drm/panel: Add Samsung AMS495QA01 Panel

From: Chris Morgan <[email protected]>

Add documentation for the Samsung AMS495QA01 panel.

Signed-off-by Chris Morgan <[email protected]>

---
 .../display/panel/samsung,ams495qa01.yaml     | 46 +++++++++++++++++++
 1 file changed, 46 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/display/panel/samsung,ams495qa01.yaml

Documentation/devicetree/bindings/display/panel/samsung,ams495qa01.yaml new file +11 -0

new file mode 100644
index 000000000000..08358cdad19c
@@ -0,0 +1,46 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/display/panel/samsung,ams495qa01.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Samsung AMS495QA01 4.95in 960x544 DSI/SPI panel
+
+maintainers:
+  - Chris Morgan <[email protected]>
+

Documentation/devicetree/bindings/display/panel/samsung,ams495qa01.yaml new file +8 -0

+
+required:
+  - compatible
+  - reg
+  - vdd-supply
+
+additionalProperties: false
+

Documentation/devicetree/bindings/display/panel/samsung,ams495qa01.yaml new file +3 -1

+    };
+
+...
--

2.25.1

From: Chris Morgan <[email protected]>

Add documentation for the Samsung AMS495QA01 panel.

Signed-off-by Chris Morgan <[email protected]>

---
 .../display/panel/samsung,ams495qa01.yaml     | 46 +++++++++++++++++++
 1 file changed, 46 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/display/panel/samsung,ams495qa01.yaml

Documentation/devicetree/bindings/display/panel/samsung,ams495qa01.yaml new file +7 -0

new file mode 100644
index 000000000000..08358cdad19c
@@ -0,0 +1,46 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/display/panel/samsung,ams495qa01.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Samsung AMS495QA01 4.95in 960x544 DSI/SPI panel

From: Chris Morgan <[email protected]>

Support Samsung AMS495QA01 panel as found on the Anbernic RG503. Note This panel receives video signals via DSI, however it receives commands via 3-wire SPI.

Signed-off-by Chris Morgan <[email protected]>

---
 drivers/gpu/drm/panel/Kconfig                 |  10 +
 drivers/gpu/drm/panel/Makefile                |   1 +
 .../gpu/drm/panel/panel-samsung-ams495qa01.c  | 505 ++++++++++++++++++
 3 files changed, 516 insertions(+)
 create mode 100644 drivers/gpu/drm/panel/panel-samsung-ams495qa01.c

drivers/gpu/drm/panel/Kconfig +10 -0

index a9043eacce97..954b66a2adee 100644
@@ -444,6 +444,16 @@ 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_AMS495QA01
+       tristate "Samsung AMS495QA01 DSI panel"
+       depends on OF && SPI
+       depends on DRM_MIPI_DSI
+       select DRM_MIPI_DBI
+       help
+         DRM panel driver for the Samsung AMS495QA01 panel. This panel
+         receives video data via DSI but commands via 3-Wire 9-bit
+         SPI.
+
 config DRM_PANEL_SAMSUNG_ATNA33XC20
        tristate "Samsung ATNA33XC20 eDP panel"
        depends on OF

drivers/gpu/drm/panel/Makefile +1 -0

index 34e717382dbb..de0b57baf851 100644
@@ -42,6 +42,7 @@ 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-$(CONFIG_DRM_PANEL_SAMSUNG_AMS495QA01) += panel-samsung-ams495qa01.o
 obj-$(CONFIG_DRM_PANEL_SAMSUNG_ATNA33XC20) += panel-samsung-atna33xc20.o
 obj-$(CONFIG_DRM_PANEL_SAMSUNG_DB7430) += panel-samsung-db7430.o
 obj-$(CONFIG_DRM_PANEL_SAMSUNG_LD9040) += panel-samsung-ld9040.o

