poweroff:
+	regulator_disable(wuxga_nt->supply);
+
+	return ret;
+}
+
+static int wuxga_nt_panel_enable(struct drm_panel *panel)
+{
+	struct wuxga_nt_panel *wuxga_nt = to_wuxga_nt_panel(panel);
+
+	if (wuxga_nt->enabled)
+		return 0;
+
+	if (wuxga_nt->backlight) {
+		wuxga_nt->backlight->props.power = FB_BLANK_UNBLANK;
+		wuxga_nt->backlight->props.state &= ~BL_CORE_FBBLANK;
+		backlight_update_status(wuxga_nt->backlight);
+	}
+
+	wuxga_nt->enabled = true;
+
+	return 0;
+}
+
+static const struct drm_display_mode default_mode = {
+	.clock = 164402,
+	.hdisplay = 1920,
+	.hsync_start = 1920 + 152,
+	.hsync_end = 1920 + 152 + 52,
+	.htotal = 1920 + 152 + 52 + 20,
+	.vdisplay = 1200,
+	.vsync_start = 1200 + 24,
+	.vsync_end = 1200 + 24 + 6,
+	.vtotal = 1200 + 24 + 6 + 48,
+	.vrefresh = 60,
+};
+
+static int wuxga_nt_panel_get_modes(struct drm_panel *panel)
+{
+	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);
+
+	drm_mode_probed_add(panel->connector, mode);
+
+	panel->connector->display_info.width_mm = 217;
+	panel->connector->display_info.height_mm = 136;
+
+	return 1;
+}
+
+static const struct drm_panel_funcs wuxga_nt_panel_funcs = {
+	.disable = wuxga_nt_panel_disable,
+	.unprepare = wuxga_nt_panel_unprepare,
+	.prepare = wuxga_nt_panel_prepare,
+	.enable = wuxga_nt_panel_enable,
+	.get_modes = wuxga_nt_panel_get_modes,
+};
+
+static const struct of_device_id wuxga_nt_of_match[] = {
+	{ .compatible = "panasonic,vvx10f034n00", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, wuxga_nt_of_match);
+
+static int wuxga_nt_panel_add(struct wuxga_nt_panel *wuxga_nt)
+{
+	struct device *dev = &wuxga_nt->dsi->dev;
+	struct device_node *np;
+	int ret;
+
+	wuxga_nt->mode = &default_mode;
+
+	wuxga_nt->supply = devm_regulator_get(dev, "power");
+	if (IS_ERR(wuxga_nt->supply))
+		return PTR_ERR(wuxga_nt->supply);
+
+	np = of_parse_phandle(dev->of_node, "backlight", 0);
+	if (np) {
+		wuxga_nt->backlight = of_find_backlight_by_node(np);
+		of_node_put(np);
+
+		if (!wuxga_nt->backlight)
+			return -EPROBE_DEFER;
+	}
+
+	drm_panel_init(&wuxga_nt->base);
+	wuxga_nt->base.funcs = &wuxga_nt_panel_funcs;
+	wuxga_nt->base.dev = &wuxga_nt->dsi->dev;
+
+	ret = drm_panel_add(&wuxga_nt->base);
+	if (ret < 0)
+		goto put_backlight;
+
+	return 0;
+
+put_backlight:
+	if (wuxga_nt->backlight)
+		put_device(&wuxga_nt->backlight->dev);
+
+	return ret;
+}
+
+static void wuxga_nt_panel_del(struct wuxga_nt_panel *wuxga_nt)
+{
+	if (wuxga_nt->base.dev)
+		drm_panel_remove(&wuxga_nt->base);
+
+	if (wuxga_nt->backlight)
+		put_device(&wuxga_nt->backlight->dev);
+}
+
+static int wuxga_nt_panel_probe(struct mipi_dsi_device *dsi)
+{
+	struct wuxga_nt_panel *wuxga_nt;
+	int ret;
+
+	dsi->lanes = 4;
+	dsi->format = MIPI_DSI_FMT_RGB888;
+	dsi->mode_flags = MIPI_DSI_MODE_VIDEO |
+			MIPI_DSI_MODE_VIDEO_HSE |
+			MIPI_DSI_CLOCK_NON_CONTINUOUS |
+			MIPI_DSI_MODE_LPM;
+
+	wuxga_nt = devm_kzalloc(&dsi->dev, sizeof(*wuxga_nt), GFP_KERNEL);
+	if (!wuxga_nt)
+		return -ENOMEM;
+
+	mipi_dsi_set_drvdata(dsi, wuxga_nt);
+
+	wuxga_nt->dsi = dsi;
+
+	ret = wuxga_nt_panel_add(wuxga_nt);
+	if (ret < 0)
+		return ret;
+
+	return mipi_dsi_attach(dsi);
+}
+
+static int wuxga_nt_panel_remove(struct mipi_dsi_device *dsi)
+{
+	struct wuxga_nt_panel *wuxga_nt = mipi_dsi_get_drvdata(dsi);
+	int ret;
+
+	ret = wuxga_nt_panel_disable(&wuxga_nt->base);
+	if (ret < 0)
+		dev_err(&dsi->dev, "failed to disable panel: %d\n", ret);
+
+	ret = mipi_dsi_detach(dsi);
+	if (ret < 0)
+		dev_err(&dsi->dev, "failed to detach from DSI host: %d\n", ret);
+
+	drm_panel_detach(&wuxga_nt->base);
+	wuxga_nt_panel_del(wuxga_nt);
+
+	return 0;
+}
+
+static void wuxga_nt_panel_shutdown(struct mipi_dsi_device *dsi)
+{
+	struct wuxga_nt_panel *wuxga_nt = mipi_dsi_get_drvdata(dsi);
+
+	wuxga_nt_panel_disable(&wuxga_nt->base);
+}
+
+static struct mipi_dsi_driver wuxga_nt_panel_driver = {
+	.driver = {
+		.name = "panel-panasonic-vvx10f034n00",
+		.of_match_table = wuxga_nt_of_match,
+	},
+	.probe = wuxga_nt_panel_probe,
+	.remove = wuxga_nt_panel_remove,
+	.shutdown = wuxga_nt_panel_shutdown,
+};
+module_mipi_dsi_driver(wuxga_nt_panel_driver);
+
+MODULE_AUTHOR("Werner Johansson <werner.johansson@sonymobile.com>");
+MODULE_DESCRIPTION("Panasonic VVX10F034N00 Novatek NT1397-based WUXGA (1920x1200) video mode panel driver");
+MODULE_LICENSE("GPL v2");
-- 
2.3.2 (Apple Git-55)

