On 2019-12-02 5:12 AM, Shawn Guo wrote:
> On Thu, Oct 31, 2019 at 11:50:22PM +0200, Leonard Crestez wrote:
>> These clocks are only modified as part of DRAM frequency switches during
>> which DRAM itself is briefly inaccessible. The switch is performed with
>> a SMC call to by TF-A which runs from a SRAM area; upon returning to
>> linux several clocks bits are modified and we need to update them.
>>
>> For rate bits an easy solution is to just mark with
>> CLK_GET_RATE_NOCACHE so that new rates are always read back from
>> registers.
>>
>> Signed-off-by: Leonard Crestez <leonard.crestez@xxxxxxx>
>> ---
>> drivers/clk/imx/clk-imx8mm.c | 11 +++++++++--
>> drivers/clk/imx/clk-imx8mn.c | 12 ++++++++++--
>> drivers/clk/imx/clk-imx8mq.c | 15 +++++++++++----
>> 3 files changed, 30 insertions(+), 8 deletions(-)
>>
>> diff --git a/drivers/clk/imx/clk-imx8mm.c b/drivers/clk/imx/clk-imx8mm.c
>> index 030b15d7c0ce..c58f988191a5 100644
>> --- a/drivers/clk/imx/clk-imx8mm.c
>> +++ b/drivers/clk/imx/clk-imx8mm.c
>> @@ -440,13 +440,20 @@ static int imx8mm_clocks_probe(struct platform_device *pdev)
>>
>> /* IPG */
>> clks[IMX8MM_CLK_IPG_ROOT] = imx_clk_divider2("ipg_root", "ahb", base + 0x9080, 0, 1);
>> clks[IMX8MM_CLK_IPG_AUDIO_ROOT] = imx_clk_divider2("ipg_audio_root", "audio_ahb", base + 0x9180, 0, 1);
>>
>> + /*
>> + * DRAM clocks are manipulated from TF-A outside clock framework.
>> + * Mark with GET_RATE_NOCACHE to always read div value from hardware
>> + */
>> + clks[IMX8MM_CLK_DRAM_ALT] = __imx8m_clk_composite("dram_alt", imx8mm_dram_alt_sels, base + 0xa000,
>> + CLK_GET_RATE_NOCACHE);
>> + clks[IMX8MM_CLK_DRAM_APB] = __imx8m_clk_composite("dram_apb", imx8mm_dram_apb_sels, base + 0xa080,
>> + CLK_IS_CRITICAL | CLK_GET_RATE_NOCACHE);
>> +
>
> I think we prefer to ignore over-80-column warnings for i.MX clock
> drivers, because doing that improve the readability of code.
You're replying to an old version, v7 doesn't have this issue:
* https://patchwork.kernel.org/patch/11258501/
* https://patchwork.kernel.org/patch/11258505/
It also has additional acks from Abel and Stephen and the devfreq parts
of this series have already been accepted.
--
Regards,
Leonard
