On 29-Nov-17 10:21 PM, Bjorn Helgaas wrote:
> On Sun, Nov 26, 2017 at 01:02:12AM +0530, 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.
>
> s/PME_turn_Off/PME_Turn_Off/ above to match spec.
>
> I thought PME_TO_Ack was also mis-capitalized, but it's not. Guess
> that "TO" stands for "Turn Off".
>
>> 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;
>
> Unnecessary initialization. In fact, the variable is unnecessary; you
> can just return the value directly as soon as you know it.
>
I can get rid of this function with Mikko's suggestion to use soc data
>> +
>> + 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;
>
> Similar.
>
Similar
>> +
>> + 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;
>> +}
>> +
>> +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);
>> +
>> + if (data)
>> + dev_err(pcie->dev, "PME Ack is not receieved on port: %d\n",
>
> s/receieved/received/
>
>> + port->index);
>> +
>> + 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);
>> --
>> 2.1.4
>>
--
To unsubscribe from this list: send the line "unsubscribe linux-tegra" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
