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-de...@vger.kernel.org
Cc: Douglas Anderson <diand...@chromium.org>
Cc: Noralf Trønnes <nor...@tronnes.org>
Signed-off-by: Linus Walleij <linus.wall...@linaro.org>
---
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    | 440 ++++++++++++++++++
 4 files changed, 457 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.wall...@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 <airl...@linux.ie>
 M:     Daniel Vetter <dan...@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..e5731c08fc94
--- /dev/null
+++ b/drivers/gpu/drm/panel/panel-widechips-ws2401.c
@@ -0,0 +1,440 @@
+// 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.wall...@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);
+}
+
+#define ws2401_command(ws, cmd, seq...) \
+({ \
+       struct mipi_dbi *dbi = &ws->dbi; \
+       int ret; \
+       ret = mipi_dbi_command(dbi, cmd, seq);  \
+       if (ret) \
+               dev_err(ws->dev, "failure in writing command %#02x\n", cmd); \
+})
+
+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, &id1);
+       if (ret) {
+               dev_err(ws->dev, "unable to read MTP ID 2\n");
+               return;
+       }
+       ret = mipi_dbi_command_read(dbi, WS2401_READ_ID3, &id1);
+       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)
+{
+       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");
+
+       /*
+        * Exit sleep mode and initialize display - some hammering is
+        * necessary.
+        */
+       ws2401_command(ws, MIPI_DCS_EXIT_SLEEP_MODE);
+       ws2401_command(ws, MIPI_DCS_EXIT_SLEEP_MODE);
+       msleep(50);
+
+       /* Magic to unlock level 2 control of the display */
+       ws2401_command(ws, WS2401_PASSWD1, 0x5a, 0x5a);
+       /* Configure resolution to 480RGBx800 */
+       ws2401_command(ws, WS2401_RESCTL, 0x12);
+       /* Set addressing mode Flip V(d0), Flip H(d1) RGB/BGR(d3) */
+       ws2401_command(ws, MIPI_DCS_SET_ADDRESS_MODE, 0x01);
+       /* Set pixel format: 24 bpp */
+       ws2401_command(ws, MIPI_DCS_SET_PIXEL_FORMAT, 0x70);
+       ws2401_command(ws, WS2401_SMPS, 0x00, 0x0f);
+       ws2401_command(ws, WS2401_PSMPS, 0x06, 0x03, /* DDVDH: 4.6v */
+                      0x7e, 0x03, 0x12, 0x37);
+       ws2401_command(ws, WS2401_NSMPS, 0x06, 0x03, /* DDVDH: -4.6v */
+                      0x7e, 0x02, 0x15, 0x37);
+       ws2401_command(ws, WS2401_SMPS, 0x02, 0x0f);
+       ws2401_command(ws, WS2401_PWRCTL, 0x10, 0xA9, 0x00, 0x01, 0x44,
+                      0xb4,    /* VGH:16.1v, VGL:-13.8v */
+                      0x50,    /* GREFP:4.2v (default) */
+                      0x50,    /* GREFN:-4.2v (default) */
+                      0x00,
+                      0x44);   /* VOUTL:-10v (default) */
+       ws2401_command(ws, WS2401_DISCTL, 0x01, 0x00, 0x00, 0x00, 0x14,
+                      0x16);
+       ws2401_command(ws, WS2401_VCOMCTL, 0x30, 0x53, 0x53);
+       ws2401_command(ws, WS2401_SRCCTL, 0x03, 0x0C, 0x00, 0x00, 0x00,
+                      0x01,    /* 2 dot inversion */
+                      0x01, 0x06, 0x03);
+       ws2401_command(ws, WS2401_PANELCTL, 0x14, 0x00, 0x80, 0x00);
+       ws2401_command(ws, WS2401_WRMIE, 0x01);
+
+       /* Set up gamma, probably these are P-gamma and N-gamma for each color 
*/
+       ws2401_command(ws, WS2401_GAMMA_R1, 0x00,
+                      0x5b, 0x42, 0x41, 0x3f, 0x42, 0x3d, 0x38, 0x2e,
