Re: [PATCH v7 02/16] PCI: imx6: Simplify phy handling by using by using IMX6_PCIE_FLAG_HAS_PHY

From: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
To: Frank Li <Frank.li@nxp.com>
Cc: krzysztof.kozlowski@linaro.org, bhelgaas@google.com,
	conor+dt@kernel.org, devicetree@vger.kernel.org,
	festevam@gmail.com, helgaas@kernel.org, hongxing.zhu@nxp.com,
	imx@lists.linux.dev, kernel@pengutronix.de,
	krzysztof.kozlowski+dt@linaro.org, kw@linux.com,
	l.stach@pengutronix.de, linux-arm-kernel@lists.infradead.org,
	linux-imx@nxp.com, linux-kernel@vger.kernel.org,
	linux-pci@vger.kernel.org, lpieralisi@kernel.org,
	robh@kernel.org, s.hauer@pengutronix.de, shawnguo@kernel.org
Subject: Re: [PATCH v7 02/16] PCI: imx6: Simplify phy handling by using by using IMX6_PCIE_FLAG_HAS_PHY
Date: Sun, 7 Jan 2024 08:34:18 +0530	[thread overview]
Message-ID: <20240107030418.GB3416@thinkpad> (raw)
In-Reply-To: <ZZmE1NV6ShVBm5FU@lizhi-Precision-Tower-5810>

On Sat, Jan 06, 2024 at 11:50:28AM -0500, Frank Li wrote:
> On Sat, Jan 06, 2024 at 09:03:23PM +0530, Manivannan Sadhasivam wrote:
> > On Wed, Dec 27, 2023 at 01:27:13PM -0500, Frank Li wrote:
> > > Refactors the phy handling logic in the imx6 PCI driver by adding
> > > IMX6_PCIE_FLAG_HAS_PHY bitmask define for drvdata::flags.
> > > 
> > > The drvdata::flags and a bitmask ensures a cleaner and more scalable
> > > switch-case structure for handling phy.
> > > 
> > > Signed-off-by: Frank Li <Frank.Li@nxp.com>
> > > ---
> > > 
> > > Notes:
> > >     Change from v4 to v5:
> > >     - none, Keep IMX6_PCIE_FLAG_HAS_PHY to indicate dts mismatch when platform
> > >     require phy suppport.
> > >     
> > >     Change from v1 to v3:
> > >     - none
> > > 
> > >  drivers/pci/controller/dwc/pci-imx6.c | 23 ++++++++++++++++-------
> > >  1 file changed, 16 insertions(+), 7 deletions(-)
> > > 
> > > diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
> > > index 50d9faaa17f71..4d620249f3d52 100644
> > > --- a/drivers/pci/controller/dwc/pci-imx6.c
> > > +++ b/drivers/pci/controller/dwc/pci-imx6.c
> > > @@ -60,6 +60,9 @@ enum imx6_pcie_variants {
> > >  #define IMX6_PCIE_FLAG_IMX6_PHY			BIT(0)
> > >  #define IMX6_PCIE_FLAG_IMX6_SPEED_CHANGE	BIT(1)
> > >  #define IMX6_PCIE_FLAG_SUPPORTS_SUSPEND		BIT(2)
> > > +#define IMX6_PCIE_FLAG_HAS_PHY			BIT(3)
> > 
> > Every PCIe setup requires PHY for its operation. Perhaps you are referring to
> > external PHY? If so, please rename this to IMX6_PCIE_FLAG_HAS_EXT_PHY.
> 
> Actually, it means use phy driver. How about using IMX6_PCIE_HAS_PHYDRV?
> 

Ah, ok. Yes, this makes sense.

