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author | Luis Oliveira <Luis.Oliveira@synopsys.com> | 2017-01-26 17:45:32 +0000 |
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committer | Wolfram Sang <wsa@the-dreams.de> | 2017-01-28 22:12:37 +0100 |
commit | cefae80249f6bf3fdbc7c3a00bc43deb4c1bccf0 (patch) | |
tree | 019fc491fc1a6a0ec825c98d60b8f8268884d40b /drivers/i2c/i2c-core.c | |
parent | 50b918c5a6ffad1d9fae29c4fdcb52383b123665 (diff) | |
download | linux-cefae80249f6bf3fdbc7c3a00bc43deb4c1bccf0.tar.gz linux-cefae80249f6bf3fdbc7c3a00bc43deb4c1bccf0.tar.bz2 linux-cefae80249f6bf3fdbc7c3a00bc43deb4c1bccf0.zip |
i2c: core: helper function to detect slave mode
This function has the purpose of mode detection by checking the
device nodes for a reg matching with the I2C_OWN_SLAVE_ADDREESS flag.
Currently only checks using OF functions (ACPI slave not supported yet).
Signed-off-by: Luis Oliveira <lolivei@synopsys.com>
Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'drivers/i2c/i2c-core.c')
-rw-r--r-- | drivers/i2c/i2c-core.c | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index 583e95042a21..408de741fec5 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -3690,6 +3690,39 @@ int i2c_slave_unregister(struct i2c_client *client) return ret; } EXPORT_SYMBOL_GPL(i2c_slave_unregister); + +/** + * i2c_detect_slave_mode - detect operation mode + * @dev: The device owning the bus + * + * This checks the device nodes for an I2C slave by checking the address + * used in the reg property. If the address match the I2C_OWN_SLAVE_ADDRESS + * flag this means the device is configured to act as a I2C slave and it will + * be listening at that address. + * + * Returns true if an I2C own slave address is detected, otherwise returns + * false. + */ +bool i2c_detect_slave_mode(struct device *dev) +{ + if (IS_BUILTIN(CONFIG_OF) && dev->of_node) { + struct device_node *child; + u32 reg; + + for_each_child_of_node(dev->of_node, child) { + of_property_read_u32(child, "reg", ®); + if (reg & I2C_OWN_SLAVE_ADDRESS) { + of_node_put(child); + return true; + } + } + } else if (IS_BUILTIN(CONFIG_ACPI) && ACPI_HANDLE(dev)) { + dev_dbg(dev, "ACPI slave is not supported yet\n"); + } + return false; +} +EXPORT_SYMBOL_GPL(i2c_detect_slave_mode); + #endif MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>"); |