drivers/gpu/drm/panel/panel-samsung-ams495qa01.c new file +107 -0

new file mode 100644
index 000000000000..d693ba5f20c9
@@ -0,0 +1,505 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Samsung ams495qa01 MIPI-DSI panel driver
+ * Copyright (C) 2022 Chris Morgan
+ */
+
+#include <drm/drm_mipi_dbi.h>
+#include <drm/drm_mipi_dsi.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/of.h>
+#include <linux/of_graph.h>
+#include <linux/regulator/consumer.h>
+#include <linux/spi/spi.h>
+
+#include <video/mipi_display.h>
+
+struct ams495qa01 {
+       /** @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;
+       /** @reset: reset GPIO line */
+       struct gpio_desc *reset;
+       /** @enable: enable GPIO line */
+       struct gpio_desc *enable;
+       /** @reg_vdd: VDD supply regulator for panel logic */
+       struct regulator *reg_vdd;
+       /** @reg_elvdd: ELVDD supply regulator for panel display */
+       struct regulator *reg_elvdd;
+       /** @dsi_dev: DSI child device (panel) */
+       struct mipi_dsi_device *dsi_dev;
+       /** @bl_dev: pseudo-backlight device for oled panel */
+       struct backlight_device *bl_dev;
+       /** @prepared: value tracking panel prepare status */
+       bool prepared;
+};
+
+static const struct drm_display_mode ams495qa01_mode = {
+       .clock = 33500,
+       .hdisplay = 960,
+       .hsync_start = 960 + 10,
+       .hsync_end = 960 + 10 + 2,
+       .htotal = 960 + 10 + 2 + 10,
+       .vdisplay = 544,
+       .vsync_start = 544 + 10,
+       .vsync_end = 544 + 10 + 2,
+       .vtotal = 544 + 10 + 2 + 10,
+       .width_mm = 117,
+       .height_mm = 74,
+       .flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
+};
+
+#define NUM_GAMMA_LEVELS       16
+#define GAMMA_TABLE_COUNT      23
+#define MAX_BRIGHTNESS         (NUM_GAMMA_LEVELS - 1)
+
+/* Table of gamma values provided in datasheet */
+static u8 ams495qa01_gamma[NUM_GAMMA_LEVELS][GAMMA_TABLE_COUNT] = {
+       {0x01, 0x79, 0x78, 0x8d, 0xd9, 0xdf, 0xd5, 0xcb, 0xcf, 0xc5,
+        0xe5, 0xe0, 0xe4, 0xdc, 0xb8, 0xd4, 0xfa, 0xed, 0xe6, 0x2f,
+        0x00, 0x2f},
+       {0x01, 0x7d, 0x7c, 0x92, 0xd7, 0xdd, 0xd2, 0xcb, 0xd0, 0xc6,
+        0xe5, 0xe1, 0xe3, 0xda, 0xbd, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
+        0x00, 0x2f},
+       {0x01, 0x7f, 0x7e, 0x95, 0xd7, 0xde, 0xd2, 0xcb, 0xcf, 0xc5,
+        0xe5, 0xe3, 0xe3, 0xda, 0xbf, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
+        0x00, 0x2f},
+       {0x01, 0x82, 0x81, 0x99, 0xd6, 0xdd, 0xd1, 0xca, 0xcf, 0xc3,
+        0xe4, 0xe3, 0xe3, 0xda, 0xc2, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
+        0x00, 0x2f},
+       {0x01, 0x84, 0x83, 0x9b, 0xd7, 0xde, 0xd2, 0xc8, 0xce, 0xc2,
+        0xe4, 0xe3, 0xe2, 0xd9, 0xc3, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
+        0x00, 0x2f},
+       {0x01, 0x87, 0x86, 0x9f, 0xd6, 0xdd, 0xd1, 0xc7, 0xce, 0xc1,
+        0xe4, 0xe3, 0xe2, 0xd9, 0xc6, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
+        0x00, 0x2f},
+       {0x01, 0x89, 0x89, 0xa2, 0xd5, 0xdb, 0xcf, 0xc8, 0xcf, 0xc2,
+        0xe3, 0xe3, 0xe1, 0xd9, 0xc7, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
+        0x00, 0x2f},
+       {0x01, 0x8b, 0x8b, 0xa5, 0xd5, 0xdb, 0xcf, 0xc7, 0xce, 0xc0,
+        0xe3, 0xe3, 0xe1, 0xd8, 0xc7, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
+        0x00, 0x2f},
+       {0x01, 0x8d, 0x8d, 0xa7, 0xd5, 0xdb, 0xcf, 0xc6, 0xce, 0xc0,
+        0xe4, 0xe4, 0xe1, 0xd7, 0xc8, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
+        0x00, 0x2f},
+       {0x01, 0x8f, 0x8f, 0xaa, 0xd4, 0xdb, 0xce, 0xc6, 0xcd, 0xbf,
+        0xe3, 0xe3, 0xe1, 0xd7, 0xca, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
+        0x00, 0x2f},
+       {0x01, 0x91, 0x91, 0xac, 0xd3, 0xda, 0xce, 0xc5, 0xcd, 0xbe,
+        0xe3, 0xe3, 0xe0, 0xd7, 0xca, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
+        0x00, 0x2f},
+       {0x01, 0x93, 0x93, 0xaf, 0xd3, 0xda, 0xcd, 0xc5, 0xcd, 0xbe,
+        0xe2, 0xe3, 0xdf, 0xd6, 0xca, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
+        0x00, 0x2f},
+       {0x01, 0x95, 0x95, 0xb1, 0xd2, 0xd9, 0xcc, 0xc4, 0xcd, 0xbe,
+        0xe2, 0xe3, 0xdf, 0xd7, 0xcc, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,

drivers/gpu/drm/panel/panel-samsung-ams495qa01.c new file +12 -0

+};
+
+/*
+ * Table of elvss values provided in datasheet and corresponds to
+ * gamma values.
+ */
+static u8 ams495qa01_elvss[NUM_GAMMA_LEVELS] = {
+       0x15, 0x15, 0x15, 0x15, 0x15, 0x15, 0x15, 0x15, 0x15, 0x15,
+       0x15, 0x15, 0x14, 0x14, 0x13, 0x12,
+};
+
+static inline struct ams495qa01 *to_ams495qa01(struct drm_panel *panel)

drivers/gpu/drm/panel/panel-samsung-ams495qa01.c new file +28 -0

+
+       /* Set gamma values */
+       mipi_dbi_command_buf(dbi, 0xf9, ams495qa01_gamma[tmp],
+                            ARRAY_SIZE(ams495qa01_gamma[tmp]));
+       /* Set gamma change */
+       mipi_dbi_command(dbi, 0xf9, 0x00);
+       /* Undocumented command */
+       mipi_dbi_command(dbi, 0x26, 0x00);
+       /* Set ELVSS value */
+       mipi_dbi_command(dbi, 0xb2, ams495qa01_elvss[tmp]);
+
+       return 0;
+}
+
+static int ams495qa01_prepare(struct drm_panel *panel)
+{
+       struct ams495qa01 *db = to_ams495qa01(panel);
+       struct mipi_dbi *dbi = &db->dbi;
+       int ret;
+
+       if (db->prepared)
+               return 0;
+
+       /* Power up */
+       ret = regulator_enable(db->reg_vdd);
+       if (ret) {
+               dev_err(db->dev, "failed to enable vdd regulator: %d\n", ret);
+               return ret;

