i2c: qup: New bus driver for the Qualcomm QUP I2C controller

This bus driver supports the QUP i2c hardware controller in the Qualcomm SOCs.
The Qualcomm Universal Peripheral Engine (QUP) is a general purpose data path
engine with input/output FIFOs and an embedded i2c mini-core. The driver
supports FIFO mode (for low bandwidth applications) and block mode (interrupt
generated for each block-size data transfer).

Signed-off-by: Ivan T. Ivanov <iivanov@mm-sol.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
Reviewed-by: Andy Gross <agross@codeaurora.org>
Tested-by: Philip Elcan <pelcan@codeaurora.org>
[wsa: removed needless IS_ERR_VALUE]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

3 files changed, 779 insertions, 0 deletions

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 80998d738fc..a70012b9fee 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -656,6 +656,16 @@ config I2C_PXA_SLAVE
 	  is necessary for systems where the PXA may be a target on the
 	  I2C bus.
 
+config I2C_QUP
+	tristate "Qualcomm QUP based I2C controller"
+	depends on ARCH_QCOM
+	help
+	  If you say yes to this option, support will be included for the
+	  built-in I2C interface on the Qualcomm SoCs.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called i2c-qup.
+
 config I2C_RIIC
 	tristate "Renesas RIIC adapter"
 	depends on ARCH_SHMOBILE || COMPILE_TEST
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 2a56ab18185..aa6406f8094 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -64,6 +64,7 @@ obj-$(CONFIG_I2C_PNX)		+= i2c-pnx.o
 obj-$(CONFIG_I2C_PUV3)		+= i2c-puv3.o
 obj-$(CONFIG_I2C_PXA)		+= i2c-pxa.o
 obj-$(CONFIG_I2C_PXA_PCI)	+= i2c-pxa-pci.o
+obj-$(CONFIG_I2C_QUP)		+= i2c-qup.o
 obj-$(CONFIG_I2C_RIIC)		+= i2c-riic.o
 obj-$(CONFIG_I2C_S3C2410)	+= i2c-s3c2410.o
 obj-$(CONFIG_I2C_S6000)		+= i2c-s6000.o
diff --git a/drivers/i2c/busses/i2c-qup.c b/drivers/i2c/busses/i2c-qup.c
new file mode 100644
index 00000000000..c9d5f788e36
--- /dev/null
+++ b/drivers/i2c/busses/i2c-qup.c
@@ -0,0 +1,768 @@
+/*
+ * Copyright (c) 2009-2013, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2014, Sony Mobile Communications AB.
+ *
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+
+/* QUP Registers */
+#define QUP_CONFIG		0x000
+#define QUP_STATE		0x004
+#define QUP_IO_MODE		0x008
+#define QUP_SW_RESET		0x00c
+#define QUP_OPERATIONAL		0x018
+#define QUP_ERROR_FLAGS		0x01c
+#define QUP_ERROR_FLAGS_EN	0x020
+#define QUP_HW_VERSION		0x030
+#define QUP_MX_OUTPUT_CNT	0x100
+#define QUP_OUT_FIFO_BASE	0x110
+#define QUP_MX_WRITE_CNT	0x150
+#define QUP_MX_INPUT_CNT	0x200
+#define QUP_MX_READ_CNT		0x208
+#define QUP_IN_FIFO_BASE	0x218
+#define QUP_I2C_CLK_CTL		0x400
+#define QUP_I2C_STATUS		0x404
+
+/* QUP States and reset values */
+#define QUP_RESET_STATE		0
+#define QUP_RUN_STATE		1
+#define QUP_PAUSE_STATE		3
+#define QUP_STATE_MASK		3
+
+#define QUP_STATE_VALID		BIT(2)
+#define QUP_I2C_MAST_GEN	BIT(4)
+
+#define QUP_OPERATIONAL_RESET	0x000ff0
+#define QUP_I2C_STATUS_RESET	0xfffffc
+
+/* QUP OPERATIONAL FLAGS */
