Adding upstream version 6.1.76.upstream/6.1.76upstream

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

1 files changed, 1613 insertions, 0 deletions

diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
new file mode 100644
index 000000000..7ec252199
--- /dev/null
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -0,0 +1,1613 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * TI OMAP I2C master mode driver
+ *
+ * Copyright (C) 2003 MontaVista Software, Inc.
+ * Copyright (C) 2005 Nokia Corporation
+ * Copyright (C) 2004 - 2007 Texas Instruments.
+ *
+ * Originally written by MontaVista Software, Inc.
+ * Additional contributions by:
+ *	Tony Lindgren <tony@atomide.com>
+ *	Imre Deak <imre.deak@nokia.com>
+ *	Juha Yrjölä <juha.yrjola@solidboot.com>
+ *	Syed Khasim <x0khasim@ti.com>
+ *	Nishant Menon <nm@ti.com>
+ */
+
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/completion.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/slab.h>
+#include <linux/platform_data/i2c-omap.h>
+#include <linux/pm_runtime.h>
+#include <linux/pinctrl/consumer.h>
+
+/* I2C controller revisions */
+#define OMAP_I2C_OMAP1_REV_2		0x20
+
+/* I2C controller revisions present on specific hardware */
+#define OMAP_I2C_REV_ON_2430		0x00000036
+#define OMAP_I2C_REV_ON_3430_3530	0x0000003C
+#define OMAP_I2C_REV_ON_3630		0x00000040
+#define OMAP_I2C_REV_ON_4430_PLUS	0x50400002
+
+/* timeout waiting for the controller to respond */
+#define OMAP_I2C_TIMEOUT (msecs_to_jiffies(1000))
+
+/* timeout for pm runtime autosuspend */
+#define OMAP_I2C_PM_TIMEOUT		1000	/* ms */
+
+/* timeout for making decision on bus free status */
+#define OMAP_I2C_BUS_FREE_TIMEOUT (msecs_to_jiffies(10))
+
+/* For OMAP3 I2C_IV has changed to I2C_WE (wakeup enable) */
+enum {
+	OMAP_I2C_REV_REG = 0,
+	OMAP_I2C_IE_REG,
+	OMAP_I2C_STAT_REG,
+	OMAP_I2C_IV_REG,
+	OMAP_I2C_WE_REG,
+	OMAP_I2C_SYSS_REG,
+	OMAP_I2C_BUF_REG,
+	OMAP_I2C_CNT_REG,
+	OMAP_I2C_DATA_REG,
+	OMAP_I2C_SYSC_REG,
+	OMAP_I2C_CON_REG,
+	OMAP_I2C_OA_REG,
+	OMAP_I2C_SA_REG,
+	OMAP_I2C_PSC_REG,
+	OMAP_I2C_SCLL_REG,
+	OMAP_I2C_SCLH_REG,
+	OMAP_I2C_SYSTEST_REG,
+	OMAP_I2C_BUFSTAT_REG,
+	/* only on OMAP4430 */
+	OMAP_I2C_IP_V2_REVNB_LO,
+	OMAP_I2C_IP_V2_REVNB_HI,
+	OMAP_I2C_IP_V2_IRQSTATUS_RAW,
+	OMAP_I2C_IP_V2_IRQENABLE_SET,
+	OMAP_I2C_IP_V2_IRQENABLE_CLR,
+};
+
+/* I2C Interrupt Enable Register (OMAP_I2C_IE): */
+#define OMAP_I2C_IE_XDR		(1 << 14)	/* TX Buffer drain int enable */
+#define OMAP_I2C_IE_RDR		(1 << 13)	/* RX Buffer drain int enable */
+#define OMAP_I2C_IE_XRDY	(1 << 4)	/* TX data ready int enable */
+#define OMAP_I2C_IE_RRDY	(1 << 3)	/* RX data ready int enable */
+#define OMAP_I2C_IE_ARDY	(1 << 2)	/* Access ready int enable */
+#define OMAP_I2C_IE_NACK	(1 << 1)	/* No ack interrupt enable */
+#define OMAP_I2C_IE_AL		(1 << 0)	/* Arbitration lost int ena */
+
+/* I2C Status Register (OMAP_I2C_STAT): */
+#define OMAP_I2C_STAT_XDR	(1 << 14)	/* TX Buffer draining */
+#define OMAP_I2C_STAT_RDR	(1 << 13)	/* RX Buffer draining */
+#define OMAP_I2C_STAT_BB	(1 << 12)	/* Bus busy */
+#define OMAP_I2C_STAT_ROVR	(1 << 11)	/* Receive overrun */
+#define OMAP_I2C_STAT_XUDF	(1 << 10)	/* Transmit underflow */
+#define OMAP_I2C_STAT_AAS	(1 << 9)	/* Address as slave */
+#define OMAP_I2C_STAT_BF	(1 << 8)	/* Bus Free */
+#define OMAP_I2C_STAT_XRDY	(1 << 4)	/* Transmit data ready */
+#define OMAP_I2C_STAT_RRDY	(1 << 3)	/* Receive data ready */
+#define OMAP_I2C_STAT_ARDY	(1 << 2)	/* Register access ready */
+#define OMAP_I2C_STAT_NACK	(1 << 1)	/* No ack interrupt enable */
+#define OMAP_I2C_STAT_AL	(1 << 0)	/* Arbitration lost int ena */
+
+/* I2C WE wakeup enable register */
+#define OMAP_I2C_WE_XDR_WE	(1 << 14)	/* TX drain wakup */
+#define OMAP_I2C_WE_RDR_WE	(1 << 13)	/* RX drain wakeup */
+#define OMAP_I2C_WE_AAS_WE	(1 << 9)	/* Address as slave wakeup*/
+#define OMAP_I2C_WE_BF_WE	(1 << 8)	/* Bus free wakeup */
+#define OMAP_I2C_WE_STC_WE	(1 << 6)	/* Start condition wakeup */
+#define OMAP_I2C_WE_GC_WE	(1 << 5)	/* General call wakeup */
+#define OMAP_I2C_WE_DRDY_WE	(1 << 3)	/* TX/RX data ready wakeup */
+#define OMAP_I2C_WE_ARDY_WE	(1 << 2)	/* Reg access ready wakeup */
+#define OMAP_I2C_WE_NACK_WE	(1 << 1)	/* No acknowledgment wakeup */
+#define OMAP_I2C_WE_AL_WE	(1 << 0)	/* Arbitration lost wakeup */
+
+#define OMAP_I2C_WE_ALL		(OMAP_I2C_WE_XDR_WE | OMAP_I2C_WE_RDR_WE | \
+				OMAP_I2C_WE_AAS_WE | OMAP_I2C_WE_BF_WE | \
+				OMAP_I2C_WE_STC_WE | OMAP_I2C_WE_GC_WE | \
+				OMAP_I2C_WE_DRDY_WE | OMAP_I2C_WE_ARDY_WE | \
+				OMAP_I2C_WE_NACK_WE | OMAP_I2C_WE_AL_WE)
+
+/* I2C Buffer Configuration Register (OMAP_I2C_BUF): */
+#define OMAP_I2C_BUF_RDMA_EN	(1 << 15)	/* RX DMA channel enable */
+#define OMAP_I2C_BUF_RXFIF_CLR	(1 << 14)	/* RX FIFO Clear */
+#define OMAP_I2C_BUF_XDMA_EN	(1 << 7)	/* TX DMA channel enable */
+#define OMAP_I2C_BUF_TXFIF_CLR	(1 << 6)	/* TX FIFO Clear */
+
+/* I2C Configuration Register (OMAP_I2C_CON): */
+#define OMAP_I2C_CON_EN		(1 << 15)	/* I2C module enable */
+#define OMAP_I2C_CON_BE		(1 << 14)	/* Big endian mode */
+#define OMAP_I2C_CON_OPMODE_HS	(1 << 12)	/* High Speed support */
+#define OMAP_I2C_CON_STB	(1 << 11)	/* Start byte mode (master) */
+#define OMAP_I2C_CON_MST	(1 << 10)	/* Master/slave mode */
+#define OMAP_I2C_CON_TRX	(1 << 9)	/* TX/RX mode (master only) */
+#define OMAP_I2C_CON_XA		(1 << 8)	/* Expand address */
