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Date:   Fri, 13 Aug 2021 16:22:40 +0100
From:   Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
To:     Bjorn Helgaas <helgaas@kernel.org>,
        Chuanjia Liu <chuanjia.liu@mediatek.com>
Cc:     robh+dt@kernel.org, bhelgaas@google.com, matthias.bgg@gmail.com,
        ryder.lee@mediatek.com, jianjun.wang@mediatek.com,
        yong.wu@mediatek.com, Frank Wunderlich <frank-w@public-files.de>,
        linux-pci@vger.kernel.org, linux-mediatek@lists.infradead.org,
        devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v11 2/4] PCI: mediatek: Add new method to get shared
 pcie-cfg base address and parse node
Message-ID: <20210813152239.GA15515@lpieralisi>
References: <20210719073456.28666-3-chuanjia.liu@mediatek.com>
 <20210810194250.GA2276275@bjorn-Precision-5520>
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In-Reply-To: <20210810194250.GA2276275@bjorn-Precision-5520>
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On Tue, Aug 10, 2021 at 02:42:50PM -0500, Bjorn Helgaas wrote:
> On Mon, Jul 19, 2021 at 03:34:54PM +0800, Chuanjia Liu wrote:
> > For the new dts format, add a new method to get
> > shared pcie-cfg base address and parse node.
> 
> This commit log doesn't seem to really cover what's going on here.  It
> looks like:
> 
>   - You added a check for "mediatek,generic-pciecfg" (I guess this is
>     the "shared pcie-cfg base address" part).  Probably could have
>     been its own patch.
> 
>   - You added checks for "interrupt-names" and "pcie_irq".  Not
>     explained in commit log; probably could have been its own patch,
>     too.
> 
>   - You now look for "linux,pci-domain" (via of_get_pci_domain_nr()).
>     If present, you parse only one port instead of looking for all the
>     children of the node.
> 
>     That's sort of weird behavior -- why should the presence of
>     "linux,pci-domain" determine whether the node can have children?
>     Is that really what you intend?
> 
>     Should be explained in the commit log and could have been its own
>     patch, too.

I agree with Bjorn, this patch should be split (and commit logs
rewritten). I will drop it from my tree, waiting for a v12.

