Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1396 insertions, 0 deletions

diff --git a/drivers/iio/adc/xilinx-xadc-core.c b/drivers/iio/adc/xilinx-xadc-core.c
new file mode 100644
index 000000000..1b0046cc7
--- /dev/null
+++ b/drivers/iio/adc/xilinx-xadc-core.c
@@ -0,0 +1,1396 @@
+/*
+ * Xilinx XADC driver
+ *
+ * Copyright 2013-2014 Analog Devices Inc.
+ *  Author: Lars-Peter Clauen <lars@metafoo.de>
+ *
+ * Licensed under the GPL-2.
+ *
+ * Documentation for the parts can be found at:
+ *  - XADC hardmacro: Xilinx UG480
+ *  - ZYNQ XADC interface: Xilinx UG585
+ *  - AXI XADC interface: Xilinx PG019
+ */
+
+#include <linux/clk.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+
+#include <linux/iio/buffer.h>
+#include <linux/iio/events.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+
+#include "xilinx-xadc.h"
+
+static const unsigned int XADC_ZYNQ_UNMASK_TIMEOUT = 500;
+
+/* ZYNQ register definitions */
+#define XADC_ZYNQ_REG_CFG	0x00
+#define XADC_ZYNQ_REG_INTSTS	0x04
+#define XADC_ZYNQ_REG_INTMSK	0x08
+#define XADC_ZYNQ_REG_STATUS	0x0c
+#define XADC_ZYNQ_REG_CFIFO	0x10
+#define XADC_ZYNQ_REG_DFIFO	0x14
+#define XADC_ZYNQ_REG_CTL		0x18
+
+#define XADC_ZYNQ_CFG_ENABLE		BIT(31)
+#define XADC_ZYNQ_CFG_CFIFOTH_MASK	(0xf << 20)
+#define XADC_ZYNQ_CFG_CFIFOTH_OFFSET	20
+#define XADC_ZYNQ_CFG_DFIFOTH_MASK	(0xf << 16)
+#define XADC_ZYNQ_CFG_DFIFOTH_OFFSET	16
+#define XADC_ZYNQ_CFG_WEDGE		BIT(13)
+#define XADC_ZYNQ_CFG_REDGE		BIT(12)
+#define XADC_ZYNQ_CFG_TCKRATE_MASK	(0x3 << 8)
+#define XADC_ZYNQ_CFG_TCKRATE_DIV2	(0x0 << 8)
+#define XADC_ZYNQ_CFG_TCKRATE_DIV4	(0x1 << 8)
+#define XADC_ZYNQ_CFG_TCKRATE_DIV8	(0x2 << 8)
+#define XADC_ZYNQ_CFG_TCKRATE_DIV16	(0x3 << 8)
+#define XADC_ZYNQ_CFG_IGAP_MASK		0x1f
+#define XADC_ZYNQ_CFG_IGAP(x)		(x)
+
+#define XADC_ZYNQ_INT_CFIFO_LTH		BIT(9)
+#define XADC_ZYNQ_INT_DFIFO_GTH		BIT(8)
+#define XADC_ZYNQ_INT_ALARM_MASK	0xff
+#define XADC_ZYNQ_INT_ALARM_OFFSET	0
+
+#define XADC_ZYNQ_STATUS_CFIFO_LVL_MASK	(0xf << 16)
+#define XADC_ZYNQ_STATUS_CFIFO_LVL_OFFSET	16
+#define XADC_ZYNQ_STATUS_DFIFO_LVL_MASK	(0xf << 12)
+#define XADC_ZYNQ_STATUS_DFIFO_LVL_OFFSET	12
+#define XADC_ZYNQ_STATUS_CFIFOF		BIT(11)
+#define XADC_ZYNQ_STATUS_CFIFOE		BIT(10)
+#define XADC_ZYNQ_STATUS_DFIFOF		BIT(9)
+#define XADC_ZYNQ_STATUS_DFIFOE		BIT(8)
+#define XADC_ZYNQ_STATUS_OT		BIT(7)
+#define XADC_ZYNQ_STATUS_ALM(x)		BIT(x)
+
+#define XADC_ZYNQ_CTL_RESET		BIT(4)
+
+#define XADC_ZYNQ_CMD_NOP		0x00
+#define XADC_ZYNQ_CMD_READ		0x01
+#define XADC_ZYNQ_CMD_WRITE		0x02
+
+#define XADC_ZYNQ_CMD(cmd, addr, data) (((cmd) << 26) | ((addr) << 16) | (data))
+
+/* AXI register definitions */
+#define XADC_AXI_REG_RESET		0x00
+#define XADC_AXI_REG_STATUS		0x04
+#define XADC_AXI_REG_ALARM_STATUS	0x08
+#define XADC_AXI_REG_CONVST		0x0c
+#define XADC_AXI_REG_XADC_RESET		0x10
+#define XADC_AXI_REG_GIER		0x5c
+#define XADC_AXI_REG_IPISR		0x60
+#define XADC_AXI_REG_IPIER		0x68
+#define XADC_AXI_ADC_REG_OFFSET		0x200
+
+#define XADC_AXI_RESET_MAGIC		0xa
+#define XADC_AXI_GIER_ENABLE		BIT(31)
+
+#define XADC_AXI_INT_EOS		BIT(4)
+#define XADC_AXI_INT_ALARM_MASK		0x3c0f
+
+#define XADC_FLAGS_BUFFERED BIT(0)
+
+/*
+ * The XADC hardware supports a samplerate of up to 1MSPS. Unfortunately it does
+ * not have a hardware FIFO. Which means an interrupt is generated for each
+ * conversion sequence. At 1MSPS sample rate the CPU in ZYNQ7000 is completely
+ * overloaded by the interrupts that it soft-lockups. For this reason the driver
+ * limits the maximum samplerate 150kSPS. At this rate the CPU is fairly busy,
+ * but still responsive.
+ */
+#define XADC_MAX_SAMPLERATE 150000
+
+static void xadc_write_reg(struct xadc *xadc, unsigned int reg,
+	uint32_t val)
+{
+	writel(val, xadc->base + reg);
+}
+
+static void xadc_read_reg(struct xadc *xadc, unsigned int reg,
+	uint32_t *val)
+{
+	*val = readl(xadc->base + reg);
+}
+
+/*
+ * The ZYNQ interface uses two asynchronous FIFOs for communication with the
+ * XADC. Reads and writes to the XADC register are performed by submitting a
+ * request to the command FIFO (CFIFO), once the request has been completed the
+ * result can be read from the data FIFO (DFIFO). The method currently used in
+ * this driver is to submit the request for a read/write operation, then go to
+ * sleep and wait for an interrupt that signals that a response is available in
+ * the data FIFO.
