Re: [PATCH 2/4] drm/panel: samsung-s6e88a0-ams427ap24: Add initial driver

From: Jessica Zhang
Date: Fri Oct 11 2024 - 12:52:52 EST




On 10/10/2024 11:31 AM, Jakob Hauser wrote:
This initial part of the panel driver was mostly generated by the
"linux-mdss-dsi-panel-driver-generator" tool [1], reading downstream
Android kernel file "dsi_panel_S6E88A0_AMS427AP24_qhd_octa_video.dtsi" [2].

On top of the generic output of the tool, there were a couple of changes
applied:
- Added mipi_dsi_dcs_set_display_on() to function s6e88a0_ams427ap24_on(),
otherwise the display does not show up.
- In functions s6e88a0_ams427ap24_on() and s6e88a0_ams427ap24_off()
changed DSI commands to multi context and used "accum_err" returns.
- In functions s6e88a0_ams427ap24_on() and s6e88a0_ams427ap24_off() replaced
msleep() by mipi_dsi_msleep().
- The function s6e88a0_ams427ap24_get_modes() was changed to make use of
drm_connector_helper_get_modes_fixed(). This also required to include
drm/drm_probe_helper.h.
- In function s6e88a0_ams427ap24_probe() registring the regulators was changed
to devm_regulator_bulk_get_const(). This required to change supplies in struct
s6e88a0_ams427ap24 to a pointer.

Coulnd't read out RAW EDID, /sys/class/drm/card0-DSI-1/edid is empty.

[1] https://github.com/msm8916-mainline/linux-mdss-dsi-panel-driver-generator
[2] https://github.com/msm8916-mainline/linux-downstream/blob/GT-I9195I/drivers/video/msm/mdss/samsung/S6E88A0_AMS427AP24/dsi_panel_S6E88A0_AMS427AP24_qhd_octa_video.dtsi

Signed-off-by: Jakob Hauser <jahau@xxxxxxxxxxxxxx>
---
drivers/gpu/drm/panel/Kconfig | 9 +
drivers/gpu/drm/panel/Makefile | 1 +
.../panel/panel-samsung-s6e88a0-ams427ap24.c | 261 ++++++++++++++++++
3 files changed, 271 insertions(+)
create mode 100644 drivers/gpu/drm/panel/panel-samsung-s6e88a0-ams427ap24.c

diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
index ddfaa99ea9dd..fa6a8c6cac5b 100644
--- a/drivers/gpu/drm/panel/Kconfig
+++ b/drivers/gpu/drm/panel/Kconfig
@@ -623,6 +623,15 @@ config DRM_PANEL_SAMSUNG_AMS639RQ08
Say Y or M here if you want to enable support for the
Samsung AMS639RQ08 FHD Plus (2340x1080@60Hz) CMD mode panel.
+config DRM_PANEL_SAMSUNG_S6E88A0_AMS427AP24
+ tristate "Samsung AMS427AP24 panel with S6E88A0 controller"
+ depends on GPIOLIB && OF && REGULATOR
+ depends on DRM_MIPI_DSI
+ help
+ Say Y here if you want to enable support for Samsung AMS427AP24 panel
+ with S6E88A0 controller (found in Samsung Galaxy S4 Mini Value Edition
+ GT-I9195I). To compile this driver as a module, choose M here.
+
config DRM_PANEL_SAMSUNG_S6E88A0_AMS452EF01
tristate "Samsung AMS452EF01 panel with S6E88A0 DSI video mode controller"
depends on OF
diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
index 4b5eaf111676..3002087c26d1 100644
--- a/drivers/gpu/drm/panel/Makefile
+++ b/drivers/gpu/drm/panel/Makefile
@@ -76,6 +76,7 @@ obj-$(CONFIG_DRM_PANEL_SAMSUNG_S6E63J0X03) += panel-samsung-s6e63j0x03.o
obj-$(CONFIG_DRM_PANEL_SAMSUNG_S6E63M0) += panel-samsung-s6e63m0.o
obj-$(CONFIG_DRM_PANEL_SAMSUNG_S6E63M0_SPI) += panel-samsung-s6e63m0-spi.o
obj-$(CONFIG_DRM_PANEL_SAMSUNG_S6E63M0_DSI) += panel-samsung-s6e63m0-dsi.o
+obj-$(CONFIG_DRM_PANEL_SAMSUNG_S6E88A0_AMS427AP24) += panel-samsung-s6e88a0-ams427ap24.o
obj-$(CONFIG_DRM_PANEL_SAMSUNG_S6E88A0_AMS452EF01) += panel-samsung-s6e88a0-ams452ef01.o
obj-$(CONFIG_DRM_PANEL_SAMSUNG_S6E8AA0) += panel-samsung-s6e8aa0.o
obj-$(CONFIG_DRM_PANEL_SAMSUNG_SOFEF00) += panel-samsung-sofef00.o
diff --git a/drivers/gpu/drm/panel/panel-samsung-s6e88a0-ams427ap24.c b/drivers/gpu/drm/panel/panel-samsung-s6e88a0-ams427ap24.c
new file mode 100644
index 000000000000..182ba8c347e2
--- /dev/null
+++ b/drivers/gpu/drm/panel/panel-samsung-s6e88a0-ams427ap24.c
@@ -0,0 +1,261 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Samsung AMS427AP24 panel with S6E88A0 controller
+ * Copyright (c) 2024 Jakob Hauser <jahau@xxxxxxxxxxxxxx>
+ */
+
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/regulator/consumer.h>
+
+#include <video/mipi_display.h>
+
+#include <drm/drm_mipi_dsi.h>
+#include <drm/drm_modes.h>
+#include <drm/drm_panel.h>
+#include <drm/drm_probe_helper.h>
+
+struct s6e88a0_ams427ap24 {
+ struct drm_panel panel;
+ struct mipi_dsi_device *dsi;
+ struct regulator_bulk_data *supplies;
+ struct gpio_desc *reset_gpio;
+ bool prepared;

Hi Jakob,

I think you can drop the `prepared` here as it should be handled by framework now [1]

