drivers/spi/spi-cavium-thunderx.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Cavium ThunderX SPI driver.
   4  *
   5  * Copyright (C) 2016 Cavium Inc.
   6  * Authors: Jan Glauber <jglauber@cavium.com>
   7  */
   8
   9 #include <linux/module.h>
  10 #include <linux/pci.h>
  11 #include <linux/spi/spi.h>
  12
  13 #include "spi-cavium.h"
  14
  15 #define DRV_NAME "spi-thunderx"
  16
  17 #define SYS_FREQ_DEFAULT 700000000 /* 700 Mhz */
  18
  19 static int thunderx_spi_probe(struct pci_dev *pdev,
  20                               const struct pci_device_id *ent)
  21 {
  22         struct device *dev = &pdev->dev;
  23         struct spi_master *master;
  24         struct octeon_spi *p;
  25         int ret;
  26
  27         master = spi_alloc_master(dev, sizeof(struct octeon_spi));
  28         if (!master)
  29                 return -ENOMEM;
  30
  31         p = spi_master_get_devdata(master);
  32
  33         ret = pcim_enable_device(pdev);
  34         if (ret)
  35                 goto error;
  36
  37         ret = pci_request_regions(pdev, DRV_NAME);
  38         if (ret)
  39                 goto error;
  40
  41         p->register_base = pcim_iomap(pdev, 0, pci_resource_len(pdev, 0));
  42         if (!p->register_base) {
  43                 ret = -EINVAL;
  44                 goto error;
  45         }
  46
  47         p->regs.config = 0x1000;
  48         p->regs.status = 0x1008;
  49         p->regs.tx = 0x1010;
  50         p->regs.data = 0x1080;
  51
  52         p->clk = devm_clk_get(dev, NULL);
  53         if (IS_ERR(p->clk)) {
  54                 ret = PTR_ERR(p->clk);
  55                 goto error;
  56         }
  57
  58         ret = clk_prepare_enable(p->clk);
  59         if (ret)
  60                 goto error;
  61
  62         p->sys_freq = clk_get_rate(p->clk);
  63         if (!p->sys_freq)
  64                 p->sys_freq = SYS_FREQ_DEFAULT;
  65         dev_info(dev, "Set system clock to %u\n", p->sys_freq);
  66
  67         master->flags = SPI_MASTER_HALF_DUPLEX;
  68         master->num_chipselect = 4;
  69         master->mode_bits = SPI_CPHA | SPI_CPOL | SPI_CS_HIGH |
  70                             SPI_LSB_FIRST | SPI_3WIRE;
  71         master->transfer_one_message = octeon_spi_transfer_one_message;
  72         master->bits_per_word_mask = SPI_BPW_MASK(8);
  73         master->max_speed_hz = OCTEON_SPI_MAX_CLOCK_HZ;
  74         master->dev.of_node = pdev->dev.of_node;
  75
  76         pci_set_drvdata(pdev, master);
  77
  78         ret = devm_spi_register_master(dev, master);
  79         if (ret)
  80                 goto error;
  81
  82         return 0;
  83
  84 error:
  85         clk_disable_unprepare(p->clk);
  86         pci_release_regions(pdev);
  87         spi_master_put(master);
  88         return ret;
  89 }
  90
  91 static void thunderx_spi_remove(struct pci_dev *pdev)
  92 {
  93         struct spi_master *master = pci_get_drvdata(pdev);
  94         struct octeon_spi *p;
  95
  96         p = spi_master_get_devdata(master);
  97         if (!p)
  98                 return;
  99
 100         clk_disable_unprepare(p->clk);
 101         pci_release_regions(pdev);
 102         /* Put everything in a known state. */
 103         writeq(0, p->register_base + OCTEON_SPI_CFG(p));
 104 }
 105
 106 static const struct pci_device_id thunderx_spi_pci_id_table[] = {
 107         { PCI_DEVICE(PCI_VENDOR_ID_CAVIUM, 0xa00b) },
 108         { 0, }
 109 };
 110
 111 MODULE_DEVICE_TABLE(pci, thunderx_spi_pci_id_table);
 112
 113 static struct pci_driver thunderx_spi_driver = {
 114         .name           = DRV_NAME,
 115         .id_table       = thunderx_spi_pci_id_table,
 116         .probe          = thunderx_spi_probe,
 117         .remove         = thunderx_spi_remove,
 118 };
 119
 120 module_pci_driver(thunderx_spi_driver);
 121
 122 MODULE_DESCRIPTION("Cavium, Inc. ThunderX SPI bus driver");
 123 MODULE_AUTHOR("Jan Glauber");
 124 MODULE_LICENSE("GPL");