Re: [PATCH 11/19] PCI: keystone: Cleanup PHY handling

From: Kishon Vijay Abraham I <kishon@ti.com>
To: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>,
	Murali Karicheri <m-karicheri2@ti.com>,
	Jingoo Han <jingoohan1@gmail.com>,
	Gustavo Pimentel <gustavo.pimentel@synopsys.com>,
	Rob Herring <robh+dt@kernel.org>, <linux-pci@vger.kernel.org>,
	<devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
	<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH 11/19] PCI: keystone: Cleanup PHY handling
Date: Wed, 17 Oct 2018 08:51:39 +0530	[thread overview]
Message-ID: <647103e4-1a38-d3f8-9779-3429530e2f31@ti.com> (raw)
In-Reply-To: <20181016170656.GD16390@e107981-ln.cambridge.arm.com>

Lorenzo,

On Tuesday 16 October 2018 10:36 PM, Lorenzo Pieralisi wrote:
> On Mon, Oct 15, 2018 at 06:37:13PM +0530, Kishon Vijay Abraham I wrote:
>> Cleanup PHY handling by using devm_phy_optional_get to get PHYs if
>> the PHYs are optional, creating a device link between the PHY device
>> and the controller device and disable PHY on error cases here.
>> Also invoke phy_reset() as part of initializing PHY.
> 
> Hi Kishon,
> 
> it is a bit of nitpicking, I know it is annoying but when I read "Also"
> in commit logs there is almost certainly a reason to split the patch
> into logical standalone entities, this one looks like one.
> 
> Every patch must be a self-contained change that, in case we have to
> revert it, must not affect other patches.
> 
> There are some more patches in the series that would benefit from
> splitting so I kindly ask you to go through them and repost, we
> should still be able to hit v4.20.

Sure, I'll repost them.

