From e1dba01ca620bb0b3864d5237c1c597d9e012ebf Mon Sep 17 00:00:00 2001 From: Wolfram Sang Date: Tue, 8 Dec 2015 10:37:46 +0100 Subject: i2c: add generic routine to parse DT for timing information Inspired from the i2c-rk3x driver (thanks guys!) but refactored and extended. See built-in docs for further information. Signed-off-by: Wolfram Sang Reviewed-by: Mika Westerberg Signed-off-by: Wolfram Sang --- include/linux/i2c.h | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'include') diff --git a/include/linux/i2c.h b/include/linux/i2c.h index 51028f351d13..bc2b19ad9357 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -413,6 +413,22 @@ struct i2c_algorithm { #endif }; +/** + * struct i2c_timings - I2C timing information + * @bus_freq_hz: the bus frequency in Hz + * @scl_rise_ns: time SCL signal takes to rise in ns; t(r) in the I2C specification + * @scl_fall_ns: time SCL signal takes to fall in ns; t(f) in the I2C specification + * @scl_int_delay_ns: time IP core additionally needs to setup SCL in ns + * @sda_fall_ns: time SDA signal takes to fall in ns; t(f) in the I2C specification + */ +struct i2c_timings { + u32 bus_freq_hz; + u32 scl_rise_ns; + u32 scl_fall_ns; + u32 scl_int_delay_ns; + u32 sda_fall_ns; +}; + /** * struct i2c_bus_recovery_info - I2C bus recovery information * @recover_bus: Recover routine. Either pass driver's recover_bus() routine, or @@ -604,6 +620,7 @@ extern void i2c_clients_command(struct i2c_adapter *adap, extern struct i2c_adapter *i2c_get_adapter(int nr); extern void i2c_put_adapter(struct i2c_adapter *adap); +void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults); /* Return the functionality mask */ static inline u32 i2c_get_functionality(struct i2c_adapter *adap) @@ -660,6 +677,7 @@ extern struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node) /* must call i2c_put_adapter() when done with returned i2c_adapter device */ struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node); + #else static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node) -- cgit v1.2.3