Re: [PATCH] pci: cadence: Host and EP driver updates for PHY and power management

From: Lorenzo Pieralisi
Date: Thu May 17 2018 - 12:09:16 EST


On Wed, May 16, 2018 at 01:06:05PM +0000, Alan Douglas wrote:
> From: Alan Douglas <adouglas@xxxxxxxxxxx>
>
> This patch is based on next branch in Bjorn Helgaas' linux-pci git repository.
This sentence does not belong in a commit log and you should not be
basing patches on top of Bjorn's next branch, use v4.17-rc1, that is
an immutable commit.

> Allow optional list of generic PHYs to be provided via DTS for cadence
> RP and EP drivers. Added power management ops which will
> enable/disable these PHYs. Corrected parameters for cdns_pcie_writel
> function, value to be written had too small width.

Too many things at once. Each patch must solve one logical problem
and one only - it is easier to understand why if you think that
a patch may need to be reverted - if many changes are lumped together
this becomes complicated, that's one of the reasons.

So, please split this patch and send a v2, thank you.

Lorenzo

> Signed-off-by: Alan Douglas <adouglas@xxxxxxxxxxx>
> ---
> .../devicetree/bindings/pci/cdns,cdns-pcie-ep.txt | 4 +
> .../bindings/pci/cdns,cdns-pcie-host.txt | 5 +
> drivers/pci/cadence/pcie-cadence-ep.c | 15 +++-
> drivers/pci/cadence/pcie-cadence-host.c | 36 ++++++-
> drivers/pci/cadence/pcie-cadence.c | 123 ++++++++++++++++++++
> drivers/pci/cadence/pcie-cadence.h | 13 ++-
> 6 files changed, 193 insertions(+), 3 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/pci/cdns,cdns-pcie-ep.txt b/Documentation/devicetree/bindings/pci/cdns,cdns-pcie-ep.txt
> index 9a30523..e40c635 100644
> --- a/Documentation/devicetree/bindings/pci/cdns,cdns-pcie-ep.txt
> +++ b/Documentation/devicetree/bindings/pci/cdns,cdns-pcie-ep.txt
> @@ -9,6 +9,8 @@ Required properties:
>
> Optional properties:
> - max-functions: Maximum number of functions that can be configured (default 1).
> +- phys: From PHY bindings: List of Generic PHY phandles.
> +- phy-names: List of names to identify the PHY.
>
> Example:
>
> @@ -19,4 +21,6 @@ pcie@fc000000 {
> reg-names = "reg", "mem";
> cdns,max-outbound-regions = <16>;
> max-functions = /bits/ 8 <8>;
> + phys = <&ep_phy0 &ep_phy1>;
> + phy-names = "pcie-lane0","pcie-lane1";
> };
> diff --git a/Documentation/devicetree/bindings/pci/cdns,cdns-pcie-host.txt b/Documentation/devicetree/bindings/pci/cdns,cdns-pcie-host.txt
> index 20a33f3..13be218 100644
> --- a/Documentation/devicetree/bindings/pci/cdns,cdns-pcie-host.txt
> +++ b/Documentation/devicetree/bindings/pci/cdns,cdns-pcie-host.txt
> @@ -24,6 +24,8 @@ Optional properties:
> translations (default 32)
> - vendor-id: The PCI vendor ID (16 bits, default is design dependent)
> - device-id: The PCI device ID (16 bits, default is design dependent)
> +- phys: From PHY bindings: List of Generic PHY phandles.
> +- phy-names: List of names to identify the PHY.
>
> Example:
>
> @@ -57,4 +59,7 @@ pcie@fb000000 {
> interrupt-map-mask = <0x0 0x0 0x0 0x7>;
