From: Gabriel Fernandez <gabriel.fernandez@linaro.org>
To: Kishon Vijay Abraham I <kishon@ti.com>
Cc: Gabriel FERNANDEZ <gabriel.fernandez@st.com>,
Rob Herring <robh+dt@kernel.org>, Pawel Moll <pawel.moll@arm.com>,
Mark Rutland <mark.rutland@arm.com>,
Ian Campbell <ijc+devicetree@hellion.org.uk>,
Kumar Gala <galak@codeaurora.org>,
Srinivas Kandagatla <srinivas.kandagatla@gmail.com>,
Maxime Coquelin <maxime.coquelin@st.com>,
Patrice Chotard <patrice.chotard@st.com>,
Russell King <linux@arm.linux.org.uk>,
Grant Likely <grant.likely@linaro.org>,
"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"kernel@stlinux.com" <kernel@stlinux.com>,
Harsh Gupta <harsh.gupta@st.com>,
Gabriel Fernandez <gabriel.fernandez@linaro.orgm>
Subject: Re: [PATCH v2 7/8] phy: miphy28lp: Add SSC support for PCIE
Date: Tue, 9 Sep 2014 11:23:45 +0200 [thread overview]
Message-ID: <CAG374jAGFXFJJkNjHBcApgzMw+VdfFQJOFmvOnvzozknk20XDw@mail.gmail.com> (raw)
In-Reply-To: <540DC81F.6000901@ti.com>
Hi Kishon,
On 8 September 2014 17:15, Kishon Vijay Abraham I <kishon@ti.com> wrote:
>
>
> On Wednesday 03 September 2014 09:07 PM, Gabriel FERNANDEZ wrote:
>> SSC is the technique of modulating the operating frequency of a signal
>> slightly to spread its radiated emissions over a range of frequencies.
>> This reduction in the maximum emission for a given frequency helps meet
>> radiated emission requirements.
>> These settings are applicable for PCIE with Internal clock.
>>
>> Signed-off-by: Harsh Gupta <harsh.gupta@st.com>
>> Signed-off-by: Gabriel Fernandez <gabriel.fernandez@linaro.orgm>
>> ---
>> drivers/phy/phy-miphy28lp.c | 32 ++++++++++++++++++++++++++++++++
>> 1 file changed, 32 insertions(+)
>>
>> diff --git a/drivers/phy/phy-miphy28lp.c b/drivers/phy/phy-miphy28lp.c
>> index b36e737..976fdda 100644
>> --- a/drivers/phy/phy-miphy28lp.c
>> +++ b/drivers/phy/phy-miphy28lp.c
>> @@ -679,6 +679,36 @@ static int miphy28lp_init_sata(struct miphy28lp_phy *miphy_phy)
>> return miphy_is_ready(miphy_phy);
>> }
>>
>> +static void miphy_pcie_tune_ssc(struct miphy28lp_phy *miphy_phy)
>> +{
>> + u8 val;
>> +
>> + /* Compensate Tx impedance to avoid out of range values */
>> + if (miphy_phy->ssc) {
>> + /*
>> + * Enable the SSC on PLL for all banks
>> + * SSC Modulation @ 31 KHz and 4000 ppm modulation amp
>> + */
>> + val = readb_relaxed(miphy_phy->base + 0x0c);
>> + val |= 0x04;
>> + writeb_relaxed(val, miphy_phy->base + 0x0c);
>> + val = readb_relaxed(miphy_phy->base + 0x0a);
>> + val |= 0x10;
>> + writeb_relaxed(val, miphy_phy->base + 0x0a);
>
> macros for these registers and values is needed. Or else it's difficult to review.
ok will be fix to v3
>> +
>> + for (val = 0; val < 2; val++) {
>> + writeb_relaxed(val, miphy_phy->base + 0x0f);
>> + writeb_relaxed(0x69, miphy_phy->base + 0xe5);
>
> Do these registers have to be written for every iteration?
Yes because we select the bank value before (with val)
>
> Thanks
> Kishon
next prev parent reply other threads:[~2014-09-09 9:23 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-03 15:37 [PATCH v2 0/8] phy: miphy28lp: Introduce support for MiPHY28lp Gabriel FERNANDEZ
2014-09-03 15:37 ` [PATCH v2 1/8] phy: miphy28lp: Add Device Tree bindings for the MiPHY28lp Gabriel FERNANDEZ
2014-09-08 14:33 ` Kishon Vijay Abraham I
2014-09-09 9:24 ` Gabriel Fernandez
2014-09-03 15:37 ` [PATCH v2 2/8] phy: miphy28lp: Add MiPHY28lp header file for DT x Driver defines Gabriel FERNANDEZ
2014-09-03 15:37 ` [PATCH v2 3/8] phy: miphy28lp: Provide support for the MiPHY28lp Generic PHY Gabriel FERNANDEZ
2014-09-08 15:12 ` Kishon Vijay Abraham I
2014-09-09 9:15 ` Gabriel Fernandez
2014-09-03 15:37 ` [PATCH v2 4/8] ARM: DT: STi: STiH407: Add DT node for MiPHY28lp Gabriel FERNANDEZ
2014-09-03 15:37 ` [PATCH v2 5/8] ARM: multi_v7_defconfig: Enable MiPHY28lp - ST's Generic (SATA, PCIe & USB3) PHY Gabriel FERNANDEZ
2014-09-03 15:37 ` [PATCH v2 6/8] phy: miphy28lp: Add SSC support for SATA Gabriel FERNANDEZ
2014-09-03 15:37 ` [PATCH v2 7/8] phy: miphy28lp: Add SSC support for PCIE Gabriel FERNANDEZ
2014-09-08 15:15 ` Kishon Vijay Abraham I
2014-09-09 9:23 ` Gabriel Fernandez [this message]
2014-09-03 15:37 ` [PATCH v2 8/8] phy: miphy28lp: Tune tx impedance across Soc cuts Gabriel FERNANDEZ
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