From: Adam Ford <aford173-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
To: David Lechner <david-nq/r/kbU++upp/zk7JDF2g@public.gmane.org>
Cc: Sekhar Nori <nsekhar-l0cyMroinI0@public.gmane.org>,
linux-clk-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
Michael Turquette
<mturquette-rdvid1DuHRBWk0Htik3J/w@public.gmane.org>,
Stephen Boyd <sboyd-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>,
Rob Herring <robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
Mark Rutland <mark.rutland-5wv7dgnIgG8@public.gmane.org>,
Kevin Hilman <khilman-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: Re: [PATCH v5 02/44] clk: davinci: New driver for davinci PLL clocks
Date: Fri, 12 Jan 2018 09:30:37 -0600 [thread overview]
Message-ID: <CAHCN7xK44_zv27xe5yxL8Efey=VC-nypK6hY6VWqsoLqnKe04g@mail.gmail.com> (raw)
In-Reply-To: <01fbde0e-36a0-2b19-e385-e63bc4a3ae4a-nq/r/kbU++upp/zk7JDF2g@public.gmane.org>
On Fri, Jan 12, 2018 at 9:25 AM, David Lechner <david-nq/r/kbU++upp/zk7JDF2g@public.gmane.org> wrote:
> On 01/12/2018 03:21 AM, Sekhar Nori wrote:
>>
>> On Monday 08 January 2018 07:47 AM, David Lechner wrote:
>>>
>>> This adds a new driver for mach-davinci PLL clocks. This is porting the
>>> code from arch/arm/mach-davinci/clock.c to the common clock framework.
>>> Additionally, it adds device tree support for these clocks.
>>>
>>> The ifeq ($(CONFIG_COMMON_CLK), y) in the Makefile is needed to prevent
>>> compile errors until the clock code in arch/arm/mach-davinci is removed.
>>>
>>> Note: although there are similar clocks for TI Keystone we are not able
>>> to share the code for a few reasons. The keystone clocks are device tree
>>> only and use legacy one-node-per-clock bindings. Also the register
>>> layouts are a bit different, which would add even more if/else mess
>>> to the keystone clocks. And the keystone PLL driver doesn't support
>>> setting clock rates.
>>>
>>> Signed-off-by: David Lechner <david-nq/r/kbU++upp/zk7JDF2g@public.gmane.org>
>>> ---
>
>
>>> +
>>> +#define PLLM_MASK 0x1f
>>> +#define PREDIV_RATIO_MASK 0x1f
>>
>>
>> May be use the mode modern GENMASK()?
>
>
> I haven't seen that one before. Thanks.
>
> ...
>
>>> +static unsigned long davinci_pll_clk_recalc(struct clk_hw *hw,
>>> + unsigned long parent_rate)
>>> +{
>>> + struct davinci_pll_clk *pll = to_davinci_pll_clk(hw);
>>> + unsigned long rate = parent_rate;
>>> + u32 prediv, mult, postdiv;
>>> +
>>> + prediv = readl(pll->base + PREDIV) & PREDIV_RATIO_MASK;
>>> + mult = readl(pll->base + PLLM) & PLLM_MASK;
>>> + postdiv = readl(pll->base + POSTDIV) & POSTDIV_RATIO_MASK;
>>
>>
>> Shouldn't we check if the pre and post dividers are enabled before using
>> them?
>
>
> Indeed.
>
>>
>>> +
>>> + rate /= prediv + 1;
>>> + rate *= mult + 1;
>>> + rate /= postdiv + 1;
>>> +
>>> + return rate;
>>> +}
>>> +
>
>
> ...
>
>>
>> PLL output on DA850 must never be below 300MHz or above 600MHz (see
>> datasheet table "Allowed PLL Operating Conditions"). Does this take care
>> of that? Thats one of the main reasons I recall I went with some
>> specific values of prediv, pllm and post div in
>> arch/arm/mach-davinci/da850.c
>
>
> Apparently, I missed this requirement. It looks like I am going to have to
> rework things so that there is some coordination between the PLL and the
> PLLDIV clocks in order to get the < 300MHz operating points.
