[PATCH 0/2] flexcan driver updates

[PATCH 0/2] flexcan driver updates

[Shawn Guo]

Here are a couple of flexcan driver/bindings updates, which are meant
to get the driver more device tree friendly.

Shawn Guo (2):
  net: flexcan: clock-frequency is optional for device tree probe
  net: flexcan: add transceiver switch gpio support

 .../devicetree/bindings/net/can/fsl-flexcan.txt    |    6 ++++
 drivers/net/can/flexcan.c                          |   30 ++++++++++++++++++++
 2 files changed, 36 insertions(+), 0 deletions(-)

-- 
1.7.5.4

[PATCH 1/2] net: flexcan: clock-frequency is optional for device tree probe

[Shawn Guo]

The property clock-frequency is optional for device tree probe.  When
it's absent, the flexcan driver will try to get the frequency from clk
system by calling clk_get_rate.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
---
 .../devicetree/bindings/net/can/fsl-flexcan.txt    |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/Documentation/devicetree/bindings/net/can/fsl-flexcan.txt b/Documentation/devicetree/bindings/net/can/fsl-flexcan.txt
index f31b686..8ff324e 100644
--- a/Documentation/devicetree/bindings/net/can/fsl-flexcan.txt
+++ b/Documentation/devicetree/bindings/net/can/fsl-flexcan.txt
@@ -11,6 +11,9 @@ Required properties:
 
 - reg : Offset and length of the register set for this device
 - interrupts : Interrupt tuple for this device
+
+Optional properties:
+
 - clock-frequency : The oscillator frequency driving the flexcan device
 
 Example:
-- 
1.7.5.4

Re: [PATCH 1/2] net: flexcan: clock-frequency is optional for device tree probe

[Marc Kleine-Budde]

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On 06/26/2012 10:49 AM, Shawn Guo wrote:
> The property clock-frequency is optional for device tree probe.  When
> it's absent, the flexcan driver will try to get the frequency from clk
> system by calling clk_get_rate.
> 
> Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>

As Oliver pointed out, this doesn't go through the net tree.

Marc

> ---
>  .../devicetree/bindings/net/can/fsl-flexcan.txt    |    3 +++
>  1 files changed, 3 insertions(+), 0 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/net/can/fsl-flexcan.txt b/Documentation/devicetree/bindings/net/can/fsl-flexcan.txt
> index f31b686..8ff324e 100644
> --- a/Documentation/devicetree/bindings/net/can/fsl-flexcan.txt
> +++ b/Documentation/devicetree/bindings/net/can/fsl-flexcan.txt
> @@ -11,6 +11,9 @@ Required properties:
>  
>  - reg : Offset and length of the register set for this device
>  - interrupts : Interrupt tuple for this device
> +
> +Optional properties:
> +
>  - clock-frequency : The oscillator frequency driving the flexcan device
>  
>  Example:


-- 
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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Re: [PATCH 1/2] net: flexcan: clock-frequency is optional for device tree probe

[Shawn Guo]

On Wed, Jun 27, 2012 at 10:47:24AM +0200, Marc Kleine-Budde wrote:
> On 06/26/2012 10:49 AM, Shawn Guo wrote:
> > The property clock-frequency is optional for device tree probe.  When
> > it's absent, the flexcan driver will try to get the frequency from clk
> > system by calling clk_get_rate.
> > 
> > Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
> Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>

Thanks.

> 
> As Oliver pointed out, this doesn't go through the net tree.
> 
>From what I have seen, device tree maintainers are generally fine with
having binding document updates go through subsystem tree.

-- 
Regards,
Shawn

Re: [PATCH 1/2] net: flexcan: clock-frequency is optional for device tree probe

[Marc Kleine-Budde]

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On 06/27/2012 10:56 AM, Shawn Guo wrote:
> On Wed, Jun 27, 2012 at 10:47:24AM +0200, Marc Kleine-Budde wrote:
>> On 06/26/2012 10:49 AM, Shawn Guo wrote:
>>> The property clock-frequency is optional for device tree probe.  When
>>> it's absent, the flexcan driver will try to get the frequency from clk
>>> system by calling clk_get_rate.
>>>
>>> Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
>> Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
> 
> Thanks.
> 
>>
>> As Oliver pointed out, this doesn't go through the net tree.
>>
> From what I have seen, device tree maintainers are generally fine with
> having binding document updates go through subsystem tree.

