Re: [PATCH RFC v6 16/21] drm: panel: Add support for Himax HX8369A MIPI DSI panel

On 12/29/2014 11:07 AM, Liu Ying wrote:

On 12/29/2014 05:09 PM, Andrzej Hajda wrote:

...

On 12/29/2014 07:39 AM, Liu Ying wrote:

...

This patch adds support for Himax HX8369A MIPI DSI panel.

Signed-off-by: Liu Ying Ying.Liu@freescale.com

v5->v6:

• Make the checkpatch.pl script be happier.
• Do not set the dsi channel number to be zero in probe(), because the MIPI DSI bus driver would set it.

v4->v5:

• Address Andrzej Hajda's comments.
• Get the bs-gpios property instead of the bs[3:0]-gpios properties.
• Implement error propagation for panel register configurations.
• Other minor changes to improve the code quality.

v3->v4:

• Move the relevant dt-bindings to a separate patch to address Stefan Wahren's comment.

v2->v3:

• Sort the included header files alphabetically.

v1->v2:

• Address almost all comments from Thierry Reding.
• Remove several DT properties as they can be implied by the compatible string.
• Add the HIMAX/himax prefixes to the driver's Kconfig name and driver name.
• Move the driver's Makefile entry place to sort the entries alphabetically.
• Reuse several standard DCS functions instead of inventing wheels.
• Move the panel resetting and power logics to the driver probe/remove stages. This may simplify panel prepare/unprepare hooks. The power consumption should not change a lot at DPMS since the panel enters sleep mode at that time.
• Add the module author.
• Other minor changes, such as coding style issues.

drivers/gpu/drm/panel/Kconfig | 5 + drivers/gpu/drm/panel/Makefile | 1 + drivers/gpu/drm/panel/panel-himax-hx8369a.c | 614 ++++++++++++++++++++++++++++ 3 files changed, 620 insertions(+) create mode 100644 drivers/gpu/drm/panel/panel-himax-hx8369a.c

diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig index 024e98e..81b0bf0 100644 --- a/drivers/gpu/drm/panel/Kconfig +++ b/drivers/gpu/drm/panel/Kconfig @@ -16,6 +16,11 @@ config DRM_PANEL_SIMPLE that it can be automatically turned off when the panel goes into a low power state.

+config DRM_PANEL_HIMAX_HX8369A

• tristate "Himax HX8369A panel"
• depends on OF
• select DRM_MIPI_DSI
• config DRM_PANEL_LD9040 tristate "LD9040 RGB/SPI panel" depends on OF && SPI

diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile index 4b2a043..d5dbe06 100644 --- a/drivers/gpu/drm/panel/Makefile +++ b/drivers/gpu/drm/panel/Makefile @@ -1,4 +1,5 @@ obj-$(CONFIG_DRM_PANEL_SIMPLE) += panel-simple.o +obj-$(CONFIG_DRM_PANEL_HIMAX_HX8369A) += panel-himax-hx8369a.o obj-$(CONFIG_DRM_PANEL_LD9040) += panel-ld9040.o obj-$(CONFIG_DRM_PANEL_S6E8AA0) += panel-s6e8aa0.o obj-$(CONFIG_DRM_PANEL_SHARP_LQ101R1SX01) += panel-sharp-lq101r1sx01.o diff --git a/drivers/gpu/drm/panel/panel-himax-hx8369a.c b/drivers/gpu/drm/panel/panel-himax-hx8369a.c new file mode 100644 index 0000000..eee36a7 --- /dev/null +++ b/drivers/gpu/drm/panel/panel-himax-hx8369a.c @@ -0,0 +1,614 @@ +/*

• • Himax HX8369A panel driver.
• • Copyright (C) 2011-2014 Freescale Semiconductor, Inc.
• • This program is free software; you can redistribute it and/or modify
• • it under the terms of the GNU General Public License version 2 as
• • published by the Free Software Foundation.
• • This driver is based on Samsung s6e8aa0 panel driver.
• */

+#include <drm/drmP.h> +#include <drm/drm_mipi_dsi.h> +#include <drm/drm_panel.h>

