[PATCH 21/60] drm/panel: Add driver for the Sharp LS037V7DW01 panel

Laurent Pinchart laurent.pinchart at ideasonboard.com
Thu Aug 8 15:31:25 UTC 2019


Hi Sam,

On Mon, Jul 08, 2019 at 09:44:52PM +0200, Sam Ravnborg wrote:
> Hi Laurent.
> 
> Third panel driver in line for review.
> Review comments that are duplicates from the first two will have only a
> brief remark - if any.

I'll address them the same way. Please consider all unanswered comments
below as addressed.

> On Sun, Jul 07, 2019 at 09:18:58PM +0300, Laurent Pinchart wrote:
> > This panel is used on the SDP3430.
>
> Add a little more context and put it in Kconfig help.
> Maybe this is the TI board, and maybe it is something else.
> 
> > Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> > ---
> >  drivers/gpu/drm/panel/Kconfig                 |   7 +
> >  drivers/gpu/drm/panel/Makefile                |   1 +
> >  .../gpu/drm/panel/panel-sharp-ls037v7dw01.c   | 231 ++++++++++++++++++
> >  3 files changed, 239 insertions(+)
> >  create mode 100644 drivers/gpu/drm/panel/panel-sharp-ls037v7dw01.c
> > 
> > diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
> > index da613c04b835..04fd152efe4c 100644
> > --- a/drivers/gpu/drm/panel/Kconfig
> > +++ b/drivers/gpu/drm/panel/Kconfig
> > @@ -271,6 +271,13 @@ config DRM_PANEL_SHARP_LS043T1LE01
> >  	  Say Y here if you want to enable support for Sharp LS043T1LE01 qHD
> >  	  (540x960) DSI panel as found on the Qualcomm APQ8074 Dragonboard
> >  
> > +config DRM_PANEL_SHARP_LS037V7DW01
> > +	tristate "Sharp LS037V7DW01 VGA LCD panel"
> > +	depends on GPIOLIB && OF && REGULATOR
> > +	help
> > +	  Say Y here if you want to enable support for Sharp LS037V7DW01 VGA
> > +	  (480x640) LCD panel.
> > +
> 
> Alphabetical order, so it comes before DRM_PANEL_SHARP_LS043T1LE01
> 
> >  config DRM_PANEL_SITRONIX_ST7701
> >  	tristate "Sitronix ST7701 panel driver"
> >  	depends on OF
> > diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
> > index e81ed1535024..12dcd76eb87c 100644
> > --- a/drivers/gpu/drm/panel/Makefile
> > +++ b/drivers/gpu/drm/panel/Makefile
> > @@ -27,6 +27,7 @@ obj-$(CONFIG_DRM_PANEL_SAMSUNG_S6E63M0) += panel-samsung-s6e63m0.o
> >  obj-$(CONFIG_DRM_PANEL_SAMSUNG_S6E8AA0) += panel-samsung-s6e8aa0.o
> >  obj-$(CONFIG_DRM_PANEL_SEIKO_43WVF1G) += panel-seiko-43wvf1g.o
> >  obj-$(CONFIG_DRM_PANEL_SHARP_LQ101R1SX01) += panel-sharp-lq101r1sx01.o
> > +obj-$(CONFIG_DRM_PANEL_SHARP_LS037V7DW01) += panel-sharp-ls037v7dw01.o
> >  obj-$(CONFIG_DRM_PANEL_SHARP_LS043T1LE01) += panel-sharp-ls043t1le01.o
> 
> And here it is right.
> 
> > --- /dev/null
> > +++ b/drivers/gpu/drm/panel/panel-sharp-ls037v7dw01.c
> > @@ -0,0 +1,231 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Sharp LS037V7DW01 LCD Panel Driver
> > + *
> > + * Copyright (C) 2019 Texas Instruments Incorporated
> > + *
> > + * Based on the omapdrm-specific panel-sharp-ls037v7dw01 driver
> > + *
> > + * Copyright (C) 2013 Texas Instruments Incorporated
> > + * Author: Tomi Valkeinen <tomi.valkeinen at ti.com>
> 
> Add your copyright?

As with the previous patches, the copyright goes to TI.

> > +struct ls037v7dw01_device {
> > +	struct drm_panel panel;
> > +	struct platform_device *pdev;
> > +
> > +	struct regulator *vcc;
> 
> The property is named envdd - should they use the same name?