drivers/gpu/drm/panel/panel-samsung-ams495qa01.c new file +163 -0

+
+       /* Enable */
+       if (db->enable)
+               gpiod_set_value_cansleep(db->enable, 1);
+
+       msleep(50);
+
+       /* Reset */
+       gpiod_set_value_cansleep(db->reset, 1);
+       usleep_range(1000, 5000);
+       gpiod_set_value_cansleep(db->reset, 0);
+       msleep(20);
+
+       /* Panel Init Sequence */
+
+       /* Password to start command sequence */
+       mipi_dbi_command(dbi, 0xf0, 0x5a, 0x5a);
+       mipi_dbi_command(dbi, 0xf1, 0x5a, 0x5a);
+
+       /* Undocumented commands */
+       mipi_dbi_command(dbi, 0xb0, 0x02);
+       mipi_dbi_command(dbi, 0xf3, 0x3b);
+
+       /* Analog Power condition set */
+       mipi_dbi_command(dbi, 0xf4, 0x33, 0x42, 0x00, 0x08);
+       mipi_dbi_command(dbi, 0xf5, 0x00, 0x06, 0x26, 0x35, 0x03);
+
+       /* Undocumented commands */
+       mipi_dbi_command(dbi, 0xf6, 0x02);
+       mipi_dbi_command(dbi, 0xc6, 0x0b, 0x00, 0x00, 0x3c, 0x00, 0x22,
+                        0x00, 0x00, 0x00, 0x00);
+
+       /* GTCON set */
+       mipi_dbi_command(dbi, 0xf7, 0x20);
+
+       /* TEMP_SWIRE set */
+       mipi_dbi_command(dbi, 0xb2, 0x06, 0x06, 0x06, 0x06);
+
+       /* ELVSS_CON set */
+       mipi_dbi_command(dbi, 0xb1, 0x07, 0x00, 0x10);
+
+       /* Gateless signal set */
+       mipi_dbi_command(dbi, 0xf8, 0x7f, 0x7a, 0x89, 0x67, 0x26, 0x38,
+                        0x00, 0x00, 0x09, 0x67, 0x70, 0x88, 0x7a,
+                        0x76, 0x05, 0x09, 0x23, 0x23, 0x23);
+
+       /* Undocumented commands */
+       mipi_dbi_command(dbi, 0xb5, 0xff, 0xef, 0x35, 0x42, 0x0d, 0xd7,
+                        0xff, 0x07, 0xff, 0xff, 0xfd, 0x00, 0x01,
+                        0xff, 0x05, 0x12, 0x0f, 0xff, 0xff, 0xff,
+                        0xff);
+       mipi_dbi_command(dbi, 0xb4, 0x15);
+       mipi_dbi_command(dbi, 0xb3, 0x00);
+
+       ams495qa01_update_gamma(dbi, MAX_BRIGHTNESS);
+
+       mipi_dbi_command(dbi, MIPI_DCS_EXIT_SLEEP_MODE);
+       msleep(200);
+       mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_ON);
+       usleep_range(10000, 15000);
+
+       db->prepared = true;
+
+       return 0;
+}
+
+static int ams495qa01_unprepare(struct drm_panel *panel)
+{
+       struct ams495qa01 *db = to_ams495qa01(panel);
+       struct mipi_dbi *dbi = &db->dbi;
+
+       if (!db->prepared)
+               return 0;
+
+       /* Panel Exit Sequence */
+       mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_OFF);
+       msleep(20);
+       mipi_dbi_command(dbi, MIPI_DCS_ENTER_SLEEP_MODE);
+       usleep_range(10000, 15000);
+
+       if (db->enable)
+               gpiod_set_value_cansleep(db->enable, 0);
+       if (db->reg_elvdd)
+               regulator_disable(db->reg_elvdd);
+       regulator_disable(db->reg_vdd);
+       msleep(20);
+
+       db->prepared = false;
+
+       return 0;
+}
+
+static int ams495qa01_get_modes(struct drm_panel *panel,
+                               struct drm_connector *connector)
+{
+       struct ams495qa01 *db = to_ams495qa01(panel);
+       struct drm_display_mode *mode;
+       static const u32 bus_format = MEDIA_BUS_FMT_RGB888_1X24;
+
+       mode = drm_mode_duplicate(connector->dev, &ams495qa01_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_BUS_FLAG_DE_LOW;
+       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 ams495qa01_drm_funcs = {
+       .unprepare = ams495qa01_unprepare,
+       .prepare = ams495qa01_prepare,
+       .get_modes = ams495qa01_get_modes,
+};
+
+static int ams495qa01_set_brightness(struct backlight_device *bd)
+{
+       struct ams495qa01 *db = bl_get_data(bd);
+       struct mipi_dbi *dbi = &db->dbi;
+       int brightness = bd->props.brightness;
+
+       ams495qa01_update_gamma(dbi, brightness);
+
+       return 0;
+}
+
+static const struct backlight_ops ams495qa01_backlight_ops = {
+       .update_status  = ams495qa01_set_brightness,
+};
+
+static int ams495qa01_backlight_register(struct ams495qa01 *db)
+{
+       struct backlight_properties props = {
+               .type           = BACKLIGHT_RAW,
+               .brightness     = MAX_BRIGHTNESS,
+               .max_brightness = MAX_BRIGHTNESS,
+       };
+       struct device *dev = db->dev;
+       int ret = 0;
+
+       db->bl_dev = devm_backlight_device_register(dev, "panel", dev, db,
+                                                    &ams495qa01_backlight_ops,
+                                                    &props);
+       if (IS_ERR(db->bl_dev)) {
+               ret = PTR_ERR(db->bl_dev);
+               dev_err(dev, "error registering backlight device (%d)\n", ret);
+       }
+
+       return ret;
+}

drivers/gpu/drm/panel/panel-samsung-ams495qa01.c new file +15 -0

+               .channel = 0,
+               .node = NULL,
+       };
+
+       db = devm_kzalloc(dev, sizeof(*db), GFP_KERNEL);
+       if (!db)
+               return -ENOMEM;
+
+       spi_set_drvdata(spi, db);
+
+       db->dev = dev;
+
+       db->reg_vdd = devm_regulator_get(dev, "vdd");
+       if (IS_ERR(db->reg_vdd))
+               return dev_err_probe(dev, PTR_ERR(db->reg_vdd),