+#include <linux/gpio/consumer.h> +#include <linux/of_device.h> +#include <linux/regulator/consumer.h>

+#include <video/mipi_display.h> +#include <video/of_videomode.h> +#include <video/videomode.h>

+#define WRDISBV 0x51 +#define WRCTRLD 0x53 +#define WRCABC 0x55 +#define SETPOWER 0xb1 +#define SETDISP 0xb2 +#define SETCYC 0xb4 +#define SETVCOM 0xb6 +#define SETEXTC 0xb9 +#define SETMIPI 0xba +#define SETPANEL 0xcc +#define SETGIP 0xd5 +#define SETGAMMA 0xe0

+#define HX8369A_MIN_BRIGHTNESS 0x00 +#define HX8369A_MAX_BRIGHTNESS 0xff

+enum hx8369a_mpu_interface {

• HX8369A_DBI_TYPE_A_8BIT,
• HX8369A_DBI_TYPE_A_9BIT,
• HX8369A_DBI_TYPE_A_16BIT,
• HX8369A_DBI_TYPE_A_18BIT,
• HX8369A_DBI_TYPE_B_8BIT,
• HX8369A_DBI_TYPE_B_9BIT,
• HX8369A_DBI_TYPE_B_16BIT,
• HX8369A_DBI_TYPE_B_18BIT,
• HX8369A_DSI_CMD_MODE,
• HX8369A_DBI_TYPE_B_24BIT,
• HX8369A_DSI_VIDEO_MODE,
• HX8369A_MDDI,
• HX8369A_DPI_DBI_TYPE_C_OPT1,
• HX8369A_DPI_DBI_TYPE_C_OPT2,
• HX8369A_DPI_DBI_TYPE_C_OPT3

+};

+enum hx8369a_resolution {

• HX8369A_RES_480_864,
• HX8369A_RES_480_854,
• HX8369A_RES_480_800,
• HX8369A_RES_480_640,
• HX8369A_RES_360_640,
• HX8369A_RES_480_720,

+};

+struct hx8369a_panel_desc {

• const struct drm_display_mode *mode;
• /* ms */
• unsigned int power_on_delay;
• unsigned int reset_delay;
• unsigned int dsi_lanes;

+};

+struct hx8369a {

• struct device *dev;
• struct drm_panel panel;
• const struct hx8369a_panel_desc *pd;
• struct regulator_bulk_data supplies[5];
• struct gpio_desc *reset_gpio;
• struct gpio_desc *bs_gpio[4];
• u8 res_sel;

+};

+static inline struct hx8369a *panel_to_hx8369a(struct drm_panel *panel) +{

• return container_of(panel, struct hx8369a, panel);

+}

+static int hx8369a_dcs_write(struct hx8369a *ctx, const char *func,

• 	     const void *data, size_t len)
  

+{

• struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
• ssize_t ret;
• ret = mipi_dsi_dcs_write_buffer(dsi, data, len);
• if (ret < 0) {

• dev_err(ctx->dev, "%s failed: %d\n", func, ret);
  

• return ret;
  

• }
• return 0;

Nitpick. You can replace 4 lines above with: if (ret < 0) dev_err(ctx->dev, "%s failed: %d\n", func, ret); return ret;

I'll do that.

...

...

+}

+#define hx8369a_dcs_write_seq(ctx, seq...) \ +({ \

• const u8 d[] = { seq }; \
• BUILD_BUG_ON_MSG(ARRAY_SIZE(d) > 64, \

• 	 "DCS sequence too big for stack"); \
  

• hx8369a_dcs_write(ctx, __func__, d, ARRAY_SIZE(d)); \

+})

+#define hx8369a_dcs_write_seq_static(ctx, seq...) \ +({ \

• static const u8 d[] = { seq }; \
• hx8369a_dcs_write(ctx, __func__, d, ARRAY_SIZE(d)); \

+})

+static int hx8369a_dsi_set_display_related_register(struct hx8369a *ctx) +{

• u8 sec_p = (ctx->res_sel << 4) | 0x03;
• return hx8369a_dcs_write_seq(ctx, SETDISP, 0x00, sec_p, 0x03,

