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Date:   Sat, 15 Aug 2020 23:28:25 +0200
From:   Guido =?iso-8859-1?Q?G=FCnther?= <agx@sigxcpu.org>
To:     Sam Ravnborg <sam@ravnborg.org>
Cc:     Thierry Reding <thierry.reding@gmail.com>,
        David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        Rob Herring <robh+dt@kernel.org>,
        Arnd Bergmann <arnd@arndb.de>,
        Linus Walleij <linus.walleij@linaro.org>,
        Heiko Stuebner <heiko.stuebner@theobroma-systems.com>,
        Daniel Palmer <daniel@0x0f.com>,
        Lubomir Rintel <lkundrak@v3.sk>,
        Mark Brown <broonie@kernel.org>,
        Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>,
        allen <allen.chen@ite.com.tw>,
        Mauro Carvalho Chehab <mchehab+huawei@kernel.org>,
        "David S. Miller" <davem@davemloft.net>,
        dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 3/3] drm/panel: Add panel driver for the Mantix
 MLAF057WE51-X DSI panel
Message-ID: <20200815212825.GB134339@bogon.m.sigxcpu.org>
References: <cover.1597412076.git.agx@sigxcpu.org>
 <0a7539135cc46eec5636ca89f52695f4a1197841.1597412076.git.agx@sigxcpu.org>
 <20200815093226.GB993113@ravnborg.org>
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Hi Sam,
On Sat, Aug 15, 2020 at 11:32:26AM +0200, Sam Ravnborg wrote:
> Hi Guido.
> 
> On Fri, Aug 14, 2020 at 03:36:23PM +0200, Guido G?nther wrote:
> > The panel uses a Focaltech FT8006p, the touch part is handled by the
> > already existing edt-ft5x06.
> > 
> > Signed-off-by: Guido G?nther <agx@sigxcpu.org>
> 
> Looks good.
> A few notes in the following, nothing major.

Thanks. I've added your suggestions to v2.
 -- Guido
> 
> 	Sam
> 
> > ---
> >  MAINTAINERS                                   |   7 +
> >  drivers/gpu/drm/panel/Kconfig                 |  11 +
> >  drivers/gpu/drm/panel/Makefile                |   1 +
> >  .../gpu/drm/panel/panel-mantix-mlaf057we51.c  | 362 ++++++++++++++++++
> >  4 files changed, 381 insertions(+)
> >  create mode 100644 drivers/gpu/drm/panel/panel-mantix-mlaf057we51.c
> > 
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index 83ba7b62651f7..7dfe4cc3d4ec8 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -5474,6 +5474,13 @@ S:	Maintained
> >  F:	drivers/gpu/drm/panel/panel-lvds.c
> >  F:	Documentation/devicetree/bindings/display/panel/lvds.yaml
> >  
> > +DRM DRIVER FOR MANTIX MLAF057WE51 PANELS
> > +M:	Guido G?nther <agx@sigxcpu.org>
> > +R:	Purism Kernel Team <kernel@puri.sm>
> > +S:	Maintained
> > +F:	Documentation/devicetree/bindings/display/panel/mantix,mlaf057we51-x.yaml
> > +F:	drivers/gpu/drm/panel/panel-mantix-mlaf057we51.c
> > +
> >  DRM DRIVER FOR MATROX G200/G400 GRAPHICS CARDS
> >  S:	Orphan / Obsolete
> >  F:	drivers/gpu/drm/mga/
> > diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
> > index de2f2a452be55..8d97d07c58713 100644
> > --- a/drivers/gpu/drm/panel/Kconfig
> > +++ b/drivers/gpu/drm/panel/Kconfig
> > @@ -217,6 +217,17 @@ config DRM_PANEL_NOVATEK_NT39016
> >  	  Say Y here if you want to enable support for the panels built
> >  	  around the Novatek NT39016 display controller.
> >  
> > +config DRM_PANEL_MANTIX_MLAF057WE51
> > +	tristate "Mantix MLAF057WE51-X MIPI-DSI LCD panel"
> > +	depends on OF
> > +	depends on DRM_MIPI_DSI
> > +	depends on BACKLIGHT_CLASS_DEVICE
> > +	help
> > +	  Say Y here if you want to enable support for the Mantix
> > +	  MLAF057WE51-X MIPI DSI panel as e.g. used in the Librem 5. It
> > +	  has a resolution of 720x1440 pixels, a built in backlight and touch
> > +	  controller.
