LXR linux/drivers/spi/dw_spi

   1/*
   2 * dw_spi_mmio.c - Memory-mapped interface driver for DW SPI Core
   3 *
   4 * Copyright (c) 2010, Octasic semiconductor.
   5 *
   6 * This program is free software; you can redistribute it and/or modify it
   7 * under the terms and conditions of the GNU General Public License,
   8 * version 2, as published by the Free Software Foundation.
   9 */
  10
  11#include <linux/clk.h>
  12#include <linux/err.h>
  13#include <linux/interrupt.h>
  14#include <linux/platform_device.h>
  15#include <linux/slab.h>
  16#include <linux/spi/spi.h>
  17#include <linux/scatterlist.h>
  18
  19#include "dw_spi.h"
  20
  21#define DRIVER_NAME "dw_spi_mmio"
  22
  23struct dw_spi_mmio {
  24        struct dw_spi  dws;
  25        struct clk     *clk;
  26};
  27
  28static int __devinit dw_spi_mmio_probe(struct platform_device *pdev)
  29{
  30        struct dw_spi_mmio *dwsmmio;
  31        struct dw_spi *dws;
  32        struct resource *mem, *ioarea;
  33        int ret;
  34
  35        dwsmmio = kzalloc(sizeof(struct dw_spi_mmio), GFP_KERNEL);
  36        if (!dwsmmio) {
  37                ret = -ENOMEM;
  38                goto err_end;
  39        }
  40
  41        dws = &dwsmmio->dws;
  42
  43        /* Get basic io resource and map it */
  44        mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  45        if (!mem) {
  46                dev_err(&pdev->dev, "no mem resource?\n");
  47                ret = -EINVAL;
  48                goto err_kfree;
  49        }
  50
  51        ioarea = request_mem_region(mem->start, resource_size(mem),
  52                        pdev->name);
  53        if (!ioarea) {
  54                dev_err(&pdev->dev, "SPI region already claimed\n");
  55                ret = -EBUSY;
  56                goto err_kfree;
  57        }
  58
  59        dws->regs = ioremap_nocache(mem->start, resource_size(mem));
  60        if (!dws->regs) {
  61                dev_err(&pdev->dev, "SPI region already mapped\n");
  62                ret = -ENOMEM;
  63                goto err_release_reg;
  64        }
  65
  66        dws->irq = platform_get_irq(pdev, 0);
  67        if (dws->irq < 0) {
  68                dev_err(&pdev->dev, "no irq resource?\n");
  69                ret = dws->irq; /* -ENXIO */
  70                goto err_unmap;
  71        }
  72
  73        dwsmmio->clk = clk_get(&pdev->dev, NULL);
  74        if (IS_ERR(dwsmmio->clk)) {
  75                ret = PTR_ERR(dwsmmio->clk);
  76                goto err_irq;
  77        }
  78        clk_enable(dwsmmio->clk);
  79
  80        dws->parent_dev = &pdev->dev;
  81        dws->bus_num = 0;
  82        dws->num_cs = 4;
  83        dws->max_freq = clk_get_rate(dwsmmio->clk);
  84
  85        ret = dw_spi_add_host(dws);
  86        if (ret)
  87                goto err_clk;
  88
  89        platform_set_drvdata(pdev, dwsmmio);
  90        return 0;
  91
  92err_clk:
  93        clk_disable(dwsmmio->clk);
  94        clk_put(dwsmmio->clk);
  95        dwsmmio->clk = NULL;
  96err_irq:
  97        free_irq(dws->irq, dws);
  98err_unmap:
  99        iounmap(dws->regs);
 100err_release_reg:
 101        release_mem_region(mem->start, resource_size(mem));
 102err_kfree:
 103        kfree(dwsmmio);
 104err_end:
 105        return ret;
 106}
 107
 108static int __devexit dw_spi_mmio_remove(struct platform_device *pdev)
 109{
 110        struct dw_spi_mmio *dwsmmio = platform_get_drvdata(pdev);
 111        struct resource *mem;
 112
 113        platform_set_drvdata(pdev, NULL);
 114
 115        clk_disable(dwsmmio->clk);
 116        clk_put(dwsmmio->clk);
 117        dwsmmio->clk = NULL;
 118
 119        free_irq(dwsmmio->dws.irq, &dwsmmio->dws);
 120        dw_spi_remove_host(&dwsmmio->dws);
 121        iounmap(dwsmmio->dws.regs);
 122        kfree(dwsmmio);
 123
 124        mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 125        release_mem_region(mem->start, resource_size(mem));
 126        return 0;
 127}
 128
 129static struct platform_driver dw_spi_mmio_driver = {
 130        .remove         = __devexit_p(dw_spi_mmio_remove),
 131        .driver         = {
 132                .name   = DRIVER_NAME,
 133                .owner  = THIS_MODULE,
 134        },
 135};
 136
 137static int __init dw_spi_mmio_init(void)
 138{
 139        return platform_driver_probe(&dw_spi_mmio_driver, dw_spi_mmio_probe);
 140}
 141module_init(dw_spi_mmio_init);
 142
 143static void __exit dw_spi_mmio_exit(void)
 144{
 145        platform_driver_unregister(&dw_spi_mmio_driver);
 146}
 147module_exit(dw_spi_mmio_exit);
 148
 149MODULE_AUTHOR("Jean-Hugues Deschenes <jean-hugues.deschenes@octasic.com>");
 150MODULE_DESCRIPTION("Memory-mapped I/O interface driver for DW SPI Core");
 151MODULE_LICENSE("GPL v2");
 152