• 	   0x03, 0x70, 0x00, 0xff, 0x00, 0x00, 0x00,
  

• 	   0x00, 0x03, 0x03, 0x00, 0x01);
  

+}

+static int hx8369a_dsi_set_display_waveform_cycle(struct hx8369a *ctx) +{

• return hx8369a_dcs_write_seq_static(ctx, SETCYC, 0x00, 0x1d,

• 			0x5f, 0x0e, 0x06);
  

+}

+static int hx8369a_dsi_set_gip(struct hx8369a *ctx) +{

• return hx8369a_dcs_write_seq_static(ctx, SETGIP, 0x00, 0x04,

• 		 0x03, 0x00, 0x01, 0x05, 0x1c, 0x70,
  

• 		 0x01, 0x03, 0x00, 0x00, 0x40, 0x06,
  

• 		 0x51, 0x07, 0x00, 0x00, 0x41, 0x06,
  

• 		 0x50, 0x07, 0x07, 0x0f, 0x04);
  

+}

+static int hx8369a_dsi_set_power(struct hx8369a *ctx) +{

• return hx8369a_dcs_write_seq_static(ctx, SETPOWER, 0x01, 0x00,

• 		   0x34, 0x06, 0x00, 0x0f, 0x0f, 0x2a,
  

• 		   0x32, 0x3f, 0x3f, 0x07, 0x3a, 0x01,
  

• 		   0xe6, 0xe6, 0xe6, 0xe6, 0xe6);
  

+}

+static int hx8369a_dsi_set_vcom_voltage(struct hx8369a *ctx) +{

• return hx8369a_dcs_write_seq_static(ctx, SETVCOM, 0x56, 0x56);

+}

+static int hx8369a_dsi_set_panel(struct hx8369a *ctx) +{

• return hx8369a_dcs_write_seq_static(ctx, SETPANEL, 0x02);

+}

+static int hx8369a_dsi_set_gamma_curve(struct hx8369a *ctx) +{

• return hx8369a_dcs_write_seq_static(ctx, SETGAMMA, 0x00, 0x1d,

• 		   0x22, 0x38, 0x3d, 0x3f, 0x2e, 0x4a,
  

• 		   0x06, 0x0d, 0x0f, 0x13, 0x15, 0x13,
  

• 		   0x16, 0x10, 0x19, 0x00, 0x1d, 0x22,
  

• 		   0x38, 0x3d, 0x3f, 0x2e, 0x4a, 0x06,
  

• 		   0x0d, 0x0f, 0x13, 0x15, 0x13, 0x16,
  

• 		   0x10, 0x19);
  

+}

+static int hx8369a_dsi_set_mipi(struct hx8369a *ctx) +{

• u8 eleventh_p = ctx->pd->dsi_lanes == 2 ? 0x11 : 0x10;
• return hx8369a_dcs_write_seq(ctx, SETMIPI, 0x00, 0xa0, 0xc6,

• 		 0x00, 0x0a, 0x00, 0x10, 0x30, 0x6f,
  

• 		 0x02, eleventh_p, 0x18, 0x40);
  

+}

+static int hx8369a_dsi_set_interface_pixel_fomat(struct hx8369a *ctx) +{

• struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
• u8 format;
• int ret;
• switch (dsi->format) {
• case MIPI_DSI_FMT_RGB888:
• case MIPI_DSI_FMT_RGB666:

• format = 0x77;
  

• break;
  

• case MIPI_DSI_FMT_RGB565:

• format = 0x55;
  

• break;
  

• case MIPI_DSI_FMT_RGB666_PACKED:

• format = 0x66;
  

• break;
  

• default:

• dev_err(ctx->dev, "unsupported DSI pixel format\n");
  

• return -EINVAL;
  

• }
• ret = mipi_dsi_dcs_set_pixel_format(dsi, format);
• if (ret < 0)

• dev_err(ctx->dev, "%s failed: %d\n", __func__, ret);
  

• return ret;

+}

This functions could be also DSI helper, it is not specific to this panel, but it is just a suggestion.