+#define QUP_I2C_NACK_FLAG	BIT(3)
+#define QUP_OUT_NOT_EMPTY	BIT(4)
+#define QUP_IN_NOT_EMPTY	BIT(5)
+#define QUP_OUT_FULL		BIT(6)
+#define QUP_OUT_SVC_FLAG	BIT(8)
+#define QUP_IN_SVC_FLAG		BIT(9)
+#define QUP_MX_OUTPUT_DONE	BIT(10)
+#define QUP_MX_INPUT_DONE	BIT(11)
+
+/* I2C mini core related values */
+#define QUP_CLOCK_AUTO_GATE	BIT(13)
+#define I2C_MINI_CORE		(2 << 8)
+#define I2C_N_VAL		15
+/* Most significant word offset in FIFO port */
+#define QUP_MSW_SHIFT		(I2C_N_VAL + 1)
+
+/* Packing/Unpacking words in FIFOs, and IO modes */
+#define QUP_OUTPUT_BLK_MODE	(1 << 10)
+#define QUP_INPUT_BLK_MODE	(1 << 12)
+#define QUP_UNPACK_EN		BIT(14)
+#define QUP_PACK_EN		BIT(15)
+
+#define QUP_REPACK_EN		(QUP_UNPACK_EN | QUP_PACK_EN)
+
+#define QUP_OUTPUT_BLOCK_SIZE(x)(((x) >> 0) & 0x03)
+#define QUP_OUTPUT_FIFO_SIZE(x)	(((x) >> 2) & 0x07)
+#define QUP_INPUT_BLOCK_SIZE(x)	(((x) >> 5) & 0x03)
+#define QUP_INPUT_FIFO_SIZE(x)	(((x) >> 7) & 0x07)
+
+/* QUP tags */
+#define QUP_TAG_START		(1 << 8)
+#define QUP_TAG_DATA		(2 << 8)
+#define QUP_TAG_STOP		(3 << 8)
+#define QUP_TAG_REC		(4 << 8)
+
+/* Status, Error flags */
+#define I2C_STATUS_WR_BUFFER_FULL	BIT(0)
+#define I2C_STATUS_BUS_ACTIVE		BIT(8)
+#define I2C_STATUS_ERROR_MASK		0x38000fc
+#define QUP_STATUS_ERROR_FLAGS		0x7c
+
+#define QUP_READ_LIMIT			256
+
+struct qup_i2c_dev {
+	struct device		*dev;
+	void __iomem		*base;
+	int			irq;
+	struct clk		*clk;
+	struct clk		*pclk;
+	struct i2c_adapter	adap;
+
+	int			clk_ctl;
+	int			out_fifo_sz;
+	int			in_fifo_sz;
+	int			out_blk_sz;
+	int			in_blk_sz;
+
+	unsigned long		one_byte_t;
+
+	struct i2c_msg		*msg;
+	/* Current posion in user message buffer */
+	int			pos;
+	/* I2C protocol errors */
+	u32			bus_err;
+	/* QUP core errors */
+	u32			qup_err;
+
+	struct completion	xfer;
+};
+
+static irqreturn_t qup_i2c_interrupt(int irq, void *dev)
+{
+	struct qup_i2c_dev *qup = dev;
+	u32 bus_err;
+	u32 qup_err;
+	u32 opflags;
+
+	bus_err = readl(qup->base + QUP_I2C_STATUS);
+	qup_err = readl(qup->base + QUP_ERROR_FLAGS);
+	opflags = readl(qup->base + QUP_OPERATIONAL);
+
+	if (!qup->msg) {
+		/* Clear Error interrupt */
+		writel(QUP_RESET_STATE, qup->base + QUP_STATE);
+		return IRQ_HANDLED;
+	}
+
+	bus_err &= I2C_STATUS_ERROR_MASK;
+	qup_err &= QUP_STATUS_ERROR_FLAGS;
+
+	if (qup_err) {
+		/* Clear Error interrupt */
+		writel(qup_err, qup->base + QUP_ERROR_FLAGS);
+		goto done;
+	}
+
+	if (bus_err) {
+		/* Clear Error interrupt */
+		writel(QUP_RESET_STATE, qup->base + QUP_STATE);
+		goto done;
+	}
+
+	if (opflags & QUP_IN_SVC_FLAG)
+		writel(QUP_IN_SVC_FLAG, qup->base + QUP_OPERATIONAL);
+
+	if (opflags & QUP_OUT_SVC_FLAG)
+		writel(QUP_OUT_SVC_FLAG, qup->base + QUP_OPERATIONAL);
+
+done:
+	qup->qup_err = qup_err;
+	qup->bus_err = bus_err;
+	complete(&qup->xfer);
+	return IRQ_HANDLED;
+}
+
+static int qup_i2c_poll_state_mask(struct qup_i2c_dev *qup,
+				   u32 req_state, u32 req_mask)
+{
+	int retries = 1;
+	u32 state;
+
+	/*
+	 * State transition takes 3 AHB clocks cycles + 3 I2C master clock
+	 * cycles. So retry once after a 1uS delay.
