Re: [PATCH V15 6/6] i2c: tegra: add i2c interface timing support

Dmitry Osipenko
2019-02-08T13:00:57Z

08.02.2019 15:53, Dmitry Osipenko пишет:
> 08.02.2019 0:47, Sowjanya Komatineni пишет:
>> This patch adds I2C interface timing registers support for
>> proper bus rate configuration along with meeting the I2C spec
>> setup and hold times based on the tuning performed on Tegra210,
>> Tegra186 and Tegra194 platforms.
>>
>> I2C_INTERFACE_TIMING_0 register contains TLOW and THIGH field
>> and Tegra I2C controller design uses them as a part of internal
>> clock divisor.
>>
>> I2C_INTERFACE_TIMING_1 register contains the setup and hold times
>> for start and stop conditions.
>>
>> Acked-by: Thierry Reding <treding@nvidia.com>
>> Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
>> ---
>
> [snip]
>
>>
>> + if (i2c_dev->bus_clk_rate > I2C_STANDARD_MODE &&
>> + i2c_dev->bus_clk_rate <= I2C_FAST_PLUS_MODE) {
>> + tlow = i2c_dev->hw->tlow_fast_fastplus_mode;
>> + thigh = i2c_dev->hw->thigh_fast_fastplus_mode;
>> + tsu_thd = i2c_dev->hw->setup_hold_time_fast_fast_plus_mode;
>> + } else {
>> + tlow = i2c_dev->hw->tlow_std_mode;
>> + thigh = i2c_dev->hw->thigh_std_mode;
>> + tsu_thd = i2c_dev->hw->setup_hold_time_std_mode;
>> + }
>> +
>> + if (i2c_dev->hw->has_interface_timing_reg && val) {
>
> Shouldn't it be "&& tlow"?

Ah, there is "thigh" in use here.. so it all just doesn't make sense since "&& val" is always true.

>
>> + val = (thigh << I2C_THIGH_SHIFT) | tlow;
>> + i2c_writel(i2c_dev, val, I2C_INTERFACE_TIMING_0);
>> + }
>> +
>> + if (i2c_dev->hw->has_interface_timing_reg && tsu_thd)
>> + i2c_writel(i2c_dev, tsu_thd, I2C_INTERFACE_TIMING_1);
>
> Do we really need those "&& tlow" and "&& tsu_thd" at all? It looks to me that checking for "has_interface_timing_reg" should be enough.
>