Re: [PATCH 3/3] drm/panel: Add Panasonic VVX10F034N00 MIPI DSI panel

[Bjorn Andersson]

On Fri, Oct 30, 2015 at 5:38 PM,  <bjorn@kryo.se> wrote:

Ping?

> From: Werner Johansson <werner.johansson@sonymobile.com>
>
> This adds support for the Panasonic panel found in some Xperia Z2
> tablets.
>
> Signed-off-by: Werner Johansson <werner.johansson@sonymobile.com>
> Signed-off-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
> ---
>  drivers/gpu/drm/panel/Kconfig                      |  10 +
>  drivers/gpu/drm/panel/Makefile                     |   1 +
>  .../gpu/drm/panel/panel-panasonic-vvx10f034n00.c   | 334 +++++++++++++++++++++
>  3 files changed, 345 insertions(+)
>  create mode 100644 drivers/gpu/drm/panel/panel-panasonic-vvx10f034n00.c
>
> diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
> index 7d4704b..77a20d6 100644
> --- a/drivers/gpu/drm/panel/Kconfig
> +++ b/drivers/gpu/drm/panel/Kconfig
> @@ -51,4 +51,14 @@ config DRM_PANEL_SHARP_LQ101R1SX01
>           To compile this driver as a module, choose M here: the module
>           will be called panel-sharp-lq101r1sx01.
>
> +config DRM_PANEL_PANASONIC_VVX10F034N00
> +       tristate "Panasonic VVX10F034N00 1920x1200 video mode 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 Panasonic VVX10F034N00
> +         WUXGA (1920x1200) Novatek NT1397-based DSI panel as found in some
> +         Xperia Z2 tablets
> +
>  endmenu
> diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
> index d0f016d..a2ca8ff 100644
> --- a/drivers/gpu/drm/panel/Makefile
> +++ b/drivers/gpu/drm/panel/Makefile
> @@ -3,3 +3,4 @@ obj-$(CONFIG_DRM_PANEL_LG_LG4573) += panel-lg-lg4573.o
>  obj-$(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_PANASONIC_VVX10F034N00) += panel-panasonic-vvx10f034n00.o
> diff --git a/drivers/gpu/drm/panel/panel-panasonic-vvx10f034n00.c b/drivers/gpu/drm/panel/panel-panasonic-vvx10f034n00.c
> new file mode 100644
> index 0000000..7f915f7
> --- /dev/null
> +++ b/drivers/gpu/drm/panel/panel-panasonic-vvx10f034n00.c
> @@ -0,0 +1,334 @@
> +/*
> + * Copyright (C) 2015 Red Hat
> + * Copyright (C) 2015 Sony Mobile Communications Inc.
> + * Author: Werner Johansson <werner.johansson@sonymobile.com>
> + *
> + * Based on AUO panel driver by Rob Clark <robdclark@gmail.com>
> + *
> + * 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.
> + *
> + * This program is distributed in the hope that it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
> + * more details.
> + *
> + * You should have received a copy of the GNU General Public License along with
> + * this program.  If not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#include <linux/backlight.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/regulator/consumer.h>
> +
> +#include <drm/drmP.h>
> +#include <drm/drm_crtc.h>
> +#include <drm/drm_mipi_dsi.h>
> +#include <drm/drm_panel.h>
> +
> +#include <video/mipi_display.h>
> +
> +/*
> + * When power is turned off to this panel a minimum off time of 500ms has to be
> + * observed before powering back on as there's no external reset pin. Keep
> + * track of earliest wakeup time and delay subsequent prepare call accordingly
> + */
> +#define MIN_POFF_MS (500)
> +
> +struct wuxga_nt_panel {
> +       struct drm_panel base;
> +       struct mipi_dsi_device *dsi;
> +
> +       struct backlight_device *backlight;
> +       struct regulator *supply;
> +
> +       bool prepared;
> +       bool enabled;
> +
> +       ktime_t earliest_wake;
> +
> +       const struct drm_display_mode *mode;
> +};
> +
> +static inline struct wuxga_nt_panel *to_wuxga_nt_panel(struct drm_panel *panel)
> +{
> +       return container_of(panel, struct wuxga_nt_panel, base);
> +}
> +
> +static int wuxga_nt_panel_on(struct wuxga_nt_panel *wuxga_nt)
> +{
> +       struct mipi_dsi_device *dsi = wuxga_nt->dsi;
> +       int ret;
> +
> +       ret = mipi_dsi_turn_on_peripheral(dsi);
> +       if (ret < 0)
