PCI: tegra: Add power management support

Tegra186 powergate driver is implemented as power domain driver, power
partition ungate/gate are registered as power_on/power_off callback
functions. There are no direct functions to power gate/ungate host
controller in Tegra186. Host controller driver should add "power-domains"
property in device tree and implement runtime suspend and resume
callback functons. Power gate and ungate is taken care by power domain
driver when host controller driver calls pm_runtime_put_sync and
pm_runtime_get_sync respectively.

Register suspend_noirq & resume_noirq callback functions to allow PCIe to
come up after resume from RAM. Both runtime and noirq pm ops share same
callback functions.

Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
[lorenzo.pieralisi@arm.com: squashed patch to fix compilation]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Tested-by: Thierry Reding <treding@nvidia.com>

1 files changed, 113 insertions, 67 deletions

diff --git a/drivers/pci/host/pci-tegra.c b/drivers/pci/host/pci-tegra.c
index ab057f6f5153..389e74be846c 100644
--- a/drivers/pci/host/pci-tegra.c
+++ b/drivers/pci/host/pci-tegra.c
@@ -1280,31 +1280,25 @@ static int tegra_pcie_get_resources(struct tegra_pcie *pcie)
                 }
         }
 
-        err = tegra_pcie_power_on(pcie);
-        if (err) {
-                dev_err(dev, "failed to power up: %d\n", err);
-                goto phys_put;
-        }
-
         pads = platform_get_resource_byname(pdev, IORESOURCE_MEM, "pads");
         pcie->pads = devm_ioremap_resource(dev, pads);
         if (IS_ERR(pcie->pads)) {
                 err = PTR_ERR(pcie->pads);
-                goto poweroff;
+                goto phys_put;
         }
 
         afi = platform_get_resource_byname(pdev, IORESOURCE_MEM, "afi");
         pcie->afi = devm_ioremap_resource(dev, afi);
         if (IS_ERR(pcie->afi)) {
                 err = PTR_ERR(pcie->afi);
-                goto poweroff;
+                goto phys_put;
         }
 
         /* request configuration space, but remap later, on demand */
         res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "cs");
         if (!res) {
                 err = -EADDRNOTAVAIL;
-                goto poweroff;
+                goto phys_put;
         }
 
         pcie->cs = *res;
@@ -1315,14 +1309,14 @@ static int tegra_pcie_get_resources(struct tegra_pcie *pcie)
         pcie->cfg = devm_ioremap_resource(dev, &pcie->cs);
         if (IS_ERR(pcie->cfg)) {
                 err = PTR_ERR(pcie->cfg);
-                goto poweroff;
+                goto phys_put;
         }
 
         /* request interrupt */
         err = platform_get_irq_byname(pdev, "intr");
         if (err < 0) {
                 dev_err(dev, "failed to get IRQ: %d\n", err);
-                goto poweroff;
+                goto phys_put;
         }
 
         pcie->irq = err;
@@ -1330,7 +1324,7 @@ static int tegra_pcie_get_resources(struct tegra_pcie *pcie)
         err = request_irq(pcie->irq, tegra_pcie_isr, IRQF_SHARED, "PCIE", pcie);
         if (err) {
                 dev_err(dev, "failed to register IRQ: %d\n", err);
-                goto poweroff;
+                goto phys_put;
         }
 
         return 0;
@@ -1338,8 +1332,6 @@ static int tegra_pcie_get_resources(struct tegra_pcie *pcie)
 phys_put:
         if (soc->program_uphy)
                 tegra_pcie_phys_put(pcie);
-poweroff:
-        tegra_pcie_power_off(pcie);
         return err;
 }
 
@@ -1350,8 +1342,6 @@ static int tegra_pcie_put_resources(struct tegra_pcie *pcie)
         if (pcie->irq > 0)
                 free_irq(pcie->irq, pcie);
 
-        tegra_pcie_power_off(pcie);
-
         if (soc->program_uphy)
                 tegra_pcie_phys_put(pcie);
 
@@ -1520,15 +1510,13 @@ static const struct irq_domain_ops msi_domain_ops = {
         .map = tegra_msi_map,
 };
 
-static int tegra_pcie_enable_msi(struct tegra_pcie *pcie)
+static int tegra_pcie_msi_setup(struct tegra_pcie *pcie)
 {
         struct pci_host_bridge *host = pci_host_bridge_from_priv(pcie);
         struct platform_device *pdev = to_platform_device(pcie->dev);
-        const struct tegra_pcie_soc *soc = pcie->soc;
         struct tegra_msi *msi = &pcie->msi;
         struct device *dev = pcie->dev;
         int err;
-        u32 reg;
 
         mutex_init(&msi->lock);
 
