Re: [PATCH 3/5] drm/panel: Add Feixin K101 IM2BA02 panel

Sam Ravnborg
2020-01-10T17:46:11Z

Hi Icenowy.

On Fri, Jan 10, 2020 at 11:52:23PM +0800, Icenowy Zheng wrote:
> Feixin K101 IM2BA02 is a 800x1280 4-lane MIPI-DSI LCD panel.
>
> Add a panel driver for it.
Thanks, driver looks really good.
Only a few comments/nits below.

Sam
>
> Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
> ---
> MAINTAINERS | 6 +
> drivers/gpu/drm/panel/Kconfig | 9 +
> drivers/gpu/drm/panel/Makefile | 1 +
> .../gpu/drm/panel/panel-feixin-k101-im2ba02.c | 548 ++++++++++++++++++
> 4 files changed, 564 insertions(+)
> create mode 100644 drivers/gpu/drm/panel/panel-feixin-k101-im2ba02.c
>

> new file mode 100644
> index 000000000000..45a62bdabb3f
> --- /dev/null
> +++ b/drivers/gpu/drm/panel/panel-feixin-k101-im2ba02.c
> @@ -0,0 +1,548 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (C) 2019-2020 Icenowy Zheng <icenowy@aosc.io>
> + */
> +
> +#include <linux/gpio/consumer.h>
> +#include <linux/delay.h>
> +#include <linux/mod_devicetable.h>
> +#include <linux/module.h>
> +#include <linux/of_device.h>
> +#include <linux/regulator/consumer.h>
> +
> +#include <drm/drm_mipi_dsi.h>
> +#include <drm/drm_modes.h>
> +#include <drm/drm_panel.h>
> +#include <drm/drm_print.h>
Sorted and in the right order - good.

> +
> +static int k101_im2ba02_prepare(struct drm_panel *panel)
> +{
> + struct k101_im2ba02 *ctx = panel_to_k101_im2ba02(panel);
> + struct mipi_dsi_device *dsi = ctx->dsi;
> + unsigned int i;
> + int ret;
> +
> + ret = regulator_enable(ctx->avdd);
> + if (ret)
> + return ret;
> +
> + msleep(20);
> +
> + ret = regulator_enable(ctx->dvdd);
> + if (ret)
> + return ret;
> +
> + msleep(20);
> +
> + ret = regulator_enable(ctx->cvdd);
> + if (ret)
> + return ret;

Unless the msleep() between is regulator_enable() really is needed,
this change this to use regulator_bulk_enable().

If the above is kept then please do proper error handling
where all enabled regulators are disable in case of errors.

> +
> + msleep(30);
> +
> + gpiod_set_value(ctx->reset, 1);
> + msleep(50);
> +
> + gpiod_set_value(ctx->reset, 0);
> + msleep(50);
> +
> + gpiod_set_value(ctx->reset, 1);
> + msleep(200);
> +
> + for (i = 0; i < ARRAY_SIZE(k101_im2ba02_init_cmds); i++) {
> + const struct k101_im2ba02_init_cmd *cmd = &k101_im2ba02_init_cmds[i];
> +
> + ret = mipi_dsi_dcs_write_buffer(dsi, cmd->data, K101_IM2BA02_INIT_CMD_LEN);
> + if (ret < 0)
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int k101_im2ba02_enable(struct drm_panel *panel)
> +{
> + struct k101_im2ba02 *ctx = panel_to_k101_im2ba02(panel);
> + const struct k101_im2ba02_init_cmd *cmd = &timed_cmds[1];
> + int ret;
> +
> + msleep(150);
> +
> + ret = mipi_dsi_dcs_set_display_on(ctx->dsi);
> + if (ret < 0)
> + return ret;
> +
> + msleep(50);
> +
> + return mipi_dsi_dcs_write_buffer(ctx->dsi, cmd->data, K101_IM2BA02_INIT_CMD_LEN);
> + if (ret < 0)
> + return ret;
The last two lines can be deleted - they are never reached.

> +}
> +
> +static int k101_im2ba02_disable(struct drm_panel *panel)
> +{
> + struct k101_im2ba02 *ctx = panel_to_k101_im2ba02(panel);
> +
> + return mipi_dsi_dcs_set_display_off(ctx->dsi);
> +}
> +
> +static int k101_im2ba02_unprepare(struct drm_panel *panel)
> +{
> + struct k101_im2ba02 *ctx = panel_to_k101_im2ba02(panel);
> + int ret;
> +
> + ret = mipi_dsi_dcs_set_display_off(ctx->dsi);
> + if (ret < 0)
> + DRM_DEV_ERROR(panel->dev, "failed to set display off: %d\n",
> + ret);
> +
> + ret = mipi_dsi_dcs_enter_sleep_mode(ctx->dsi);
> + if (ret < 0)
> + DRM_DEV_ERROR(panel->dev, "failed to enter sleep mode: %d\n",
> + ret);
> +
> + msleep(200);
> +
> + gpiod_set_value(ctx->reset, 0);
> +
> + msleep(20);
> +
> + regulator_disable(ctx->cvdd);
> +
> + msleep(20);
> +
> + regulator_disable(ctx->dvdd);
> +
> + msleep(20);
> +
> + regulator_disable(ctx->avdd);
Can we get rid of a few empty lines here?
If the 20 msecs are not really needed then use regulator_bulk_disable()

