1 files changed, 723 insertions, 0 deletions

diff --git a/drivers/comedi/drivers/gsc_hpdi.c b/drivers/comedi/drivers/gsc_hpdi.c
new file mode 100644
index 000000000000..e35e4a743714
--- /dev/null
+++ b/drivers/comedi/drivers/gsc_hpdi.c
@@ -0,0 +1,723 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * gsc_hpdi.c
+ * Comedi driver the General Standards Corporation
+ * High Speed Parallel Digital Interface rs485 boards.
+ *
+ * Author:  Frank Mori Hess <fmhess@users.sourceforge.net>
+ * Copyright (C) 2003 Coherent Imaging Systems
+ *
+ * COMEDI - Linux Control and Measurement Device Interface
+ * Copyright (C) 1997-8 David A. Schleef <ds@schleef.org>
+ */
+
+/*
+ * Driver: gsc_hpdi
+ * Description: General Standards Corporation High
+ *    Speed Parallel Digital Interface rs485 boards
+ * Author: Frank Mori Hess <fmhess@users.sourceforge.net>
+ * Status: only receive mode works, transmit not supported
+ * Updated: Thu, 01 Nov 2012 16:17:38 +0000
+ * Devices: [General Standards Corporation] PCI-HPDI32 (gsc_hpdi),
+ *   PMC-HPDI32
+ *
+ * Configuration options:
+ *    None.
+ *
+ * Manual configuration of supported devices is not supported; they are
+ * configured automatically.
+ *
+ * There are some additional hpdi models available from GSC for which
+ * support could be added to this driver.
+ */
+
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+
+#include "../comedi_pci.h"
+
+#include "plx9080.h"
+
+/*
+ * PCI BAR2 Register map (dev->mmio)
+ */
+#define FIRMWARE_REV_REG			0x00
+#define FEATURES_REG_PRESENT_BIT		BIT(15)
+#define BOARD_CONTROL_REG			0x04
+#define BOARD_RESET_BIT				BIT(0)
+#define TX_FIFO_RESET_BIT			BIT(1)
+#define RX_FIFO_RESET_BIT			BIT(2)
+#define TX_ENABLE_BIT				BIT(4)
+#define RX_ENABLE_BIT				BIT(5)
+#define DEMAND_DMA_DIRECTION_TX_BIT		BIT(6)  /* ch 0 only */
+#define LINE_VALID_ON_STATUS_VALID_BIT		BIT(7)
+#define START_TX_BIT				BIT(8)
+#define CABLE_THROTTLE_ENABLE_BIT		BIT(9)
+#define TEST_MODE_ENABLE_BIT			BIT(31)
+#define BOARD_STATUS_REG			0x08
+#define COMMAND_LINE_STATUS_MASK		(0x7f << 0)
+#define TX_IN_PROGRESS_BIT			BIT(7)
+#define TX_NOT_EMPTY_BIT			BIT(8)
+#define TX_NOT_ALMOST_EMPTY_BIT			BIT(9)
+#define TX_NOT_ALMOST_FULL_BIT			BIT(10)
+#define TX_NOT_FULL_BIT				BIT(11)
+#define RX_NOT_EMPTY_BIT			BIT(12)
+#define RX_NOT_ALMOST_EMPTY_BIT			BIT(13)
+#define RX_NOT_ALMOST_FULL_BIT			BIT(14)
+#define RX_NOT_FULL_BIT				BIT(15)
+#define BOARD_JUMPER0_INSTALLED_BIT		BIT(16)
+#define BOARD_JUMPER1_INSTALLED_BIT		BIT(17)
+#define TX_OVERRUN_BIT				BIT(21)
+#define RX_UNDERRUN_BIT				BIT(22)
+#define RX_OVERRUN_BIT				BIT(23)
+#define TX_PROG_ALMOST_REG			0x0c
+#define RX_PROG_ALMOST_REG			0x10
