[PATCH v8 2/2] drm/panel: Add JDI LT070ME05000 WUXGA DSI Panel

[Vinay Simha BN]

Add support for the JDI LT070ME05000 WUXGA DSI panel used in
Nexus 7 2013 devices.

Programming sequence for the panel is was originally found in the
android-msm-flo-3.4-lollipop-release branch from:
    https://android.googlesource.com/kernel/msm.git

And video mode setting is from dsi-panel-jdi-dualmipi1-video.dtsi
file in:
    git://codeaurora.org/kernel/msm-3.10.git  LNX.LA.3.6_rb1.27

Cc: Archit Taneja <archit.taneja@xxxxxxxxx>
Cc: Rob Clark <robdclark@xxxxxxxxx>
Cc: Sumit Semwal <sumit.semwal@xxxxxxxxxx>
Cc: John Stultz <john.stultz@xxxxxxxxxx>
Cc: Emil Velikov <emil.l.velikov@xxxxxxxxx>
Cc: Thierry Reding <thierry.reding@xxxxxxxxx>
Cc: David Airlie <airlied@xxxxxxxx>
Signed-off-by: Sumit Semwal <sumit.semwal@xxxxxxxxxx>
Signed-off-by: John Stultz <john.stultz@xxxxxxxxxx>
Signed-off-by: Vinay Simha BN <simhavcs@xxxxxxxxx>
Tested-by: John Stultz <john.stultz@xxxxxxxxxx>
Reviewed-by: Emil Velikov <emil.l.velikov@xxxxxxxxx>

---
v1:
 * sumit ported to drm/panel framework, john cherry-picked to mainline,
   folded down other fixes from Vinay and Archit, vinay removed interface
   setting cmd mode, video mode panel selected

v2:
 * incorporated code reviews from theiry, archit
   code style, alphabetical soring in Makefile, Kconfig, regulator_bulk,
   arrays of u8, generic helper function, documentation bindings,

v3:
 * dcs backlight support added
 * tested this panel driver in nexus7 2013 device

v4:
 * backlight interface added in the panel driver
 * incorporated width_mm and height_mm suggested by rob herring

v5:
 * theirry review comments incorporated
   panel model naming consistent, alphabetical soring in Kconfig
   Makefile, MAX_BRIGHTNESS dropped, regulator_names, parameterize
   panel width and height, descprition for control display, cabc
   and interface setting, temporary variable removed, consistent
   error reporting and commit message
 * removed tear on/off, scanline, since these are required only
   for command mode panels

v6:
 * emil review comments incorporated
   PANEL_NUM_REGULATORS dropped, return ret added at necessary
   places, if checks dropped for backlight and gpios

v7:
 * emil review comments incorporated
   added ARRAY_SIZE in struct, regulator_bulk_disable in poweroff,
   gpios checks dropped.
   some returns cannot be dropped, since drm panel framework return
   type required.

v8:
 * emil review commnets incorporated for jdi_panel_unprepare,
   dropped the returns (ref: panel-sharp-lq101r1sx01.c) and
   for jdi_panel_prepare(panel_on) it does not return prematurely
   and goes to poweroff if not success
 * few dev_err's for panel_init
---
 drivers/gpu/drm/panel/Kconfig                  |  11 +
 drivers/gpu/drm/panel/Makefile                 |   1 +
 drivers/gpu/drm/panel/panel-jdi-lt070me05000.c | 518 +++++++++++++++++++++++++
 3 files changed, 530 insertions(+)
 create mode 100644 drivers/gpu/drm/panel/panel-jdi-lt070me05000.c

diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
index 1500ab9..62aba97 100644
--- a/drivers/gpu/drm/panel/Kconfig
+++ b/drivers/gpu/drm/panel/Kconfig
@@ -18,6 +18,17 @@ config DRM_PANEL_SIMPLE
 	  that it can be automatically turned off when the panel goes into a
 	  low power state.
 