Thanks,

Jessica Zhang

[1] https://elixir.bootlin.com/linux/v6.11.3/source/include/drm/drm_panel.h#L262

+};
+
+const struct regulator_bulk_data s6e88a0_ams427ap24_supplies[] = {
+ { .supply = "vdd3" },
+ { .supply = "vci" },
+};
+
+static inline
+struct s6e88a0_ams427ap24 *to_s6e88a0_ams427ap24(struct drm_panel *panel)
+{
+ return container_of(panel, struct s6e88a0_ams427ap24, panel);
+}
+
+static void s6e88a0_ams427ap24_reset(struct s6e88a0_ams427ap24 *ctx)
+{
+ gpiod_set_value_cansleep(ctx->reset_gpio, 0);
+ usleep_range(5000, 6000);
+ gpiod_set_value_cansleep(ctx->reset_gpio, 1);
+ usleep_range(1000, 2000);
+ gpiod_set_value_cansleep(ctx->reset_gpio, 0);
+ usleep_range(18000, 19000);
+}
+
+static int s6e88a0_ams427ap24_on(struct s6e88a0_ams427ap24 *ctx)
+{
+ struct mipi_dsi_device *dsi = ctx->dsi;
+ struct mipi_dsi_multi_context dsi_ctx = { .dsi = dsi };
+
+ dsi->mode_flags |= MIPI_DSI_MODE_LPM;
+
+ mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xf0, 0x5a, 0x5a);
+ mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xfc, 0x5a, 0x5a);
+ mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xb0, 0x11);
+ mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xfd, 0x11);
+ mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xb0, 0x13);
+ mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xfd, 0x18);
+ mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xb0, 0x02);
+ mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xb8, 0x30);
+
+ mipi_dsi_dcs_exit_sleep_mode_multi(&dsi_ctx);
+ mipi_dsi_msleep(&dsi_ctx, 20);
+
+ mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xf1, 0x5a, 0x5a);
+ mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xcc, 0x4c);
+ mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xf2, 0x03, 0x0d);
+ mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xf1, 0xa5, 0xa5);
+ mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xca,
+ 0x01, 0x00, 0x01, 0x00, 0x01, 0x00, 0x80,
+ 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80,
+ 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80,
+ 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80,
+ 0x80, 0x80, 0x00, 0x00, 0x00);
+ mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xb2,
+ 0x40, 0x08, 0x20, 0x00, 0x08);
+ mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xb6, 0x28, 0x0b);
+ mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xf7, 0x03);
+ mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0x55, 0x00);
+ mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xf0, 0xa5, 0xa5);
+ mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xfc, 0xa5, 0xa5);
+
+ mipi_dsi_dcs_set_display_on_multi(&dsi_ctx);
+
+ return dsi_ctx.accum_err;
+}
+
+static int s6e88a0_ams427ap24_off(struct s6e88a0_ams427ap24 *ctx)
+{
+ struct mipi_dsi_device *dsi = ctx->dsi;
+ struct mipi_dsi_multi_context dsi_ctx = { .dsi = dsi };
+
+ dsi->mode_flags &= ~MIPI_DSI_MODE_LPM;
+
+ mipi_dsi_dcs_set_display_off_multi(&dsi_ctx);
+ mipi_dsi_dcs_enter_sleep_mode_multi(&dsi_ctx);
+ mipi_dsi_msleep(&dsi_ctx, 120);
+
+ return dsi_ctx.accum_err;
+}
+
+static int s6e88a0_ams427ap24_prepare(struct drm_panel *panel)
+{
+ struct s6e88a0_ams427ap24 *ctx = to_s6e88a0_ams427ap24(panel);
+ struct device *dev = &ctx->dsi->dev;
+ int ret;
+
+ if (ctx->prepared)
+ return 0;
+
+ ret = regulator_bulk_enable(ARRAY_SIZE(s6e88a0_ams427ap24_supplies),
+ ctx->supplies);
+ if (ret < 0) {
+ dev_err(dev, "Failed to enable regulators: %d\n", ret);
+ return ret;
+ }
+
+ s6e88a0_ams427ap24_reset(ctx);
+
+ ret = s6e88a0_ams427ap24_on(ctx);
+ if (ret < 0) {
+ dev_err(dev, "Failed to initialize panel: %d\n", ret);
+ gpiod_set_value_cansleep(ctx->reset_gpio, 1);
