[PATCH V2] 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: 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()
---
 drivers/pci/host/pcie-rcar.c | 37 ++++++++++++-------------------------
 1 file changed, 12 insertions(+), 25 deletions(-)

diff --git a/drivers/pci/host/pcie-rcar.c b/drivers/pci/host/pcie-rcar.c
index 12796eccb2be..1a7254ec16da 100644
--- a/drivers/pci/host/pcie-rcar.c
+++ b/drivers/pci/host/pcie-rcar.c
@@ -145,7 +145,6 @@ 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;
 };
@@ -917,24 +916,14 @@ 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) {
@@ -956,8 +945,6 @@ 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;
 }
@@ -1125,6 +1112,13 @@ static int rcar_pcie_probe(struct platform_device *pdev)
 
 	rcar_pcie_parse_request_of_pci_ranges(pcie);
 
+	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);
@@ -1135,13 +1129,6 @@ static int rcar_pcie_probe(struct platform_device *pdev)
 	if (err)
 		goto err_free_bridge;
 
-	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;
-	}
-
 	/* Failure to get a link might just be that no cards are inserted */
 	hw_init_fn = of_device_get_match_data(dev);
 	err = hw_init_fn(pcie);
@@ -1173,13 +1160,13 @@ static int rcar_pcie_probe(struct platform_device *pdev)
 err_pm_put:
 	pm_runtime_put(dev);
 
-err_pm_disable:
-	pm_runtime_disable(dev);
-
 err_free_bridge:
 	pci_free_host_bridge(bridge);
 	pci_free_resource_list(&pcie->resources);
 
+err_pm_disable:
+	pm_runtime_disable(dev);
+
 	return err;
 }
 
-- 
2.11.0