From: Marc Kleine-Budde <mkl-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
To: Robin Holt <holt-sJ/iWh9BUns@public.gmane.org>
Cc: socketcan-core-0fE9KPoRgkgATYTw5x5z8w@public.gmane.org,
netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org,
U Bhaskar-B22300 <B22300-KZfg59tc24xl57MIdRCFDg@public.gmane.org>,
Kumar Gala
<galak-XVmvHMARGAS8U2dJNN8I7kB+6BGkLq7r@public.gmane.org>,
Grant Likely
<grant.likely-s3s/WqlpOiPyB63q8FvJNQ@public.gmane.org>,
Scott Wood <scottwood-KZfg59tc24xl57MIdRCFDg@public.gmane.org>,
PPC list <linuxppc-dev-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org>,
Wolfgang Grandegger <wg-5Yr1BZd7O62+XT7JhA+gdA@public.gmane.org>
Subject: Re: [PATCH v11 5/6] flexcan: Prefer device tree clock frequency if available.
Date: Thu, 11 Aug 2011 18:18:20 +0200 [thread overview]
Message-ID: <4E4400CC.3020704@pengutronix.de> (raw)
In-Reply-To: <1313078831-2511-6-git-send-email-holt-sJ/iWh9BUns@public.gmane.org>
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On 08/11/2011 06:07 PM, Robin Holt wrote:
> 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.
nitpicking follows inline:
> Signed-off-by: Robin Holt <holt-sJ/iWh9BUns@public.gmane.org>
> To: Kumar Gala <galak-XVmvHMARGAS8U2dJNN8I7kB+6BGkLq7r@public.gmane.org>
> To: Wolfgang Grandegger <wg-5Yr1BZd7O62+XT7JhA+gdA@public.gmane.org>,
> To: Marc Kleine-Budde <mkl-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>,
> To: U Bhaskar-B22300 <B22300-KZfg59tc24xl57MIdRCFDg@public.gmane.org>
> To: Scott Wood <scottwood-KZfg59tc24xl57MIdRCFDg@public.gmane.org>
> To: Grant Likely <grant.likely-s3s/WqlpOiPyB63q8FvJNQ@public.gmane.org>
> Cc: socketcan-core-0fE9KPoRgkgATYTw5x5z8w@public.gmane.org,
> Cc: netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
> Cc: PPC list <linuxppc-dev-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org>
> Cc: devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org
> ---
> .../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>;
Does the device tree support dec coded integers? IMHO a frequency is
best expressed in decimal.
> };
> 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;
Hmmm - what about moving the clk = NULL into the definition of clk?
> + 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);
>
Marc
--
Pengutronix e.K. | Marc Kleine-Budde |
Industrial Linux Solutions | Phone: +49-231-2826-924 |
Vertretung West/Dortmund | Fax: +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de |
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next prev parent reply other threads:[~2011-08-11 16:18 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-08-11 16:07 [PATCH v12 0/6] flexcan/powerpc: Add support for powerpc flexcan (freescale p1010) Robin Holt
[not found] ` <1313078831-2511-1-git-send-email-holt-sJ/iWh9BUns@public.gmane.org>
2011-08-11 16:07 ` [PATCH v11 1/6] flexcan: Remove #include <mach/clock.h> Robin Holt
2011-08-11 16:07 ` [PATCH v11 2/6] flexcan: Abstract off read/write for big/little endian Robin Holt
2011-08-11 16:07 ` [PATCH v11 3/6] flexcan: Fix up fsl-flexcan device tree binding Robin Holt
2011-08-11 16:53 ` Grant Likely
[not found] ` <CACxGe6vA8K7fhrSvBpKC+9aKftUc2+1EAUQ=A0SmmwzJ2Le=9A-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2011-08-12 8:28 ` Robin Holt
2011-08-11 16:07 ` [PATCH v11 4/6] flexcan: Add of_match to platform_device definition Robin Holt
2011-08-11 16:07 ` [PATCH v11 6/6] powerpc: Add flexcan device support for p1010rdb Robin Holt
[not found] ` <1313078831-2511-7-git-send-email-holt-sJ/iWh9BUns@public.gmane.org>
2011-08-11 16:35 ` Wolfgang Grandegger
[not found] ` <4E4404BC.7060502-5Yr1BZd7O62+XT7JhA+gdA@public.gmane.org>
2011-08-11 16:48 ` Robin Holt
2011-08-11 17:41 ` Kumar Gala
[not found] ` <9C81E6C0-D278-40BF-8F32-445F870F845A-XVmvHMARGAS8U2dJNN8I7kB+6BGkLq7r@public.gmane.org>
2011-08-11 18:12 ` Robin Holt
2011-08-11 16:07 ` [PATCH v11 5/6] flexcan: Prefer device tree clock frequency if available Robin Holt
[not found] ` <1313078831-2511-6-git-send-email-holt-sJ/iWh9BUns@public.gmane.org>
2011-08-11 16:18 ` Marc Kleine-Budde [this message]
[not found] ` <4E4400CC.3020704-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
2011-08-11 17:40 ` Kumar Gala
2011-08-11 16:35 ` Wolfgang Grandegger
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