drivers/gpu/drm/panel/panel-samsung-ams495qa01.c new file +115 -1

+        */
+       endpoint = of_graph_get_next_endpoint(dev->of_node, NULL);
+       if (!endpoint) {
+               dev_err(dev, "failed to get endpoint\n");
+               return -ENODEV;
+       }
+       dsi_host_node = of_graph_get_remote_port_parent(endpoint);
+       if (!dsi_host_node) {
+               dev_err(dev, "failed to get remote port parent\n");
+               goto put_endpoint;
+       }
+       dsi_host = of_find_mipi_dsi_host_by_node(dsi_host_node);
+       if (!dsi_host) {
+               dev_err(dev, "failed to find dsi host\n");
+               goto put_host;
+       }
+       info.node = of_graph_get_remote_port(endpoint);
+       if (!info.node) {
+               dev_err(dev, "failed to get remote port node\n");
+               ret = -ENODEV;
+               goto put_host;
+       }
+
+       db->dsi_dev = devm_mipi_dsi_device_register_full(dev, dsi_host, &info);
+       if (IS_ERR(db->dsi_dev)) {
+               dev_err(dev, "failed to register dsi device: %ld\n",
+                       PTR_ERR(db->dsi_dev));
+               ret = PTR_ERR(db->dsi_dev);
+               goto put_host;
+       }
+
+       db->dsi_dev->lanes = 2;
+       db->dsi_dev->format = MIPI_DSI_FMT_RGB888;
+       db->dsi_dev->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_BURST |
+                         MIPI_DSI_MODE_LPM | MIPI_DSI_MODE_NO_EOT_PACKET;
+
+       drm_panel_init(&db->panel, dev, &ams495qa01_drm_funcs,
+                      DRM_MODE_CONNECTOR_DSI);
+
+       ret = ams495qa01_backlight_register(db);
+       if (ret < 0)
+               return ret;
+
+       drm_panel_add(&db->panel);
+
+       ret = devm_mipi_dsi_attach(dev, db->dsi_dev);
+       if (ret < 0) {
+               dev_err(dev, "mipi_dsi_attach failed: %d\n", ret);
+               drm_panel_remove(&db->panel);
+               return ret;
+       }
+
+       of_node_put(dsi_host_node);
+       of_node_put(endpoint);
+
+       return 0;
+
+put_host:
+       of_node_put(dsi_host_node);
+
+put_endpoint:
+       of_node_put(endpoint);
+       return -ENODEV;
+}
+
+static void ams495qa01_shutdown(struct spi_device *spi)
+{
+       struct ams495qa01 *db = spi_get_drvdata(spi);
+       int ret;
+
+       ret = drm_panel_unprepare(&db->panel);
+       if (ret < 0)
+               dev_err(&spi->dev, "Failed to unprepare panel: %d\n", ret);
+
+       ret = drm_panel_disable(&db->panel);
+       if (ret < 0)
+               dev_err(&spi->dev, "Failed to disable panel: %d\n", ret);
+}
+
+static void ams495qa01_remove(struct spi_device *spi)
+{
+       struct ams495qa01 *db = spi_get_drvdata(spi);
+
+       ams495qa01_shutdown(spi);
+
+       drm_panel_remove(&db->panel);
+}
+
+static const struct of_device_id ams495qa01_match[] = {
+       { .compatible = "samsung,ams495qa01", },
+       {},
+};
+MODULE_DEVICE_TABLE(of, ams495qa01_match);
+
+static const struct spi_device_id ams495qa01_ids[] = {
+       { "ams495qa01", 0 },
+       {},
+};
+MODULE_DEVICE_TABLE(spi, ams495qa01_ids);
+
+static struct spi_driver ams495qa01_driver = {
+       .driver         = {
+               .name   = "ams495qa01-panel",
+               .of_match_table = ams495qa01_match,
+       },
+       .id_table       = ams495qa01_ids,
+       .probe          = ams495qa01_probe,
+       .remove         = ams495qa01_remove,
+       .shutdown       = ams495qa01_shutdown,
+};
+module_spi_driver(ams495qa01_driver);
+
+MODULE_AUTHOR("Chris Morgan <[email protected]>");
+MODULE_DESCRIPTION("Samsung ams495qa01 panel driver");
+MODULE_LICENSE("GPL");
--

2.25.1

Hi Chris,
Thanks for this patch,

wt., 20 wrz 2022 o 19:10 Chris Morgan <[email protected]> napisał(a):

Quoted 161 lines

From: Chris Morgan <[email protected]>

Support Samsung AMS495QA01 panel as found on the Anbernic RG503. Note This panel receives video signals via DSI, however it receives commands via 3-wire SPI.

Signed-off-by Chris Morgan <[email protected]>

---
 drivers/gpu/drm/panel/Kconfig                 |  10 +
 drivers/gpu/drm/panel/Makefile                |   1 +
 .../gpu/drm/panel/panel-samsung-ams495qa01.c  | 505 ++++++++++++++++++
 3 files changed, 516 insertions(+)
 create mode 100644 drivers/gpu/drm/panel/panel-samsung-ams495qa01.c

drivers/gpu/drm/panel/Kconfig +10 -0

index a9043eacce97..954b66a2adee 100644
@@ -444,6 +444,16 @@ 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_AMS495QA01
+       tristate "Samsung AMS495QA01 DSI panel"
+       depends on OF && SPI
+       depends on DRM_MIPI_DSI
+       select DRM_MIPI_DBI
+       help
+         DRM panel driver for the Samsung AMS495QA01 panel. This panel
+         receives video data via DSI but commands via 3-Wire 9-bit
+         SPI.
+
 config DRM_PANEL_SAMSUNG_ATNA33XC20
        tristate "Samsung ATNA33XC20 eDP panel"
        depends on OF

drivers/gpu/drm/panel/Makefile +1 -0

index 34e717382dbb..de0b57baf851 100644
@@ -42,6 +42,7 @@ 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-$(CONFIG_DRM_PANEL_SAMSUNG_AMS495QA01) += panel-samsung-ams495qa01.o
 obj-$(CONFIG_DRM_PANEL_SAMSUNG_ATNA33XC20) += panel-samsung-atna33xc20.o
 obj-$(CONFIG_DRM_PANEL_SAMSUNG_DB7430) += panel-samsung-db7430.o
 obj-$(CONFIG_DRM_PANEL_SAMSUNG_LD9040) += panel-samsung-ld9040.o