+#define OMAP_I2C_CON_RM		(1 << 2)	/* Repeat mode (master only) */
+#define OMAP_I2C_CON_STP	(1 << 1)	/* Stop cond (master only) */
+#define OMAP_I2C_CON_STT	(1 << 0)	/* Start condition (master) */
+
+/* I2C SCL time value when Master */
+#define OMAP_I2C_SCLL_HSSCLL	8
+#define OMAP_I2C_SCLH_HSSCLH	8
+
+/* I2C System Test Register (OMAP_I2C_SYSTEST): */
+#define OMAP_I2C_SYSTEST_ST_EN		(1 << 15)	/* System test enable */
+#define OMAP_I2C_SYSTEST_FREE		(1 << 14)	/* Free running mode */
+#define OMAP_I2C_SYSTEST_TMODE_MASK	(3 << 12)	/* Test mode select */
+#define OMAP_I2C_SYSTEST_TMODE_SHIFT	(12)		/* Test mode select */
+/* Functional mode */
+#define OMAP_I2C_SYSTEST_SCL_I_FUNC	(1 << 8)	/* SCL line input value */
+#define OMAP_I2C_SYSTEST_SCL_O_FUNC	(1 << 7)	/* SCL line output value */
+#define OMAP_I2C_SYSTEST_SDA_I_FUNC	(1 << 6)	/* SDA line input value */
+#define OMAP_I2C_SYSTEST_SDA_O_FUNC	(1 << 5)	/* SDA line output value */
+/* SDA/SCL IO mode */
+#define OMAP_I2C_SYSTEST_SCL_I		(1 << 3)	/* SCL line sense in */
+#define OMAP_I2C_SYSTEST_SCL_O		(1 << 2)	/* SCL line drive out */
+#define OMAP_I2C_SYSTEST_SDA_I		(1 << 1)	/* SDA line sense in */
+#define OMAP_I2C_SYSTEST_SDA_O		(1 << 0)	/* SDA line drive out */
+
+/* OCP_SYSSTATUS bit definitions */
+#define SYSS_RESETDONE_MASK		(1 << 0)
+
+/* OCP_SYSCONFIG bit definitions */
+#define SYSC_CLOCKACTIVITY_MASK		(0x3 << 8)
+#define SYSC_SIDLEMODE_MASK		(0x3 << 3)
+#define SYSC_ENAWAKEUP_MASK		(1 << 2)
+#define SYSC_SOFTRESET_MASK		(1 << 1)
+#define SYSC_AUTOIDLE_MASK		(1 << 0)
+
+#define SYSC_IDLEMODE_SMART		0x2
+#define SYSC_CLOCKACTIVITY_FCLK		0x2
+
+/* Errata definitions */
+#define I2C_OMAP_ERRATA_I207		(1 << 0)
+#define I2C_OMAP_ERRATA_I462		(1 << 1)
+
+#define OMAP_I2C_IP_V2_INTERRUPTS_MASK	0x6FFF
+
+struct omap_i2c_dev {
+	struct device		*dev;
+	void __iomem		*base;		/* virtual */
+	int			irq;
+	int			reg_shift;      /* bit shift for I2C register addresses */
+	struct completion	cmd_complete;
+	struct resource		*ioarea;
+	u32			latency;	/* maximum mpu wkup latency */
+	void			(*set_mpu_wkup_lat)(struct device *dev,
+						    long latency);
+	u32			speed;		/* Speed of bus in kHz */
+	u32			flags;
+	u16			scheme;
+	u16			cmd_err;
+	u8			*buf;
+	u8			*regs;
+	size_t			buf_len;
+	struct i2c_adapter	adapter;
+	u8			threshold;
+	u8			fifo_size;	/* use as flag and value
+						 * fifo_size==0 implies no fifo
+						 * if set, should be trsh+1
+						 */
+	u32			rev;
+	unsigned		b_hw:1;		/* bad h/w fixes */
+	unsigned		bb_valid:1;	/* true when BB-bit reflects
+						 * the I2C bus state
+						 */
+	unsigned		receiver:1;	/* true when we're in receiver mode */
+	u16			iestate;	/* Saved interrupt register */
+	u16			pscstate;
+	u16			scllstate;
+	u16			sclhstate;
+	u16			syscstate;
+	u16			westate;
+	u16			errata;
+};
+
+static const u8 reg_map_ip_v1[] = {
+	[OMAP_I2C_REV_REG] = 0x00,
+	[OMAP_I2C_IE_REG] = 0x01,
+	[OMAP_I2C_STAT_REG] = 0x02,
+	[OMAP_I2C_IV_REG] = 0x03,
+	[OMAP_I2C_WE_REG] = 0x03,
+	[OMAP_I2C_SYSS_REG] = 0x04,
+	[OMAP_I2C_BUF_REG] = 0x05,
+	[OMAP_I2C_CNT_REG] = 0x06,
+	[OMAP_I2C_DATA_REG] = 0x07,
+	[OMAP_I2C_SYSC_REG] = 0x08,
+	[OMAP_I2C_CON_REG] = 0x09,
+	[OMAP_I2C_OA_REG] = 0x0a,
+	[OMAP_I2C_SA_REG] = 0x0b,
+	[OMAP_I2C_PSC_REG] = 0x0c,
+	[OMAP_I2C_SCLL_REG] = 0x0d,
+	[OMAP_I2C_SCLH_REG] = 0x0e,
+	[OMAP_I2C_SYSTEST_REG] = 0x0f,
+	[OMAP_I2C_BUFSTAT_REG] = 0x10,
+};
+
+static const u8 reg_map_ip_v2[] = {
+	[OMAP_I2C_REV_REG] = 0x04,
+	[OMAP_I2C_IE_REG] = 0x2c,
+	[OMAP_I2C_STAT_REG] = 0x28,
+	[OMAP_I2C_IV_REG] = 0x34,
+	[OMAP_I2C_WE_REG] = 0x34,
+	[OMAP_I2C_SYSS_REG] = 0x90,
+	[OMAP_I2C_BUF_REG] = 0x94,
+	[OMAP_I2C_CNT_REG] = 0x98,
+	[OMAP_I2C_DATA_REG] = 0x9c,
+	[OMAP_I2C_SYSC_REG] = 0x10,
+	[OMAP_I2C_CON_REG] = 0xa4,
+	[OMAP_I2C_OA_REG] = 0xa8,
+	[OMAP_I2C_SA_REG] = 0xac,
+	[OMAP_I2C_PSC_REG] = 0xb0,
+	[OMAP_I2C_SCLL_REG] = 0xb4,
+	[OMAP_I2C_SCLH_REG] = 0xb8,
+	[OMAP_I2C_SYSTEST_REG] = 0xbC,
+	[OMAP_I2C_BUFSTAT_REG] = 0xc0,
+	[OMAP_I2C_IP_V2_REVNB_LO] = 0x00,
+	[OMAP_I2C_IP_V2_REVNB_HI] = 0x04,
+	[OMAP_I2C_IP_V2_IRQSTATUS_RAW] = 0x24,
+	[OMAP_I2C_IP_V2_IRQENABLE_SET] = 0x2c,
+	[OMAP_I2C_IP_V2_IRQENABLE_CLR] = 0x30,
+};
+
+static int omap_i2c_xfer_data(struct omap_i2c_dev *omap);
+
+static inline void omap_i2c_write_reg(struct omap_i2c_dev *omap,
+				      int reg, u16 val)
+{
+	writew_relaxed(val, omap->base +
+			(omap->regs[reg] << omap->reg_shift));
+}
+
+static inline u16 omap_i2c_read_reg(struct omap_i2c_dev *omap, int reg)
+{
+	return readw_relaxed(omap->base +
+				(omap->regs[reg] << omap->reg_shift));
+}
+
+static void __omap_i2c_init(struct omap_i2c_dev *omap)
+{
+
+	omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, 0);
+
+	/* Setup clock prescaler to obtain approx 12MHz I2C module clock: */
+	omap_i2c_write_reg(omap, OMAP_I2C_PSC_REG, omap->pscstate);
+
+	/* SCL low and high time values */
+	omap_i2c_write_reg(omap, OMAP_I2C_SCLL_REG, omap->scllstate);
+	omap_i2c_write_reg(omap, OMAP_I2C_SCLH_REG, omap->sclhstate);
+	if (omap->rev >= OMAP_I2C_REV_ON_3430_3530)
+		omap_i2c_write_reg(omap, OMAP_I2C_WE_REG, omap->westate);
+
+	/* Take the I2C module out of reset: */
+	omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
+
+	/*
+	 * NOTE: right after setting CON_EN, STAT_BB could be 0 while the
+	 * bus is busy. It will be changed to 1 on the next IP FCLK clock.
