diff options
Diffstat (limited to 'drivers/media/i2c/smiapp/smiapp-regs.c')
| -rw-r--r-- | drivers/media/i2c/smiapp/smiapp-regs.c | 273 |
1 files changed, 273 insertions, 0 deletions
diff --git a/drivers/media/i2c/smiapp/smiapp-regs.c b/drivers/media/i2c/smiapp/smiapp-regs.c new file mode 100644 index 000000000000..70e0d8db0130 --- /dev/null +++ b/drivers/media/i2c/smiapp/smiapp-regs.c @@ -0,0 +1,273 @@ +/* + * 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@maxwell.research.nokia.com> + * + * 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. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA + * 02110-1301 USA + * + */ + +#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 SMIA_REG_32BIT: + *val = (data[0] << 24) + (data[1] << 16) + (data[2] << 8) + + data[3]; + break; + case SMIA_REG_16BIT: + *val = (data[0] << 8) + data[1]; + break; + case SMIA_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); + unsigned int len = (u8)(reg >> 16); + int rval; + + if (len != SMIA_REG_8BIT && len != SMIA_REG_16BIT + && len != SMIA_REG_32BIT) + return -EINVAL; + + if (smiapp_quirk_reg(sensor, reg, val)) + goto found_quirk; + + if (len == SMIA_REG_8BIT && !only8) + rval = ____smiapp_read(sensor, (u16)reg, len, val); + else + rval = ____smiapp_read_8only(sensor, (u16)reg, len, val); + if (rval < 0) + return rval; + +found_quirk: + if (reg & SMIA_REG_FLAG_FLOAT) + *val = float_to_u32_mul_1000000(client, *val); + + return 0; +} + +int smiapp_read(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_8only(struct smiapp_sensor *sensor, u32 reg, u32 *val) +{ + return __smiapp_read(sensor, reg, val, true); +} + +/* + * 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) +{ + struct i2c_client *client = v4l2_get_subdevdata(&sensor->src->sd); + struct i2c_msg msg; + unsigned char data[6]; + unsigned int retries; + unsigned int flags = reg >> 24; + unsigned int len = (u8)(reg >> 16); + u16 offset = reg; + int r; + + if ((len != SMIA_REG_8BIT && len != SMIA_REG_16BIT && + len != SMIA_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 SMIA_REG_8BIT: + data[2] = val; + break; + case SMIA_REG_16BIT: + data[2] = val >> 8; + data[3] = val; + break; + case SMIA_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; +} |