If our CAN device's device tree node has a clock-frequency property,
then use that value for the can devices clock frequency. If not, fall
back to asking the platform/mach code for the clock frequency associated
with the flexcan device.
Signed-off-by: Robin Holt <redacted>
To: Kumar Gala <redacted>
To: Wolfgang Grandegger <redacted>,
To: Marc Kleine-Budde <mkl@pengutronix.de>,
To: U Bhaskar-B22300 <redacted>
To: Scott Wood <redacted>
To: Grant Likely <redacted>
Cc: <redacted>,
Cc: <redacted>,
Cc: PPC list <redacted>
Cc: <redacted>
---
.../devicetree/bindings/net/can/fsl-flexcan.txt | 2 +
drivers/net/can/flexcan.c | 33 +++++++++++++++-----
2 files changed, 27 insertions(+), 8 deletions(-)
diff --git a/Documentation/devicetree/bindings/net/can/fsl-flexcan.txt b/Documentation/devicetree/bindings/net/can/fsl-flexcan.txt
index c78dcbb..a4382c7 100644
--- a/Documentation/devicetree/bindings/net/can/fsl-flexcan.txt
+++ b/Documentation/devicetree/bindings/net/can/fsl-flexcan.txt
@@ -11,6 +11,7 @@ Required properties:
- reg : Offset and length of the register set for this device
- interrupts : Interrupt tuple for this device
+- clock-frequency : The oscillator frequency driving the flexcan device
Example:
@@ -19,4 +20,5 @@ Example:
reg = <0x1c000 0x1000>;
interrupts = <48 0x2>;
interrupt-parent = <&mpic>;
+ clock-frequency = <0x0bebc1fc>;
};diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
index 662f832..d40c38e 100644
--- a/drivers/net/can/flexcan.c
+++ b/drivers/net/can/flexcan.c
@@ -33,6 +33,7 @@
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
+#include <linux/of.h>
#include <linux/platform_device.h>
#define DRV_NAME "flexcan"
@@ -929,12 +930,26 @@ static int __devinit flexcan_probe(struct platform_device *pdev)
void __iomem *base;
resource_size_t mem_size;
int err, irq;
+ u32 clock_freq = 0;
- clk = clk_get(&pdev->dev, NULL);
- if (IS_ERR(clk)) {
- dev_err(&pdev->dev, "no clock defined\n");
- err = PTR_ERR(clk);
- goto failed_clock;
+ if (pdev->dev.of_node) {
+ const u32 *clock_freq_p;
+
+ clk = NULL;
+ clock_freq_p = of_get_property(pdev->dev.of_node,
+ "clock-frequency", NULL);
+ if (clock_freq_p)
+ clock_freq = *clock_freq_p;
+ }
+
+ if (!clock_freq) {
+ clk = clk_get(&pdev->dev, NULL);
+ if (IS_ERR(clk)) {
+ dev_err(&pdev->dev, "no clock defined\n");
+ err = PTR_ERR(clk);
+ goto failed_clock;
+ }
+ clock_freq = clk_get_rate(clk);
}
mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);@@ -967,7 +982,7 @@ static int __devinit flexcan_probe(struct platform_device *pdev)
dev->flags |= IFF_ECHO; /* we support local echo in hardware */
priv = netdev_priv(dev);
- priv->can.clock.freq = clk_get_rate(clk);
+ priv->can.clock.freq = clock_freq;
priv->can.bittiming_const = &flexcan_bittiming_const;
priv->can.do_set_mode = flexcan_set_mode;
priv->can.do_get_berr_counter = flexcan_get_berr_counter;
@@ -1002,7 +1017,8 @@ static int __devinit flexcan_probe(struct platform_device *pdev)
failed_map:
release_mem_region(mem->start, mem_size);
failed_get:
- clk_put(clk);
+ if (clk)
+ clk_put(clk);
failed_clock:
return err;
}
@@ -1020,7 +1036,8 @@ static int __devexit flexcan_remove(struct platform_device *pdev)
mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
release_mem_region(mem->start, resource_size(mem));
- clk_put(priv->clk);
+ if (priv->clk)
+ clk_put(priv->clk);
free_candev(dev);
--
1.7.2.1