+	 * udelay(1) will be enough to fix that.
+	 */
+
+	/*
+	 * Don't write to this register if the IE state is 0 as it can
+	 * cause deadlock.
+	 */
+	if (omap->iestate)
+		omap_i2c_write_reg(omap, OMAP_I2C_IE_REG, omap->iestate);
+}
+
+static int omap_i2c_reset(struct omap_i2c_dev *omap)
+{
+	unsigned long timeout;
+	u16 sysc;
+
+	if (omap->rev >= OMAP_I2C_OMAP1_REV_2) {
+		sysc = omap_i2c_read_reg(omap, OMAP_I2C_SYSC_REG);
+
+		/* Disable I2C controller before soft reset */
+		omap_i2c_write_reg(omap, OMAP_I2C_CON_REG,
+			omap_i2c_read_reg(omap, OMAP_I2C_CON_REG) &
+				~(OMAP_I2C_CON_EN));
+
+		omap_i2c_write_reg(omap, OMAP_I2C_SYSC_REG, SYSC_SOFTRESET_MASK);
+		/* For some reason we need to set the EN bit before the
+		 * reset done bit gets set. */
+		timeout = jiffies + OMAP_I2C_TIMEOUT;
+		omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
+		while (!(omap_i2c_read_reg(omap, OMAP_I2C_SYSS_REG) &
+			 SYSS_RESETDONE_MASK)) {
+			if (time_after(jiffies, timeout)) {
+				dev_warn(omap->dev, "timeout waiting "
+						"for controller reset\n");
+				return -ETIMEDOUT;
+			}
+			msleep(1);
+		}
+
+		/* SYSC register is cleared by the reset; rewrite it */
+		omap_i2c_write_reg(omap, OMAP_I2C_SYSC_REG, sysc);
+
+		if (omap->rev > OMAP_I2C_REV_ON_3430_3530) {
+			/* Schedule I2C-bus monitoring on the next transfer */
+			omap->bb_valid = 0;
+		}
+	}
+
+	return 0;
+}
+
+static int omap_i2c_init(struct omap_i2c_dev *omap)
+{
+	u16 psc = 0, scll = 0, sclh = 0;
+	u16 fsscll = 0, fssclh = 0, hsscll = 0, hssclh = 0;
+	unsigned long fclk_rate = 12000000;
+	unsigned long internal_clk = 0;
+	struct clk *fclk;
+	int error;
+
+	if (omap->rev >= OMAP_I2C_REV_ON_3430_3530) {
+		/*
+		 * Enabling all wakup sources to stop I2C freezing on
+		 * WFI instruction.
+		 * REVISIT: Some wkup sources might not be needed.
+		 */
+		omap->westate = OMAP_I2C_WE_ALL;
+	}
+
+	if (omap->flags & OMAP_I2C_FLAG_ALWAYS_ARMXOR_CLK) {
+		/*
+		 * The I2C functional clock is the armxor_ck, so there's
+		 * no need to get "armxor_ck" separately.  Now, if OMAP2420
+		 * always returns 12MHz for the functional clock, we can
+		 * do this bit unconditionally.
+		 */
+		fclk = clk_get(omap->dev, "fck");
+		if (IS_ERR(fclk)) {
+			error = PTR_ERR(fclk);
+			dev_err(omap->dev, "could not get fck: %i\n", error);
+
+			return error;
+		}
+
+		fclk_rate = clk_get_rate(fclk);
+		clk_put(fclk);
+
+		/* TRM for 5912 says the I2C clock must be prescaled to be
+		 * between 7 - 12 MHz. The XOR input clock is typically
+		 * 12, 13 or 19.2 MHz. So we should have code that produces:
+		 *
+		 * XOR MHz	Divider		Prescaler
+		 * 12		1		0
+		 * 13		2		1
+		 * 19.2		2		1
+		 */
+		if (fclk_rate > 12000000)
+			psc = fclk_rate / 12000000;
+	}
+
+	if (!(omap->flags & OMAP_I2C_FLAG_SIMPLE_CLOCK)) {
+
+		/*
+		 * HSI2C controller internal clk rate should be 19.2 Mhz for
+		 * HS and for all modes on 2430. On 34xx we can use lower rate
+		 * to get longer filter period for better noise suppression.
+		 * The filter is iclk (fclk for HS) period.
+		 */
+		if (omap->speed > 400 ||
+			       omap->flags & OMAP_I2C_FLAG_FORCE_19200_INT_CLK)
+			internal_clk = 19200;
+		else if (omap->speed > 100)
+			internal_clk = 9600;
+		else
+			internal_clk = 4000;
+		fclk = clk_get(omap->dev, "fck");
+		if (IS_ERR(fclk)) {
+			error = PTR_ERR(fclk);
+			dev_err(omap->dev, "could not get fck: %i\n", error);
+
+			return error;
+		}
+		fclk_rate = clk_get_rate(fclk) / 1000;
+		clk_put(fclk);
+
+		/* Compute prescaler divisor */
+		psc = fclk_rate / internal_clk;
+		psc = psc - 1;
+
+		/* If configured for High Speed */
+		if (omap->speed > 400) {
+			unsigned long scl;
+
+			/* For first phase of HS mode */
+			scl = internal_clk / 400;
+			fsscll = scl - (scl / 3) - 7;
+			fssclh = (scl / 3) - 5;
+
+			/* For second phase of HS mode */
+			scl = fclk_rate / omap->speed;
+			hsscll = scl - (scl / 3) - 7;
+			hssclh = (scl / 3) - 5;
+		} else if (omap->speed > 100) {
+			unsigned long scl;
+
+			/* Fast mode */
+			scl = internal_clk / omap->speed;
+			fsscll = scl - (scl / 3) - 7;
+			fssclh = (scl / 3) - 5;
+		} else {
+			/* Standard mode */
+			fsscll = internal_clk / (omap->speed * 2) - 7;
+			fssclh = internal_clk / (omap->speed * 2) - 5;
+		}
+		scll = (hsscll << OMAP_I2C_SCLL_HSSCLL) | fsscll;
+		sclh = (hssclh << OMAP_I2C_SCLH_HSSCLH) | fssclh;
+	} else {
+		/* Program desired operating rate */
+		fclk_rate /= (psc + 1) * 1000;
+		if (psc > 2)
+			psc = 2;
+		scll = fclk_rate / (omap->speed * 2) - 7 + psc;
+		sclh = fclk_rate / (omap->speed * 2) - 7 + psc;
+	}
+
+	omap->iestate = (OMAP_I2C_IE_XRDY | OMAP_I2C_IE_RRDY |
+			OMAP_I2C_IE_ARDY | OMAP_I2C_IE_NACK |
+			OMAP_I2C_IE_AL)  | ((omap->fifo_size) ?
+				(OMAP_I2C_IE_RDR | OMAP_I2C_IE_XDR) : 0);
+
+	omap->pscstate = psc;
+	omap->scllstate = scll;
+	omap->sclhstate = sclh;
+
+	if (omap->rev <= OMAP_I2C_REV_ON_3430_3530) {
+		/* Not implemented */
+		omap->bb_valid = 1;
+	}
+
+	__omap_i2c_init(omap);
+
+	return 0;
+}
+
+/*
+ * Try bus recovery, but only if SDA is actually low.
