Commit cfb4bbd8 authored by Torsten Fleischer's avatar Torsten Fleischer Committed by Mark Brown
Browse files

spi: spi-gpio: Fix compiler warning when building for 64 bit systems 



The assignment of SPI_GPIO_NO_CHIPSELECT to cs_gpios[0] causes the following
compiler warning, when building for 64 bit systems:
"warning: overflow in implicit constant conversion [-Woverflow]".

This is because the SPI_GPIO_NO_CHIPSELECT flag is a '-1' type casted to
unsigned long and cs_gpios is of the type int.

Furthermore the chip select's GPIO number is locally stored as unsigned int
and compared with SPI_GPIO_NO_CHIPSELECT. Thus the result of the comparison
is always false, if unsigned long and unsigned int have a different size.

As part of the fix this patch adds a check for the device tree's cs-gpios
property.

Reported-by: default avatarkbuild test robot <fengguang.wu@intel.com>
Signed-off-by: default avatarTorsten Fleischer <torfl6749@gmail.com>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent d1d81802

drivers/spi/spi-gpio.c

+15 −9
Original line number Diff line number Diff line
@@ -48,7 +48,7 @@ struct spi_gpio { 
	struct spi_bitbang		bitbang;

	struct spi_gpio_platform_data	pdata;

	struct platform_device		*pdev;

	int				cs_gpios[0];

	unsigned long			cs_gpios[0];

};



/*----------------------------------------------------------------------*/
@@ -220,7 +220,7 @@ static u32 spi_gpio_spec_txrx_word_mode3(struct spi_device *spi, 
static void spi_gpio_chipselect(struct spi_device *spi, int is_active)

{

	struct spi_gpio *spi_gpio = spi_to_spi_gpio(spi);

	unsigned int cs = spi_gpio->cs_gpios[spi->chip_select];

	unsigned long cs = spi_gpio->cs_gpios[spi->chip_select];



	/* set initial clock polarity */

	if (is_active)
@@ -234,7 +234,7 @@ static void spi_gpio_chipselect(struct spi_device *spi, int is_active) 


static int spi_gpio_setup(struct spi_device *spi)

{

	unsigned int		cs;

	unsigned long		cs;

	int			status = 0;

	struct spi_gpio		*spi_gpio = spi_to_spi_gpio(spi);

	struct device_node	*np = spi->master->dev.of_node;
@@ -249,7 +249,7 @@ static int spi_gpio_setup(struct spi_device *spi) 
		/*

		 * ... otherwise, take it from spi->controller_data

		 */

		cs = (unsigned int)(uintptr_t) spi->controller_data;

		cs = (uintptr_t) spi->controller_data;

	}



	if (!spi->controller_state) {
@@ -277,7 +277,7 @@ static int spi_gpio_setup(struct spi_device *spi) 
static void spi_gpio_cleanup(struct spi_device *spi)

{

	struct spi_gpio *spi_gpio = spi_to_spi_gpio(spi);

	unsigned int cs = spi_gpio->cs_gpios[spi->chip_select];

	unsigned long cs = spi_gpio->cs_gpios[spi->chip_select];



	if (cs != SPI_GPIO_NO_CHIPSELECT)

		gpio_free(cs);
@@ -437,7 +437,7 @@ static int spi_gpio_probe(struct platform_device *pdev) 
		return status;



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

					(sizeof(int) * num_devices));

					(sizeof(unsigned long) * num_devices));

	if (!master) {

		status = -ENOMEM;

		goto gpio_free;
@@ -470,9 +470,15 @@ static int spi_gpio_probe(struct platform_device *pdev) 
		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);

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

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

				if (status < 0) {

					dev_err(&pdev->dev,

						"invalid cs-gpios property\n");

					goto gpio_free;

				}

				spi_gpio->cs_gpios[i] = status;

			}

	}

#endif

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