spi: spi-ath79: Add device tree support

Set the OF node of the spi controller and use the generic GPIO based
chip select instead of the custom controller data. As the controller
data isn't used by any board just drop it.

Signed-off-by: Alban Bedel <albeu@free.fr>
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/drivers/spi/spi-ath79.c b/drivers/spi/spi-ath79.c
index b02eb4a..239bc31 100644
--- a/drivers/spi/spi-ath79.c
+++ b/drivers/spi/spi-ath79.c
@@ -79,10 +79,8 @@
 	}
 
 	if (spi->chip_select) {
-		struct ath79_spi_controller_data *cdata = spi->controller_data;
-
 		/* SPI is normally active-low */
-		gpio_set_value(cdata->gpio, cs_high);
+		gpio_set_value(spi->cs_gpio, cs_high);
 	} else {
 		if (cs_high)
 			sp->ioc_base |= AR71XX_SPI_IOC_CS0;
@@ -117,11 +115,9 @@
 
 static int ath79_spi_setup_cs(struct spi_device *spi)
 {
-	struct ath79_spi_controller_data *cdata;
 	int status;
 
-	cdata = spi->controller_data;
-	if (spi->chip_select && !cdata)
+	if (spi->chip_select && !gpio_is_valid(spi->cs_gpio))
 		return -EINVAL;
 
 	status = 0;
@@ -134,7 +130,7 @@
 		else
 			flags |= GPIOF_INIT_HIGH;
 
-		status = gpio_request_one(cdata->gpio, flags,
+		status = gpio_request_one(spi->cs_gpio, flags,
 					  dev_name(&spi->dev));
 	}
 
@@ -144,8 +140,7 @@
 static void ath79_spi_cleanup_cs(struct spi_device *spi)
 {
 	if (spi->chip_select) {
-		struct ath79_spi_controller_data *cdata = spi->controller_data;
-		gpio_free(cdata->gpio);
+		gpio_free(spi->cs_gpio);
 	}
 }
 
@@ -217,6 +212,7 @@
 	}
 
 	sp = spi_master_get_devdata(master);
+	master->dev.of_node = pdev->dev.of_node;
 	platform_set_drvdata(pdev, sp);
 
 	pdata = dev_get_platdata(&pdev->dev);
@@ -301,12 +297,18 @@
 	ath79_spi_remove(pdev);
 }
 
+static const struct of_device_id ath79_spi_of_match[] = {
+	{ .compatible = "qca,ar7100-spi", },
+	{ },
+};
+
 static struct platform_driver ath79_spi_driver = {
 	.probe		= ath79_spi_probe,
 	.remove		= ath79_spi_remove,
 	.shutdown	= ath79_spi_shutdown,
 	.driver		= {
 		.name	= DRV_NAME,
+		.of_match_table = ath79_spi_of_match,
 	},
 };
 module_platform_driver(ath79_spi_driver);