- Mani

> > 
> > > +
> > > +#define imx6_check_flag(pci, val)     (pci->drvdata->flags & val)
> > >  
> > >  #define IMX6_PCIE_MAX_CLKS       6
> > >  
> > > @@ -1277,6 +1280,13 @@ static int imx6_pcie_probe(struct platform_device *pdev)
> > >  	if (ret)
> > >  		return ret;
> > >  
> > > +	if (imx6_check_flag(imx6_pcie, IMX6_PCIE_FLAG_HAS_PHY)) {
> > 
> > IMO, we would not need these kind of checks in the driver if the DT binding is
> > properly validated using schema. But folks always want to validate "broken DT"
> > in the drivers :(
> > 
> > But I'm fine with this check for now since not everyone agree with above.
> > 
> > - Mani
> > 
> > > +		imx6_pcie->phy = devm_phy_get(dev, "pcie-phy");
> > > +		if (IS_ERR(imx6_pcie->phy))
> > > +			return dev_err_probe(dev, PTR_ERR(imx6_pcie->phy),
> > > +					     "failed to get pcie phy\n");
> > > +	}
> > > +
> > >  	switch (imx6_pcie->drvdata->variant) {
> > >  	case IMX7D:
> > >  		if (dbi_base->start == IMX8MQ_PCIE2_BASE_ADDR)
> > > @@ -1306,11 +1316,6 @@ static int imx6_pcie_probe(struct platform_device *pdev)
> > >  			return dev_err_probe(dev, PTR_ERR(imx6_pcie->apps_reset),
> > >  					     "failed to get pcie apps reset control\n");
> > >  
> > > -		imx6_pcie->phy = devm_phy_get(dev, "pcie-phy");
> > > -		if (IS_ERR(imx6_pcie->phy))
> > > -			return dev_err_probe(dev, PTR_ERR(imx6_pcie->phy),
> > > -					     "failed to get pcie phy\n");
> > > -
> > >  		break;
> > >  	default:
> > >  		break;
> > > @@ -1444,13 +1449,15 @@ static const struct imx6_pcie_drvdata drvdata[] = {
> > >  	},
> > >  	[IMX8MM] = {
> > >  		.variant = IMX8MM,
> > > -		.flags = IMX6_PCIE_FLAG_SUPPORTS_SUSPEND,
> > > +		.flags = IMX6_PCIE_FLAG_SUPPORTS_SUSPEND |
> > > +			 IMX6_PCIE_FLAG_HAS_PHY,
> > >  		.gpr = "fsl,imx8mm-iomuxc-gpr",
> > >  		.clk_names = {"pcie_bus", "pcie", "pcie_aux"},
> > >  	},
> > >  	[IMX8MP] = {
> > >  		.variant = IMX8MP,
> > > -		.flags = IMX6_PCIE_FLAG_SUPPORTS_SUSPEND,
> > > +		.flags = IMX6_PCIE_FLAG_SUPPORTS_SUSPEND |
> > > +			 IMX6_PCIE_FLAG_HAS_PHY,
> > >  		.gpr = "fsl,imx8mp-iomuxc-gpr",
> > >  		.clk_names = {"pcie_bus", "pcie", "pcie_aux"},
> > >  	},
> > > @@ -1462,12 +1469,14 @@ static const struct imx6_pcie_drvdata drvdata[] = {
> > >  	},
> > >  	[IMX8MM_EP] = {
> > >  		.variant = IMX8MM_EP,
> > > +		.flags = IMX6_PCIE_FLAG_HAS_PHY,
> > >  		.mode = DW_PCIE_EP_TYPE,
> > >  		.gpr = "fsl,imx8mm-iomuxc-gpr",
> > >  		.clk_names = {"pcie_bus", "pcie", "pcie_aux"},
> > >  	},
> > >  	[IMX8MP_EP] = {
> > >  		.variant = IMX8MP_EP,
> > > +		.flags = IMX6_PCIE_FLAG_HAS_PHY,
> > >  		.mode = DW_PCIE_EP_TYPE,
> > >  		.gpr = "fsl,imx8mp-iomuxc-gpr",
> > >  		.clk_names = {"pcie_bus", "pcie", "pcie_aux"},
> > > -- 
> > > 2.34.1
> > > 
> > 
> > -- 
> > மணிவண்ணன் சதாசிவம்

-- 
மணிவண்ணன் சதாசிவம்