+config DRM_PANEL_JDI_LT070ME05000
+	tristate "JDI LT070ME05000 WUXGA DSI 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 JDI DSI video mode
+	  panel as found in Google Nexus 7 (2013) devices.
+	  The panel has a 1200(RGB)Ã1920 (WUXGA) resolution and uses
+	  24 bit per pixel.
+
 config DRM_PANEL_SAMSUNG_LD9040
 	tristate "Samsung LD9040 RGB/SPI panel"
 	depends on OF && SPI
diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
index f277eed..a5c7ec0 100644
--- a/drivers/gpu/drm/panel/Makefile
+++ b/drivers/gpu/drm/panel/Makefile
@@ -1,4 +1,5 @@
 obj-$(CONFIG_DRM_PANEL_SIMPLE) += panel-simple.o
+obj-$(CONFIG_DRM_PANEL_JDI_LT070ME05000) += panel-jdi-lt070me05000.o
 obj-$(CONFIG_DRM_PANEL_LG_LG4573) += panel-lg-lg4573.o
 obj-$(CONFIG_DRM_PANEL_PANASONIC_VVX10F034N00) += panel-panasonic-vvx10f034n00.o
 obj-$(CONFIG_DRM_PANEL_SAMSUNG_LD9040) += panel-samsung-ld9040.o
diff --git a/drivers/gpu/drm/panel/panel-jdi-lt070me05000.c b/drivers/gpu/drm/panel/panel-jdi-lt070me05000.c
new file mode 100644
index 0000000..3af35ad
--- /dev/null
+++ b/drivers/gpu/drm/panel/panel-jdi-lt070me05000.c
@@ -0,0 +1,518 @@
+/*
+ * Copyright (C) 2016 InforceComputing
+ * Author: Vinay Simha BN <simhavcs@xxxxxxxxx>
+ *
+ * Copyright (C) 2016 Linaro Ltd
+ * Author: Sumit Semwal <sumit.semwal@xxxxxxxxxx>
+ *
+ * From internet archives, the panel for Nexus 7 2nd Gen, 2013 model is a
+ * JDI model LT070ME05000, and its data sheet is at:
+ * http://panelone.net/en/7-0-inch/JDI_LT070ME05000_7.0_inch-datasheet
+ *
+ * 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/gpio/consumer.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>
+
+static const char * const regulator_names[] = {
+	"vddp",
+	"dcdc_en",
+	"vcc"
+};
+
+struct jdi_panel {
+	struct drm_panel base;
+	struct mipi_dsi_device *dsi;
+
+	struct regulator_bulk_data supplies[ARRAY_SIZE(regulator_names)];
+
+	struct gpio_desc *reset_gpio;
+	struct gpio_desc *enable_gpio;
+	struct backlight_device *backlight;
+
+	bool prepared;
+	bool enabled;
+
+	const struct drm_display_mode *mode;
+};
+
+static inline struct jdi_panel *to_jdi_panel(struct drm_panel *panel)
+{
+	return container_of(panel, struct jdi_panel, base);
+}
+
+static int jdi_panel_init(struct jdi_panel *jdi)
+{
+	struct mipi_dsi_device *dsi = jdi->dsi;
+	struct device *dev = &jdi->dsi->dev;
+	int ret;
+
+	dsi->mode_flags |= MIPI_DSI_MODE_LPM;
+
+	ret = mipi_dsi_dcs_soft_reset(dsi);
+	if (ret < 0)
+		return ret;
+
+	usleep_range(10000, 20000);
+
+	ret = mipi_dsi_dcs_set_pixel_format(dsi, MIPI_DCS_PIXEL_FMT_24BIT << 4);
+	if (ret < 0) {
+		dev_err(dev, "failed to set pixel format: %d\n", ret);
+		return ret;
+	}
+
+	ret = mipi_dsi_dcs_set_column_address(dsi, 0, jdi->mode->hdisplay - 1);
+	if (ret < 0) {
+		dev_err(dev, "failed to set column address: %d\n", ret);
+		return ret;
+	}
+
+	ret = mipi_dsi_dcs_set_page_address(dsi, 0, jdi->mode->vdisplay - 1);
+	if (ret < 0) {
+		dev_err(dev, "failed to set page address: %d\n", ret);
+		return ret;
+	}
+
+	/*
+	 * BIT(5) BCTRL = 1 Backlight Control Block On, Brightness registers
+	 *                  are active
