[PATCH v5] drm/panel: db7430: Add driver for Samsung DB7430
Linus Walleij
linus.walleij at linaro.org
Thu Jun 10 22:05:27 UTC 2021
This adds a new driver for the Samsung DB7430 DPI display
controller as controlled over SPI.
Right now the only panel product we know that is using this
display controller is the LMS397KF04 but there may be more.
This is the first regular panel driver making use of the
MIPI DBI helper library. The DBI "device" portions can not
be used because that code assumes the use of a single
regulator and specific timings around the reset pulse that
do not match the DB7430 datasheet.
Cc: Paul Cercueil <paul at crapouillou.net>
Cc: Doug Anderson <dianders at chromium.org>
Acked-by: Noralf Trønnes <noralf at tronnes.org>
Signed-off-by: Linus Walleij <linus.walleij at linaro.org>
---
ChangeLog v4->v5:
- Drop the SPI hardcoding to 9 BPW, so the DBI emulation
will be utilized if needed.
- Drop the MODE_3 setting: we can set this up in the DTS
instead.
- Collect Noralf's ACK.
ChangeLog v3->v4:
- Managed to make use of the in-kernel DBI support to
conjure and send 9bit DBI SPI messages.
- This cuts out a bit of overhead.
- Deeper integration with the DBI library is not done, as
assumes too much about the device, such as being used
as a stand-alone framebuffer (this device is not).
ChangeLog v2->v3:
- Fix some minor comments and formatting.
- Print an error if the DCS sequence write fails.
- Set BPC (bits per color) to 8 on the display_info. Some
drivers may need this.
ChangeLog v1->v2:
- Rename driver and variables with the db7430_* prefix instead
of lms397kf04 as there may be more display products out there
using this display controller. Also change Kconfig symbol.
- Push doc comments together on one line where possible.
- Rename DB7430_MANUFACTURER_CMD to DB7430_ACCESS_PROT_OFF
- Return error from regulator_bulk_disable() down to
db7430_unprepare() and propagate.
- Use usleep_range(1000, 5000) instead of msleep(1)
- Shorten prepare/unprepare callbacks by more compact code.
- Use devm_err_probe() and provide proper probe errors all
the way through the probe() function.
---
MAINTAINERS | 7 +
drivers/gpu/drm/panel/Kconfig | 10 +
drivers/gpu/drm/panel/Makefile | 1 +
drivers/gpu/drm/panel/panel-samsung-db7430.c | 347 +++++++++++++++++++
4 files changed, 365 insertions(+)
create mode 100644 drivers/gpu/drm/panel/panel-samsung-db7430.c
diff --git a/MAINTAINERS b/MAINTAINERS
index bd7aff0c120f..6ff4777b1018 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5857,6 +5857,13 @@ S: Maintained
F: Documentation/devicetree/bindings/display/panel/raydium,rm67191.yaml
F: drivers/gpu/drm/panel/panel-raydium-rm67191.c
+DRM DRIVER FOR SAMSUNG DB7430 PANELS
+M: Linus Walleij <linus.walleij at linaro.org>
+S: Maintained
+T: git git://anongit.freedesktop.org/drm/drm-misc
+F: Documentation/devicetree/bindings/display/panel/samsung,lms397kf04.yaml
+F: drivers/gpu/drm/panel/panel-samsung-db7430.c
+
DRM DRIVER FOR SITRONIX ST7703 PANELS
M: Guido Günther <agx at sigxcpu.org>
R: Purism Kernel Team <kernel at puri.sm>
diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
index 4894913936e9..6d1b90f4f2bb 100644
--- a/drivers/gpu/drm/panel/Kconfig
+++ b/drivers/gpu/drm/panel/Kconfig
@@ -342,6 +342,16 @@ config DRM_PANEL_RONBO_RB070D30
Say Y here if you want to enable support for Ronbo Electronics
RB070D30 1024x600 DSI panel.