>
> ...
>
>>> +
>>> + divider->reg = base + OSCDIV;
>>> + divider->width = OSCDIV_RATIO_WIDTH;
>>
>>
>> can you write OD1EN of OSCDIV here? I guess the reset default is 1 so
>> you didnt need to do that. But not doing exposes us to settings that
>> bootloader left us in.
>>
>
> It looks like I am going to have to make a custom implementation for parts
> of this clock anyway, so I will probably just make new enable/disable
> callbacks that set both OSCDIV_OD1EN and CKEN_OBSCLK.
>
>
>>> +
>>> + clk = clk_register_composite(NULL, name, parent_names,
>>> num_parents,
>>> + &mux->hw, &clk_mux_ops,
>>> + ÷r->hw, &clk_divider_ops,
>>> + &gate->hw, &clk_gate_ops, 0);
>>> + if (IS_ERR(clk)) {
>>> + kfree(divider);
>>> + kfree(gate);
>>> + kfree(mux);
>>> + }
>>> +
>>> + return clk;
>>> +}
>>> +
>>> +struct clk *
>>> +davinci_pll_divclk_register(const struct davinci_pll_divclk_info *info,
>>> + void __iomem *base)
>>> +{
>>> + const struct clk_ops *divider_ops = &clk_divider_ops;
>>
>>
>> setting the sysclk divider requires GOSTAT handling apart from setting
>> the divider value. So I think .set_rate ops above wont work. Other ops
>> can be used, I guess. So we need a private structure here.
>>
>> Can you port over davinci_set_sysclk_rate() too? I understand you cannot
>> test it due to lack of cpufreq support in DT, but I can help testing
>> there.
>>
>> Or leave .set_rate NULL and it can be added later.
>
>
> Yes, I noticed that I missed this after I submitted this series. And I
> will have to rework things to coordinate with the PLL as mentioned above.
>
> FYI, I do have cpufreq-dt working, although the LEGO EV3 has a fixed 1.2V
> regulator, so I am limited in what I can test. Basically, I can only switch
I can test the cpufreq-dt. Are there additional patches or are they
part of the same git repo I have been testing?
The DA850 I have may not run all the way to highest speed, but I'll
see what I can find. I think I had a few at one point, but I don't
think it was part of Logic PD's standard product lineup.
adam
> between 300MHz and 375MHz according to the datasheets. The chip is
> technically
> the 456MHz version. What would happen if I ran it faster or slower with the
> wrong voltage?
>
> ...
>
>>> +
>>> + child = of_get_child_by_name(node, "auxclk");
>>> + if (child && of_device_is_available(child)) {
>>> + char child_name[MAX_NAME_SIZE];
>>> +
>>> + snprintf(child_name, MAX_NAME_SIZE, "%s_aux_clk", name);
>>> +
>>> + clk = davinci_pll_aux_clk_register(child_name,
>>> parent_name, base);
>>> + if (IS_ERR(clk))
>>> + pr_warn("%s: failed to register %s (%ld)\n",
>>> __func__,
>>> + child_name, PTR_ERR(clk));
>>> + else
>>> + of_clk_add_provider(child, of_clk_src_simple_get,
>>> clk);
>>> + }
>>
>>
>> davinci_pll_obs_clk_register() should also be handled here?
>
>
> I omitted it because no one is using it (same reason I left it out of the
> device tree bindings). We can certainly add it, though.
