From: Stefan Agner <stefan@agner.ch>
To: Anson Huang <anson.huang@nxp.com>
Cc: Fabio Estevam <festevam@gmail.com>,
rjw@rjwysocki.net, viresh kumar <viresh.kumar@linaro.org>,
linux-pm@vger.kernel.org,
Marcel Ziswiler <marcel.ziswiler@toradex.com>,
max.oss.09@gmail.com, linux-kernel <linux-kernel@vger.kernel.org>,
Octavian Purdila <octavian.purdila@nxp.com>,
Fabio Estevam <fabio.estevam@nxp.com>,
Shawn Guo <shawnguo@kernel.org>,
"moderated list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE"
<linux-arm-kernel@lists.infradead.org>,
dl-linux-imx <linux-imx@nxp.com>
Subject: Re: [PATCH] cpufreq: imx6q: support frequencies >528MHz for i.MX6UL/ULL
Date: Sun, 11 Feb 2018 17:17:32 +0100 [thread overview]
Message-ID: <79baed40abbcc72920fd133bc43e378a@agner.ch> (raw)
In-Reply-To: <AM3PR04MB1315240E4A77431A58AC8501F5F00@AM3PR04MB1315.eurprd04.prod.outlook.com>
On 11.02.2018 02:42, Anson Huang wrote:
> Anson Huang
> Best Regards!
>
>
>> -----Original Message-----
>> From: Fabio Estevam [mailto:festevam@gmail.com]
>> Sent: Sunday, February 11, 2018 12:26 AM
>> To: Stefan Agner <stefan@agner.ch>; Anson Huang <anson.huang@nxp.com>
>> Cc: rjw@rjwysocki.net; viresh kumar <viresh.kumar@linaro.org>;
>> linux-pm@vger.kernel.org; Marcel Ziswiler <marcel.ziswiler@toradex.com>;
>> max.oss.09@gmail.com; linux-kernel <linux-kernel@vger.kernel.org>; Octavian
>> Purdila <octavian.purdila@nxp.com>; Fabio Estevam
>> <fabio.estevam@nxp.com>; Shawn Guo <shawnguo@kernel.org>; moderated
>> list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE
>> <linux-arm-kernel@lists.infradead.org>; dl-linux-imx <linux-imx@nxp.com>
>> Subject: Re: [PATCH] cpufreq: imx6q: support frequencies >528MHz for
>> i.MX6UL/ULL
>>
>> Hi Anson,
>>
>> On Thu, Jan 18, 2018 at 9:58 PM, Stefan Agner <stefan@agner.ch> wrote:
>> > Depending on SKU i.MX6UL/i.MX6ULL support frequencies up to 900MHz.
>> > Use PLL1 sys clock for all operating points higher than 528MHz.
>> >
>> > Note: For higher operating points VDD_SOC_IN needs to be 125mV higher
>> > than the ARM set-point (see datasheet). Specifically, the i.MX6UL/ULL
>> > EVK boards have an external DC regulator which needs adjustment. The
>> > regulator adjustment is not covered with this change.
