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- /*
- * 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, ®, 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, ®, 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, ®, &val);
- if (rval == -ENOIOCTLCMD)
- return 0;
- if (rval < 0)
- return rval;
- return smiapp_write_no_quirk(sensor, reg, val);
- }
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