> +               return ret;
> +
> +       return 0;
> +}
> +
> +static int wuxga_nt_panel_disable(struct drm_panel *panel)
> +{
> +       struct wuxga_nt_panel *wuxga_nt = to_wuxga_nt_panel(panel);
> +
> +       if (!wuxga_nt->enabled)
> +               return 0;
> +
> +       mipi_dsi_shutdown_peripheral(wuxga_nt->dsi);
> +
> +       if (wuxga_nt->backlight) {
> +               wuxga_nt->backlight->props.power = FB_BLANK_POWERDOWN;
> +               wuxga_nt->backlight->props.state |= BL_CORE_FBBLANK;
> +               backlight_update_status(wuxga_nt->backlight);
> +       }
> +
> +       wuxga_nt->enabled = false;
> +
> +       return 0;
> +}
> +
> +static int wuxga_nt_panel_unprepare(struct drm_panel *panel)
> +{
> +       struct wuxga_nt_panel *wuxga_nt = to_wuxga_nt_panel(panel);
> +
> +       if (!wuxga_nt->prepared)
> +               return 0;
> +
> +       regulator_disable(wuxga_nt->supply);
> +       wuxga_nt->earliest_wake = ktime_add_ms(ktime_get_real(), MIN_POFF_MS);
> +       wuxga_nt->prepared = false;
> +
> +       return 0;
> +}
> +
> +static int wuxga_nt_panel_prepare(struct drm_panel *panel)
> +{
> +       struct wuxga_nt_panel *wuxga_nt = to_wuxga_nt_panel(panel);
> +       int ret;
> +       s64 enablewait;
> +
> +       if (wuxga_nt->prepared)
> +               return 0;
> +
> +       /*
> +        * If the user re-enabled the panel before the required off-time then
> +        * we need to wait the remaining period before re-enabling regulator
> +        */
> +       enablewait = ktime_ms_delta(wuxga_nt->earliest_wake, ktime_get_real());
> +
> +       /* Sanity check, this should never happen */
> +       if (enablewait > MIN_POFF_MS)
> +               enablewait = MIN_POFF_MS;
> +
> +       if (enablewait > 0)
> +               msleep(enablewait);
> +
> +       ret = regulator_enable(wuxga_nt->supply);
> +       if (ret < 0)
> +               return ret;
> +
> +       /*
> +        * A minimum delay of 250ms is required after power-up until commands
> +        * can be sent
> +        */
> +       msleep(250);
> +
> +       ret = wuxga_nt_panel_on(wuxga_nt);
> +       if (ret < 0) {
> +               dev_err(panel->dev, "failed to set panel on: %d\n", ret);
> +               goto poweroff;
> +       }
> +
> +       wuxga_nt->prepared = true;
> +
> +       return 0;
> +
> +poweroff:
> +       regulator_disable(wuxga_nt->supply);
> +
> +       return ret;
> +}
> +
> +static int wuxga_nt_panel_enable(struct drm_panel *panel)
> +{
> +       struct wuxga_nt_panel *wuxga_nt = to_wuxga_nt_panel(panel);
> +
> +       if (wuxga_nt->enabled)
> +               return 0;
> +
> +       if (wuxga_nt->backlight) {
> +               wuxga_nt->backlight->props.power = FB_BLANK_UNBLANK;
> +               wuxga_nt->backlight->props.state &= ~BL_CORE_FBBLANK;
> +               backlight_update_status(wuxga_nt->backlight);
> +       }
> +
> +       wuxga_nt->enabled = true;
> +
> +       return 0;
> +}
> +
> +static const struct drm_display_mode default_mode = {
> +       .clock = 164402,
> +       .hdisplay = 1920,
> +       .hsync_start = 1920 + 152,
> +       .hsync_end = 1920 + 152 + 52,
> +       .htotal = 1920 + 152 + 52 + 20,
> +       .vdisplay = 1200,
> +       .vsync_start = 1200 + 24,
> +       .vsync_end = 1200 + 24 + 6,
> +       .vtotal = 1200 + 24 + 6 + 48,
> +       .vrefresh = 60,
> +};
> +
> +static int wuxga_nt_panel_get_modes(struct drm_panel *panel)
> +{
> +       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);
> +
> +       drm_mode_probed_add(panel->connector, mode);
> +
> +       panel->connector->display_info.width_mm = 217;
> +       panel->connector->display_info.height_mm = 136;
> +
> +       return 1;
> +}
> +
> +static const struct drm_panel_funcs wuxga_nt_panel_funcs = {
> +       .disable = wuxga_nt_panel_disable,
> +       .unprepare = wuxga_nt_panel_unprepare,
> +       .prepare = wuxga_nt_panel_prepare,
