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Commit 97efe9ae authored by holt@sgi.com's avatar holt@sgi.com Committed by David S. Miller
Browse files

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: default avatarRobin Holt <holt@sgi.com>
Acked-by: default avatarWolfgang Grandegger <wg@grandegger.com&gt;,>
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: default avatarDavid S. Miller <davem@davemloft.net>
parent c8aef4cb

Documentation/devicetree/bindings/net/can/fsl-flexcan.txt

+2 −0
Original line number Diff line number Diff line
@@ -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 = <200000000>; // filled in by bootloader

	};

drivers/net/can/flexcan.c

+25 −9
Original line number Diff line number Diff line
@@ -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"
@@ -925,17 +926,30 @@ static int __devinit flexcan_probe(struct platform_device *pdev) 
	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;



	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);

	irq = platform_get_irq(pdev, 0);
@@ -967,7 +981,7 @@ 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;
@@ -1002,6 +1016,7 @@ static int __devinit flexcan_probe(struct platform_device *pdev) 
 failed_map:

	release_mem_region(mem->start, mem_size);

 failed_get:

	if (clk)

		clk_put(clk);

 failed_clock:

	return err;
@@ -1020,6 +1035,7 @@ 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));



	if (priv->clk)

		clk_put(priv->clk);



	free_candev(dev);