>
>
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next prev parent reply other threads:[~2018-01-12 15:30 UTC|newest]
Thread overview: 121+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-08 2:16 [PATCH v5 00/44] ARM: davinci: convert to common clock framework David Lechner
2018-01-08 2:17 ` [PATCH v5 01/44] dt-bindings: clock: Add new bindings for TI Davinci PLL clocks David Lechner
[not found] ` <1515377863-20358-2-git-send-email-david-nq/r/kbU++upp/zk7JDF2g@public.gmane.org>
2018-01-08 14:00 ` Sekhar Nori
2018-01-08 16:29 ` David Lechner
2018-01-09 12:35 ` Sekhar Nori
[not found] ` <0f90b5f7-f21e-5f81-1154-9a815bbb786d-l0cyMroinI0@public.gmane.org>
2018-01-10 3:01 ` David Lechner
2018-01-10 18:52 ` Sekhar Nori
2018-01-10 22:24 ` Adam Ford
[not found] ` <CAHCN7x+ZYezmEU_0mF=6_gF14DZxKnuDp1Cx=aC2=eN_QLNdJQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2018-01-11 2:50 ` David Lechner
2018-01-11 12:45 ` Adam Ford
2018-01-11 15:47 ` Sekhar Nori
[not found] ` <14320e05-c6f7-fa2d-35cd-c01414c59f2f-l0cyMroinI0@public.gmane.org>
2018-01-11 16:14 ` Adam Ford
2018-01-11 17:22 ` David Lechner
2018-01-11 18:09 ` Adam Ford
2018-01-11 18:29 ` David Lechner
2018-01-11 18:50 ` Adam Ford
[not found] ` <CAHCN7x+G5pxOeD7TahqiQUePEu1Z4Hyinkjq_bcSM+Hz36xoSg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2018-01-11 20:04 ` David Lechner
2018-01-11 20:58 ` Adam Ford
[not found] ` <CAHCN7x+EtQs6NHAYbVga7vU1U+qQLqOxdf+1MW6HewaT+ZF_Xg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2018-01-11 21:04 ` David Lechner
[not found] ` <5832fd62-16aa-e167-7e52-2ce493e33cdc-nq/r/kbU++upp/zk7JDF2g@public.gmane.org>
2018-01-11 21:34 ` Adam Ford
2018-01-11 21:46 ` David Lechner
[not found] ` <c1e27013-cbad-3b09-0e0d-f68d75162c1f-nq/r/kbU++upp/zk7JDF2g@public.gmane.org>
2018-01-12 6:03 ` Sekhar Nori
2018-01-16 11:22 ` Sekhar Nori
2018-01-16 12:21 ` Adam Ford
2018-01-16 16:41 ` David Lechner
2018-01-11 23:20 ` David Lechner
2018-01-11 2:54 ` David Lechner
2018-01-08 2:17 ` [PATCH v5 02/44] clk: davinci: New driver for davinci " David Lechner
2018-01-12 9:21 ` Sekhar Nori
2018-01-12 15:25 ` David Lechner
[not found] ` <01fbde0e-36a0-2b19-e385-e63bc4a3ae4a-nq/r/kbU++upp/zk7JDF2g@public.gmane.org>
2018-01-12 15:30 ` Adam Ford [this message]
[not found] ` <CAHCN7xK44_zv27xe5yxL8Efey=VC-nypK6hY6VWqsoLqnKe04g-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2018-01-12 15:48 ` David Lechner
2018-01-12 16:18 ` Sekhar Nori
[not found] ` <eb2b1a63-9c7c-aeca-170f-d38642442438-l0cyMroinI0@public.gmane.org>
2018-01-13 1:11 ` David Lechner
2018-01-16 6:48 ` Sekhar Nori
2018-01-13 2:13 ` David Lechner
2018-01-16 6:32 ` Sekhar Nori
2018-01-08 2:17 ` [PATCH v5 03/44] clk: davinci: Add platform information for TI DA830 PLL David Lechner
[not found] ` <1515377863-20358-4-git-send-email-david-nq/r/kbU++upp/zk7JDF2g@public.gmane.org>
2018-01-12 9:41 ` Sekhar Nori
