drivers/spi/spi-dw-mmio.c

   1 /*
   2  * 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 #include <linux/module.h>
  19
  20 #include "spi-dw.h"
  21
  22 #define DRIVER_NAME "dw_spi_mmio"
  23
  24 struct dw_spi_mmio {
  25         struct dw_spi  dws;
  26         struct clk     *clk;
  27 };
  28
  29 static int dw_spi_mmio_probe(struct platform_device *pdev)
  30 {
  31         struct dw_spi_mmio *dwsmmio;
  32         struct dw_spi *dws;
  33         struct resource *mem;
  34         int ret;
  35
  36         dwsmmio = devm_kzalloc(&pdev->dev, sizeof(struct dw_spi_mmio),
  37                         GFP_KERNEL);
  38         if (!dwsmmio)
  39                 return -ENOMEM;
  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                 return -EINVAL;
  48         }
  49
  50         dws->regs = devm_ioremap_resource(&pdev->dev, mem);
  51         if (IS_ERR(dws->regs)) {
  52                 dev_err(&pdev->dev, "SPI region map failed\n");
  53                 return PTR_ERR(dws->regs);
  54         }
  55
  56         dws->irq = platform_get_irq(pdev, 0);
  57         if (dws->irq < 0) {
  58                 dev_err(&pdev->dev, "no irq resource?\n");
  59                 return dws->irq; /* -ENXIO */
  60         }
  61
  62         dwsmmio->clk = devm_clk_get(&pdev->dev, NULL);
  63         if (IS_ERR(dwsmmio->clk))
  64                 return PTR_ERR(dwsmmio->clk);
  65         ret = clk_prepare_enable(dwsmmio->clk);
  66         if (ret)
  67                 return ret;
  68
  69         dws->bus_num = 0;
  70         dws->num_cs = 4;
  71         dws->max_freq = clk_get_rate(dwsmmio->clk);
  72
  73         ret = dw_spi_add_host(&pdev->dev, dws);
  74         if (ret)
  75                 goto out;
  76
  77         platform_set_drvdata(pdev, dwsmmio);
  78         return 0;
  79
  80 out:
  81         clk_disable_unprepare(dwsmmio->clk);
  82         return ret;
  83 }
  84
  85 static int dw_spi_mmio_remove(struct platform_device *pdev)
  86 {
  87         struct dw_spi_mmio *dwsmmio = platform_get_drvdata(pdev);
  88
  89         clk_disable_unprepare(dwsmmio->clk);
  90         dw_spi_remove_host(&dwsmmio->dws);
  91
  92         return 0;
  93 }
  94
  95 static struct platform_driver dw_spi_mmio_driver = {
  96         .probe          = dw_spi_mmio_probe,
  97         .remove         = dw_spi_mmio_remove,
  98         .driver         = {
  99                 .name   = DRIVER_NAME,
 100                 .owner  = THIS_MODULE,
 101         },
 102 };
 103 module_platform_driver(dw_spi_mmio_driver);
 104
 105 MODULE_AUTHOR("Jean-Hugues Deschenes <jean-hugues.deschenes@octasic.com>");
 106 MODULE_DESCRIPTION("Memory-mapped I/O interface driver for DW SPI Core");
 107 MODULE_LICENSE("GPL v2");