[PATCH 1/9] PCI: mvebu: move clock enable before register access

Sebastian Hesselbarth
2013-08-12T18:47:08Z

The clock passed to PCI controller found on MVEBU SoCs may come from a
clock gate. This requires the clock to be enabled before any registers
are accessed. Therefore, move the clock enable before register iomap to
ensure it is enabled.

Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
---
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-pci@vger.kernel.org
---
drivers/pci/host/pci-mvebu.c | 23 ++++++++++-------------
1 file changed, 10 insertions(+), 13 deletions(-)

diff --git a/drivers/pci/host/pci-mvebu.c b/drivers/pci/host/pci-mvebu.c
index 6aa0daf..d5fe674 100644
--- a/drivers/pci/host/pci-mvebu.c
+++ b/drivers/pci/host/pci-mvebu.c
@@ -897,6 +897,16 @@ static int __init mvebu_pcie_probe(struct platform_device *pdev)
continue;
}

+ port->clk = of_clk_get_by_name(child, NULL);
+ if (IS_ERR(port->clk)) {
+ dev_err(&pdev->dev, "PCIe%d.%d: cannot get clock\n",
+ port->port, port->lane);
+ iounmap(port->base);
+ port->haslink = 0;
+ continue;
+ }
+ clk_prepare_enable(port->clk);
+
port->base = mvebu_pcie_map_registers(pdev, child, port);
if (!port->base) {
dev_err(&pdev->dev, "PCIe%d.%d: cannot map registers\n",
@@ -916,22 +926,9 @@ static int __init mvebu_pcie_probe(struct platform_device *pdev)
port->port, port->lane);
}

- port->clk = of_clk_get_by_name(child, NULL);
- if (IS_ERR(port->clk)) {
- dev_err(&pdev->dev, "PCIe%d.%d: cannot get clock\n",
- port->port, port->lane);
- iounmap(port->base);
- port->haslink = 0;
- continue;
- }
-
port->dn = child;
-
- clk_prepare_enable(port->clk);
spin_lock_init(&port->conf_lock);
-
mvebu_sw_pci_bridge_init(port);
-
i++;
}

--
1.7.10.4