> +       .enable = wuxga_nt_panel_enable,
> +       .get_modes = wuxga_nt_panel_get_modes,
> +};
> +
> +static const struct of_device_id wuxga_nt_of_match[] = {
> +       { .compatible = "panasonic,vvx10f034n00", },
> +       { }
> +};
> +MODULE_DEVICE_TABLE(of, wuxga_nt_of_match);
> +
> +static int wuxga_nt_panel_add(struct wuxga_nt_panel *wuxga_nt)
> +{
> +       struct device *dev = &wuxga_nt->dsi->dev;
> +       struct device_node *np;
> +       int ret;
> +
> +       wuxga_nt->mode = &default_mode;
> +
> +       wuxga_nt->supply = devm_regulator_get(dev, "power");
> +       if (IS_ERR(wuxga_nt->supply))
> +               return PTR_ERR(wuxga_nt->supply);
> +
> +       np = of_parse_phandle(dev->of_node, "backlight", 0);
> +       if (np) {
> +               wuxga_nt->backlight = of_find_backlight_by_node(np);
> +               of_node_put(np);
> +
> +               if (!wuxga_nt->backlight)
> +                       return -EPROBE_DEFER;
> +       }
> +
> +       drm_panel_init(&wuxga_nt->base);
> +       wuxga_nt->base.funcs = &wuxga_nt_panel_funcs;
> +       wuxga_nt->base.dev = &wuxga_nt->dsi->dev;
> +
> +       ret = drm_panel_add(&wuxga_nt->base);
> +       if (ret < 0)
> +               goto put_backlight;
> +
> +       return 0;
> +
> +put_backlight:
> +       if (wuxga_nt->backlight)
> +               put_device(&wuxga_nt->backlight->dev);
> +
> +       return ret;
> +}
> +
> +static void wuxga_nt_panel_del(struct wuxga_nt_panel *wuxga_nt)
> +{
> +       if (wuxga_nt->base.dev)
> +               drm_panel_remove(&wuxga_nt->base);
> +
> +       if (wuxga_nt->backlight)
> +               put_device(&wuxga_nt->backlight->dev);
> +}
> +
> +static int wuxga_nt_panel_probe(struct mipi_dsi_device *dsi)
> +{
> +       struct wuxga_nt_panel *wuxga_nt;
> +       int ret;
> +
> +       dsi->lanes = 4;
> +       dsi->format = MIPI_DSI_FMT_RGB888;
> +       dsi->mode_flags = MIPI_DSI_MODE_VIDEO |
> +                       MIPI_DSI_MODE_VIDEO_HSE |
> +                       MIPI_DSI_CLOCK_NON_CONTINUOUS |
> +                       MIPI_DSI_MODE_LPM;
> +
> +       wuxga_nt = devm_kzalloc(&dsi->dev, sizeof(*wuxga_nt), GFP_KERNEL);
> +       if (!wuxga_nt)
> +               return -ENOMEM;
> +
> +       mipi_dsi_set_drvdata(dsi, wuxga_nt);
> +
> +       wuxga_nt->dsi = dsi;
> +
> +       ret = wuxga_nt_panel_add(wuxga_nt);
> +       if (ret < 0)
> +               return ret;
> +
> +       return mipi_dsi_attach(dsi);
> +}
> +
> +static int wuxga_nt_panel_remove(struct mipi_dsi_device *dsi)
> +{
> +       struct wuxga_nt_panel *wuxga_nt = mipi_dsi_get_drvdata(dsi);
> +       int ret;
> +
> +       ret = wuxga_nt_panel_disable(&wuxga_nt->base);
> +       if (ret < 0)
> +               dev_err(&dsi->dev, "failed to disable panel: %d\n", ret);
> +
> +       ret = mipi_dsi_detach(dsi);
> +       if (ret < 0)
> +               dev_err(&dsi->dev, "failed to detach from DSI host: %d\n", ret);
> +
> +       drm_panel_detach(&wuxga_nt->base);
> +       wuxga_nt_panel_del(wuxga_nt);
> +
> +       return 0;
> +}
> +
> +static void wuxga_nt_panel_shutdown(struct mipi_dsi_device *dsi)
> +{
> +       struct wuxga_nt_panel *wuxga_nt = mipi_dsi_get_drvdata(dsi);
> +
> +       wuxga_nt_panel_disable(&wuxga_nt->base);
> +}
> +
> +static struct mipi_dsi_driver wuxga_nt_panel_driver = {
> +       .driver = {
> +               .name = "panel-panasonic-vvx10f034n00",
> +               .of_match_table = wuxga_nt_of_match,
> +       },
> +       .probe = wuxga_nt_panel_probe,
> +       .remove = wuxga_nt_panel_remove,
> +       .shutdown = wuxga_nt_panel_shutdown,
> +};
> +module_mipi_dsi_driver(wuxga_nt_panel_driver);
> +
> +MODULE_AUTHOR("Werner Johansson <werner.johansson@sonymobile.com>");
> +MODULE_DESCRIPTION("Panasonic VVX10F034N00 Novatek NT1397-based WUXGA (1920x1200) video mode panel driver");
> +MODULE_LICENSE("GPL v2");
> --
> 2.3.2 (Apple Git-55)
>

