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Commit d1d81802 authored by Torsten Fleischer's avatar Torsten Fleischer Committed by Mark Brown
Browse files

spi: spi-gpio: Add dt support for a single device with no chip select 



In order to describe a single slave device that has no chip select line
the 'num-chipselects' property has to be <0> and the 'cs-gpios' property
doesn't need to be set.

Signed-off-by: default avatarTorsten Fleischer <torfl6749@gmail.com>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent f114040e

Documentation/devicetree/bindings/spi/spi-gpio.txt

+4 −2
Original line number Diff line number Diff line
@@ -8,8 +8,10 @@ Required properties: 
 - gpio-sck: GPIO spec for the SCK line to use

 - gpio-miso: GPIO spec for the MISO line to use

 - gpio-mosi: GPIO spec for the MOSI line to use

 - cs-gpios: GPIOs to use for chipselect lines

 - num-chipselects: number of chipselect lines

 - cs-gpios: GPIOs to use for chipselect lines.

             Not needed if num-chipselects = <0>.

 - num-chipselects: Number of chipselect lines. Should be <0> if a single device

                    with no chip select is connected.



Example:

drivers/spi/spi-gpio.c

+15 −6
Original line number Diff line number Diff line
@@ -413,6 +413,7 @@ static int spi_gpio_probe(struct platform_device *pdev) 
	struct spi_gpio_platform_data	*pdata;

	u16 master_flags = 0;

	bool use_of = 0;

	int num_devices;



	status = spi_gpio_probe_dt(pdev);

	if (status < 0)
@@ -422,16 +423,21 @@ static int spi_gpio_probe(struct platform_device *pdev) 


	pdata = dev_get_platdata(&pdev->dev);

#ifdef GENERIC_BITBANG

	if (!pdata || !pdata->num_chipselect)

	if (!pdata || (!use_of && !pdata->num_chipselect))

		return -ENODEV;

#endif



	if (use_of && !SPI_N_CHIPSEL)

		num_devices = 1;

	else

		num_devices = SPI_N_CHIPSEL;



	status = spi_gpio_request(pdata, dev_name(&pdev->dev), &master_flags);

	if (status < 0)

		return status;



	master = spi_alloc_master(&pdev->dev, sizeof(*spi_gpio) +

					(sizeof(int) * SPI_N_CHIPSEL));

					(sizeof(int) * num_devices));

	if (!master) {

		status = -ENOMEM;

		goto gpio_free;
@@ -446,7 +452,7 @@ static int spi_gpio_probe(struct platform_device *pdev) 
	master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 32);

	master->flags = master_flags;

	master->bus_num = pdev->id;

	master->num_chipselect = SPI_N_CHIPSEL;

	master->num_chipselect = num_devices;

	master->setup = spi_gpio_setup;

	master->cleanup = spi_gpio_cleanup;

#ifdef CONFIG_OF
@@ -461,6 +467,9 @@ static int spi_gpio_probe(struct platform_device *pdev) 
		 * property of the node.

		 */



		if (!SPI_N_CHIPSEL)

			spi_gpio->cs_gpios[0] = SPI_GPIO_NO_CHIPSELECT;

		else

			for (i = 0; i < SPI_N_CHIPSEL; i++)

				spi_gpio->cs_gpios[i] =

					of_get_named_gpio(np, "cs-gpios", i);