+#define ALMOST_EMPTY_BITS(x)			(((x) & 0xffff) << 0)
+#define ALMOST_FULL_BITS(x)			(((x) & 0xff) << 16)
+#define FEATURES_REG				0x14
+#define FIFO_SIZE_PRESENT_BIT			BIT(0)
+#define FIFO_WORDS_PRESENT_BIT			BIT(1)
+#define LEVEL_EDGE_INTERRUPTS_PRESENT_BIT	BIT(2)
+#define GPIO_SUPPORTED_BIT			BIT(3)
+#define PLX_DMA_CH1_SUPPORTED_BIT		BIT(4)
+#define OVERRUN_UNDERRUN_SUPPORTED_BIT		BIT(5)
+#define FIFO_REG				0x18
+#define TX_STATUS_COUNT_REG			0x1c
+#define TX_LINE_VALID_COUNT_REG			0x20,
+#define TX_LINE_INVALID_COUNT_REG		0x24
+#define RX_STATUS_COUNT_REG			0x28
+#define RX_LINE_COUNT_REG			0x2c
+#define INTERRUPT_CONTROL_REG			0x30
+#define FRAME_VALID_START_INTR			BIT(0)
+#define FRAME_VALID_END_INTR			BIT(1)
+#define TX_FIFO_EMPTY_INTR			BIT(8)
+#define TX_FIFO_ALMOST_EMPTY_INTR		BIT(9)
+#define TX_FIFO_ALMOST_FULL_INTR		BIT(10)
+#define TX_FIFO_FULL_INTR			BIT(11)
+#define RX_EMPTY_INTR				BIT(12)
+#define RX_ALMOST_EMPTY_INTR			BIT(13)
+#define RX_ALMOST_FULL_INTR			BIT(14)
+#define RX_FULL_INTR				BIT(15)
+#define INTERRUPT_STATUS_REG			0x34
+#define TX_CLOCK_DIVIDER_REG			0x38
+#define TX_FIFO_SIZE_REG			0x40
+#define RX_FIFO_SIZE_REG			0x44
+#define FIFO_SIZE_MASK				(0xfffff << 0)
+#define TX_FIFO_WORDS_REG			0x48
+#define RX_FIFO_WORDS_REG			0x4c
+#define INTERRUPT_EDGE_LEVEL_REG		0x50
+#define INTERRUPT_POLARITY_REG			0x54
+
+#define TIMER_BASE				50	/* 20MHz master clock */
+#define DMA_BUFFER_SIZE				0x10000
+#define NUM_DMA_BUFFERS				4
+#define NUM_DMA_DESCRIPTORS			256
+
+struct hpdi_private {
+	void __iomem *plx9080_mmio;
+	u32 *dio_buffer[NUM_DMA_BUFFERS];	/* dma buffers */
+	/* physical addresses of dma buffers */
+	dma_addr_t dio_buffer_phys_addr[NUM_DMA_BUFFERS];
+	/*
+	 * array of dma descriptors read by plx9080, allocated to get proper
+	 * alignment
+	 */
+	struct plx_dma_desc *dma_desc;
+	/* physical address of dma descriptor array */
+	dma_addr_t dma_desc_phys_addr;
+	unsigned int num_dma_descriptors;
+	/* pointer to start of buffers indexed by descriptor */
+	u32 *desc_dio_buffer[NUM_DMA_DESCRIPTORS];
+	/* index of the dma descriptor that is currently being used */
+	unsigned int dma_desc_index;
+	unsigned int tx_fifo_size;
+	unsigned int rx_fifo_size;
+	unsigned long dio_count;
+	/* number of bytes at which to generate COMEDI_CB_BLOCK events */
+	unsigned int block_size;
+};
+
+static void gsc_hpdi_drain_dma(struct comedi_device *dev, unsigned int channel)
+{
+	struct hpdi_private *devpriv = dev->private;
+	struct comedi_subdevice *s = dev->read_subdev;
+	struct comedi_cmd *cmd = &s->async->cmd;
+	unsigned int idx;
+	unsigned int start;
+	unsigned int desc;
+	unsigned int size;
