[PATCH V5] PCI: rcar: Use runtime PM to control controller clock

[Marek Vasut <marek.vasut@xxxxxxxxx>]

From: Dien Pham <dien.pham.ry@xxxxxxxxxxxxxxx>

The controller clock can be switched off during suspend/resume,
let runtime PM take care of that.

Signed-off-by: Dien Pham <dien.pham.ry@xxxxxxxxxxxxxxx>
Signed-off-by: Hien Dang <hien.dang.eb@xxxxxxxxxxx>
Signed-off-by: Marek Vasut <marek.vasut+renesas@xxxxxxxxx>
Cc: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
Cc: Phil Edworthy <phil.edworthy@xxxxxxxxxxx>
Cc: Simon Horman <horms+renesas@xxxxxxxxxxxx>
Cc: Wolfram Sang <wsa@xxxxxxxxxxxxx>
Cc: linux-renesas-soc@xxxxxxxxxxxxxxx
To: linux-pci@xxxxxxxxxxxxxxx
---
V2: - Reorder the fail path in rcar_pcie_probe() to cater for the
      reordering of function calls in probe
    - Dispose of fail_clk in rcar_pcie_get_resources()
V3: - Fix up the failpath in probe function
V4: - Rebase on recent linux-next
V5: - Do not call pci_free_resource_list(&pcie->resources) if
      rcar_pcie_parse_request_of_pci_ranges() fails, since that
      functiona calls pci_free_resource_list() already.
---
 drivers/pci/host/pcie-rcar.c | 38 ++++++++++++--------------------------
 1 file changed, 12 insertions(+), 26 deletions(-)

diff --git a/drivers/pci/host/pcie-rcar.c b/drivers/pci/host/pcie-rcar.c
index 6ab28f29ac6a..25f68305322c 100644
--- a/drivers/pci/host/pcie-rcar.c
+++ b/drivers/pci/host/pcie-rcar.c
@@ -142,7 +142,6 @@ struct rcar_pcie {
 	void __iomem		*base;
 	struct list_head	resources;
 	int			root_bus_nr;
-	struct clk		*clk;
 	struct clk		*bus_clk;
 	struct			rcar_msi msi;
 };
@@ -914,24 +913,14 @@ static int rcar_pcie_get_resources(struct rcar_pcie *pcie)
 	if (IS_ERR(pcie->base))
 		return PTR_ERR(pcie->base);
 
-	pcie->clk = devm_clk_get(dev, "pcie");
-	if (IS_ERR(pcie->clk)) {
-		dev_err(dev, "cannot get platform clock\n");
-		return PTR_ERR(pcie->clk);
-	}
-	err = clk_prepare_enable(pcie->clk);
-	if (err)
-		return err;
-
 	pcie->bus_clk = devm_clk_get(dev, "pcie_bus");
 	if (IS_ERR(pcie->bus_clk)) {
 		dev_err(dev, "cannot get pcie bus clock\n");
-		err = PTR_ERR(pcie->bus_clk);
-		goto fail_clk;
+		return PTR_ERR(pcie->bus_clk);
 	}
 	err = clk_prepare_enable(pcie->bus_clk);
 	if (err)
-		goto fail_clk;
+		return err;
 
 	i = irq_of_parse_and_map(dev->of_node, 0);
 	if (!i) {
@@ -953,8 +942,6 @@ static int rcar_pcie_get_resources(struct rcar_pcie *pcie)
 
 err_map_reg:
 	clk_disable_unprepare(pcie->bus_clk);
-fail_clk:
-	clk_disable_unprepare(pcie->clk);
 
 	return err;
 }
@@ -1124,22 +1111,22 @@ static int rcar_pcie_probe(struct platform_device *pdev)
 	if (err)
 		goto err_free_bridge;
 
+	pm_runtime_enable(pcie->dev);
+	err = pm_runtime_get_sync(pcie->dev);
+	if (err < 0) {
+		dev_err(pcie->dev, "pm_runtime_get_sync failed\n");
+		goto err_pm_disable;
+	}
+
 	err = rcar_pcie_get_resources(pcie);
 	if (err < 0) {
 		dev_err(dev, "failed to request resources: %d\n", err);
-		goto err_free_resource_list;
+		goto err_pm_put;
 	}
 
 	err = rcar_pcie_parse_map_dma_ranges(pcie, dev->of_node);
 	if (err)
-		goto err_free_resource_list;
-
-	pm_runtime_enable(dev);
-	err = pm_runtime_get_sync(dev);
-	if (err < 0) {
-		dev_err(dev, "pm_runtime_get_sync failed\n");
-		goto err_pm_disable;
-	}
+		goto err_pm_put;
 
 	/* Failure to get a link might just be that no cards are inserted */
 	hw_init_fn = of_device_get_match_data(dev);
@@ -1174,9 +1161,8 @@ static int rcar_pcie_probe(struct platform_device *pdev)
 
 err_pm_disable:
 	pm_runtime_disable(dev);
-
-err_free_resource_list:
 	pci_free_resource_list(&pcie->resources);
+
 err_free_bridge:
 	pci_free_host_bridge(bridge);
 
-- 
2.16.2