+ */
+static int omap_i2c_recover_bus(struct omap_i2c_dev *omap)
+{
+	u16 systest;
+
+	systest = omap_i2c_read_reg(omap, OMAP_I2C_SYSTEST_REG);
+	if ((systest & OMAP_I2C_SYSTEST_SCL_I_FUNC) &&
+	    (systest & OMAP_I2C_SYSTEST_SDA_I_FUNC))
+		return 0; /* bus seems to already be fine */
+	if (!(systest & OMAP_I2C_SYSTEST_SCL_I_FUNC))
+		return -EBUSY; /* recovery would not fix SCL */
+	return i2c_recover_bus(&omap->adapter);
+}
+
+/*
+ * Waiting on Bus Busy
+ */
+static int omap_i2c_wait_for_bb(struct omap_i2c_dev *omap)
+{
+	unsigned long timeout;
+
+	timeout = jiffies + OMAP_I2C_TIMEOUT;
+	while (omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG) & OMAP_I2C_STAT_BB) {
+		if (time_after(jiffies, timeout))
+			return omap_i2c_recover_bus(omap);
+		msleep(1);
+	}
+
+	return 0;
+}
+
+/*
+ * Wait while BB-bit doesn't reflect the I2C bus state
+ *
+ * In a multimaster environment, after IP software reset, BB-bit value doesn't
+ * correspond to the current bus state. It may happen what BB-bit will be 0,
+ * while the bus is busy due to another I2C master activity.
+ * Here are BB-bit values after reset:
+ *     SDA   SCL   BB   NOTES
+ *       0     0    0   1, 2
+ *       1     0    0   1, 2
+ *       0     1    1
+ *       1     1    0   3
+ * Later, if IP detect SDA=0 and SCL=1 (ACK) or SDA 1->0 while SCL=1 (START)
+ * combinations on the bus, it set BB-bit to 1.
+ * If IP detect SDA 0->1 while SCL=1 (STOP) combination on the bus,
+ * it set BB-bit to 0 and BF to 1.
+ * BB and BF bits correctly tracks the bus state while IP is suspended
+ * BB bit became valid on the next FCLK clock after CON_EN bit set
+ *
+ * NOTES:
+ * 1. Any transfer started when BB=0 and bus is busy wouldn't be
+ *    completed by IP and results in controller timeout.
+ * 2. Any transfer started when BB=0 and SCL=0 results in IP
+ *    starting to drive SDA low. In that case IP corrupt data
+ *    on the bus.
+ * 3. Any transfer started in the middle of another master's transfer
+ *    results in unpredictable results and data corruption
+ */
+static int omap_i2c_wait_for_bb_valid(struct omap_i2c_dev *omap)
+{
+	unsigned long bus_free_timeout = 0;
+	unsigned long timeout;
+	int bus_free = 0;
+	u16 stat, systest;
+
+	if (omap->bb_valid)
+		return 0;
+
+	timeout = jiffies + OMAP_I2C_TIMEOUT;
+	while (1) {
+		stat = omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG);
+		/*
+		 * We will see BB or BF event in a case IP had detected any
+		 * activity on the I2C bus. Now IP correctly tracks the bus
+		 * state. BB-bit value is valid.
+		 */
+		if (stat & (OMAP_I2C_STAT_BB | OMAP_I2C_STAT_BF))
+			break;
+
+		/*
+		 * Otherwise, we must look signals on the bus to make
+		 * the right decision.
+		 */
+		systest = omap_i2c_read_reg(omap, OMAP_I2C_SYSTEST_REG);
+		if ((systest & OMAP_I2C_SYSTEST_SCL_I_FUNC) &&
+		    (systest & OMAP_I2C_SYSTEST_SDA_I_FUNC)) {
+			if (!bus_free) {
+				bus_free_timeout = jiffies +
+					OMAP_I2C_BUS_FREE_TIMEOUT;
+				bus_free = 1;
+			}
+
+			/*
+			 * SDA and SCL lines was high for 10 ms without bus
+			 * activity detected. The bus is free. Consider
+			 * BB-bit value is valid.
+			 */
+			if (time_after(jiffies, bus_free_timeout))
+				break;
+		} else {
+			bus_free = 0;
+		}
+
+		if (time_after(jiffies, timeout)) {
+			/*
+			 * SDA or SCL were low for the entire timeout without
+			 * any activity detected. Most likely, a slave is
+			 * locking up the bus with no master driving the clock.
+			 */
+			dev_warn(omap->dev, "timeout waiting for bus ready\n");
+			return omap_i2c_recover_bus(omap);
+		}
+
+		msleep(1);
+	}
+
+	omap->bb_valid = 1;
+	return 0;
+}
+
+static void omap_i2c_resize_fifo(struct omap_i2c_dev *omap, u8 size, bool is_rx)
+{
+	u16		buf;
+
+	if (omap->flags & OMAP_I2C_FLAG_NO_FIFO)
+		return;
+
+	/*
+	 * Set up notification threshold based on message size. We're doing
+	 * this to try and avoid draining feature as much as possible. Whenever
+	 * we have big messages to transfer (bigger than our total fifo size)
+	 * then we might use draining feature to transfer the remaining bytes.
+	 */
+
+	omap->threshold = clamp(size, (u8) 1, omap->fifo_size);
+
+	buf = omap_i2c_read_reg(omap, OMAP_I2C_BUF_REG);
+
+	if (is_rx) {
+		/* Clear RX Threshold */
+		buf &= ~(0x3f << 8);
+		buf |= ((omap->threshold - 1) << 8) | OMAP_I2C_BUF_RXFIF_CLR;
+	} else {
+		/* Clear TX Threshold */
+		buf &= ~0x3f;
+		buf |= (omap->threshold - 1) | OMAP_I2C_BUF_TXFIF_CLR;
+	}
+
+	omap_i2c_write_reg(omap, OMAP_I2C_BUF_REG, buf);
+
+	if (omap->rev < OMAP_I2C_REV_ON_3630)
+		omap->b_hw = 1; /* Enable hardware fixes */
+
+	/* calculate wakeup latency constraint for MPU */
+	if (omap->set_mpu_wkup_lat != NULL)
+		omap->latency = (1000000 * omap->threshold) /
+			(1000 * omap->speed / 8);
+}
+
+static void omap_i2c_wait(struct omap_i2c_dev *omap)
+{
+	u16 stat;
+	u16 mask = omap_i2c_read_reg(omap, OMAP_I2C_IE_REG);
+	int count = 0;
+
+	do {
+		stat = omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG);
+		count++;
+	} while (!(stat & mask) && count < 5);
+}
+
+/*
+ * Low level master read/write transaction.
+ */
+static int omap_i2c_xfer_msg(struct i2c_adapter *adap,
+			     struct i2c_msg *msg, int stop, bool polling)
+{
+	struct omap_i2c_dev *omap = i2c_get_adapdata(adap);
+	unsigned long timeout;
+	u16 w;
+	int ret;
+
+	dev_dbg(omap->dev, "addr: 0x%04x, len: %d, flags: 0x%x, stop: %d\n",
+		msg->addr, msg->len, msg->flags, stop);
+
+	omap->receiver = !!(msg->flags & I2C_M_RD);
+	omap_i2c_resize_fifo(omap, msg->len, omap->receiver);
+
+	omap_i2c_write_reg(omap, OMAP_I2C_SA_REG, msg->addr);
+
+	/* REVISIT: Could the STB bit of I2C_CON be used with probing? */
+	omap->buf = msg->buf;
+	omap->buf_len = msg->len;
+
+	/* make sure writes to omap->buf_len are ordered */
+	barrier();
+
+	omap_i2c_write_reg(omap, OMAP_I2C_CNT_REG, omap->buf_len);
+
+	/* Clear the FIFO Buffers */
+	w = omap_i2c_read_reg(omap, OMAP_I2C_BUF_REG);
+	w |= OMAP_I2C_BUF_RXFIF_CLR | OMAP_I2C_BUF_TXFIF_CLR;
+	omap_i2c_write_reg(omap, OMAP_I2C_BUF_REG, w);
+
+	if (!polling)
+		reinit_completion(&omap->cmd_complete);
+	omap->cmd_err = 0;
+
+	w = OMAP_I2C_CON_EN | OMAP_I2C_CON_MST | OMAP_I2C_CON_STT;
+
+	/* High speed configuration */
+	if (omap->speed > 400)
+		w |= OMAP_I2C_CON_OPMODE_HS;
+
+	if (msg->flags & I2C_M_STOP)
+		stop = 1;
+	if (msg->flags & I2C_M_TEN)
+		w |= OMAP_I2C_CON_XA;
+	if (!(msg->flags & I2C_M_RD))
+		w |= OMAP_I2C_CON_TRX;
+
+	if (!omap->b_hw && stop)
+		w |= OMAP_I2C_CON_STP;
+	/*
+	 * NOTE: STAT_BB bit could became 1 here if another master occupy
+	 * the bus. IP successfully complete transfer when the bus will be
+	 * free again (BB reset to 0).