2018-01-08 2:17 ` [PATCH v5 04/44] clk: davinci: Add platform information for TI DA850 PLL David Lechner
2018-01-16 8:37 ` Sekhar Nori
2018-01-08 2:17 ` [PATCH v5 05/44] clk: davinci: Add platform information for TI DM355 PLL David Lechner
2018-01-16 8:38 ` Sekhar Nori
2018-01-08 2:17 ` [PATCH v5 06/44] clk: davinci: Add platform information for TI DM365 PLL David Lechner
[not found] ` <1515377863-20358-7-git-send-email-david-nq/r/kbU++upp/zk7JDF2g@public.gmane.org>
2018-01-16 8:48 ` Sekhar Nori
2018-01-08 2:17 ` [PATCH v5 07/44] clk: davinci: Add platform information for TI DM644x PLL David Lechner
[not found] ` <1515377863-20358-8-git-send-email-david-nq/r/kbU++upp/zk7JDF2g@public.gmane.org>
2018-01-16 8:56 ` Sekhar Nori
2018-01-08 2:17 ` [PATCH v5 08/44] clk: davinci: Add platform information for TI DM646x PLL David Lechner
2018-01-16 9:01 ` Sekhar Nori
2018-01-08 2:17 ` [PATCH v5 09/44] dt-bindings: clock: New bindings for TI Davinci PSC David Lechner
[not found] ` <1515377863-20358-10-git-send-email-david-nq/r/kbU++upp/zk7JDF2g@public.gmane.org>
2018-01-11 21:22 ` Rob Herring
2018-01-08 2:17 ` [PATCH v5 10/44] clk: davinci: New driver for davinci PSC clocks David Lechner
2018-01-16 11:03 ` Sekhar Nori
2018-01-16 16:51 ` David Lechner
[not found] ` <83f3d207-9645-cbdf-d6cf-b6e6a8458abe-nq/r/kbU++upp/zk7JDF2g@public.gmane.org>
2018-01-17 12:25 ` Sekhar Nori
2018-01-17 17:28 ` David Lechner
2018-01-08 2:17 ` [PATCH v5 11/44] clk: davinci: Add platform information for TI DA830 PSC David Lechner
[not found] ` <1515377863-20358-12-git-send-email-david-nq/r/kbU++upp/zk7JDF2g@public.gmane.org>
2018-01-16 13:38 ` Sekhar Nori
[not found] ` <91fe16dc-907e-6dbb-c8db-c27561132093-l0cyMroinI0@public.gmane.org>
2018-01-16 17:16 ` David Lechner
[not found] ` <4dd36ca7-e41d-58d8-ec8c-787978307943-nq/r/kbU++upp/zk7JDF2g@public.gmane.org>
2018-01-17 12:18 ` Sekhar Nori
[not found] ` <86581de6-a982-7a7b-9a83-22c869417211-l0cyMroinI0@public.gmane.org>
2018-01-17 17:32 ` David Lechner
2018-01-18 7:53 ` Sekhar Nori
[not found] ` <1515377863-20358-1-git-send-email-david-nq/r/kbU++upp/zk7JDF2g@public.gmane.org>
2018-01-08 2:17 ` [PATCH v5 12/44] clk: davinci: Add platform information for TI DA850 PSC David Lechner
[not found] ` <1515377863-20358-13-git-send-email-david-nq/r/kbU++upp/zk7JDF2g@public.gmane.org>
2018-01-16 14:00 ` Sekhar Nori
2018-01-16 17:21 ` David Lechner
2018-01-17 11:57 ` Sekhar Nori
2018-01-17 17:33 ` David Lechner
2018-01-17 19:08 ` David Lechner
2018-01-18 6:37 ` Sekhar Nori
2018-02-09 16:22 ` Bartosz Golaszewski
2018-02-09 16:48 ` Michael Turquette
2018-02-12 3:03 ` David Lechner
2018-04-05 13:09 ` Sekhar Nori
2018-04-05 13:44 ` Bartosz Golaszewski
2018-04-05 14:36 ` Sekhar Nori
2018-04-05 15:37 ` David Lechner
2018-04-05 15:51 ` Bartosz Golaszewski
2018-04-06 9:37 ` Sekhar Nori
2018-04-06 16:46 ` Stephen Boyd
2018-04-23 14:59 ` David Lechner
2018-04-24 8:28 ` Sekhar Nori