+	unsigned int next;
+
+	next = readl(devpriv->plx9080_mmio + PLX_REG_DMAPADR(channel));
+
+	idx = devpriv->dma_desc_index;
+	start = le32_to_cpu(devpriv->dma_desc[idx].pci_start_addr);
+	/* loop until we have read all the full buffers */
+	for (desc = 0; (next < start || next >= start + devpriv->block_size) &&
+	     desc < devpriv->num_dma_descriptors; desc++) {
+		/* transfer data from dma buffer to comedi buffer */
+		size = devpriv->block_size / sizeof(u32);
+		if (cmd->stop_src == TRIG_COUNT) {
+			if (size > devpriv->dio_count)
+				size = devpriv->dio_count;
+			devpriv->dio_count -= size;
+		}
+		comedi_buf_write_samples(s, devpriv->desc_dio_buffer[idx],
+					 size);
+		idx++;
+		idx %= devpriv->num_dma_descriptors;
+		start = le32_to_cpu(devpriv->dma_desc[idx].pci_start_addr);
+
+		devpriv->dma_desc_index = idx;
+	}
+	/* XXX check for buffer overrun somehow */
+}
+
+static irqreturn_t gsc_hpdi_interrupt(int irq, void *d)
+{
+	struct comedi_device *dev = d;
+	struct hpdi_private *devpriv = dev->private;
+	struct comedi_subdevice *s = dev->read_subdev;
+	struct comedi_async *async = s->async;
+	u32 hpdi_intr_status, hpdi_board_status;
+	u32 plx_status;
+	u32 plx_bits;
+	u8 dma0_status, dma1_status;
+	unsigned long flags;
+
+	if (!dev->attached)
+		return IRQ_NONE;
+
+	plx_status = readl(devpriv->plx9080_mmio + PLX_REG_INTCSR);
+	if ((plx_status &
+	     (PLX_INTCSR_DMA0IA | PLX_INTCSR_DMA1IA | PLX_INTCSR_PLIA)) == 0)
+		return IRQ_NONE;
+
+	hpdi_intr_status = readl(dev->mmio + INTERRUPT_STATUS_REG);
+	hpdi_board_status = readl(dev->mmio + BOARD_STATUS_REG);
+
+	if (hpdi_intr_status)
+		writel(hpdi_intr_status, dev->mmio + INTERRUPT_STATUS_REG);
+
+	/* spin lock makes sure no one else changes plx dma control reg */
+	spin_lock_irqsave(&dev->spinlock, flags);
+	dma0_status = readb(devpriv->plx9080_mmio + PLX_REG_DMACSR0);
+	if (plx_status & PLX_INTCSR_DMA0IA) {
+		/* dma chan 0 interrupt */
+		writeb((dma0_status & PLX_DMACSR_ENABLE) | PLX_DMACSR_CLEARINTR,
+		       devpriv->plx9080_mmio + PLX_REG_DMACSR0);
+
+		if (dma0_status & PLX_DMACSR_ENABLE)
+			gsc_hpdi_drain_dma(dev, 0);
+	}
+	spin_unlock_irqrestore(&dev->spinlock, flags);
+
+	/* spin lock makes sure no one else changes plx dma control reg */
+	spin_lock_irqsave(&dev->spinlock, flags);
+	dma1_status = readb(devpriv->plx9080_mmio + PLX_REG_DMACSR1);
+	if (plx_status & PLX_INTCSR_DMA1IA) {
+		/* XXX */ /* dma chan 1 interrupt */
+		writeb((dma1_status & PLX_DMACSR_ENABLE) | PLX_DMACSR_CLEARINTR,
+		       devpriv->plx9080_mmio + PLX_REG_DMACSR1);
+	}
+	spin_unlock_irqrestore(&dev->spinlock, flags);
+
+	/* clear possible plx9080 interrupt sources */
