Re: [PATCH v11 2/4] PCI: mediatek: Add new method to get shared pcie-cfg base address and parse node

Bjorn Helgaas
2021-08-10T19:43:21Z

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.

> 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