+ */
+
+static void xadc_zynq_write_fifo(struct xadc *xadc, uint32_t *cmd,
+	unsigned int n)
+{
+	unsigned int i;
+
+	for (i = 0; i < n; i++)
+		xadc_write_reg(xadc, XADC_ZYNQ_REG_CFIFO, cmd[i]);
+}
+
+static void xadc_zynq_drain_fifo(struct xadc *xadc)
+{
+	uint32_t status, tmp;
+
+	xadc_read_reg(xadc, XADC_ZYNQ_REG_STATUS, &status);
+
+	while (!(status & XADC_ZYNQ_STATUS_DFIFOE)) {
+		xadc_read_reg(xadc, XADC_ZYNQ_REG_DFIFO, &tmp);
+		xadc_read_reg(xadc, XADC_ZYNQ_REG_STATUS, &status);
+	}
+}
+
+static void xadc_zynq_update_intmsk(struct xadc *xadc, unsigned int mask,
+	unsigned int val)
+{
+	xadc->zynq_intmask &= ~mask;
+	xadc->zynq_intmask |= val;
+
+	xadc_write_reg(xadc, XADC_ZYNQ_REG_INTMSK,
+		xadc->zynq_intmask | xadc->zynq_masked_alarm);
+}
+
+static int xadc_zynq_write_adc_reg(struct xadc *xadc, unsigned int reg,
+	uint16_t val)
+{
+	uint32_t cmd[1];
+	uint32_t tmp;
+	int ret;
+
+	spin_lock_irq(&xadc->lock);
+	xadc_zynq_update_intmsk(xadc, XADC_ZYNQ_INT_DFIFO_GTH,
+			XADC_ZYNQ_INT_DFIFO_GTH);
+
+	reinit_completion(&xadc->completion);
+
+	cmd[0] = XADC_ZYNQ_CMD(XADC_ZYNQ_CMD_WRITE, reg, val);
+	xadc_zynq_write_fifo(xadc, cmd, ARRAY_SIZE(cmd));
+	xadc_read_reg(xadc, XADC_ZYNQ_REG_CFG, &tmp);
+	tmp &= ~XADC_ZYNQ_CFG_DFIFOTH_MASK;
+	tmp |= 0 << XADC_ZYNQ_CFG_DFIFOTH_OFFSET;
+	xadc_write_reg(xadc, XADC_ZYNQ_REG_CFG, tmp);
+
+	xadc_zynq_update_intmsk(xadc, XADC_ZYNQ_INT_DFIFO_GTH, 0);
+	spin_unlock_irq(&xadc->lock);
+
+	ret = wait_for_completion_interruptible_timeout(&xadc->completion, HZ);
+	if (ret == 0)
+		ret = -EIO;
+	else
+		ret = 0;
+
+	xadc_read_reg(xadc, XADC_ZYNQ_REG_DFIFO, &tmp);
+
+	return ret;
+}
+
+static int xadc_zynq_read_adc_reg(struct xadc *xadc, unsigned int reg,
+	uint16_t *val)
+{
+	uint32_t cmd[2];
+	uint32_t resp, tmp;
+	int ret;
+
+	cmd[0] = XADC_ZYNQ_CMD(XADC_ZYNQ_CMD_READ, reg, 0);
+	cmd[1] = XADC_ZYNQ_CMD(XADC_ZYNQ_CMD_NOP, 0, 0);
+
+	spin_lock_irq(&xadc->lock);
+	xadc_zynq_update_intmsk(xadc, XADC_ZYNQ_INT_DFIFO_GTH,
+			XADC_ZYNQ_INT_DFIFO_GTH);
+	xadc_zynq_drain_fifo(xadc);
+	reinit_completion(&xadc->completion);
+
+	xadc_zynq_write_fifo(xadc, cmd, ARRAY_SIZE(cmd));
+	xadc_read_reg(xadc, XADC_ZYNQ_REG_CFG, &tmp);
+	tmp &= ~XADC_ZYNQ_CFG_DFIFOTH_MASK;
+	tmp |= 1 << XADC_ZYNQ_CFG_DFIFOTH_OFFSET;
+	xadc_write_reg(xadc, XADC_ZYNQ_REG_CFG, tmp);
+
+	xadc_zynq_update_intmsk(xadc, XADC_ZYNQ_INT_DFIFO_GTH, 0);
+	spin_unlock_irq(&xadc->lock);
+	ret = wait_for_completion_interruptible_timeout(&xadc->completion, HZ);
+	if (ret == 0)
+		ret = -EIO;
+	if (ret < 0)
+		return ret;
+
+	xadc_read_reg(xadc, XADC_ZYNQ_REG_DFIFO, &resp);
+	xadc_read_reg(xadc, XADC_ZYNQ_REG_DFIFO, &resp);
+
+	*val = resp & 0xffff;
+
+	return 0;
+}
+
+static unsigned int xadc_zynq_transform_alarm(unsigned int alarm)
+{
+	return ((alarm & 0x80) >> 4) |
+		((alarm & 0x78) << 1) |
+		(alarm & 0x07);
+}
+
+/*
+ * The ZYNQ threshold interrupts are level sensitive. Since we can't make the
+ * threshold condition go way from within the interrupt handler, this means as
+ * soon as a threshold condition is present we would enter the interrupt handler
+ * again and again. To work around this we mask all active thresholds interrupts
+ * in the interrupt handler and start a timer. In this timer we poll the
+ * interrupt status and only if the interrupt is inactive we unmask it again.
+ */
+static void xadc_zynq_unmask_worker(struct work_struct *work)
+{
+	struct xadc *xadc = container_of(work, struct xadc, zynq_unmask_work.work);
+	unsigned int misc_sts, unmask;
+
+	xadc_read_reg(xadc, XADC_ZYNQ_REG_STATUS, &misc_sts);
+
+	misc_sts &= XADC_ZYNQ_INT_ALARM_MASK;
+
+	spin_lock_irq(&xadc->lock);
+
+	/* Clear those bits which are not active anymore */
+	unmask = (xadc->zynq_masked_alarm ^ misc_sts) & xadc->zynq_masked_alarm;
+	xadc->zynq_masked_alarm &= misc_sts;
+
+	/* Also clear those which are masked out anyway */
+	xadc->zynq_masked_alarm &= ~xadc->zynq_intmask;
+
+	/* Clear the interrupts before we unmask them */
+	xadc_write_reg(xadc, XADC_ZYNQ_REG_INTSTS, unmask);
+
+	xadc_zynq_update_intmsk(xadc, 0, 0);
+
+	spin_unlock_irq(&xadc->lock);
+
+	/* if still pending some alarm re-trigger the timer */
+	if (xadc->zynq_masked_alarm) {
+		schedule_delayed_work(&xadc->zynq_unmask_work,
+				msecs_to_jiffies(XADC_ZYNQ_UNMASK_TIMEOUT));
+	}
+
+}
+
+static irqreturn_t xadc_zynq_interrupt_handler(int irq, void *devid)
+{
+	struct iio_dev *indio_dev = devid;
+	struct xadc *xadc = iio_priv(indio_dev);
+	uint32_t status;
+
+	xadc_read_reg(xadc, XADC_ZYNQ_REG_INTSTS, &status);
+
+	status &= ~(xadc->zynq_intmask | xadc->zynq_masked_alarm);
+
+	if (!status)
+		return IRQ_NONE;
+
+	spin_lock(&xadc->lock);
+
+	xadc_write_reg(xadc, XADC_ZYNQ_REG_INTSTS, status);
+
+	if (status & XADC_ZYNQ_INT_DFIFO_GTH) {
+		xadc_zynq_update_intmsk(xadc, XADC_ZYNQ_INT_DFIFO_GTH,
+			XADC_ZYNQ_INT_DFIFO_GTH);
+		complete(&xadc->completion);
+	}
+
+	status &= XADC_ZYNQ_INT_ALARM_MASK;
+	if (status) {
+		xadc->zynq_masked_alarm |= status;
+		/*
+		 * mask the current event interrupt,
+		 * unmask it when the interrupt is no more active.