+	 */
+	omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, w);
+
+	/*
+	 * Don't write stt and stp together on some hardware.
+	 */
+	if (omap->b_hw && stop) {
+		unsigned long delay = jiffies + OMAP_I2C_TIMEOUT;
+		u16 con = omap_i2c_read_reg(omap, OMAP_I2C_CON_REG);
+		while (con & OMAP_I2C_CON_STT) {
+			con = omap_i2c_read_reg(omap, OMAP_I2C_CON_REG);
+
+			/* Let the user know if i2c is in a bad state */
+			if (time_after(jiffies, delay)) {
+				dev_err(omap->dev, "controller timed out "
+				"waiting for start condition to finish\n");
+				return -ETIMEDOUT;
+			}
+			cpu_relax();
+		}
+
+		w |= OMAP_I2C_CON_STP;
+		w &= ~OMAP_I2C_CON_STT;
+		omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, w);
+	}
+
+	/*
+	 * REVISIT: We should abort the transfer on signals, but the bus goes
+	 * into arbitration and we're currently unable to recover from it.
+	 */
+	if (!polling) {
+		timeout = wait_for_completion_timeout(&omap->cmd_complete,
+						      OMAP_I2C_TIMEOUT);
+	} else {
+		do {
+			omap_i2c_wait(omap);
+			ret = omap_i2c_xfer_data(omap);
+		} while (ret == -EAGAIN);
+
+		timeout = !ret;
+	}
+
+	if (timeout == 0) {
+		dev_err(omap->dev, "controller timed out\n");
+		omap_i2c_reset(omap);
+		__omap_i2c_init(omap);
+		return -ETIMEDOUT;
+	}
+
+	if (likely(!omap->cmd_err))
+		return 0;
+
+	/* We have an error */
+	if (omap->cmd_err & (OMAP_I2C_STAT_ROVR | OMAP_I2C_STAT_XUDF)) {
+		omap_i2c_reset(omap);
+		__omap_i2c_init(omap);
+		return -EIO;
+	}
+
+	if (omap->cmd_err & OMAP_I2C_STAT_AL)
+		return -EAGAIN;
+
+	if (omap->cmd_err & OMAP_I2C_STAT_NACK) {
+		if (msg->flags & I2C_M_IGNORE_NAK)
+			return 0;
+
+		w = omap_i2c_read_reg(omap, OMAP_I2C_CON_REG);
+		w |= OMAP_I2C_CON_STP;
+		omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, w);
+		return -EREMOTEIO;
+	}
+	return -EIO;
+}
+
+
+/*
+ * Prepare controller for a transaction and call omap_i2c_xfer_msg
+ * to do the work during IRQ processing.
+ */
+static int
+omap_i2c_xfer_common(struct i2c_adapter *adap, struct i2c_msg msgs[], int num,
+		     bool polling)
+{
+	struct omap_i2c_dev *omap = i2c_get_adapdata(adap);
+	int i;
+	int r;
+
+	r = pm_runtime_get_sync(omap->dev);
+	if (r < 0)
+		goto out;
+
+	r = omap_i2c_wait_for_bb_valid(omap);
+	if (r < 0)
+		goto out;
+
+	r = omap_i2c_wait_for_bb(omap);
+	if (r < 0)
+		goto out;
+
+	if (omap->set_mpu_wkup_lat != NULL)
+		omap->set_mpu_wkup_lat(omap->dev, omap->latency);
+
+	for (i = 0; i < num; i++) {
+		r = omap_i2c_xfer_msg(adap, &msgs[i], (i == (num - 1)),
+				      polling);
+		if (r != 0)
+			break;
+	}
+
+	if (r == 0)
+		r = num;
+
+	omap_i2c_wait_for_bb(omap);
+
+	if (omap->set_mpu_wkup_lat != NULL)
+		omap->set_mpu_wkup_lat(omap->dev, -1);
+
+out:
+	pm_runtime_mark_last_busy(omap->dev);
+	pm_runtime_put_autosuspend(omap->dev);
+	return r;
+}
+
+static int
+omap_i2c_xfer_irq(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
+{
+	return omap_i2c_xfer_common(adap, msgs, num, false);
+}
+
+static int
+omap_i2c_xfer_polling(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
+{
+	return omap_i2c_xfer_common(adap, msgs, num, true);
+}
+
+static u32
+omap_i2c_func(struct i2c_adapter *adap)
+{
+	return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK) |
+	       I2C_FUNC_PROTOCOL_MANGLING;
+}
+
+static inline void
+omap_i2c_complete_cmd(struct omap_i2c_dev *omap, u16 err)
+{
+	omap->cmd_err |= err;
+	complete(&omap->cmd_complete);
+}
+
+static inline void
+omap_i2c_ack_stat(struct omap_i2c_dev *omap, u16 stat)
+{
+	omap_i2c_write_reg(omap, OMAP_I2C_STAT_REG, stat);
+}
+
+static inline void i2c_omap_errata_i207(struct omap_i2c_dev *omap, u16 stat)
+{
+	/*
+	 * I2C Errata(Errata Nos. OMAP2: 1.67, OMAP3: 1.8)
+	 * Not applicable for OMAP4.
+	 * Under certain rare conditions, RDR could be set again
+	 * when the bus is busy, then ignore the interrupt and
+	 * clear the interrupt.
+	 */
+	if (stat & OMAP_I2C_STAT_RDR) {
+		/* Step 1: If RDR is set, clear it */
+		omap_i2c_ack_stat(omap, OMAP_I2C_STAT_RDR);
+
+		/* Step 2: */
+		if (!(omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG)
+						& OMAP_I2C_STAT_BB)) {
+
+			/* Step 3: */
+			if (omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG)
+						& OMAP_I2C_STAT_RDR) {
+				omap_i2c_ack_stat(omap, OMAP_I2C_STAT_RDR);
+				dev_dbg(omap->dev, "RDR when bus is busy.\n");
+			}
+
+		}
+	}
+}
+
+/* rev1 devices are apparently only on some 15xx */
+#ifdef CONFIG_ARCH_OMAP15XX
+
+static irqreturn_t
+omap_i2c_omap1_isr(int this_irq, void *dev_id)
+{
+	struct omap_i2c_dev *omap = dev_id;
+	u16 iv, w;
+
+	if (pm_runtime_suspended(omap->dev))
+		return IRQ_NONE;
+
+	iv = omap_i2c_read_reg(omap, OMAP_I2C_IV_REG);
+	switch (iv) {
+	case 0x00:	/* None */
+		break;
+	case 0x01:	/* Arbitration lost */
+		dev_err(omap->dev, "Arbitration lost\n");
+		omap_i2c_complete_cmd(omap, OMAP_I2C_STAT_AL);
+		break;
+	case 0x02:	/* No acknowledgement */
+		omap_i2c_complete_cmd(omap, OMAP_I2C_STAT_NACK);
+		omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, OMAP_I2C_CON_STP);
+		break;
+	case 0x03:	/* Register access ready */
+		omap_i2c_complete_cmd(omap, 0);
+		break;
+	case 0x04:	/* Receive data ready */
+		if (omap->buf_len) {
+			w = omap_i2c_read_reg(omap, OMAP_I2C_DATA_REG);
+			*omap->buf++ = w;
+			omap->buf_len--;
+			if (omap->buf_len) {
+				*omap->buf++ = w >> 8;
+				omap->buf_len--;
+			}
+		} else
+			dev_err(omap->dev, "RRDY IRQ while no data requested\n");
+		break;
+	case 0x05:	/* Transmit data ready */
+		if (omap->buf_len) {
+			w = *omap->buf++;
+			omap->buf_len--;
+			if (omap->buf_len) {
+				w |= *omap->buf++ << 8;
+				omap->buf_len--;
+			}
+			omap_i2c_write_reg(omap, OMAP_I2C_DATA_REG, w);
+		} else
+			dev_err(omap->dev, "XRDY IRQ while no data to send\n");
+		break;
+	default:
+		return IRQ_NONE;
+	}
+
+	return IRQ_HANDLED;
+}
+#else
+#define omap_i2c_omap1_isr		NULL
+#endif
+
+/*
+ * OMAP3430 Errata i462: When an XRDY/XDR is hit, wait for XUDF before writing
+ * data to DATA_REG. Otherwise some data bytes can be lost while transferring
+ * them from the memory to the I2C interface.
