Re: [PATCH v7 3/3] can: Allwinner A10/A20 CAN Controller support - Kernel module

[Maxime Ripard]

On Tue, Sep 15, 2015 at 01:17:12AM +0200, Gerhard Bertelsmann wrote:
> Kernel module for Allwinner A10/A20 CAN
> 
> Signed-off-by: Gerhard Bertelsmann 
> ---
> 
>  drivers/net/can/Kconfig|  10 +
>  drivers/net/can/Makefile   |   1 +
>  drivers/net/can/sun4i_can.c| 857 
> +
>  3 files changed, 868 insertions(+)
> 
> 
> diff --git a/drivers/net/can/Kconfig b/drivers/net/can/Kconfig
> index e8c96b8..6d04183 100644
> --- a/drivers/net/can/Kconfig
> +++ b/drivers/net/can/Kconfig
> @@ -129,6 +129,16 @@ config CAN_RCAR
> To compile this driver as a module, choose M here: the module will
> be called rcar_can.
>  
> +config CAN_SUN4I
> + tristate "Allwinner A10 CAN controller"
> + depends on MACH_SUN4I || MACH_SUN7I || COMPILE_TEST
> + ---help---
> +   Say Y here if you want to use CAN controller found on Allwinner
> +   A10/A20 SoCs.
> +
> +   To compile this driver as a module, choose M here: the module will
> +   be called sun4i_can.
> +
>  config CAN_XILINXCAN
>   tristate "Xilinx CAN"
>   depends on ARCH_ZYNQ || ARM64 || MICROBLAZE || COMPILE_TEST
> diff --git a/drivers/net/can/Makefile b/drivers/net/can/Makefile
> index c533c62..1f21cef 100644
> --- a/drivers/net/can/Makefile
> +++ b/drivers/net/can/Makefile
> @@ -27,6 +27,7 @@ obj-$(CONFIG_CAN_FLEXCAN)   += flexcan.o
>  obj-$(CONFIG_PCH_CAN)+= pch_can.o
>  obj-$(CONFIG_CAN_GRCAN)  += grcan.o
>  obj-$(CONFIG_CAN_RCAR)   += rcar_can.o
> +obj-$(CONFIG_CAN_SUN4I)  += sun4i_can.o
>  obj-$(CONFIG_CAN_XILINXCAN)  += xilinx_can.o
>  
>  subdir-ccflags-y += -D__CHECK_ENDIAN__
> diff --git a/drivers/net/can/sun4i_can.c b/drivers/net/can/sun4i_can.c
> new file mode 100644
> index 000..8e32520
> --- /dev/null
> +++ b/drivers/net/can/sun4i_can.c
> @@ -0,0 +1,857 @@
> +/*
> + * sun4i_can.c - CAN bus controller driver for Allwinner SUN4I based 
> SoCs
> + *
> + * Copyright (C) 2013 Peter Chen
> + * Copyright (C) 2015 Gerhard Bertelsmann
> + * All rights reserved.
> + *
> + * Parts of this software are based on (derived from) the SJA1000 code by:
> + *   Copyright (C) 2014 Oliver Hartkopp 
> + *   Copyright (C) 2007 Wolfgang Grandegger 
> + *   Copyright (C) 2002-2007 Volkswagen Group Electronic Research
> + *   Copyright (C) 2003 Matthias Brukner, Trajet Gmbh, Rebenring 33,
> + *   38106 Braunschweig, GERMANY
> + *
> + * Redistribution and use in source and binary forms, with or without
> + * modification, are permitted provided that the following conditions
> + * are met:
> + * 1. Redistributions of source code must retain the above copyright
> + *notice, this list of conditions and the following disclaimer.
> + * 2. Redistributions in binary form must reproduce the above copyright
> + *notice, this list of conditions and the following disclaimer in the
> + *documentation and/or other materials provided with the distribution.
> + * 3. Neither the name of Volkswagen nor the names of its contributors
> + *may be used to endorse or promote products derived from this software
> + *without specific prior written permission.
> + *
> + * Alternatively, provided that this notice is retained in full, this
> + * software may be distributed under the terms of the GNU General
> + * Public License ("GPL") version 2, in which case the provisions of the
> + * GPL apply INSTEAD OF those given above.
> + *
> + * The provided data structures and external interfaces from this code
> + * are not restricted to be used by modules with a GPL compatible license.
> + *
> + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
> + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
> + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
> + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
> + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
> + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
> + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
> + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
> + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
> + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
> + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
> + * DAMAGE.
> + *
> + */
> +
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +#include 
> +
> +#define DRV_NAME "sun4i_can"
> +
> +/* Registers address (physical base address 0x01C2BC00) */
> +#define SUNXI_REG_MSEL_ADDR  0x  /* CAN Mode Select */
> +#define SUNXI_REG_CMD_ADDR   0x0004  /* CAN Command */
> 