+	 * BIT(3) BL = 1    Backlight Control On
+	 * BIT(2) DD = 0    Display Dimming is Off
+	 */
+	ret = mipi_dsi_dcs_write(dsi, MIPI_DCS_WRITE_CONTROL_DISPLAY,
+				 (u8[]){ 0x24 }, 1);
+	if (ret < 0) {
+		dev_err(dev, "failed to write control display: %d\n", ret);
+		return ret;
+	}
+
+	/* CABC off */
+	ret = mipi_dsi_dcs_write(dsi, MIPI_DCS_WRITE_POWER_SAVE,
+				 (u8[]){ 0x00 }, 1);
+	if (ret < 0) {
+		dev_err(dev, "failed to set cabc off: %d\n", ret);
+		return ret;
+	}
+
+	ret = mipi_dsi_dcs_exit_sleep_mode(dsi);
+	if (ret < 0) {
+		dev_err(dev, "failed to set exit sleep mode: %d\n", ret);
+		return ret;
+	}
+
+	msleep(120);
+
+	ret = mipi_dsi_generic_write(dsi, (u8[]){0xB0, 0x00}, 2);
+	if (ret < 0) {
+		dev_err(dev, "failed to set mcap: %d\n", ret);
+		return ret;
+	}
+
+	mdelay(10);
+
+	/* Interface setting, video mode */
+	ret = mipi_dsi_generic_write(dsi, (u8[])
+				     {0xB3, 0x26, 0x08, 0x00, 0x20, 0x00}, 6);
+	if (ret < 0) {
+		dev_err(dev, "failed to set display interface setting: %d\n"
+			, ret);
+		return ret;
+	}
+
+	mdelay(20);
+
+	ret = mipi_dsi_generic_write(dsi, (u8[]){0xB0, 0x03}, 2);
+	if (ret < 0) {
+		dev_err(dev, "failed to set default values for mcap: %d\n"
+			, ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int jdi_panel_on(struct jdi_panel *jdi)
+{
+	struct mipi_dsi_device *dsi = jdi->dsi;
+	struct device *dev = &jdi->dsi->dev;
+	int ret;
+
+	dsi->mode_flags |= MIPI_DSI_MODE_LPM;
+
+	ret = mipi_dsi_dcs_set_display_on(dsi);
+	if (ret < 0)
+		dev_err(dev, "failed to set display on: %d\n", ret);
+
+	return ret;
+}
+
+static void jdi_panel_off(struct jdi_panel *jdi)
+{
+	struct mipi_dsi_device *dsi = jdi->dsi;
+	struct device *dev = &jdi->dsi->dev;
+	int ret;
+
+	dsi->mode_flags &= ~MIPI_DSI_MODE_LPM;
+
+	ret = mipi_dsi_dcs_set_display_off(dsi);
+	if (ret < 0)
+		dev_err(dev, "failed to set display off: %d\n", ret);
+
+	ret = mipi_dsi_dcs_enter_sleep_mode(dsi);
+	if (ret < 0)
+		dev_err(dev, "failed to enter sleep mode: %d\n", ret);
+
+	msleep(100);
+}
+
+static int jdi_panel_disable(struct drm_panel *panel)
+{
+	struct jdi_panel *jdi = to_jdi_panel(panel);
+
+	if (!jdi->enabled)
+		return 0;
+
+	jdi->backlight->props.power = FB_BLANK_POWERDOWN;
+	backlight_update_status(jdi->backlight);
+
+	jdi->enabled = false;
+
+	return 0;
+}
+
+static int jdi_panel_unprepare(struct drm_panel *panel)
+{
+	struct jdi_panel *jdi = to_jdi_panel(panel);
+	struct device *dev = &jdi->dsi->dev;
+	int ret;
+
+	if (!jdi->prepared)
+		return 0;
+
+	jdi_panel_off(jdi);
+
+	ret = regulator_bulk_disable(ARRAY_SIZE(jdi->supplies), jdi->supplies);
+	if (ret < 0)
+		dev_err(dev, "regulator disable failed, %d\n", ret);
+
+	gpiod_set_value(jdi->enable_gpio, 0);
+
+	gpiod_set_value(jdi->reset_gpio, 0);
+
+	jdi->prepared = false;
+
+	return 0;
+}
+
+static int jdi_panel_prepare(struct drm_panel *panel)
+{
+	struct jdi_panel *jdi = to_jdi_panel(panel);
+	struct device *dev = &jdi->dsi->dev;
+	int ret;
+
+	if (jdi->prepared)
+		return 0;
+
+	ret = regulator_bulk_enable(ARRAY_SIZE(jdi->supplies), jdi->supplies);
+	if (ret < 0) {