Re: [PATCH 3/3] drm/panel: Add Panasonic VVX10F034N00 MIPI DSI panel

[Thierry Reding]

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On Fri, Oct 30, 2015 at 05:38:28PM -0700, bjorn@kryo.se wrote:
> From: Werner Johansson <werner.johansson@sonymobile.com>
> 
> This adds support for the Panasonic panel found in some Xperia Z2
> tablets.
> 
> Signed-off-by: Werner Johansson <werner.johansson@sonymobile.com>
> Signed-off-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
> ---
>  drivers/gpu/drm/panel/Kconfig                      |  10 +
>  drivers/gpu/drm/panel/Makefile                     |   1 +
>  .../gpu/drm/panel/panel-panasonic-vvx10f034n00.c   | 334 +++++++++++++++++++++
>  3 files changed, 345 insertions(+)
>  create mode 100644 drivers/gpu/drm/panel/panel-panasonic-vvx10f034n00.c

Applied, though I had to reorder Makefile and Kconfig entries to keep
alphabetic ordering.

Thanks,
Thierry

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Re: [PATCH 3/3] drm/panel: Add Panasonic VVX10F034N00 MIPI DSI panel

[Bjorn Andersson]

On Mon, Nov 23, 2015 at 3:33 AM, Thierry Reding
<thierry.reding@gmail.com> wrote:
> On Fri, Oct 30, 2015 at 05:38:28PM -0700, bjorn@kryo.se wrote:
>> From: Werner Johansson <werner.johansson@sonymobile.com>
>>
>> This adds support for the Panasonic panel found in some Xperia Z2
>> tablets.
>>
>> Signed-off-by: Werner Johansson <werner.johansson@sonymobile.com>
>> Signed-off-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
>> ---
>>  drivers/gpu/drm/panel/Kconfig                      |  10 +
>>  drivers/gpu/drm/panel/Makefile                     |   1 +
>>  .../gpu/drm/panel/panel-panasonic-vvx10f034n00.c   | 334 +++++++++++++++++++++
>>  3 files changed, 345 insertions(+)
>>  create mode 100644 drivers/gpu/drm/panel/panel-panasonic-vvx10f034n00.c
>
> Applied, though I had to reorder Makefile and Kconfig entries to keep
> alphabetic ordering.
>

Thanks, now we're close to play Quake3 on the mainline kernel on the
Xperia Z2 Tablet :)

Did you pull patch 1/3 from this set as well? I didn't get a reply on
it and wanted to check as this patch (3/3) has a build dependency on
it.

Patch 1/3: https://patchwork.kernel.org/patch/7530121/

Regards,
Bjorn

Re: [PATCH 1/3] drm/dsi: Add support for Turn on/Shutdown peripheral packets

[Bjorn Andersson]

On Fri, Oct 30, 2015 at 5:38 PM,  <bjorn@kryo.se> wrote:

Ping?

> From: Werner Johansson <werner.johansson@sonymobile.com>
>
> The MIPI_DSI_TURN_ON_PERIPHERAL and MIPI_DSI_SHUTDOWN_PERIPHERAL
> packets are required for some panels, one example being the
> Panasonic VVX10F034N00 panel.
>
> Signed-off-by: Werner Johansson <werner.johansson@sonymobile.com>
> Signed-off-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
> ---
