Xilinx: SPI: updated driver for device tree

The driver was updated to use the device tree rather than the platform data.
Signed-off-by: John Linn <john.linn@xilinx.com>

drivers/spi/xilinx_spi.c

@@ -15,12 +15,15 @@
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/platform_device.h>
+
+#include <linux/of_platform.h>
+#include <linux/of_device.h>
+#include <linux/of_spi.h>
+
 #include <linux/spi/spi.h>
 #include <linux/spi/spi_bitbang.h>
 #include <linux/io.h>
 
-#include <syslib/virtex_devices.h>
-
 #define XILINX_SPI_NAME "xilinx_spi"
 
 /* Register definitions as per "OPB Serial Peripheral Interface (SPI) (v1.00e)
@@ -144,23 +147,14 @@ static int xilinx_spi_setup_transfer(struct spi_device *spi,
 		struct spi_transfer *t)
 {
 	u8 bits_per_word;
-	u32 hz;
-	struct xilinx_spi *xspi = spi_master_get_devdata(spi->master);
 
 	bits_per_word = (t) ? t->bits_per_word : spi->bits_per_word;
-	hz = (t) ? t->speed_hz : spi->max_speed_hz;
 	if (bits_per_word != 8) {
 		dev_err(&spi->dev, "%s, unsupported bits_per_word=%d\n",
 			__func__, bits_per_word);
 		return -EINVAL;
 	}
 
-	if (hz && xspi->speed_hz > hz) {
-		dev_err(&spi->dev, "%s, unsupported clock rate %uHz\n",
-			__func__, hz);
-		return -EINVAL;
-	}
-
 	return 0;
 }
 
@@ -304,32 +298,38 @@ static irqreturn_t xilinx_spi_irq(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
-static int __init xilinx_spi_probe(struct platform_device *dev)
+static int __init xilinx_spi_of_probe(struct of_device *ofdev,
+					const struct of_device_id *match)
 {
-	int ret = 0;
 	struct spi_master *master;
 	struct xilinx_spi *xspi;
-	struct xspi_platform_data *pdata;
-	struct resource *r;
+	struct resource r_irq_struct;
+	struct resource r_mem_struct;
+
+	struct resource *r_irq = &r_irq_struct;
+	struct resource *r_mem = &r_mem_struct;
+	int rc = 0;
+	const u32 *prop;
+	int len;
 
 	/* Get resources(memory, IRQ) associated with the device */
-	master = spi_alloc_master(&dev->dev, sizeof(struct xilinx_spi));
+	master = spi_alloc_master(&ofdev->dev, sizeof(struct xilinx_spi));
 
 	if (master == NULL) {
 		return -ENOMEM;
 	}
 
-	platform_set_drvdata(dev, master);
-	pdata = dev->dev.platform_data;
+	dev_set_drvdata(&ofdev->dev, master);
 
-	if (pdata == NULL) {
-		ret = -ENODEV;
+	rc = of_address_to_resource(ofdev->node, 0, r_mem);
+	if (rc) {
+		dev_warn(&ofdev->dev, "invalid address\n");
 		goto put_master;
 	}
 
-	r = platform_get_resource(dev, IORESOURCE_MEM, 0);
-	if (r == NULL) {
-		ret = -ENODEV;
+	rc = of_irq_to_resource(ofdev->node, 0, r_irq);
+	if (rc == NO_IRQ) {
+		dev_warn(&ofdev->dev, "no IRQ found\n");
 		goto put_master;
 	}
 
@@ -341,47 +341,57 @@ static int __init xilinx_spi_probe(struct platform_device *dev)
 	xspi->bitbang.master->setup = xilinx_spi_setup;
 	init_completion(&xspi->done);
 
-	if (!request_mem_region(r->start,
-			r->end - r->start + 1, XILINX_SPI_NAME)) {
-		ret = -ENXIO;
+	xspi->irq = r_irq->start;
+
+	if (!request_mem_region(r_mem->start,
+			r_mem->end - r_mem->start + 1, XILINX_SPI_NAME)) {
+		rc = -ENXIO;
+		dev_warn(&ofdev->dev, "memory request failure\n");
 		goto put_master;
 	}
 
-	xspi->regs = ioremap(r->start, r->end - r->start + 1);
+	xspi->regs = ioremap(r_mem->start, r_mem->end - r_mem->start + 1);
 	if (xspi->regs == NULL) {
-		ret = -ENOMEM;
+		rc = -ENOMEM;
+		dev_warn(&ofdev->dev, "ioremap failure\n");
 		goto put_master;
 	}
+	xspi->irq = r_irq->start;
 
-	ret = platform_get_irq(dev, 0);
-	if (ret < 0) {
-		ret = -ENXIO;
-		goto unmap_io;
-	}
-	xspi->irq = ret;
+	/* dynamic bus assignment */
+	master->bus_num = -1;
 
