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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: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Torsten Fleischer <torfl6749@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Torsten Fleischer 2014-11-07 18:11:58 +01:00 committed by Mark Brown
parent d1d8180252
commit cfb4bbd8fb
1 changed files with 15 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

24
drivers/spi/spi-gpio.c
View File

@ -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