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

From: Alan Douglas
Date: Wed May 16 2018 - 08:33:31 EST


From: Alan Douglas <adouglas@xxxxxxxxxxx>

This patch is based on next branch in Bjorn Helgaas' linux-pci git repository.

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.

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