drivers/spi/dw_spi_mmio.c

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