+		dev_err(dev, "regulator enable failed, %d\n", ret);
+		return ret;
+	}
+
+	msleep(20);
+
+	gpiod_set_value(jdi->reset_gpio, 1);
+	usleep_range(10, 20);
+
+	gpiod_set_value(jdi->enable_gpio, 1);
+	usleep_range(10, 20);
+
+	ret = jdi_panel_init(jdi);
+	if (ret < 0) {
+		dev_err(panel->dev, "failed to init panel: %d\n", ret);
+		goto poweroff;
+	}
+
+	ret = jdi_panel_on(jdi);
+	if (ret < 0) {
+		dev_err(panel->dev, "failed to set panel on: %d\n", ret);
+		goto poweroff;
+	}
+
+	jdi->prepared = true;
+
+	return 0;
+
+poweroff:
+	ret = regulator_bulk_disable(ARRAY_SIZE(jdi->supplies), jdi->supplies);
+	if (ret < 0)
+		dev_err(dev, "regulator disable failed, %d\n", ret);
+
+	gpiod_set_value(jdi->enable_gpio, 0);
+
+	gpiod_set_value(jdi->reset_gpio, 0);
+
+	return ret;
+}
+
+static int jdi_panel_enable(struct drm_panel *panel)
+{
+	struct jdi_panel *jdi = to_jdi_panel(panel);
+
+	if (jdi->enabled)
+		return 0;
+
+	jdi->backlight->props.power = FB_BLANK_UNBLANK;
+	backlight_update_status(jdi->backlight);
+
+	jdi->enabled = true;
+
+	return 0;
+}
+
+static const struct drm_display_mode default_mode = {
+		.clock = 155493,
+		.hdisplay = 1200,
+		.hsync_start = 1200 + 48,
+		.hsync_end = 1200 + 48 + 32,
+		.htotal = 1200 + 48 + 32 + 60,
+		.vdisplay = 1920,
+		.vsync_start = 1920 + 3,
+		.vsync_end = 1920 + 3 + 5,
+		.vtotal = 1920 + 3 + 5 + 6,
+		.vrefresh = 60,
+		.flags = 0,
+};
+
+static int jdi_panel_get_modes(struct drm_panel *panel)
+{
+	struct drm_display_mode *mode;
+	struct jdi_panel *jdi = to_jdi_panel(panel);
+	struct device *dev = &jdi->dsi->dev;
+
+	mode = drm_mode_duplicate(panel->drm, &default_mode);
+	if (!mode) {
+		dev_err(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 = 95;
+	panel->connector->display_info.height_mm = 151;
+
+	return 1;
+}
+
+static int dsi_dcs_bl_get_brightness(struct backlight_device *bl)
+{
+	struct mipi_dsi_device *dsi = bl_get_data(bl);
+	int ret;
+	u16 brightness = bl->props.brightness;
+
+	dsi->mode_flags &= ~MIPI_DSI_MODE_LPM;
+
+	ret = mipi_dsi_dcs_get_display_brightness(dsi, &brightness);
+	if (ret < 0)
+		return ret;
+
+	dsi->mode_flags |= MIPI_DSI_MODE_LPM;
+
+	return brightness & 0xff;
+}
+
+static int dsi_dcs_bl_update_status(struct backlight_device *bl)
+{
+	struct mipi_dsi_device *dsi = bl_get_data(bl);
+	int ret;
+
+	dsi->mode_flags &= ~MIPI_DSI_MODE_LPM;
+
+	ret = mipi_dsi_dcs_set_display_brightness(dsi, bl->props.brightness);
+	if (ret < 0)
+		return ret;
+
+	dsi->mode_flags |= MIPI_DSI_MODE_LPM;
+
+	return 0;
+}
+
+static const struct backlight_ops dsi_bl_ops = {
+	.update_status = dsi_dcs_bl_update_status,
+	.get_brightness = dsi_dcs_bl_get_brightness,
+};
+
+struct backlight_device *
+drm_panel_create_dsi_backlight(struct mipi_dsi_device *dsi)
+{
+	struct device *dev = &dsi->dev;
+	struct backlight_properties props;
+
+	memset(&props, 0, sizeof(props));
+	props.type = BACKLIGHT_RAW;
+	props.brightness = 255;
+	props.max_brightness = 255;
+
+	return devm_backlight_device_register(dev, dev_name(dev), dev, dsi,
+					      &dsi_bl_ops, &props);
+}
+
+static const struct drm_panel_funcs jdi_panel_funcs = {
