[PATCH] Memory-mapped Dwsignware SPI driver

[Jean-Hugues Deschenes <jean-hugues.deschenes-YGVykHU+fedBDgjK7y7TUQ@public.gmane.org>]

Adds a memory-mapped I/O dw_spi platform device.

Signed-off-by: Jean-Hugues Deschenes <jean-hugues.deschenes-YGVykHU+fedBDgjK7y7TUQ@public.gmane.org>
---
 drivers/spi/Kconfig       |   16 ++++
 drivers/spi/Makefile      |    1 
 drivers/spi/dw_spi_mmio.c |  164 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 178 insertions(+), 3 deletions(-)
 create mode 100644 drivers/spi/dw_spi_mmio.c

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index f55eb01..79c8d5f 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -308,14 +308,24 @@ config SPI_NUC900
 #
 
 config SPI_DESIGNWARE
-	bool "DesignWare SPI controller core support"
+	tristate "DesignWare SPI controller core support"
 	depends on SPI_MASTER
 	help
 	  general driver for SPI controller core from DesignWare
 
+choice
+	prompt "Designware bus type"
+	depends on SPI_DESIGNWARE
+	default SPI_DW_PCI
+
 config SPI_DW_PCI
-	tristate "PCI interface driver for DW SPI core"
-	depends on SPI_DESIGNWARE && PCI
+	bool "PCI interface driver for DW SPI core"
+	depends on PCI
+
+config SPI_DW_MMIO
+	bool "Memory-mapped io interface driver for DW SPI core"
+
+endchoice
 
 #
 # There are lots of SPI device types, with sensors and memory
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index f3d2810..c3e5ce7 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -18,6 +18,7 @@ obj-$(CONFIG_SPI_AU1550)		+= au1550_spi.o
 obj-$(CONFIG_SPI_BUTTERFLY)		+= spi_butterfly.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
diff --git a/drivers/spi/dw_spi_mmio.c b/drivers/spi/dw_spi_mmio.c
new file mode 100644
index 0000000..9abeb45
--- /dev/null
+++ b/drivers/spi/dw_spi_mmio.c
@@ -0,0 +1,164 @@
+/*
+ * dw_spi_mmio.c - Memory-mapped interface driver for DW SPI Core
+ *
+ * Copyright (c) 2010, Octasic semiconductor.
+ *
+ * Somewhat derived from PCI implementation,
+ * Copyright (c) 2009, Intel Corporation.
+ *
+ * ...and from designware i2c driver
+ * Copyright (C) 2006 Texas Instruments.
+ * Copyright (C) 2007 MontaVista Software Inc.
+ * Copyright (C) 2009 Provigent Ltd.
+ *
+ * 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.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#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);
+	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-YGVykHU+fedBDgjK7y7TUQ@public.gmane.org>");
+MODULE_DESCRIPTION("Memory-mapped I/O interface driver for DW SPI Core");
+MODULE_LICENSE("GPL v2");


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