+	if (plx_status & PLX_INTCSR_LDBIA) {
+		/* clear local doorbell interrupt */
+		plx_bits = readl(devpriv->plx9080_mmio + PLX_REG_L2PDBELL);
+		writel(plx_bits, devpriv->plx9080_mmio + PLX_REG_L2PDBELL);
+	}
+
+	if (hpdi_board_status & RX_OVERRUN_BIT) {
+		dev_err(dev->class_dev, "rx fifo overrun\n");
+		async->events |= COMEDI_CB_ERROR;
+	}
+
+	if (hpdi_board_status & RX_UNDERRUN_BIT) {
+		dev_err(dev->class_dev, "rx fifo underrun\n");
+		async->events |= COMEDI_CB_ERROR;
+	}
+
+	if (devpriv->dio_count == 0)
+		async->events |= COMEDI_CB_EOA;
+
+	comedi_handle_events(dev, s);
+
+	return IRQ_HANDLED;
+}
+
+static void gsc_hpdi_abort_dma(struct comedi_device *dev, unsigned int channel)
+{
+	struct hpdi_private *devpriv = dev->private;
+	unsigned long flags;
+
+	/* spinlock for plx dma control/status reg */
+	spin_lock_irqsave(&dev->spinlock, flags);
+
+	plx9080_abort_dma(devpriv->plx9080_mmio, channel);
+
+	spin_unlock_irqrestore(&dev->spinlock, flags);
+}
+
+static int gsc_hpdi_cancel(struct comedi_device *dev,
+			   struct comedi_subdevice *s)
+{
+	writel(0, dev->mmio + BOARD_CONTROL_REG);
+	writel(0, dev->mmio + INTERRUPT_CONTROL_REG);
+
+	gsc_hpdi_abort_dma(dev, 0);
+
+	return 0;
+}
+
+static int gsc_hpdi_cmd(struct comedi_device *dev,
+			struct comedi_subdevice *s)
+{
+	struct hpdi_private *devpriv = dev->private;
+	struct comedi_async *async = s->async;
+	struct comedi_cmd *cmd = &async->cmd;
+	unsigned long flags;
+	u32 bits;
+
+	if (s->io_bits)
+		return -EINVAL;
+
+	writel(RX_FIFO_RESET_BIT, dev->mmio + BOARD_CONTROL_REG);
+
+	gsc_hpdi_abort_dma(dev, 0);
+
+	devpriv->dma_desc_index = 0;
+
+	/*
+	 * These register are supposedly unused during chained dma,
+	 * but I have found that left over values from last operation
+	 * occasionally cause problems with transfer of first dma
+	 * block.  Initializing them to zero seems to fix the problem.
+	 */
+	writel(0, devpriv->plx9080_mmio + PLX_REG_DMASIZ0);
+	writel(0, devpriv->plx9080_mmio + PLX_REG_DMAPADR0);
+	writel(0, devpriv->plx9080_mmio + PLX_REG_DMALADR0);
+
+	/* give location of first dma descriptor */
+	bits = devpriv->dma_desc_phys_addr | PLX_DMADPR_DESCPCI |
+	       PLX_DMADPR_TCINTR | PLX_DMADPR_XFERL2P;
+	writel(bits, devpriv->plx9080_mmio + PLX_REG_DMADPR0);
+
+	/* enable dma transfer */
+	spin_lock_irqsave(&dev->spinlock, flags);
+	writeb(PLX_DMACSR_ENABLE | PLX_DMACSR_START | PLX_DMACSR_CLEARINTR,
+	       devpriv->plx9080_mmio + PLX_REG_DMACSR0);
+	spin_unlock_irqrestore(&dev->spinlock, flags);
+
+	if (cmd->stop_src == TRIG_COUNT)
+		devpriv->dio_count = cmd->stop_arg;
+	else
+		devpriv->dio_count = 1;
+
+	/* clear over/under run status flags */
