Re: [PATCH 2/2 v3] drm/panel: ws2401: Add driver for WideChips WS2401

On Thu, Jul 8, 2021 at 5:25 AM Linus Walleij linus.walleij@linaro.org wrote:

This adds a driver for panels based on the WideChips WS2401 display controller. This display controller is used in the Samsung LMS380KF01 display found in the Samsung GT-I8160 (Codina) mobile phone and possibly others.

As is common with Samsung displays manufacturer commands are necessary to configure the display to a working state.

The display optionally supports internal backlight control, but can also use an external backlight.

This driver re-uses the DBI infrastructure to communicate with the display.

Cc: phone-devel@vger.kernel.org Cc: Douglas Anderson dianders@chromium.org Cc: Noralf Trønnes noralf@tronnes.org Signed-off-by: Linus Walleij linus.walleij@linaro.org

---

ChangeLog v2->v3:

• Drop the ws2401_command() macro - we enhanced the mipi_dbi_command() to print errors for everyone instead.
• Read out MTP properly (used wrong variables)
• Register internal backlight if and only if the panel->backlight field is NULL after trying to look up external backlight.

ChangeLog v1->v2:

• Disable the backlight in ->unprepare() before entering sleep mode.
• If we are not using internal backlight, close the L2 access after initializing.
• Depromote some talkative dev_info()s to dev_dbg().
• Power up and read the MTP values before we register the display. This works fine and is probably how MTP is supposed to work.
• Fix the set-up of gamma values, this was found in the GT-I8160 HD kernel tree.
• Bail out properly if drm_panel_of_backlight() returns -EDEFER_PROBE.
• Drop OF from dependencies since drm_panel_of_backlight() has static inline stubs in the header file.
• Sort MAINTAINERS properly.
• Alphabetize includes
• Use format specifier %#02x so we get 0x... output in debug
• Drop unnecessary braces around if () in debug macro
• Drop unused <of.h> include.

---

MAINTAINERS | 7 + drivers/gpu/drm/panel/Kconfig | 9 + drivers/gpu/drm/panel/Makefile | 1 + .../gpu/drm/panel/panel-widechips-ws2401.c | 436 ++++++++++++++++++ 4 files changed, 453 insertions(+) create mode 100644 drivers/gpu/drm/panel/panel-widechips-ws2401.c

diff --git a/MAINTAINERS b/MAINTAINERS index bd7aff0c120f..10bba4be1678 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -5956,6 +5956,13 @@ T: git git://people.freedesktop.org/~sroland/linux F: drivers/gpu/drm/vmwgfx/ F: include/uapi/drm/vmwgfx_drm.h

+DRM DRIVER FOR WIDECHIPS WS2401 PANELS +M: Linus Walleij linus.walleij@linaro.org +S: Maintained +T: git git://anongit.freedesktop.org/drm/drm-misc +F: Documentation/devicetree/bindings/display/panel/samsung,lms380kf01.yaml +F: drivers/gpu/drm/panel/panel-widechips-ws2401.c

DRM DRIVERS M: David Airlie airlied@linux.ie M: Daniel Vetter daniel@ffwll.ch diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig index 4894913936e9..319fa44c4bc9 100644 --- a/drivers/gpu/drm/panel/Kconfig +++ b/drivers/gpu/drm/panel/Kconfig @@ -552,6 +552,15 @@ config DRM_PANEL_VISIONOX_RM69299 Say Y here if you want to enable support for Visionox RM69299 DSI Video Mode panel.

