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From:   <ansuelsmth@gmail.com>
To:     "'Stanimir Varbanov'" <svarbanov@mm-sol.com>,
        "'Bjorn Andersson'" <bjorn.andersson@linaro.org>
Cc:     "'Sham Muthayyan'" <smuthayy@codeaurora.org>,
        "'Andy Gross'" <agross@kernel.org>,
        "'Bjorn Helgaas'" <bhelgaas@google.com>,
        "'Rob Herring'" <robh+dt@kernel.org>,
        "'Mark Rutland'" <mark.rutland@arm.com>,
        "'Lorenzo Pieralisi'" <lorenzo.pieralisi@arm.com>,
        "'Andrew Murray'" <amurray@thegoodpenguin.co.uk>,
        "'Philipp Zabel'" <p.zabel@pengutronix.de>,
        <linux-arm-msm@vger.kernel.org>, <linux-pci@vger.kernel.org>,
        <devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>
References: <20200430220619.3169-1-ansuelsmth@gmail.com> <20200430220619.3169-10-ansuelsmth@gmail.com> <3dc89ec6-d550-9402-1a4a-ca0c6f1e1fb9@mm-sol.com>
In-Reply-To: <3dc89ec6-d550-9402-1a4a-ca0c6f1e1fb9@mm-sol.com>
Subject: R: [PATCH v3 09/11] PCI: qcom: add ipq8064 rev2 variant and set tx term offset
Date:   Wed, 13 May 2020 14:54:41 +0200
Message-ID: <02df01d62925$acd160a0$067421e0$@gmail.com>
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> Hi Ansuel,
> 
> On 5/1/20 1:06 AM, Ansuel Smith wrote:
> > From: Sham Muthayyan <smuthayy@codeaurora.org>
> >
> > Add tx term offset support to pcie qcom driver need in some revision of
> > the ipq806x SoC.
> > Ipq8064 have tx term offset set to 7.
> > Ipq8064-v2 revision and ipq8065 have the tx term offset set to 0.
> >
> > Signed-off-by: Sham Muthayyan <smuthayy@codeaurora.org>
> > Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>
> > ---
> >  drivers/pci/controller/dwc/pcie-qcom.c | 15 +++++++++++++++
> >  1 file changed, 15 insertions(+)
> >
> > diff --git a/drivers/pci/controller/dwc/pcie-qcom.c
> b/drivers/pci/controller/dwc/pcie-qcom.c
> > index da8058fd1925..372d2c8508b5 100644
> > --- a/drivers/pci/controller/dwc/pcie-qcom.c
> > +++ b/drivers/pci/controller/dwc/pcie-qcom.c
> > @@ -45,6 +45,9 @@
> >  #define PCIE_CAP_CPL_TIMEOUT_DISABLE		0x10
> >
> >  #define PCIE20_PARF_PHY_CTRL			0x40
> > +#define PHY_CTRL_PHY_TX0_TERM_OFFSET_MASK	GENMASK(12,
> 16)
> 
> The mask definition is not correct. Should be GENMASK(20, 16)
> 
> > +#define PHY_CTRL_PHY_TX0_TERM_OFFSET(x)		((x) << 16)
> > +
> >  #define PCIE20_PARF_PHY_REFCLK			0x4C
> >  #define PHY_REFCLK_SSP_EN			BIT(16)
> >  #define PHY_REFCLK_USE_PAD			BIT(12)
> > @@ -118,6 +121,7 @@ struct qcom_pcie_resources_2_1_0 {
> >  	u32 tx_swing_full;
> >  	u32 tx_swing_low;
> >  	u32 rx0_eq;
> > +	u8 phy_tx0_term_offset;
> >  };
> >
> >  struct qcom_pcie_resources_1_0_0 {
> > @@ -318,6 +322,11 @@ static int
> qcom_pcie_get_resources_2_1_0(struct qcom_pcie *pcie)
> >  	if (IS_ERR(res->ext_reset))
> >  		return PTR_ERR(res->ext_reset);
> >
> > +	if (of_device_is_compatible(dev->of_node, "qcom,pcie-ipq8064"))
> > +		res->phy_tx0_term_offset = 7;
> 
> Before your change the phy_tx0_term_offser was 0 for apq8064, but here
> you change it to 7, why?
> 

apq8064 board should use qcom,pcie-apq8064 right? This should be set to 0
only with pcie-ipq8064 compatible. Tell me if I'm wrong.

> > +	else
> > +		res->phy_tx0_term_offset = 0;
> > +
> >  	res->phy_reset = devm_reset_control_get_exclusive(dev, "phy");
> >  	return PTR_ERR_OR_ZERO(res->phy_reset);
> >  }
> > @@ -402,6 +411,11 @@ static int qcom_pcie_init_2_1_0(struct
> qcom_pcie *pcie)
> >  	/* enable PCIe clocks and resets */
> >  	qcom_clear_and_set_dword(pcie->parf + PCIE20_PARF_PHY_CTRL,
> BIT(0), 0);
> >
> > +	/* set TX termination offset */
> > +	qcom_clear_and_set_dword(pcie->parf + PCIE20_PARF_PHY_CTRL,
> > +			PHY_CTRL_PHY_TX0_TERM_OFFSET_MASK,
> 
> As the mask definition is incorrect you actually clear 12 to 16 bit in
> the register where is another PHY parameter. Is that was intentional?
> 

Will check this and the wrong genmask.

> > +			PHY_CTRL_PHY_TX0_TERM_OFFSET(res-
> >phy_tx0_term_offset));
> > +
> >  	writel(PCS_DEEMPH_TX_DEEMPH_GEN1(res->tx_deemph_gen1) |
> >  	       PCS_DEEMPH_TX_DEEMPH_GEN2_3_5DB(res-
> >tx_deemph_gen2_3p5db) |
> >  	       PCS_DEEMPH_TX_DEEMPH_GEN2_6DB(res-
> >tx_deemph_gen2_6db),
> > @@ -1485,6 +1499,7 @@ static int qcom_pcie_probe(struct
> platform_device *pdev)
> >  static const struct of_device_id qcom_pcie_match[] = {
> >  	{ .compatible = "qcom,pcie-apq8084", .data = &ops_1_0_0 },
> >  	{ .compatible = "qcom,pcie-ipq8064", .data = &ops_2_1_0 },
> > +	{ .compatible = "qcom,pcie-ipq8064-v2", .data = &ops_2_1_0 },
> >  	{ .compatible = "qcom,pcie-apq8064", .data = &ops_2_1_0 },
> >  	{ .compatible = "qcom,pcie-msm8996", .data = &ops_2_3_2 },
> >  	{ .compatible = "qcom,pcie-ipq8074", .data = &ops_2_3_3 },
> >
> 
> --
> regards,
> Stan