+config DRM_PANEL_SAMSUNG_DB7430
+ tristate "Samsung DB7430-based DPI panels"
+ depends on OF && SPI && GPIOLIB
+ depends on BACKLIGHT_CLASS_DEVICE
+ select DRM_MIPI_DBI
+ help
+ Say Y here if you want to enable support for the Samsung
+ DB7430 DPI display controller used in such devices as the
+ LMS397KF04 480x800 DPI panel.
+
config DRM_PANEL_SAMSUNG_S6D16D0
tristate "Samsung S6D16D0 DSI video mode panel"
depends on OF
diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
index cae4d976c069..a350e0990d17 100644
--- a/drivers/gpu/drm/panel/Makefile
+++ b/drivers/gpu/drm/panel/Makefile
@@ -33,6 +33,7 @@ obj-$(CONFIG_DRM_PANEL_RASPBERRYPI_TOUCHSCREEN) += panel-raspberrypi-touchscreen
obj-$(CONFIG_DRM_PANEL_RAYDIUM_RM67191) += panel-raydium-rm67191.o
obj-$(CONFIG_DRM_PANEL_RAYDIUM_RM68200) += panel-raydium-rm68200.o
obj-$(CONFIG_DRM_PANEL_RONBO_RB070D30) += panel-ronbo-rb070d30.o
+obj-$(CONFIG_DRM_PANEL_SAMSUNG_DB7430) += panel-samsung-db7430.o
obj-$(CONFIG_DRM_PANEL_SAMSUNG_LD9040) += panel-samsung-ld9040.o
obj-$(CONFIG_DRM_PANEL_SAMSUNG_S6D16D0) += panel-samsung-s6d16d0.o
obj-$(CONFIG_DRM_PANEL_SAMSUNG_S6E3HA2) += panel-samsung-s6e3ha2.o
diff --git a/drivers/gpu/drm/panel/panel-samsung-db7430.c b/drivers/gpu/drm/panel/panel-samsung-db7430.c
new file mode 100644
index 000000000000..fe58263bd9cd
--- /dev/null
+++ b/drivers/gpu/drm/panel/panel-samsung-db7430.c
@@ -0,0 +1,347 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Panel driver for the Samsung LMS397KF04 480x800 DPI RGB panel.
+ * According to the data sheet the display controller is called DB7430.
+ * Found in the Samsung Galaxy Beam GT-I8350 mobile phone.
+ * Linus Walleij <linus.walleij at linaro.org>
+ */
+#include <drm/drm_modes.h>
+#include <drm/drm_mipi_dbi.h>
+#include <drm/drm_panel.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/of.h>
+#include <linux/regulator/consumer.h>
+#include <linux/spi/spi.h>
+
+#include <video/mipi_display.h>
+
+#define DB7430_ACCESS_PROT_OFF 0xb0
+#define DB7430_UNKNOWN_B4 0xb4
+#define DB7430_USER_SELECT 0xb5
+#define DB7430_UNKNOWN_B7 0xb7
+#define DB7430_UNKNOWN_B8 0xb8
+#define DB7430_PANEL_DRIVING 0xc0
+#define DB7430_SOURCE_CONTROL 0xc1
+#define DB7430_GATE_INTERFACE 0xc4
+#define DB7430_DISPLAY_H_TIMING 0xc5
+#define DB7430_RGB_SYNC_OPTION 0xc6
+#define DB7430_GAMMA_SET_RED 0xc8
+#define DB7430_GAMMA_SET_GREEN 0xc9
+#define DB7430_GAMMA_SET_BLUE 0xca
+#define DB7430_BIAS_CURRENT_CTRL 0xd1
+#define DB7430_DDV_CTRL 0xd2
+#define DB7430_GAMMA_CTRL_REF 0xd3
+#define DB7430_UNKNOWN_D4 0xd4
+#define DB7430_DCDC_CTRL 0xd5
+#define DB7430_VCL_CTRL 0xd6
+#define DB7430_UNKNOWN_F8 0xf8
+#define DB7430_UNKNOWN_FC 0xfc
+
+#define DATA_MASK 0x100
+
+/**
+ * struct db7430 - state container for a panel controlled by the DB7430
+ * controller
+ */
+struct db7430 {
+ /** @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];
+};
+
+static const struct drm_display_mode db7430_480_800_mode = {
+ /*
+ * 31 ns period min (htotal*vtotal*vrefresh)/1000
+ * gives a Vrefresh of ~71 Hz.