drivers/gpu/drm/panel/panel-samsung-ams495qa01.c new file +107 -0

new file mode 100644
index 000000000000..d693ba5f20c9
@@ -0,0 +1,505 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Samsung ams495qa01 MIPI-DSI panel driver
+ * Copyright (C) 2022 Chris Morgan
+ */
+
+#include <drm/drm_mipi_dbi.h>
+#include <drm/drm_mipi_dsi.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/of.h>
+#include <linux/of_graph.h>
+#include <linux/regulator/consumer.h>
+#include <linux/spi/spi.h>
+
+#include <video/mipi_display.h>
+
+struct ams495qa01 {
+       /** @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;
+       /** @reset: reset GPIO line */
+       struct gpio_desc *reset;
+       /** @enable: enable GPIO line */
+       struct gpio_desc *enable;
+       /** @reg_vdd: VDD supply regulator for panel logic */
+       struct regulator *reg_vdd;
+       /** @reg_elvdd: ELVDD supply regulator for panel display */
+       struct regulator *reg_elvdd;
+       /** @dsi_dev: DSI child device (panel) */
+       struct mipi_dsi_device *dsi_dev;
+       /** @bl_dev: pseudo-backlight device for oled panel */
+       struct backlight_device *bl_dev;
+       /** @prepared: value tracking panel prepare status */
+       bool prepared;
+};
+
+static const struct drm_display_mode ams495qa01_mode = {
+       .clock = 33500,
+       .hdisplay = 960,
+       .hsync_start = 960 + 10,
+       .hsync_end = 960 + 10 + 2,
+       .htotal = 960 + 10 + 2 + 10,
+       .vdisplay = 544,
+       .vsync_start = 544 + 10,
+       .vsync_end = 544 + 10 + 2,
+       .vtotal = 544 + 10 + 2 + 10,
+       .width_mm = 117,
+       .height_mm = 74,
+       .flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
+};
+
+#define NUM_GAMMA_LEVELS       16
+#define GAMMA_TABLE_COUNT      23
+#define MAX_BRIGHTNESS         (NUM_GAMMA_LEVELS - 1)
+
+/* Table of gamma values provided in datasheet */
+static u8 ams495qa01_gamma[NUM_GAMMA_LEVELS][GAMMA_TABLE_COUNT] = {
+       {0x01, 0x79, 0x78, 0x8d, 0xd9, 0xdf, 0xd5, 0xcb, 0xcf, 0xc5,
+        0xe5, 0xe0, 0xe4, 0xdc, 0xb8, 0xd4, 0xfa, 0xed, 0xe6, 0x2f,
+        0x00, 0x2f},
+       {0x01, 0x7d, 0x7c, 0x92, 0xd7, 0xdd, 0xd2, 0xcb, 0xd0, 0xc6,
+        0xe5, 0xe1, 0xe3, 0xda, 0xbd, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
+        0x00, 0x2f},
+       {0x01, 0x7f, 0x7e, 0x95, 0xd7, 0xde, 0xd2, 0xcb, 0xcf, 0xc5,
+        0xe5, 0xe3, 0xe3, 0xda, 0xbf, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
+        0x00, 0x2f},
+       {0x01, 0x82, 0x81, 0x99, 0xd6, 0xdd, 0xd1, 0xca, 0xcf, 0xc3,
+        0xe4, 0xe3, 0xe3, 0xda, 0xc2, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
+        0x00, 0x2f},
+       {0x01, 0x84, 0x83, 0x9b, 0xd7, 0xde, 0xd2, 0xc8, 0xce, 0xc2,
+        0xe4, 0xe3, 0xe2, 0xd9, 0xc3, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
+        0x00, 0x2f},
+       {0x01, 0x87, 0x86, 0x9f, 0xd6, 0xdd, 0xd1, 0xc7, 0xce, 0xc1,
+        0xe4, 0xe3, 0xe2, 0xd9, 0xc6, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
+        0x00, 0x2f},
+       {0x01, 0x89, 0x89, 0xa2, 0xd5, 0xdb, 0xcf, 0xc8, 0xcf, 0xc2,
+        0xe3, 0xe3, 0xe1, 0xd9, 0xc7, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
+        0x00, 0x2f},
+       {0x01, 0x8b, 0x8b, 0xa5, 0xd5, 0xdb, 0xcf, 0xc7, 0xce, 0xc0,
+        0xe3, 0xe3, 0xe1, 0xd8, 0xc7, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
+        0x00, 0x2f},
+       {0x01, 0x8d, 0x8d, 0xa7, 0xd5, 0xdb, 0xcf, 0xc6, 0xce, 0xc0,
+        0xe4, 0xe4, 0xe1, 0xd7, 0xc8, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
+        0x00, 0x2f},
+       {0x01, 0x8f, 0x8f, 0xaa, 0xd4, 0xdb, 0xce, 0xc6, 0xcd, 0xbf,
+        0xe3, 0xe3, 0xe1, 0xd7, 0xca, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
+        0x00, 0x2f},
+       {0x01, 0x91, 0x91, 0xac, 0xd3, 0xda, 0xce, 0xc5, 0xcd, 0xbe,
+        0xe3, 0xe3, 0xe0, 0xd7, 0xca, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
+        0x00, 0x2f},
+       {0x01, 0x93, 0x93, 0xaf, 0xd3, 0xda, 0xcd, 0xc5, 0xcd, 0xbe,
+        0xe2, 0xe3, 0xdf, 0xd6, 0xca, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
+        0x00, 0x2f},
+       {0x01, 0x95, 0x95, 0xb1, 0xd2, 0xd9, 0xcc, 0xc4, 0xcd, 0xbe,
+        0xe2, 0xe3, 0xdf, 0xd7, 0xcc, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,

drivers/gpu/drm/panel/panel-samsung-ams495qa01.c line 117

Quoted 10 lines

drivers/gpu/drm/panel/panel-samsung-ams495qa01.c new file +10 -0

+        0x00, 0x2f},
+       {0x01, 0x99, 0x99, 0xb6, 0xd1, 0xd9, 0xcc, 0xc3, 0xcb, 0xbc,
+        0xe2, 0xe4, 0xdf, 0xd6, 0xcc, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
+        0x00, 0x2f},
+       {0x01, 0x9c, 0x9c, 0xba, 0xd0, 0xd8, 0xcb, 0xc3, 0xcb, 0xbb,
+        0xe2, 0xe4, 0xdf, 0xd6, 0xce, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
+        0x00, 0x2f},
+       {0x01, 0x9f, 0x9f, 0xbe, 0xcf, 0xd7, 0xc9, 0xc2, 0xcb, 0xbb,
+        0xe1, 0xe3, 0xde, 0xd6, 0xd0, 0xd3, 0xfa, 0xed, 0xe6, 0x2f,
+        0x00, 0x2f},

