[PATCH v2 5/9] drm/panel: Add driver for the NEC NL8048HL11 panel

Sam Ravnborg sam at ravnborg.org
Sun Aug 11 17:10:05 UTC 2019


Hi Laurent.

On Sun, Aug 11, 2019 at 02:10:44AM +0300, Laurent Pinchart wrote:
> This panel is used on the Zoom2/3/3630 SDP boards.
> 
> The code is based on the omapdrm-specific panel-nec-nl8048hl11 driver
> 
> Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> ---
> Changes since v1:
> 
> - Mention boards using the panel in Kconfig
> - Renamed nl8048_device to nl8048_panel
> - Comments updates
> - Store width_mm and height_mm in drm_display_mode
> - Use drm_panel_disable() in .remove() handler
> ---
>  drivers/gpu/drm/panel/Kconfig                |   8 +
>  drivers/gpu/drm/panel/Makefile               |   1 +
>  drivers/gpu/drm/panel/panel-nec-nl8048hl11.c | 247 +++++++++++++++++++
>  3 files changed, 256 insertions(+)
>  create mode 100644 drivers/gpu/drm/panel/panel-nec-nl8048hl11.c
> 
> diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
> index 87cdc330672b..d28133c6aa0a 100644
> --- a/drivers/gpu/drm/panel/Kconfig
> +++ b/drivers/gpu/drm/panel/Kconfig
> @@ -119,6 +119,14 @@ config DRM_PANEL_LG_LG4573
>  	  Say Y here if you want to enable support for LG4573 RGB panel.
>  	  To compile this driver as a module, choose M here.
>  
> +config DRM_PANEL_NEC_NL8048HL11
> +	tristate "NEC NL8048HL11 RGB panel"
> +	depends on GPIOLIB && OF && SPI
> +	help
> +	  Say Y here if you want to enable support for the NEC NL8048HL11 RGB
> +	  panel (found on the Zoom2/3/3630 SDP boards). To compile this driver
> +	  as a module, choose M here.
> +
>  config DRM_PANEL_NOVATEK_NT39016
>  	tristate "Novatek NT39016 RGB/SPI panel"
>  	depends on OF && SPI
> diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
> index 9bc6f3c5bf96..8052f9a7ad60 100644
> --- a/drivers/gpu/drm/panel/Makefile
> +++ b/drivers/gpu/drm/panel/Makefile
> @@ -10,6 +10,7 @@ obj-$(CONFIG_DRM_PANEL_JDI_LT070ME05000) += panel-jdi-lt070me05000.o
>  obj-$(CONFIG_DRM_PANEL_KINGDISPLAY_KD097D04) += panel-kingdisplay-kd097d04.o
>  obj-$(CONFIG_DRM_PANEL_LG_LB035Q02) += panel-lg-lb035q02.o
>  obj-$(CONFIG_DRM_PANEL_LG_LG4573) += panel-lg-lg4573.o
> +obj-$(CONFIG_DRM_PANEL_NEC_NL8048HL11) += panel-nec-nl8048hl11.o
>  obj-$(CONFIG_DRM_PANEL_NOVATEK_NT39016) += panel-novatek-nt39016.o
>  obj-$(CONFIG_DRM_PANEL_OLIMEX_LCD_OLINUXINO) += panel-olimex-lcd-olinuxino.o
>  obj-$(CONFIG_DRM_PANEL_ORISETECH_OTM8009A) += panel-orisetech-otm8009a.o
> diff --git a/drivers/gpu/drm/panel/panel-nec-nl8048hl11.c b/drivers/gpu/drm/panel/panel-nec-nl8048hl11.c
> new file mode 100644
> index 000000000000..7c1b77a0b024
> --- /dev/null
> +++ b/drivers/gpu/drm/panel/panel-nec-nl8048hl11.c
> @@ -0,0 +1,247 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * NEC NL8048HL11 Panel Driver
> + *
> + * Copyright (C) 2019 Texas Instruments Incorporated
> + *
> + * Based on the omapdrm-specific panel-nec-nl8048hl11 driver
> + *
> + * Copyright (C) 2010 Texas Instruments Incorporated
> + * Author: Erik Gilling <konkers at android.com>
> + */
> +
> +#include <linux/delay.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/module.h>
> +#include <linux/pm.h>
> +#include <linux/spi/spi.h>
> +
> +#include <drm/drm_connector.h>
> +#include <drm/drm_modes.h>
> +#include <drm/drm_panel.h>
> +
> +struct nl8048_panel {
> +	struct drm_panel panel;
> +
> +	struct spi_device *spi;
> +	struct gpio_desc *reset_gpio;
> +};
> +
> +#define to_nl8048_device(p) container_of(p, struct nl8048_panel, panel)
> +
> +static int nl8048_write(struct nl8048_panel *lcd, unsigned char addr,
> +			unsigned char value)
> +{
> +	u8 data[4] = { value, 0x01, addr, 0x00 };
> +	int ret;
> +
> +	ret = spi_write(lcd->spi, data, sizeof(data));
> +	if (ret)
> +		dev_err(&lcd->spi->dev, "SPI write to %u failed: %d\n",
> +			addr, ret);
> +
> +	return ret;
> +}
> +
> +static int nl8048_init(struct nl8048_panel *lcd)
> +{
> +	static const struct {
> +		unsigned char addr;
> +		unsigned char data;
> +	} nl8048_init_seq[] = {
> +		{   3, 0x01 }, {   0, 0x00 }, {   1, 0x01 }, {   4, 0x00 },
> +		{   5, 0x14 }, {   6, 0x24 }, {  16, 0xd7 }, {  17, 0x00 },
> +		{  18, 0x00 }, {  19, 0x55 }, {  20, 0x01 }, {  21, 0x70 },
> +		{  22, 0x1e }, {  23, 0x25 }, {  24, 0x25 }, {  25, 0x02 },
> +		{  26, 0x02 }, {  27, 0xa0 }, {  32, 0x2f }, {  33, 0x0f },
> +		{  34, 0x0f }, {  35, 0x0f }, {  36, 0x0f }, {  37, 0x0f },
> +		{  38, 0x0f }, {  39, 0x00 }, {  40, 0x02 }, {  41, 0x02 },
> +		{  42, 0x02 }, {  43, 0x0f }, {  44, 0x0f }, {  45, 0x0f },
> +		{  46, 0x0f }, {  47, 0x0f }, {  48, 0x0f }, {  49, 0x0f },
