LXR linux/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#define PCI_DEVICE_ID_INTEL_MFLD_HSU_DMA        0x081e
  27#define PCI_DEVICE_ID_INTEL_MRFLD_HSU_DMA       0x1192
  28
  29static irqreturn_t hsu_pci_irq(int irq, void *dev)
  30{
  31        struct hsu_dma_chip *chip = dev;
  32        struct pci_dev *pdev = to_pci_dev(chip->dev);
  33        u32 dmaisr;
  34        u32 status;
  35        unsigned short i;
  36        int ret = 0;
  37        int err;
  38
  39        /*
  40         * On Intel Tangier B0 and Anniedale the interrupt line, disregarding
  41         * to have different numbers, is shared between HSU DMA and UART IPs.
  42         * Thus on such SoCs we are expecting that IRQ handler is called in
  43         * UART driver only.
  44         */
  45        if (pdev->device == PCI_DEVICE_ID_INTEL_MRFLD_HSU_DMA)
  46                return IRQ_HANDLED;
  47
  48        dmaisr = readl(chip->regs + HSU_PCI_DMAISR);
  49        for (i = 0; i < chip->hsu->nr_channels; i++) {
  50                if (dmaisr & 0x1) {
  51                        err = hsu_dma_get_status(chip, i, &status);
  52                        if (err > 0)
  53                                ret |= 1;
  54                        else if (err == 0)
  55                                ret |= hsu_dma_do_irq(chip, i, status);
  56                }
  57                dmaisr >>= 1;
  58        }
  59
  60        return IRQ_RETVAL(ret);
  61}
  62
  63static int hsu_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
  64{
  65        struct hsu_dma_chip *chip;
  66        int ret;
  67
  68        ret = pcim_enable_device(pdev);
  69        if (ret)
  70                return ret;
  71
  72        ret = pcim_iomap_regions(pdev, BIT(0), pci_name(pdev));
  73        if (ret) {
  74                dev_err(&pdev->dev, "I/O memory remapping failed\n");
  75                return ret;
  76        }
  77
  78        pci_set_master(pdev);
  79        pci_try_set_mwi(pdev);
  80
  81        ret = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
  82        if (ret)
  83                return ret;
  84
  85        ret = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(32));
  86        if (ret)
  87                return ret;
  88
  89        chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
  90        if (!chip)
  91                return -ENOMEM;
  92
  93        ret = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_ALL_TYPES);
  94        if (ret < 0)
  95                return ret;
  96
  97        chip->dev = &pdev->dev;
  98        chip->regs = pcim_iomap_table(pdev)[0];
  99        chip->length = pci_resource_len(pdev, 0);
 100        chip->offset = HSU_PCI_CHAN_OFFSET;
 101        chip->irq = pci_irq_vector(pdev, 0);
 102
 103        ret = hsu_dma_probe(chip);
 104        if (ret)
 105                return ret;
 106
 107        ret = request_irq(chip->irq, hsu_pci_irq, 0, "hsu_dma_pci", chip);
 108        if (ret)
 109                goto err_register_irq;
 110
 111        pci_set_drvdata(pdev, chip);
 112
 113        return 0;
 114
 115err_register_irq:
 116        hsu_dma_remove(chip);
 117        return ret;
 118}
 119
 120static void hsu_pci_remove(struct pci_dev *pdev)
 121{
 122        struct hsu_dma_chip *chip = pci_get_drvdata(pdev);
 123
 124        free_irq(chip->irq, chip);
 125        hsu_dma_remove(chip);
 126}
 127
 128static const struct pci_device_id hsu_pci_id_table[] = {
 129        { PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_MFLD_HSU_DMA), 0 },
 130        { PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_MRFLD_HSU_DMA), 0 },
 131        { }
 132};
 133MODULE_DEVICE_TABLE(pci, hsu_pci_id_table);
 134
 135static struct pci_driver hsu_pci_driver = {
 136        .name           = "hsu_dma_pci",
 137        .id_table       = hsu_pci_id_table,
 138        .probe          = hsu_pci_probe,
 139        .remove         = hsu_pci_remove,
 140};
 141
 142module_pci_driver(hsu_pci_driver);
 143
 144MODULE_LICENSE("GPL v2");
 145MODULE_DESCRIPTION("High Speed UART DMA PCI driver");
 146MODULE_AUTHOR("Andy Shevchenko <andriy.shevchenko@linux.intel.com>");
 147