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

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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: Torsten Fleischer <torfl6749@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Torsten Fleischer 2014-11-03 17:17:55 +01:00 committed by Mark Brown
parent f114040e3e
commit d1d8180252
2 changed files with 19 additions and 8 deletions
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6
Documentation/devicetree/bindings/spi/spi-gpio.txt
View File

@ -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:

21
drivers/spi/spi-gpio.c
View File

@ -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
@ -461,9 +467,12 @@ static int spi_gpio_probe(struct platform_device *pdev)
* property of the node.
*/
for (i = 0; i < SPI_N_CHIPSEL; i++)
spi_gpio->cs_gpios[i] =
of_get_named_gpio(np, "cs-gpios", i);
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);
}
#endif