[PATCH 1/6] PCI: rcar-gen2: Add support for clocks

[Herve Codina <herve.codina@bootlin.com>]

The PCI rcar-gen2 does not call any clk_prepare_enable().
This lead to an access failure when the driver tries to access
the IP (at least on a RZ/N1D platform).

Prepare and enable clocks using the bulk version of
clk_prepare_enable() in order to prepare and enable all clocks
attached to this device.

Signed-off-by: Herve Codina <herve.codina@bootlin.com>
---
 drivers/pci/controller/pci-rcar-gen2.c | 28 ++++++++++++++++++++++++--
 1 file changed, 26 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/controller/pci-rcar-gen2.c b/drivers/pci/controller/pci-rcar-gen2.c
index 35804ea394fd..528bc3780e01 100644
--- a/drivers/pci/controller/pci-rcar-gen2.c
+++ b/drivers/pci/controller/pci-rcar-gen2.c
@@ -8,6 +8,7 @@
  * Author: Valentine Barshak <valentine.barshak@cogentembedded.com>
  */
 
+#include <linux/clk.h>
 #include <linux/delay.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
@@ -99,6 +100,8 @@ struct rcar_pci {
 	struct resource mem_res;
 	struct resource *cfg_res;
 	int irq;
+	struct clk_bulk_data *clocks;
+	int nclocks;
 };
 
 /* PCI configuration space operations */
@@ -282,6 +285,7 @@ static int rcar_pci_probe(struct platform_device *pdev)
 	struct rcar_pci *priv;
 	struct pci_host_bridge *bridge;
 	void __iomem *reg;
+	int ret;
 
 	bridge = devm_pci_alloc_host_bridge(dev, sizeof(*priv));
 	if (!bridge)
@@ -305,13 +309,25 @@ static int rcar_pci_probe(struct platform_device *pdev)
 	priv->mem_res = *mem_res;
 	priv->cfg_res = cfg_res;
 
+	ret = devm_clk_bulk_get_all(dev, &priv->clocks);
+	if (ret < 0) {
+		dev_err(dev, "failed to get clocks %d\n", ret);
+		return ret;
+	}
+	priv->nclocks = ret;
+
+	ret = clk_bulk_prepare_enable(priv->nclocks, priv->clocks);
+	if (ret)
+		return ret;
+
 	priv->irq = platform_get_irq(pdev, 0);
 	priv->reg = reg;
 	priv->dev = dev;
 
 	if (priv->irq < 0) {
 		dev_err(dev, "no valid irq found\n");
-		return priv->irq;
+		ret = priv->irq;
+		goto disable_clocks;
 	}
 
 	bridge->ops = &rcar_pci_ops;
@@ -320,7 +336,15 @@ static int rcar_pci_probe(struct platform_device *pdev)
 
 	rcar_pci_setup(priv);
 
-	return pci_host_probe(bridge);
+	ret = pci_host_probe(bridge);
+	if (ret < 0)
+		goto disable_clocks;
+
+	return 0;
+
+disable_clocks:
+	clk_bulk_disable_unprepare(priv->nclocks, priv->clocks);
+	return ret;
 }
 
 static const struct of_device_id rcar_pci_of_match[] = {
-- 
2.35.1