linux/drivers/spi/dw_spi_mmio.c

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/*
* 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");