+ */
+ .clock = 32258,
+ .hdisplay = 480,
+ .hsync_start = 480 + 10,
+ .hsync_end = 480 + 10 + 4,
+ .htotal = 480 + 10 + 4 + 40,
+ .vdisplay = 800,
+ .vsync_start = 800 + 6,
+ .vsync_end = 800 + 6 + 1,
+ .vtotal = 800 + 6 + 1 + 7,
+ .width_mm = 53,
+ .height_mm = 87,
+ .flags = DRM_MODE_FLAG_NVSYNC | DRM_MODE_FLAG_NHSYNC,
+};
+
+static inline struct db7430 *to_db7430(struct drm_panel *panel)
+{
+ return container_of(panel, struct db7430, panel);
+}
+
+static int db7430_power_on(struct db7430 *db)
+{
+ struct mipi_dbi *dbi = &db->dbi;
+ int ret;
+
+ /* Power up */
+ ret = regulator_bulk_enable(ARRAY_SIZE(db->regulators),
+ db->regulators);
+ if (ret) {
+ dev_err(db->dev, "failed to enable regulators: %d\n", ret);
+ return ret;
+ }
+ msleep(50);
+
+ /* Assert reset >=1 ms */
+ gpiod_set_value_cansleep(db->reset, 1);
+ usleep_range(1000, 5000);
+ /* De-assert reset */
+ gpiod_set_value_cansleep(db->reset, 0);
+ /* Wait >= 10 ms */
+ msleep(10);
+ dev_dbg(db->dev, "de-asserted RESET\n");
+
+ /*
+ * This is set to 0x0a (RGB/BGR order + horizontal flip) in order
+ * to make the display behave normally. If this is not set the displays
+ * normal output behaviour is horizontally flipped and BGR ordered. Do
+ * it twice because the first message doesn't always "take".
+ */
+ mipi_dbi_command(dbi, MIPI_DCS_SET_ADDRESS_MODE, 0x0a);
+ mipi_dbi_command(dbi, MIPI_DCS_SET_ADDRESS_MODE, 0x0a);
+ mipi_dbi_command(dbi, DB7430_ACCESS_PROT_OFF, 0x00);
+ mipi_dbi_command(dbi, DB7430_PANEL_DRIVING, 0x28, 0x08);
+ mipi_dbi_command(dbi, DB7430_SOURCE_CONTROL,
+ 0x01, 0x30, 0x15, 0x05, 0x22);
+ mipi_dbi_command(dbi, DB7430_GATE_INTERFACE,
+ 0x10, 0x01, 0x00);
+ mipi_dbi_command(dbi, DB7430_DISPLAY_H_TIMING,
+ 0x06, 0x55, 0x03, 0x07, 0x0b,
+ 0x33, 0x00, 0x01, 0x03);
+ /*
+ * 0x00 in datasheet 0x01 in vendor code 0x00, it seems 0x01 means
+ * DE active high and 0x00 means DE active low.
