Messages in this thread Patch in this message | | | From | Mark Brown <> | Subject | [PATCH 2/8] regmap: Add I2C bus support | Date | Mon, 20 Jun 2011 13:54:43 +0100 |
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We initialise at postcore_initcall() so that we are available before users - some users such as PMICs initialise very early. We won't actually try to use any of the bus until a device initialises a register map.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> --- drivers/regmap/Makefile | 2 +- drivers/regmap/regmap-i2c.c | 112 +++++++++++++++++++++++++++++++++++++++++++ drivers/regmap/regmap.c | 4 +- 3 files changed, 115 insertions(+), 3 deletions(-) create mode 100644 drivers/regmap/regmap-i2c.c
diff --git a/drivers/regmap/Makefile b/drivers/regmap/Makefile index 1e5037e..641c20a 100644 --- a/drivers/regmap/Makefile +++ b/drivers/regmap/Makefile @@ -1,2 +1,2 @@ obj-$(CONFIG_REGMAP) += regmap.o - +obj-$(CONFIG_I2C) += regmap-i2c.o diff --git a/drivers/regmap/regmap-i2c.c b/drivers/regmap/regmap-i2c.c new file mode 100644 index 0000000..4a61560 --- /dev/null +++ b/drivers/regmap/regmap-i2c.c @@ -0,0 +1,112 @@ +/* + * Register map access API - I2C support + * + * Copyright 2011 Wolfson Microelectronics plc + * + * Author: Mark Brown <broonie@opensource.wolfsonmicro.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. + */ + +#include <linux/regmap.h> +#include <linux/i2c.h> + +static int regmap_i2c_write(struct device *dev, const void *data, size_t count) +{ + struct i2c_client *i2c = to_i2c_client(dev); + int ret; + + ret = i2c_master_send(i2c, data, count); + if (ret == count) + return 0; + else if (ret < 0) + return ret; + else + return -EIO; +} + +static int regmap_i2c_gather_write(struct device *dev, + const void *reg, size_t reg_size, + const void *val, size_t val_size) +{ + struct i2c_client *i2c = to_i2c_client(dev); + struct i2c_msg xfer[2]; + int ret; + + /* If the I2C controller can't do a gather tell the core, it + * will substitute in a linear write for us. + */ + if (!i2c_check_functionality(i2c->adapter, I2C_FUNC_PROTOCOL_MANGLING)) + return -ENOTSUPP; + + xfer[0].addr = i2c->addr; + xfer[0].flags = 0; + xfer[0].len = reg_size; + xfer[0].buf = (void *)reg; + + xfer[1].addr = i2c->addr; + xfer[1].flags = I2C_M_NOSTART; + xfer[1].len = val_size; + xfer[1].buf = (void *)val; + + ret = i2c_transfer(i2c->adapter, xfer, 2); + if (ret == 2) + return 0; + if (ret < 0) + return ret; + else + return -EIO; +} + +static int regmap_i2c_read(struct device *dev, + const void *reg, size_t reg_size, + void *val, size_t val_size) +{ + struct i2c_client *i2c = to_i2c_client(dev); + struct i2c_msg xfer[2]; + int ret; + + if (!i2c_check_functionality(i2c->adapter, I2C_FUNC_PROTOCOL_MANGLING)) + return -ENOTSUPP; + + xfer[0].addr = i2c->addr; + xfer[0].flags = 0; + xfer[0].len = reg_size; + xfer[0].buf = (void *)reg; + + xfer[1].addr = i2c->addr; + xfer[1].flags = I2C_M_RD; + xfer[1].len = val_size; + xfer[1].buf = val; + + ret = i2c_transfer(i2c->adapter, xfer, 2); + if (ret == 2) + return 0; + else if (ret < 0) + return ret; + else + return -EIO; +} + +static struct regmap_bus regmap_i2c = { + .type = &i2c_bus_type, + .write = regmap_i2c_write, + .gather_write = regmap_i2c_gather_write, + .read = regmap_i2c_read, + .owner = THIS_MODULE, +}; + +static int __init regmap_i2c_init(void) +{ + regmap_add_bus(®map_i2c); + return 0; +} +postcore_initcall(regmap_i2c_init); + +static void __exit regmap_i2c_exit(void) +{ + regmap_del_bus(®map_i2c); +} +module_exit(regmap_i2c_exit); diff --git a/drivers/regmap/regmap.c b/drivers/regmap/regmap.c index a8610c7..896b710 100644 --- a/drivers/regmap/regmap.c +++ b/drivers/regmap/regmap.c @@ -461,7 +461,7 @@ out: } EXPORT_SYMBOL_GPL(regmap_update_bits); -int regmap_add_bus(struct regmap_bus *bus) +void regmap_add_bus(struct regmap_bus *bus) { mutex_lock(®map_bus_lock); list_add(&bus->list, ®map_bus_list); @@ -469,7 +469,7 @@ int regmap_add_bus(struct regmap_bus *bus) } EXPORT_SYMBOL_GPL(regmap_add_bus); -int regmap_del_bus(struct regmap_bus *bus) +void regmap_del_bus(struct regmap_bus *bus) { mutex_lock(®map_bus_lock); list_del(&bus->list); -- 1.7.5.4
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