[PATCH 0/2] flexcan driver updates

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

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 <redacted>
---
 .../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

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 <redacted>
---
 .../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

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 [off-list ref]
M:	Rob Herring [off-list ref]
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 [off-list ref]
M:	Marc Kleine-Budde [off-list ref]
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

On 27 June 2012 00:55, Oliver Hartkopp [off-list ref] 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

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 <redacted>

Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>

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

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   |

On Wed, Jun 27, 2012 at 10:47:24AM +0200, Marc Kleine-Budde wrote:

On 06/26/2012 10:49 AM, Shawn Guo wrote:

quoted

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 <redacted>

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

On 06/27/2012 10:56 AM, Shawn Guo wrote:

On Wed, Jun 27, 2012 at 10:47:24AM +0200, Marc Kleine-Budde wrote:

quoted

On 06/26/2012 10:49 AM, Shawn Guo wrote:

quoted

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 <redacted>

Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>

Thanks.

quoted

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   |