Subject: Re: [PATCH v2 net-next] net: ethernet: enc28j60: add device tree support

From: Michael Heimpold <[email-masked]>
Date: Mon, 25 Apr 2016 19:46:53 +0200

Hi,

Am Monday 25 April 2016, 10:39:41 schrieben Sie:
> On 04/24/2016 04:28 PM, Michael Heimpold wrote:
> > The following patch adds the required match table for device tree support
> > (and while at, fix the indent). It's also possible to specify the
> > MAC address in the DT blob.
> > 
> > Also add the corresponding binding documentation file.
> > 
> > Signed-off-by: Michael Heimpold <[email-masked]>
> > ---
> > 
> > v2: * took care of Arnd Bergmann's review comments
> > 
> >       - allow to specify MAC address via DT
> >       - unconditionally define DT id table
> >     
> >     * increased the driver version minor number
> >     * driver author's email address bounces, removed from address list
> >  
> >  .../devicetree/bindings/net/microchip-enc28j60.txt | 50
> >  ++++++++++++++++++++++ drivers/net/ethernet/microchip/enc28j60.c        
> >   | 20 +++++++--
> >  2 files changed, 67 insertions(+), 3 deletions(-)
> >  create mode 100644
> >  Documentation/devicetree/bindings/net/microchip-enc28j60.txt> 
> > diff --git a/Documentation/devicetree/bindings/net/microchip-enc28j60.txt
> > b/Documentation/devicetree/bindings/net/microchip-enc28j60.txt new file
> > mode 100644
> > index 0000000..847a97b
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/net/microchip-enc28j60.txt
> > @@ -0,0 +1,50 @@
> > +* Microchip ENC28J60
> > +
> > +This is a standalone 10 MBit ethernet controller with SPI interface.
> > +
> > +For each device connected to a SPI bus, define a child node within
> > +the SPI master node.
> > +
> > +Required properties:
> > +- compatible: Should be "microchip,enc28j60"
> > +- reg: Specify the SPI chip select the ENC28J60 is wired to
> > +- interrupts: Specify the interrupt and interrupt type (usually falling
> > edge) +
> > +Optional properties:
> > +- interrupt-parent: Specify the pHandle of the source interrupt
> > +- spi-max-frequency: Maximum frequency of the SPI bus when accessing the
> > ENC28J60. +  According to the ENC28J80 datasheet, the chip allows a
> > maximum of 20 MHz, however, +  board designs may need to limit this
> > value.
> > +- local-mac-address: See ethernet.txt in the same directory.
> > +
> > +
> > +Example (for NXP i.MX28 with pin control stuff for GPIO irq):
> > +
> > +        ssp2: ssp@80014000 {
> > +                compatible = "fsl,imx28-spi";
> > +                pinctrl-names = "default";
> > +                pinctrl-0 = <&spi2_pins_b &spi2_sck_cfg>;
> > +                status = "okay";
> > +
> > +                enc28j60: ethernet@0 {
> > +                        compatible = "microchip,enc28j60";
> > +                        pinctrl-names = "default";
> > +                        pinctrl-0 = <&enc28j60_pins>;
> > +                        reg = <0>;
> > +                        interrupt-parent = <&gpio3>;
> > +                        interrupts = <3 IRQ_TYPE_EDGE_FALLING>;
> > +                        spi-max-frequency = <12000000>;
> > +                };
> > +        };
> > +
> > +        pinctrl@80018000 {
> > +                enc28j60_pins: enc28j60_pins@0 {
> > +                        reg = <0>;
> > +                        fsl,pinmux-ids = <
> > +                                MX28_PAD_AUART0_RTS__GPIO_3_3    /*
> > Interrupt */ +                        >;
> > +                        fsl,drive-strength = <MXS_DRIVE_4mA>;
> > +                        fsl,voltage = <MXS_VOLTAGE_HIGH>;
> > +                        fsl,pull-up = <MXS_PULL_DISABLE>;
> > +                };
> > +        };
> > diff --git a/drivers/net/ethernet/microchip/enc28j60.c
> > b/drivers/net/ethernet/microchip/enc28j60.c index b723622..7066954 100644
> > --- a/drivers/net/ethernet/microchip/enc28j60.c
> > +++ b/drivers/net/ethernet/microchip/enc28j60.c
> > @@ -28,11 +28,12 @@
> > 
> >  #include <linux/skbuff.h>
> >  #include <linux/delay.h>
> >  #include <linux/spi/spi.h>
> > 
> > +#include <linux/of_net.h>
> > 
> >  #include "enc28j60_hw.h"
> >  
> >  #define DRV_NAME	"enc28j60"
> > 
> > -#define DRV_VERSION	"1.01"
> > +#define DRV_VERSION	"1.02"
> > 
> >  #define SPI_OPLEN	1
> > 
> > @@ -1548,6 +1549,7 @@ static int enc28j60_probe(struct spi_device *spi)
> > 
> >  {
> >  
> >  	struct net_device *dev;
> >  	struct enc28j60_net *priv;
> > 
> > +	const void *macaddr;
> > 
> >  	int ret = 0;
> >  	
> >  	if (netif_msg_drv(&debug))
> > 
> > @@ -1579,7 +1581,12 @@ static int enc28j60_probe(struct spi_device *spi)
> > 
> >  		ret = -EIO;
> >  		goto error_irq;
> >  	
> >  	}
> > 
> > -	eth_hw_addr_random(dev);
> > +
> > +	macaddr = of_get_mac_address(spi->dev.of_node);
> > +	if (macaddr)
> 
> You should also check if it is a valid MAC for Ethernet, recommend:
> 
> if (macaddr && is_valid_ether_addr(macaddr))
> 

But of_get_mac_address already takes care of this, see
http://lxr.free-electrons.com/source/drivers/of/of_net.c#L45
Also it already checks whether spi->dev.of_node is populated at all.
It returns NULL in both error cases.
So I prefered to omit both test here.

Regards,
Michael

> > +		ether_addr_copy(dev->dev_addr, macaddr);
> > +	else
> > +		eth_hw_addr_random(dev);
> > 
> >  	enc28j60_set_hw_macaddr(dev);
> >  	
> >  	/* Board setup must set the relevant edge trigger type;
> > 
> > @@ -1634,9 +1641,16 @@ static int enc28j60_remove(struct spi_device *spi)
> > 
> >  	return 0;
> >  
> >  }
> > 
> > +static const struct of_device_id enc28j60_dt_ids[] = {
> > +	{ .compatible = "microchip,enc28j60" },
> > +	{ /* sentinel */ }
> > +};
> > +MODULE_DEVICE_TABLE(of, enc28j60_dt_ids);
> > +
> > 
> >  static struct spi_driver enc28j60_driver = {
> >  
> >  	.driver = {
> > 
> > -		   .name = DRV_NAME,
> > +		.name = DRV_NAME,
> > +		.of_match_table = enc28j60_dt_ids,
> > 
> >  	 },
> >  	
> >  	.probe = enc28j60_probe,
> >  	.remove = enc28j60_remove,