Any documentation can reflect this could be a common DSI helper, maybe the MIPI DSI spec? I wrote this function by taking the HX8369A panel data sheet as a reference.

MIPI DSI specification describes MIPI_DSI_FMT_* values and MIPI DCS specification describes 'format' values (ie. 0x77, 0x55, 0x66). For reference please look for phrase "Table 6 Interface Pixel Formats" in MIPI DCS specification (or in google :) ).

...

...

+static int hx8369a_dsi_set_column_address(struct hx8369a *ctx) +{

• struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
• const struct drm_display_mode *mode = ctx->pd->mode;
• int ret;
• ret = mipi_dsi_dcs_set_column_address(dsi, 0, mode->hdisplay - 1);
• if (ret < 0)

• dev_err(ctx->dev, "%s failed: %d\n", __func__, ret);
  

• return ret;

+}

+static int hx8369a_dsi_set_page_address(struct hx8369a *ctx) +{

• struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
• const struct drm_display_mode *mode = ctx->pd->mode;
• int ret;
• ret = mipi_dsi_dcs_set_page_address(dsi, 0, mode->vdisplay - 1);
• if (ret < 0)

• dev_err(ctx->dev, "%s failed: %d\n", __func__, ret);
  

• return ret;

+}

+static int hx8369a_dsi_write_display_brightness(struct hx8369a *ctx,

• 				u8 brightness)
  

+{

• return hx8369a_dcs_write_seq(ctx, WRDISBV, brightness);

+}

+static int hx8369a_dsi_write_cabc(struct hx8369a *ctx) +{

• return hx8369a_dcs_write_seq_static(ctx, WRCABC, 0x01);

+}

+static int hx8369a_dsi_write_control_display(struct hx8369a *ctx) +{

• return hx8369a_dcs_write_seq_static(ctx, WRCTRLD, 0x24);

+}

+#define hx8369a_dsi_init_helper(ctx, ret, name) \ +({ \

• ret = hx8369a_dsi_##name(ctx); \
• if (ret < 0) \

• return ret; \
  

+})

Yeah, another hack to get rid of redundant code :) Two ugly things here: ## and return from macro.

...

+static int hx8369a_dsi_panel_init(struct hx8369a *ctx) +{

• int ret;
• hx8369a_dsi_init_helper(ctx, ret, set_display_related_register);
• hx8369a_dsi_init_helper(ctx, ret, set_display_waveform_cycle);
• hx8369a_dsi_init_helper(ctx, ret, set_gip);
• hx8369a_dsi_init_helper(ctx, ret, set_power);
• hx8369a_dsi_init_helper(ctx, ret, set_vcom_voltage);
• hx8369a_dsi_init_helper(ctx, ret, set_panel);
• hx8369a_dsi_init_helper(ctx, ret, set_gamma_curve);
• hx8369a_dsi_init_helper(ctx, ret, set_mipi);
• hx8369a_dsi_init_helper(ctx, ret, set_interface_pixel_fomat);
• hx8369a_dsi_init_helper(ctx, ret, set_column_address);
• hx8369a_dsi_init_helper(ctx, ret, set_page_address);
• hx8369a_dsi_init_helper(ctx, ret, write_cabc);
• hx8369a_dsi_init_helper(ctx, ret, write_control_display);

Maybe it would be better to replace the hack above with something like: { int (*)(struct hx8369a *ctx) funcs[] = { hx8369a_dsi_set_display_related_register, hx8369a_dsi_set_display_waveform_cycle, ... }; int ret, i;

 for (i = 0; i < ARRAY_SIZE(funcs); ++i) {
     ret = funcs[i](ctx);
     if (ret)
         return ret;
 }

I'll change to use this. Thanks.

...

...

