spi/imx: use gpio_is_valid to determine if a gpio is valid

Use gpio_is_valid() to replace "gpio >= 0" or "gpio < 0".

Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Hui Wang <jason77.wang@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

drivers/spi/spi-imx.c

@@ -626,7 +626,7 @@ static void spi_imx_chipselect(struct spi_device *spi, int is_active)
 	int active = is_active != BITBANG_CS_INACTIVE;
 	int dev_is_lowactive = !(spi->mode & SPI_CS_HIGH);
 
-	if (gpio < 0)
+	if (!gpio_is_valid(gpio))
 		return;
 
 	gpio_set_value(gpio, dev_is_lowactive ^ active);
@@ -736,7 +736,7 @@ static int spi_imx_setup(struct spi_device *spi)
 	dev_dbg(&spi->dev, "%s: mode %d, %u bpw, %d hz\n", __func__,
 		 spi->mode, spi->bits_per_word, spi->max_speed_hz);
 
-	if (gpio >= 0)
+	if (gpio_is_valid(gpio))
 		gpio_direction_output(gpio, spi->mode & SPI_CS_HIGH ? 0 : 1);
 
 	spi_imx_chipselect(spi, BITBANG_CS_INACTIVE);
@@ -789,11 +789,11 @@ static int __devinit spi_imx_probe(struct platform_device *pdev)
 
 	for (i = 0; i < master->num_chipselect; i++) {
 		int cs_gpio = of_get_named_gpio(np, "cs-gpios", i);
-		if (cs_gpio < 0 && mxc_platform_info)
+		if (!gpio_is_valid(cs_gpio) && mxc_platform_info)
 			cs_gpio = mxc_platform_info->chipselect[i];
 
 		spi_imx->chipselect[i] = cs_gpio;
-		if (cs_gpio < 0)
+		if (!gpio_is_valid(cs_gpio))
 			continue;
 
 		ret = gpio_request(spi_imx->chipselect[i], DRIVER_NAME);
@@ -895,7 +895,7 @@ static int __devinit spi_imx_probe(struct platform_device *pdev)
 	release_mem_region(res->start, resource_size(res));
 out_gpio_free:
 	while (--i >= 0) {
-		if (spi_imx->chipselect[i] >= 0)
+		if (gpio_is_valid(spi_imx->chipselect[i]))
 			gpio_free(spi_imx->chipselect[i]);
 	}
 	spi_master_put(master);
@@ -920,7 +920,7 @@ static int __devexit spi_imx_remove(struct platform_device *pdev)
 	iounmap(spi_imx->base);
 
 	for (i = 0; i < master->num_chipselect; i++)
-		if (spi_imx->chipselect[i] >= 0)
+		if (gpio_is_valid(spi_imx->chipselect[i]))
 			gpio_free(spi_imx->chipselect[i]);
 
 	spi_master_put(master);