2018-04-24 16:11 ` David Lechner
2018-04-25 6:07 ` Sekhar Nori
2018-04-25 10:09 ` Bartosz Golaszewski
2018-04-25 10:26 ` Bartosz Golaszewski
2018-01-08 2:17 ` [PATCH v5 13/44] clk: davinci: Add platform information for TI DM355 PSC David Lechner
[not found] ` <1515377863-20358-14-git-send-email-david-nq/r/kbU++upp/zk7JDF2g@public.gmane.org>
2018-01-16 14:15 ` Sekhar Nori
2018-01-08 2:17 ` [PATCH v5 14/44] clk: davinci: Add platform information for TI DM365 PSC David Lechner
2018-01-16 14:16 ` Sekhar Nori
2018-01-08 2:17 ` [PATCH v5 15/44] clk: davinci: Add platform information for TI DM644x PSC David Lechner
2018-01-17 13:57 ` Sekhar Nori
2018-01-08 2:17 ` [PATCH v5 16/44] clk: davinci: Add platform information for TI DM646x PSC David Lechner
2018-01-17 14:59 ` Sekhar Nori
2018-01-08 2:17 ` [PATCH v5 17/44] dt-bindings: clock: Add bindings for DA8XX CFGCHIP gate clocks David Lechner
[not found] ` <1515377863-20358-18-git-send-email-david-nq/r/kbU++upp/zk7JDF2g@public.gmane.org>
2018-01-11 21:45 ` Rob Herring
2018-01-11 21:51 ` David Lechner
2018-01-08 2:17 ` [PATCH v5 18/44] dt-bindings: clock: Add binding for TI DA8XX CFGCHIP mux clocks David Lechner
2018-01-08 2:17 ` [PATCH v5 19/44] clk: davinci: New driver for TI DA8XX CFGCHIP clocks David Lechner
2018-01-17 15:31 ` Sekhar Nori
2018-01-17 17:35 ` David Lechner
2018-01-08 2:17 ` [PATCH v5 20/44] dt-bindings: clock: Add bindings for TI DA8XX USB PHY clocks David Lechner
2018-01-18 12:10 ` Sekhar Nori
[not found] ` <33f0feba-adee-e365-54d5-16fe3d49302d-l0cyMroinI0@public.gmane.org>
2018-01-18 19:00 ` David Lechner
2018-01-19 6:17 ` Sekhar Nori
2018-01-08 2:17 ` [PATCH v5 21/44] clk: davinci: New driver " David Lechner
2018-01-18 13:05 ` Sekhar Nori
[not found] ` <493e4809-6b77-7772-70c7-ad0fa04e9033-l0cyMroinI0@public.gmane.org>
2018-01-18 18:49 ` David Lechner
2018-01-19 5:04 ` Sekhar Nori
2018-01-08 2:17 ` [PATCH v5 22/44] ARM: davinci: move davinci_clk_init() to init_time David Lechner
2018-01-08 2:17 ` [PATCH v5 23/44] ARM: da830: add new clock init using common clock framework David Lechner
2018-01-08 2:17 ` [PATCH v5 24/44] ARM: da850: " David Lechner
[not found] ` <1515377863-20358-25-git-send-email-david-nq/r/kbU++upp/zk7JDF2g@public.gmane.org>
2018-01-18 15:24 ` Sekhar Nori
2018-01-08 2:17 ` [PATCH v5 25/44] ARM: dm355: " David Lechner
2018-01-08 2:17 ` [PATCH v5 26/44] ARM: dm365: " David Lechner
2018-01-08 2:17 ` [PATCH v5 27/44] ARM: dm644x: " David Lechner
2018-01-08 2:17 ` [PATCH v5 28/44] ARM: dm646x: " David Lechner
2018-01-08 2:17 ` [PATCH v5 29/44] ARM: da8xx: add new USB PHY " David Lechner
2018-01-18 15:14 ` Sekhar Nori
[not found] ` <83dfab9a-be30-6313-d756-50fa018e757e-l0cyMroinI0@public.gmane.org>
2018-01-18 18:43 ` David Lechner
2018-01-19 5:08 ` Sekhar Nori
2018-01-08 2:17 ` [PATCH v5 35/44] ARM: da850: Remove legacy clock init David Lechner
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