@@ -1561,6 +1549,20 @@ static int tegra_pcie_enable_msi(struct tegra_pcie *pcie)
         /* setup AFI/FPCI range */
         msi->pages = __get_free_pages(GFP_KERNEL, 0);
         msi->phys = virt_to_phys((void *)msi->pages);
+        host->msi = &msi->chip;
+
+        return 0;
+
+err:
+        irq_domain_remove(msi->domain);
+        return err;
+}
+
+static void tegra_pcie_enable_msi(struct tegra_pcie *pcie)
+{
+        const struct tegra_pcie_soc *soc = pcie->soc;
+        struct tegra_msi *msi = &pcie->msi;
+        u32 reg;
 
         afi_writel(pcie, msi->phys >> soc->msi_base_shift, AFI_MSI_FPCI_BAR_ST);
         afi_writel(pcie, msi->phys, AFI_MSI_AXI_BAR_ST);
@@ -1581,20 +1583,29 @@ static int tegra_pcie_enable_msi(struct tegra_pcie *pcie)
         reg = afi_readl(pcie, AFI_INTR_MASK);
         reg |= AFI_INTR_MASK_MSI_MASK;
         afi_writel(pcie, reg, AFI_INTR_MASK);
+}
 
-        host->msi = &msi->chip;
+static void tegra_pcie_msi_teardown(struct tegra_pcie *pcie)
+{
+        struct tegra_msi *msi = &pcie->msi;
+        unsigned int i, irq;
 
-        return 0;
+        free_pages(msi->pages, 0);
+
+        if (msi->irq > 0)
+                free_irq(msi->irq, pcie);
+
+        for (i = 0; i < INT_PCI_MSI_NR; i++) {
+                irq = irq_find_mapping(msi->domain, i);
+                if (irq > 0)
+                        irq_dispose_mapping(irq);
+        }
 
-err:
         irq_domain_remove(msi->domain);
-        return err;
 }
 
 static int tegra_pcie_disable_msi(struct tegra_pcie *pcie)
 {
-        struct tegra_msi *msi = &pcie->msi;
-        unsigned int i, irq;
         u32 value;
 
         /* mask the MSI interrupt */
@@ -1612,19 +1623,6 @@ static int tegra_pcie_disable_msi(struct tegra_pcie *pcie)
         afi_writel(pcie, 0, AFI_MSI_EN_VEC6);
         afi_writel(pcie, 0, AFI_MSI_EN_VEC7);
 
-        free_pages(msi->pages, 0);
-
-        if (msi->irq > 0)
-                free_irq(msi->irq, pcie);
-
-        for (i = 0; i < INT_PCI_MSI_NR; i++) {
-                irq = irq_find_mapping(msi->domain, i);
-                if (irq > 0)
-                        irq_dispose_mapping(irq);
-        }
-
-        irq_domain_remove(msi->domain);
-
         return 0;
 }
 
@@ -2123,10 +2121,8 @@ static void tegra_pcie_disable_ports(struct tegra_pcie *pcie)
 {
         struct tegra_pcie_port *port, *tmp;
 
-        list_for_each_entry_safe(port, tmp, &pcie->ports, list) {
+        list_for_each_entry_safe(port, tmp, &pcie->ports, list)
                 tegra_pcie_port_disable(port);
-                tegra_pcie_port_free(port);
-        }
 }
 
 static const struct tegra_pcie_port_soc tegra20_pcie_ports[] = {
@@ -2381,26 +2377,22 @@ static int tegra_pcie_probe(struct platform_device *pdev)
                 return err;
         }
 
-        err = tegra_pcie_enable_controller(pcie);
-        if (err)
+        err = tegra_pcie_msi_setup(pcie);
+        if (err < 0) {
+                dev_err(dev, "failed to enable MSI support: %d\n", err);
                 goto put_resources;
+        }
 
-        err = tegra_pcie_request_resources(pcie);
-        if (err)
-                goto disable_controller;
-
-        /* setup the AFI address translations */
-        tegra_pcie_setup_translations(pcie);
-
-        if (IS_ENABLED(CONFIG_PCI_MSI)) {
-                err = tegra_pcie_enable_msi(pcie);
-                if (err < 0) {
-                        dev_err(dev, "failed to enable MSI support: %d\n", err);
-                        goto free_resources;
-                }
+        pm_runtime_enable(pcie->dev);
+        err = pm_runtime_get_sync(pcie->dev);
+        if (err) {
+                dev_err(dev, "fail to enable pcie controller: %d\n", err);
+                goto teardown_msi;
         }
 