>
> msi-parent = <&its_pci>;
> +
> + phys = <&pcie_phy0>;
> + phy-names = "pcie-phy";
> };
> diff --git a/drivers/pci/cadence/pcie-cadence-ep.c b/drivers/pci/cadence/pcie-cadence-ep.c
> index 3d8283e..e74b8a4 100644
> --- a/drivers/pci/cadence/pcie-cadence-ep.c
> +++ b/drivers/pci/cadence/pcie-cadence-ep.c
> @@ -439,6 +439,7 @@ static int cdns_pcie_ep_probe(struct platform_device *pdev)
> struct pci_epc *epc;
> struct resource *res;
> int ret;
> + int phy_count;
>
> ep = devm_kzalloc(dev, sizeof(*ep), GFP_KERNEL);
> if (!ep)
> @@ -472,6 +473,12 @@ static int cdns_pcie_ep_probe(struct platform_device *pdev)
> if (!ep->ob_addr)
> return -ENOMEM;
>
> + ret = cdns_pcie_init_phy(dev, pcie);
> + if (ret) {
> + dev_err(dev, "failed to init phy\n");
> + return ret;
> + }
> + platform_set_drvdata(pdev, pcie);
> pm_runtime_enable(dev);
> ret = pm_runtime_get_sync(dev);
> if (ret < 0) {
> @@ -520,6 +527,10 @@ static int cdns_pcie_ep_probe(struct platform_device *pdev)
>
> err_get_sync:
> pm_runtime_disable(dev);
> + cdns_pcie_disable_phy(pcie);
> + phy_count = pcie->phy_count;
> + while (phy_count--)
> + device_link_del(pcie->link[phy_count]);
>
> return ret;
> }
> @@ -527,6 +538,7 @@ static int cdns_pcie_ep_probe(struct platform_device *pdev)
> static void cdns_pcie_ep_shutdown(struct platform_device *pdev)
> {
> struct device *dev = &pdev->dev;
> + struct cdns_pcie *pcie = dev_get_drvdata(dev);
> int ret;
>
> ret = pm_runtime_put_sync(dev);
> @@ -535,13 +547,14 @@ static void cdns_pcie_ep_shutdown(struct platform_device *pdev)
>
> pm_runtime_disable(dev);
>
> - /* The PCIe controller can't be disabled. */
> + cdns_pcie_disable_phy(pcie);
> }
>
> static struct platform_driver cdns_pcie_ep_driver = {
> .driver = {
> .name = "cdns-pcie-ep",
> .of_match_table = cdns_pcie_ep_of_match,
> + .pm = &cdns_pcie_pm_ops,
> },
> .probe = cdns_pcie_ep_probe,
> .shutdown = cdns_pcie_ep_shutdown,
> diff --git a/drivers/pci/cadence/pcie-cadence-host.c b/drivers/pci/cadence/pcie-cadence-host.c
> index a4ebbd3..992ebe2 100644
> --- a/drivers/pci/cadence/pcie-cadence-host.c
> +++ b/drivers/pci/cadence/pcie-cadence-host.c
> @@ -37,7 +37,6 @@ struct cdns_pcie_rc {
> u16 vendor_id;
> u16 device_id;
> };
> -
> static void __iomem *cdns_pci_map_bus(struct pci_bus *bus, unsigned int devfn,
> int where)
> {
> @@ -46,6 +45,7 @@ struct cdns_pcie_rc {
> struct cdns_pcie *pcie = &rc->pcie;
> unsigned int busn = bus->number;
> u32 addr0, desc0;
> + u32 link_status;
>
> if (busn == rc->bus_range->start) {
> /*
> @@ -58,6 +58,11 @@ struct cdns_pcie_rc {
>
> return pcie->reg_base + (where & 0xfff);
> }
> + /* Check that the link is up. Clear AXI link-down status */
> + link_status = cdns_pcie_readl(pcie, CDNS_PCIE_LM_BASE);
> + if (!(link_status & 0x1))
> + return NULL;
> + cdns_pcie_writel(pcie, CDNS_PCIE_AT_LINKDOWN, 0x0);
>
> /* Update Output registers for AXI region 0. */
> addr0 = CDNS_PCIE_AT_OB_REGION_PCI_ADDR0_NBITS(12) |
> @@ -239,6 +244,7 @@ static int cdns_pcie_host_probe(struct platform_device *pdev)