>  drivers/gpu/drm/drm_mipi_dsi.c | 47 ++++++++++++++++++++++++++++++++++++++++++
>  include/drm/drm_mipi_dsi.h     |  3 +++
>  2 files changed, 50 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_mipi_dsi.c b/drivers/gpu/drm/drm_mipi_dsi.c
> index 2d5ca8ee..13b4a9c 100644
> --- a/drivers/gpu/drm/drm_mipi_dsi.c
> +++ b/drivers/gpu/drm/drm_mipi_dsi.c
> @@ -862,6 +862,53 @@ int mipi_dsi_dcs_set_pixel_format(struct mipi_dsi_device *dsi, u8 format)
>  }
>  EXPORT_SYMBOL(mipi_dsi_dcs_set_pixel_format);
>
> +/**
> + * mipi_dsi_raw_short_write() - Sends a data-less short DSI packet
> + * @dsi: DSI peripheral device
> + * @type: Data Type of packet to send
> + *
> + * Return: 0 on success or a negative error code on failure.
> + */
> +static ssize_t mipi_dsi_raw_short_write(struct mipi_dsi_device *dsi, u8 type)
> +{
> +       u8 dummy[2] = { 0, 0 };
> +       struct mipi_dsi_msg msg = {
> +               .channel = dsi->channel,
> +               .tx_buf = dummy,
> +               .tx_len = sizeof(dummy),
> +               .type = type
> +       };
> +
> +       if (mipi_dsi_packet_format_is_short(type))
> +               return mipi_dsi_device_transfer(dsi, &msg);
> +       else
> +               return -1;
> +}
> +
> +/**
> + * mipi_dsi_turn_on_peripheral() - Sends Turn On Peripheral DSI command
> + * @dsi: DSI peripheral device
> + *
> + * Return: 0 on success or a negative error code on failure.
> + */
> +ssize_t mipi_dsi_turn_on_peripheral(struct mipi_dsi_device *dsi)
> +{
> +       return mipi_dsi_raw_short_write(dsi, MIPI_DSI_TURN_ON_PERIPHERAL);
> +}
> +EXPORT_SYMBOL(mipi_dsi_turn_on_peripheral);
> +
> +/**
> + * mipi_dsi_shutdown_peripheral() - Sends Shutdown Peripheral DSI command
> + * @dsi: DSI peripheral device
> + *
> + * Return: 0 on success or a negative error code on failure.
> + */
> +ssize_t mipi_dsi_shutdown_peripheral(struct mipi_dsi_device *dsi)
> +{
> +       return mipi_dsi_raw_short_write(dsi, MIPI_DSI_SHUTDOWN_PERIPHERAL);
> +}
> +EXPORT_SYMBOL(mipi_dsi_shutdown_peripheral);
> +
>  static int mipi_dsi_drv_probe(struct device *dev)
>  {
>         struct mipi_dsi_driver *drv = to_mipi_dsi_driver(dev->driver);
> diff --git a/include/drm/drm_mipi_dsi.h b/include/drm/drm_mipi_dsi.h
> index f1d8d0d..2e0f057 100644
> --- a/include/drm/drm_mipi_dsi.h
> +++ b/include/drm/drm_mipi_dsi.h
> @@ -215,6 +215,9 @@ int mipi_dsi_dcs_set_tear_on(struct mipi_dsi_device *dsi,
>                              enum mipi_dsi_dcs_tear_mode mode);
>  int mipi_dsi_dcs_set_pixel_format(struct mipi_dsi_device *dsi, u8 format);
>
> +ssize_t mipi_dsi_turn_on_peripheral(struct mipi_dsi_device *dsi);
> +ssize_t mipi_dsi_shutdown_peripheral(struct mipi_dsi_device *dsi);
> +
>  /**
>   * struct mipi_dsi_driver - DSI driver
>   * @driver: device driver model driver
> --
> 2.3.2 (Apple Git-55)
>

