Re: [PATCH v1 1/4] clk: tegra20: Add DEV1/DEV2 OSC dividers

Dmitry Osipenko
2018-05-03T11:59:34Z

On 27.04.2018 16:00, Marcel Ziswiler wrote:
> On Fri, 2018-04-27 at 15:54 +0300, Dmitry Osipenko wrote:
>> Hi Marcel,
>>
>> On 27.04.2018 15:33, Ziswiler wrote:
>>> Hi Dmitry
>>>
>>> Isn't the CLK_RST_CONTROLLER_MISC_CLK_ENB_0 the other way around
>>> e.g.
>>> DEV1_OSC_DIV_SEL at bit 23:22 and DEV2_OSC_DIV_SEL at 21:20?
>>>
>>> On Fri, 2018-04-27 at 02:58 +0300, Dmitry Osipenko wrote:
>>>> CDEV1/CDEV2 clocks could have corresponding oscillator clock
>>>> divider
>>>> as
>>>> a parent. Add these dividers in order to be able to provide that
>>>> parent
>>>> option.
>>>>
>>>> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
>>>> ---
>>>> drivers/clk/tegra/clk-tegra20.c | 12 ++++++++++++
>>>> 1 file changed, 12 insertions(+)
>>>>
>>>> diff --git a/drivers/clk/tegra/clk-tegra20.c
>>>> b/drivers/clk/tegra/clk-
>>>> tegra20.c
>>>> index 0ee56dd04cec..16cf4108f2ff 100644
>>>> --- a/drivers/clk/tegra/clk-tegra20.c
>>>> +++ b/drivers/clk/tegra/clk-tegra20.c
>>>> @@ -26,6 +26,8 @@
>>>> #include "clk.h"
>>>> #include "clk-id.h"
>>>>
>>>> +#define MISC_CLK_ENB 0x48
>>>> +
>>>> #define OSC_CTRL 0x50
>>>> #define OSC_CTRL_OSC_FREQ_MASK (3<<30)
>>>> #define OSC_CTRL_OSC_FREQ_13MHZ (0<<30)
>>>> @@ -831,6 +833,16 @@ static void __init
>>>> tegra20_periph_clk_init(void)
>>>> periph_clk_enb_refcnt);
>>>> clks[TEGRA20_CLK_PEX] = clk;
>>>>
>>>> + /* cdev1 OSC divider */
>>>> + clk_register_divider(NULL, "cdev1_osc_div", "clk_m",
>>>> + 0, clk_base + MISC_CLK_ENB, 20, 2,
>>>
>>> So it would be:
>>>
>>> + 0, clk_base + MISC_CLK_ENB, 22, 2,
>>>
>>>> + CLK_DIVIDER_POWER_OF_TWO, NULL);
>>>> +
>>>> + /* cdev2 OSC divider */
>>>> + clk_register_divider(NULL, "cdev2_osc_div", "clk_m",
>>>> + 0, clk_base + MISC_CLK_ENB, 22, 2,
>>>
>>> And:
>>>
>>> + 0, clk_base + MISC_CLK_ENB, 20, 2,
>>>
>>>> + CLK_DIVIDER_POWER_OF_TWO, NULL);
>>>> +
>>>> /* cdev1 */
>>>> clk = clk_register_fixed_rate(NULL, "cdev1_fixed", NULL,
>>>> 0,
>>>> 26000000);
>>>> clk = tegra_clk_register_periph_gate("cdev1",
>>>> "cdev1_fixed",
>>>> 0,
>>
>> Indeed, good catch! I'll wait for more comments and then re-spin
>> patchset with
>> the fix. Thank you.
>
> You are very welcome. Thank you!
>
> Other than that it all looks proper and works fine at least in the
> configuration we use on Colibri T20. So you may add my reviewed and
> tested bys to the whole series:
>
> Reviewed-by: Marcel Ziswiler <marcel@ziswiler.com>
> Tested-by: Marcel Ziswiler <marcel@ziswiler.com>

Marcel, you previously mentioned that reverting of your DT patch works for the
Colibri now. Does that reverting also work for the 4.17 kernel? If yes, I may
add stable tag to the revert-patch to get back paz00 working with 4.17. If it's
not working, we should figure out why pll_p_out4 is getting disabled as it
should be a distinct issue.