> struct cdns_pcie *pcie;
> struct resource *res;
> int ret;
> + int phy_count;
>
> bridge = devm_pci_alloc_host_bridge(dev, sizeof(*rc));
> if (!bridge)
> @@ -290,6 +296,13 @@ static int cdns_pcie_host_probe(struct platform_device *pdev)
> }
> pcie->mem_res = res;
>
> + ret = cdns_pcie_init_phy(dev, pcie);
> + if (ret) {
> + dev_err(dev, "failed to init phy\n");
> + return ret;
> + }
> + platform_set_drvdata(pdev, pcie);
> +
> pm_runtime_enable(dev);
> ret = pm_runtime_get_sync(dev);
> if (ret < 0) {
> @@ -322,15 +335,36 @@ static int cdns_pcie_host_probe(struct platform_device *pdev)
>
> err_get_sync:
> pm_runtime_disable(dev);
> + cdns_pcie_disable_phy(pcie);
> + phy_count = pcie->phy_count;
> + while (phy_count--)
> + device_link_del(pcie->link[phy_count]);
>
> return ret;
> }
>
> +static void cdns_pcie_shutdown(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct cdns_pcie *pcie = dev_get_drvdata(dev);
> + int ret;
> +
> + ret = pm_runtime_put_sync(dev);
> + if (ret < 0)
> + dev_dbg(dev, "pm_runtime_put_sync failed\n");
> +
> + pm_runtime_disable(dev);
> + cdns_pcie_disable_phy(pcie);
> +}
> +
> +
> static struct platform_driver cdns_pcie_host_driver = {
> .driver = {
> .name = "cdns-pcie-host",
> .of_match_table = cdns_pcie_host_of_match,
> + .pm = &cdns_pcie_pm_ops,
> },
> .probe = cdns_pcie_host_probe,
> + .shutdown = cdns_pcie_shutdown,
> };
> builtin_platform_driver(cdns_pcie_host_driver);
> diff --git a/drivers/pci/cadence/pcie-cadence.c b/drivers/pci/cadence/pcie-cadence.c
> index 138d113..7a34780 100644
> --- a/drivers/pci/cadence/pcie-cadence.c
> +++ b/drivers/pci/cadence/pcie-cadence.c
> @@ -124,3 +124,126 @@ void cdns_pcie_reset_outbound_region(struct cdns_pcie *pcie, u32 r)
> cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_CPU_ADDR0(r), 0);
> cdns_pcie_writel(pcie, CDNS_PCIE_AT_OB_REGION_CPU_ADDR1(r), 0);
> }
> +
> +void cdns_pcie_disable_phy(struct cdns_pcie *pcie)
> +{
> + int i = pcie->phy_count;
> +
> + while (i--) {
> + phy_power_off(pcie->phy[i]);
> + phy_exit(pcie->phy[i]);
> + }
> +}
> +
> +int cdns_pcie_enable_phy(struct cdns_pcie *pcie)
> +{
> + int ret;
> + int i;
> +
> + for (i = 0; i < pcie->phy_count; i++) {
> + ret = phy_init(pcie->phy[i]);
> + if (ret < 0)
> + goto err_phy;
> +
> + ret = phy_power_on(pcie->phy[i]);
> + if (ret < 0) {
> + phy_exit(pcie->phy[i]);
> + goto err_phy;
> + }
> + }
> +
> + return 0;
> +
> +err_phy:
> + while (--i >= 0) {
> + phy_power_off(pcie->phy[i]);
> + phy_exit(pcie->phy[i]);
> + }
> +
> + return ret;
> +}
> +
> +int cdns_pcie_init_phy(struct device *dev, struct cdns_pcie *pcie)
> +{
> + struct device_node *np = dev->of_node;
> + int phy_count;
> + struct phy **phy;
> + struct device_link **link;
> + int i;
> + int ret;
> + const char *name;
> +
> + phy_count = of_property_count_strings(np, "phy-names");
> + if (phy_count < 1) {
> + dev_err(dev, "no phy-names. PHY will not be initialized\n");
> + pcie->phy_count = 0;
> + return 0;
> + }
> +
> + phy = devm_kzalloc(dev, sizeof(*phy) * phy_count, GFP_KERNEL);