+ */
+static int errata_omap3_i462(struct omap_i2c_dev *omap)
+{
+	unsigned long timeout = 10000;
+	u16 stat;
+
+	do {
+		stat = omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG);
+		if (stat & OMAP_I2C_STAT_XUDF)
+			break;
+
+		if (stat & (OMAP_I2C_STAT_NACK | OMAP_I2C_STAT_AL)) {
+			omap_i2c_ack_stat(omap, (OMAP_I2C_STAT_XRDY |
+							OMAP_I2C_STAT_XDR));
+			if (stat & OMAP_I2C_STAT_NACK) {
+				omap->cmd_err |= OMAP_I2C_STAT_NACK;
+				omap_i2c_ack_stat(omap, OMAP_I2C_STAT_NACK);
+			}
+
+			if (stat & OMAP_I2C_STAT_AL) {
+				dev_err(omap->dev, "Arbitration lost\n");
+				omap->cmd_err |= OMAP_I2C_STAT_AL;
+				omap_i2c_ack_stat(omap, OMAP_I2C_STAT_AL);
+			}
+
+			return -EIO;
+		}
+
+		cpu_relax();
+	} while (--timeout);
+
+	if (!timeout) {
+		dev_err(omap->dev, "timeout waiting on XUDF bit\n");
+		return 0;
+	}
+
+	return 0;
+}
+
+static void omap_i2c_receive_data(struct omap_i2c_dev *omap, u8 num_bytes,
+		bool is_rdr)
+{
+	u16		w;
+
+	while (num_bytes--) {
+		w = omap_i2c_read_reg(omap, OMAP_I2C_DATA_REG);
+		*omap->buf++ = w;
+		omap->buf_len--;
+
+		/*
+		 * Data reg in 2430, omap3 and
+		 * omap4 is 8 bit wide
+		 */
+		if (omap->flags & OMAP_I2C_FLAG_16BIT_DATA_REG) {
+			*omap->buf++ = w >> 8;
+			omap->buf_len--;
+		}
+	}
+}
+
+static int omap_i2c_transmit_data(struct omap_i2c_dev *omap, u8 num_bytes,
+		bool is_xdr)
+{
+	u16		w;
+
+	while (num_bytes--) {
+		w = *omap->buf++;
+		omap->buf_len--;
+
+		/*
+		 * Data reg in 2430, omap3 and
+		 * omap4 is 8 bit wide
+		 */
+		if (omap->flags & OMAP_I2C_FLAG_16BIT_DATA_REG) {
+			w |= *omap->buf++ << 8;
+			omap->buf_len--;
+		}
+
+		if (omap->errata & I2C_OMAP_ERRATA_I462) {
+			int ret;
+
+			ret = errata_omap3_i462(omap);
+			if (ret < 0)
+				return ret;
+		}
+
+		omap_i2c_write_reg(omap, OMAP_I2C_DATA_REG, w);
+	}
+
+	return 0;
+}
+
+static irqreturn_t
+omap_i2c_isr(int irq, void *dev_id)
+{
+	struct omap_i2c_dev *omap = dev_id;
+	irqreturn_t ret = IRQ_HANDLED;
+	u16 mask;
+	u16 stat;
+
+	stat = omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG);
+	mask = omap_i2c_read_reg(omap, OMAP_I2C_IE_REG) & ~OMAP_I2C_STAT_NACK;
+
+	if (stat & mask)
+		ret = IRQ_WAKE_THREAD;
+
+	return ret;
+}
+
+static int omap_i2c_xfer_data(struct omap_i2c_dev *omap)
+{
+	u16 bits;
+	u16 stat;
+	int err = 0, count = 0;
+
+	do {
+		bits = omap_i2c_read_reg(omap, OMAP_I2C_IE_REG);
+		stat = omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG);
+		stat &= bits;
+
+		/* If we're in receiver mode, ignore XDR/XRDY */
+		if (omap->receiver)
+			stat &= ~(OMAP_I2C_STAT_XDR | OMAP_I2C_STAT_XRDY);
+		else
+			stat &= ~(OMAP_I2C_STAT_RDR | OMAP_I2C_STAT_RRDY);
+
+		if (!stat) {
+			/* my work here is done */
+			err = -EAGAIN;
+			break;
+		}
+
+		dev_dbg(omap->dev, "IRQ (ISR = 0x%04x)\n", stat);
+		if (count++ == 100) {
+			dev_warn(omap->dev, "Too much work in one IRQ\n");
+			break;
+		}
+
+		if (stat & OMAP_I2C_STAT_NACK) {
+			err |= OMAP_I2C_STAT_NACK;
+			omap_i2c_ack_stat(omap, OMAP_I2C_STAT_NACK);
+		}
+
+		if (stat & OMAP_I2C_STAT_AL) {
+			dev_err(omap->dev, "Arbitration lost\n");
+			err |= OMAP_I2C_STAT_AL;
+			omap_i2c_ack_stat(omap, OMAP_I2C_STAT_AL);
+		}
+
+		/*
+		 * ProDB0017052: Clear ARDY bit twice
+		 */
+		if (stat & OMAP_I2C_STAT_ARDY)
+			omap_i2c_ack_stat(omap, OMAP_I2C_STAT_ARDY);
+
+		if (stat & (OMAP_I2C_STAT_ARDY | OMAP_I2C_STAT_NACK |
+					OMAP_I2C_STAT_AL)) {
+			omap_i2c_ack_stat(omap, (OMAP_I2C_STAT_RRDY |
+						OMAP_I2C_STAT_RDR |
+						OMAP_I2C_STAT_XRDY |
+						OMAP_I2C_STAT_XDR |
+						OMAP_I2C_STAT_ARDY));
+			break;
+		}
+
+		if (stat & OMAP_I2C_STAT_RDR) {
+			u8 num_bytes = 1;
+
+			if (omap->fifo_size)
+				num_bytes = omap->buf_len;
+
+			if (omap->errata & I2C_OMAP_ERRATA_I207) {
+				i2c_omap_errata_i207(omap, stat);
+				num_bytes = (omap_i2c_read_reg(omap,
+					OMAP_I2C_BUFSTAT_REG) >> 8) & 0x3F;
+			}
+
+			omap_i2c_receive_data(omap, num_bytes, true);
+			omap_i2c_ack_stat(omap, OMAP_I2C_STAT_RDR);
+			continue;
+		}
+
+		if (stat & OMAP_I2C_STAT_RRDY) {
+			u8 num_bytes = 1;
+
+			if (omap->threshold)
+				num_bytes = omap->threshold;
+
+			omap_i2c_receive_data(omap, num_bytes, false);
+			omap_i2c_ack_stat(omap, OMAP_I2C_STAT_RRDY);
+			continue;
+		}
+
+		if (stat & OMAP_I2C_STAT_XDR) {
+			u8 num_bytes = 1;
+			int ret;
+
+			if (omap->fifo_size)
+				num_bytes = omap->buf_len;
+
+			ret = omap_i2c_transmit_data(omap, num_bytes, true);
+			if (ret < 0)
+				break;
+
+			omap_i2c_ack_stat(omap, OMAP_I2C_STAT_XDR);
+			continue;
+		}
+
+		if (stat & OMAP_I2C_STAT_XRDY) {
+			u8 num_bytes = 1;
+			int ret;
+
+			if (omap->threshold)
+				num_bytes = omap->threshold;
+
+			ret = omap_i2c_transmit_data(omap, num_bytes, false);
+			if (ret < 0)
+				break;
+
+			omap_i2c_ack_stat(omap, OMAP_I2C_STAT_XRDY);
+			continue;
+		}
+
+		if (stat & OMAP_I2C_STAT_ROVR) {
+			dev_err(omap->dev, "Receive overrun\n");
+			err |= OMAP_I2C_STAT_ROVR;
+			omap_i2c_ack_stat(omap, OMAP_I2C_STAT_ROVR);
+			break;
+		}
+
+		if (stat & OMAP_I2C_STAT_XUDF) {
+			dev_err(omap->dev, "Transmit underflow\n");
+			err |= OMAP_I2C_STAT_XUDF;
+			omap_i2c_ack_stat(omap, OMAP_I2C_STAT_XUDF);
+			break;
+		}
+	} while (stat);
+
+	return err;
+}
+
+static irqreturn_t
+omap_i2c_isr_thread(int this_irq, void *dev_id)
+{
+	int ret;
+	struct omap_i2c_dev *omap = dev_id;
+
+	ret = omap_i2c_xfer_data(omap);
+	if (ret != -EAGAIN)
+		omap_i2c_complete_cmd(omap, ret);
+
