From: Stephen Boyd <sboyd@kernel.org>
To: "Simek, Michal" <michal.simek@amd.com>,
"Trivedi Manojbhai, Naman" <Naman.TrivediManojbhai@amd.com>,
robh@kernel.org
Cc: linux-clk@vger.kernel.org <linux-clk@vger.kernel.org>,
linux-arm-kernel@lists.infradead.org
<linux-arm-kernel@lists.infradead.org>,
linux-kernel@vger.kernel.org <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH] drivers: clk: zynqmp: remove clock name dependency
Date: Wed, 10 Apr 2024 21:17:52 -0700 [thread overview]
Message-ID: <a48f6017bacb4aacb0a318554229cb65.sboyd@kernel.org> (raw)
In-Reply-To: <PH7PR12MB728433875E7B7DD673E8785D8A342@PH7PR12MB7284.namprd12.prod.outlook.com>
Quoting Trivedi Manojbhai, Naman (2024-03-26 22:47:28)
> >>Quoting Naman Trivedi Manojbhai (2024-01-02 23:20:17)
> >>> Currently, from zynqmp_get_parent_list() function the clock driver
> >>> references the clock by name instead of its reference from device tree.
> >>> This causes problem when the clock name in the device tree is changed.
> >>>
> >>> Remove hard dependency of clock name and update the logic to use
> >>> clock reference from device tree instead of clock name.
> >>
> >>Please use struct clk_parent_data instead.
> >Thanks for review. As per my understanding, you suggest to replace the
> >proposed logic, and use "struct clk_parent_data" to get the clock name from
> >device tree.
No, do not get the clock name of a parent in the driver. Use struct
clk_parent_data to tell the clk framework what the parent is.
> >
> >I have gone through other drivers which use the "struct clk_parent_data"
> >structure, they have hard coded clock names in the driver. In zynqmp, the
> >driver receives clock name from firmware.
Don't use a string name. The devicetree index must be stable, so simply
use the index that the binding has as the index in struct
clk_parent_data.
struct clk_parent_data parent_map[] = {
{ .index = MY_DT_PARENT_1 }, /* parent index 0 */
{ .index = MT_DT_PARENT_2 }, /* parent index 1 */
};
> >
> >Also, the "zynqmp_get_parent_list" function is called before clocks are
> >registered. So at this point, we don't have the hw structure which has
> >clk_parent_data.
I guess that's a problem with how the code is written?
> >
> >So, I did not get how to use the struct clk_parent_data in this case. Can you
> >please provide an example which I can look at as a reference?
> >
There are many references. A new qcom one is drivers/clk/qcom/gcc-x1e80100.c
next prev parent reply other threads:[~2024-04-11 4:17 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-03 7:20 [PATCH] drivers: clk: zynqmp: remove clock name dependency Naman Trivedi Manojbhai
2024-01-03 10:03 ` Michal Simek
2024-01-03 22:28 ` kernel test robot
2024-01-04 1:00 ` Stephen Boyd
2024-01-09 11:24 ` Trivedi Manojbhai, Naman
2024-01-29 16:48 ` Trivedi Manojbhai, Naman
2024-01-22 12:05 ` Trivedi Manojbhai, Naman
2024-03-07 6:06 ` Trivedi Manojbhai, Naman
2024-03-27 5:47 ` Trivedi Manojbhai, Naman
2024-04-11 4:17 ` Stephen Boyd [this message]
2024-01-04 1:41 ` kernel test robot
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