+	 */
+	do {
+		state = readl(qup->base + QUP_STATE);
+
+		if (state & QUP_STATE_VALID &&
+		    (state & req_mask) == req_state)
+			return 0;
+
+		udelay(1);
+	} while (retries--);
+
+	return -ETIMEDOUT;
+}
+
+static int qup_i2c_poll_state(struct qup_i2c_dev *qup, u32 req_state)
+{
+	return qup_i2c_poll_state_mask(qup, req_state, QUP_STATE_MASK);
+}
+
+static int qup_i2c_poll_state_valid(struct qup_i2c_dev *qup)
+{
+	return qup_i2c_poll_state_mask(qup, 0, 0);
+}
+
+static int qup_i2c_poll_state_i2c_master(struct qup_i2c_dev *qup)
+{
+	return qup_i2c_poll_state_mask(qup, QUP_I2C_MAST_GEN, QUP_I2C_MAST_GEN);
+}
+
+static int qup_i2c_change_state(struct qup_i2c_dev *qup, u32 state)
+{
+	if (qup_i2c_poll_state_valid(qup) != 0)
+		return -EIO;
+
+	writel(state, qup->base + QUP_STATE);
+
+	if (qup_i2c_poll_state(qup, state) != 0)
+		return -EIO;
+	return 0;
+}
+
+static int qup_i2c_wait_writeready(struct qup_i2c_dev *qup)
+{
+	unsigned long timeout;
+	u32 opflags;
+	u32 status;
+
+	timeout = jiffies + HZ;
+
+	for (;;) {
+		opflags = readl(qup->base + QUP_OPERATIONAL);
+		status = readl(qup->base + QUP_I2C_STATUS);
+
+		if (!(opflags & QUP_OUT_NOT_EMPTY) &&
+		    !(status & I2C_STATUS_BUS_ACTIVE))
+			return 0;
+
+		if (time_after(jiffies, timeout))
+			return -ETIMEDOUT;
+
+		usleep_range(qup->one_byte_t, qup->one_byte_t * 2);
+	}
+}
+
+static void qup_i2c_set_write_mode(struct qup_i2c_dev *qup, struct i2c_msg *msg)
+{
+	/* Number of entries to shift out, including the start */
+	int total = msg->len + 1;
+
+	if (total < qup->out_fifo_sz) {
+		/* FIFO mode */
+		writel(QUP_REPACK_EN, qup->base + QUP_IO_MODE);
+		writel(total, qup->base + QUP_MX_WRITE_CNT);
+	} else {
+		/* BLOCK mode (transfer data on chunks) */
+		writel(QUP_OUTPUT_BLK_MODE | QUP_REPACK_EN,
+		       qup->base + QUP_IO_MODE);
+		writel(total, qup->base + QUP_MX_OUTPUT_CNT);
+	}
+}
+
+static void qup_i2c_issue_write(struct qup_i2c_dev *qup, struct i2c_msg *msg)
+{
+	u32 addr = msg->addr << 1;
+	u32 qup_tag;
+	u32 opflags;
+	int idx;
+	u32 val;
+
+	if (qup->pos == 0) {
+		val = QUP_TAG_START | addr;
+		idx = 1;
+	} else {
+		val = 0;
+		idx = 0;
+	}
+
+	while (qup->pos < msg->len) {
+		/* Check that there's space in the FIFO for our pair */
+		opflags = readl(qup->base + QUP_OPERATIONAL);
+		if (opflags & QUP_OUT_FULL)
+			break;
+
+		if (qup->pos == msg->len - 1)
+			qup_tag = QUP_TAG_STOP;
+		else
+			qup_tag = QUP_TAG_DATA;
+
+		if (idx & 1)
+			val |= (qup_tag | msg->buf[qup->pos]) << QUP_MSW_SHIFT;
+		else
+			val = qup_tag | msg->buf[qup->pos];
+
+		/* Write out the pair and the last odd value */
+		if (idx & 1 || qup->pos == msg->len - 1)
+			writel(val, qup->base + QUP_OUT_FIFO_BASE);
+
+		qup->pos++;
+		idx++;
+	}
+}