-	master->bus_num = pdata->bus_num;
-	master->num_chipselect = pdata->num_chipselect;
-	xspi->speed_hz = pdata->speed_hz;
+	/* number of slave select bits is required */
+	prop = of_get_property(ofdev->node, "xlnx,num-ss-bits", &len);
+	if (!prop || len < sizeof(*prop)) {
+		dev_warn(&ofdev->dev, "no 'xlnx,num-ss-bits' property\n");
+		goto put_master;
+	}
+	master->num_chipselect = *prop;
 
 	/* SPI controller initializations */
 	xspi_init_hw(xspi->regs);
 
 	/* Register for SPI Interrupt */
-	ret = request_irq(xspi->irq, xilinx_spi_irq, 0, XILINX_SPI_NAME, xspi);
-	if (ret != 0)
+	rc = request_irq(xspi->irq, xilinx_spi_irq, 0, XILINX_SPI_NAME, xspi);
+	if (rc != 0) {
+		dev_warn(&ofdev->dev, "irq request failure: %d\n", xspi->irq);
 		goto unmap_io;
+	}
 
-	ret = spi_bitbang_start(&xspi->bitbang);
-	if (ret != 0) {
-		dev_err(&dev->dev, "spi_bitbang_start FAILED\n");
+	rc = spi_bitbang_start(&xspi->bitbang);
+	if (rc != 0) {
+		dev_err(&ofdev->dev, "spi_bitbang_start FAILED\n");
 		goto free_irq;
 	}
 
-	dev_info(&dev->dev, "at 0x%08X mapped to 0x%08X, irq=%d\n",
-			r->start, (u32)xspi->regs, xspi->irq);
+	dev_info(&ofdev->dev, "at 0x%08X mapped to 0x%08X, irq=%d\n",
+			(unsigned int)r_mem->start, (u32)xspi->regs, xspi->irq);
+
+	/* Add any subnodes on the SPI bus */
+	of_register_spi_devices(master, ofdev->node);
 
-	return ret;
+	return rc;
 
 free_irq:
 	free_irq(xspi->irq, xspi);
@@ -389,21 +399,21 @@ static int __init xilinx_spi_probe(struct platform_device *dev)
 	iounmap(xspi->regs);
 put_master:
 	spi_master_put(master);
-	return ret;
+	return rc;
 }
 
-static int __devexit xilinx_spi_remove(struct platform_device *dev)
+static int __devexit xilinx_spi_remove(struct of_device *ofdev)
 {
 	struct xilinx_spi *xspi;
 	struct spi_master *master;
 
-	master = platform_get_drvdata(dev);
+	master = platform_get_drvdata(ofdev);
 	xspi = spi_master_get_devdata(master);
 
 	spi_bitbang_stop(&xspi->bitbang);
 	free_irq(xspi->irq, xspi);
 	iounmap(xspi->regs);
-	platform_set_drvdata(dev, 0);
+	dev_set_drvdata(&ofdev->dev, 0);
 	spi_master_put(xspi->bitbang.master);
 
 	return 0;
@@ -412,27 +422,42 @@ static int __devexit xilinx_spi_remove(struct platform_device *dev)
 /* work with hotplug and coldplug */
 MODULE_ALIAS("platform:" XILINX_SPI_NAME);
 
-static struct platform_driver xilinx_spi_driver = {
-	.probe	= xilinx_spi_probe,
-	.remove	= __devexit_p(xilinx_spi_remove),
+static int __exit xilinx_spi_of_remove(struct of_device *op)
+{
+	return xilinx_spi_remove(op);
+}
+
+static struct of_device_id xilinx_spi_of_match[] = {
+	{ .compatible = "xlnx,xps-spi-2.00.a", },
+	{ .compatible = "xlnx,xps-spi-2.00.b", },
+	{}
+};
+
+MODULE_DEVICE_TABLE(of, xilinx_spi_of_match);
+
+static struct of_platform_driver xilinx_spi_of_driver = {
+	.owner = THIS_MODULE,
+	.name = "xilinx-xps-spi",
+	.match_table = xilinx_spi_of_match,
+	.probe = xilinx_spi_of_probe,
+	.remove = __exit_p(xilinx_spi_of_remove),
 	.driver = {
-		.name = XILINX_SPI_NAME,
+		.name = "xilinx-xps-spi",
 		.owner = THIS_MODULE,
 	},
 };
 
 static int __init xilinx_spi_init(void)
 {
-	return platform_driver_register(&xilinx_spi_driver);
+	return of_register_platform_driver(&xilinx_spi_of_driver);
 }
 module_init(xilinx_spi_init);
 
 static void __exit xilinx_spi_exit(void)
 {
-	platform_driver_unregister(&xilinx_spi_driver);
+	of_unregister_platform_driver(&xilinx_spi_of_driver);
 }
 module_exit(xilinx_spi_exit);
-
 MODULE_AUTHOR("MontaVista Software, Inc. <source@mvista.com>");
 MODULE_DESCRIPTION("Xilinx SPI driver");
 MODULE_LICENSE("GPL");