> > +
> >  config DRM_PANEL_OLIMEX_LCD_OLINUXINO
> >  	tristate "Olimex LCD-OLinuXino panel"
> >  	depends on OF
> > diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
> > index e45ceac6286fd..15a4e77529514 100644
> > --- a/drivers/gpu/drm/panel/Makefile
> > +++ b/drivers/gpu/drm/panel/Makefile
> > @@ -20,6 +20,7 @@ obj-$(CONFIG_DRM_PANEL_LG_LG4573) += panel-lg-lg4573.o
> >  obj-$(CONFIG_DRM_PANEL_NEC_NL8048HL11) += panel-nec-nl8048hl11.o
> >  obj-$(CONFIG_DRM_PANEL_NOVATEK_NT35510) += panel-novatek-nt35510.o
> >  obj-$(CONFIG_DRM_PANEL_NOVATEK_NT39016) += panel-novatek-nt39016.o
> > +obj-$(CONFIG_DRM_PANEL_MANTIX_MLAF057WE51) += panel-mantix-mlaf057we51.o
> >  obj-$(CONFIG_DRM_PANEL_OLIMEX_LCD_OLINUXINO) += panel-olimex-lcd-olinuxino.o
> >  obj-$(CONFIG_DRM_PANEL_ORISETECH_OTM8009A) += panel-orisetech-otm8009a.o
> >  obj-$(CONFIG_DRM_PANEL_OSD_OSD101T2587_53TS) += panel-osd-osd101t2587-53ts.o
> > diff --git a/drivers/gpu/drm/panel/panel-mantix-mlaf057we51.c b/drivers/gpu/drm/panel/panel-mantix-mlaf057we51.c
> > new file mode 100644
> > index 0000000000000..6c07bcdb75937
> > --- /dev/null
> > +++ b/drivers/gpu/drm/panel/panel-mantix-mlaf057we51.c
> > @@ -0,0 +1,362 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Mantix MLAF057WE51 5.7" MIPI-DSI panel driver
> > + *
> > + * Copyright (C) Purism SPC 2020
> > + */
> > +
> > +#include <linux/backlight.h>
> > +#include <linux/delay.h>
> > +#include <linux/gpio/consumer.h>
> > +#include <linux/media-bus-format.h>
> Include not needed.
> 
> > +#include <linux/module.h>
> > +#include <linux/regulator/consumer.h>
> > +
> > +#include <video/display_timing.h>
> I do not think this include is needed
> 
> > +#include <video/mipi_display.h>
> > +
> > +#include <drm/drm_mipi_dsi.h>
> > +#include <drm/drm_modes.h>
> > +#include <drm/drm_panel.h>
> > +#include <drm/drm_print.h>
> > +
> > +#define DRV_NAME "panel-mantix-mlaf057we51"
> > +
> > +/* Manufacturer specific Commands send via DSI */
> > +#define MANTIX_CMD_OTP_STOP_RELOAD_MIPI 0x41
> > +#define MANTIX_CMD_INT_CANCEL           0x4C
> > +
> > +struct mantix {
> > +	struct device *dev;
> > +	struct drm_panel panel;
> > +	struct gpio_desc *reset_gpio;
> > +
> > +	struct regulator *avdd;
> > +	struct regulator *avee;
> > +	struct regulator *vddi;
> > +};
> > +
> > +static inline struct mantix *panel_to_mantix(struct drm_panel *panel)
> > +{
> > +	return container_of(panel, struct mantix, panel);
> > +}
> > +
> > +#define dsi_generic_write_seq(dsi, seq...) do {				\
> > +		static const u8 d[] = { seq };				\
> > +		int ret;						\
> > +		ret = mipi_dsi_generic_write(dsi, d, ARRAY_SIZE(d));	\
> > +		if (ret < 0)						\
> > +			return ret;					\
> > +	} while (0)
> > +
> > +static int mantix_init_sequence(struct mantix *ctx)
> > +{
> > +	struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
> > +	struct device *dev = ctx->dev;
> > +
> > +	/*
> > +	 * Init sequence was supplied by the panel vendor.