+
+static int qup_i2c_write_one(struct qup_i2c_dev *qup, struct i2c_msg *msg)
+{
+	unsigned long left;
+	int ret;
+
+	qup->msg = msg;
+	qup->pos = 0;
+
+	enable_irq(qup->irq);
+
+	qup_i2c_set_write_mode(qup, msg);
+
+	ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
+	if (ret)
+		goto err;
+
+	writel(qup->clk_ctl, qup->base + QUP_I2C_CLK_CTL);
+
+	do {
+		ret = qup_i2c_change_state(qup, QUP_PAUSE_STATE);
+		if (ret)
+			goto err;
+
+		qup_i2c_issue_write(qup, msg);
+
+		ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
+		if (ret)
+			goto err;
+
+		left = wait_for_completion_timeout(&qup->xfer, HZ);
+		if (!left) {
+			writel(1, qup->base + QUP_SW_RESET);
+			ret = -ETIMEDOUT;
+			goto err;
+		}
+
+		if (qup->bus_err || qup->qup_err) {
+			if (qup->bus_err & QUP_I2C_NACK_FLAG)
+				dev_err(qup->dev, "NACK from %x\n", msg->addr);
+			ret = -EIO;
+			goto err;
+		}
+	} while (qup->pos < msg->len);
+
+	/* Wait for the outstanding data in the fifo to drain */
+	ret = qup_i2c_wait_writeready(qup);
+
+err:
+	disable_irq(qup->irq);
+	qup->msg = NULL;
+
+	return ret;
+}
+
+static void qup_i2c_set_read_mode(struct qup_i2c_dev *qup, int len)
+{
+	if (len < qup->in_fifo_sz) {
+		/* FIFO mode */
+		writel(QUP_REPACK_EN, qup->base + QUP_IO_MODE);
+		writel(len, qup->base + QUP_MX_READ_CNT);
+	} else {
+		/* BLOCK mode (transfer data on chunks) */
+		writel(QUP_INPUT_BLK_MODE | QUP_REPACK_EN,
+		       qup->base + QUP_IO_MODE);
+		writel(len, qup->base + QUP_MX_INPUT_CNT);
+	}
+}
+
+static void qup_i2c_issue_read(struct qup_i2c_dev *qup, struct i2c_msg *msg)
+{
+	u32 addr, len, val;
+
+	addr = (msg->addr << 1) | 1;
+
+	/* 0 is used to specify a length 256 (QUP_READ_LIMIT) */
+	len = (msg->len == QUP_READ_LIMIT) ? 0 : msg->len;
+
+	val = ((QUP_TAG_REC | len) << QUP_MSW_SHIFT) | QUP_TAG_START | addr;
+	writel(val, qup->base + QUP_OUT_FIFO_BASE);
+}
+
+
+static void qup_i2c_read_fifo(struct qup_i2c_dev *qup, struct i2c_msg *msg)
+{
+	u32 opflags;
+	u32 val = 0;
+	int idx;
+
+	for (idx = 0; qup->pos < msg->len; idx++) {
+		if ((idx & 1) == 0) {
+			/* Check that FIFO have data */
+			opflags = readl(qup->base + QUP_OPERATIONAL);
+			if (!(opflags & QUP_IN_NOT_EMPTY))
+				break;
+
+			/* Reading 2 words at time */
+			val = readl(qup->base + QUP_IN_FIFO_BASE);
+
+			msg->buf[qup->pos++] = val & 0xFF;
+		} else {
+			msg->buf[qup->pos++] = val >> QUP_MSW_SHIFT;
+		}
+	}
+}
+
+static int qup_i2c_read_one(struct qup_i2c_dev *qup, struct i2c_msg *msg)
+{
+	unsigned long left;
+	int ret;
+
+	/*
+	 * The QUP block will issue a NACK and STOP on the bus when reaching
+	 * the end of the read, the length of the read is specified as one byte
+	 * which limits the possible read to 256 (QUP_READ_LIMIT) bytes.