Okay. Then I'll take that patch.

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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[PATCH 2/2] net: flexcan: add transceiver switch gpio support

[Shawn Guo]

The flexcan driver has function pointer transceiver_switch defined in
flexcan_platform_data for platform codes to hook up their transceiver
switch implementation.  However this does not cope with device tree
probe.

It's been observed that platforms mostly use gpio to control the
switch of flexcan transceiver.  The patch adds transceiver switch gpio
support into flexcan driver, so that platforms that have transceiver
switch controlled by gpio can just define property transceiver-switch-gpios
in their device tree, and then device tree boot just works with it.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
---
 .../devicetree/bindings/net/can/fsl-flexcan.txt    |    3 ++
 drivers/net/can/flexcan.c                          |   30 ++++++++++++++++++++
 2 files changed, 33 insertions(+), 0 deletions(-)

diff --git a/Documentation/devicetree/bindings/net/can/fsl-flexcan.txt b/Documentation/devicetree/bindings/net/can/fsl-flexcan.txt
index 8ff324e..5ca91d1 100644
--- a/Documentation/devicetree/bindings/net/can/fsl-flexcan.txt
+++ b/Documentation/devicetree/bindings/net/can/fsl-flexcan.txt
@@ -15,6 +15,9 @@ Required properties:
 Optional properties:
 
 - clock-frequency : The oscillator frequency driving the flexcan device
+- transceiver-switch-gpios : Should specify the gpio for transceiver switch
+- enable-active-low : Polarity of transceiver switch gpio is active low.
+  If this property is missing, the default assumed is active high.
 
 Example:
 
diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c
index 38c0690..bc47595 100644
--- a/drivers/net/can/flexcan.c
+++ b/drivers/net/can/flexcan.c
@@ -26,6 +26,7 @@
 #include <linux/can/platform/flexcan.h>
 #include <linux/clk.h>
 #include <linux/delay.h>
+#include <linux/gpio.h>
 #include <linux/if_arp.h>
 #include <linux/if_ether.h>
 #include <linux/interrupt.h>
@@ -34,6 +35,7 @@
 #include <linux/list.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/of_gpio.h>
 #include <linux/platform_device.h>
 #include <linux/pinctrl/consumer.h>
 
@@ -180,6 +182,9 @@ struct flexcan_priv {
 
 	struct clk *clk;
 	struct flexcan_platform_data *pdata;
+
+	int switch_gpio;
+	bool enable_high;
 };
 
 static struct can_bittiming_const flexcan_bittiming_const = {
@@ -224,6 +229,9 @@ static inline void flexcan_write(u32 val, void __iomem *addr)
  */
 static void flexcan_transceiver_switch(const struct flexcan_priv *priv, int on)
 {
+	if (gpio_is_valid(priv->switch_gpio))
+		gpio_set_value(priv->switch_gpio, priv->enable_high ? on : !on);
+
 	if (priv->pdata && priv->pdata->transceiver_switch)
 		priv->pdata->transceiver_switch(on);
 }
@@ -933,6 +941,8 @@ static int __devinit flexcan_probe(struct platform_device *pdev)
 	resource_size_t mem_size;
 	int err, irq;
 	u32 clock_freq = 0;
+	int switch_gpio = -EINVAL;
+	bool enable_high = true;
 
