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