v4.19.13 snapshot.
diff --git a/drivers/media/i2c/smiapp/smiapp-regs.c b/drivers/media/i2c/smiapp/smiapp-regs.c
new file mode 100644
index 0000000..145653d
--- /dev/null
+++ b/drivers/media/i2c/smiapp/smiapp-regs.c
@@ -0,0 +1,303 @@
+/*
+ * drivers/media/i2c/smiapp/smiapp-regs.c
+ *
+ * Generic driver for SMIA/SMIA++ compliant camera modules
+ *
+ * Copyright (C) 2011--2012 Nokia Corporation
+ * Contact: Sakari Ailus <sakari.ailus@iki.fi>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * 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/delay.h>
+#include <linux/i2c.h>
+
+#include "smiapp.h"
+#include "smiapp-regs.h"
+
+static uint32_t float_to_u32_mul_1000000(struct i2c_client *client,
+					 uint32_t phloat)
+{
+	int32_t exp;
+	uint64_t man;
+
+	if (phloat >= 0x80000000) {
+		dev_err(&client->dev, "this is a negative number\n");
+		return 0;
+	}
+
+	if (phloat == 0x7f800000)
+		return ~0; /* Inf. */
+
+	if ((phloat & 0x7f800000) == 0x7f800000) {
+		dev_err(&client->dev, "NaN or other special number\n");
+		return 0;
+	}
+
+	/* Valid cases begin here */
+	if (phloat == 0)
+		return 0; /* Valid zero */
+
+	if (phloat > 0x4f800000)
+		return ~0; /* larger than 4294967295 */
+
+	/*
+	 * Unbias exponent (note how phloat is now guaranteed to
+	 * have 0 in the high bit)
+	 */
+	exp = ((int32_t)phloat >> 23) - 127;
+
+	/* Extract mantissa, add missing '1' bit and it's in MHz */
+	man = ((phloat & 0x7fffff) | 0x800000) * 1000000ULL;
+
+	if (exp < 0)
+		man >>= -exp;
+	else
+		man <<= exp;
+
+	man >>= 23; /* Remove mantissa bias */
+
+	return man & 0xffffffff;
+}
+
+
+/*
+ * Read a 8/16/32-bit i2c register.  The value is returned in 'val'.
+ * Returns zero if successful, or non-zero otherwise.
+ */
+static int ____smiapp_read(struct smiapp_sensor *sensor, u16 reg,
+			   u16 len, u32 *val)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(&sensor->src->sd);
+	struct i2c_msg msg;
+	unsigned char data[4];
+	u16 offset = reg;
+	int r;
+
+	msg.addr = client->addr;
+	msg.flags = 0;
+	msg.len = 2;
+	msg.buf = data;
+
+	/* high byte goes out first */
+	data[0] = (u8) (offset >> 8);
+	data[1] = (u8) offset;
+	r = i2c_transfer(client->adapter, &msg, 1);
+	if (r != 1) {
+		if (r >= 0)
+			r = -EBUSY;
+		goto err;
+	}
+
+	msg.len = len;
+	msg.flags = I2C_M_RD;
+	r = i2c_transfer(client->adapter, &msg, 1);
+	if (r != 1) {
+		if (r >= 0)
+			r = -EBUSY;
+		goto err;
+	}
+
+	*val = 0;
+	/* high byte comes first */
+	switch (len) {
+	case SMIAPP_REG_32BIT:
+		*val = (data[0] << 24) + (data[1] << 16) + (data[2] << 8) +
+			data[3];
+		break;
+	case SMIAPP_REG_16BIT:
+		*val = (data[0] << 8) + data[1];
+		break;
+	case SMIAPP_REG_8BIT:
+		*val = data[0];
+		break;
+	default:
+		BUG();
+	}
+
+	return 0;
+
+err:
+	dev_err(&client->dev, "read from offset 0x%x error %d\n", offset, r);
+
+	return r;
+}
+
+/* Read a register using 8-bit access only. */
+static int ____smiapp_read_8only(struct smiapp_sensor *sensor, u16 reg,
+				 u16 len, u32 *val)
+{
+	unsigned int i;
+	int rval;
+
+	*val = 0;
+
+	for (i = 0; i < len; i++) {
+		u32 val8;
+
+		rval = ____smiapp_read(sensor, reg + i, 1, &val8);
+		if (rval < 0)
+			return rval;
+		*val |= val8 << ((len - i - 1) << 3);
+	}
+
+	return 0;
+}
+
+/*
+ * Read a 8/16/32-bit i2c register.  The value is returned in 'val'.
+ * Returns zero if successful, or non-zero otherwise.