Re: [PATCH v7 3/3] can: Allwinner A10/A20 CAN Controller support - Kernel module

[Marc Kleine-Budde]

On 09/15/2015 04:28 PM, Maxime Ripard wrote:
>> +static int sunxican_get_berr_counter(const struct net_device *dev,
>> + struct can_berr_counter *bec)
>> +{
>> +struct sunxican_priv *priv = netdev_priv(dev);
>> +u32 errors;
>> +int err;
>> +
>> +err = clk_prepare_enable(priv->clk);
>> +if (err) {
>> +netdev_err(dev, "could not enable clock\n");
>> +return err;
>> +}
> 
> Can this function be called if the device is closed? If not, then this
> clock calls are useless.

Yes, that's why there are there.

> 
>> +errors = readl(priv->base + SUNXI_REG_ERRC_ADDR);
>> +
>> +bec->txerr = errors & 0xFF;
>> +bec->rxerr = (errors >> 16) & 0xFF;
>> +
>> +clk_disable_unprepare(priv->clk);
>> +
>> +return 0;
>> +}

[...]

>> +static int sunxican_open(struct net_device *dev)
>> +{
>> +struct sunxican_priv *priv = netdev_priv(dev);
>> +int err;
>> +
>> +/* common open */
>> +err = open_candev(dev);
>> +if (err)
>> +return err;
>> +
>> +/* register interrupt handler */
>> +err = request_irq(dev->irq, sunxi_can_interrupt, IRQF_SHARED,
> 
> We don't have any shared interrupt as far as I know, do you really
> need this flag?

Not needed, but the IRQ handler properly returns HANDLED or NONE. So
it's better to remove this flag then?

> 
>> +  dev->name, dev);
>> +if (err) {
>> +netdev_err(dev, "request_irq err: %d\n", err);
>> +goto exit_irq;
>> +}
>> +
>> +/* turn on clocking for CAN peripheral block */
>> +err = clk_prepare_enable(priv->clk);
>> +if (err) {
>> +netdev_err(dev, "could not enable CAN peripheral clock\n");
>> +goto exit_clock;
>> +}
>> +
>> +err = sunxi_can_start(dev);
>> +if (err) {
>> +netdev_err(dev, "could not start CAN peripheral\n");
>> +goto exit_can_start;
>> +}
>> +
>> +can_led_event(dev, CAN_LED_EVENT_OPEN);
>> +netif_start_queue(dev);
>> +
>> +return 0;
>> +
>> +exit_can_start:
>> +clk_disable_unprepare(priv->clk);
>> +exit_clock:
>> +free_irq(dev->irq, dev);
>> +exit_irq:
>> +close_candev(dev);
>> +return err;
>> +}

Marc

-- 
Pengutronix e.K.  | Marc Kleine-Budde   |
Industrial Linux Solutions| Phone: +49-231-2826-924 |
Vertretung West/Dortmund  | Fax:   +49-5121-206917- |
Amtsgericht Hildesheim, HRA 2686  | http://www.pengutronix.de   |



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[PATCH v7 3/3] can: Allwinner A10/A20 CAN Controller support - Kernel module

[Gerhard Bertelsmann]

Kernel module for Allwinner A10/A20 CAN

Signed-off-by: Gerhard Bertelsmann 
---

 drivers/net/can/Kconfig|  10 +
 drivers/net/can/Makefile   |   1 +
 drivers/net/can/sun4i_can.c| 857 +
 3 files changed, 868 insertions(+)


diff --git a/drivers/net/can/Kconfig b/drivers/net/can/Kconfig
index e8c96b8..6d04183 100644
--- a/drivers/net/can/Kconfig
+++ b/drivers/net/can/Kconfig
@@ -129,6 +129,16 @@ config CAN_RCAR
  To compile this driver as a module, choose M here: the module will
  be called rcar_can.
 
