dmaengine: append hsu DMA driver

The HSU DMA is developed to support High Speed UART controllers found in
particular on Intel MID platforms such as Intel Medfield.

The existing implementation is tighten to the drivers/tty/serial/mfd.c driver
and has a lot of disadvantages. Besides that we would like to get rid of the
old HS UART driver in regarding to extending the 8250 which supports generic
DMAEngine API. That's why the current driver has been developed.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 123 insertions, 0 deletions

diff --git a/drivers/dma/hsu/pci.c b/drivers/dma/hsu/pci.c
new file mode 100644
index 000000000000..563b4685d766
--- /dev/null
+++ b/drivers/dma/hsu/pci.c
@@ -0,0 +1,123 @@
+/*
+ * 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;
+	unsigned short i;
+	irqreturn_t ret = IRQ_NONE;
+
+	dmaisr = readl(chip->regs + HSU_PCI_DMAISR);
+	for (i = 0; i < chip->pdata->nr_channels; i++) {
+		if (dmaisr & 0x1)
+			ret |= hsu_dma_irq(chip, i);
+		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 },
+	{ }
+};
+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>");