+		 */
+		xadc_zynq_update_intmsk(xadc, 0, 0);
+
+		xadc_handle_events(indio_dev,
+				xadc_zynq_transform_alarm(status));
+
+		/* unmask the required interrupts in timer. */
+		schedule_delayed_work(&xadc->zynq_unmask_work,
+				msecs_to_jiffies(XADC_ZYNQ_UNMASK_TIMEOUT));
+	}
+	spin_unlock(&xadc->lock);
+
+	return IRQ_HANDLED;
+}
+
+#define XADC_ZYNQ_TCK_RATE_MAX 50000000
+#define XADC_ZYNQ_IGAP_DEFAULT 20
+#define XADC_ZYNQ_PCAP_RATE_MAX 200000000
+
+static int xadc_zynq_setup(struct platform_device *pdev,
+	struct iio_dev *indio_dev, int irq)
+{
+	struct xadc *xadc = iio_priv(indio_dev);
+	unsigned long pcap_rate;
+	unsigned int tck_div;
+	unsigned int div;
+	unsigned int igap;
+	unsigned int tck_rate;
+	int ret;
+
+	/* TODO: Figure out how to make igap and tck_rate configurable */
+	igap = XADC_ZYNQ_IGAP_DEFAULT;
+	tck_rate = XADC_ZYNQ_TCK_RATE_MAX;
+
+	xadc->zynq_intmask = ~0;
+
+	pcap_rate = clk_get_rate(xadc->clk);
+	if (!pcap_rate)
+		return -EINVAL;
+
+	if (pcap_rate > XADC_ZYNQ_PCAP_RATE_MAX) {
+		ret = clk_set_rate(xadc->clk,
+				   (unsigned long)XADC_ZYNQ_PCAP_RATE_MAX);
+		if (ret)
+			return ret;
+	}
+
+	if (tck_rate > pcap_rate / 2) {
+		div = 2;
+	} else {
+		div = pcap_rate / tck_rate;
+		if (pcap_rate / div > XADC_ZYNQ_TCK_RATE_MAX)
+			div++;
+	}
+
+	if (div <= 3)
+		tck_div = XADC_ZYNQ_CFG_TCKRATE_DIV2;
+	else if (div <= 7)
+		tck_div = XADC_ZYNQ_CFG_TCKRATE_DIV4;
+	else if (div <= 15)
+		tck_div = XADC_ZYNQ_CFG_TCKRATE_DIV8;
+	else
+		tck_div = XADC_ZYNQ_CFG_TCKRATE_DIV16;
+
+	xadc_write_reg(xadc, XADC_ZYNQ_REG_CTL, XADC_ZYNQ_CTL_RESET);
+	xadc_write_reg(xadc, XADC_ZYNQ_REG_CTL, 0);
+	xadc_write_reg(xadc, XADC_ZYNQ_REG_INTSTS, ~0);
+	xadc_write_reg(xadc, XADC_ZYNQ_REG_INTMSK, xadc->zynq_intmask);
+	xadc_write_reg(xadc, XADC_ZYNQ_REG_CFG, XADC_ZYNQ_CFG_ENABLE |
+			XADC_ZYNQ_CFG_REDGE | XADC_ZYNQ_CFG_WEDGE |
+			tck_div | XADC_ZYNQ_CFG_IGAP(igap));
+
+	if (pcap_rate > XADC_ZYNQ_PCAP_RATE_MAX) {
+		ret = clk_set_rate(xadc->clk, pcap_rate);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static unsigned long xadc_zynq_get_dclk_rate(struct xadc *xadc)
+{
+	unsigned int div;
+	uint32_t val;
+
+	xadc_read_reg(xadc, XADC_ZYNQ_REG_CFG, &val);
+
+	switch (val & XADC_ZYNQ_CFG_TCKRATE_MASK) {
+	case XADC_ZYNQ_CFG_TCKRATE_DIV4:
+		div = 4;
+		break;
+	case XADC_ZYNQ_CFG_TCKRATE_DIV8:
+		div = 8;
+		break;
+	case XADC_ZYNQ_CFG_TCKRATE_DIV16:
+		div = 16;
+		break;
+	default:
+		div = 2;
+		break;
+	}
+
+	return clk_get_rate(xadc->clk) / div;
+}
+
+static void xadc_zynq_update_alarm(struct xadc *xadc, unsigned int alarm)
+{
+	unsigned long flags;
+	uint32_t status;
+
+	/* Move OT to bit 7 */
+	alarm = ((alarm & 0x08) << 4) | ((alarm & 0xf0) >> 1) | (alarm & 0x07);
+
+	spin_lock_irqsave(&xadc->lock, flags);
+
+	/* Clear previous interrupts if any. */
+	xadc_read_reg(xadc, XADC_ZYNQ_REG_INTSTS, &status);
+	xadc_write_reg(xadc, XADC_ZYNQ_REG_INTSTS, status & alarm);
+
+	xadc_zynq_update_intmsk(xadc, XADC_ZYNQ_INT_ALARM_MASK,
+		~alarm & XADC_ZYNQ_INT_ALARM_MASK);
+
+	spin_unlock_irqrestore(&xadc->lock, flags);
+}
+
+static const struct xadc_ops xadc_zynq_ops = {
+	.read = xadc_zynq_read_adc_reg,
+	.write = xadc_zynq_write_adc_reg,
+	.setup = xadc_zynq_setup,
+	.get_dclk_rate = xadc_zynq_get_dclk_rate,
+	.interrupt_handler = xadc_zynq_interrupt_handler,
+	.update_alarm = xadc_zynq_update_alarm,
+};
+
+static int xadc_axi_read_adc_reg(struct xadc *xadc, unsigned int reg,
+	uint16_t *val)
+{
+	uint32_t val32;
+
+	xadc_read_reg(xadc, XADC_AXI_ADC_REG_OFFSET + reg * 4, &val32);
+	*val = val32 & 0xffff;
+
+	return 0;
+}
+
+static int xadc_axi_write_adc_reg(struct xadc *xadc, unsigned int reg,
+	uint16_t val)
+{
+	xadc_write_reg(xadc, XADC_AXI_ADC_REG_OFFSET + reg * 4, val);
+
+	return 0;
+}
+
+static int xadc_axi_setup(struct platform_device *pdev,
+	struct iio_dev *indio_dev, int irq)
+{
+	struct xadc *xadc = iio_priv(indio_dev);
+
+	xadc_write_reg(xadc, XADC_AXI_REG_RESET, XADC_AXI_RESET_MAGIC);
+	xadc_write_reg(xadc, XADC_AXI_REG_GIER, XADC_AXI_GIER_ENABLE);
+
+	return 0;
+}
+
+static irqreturn_t xadc_axi_interrupt_handler(int irq, void *devid)
+{
+	struct iio_dev *indio_dev = devid;
+	struct xadc *xadc = iio_priv(indio_dev);
+	uint32_t status, mask;
+	unsigned int events;
+
+	xadc_read_reg(xadc, XADC_AXI_REG_IPISR, &status);
+	xadc_read_reg(xadc, XADC_AXI_REG_IPIER, &mask);
+	status &= mask;
+
+	if (!status)
+		return IRQ_NONE;
+
+	if ((status & XADC_AXI_INT_EOS) && xadc->trigger)
+		iio_trigger_poll(xadc->trigger);
+
+	if (status & XADC_AXI_INT_ALARM_MASK) {
+		/*
+		 * The order of the bits in the AXI-XADC status register does
+		 * not match the order of the bits in the XADC alarm enable
+		 * register. xadc_handle_events() expects the events to be in
+		 * the same order as the XADC alarm enable register.