> +		{  50, 0x00 }, {  51, 0x02 }, {  52, 0x02 }, {  53, 0x02 },
> +		{  80, 0x0c }, {  83, 0x42 }, {  84, 0x42 }, {  85, 0x41 },
> +		{  86, 0x14 }, {  89, 0x88 }, {  90, 0x01 }, {  91, 0x00 },
> +		{  92, 0x02 }, {  93, 0x0c }, {  94, 0x1c }, {  95, 0x27 },
> +		{  98, 0x49 }, {  99, 0x27 }, { 102, 0x76 }, { 103, 0x27 },
> +		{ 112, 0x01 }, { 113, 0x0e }, { 114, 0x02 }, { 115, 0x0c },
> +		{ 118, 0x0c }, { 121, 0x30 }, { 130, 0x00 }, { 131, 0x00 },
> +		{ 132, 0xfc }, { 134, 0x00 }, { 136, 0x00 }, { 138, 0x00 },
> +		{ 139, 0x00 }, { 140, 0x00 }, { 141, 0xfc }, { 143, 0x00 },
> +		{ 145, 0x00 }, { 147, 0x00 }, { 148, 0x00 }, { 149, 0x00 },
> +		{ 150, 0xfc }, { 152, 0x00 }, { 154, 0x00 }, { 156, 0x00 },
> +		{ 157, 0x00 },
> +	};
> +
> +	unsigned int i;
> +	int ret;
> +
> +	for (i = 0; i < ARRAY_SIZE(nl8048_init_seq); ++i) {
> +		ret = nl8048_write(lcd, nl8048_init_seq[i].addr,
> +				   nl8048_init_seq[i].data);
> +		if (ret < 0)
> +			return ret;
> +	}
> +
> +	udelay(20);
> +
> +	return nl8048_write(lcd, 2, 0x00);
> +}
> +
> +static int nl8048_disable(struct drm_panel *panel)
> +{
> +	struct nl8048_panel *lcd = to_nl8048_device(panel);
> +
> +	gpiod_set_value_cansleep(lcd->reset_gpio, 0);
> +
> +	return 0;
> +}
> +
> +static int nl8048_enable(struct drm_panel *panel)
> +{
> +	struct nl8048_panel *lcd = to_nl8048_device(panel);
> +
> +	gpiod_set_value_cansleep(lcd->reset_gpio, 1);
> +
> +	return 0;
> +}
> +
> +static const struct drm_display_mode nl8048_mode = {
> +	/*  NEC PIX Clock Ratings MIN:21.8MHz TYP:23.8MHz MAX:25.7MHz */
> +	.clock	= 23800,
> +	.hdisplay = 800,
> +	.hsync_start = 800 + 6,
> +	.hsync_end = 800 + 6 + 1,
> +	.htotal = 800 + 6 + 1 + 4,
> +	.vdisplay = 480,
> +	.vsync_start = 480 + 3,
> +	.vsync_end = 480 + 3 + 1,
> +	.vtotal = 480 + 3 + 1 + 4,
> +	.vrefresh = 60,
> +	.type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED,
> +	.flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
> +	.width_mm = 89,
> +	.height_mm = 53,
> +};
> +
> +static int nl8048_get_modes(struct drm_panel *panel)
> +{
> +	struct drm_connector *connector = panel->connector;
> +	struct drm_display_mode *mode;
> +
> +	mode = drm_mode_duplicate(panel->drm, &nl8048_mode);
> +	if (!mode)
> +		return -ENOMEM;
> +
> +	drm_mode_set_name(mode);
> +	drm_mode_probed_add(connector, mode);
> +
> +	connector->display_info.width_mm = nl8048_mode.width_mm;
> +	connector->display_info.height_mm = nl8048_mode.height_mm;
> +	connector->display_info.bus_flags = DRM_BUS_FLAG_DE_HIGH
> +					  | DRM_BUS_FLAG_SYNC_SAMPLE_NEGEDGE
> +					  | DRM_BUS_FLAG_PIXDATA_SAMPLE_NEGEDGE;
> +
> +	return 1;
> +}
> +
> +static const struct drm_panel_funcs nl8048_funcs = {
> +	.disable = nl8048_disable,
> +	.enable = nl8048_enable,
> +	.get_modes = nl8048_get_modes,
> +};
> +
> +static int __maybe_unused nl8048_suspend(struct device *dev)
> +{
> +	struct nl8048_panel *lcd = dev_get_drvdata(dev);
> +
> +	nl8048_write(lcd, 2, 0x01);
> +	msleep(40);
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused nl8048_resume(struct device *dev)
> +{
> +	struct nl8048_panel *lcd = dev_get_drvdata(dev);
> +
> +	/* Reinitialize the panel. */
> +	spi_setup(lcd->spi);
> +	nl8048_write(lcd, 2, 0x00);
> +	nl8048_init(lcd);
> +
> +	return 0;
> +}
> +
> +static SIMPLE_DEV_PM_OPS(nl8048_pm_ops, nl8048_suspend, nl8048_resume);
> +
> +static int nl8048_probe(struct spi_device *spi)
> +{
> +	struct nl8048_panel *lcd;
> +	int ret;
> +
> +	lcd = devm_kzalloc(&spi->dev, sizeof(*lcd), GFP_KERNEL);
> +	if (lcd == NULL)
> +		return -ENOMEM;
> +
> +	spi_set_drvdata(spi, lcd);
> +	lcd->spi = spi;
> +
> +	lcd->reset_gpio = devm_gpiod_get(&spi->dev, "reset", GPIOD_OUT_LOW);
> +	if (IS_ERR(lcd->reset_gpio)) {
> +		dev_err(&spi->dev, "failed to parse reset gpio\n");
> +		return PTR_ERR(lcd->reset_gpio);
> +	}
> +
> +	spi->mode = SPI_MODE_0;
> +	spi->bits_per_word = 32;
> +
> +	ret = spi_setup(spi);
> +	if (ret < 0) {
> +		dev_err(&spi->dev, "failed to setup SPI: %d\n", ret);
> +		return ret;
> +	}
> +
> +	ret = nl8048_init(lcd);
> +	if (ret < 0)
> +		return ret;
> +
> +	drm_panel_init(&lcd->panel);
> +	lcd->panel.dev = &lcd->spi->dev;
> +	lcd->panel.funcs = &nl8048_funcs;
> +
> +	return drm_panel_add(&lcd->panel);
> +}
> +
> +static int nl8048_remove(struct spi_device *spi)
> +{
> +	struct nl8048_panel *lcd = spi_get_drvdata(spi);
> +
> +	drm_panel_remove(&lcd->panel);
> +	drm_panel_disable(&lcd->panel);
We are missing a drm_panel_unprepare() here.
This is required by the core - but not by this driver.
(At least with the patch I have in the works).

