drivers/spi/xilinx_spi_of.c

   1 /*
   2  * Xilinx SPI OF device driver
   3  *
   4  * Copyright (c) 2009 Intel Corporation
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  18  */
  19
  20 /* Supports:
  21  * Xilinx SPI devices as OF devices
  22  *
  23  * Inspired by xilinx_spi.c, 2002-2007 (c) MontaVista Software, Inc.
  24  */
  25
  26 #include <linux/module.h>
  27 #include <linux/init.h>
  28 #include <linux/interrupt.h>
  29 #include <linux/io.h>
  30 #include <linux/slab.h>
  31
  32 #include <linux/of_address.h>
  33 #include <linux/of_platform.h>
  34 #include <linux/of_device.h>
  35 #include <linux/of_spi.h>
  36
  37 #include <linux/spi/xilinx_spi.h>
  38 #include "xilinx_spi.h"
  39
  40
  41 static int __devinit xilinx_spi_of_probe(struct platform_device *ofdev,
  42         const struct of_device_id *match)
  43 {
  44         struct spi_master *master;
  45         struct xspi_platform_data *pdata;
  46         struct resource r_mem;
  47         struct resource r_irq;
  48         int rc = 0;
  49         const u32 *prop;
  50         int len;
  51
  52         rc = of_address_to_resource(ofdev->dev.of_node, 0, &r_mem);
  53         if (rc) {
  54                 dev_warn(&ofdev->dev, "invalid address\n");
  55                 return rc;
  56         }
  57
  58         rc = of_irq_to_resource(ofdev->dev.of_node, 0, &r_irq);
  59         if (rc == NO_IRQ) {
  60                 dev_warn(&ofdev->dev, "no IRQ found\n");
  61                 return -ENODEV;
  62         }
  63
  64         ofdev->dev.platform_data =
  65                 kzalloc(sizeof(struct xspi_platform_data), GFP_KERNEL);
  66         pdata = ofdev->dev.platform_data;
  67         if (!pdata)
  68                 return -ENOMEM;
  69
  70         /* number of slave select bits is required */
  71         prop = of_get_property(ofdev->dev.of_node, "xlnx,num-ss-bits", &len);
  72         if (!prop || len < sizeof(*prop)) {
  73                 dev_warn(&ofdev->dev, "no 'xlnx,num-ss-bits' property\n");
  74                 return -EINVAL;
  75         }
  76         pdata->num_chipselect = *prop;
  77         pdata->bits_per_word = 8;
  78         master = xilinx_spi_init(&ofdev->dev, &r_mem, r_irq.start, -1);
  79         if (!master)
  80                 return -ENODEV;
  81
  82         dev_set_drvdata(&ofdev->dev, master);
  83
  84         return 0;
  85 }
  86
  87 static int __devexit xilinx_spi_remove(struct platform_device *ofdev)
  88 {
  89         xilinx_spi_deinit(dev_get_drvdata(&ofdev->dev));
  90         dev_set_drvdata(&ofdev->dev, 0);
  91         kfree(ofdev->dev.platform_data);
  92         ofdev->dev.platform_data = NULL;
  93         return 0;
  94 }
  95
  96 static int __exit xilinx_spi_of_remove(struct platform_device *op)
  97 {
  98         return xilinx_spi_remove(op);
  99 }
 100
 101 static const struct of_device_id xilinx_spi_of_match[] = {
 102         { .compatible = "xlnx,xps-spi-2.00.a", },
 103         { .compatible = "xlnx,xps-spi-2.00.b", },
 104         {}
 105 };
 106
 107 MODULE_DEVICE_TABLE(of, xilinx_spi_of_match);
 108
 109 static struct of_platform_driver xilinx_spi_of_driver = {
 110         .probe = xilinx_spi_of_probe,
 111         .remove = __exit_p(xilinx_spi_of_remove),
 112         .driver = {
 113                 .name = "xilinx-xps-spi",
 114                 .owner = THIS_MODULE,
 115                 .of_match_table = xilinx_spi_of_match,
 116         },
 117 };
 118
 119 static int __init xilinx_spi_of_init(void)
 120 {
 121         return of_register_platform_driver(&xilinx_spi_of_driver);
 122 }
 123 module_init(xilinx_spi_of_init);
 124
 125 static void __exit xilinx_spi_of_exit(void)
 126 {
 127         of_unregister_platform_driver(&xilinx_spi_of_driver);
 128 }
 129 module_exit(xilinx_spi_of_exit);
 130
 131 MODULE_AUTHOR("Mocean Laboratories <info@mocean-labs.com>");
 132 MODULE_DESCRIPTION("Xilinx SPI platform driver");
 133 MODULE_LICENSE("GPL v2");