+		 */
+		events = (status & 0x000e) >> 1;
+		events |= (status & 0x0001) << 3;
+		events |= (status & 0x3c00) >> 6;
+		xadc_handle_events(indio_dev, events);
+	}
+
+	xadc_write_reg(xadc, XADC_AXI_REG_IPISR, status);
+
+	return IRQ_HANDLED;
+}
+
+static void xadc_axi_update_alarm(struct xadc *xadc, unsigned int alarm)
+{
+	uint32_t val;
+	unsigned long flags;
+
+	/*
+	 * The order of the bits in the AXI-XADC status register does not match
+	 * the order of the bits in the XADC alarm enable register. We get
+	 * passed the alarm mask in the same order as in the XADC alarm enable
+	 * register.
+	 */
+	alarm = ((alarm & 0x07) << 1) | ((alarm & 0x08) >> 3) |
+			((alarm & 0xf0) << 6);
+
+	spin_lock_irqsave(&xadc->lock, flags);
+	xadc_read_reg(xadc, XADC_AXI_REG_IPIER, &val);
+	val &= ~XADC_AXI_INT_ALARM_MASK;
+	val |= alarm;
+	xadc_write_reg(xadc, XADC_AXI_REG_IPIER, val);
+	spin_unlock_irqrestore(&xadc->lock, flags);
+}
+
+static unsigned long xadc_axi_get_dclk(struct xadc *xadc)
+{
+	return clk_get_rate(xadc->clk);
+}
+
+static const struct xadc_ops xadc_axi_ops = {
+	.read = xadc_axi_read_adc_reg,
+	.write = xadc_axi_write_adc_reg,
+	.setup = xadc_axi_setup,
+	.get_dclk_rate = xadc_axi_get_dclk,
+	.update_alarm = xadc_axi_update_alarm,
+	.interrupt_handler = xadc_axi_interrupt_handler,
+	.flags = XADC_FLAGS_BUFFERED,
+};
+
+static int _xadc_update_adc_reg(struct xadc *xadc, unsigned int reg,
+	uint16_t mask, uint16_t val)
+{
+	uint16_t tmp;
+	int ret;
+
+	ret = _xadc_read_adc_reg(xadc, reg, &tmp);
+	if (ret)
+		return ret;
+
+	return _xadc_write_adc_reg(xadc, reg, (tmp & ~mask) | val);
+}
+
+static int xadc_update_adc_reg(struct xadc *xadc, unsigned int reg,
+	uint16_t mask, uint16_t val)
+{
+	int ret;
+
+	mutex_lock(&xadc->mutex);
+	ret = _xadc_update_adc_reg(xadc, reg, mask, val);
+	mutex_unlock(&xadc->mutex);
+
+	return ret;
+}
+
+static unsigned long xadc_get_dclk_rate(struct xadc *xadc)
+{
+	return xadc->ops->get_dclk_rate(xadc);
+}
+
+static int xadc_update_scan_mode(struct iio_dev *indio_dev,
+	const unsigned long *mask)
+{
+	struct xadc *xadc = iio_priv(indio_dev);
+	unsigned int n;
+
+	n = bitmap_weight(mask, indio_dev->masklength);
+
+	kfree(xadc->data);
+	xadc->data = kcalloc(n, sizeof(*xadc->data), GFP_KERNEL);
+	if (!xadc->data)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static unsigned int xadc_scan_index_to_channel(unsigned int scan_index)
+{
+	switch (scan_index) {
+	case 5:
+		return XADC_REG_VCCPINT;
+	case 6:
+		return XADC_REG_VCCPAUX;
+	case 7:
+		return XADC_REG_VCCO_DDR;
+	case 8:
+		return XADC_REG_TEMP;
+	case 9:
+		return XADC_REG_VCCINT;
+	case 10:
+		return XADC_REG_VCCAUX;
+	case 11:
+		return XADC_REG_VPVN;
+	case 12:
+		return XADC_REG_VREFP;
+	case 13:
+		return XADC_REG_VREFN;
+	case 14:
+		return XADC_REG_VCCBRAM;
+	default:
+		return XADC_REG_VAUX(scan_index - 16);
+	}
+}
+
+static irqreturn_t xadc_trigger_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct xadc *xadc = iio_priv(indio_dev);
+	unsigned int chan;
+	int i, j;
+
+	if (!xadc->data)
+		goto out;
+
+	j = 0;
+	for_each_set_bit(i, indio_dev->active_scan_mask,
+		indio_dev->masklength) {
+		chan = xadc_scan_index_to_channel(i);
+		xadc_read_adc_reg(xadc, chan, &xadc->data[j]);
+		j++;
+	}
+
+	iio_push_to_buffers(indio_dev, xadc->data);
+
+out:
+	iio_trigger_notify_done(indio_dev->trig);
+
+	return IRQ_HANDLED;
+}
+
+static int xadc_trigger_set_state(struct iio_trigger *trigger, bool state)
+{
+	struct xadc *xadc = iio_trigger_get_drvdata(trigger);
+	unsigned long flags;
+	unsigned int convst;
+	unsigned int val;
+	int ret = 0;
+
+	mutex_lock(&xadc->mutex);
+
+	if (state) {
+		/* Only one of the two triggers can be active at the a time. */
+		if (xadc->trigger != NULL) {