Then again:

    $ git grep -C 3 drm_panel_remove

tell a story that many users of drm_panel_remove do MOT
call drm_panel_disable() / drm_panel_unprepare() after
drm_panel_remove()

Maybe we should just add it to the core so disable/unprepare
is done by the core when a panel is removed?

	Sam

> +
> +	return 0;
> +}
> +
> +static const struct of_device_id nl8048_of_match[] = {
> +	{ .compatible = "nec,nl8048hl11", },
> +	{ /* sentinel */ },
> +};
> +
> +MODULE_DEVICE_TABLE(of, nl8048_of_match);
> +
> +static struct spi_driver nl8048_driver = {
> +	.probe		= nl8048_probe,
> +	.remove		= nl8048_remove,
> +	.driver		= {
> +		.name	= "panel-nec-nl8048hl11",
> +		.pm	= &nl8048_pm_ops,
> +		.of_match_table = nl8048_of_match,
> +	},
> +};
> +
> +module_spi_driver(nl8048_driver);
> +
> +MODULE_ALIAS("spi:nec,nl8048hl11");
> +MODULE_AUTHOR("Erik Gilling <konkers at android.com>");
> +MODULE_DESCRIPTION("NEC-NL8048HL11 Driver");
> +MODULE_LICENSE("GPL");
> -- 
> Regards,
> 
> Laurent Pinchart


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