+	.disable = jdi_panel_disable,
+	.unprepare = jdi_panel_unprepare,
+	.prepare = jdi_panel_prepare,
+	.enable = jdi_panel_enable,
+	.get_modes = jdi_panel_get_modes,
+};
+
+static const struct of_device_id jdi_of_match[] = {
+	{ .compatible = "jdi,lt070me05000", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, jdi_of_match);
+
+static int jdi_panel_add(struct jdi_panel *jdi)
+{
+	struct device *dev = &jdi->dsi->dev;
+	int ret;
+	unsigned int i;
+
+	jdi->mode = &default_mode;
+
+	for (i = 0; i < ARRAY_SIZE(jdi->supplies); i++)
+		jdi->supplies[i].supply = regulator_names[i];
+
+	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(jdi->supplies),
+				      jdi->supplies);
+	if (ret < 0) {
+		dev_err(dev, "failed to init regulator, ret=%d\n", ret);
+		return ret;
+	}
+
+	jdi->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
+	if (IS_ERR(jdi->reset_gpio)) {
+		ret = PTR_ERR(jdi->reset_gpio);
+		dev_err(dev, "cannot get reset-gpios %d\n", ret);
+		return ret;
+	}
+
+	jdi->enable_gpio = devm_gpiod_get(dev, "enable", GPIOD_OUT_LOW);
+	if (IS_ERR(jdi->enable_gpio)) {
+		ret = PTR_ERR(jdi->enable_gpio);
+		dev_err(dev, "cannot get enable-gpio %d\n", ret);
+		return ret;
+	}
+
+	jdi->backlight = drm_panel_create_dsi_backlight(jdi->dsi);
+	if (IS_ERR(jdi->backlight)) {
+		ret = PTR_ERR(jdi->backlight);
+		dev_err(dev, "failed to register backlight %d\n", ret);
+		return ret;
+	}
+
+	drm_panel_init(&jdi->base);
+	jdi->base.funcs = &jdi_panel_funcs;
+	jdi->base.dev = &jdi->dsi->dev;
+
+	ret = drm_panel_add(&jdi->base);
+
+	return ret;
+}
+
+static void jdi_panel_del(struct jdi_panel *jdi)
+{
+	if (jdi->base.dev)
+		drm_panel_remove(&jdi->base);
+}
+
+static int jdi_panel_probe(struct mipi_dsi_device *dsi)
+{
+	struct jdi_panel *jdi;
+	int ret;
+
+	dsi->lanes = 4;
+	dsi->format = MIPI_DSI_FMT_RGB888;
+	dsi->mode_flags =  MIPI_DSI_MODE_VIDEO_HSE | MIPI_DSI_MODE_VIDEO |
+			   MIPI_DSI_CLOCK_NON_CONTINUOUS;
+
+	jdi = devm_kzalloc(&dsi->dev, sizeof(*jdi), GFP_KERNEL);
+	if (!jdi)
+		return -ENOMEM;
+
+	mipi_dsi_set_drvdata(dsi, jdi);
+
+	jdi->dsi = dsi;
+
+	ret = jdi_panel_add(jdi);
+	if (ret < 0)
+		return ret;
+
+	return mipi_dsi_attach(dsi);
+}
+
+static int jdi_panel_remove(struct mipi_dsi_device *dsi)
+{
+	struct jdi_panel *jdi = mipi_dsi_get_drvdata(dsi);
+	int ret;
+
+	ret = jdi_panel_disable(&jdi->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(&jdi->base);
+	jdi_panel_del(jdi);
+
+	return 0;
+}
+
+static void jdi_panel_shutdown(struct mipi_dsi_device *dsi)
+{
+	struct jdi_panel *jdi = mipi_dsi_get_drvdata(dsi);
+
+	jdi_panel_disable(&jdi->base);
+}
+
+static struct mipi_dsi_driver jdi_panel_driver = {
+	.driver = {
+		.name = "panel-jdi-lt070me05000",
+		.of_match_table = jdi_of_match,
+	},
+	.probe = jdi_panel_probe,
+	.remove = jdi_panel_remove,
+	.shutdown = jdi_panel_shutdown,
+};
+module_mipi_dsi_driver(jdi_panel_driver);
+
+MODULE_AUTHOR("Sumit Semwal <sumit.semwal@xxxxxxxxxx>");
+MODULE_AUTHOR("Vinay Simha BN <simhavcs@xxxxxxxxx>");
+MODULE_DESCRIPTION("JDI LT070ME05000 WUXGA");
+MODULE_LICENSE("GPL v2");
-- 
2.1.2