Re: [PATCH 1/3] drm/dsi: Add support for Turn on/Shutdown peripheral packets

[Thierry Reding]

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On Fri, Oct 30, 2015 at 05:38:26PM -0700, bjorn@kryo.se wrote:
> From: Werner Johansson <werner.johansson@sonymobile.com>
> 
> The MIPI_DSI_TURN_ON_PERIPHERAL and MIPI_DSI_SHUTDOWN_PERIPHERAL
> packets are required for some panels, one example being the
> Panasonic VVX10F034N00 panel.
> 
> Signed-off-by: Werner Johansson <werner.johansson@sonymobile.com>
> Signed-off-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
> ---
>  drivers/gpu/drm/drm_mipi_dsi.c | 47 ++++++++++++++++++++++++++++++++++++++++++
>  include/drm/drm_mipi_dsi.h     |  3 +++
>  2 files changed, 50 insertions(+)

This being a dependency on 3/3 it would've been good to send this To: me
as well. I hadn't seen this in my inbox and had simply discarded it as
being independent. Of course if I had properly checked the build I
would've noticed...

Anyway, I've applied this with slight modifications. I removed the raw
short write helper. I don't think it buys us much and we already have an
open-coded variant in mipi_dsi_set_maximum_return_packet_size(). I've
also moved these functions closer to the Set Maximum Return Packet Size
command implementation because they are part of the same command set. I
also made the functions return int instead of ssize_t to avoid potential
confusion about their return value (ssize_t implies "number of bytes
transferred, or a negative error code on failure).

One minor comment below...

> diff --git a/drivers/gpu/drm/drm_mipi_dsi.c b/drivers/gpu/drm/drm_mipi_dsi.c
> index 2d5ca8ee..13b4a9c 100644
> --- a/drivers/gpu/drm/drm_mipi_dsi.c
> +++ b/drivers/gpu/drm/drm_mipi_dsi.c
> @@ -862,6 +862,53 @@ int mipi_dsi_dcs_set_pixel_format(struct mipi_dsi_device *dsi, u8 format)
>  }
>  EXPORT_SYMBOL(mipi_dsi_dcs_set_pixel_format);
>  
> +/**
> + * mipi_dsi_raw_short_write() - Sends a data-less short DSI packet
> + * @dsi: DSI peripheral device
> + * @type: Data Type of packet to send
> + *
> + * Return: 0 on success or a negative error code on failure.
> + */
> +static ssize_t mipi_dsi_raw_short_write(struct mipi_dsi_device *dsi, u8 type)
> +{
> +	u8 dummy[2] = { 0, 0 };
> +	struct mipi_dsi_msg msg = {
> +		.channel = dsi->channel,
> +		.tx_buf = dummy,
> +		.tx_len = sizeof(dummy),
> +		.type = type
> +	};
> +
> +	if (mipi_dsi_packet_format_is_short(type))
> +		return mipi_dsi_device_transfer(dsi, &msg);
> +	else
> +		return -1;
> +}

When the kerneldoc comment says "negative error code", developers will
expect one of the -E* constants. -1 maps to -EPERM (operation not
permitted), which isn't a good error code for this case. This is also an
internal function, so these errors really should never happen.