+			ret = -EBUSY;
+			goto err_out;
+		} else {
+			xadc->trigger = trigger;
+			if (trigger == xadc->convst_trigger)
+				convst = XADC_CONF0_EC;
+			else
+				convst = 0;
+		}
+		ret = _xadc_update_adc_reg(xadc, XADC_REG_CONF1, XADC_CONF0_EC,
+					convst);
+		if (ret)
+			goto err_out;
+	} else {
+		xadc->trigger = NULL;
+	}
+
+	spin_lock_irqsave(&xadc->lock, flags);
+	xadc_read_reg(xadc, XADC_AXI_REG_IPIER, &val);
+	xadc_write_reg(xadc, XADC_AXI_REG_IPISR, XADC_AXI_INT_EOS);
+	if (state)
+		val |= XADC_AXI_INT_EOS;
+	else
+		val &= ~XADC_AXI_INT_EOS;
+	xadc_write_reg(xadc, XADC_AXI_REG_IPIER, val);
+	spin_unlock_irqrestore(&xadc->lock, flags);
+
+err_out:
+	mutex_unlock(&xadc->mutex);
+
+	return ret;
+}
+
+static const struct iio_trigger_ops xadc_trigger_ops = {
+	.set_trigger_state = &xadc_trigger_set_state,
+};
+
+static struct iio_trigger *xadc_alloc_trigger(struct iio_dev *indio_dev,
+	const char *name)
+{
+	struct iio_trigger *trig;
+	int ret;
+
+	trig = iio_trigger_alloc("%s%d-%s", indio_dev->name,
+				indio_dev->id, name);
+	if (trig == NULL)
+		return ERR_PTR(-ENOMEM);
+
+	trig->dev.parent = indio_dev->dev.parent;
+	trig->ops = &xadc_trigger_ops;
+	iio_trigger_set_drvdata(trig, iio_priv(indio_dev));
+
+	ret = iio_trigger_register(trig);
+	if (ret)
+		goto error_free_trig;
+
+	return trig;
+
+error_free_trig:
+	iio_trigger_free(trig);
+	return ERR_PTR(ret);
+}
+
+static int xadc_power_adc_b(struct xadc *xadc, unsigned int seq_mode)
+{
+	uint16_t val;
+
+	/* Powerdown the ADC-B when it is not needed. */
+	switch (seq_mode) {
+	case XADC_CONF1_SEQ_SIMULTANEOUS:
+	case XADC_CONF1_SEQ_INDEPENDENT:
+		val = 0;
+		break;
+	default:
+		val = XADC_CONF2_PD_ADC_B;
+		break;
+	}
+
+	return xadc_update_adc_reg(xadc, XADC_REG_CONF2, XADC_CONF2_PD_MASK,
+		val);
+}
+
+static int xadc_get_seq_mode(struct xadc *xadc, unsigned long scan_mode)
+{
+	unsigned int aux_scan_mode = scan_mode >> 16;
+
+	if (xadc->external_mux_mode == XADC_EXTERNAL_MUX_DUAL)
+		return XADC_CONF1_SEQ_SIMULTANEOUS;
+
+	if ((aux_scan_mode & 0xff00) == 0 ||
+		(aux_scan_mode & 0x00ff) == 0)
+		return XADC_CONF1_SEQ_CONTINUOUS;
+
+	return XADC_CONF1_SEQ_SIMULTANEOUS;
+}
+
+static int xadc_postdisable(struct iio_dev *indio_dev)
+{
+	struct xadc *xadc = iio_priv(indio_dev);
+	unsigned long scan_mask;
+	int ret;
+	int i;
+
+	scan_mask = 1; /* Run calibration as part of the sequence */
+	for (i = 0; i < indio_dev->num_channels; i++)
+		scan_mask |= BIT(indio_dev->channels[i].scan_index);
+
+	/* Enable all channels and calibration */
+	ret = xadc_write_adc_reg(xadc, XADC_REG_SEQ(0), scan_mask & 0xffff);
+	if (ret)
+		return ret;
+
+	ret = xadc_write_adc_reg(xadc, XADC_REG_SEQ(1), scan_mask >> 16);
+	if (ret)
+		return ret;
+
+	ret = xadc_update_adc_reg(xadc, XADC_REG_CONF1, XADC_CONF1_SEQ_MASK,
+		XADC_CONF1_SEQ_CONTINUOUS);
+	if (ret)
+		return ret;
+
+	return xadc_power_adc_b(xadc, XADC_CONF1_SEQ_CONTINUOUS);
+}
+
+static int xadc_preenable(struct iio_dev *indio_dev)
+{
+	struct xadc *xadc = iio_priv(indio_dev);
+	unsigned long scan_mask;
+	int seq_mode;
+	int ret;
+
+	ret = xadc_update_adc_reg(xadc, XADC_REG_CONF1, XADC_CONF1_SEQ_MASK,
+		XADC_CONF1_SEQ_DEFAULT);
+	if (ret)
+		goto err;
+
+	scan_mask = *indio_dev->active_scan_mask;
+	seq_mode = xadc_get_seq_mode(xadc, scan_mask);
+
+	ret = xadc_write_adc_reg(xadc, XADC_REG_SEQ(0), scan_mask & 0xffff);
+	if (ret)
+		goto err;
+
+	/*
+	 * In simultaneous mode the upper and lower aux channels are samples at
+	 * the same time. In this mode the upper 8 bits in the sequencer
+	 * register are don't care and the lower 8 bits control two channels
+	 * each. As such we must set the bit if either the channel in the lower
+	 * group or the upper group is enabled.
