flexcan: Prefer device tree clock frequency if available.
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 <holt@sgi.com>
Acked-by: Wolfgang Grandegger <wg@grandegger.com>,
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Marc Kleine-Budde <mkl@pengutronix.de>,
Cc: U Bhaskar-B22300 <B22300@freescale.com>
Cc: Scott Wood <scottwood@freescale.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: socketcan-core@lists.berlios.de,
Cc: netdev@vger.kernel.org,
Cc: PPC list <linuxppc-dev@lists.ozlabs.org>
Cc: devicetree-discuss@lists.ozlabs.org
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
index cc1e0a7..e023379 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"
@@ -925,16 +926,29 @@
struct net_device *dev;
struct flexcan_priv *priv;
struct resource *mem;
- struct clk *clk;
+ struct clk *clk = NULL;
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;
+
+ 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 +981,7 @@
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 +1016,8 @@
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 +1035,8 @@
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);