spi/pl022: Devicetree support w/o platform data

Even with devicetree support, we needed platform data to provide some data,
leading to mixed device tree and platform data. This patch makes it possible to
provide all that information via device tree. Now, the data must be provided
via platform data _or_ device tree completely.

Only in case of DMA where a callback specification is necessary (dma_filter()),
platform data is the only option.

Signed-off-by: Roland Stigge <stigge@antcom.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/drivers/spi/spi-pl022.c b/drivers/spi/spi-pl022.c
index b6cfb7b..3f2f36c 100644
--- a/drivers/spi/spi-pl022.c
+++ b/drivers/spi/spi-pl022.c
@@ -2029,6 +2029,34 @@
 	kfree(chip);
 }
 
+static struct pl022_ssp_controller *
+pl022_platform_data_dt_get(struct device *dev)
+{
+	struct device_node *np = dev->of_node;
+	struct pl022_ssp_controller *pd;
+	u32 tmp;
+
+	if (!np) {
+		dev_err(dev, "no dt node defined\n");
+		return NULL;
+	}
+
+	pd = devm_kzalloc(dev, sizeof(struct pl022_ssp_controller), GFP_KERNEL);
+	if (!pd) {
+		dev_err(dev, "cannot allocate platform data memory\n");
+		return NULL;
+	}
+
+	pd->bus_id = -1;
+	of_property_read_u32(np, "num-cs", &tmp);
+	pd->num_chipselect = tmp;
+	of_property_read_u32(np, "pl022,autosuspend-delay",
+			     &pd->autosuspend_delay);
+	pd->rt = of_property_read_bool(np, "pl022,rt");
+
+	return pd;
+}
+
 static int __devinit
 pl022_probe(struct amba_device *adev, const struct amba_id *id)
 {
@@ -2041,18 +2069,19 @@
 
 	dev_info(&adev->dev,
 		 "ARM PL022 driver, device ID: 0x%08x\n", adev->periphid);
-	if (platform_info == NULL) {
-		dev_err(&adev->dev, "probe - no platform data supplied\n");
+	if (!platform_info && IS_ENABLED(CONFIG_OF))
+		platform_info = pl022_platform_data_dt_get(dev);
+
+	if (!platform_info) {
+		dev_err(dev, "probe: no platform data defined\n");
 		status = -ENODEV;
 		goto err_no_pdata;
 	}
 
 	if (platform_info->num_chipselect) {
 		num_cs = platform_info->num_chipselect;
-	} else if (IS_ENABLED(CONFIG_OF)) {
-		of_property_read_u32(np, "num-cs", &num_cs);
 	} else {
-		dev_err(&adev->dev, "probe: no chip select defined\n");
+		dev_err(dev, "probe: no chip select defined\n");
 		status = -ENODEV;
 		goto err_no_pdata;
 	}