On 25.11.2017 21:32, Manikanta Maddireddy wrote:
Per PCIe r3.0, sec 5.3.3.2.1, PCIe root port shoould broadcast PME_turn_Off
message before PCIe link goes to L2. PME_turn_Off broadcast mechanism is
implemented in AFI module. Each Tegra PCIe root port has its own
PME_turn_Off and PME_TO_Ack bitmap in AFI_PME register, program this
register to broadcast PME_turn_Off message.
Signed-off-by: Manikanta Maddireddy <mmaddireddy@xxxxxxxxxx>
---
V2:
* no change in this patch
drivers/pci/host/pci-tegra.c | 76 ++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 76 insertions(+)
diff --git a/drivers/pci/host/pci-tegra.c b/drivers/pci/host/pci-tegra.c
index bbc2807bcd4a..b380958a3deb 100644
--- a/drivers/pci/host/pci-tegra.c
+++ b/drivers/pci/host/pci-tegra.c
@@ -155,6 +155,8 @@
#define AFI_INTR_EN_FPCI_TIMEOUT (1 << 7)
#define AFI_INTR_EN_PRSNT_SENSE (1 << 8)
+#define AFI_PCIE_PME 0xf0
+
#define AFI_PCIE_CONFIG 0x0f8
#define AFI_PCIE_CONFIG_PCIE_DISABLE(x) (1 << ((x) + 1))
#define AFI_PCIE_CONFIG_PCIE_DISABLE_ALL 0xe
@@ -315,6 +317,7 @@
#define PADS_REFCLK_CFG_DRVI_SHIFT 12 /* 15:12 */
#define LINK_RETRAIN_TIMEOUT 100000
+#define PME_ACK_TIMEOUT 10000
struct tegra_msi {
struct msi_controller chip;
@@ -1503,6 +1506,76 @@ static int tegra_pcie_put_resources(struct tegra_pcie *pcie)
return 0;
}
+static inline u32 get_pme_turnoff_bitmap(struct tegra_pcie_port *port)
+{
+ struct device *dev = port->pcie->dev;
+ struct device_node *np = dev->of_node;
+ int ret = 0;
+
+ switch (port->index) {
+ case 0:
+ ret = 0;
+ case 1:
+ ret = 8;
+ case 2:
+ if (of_device_is_compatible(np, "nvidia,tegra30-pcie"))
+ ret = 16;
+ else
+ ret = 12;
+ }
+ return ret;
+}
+
+static inline u32 get_pme_ack_bitmap(struct tegra_pcie_port *port)
+{
+ struct device *dev = port->pcie->dev;
+ struct device_node *np = dev->of_node;
+ int ret = 0;
+
+ switch (port->index) {
+ case 0:
+ ret = 5;
+ case 1:
+ ret = 10;
+ case 2:
+ if (of_device_is_compatible(np, "nvidia,tegra30-pcie"))
+ ret = 18;
+ else
+ ret = 14;
+ }
+ return ret;
+}
From what I can tell, the port 2 bit is 12/14 on everything after
Tegra30 as well, so I don't think this actually works?
I think simpler would be to add a SoC data fields 'u8
pme_turnoff_bit[3]' and 'u8 pme_ack_bit[3]' and then set that
to '.pme_turnoff_bit = { 0, 8, 16 }' and so on.
+
+static void tegra_pcie_pme_turnoff(struct tegra_pcie_port *port)
+{
+ struct tegra_pcie *pcie = port->pcie;
+ ktime_t deadline;
+ unsigned int data;
+
+ data = afi_readl(pcie, AFI_PCIE_PME);
+ data |= (0x1 << get_pme_turnoff_bitmap(port));
+ afi_writel(pcie, data, AFI_PCIE_PME);
+
+ deadline = ktime_add_us(ktime_get(), PME_ACK_TIMEOUT);
+ do {
+ data = afi_readl(pcie, AFI_PCIE_PME);
+ data &= (0x1 << get_pme_ack_bitmap(port));
+ udelay(1);
+ if (ktime_after(ktime_get(), deadline))
+ break;
+ } while (!data);
Since this is a normal MMIO read, we could replace the whole loop with a
call to readl_poll_timeout (or readl_relaxed_poll_timeout, or if we
really must delay and not sleep, readl_poll_timeout_atomic etc.) from
iopoll.h
int err;
u32 val;
err = readl_poll_timeout(pcie->afi + AFI_PCIE_PME, val,
val & (0x1 << pcie->soc->pme_ack_bit[port]),
1, PME_ACK_TIMEOUT);
if (err)
...
+
+ if (data)
+ dev_err(pcie->dev, "PME Ack is not receieved on port: %d\n",
+ port->index);
+
Typo here, s/receieved/received/
Cheers,
Mikko
+ usleep_range(10000, 11000);
+
+ data = afi_readl(pcie, AFI_PCIE_PME);
+ data &= ~(0x1 << get_pme_turnoff_bitmap(port));
+ afi_writel(pcie, data, AFI_PCIE_PME);
+}
+
static int tegra_msi_alloc(struct tegra_msi *chip)
{
int msi;
@@ -2828,6 +2901,7 @@ static int tegra_pcie_remove(struct platform_device *pdev)
{
struct tegra_pcie *pcie = platform_get_drvdata(pdev);
struct pci_host_bridge *host = pci_host_bridge_from_priv(pcie);
+ struct tegra_pcie_port *port, *tmp;
if (IS_ENABLED(CONFIG_DEBUG_FS))
tegra_pcie_debugfs_exit(pcie);
@@ -2835,6 +2909,8 @@ static int tegra_pcie_remove(struct platform_device *pdev)
pci_remove_root_bus(host->bus);
if (IS_ENABLED(CONFIG_PCI_MSI))
tegra_pcie_disable_msi(pcie);
+ list_for_each_entry_safe(port, tmp, &pcie->ports, list)
+ tegra_pcie_pme_turnoff(port);
tegra_pcie_disable_ports(pcie);
tegra_pcie_free_resources(pcie);
tegra_pcie_disable_controller(pcie);