+	 */
+	if (msg->len > QUP_READ_LIMIT) {
+		dev_err(qup->dev, "HW not capable of reads over %d bytes\n",
+			QUP_READ_LIMIT);
+		return -EINVAL;
+	}
+
+	qup->msg = msg;
+	qup->pos  = 0;
+
+	enable_irq(qup->irq);
+
+	qup_i2c_set_read_mode(qup, msg->len);
+
+	ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
+	if (ret)
+		goto err;
+
+	writel(qup->clk_ctl, qup->base + QUP_I2C_CLK_CTL);
+
+	ret = qup_i2c_change_state(qup, QUP_PAUSE_STATE);
+	if (ret)
+		goto err;
+
+	qup_i2c_issue_read(qup, msg);
+
+	ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
+	if (ret)
+		goto err;
+
+	do {
+		left = wait_for_completion_timeout(&qup->xfer, HZ);
+		if (!left) {
+			writel(1, qup->base + QUP_SW_RESET);
+			ret = -ETIMEDOUT;
+			goto err;
+		}
+
+		if (qup->bus_err || qup->qup_err) {
+			if (qup->bus_err & QUP_I2C_NACK_FLAG)
+				dev_err(qup->dev, "NACK from %x\n", msg->addr);
+			ret = -EIO;
+			goto err;
+		}
+
+		qup_i2c_read_fifo(qup, msg);
+	} while (qup->pos < msg->len);
+
+err:
+	disable_irq(qup->irq);
+	qup->msg = NULL;
+
+	return ret;
+}
+
+static int qup_i2c_xfer(struct i2c_adapter *adap,
+			struct i2c_msg msgs[],
+			int num)
+{
+	struct qup_i2c_dev *qup = i2c_get_adapdata(adap);
+	int ret, idx;
+
+	ret = pm_runtime_get_sync(qup->dev);
+	if (ret)
+		goto out;
+
+	writel(1, qup->base + QUP_SW_RESET);
+	ret = qup_i2c_poll_state(qup, QUP_RESET_STATE);
+	if (ret)
+		goto out;
+
+	/* Configure QUP as I2C mini core */
+	writel(I2C_MINI_CORE | I2C_N_VAL, qup->base + QUP_CONFIG);
+
+	for (idx = 0; idx < num; idx++) {
+		if (msgs[idx].len == 0) {
+			ret = -EINVAL;
+			goto out;
+		}
+
+		if (qup_i2c_poll_state_i2c_master(qup)) {
+			ret = -EIO;
+			goto out;
+		}
+
+		if (msgs[idx].flags & I2C_M_RD)
+			ret = qup_i2c_read_one(qup, &msgs[idx]);
+		else
+			ret = qup_i2c_write_one(qup, &msgs[idx]);
+
+		if (ret)
+			break;
+
+		ret = qup_i2c_change_state(qup, QUP_RESET_STATE);
+		if (ret)
+			break;
+	}
+
+	if (ret == 0)
+		ret = num;
+out:
+
+	pm_runtime_mark_last_busy(qup->dev);
+	pm_runtime_put_autosuspend(qup->dev);
+
+	return ret;
+}
+
+static u32 qup_i2c_func(struct i2c_adapter *adap)
+{
+	return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
+}
+
+static const struct i2c_algorithm qup_i2c_algo = {
+	.master_xfer	= qup_i2c_xfer,
+	.functionality	= qup_i2c_func,
+};
+
+static void qup_i2c_enable_clocks(struct qup_i2c_dev *qup)
+{
+	clk_prepare_enable(qup->clk);
+	clk_prepare_enable(qup->pclk);
+}
+
+static void qup_i2c_disable_clocks(struct qup_i2c_dev *qup)
+{
+	u32 config;
+
+	qup_i2c_change_state(qup, QUP_RESET_STATE);
+	clk_disable_unprepare(qup->clk);
+	config = readl(qup->base + QUP_CONFIG);
+	config |= QUP_CLOCK_AUTO_GATE;
+	writel(config, qup->base + QUP_CONFIG);
+	clk_disable_unprepare(qup->pclk);
+}
+
+static int qup_i2c_probe(struct platform_device *pdev)