There might be some use in adding unofficial gamma values,

for higher and lower brightness values than officially supported, For example, vitabright repository of devnoname120 contains gamma lookup tables that should be compatible with this display.
Perhaps it's worth checking out, for low-light and outdoors use case, as the display is meant to be used in handheld gaming devices:
https://nam12.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fdevnoname120%2Fvitabright&amp;data=05%7C01%7C%7Cb6531a6abc1940709ccd08da9b2e3fbc%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C637992920188081853%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&amp;sdata=KColbBBN2hg6c3L%2F7XuXkIBWQxoxoaHE9WxcEXP%2BoKw%3D&amp;reserved=0

Quoted 16 lines

drivers/gpu/drm/panel/panel-samsung-ams495qa01.c new file +15 -0

+};
+
+/*
+ * Table of elvss values provided in datasheet and corresponds to
+ * gamma values.
+ */
+static u8 ams495qa01_elvss[NUM_GAMMA_LEVELS] = {
+       0x15, 0x15, 0x15, 0x15, 0x15, 0x15, 0x15, 0x15, 0x15, 0x15,
+       0x15, 0x15, 0x14, 0x14, 0x13, 0x12,
+};
+
+static inline struct ams495qa01 *to_ams495qa01(struct drm_panel *panel)
+{
+       return container_of(panel, struct ams495qa01, panel);
+}

drivers/gpu/drm/panel/panel-samsung-ams495qa01.c line 139

Quoted 7 lines

drivers/gpu/drm/panel/panel-samsung-ams495qa01.c new file +7 -0

+
+static int ams495qa01_update_gamma(struct mipi_dbi *dbi, u32 brightness)
+{
+       u32 tmp = brightness;
+
+       if (brightness > MAX_BRIGHTNESS)
+               tmp = MAX_BRIGHTNESS;

Shouldn't we return -EINVAL in this case?

Quoted 32 lines

drivers/gpu/drm/panel/panel-samsung-ams495qa01.c new file +32 -0

+
+       /* Set gamma values */
+       mipi_dbi_command_buf(dbi, 0xf9, ams495qa01_gamma[tmp],
+                            ARRAY_SIZE(ams495qa01_gamma[tmp]));
+       /* Set gamma change */
+       mipi_dbi_command(dbi, 0xf9, 0x00);
+       /* Undocumented command */
+       mipi_dbi_command(dbi, 0x26, 0x00);
+       /* Set ELVSS value */
+       mipi_dbi_command(dbi, 0xb2, ams495qa01_elvss[tmp]);
+
+       return 0;
+}
+
+static int ams495qa01_prepare(struct drm_panel *panel)
+{
+       struct ams495qa01 *db = to_ams495qa01(panel);
+       struct mipi_dbi *dbi = &db->dbi;
+       int ret;
+
+       if (db->prepared)
+               return 0;
+
+       /* Power up */
+       ret = regulator_enable(db->reg_vdd);
+       if (ret) {
+               dev_err(db->dev, "failed to enable vdd regulator: %d\n", ret);
+               return ret;
+       }
+       if (db->reg_elvdd) {
+               ret = regulator_enable(db->reg_elvdd);
+               if (ret) {

drivers/gpu/drm/panel/panel-samsung-ams495qa01.c line 177

Quoted 6 lines

drivers/gpu/drm/panel/panel-samsung-ams495qa01.c new file +6 -0

+                       dev_err(db->dev,
+                               "failed to enable elvdd regulator: %d\n", ret);
+                       regulator_disable(db->reg_vdd);
+                       return ret;
+               }
+       }

Maybe ret could be initialized with 0 value, and couple gotos like with some other drivers?