+ */
+ mipi_dbi_command(dbi, DB7430_RGB_SYNC_OPTION, 0x01);
+ mipi_dbi_command(dbi, DB7430_GAMMA_SET_RED,
+ /* R positive gamma */ 0x00,
+ 0x0A, 0x31, 0x3B, 0x4E, 0x58, 0x59, 0x5B, 0x58, 0x5E, 0x62,
+ 0x60, 0x61, 0x5E, 0x62, 0x55, 0x55, 0x7F, 0x08,
+ /* R negative gamma */ 0x00,
+ 0x0A, 0x31, 0x3B, 0x4E, 0x58, 0x59, 0x5B, 0x58, 0x5E, 0x62,
+ 0x60, 0x61, 0x5E, 0x62, 0x55, 0x55, 0x7F, 0x08);
+ mipi_dbi_command(dbi, DB7430_GAMMA_SET_GREEN,
+ /* G positive gamma */ 0x00,
+ 0x25, 0x15, 0x28, 0x3D, 0x4A, 0x48, 0x4C, 0x4A, 0x52, 0x59,
+ 0x59, 0x5B, 0x56, 0x60, 0x5D, 0x55, 0x7F, 0x0A,
+ /* G negative gamma */ 0x00,
+ 0x25, 0x15, 0x28, 0x3D, 0x4A, 0x48, 0x4C, 0x4A, 0x52, 0x59,
+ 0x59, 0x5B, 0x56, 0x60, 0x5D, 0x55, 0x7F, 0x0A);
+ mipi_dbi_command(dbi, DB7430_GAMMA_SET_BLUE,
+ /* B positive gamma */ 0x00,
+ 0x48, 0x10, 0x1F, 0x2F, 0x35, 0x38, 0x3D, 0x3C, 0x45, 0x4D,
+ 0x4E, 0x52, 0x51, 0x60, 0x7F, 0x7E, 0x7F, 0x0C,
+ /* B negative gamma */ 0x00,
+ 0x48, 0x10, 0x1F, 0x2F, 0x35, 0x38, 0x3D, 0x3C, 0x45, 0x4D,
+ 0x4E, 0x52, 0x51, 0x60, 0x7F, 0x7E, 0x7F, 0x0C);
+ mipi_dbi_command(dbi, DB7430_BIAS_CURRENT_CTRL, 0x33, 0x13);
+ mipi_dbi_command(dbi, DB7430_DDV_CTRL, 0x11, 0x00, 0x00);
+ mipi_dbi_command(dbi, DB7430_GAMMA_CTRL_REF, 0x50, 0x50);
+ mipi_dbi_command(dbi, DB7430_DCDC_CTRL, 0x2f, 0x11, 0x1e, 0x46);
+ mipi_dbi_command(dbi, DB7430_VCL_CTRL, 0x11, 0x0a);
+
+ return 0;
+}
+
+static int db7430_power_off(struct db7430 *db)
+{
+ /* Go into RESET and disable regulators */
+ gpiod_set_value_cansleep(db->reset, 1);
+ return regulator_bulk_disable(ARRAY_SIZE(db->regulators),
+ db->regulators);
+}
+
+static int db7430_unprepare(struct drm_panel *panel)
+{
+ return db7430_power_off(to_db7430(panel));
+}
+
+static int db7430_disable(struct drm_panel *panel)
+{
+ struct db7430 *db = to_db7430(panel);
+ struct mipi_dbi *dbi = &db->dbi;
+
+ mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_OFF);
+ msleep(25);
+ mipi_dbi_command(dbi, MIPI_DCS_ENTER_SLEEP_MODE);
+ msleep(120);
+
+ return 0;
+}
+
+static int db7430_prepare(struct drm_panel *panel)
+{
+ return db7430_power_on(to_db7430(panel));
+}
+
+static int db7430_enable(struct drm_panel *panel)
+{
+ struct db7430 *db = to_db7430(panel);
+ struct mipi_dbi *dbi = &db->dbi;
+
+ /* Exit sleep mode */
+ mipi_dbi_command(dbi, MIPI_DCS_EXIT_SLEEP_MODE);
+ msleep(20);
+
+ /* NVM (non-volatile memory) load sequence */
+ mipi_dbi_command(dbi, DB7430_UNKNOWN_D4, 0x52, 0x5e);
+ mipi_dbi_command(dbi, DB7430_UNKNOWN_F8, 0x01, 0xf5, 0xf2, 0x71, 0x44);
+ mipi_dbi_command(dbi, DB7430_UNKNOWN_FC, 0x00, 0x08);
+ msleep(150);
+
+ /* CABC turn on sequence (BC = backlight control) */
+ mipi_dbi_command(dbi, DB7430_UNKNOWN_B4, 0x0f, 0x00, 0x50);
+ mipi_dbi_command(dbi, DB7430_USER_SELECT, 0x80);
+ mipi_dbi_command(dbi, DB7430_UNKNOWN_B7, 0x24);
+ mipi_dbi_command(dbi, DB7430_UNKNOWN_B8, 0x01);
+
+ /* Turn on display */
+ mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_ON);
+
+ return 0;
+}
+
+/**
+ * db7430_get_modes() - return the mode
+ * @panel: the panel to get the mode for
+ * @connector: reference to the central DRM connector control structure
+ */
+static int db7430_get_modes(struct drm_panel *panel,
+ struct drm_connector *connector)
+{
+ struct db7430 *db = to_db7430(panel);
+ struct drm_display_mode *mode;
+ static const u32 bus_format = MEDIA_BUS_FMT_RGB888_1X24;
+
+ mode = drm_mode_duplicate(connector->dev, &db7430_480_800_mode);
+ if (!mode) {
+ dev_err(db->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 db7430_drm_funcs = {
+ .disable = db7430_disable,
+ .unprepare = db7430_unprepare,
+ .prepare = db7430_prepare,
+ .enable = db7430_enable,
+ .get_modes = db7430_get_modes,
+};
+
+static int db7430_probe(struct spi_device *spi)
+{
+ struct device *dev = &spi->dev;
+ struct db7430 *db;
+ int ret;
+
+ db = devm_kzalloc(dev, sizeof(*db), GFP_KERNEL);
+ if (!db)
+ return -ENOMEM;
+ db->dev = dev;
+
+ /*
+ * VCI is the analog voltage supply
+ * VCCIO is the digital I/O voltage supply
+ */
+ db->regulators[0].supply = "vci";
+ db->regulators[1].supply = "vccio";
+ ret = devm_regulator_bulk_get(dev,
+ ARRAY_SIZE(db->regulators),
+ db->regulators);
+ if (ret)
+ return dev_err_probe(dev, ret, "failed to get regulators\n");
+
+ db->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
+ if (IS_ERR(db->reset)) {
+ ret = PTR_ERR(db->reset);
+ return dev_err_probe(dev, ret, "no RESET GPIO\n");
+ }
+
+ ret = mipi_dbi_spi_init(spi, &db->dbi, NULL);
+ if (ret)
+ return dev_err_probe(dev, ret, "MIPI DBI init failed\n");
+
+ drm_panel_init(&db->panel, dev, &db7430_drm_funcs,
+ DRM_MODE_CONNECTOR_DPI);
+
+ /* FIXME: if no external backlight, use internal backlight */
+ ret = drm_panel_of_backlight(&db->panel);
+ if (ret)
+ return dev_err_probe(dev, ret, "failed to add backlight\n");
+
+ spi_set_drvdata(spi, db);
+
+ drm_panel_add(&db->panel);
+ dev_dbg(dev, "added panel\n");
+
+ return 0;
+}
+
+static int db7430_remove(struct spi_device *spi)
+{
+ struct db7430 *db = spi_get_drvdata(spi);
+
+ drm_panel_remove(&db->panel);
+ return 0;
+}
+
+/*
+ * The DB7430 display controller may be used in several display products,
+ * so list the different variants here and add per-variant data if needed.
+ */
+static const struct of_device_id db7430_match[] = {
+ { .compatible = "samsung,lms397kf04", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, db7430_match);
+
+static struct spi_driver db7430_driver = {
+ .probe = db7430_probe,
+ .remove = db7430_remove,
+ .driver = {
+ .name = "db7430-panel",
+ .of_match_table = db7430_match,
+ },
+};
+module_spi_driver(db7430_driver);
+
+MODULE_AUTHOR("Linus Walleij <linus.walleij at linaro.org>");
+MODULE_DESCRIPTION("Samsung DB7430 panel driver");
+MODULE_LICENSE("GPL v2");
--
2.31.1
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