Re: [PATCH v2 3/6] PCI: j721e: Add PCIe support for J7200

From: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
To: Kishon Vijay Abraham I <kishon@ti.com>
Cc: Arnd Bergmann <arnd@arndb.de>, Rob Herring <robh@kernel.org>,
	Bjorn Helgaas <bhelgaas@google.com>,
	Lokesh Vutla <lokeshvutla@ti.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Tom Joseph <tjoseph@cadence.com>,
	linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	nadeem@cadence.com
Subject: Re: [PATCH v2 3/6] PCI: j721e: Add PCIe support for J7200
Date: Tue, 3 Aug 2021 11:14:54 +0100	[thread overview]
Message-ID: <20210803101454.GC11252@lpieralisi> (raw)
In-Reply-To: <20210803074932.19820-4-kishon@ti.com>

On Tue, Aug 03, 2021 at 01:19:29PM +0530, Kishon Vijay Abraham I wrote:
> J7200 has the same PCIe IP as in J721E with minor changes in the
> wrapper. J7200 allows byte access of bridge configuration space
> registers and the register field for LINK_DOWN interrupt is different.
> J7200 also requires "quirk_detect_quiet_flag" to be set. Configure these
> changes as part of driver data applicable only to J7200.
> 
> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
> ---
>  drivers/pci/controller/cadence/pci-j721e.c | 40 +++++++++++++++++++---
>  1 file changed, 36 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/pci/controller/cadence/pci-j721e.c b/drivers/pci/controller/cadence/pci-j721e.c
> index 0c5813b230b4..8e76f2e7e782 100644
> --- a/drivers/pci/controller/cadence/pci-j721e.c
> +++ b/drivers/pci/controller/cadence/pci-j721e.c
> @@ -27,6 +27,7 @@
>  #define STATUS_REG_SYS_2	0x508
>  #define STATUS_CLR_REG_SYS_2	0x708
>  #define LINK_DOWN		BIT(1)
> +#define J7200_LINK_DOWN		BIT(10)
>  
>  #define J721E_PCIE_USER_CMD_STATUS	0x4
>  #define LINK_TRAINING_ENABLE		BIT(0)
> @@ -57,6 +58,7 @@ struct j721e_pcie {
>  	struct cdns_pcie	*cdns_pcie;
>  	void __iomem		*user_cfg_base;
>  	void __iomem		*intd_cfg_base;
> +	u32			linkdown_irq_regfield;
>  };
>  
>  enum j721e_pcie_mode {
> @@ -67,6 +69,9 @@ enum j721e_pcie_mode {
>  struct j721e_pcie_data {
>  	enum j721e_pcie_mode	mode;
>  	unsigned int		quirk_retrain_flag:1;
> +	unsigned int		quirk_detect_quiet_flag:1;
> +	u32			linkdown_irq_regfield;
> +	unsigned int		byte_access_allowed:1;
>  };
>  
>  static inline u32 j721e_pcie_user_readl(struct j721e_pcie *pcie, u32 offset)
> @@ -98,12 +103,12 @@ static irqreturn_t j721e_pcie_link_irq_handler(int irq, void *priv)
>  	u32 reg;
>  
>  	reg = j721e_pcie_intd_readl(pcie, STATUS_REG_SYS_2);
> -	if (!(reg & LINK_DOWN))
> +	if (!(reg & pcie->linkdown_irq_regfield))
>  		return IRQ_NONE;
>  
>  	dev_err(dev, "LINK DOWN!\n");
>  
> -	j721e_pcie_intd_writel(pcie, STATUS_CLR_REG_SYS_2, LINK_DOWN);
> +	j721e_pcie_intd_writel(pcie, STATUS_CLR_REG_SYS_2, pcie->linkdown_irq_regfield);
>  	return IRQ_HANDLED;
>  }
>  
> @@ -112,7 +117,7 @@ static void j721e_pcie_config_link_irq(struct j721e_pcie *pcie)
>  	u32 reg;
>  
>  	reg = j721e_pcie_intd_readl(pcie, ENABLE_REG_SYS_2);
> -	reg |= LINK_DOWN;
> +	reg |= pcie->linkdown_irq_regfield;
>  	j721e_pcie_intd_writel(pcie, ENABLE_REG_SYS_2, reg);
>  }
>  
> @@ -284,10 +289,25 @@ static struct pci_ops cdns_ti_pcie_host_ops = {
>  static const struct j721e_pcie_data j721e_pcie_rc_data = {
>  	.mode = PCI_MODE_RC,
>  	.quirk_retrain_flag = true,
> +	.byte_access_allowed = false,
> +	.linkdown_irq_regfield = LINK_DOWN,
>  };
>  
>  static const struct j721e_pcie_data j721e_pcie_ep_data = {
>  	.mode = PCI_MODE_EP,
> +	.linkdown_irq_regfield = LINK_DOWN,
> +};
> +
> +static const struct j721e_pcie_data j7200_pcie_rc_data = {
> +	.mode = PCI_MODE_RC,
> +	.quirk_detect_quiet_flag = true,
> +	.linkdown_irq_regfield = J7200_LINK_DOWN,
> +	.byte_access_allowed = true,
> +};
> +
> +static const struct j721e_pcie_data j7200_pcie_ep_data = {
> +	.mode = PCI_MODE_EP,
> +	.quirk_detect_quiet_flag = true,
>  };
>  
>  static const struct of_device_id of_j721e_pcie_match[] = {
> @@ -299,6 +319,14 @@ static const struct of_device_id of_j721e_pcie_match[] = {
>  		.compatible = "ti,j721e-pcie-ep",
>  		.data = &j721e_pcie_ep_data,
>  	},
> +	{
> +		.compatible = "ti,j7200-pcie-host",
> +		.data = &j7200_pcie_rc_data,
> +	},
> +	{
> +		.compatible = "ti,j7200-pcie-ep",
> +		.data = &j7200_pcie_ep_data,
> +	},
>  	{},
>  };
>  
> @@ -332,6 +360,7 @@ static int j721e_pcie_probe(struct platform_device *pdev)
>  
>  	pcie->dev = dev;
>  	pcie->mode = mode;
> +	pcie->linkdown_irq_regfield =  data->linkdown_irq_regfield;
                                     ^
Nit: too many spaces

>  	base = devm_platform_ioremap_resource_byname(pdev, "intd_cfg");
>  	if (IS_ERR(base))
> @@ -391,9 +420,11 @@ static int j721e_pcie_probe(struct platform_device *pdev)
>  			goto err_get_sync;
>  		}
>  
> -		bridge->ops = &cdns_ti_pcie_host_ops;
> +		if (!data->byte_access_allowed)
> +			bridge->ops = &cdns_ti_pcie_host_ops;
>  		rc = pci_host_bridge_priv(bridge);
>  		rc->quirk_retrain_flag = data->quirk_retrain_flag;
> +		rc->quirk_detect_quiet_flag = data->quirk_detect_quiet_flag;
>  
>  		cdns_pcie = &rc->pcie;
>  		cdns_pcie->dev = dev;
> @@ -459,6 +490,7 @@ static int j721e_pcie_probe(struct platform_device *pdev)
>  			ret = -ENOMEM;
>  			goto err_get_sync;
>  		}
> +		ep->quirk_detect_quiet_flag = data->quirk_detect_quiet_flag;
>  
>  		cdns_pcie = &ep->pcie;
>  		cdns_pcie->dev = dev;
> -- 
> 2.17.1
>