+	writel(RX_UNDERRUN_BIT | RX_OVERRUN_BIT, dev->mmio + BOARD_STATUS_REG);
+
+	/* enable interrupts */
+	writel(RX_FULL_INTR, dev->mmio + INTERRUPT_CONTROL_REG);
+
+	writel(RX_ENABLE_BIT, dev->mmio + BOARD_CONTROL_REG);
+
+	return 0;
+}
+
+static int gsc_hpdi_check_chanlist(struct comedi_device *dev,
+				   struct comedi_subdevice *s,
+				   struct comedi_cmd *cmd)
+{
+	int i;
+
+	for (i = 0; i < cmd->chanlist_len; i++) {
+		unsigned int chan = CR_CHAN(cmd->chanlist[i]);
+
+		if (chan != i) {
+			dev_dbg(dev->class_dev,
+				"chanlist must be ch 0 to 31 in order\n");
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+static int gsc_hpdi_cmd_test(struct comedi_device *dev,
+			     struct comedi_subdevice *s,
+			     struct comedi_cmd *cmd)
+{
+	int err = 0;
+
+	if (s->io_bits)
+		return -EINVAL;
+
+	/* Step 1 : check if triggers are trivially valid */
+
+	err |= comedi_check_trigger_src(&cmd->start_src, TRIG_NOW);
+	err |= comedi_check_trigger_src(&cmd->scan_begin_src, TRIG_EXT);
+	err |= comedi_check_trigger_src(&cmd->convert_src, TRIG_NOW);
+	err |= comedi_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
+	err |= comedi_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);
+
+	if (err)
+		return 1;
+
+	/* Step 2a : make sure trigger sources are unique */
+
+	err |= comedi_check_trigger_is_unique(cmd->stop_src);
+
+	/* Step 2b : and mutually compatible */
+
+	if (err)
+		return 2;
+
+	/* Step 3: check if arguments are trivially valid */
+
+	err |= comedi_check_trigger_arg_is(&cmd->start_arg, 0);
+
+	if (!cmd->chanlist_len || !cmd->chanlist) {
+		cmd->chanlist_len = 32;
+		err |= -EINVAL;
+	}
+	err |= comedi_check_trigger_arg_is(&cmd->scan_end_arg,
+					   cmd->chanlist_len);
+
+	if (cmd->stop_src == TRIG_COUNT)
+		err |= comedi_check_trigger_arg_min(&cmd->stop_arg, 1);
+	else	/* TRIG_NONE */
+		err |= comedi_check_trigger_arg_is(&cmd->stop_arg, 0);
+
+	if (err)
+		return 3;
+
+	/* Step 4: fix up any arguments */
+
+	/* Step 5: check channel list if it exists */
+
+	if (cmd->chanlist && cmd->chanlist_len > 0)
+		err |= gsc_hpdi_check_chanlist(dev, s, cmd);
+
+	if (err)
+		return 5;
+
+	return 0;
+}
+
+/* setup dma descriptors so a link completes every 'len' bytes */
+static int gsc_hpdi_setup_dma_descriptors(struct comedi_device *dev,
+					  unsigned int len)
+{
+	struct hpdi_private *devpriv = dev->private;
+	dma_addr_t phys_addr = devpriv->dma_desc_phys_addr;
+	u32 next_bits = PLX_DMADPR_DESCPCI | PLX_DMADPR_TCINTR |
+			PLX_DMADPR_XFERL2P;
+	unsigned int offset = 0;
+	unsigned int idx = 0;
+	unsigned int i;
+
+	if (len > DMA_BUFFER_SIZE)
+		len = DMA_BUFFER_SIZE;
+	len -= len % sizeof(u32);
+	if (len == 0)
+		return -EINVAL;