+	return IRQ_HANDLED;
+}
+
+static const struct i2c_algorithm omap_i2c_algo = {
+	.master_xfer	= omap_i2c_xfer_irq,
+	.master_xfer_atomic	= omap_i2c_xfer_polling,
+	.functionality	= omap_i2c_func,
+};
+
+static const struct i2c_adapter_quirks omap_i2c_quirks = {
+	.flags = I2C_AQ_NO_ZERO_LEN,
+};
+
+#ifdef CONFIG_OF
+static struct omap_i2c_bus_platform_data omap2420_pdata = {
+	.rev = OMAP_I2C_IP_VERSION_1,
+	.flags = OMAP_I2C_FLAG_NO_FIFO |
+			OMAP_I2C_FLAG_SIMPLE_CLOCK |
+			OMAP_I2C_FLAG_16BIT_DATA_REG |
+			OMAP_I2C_FLAG_BUS_SHIFT_2,
+};
+
+static struct omap_i2c_bus_platform_data omap2430_pdata = {
+	.rev = OMAP_I2C_IP_VERSION_1,
+	.flags = OMAP_I2C_FLAG_BUS_SHIFT_2 |
+			OMAP_I2C_FLAG_FORCE_19200_INT_CLK,
+};
+
+static struct omap_i2c_bus_platform_data omap3_pdata = {
+	.rev = OMAP_I2C_IP_VERSION_1,
+	.flags = OMAP_I2C_FLAG_BUS_SHIFT_2,
+};
+
+static struct omap_i2c_bus_platform_data omap4_pdata = {
+	.rev = OMAP_I2C_IP_VERSION_2,
+};
+
+static const struct of_device_id omap_i2c_of_match[] = {
+	{
+		.compatible = "ti,omap4-i2c",
+		.data = &omap4_pdata,
+	},
+	{
+		.compatible = "ti,omap3-i2c",
+		.data = &omap3_pdata,
+	},
+	{
+		.compatible = "ti,omap2430-i2c",
+		.data = &omap2430_pdata,
+	},
+	{
+		.compatible = "ti,omap2420-i2c",
+		.data = &omap2420_pdata,
+	},
+	{ },
+};
+MODULE_DEVICE_TABLE(of, omap_i2c_of_match);
+#endif
+
+#define OMAP_I2C_SCHEME(rev)		((rev & 0xc000) >> 14)
+
+#define OMAP_I2C_REV_SCHEME_0_MAJOR(rev) (rev >> 4)
+#define OMAP_I2C_REV_SCHEME_0_MINOR(rev) (rev & 0xf)
+
+#define OMAP_I2C_REV_SCHEME_1_MAJOR(rev) ((rev & 0x0700) >> 7)
+#define OMAP_I2C_REV_SCHEME_1_MINOR(rev) (rev & 0x1f)
+#define OMAP_I2C_SCHEME_0		0
+#define OMAP_I2C_SCHEME_1		1
+
+static int omap_i2c_get_scl(struct i2c_adapter *adap)
+{
+	struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
+	u32 reg;
+
+	reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG);
+
+	return reg & OMAP_I2C_SYSTEST_SCL_I_FUNC;
+}
+
+static int omap_i2c_get_sda(struct i2c_adapter *adap)
+{
+	struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
+	u32 reg;
+
+	reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG);
+
+	return reg & OMAP_I2C_SYSTEST_SDA_I_FUNC;
+}
+
+static void omap_i2c_set_scl(struct i2c_adapter *adap, int val)
+{
+	struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
+	u32 reg;
+
+	reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG);
+	if (val)
+		reg |= OMAP_I2C_SYSTEST_SCL_O;
+	else
+		reg &= ~OMAP_I2C_SYSTEST_SCL_O;
+	omap_i2c_write_reg(dev, OMAP_I2C_SYSTEST_REG, reg);
+}
+
+static void omap_i2c_prepare_recovery(struct i2c_adapter *adap)
+{
+	struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
+	u32 reg;
+
+	reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG);
+	/* enable test mode */
+	reg |= OMAP_I2C_SYSTEST_ST_EN;
+	/* select SDA/SCL IO mode */
+	reg |= 3 << OMAP_I2C_SYSTEST_TMODE_SHIFT;
+	/* set SCL to high-impedance state (reset value is 0) */
+	reg |= OMAP_I2C_SYSTEST_SCL_O;
+	/* set SDA to high-impedance state (reset value is 0) */
+	reg |= OMAP_I2C_SYSTEST_SDA_O;
+	omap_i2c_write_reg(dev, OMAP_I2C_SYSTEST_REG, reg);
+}
+
+static void omap_i2c_unprepare_recovery(struct i2c_adapter *adap)
+{
+	struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
+	u32 reg;
+
+	reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG);
+	/* restore reset values */
+	reg &= ~OMAP_I2C_SYSTEST_ST_EN;
+	reg &= ~OMAP_I2C_SYSTEST_TMODE_MASK;
+	reg &= ~OMAP_I2C_SYSTEST_SCL_O;
+	reg &= ~OMAP_I2C_SYSTEST_SDA_O;
+	omap_i2c_write_reg(dev, OMAP_I2C_SYSTEST_REG, reg);
+}
+
+static struct i2c_bus_recovery_info omap_i2c_bus_recovery_info = {
+	.get_scl		= omap_i2c_get_scl,
+	.get_sda		= omap_i2c_get_sda,
+	.set_scl		= omap_i2c_set_scl,
+	.prepare_recovery	= omap_i2c_prepare_recovery,
+	.unprepare_recovery	= omap_i2c_unprepare_recovery,
+	.recover_bus		= i2c_generic_scl_recovery,
+};
+
+static int
+omap_i2c_probe(struct platform_device *pdev)
+{
+	struct omap_i2c_dev	*omap;
+	struct i2c_adapter	*adap;
+	const struct omap_i2c_bus_platform_data *pdata =
+		dev_get_platdata(&pdev->dev);
+	struct device_node	*node = pdev->dev.of_node;
+	const struct of_device_id *match;
+	int irq;
+	int r;
+	u32 rev;
+	u16 minor, major;
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	omap = devm_kzalloc(&pdev->dev, sizeof(struct omap_i2c_dev), GFP_KERNEL);
+	if (!omap)
+		return -ENOMEM;
+
+	omap->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(omap->base))
+		return PTR_ERR(omap->base);
+
+	match = of_match_device(of_match_ptr(omap_i2c_of_match), &pdev->dev);
+	if (match) {
+		u32 freq = I2C_MAX_STANDARD_MODE_FREQ;
+
+		pdata = match->data;
+		omap->flags = pdata->flags;
+
+		of_property_read_u32(node, "clock-frequency", &freq);
+		/* convert DT freq value in Hz into kHz for speed */
+		omap->speed = freq / 1000;
+	} else if (pdata != NULL) {
+		omap->speed = pdata->clkrate;
+		omap->flags = pdata->flags;
+		omap->set_mpu_wkup_lat = pdata->set_mpu_wkup_lat;
+	}
+
+	omap->dev = &pdev->dev;
+	omap->irq = irq;
+
+	platform_set_drvdata(pdev, omap);
+	init_completion(&omap->cmd_complete);
+
+	omap->reg_shift = (omap->flags >> OMAP_I2C_FLAG_BUS_SHIFT__SHIFT) & 3;
+
+	pm_runtime_enable(omap->dev);
+	pm_runtime_set_autosuspend_delay(omap->dev, OMAP_I2C_PM_TIMEOUT);
+	pm_runtime_use_autosuspend(omap->dev);
+
+	r = pm_runtime_resume_and_get(omap->dev);
+	if (r < 0)
+		goto err_disable_pm;
+
+	/*
+	 * Read the Rev hi bit-[15:14] ie scheme this is 1 indicates ver2.