I'll rename that to vdd.

> > +	struct gpio_desc *resb_gpio;	/* low = reset active min 20 us */
> > +	struct gpio_desc *ini_gpio;	/* high = power on */
> > +	struct gpio_desc *mo_gpio;	/* low = 480x640, high = 240x320 */
> > +	struct gpio_desc *lr_gpio;	/* high = conventional horizontal scanning */
> > +	struct gpio_desc *ud_gpio;	/* high = conventional vertical scanning */
> > +};
> 
> device versus panel, but bikeshedding, so feel free to ignore.

I'll rename it.

> > +
> > +static int ls037v7dw01_disable(struct drm_panel *panel)
> > +{
> > +	struct ls037v7dw01_device *lcd = to_ls037v7dw01_device(panel);
> > +
> > +	gpiod_set_value_cansleep(lcd->ini_gpio, 0);
> > +	gpiod_set_value_cansleep(lcd->resb_gpio, 0);
> > +
> > +	/* Wait at least 5 vsyncs after disabling the LCD. */
> > +	msleep(100);
> > +
> > +	return 0;
> > +}
> > +
> > +static int ls037v7dw01_unprepare(struct drm_panel *panel)
> > +{
> > +	struct ls037v7dw01_device *lcd = to_ls037v7dw01_device(panel);
> > +
> > +	if (lcd->vcc)
> > +		regulator_disable(lcd->vcc);
> 
> Why is the if (lcd-vcc) needed?
> If I read the probe code correct then we either get a regulator or we
> error out.
> 
> Same goes for all other checks of lcd->vcc
> 
> > +static const struct drm_display_mode ls037v7dw01_mode = {
> > +	.clock = 19200,
> > +	.hdisplay = 480,
> > +	.hsync_start = 480 + 1,
> > +	.hsync_end = 480 + 1 + 2,
> > +	.htotal = 480 + 1 + 2 + 28,
> > +	.vdisplay = 640,
> > +	.vsync_start = 640 + 1,
> > +	.vsync_end = 640 + 1 + 1,
> > +	.vtotal = 640 + 1 + 1 + 1,
> > +	.vrefresh = 58,
> > +	.type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED,
> > +	.flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
> > +};
> > +
> > +static int ls037v7dw01_get_modes(struct drm_panel *panel)
> > +{
> > +	struct drm_connector *connector = panel->connector;
> > +	struct drm_display_mode *mode;
> > +
> > +	mode = drm_mode_duplicate(panel->drm, &ls037v7dw01_mode);
> > +	if (!mode)
> > +		return -ENOMEM;
> > +
> > +	drm_mode_set_name(mode);
> > +	drm_mode_probed_add(connector, mode);
> > +
> > +	connector->display_info.width_mm = 56;
> > +	connector->display_info.height_mm = 75;
> > +	/*
> > +	 * FIXME: According to the datasheet pixel data is sampled on the
> > +	 * rising edge of the clock, but the code running on the SDP3430
> > +	 * indicates sampling on the negative edge. This should be tested on a
> > +	 * real device.
> > +	 */
> > +	connector->display_info.bus_flags = DRM_BUS_FLAG_DE_HIGH
> > +					  | DRM_BUS_FLAG_SYNC_SAMPLE_POSEDGE
> > +					  | DRM_BUS_FLAG_PIXDATA_SAMPLE_NEGEDGE;
> > +
> > +	return 1;
> > +}
> > +
> > +static const struct drm_panel_funcs ls037v7dw01_funcs = {
> > +	.disable = ls037v7dw01_disable,
> > +	.unprepare = ls037v7dw01_unprepare,
> > +	.prepare = ls037v7dw01_prepare,
> > +	.enable = ls037v7dw01_enable,
> > +	.get_modes = ls037v7dw01_get_modes,
> > +};
> > +
> > +static int ls037v7dw01_probe(struct platform_device *pdev)
> > +{
> > +	struct ls037v7dw01_device *lcd;
> > +
> > +	lcd = devm_kzalloc(&pdev->dev, sizeof(*lcd), GFP_KERNEL);
> > +	if (lcd == NULL)
> > +		return -ENOMEM;
> > +
> > +	platform_set_drvdata(pdev, lcd);
> > +	lcd->pdev = pdev;
> > +
> > +	lcd->vcc = devm_regulator_get(&pdev->dev, "envdd");
> > +	if (IS_ERR(lcd->vcc)) {
> > +		dev_err(&pdev->dev, "failed to get regulator\n");
> > +		return PTR_ERR(lcd->vcc);
> > +	}
> > +
> > +	lcd->ini_gpio = devm_gpiod_get_index(&pdev->dev, "enable", 0,
> > +					    GPIOD_OUT_LOW);
> > +	if (IS_ERR(lcd->ini_gpio)) {
> > +		dev_err(&pdev->dev, "failed to get enable gpio\n");
> > +		return PTR_ERR(lcd->ini_gpio);
> > +	}
> 
> I fail to see why the _index() variant is used here.
> But then I did not check the binding, so it may originate from that.
> Same goes for ireset gpio
> 
> > +
> > +	lcd->resb_gpio = devm_gpiod_get_index(&pdev->dev, "reset", 0,
> > +					     GPIOD_OUT_LOW);
> > +	if (IS_ERR(lcd->resb_gpio)) {
> > +		dev_err(&pdev->dev, "failed to get reset gpio\n");
> > +		return PTR_ERR(lcd->resb_gpio);
> > +	}
> > +
> > +	lcd->mo_gpio = devm_gpiod_get_index(&pdev->dev, "mode", 0,
> > +					   GPIOD_OUT_LOW);
> > +	if (IS_ERR(lcd->mo_gpio)) {
> > +		dev_err(&pdev->dev, "failed to get mode[0] gpio\n");
> > +		return PTR_ERR(lcd->mo_gpio);
> > +	}
> > +
> > +	lcd->lr_gpio = devm_gpiod_get_index(&pdev->dev, "mode", 1,
> > +					   GPIOD_OUT_LOW);
> > +	if (IS_ERR(lcd->lr_gpio)) {
> > +		dev_err(&pdev->dev, "failed to get mode[1] gpio\n");
> > +		return PTR_ERR(lcd->lr_gpio);
> > +	}
> > +
> > +	lcd->ud_gpio = devm_gpiod_get_index(&pdev->dev, "mode", 2,
> > +					   GPIOD_OUT_LOW);
> > +	if (IS_ERR(lcd->ud_gpio)) {
> > +		dev_err(&pdev->dev, "failed to get mode[2] gpio\n");
> > +		return PTR_ERR(lcd->ud_gpio);
> > +	}
> 
> Do we set mo, lr ,ud gpio when we call devm_gpiod_get, or are they
> unused?