+{
+	static const int blk_sizes[] = {4, 16, 32};
+	struct device_node *node = pdev->dev.of_node;
+	struct qup_i2c_dev *qup;
+	unsigned long one_bit_t;
+	struct resource *res;
+	u32 io_mode, hw_ver, size;
+	int ret, fs_div, hs_div;
+	int src_clk_freq;
+	int clk_freq = 100000;
+
+	qup = devm_kzalloc(&pdev->dev, sizeof(*qup), GFP_KERNEL);
+	if (!qup)
+		return -ENOMEM;
+
+	qup->dev = &pdev->dev;
+	init_completion(&qup->xfer);
+	platform_set_drvdata(pdev, qup);
+
+	of_property_read_u32(node, "clock-frequency", &clk_freq);
+
+	/* We support frequencies up to FAST Mode (400KHz) */
+	if (!clk_freq || clk_freq > 400000) {
+		dev_err(qup->dev, "clock frequency not supported %d\n",
+			clk_freq);
+		return -EINVAL;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	qup->base = devm_ioremap_resource(qup->dev, res);
+	if (IS_ERR(qup->base))
+		return PTR_ERR(qup->base);
+
+	qup->irq = platform_get_irq(pdev, 0);
+	if (qup->irq < 0) {
+		dev_err(qup->dev, "No IRQ defined\n");
+		return qup->irq;
+	}
+
+	qup->clk = devm_clk_get(qup->dev, "core");
+	if (IS_ERR(qup->clk)) {
+		dev_err(qup->dev, "Could not get core clock\n");
+		return PTR_ERR(qup->clk);
+	}
+
+	qup->pclk = devm_clk_get(qup->dev, "iface");
+	if (IS_ERR(qup->pclk)) {
+		dev_err(qup->dev, "Could not get iface clock\n");
+		return PTR_ERR(qup->pclk);
+	}
+
+	qup_i2c_enable_clocks(qup);
+
+	/*
+	 * Bootloaders might leave a pending interrupt on certain QUP's,
+	 * so we reset the core before registering for interrupts.
+	 */
+	writel(1, qup->base + QUP_SW_RESET);
+	ret = qup_i2c_poll_state_valid(qup);
+	if (ret)
+		goto fail;
+
+	ret = devm_request_irq(qup->dev, qup->irq, qup_i2c_interrupt,
+			       IRQF_TRIGGER_HIGH, "i2c_qup", qup);
+	if (ret) {
+		dev_err(qup->dev, "Request %d IRQ failed\n", qup->irq);
+		goto fail;
+	}
+	disable_irq(qup->irq);
+
+	hw_ver = readl(qup->base + QUP_HW_VERSION);
+	dev_dbg(qup->dev, "Revision %x\n", hw_ver);
+
+	io_mode = readl(qup->base + QUP_IO_MODE);
+
+	/*
+	 * The block/fifo size w.r.t. 'actual data' is 1/2 due to 'tag'
+	 * associated with each byte written/received
+	 */
+	size = QUP_OUTPUT_BLOCK_SIZE(io_mode);
+	if (size > ARRAY_SIZE(blk_sizes))
+		return -EIO;
+	qup->out_blk_sz = blk_sizes[size] / 2;
+
+	size = QUP_INPUT_BLOCK_SIZE(io_mode);
+	if (size > ARRAY_SIZE(blk_sizes))
+		return -EIO;
+	qup->in_blk_sz = blk_sizes[size] / 2;
+
+	size = QUP_OUTPUT_FIFO_SIZE(io_mode);
+	qup->out_fifo_sz = qup->out_blk_sz * (2 << size);
+
+	size = QUP_INPUT_FIFO_SIZE(io_mode);
+	qup->in_fifo_sz = qup->in_blk_sz * (2 << size);
+
+	src_clk_freq = clk_get_rate(qup->clk);
+	fs_div = ((src_clk_freq / clk_freq) / 2) - 3;
+	hs_div = 3;
+	qup->clk_ctl = (hs_div << 8) | (fs_div & 0xff);
+
+	/*
+	 * Time it takes for a byte to be clocked out on the bus.