+	 */
+	if (seq_mode == XADC_CONF1_SEQ_SIMULTANEOUS)
+		scan_mask = ((scan_mask >> 8) | scan_mask) & 0xff0000;
+
+	ret = xadc_write_adc_reg(xadc, XADC_REG_SEQ(1), scan_mask >> 16);
+	if (ret)
+		goto err;
+
+	ret = xadc_power_adc_b(xadc, seq_mode);
+	if (ret)
+		goto err;
+
+	ret = xadc_update_adc_reg(xadc, XADC_REG_CONF1, XADC_CONF1_SEQ_MASK,
+		seq_mode);
+	if (ret)
+		goto err;
+
+	return 0;
+err:
+	xadc_postdisable(indio_dev);
+	return ret;
+}
+
+static const struct iio_buffer_setup_ops xadc_buffer_ops = {
+	.preenable = &xadc_preenable,
+	.postenable = &iio_triggered_buffer_postenable,
+	.predisable = &iio_triggered_buffer_predisable,
+	.postdisable = &xadc_postdisable,
+};
+
+static int xadc_read_samplerate(struct xadc *xadc)
+{
+	unsigned int div;
+	uint16_t val16;
+	int ret;
+
+	ret = xadc_read_adc_reg(xadc, XADC_REG_CONF2, &val16);
+	if (ret)
+		return ret;
+
+	div = (val16 & XADC_CONF2_DIV_MASK) >> XADC_CONF2_DIV_OFFSET;
+	if (div < 2)
+		div = 2;
+
+	return xadc_get_dclk_rate(xadc) / div / 26;
+}
+
+static int xadc_read_raw(struct iio_dev *indio_dev,
+	struct iio_chan_spec const *chan, int *val, int *val2, long info)
+{
+	struct xadc *xadc = iio_priv(indio_dev);
+	uint16_t val16;
+	int ret;
+
+	switch (info) {
+	case IIO_CHAN_INFO_RAW:
+		if (iio_buffer_enabled(indio_dev))
+			return -EBUSY;
+		ret = xadc_read_adc_reg(xadc, chan->address, &val16);
+		if (ret < 0)
+			return ret;
+
+		val16 >>= 4;
+		if (chan->scan_type.sign == 'u')
+			*val = val16;
+		else
+			*val = sign_extend32(val16, 11);
+
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		switch (chan->type) {
+		case IIO_VOLTAGE:
+			/* V = (val * 3.0) / 4096 */
+			switch (chan->address) {
+			case XADC_REG_VCCINT:
+			case XADC_REG_VCCAUX:
+			case XADC_REG_VREFP:
+			case XADC_REG_VREFN:
+			case XADC_REG_VCCBRAM:
+			case XADC_REG_VCCPINT:
+			case XADC_REG_VCCPAUX:
+			case XADC_REG_VCCO_DDR:
+				*val = 3000;
+				break;
+			default:
+				*val = 1000;
+				break;
+			}
+			*val2 = 12;
+			return IIO_VAL_FRACTIONAL_LOG2;
+		case IIO_TEMP:
+			/* Temp in C = (val * 503.975) / 4096 - 273.15 */
+			*val = 503975;
+			*val2 = 12;
+			return IIO_VAL_FRACTIONAL_LOG2;
+		default:
+			return -EINVAL;
+		}
+	case IIO_CHAN_INFO_OFFSET:
+		/* Only the temperature channel has an offset */
+		*val = -((273150 << 12) / 503975);
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		ret = xadc_read_samplerate(xadc);
+		if (ret < 0)
+			return ret;
+
+		*val = ret;
+		return IIO_VAL_INT;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int xadc_write_samplerate(struct xadc *xadc, int val)
+{
+	unsigned long clk_rate = xadc_get_dclk_rate(xadc);
+	unsigned int div;
+
+	if (!clk_rate)
+		return -EINVAL;
+
+	if (val <= 0)
+		return -EINVAL;
+
+	/* Max. 150 kSPS */
+	if (val > XADC_MAX_SAMPLERATE)
+		val = XADC_MAX_SAMPLERATE;
+
+	val *= 26;
+
+	/* Min 1MHz */
+	if (val < 1000000)
+		val = 1000000;
+
+	/*
+	 * We want to round down, but only if we do not exceed the 150 kSPS
+	 * limit.
+	 */
+	div = clk_rate / val;
+	if (clk_rate / div / 26 > XADC_MAX_SAMPLERATE)
+		div++;
+	if (div < 2)
+		div = 2;
+	else if (div > 0xff)
+		div = 0xff;
+
+	return xadc_update_adc_reg(xadc, XADC_REG_CONF2, XADC_CONF2_DIV_MASK,
+		div << XADC_CONF2_DIV_OFFSET);
+}
+
+static int xadc_write_raw(struct iio_dev *indio_dev,
+	struct iio_chan_spec const *chan, int val, int val2, long info)
+{
+	struct xadc *xadc = iio_priv(indio_dev);
+
+	if (info != IIO_CHAN_INFO_SAMP_FREQ)
+		return -EINVAL;
+
+	return xadc_write_samplerate(xadc, val);
+}
+
+static const struct iio_event_spec xadc_temp_events[] = {
+	{
+		.type = IIO_EV_TYPE_THRESH,
+		.dir = IIO_EV_DIR_RISING,
+		.mask_separate = BIT(IIO_EV_INFO_ENABLE) |
+				BIT(IIO_EV_INFO_VALUE) |
+				BIT(IIO_EV_INFO_HYSTERESIS),
+	},
+};
+
+/* Separate values for upper and lower thresholds, but only a shared enabled */
+static const struct iio_event_spec xadc_voltage_events[] = {
+	{
+		.type = IIO_EV_TYPE_THRESH,
+		.dir = IIO_EV_DIR_RISING,
+		.mask_separate = BIT(IIO_EV_INFO_VALUE),
+	}, {
+		.type = IIO_EV_TYPE_THRESH,
+		.dir = IIO_EV_DIR_FALLING,
+		.mask_separate = BIT(IIO_EV_INFO_VALUE),
+	}, {
+		.type = IIO_EV_TYPE_THRESH,
+		.dir = IIO_EV_DIR_EITHER,
+		.mask_separate = BIT(IIO_EV_INFO_ENABLE),
+	},
+};
+
+#define XADC_CHAN_TEMP(_chan, _scan_index, _addr) { \
+	.type = IIO_TEMP, \
+	.indexed = 1, \
+	.channel = (_chan), \
+	.address = (_addr), \
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
+		BIT(IIO_CHAN_INFO_SCALE) | \
+		BIT(IIO_CHAN_INFO_OFFSET), \
+	.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
+	.event_spec = xadc_temp_events, \
+	.num_event_specs = ARRAY_SIZE(xadc_temp_events), \
+	.scan_index = (_scan_index), \
+	.scan_type = { \
+		.sign = 'u', \
+		.realbits = 12, \
+		.storagebits = 16, \
+		.shift = 4, \
+		.endianness = IIO_CPU, \
+	}, \
+}
+
+#define XADC_CHAN_VOLTAGE(_chan, _scan_index, _addr, _ext, _alarm) { \
+	.type = IIO_VOLTAGE, \
+	.indexed = 1, \
+	.channel = (_chan), \
+	.address = (_addr), \
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
+		BIT(IIO_CHAN_INFO_SCALE), \
+	.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
+	.event_spec = (_alarm) ? xadc_voltage_events : NULL, \
+	.num_event_specs = (_alarm) ? ARRAY_SIZE(xadc_voltage_events) : 0, \