+config DRM_PANEL_WIDECHIPS_WS2401

•   tristate "Widechips WS2401 DPI panel driver"
  

•   depends on SPI && GPIOLIB
  

•   depends on BACKLIGHT_CLASS_DEVICE
  

•   select DRM_MIPI_DBI
  

•   help
  

•     Say Y here if you want to enable support for the Widechips WS2401 DPI
  

•     480x800 display controller used in panels such as Samsung LMS380KF01.
  

config DRM_PANEL_XINPENG_XPP055C272 tristate "Xinpeng XPP055C272 panel driver" depends on OF diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile index cae4d976c069..d94c27df17aa 100644 --- a/drivers/gpu/drm/panel/Makefile +++ b/drivers/gpu/drm/panel/Makefile @@ -58,4 +58,5 @@ obj-$(CONFIG_DRM_PANEL_TPO_TD043MTEA1) += panel-tpo-td043mtea1.o obj-$(CONFIG_DRM_PANEL_TPO_TPG110) += panel-tpo-tpg110.o obj-$(CONFIG_DRM_PANEL_TRULY_NT35597_WQXGA) += panel-truly-nt35597.o obj-$(CONFIG_DRM_PANEL_VISIONOX_RM69299) += panel-visionox-rm69299.o +obj-$(CONFIG_DRM_PANEL_WIDECHIPS_WS2401) += panel-widechips-ws2401.o obj-$(CONFIG_DRM_PANEL_XINPENG_XPP055C272) += panel-xinpeng-xpp055c272.o diff --git a/drivers/gpu/drm/panel/panel-widechips-ws2401.c b/drivers/gpu/drm/panel/panel-widechips-ws2401.c new file mode 100644 index 000000000000..95825063f812 --- /dev/null +++ b/drivers/gpu/drm/panel/panel-widechips-ws2401.c @@ -0,0 +1,436 @@ +// SPDX-License-Identifier: GPL-2.0 +/*

• • Panel driver for the WideChips WS2401 480x800 DPI RGB panel, used in
• • the Samsung Mobile Display (SMD) LMS380KF01.
• • Found in the Samsung Galaxy Ace 2 GT-I8160 mobile phone.
• • Linus Walleij linus.walleij@linaro.org
• • Inspired by code and know-how in the vendor driver by Gareth Phillips.
• */

+#include <drm/drm_mipi_dbi.h> +#include <drm/drm_modes.h> +#include <drm/drm_panel.h>

+#include <linux/backlight.h> +#include <linux/delay.h> +#include <linux/gpio/consumer.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/media-bus-format.h> +#include <linux/module.h> +#include <linux/regulator/consumer.h> +#include <linux/spi/spi.h>

+#include <video/mipi_display.h>

+#define WS2401_RESCTL 0xb8 /* Resolution select control */ +#define WS2401_PSMPS 0xbd /* SMPS positive control */ +#define WS2401_NSMPS 0xbe /* SMPS negative control */ +#define WS2401_SMPS 0xbf +#define WS2401_BCMODE 0xc1 /* Backlight control mode */ +#define WS2401_WRBLCTL 0xc3 /* Backlight control */ +#define WS2401_WRDISBV 0xc4 /* Write manual brightness */ +#define WS2401_WRCTRLD 0xc6 /* Write BL control */ +#define WS2401_WRMIE 0xc7 /* Write MIE mode */ +#define WS2401_READ_ID1 0xda /* Read panel ID 1 */ +#define WS2401_READ_ID2 0xdb /* Read panel ID 2 */ +#define WS2401_READ_ID3 0xdc /* Read panel ID 3 */ +#define WS2401_GAMMA_R1 0xe7 /* Gamma red 1 */ +#define WS2401_GAMMA_G1 0xe8 /* Gamma green 1 */ +#define WS2401_GAMMA_B1 0xe9 /* Gamma blue 1 */ +#define WS2401_GAMMA_R2 0xea /* Gamma red 2 */ +#define WS2401_GAMMA_G2 0xeb /* Gamma green 2 */ +#define WS2401_GAMMA_B2 0xec /* Gamma blue 2 */ +#define WS2401_PASSWD1 0xf0 /* Password command for level 2 */ +#define WS2401_DISCTL 0xf2 /* Display control */ +#define WS2401_PWRCTL 0xf3 /* Power control */ +#define WS2401_VCOMCTL 0xf4 /* VCOM control */ +#define WS2401_SRCCTL 0xf5 /* Source control */ +#define WS2401_PANELCTL 0xf6 /* Panel control */