+	 * Each byte takes 9 clock cycles (8 bits + 1 ack).
+	 */
+	one_bit_t = (USEC_PER_SEC / clk_freq) + 1;
+	qup->one_byte_t = one_bit_t * 9;
+
+	dev_dbg(qup->dev, "IN:block:%d, fifo:%d, OUT:block:%d, fifo:%d\n",
+		qup->in_blk_sz, qup->in_fifo_sz,
+		qup->out_blk_sz, qup->out_fifo_sz);
+
+	i2c_set_adapdata(&qup->adap, qup);
+	qup->adap.algo = &qup_i2c_algo;
+	qup->adap.dev.parent = qup->dev;
+	qup->adap.dev.of_node = pdev->dev.of_node;
+	strlcpy(qup->adap.name, "QUP I2C adapter", sizeof(qup->adap.name));
+
+	ret = i2c_add_adapter(&qup->adap);
+	if (ret)
+		goto fail;
+
+	pm_runtime_set_autosuspend_delay(qup->dev, MSEC_PER_SEC);
+	pm_runtime_use_autosuspend(qup->dev);
+	pm_runtime_set_active(qup->dev);
+	pm_runtime_enable(qup->dev);
+	return 0;
+
+fail:
+	qup_i2c_disable_clocks(qup);
+	return ret;
+}
+
+static int qup_i2c_remove(struct platform_device *pdev)
+{
+	struct qup_i2c_dev *qup = platform_get_drvdata(pdev);
+
+	disable_irq(qup->irq);
+	qup_i2c_disable_clocks(qup);
+	i2c_del_adapter(&qup->adap);
+	pm_runtime_disable(qup->dev);
+	pm_runtime_set_suspended(qup->dev);
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int qup_i2c_pm_suspend_runtime(struct device *device)
+{
+	struct qup_i2c_dev *qup = dev_get_drvdata(device);
+
+	dev_dbg(device, "pm_runtime: suspending...\n");
+	qup_i2c_disable_clocks(qup);
+	return 0;
+}
+
+static int qup_i2c_pm_resume_runtime(struct device *device)
+{
+	struct qup_i2c_dev *qup = dev_get_drvdata(device);
+
+	dev_dbg(device, "pm_runtime: resuming...\n");
+	qup_i2c_enable_clocks(qup);
+	return 0;
+}
+#endif
+
+#ifdef CONFIG_PM_SLEEP
+static int qup_i2c_suspend(struct device *device)
+{
+	qup_i2c_pm_suspend_runtime(device);
+	return 0;
+}
+
+static int qup_i2c_resume(struct device *device)
+{
+	qup_i2c_pm_resume_runtime(device);
+	pm_runtime_mark_last_busy(device);
+	pm_request_autosuspend(device);
+	return 0;
+}
+#endif
+
+static const struct dev_pm_ops qup_i2c_qup_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(
+		qup_i2c_suspend,
+		qup_i2c_resume)
+	SET_RUNTIME_PM_OPS(
+		qup_i2c_pm_suspend_runtime,
+		qup_i2c_pm_resume_runtime,
+		NULL)
+};
+
+static const struct of_device_id qup_i2c_dt_match[] = {
+	{ .compatible = "qcom,i2c-qup-v1.1.1" },
+	{ .compatible = "qcom,i2c-qup-v2.1.1" },
+	{ .compatible = "qcom,i2c-qup-v2.2.1" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, qup_i2c_dt_match);
+
+static struct platform_driver qup_i2c_driver = {
+	.probe  = qup_i2c_probe,
+	.remove = qup_i2c_remove,
+	.driver = {
+		.name = "i2c_qup",
+		.owner = THIS_MODULE,
+		.pm = &qup_i2c_qup_pm_ops,
+		.of_match_table = qup_i2c_dt_match,
+	},
+};
+
+module_platform_driver(qup_i2c_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:i2c_qup");