• return 0;

+}

+static int hx8369a_dsi_set_extension_command(struct hx8369a *ctx) +{

• return hx8369a_dcs_write_seq_static(ctx, SETEXTC, 0xff, 0x83, 0x69);

+}

+static int hx8369a_dsi_set_maximum_return_packet_size(struct hx8369a *ctx,

• 				      u16 size)
  

+{

• struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
• int ret;
• ret = mipi_dsi_set_maximum_return_packet_size(dsi, size);
• if (ret < 0)

• dev_err(ctx->dev,
  

• 	"error %d setting maximum return packet size to %d\n",
  

• 	ret, size);
  

• return ret;

+}

+static int hx8369a_dsi_set_sequence(struct hx8369a *ctx) +{

• struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
• int ret;
• ret = hx8369a_dsi_set_extension_command(ctx);
• if (ret < 0)

• goto out;
  

• ret = hx8369a_dsi_set_maximum_return_packet_size(ctx, 4);
• if (ret < 0)

• goto out;
  

• ret = hx8369a_dsi_panel_init(ctx);
• if (ret < 0)

• goto out;
  

• ret = mipi_dsi_dcs_exit_sleep_mode(dsi);
• if (ret < 0) {

• dev_err(ctx->dev, "failed to exit sleep mode: %d\n", ret);
  

• goto out;
  

• }
• ret = mipi_dsi_dcs_set_display_on(dsi);
• if (ret < 0) {

• dev_err(ctx->dev, "failed to set display on: %d\n", ret);
  

• goto out;
  

• }
• /*

• * It's necessary to wait 120msec after sending the Sleep Out
  

• * command before Sleep In command can be sent, according to
  

• * the HX8369A data sheet.
  

• */
  

• msleep(120);

+out:

• return ret;

+}

+static int hx8369a_dsi_disable(struct drm_panel *panel) +{

• struct hx8369a *ctx = panel_to_hx8369a(panel);
• return hx8369a_dsi_write_display_brightness(ctx,

• 				HX8369A_MIN_BRIGHTNESS);
  

+}

+static int hx8369a_dsi_unprepare(struct drm_panel *panel) +{

• struct hx8369a *ctx = panel_to_hx8369a(panel);
• struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
• int ret;
• ret = mipi_dsi_dcs_enter_sleep_mode(dsi);
• if (ret < 0) {

• dev_err(ctx->dev, "failed to enter sleep mode: %d\n", ret);
  

• goto out;
  

• }
• ret = mipi_dsi_dcs_set_display_off(dsi);
• if (ret < 0) {

• dev_err(ctx->dev, "failed to set display off: %d\n", ret);
  

• goto out;
  

• }
• /*

• * This is to allow time for the supply voltages and clock
  

• * circuits to stablize, according to the HX8369A data sheet.
  

• */
  

• msleep(5);

+out:

• return ret;

+}

+static int hx8369a_dsi_prepare(struct drm_panel *panel) +{

• struct hx8369a *ctx = panel_to_hx8369a(panel);
• return hx8369a_dsi_set_sequence(ctx);

+}

+static int hx8369a_dsi_enable(struct drm_panel *panel) +{

• struct hx8369a *ctx = panel_to_hx8369a(panel);
• return hx8369a_dsi_write_display_brightness(ctx,

• 				HX8369A_MAX_BRIGHTNESS);
  

+}

+static int hx8369a_get_modes(struct drm_panel *panel) +{

• struct drm_connector *connector = panel->connector;
• struct drm_device *drm = panel->drm;
• struct hx8369a *ctx = panel_to_hx8369a(panel);
• struct drm_display_mode *mode;
• const struct drm_display_mode *m = ctx->pd->mode;
• mode = drm_mode_duplicate(drm, m);
• if (!mode) {

• dev_err(drm->dev, "failed to add mode %ux%u@%u\n",
  

• 	m->hdisplay, m->vdisplay, m->vrefresh);
  

• return 0;
  

• }
• drm_mode_set_name(mode);
• mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
• connector->display_info.bpc = 8;
• connector->display_info.width_mm = mode->width_mm;
• connector->display_info.height_mm = mode->height_mm;
• drm_mode_probed_add(connector, mode);
• return 1;