+ regulator_bulk_disable(ARRAY_SIZE(s6e88a0_ams427ap24_supplies),
+ ctx->supplies);
+ return ret;
+ }
+
+ ctx->prepared = true;
+ return 0;
+}
+
+static int s6e88a0_ams427ap24_unprepare(struct drm_panel *panel)
+{
+ struct s6e88a0_ams427ap24 *ctx = to_s6e88a0_ams427ap24(panel);
+ struct device *dev = &ctx->dsi->dev;
+ int ret;
+
+ if (!ctx->prepared)
+ return 0;
+
+ ret = s6e88a0_ams427ap24_off(ctx);
+ if (ret < 0)
+ dev_err(dev, "Failed to un-initialize panel: %d\n", ret);
+
+ gpiod_set_value_cansleep(ctx->reset_gpio, 1);
+ regulator_bulk_disable(ARRAY_SIZE(s6e88a0_ams427ap24_supplies),
+ ctx->supplies);
+
+ ctx->prepared = false;
+ return 0;
+}
+
+static const struct drm_display_mode s6e88a0_ams427ap24_mode = {
+ .clock = (540 + 94 + 4 + 18) * (960 + 12 + 1 + 3) * 60 / 1000,
+ .hdisplay = 540,
+ .hsync_start = 540 + 94,
+ .hsync_end = 540 + 94 + 4,
+ .htotal = 540 + 94 + 4 + 18,
+ .vdisplay = 960,
+ .vsync_start = 960 + 12,
+ .vsync_end = 960 + 12 + 1,
+ .vtotal = 960 + 12 + 1 + 3,
+ .width_mm = 55,
+ .height_mm = 95,
+ .type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED,
+};
+
+static int s6e88a0_ams427ap24_get_modes(struct drm_panel *panel,
+ struct drm_connector *connector)
+{
+ return drm_connector_helper_get_modes_fixed(connector,
+ &s6e88a0_ams427ap24_mode);
+}
+
+static const struct drm_panel_funcs s6e88a0_ams427ap24_panel_funcs = {
+ .prepare = s6e88a0_ams427ap24_prepare,
+ .unprepare = s6e88a0_ams427ap24_unprepare,
+ .get_modes = s6e88a0_ams427ap24_get_modes,
+};
+
+static int s6e88a0_ams427ap24_probe(struct mipi_dsi_device *dsi)
+{
+ struct device *dev = &dsi->dev;
+ struct s6e88a0_ams427ap24 *ctx;
+ int ret;
+
+ ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
+ if (!ctx)
+ return -ENOMEM;
+
+ ret = devm_regulator_bulk_get_const(dev,
+ ARRAY_SIZE(s6e88a0_ams427ap24_supplies),
+ s6e88a0_ams427ap24_supplies,
+ &ctx->supplies);
+ if (ret < 0)
+ return ret;
+
+ ctx->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
+ if (IS_ERR(ctx->reset_gpio))
+ return dev_err_probe(dev, PTR_ERR(ctx->reset_gpio),
+ "Failed to get reset-gpios\n");
+
+ ctx->dsi = dsi;
+ mipi_dsi_set_drvdata(dsi, ctx);
+
+ dsi->lanes = 2;
+ dsi->format = MIPI_DSI_FMT_RGB888;
+ dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_BURST |
+ MIPI_DSI_MODE_NO_EOT_PACKET;
+
+ drm_panel_init(&ctx->panel, dev, &s6e88a0_ams427ap24_panel_funcs,
+ DRM_MODE_CONNECTOR_DSI);
+ ctx->panel.prepare_prev_first = true;
+
+ drm_panel_add(&ctx->panel);
+
+ ret = mipi_dsi_attach(dsi);
+ if (ret < 0) {
+ dev_err(dev, "Failed to attach to DSI host: %d\n", ret);
+ drm_panel_remove(&ctx->panel);
+ return ret;
+ }
+
+ return 0;
+}
+
+static void s6e88a0_ams427ap24_remove(struct mipi_dsi_device *dsi)
+{
+ struct s6e88a0_ams427ap24 *ctx = mipi_dsi_get_drvdata(dsi);
+ int ret;
+
+ ret = mipi_dsi_detach(dsi);
+ if (ret < 0)
+ dev_err(&dsi->dev, "Failed to detach from DSI host: %d\n", ret);
+
+ drm_panel_remove(&ctx->panel);
+}
+
+static const struct of_device_id s6e88a0_ams427ap24_of_match[] = {
+ { .compatible = "samsung,s6e88a0-ams427ap24" },
+ { /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, s6e88a0_ams427ap24_of_match);
+
+static struct mipi_dsi_driver s6e88a0_ams427ap24_driver = {
+ .probe = s6e88a0_ams427ap24_probe,
+ .remove = s6e88a0_ams427ap24_remove,
+ .driver = {
+ .name = "panel-s6e88a0-ams427ap24",
+ .of_match_table = s6e88a0_ams427ap24_of_match,
+ },
+};
+module_mipi_dsi_driver(s6e88a0_ams427ap24_driver);
+
+MODULE_AUTHOR("Jakob Hauser <jahau@xxxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("Samsung AMS427AP24 panel with S6E88A0 controller");
+MODULE_LICENSE("GPL v2");
--
2.39.5