From 7e170c6e4f7501bea900aa66b2b27a6ce5001e25 Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Thu, 19 Dec 2013 16:28:29 +0100 Subject: mfd: ti_am335x_tscadc: Don't read back REG_SE The purpose of reg_se_cache has been defeated. It should avoid the read-back of the register to avoid the latency and the fact that the bits are reset to 0 after the individual conversation took place. The reason why this is required like this to work, is that read-back of the register removes the bits of the ADC so they do not start another conversation after the register is re-written from the TSC side for the update. To avoid the not required read-back I introduce a "set once" variant which does not update the cache mask. After the conversation completes, the bit is removed from the SE register anyway and we don't plan a new conversation "any time soon". The current set function is renamed to set_cache to distinguish the two operations. This is a small preparation for a larger sync-rework. Signed-off-by: Sebastian Andrzej Siewior Acked-by: Dmitry Torokhov Acked-by: Jonathan Cameron Signed-off-by: Lee Jones --- include/linux/mfd/ti_am335x_tscadc.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'include/linux/mfd/ti_am335x_tscadc.h') diff --git a/include/linux/mfd/ti_am335x_tscadc.h b/include/linux/mfd/ti_am335x_tscadc.h index 1fe72199e670..2fa9c0613da4 100644 --- a/include/linux/mfd/ti_am335x_tscadc.h +++ b/include/linux/mfd/ti_am335x_tscadc.h @@ -176,7 +176,8 @@ static inline struct ti_tscadc_dev *ti_tscadc_dev_get(struct platform_device *p) return *tscadc_dev; } -void am335x_tsc_se_set(struct ti_tscadc_dev *tsadc, u32 val); +void am335x_tsc_se_set_cache(struct ti_tscadc_dev *tsadc, u32 val); +void am335x_tsc_se_set_once(struct ti_tscadc_dev *tsadc, u32 val); void am335x_tsc_se_clr(struct ti_tscadc_dev *tsadc, u32 val); #endif -- cgit