> > +	 */
> > +	dsi_generic_write_seq(dsi, MANTIX_CMD_OTP_STOP_RELOAD_MIPI, 0x5A);
> > +
> > +	dsi_generic_write_seq(dsi, MANTIX_CMD_INT_CANCEL, 0x03);
> > +	dsi_generic_write_seq(dsi, MANTIX_CMD_OTP_STOP_RELOAD_MIPI, 0x5A, 0x03);
> > +	dsi_generic_write_seq(dsi, 0x80, 0xA9, 0x00);
> > +
> > +	dsi_generic_write_seq(dsi, MANTIX_CMD_OTP_STOP_RELOAD_MIPI, 0x5A, 0x09);
> > +	dsi_generic_write_seq(dsi, 0x80, 0x64, 0x00, 0x64, 0x00, 0x00);
> > +	msleep(20);
> > +
> > +	DRM_DEV_DEBUG_DRIVER(dev, "Panel init sequence done\n");
> > +	return 0;
> > +}
> > +
> > +static int mantix_enable(struct drm_panel *panel)
> > +{
> > +	struct mantix *ctx = panel_to_mantix(panel);
> > +	struct device *dev = ctx->dev;
> > +	struct mipi_dsi_device *dsi = to_mipi_dsi_device(dev);
> > +	int ret;
> > +
> > +	ret = mantix_init_sequence(ctx);
> > +	if (ret < 0) {
> > +		DRM_DEV_ERROR(ctx->dev, "Panel init sequence failed: %d\n",
> > +			      ret);
> > +		return ret;
> > +	}
> > +
> > +	ret = mipi_dsi_dcs_exit_sleep_mode(dsi);
> > +	if (ret < 0) {
> > +		DRM_DEV_ERROR(dev, "Failed to exit sleep mode\n");
> > +		return ret;
> > +	}
> > +	msleep(20);
> > +
> > +	ret = mipi_dsi_dcs_set_display_on(dsi);
> > +	if (ret)
> > +		return ret;
> > +	usleep_range(10000, 12000);
> > +
> > +	ret = mipi_dsi_turn_on_peripheral(dsi);
> > +	if (ret < 0) {
> > +		DRM_DEV_ERROR(dev, "Failed to turn on peripheral\n");
> > +		return ret;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static int mantix_disable(struct drm_panel *panel)
> > +{
> > +	struct mantix *ctx = panel_to_mantix(panel);
> > +	struct mipi_dsi_device *dsi = to_mipi_dsi_device(ctx->dev);
> > +	int ret;
> > +
> > +	ret = mipi_dsi_dcs_set_display_off(dsi);
> > +	if (ret < 0)
> > +		DRM_DEV_ERROR(ctx->dev,
> > +			      "Failed to turn off the display: %d\n", ret);
> > +
> > +	ret = mipi_dsi_dcs_enter_sleep_mode(dsi);
> > +	if (ret < 0)
> > +		DRM_DEV_ERROR(ctx->dev,
> > +			      "Failed to enter sleep mode: %d\n", ret);
> > +
> > +	mipi_dsi_dcs_enter_sleep_mode(dsi);
> Does the display really need to enter sleep mode twice?
> 
> > +	return 0;
> > +}
> > +
> > +static int mantix_unprepare(struct drm_panel *panel)
> > +{
> > +	struct mantix *ctx = panel_to_mantix(panel);
> > +
> > +	regulator_disable(ctx->avdd);
> > +	regulator_disable(ctx->avee);
> > +	regulator_disable(ctx->vddi);
> 
> The order the regulators are disabled is not the reverse of the order
> thay are enabled. Unless this is on purpose it would be more logical and
> less confusing if unprepare is the reverse of prepare.
