From 20c9d2c4ab8243a1c311248232954b2c1da3ba75 Mon Sep 17 00:00:00 2001 From: Kalle Jokiniemi Date: Tue, 11 May 2010 11:35:08 -0700 Subject: i2c-omap: add mpu wake up latency constraint in i2c While waiting for completion of the i2c transfer, the MPU could hit OFF mode and cause several msecs of delay that made i2c transfers fail more often. The extra delays and subsequent re-trys cause i2c clocks to be active more often. This has also an negative effect on power consumption. Created a mechanism for passing and using the constraint setting function in driver code. The used mpu wake up latency constraints are now set individually per bus, and they are calculated based on clock rate and fifo size. Thanks to Jarkko Nikula, Moiz Sonasath, Paul Walmsley, and Nishanth Menon for tuning out the details of this patch. Updates by Kevin as requested by Tony: - Remove omap_set_i2c_constraint_func() in favor of conditionally adding the flag in omap_i2c_add_bus() in order to keep all the OMAP conditional checking in a single location. - Update set_mpu_wkup_lat prototypes to match OMAP PM layer so OMAP PM function can be used directly in pdata. Cc: Moiz Sonasath Cc: Jarkko Nikula Cc: Paul Walmsley Cc: Nishanth Menon Signed-off-by: Kalle Jokiniemi Signed-off-by: Kevin Hilman Signed-off-by: Tony Lindgren Signed-off-by: Ben Dooks --- include/linux/i2c-omap.h | 9 +++++++++ 1 file changed, 9 insertions(+) create mode 100644 include/linux/i2c-omap.h (limited to 'include/linux/i2c-omap.h') diff --git a/include/linux/i2c-omap.h b/include/linux/i2c-omap.h new file mode 100644 index 000000000000..78ebf507ce56 --- /dev/null +++ b/include/linux/i2c-omap.h @@ -0,0 +1,9 @@ +#ifndef __I2C_OMAP_H__ +#define __I2C_OMAP_H__ + +struct omap_i2c_bus_platform_data { + u32 clkrate; + void (*set_mpu_wkup_lat)(struct device *dev, long set); +}; + +#endif -- cgit v1.2.3-59-g8ed1b