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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * PCI driver for the High Speed UART DMA4 *5 * Copyright (C) 2015 Intel Corporation6 * Author: Andy Shevchenko <andriy.shevchenko@linux.intel.com>7 *8 * Partially based on the bits found in drivers/tty/serial/mfd.c.9 */10 11#include <linux/bitops.h>12#include <linux/device.h>13#include <linux/interrupt.h>14#include <linux/module.h>15#include <linux/pci.h>16 17#include "hsu.h"18 19#define HSU_PCI_DMASR 0x0020#define HSU_PCI_DMAISR 0x0421 22#define HSU_PCI_CHAN_OFFSET 0x10023 24#define PCI_DEVICE_ID_INTEL_MFLD_HSU_DMA 0x081e25#define PCI_DEVICE_ID_INTEL_MRFLD_HSU_DMA 0x119226 27static irqreturn_t hsu_pci_irq(int irq, void *dev)28{29 struct hsu_dma_chip *chip = dev;30 unsigned long dmaisr;31 unsigned short i;32 u32 status;33 int ret = 0;34 int err;35 36 dmaisr = readl(chip->regs + HSU_PCI_DMAISR);37 for_each_set_bit(i, &dmaisr, chip->hsu->nr_channels) {38 err = hsu_dma_get_status(chip, i, &status);39 if (err > 0)40 ret |= 1;41 else if (err == 0)42 ret |= hsu_dma_do_irq(chip, i, status);43 }44 45 return IRQ_RETVAL(ret);46}47 48static void hsu_pci_dma_remove(void *chip)49{50 hsu_dma_remove(chip);51}52 53static int hsu_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)54{55 struct device *dev = &pdev->dev;56 struct hsu_dma_chip *chip;57 int ret;58 59 ret = pcim_enable_device(pdev);60 if (ret)61 return ret;62 63 ret = pcim_iomap_regions(pdev, BIT(0), pci_name(pdev));64 if (ret) {65 dev_err(&pdev->dev, "I/O memory remapping failed\n");66 return ret;67 }68 69 pci_set_master(pdev);70 pci_try_set_mwi(pdev);71 72 ret = dma_set_mask_and_coherent(&pdev->dev, 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 ret = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_ALL_TYPES);81 if (ret < 0)82 return ret;83 84 chip->dev = &pdev->dev;85 chip->regs = pcim_iomap_table(pdev)[0];86 chip->length = pci_resource_len(pdev, 0);87 chip->offset = HSU_PCI_CHAN_OFFSET;88 chip->irq = pci_irq_vector(pdev, 0);89 90 ret = hsu_dma_probe(chip);91 if (ret)92 return ret;93 94 ret = devm_add_action_or_reset(dev, hsu_pci_dma_remove, chip);95 if (ret)96 return ret;97 98 ret = devm_request_irq(dev, chip->irq, hsu_pci_irq, 0, "hsu_dma_pci", chip);99 if (ret)100 return ret;101 102 /*103 * On Intel Tangier B0 and Anniedale the interrupt line, disregarding104 * to have different numbers, is shared between HSU DMA and UART IPs.105 * Thus on such SoCs we are expecting that IRQ handler is called in106 * UART driver only. Instead of handling the spurious interrupt107 * from HSU DMA here and waste CPU time and delay HSU UART interrupt108 * handling, disable the interrupt entirely.109 */110 if (pdev->device == PCI_DEVICE_ID_INTEL_MRFLD_HSU_DMA)111 disable_irq_nosync(chip->irq);112 113 pci_set_drvdata(pdev, chip);114 115 return 0;116}117 118static const struct pci_device_id hsu_pci_id_table[] = {119 { PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_MFLD_HSU_DMA), 0 },120 { PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_MRFLD_HSU_DMA), 0 },121 { }122};123MODULE_DEVICE_TABLE(pci, hsu_pci_id_table);124 125static struct pci_driver hsu_pci_driver = {126 .name = "hsu_dma_pci",127 .id_table = hsu_pci_id_table,128 .probe = hsu_pci_probe,129};130 131module_pci_driver(hsu_pci_driver);132 133MODULE_LICENSE("GPL v2");134MODULE_DESCRIPTION("High Speed UART DMA PCI driver");135MODULE_AUTHOR("Andy Shevchenko <andriy.shevchenko@linux.intel.com>");136