Anyway, since I removed this helper this isn't an issue anymore, just
wanted to mention it.

Thanks,
Thierry

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Re: [PATCH 1/3] drm/dsi: Add support for Turn on/Shutdown peripheral packets

[Bjorn Andersson]

On Tue, Nov 24, 2015 at 1:33 AM, Thierry Reding
<thierry.reding@gmail.com> wrote:
> On Fri, Oct 30, 2015 at 05:38:26PM -0700, bjorn@kryo.se wrote:
>> From: Werner Johansson <werner.johansson@sonymobile.com>
>>
>> The MIPI_DSI_TURN_ON_PERIPHERAL and MIPI_DSI_SHUTDOWN_PERIPHERAL
>> packets are required for some panels, one example being the
>> Panasonic VVX10F034N00 panel.
>>
>> Signed-off-by: Werner Johansson <werner.johansson@sonymobile.com>
>> Signed-off-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
>> ---
>>  drivers/gpu/drm/drm_mipi_dsi.c | 47 ++++++++++++++++++++++++++++++++++++++++++
>>  include/drm/drm_mipi_dsi.h     |  3 +++
>>  2 files changed, 50 insertions(+)
>
> This being a dependency on 3/3 it would've been good to send this To: me
> as well. I hadn't seen this in my inbox and had simply discarded it as
> being independent. Of course if I had properly checked the build I
> would've noticed...
>

Sorry for not including you as a recipient, I relied too heavily on
get_maintainer. Thanks for fixing my misstake.

> Anyway, I've applied this with slight modifications. I removed the raw
> short write helper. I don't think it buys us much and we already have an
> open-coded variant in mipi_dsi_set_maximum_return_packet_size(). I've
> also moved these functions closer to the Set Maximum Return Packet Size
> command implementation because they are part of the same command set. I
> also made the functions return int instead of ssize_t to avoid potential
> confusion about their return value (ssize_t implies "number of bytes
> transferred, or a negative error code on failure).
>

Sounds good, thanks.

> One minor comment below...
>
>> diff --git a/drivers/gpu/drm/drm_mipi_dsi.c b/drivers/gpu/drm/drm_mipi_dsi.c
>> index 2d5ca8ee..13b4a9c 100644
>> --- a/drivers/gpu/drm/drm_mipi_dsi.c
>> +++ b/drivers/gpu/drm/drm_mipi_dsi.c
>> @@ -862,6 +862,53 @@ int mipi_dsi_dcs_set_pixel_format(struct mipi_dsi_device *dsi, u8 format)
>>  }
>>  EXPORT_SYMBOL(mipi_dsi_dcs_set_pixel_format);
>>
>> +/**
>> + * mipi_dsi_raw_short_write() - Sends a data-less short DSI packet
>> + * @dsi: DSI peripheral device
>> + * @type: Data Type of packet to send
>> + *
>> + * Return: 0 on success or a negative error code on failure.
>> + */
>> +static ssize_t mipi_dsi_raw_short_write(struct mipi_dsi_device *dsi, u8 type)
>> +{
>> +     u8 dummy[2] = { 0, 0 };
>> +     struct mipi_dsi_msg msg = {
>> +             .channel = dsi->channel,
>> +             .tx_buf = dummy,
>> +             .tx_len = sizeof(dummy),
>> +             .type = type
>> +     };
>> +
>> +     if (mipi_dsi_packet_format_is_short(type))
>> +             return mipi_dsi_device_transfer(dsi, &msg);
>> +     else
>> +             return -1;
>> +}
>
> When the kerneldoc comment says "negative error code", developers will
> expect one of the -E* constants. -1 maps to -EPERM (operation not
> permitted), which isn't a good error code for this case. This is also an
> internal function, so these errors really should never happen.
>
> Anyway, since I removed this helper this isn't an issue anymore, just
> wanted to mention it.
>

Right. Thanks for fixing it!

Regards,
Bjorn