+	 * On omap1/3/2 Offset 4 is IE Reg the bit [15:14] is 0 at reset.
+	 * Also since the omap_i2c_read_reg uses reg_map_ip_* a
+	 * readw_relaxed is done.
+	 */
+	rev = readw_relaxed(omap->base + 0x04);
+
+	omap->scheme = OMAP_I2C_SCHEME(rev);
+	switch (omap->scheme) {
+	case OMAP_I2C_SCHEME_0:
+		omap->regs = (u8 *)reg_map_ip_v1;
+		omap->rev = omap_i2c_read_reg(omap, OMAP_I2C_REV_REG);
+		minor = OMAP_I2C_REV_SCHEME_0_MAJOR(omap->rev);
+		major = OMAP_I2C_REV_SCHEME_0_MAJOR(omap->rev);
+		break;
+	case OMAP_I2C_SCHEME_1:
+	default:
+		omap->regs = (u8 *)reg_map_ip_v2;
+		rev = (rev << 16) |
+			omap_i2c_read_reg(omap, OMAP_I2C_IP_V2_REVNB_LO);
+		minor = OMAP_I2C_REV_SCHEME_1_MINOR(rev);
+		major = OMAP_I2C_REV_SCHEME_1_MAJOR(rev);
+		omap->rev = rev;
+	}
+
+	omap->errata = 0;
+
+	if (omap->rev >= OMAP_I2C_REV_ON_2430 &&
+			omap->rev < OMAP_I2C_REV_ON_4430_PLUS)
+		omap->errata |= I2C_OMAP_ERRATA_I207;
+
+	if (omap->rev <= OMAP_I2C_REV_ON_3430_3530)
+		omap->errata |= I2C_OMAP_ERRATA_I462;
+
+	if (!(omap->flags & OMAP_I2C_FLAG_NO_FIFO)) {
+		u16 s;
+
+		/* Set up the fifo size - Get total size */
+		s = (omap_i2c_read_reg(omap, OMAP_I2C_BUFSTAT_REG) >> 14) & 0x3;
+		omap->fifo_size = 0x8 << s;
+
+		/*
+		 * Set up notification threshold as half the total available
+		 * size. This is to ensure that we can handle the status on int
+		 * call back latencies.
+		 */
+
+		omap->fifo_size = (omap->fifo_size / 2);
+
+		if (omap->rev < OMAP_I2C_REV_ON_3630)
+			omap->b_hw = 1; /* Enable hardware fixes */
+
+		/* calculate wakeup latency constraint for MPU */
+		if (omap->set_mpu_wkup_lat != NULL)
+			omap->latency = (1000000 * omap->fifo_size) /
+				       (1000 * omap->speed / 8);
+	}
+
+	/* reset ASAP, clearing any IRQs */
+	omap_i2c_init(omap);
+
+	if (omap->rev < OMAP_I2C_OMAP1_REV_2)
+		r = devm_request_irq(&pdev->dev, omap->irq, omap_i2c_omap1_isr,
+				IRQF_NO_SUSPEND, pdev->name, omap);
+	else
+		r = devm_request_threaded_irq(&pdev->dev, omap->irq,
+				omap_i2c_isr, omap_i2c_isr_thread,
+				IRQF_NO_SUSPEND | IRQF_ONESHOT,
+				pdev->name, omap);
+
+	if (r) {
+		dev_err(omap->dev, "failure requesting irq %i\n", omap->irq);
+		goto err_unuse_clocks;
+	}
+
+	adap = &omap->adapter;
+	i2c_set_adapdata(adap, omap);
+	adap->owner = THIS_MODULE;
+	adap->class = I2C_CLASS_DEPRECATED;
+	strscpy(adap->name, "OMAP I2C adapter", sizeof(adap->name));
+	adap->algo = &omap_i2c_algo;
+	adap->quirks = &omap_i2c_quirks;
+	adap->dev.parent = &pdev->dev;
+	adap->dev.of_node = pdev->dev.of_node;
+	adap->bus_recovery_info = &omap_i2c_bus_recovery_info;
+
+	/* i2c device drivers may be active on return from add_adapter() */
+	adap->nr = pdev->id;
+	r = i2c_add_numbered_adapter(adap);
+	if (r)
+		goto err_unuse_clocks;
+
+	dev_info(omap->dev, "bus %d rev%d.%d at %d kHz\n", adap->nr,
+		 major, minor, omap->speed);
+
+	pm_runtime_mark_last_busy(omap->dev);
+	pm_runtime_put_autosuspend(omap->dev);
+
+	return 0;
+
+err_unuse_clocks:
+	omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, 0);
+	pm_runtime_dont_use_autosuspend(omap->dev);
+	pm_runtime_put_sync(omap->dev);
+err_disable_pm:
+	pm_runtime_disable(&pdev->dev);
+
+	return r;
+}
+
+static int omap_i2c_remove(struct platform_device *pdev)
+{
+	struct omap_i2c_dev	*omap = platform_get_drvdata(pdev);
+	int ret;
+
+	i2c_del_adapter(&omap->adapter);
+	ret = pm_runtime_resume_and_get(&pdev->dev);
+	if (ret < 0)
+		return ret;
+
+	omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, 0);
+	pm_runtime_dont_use_autosuspend(&pdev->dev);
+	pm_runtime_put_sync(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+	return 0;
+}
+
+static int __maybe_unused omap_i2c_runtime_suspend(struct device *dev)
+{
+	struct omap_i2c_dev *omap = dev_get_drvdata(dev);
+
+	omap->iestate = omap_i2c_read_reg(omap, OMAP_I2C_IE_REG);
+
+	if (omap->scheme == OMAP_I2C_SCHEME_0)
+		omap_i2c_write_reg(omap, OMAP_I2C_IE_REG, 0);
+	else
+		omap_i2c_write_reg(omap, OMAP_I2C_IP_V2_IRQENABLE_CLR,
+				   OMAP_I2C_IP_V2_INTERRUPTS_MASK);
+
+	if (omap->rev < OMAP_I2C_OMAP1_REV_2) {
+		omap_i2c_read_reg(omap, OMAP_I2C_IV_REG); /* Read clears */
+	} else {
+		omap_i2c_write_reg(omap, OMAP_I2C_STAT_REG, omap->iestate);
+
+		/* Flush posted write */
+		omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG);
+	}
+
+	pinctrl_pm_select_sleep_state(dev);
+
+	return 0;
+}
+
+static int __maybe_unused omap_i2c_runtime_resume(struct device *dev)
+{
+	struct omap_i2c_dev *omap = dev_get_drvdata(dev);
+
+	pinctrl_pm_select_default_state(dev);
+
+	if (!omap->regs)
+		return 0;
+
+	__omap_i2c_init(omap);
+
+	return 0;
+}
+
+static const struct dev_pm_ops omap_i2c_pm_ops = {
+	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
+				      pm_runtime_force_resume)
+	SET_RUNTIME_PM_OPS(omap_i2c_runtime_suspend,
+			   omap_i2c_runtime_resume, NULL)
+};
+
+static struct platform_driver omap_i2c_driver = {
+	.probe		= omap_i2c_probe,
+	.remove		= omap_i2c_remove,
+	.driver		= {
+		.name	= "omap_i2c",
+		.pm	= &omap_i2c_pm_ops,
+		.of_match_table = of_match_ptr(omap_i2c_of_match),
+	},
+};
+
+/* I2C may be needed to bring up other drivers */
+static int __init
+omap_i2c_init_driver(void)
+{
+	return platform_driver_register(&omap_i2c_driver);
+}
+subsys_initcall(omap_i2c_init_driver);
+
+static void __exit omap_i2c_exit_driver(void)
+{
+	platform_driver_unregister(&omap_i2c_driver);
+}
+module_exit(omap_i2c_exit_driver);
+
+MODULE_AUTHOR("MontaVista Software, Inc. (and others)");
+MODULE_DESCRIPTION("TI OMAP I2C bus adapter");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:omap_i2c");