They are set by GPIOD_OUT_LOW.

> > +
> > +	drm_panel_init(&lcd->panel);
> > +	lcd->panel.dev = &pdev->dev;
> > +	lcd->panel.funcs = &ls037v7dw01_funcs;
> > +
> > +	return drm_panel_add(&lcd->panel);
> > +}
> > +
> > +static int ls037v7dw01_remove(struct platform_device *pdev)
> > +{
> > +	struct ls037v7dw01_device *lcd = platform_get_drvdata(pdev);
> > +
> > +	drm_panel_remove(&lcd->panel);
> > +	ls037v7dw01_disable(&lcd->panel);
> > +	ls037v7dw01_unprepare(&lcd->panel);
> 
> Use drm_panel_disable(), drm_panel_unprepare()
> 
> > +
> > +	return 0;
> > +}
> > +
> > +static const struct of_device_id ls037v7dw01_of_match[] = {
> > +	{ .compatible = "sharp,ls037v7dw01", },
> > +	{},
> 
> { /* sentinel */ },
> 
> > +};
> > +
> > +MODULE_DEVICE_TABLE(of, ls037v7dw01_of_match);
> > +
> > +static struct platform_driver ls037v7dw01_driver = {
> > +	.probe		= ls037v7dw01_probe,
> > +	.remove		= __exit_p(ls037v7dw01_remove),
> > +	.driver		= {
> > +		.name = "panel-sharp-ls037v7dw01",
> > +		.of_match_table = ls037v7dw01_of_match,
> > +	},
> > +};
> > +
> > +module_platform_driver(ls037v7dw01_driver);
> > +
> > +MODULE_AUTHOR("Tomi Valkeinen <tomi.valkeinen at ti.com>");
> > +MODULE_DESCRIPTION("Sharp LS037V7DW01 Panel Driver");
> > +MODULE_LICENSE("GPL");
> 
> "GPL v2"?

-- 
Regards,

Laurent Pinchart


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