14674e7011
Since there are uses for I2C_M_NOSTART which are much more sensible and standard than most of the protocol mangling functionality (the main one being gather writes to devices where something like a register address needs to be inserted before a block of data) create a new I2C_FUNC_NOSTART for this feature and update all the users to use it. Also strengthen the disrecommendation of the protocol mangling while we're at it. In the case of regmap-i2c we remove the requirement for mangling as I2C_M_NOSTART is the only mangling feature which is being used. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Acked-by: Wolfram Sang <w.sang@pengutronix.de> Signed-off-by: Jean Delvare <khali@linux-fr.org>
135 lines
3.2 KiB
C
135 lines
3.2 KiB
C
/*
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* Register map access API - I2C support
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*
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* Copyright 2011 Wolfson Microelectronics plc
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*
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* Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/regmap.h>
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#include <linux/i2c.h>
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#include <linux/module.h>
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#include <linux/init.h>
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static int regmap_i2c_write(void *context, const void *data, size_t count)
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{
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struct device *dev = context;
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struct i2c_client *i2c = to_i2c_client(dev);
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int ret;
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ret = i2c_master_send(i2c, data, count);
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if (ret == count)
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return 0;
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else if (ret < 0)
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return ret;
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else
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return -EIO;
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}
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static int regmap_i2c_gather_write(void *context,
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const void *reg, size_t reg_size,
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const void *val, size_t val_size)
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{
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struct device *dev = context;
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struct i2c_client *i2c = to_i2c_client(dev);
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struct i2c_msg xfer[2];
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int ret;
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/* If the I2C controller can't do a gather tell the core, it
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* will substitute in a linear write for us.
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*/
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if (!i2c_check_functionality(i2c->adapter, I2C_FUNC_NOSTART))
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return -ENOTSUPP;
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xfer[0].addr = i2c->addr;
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xfer[0].flags = 0;
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xfer[0].len = reg_size;
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xfer[0].buf = (void *)reg;
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xfer[1].addr = i2c->addr;
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xfer[1].flags = I2C_M_NOSTART;
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xfer[1].len = val_size;
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xfer[1].buf = (void *)val;
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ret = i2c_transfer(i2c->adapter, xfer, 2);
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if (ret == 2)
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return 0;
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if (ret < 0)
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return ret;
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else
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return -EIO;
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}
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static int regmap_i2c_read(void *context,
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const void *reg, size_t reg_size,
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void *val, size_t val_size)
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{
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struct device *dev = context;
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struct i2c_client *i2c = to_i2c_client(dev);
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struct i2c_msg xfer[2];
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int ret;
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xfer[0].addr = i2c->addr;
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xfer[0].flags = 0;
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xfer[0].len = reg_size;
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xfer[0].buf = (void *)reg;
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xfer[1].addr = i2c->addr;
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xfer[1].flags = I2C_M_RD;
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xfer[1].len = val_size;
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xfer[1].buf = val;
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ret = i2c_transfer(i2c->adapter, xfer, 2);
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if (ret == 2)
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return 0;
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else if (ret < 0)
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return ret;
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else
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return -EIO;
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}
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static struct regmap_bus regmap_i2c = {
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.write = regmap_i2c_write,
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.gather_write = regmap_i2c_gather_write,
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.read = regmap_i2c_read,
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};
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/**
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* regmap_init_i2c(): Initialise register map
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*
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* @i2c: Device that will be interacted with
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* @config: Configuration for register map
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*
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* The return value will be an ERR_PTR() on error or a valid pointer to
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* a struct regmap.
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*/
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struct regmap *regmap_init_i2c(struct i2c_client *i2c,
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const struct regmap_config *config)
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{
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return regmap_init(&i2c->dev, ®map_i2c, &i2c->dev, config);
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}
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EXPORT_SYMBOL_GPL(regmap_init_i2c);
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/**
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* devm_regmap_init_i2c(): Initialise managed register map
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*
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* @i2c: Device that will be interacted with
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* @config: Configuration for register map
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*
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* The return value will be an ERR_PTR() on error or a valid pointer
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* to a struct regmap. The regmap will be automatically freed by the
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* device management code.
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*/
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struct regmap *devm_regmap_init_i2c(struct i2c_client *i2c,
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const struct regmap_config *config)
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{
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return devm_regmap_init(&i2c->dev, ®map_i2c, &i2c->dev, config);
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}
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EXPORT_SYMBOL_GPL(devm_regmap_init_i2c);
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MODULE_LICENSE("GPL");
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