+                      0x2b, 0x2a, 0x27, 0x22, 0x27, 0x0f, 0x00, 0x00);
+       ws2401_command(ws, WS2401_GAMMA_R2, 0x00,
+                      0x5b, 0x42, 0x41, 0x3f, 0x42, 0x3d, 0x38, 0x2e,
+                      0x2b, 0x2a, 0x27, 0x22, 0x27, 0x0f, 0x00, 0x00);
+       ws2401_command(ws, WS2401_GAMMA_G1, 0x00,
+                      0x59, 0x40, 0x3f, 0x3e, 0x41, 0x3d, 0x39, 0x2f,
+                      0x2c, 0x2b, 0x29, 0x25, 0x29, 0x19, 0x08, 0x00);
+       ws2401_command(ws, WS2401_GAMMA_G2, 0x00,
+                      0x59, 0x40, 0x3f, 0x3e, 0x41, 0x3d, 0x39, 0x2f,
+                      0x2c, 0x2b, 0x29, 0x25, 0x29, 0x19, 0x08, 0x00);
+       ws2401_command(ws, WS2401_GAMMA_B1, 0x00,
+                      0x57, 0x3b, 0x3a, 0x3b, 0x3f, 0x3b, 0x38, 0x27,
+                      0x38, 0x2a, 0x26, 0x22, 0x34, 0x0c, 0x09, 0x00);
+       ws2401_command(ws, WS2401_GAMMA_B2, 0x00,
+                      0x57, 0x3b, 0x3a, 0x3b, 0x3f, 0x3b, 0x38, 0x27,
+                      0x38, 0x2a, 0x26, 0x22, 0x34, 0x0c, 0x09, 0x00);
+
+       if (ws->bl) {
+               ws2401_command(ws, WS2401_WRCTRLD, 0x2c);
+       } else {
+               ws2401_command(ws, WS2401_WRCTRLD, 0x00);
+               /*
+                * When not using internal backlight we do not need any further
+                * L2 accesses to the panel so we close the door on our way out.
+                * Otherwise we need to leave the L2 door open.
+                */
+               ws2401_command(ws, WS2401_PASSWD1, 0xa5, 0xa5);
+       }
+
+       return 0;
+}
+
+static int ws2401_power_off(struct ws2401 *ws)
+{
+       /* Go into RESET and disable regulators */
+       gpiod_set_value_cansleep(ws->reset, 1);
+       return regulator_bulk_disable(ARRAY_SIZE(ws->regulators),
+                                     ws->regulators);
+}
+
+static int ws2401_unprepare(struct drm_panel *panel)
+{
+       struct ws2401 *ws = to_ws2401(panel);
+
+       /* Make sure we disable backlight, if any */
+       if (ws->bl)
+               ws2401_command(ws, WS2401_WRCTRLD, 0x00);
+       ws2401_command(ws, MIPI_DCS_ENTER_SLEEP_MODE);
+       msleep(120);
+       return ws2401_power_off(to_ws2401(panel));
+}
+
+static int ws2401_disable(struct drm_panel *panel)
+{
+       struct ws2401 *ws = to_ws2401(panel);
+
+       ws2401_command(ws, MIPI_DCS_SET_DISPLAY_OFF);
+       msleep(25);
+
+       return 0;
+}
+
+static int ws2401_prepare(struct drm_panel *panel)
+{
+       return ws2401_power_on(to_ws2401(panel));
+}
+
+static int ws2401_enable(struct drm_panel *panel)
+{
+       struct ws2401 *ws = to_ws2401(panel);
+
+       ws2401_command(ws, MIPI_DCS_SET_DISPLAY_ON);
+
+       return 0;
+}
+
+/**
+ * ws2401_get_modes() - return the mode
+ * @panel: the panel to get the mode for
+ * @connector: reference to the central DRM connector control structure
+ */
+static int ws2401_get_modes(struct drm_panel *panel,
+                           struct drm_connector *connector)
+{
+       struct ws2401 *ws = to_ws2401(panel);
+       struct drm_display_mode *mode;
+       static const u32 bus_format = MEDIA_BUS_FMT_RGB888_1X24;
+
+       /*
+        * We just support the LMS380KF01 so far, if we implement more panels
+        * this mode, the following connector display_info settings and
+        * probably the custom DCS sequences needs to selected based on what
+        * the target panel needs.