+config CAN_SUN4I
+   tristate "Allwinner A10 CAN controller"
+   depends on MACH_SUN4I || MACH_SUN7I || COMPILE_TEST
+   ---help---
+ Say Y here if you want to use CAN controller found on Allwinner
+ A10/A20 SoCs.
+
+ To compile this driver as a module, choose M here: the module will
+ be called sun4i_can.
+
 config CAN_XILINXCAN
tristate "Xilinx CAN"
depends on ARCH_ZYNQ || ARM64 || MICROBLAZE || COMPILE_TEST
diff --git a/drivers/net/can/Makefile b/drivers/net/can/Makefile
index c533c62..1f21cef 100644
--- a/drivers/net/can/Makefile
+++ b/drivers/net/can/Makefile
@@ -27,6 +27,7 @@ obj-$(CONFIG_CAN_FLEXCAN) += flexcan.o
 obj-$(CONFIG_PCH_CAN)  += pch_can.o
 obj-$(CONFIG_CAN_GRCAN)+= grcan.o
 obj-$(CONFIG_CAN_RCAR) += rcar_can.o
+obj-$(CONFIG_CAN_SUN4I)+= sun4i_can.o
 obj-$(CONFIG_CAN_XILINXCAN)+= xilinx_can.o
 
 subdir-ccflags-y += -D__CHECK_ENDIAN__
diff --git a/drivers/net/can/sun4i_can.c b/drivers/net/can/sun4i_can.c
new file mode 100644
index 000..8e32520
--- /dev/null
+++ b/drivers/net/can/sun4i_can.c
@@ -0,0 +1,857 @@
+/*
+ * sun4i_can.c - CAN bus controller driver for Allwinner SUN4I based SoCs
+ *
+ * Copyright (C) 2013 Peter Chen
+ * Copyright (C) 2015 Gerhard Bertelsmann
+ * All rights reserved.
+ *
+ * Parts of this software are based on (derived from) the SJA1000 code by:
+ *   Copyright (C) 2014 Oliver Hartkopp 
+ *   Copyright (C) 2007 Wolfgang Grandegger 
+ *   Copyright (C) 2002-2007 Volkswagen Group Electronic Research
+ *   Copyright (C) 2003 Matthias Brukner, Trajet Gmbh, Rebenring 33,
+ *   38106 Braunschweig, GERMANY
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *notice, this list of conditions and the following disclaimer in the
+ *documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of Volkswagen nor the names of its contributors
+ *may be used to endorse or promote products derived from this software
+ *without specific prior written permission.
+ *
+ * Alternatively, provided that this notice is retained in full, this
+ * software may be distributed under the terms of the GNU General
+ * Public License ("GPL") version 2, in which case the provisions of the
+ * GPL apply INSTEAD OF those given above.
+ *
+ * The provided data structures and external interfaces from this code
+ * are not restricted to be used by modules with a GPL compatible license.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
+ * DAMAGE.
+ *
+ */
+
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+#include 
+
+#define DRV_NAME "sun4i_can"
+
+/* Registers address (physical base address 0x01C2BC00) */
+#define SUNXI_REG_MSEL_ADDR0x  /* CAN Mode Select */
+#define SUNXI_REG_CMD_ADDR 0x0004  /* CAN Command */
+#define SUNXI_REG_STA_ADDR 0x0008  /* CAN Status */
+#define SUNXI_REG_INT_ADDR 0x000c  /* CAN Interrupt Flag */
+#define SUNXI_REG_INTEN_ADDR   0x0010  /* CAN Interrupt Enable */
+#define SUNXI_REG_BTIME_ADDR   0x0014  /* CAN Bus Timing 0 */
+#define SUNXI_REG_TEWL_ADDR0x0018  /*