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From: "Chanho Park" <chanho61.park@samsung.com>
To: "'Inki Dae'" <inki.dae@samsung.com>,
	"'Alim Akhtar'" <alim.akhtar@samsung.com>,
	"'Avri Altman'" <avri.altman@wdc.com>,
	"'James E . J . Bottomley'" <jejb@linux.ibm.com>,
	"'Martin K . Petersen'" <martin.petersen@oracle.com>,
	"'Krzysztof Kozlowski'" <krzysztof.kozlowski@canonical.com>
Cc: "'Bean Huo'" <beanhuo@micron.com>,
	"'Bart Van Assche'" <bvanassche@acm.org>,
	"'Adrian Hunter'" <adrian.hunter@intel.com>,
	"'Christoph Hellwig'" <hch@infradead.org>,
	"'Can Guo'" <cang@codeaurora.org>,
	"'Jaegeuk Kim'" <jaegeuk@kernel.org>,
	"'Gyunghoon Kwon'" <goodjob.kwon@samsung.com>,
	<linux-samsung-soc@vger.kernel.org>, <linux-scsi@vger.kernel.org>,
	<cpgs@samsung.com>
Subject: RE: [PATCH v3 03/17] scsi: ufs: ufs-exynos: change pclk available max value
Date: Mon, 27 Sep 2021 20:08:31 +0900	[thread overview]
Message-ID: <00f401d7b390$017ed1f0$047c75d0$@samsung.com> (raw)
In-Reply-To: <1891546521.01632738482290.JavaMail.epsvc@epcpadp4>

> >>>  #define PCLK_AVAIL_MIN	70000000
> >>> -#define PCLK_AVAIL_MAX	133000000
> >>> +#define PCLK_AVAIL_MAX	167000000
> >>>
> >>
> >> I'm not sure but doesn't the maximum clock frequency depend on a
> >> given machine? Is it true for all machines using different SoC?
> >
> > Regarding pclk(sclk_unipro)of the ufs, it can be defined by
> mux(MUX_CLK_FSYS2_UFS_EMBD).
> > It can be either 167MHz or 160MHz. And it can be defined by OSCCLK(26MHz)
> as well. The value was up to 133Mhz in case of exynos7 but can be extended
> up to 167MHz for later SoCs, AFAIK.
> 
> Oscillator clock frequency could be different according to machine. And
> what if UFS driver is enabled for other machine using Exynos7? Is it true
> to use a fixed 167MHz frequency for these machines?
> I think you could get a proper pclk frequency from device tree specific to
> machine.

The actual pclk value will be get by CCF's clk_get_rate. PCLK_AVAIL_MAX represents the available maximum value of UFS's pclk to find an optimal value of unipro clock. I just extend the maximum pclk rate from 133MHz to 167MHz. The divider will be calculated according to the actual pclk value :)

[1]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/scsi/ufs/ufs-exynos.c?h=v5.15-rc3#n287

Best Regards,
Chanho Park


  reply	other threads:[~2021-09-27 11:08 UTC|newest]

