Memory-mapped dw_spi driver

Adds a memory-mapped I/O dw_spi platform device.
Signed-off-by: Jean-Hugues Deschenes <jean-hugues.deschenes@octasic.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

drivers/spi/Kconfig

@@ -334,6 +334,10 @@ config SPI_DW_PCI
 	tristate "PCI interface driver for DW SPI core"
 	depends on SPI_DESIGNWARE && PCI
 
+config SPI_DW_MMIO
+	tristate "Memory-mapped io interface driver for DW SPI core"
+	depends on SPI_DESIGNWARE
+
 #
 # There are lots of SPI device types, with sensors and memory
 # being probably the most widely used ones.

drivers/spi/Makefile

@@ -20,6 +20,7 @@ obj-$(CONFIG_SPI_COLDFIRE_QSPI)		+= coldfire_qspi.o
 obj-$(CONFIG_SPI_DAVINCI)		+= davinci_spi.o
 obj-$(CONFIG_SPI_DESIGNWARE)		+= dw_spi.o
 obj-$(CONFIG_SPI_DW_PCI)		+= dw_spi_pci.o
+obj-$(CONFIG_SPI_DW_MMIO)		+= dw_spi_mmio.o
 obj-$(CONFIG_SPI_GPIO)			+= spi_gpio.o
 obj-$(CONFIG_SPI_IMX)			+= spi_imx.o
 obj-$(CONFIG_SPI_LM70_LLP)		+= spi_lm70llp.o

drivers/spi/dw_spi_mmio.c

+/*
+ * dw_spi_mmio.c - Memory-mapped interface driver for DW SPI Core
+ *
+ * Copyright (c) 2010, Octasic semiconductor.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ */
+
+#include <linux/clk.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/spi/dw_spi.h>
+#include <linux/spi/spi.h>
+
+#define DRIVER_NAME "dw_spi_mmio"
+
+struct dw_spi_mmio {
+	struct dw_spi	dws;
+	struct clk		*clk;
+};
+
+static int __devinit dw_spi_mmio_probe(struct platform_device *pdev)
+{
+	struct dw_spi_mmio *dwsmmio;
+	struct dw_spi *dws;
+	struct resource *mem, *ioarea;
+	int ret;
+
+	dwsmmio = kzalloc(sizeof(struct dw_spi_mmio), GFP_KERNEL);
+	if (!dwsmmio) {
+		ret = -ENOMEM;
+		goto err_end;
+	}
+
+	dws = &dwsmmio->dws;
+
+	/* Get basic io resource and map it */
+	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!mem) {
+		dev_err(&pdev->dev, "no mem resource?\n");
+		ret = -EINVAL;
+		goto err_kfree;
+	}
+
+	ioarea = request_mem_region(mem->start, resource_size(mem),
+			pdev->name);
+	if (!ioarea) {
+		dev_err(&pdev->dev, "SPI region already claimed\n");
+		ret = -EBUSY;
+		goto err_kfree;
+	}
+
+	dws->regs = ioremap_nocache(mem->start, resource_size(mem));
+	if (!dws->regs) {
+		dev_err(&pdev->dev, "SPI region already mapped\n");
+		ret = -ENOMEM;
+		goto err_release_reg;
+	}
+
+	dws->irq = platform_get_irq(pdev, 0);
+	if (dws->irq < 0) {
+		dev_err(&pdev->dev, "no irq resource?\n");
+		ret = dws->irq; /* -ENXIO */
+		goto err_unmap;
+	}
+
+	dwsmmio->clk = clk_get(&pdev->dev, NULL);
+	if (!dwsmmio->clk) {
+		ret = -ENODEV;
+		goto err_irq;
+	}
+	clk_enable(dwsmmio->clk);
+
+	dws->parent_dev = &pdev->dev;
+	dws->bus_num = 0;
+	dws->num_cs = 4;
+	dws->max_freq = clk_get_rate(dwsmmio->clk);
+
+	ret = dw_spi_add_host(dws);
+	if (ret)
+		goto err_clk;
+
+	platform_set_drvdata(pdev, dwsmmio);
+	return 0;
+
+err_clk:
+	clk_disable(dwsmmio->clk);
+	clk_put(dwsmmio->clk);
+	dwsmmio->clk = NULL;
+err_irq:
+	free_irq(dws->irq, dws);
+err_unmap:
+	iounmap(dws->regs);
+err_release_reg:
+	release_mem_region(mem->start, resource_size(mem));
+err_kfree:
+	kfree(dwsmmio);
+err_end:
+	return ret;
+}
+
+static int __devexit dw_spi_mmio_remove(struct platform_device *pdev)
+{
+	struct dw_spi_mmio *dwsmmio = platform_get_drvdata(pdev);
+	struct resource *mem;
+
+	platform_set_drvdata(pdev, NULL);
+
+	clk_disable(dwsmmio->clk);
+	clk_put(dwsmmio->clk);
+	dwsmmio->clk = NULL;
+
+	free_irq(dwsmmio->dws.irq, &dwsmmio->dws);
+	dw_spi_remove_host(&dwsmmio->dws);
+	iounmap(dwsmmio->dws.regs);
+	kfree(dwsmmio);
+
+	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	release_mem_region(mem->start, resource_size(mem));
+	return 0;
+}
+
+static struct platform_driver dw_spi_mmio_driver = {
+	.remove		= __devexit_p(dw_spi_mmio_remove),
+	.driver		= {
+		.name	= DRIVER_NAME,
+		.owner	= THIS_MODULE,
+	},
+};
+
+static int __init dw_spi_mmio_init(void)
+{
+	return platform_driver_probe(&dw_spi_mmio_driver, dw_spi_mmio_probe);
+}
+
+static void __exit dw_spi_mmio_exit(void)
+{
+	platform_driver_unregister(&dw_spi_mmio_driver);
+}
+
+module_init(dw_spi_mmio_init);
+module_exit(dw_spi_mmio_exit);
+
+MODULE_AUTHOR("Jean-Hugues Deschenes <jean-hugues.deschenes@octasic.com>");
+MODULE_DESCRIPTION("Memory-mapped I/O interface driver for DW SPI Core");
+MODULE_LICENSE("GPL v2");