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         void __iomem *reg_base;
  22         struct spi_master *master;
  23         struct octeon_spi *p;
  24         int err = -ENOENT;
  25
  26         master = spi_alloc_master(&pdev->dev, sizeof(struct octeon_spi));
  27         if (!master)
  28                 return -ENOMEM;
  29         p = spi_master_get_devdata(master);
  30         platform_set_drvdata(pdev, master);
  31
  32         reg_base = devm_platform_ioremap_resource(pdev, 0);
  33         if (IS_ERR(reg_base)) {
  34                 err = PTR_ERR(reg_base);
  35                 goto fail;
  36         }
  37
  38         p->register_base = reg_base;
  39         p->sys_freq = octeon_get_io_clock_rate();
  40
  41         p->regs.config = 0;
  42         p->regs.status = 0x08;
  43         p->regs.tx = 0x10;
  44         p->regs.data = 0x80;
  45
  46         master->num_chipselect = 4;
  47         master->mode_bits = SPI_CPHA |
  48                             SPI_CPOL |
  49                             SPI_CS_HIGH |
  50                             SPI_LSB_FIRST |
  51                             SPI_3WIRE;
  52
  53         master->transfer_one_message = octeon_spi_transfer_one_message;
  54         master->bits_per_word_mask = SPI_BPW_MASK(8);
  55         master->max_speed_hz = OCTEON_SPI_MAX_CLOCK_HZ;
  56
  57         master->dev.of_node = pdev->dev.of_node;
  58         err = devm_spi_register_master(&pdev->dev, master);
  59         if (err) {
  60                 dev_err(&pdev->dev, "register master failed: %d\n", err);
  61                 goto fail;
  62         }
  63
  64         dev_info(&pdev->dev, "OCTEON SPI bus driver\n");
  65
  66         return 0;
  67 fail:
  68         spi_master_put(master);
  69         return err;
  70 }
  71
  72 static int octeon_spi_remove(struct platform_device *pdev)
  73 {
  74         struct spi_master *master = platform_get_drvdata(pdev);
  75         struct octeon_spi *p = spi_master_get_devdata(master);
  76
  77         /* Clear the CSENA* and put everything in a known state. */
  78         writeq(0, p->register_base + OCTEON_SPI_CFG(p));
  79
  80         return 0;
  81 }
  82
  83 static const struct of_device_id octeon_spi_match[] = {
  84         { .compatible = "cavium,octeon-3010-spi", },
  85         {},
  86 };
  87 MODULE_DEVICE_TABLE(of, octeon_spi_match);
  88
  89 static struct platform_driver octeon_spi_driver = {
  90         .driver = {
  91                 .name           = "spi-octeon",
  92                 .of_match_table = octeon_spi_match,
  93         },
  94         .probe          = octeon_spi_probe,
  95         .remove         = octeon_spi_remove,
  96 };
  97
  98 module_platform_driver(octeon_spi_driver);
  99
 100 MODULE_DESCRIPTION("Cavium, Inc. OCTEON SPI bus driver");
 101 MODULE_AUTHOR("David Daney");
 102 MODULE_LICENSE("GPL");