Re: [PATCH 05/17] pci: host: pcie-dra7xx: add support for pcie-dra7xx controller

Kishon Vijay Abraham I
2014-05-07T08:21:57Z

Hi,

On Tuesday 06 May 2014 07:14 PM, Marek Vasut wrote:
> On Tuesday, May 06, 2014 at 03:33:51 PM, Kishon Vijay Abraham I wrote:
>> Added support for pcie controller in dra7xx. This driver re-uses
>> the designware core code that is already present in kernel.
>
> [...]
>
>> +#define to_dra7xx_pcie(x) container_of((x), struct dra7xx_pcie, pp)
>> +
>> +static inline u32 dra7xx_pcie_readl(void __iomem *base, u32 offset)
>
> Just pass struct dra7xx_pcie * instead of *base here , it will make the code
> below shorter.
>
>> +{
>> + return readl(base + offset);
>> +}
>> +
>> +static inline void dra7xx_pcie_writel(void __iomem *base, u32 offset, u32
>> value) +{
>
> DTTO.
>
>> + writel(value, base + offset);
>> +}
>> +
>> +static int dra7xx_pcie_link_up(struct pcie_port *pp)
>> +{
>> + struct dra7xx_pcie *dra7xx = to_dra7xx_pcie(pp);
>> + u32 reg = dra7xx_pcie_readl(dra7xx->base, PCIECTRL_DRA7XX_CONF_PHY_CS);
>> +
>> + if (reg & LINK_UP)
>> + return true;
>> + return false;
>
> return reg & LINK_UP;
>
>> +}
>> +
>> +static int dra7xx_pcie_establish_link(struct pcie_port *pp)
>> +{
>> + u32 reg;
>> + int retries = 1000;
>> + struct dra7xx_pcie *dra7xx = to_dra7xx_pcie(pp);
>> +
>> + if (dw_pcie_link_up(pp)) {
>> + dev_err(pp->dev, "link is already up\n");
>
> This will spew, since the .link_up (and thus this function) can be called
> repeatedly. The subsystem will query if the link is up via this function.

*dra7xx_pcie_establish_link* is not the callback for link_up function, so it's
actually called only once.
>
>> + return 0;
>> + }
>> +
>> + reg = dra7xx_pcie_readl(dra7xx->base, PCIECTRL_DRA7XX_CONF_DEVICE_CMD);
>> + reg |= LTSSM_EN;
>> + dra7xx_pcie_writel(dra7xx->base, PCIECTRL_DRA7XX_CONF_DEVICE_CMD, reg);
>> +
>> + while (--retries) {
>
> Use retries--
>
>> + reg = dra7xx_pcie_readl(dra7xx->base,
>> + PCIECTRL_DRA7XX_CONF_PHY_CS);
>> + if (reg & LINK_UP)
>> + break;
>> + usleep_range(10, 20);
>> + }
>> +
>> + if (retries <= 0) {
>
> Then check if retries == 0 and retries can be unsigned int.
>
>> + dev_err(pp->dev, "link is not up\n");
>> + return -ETIMEDOUT;
>> + }
>> +
>> + return 0;
>> +}
> [...]
>> +static int __init dra7xx_pcie_probe(struct platform_device *pdev)
>> +{
>> + u32 reg;
>> + int ret;
>> + int irq;
>> + struct phy *phy;
>> + void __iomem *base;
>> + struct resource *res;
>> + struct dra7xx_pcie *dra7xx;
>> + struct device *dev = &pdev->dev;
>> +
>> + dra7xx = devm_kzalloc(&pdev->dev, sizeof(*dra7xx), GFP_KERNEL);
>> + if (!dra7xx)
>> + return -ENOMEM;
>> +
>> + irq = platform_get_irq(pdev, 0);
>> + if (irq < 0) {
>> + dev_err(dev, "missing IRQ resource\n");
>> + return -EINVAL;
>> + }
>> +
>> + ret = devm_request_irq(&pdev->dev, irq, dra7xx_pcie_irq_handler,
>> + IRQF_SHARED, "dra7xx-pcie-main", dra7xx);
>> + if (ret) {
>> + dev_err(&pdev->dev, "failed to request irq\n");
>> + return ret;
>> + }
>> +
>> + res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "ti_conf");
>> + base = devm_ioremap_nocache(dev, res->start, resource_size(res));
>> + if (!base)
>> + return -ENOMEM;
>> +
>> + phy = devm_phy_get(dev, "pcie-phy");
>> + if (IS_ERR(phy))
>> + return PTR_ERR(phy);
>> +
>> + ret = phy_init(phy);
>> + if (ret < 0)
>> + return ret;
>> +
>> + ret = phy_power_on(phy);
>> + if (ret < 0)
>> + goto err_power_on;
>> +
>> + dra7xx->base = base;
>> + dra7xx->phy = phy;
>> + dra7xx->dev = dev;
>> +
>> + pm_runtime_enable(&pdev->dev);
>> + ret = pm_runtime_get_sync(&pdev->dev);
>> + if (IS_ERR_VALUE(ret)) {
>> + dev_err(dev, "pm_runtime_get_sync failed\n");
>> + goto err_runtime_get;
>> + }
>> +
>> + reg = dra7xx_pcie_readl(dra7xx->base, PCIECTRL_DRA7XX_CONF_DEVICE_CMD);
>> + reg &= ~LTSSM_EN;
>> + dra7xx_pcie_writel(dra7xx->base, PCIECTRL_DRA7XX_CONF_DEVICE_CMD, reg);
>
> platform_set_drvdata() should be here, before you add the port.
>
>> + ret = add_pcie_port(dra7xx, pdev);
>> + if (ret < 0)
>> + goto err_add_port;
>> +
>> + platform_set_drvdata(pdev, dra7xx);

Al-right. Will fix this and all your other comments.

Thanks
Kishon
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