-        tegra_pcie_enable_ports(pcie);
+        err = tegra_pcie_request_resources(pcie);
+        if (err)
+                goto pm_runtime_put;
 
         host->busnr = pcie->busn.start;
         host->dev.parent = &pdev->dev;
@@ -2411,7 +2403,7 @@ static int tegra_pcie_probe(struct platform_device *pdev)
         err = pci_scan_root_bus_bridge(host);
         if (err < 0) {
                 dev_err(dev, "failed to register host: %d\n", err);
-                goto disable_ports;
+                goto free_resources;
         }
 
         pci_bus_size_bridges(host->bus);
@@ -2430,14 +2422,13 @@ static int tegra_pcie_probe(struct platform_device *pdev)
 
         return 0;
 
-disable_ports:
-        tegra_pcie_disable_ports(pcie);
-        if (IS_ENABLED(CONFIG_PCI_MSI))
-                tegra_pcie_disable_msi(pcie);
 free_resources:
         tegra_pcie_free_resources(pcie);
-disable_controller:
-        tegra_pcie_disable_controller(pcie);
+pm_runtime_put:
+        pm_runtime_put_sync(pcie->dev);
+        pm_runtime_disable(pcie->dev);
+teardown_msi:
+        tegra_pcie_msi_teardown(pcie);
 put_resources:
         tegra_pcie_put_resources(pcie);
         return err;
@@ -2447,13 +2438,32 @@ 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;
+        struct tegra_pcie_port *port, *tmp;
 
         if (IS_ENABLED(CONFIG_DEBUG_FS))
                 tegra_pcie_debugfs_exit(pcie);
 
         pci_stop_root_bus(host->bus);
         pci_remove_root_bus(host->bus);
+        tegra_pcie_free_resources(pcie);
+        pm_runtime_put_sync(pcie->dev);
+        pm_runtime_disable(pcie->dev);
+
+        if (IS_ENABLED(CONFIG_PCI_MSI))
+                tegra_pcie_msi_teardown(pcie);
+
+        tegra_pcie_put_resources(pcie);
+
+        list_for_each_entry_safe(port, tmp, &pcie->ports, list)
+                tegra_pcie_port_free(port);
+
+        return 0;
+}
+
+static int __maybe_unused tegra_pcie_pm_suspend(struct device *dev)
+{
+        struct tegra_pcie *pcie = dev_get_drvdata(dev);
+        struct tegra_pcie_port *port;
 
         list_for_each_entry(port, &pcie->ports, list)
                 tegra_pcie_pme_turnoff(port);
@@ -2463,18 +2473,54 @@ static int tegra_pcie_remove(struct platform_device *pdev)
         if (IS_ENABLED(CONFIG_PCI_MSI))
                 tegra_pcie_disable_msi(pcie);
 
-        tegra_pcie_free_resources(pcie);
         tegra_pcie_disable_controller(pcie);
-        tegra_pcie_put_resources(pcie);
+        tegra_pcie_power_off(pcie);
+
+        return 0;
+}
+
+static int __maybe_unused tegra_pcie_pm_resume(struct device *dev)
+{
+        struct tegra_pcie *pcie = dev_get_drvdata(dev);
+        int err;
+
+        err = tegra_pcie_power_on(pcie);
+        if (err) {
+                dev_err(dev, "tegra pcie power on fail: %d\n", err);
+                return err;
+        }
+        err = tegra_pcie_enable_controller(pcie);
+        if (err) {
+                dev_err(dev, "tegra pcie controller enable fail: %d\n", err);
+                goto poweroff;
+        }
+        tegra_pcie_setup_translations(pcie);
+
+        if (IS_ENABLED(CONFIG_PCI_MSI))
+                tegra_pcie_enable_msi(pcie);
+
+        tegra_pcie_enable_ports(pcie);
 
         return 0;
+
+poweroff:
+        tegra_pcie_power_off(pcie);
+
+        return err;
 }
 
+static const struct dev_pm_ops tegra_pcie_pm_ops = {
+        SET_RUNTIME_PM_OPS(tegra_pcie_pm_suspend, tegra_pcie_pm_resume, NULL)
+        SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(tegra_pcie_pm_suspend,
+                                      tegra_pcie_pm_resume)
+};
+
 static struct platform_driver tegra_pcie_driver = {
         .driver = {
                 .name = "tegra-pcie",
                 .of_match_table = tegra_pcie_of_match,
                 .suppress_bind_attrs = true,
+                .pm = &tegra_pcie_pm_ops,
         },
         .probe = tegra_pcie_probe,
         .remove = tegra_pcie_remove,