+
+	for (i = 0; i < NUM_DMA_DESCRIPTORS && idx < NUM_DMA_BUFFERS; i++) {
+		devpriv->dma_desc[i].pci_start_addr =
+		    cpu_to_le32(devpriv->dio_buffer_phys_addr[idx] + offset);
+		devpriv->dma_desc[i].local_start_addr = cpu_to_le32(FIFO_REG);
+		devpriv->dma_desc[i].transfer_size = cpu_to_le32(len);
+		devpriv->dma_desc[i].next = cpu_to_le32((phys_addr +
+			(i + 1) * sizeof(devpriv->dma_desc[0])) | next_bits);
+
+		devpriv->desc_dio_buffer[i] = devpriv->dio_buffer[idx] +
+					      (offset / sizeof(u32));
+
+		offset += len;
+		if (len + offset > DMA_BUFFER_SIZE) {
+			offset = 0;
+			idx++;
+		}
+	}
+	devpriv->num_dma_descriptors = i;
+	/* fix last descriptor to point back to first */
+	devpriv->dma_desc[i - 1].next = cpu_to_le32(phys_addr | next_bits);
+
+	devpriv->block_size = len;
+
+	return len;
+}
+
+static int gsc_hpdi_dio_insn_config(struct comedi_device *dev,
+				    struct comedi_subdevice *s,
+				    struct comedi_insn *insn,
+				    unsigned int *data)
+{
+	int ret;
+
+	switch (data[0]) {
+	case INSN_CONFIG_BLOCK_SIZE:
+		ret = gsc_hpdi_setup_dma_descriptors(dev, data[1]);
+		if (ret)
+			return ret;
+
+		data[1] = ret;
+		break;
+	default:
+		ret = comedi_dio_insn_config(dev, s, insn, data, 0xffffffff);
+		if (ret)
+			return ret;
+		break;
+	}
+
+	return insn->n;
+}
+
+static void gsc_hpdi_free_dma(struct comedi_device *dev)
+{
+	struct pci_dev *pcidev = comedi_to_pci_dev(dev);
+	struct hpdi_private *devpriv = dev->private;
+	int i;
+
+	if (!devpriv)
+		return;
+
+	/* free pci dma buffers */
+	for (i = 0; i < NUM_DMA_BUFFERS; i++) {
+		if (devpriv->dio_buffer[i])
+			dma_free_coherent(&pcidev->dev,
+					  DMA_BUFFER_SIZE,
+					  devpriv->dio_buffer[i],
+					  devpriv->dio_buffer_phys_addr[i]);
+	}
+	/* free dma descriptors */
+	if (devpriv->dma_desc)
+		dma_free_coherent(&pcidev->dev,
+				  sizeof(struct plx_dma_desc) *
+				  NUM_DMA_DESCRIPTORS,
+				  devpriv->dma_desc,
+				  devpriv->dma_desc_phys_addr);
+}
+
+static int gsc_hpdi_init(struct comedi_device *dev)
+{
+	struct hpdi_private *devpriv = dev->private;
+	u32 plx_intcsr_bits;
+
+	/* wait 10usec after reset before accessing fifos */
+	writel(BOARD_RESET_BIT, dev->mmio + BOARD_CONTROL_REG);
+	usleep_range(10, 1000);
+
+	writel(ALMOST_EMPTY_BITS(32) | ALMOST_FULL_BITS(32),
+	       dev->mmio + RX_PROG_ALMOST_REG);
+	writel(ALMOST_EMPTY_BITS(32) | ALMOST_FULL_BITS(32),
+	       dev->mmio + TX_PROG_ALMOST_REG);
+
+	devpriv->tx_fifo_size = readl(dev->mmio + TX_FIFO_SIZE_REG) &
+				FIFO_SIZE_MASK;
+	devpriv->rx_fifo_size = readl(dev->mmio + RX_FIFO_SIZE_REG) &
+				FIFO_SIZE_MASK;
+
+	writel(0, dev->mmio + INTERRUPT_CONTROL_REG);
+
