[PATCH v2 1/8] PCI: rcar-gen2: Add support for clocks

Herve Codina
2022-04-14T07:42:39Z

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