+}

+static const struct drm_panel_funcs hx8369a_dsi_drm_funcs = {

• .disable = hx8369a_dsi_disable,
• .unprepare = hx8369a_dsi_unprepare,
• .prepare = hx8369a_dsi_prepare,
• .enable = hx8369a_dsi_enable,
• .get_modes = hx8369a_get_modes,

+};

+static int hx8369a_power_on(struct hx8369a *ctx) +{

• int ret;
• ret = regulator_bulk_enable(ARRAY_SIZE(ctx->supplies), ctx->supplies);
• if (ret < 0)

• return ret;
  

• msleep(ctx->pd->power_on_delay);
• gpiod_set_value(ctx->reset_gpio, 1);
• usleep_range(50, 60);
• gpiod_set_value(ctx->reset_gpio, 0);
• msleep(ctx->pd->reset_delay);
• return 0;

+}

+static int hx8369a_power_off(struct hx8369a *ctx) +{

• return regulator_bulk_disable(ARRAY_SIZE(ctx->supplies),

• 		      ctx->supplies);
  

+}

+static void hx8369a_vm_to_res_sel(struct hx8369a *ctx) +{

• const struct drm_display_mode *mode = ctx->pd->mode;
• switch (mode->hdisplay) {
• case 480:

• switch (mode->vdisplay) {
  

• case 864:
  

• 	ctx->res_sel = HX8369A_RES_480_864;
  

• 	break;
  

• case 854:
  

• 	ctx->res_sel = HX8369A_RES_480_854;
  

• 	break;
  

• case 800:
  

• 	ctx->res_sel = HX8369A_RES_480_800;
  

• 	break;
  

• case 640:
  

• 	ctx->res_sel = HX8369A_RES_480_640;
  

• 	break;
  

• case 720:
  

• 	ctx->res_sel = HX8369A_RES_480_720;
  

• 	break;
  

• default:
  

• 	break;
  

• }
  

• break;
  

• case 360:

• if (mode->vdisplay == 640)
  

• 	ctx->res_sel = HX8369A_RES_360_640;
  

• break;
  

• default:

• break;
  

• }

+}

+static const struct drm_display_mode truly_tft480800_16_e_mode = {

• .clock = 26400,
• .hdisplay = 480,
• .hsync_start = 480 + 8,
• .hsync_end = 480 + 8 + 8,
• .htotal = 480 + 8 + 8 + 8,
• .vdisplay = 800,
• .vsync_start = 800 + 6,
• .vsync_end = 800 + 6 + 6,
• .vtotal = 800 + 6 + 6 + 6,
• .vrefresh = 60,
• .width_mm = 45,
• .height_mm = 76,

+};

+static const struct hx8369a_panel_desc truly_tft480800_16_e_dsi = {

• .mode = &truly_tft480800_16_e_mode,
• .power_on_delay = 10,
• .reset_delay = 10,
• .dsi_lanes = 2,

+};

+static const struct of_device_id hx8369a_dsi_of_match[] = {

• {

• .compatible = "truly,tft480800-16-e-dsi",
  

• .data = &truly_tft480800_16_e_dsi,
  

• }, {

• /* sentinel */
  

• },

+}; +MODULE_DEVICE_TABLE(of, hx8369a_dsi_of_match);

+static int hx8369a_dsi_probe(struct mipi_dsi_device *dsi) +{

• struct device *dev = &dsi->dev;
• const struct of_device_id *of_id =

• 	of_match_device(hx8369a_dsi_of_match, dev);
  

• struct hx8369a *ctx;
• int ret, i;
• ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
• if (!ctx)

• return -ENOMEM;
  

• ctx->dev = dev;
• if (of_id) {

• ctx->pd = of_id->data;
  

• } else {

• dev_err(dev, "cannot find compatible device\n");
  

• return -ENODEV;
  

• }
• hx8369a_vm_to_res_sel(ctx);
• ctx->supplies[0].supply = "vdd1";
• ctx->supplies[1].supply = "vdd2";
• ctx->supplies[2].supply = "vdd3";
• ctx->supplies[3].supply = "dsi-vcc";
• ctx->supplies[4].supply = "vpp";
• ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(ctx->supplies),

