[U-Boot] [PATCH 2/3] lcd: add DataImage SCF0403x LCD panel support

[Igor Grinberg <grinberg@compulab.co.il>]

Hi Nikita,

On 10/09/13 16:46, Nikita Kiryanov wrote:
> Add SPI-based driver for DataImage SCF0403852GGU04 and SCF0403526GGU20
> LCD panels.
> 
> Cc: Tom Rini <trini@ti.com>
> Cc: Anatolij Gustschin <agust@denx.de>
> Cc: Igor Grinberg <grinberg@compulab.co.il>
> Signed-off-by: Nikita Kiryanov <nikita@compulab.co.il>
> ---
>  drivers/video/Makefile      |   1 +
>  drivers/video/scf0403_lcd.c | 298 ++++++++++++++++++++++++++++++++++++++++++++
>  include/scf0403_lcd.h       |  22 ++++
>  include/spi.h               |   1 +
>  4 files changed, 322 insertions(+)
>  create mode 100644 drivers/video/scf0403_lcd.c
>  create mode 100644 include/scf0403_lcd.h

[...]

> diff --git a/drivers/video/scf0403_lcd.c b/drivers/video/scf0403_lcd.c
> new file mode 100644
> index 0000000..1d1c3ff
> --- /dev/null
> +++ b/drivers/video/scf0403_lcd.c
> @@ -0,0 +1,298 @@

[...]

> +static void scf0403_gpio_reset(unsigned int gpio)
> +{
> +	if (!gpio_is_valid(gpio))
> +		return;
> +
> +	gpio_set_value(gpio, 1);
> +	mdelay(100);
> +	gpio_set_value(gpio, 0);
> +	mdelay(40);
> +	gpio_set_value(gpio, 1);
> +	mdelay(100);
> +}

[...]

> +int scf0403_init(int reset_gpio)
> +{
> +	int error;
> +
> +	if (!gpio_is_valid(reset_gpio)) {
> +		printf("scf0403 reset_gpio not valid\n");
> +		return -1;

The LCD reset pin does not have to be connected to a GPIO.
Instead, it can be handled in another manner (e.g. by hardware).
So, I don't think you should fail the LCD initialization if
some kind of -EINVAL is passed.

> +	}
> +
> +	priv.reset_gpio = reset_gpio;
> +	error = scf0403_request_reset_gpio(reset_gpio);
> +	if (error) {
> +		printf("Failed requesting reset GPIO%d: %d\n",
> +		       reset_gpio, error);
> +		return error;
> +	}
> +
> +	priv.spi = spi_setup_slave(3, 0, 1000000, SPI_MODE_0);
> +	error = spi_claim_bus(priv.spi);
> +	if (error) {
> +		gpio_free(priv.reset_gpio);
> +		return error;
> +	}
> +
> +	/* reset LCD */
> +	scf0403_gpio_reset(reset_gpio);
> +
> +	error = scf0403_spi_read_rddid(priv.spi, &priv.rddid);
> +	if (error) {
> +		printf("IDs read failed\n");
> +		gpio_free(priv.reset_gpio);
> +		spi_release_bus(priv.spi);
> +
> +		return error;
> +	}
> +
> +	if (priv.rddid == SCF0403852GGU04_ID) {
> +		priv.init_seq = scf0403_initseq_sn04;
> +		priv.seq_size = ARRAY_SIZE(scf0403_initseq_sn04);
> +	} else {
> +		priv.init_seq = scf0403_initseq_sn20;
> +		priv.seq_size = ARRAY_SIZE(scf0403_initseq_sn20);
> +	}
> +
> +	scf0403_lcd_init(&priv);
> +
> +	/* Start operation */
> +	scf0403_spi_transfer(priv.spi, &scf0403_cmd_dison);
> +	mdelay(100);
> +	scf0403_spi_transfer(priv.spi, &scf0403_cmd_slpout);
> +	spi_release_bus(priv.spi);
> +
> +	return 0;
> +}

[...]

> diff --git a/include/spi.h b/include/spi.h
> index ae318ff..4441527 100644
> --- a/include/spi.h
> +++ b/include/spi.h
> @@ -27,6 +27,7 @@
>  /* SPI transfer flags */
>  #define SPI_XFER_BEGIN	0x01			/* Assert CS before transfer */
>  #define SPI_XFER_END	0x02			/* Deassert CS after transfer */
> +#define SPI_XFER_ONCE	(SPI_XFER_BEGIN | SPI_XFER_END)

This bit does not belong to the patch.

>  
>  /* Header byte that marks the start of the message */
>  #define SPI_PREAMBLE_END_BYTE	0xec
> 

-- 
Regards,
Igor.