Lorenzo

> > Signed-off-by: Chuanjia Liu <chuanjia.liu@mediatek.com>
> > Acked-by: Ryder Lee <ryder.lee@mediatek.com>
> > ---
> >  drivers/pci/controller/pcie-mediatek.c | 52 +++++++++++++++++++-------
> >  1 file changed, 39 insertions(+), 13 deletions(-)
> > 
> > diff --git a/drivers/pci/controller/pcie-mediatek.c b/drivers/pci/controller/pcie-mediatek.c
> > index 25bee693834f..928e0983a900 100644
> > --- a/drivers/pci/controller/pcie-mediatek.c
> > +++ b/drivers/pci/controller/pcie-mediatek.c
> > @@ -14,6 +14,7 @@
> >  #include <linux/irqchip/chained_irq.h>
> >  #include <linux/irqdomain.h>
> >  #include <linux/kernel.h>
> > +#include <linux/mfd/syscon.h>
> >  #include <linux/msi.h>
> >  #include <linux/module.h>
> >  #include <linux/of_address.h>
> > @@ -23,6 +24,7 @@
> >  #include <linux/phy/phy.h>
> >  #include <linux/platform_device.h>
> >  #include <linux/pm_runtime.h>
> > +#include <linux/regmap.h>
> >  #include <linux/reset.h>
> >  
> >  #include "../pci.h"
> > @@ -207,6 +209,7 @@ struct mtk_pcie_port {
> >   * struct mtk_pcie - PCIe host information
> >   * @dev: pointer to PCIe device
> >   * @base: IO mapped register base
> > + * @cfg: IO mapped register map for PCIe config
> >   * @free_ck: free-run reference clock
> >   * @mem: non-prefetchable memory resource
> >   * @ports: pointer to PCIe port information
> > @@ -215,6 +218,7 @@ struct mtk_pcie_port {
> >  struct mtk_pcie {
> >  	struct device *dev;
> >  	void __iomem *base;
> > +	struct regmap *cfg;
> >  	struct clk *free_ck;
> >  
> >  	struct list_head ports;
> > @@ -650,7 +654,11 @@ static int mtk_pcie_setup_irq(struct mtk_pcie_port *port,
> >  		return err;
> >  	}
> >  
> > -	port->irq = platform_get_irq(pdev, port->slot);
> > +	if (of_find_property(dev->of_node, "interrupt-names", NULL))
> > +		port->irq = platform_get_irq_byname(pdev, "pcie_irq");
> > +	else
> > +		port->irq = platform_get_irq(pdev, port->slot);
> > +
> >  	if (port->irq < 0)
> >  		return port->irq;
> >  
> > @@ -682,6 +690,10 @@ static int mtk_pcie_startup_port_v2(struct mtk_pcie_port *port)
> >  		val |= PCIE_CSR_LTSSM_EN(port->slot) |
> >  		       PCIE_CSR_ASPM_L1_EN(port->slot);
> >  		writel(val, pcie->base + PCIE_SYS_CFG_V2);
> > +	} else if (pcie->cfg) {
> > +		val = PCIE_CSR_LTSSM_EN(port->slot) |
> > +		      PCIE_CSR_ASPM_L1_EN(port->slot);
> > +		regmap_update_bits(pcie->cfg, PCIE_SYS_CFG_V2, val, val);
> >  	}
> >  
> >  	/* Assert all reset signals */
> > @@ -985,6 +997,7 @@ static int mtk_pcie_subsys_powerup(struct mtk_pcie *pcie)
> >  	struct device *dev = pcie->dev;
> >  	struct platform_device *pdev = to_platform_device(dev);
> >  	struct resource *regs;
> > +	struct device_node *cfg_node;
> >  	int err;
> >  
> >  	/* get shared registers, which are optional */
> > @@ -995,6 +1008,14 @@ static int mtk_pcie_subsys_powerup(struct mtk_pcie *pcie)
> >  			return PTR_ERR(pcie->base);
> >  	}
> >  
> > +	cfg_node = of_find_compatible_node(NULL, NULL,
> > +					   "mediatek,generic-pciecfg");
> > +	if (cfg_node) {
> > +		pcie->cfg = syscon_node_to_regmap(cfg_node);
> > +		if (IS_ERR(pcie->cfg))
> > +			return PTR_ERR(pcie->cfg);
> > +	}
> > +
> >  	pcie->free_ck = devm_clk_get(dev, "free_ck");
> >  	if (IS_ERR(pcie->free_ck)) {
> >  		if (PTR_ERR(pcie->free_ck) == -EPROBE_DEFER)
> > @@ -1027,22 +1048,27 @@ static int mtk_pcie_setup(struct mtk_pcie *pcie)
> >  	struct device *dev = pcie->dev;
> >  	struct device_node *node = dev->of_node, *child;
> >  	struct mtk_pcie_port *port, *tmp;
> > -	int err;
> > +	int err, slot;
> > +
> > +	slot = of_get_pci_domain_nr(dev->of_node);
> > +	if (slot < 0) {
> > +		for_each_available_child_of_node(node, child) {
> > +			err = of_pci_get_devfn(child);
> > +			if (err < 0) {
> > +				dev_err(dev, "failed to get devfn: %d\n", err);
> > +				goto error_put_node;
> > +			}
> >  
> > -	for_each_available_child_of_node(node, child) {
> > -		int slot;
> > +			slot = PCI_SLOT(err);
> >  
> > -		err = of_pci_get_devfn(child);
> > -		if (err < 0) {
> > -			dev_err(dev, "failed to parse devfn: %d\n", err);
> > -			goto error_put_node;
> > +			err = mtk_pcie_parse_port(pcie, child, slot);
> > +			if (err)
> > +				goto error_put_node;
> >  		}
> > -
> > -		slot = PCI_SLOT(err);
> > -
> > -		err = mtk_pcie_parse_port(pcie, child, slot);
> > +	} else {
> > +		err = mtk_pcie_parse_port(pcie, node, slot);
> >  		if (err)
> > -			goto error_put_node;
> > +			return err;
> >  	}
> >  
> >  	err = mtk_pcie_subsys_powerup(pcie);
> > -- 
> > 2.18.0
> >