> + if (!phy)
> + return -ENOMEM;
> +
> + link = devm_kzalloc(dev, sizeof(*link) * phy_count, GFP_KERNEL);
> + if (!link)
> + return -ENOMEM;
> +
> + for (i = 0; i < phy_count; i++) {
> + of_property_read_string_index(np, "phy-names", i, &name);
> + phy[i] = devm_phy_get(dev, name);
> + if (IS_ERR(phy))
> + return PTR_ERR(phy);
> +
> + link[i] = device_link_add(dev, &phy[i]->dev, DL_FLAG_STATELESS);
> + if (!link[i]) {
> + ret = -EINVAL;
> + goto err_link;
> + }
> + }
> +
> + pcie->phy_count = phy_count;
> + pcie->phy = phy;
> + pcie->link = link;
> +
> + ret = cdns_pcie_enable_phy(pcie);
> + if (ret)
> + goto err_link;
> +
> + return 0;
> +
> +err_link:
> + while (--i >= 0)
> + device_link_del(link[i]);
> +
> + return ret;
> +}
> +
> +#ifdef CONFIG_PM_SLEEP
> +static int cdns_pcie_suspend_noirq(struct device *dev)
> +{
> + struct cdns_pcie *pcie = dev_get_drvdata(dev);
> +
> + cdns_pcie_disable_phy(pcie);
> +
> + return 0;
> +}
> +
> +static int cdns_pcie_resume_noirq(struct device *dev)
> +{
> + struct cdns_pcie *pcie = dev_get_drvdata(dev);
> + int ret;
> +
> + ret = cdns_pcie_enable_phy(pcie);
> + if (ret) {
> + dev_err(dev, "failed to enable phy\n");
> + return ret;
> + }
> +
> + return 0;
> +}
> +#endif
> +
> +const struct dev_pm_ops cdns_pcie_pm_ops = {
> + SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(cdns_pcie_suspend_noirq,
> + cdns_pcie_resume_noirq)
> +};
> diff --git a/drivers/pci/cadence/pcie-cadence.h b/drivers/pci/cadence/pcie-cadence.h
> index 4bb2733..ae6bf2a 100644
> --- a/drivers/pci/cadence/pcie-cadence.h
> +++ b/drivers/pci/cadence/pcie-cadence.h
> @@ -8,6 +8,7 @@
>
> #include <linux/kernel.h>
> #include <linux/pci.h>
> +#include <linux/phy/phy.h>
>
> /*
> * Local Management Registers
> @@ -165,6 +166,9 @@
> #define CDNS_PCIE_AT_IB_RP_BAR_ADDR1(bar) \
> (CDNS_PCIE_AT_BASE + 0x0804 + (bar) * 0x0008)
>
> +/* AXI link down register */
> +#define CDNS_PCIE_AT_LINKDOWN (CDNS_PCIE_AT_BASE + 0x0824)
> +
> enum cdns_pcie_rp_bar {
> RP_BAR0,
> RP_BAR1,
> @@ -229,6 +233,9 @@ struct cdns_pcie {
> struct resource *mem_res;
> bool is_rc;
> u8 bus;
> + int phy_count;
> + struct phy **phy;
> + struct device_link **link;
> };
>
> /* Register access */
> @@ -279,7 +286,7 @@ static inline void cdns_pcie_ep_fn_writew(struct cdns_pcie *pcie, u8 fn,
> }
>
> static inline void cdns_pcie_ep_fn_writel(struct cdns_pcie *pcie, u8 fn,
> - u32 reg, u16 value)
> + u32 reg, u32 value)
> {
> writel(value, pcie->reg_base + CDNS_PCIE_EP_FUNC_BASE(fn) + reg);
> }
> @@ -307,5 +314,9 @@ void cdns_pcie_set_outbound_region_for_normal_msg(struct cdns_pcie *pcie, u8 fn,
> u32 r, u64 cpu_addr);
>
> void cdns_pcie_reset_outbound_region(struct cdns_pcie *pcie, u32 r);
> +void cdns_pcie_disable_phy(struct cdns_pcie *pcie);
> +int cdns_pcie_enable_phy(struct cdns_pcie *pcie);
> +int cdns_pcie_init_phy(struct device *dev, struct cdns_pcie *pcie);
> +extern const struct dev_pm_ops cdns_pcie_pm_ops;
>
> #endif /* _PCIE_CADENCE_H */
> --
> 1.7.1
>