linux/drivers/dma/hsu/pci.c
Chuah, Kim Tatt c6f82787a5 dmaengine: hsu: Export hsu_dma_get_status()
To allow other code to safely read DMA Channel Status Register (where
the register attribute for Channel Error, Descriptor Time Out &
Descriptor Done fields are read-clear), export hsu_dma_get_status().
hsu_dma_irq() is renamed to hsu_dma_do_irq() and requires Status
Register value to be passed in.

Signed-off-by: Chuah, Kim Tatt <kim.tatt.chuah@intel.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-25 14:30:42 -07:00

132 lines
2.8 KiB
C

/*
* PCI driver for the High Speed UART DMA
*
* Copyright (C) 2015 Intel Corporation
* Author: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
*
* Partially based on the bits found in drivers/tty/serial/mfd.c.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/bitops.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/pci.h>
#include "hsu.h"
#define HSU_PCI_DMASR 0x00
#define HSU_PCI_DMAISR 0x04
#define HSU_PCI_CHAN_OFFSET 0x100
static irqreturn_t hsu_pci_irq(int irq, void *dev)
{
struct hsu_dma_chip *chip = dev;
u32 dmaisr;
u32 status;
unsigned short i;
irqreturn_t ret = IRQ_NONE;
int err;
dmaisr = readl(chip->regs + HSU_PCI_DMAISR);
for (i = 0; i < chip->hsu->nr_channels; i++) {
if (dmaisr & 0x1) {
err = hsu_dma_get_status(chip, i, &status);
if (err > 0)
ret |= IRQ_HANDLED;
else if (err == 0)
ret |= hsu_dma_do_irq(chip, i, status);
}
dmaisr >>= 1;
}
return ret;
}
static int hsu_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
{
struct hsu_dma_chip *chip;
int ret;
ret = pcim_enable_device(pdev);
if (ret)
return ret;
ret = pcim_iomap_regions(pdev, BIT(0), pci_name(pdev));
if (ret) {
dev_err(&pdev->dev, "I/O memory remapping failed\n");
return ret;
}
pci_set_master(pdev);
pci_try_set_mwi(pdev);
ret = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
if (ret)
return ret;
ret = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(32));
if (ret)
return ret;
chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
if (!chip)
return -ENOMEM;
chip->dev = &pdev->dev;
chip->regs = pcim_iomap_table(pdev)[0];
chip->length = pci_resource_len(pdev, 0);
chip->offset = HSU_PCI_CHAN_OFFSET;
chip->irq = pdev->irq;
pci_enable_msi(pdev);
ret = hsu_dma_probe(chip);
if (ret)
return ret;
ret = request_irq(chip->irq, hsu_pci_irq, 0, "hsu_dma_pci", chip);
if (ret)
goto err_register_irq;
pci_set_drvdata(pdev, chip);
return 0;
err_register_irq:
hsu_dma_remove(chip);
return ret;
}
static void hsu_pci_remove(struct pci_dev *pdev)
{
struct hsu_dma_chip *chip = pci_get_drvdata(pdev);
free_irq(chip->irq, chip);
hsu_dma_remove(chip);
}
static const struct pci_device_id hsu_pci_id_table[] = {
{ PCI_VDEVICE(INTEL, 0x081e), 0 },
{ PCI_VDEVICE(INTEL, 0x1192), 0 },
{ }
};
MODULE_DEVICE_TABLE(pci, hsu_pci_id_table);
static struct pci_driver hsu_pci_driver = {
.name = "hsu_dma_pci",
.id_table = hsu_pci_id_table,
.probe = hsu_pci_probe,
.remove = hsu_pci_remove,
};
module_pci_driver(hsu_pci_driver);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("High Speed UART DMA PCI driver");
MODULE_AUTHOR("Andy Shevchenko <andriy.shevchenko@linux.intel.com>");