+static const u8 ws2401_dbi_read_commands[] = {

•   WS2401_READ_ID1,
  

•   WS2401_READ_ID2,
  

•   WS2401_READ_ID3,
  

•   0, /* sentinel */
  

+};

+/**

• • struct ws2401 - state container for a panel controlled by the WS2401
• • controller
• */

+struct ws2401 {

•   /** @dev: the container device */
  

•   struct device *dev;
  

•   /** @dbi: the DBI bus abstraction handle */
  

•   struct mipi_dbi dbi;
  

•   /** @panel: the DRM panel instance for this device */
  

•   struct drm_panel panel;
  

•   /** @width: the width of this panel in mm */
  

•   u32 width;
  

•   /** @height: the height of this panel in mm */
  

•   u32 height;
  

•   /** @reset: reset GPIO line */
  

•   struct gpio_desc *reset;
  

•   /** @regulators: VCCIO and VIO supply regulators */
  

•   struct regulator_bulk_data regulators[2];
  

•   /** @bl: Backlight, if using internal backlight */
  

•   struct backlight_device *bl;
  

+};

+static const struct drm_display_mode lms380kf01_480_800_mode = {

•   /*
  

•    * The vendor driver states that the "SMD panel" has a clock
  

•    * frequency of 49920000 Hz / 2 = 24960000 Hz.
  

•    */
  

•   .clock = 24960,
  

•   .hdisplay = 480,
  

•   .hsync_start = 480 + 8,
  

•   .hsync_end = 480 + 8 + 10,
  

•   .htotal = 480 + 8 + 10 + 8,
  

•   .vdisplay = 800,
  

•   .vsync_start = 800 + 8,
  

•   .vsync_end = 800 + 8 + 2,
  

•   .vtotal = 800 + 8 + 2 + 18,
  

•   .width_mm = 50,
  

•   .height_mm = 84,
  

•   .flags = DRM_MODE_FLAG_NVSYNC | DRM_MODE_FLAG_NHSYNC,
  

+};

+static inline struct ws2401 *to_ws2401(struct drm_panel *panel) +{

•   return container_of(panel, struct ws2401, panel);
  

+}

+static void ws2401_read_mtp_id(struct ws2401 *ws) +{

•   struct mipi_dbi *dbi = &ws->dbi;
  

•   u8 id1, id2, id3;
  

•   int ret;
  

•   ret = mipi_dbi_command_read(dbi, WS2401_READ_ID1, &id1);
  

•   if (ret) {
  

•           dev_err(ws->dev, "unable to read MTP ID 1\n");
  

•           return;
  

•   }
  

•   ret = mipi_dbi_command_read(dbi, WS2401_READ_ID2, &id2);
  

•   if (ret) {
  

•           dev_err(ws->dev, "unable to read MTP ID 2\n");
  

•           return;
  

•   }
  

•   ret = mipi_dbi_command_read(dbi, WS2401_READ_ID3, &id3);
  

•   if (ret) {
  

•           dev_err(ws->dev, "unable to read MTP ID 3\n");
  

•           return;
  

•   }
  

•   dev_info(ws->dev, "MTP ID: %02x %02x %02x\n", id1, id2, id3);
  

+}

+static int ws2401_power_on(struct ws2401 *ws) +{

•   struct mipi_dbi *dbi = &ws->dbi;
  

•   int ret;
  

•   /* Power up */
  

•   ret = regulator_bulk_enable(ARRAY_SIZE(ws->regulators),
  

•                               ws->regulators);
  

•   if (ret) {
  

•           dev_err(ws->dev, "failed to enable regulators: %d\n", ret);
  

•           return ret;
  

•   }
  

•   msleep(10);
  

•   /* Assert reset >=1 ms */
  

•   gpiod_set_value_cansleep(ws->reset, 1);
  

•   usleep_range(1000, 5000);
  

•   /* De-assert reset */
  

•   gpiod_set_value_cansleep(ws->reset, 0);
  

•   /* Wait >= 10 ms */
  

•   msleep(10);
  

•   dev_dbg(ws->dev, "de-asserted RESET\n");
  

Just a small comment, are these delays are as per init sequence mentioned in datasheet?

Jagan,