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
  31 #include <linux/of_platform.h>
  32 #include <linux/of_device.h>
  33 #include <linux/of_spi.h>
  34
  35 #include <linux/spi/xilinx_spi.h>
  36 #include "xilinx_spi.h"
  37
  38
  39 static int __devinit xilinx_spi_of_probe(struct of_device *ofdev,
  40         const struct of_device_id *match)
  41 {
  42         struct spi_master *master;
  43         struct xspi_platform_data *pdata;
  44         struct resource r_mem;
  45         struct resource r_irq;
  46         int rc = 0;
  47         const u32 *prop;
  48         int len;
  49
  50         rc = of_address_to_resource(ofdev->node, 0, &r_mem);
  51         if (rc) {
  52                 dev_warn(&ofdev->dev, "invalid address\n");
  53                 return rc;
  54         }
  55
  56         rc = of_irq_to_resource(ofdev->node, 0, &r_irq);
  57         if (rc == NO_IRQ) {
  58                 dev_warn(&ofdev->dev, "no IRQ found\n");
  59                 return -ENODEV;
  60         }
  61
  62         ofdev->dev.platform_data =
  63                 kzalloc(sizeof(struct xspi_platform_data), GFP_KERNEL);
  64         pdata = ofdev->dev.platform_data;
  65         if (!pdata)
  66                 return -ENOMEM;
  67
  68         /* number of slave select bits is required */
  69         prop = of_get_property(ofdev->node, "xlnx,num-ss-bits", &len);
  70         if (!prop || len < sizeof(*prop)) {
  71                 dev_warn(&ofdev->dev, "no 'xlnx,num-ss-bits' property\n");
  72                 return -EINVAL;
  73         }
  74         pdata->num_chipselect = *prop;
  75         pdata->bits_per_word = 8;
  76         master = xilinx_spi_init(&ofdev->dev, &r_mem, r_irq.start, -1);
  77         if (!master)
  78                 return -ENODEV;
  79
  80         dev_set_drvdata(&ofdev->dev, master);
  81
  82         /* Add any subnodes on the SPI bus */
  83         of_register_spi_devices(master, ofdev->node);
  84
  85         return 0;
  86 }
  87
  88 static int __devexit xilinx_spi_remove(struct of_device *ofdev)
  89 {
  90         xilinx_spi_deinit(dev_get_drvdata(&ofdev->dev));
  91         dev_set_drvdata(&ofdev->dev, 0);
  92         kfree(ofdev->dev.platform_data);
  93         ofdev->dev.platform_data = NULL;
  94         return 0;
  95 }
  96
  97 static int __exit xilinx_spi_of_remove(struct of_device *op)
  98 {
  99         return xilinx_spi_remove(op);
 100 }
 101
 102 static const struct of_device_id xilinx_spi_of_match[] = {
 103         { .compatible = "xlnx,xps-spi-2.00.a", },
 104         { .compatible = "xlnx,xps-spi-2.00.b", },
 105         {}
 106 };
 107
 108 MODULE_DEVICE_TABLE(of, xilinx_spi_of_match);
 109
 110 static struct of_platform_driver xilinx_spi_of_driver = {
 111         .match_table = xilinx_spi_of_match,
 112         .probe = xilinx_spi_of_probe,
 113         .remove = __exit_p(xilinx_spi_of_remove),
 114         .driver = {
 115                 .name = "xilinx-xps-spi",
 116                 .owner = THIS_MODULE,
 117         },
 118 };
 119
 120 static int __init xilinx_spi_of_init(void)
 121 {
 122         return of_register_platform_driver(&xilinx_spi_of_driver);
 123 }
 124 module_init(xilinx_spi_of_init);
 125
 126 static void __exit xilinx_spi_of_exit(void)
 127 {
 128         of_unregister_platform_driver(&xilinx_spi_of_driver);
 129 }
 130 module_exit(xilinx_spi_of_exit);
 131
 132 MODULE_AUTHOR("Mocean Laboratories <info@mocean-labs.com>");
 133 MODULE_DESCRIPTION("Xilinx SPI platform driver");
 134 MODULE_LICENSE("GPL v2");