• 		      ctx->supplies);
  

• if (ret < 0) {

• dev_info(dev, "failed to get regulators: %d\n", ret);
  

• return ret;
  

• }
• ctx->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
• if (IS_ERR(ctx->reset_gpio)) {

• dev_info(dev, "cannot get reset-gpios %ld\n",
  

• 	 PTR_ERR(ctx->reset_gpio));
  

• return PTR_ERR(ctx->reset_gpio);
  

• }
• for (i = 0; i < 4; i++) {

• ctx->bs_gpio[i] = devm_gpiod_get_index(dev, "bs", i,
  

• 					GPIOD_OUT_HIGH);
  

• if (!IS_ERR_OR_NULL(ctx->bs_gpio[i]))
  

• 	dev_dbg(dev, "bs%d-gpio is configured\n", i);
  

Are you sure you want to continue probe on error during getting gpios?

There could be holes in the gpio list as mentioned in [1]. For this panel, the potential holes mean that the relevant gpios are not controlled by the driver but only by the hardware.

Perhaps, I need to handle the error case. I tried to implement it in the following way.

ctx->bs_gpio[i] = devm_gpiod_get_index(dev, "bs", i, GPIOD_OUT_HIGH); if (!IS_ERR_OR_NULL(ctx->bs_gpio[i])) { dev_dbg(dev, "bs%d-gpio is configured\n", i); } else if (IS_ERR(ctx->bs_gpio[i])) { dev_info(dev, "failed to get bs%d-gpio\n", i); return PTR_ERR(ctx->bs_gpio[i]); }

But, I get this in dmesg. Any idea? [ 1.625634] panel-hx8369a-dsi 21e0000.mipi.0: failed to get bs0-gpio [ 1.633060] panel-hx8369a-dsi: probe of 21e0000.mipi.0 failed with error -2

I guess you should use devm_gpiod_get_index_optional .

Regards Andrzej

[1] Documentation/devicetree/bindings/gpio/gpio.txt.

Regards,

Liu Ying

...

After addressing above comments you can add:

Reviewed-by: Andrzej Hajda a.hajda@samsung.com

Regards Andrzej

...

• }
• ret = hx8369a_power_on(ctx);
• if (ret < 0) {

• dev_err(dev, "cannot power on\n");
  

• return ret;
  

• }
• drm_panel_init(&ctx->panel);
• ctx->panel.dev = dev;
• ctx->panel.funcs = &hx8369a_dsi_drm_funcs;
• ret = drm_panel_add(&ctx->panel);
• if (ret < 0)

• return ret;
  

• mipi_dsi_set_drvdata(dsi, ctx);
• dsi->lanes = ctx->pd->dsi_lanes;
• dsi->format = MIPI_DSI_FMT_RGB888;
• dsi->mode_flags = MIPI_DSI_MODE_VIDEO |

• 	  MIPI_DSI_MODE_VIDEO_BURST |
  

• 	  MIPI_DSI_MODE_VIDEO_SYNC_PULSE;
  

• ret = mipi_dsi_attach(dsi);
• if (ret < 0)

• drm_panel_remove(&ctx->panel);
  

• return ret;

+}

+static int hx8369a_dsi_remove(struct mipi_dsi_device *dsi) +{

• struct hx8369a *ctx = mipi_dsi_get_drvdata(dsi);
• mipi_dsi_detach(dsi);
• drm_panel_remove(&ctx->panel);
• return hx8369a_power_off(ctx);

+}

+static struct mipi_dsi_driver hx8369a_dsi_driver = {

• .probe = hx8369a_dsi_probe,
• .remove = hx8369a_dsi_remove,
• .driver = {

• .name = "panel-hx8369a-dsi",
  

• .of_match_table = hx8369a_dsi_of_match,
  

• },

+}; +module_mipi_dsi_driver(hx8369a_dsi_driver);

+MODULE_DESCRIPTION("Himax HX8369A panel driver"); +MODULE_AUTHOR("Liu Ying Ying.Liu@freescale.com"); +MODULE_LICENSE("GPL v2");