drivers/media/i2c/smiapp/smiapp-regs.c - kernel/mindspeed - Git at Google

 /*
  * 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));
 }

 int smiapp_read(struct smiapp_sensor *sensor, u32 reg, u32 *val)
 {
 	int rval;

 	*val = 0;
 	rval = smiapp_call_quirk(sensor, reg_access, false, &reg, val);
 	if (rval == -ENOIOCTLCMD)
 		return 0;
 	if (rval < 0)
 		return rval;

 	return smiapp_read_no_quirk(sensor, reg, val);
 }

 int smiapp_read_8only(struct smiapp_sensor *sensor, u32 reg, u32 *val)
 {
 	int rval;

 	*val = 0;
 	rval = smiapp_call_quirk(sensor, reg_access, false, &reg, val);
 	if (rval == -ENOIOCTLCMD)
 		return 0;
 	if (rval < 0)
 		return rval;

 	return __smiapp_read(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;

 	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);
 }
	/*
	* 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));
	}

	int smiapp_read(struct smiapp_sensor sensor, u32 reg, u32 val)
	{
	int rval;

	*val = 0;
	rval = smiapp_call_quirk(sensor, reg_access, false, &reg, val);
	if (rval == -ENOIOCTLCMD)
	return 0;
	if (rval < 0)
	return rval;

	return smiapp_read_no_quirk(sensor, reg, val);
	}

	int smiapp_read_8only(struct smiapp_sensor sensor, u32 reg, u32 val)
	{
	int rval;

	*val = 0;
	rval = smiapp_call_quirk(sensor, reg_access, false, &reg, val);
	if (rval == -ENOIOCTLCMD)
	return 0;
	if (rval < 0)
	return rval;

	return __smiapp_read(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;

	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);
	}