Quoted 163 lines

drivers/gpu/drm/panel/panel-samsung-ams495qa01.c new file +163 -0

+
+       /* Enable */
+       if (db->enable)
+               gpiod_set_value_cansleep(db->enable, 1);
+
+       msleep(50);
+
+       /* Reset */
+       gpiod_set_value_cansleep(db->reset, 1);
+       usleep_range(1000, 5000);
+       gpiod_set_value_cansleep(db->reset, 0);
+       msleep(20);
+
+       /* Panel Init Sequence */
+
+       /* Password to start command sequence */
+       mipi_dbi_command(dbi, 0xf0, 0x5a, 0x5a);
+       mipi_dbi_command(dbi, 0xf1, 0x5a, 0x5a);
+
+       /* Undocumented commands */
+       mipi_dbi_command(dbi, 0xb0, 0x02);
+       mipi_dbi_command(dbi, 0xf3, 0x3b);
+
+       /* Analog Power condition set */
+       mipi_dbi_command(dbi, 0xf4, 0x33, 0x42, 0x00, 0x08);
+       mipi_dbi_command(dbi, 0xf5, 0x00, 0x06, 0x26, 0x35, 0x03);
+
+       /* Undocumented commands */
+       mipi_dbi_command(dbi, 0xf6, 0x02);
+       mipi_dbi_command(dbi, 0xc6, 0x0b, 0x00, 0x00, 0x3c, 0x00, 0x22,
+                        0x00, 0x00, 0x00, 0x00);
+
+       /* GTCON set */
+       mipi_dbi_command(dbi, 0xf7, 0x20);
+
+       /* TEMP_SWIRE set */
+       mipi_dbi_command(dbi, 0xb2, 0x06, 0x06, 0x06, 0x06);
+
+       /* ELVSS_CON set */
+       mipi_dbi_command(dbi, 0xb1, 0x07, 0x00, 0x10);
+
+       /* Gateless signal set */
+       mipi_dbi_command(dbi, 0xf8, 0x7f, 0x7a, 0x89, 0x67, 0x26, 0x38,
+                        0x00, 0x00, 0x09, 0x67, 0x70, 0x88, 0x7a,
+                        0x76, 0x05, 0x09, 0x23, 0x23, 0x23);
+
+       /* Undocumented commands */
+       mipi_dbi_command(dbi, 0xb5, 0xff, 0xef, 0x35, 0x42, 0x0d, 0xd7,
+                        0xff, 0x07, 0xff, 0xff, 0xfd, 0x00, 0x01,
+                        0xff, 0x05, 0x12, 0x0f, 0xff, 0xff, 0xff,
+                        0xff);
+       mipi_dbi_command(dbi, 0xb4, 0x15);
+       mipi_dbi_command(dbi, 0xb3, 0x00);
+
+       ams495qa01_update_gamma(dbi, MAX_BRIGHTNESS);
+
+       mipi_dbi_command(dbi, MIPI_DCS_EXIT_SLEEP_MODE);
+       msleep(200);
+       mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_ON);
+       usleep_range(10000, 15000);
+
+       db->prepared = true;
+
+       return 0;
+}
+
+static int ams495qa01_unprepare(struct drm_panel *panel)
+{
+       struct ams495qa01 *db = to_ams495qa01(panel);
+       struct mipi_dbi *dbi = &db->dbi;
+
+       if (!db->prepared)
+               return 0;
+
+       /* Panel Exit Sequence */
+       mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_OFF);
+       msleep(20);
+       mipi_dbi_command(dbi, MIPI_DCS_ENTER_SLEEP_MODE);
+       usleep_range(10000, 15000);
+
+       if (db->enable)
+               gpiod_set_value_cansleep(db->enable, 0);
+       if (db->reg_elvdd)
+               regulator_disable(db->reg_elvdd);
+       regulator_disable(db->reg_vdd);
+       msleep(20);
+
+       db->prepared = false;
+
+       return 0;
+}
+
+static int ams495qa01_get_modes(struct drm_panel *panel,
+                               struct drm_connector *connector)
+{
+       struct ams495qa01 *db = to_ams495qa01(panel);
+       struct drm_display_mode *mode;
+       static const u32 bus_format = MEDIA_BUS_FMT_RGB888_1X24;
+
+       mode = drm_mode_duplicate(connector->dev, &ams495qa01_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_BUS_FLAG_DE_LOW;
+       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 ams495qa01_drm_funcs = {
+       .unprepare = ams495qa01_unprepare,
+       .prepare = ams495qa01_prepare,
+       .get_modes = ams495qa01_get_modes,
+};
+
+static int ams495qa01_set_brightness(struct backlight_device *bd)
+{
+       struct ams495qa01 *db = bl_get_data(bd);
+       struct mipi_dbi *dbi = &db->dbi;
+       int brightness = bd->props.brightness;
+
+       ams495qa01_update_gamma(dbi, brightness);
+
+       return 0;
+}
+
+static const struct backlight_ops ams495qa01_backlight_ops = {
+       .update_status  = ams495qa01_set_brightness,
+};
+
+static int ams495qa01_backlight_register(struct ams495qa01 *db)
+{
+       struct backlight_properties props = {
+               .type           = BACKLIGHT_RAW,
+               .brightness     = MAX_BRIGHTNESS,
+               .max_brightness = MAX_BRIGHTNESS,
+       };
+       struct device *dev = db->dev;
+       int ret = 0;
+
+       db->bl_dev = devm_backlight_device_register(dev, "panel", dev, db,
+                                                    &ams495qa01_backlight_ops,
+                                                    &props);
+       if (IS_ERR(db->bl_dev)) {
+               ret = PTR_ERR(db->bl_dev);
+               dev_err(dev, "error registering backlight device (%d)\n", ret);
+       }
+
+       return ret;
+}

drivers/gpu/drm/panel/panel-samsung-ams495qa01.c line 350

Quoted 10 lines

drivers/gpu/drm/panel/panel-samsung-ams495qa01.c new file +10 -0

+
+static int ams495qa01_probe(struct spi_device *spi)
+{
+       struct device *dev = &spi->dev;
+       struct device_node *endpoint, *dsi_host_node;
+       struct mipi_dsi_host *dsi_host;
+       struct ams495qa01 *db;
+       int ret;
+       struct mipi_dsi_device_info info = {
+               .type = "dupa",

You might want to change this to something more appropiate for Linux.

I see this was left from a prototype driver that I wrote, which you might have based this one on.

Quoted 20 lines

drivers/gpu/drm/panel/panel-samsung-ams495qa01.c new file +19 -0

+               .channel = 0,
+               .node = NULL,
+       };
+
+       db = devm_kzalloc(dev, sizeof(*db), GFP_KERNEL);
+       if (!db)
+               return -ENOMEM;
+
+       spi_set_drvdata(spi, db);
+
+       db->dev = dev;
+
+       db->reg_vdd = devm_regulator_get(dev, "vdd");
+       if (IS_ERR(db->reg_vdd))
+               return dev_err_probe(dev, PTR_ERR(db->reg_vdd),
+                                    "Failed to get vdd supply\n");
+
+       db->reg_elvdd = devm_regulator_get_optional(dev, "elvdd");
+       if (IS_ERR(db->reg_elvdd))

drivers/gpu/drm/panel/panel-samsung-ams495qa01.c line 375

Quoted 6 lines

drivers/gpu/drm/panel/panel-samsung-ams495qa01.c new file +6 -0

+               db->reg_elvdd = NULL;
+
+       db->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
+       if (IS_ERR(db->reset)) {
+               ret = PTR_ERR(db->reset);
+               return dev_err_probe(dev, ret, "no RESET GPIO\n");