> 
> 
> > +
> > +	return 0;
> > +}
> > +
> > +static int mantix_prepare(struct drm_panel *panel)
> > +{
> > +	struct mantix *ctx = panel_to_mantix(panel);
> > +	int ret;
> > +
> > +	/* Focaltech FT8006P, section 7.3.1 and 7.3.4 */
> > +	DRM_DEV_DEBUG_DRIVER(ctx->dev, "Resetting the panel\n");
> > +	ret = regulator_enable(ctx->vddi);
> > +	if (ret < 0) {
> > +		DRM_DEV_ERROR(ctx->dev,
> > +			      "Failed to enable vddi supply: %d\n", ret);
> > +		return ret;
> > +	}
> > +	/* T1 + T2 */
> > +	usleep_range(8000, 10000);
> > +
> > +	ret = regulator_enable(ctx->avdd);
> > +	if (ret < 0) {
> > +		DRM_DEV_ERROR(ctx->dev,
> > +			      "Failed to enable avdd supply: %d\n", ret);
> > +		return ret;
> > +	}
> > +
> > +	/* T2d */
> > +	usleep_range(3500, 4000);
> > +	ret = regulator_enable(ctx->avee);
> > +	if (ret < 0) {
> > +		DRM_DEV_ERROR(ctx->dev,
> > +			      "Failed to enable avee supply: %d\n", ret);
> > +		return ret;
> > +	}
> > +
> > +	/* T3+T5 */
> > +	usleep_range(10000, 12000);
> > +
> > +	gpiod_set_value_cansleep(ctx->reset_gpio, 1);
> > +	usleep_range(5150, 7000);
> > +
> > +	gpiod_set_value_cansleep(ctx->reset_gpio, 0);
> > +
> > +	/* T6 */
> > +	msleep(50);
> > +
> > +	return 0;
> > +}
> > +
> > +static const struct drm_display_mode default_mode = {
> > +	.hdisplay    = 720,
> > +	.hsync_start = 720 + 45,
> > +	.hsync_end   = 720 + 45 + 14,
> > +	.htotal	     = 720 + 45 + 14 + 25,
> > +	.vdisplay    = 1440,
> > +	.vsync_start = 1440 + 130,
> > +	.vsync_end   = 1440 + 130 + 8,
> > +	.vtotal	     = 1440 + 130 + 8 + 106,
> > +	.clock	     = 85298,
> > +	.flags	     = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
> > +	.width_mm    = 65,
> > +	.height_mm   = 130,
> > +};
> > +
> > +static int mantix_get_modes(struct drm_panel *panel,
> > +			    struct drm_connector *connector)
> > +{
> > +	struct mantix *ctx = panel_to_mantix(panel);
> > +	struct drm_display_mode *mode;
> > +
> > +	mode = drm_mode_duplicate(connector->dev, &default_mode);
> > +	if (!mode) {
> > +		DRM_DEV_ERROR(ctx->dev, "Failed to add mode %ux%u@%u\n",
> > +			      default_mode.hdisplay, default_mode.vdisplay,
> > +			      drm_mode_vrefresh(mode));
> > +		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 mantix_drm_funcs = {
> > +	.disable   = mantix_disable,
> > +	.unprepare = mantix_unprepare,
> > +	.prepare   = mantix_prepare,
> > +	.enable	   = mantix_enable,
> > +	.get_modes = mantix_get_modes,
> > +};
> > +
> > +static int mantix_probe(struct mipi_dsi_device *dsi)
> > +{
> > +	struct device *dev = &dsi->dev;
> > +	struct mantix *ctx;
> > +	int ret;
> > +
> > +	ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL);
> > +	if (!ctx)
> > +		return -ENOMEM;
> > +
> > +	ctx->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
> > +	if (IS_ERR(ctx->reset_gpio)) {
> > +		DRM_DEV_ERROR(dev, "cannot get reset gpio\n");
> > +		return PTR_ERR(ctx->reset_gpio);
> > +	}
> > +
> > +	mipi_dsi_set_drvdata(dsi, ctx);
> > +	ctx->dev = dev;
> > +
> > +	dsi->lanes = 4;
> > +	dsi->format = MIPI_DSI_FMT_RGB888;
> > +	dsi->mode_flags = MIPI_DSI_MODE_VIDEO |
> > +		MIPI_DSI_MODE_VIDEO_BURST | MIPI_DSI_MODE_VIDEO_SYNC_PULSE;
> > +
> > +	ctx->avdd = devm_regulator_get(dev, "avdd");
> > +	if (IS_ERR(ctx->avdd)) {
> > +		ret = PTR_ERR(ctx->avdd);
> > +		if (ret != -EPROBE_DEFER)
> > +			DRM_DEV_ERROR(dev,
> > +				      "Failed to request avdd regulator: %d\n",
> > +				      ret);
> In these modern times linelegth of 100 is acceptable, so avoid
> linewrapping here and likewise below.