+ */
+static int __smiapp_read(struct smiapp_sensor *sensor, u32 reg, u32 *val,
+			 bool only8)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(&sensor->src->sd);
+	u8 len = SMIAPP_REG_WIDTH(reg);
+	int rval;
+
+	if (len != SMIAPP_REG_8BIT && len != SMIAPP_REG_16BIT
+	    && len != SMIAPP_REG_32BIT)
+		return -EINVAL;
+
+	if (len == SMIAPP_REG_8BIT || !only8)
+		rval = ____smiapp_read(sensor, SMIAPP_REG_ADDR(reg), len, val);
+	else
+		rval = ____smiapp_read_8only(sensor, SMIAPP_REG_ADDR(reg), len,
+					     val);
+	if (rval < 0)
+		return rval;
+
+	if (reg & SMIAPP_REG_FLAG_FLOAT)
+		*val = float_to_u32_mul_1000000(client, *val);
+
+	return 0;
+}
+
+int smiapp_read_no_quirk(struct smiapp_sensor *sensor, u32 reg, u32 *val)
+{
+	return __smiapp_read(
+		sensor, reg, val,
+		smiapp_needs_quirk(sensor,
+				   SMIAPP_QUIRK_FLAG_8BIT_READ_ONLY));
+}
+
+static int smiapp_read_quirk(struct smiapp_sensor *sensor, u32 reg, u32 *val,
+			     bool force8)
+{
+	int rval;
+
+	*val = 0;
+	rval = smiapp_call_quirk(sensor, reg_access, false, &reg, val);
+	if (rval == -ENOIOCTLCMD)
+		return 0;
+	if (rval < 0)
+		return rval;
+
+	if (force8)
+		return __smiapp_read(sensor, reg, val, true);
+
+	return smiapp_read_no_quirk(sensor, reg, val);
+}
+
+int smiapp_read(struct smiapp_sensor *sensor, u32 reg, u32 *val)
+{
+	return smiapp_read_quirk(sensor, reg, val, false);
+}
+
+int smiapp_read_8only(struct smiapp_sensor *sensor, u32 reg, u32 *val)
+{
+	return smiapp_read_quirk(sensor, reg, val, true);
+}
+
+int smiapp_write_no_quirk(struct smiapp_sensor *sensor, u32 reg, u32 val)
+{
+	struct i2c_client *client = v4l2_get_subdevdata(&sensor->src->sd);
+	struct i2c_msg msg;
+	unsigned char data[6];
+	unsigned int retries;
+	u8 flags = SMIAPP_REG_FLAGS(reg);
+	u8 len = SMIAPP_REG_WIDTH(reg);
+	u16 offset = SMIAPP_REG_ADDR(reg);
+	int r;
+
+	if ((len != SMIAPP_REG_8BIT && len != SMIAPP_REG_16BIT &&
+	     len != SMIAPP_REG_32BIT) || flags)
+		return -EINVAL;
+
+	if (!sensor->active)
+		return 0;
+
+	msg.addr = client->addr;
+	msg.flags = 0; /* Write */
+	msg.len = 2 + len;
+	msg.buf = data;
+
+	/* high byte goes out first */
+	data[0] = (u8) (reg >> 8);
+	data[1] = (u8) (reg & 0xff);
+
+	switch (len) {
+	case SMIAPP_REG_8BIT:
+		data[2] = val;
+		break;
+	case SMIAPP_REG_16BIT:
+		data[2] = val >> 8;
+		data[3] = val;
+		break;
+	case SMIAPP_REG_32BIT:
+		data[2] = val >> 24;
+		data[3] = val >> 16;
+		data[4] = val >> 8;
+		data[5] = val;
+		break;
+	default:
+		BUG();
+	}
+
+	for (retries = 0; retries < 5; retries++) {
+		/*
+		 * Due to unknown reason sensor stops responding. This
+		 * loop is a temporaty solution until the root cause
+		 * is found.
+		 */
+		r = i2c_transfer(client->adapter, &msg, 1);
+		if (r == 1) {
+			if (retries)
+				dev_err(&client->dev,
+					"sensor i2c stall encountered. retries: %d\n",
+					retries);
+			return 0;
+		}
+
+		usleep_range(2000, 2000);
+	}
+
+	dev_err(&client->dev,
+		"wrote 0x%x to offset 0x%x error %d\n", val, offset, r);
+
+	return r;
+}
+
+/*
+ * Write to a 8/16-bit register.
+ * Returns zero if successful, or non-zero otherwise.
+ */
+int smiapp_write(struct smiapp_sensor *sensor, u32 reg, u32 val)
+{
+	int rval;
+
+	rval = smiapp_call_quirk(sensor, reg_access, true, &reg, &val);
+	if (rval == -ENOIOCTLCMD)
+		return 0;
+	if (rval < 0)
+		return rval;
+
+	return smiapp_write_no_quirk(sensor, reg, val);
+}