+	.scan_index = (_scan_index), \
+	.scan_type = { \
+		.sign = ((_addr) == XADC_REG_VREFN) ? 's' : 'u', \
+		.realbits = 12, \
+		.storagebits = 16, \
+		.shift = 4, \
+		.endianness = IIO_CPU, \
+	}, \
+	.extend_name = _ext, \
+}
+
+static const struct iio_chan_spec xadc_channels[] = {
+	XADC_CHAN_TEMP(0, 8, XADC_REG_TEMP),
+	XADC_CHAN_VOLTAGE(0, 9, XADC_REG_VCCINT, "vccint", true),
+	XADC_CHAN_VOLTAGE(1, 10, XADC_REG_VCCAUX, "vccaux", true),
+	XADC_CHAN_VOLTAGE(2, 14, XADC_REG_VCCBRAM, "vccbram", true),
+	XADC_CHAN_VOLTAGE(3, 5, XADC_REG_VCCPINT, "vccpint", true),
+	XADC_CHAN_VOLTAGE(4, 6, XADC_REG_VCCPAUX, "vccpaux", true),
+	XADC_CHAN_VOLTAGE(5, 7, XADC_REG_VCCO_DDR, "vccoddr", true),
+	XADC_CHAN_VOLTAGE(6, 12, XADC_REG_VREFP, "vrefp", false),
+	XADC_CHAN_VOLTAGE(7, 13, XADC_REG_VREFN, "vrefn", false),
+	XADC_CHAN_VOLTAGE(8, 11, XADC_REG_VPVN, NULL, false),
+	XADC_CHAN_VOLTAGE(9, 16, XADC_REG_VAUX(0), NULL, false),
+	XADC_CHAN_VOLTAGE(10, 17, XADC_REG_VAUX(1), NULL, false),
+	XADC_CHAN_VOLTAGE(11, 18, XADC_REG_VAUX(2), NULL, false),
+	XADC_CHAN_VOLTAGE(12, 19, XADC_REG_VAUX(3), NULL, false),
+	XADC_CHAN_VOLTAGE(13, 20, XADC_REG_VAUX(4), NULL, false),
+	XADC_CHAN_VOLTAGE(14, 21, XADC_REG_VAUX(5), NULL, false),
+	XADC_CHAN_VOLTAGE(15, 22, XADC_REG_VAUX(6), NULL, false),
+	XADC_CHAN_VOLTAGE(16, 23, XADC_REG_VAUX(7), NULL, false),
+	XADC_CHAN_VOLTAGE(17, 24, XADC_REG_VAUX(8), NULL, false),
+	XADC_CHAN_VOLTAGE(18, 25, XADC_REG_VAUX(9), NULL, false),
+	XADC_CHAN_VOLTAGE(19, 26, XADC_REG_VAUX(10), NULL, false),
+	XADC_CHAN_VOLTAGE(20, 27, XADC_REG_VAUX(11), NULL, false),
+	XADC_CHAN_VOLTAGE(21, 28, XADC_REG_VAUX(12), NULL, false),
+	XADC_CHAN_VOLTAGE(22, 29, XADC_REG_VAUX(13), NULL, false),
+	XADC_CHAN_VOLTAGE(23, 30, XADC_REG_VAUX(14), NULL, false),
+	XADC_CHAN_VOLTAGE(24, 31, XADC_REG_VAUX(15), NULL, false),
+};
+
+static const struct iio_info xadc_info = {
+	.read_raw = &xadc_read_raw,
+	.write_raw = &xadc_write_raw,
+	.read_event_config = &xadc_read_event_config,
+	.write_event_config = &xadc_write_event_config,
+	.read_event_value = &xadc_read_event_value,
+	.write_event_value = &xadc_write_event_value,
+	.update_scan_mode = &xadc_update_scan_mode,
+};
+
+static const struct of_device_id xadc_of_match_table[] = {
+	{ .compatible = "xlnx,zynq-xadc-1.00.a", (void *)&xadc_zynq_ops },
+	{ .compatible = "xlnx,axi-xadc-1.00.a", (void *)&xadc_axi_ops },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, xadc_of_match_table);
+
+static int xadc_parse_dt(struct iio_dev *indio_dev, struct device_node *np,
+	unsigned int *conf)
+{
+	struct xadc *xadc = iio_priv(indio_dev);
+	struct iio_chan_spec *channels, *chan;
+	struct device_node *chan_node, *child;
+	unsigned int num_channels;
+	const char *external_mux;
+	u32 ext_mux_chan;
+	u32 reg;
+	int ret;
+
+	*conf = 0;
+
+	ret = of_property_read_string(np, "xlnx,external-mux", &external_mux);
+	if (ret < 0 || strcasecmp(external_mux, "none") == 0)
+		xadc->external_mux_mode = XADC_EXTERNAL_MUX_NONE;
+	else if (strcasecmp(external_mux, "single") == 0)
+		xadc->external_mux_mode = XADC_EXTERNAL_MUX_SINGLE;
+	else if (strcasecmp(external_mux, "dual") == 0)
+		xadc->external_mux_mode = XADC_EXTERNAL_MUX_DUAL;
+	else
+		return -EINVAL;
+
+	if (xadc->external_mux_mode != XADC_EXTERNAL_MUX_NONE) {
+		ret = of_property_read_u32(np, "xlnx,external-mux-channel",
+					&ext_mux_chan);
+		if (ret < 0)
+			return ret;
+
+		if (xadc->external_mux_mode == XADC_EXTERNAL_MUX_SINGLE) {
+			if (ext_mux_chan == 0)
+				ext_mux_chan = XADC_REG_VPVN;
+			else if (ext_mux_chan <= 16)
+				ext_mux_chan = XADC_REG_VAUX(ext_mux_chan - 1);
+			else
+				return -EINVAL;
+		} else {
+			if (ext_mux_chan > 0 && ext_mux_chan <= 8)
+				ext_mux_chan = XADC_REG_VAUX(ext_mux_chan - 1);
+			else
+				return -EINVAL;
+		}
+
+		*conf |= XADC_CONF0_MUX | XADC_CONF0_CHAN(ext_mux_chan);
+	}
+
+	channels = kmemdup(xadc_channels, sizeof(xadc_channels), GFP_KERNEL);
+	if (!channels)
+		return -ENOMEM;
+
+	num_channels = 9;
+	chan = &channels[9];
+
+	chan_node = of_get_child_by_name(np, "xlnx,channels");
+	if (chan_node) {
+		for_each_child_of_node(chan_node, child) {
+			if (num_channels >= ARRAY_SIZE(xadc_channels)) {
+				of_node_put(child);
+				break;
+			}
+
+			ret = of_property_read_u32(child, "reg", &reg);
+			if (ret || reg > 16)
+				continue;
+
+			if (of_property_read_bool(child, "xlnx,bipolar"))
+				chan->scan_type.sign = 's';
+
+			if (reg == 0) {
+				chan->scan_index = 11;
+				chan->address = XADC_REG_VPVN;
+			} else {
+				chan->scan_index = 15 + reg;
+				chan->address = XADC_REG_VAUX(reg - 1);
+			}
+			num_channels++;
+			chan++;
+		}
+	}
+	of_node_put(chan_node);
+
+	indio_dev->num_channels = num_channels;
+	indio_dev->channels = krealloc(channels, sizeof(*channels) *
+					num_channels, GFP_KERNEL);
+	/* If we can't resize the channels array, just use the original */
+	if (!indio_dev->channels)
+		indio_dev->channels = channels;
+
+	return 0;
+}
+
+static int xadc_probe(struct platform_device *pdev)
+{
+	const struct of_device_id *id;
+	struct iio_dev *indio_dev;
+	unsigned int bipolar_mask;
+	struct resource *mem;
+	unsigned int conf0;
+	struct xadc *xadc;
+	int ret;
+	int irq;
+	int i;
+
+	if (!pdev->dev.of_node)
+		return -ENODEV;
+
+	id = of_match_node(xadc_of_match_table, pdev->dev.of_node);
