Re: [PATCH v4 2/2] drm/panel: Add Feiyang FY07024DI26A30-D MIPI-DSI LCD panel
From: Sam Ravnborg
Date: Thu Jan 24 2019 - 14:50:44 EST
Hi Jagan.
Thanks for this nice patch, a few comments below.
On Fri, Jan 25, 2019 at 12:13:13AM +0530, Jagan Teki wrote:
> Feiyang FY07024DI26A30-D is 1024x600, 4-lane MIPI-DSI LCD panel.
>
> Add panel driver for it.
>
> Signed-off-by: Jagan Teki <jagan@xxxxxxxxxxxxxxxxxxxx>
> ---
> Changes for v5:
> - rebase on master
> - adjust the hporch values to satisfy the refresh
> Changes for v4:
> - use simple structure for command init
> - update proper comments on power, reset delay sequnce
> - fix to use set_display_off in disable function
> - move mode type to structure
> - drop refres rate value, let drm compute
> Changes for v2:
> - new patch, derived from another dsi series
>
> MAINTAINERS | 6 +
> drivers/gpu/drm/panel/Kconfig | 9 +
> drivers/gpu/drm/panel/Makefile | 1 +
> .../drm/panel/panel-feiyang-fy07024di26a30d.c | 286 ++++++++++++++++++
> 4 files changed, 302 insertions(+)
> create mode 100644 drivers/gpu/drm/panel/panel-feiyang-fy07024di26a30d.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index e3f785bad68b..5c8591eb5840 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -4831,6 +4831,12 @@ T: git git://anongit.freedesktop.org/drm/drm-misc
> S: Maintained
> F: drivers/gpu/drm/tve200/
>
> +DRM DRIVER FOR FEIYANG FY07024DI26A30-D MIPI-DSI LCD PANELS
> +M: Jagan Teki <jagan@xxxxxxxxxxxxxxxxxxxx>
> +S: Maintained
> +F: drivers/gpu/drm/panel/panel-feiyang-fy07024di26a30d.c
> +F: Documentation/devicetree/bindings/display/panel/feiyang,fy07024di26a30d.txt
> +
> DRM DRIVER FOR ILITEK ILI9225 PANELS
> M: David Lechner <david@xxxxxxxxxxxxxx>
> S: Maintained
> diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
> index 151ddf720b83..5304db7b7b55 100644
> --- a/drivers/gpu/drm/panel/Kconfig
> +++ b/drivers/gpu/drm/panel/Kconfig
> @@ -47,6 +47,15 @@ config DRM_PANEL_SIMPLE
> that it can be automatically turned off when the panel goes into a
> low power state.
>
> +config DRM_PANEL_FEIYANG_FY07024DI26A30D
> + tristate "Feiyang FY07024DI26A30-D MIPI-DSI LCD panel"
> + depends on OF
> + depends on DRM_MIPI_DSI
> + depends on BACKLIGHT_CLASS_DEVICE
> + help
> + Say Y if you want to enable support for panels based on the
> + Feiyang FY07024DI26A30-D MIPI-DSI interface.