Thread overview: 42+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <CGME20210917065522epcas2p2c9c7baccfc82b3798804c351dbf676eb@epcas2p2.samsung.com>
2021-09-17  6:54 ` [PATCH v3 00/17] introduce exynosauto v9 ufs driver Chanho Park
     [not found]   ` <CGME20210917065522epcas2p49ce06e9686c9b6f5cb1dd16ca9d82052@epcas2p4.samsung.com>
2021-09-17  6:54     ` [PATCH v3 01/17] scsi: ufs: add quirk to handle broken UIC command Chanho Park
2021-09-23  3:44       ` Alim Akhtar
     [not found]   ` <CGME20210917065522epcas2p4ed13768faa6aa6d33116606e2601321e@epcas2p4.samsung.com>
2021-09-17  6:54     ` [PATCH v3 02/17] scsi: ufs: add quirk to enable host controller without ph configuration Chanho Park
2021-09-23  3:48       ` Alim Akhtar
     [not found]   ` <CGME20210917065522epcas2p26f56b37c3f7505b9d0e34bc2162fdbbd@epcas2p2.samsung.com>
2021-09-17  6:54     ` [PATCH v3 03/17] scsi: ufs: ufs-exynos: change pclk available max value Chanho Park
2021-09-27  5:25       ` Inki Dae
2021-09-27  6:46         ` Chanho Park
2021-09-27  7:11           ` Inki Dae
2021-09-27 11:08             ` Chanho Park [this message]
2021-09-28  2:18               ` Inki Dae
     [not found]   ` <CGME20210917065522epcas2p23066a1bd5e39ac1931d7e38064fe23dd@epcas2p2.samsung.com>
2021-09-17  6:54     ` [PATCH v3 04/17] scsi: ufs: ufs-exynos: simplify drv_data retrieval Chanho Park
     [not found]   ` <CGME20210917065523epcas2p3ff66daa15c8c782f839422756c388d93@epcas2p3.samsung.com>
2021-09-17  6:54     ` [PATCH v3 05/17] dt-bindings: ufs: exynos-ufs: add sysreg regmap property Chanho Park
2021-09-22 19:57       ` Rob Herring
2021-09-23  0:47         ` Chanho Park
2021-09-23 12:39           ` Rob Herring
2021-09-24  1:10             ` Chanho Park
     [not found]   ` <CGME20210917065523epcas2p477a63b06cbb9f5588aa2c149c9d1db10@epcas2p4.samsung.com>
2021-09-17  6:54     ` [PATCH v3 06/17] scsi: ufs: ufs-exynos: get sysreg regmap for io-coherency Chanho Park
2021-09-22 19:55       ` Rob Herring
2021-09-23  0:39         ` Chanho Park
2021-09-23 12:26           ` Rob Herring
2021-09-24  0:59             ` Chanho Park
     [not found]   ` <CGME20210917065523epcas2p44a9f121c18e0f3a5614f980c9eeffa16@epcas2p4.samsung.com>
2021-09-17  6:54     ` [PATCH v3 07/17] scsi: ufs: ufs-exynos: add refclkout_stop control Chanho Park
     [not found]   ` <CGME20210917065523epcas2p1215e9f56482339ca8a9346a0ac2bfe23@epcas2p1.samsung.com>
2021-09-17  6:54     ` [PATCH v3 08/17] scsi: ufs: ufs-exynos: add setup_clocks callback Chanho Park
2021-09-23  3:51       ` Alim Akhtar
     [not found]   ` <CGME20210917065523epcas2p15b648b88af85252fe12ff8026307526a@epcas2p1.samsung.com>
2021-09-17  6:54     ` [PATCH v3 09/17] scsi: ufs: ufs-exynos: correct timeout value setting registers Chanho Park
2021-09-23  4:14       ` Alim Akhtar
2021-09-23  5:47         ` Chanho Park
     [not found]   ` <CGME20210917065523epcas2p39e18203beafe9377e9dac819f01b804f@epcas2p3.samsung.com>
2021-09-17  6:54     ` [PATCH v3 10/17] scsi: ufs: ufs-exynos: support custom version of ufs_hba_variant_ops Chanho Park
2021-09-23  4:28       ` Alim Akhtar
     [not found]   ` <CGME20210917065523epcas2p3b178e3d9d2d4db628f597732be9c6856@epcas2p3.samsung.com>
2021-09-17  6:54     ` [PATCH v3 11/17] scsi: ufs: ufs-exynos: add EXYNOS_UFS_OPT_SKIP_CONFIG_PHY_ATTR option Chanho Park
2021-09-23  4:32       ` Alim Akhtar
     [not found]   ` <CGME20210917065523epcas2p2cb63cd8924be44e6eaa42c7213bd15d4@epcas2p2.samsung.com>
2021-09-17  6:54     ` [PATCH v3 12/17] scsi: ufs: ufs-exynos: factor out priv data init Chanho Park
     [not found]   ` <CGME20210917065523epcas2p4fc1be41c739361dd6ae9d167cfc631dc@epcas2p4.samsung.com>
2021-09-17  6:54     ` [PATCH v3 13/17] scsi: ufs: ufs-exynos: add pre/post_hce_enable drv callbacks Chanho Park
2021-09-23  4:51       ` Alim Akhtar
     [not found]   ` <CGME20210917065523epcas2p47156d9fba5b8d8a5e5908ccdc0ae1655@epcas2p4.samsung.com>
2021-09-17  6:54     ` [PATCH v3 14/17] scsi: ufs: ufs-exynos: support exynosauto v9 ufs driver Chanho Park
     [not found]   ` <CGME20210917065524epcas2p18a720757ef3c4fc08d4bc8d16f9fe7fe@epcas2p1.samsung.com>
2021-09-17  6:54     ` [PATCH v3 15/17] scsi: ufs: ufs-exynos: multi-host configuration for exynosauto Chanho Park
2021-09-27  5:31       ` Inki Dae
2021-09-27  6:56         ` Chanho Park
     [not found]   ` <CGME20210917065524epcas2p3929f70cb0b62e6ca85a6f4814b61fae1@epcas2p3.samsung.com>
2021-09-17  6:54     ` [PATCH v3 16/17] scsi: ufs: ufs-exynos: introduce exynosauto v9 virtual host Chanho Park
     [not found]   ` <CGME20210917065524epcas2p455b2900227b6a20994bec4816248f2bf@epcas2p4.samsung.com>
2021-09-17  6:54     ` [PATCH v3 17/17] dt-bindings: ufs: exynos-ufs: add exynosautov9 compatible Chanho Park
2021-09-22 19:58       ` Rob Herring

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