> 
> > +		return ret;
> > +	}
> > +	ctx->avee = devm_regulator_get(dev, "avee");
> > +	if (IS_ERR(ctx->avee)) {
> > +		ret = PTR_ERR(ctx->avee);
> > +		if (ret != -EPROBE_DEFER)
> > +			DRM_DEV_ERROR(dev,
> > +				      "Failed to request avee regulator: %d\n",
> > +				      ret);
> > +		return ret;
> > +	}
> > +	ctx->vddi = devm_regulator_get(dev, "vddi");
> > +	if (IS_ERR(ctx->vddi)) {
> > +		ret = PTR_ERR(ctx->vddi);
> > +		if (ret != -EPROBE_DEFER)
> > +			DRM_DEV_ERROR(dev,
> > +				      "Failed to request vddi regulator: %d\n",
> > +				      ret);
> > +		return ret;
> > +	}
> > +
> > +	drm_panel_init(&ctx->panel, dev, &mantix_drm_funcs,
> > +		       DRM_MODE_CONNECTOR_DSI);
> > +
> > +	ret = drm_panel_of_backlight(&ctx->panel);
> > +	if (ret)
> > +		return ret;
> empty line?
> > +	drm_panel_add(&ctx->panel);
> > +
> > +	ret = mipi_dsi_attach(dsi);
> > +	if (ret < 0) {
> > +		DRM_DEV_ERROR(dev,
> > +			      "mipi_dsi_attach failed (%d). Is host ready?\n",
> > +			      ret);
> > +		drm_panel_remove(&ctx->panel);
> > +		return ret;
> > +	}
> > +
> > +	DRM_DEV_INFO(dev, "%ux%u@%u %ubpp dsi %udl - ready\n",
> > +		     default_mode.hdisplay, default_mode.vdisplay,
> > +		     drm_mode_vrefresh(&default_mode),
> > +		     mipi_dsi_pixel_format_to_bpp(dsi->format), dsi->lanes);
> > +
> > +	return 0;
> > +}
> > +
> > +static void mantix_shutdown(struct mipi_dsi_device *dsi)
> > +{
> > +	struct mantix *ctx = mipi_dsi_get_drvdata(dsi);
> > +	int ret;
> > +
> > +	ret = drm_panel_unprepare(&ctx->panel);
> > +	if (ret < 0)
> > +		DRM_DEV_ERROR(&dsi->dev, "Failed to unprepare panel: %d\n",
> > +			      ret);
> > +
> > +	ret = drm_panel_disable(&ctx->panel);
> > +	if (ret < 0)
> > +		DRM_DEV_ERROR(&dsi->dev, "Failed to disable panel: %d\n",
> > +			      ret);
> > +}
> In shutdown we usually ignore any errors.
> 
> > +
> > +static int mantix_remove(struct mipi_dsi_device *dsi)
> > +{
> > +	struct mantix *ctx = mipi_dsi_get_drvdata(dsi);
> > +	int ret;
> > +
> > +	mantix_shutdown(dsi);
> > +
> > +	ret = mipi_dsi_detach(dsi);
> > +	if (ret < 0)
> > +		DRM_DEV_ERROR(&dsi->dev, "Failed to detach from DSI host: %d\n",
> > +			      ret);
> Likewise in remove we ignore any errors.
>
> 
> > +
> > +	drm_panel_remove(&ctx->panel);
> > +
> > +	return 0;
> > +}
> > +
> > +static const struct of_device_id mantix_of_match[] = {
> > +	{ .compatible = "mantix,mlaf057we51-x" },
> > +	{ /* sentinel */ }
> > +};
> > +MODULE_DEVICE_TABLE(of, mantix_of_match);
> > +
> > +static struct mipi_dsi_driver mantix_driver = {
> > +	.probe	= mantix_probe,
> > +	.remove = mantix_remove,
> > +	.shutdown = mantix_shutdown,
> > +	.driver = {
> > +		.name = DRV_NAME,
> > +		.of_match_table = mantix_of_match,
> > +	},
> > +};
> > +module_mipi_dsi_driver(mantix_driver);
> > +
> > +MODULE_AUTHOR("Guido G?nther <agx@sigxcpu.org>");
> > +MODULE_DESCRIPTION("DRM driver for Mantix MLAF057WE51-X MIPI DSI panel");
> > +MODULE_LICENSE("GPL v2");
> > -- 
> > 2.26.2
> > 
> > _______________________________________________
> > dri-devel mailing list
> > dri-devel@lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/dri-devel
>