+	/* enable interrupts */
+	plx_intcsr_bits =
+	    PLX_INTCSR_LSEABORTEN | PLX_INTCSR_LSEPARITYEN | PLX_INTCSR_PIEN |
+	    PLX_INTCSR_PLIEN | PLX_INTCSR_PABORTIEN | PLX_INTCSR_LIOEN |
+	    PLX_INTCSR_DMA0IEN;
+	writel(plx_intcsr_bits, devpriv->plx9080_mmio + PLX_REG_INTCSR);
+
+	return 0;
+}
+
+static void gsc_hpdi_init_plx9080(struct comedi_device *dev)
+{
+	struct hpdi_private *devpriv = dev->private;
+	u32 bits;
+	void __iomem *plx_iobase = devpriv->plx9080_mmio;
+
+#ifdef __BIG_ENDIAN
+	bits = PLX_BIGEND_DMA0 | PLX_BIGEND_DMA1;
+#else
+	bits = 0;
+#endif
+	writel(bits, devpriv->plx9080_mmio + PLX_REG_BIGEND);
+
+	writel(0, devpriv->plx9080_mmio + PLX_REG_INTCSR);
+
+	gsc_hpdi_abort_dma(dev, 0);
+	gsc_hpdi_abort_dma(dev, 1);
+
+	/* configure dma0 mode */
+	bits = 0;
+	/* enable ready input */
+	bits |= PLX_DMAMODE_READYIEN;
+	/* enable dma chaining */
+	bits |= PLX_DMAMODE_CHAINEN;
+	/*
+	 * enable interrupt on dma done
+	 * (probably don't need this, since chain never finishes)
+	 */
+	bits |= PLX_DMAMODE_DONEIEN;
+	/*
+	 * don't increment local address during transfers
+	 * (we are transferring from a fixed fifo register)
+	 */
+	bits |= PLX_DMAMODE_LACONST;
+	/* route dma interrupt to pci bus */
+	bits |= PLX_DMAMODE_INTRPCI;
+	/* enable demand mode */
+	bits |= PLX_DMAMODE_DEMAND;
+	/* enable local burst mode */
+	bits |= PLX_DMAMODE_BURSTEN;
+	bits |= PLX_DMAMODE_WIDTH_32;
+	writel(bits, plx_iobase + PLX_REG_DMAMODE0);
+}
+
+static int gsc_hpdi_auto_attach(struct comedi_device *dev,
+				unsigned long context_unused)
+{
+	struct pci_dev *pcidev = comedi_to_pci_dev(dev);
+	struct hpdi_private *devpriv;
+	struct comedi_subdevice *s;
+	int i;
+	int retval;
+
+	dev->board_name = "pci-hpdi32";
+
+	devpriv = comedi_alloc_devpriv(dev, sizeof(*devpriv));
+	if (!devpriv)
+		return -ENOMEM;
+
+	retval = comedi_pci_enable(dev);
+	if (retval)
+		return retval;
+	pci_set_master(pcidev);
+
+	devpriv->plx9080_mmio = pci_ioremap_bar(pcidev, 0);
+	dev->mmio = pci_ioremap_bar(pcidev, 2);
+	if (!devpriv->plx9080_mmio || !dev->mmio) {
+		dev_warn(dev->class_dev, "failed to remap io memory\n");
+		return -ENOMEM;
+	}
+
+	gsc_hpdi_init_plx9080(dev);
+
+	/* get irq */
+	if (request_irq(pcidev->irq, gsc_hpdi_interrupt, IRQF_SHARED,
+			dev->board_name, dev)) {
+		dev_warn(dev->class_dev,
+			 "unable to allocate irq %u\n", pcidev->irq);
+		return -EINVAL;
+	}
+	dev->irq = pcidev->irq;
+
+	dev_dbg(dev->class_dev, " irq %u\n", dev->irq);
+
+	/* allocate pci dma buffers */
+	for (i = 0; i < NUM_DMA_BUFFERS; i++) {
+		devpriv->dio_buffer[i] =
+		    dma_alloc_coherent(&pcidev->dev, DMA_BUFFER_SIZE,
+				       &devpriv->dio_buffer_phys_addr[i],