>> >
>> > Signed-off-by: Stefan Agner <stefan@agner.ch>
>> > ---
>> > drivers/cpufreq/imx6q-cpufreq.c | 14 ++++++++------
>> > 1 file changed, 8 insertions(+), 6 deletions(-)
>> >
>> > diff --git a/drivers/cpufreq/imx6q-cpufreq.c
>> > b/drivers/cpufreq/imx6q-cpufreq.c index 628fe899cb48..840f6386c780
>> > 100644
>> > --- a/drivers/cpufreq/imx6q-cpufreq.c
>> > +++ b/drivers/cpufreq/imx6q-cpufreq.c
>> > @@ -114,12 +114,14 @@ static int imx6q_set_target(struct cpufreq_policy
>> *policy, unsigned int index)
>> > */
>> > clk_set_rate(arm_clk, (old_freq >> 1) * 1000);
>> > clk_set_parent(pll1_sw_clk, pll1_sys_clk);
>> > - if (freq_hz > clk_get_rate(pll2_pfd2_396m_clk))
>> > - clk_set_parent(secondary_sel_clk, pll2_bus_clk);
>> > - else
>> > - clk_set_parent(secondary_sel_clk,
>> pll2_pfd2_396m_clk);
>> > - clk_set_parent(step_clk, secondary_sel_clk);
>> > - clk_set_parent(pll1_sw_clk, step_clk);
>> > + if (freq_hz <= clk_get_rate(pll2_bus_clk)) {
>> > + if (freq_hz > clk_get_rate(pll2_pfd2_396m_clk))
>> > + clk_set_parent(secondary_sel_clk,
>> pll2_bus_clk);
>> > + else
>> > + clk_set_parent(secondary_sel_clk,
>> pll2_pfd2_396m_clk);
>> > + clk_set_parent(step_clk, secondary_sel_clk);
>> > + clk_set_parent(pll1_sw_clk, step_clk);
>> > + }
>
> For cpufreq > 528MHz, ARM PLL needs to be set_rate, I did NOT see
> where sets ARM PLL rate?
This is done unconditionally after the if statement:
if (of_machine_is_compatible("fsl,imx6ul") ||
of_machine_is_compatible("fsl,imx6ull")) {
/*
* When changing pll1_sw_clk's parent to pll1_sys_clk,
* CPU may run at higher than 528MHz, this will lead to
* the system unstable if the voltage is lower than the
* voltage of 528MHz, so lower the CPU frequency to one
* half before changing CPU frequency.
*/
clk_set_rate(arm_clk, (old_freq >> 1) * 1000);
clk_set_parent(pll1_sw_clk, pll1_sys_clk);
if (freq_hz <= clk_get_rate(pll2_bus_clk)) {
if (freq_hz > clk_get_rate(pll2_pfd2_396m_clk))
clk_set_parent(secondary_sel_clk, pll2_bus_clk);
else
clk_set_parent(secondary_sel_clk, pll2_pfd2_396m_clk);
clk_set_parent(step_clk, secondary_sel_clk);
clk_set_parent(pll1_sw_clk, step_clk);
}
} else {
clk_set_parent(step_clk, pll2_pfd2_396m_clk);
clk_set_parent(pll1_sw_clk, step_clk);
if (freq_hz > clk_get_rate(pll2_pfd2_396m_clk)) {
clk_set_rate(pll1_sys_clk, new_freq * 1000);
clk_set_parent(pll1_sw_clk, pll1_sys_clk);
} else {
/* pll1_sys needs to be enabled for divider rate change to work. */
pll1_sys_temp_enabled = true;
clk_prepare_enable(pll1_sys_clk);
}
}
/* Ensure the arm clock divider is what we expect */
ret = clk_set_rate(arm_clk, new_freq * 1000);
--
Stefan
>
> Anson.
>
>> > } else {
>> > clk_set_parent(step_clk, pll2_pfd2_396m_clk);
>> > clk_set_parent(pll1_sw_clk, step_clk);
>>
>> Could you please help reviewing this patch?
>>
>> Thanks
next prev parent reply other threads:[~2018-02-11 16:17 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-18 23:58 [PATCH] cpufreq: imx6q: support frequencies >528MHz for i.MX6UL/ULL Stefan Agner
2018-02-09 11:52 ` Rafael J. Wysocki
2018-02-09 12:05 ` Stefan Agner
2018-02-10 16:25 ` Fabio Estevam
2018-02-11 1:42 ` Anson Huang
2018-02-11 16:17 ` Stefan Agner [this message]
2018-02-12 7:24 ` Anson Huang
2018-02-12 8:53 ` Viresh Kumar
2018-02-12 10:18 ` Rafael J. Wysocki
2018-02-12 12:01 ` Stefan Agner
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