drivers/spi/spi-cavium-octeon.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 2011, 2012 Cavium, Inc.
   7  */
   8
   9 #include <linux/platform_device.h>
  10 #include <linux/spi/spi.h>
  11 #include <linux/module.h>
  12 #include <linux/io.h>
  13 #include <linux/of.h>
  14
  15 #include <asm/octeon/octeon.h>
  16
  17 #include "spi-cavium.h"
  18
  19 static int octeon_spi_probe(struct platform_device *pdev)
  20 {
  21         struct resource *res_mem;
  22         void __iomem *reg_base;
  23         struct spi_master *master;
  24         struct octeon_spi *p;
  25         int err = -ENOENT;
  26
  27         master = spi_alloc_master(&pdev->dev, sizeof(struct octeon_spi));
  28         if (!master)
  29                 return -ENOMEM;
  30         p = spi_master_get_devdata(master);
  31         platform_set_drvdata(pdev, master);
  32
  33         res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  34         reg_base = devm_ioremap_resource(&pdev->dev, res_mem);
  35         if (IS_ERR(reg_base)) {
  36                 err = PTR_ERR(reg_base);
  37                 goto fail;
  38         }
  39
  40         p->register_base = reg_base;
  41         p->sys_freq = octeon_get_io_clock_rate();
  42
  43         p->regs.config = 0;
  44         p->regs.status = 0x08;
  45         p->regs.tx = 0x10;
  46         p->regs.data = 0x80;
  47
  48         master->num_chipselect = 4;
  49         master->mode_bits = SPI_CPHA |
  50                             SPI_CPOL |
  51                             SPI_CS_HIGH |
  52                             SPI_LSB_FIRST |
  53                             SPI_3WIRE;
  54
  55         master->transfer_one_message = octeon_spi_transfer_one_message;
  56         master->bits_per_word_mask = SPI_BPW_MASK(8);
  57         master->max_speed_hz = OCTEON_SPI_MAX_CLOCK_HZ;
  58
  59         master->dev.of_node = pdev->dev.of_node;
  60         err = devm_spi_register_master(&pdev->dev, master);
  61         if (err) {
  62                 dev_err(&pdev->dev, "register master failed: %d\n", err);
  63                 goto fail;
  64         }
  65
  66         dev_info(&pdev->dev, "OCTEON SPI bus driver\n");
  67
  68         return 0;
  69 fail:
  70         spi_master_put(master);
  71         return err;
  72 }
  73
  74 static int octeon_spi_remove(struct platform_device *pdev)
  75 {
  76         struct spi_master *master = platform_get_drvdata(pdev);
  77         struct octeon_spi *p = spi_master_get_devdata(master);
  78
  79         /* Clear the CSENA* and put everything in a known state. */
  80         writeq(0, p->register_base + OCTEON_SPI_CFG(p));
  81
  82         return 0;
  83 }
  84
  85 static const struct of_device_id octeon_spi_match[] = {
  86         { .compatible = "cavium,octeon-3010-spi", },
  87         {},
  88 };
  89 MODULE_DEVICE_TABLE(of, octeon_spi_match);
  90
  91 static struct platform_driver octeon_spi_driver = {
  92         .driver = {
  93                 .name           = "spi-octeon",
  94                 .of_match_table = octeon_spi_match,
  95         },
  96         .probe          = octeon_spi_probe,
  97         .remove         = octeon_spi_remove,
  98 };
  99
 100 module_platform_driver(octeon_spi_driver);
 101
 102 MODULE_DESCRIPTION("Cavium, Inc. OCTEON SPI bus driver");
 103 MODULE_AUTHOR("David Daney");
 104 MODULE_LICENSE("GPL");