I think this can be shortened into:
return dev_err_probe(dev, PTR_ERR(db->reset), "cannot get reset gpio\n");

drivers/gpu/drm/panel/panel-samsung-ams495qa01.c line 384

Quoted 9 lines

drivers/gpu/drm/panel/panel-samsung-ams495qa01.c new file +9 -0

+       }
+
+       db->enable = devm_gpiod_get_optional(dev, "enable", GPIOD_OUT_HIGH);
+       if (IS_ERR(db->enable)) {
+               ret = PTR_ERR(db->enable);
+               return dev_err_probe(dev, ret, "cannot get ENABLE GPIO\n");
+       }
+
+       ret = mipi_dbi_spi_init(spi, &db->dbi, NULL);

It's not always controlled via SPI, sometimes(based on a strap pin) it's controlled via MIPI-DSI commands.

Maybe let's either have another DT compatible for that? I'm really not sure

drivers/gpu/drm/panel/panel-samsung-ams495qa01.c line 390

Quoted 7 lines

drivers/gpu/drm/panel/panel-samsung-ams495qa01.c new file +6 -0

+       if (ret)
+               return dev_err_probe(dev, ret, "MIPI DBI init failed\n");
+
+       /*
+        * Get the DSI controller that is supplying data for this display
+        * which is controlled via SPI 3-wire.

Same as above

Quoted 113 lines

drivers/gpu/drm/panel/panel-samsung-ams495qa01.c new file +113 -0

+        */
+       endpoint = of_graph_get_next_endpoint(dev->of_node, NULL);
+       if (!endpoint) {
+               dev_err(dev, "failed to get endpoint\n");
+               return -ENODEV;
+       }
+       dsi_host_node = of_graph_get_remote_port_parent(endpoint);
+       if (!dsi_host_node) {
+               dev_err(dev, "failed to get remote port parent\n");
+               goto put_endpoint;
+       }
+       dsi_host = of_find_mipi_dsi_host_by_node(dsi_host_node);
+       if (!dsi_host) {
+               dev_err(dev, "failed to find dsi host\n");
+               goto put_host;
+       }
+       info.node = of_graph_get_remote_port(endpoint);
+       if (!info.node) {
+               dev_err(dev, "failed to get remote port node\n");
+               ret = -ENODEV;
+               goto put_host;
+       }
+
+       db->dsi_dev = devm_mipi_dsi_device_register_full(dev, dsi_host, &info);
+       if (IS_ERR(db->dsi_dev)) {
+               dev_err(dev, "failed to register dsi device: %ld\n",
+                       PTR_ERR(db->dsi_dev));
+               ret = PTR_ERR(db->dsi_dev);
+               goto put_host;
+       }
+
+       db->dsi_dev->lanes = 2;
+       db->dsi_dev->format = MIPI_DSI_FMT_RGB888;
+       db->dsi_dev->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_BURST |
+                         MIPI_DSI_MODE_LPM | MIPI_DSI_MODE_NO_EOT_PACKET;
+
+       drm_panel_init(&db->panel, dev, &ams495qa01_drm_funcs,
+                      DRM_MODE_CONNECTOR_DSI);
+
+       ret = ams495qa01_backlight_register(db);
+       if (ret < 0)
+               return ret;
+
+       drm_panel_add(&db->panel);
+
+       ret = devm_mipi_dsi_attach(dev, db->dsi_dev);
+       if (ret < 0) {
+               dev_err(dev, "mipi_dsi_attach failed: %d\n", ret);
+               drm_panel_remove(&db->panel);
+               return ret;
+       }
+
+       of_node_put(dsi_host_node);
+       of_node_put(endpoint);
+
+       return 0;
+
+put_host:
+       of_node_put(dsi_host_node);
+
+put_endpoint:
+       of_node_put(endpoint);
+       return -ENODEV;
+}
+
+static void ams495qa01_shutdown(struct spi_device *spi)
+{
+       struct ams495qa01 *db = spi_get_drvdata(spi);
+       int ret;
+
+       ret = drm_panel_unprepare(&db->panel);
+       if (ret < 0)
+               dev_err(&spi->dev, "Failed to unprepare panel: %d\n", ret);
+
+       ret = drm_panel_disable(&db->panel);
+       if (ret < 0)
+               dev_err(&spi->dev, "Failed to disable panel: %d\n", ret);
+}
+
+static void ams495qa01_remove(struct spi_device *spi)
+{
+       struct ams495qa01 *db = spi_get_drvdata(spi);
+
+       ams495qa01_shutdown(spi);
+
+       drm_panel_remove(&db->panel);
+}
+
+static const struct of_device_id ams495qa01_match[] = {
+       { .compatible = "samsung,ams495qa01", },
+       {},
+};
+MODULE_DEVICE_TABLE(of, ams495qa01_match);
+
+static const struct spi_device_id ams495qa01_ids[] = {
+       { "ams495qa01", 0 },
+       {},
+};
+MODULE_DEVICE_TABLE(spi, ams495qa01_ids);
+
+static struct spi_driver ams495qa01_driver = {
+       .driver         = {
+               .name   = "ams495qa01-panel",
+               .of_match_table = ams495qa01_match,
+       },
+       .id_table       = ams495qa01_ids,
+       .probe          = ams495qa01_probe,
+       .remove         = ams495qa01_remove,
+       .shutdown       = ams495qa01_shutdown,
+};
+module_spi_driver(ams495qa01_driver);
+
+MODULE_AUTHOR("Chris Morgan <[email protected]>");

Quoted 5 lines

drivers/gpu/drm/panel/panel-samsung-ams495qa01.c new file +2 -1

+MODULE_DESCRIPTION("Samsung ams495qa01 panel driver");
+MODULE_LICENSE("GPL");
--

2.25.1

Best Regards,
Maya Matuszczyk