+        */
+       mode = drm_mode_duplicate(connector->dev, &lms380kf01_480_800_mode);
+       if (!mode) {
+               dev_err(ws->dev, "failed to add mode\n");
+               return -ENOMEM;
+       }
+
+       connector->display_info.bpc = 8;
+       connector->display_info.width_mm = mode->width_mm;
+       connector->display_info.height_mm = mode->height_mm;
+       connector->display_info.bus_flags =
+               DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE;
+       drm_display_info_set_bus_formats(&connector->display_info,
+                                        &bus_format, 1);
+
+       drm_mode_set_name(mode);
+       mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
+
+       drm_mode_probed_add(connector, mode);
+
+       return 1;
+}
+
+static const struct drm_panel_funcs ws2401_drm_funcs = {
+       .disable = ws2401_disable,
+       .unprepare = ws2401_unprepare,
+       .prepare = ws2401_prepare,
+       .enable = ws2401_enable,
+       .get_modes = ws2401_get_modes,
+};
+
+static int ws2401_set_brightness(struct backlight_device *bl)
+{
+       struct ws2401 *ws = bl_get_data(bl);
+       u8 brightness = bl->props.brightness;
+
+       ws2401_command(ws, WS2401_WRDISBV, brightness);
+
+       return 0;
+}
+
+static const struct backlight_ops ws2401_bl_ops = {
+       .update_status = ws2401_set_brightness,
+};
+
+static const struct backlight_properties ws2401_bl_props = {
+       .type = BACKLIGHT_PLATFORM,
+       .brightness = 120,
+       .max_brightness = U8_MAX,
+};
+
+static int ws2401_probe(struct spi_device *spi)
+{
+       struct device *dev = &spi->dev;
+       struct ws2401 *ws;
+       int ret;
+
+       ws = devm_kzalloc(dev, sizeof(*ws), GFP_KERNEL);
+       if (!ws)
+               return -ENOMEM;
+       ws->dev = dev;
+
+       /*
+        * VCI   is the analog voltage supply
+        * VCCIO is the digital I/O voltage supply
+        */
+       ws->regulators[0].supply = "vci";
+       ws->regulators[1].supply = "vccio";
+       ret = devm_regulator_bulk_get(dev,
+                                     ARRAY_SIZE(ws->regulators),
+                                     ws->regulators);
+       if (ret)
+               return dev_err_probe(dev, ret, "failed to get regulators\n");
+
+       ws->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
+       if (IS_ERR(ws->reset)) {
+               ret = PTR_ERR(ws->reset);
+               return dev_err_probe(dev, ret, "no RESET GPIO\n");
+       }
+
+       ret = mipi_dbi_spi_init(spi, &ws->dbi, NULL);
+       if (ret)
+               return dev_err_probe(dev, ret, "MIPI DBI init failed\n");
+       ws->dbi.read_commands = ws2401_dbi_read_commands;
+
+       ws2401_power_on(ws);
+       ws2401_read_mtp_id(ws);
+       ws2401_power_off(ws);
+
+       drm_panel_init(&ws->panel, dev, &ws2401_drm_funcs,
+                      DRM_MODE_CONNECTOR_DPI);
+
+       ret = drm_panel_of_backlight(&ws->panel);
+       if (ret) {
+               /* This is no real error, bail out and retry later */
+               if (ret == -EPROBE_DEFER)
+                       return ret;
+
+               dev_dbg(dev, "no external backlight, using internal 
backlight\n");
+               ws->bl = devm_backlight_device_register(dev, "ws2401", dev, ws,
+                                                       &ws2401_bl_ops, 
&ws2401_bl_props);
+               if (IS_ERR(ws->bl))
+                       return dev_err_probe(dev, PTR_ERR(ws->bl),
+                                            "failed to register backlight 
device\n");
+               ws->panel.backlight = ws->bl;
+       } else {
+               dev_dbg(dev, "using external backlight\n");
+       }
+
+       spi_set_drvdata(spi, ws);
+
+       drm_panel_add(&ws->panel);
+       dev_dbg(dev, "added panel\n");
+
+       return 0;
+}
+
+static int ws2401_remove(struct spi_device *spi)
+{
+       struct ws2401 *ws = spi_get_drvdata(spi);
+
+       drm_panel_remove(&ws->panel);
+       return 0;
+}
+
+/*
+ * Samsung LMS380KF01 is the one instance of this display controller that we
+ * know about, but if more are found, the controller can be parameterized
+ * here and used for other configurations.
+ */
+static const struct of_device_id ws2401_match[] = {
+       { .compatible = "samsung,lms380kf01", },
+       {},
+};
+MODULE_DEVICE_TABLE(of, ws2401_match);
+
+static struct spi_driver ws2401_driver = {
+       .probe          = ws2401_probe,
+       .remove         = ws2401_remove,
+       .driver         = {
+               .name   = "ws2401-panel",
+               .of_match_table = ws2401_match,
+       },
+};
+module_spi_driver(ws2401_driver);
+
+MODULE_AUTHOR("Linus Walleij <linus.wall...@linaro.org>");
+MODULE_DESCRIPTION("Samsung WS2401 panel driver");
+MODULE_LICENSE("GPL v2");
-- 
2.31.1

Reply via email to