> +
> config DRM_PANEL_ILITEK_IL9322
> tristate "Ilitek ILI9322 320x240 QVGA panels"
> depends on OF && SPI
> diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
> index 54db0921f329..c88dacf9d439 100644
> --- a/drivers/gpu/drm/panel/Makefile
> +++ b/drivers/gpu/drm/panel/Makefile
> @@ -3,6 +3,7 @@ obj-$(CONFIG_DRM_PANEL_ARM_VERSATILE) += panel-arm-versatile.o
> obj-$(CONFIG_DRM_PANEL_BANANAPI_S070WV20_ICN6211) += panel-bananapi-s070wv20-icn6211.o
> obj-$(CONFIG_DRM_PANEL_LVDS) += panel-lvds.o
> obj-$(CONFIG_DRM_PANEL_SIMPLE) += panel-simple.o
> +obj-$(CONFIG_DRM_PANEL_FEIYANG_FY07024DI26A30D) += panel-feiyang-fy07024di26a30d.o
> obj-$(CONFIG_DRM_PANEL_ILITEK_IL9322) += panel-ilitek-ili9322.o
> obj-$(CONFIG_DRM_PANEL_ILITEK_ILI9881C) += panel-ilitek-ili9881c.o
> obj-$(CONFIG_DRM_PANEL_INNOLUX_P079ZCA) += panel-innolux-p079zca.o
> diff --git a/drivers/gpu/drm/panel/panel-feiyang-fy07024di26a30d.c b/drivers/gpu/drm/panel/panel-feiyang-fy07024di26a30d.c
> new file mode 100644
> index 000000000000..f655647aeade
> --- /dev/null
> +++ b/drivers/gpu/drm/panel/panel-feiyang-fy07024di26a30d.c
> @@ -0,0 +1,286 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (C) 2018 Amarula Solutions
> + * Author: Jagan Teki <jagan@xxxxxxxxxxxxxxxxxxxx>
> + */
> +
> +#include <linux/backlight.h>
> +#include <linux/delay.h>
> +#include <linux/module.h>
> +#include <linux/of_device.h>
> +
> +#include <linux/gpio/consumer.h>
> +#include <linux/regulator/consumer.h>
> +
> +#include <drm/drmP.h>
Please do not use drmP.h in new drivers.
We are slowly gettting rid of it and in drm-misc.git the
drmP.h file no longer contains anything (other than includes/forwards).
> + gpiod_set_value(ctx->reset, 1);
> + msleep(50);
> +
> + gpiod_set_value(ctx->reset, 0);
> + /* T5 + T6 (avdd rise + video & logic signal rise)
> + * T5 >= 10ms, 0 < T6 <= 10ms
> + */
> + msleep(20);
> +
> + gpiod_set_value(ctx->reset, 1);
Is it really necessary to do a 1 => 0 => 1 cycle here for reset?
panel-simple do not need it.
> +
> +static int feiyang_dsi_probe(struct mipi_dsi_device *dsi)
> +{
> + struct feiyang *ctx;
> + int ret;
> +
> + ctx = devm_kzalloc(&dsi->dev, sizeof(*ctx), GFP_KERNEL);
> + if (!ctx)
> + return -ENOMEM;
> + mipi_dsi_set_drvdata(dsi, ctx);
Add empty line atfer return -ENOMEM;?
> + ctx->dsi = dsi;
> +
> + drm_panel_init(&ctx->panel);
> + ctx->panel.dev = &dsi->dev;
> + ctx->panel.funcs = &feiyang_funcs;
> +
> + 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->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);
> + }
> +
> + ctx->backlight = devm_of_find_backlight(&dsi->dev);
> + if (IS_ERR(ctx->backlight))
> + return PTR_ERR(ctx->backlight);
> +
> + ret = drm_panel_add(&ctx->panel);
> + if (ret < 0)
> + goto put_backlight;
> +
> + dsi->mode_flags = MIPI_DSI_MODE_VIDEO_BURST;
> + dsi->format = MIPI_DSI_FMT_RGB888;
> + dsi->lanes = 4;
> +
> + ret = mipi_dsi_attach(dsi);
> + if (ret < 0)
> + goto panel_remove;
> +
> + return ret;
> +
> +panel_remove:
> + drm_panel_remove(&ctx->panel);
> +put_backlight:
> + if (ctx->backlight)
> + put_device(&ctx->backlight->dev);
As devm_of_find_backlight() is used the put_device() will be done for you.
No need to do it here.
I think the same is true for the panel.
> +
> + return ret;
> +}
> +
> +static int feiyang_dsi_remove(struct mipi_dsi_device *dsi)
> +{
> + struct feiyang *ctx = mipi_dsi_get_drvdata(dsi);
> +
> + mipi_dsi_detach(dsi);
> + drm_panel_remove(&ctx->panel);
> +
> + if (ctx->backlight)
> + put_device(&ctx->backlight->dev);
Likewise, use of devm_of_find_backlight() will do this for you.
Sam