Thanks
Kishon
> 
> Thanks,
> Lorenzo
> 
>> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
>> ---
>>  drivers/pci/controller/dwc/pci-keystone.c | 126 +++++++++++++++++++---
>>  1 file changed, 110 insertions(+), 16 deletions(-)
>>
>> diff --git a/drivers/pci/controller/dwc/pci-keystone.c b/drivers/pci/controller/dwc/pci-keystone.c
>> index e22328f89c84..bf37609ad75b 100644
>> --- a/drivers/pci/controller/dwc/pci-keystone.c
>> +++ b/drivers/pci/controller/dwc/pci-keystone.c
>> @@ -105,6 +105,9 @@ struct keystone_pcie {
>>  
>>  	int			num_msi_host_irqs;
>>  	int			msi_host_irqs[MAX_MSI_HOST_IRQS];
>> +	int			num_lanes;
>> +	struct phy		**phy;
>> +	struct device_link	**link;
>>  	struct			device_node *msi_intc_np;
>>  	struct irq_domain	*legacy_irq_domain;
>>  	struct device_node	*np;
>> @@ -880,22 +883,61 @@ static const struct dw_pcie_ops ks_pcie_dw_pcie_ops = {
>>  	.link_up = ks_pcie_link_up,
>>  };
>>  
>> -static int __exit ks_pcie_remove(struct platform_device *pdev)
>> +static void ks_pcie_disable_phy(struct keystone_pcie *ks_pcie)
>>  {
>> -	struct keystone_pcie *ks_pcie = platform_get_drvdata(pdev);
>> +	int num_lanes = ks_pcie->num_lanes;
>>  
>> -	clk_disable_unprepare(ks_pcie->clk);
>> +	while (num_lanes--) {
>> +		phy_power_off(ks_pcie->phy[num_lanes]);
>> +		phy_exit(ks_pcie->phy[num_lanes]);
>> +	}
>> +}
>> +
>> +static int ks_pcie_enable_phy(struct keystone_pcie *ks_pcie)
>> +{
>> +	int i;
>> +	int ret;
>> +	int num_lanes = ks_pcie->num_lanes;
>> +
>> +	for (i = 0; i < num_lanes; i++) {
>> +		ret = phy_reset(ks_pcie->phy[i]);
>> +		if (ret < 0)
>> +			goto err_phy;
>> +
>> +		ret = phy_init(ks_pcie->phy[i]);
>> +		if (ret < 0)
>> +			goto err_phy;
>> +
>> +		ret = phy_power_on(ks_pcie->phy[i]);
>> +		if (ret < 0) {
>> +			phy_exit(ks_pcie->phy[i]);
>> +			goto err_phy;
>> +		}
>> +	}
>>  
>>  	return 0;
>> +
>> +err_phy:
>> +	while (--i >= 0) {
>> +		phy_power_off(ks_pcie->phy[i]);
>> +		phy_exit(ks_pcie->phy[i]);
>> +	}
>> +
>> +	return ret;
>>  }
>>  
>>  static int __init ks_pcie_probe(struct platform_device *pdev)
>>  {
>>  	struct device *dev = &pdev->dev;
>> +	struct device_node *np = dev->of_node;
>>  	struct dw_pcie *pci;
>>  	struct keystone_pcie *ks_pcie;
>> -	struct phy *phy;
>> +	struct device_link **link;
>> +	struct phy **phy;
>> +	u32 num_lanes;
>> +	char name[10];
>>  	int ret;
>> +	int i;
>>  
>>  	ks_pcie = devm_kzalloc(dev, sizeof(*ks_pcie), GFP_KERNEL);
>>  	if (!ks_pcie)
>> @@ -908,29 +950,59 @@ static int __init ks_pcie_probe(struct platform_device *pdev)
>>  	pci->dev = dev;
>>  	pci->ops = &ks_pcie_dw_pcie_ops;
>>  
>> -	ks_pcie->pci = pci;
>> +	ret = of_property_read_u32(np, "num-lanes", &num_lanes);
>> +	if (ret)
>> +		num_lanes = 1;
>>  
>> -	/* initialize SerDes Phy if present */
>> -	phy = devm_phy_get(dev, "pcie-phy");
>> -	if (PTR_ERR_OR_ZERO(phy) == -EPROBE_DEFER)
>> -		return PTR_ERR(phy);
>> +	phy = devm_kzalloc(dev, sizeof(*phy) * num_lanes, GFP_KERNEL);
>> +	if (!phy)
>> +		return -ENOMEM;
>>  
>> -	if (!IS_ERR_OR_NULL(phy)) {
>> -		ret = phy_init(phy);
>> -		if (ret < 0)
>> -			return ret;
>> +	link = devm_kzalloc(dev, sizeof(*link) * num_lanes, GFP_KERNEL);
>> +	if (!link)
>> +		return -ENOMEM;
>> +
>> +	for (i = 0; i < num_lanes; i++) {
>> +		snprintf(name, sizeof(name), "pcie-phy%d", i);
>> +		phy[i] = devm_phy_optional_get(dev, name);
>> +		if (IS_ERR(phy[i])) {
>> +			ret = PTR_ERR(phy[i]);
>> +			goto err_link;
>> +		}
>> +
>> +		if (!phy[i])
>> +			continue;
>> +
>> +		link[i] = device_link_add(dev, &phy[i]->dev, DL_FLAG_STATELESS);
>> +		if (!link[i]) {
>> +			ret = -EINVAL;
>> +			goto err_link;
>> +		}
>> +	}
>> +
>> +	ks_pcie->np = np;
>> +	ks_pcie->pci = pci;
>> +	ks_pcie->link = link;
>> +	ks_pcie->num_lanes = num_lanes;
>> +	ks_pcie->phy = phy;
>> +
>> +	ret = ks_pcie_enable_phy(ks_pcie);
>> +	if (ret) {
>> +		dev_err(dev, "failed to enable phy\n");
>> +		goto err_link;
>>  	}
>>  
>> -	ks_pcie->np = dev->of_node;
>>  	platform_set_drvdata(pdev, ks_pcie);
>>  	ks_pcie->clk = devm_clk_get(dev, "pcie");
>>  	if (IS_ERR(ks_pcie->clk)) {
>>  		dev_err(dev, "Failed to get pcie rc clock\n");
>> -		return PTR_ERR(ks_pcie->clk);
>> +		ret = PTR_ERR(ks_pcie->clk);
>> +		goto err_phy;
>>  	}
>> +
>>  	ret = clk_prepare_enable(ks_pcie->clk);
>>  	if (ret)
>> -		return ret;
>> +		goto err_phy;
>>  
>>  	ret = ks_pcie_add_pcie_port(ks_pcie, pdev);
>>  	if (ret < 0)
>> @@ -940,9 +1012,31 @@ static int __init ks_pcie_probe(struct platform_device *pdev)
>>  fail_clk:
>>  	clk_disable_unprepare(ks_pcie->clk);
>>  
>> +err_phy:
>> +	ks_pcie_disable_phy(ks_pcie);
>> +
>> +err_link:
>> +	while (--i >= 0 && link[i])
>> +		device_link_del(link[i]);
>> +
>>  	return ret;
>>  }
>>  
>> +static int __exit ks_pcie_remove(struct platform_device *pdev)
>> +{
>> +	struct keystone_pcie *ks_pcie = platform_get_drvdata(pdev);
>> +	struct device_link **link = ks_pcie->link;
>> +	int num_lanes = ks_pcie->num_lanes;
>> +
>> +	clk_disable_unprepare(ks_pcie->clk);
>> +	ks_pcie_disable_phy(ks_pcie);
>> +
>> +	while (num_lanes--)
>> +		device_link_del(link[num_lanes]);
>> +
>> +	return 0;
>> +}
>> +
>>  static struct platform_driver ks_pcie_driver __refdata = {
>>  	.probe  = ks_pcie_probe,
>>  	.remove = __exit_p(ks_pcie_remove),
>> -- 
>> 2.17.1
>>