> + return 0;
> +}
> +
> +static const struct drm_display_mode k101_im2ba02_default_mode = {
> + .clock = 70000,
> + .vrefresh = 60,
> +
> + .hdisplay = 800,
> + .hsync_start = 800 + 20,
> + .hsync_end = 800 + 20 + 20,
> + .htotal = 800 + 20 + 20 + 20,
> +
> + .vdisplay = 1280,
> + .vsync_start = 1280 + 16,
> + .vsync_end = 1280 + 16 + 4,
> + .vtotal = 1280 + 16 + 4 + 4,
> +
> + .type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED,
> + .width_mm = 136,
> + .height_mm = 217,
> +};
> +
> +static int k101_im2ba02_get_modes(struct drm_panel *panel,
> + struct drm_connector *connector)
> +{
> + struct k101_im2ba02 *ctx = panel_to_k101_im2ba02(panel);
> + struct drm_display_mode *mode;
> +
> + mode = drm_mode_duplicate(connector->dev, &k101_im2ba02_default_mode);
> + if (!mode) {
> + DRM_DEV_ERROR(&ctx->dsi->dev, "failed to add mode %ux%ux@%u\n",
> + k101_im2ba02_default_mode.hdisplay,
> + k101_im2ba02_default_mode.vdisplay,
> + k101_im2ba02_default_mode.vrefresh);
> + return -ENOMEM;
> + }
> +
> + drm_mode_set_name(mode);
> +
> + mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
> + 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 k101_im2ba02_funcs = {
> + .disable = k101_im2ba02_disable,
> + .unprepare = k101_im2ba02_unprepare,
> + .prepare = k101_im2ba02_prepare,
> + .enable = k101_im2ba02_enable,
> + .get_modes = k101_im2ba02_get_modes,
> +};
> +
> +static int k101_im2ba02_dsi_probe(struct mipi_dsi_device *dsi)
> +{
> + struct k101_im2ba02 *ctx;
> + int ret;
> +
> + ctx = devm_kzalloc(&dsi->dev, sizeof(*ctx), GFP_KERNEL);
> + if (!ctx)
> + return -ENOMEM;
> +
> + mipi_dsi_set_drvdata(dsi, ctx);
> + ctx->dsi = dsi;
> +
> + ctx->dvdd = devm_regulator_get(&dsi->dev, "dvdd");
> + if (IS_ERR(ctx->dvdd)) {
> + DRM_DEV_ERROR(&dsi->dev, "Couldn't get dvdd regulator\n");
> + return PTR_ERR(ctx->dvdd);
> + }
> +
> + ctx->avdd = devm_regulator_get(&dsi->dev, "avdd");
> + if (IS_ERR(ctx->avdd)) {
> + DRM_DEV_ERROR(&dsi->dev, "Couldn't get avdd regulator\n");
> + return PTR_ERR(ctx->avdd);
> + }
> +
> + ctx->cvdd = devm_regulator_get(&dsi->dev, "cvdd");
> + if (IS_ERR(ctx->cvdd)) {
> + DRM_DEV_ERROR(&dsi->dev, "Couldn't get cvdd regulator\n");
> + return PTR_ERR(ctx->cvdd);
> + }
> +
> + ctx->reset = devm_gpiod_get(&dsi->dev, "reset", GPIOD_OUT_LOW);
> + if (IS_ERR(ctx->reset)) {
> + DRM_DEV_ERROR(&dsi->dev, "Couldn't get our reset GPIO\n");
> + return PTR_ERR(ctx->reset);
> + }
> +
> + drm_panel_init(&ctx->panel, &dsi->dev, &k101_im2ba02_funcs,
> + DRM_MODE_CONNECTOR_DSI);
> +
> + ret = drm_panel_of_backlight(&ctx->panel);
> + if (ret)
> + return ret;
> +
> + ret = drm_panel_add(&ctx->panel);
> + if (ret < 0)
> + return ret;
> +
> + dsi->mode_flags = MIPI_DSI_MODE_VIDEO;
> + dsi->format = MIPI_DSI_FMT_RGB888;
> + dsi->lanes = 4;
> +
> + ret = mipi_dsi_attach(dsi);
> + if (ret < 0) {
> + drm_panel_remove(&ctx->panel);
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int k101_im2ba02_dsi_remove(struct mipi_dsi_device *dsi)
> +{
> + struct k101_im2ba02 *ctx = mipi_dsi_get_drvdata(dsi);
> +
> + mipi_dsi_detach(dsi);
> + drm_panel_remove(&ctx->panel);
> +
> + return 0;
> +}
> +
> +static const struct of_device_id k101_im2ba02_of_match[] = {
> + { .compatible = "feixin,k101-im2ba02", },
> + { }
Use { /* sentinel */ },

> +};
> +MODULE_DEVICE_TABLE(of, k101_im2ba02_of_match);
> +
> +static struct mipi_dsi_driver k101_im2ba02_driver = {
> + .probe = k101_im2ba02_dsi_probe,
> + .remove = k101_im2ba02_dsi_remove,
> + .driver = {
> + .name = "feixin-k101-im2ba02",
> + .of_match_table = k101_im2ba02_of_match,
> + },
> +};
> +module_mipi_dsi_driver(k101_im2ba02_driver);
> +
> +MODULE_AUTHOR("Icenowy Zheng <icenowy@aosc.io>");
> +MODULE_DESCRIPTION("Feixin K101 IM2BA02 MIPI-DSI LCD panel");
> +MODULE_LICENSE("GPL");
> --
> 2.23.0