drivers/dma/hsu/pci.c

   1 /*
   2  * PCI driver for the High Speed UART DMA
   3  *
   4  * Copyright (C) 2015 Intel Corporation
   5  * Author: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
   6  *
   7  * Partially based on the bits found in drivers/tty/serial/mfd.c.
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  */
  13
  14 #include <linux/bitops.h>
  15 #include <linux/device.h>
  16 #include <linux/module.h>
  17 #include <linux/pci.h>
  18
  19 #include "hsu.h"
  20
  21 #define HSU_PCI_DMASR           0x00
  22 #define HSU_PCI_DMAISR          0x04
  23
  24 #define HSU_PCI_CHAN_OFFSET     0x100
  25
  26 static irqreturn_t hsu_pci_irq(int irq, void *dev)
  27 {
  28         struct hsu_dma_chip *chip = dev;
  29         u32 dmaisr;
  30         unsigned short i;
  31         irqreturn_t ret = IRQ_NONE;
  32
  33         dmaisr = readl(chip->regs + HSU_PCI_DMAISR);
  34         for (i = 0; i < chip->pdata->nr_channels; i++) {
  35                 if (dmaisr & 0x1)
  36                         ret |= hsu_dma_irq(chip, i);
  37                 dmaisr >>= 1;
  38         }
  39
  40         return ret;
  41 }
  42
  43 static int hsu_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
  44 {
  45         struct hsu_dma_chip *chip;
  46         int ret;
  47
  48         ret = pcim_enable_device(pdev);
  49         if (ret)
  50                 return ret;
  51
  52         ret = pcim_iomap_regions(pdev, BIT(0), pci_name(pdev));
  53         if (ret) {
  54                 dev_err(&pdev->dev, "I/O memory remapping failed\n");
  55                 return ret;
  56         }
  57
  58         pci_set_master(pdev);
  59         pci_try_set_mwi(pdev);
  60
  61         ret = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
  62         if (ret)
  63                 return ret;
  64
  65         ret = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(32));
  66         if (ret)
  67                 return ret;
  68
  69         chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
  70         if (!chip)
  71                 return -ENOMEM;
  72
  73         chip->dev = &pdev->dev;
  74         chip->regs = pcim_iomap_table(pdev)[0];
  75         chip->length = pci_resource_len(pdev, 0);
  76         chip->offset = HSU_PCI_CHAN_OFFSET;
  77         chip->irq = pdev->irq;
  78
  79         pci_enable_msi(pdev);
  80
  81         ret = hsu_dma_probe(chip);
  82         if (ret)
  83                 return ret;
  84
  85         ret = request_irq(chip->irq, hsu_pci_irq, 0, "hsu_dma_pci", chip);
  86         if (ret)
  87                 goto err_register_irq;
  88
  89         pci_set_drvdata(pdev, chip);
  90
  91         return 0;
  92
  93 err_register_irq:
  94         hsu_dma_remove(chip);
  95         return ret;
  96 }
  97
  98 static void hsu_pci_remove(struct pci_dev *pdev)
  99 {
 100         struct hsu_dma_chip *chip = pci_get_drvdata(pdev);
 101
 102         free_irq(chip->irq, chip);
 103         hsu_dma_remove(chip);
 104 }
 105
 106 static const struct pci_device_id hsu_pci_id_table[] = {
 107         { PCI_VDEVICE(INTEL, 0x081e), 0 },
 108         { PCI_VDEVICE(INTEL, 0x1192), 0 },
 109         { }
 110 };
 111 MODULE_DEVICE_TABLE(pci, hsu_pci_id_table);
 112
 113 static struct pci_driver hsu_pci_driver = {
 114         .name           = "hsu_dma_pci",
 115         .id_table       = hsu_pci_id_table,
 116         .probe          = hsu_pci_probe,
 117         .remove         = hsu_pci_remove,
 118 };
 119
 120 module_pci_driver(hsu_pci_driver);
 121
 122 MODULE_LICENSE("GPL v2");
 123 MODULE_DESCRIPTION("High Speed UART DMA PCI driver");
 124 MODULE_AUTHOR("Andy Shevchenko <andriy.shevchenko@linux.intel.com>");