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From: nsekhar@ti•com (Sekhar Nori)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v2 03/11] ARM: davinci: da850: use clk->set_parent for async3
Date: Wed, 23 Mar 2016 22:59:35 +0530	[thread overview]
Message-ID: <56F2D27F.6040001@ti.com> (raw)
In-Reply-To: <56F2D05C.8030909@lechnology.com>

On Wednesday 23 March 2016 10:50 PM, David Lechner wrote:
> On 03/23/2016 10:56 AM, Sekhar Nori wrote:
>> On Thursday 17 March 2016 07:56 AM, David Lechner wrote:
>>> The da850 family of processors has an async3 clock domain that can be
>>> muxed to either pll0_sysclk2 or pll1_sysclk2. Now that the davinci
>>> clocks
>>> have a set_parent callback, we can use this to control the async3 mux
>>> instead of a stand-alone function.
>>>
>>> This adds a new async3_clk and sets the appropriate child clocks. The
>>> default is use to pll1_sysclk2 since it is not affected by processor
>>> frequency scaling.
>>>
>>> Signed-off-by: David Lechner <david@lechnology•com>
>>> ---
>>
>>> +static int da850_async3_set_parent(struct clk *clk, struct clk *parent)
>>> +{
>>> +    u32 __iomem *cfgchip3;
>>> +    u32 val;
>>> +
>>> +    /*
>>> +     * Can't use DA8XX_SYSCFG0_VIRT() here since this can be called
>>> before
>>> +     * da8xx_syscfg0_base is initialized.
>>> +     */
>>> +    cfgchip3 = ioremap(DA8XX_SYSCFG0_BASE + DA8XX_CFGCHIP3_REG, 4);
>>
>> Is this just a theoretical possibility or have you seen this happen? I
>> would like to see if there are ways of avoiding this rather than throw
>> away usage of DA8XX_SYSCFG0_VIRT()
> 
> Yes, it will not boot without this. The problem comes from the fact that
> clocks are setup in davinci_common_init() which is called before
> da8xx_syscfg0_base = ioremap(DA8XX_SYSCFG0_BASE, SZ_4K) in da850_init()
> (and da830_init()). I also tried moving the ioremap() before
> davinci_common_init(), but davinci_common_init() sets up the iomem, so
> that doesn't work either.
> 
> So, if you want to use DA8XX_SYSCFG0_VIRT() here, the clock init would
> have to be split out from davinci_common_init() which would affect all
> davinci devices.

Alright, I guess 'can be called' in the comment should have used
stronger language :) How about late registration of USB clocks as I
suggested. It should also help consolidate code across da830 and da850.

Thanks,
Sekhar

  reply	other threads:[~2016-03-23 17:29 UTC|newest]

Thread overview: 43+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-03-17  2:26 [PATCH v2 00/11] da8xx USB clocks David Lechner
2016-03-17  2:26 ` [PATCH v2 01/11] ARM: davinci: defined missing CFGCHIP2_REFFREQ_* macros for MUSB PHY David Lechner
2016-03-17  2:26 ` [PATCH v2 02/11] ARM: davinci: add set_parent callback for mux clocks David Lechner
2016-03-17  2:26 ` [PATCH v2 03/11] ARM: davinci: da850: use clk->set_parent for async3 David Lechner
2016-03-23 15:56   ` Sekhar Nori
2016-03-23 17:20     ` David Lechner
2016-03-23 17:29       ` Sekhar Nori [this message]
2016-03-23 18:32         ` David Lechner
2016-03-24 13:44           ` Sekhar Nori
2016-03-17  2:26 ` [PATCH v2 04/11] ARM: davinci: da8xx: add usb phy clocks David Lechner
2016-03-17 12:12   ` Sergei Shtylyov
2016-03-23 16:56   ` Sekhar Nori
2016-03-23 17:45     ` David Lechner
2016-03-23 17:54       ` Sekhar Nori
2016-03-17  2:26 ` [PATCH v2 05/11] dt-bindings: Add bindings for phy-da8xx-usb David Lechner
2016-03-19 23:56   ` Rob Herring
2016-03-23 17:06   ` Sekhar Nori
2016-03-23 17:56     ` David Lechner
2016-03-17  2:26 ` [PATCH v2 06/11] phy: da8xx-usb: new driver for DA8XX SoC USB PHY David Lechner
2016-03-17 12:38   ` Sergei Shtylyov
2016-03-23 17:21   ` Sekhar Nori
2016-03-23 18:06     ` David Lechner
2016-03-24 14:01       ` David Laight
2016-04-01 13:16   ` Kishon Vijay Abraham I
2016-04-01 14:45     ` Bin Liu
2016-04-01 16:02       ` David Lechner
2016-04-01 16:19         ` Bin Liu
2016-04-01 19:49           ` Sergei Shtylyov
2016-04-01 19:45         ` Sergei Shtylyov
2016-04-01 19:56           ` Bin Liu
2016-04-13 20:51     ` David Lechner
2016-04-14 12:32       ` Kishon Vijay Abraham I
2016-03-17  2:26 ` [PATCH v2 07/11] ARM: davinci: da8xx: Add USB PHY platform declaration David Lechner
2016-03-17  2:26 ` [PATCH v2 08/11] ARM: dt: da850: Add usb phy node David Lechner
2016-03-17  2:26 ` [PATCH v2 09/11] usb: ohci-da8xx: Remove code that references mach David Lechner
2016-03-17 12:53   ` Sergei Shtylyov
2016-03-17  2:26 ` [PATCH v2 10/11] usb: musb: da8xx: Use devm in probe David Lechner
2016-03-17 11:07   ` Sergei Shtylyov
2016-03-17  2:26 ` [PATCH v2 11/11] usb: musb: da8xx: Remove mach code David Lechner
2016-03-17 13:11   ` Sergei Shtylyov
2016-03-17 17:38     ` David Lechner
2016-03-17 13:39 ` [PATCH v2 00/11] da8xx USB clocks Sergei Shtylyov
2016-03-23 17:26   ` Sekhar Nori

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