+				       GFP_KERNEL);
+		if (!devpriv->dio_buffer[i]) {
+			dev_warn(dev->class_dev,
+				 "failed to allocate DMA buffer\n");
+			return -ENOMEM;
+		}
+	}
+	/* allocate dma descriptors */
+	devpriv->dma_desc = dma_alloc_coherent(&pcidev->dev,
+					       sizeof(struct plx_dma_desc) *
+					       NUM_DMA_DESCRIPTORS,
+					       &devpriv->dma_desc_phys_addr,
+					       GFP_KERNEL);
+	if (!devpriv->dma_desc) {
+		dev_warn(dev->class_dev,
+			 "failed to allocate DMA descriptors\n");
+		return -ENOMEM;
+	}
+	if (devpriv->dma_desc_phys_addr & 0xf) {
+		dev_warn(dev->class_dev,
+			 " dma descriptors not quad-word aligned (bug)\n");
+		return -EIO;
+	}
+
+	retval = gsc_hpdi_setup_dma_descriptors(dev, 0x1000);
+	if (retval < 0)
+		return retval;
+
+	retval = comedi_alloc_subdevices(dev, 1);
+	if (retval)
+		return retval;
+
+	/* Digital I/O subdevice */
+	s = &dev->subdevices[0];
+	dev->read_subdev = s;
+	s->type		= COMEDI_SUBD_DIO;
+	s->subdev_flags	= SDF_READABLE | SDF_WRITABLE | SDF_LSAMPL |
+			  SDF_CMD_READ;
+	s->n_chan	= 32;
+	s->len_chanlist	= 32;
+	s->maxdata	= 1;
+	s->range_table	= &range_digital;
+	s->insn_config	= gsc_hpdi_dio_insn_config;
+	s->do_cmd	= gsc_hpdi_cmd;
+	s->do_cmdtest	= gsc_hpdi_cmd_test;
+	s->cancel	= gsc_hpdi_cancel;
+
+	return gsc_hpdi_init(dev);
+}
+
+static void gsc_hpdi_detach(struct comedi_device *dev)
+{
+	struct hpdi_private *devpriv = dev->private;
+
+	if (dev->irq)
+		free_irq(dev->irq, dev);
+	if (devpriv) {
+		if (devpriv->plx9080_mmio) {
+			writel(0, devpriv->plx9080_mmio + PLX_REG_INTCSR);
+			iounmap(devpriv->plx9080_mmio);
+		}
+		if (dev->mmio)
+			iounmap(dev->mmio);
+	}
+	comedi_pci_disable(dev);
+	gsc_hpdi_free_dma(dev);
+}
+
+static struct comedi_driver gsc_hpdi_driver = {
+	.driver_name	= "gsc_hpdi",
+	.module		= THIS_MODULE,
+	.auto_attach	= gsc_hpdi_auto_attach,
+	.detach		= gsc_hpdi_detach,
+};
+
+static int gsc_hpdi_pci_probe(struct pci_dev *dev,
+			      const struct pci_device_id *id)
+{
+	return comedi_pci_auto_config(dev, &gsc_hpdi_driver, id->driver_data);
+}
+
+static const struct pci_device_id gsc_hpdi_pci_table[] = {
+	{ PCI_DEVICE_SUB(PCI_VENDOR_ID_PLX, PCI_DEVICE_ID_PLX_9080,
+			 PCI_VENDOR_ID_PLX, 0x2400) },
+	{ 0 }
+};
+MODULE_DEVICE_TABLE(pci, gsc_hpdi_pci_table);
+
+static struct pci_driver gsc_hpdi_pci_driver = {
+	.name		= "gsc_hpdi",
+	.id_table	= gsc_hpdi_pci_table,
+	.probe		= gsc_hpdi_pci_probe,
+	.remove		= comedi_pci_auto_unconfig,
+};
+module_comedi_pci_driver(gsc_hpdi_driver, gsc_hpdi_pci_driver);
+
+MODULE_AUTHOR("Comedi https://www.comedi.org");
+MODULE_DESCRIPTION("Comedi driver for General Standards PCI-HPDI32/PMC-HPDI32");
+MODULE_LICENSE("GPL");