 	pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
 	if (IS_ERR(pinctrl))
@@ -945,6 +955,23 @@ static int __devinit flexcan_probe(struct platform_device *pdev)
 						"clock-frequency", NULL);
 		if (clock_freq_p)
 			clock_freq = *clock_freq_p;
+
+		switch_gpio = of_get_named_gpio(pdev->dev.of_node,
+						"transceiver-switch-gpios", 0);
+		if (gpio_is_valid(switch_gpio)) {
+			err = gpio_request_one(switch_gpio, GPIOF_DIR_OUT,
+					       "transceiver-switch");
+			if (err) {
+				dev_err(&pdev->dev,
+					"failed to request gpio %d: %d\n",
+					switch_gpio, err);
+				goto failed_gpio;
+			}
+
+			if (of_get_property(pdev->dev.of_node,
+					    "enable-active-low", NULL))
+				enable_high = false;
+		}
 	}
 
 	if (!clock_freq) {
@@ -997,6 +1024,8 @@ static int __devinit flexcan_probe(struct platform_device *pdev)
 	priv->base = base;
 	priv->dev = dev;
 	priv->clk = clk;
+	priv->switch_gpio = switch_gpio;
+	priv->enable_high = enable_high;
 	priv->pdata = pdev->dev.platform_data;
 
 	netif_napi_add(dev, &priv->napi, flexcan_poll, FLEXCAN_NAPI_WEIGHT);
@@ -1025,6 +1054,7 @@ static int __devinit flexcan_probe(struct platform_device *pdev)
 	if (clk)
 		clk_put(clk);
  failed_clock:
+ failed_gpio:
 	return err;
 }
 
-- 
1.7.5.4

Re: [PATCH 0/2] flexcan driver updates

[Oliver Hartkopp]

On 26.06.2012 10:49, Shawn Guo wrote:

> Here are a couple of flexcan driver/bindings updates, which are meant
> to get the driver more device tree friendly.
> 
> Shawn Guo (2):
>   net: flexcan: clock-frequency is optional for device tree probe
>   net: flexcan: add transceiver switch gpio support
> 
>  .../devicetree/bindings/net/can/fsl-flexcan.txt    |    6 ++++
>  drivers/net/can/flexcan.c                          |   30 ++++++++++++++++++++
>  2 files changed, 36 insertions(+), 0 deletions(-)
> 


Sorry Shawn, but your posting is pretty misplaced ...

Please check for the maintainers and mailing lists in the MAINTAINERS file
that match your suggested changes:

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

OPEN FIRMWARE AND FLATTENED DEVICE TREE
M:	Grant Likely <grant.likely@secretlab.ca>
M:	Rob Herring <rob.herring@calxeda.com>
L:	devicetree-discuss@lists.ozlabs.org (moderated for non-subscribers)
W:	http://fdt.secretlab.ca
T:	git git://git.secretlab.ca/git/linux-2.6.git
S:	Maintained
F:	Documentation/devicetree		<<<<<------------- !!!
F:	drivers/of
F:	include/linux/of*.h
K:	of_get_property
K:	of_match_table


drivers/net/can/flexcan.c =>

CAN NETWORK DRIVERS
M:	Wolfgang Grandegger <wg@grandegger.com>
M:	Marc Kleine-Budde <mkl@pengutronix.de>
L:	linux-can@vger.kernel.org
W:	http://gitorious.org/linux-can
T:	git git://gitorious.org/linux-can/linux-can-next.git
S:	Maintained
F:	drivers/net/can/			<<<<<------------- !!!
F:	include/linux/can/dev.h
F:	include/linux/can/error.h
F:	include/linux/can/netlink.h
F:	include/linux/can/platform/

So please post your suggested changes for the flexcan driver on the mailing
lists linux-can@vger.kernel.org and devicetree-discuss@lists.ozlabs.org

Once the changes are discussed and accepted they can be pulled by Dave Miller
from the CAN development git repository into the networking tree.

Thanks,
Oliver

Re: [PATCH 0/2] flexcan driver updates

[Shawn Guo]

On 27 June 2012 00:55, Oliver Hartkopp <socketcan@hartkopp.net> wrote:
> So please post your suggested changes for the flexcan driver on the mailing
> lists linux-can@vger.kernel.org and devicetree-discuss@lists.ozlabs.org
>
Yes, you are right.  Will resend.  Thanks.

Regards,
Shawn