+	if (!id)
+		return -EINVAL;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq <= 0)
+		return -ENXIO;
+
+	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*xadc));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	xadc = iio_priv(indio_dev);
+	xadc->ops = id->data;
+	xadc->irq = irq;
+	init_completion(&xadc->completion);
+	mutex_init(&xadc->mutex);
+	spin_lock_init(&xadc->lock);
+	INIT_DELAYED_WORK(&xadc->zynq_unmask_work, xadc_zynq_unmask_worker);
+
+	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	xadc->base = devm_ioremap_resource(&pdev->dev, mem);
+	if (IS_ERR(xadc->base))
+		return PTR_ERR(xadc->base);
+
+	indio_dev->dev.parent = &pdev->dev;
+	indio_dev->dev.of_node = pdev->dev.of_node;
+	indio_dev->name = "xadc";
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->info = &xadc_info;
+
+	ret = xadc_parse_dt(indio_dev, pdev->dev.of_node, &conf0);
+	if (ret)
+		goto err_device_free;
+
+	if (xadc->ops->flags & XADC_FLAGS_BUFFERED) {
+		ret = iio_triggered_buffer_setup(indio_dev,
+			&iio_pollfunc_store_time, &xadc_trigger_handler,
+			&xadc_buffer_ops);
+		if (ret)
+			goto err_device_free;
+
+		xadc->convst_trigger = xadc_alloc_trigger(indio_dev, "convst");
+		if (IS_ERR(xadc->convst_trigger)) {
+			ret = PTR_ERR(xadc->convst_trigger);
+			goto err_triggered_buffer_cleanup;
+		}
+		xadc->samplerate_trigger = xadc_alloc_trigger(indio_dev,
+			"samplerate");
+		if (IS_ERR(xadc->samplerate_trigger)) {
+			ret = PTR_ERR(xadc->samplerate_trigger);
+			goto err_free_convst_trigger;
+		}
+	}
+
+	xadc->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(xadc->clk)) {
+		ret = PTR_ERR(xadc->clk);
+		goto err_free_samplerate_trigger;
+	}
+
+	ret = clk_prepare_enable(xadc->clk);
+	if (ret)
+		goto err_free_samplerate_trigger;
+
+	/*
+	 * Make sure not to exceed the maximum samplerate since otherwise the
+	 * resulting interrupt storm will soft-lock the system.
+	 */
+	if (xadc->ops->flags & XADC_FLAGS_BUFFERED) {
+		ret = xadc_read_samplerate(xadc);
+		if (ret < 0)
+			goto err_free_samplerate_trigger;
+		if (ret > XADC_MAX_SAMPLERATE) {
+			ret = xadc_write_samplerate(xadc, XADC_MAX_SAMPLERATE);
+			if (ret < 0)
+				goto err_free_samplerate_trigger;
+		}
+	}
+
+	ret = request_irq(xadc->irq, xadc->ops->interrupt_handler, 0,
+			dev_name(&pdev->dev), indio_dev);
+	if (ret)
+		goto err_clk_disable_unprepare;
+
+	ret = xadc->ops->setup(pdev, indio_dev, xadc->irq);
+	if (ret)
+		goto err_free_irq;
+
+	for (i = 0; i < 16; i++)
+		xadc_read_adc_reg(xadc, XADC_REG_THRESHOLD(i),
+			&xadc->threshold[i]);
+
+	ret = xadc_write_adc_reg(xadc, XADC_REG_CONF0, conf0);
+	if (ret)
+		goto err_free_irq;
+
+	bipolar_mask = 0;
+	for (i = 0; i < indio_dev->num_channels; i++) {
+		if (indio_dev->channels[i].scan_type.sign == 's')
+			bipolar_mask |= BIT(indio_dev->channels[i].scan_index);
+	}
+
+	ret = xadc_write_adc_reg(xadc, XADC_REG_INPUT_MODE(0), bipolar_mask);
+	if (ret)
+		goto err_free_irq;
+	ret = xadc_write_adc_reg(xadc, XADC_REG_INPUT_MODE(1),
+		bipolar_mask >> 16);
+	if (ret)
+		goto err_free_irq;
+
+	/* Disable all alarms */
+	ret = xadc_update_adc_reg(xadc, XADC_REG_CONF1, XADC_CONF1_ALARM_MASK,
+				  XADC_CONF1_ALARM_MASK);
+	if (ret)
+		goto err_free_irq;
+
+	/* Set thresholds to min/max */
+	for (i = 0; i < 16; i++) {
+		/*
+		 * Set max voltage threshold and both temperature thresholds to
+		 * 0xffff, min voltage threshold to 0.
+		 */
+		if (i % 8 < 4 || i == 7)
+			xadc->threshold[i] = 0xffff;
+		else
+			xadc->threshold[i] = 0;
+		xadc_write_adc_reg(xadc, XADC_REG_THRESHOLD(i),
+			xadc->threshold[i]);
+	}
+
+	/* Go to non-buffered mode */
+	xadc_postdisable(indio_dev);
+
+	ret = iio_device_register(indio_dev);
+	if (ret)
+		goto err_free_irq;
+
+	platform_set_drvdata(pdev, indio_dev);
+
+	return 0;
+
+err_free_irq:
+	free_irq(xadc->irq, indio_dev);
+	cancel_delayed_work_sync(&xadc->zynq_unmask_work);
+err_clk_disable_unprepare:
+	clk_disable_unprepare(xadc->clk);
+err_free_samplerate_trigger:
+	if (xadc->ops->flags & XADC_FLAGS_BUFFERED)
+		iio_trigger_free(xadc->samplerate_trigger);
+err_free_convst_trigger:
+	if (xadc->ops->flags & XADC_FLAGS_BUFFERED)
+		iio_trigger_free(xadc->convst_trigger);
+err_triggered_buffer_cleanup:
+	if (xadc->ops->flags & XADC_FLAGS_BUFFERED)
+		iio_triggered_buffer_cleanup(indio_dev);
+err_device_free:
+	kfree(indio_dev->channels);
+
+	return ret;
+}
+
+static int xadc_remove(struct platform_device *pdev)
+{
+	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
+	struct xadc *xadc = iio_priv(indio_dev);
+
+	iio_device_unregister(indio_dev);
+	if (xadc->ops->flags & XADC_FLAGS_BUFFERED) {
+		iio_trigger_free(xadc->samplerate_trigger);
+		iio_trigger_free(xadc->convst_trigger);
+		iio_triggered_buffer_cleanup(indio_dev);
+	}
+	free_irq(xadc->irq, indio_dev);
+	cancel_delayed_work_sync(&xadc->zynq_unmask_work);
+	clk_disable_unprepare(xadc->clk);
+	kfree(xadc->data);
+	kfree(indio_dev->channels);
+
+	return 0;
+}
+
+static struct platform_driver xadc_driver = {
+	.probe = xadc_probe,
+	.remove = xadc_remove,
+	.driver = {
+		.name = "xadc",
+		.of_match_table = xadc_of_match_table,
+	},
+};
+module_platform_driver(xadc_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
+MODULE_DESCRIPTION("Xilinx XADC IIO driver");