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

Jason Gunthorpe
2014-05-06T16:35:08Z

On Tue, May 06, 2014 at 07:03:51PM +0530, Kishon Vijay Abraham I wrote:
> +Example:
> +pcie at 51000000 {
> + compatible = "ti,dra7xx-pcie";
> + reg = <0x51002000 0x14c>, <0x51000000 0x2000>;
> + reg-names = "ti_conf", "rc_dbics";
> + interrupts = <0 232 0x4>, <0 233 0x4>;
> + #address-cells = <3>;
> + #size-cells = <2>;
> + device_type = "pci";
> + ti,device_type = <3>;
> + ranges = <0x00000800 0 0x20001000 0x20001000 0 0x00002000 /* Configuration Space */

Configuration space should not show up in the ranges, please don't
copy that mistake from other drivers, put it in reg.

> + interrupt-map-mask = <0 0 0 0>;
> + interrupt-map = <0x0 0 &gic 134>;

The HW cannot decode INTA/B/C/D?

> +#define PCIECTRL_DRA7XX_CONF_IRQSTATUS_MSI 0x0034
> +#define PCIECTRL_DRA7XX_CONF_IRQENABLE_SET_MSI 0x0038
> +#define INTA BIT(0)
> +#define INTB BIT(1)
> +#define INTC BIT(2)
> +#define INTD BIT(3)
> +#define MSI BIT(4)
> +#define LEG_EP_INTERRUPTS (INTA | INTB | INTC | INTD)

Oh, it can, it would be wise to export this from the driver. Look at
the latest patches from Srikanth Thokala for the Xilinx PCI driver to
see how this should look

> +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");
> + 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) {
> + reg = dra7xx_pcie_readl(dra7xx->base,
> + PCIECTRL_DRA7XX_CONF_PHY_CS);
> + if (reg & LINK_UP)
> + break;
> + usleep_range(10, 20);
> + }
> +
> + if (retries <= 0) {
> + dev_err(pp->dev, "link is not up\n");
> + return -ETIMEDOUT;
> + }
> +
> + return 0;
> +}

It would be really nice to see the link bring up process live in the
PCI core, every driver seems to have its own take on this.

The PCI-E spec requires a 100ms delay after link bring up (aka hot
reset) before sending any configuration TLPs.

Jason