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         u32 status;
  31         unsigned short i;
  32         irqreturn_t ret = IRQ_NONE;
  33         int err;
  34
  35         dmaisr = readl(chip->regs + HSU_PCI_DMAISR);
  36         for (i = 0; i < chip->hsu->nr_channels; i++) {
  37                 if (dmaisr & 0x1) {
  38                         err = hsu_dma_get_status(chip, i, &status);
  39                         if (err > 0)
  40                                 ret |= IRQ_HANDLED;
  41                         else if (err == 0)
  42                                 ret |= hsu_dma_do_irq(chip, i, status);
  43                 }
  44                 dmaisr >>= 1;
  45         }
  46
  47         return ret;
  48 }
  49
  50 static int hsu_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
  51 {
  52         struct hsu_dma_chip *chip;
  53         int ret;
  54
  55         ret = pcim_enable_device(pdev);
  56         if (ret)
  57                 return ret;
  58
  59         ret = pcim_iomap_regions(pdev, BIT(0), pci_name(pdev));
  60         if (ret) {
  61                 dev_err(&pdev->dev, "I/O memory remapping failed\n");
  62                 return ret;
  63         }
  64
  65         pci_set_master(pdev);
  66         pci_try_set_mwi(pdev);
  67
  68         ret = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
  69         if (ret)
  70                 return ret;
  71
  72         ret = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(32));
  73         if (ret)
  74                 return ret;
  75
  76         chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
  77         if (!chip)
  78                 return -ENOMEM;
  79
  80         chip->dev = &pdev->dev;
  81         chip->regs = pcim_iomap_table(pdev)[0];
  82         chip->length = pci_resource_len(pdev, 0);
  83         chip->offset = HSU_PCI_CHAN_OFFSET;
  84         chip->irq = pdev->irq;
  85
  86         pci_enable_msi(pdev);
  87
  88         ret = hsu_dma_probe(chip);
  89         if (ret)
  90                 return ret;
  91
  92         ret = request_irq(chip->irq, hsu_pci_irq, 0, "hsu_dma_pci", chip);
  93         if (ret)
  94                 goto err_register_irq;
  95
  96         pci_set_drvdata(pdev, chip);
  97
  98         return 0;
  99
 100 err_register_irq:
 101         hsu_dma_remove(chip);
 102         return ret;
 103 }
 104
 105 static void hsu_pci_remove(struct pci_dev *pdev)
 106 {
 107         struct hsu_dma_chip *chip = pci_get_drvdata(pdev);
 108
 109         free_irq(chip->irq, chip);
 110         hsu_dma_remove(chip);
 111 }
 112
 113 static const struct pci_device_id hsu_pci_id_table[] = {
 114         { PCI_VDEVICE(INTEL, 0x081e), 0 },
 115         { PCI_VDEVICE(INTEL, 0x1192), 0 },
 116         { }
 117 };
 118 MODULE_DEVICE_TABLE(pci, hsu_pci_id_table);
 119
 120 static struct pci_driver hsu_pci_driver = {
 121         .name           = "hsu_dma_pci",
 122         .id_table       = hsu_pci_id_table,
 123         .probe          = hsu_pci_probe,
 124         .remove         = hsu_pci_remove,
 125 };
 126
 127 module_pci_driver(hsu_pci_driver);
 128
 129 MODULE_LICENSE("GPL v2");
 130 MODULE_DESCRIPTION("High Speed UART DMA PCI driver");
 131 MODULE_AUTHOR("Andy Shevchenko <andriy.shevchenko@linux.intel.com>");