[PATCHi v2] net: sh_eth: Add support of device tree probe

Nobuhiro Iwamatsu nobuhiro.iwamatsu.yj at renesas.com
Mon Mar 18 11:53:30 EST 2013


Hi,

On Sat, Feb 16, 2013 at 1:32 AM, Mark Rutland <mark.rutland at arm.com> wrote:
> Hello,
>
> I have a couple of comments on the binding and the way it's parsed.

Thank you for your comment.

>
> On Thu, Feb 14, 2013 at 12:51:31AM +0000, Nobuhiro Iwamatsu wrote:
>> This adds support of device tree probe for Renesas sh-ether driver.
>>
>> Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj at renesas.com>
>>
>> ---
>> V2: - Removed ether_setup().
>>     - Fixed typo from "sh-etn" to "sh-eth".
>>       - Removed "needs-init" and sh-eth,endian from definition of DT.
>>       - Changed "sh-eth,edmac-endian" instead of "sh-eth,edmac-big-endain"
>>         in definition of DT.
>>
>>  Documentation/devicetree/bindings/net/sh_ether.txt |   41 +++++
>>  drivers/net/ethernet/renesas/sh_eth.c              |  156 +++++++++++++++++---
>>  2 files changed, 173 insertions(+), 24 deletions(-)
>>  create mode 100644 Documentation/devicetree/bindings/net/sh_ether.txt
>>
>> diff --git a/Documentation/devicetree/bindings/net/sh_ether.txt b/Documentation/devicetree/bindings/net/sh_ether.txt
>> new file mode 100644
>> index 0000000..7415e54
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/net/sh_ether.txt
>> @@ -0,0 +1,41 @@
>> +* Renesas Electronics SuperH EMAC
>> +
>> +This file provides information, what the device node
>> +for the sh_eth interface contains.
>> +
>> +Required properties:
>> +- compatible:                   "renesas,sh-eth";
>> +- interrupt-parent:             The phandle for the interrupt controller that
>> +                                services interrupts for this device.
>
> Is this really a required property?
>
> As it's a standard property with a well-defined meaning, is it necessary to
> document?

Yes, this is necessary.
CPU handled by this device has multiple interrupt controllers. It uses
the interrupt vector ID.
The interrupt controller may have the same vector id. This is
necessary in order to distinguish
between them.

>
>> +- reg:                          Offset and length of the register set for the
>> +                                device.
>
> The example below shows 2 reg values, yet this implies only one is necessary.

OK, I will add more infomation for first registger and 2nd register.

>
>> +- interrupts:                   Interrupt mapping for the sh_eth interrupt
>> +                                sources (vector id).
>
> How many interrupts are expected, what are they, and in what order should they be in?

This should contain sh-eth LAN interrupt line.
One value is set up. I will add these.

>
>> +- phy-mode:                     String, operation mode of the PHY interface.
>
> What are the valid values for this?

A string that of_get_phy_mode() can understand.
I will add more infomation.

>
> If they're defined in another document, it'd be good to reference it.
>
>> +- sh-eth,register-type:         String, register type of sh_eth.
>> +                                Please select "gigabit", "fast-sh4" or
>> +                                "fast-sh3-sh2".
>
> Why are these not handled as separate versions using the compatible string to
> differentiate them?

As you pointed, this line was removed and moved to using compatible string.

>
> [...]
>
>> +- sh-eth,phy-id:                PHY id.
>> +
>> +Optional properties:
>> +- local-mac-address:            6 bytes, mac address
>> +- sh-eth,no-ether-link:         Set link control by software. When device does
>> +                                not support ether-link, set.
>> +- sh-eth,ether-link-active-low: Set link check method.
>> +                                When detection of link is treated as active-low,
>> +                                set.
>> +- sh-eth,edmac-big-endian:      Set big endian for sh_eth dmac.
>> +                                It work as little endian when this is not set.
>> +- sh-etn,needs-init:            Initialization flag.
>> +                                When initialize device in probing device, set.
>> +
>> +Example (armadillo800eva):
>> +     sh-eth at e9a00000 {
>> +             compatible = "renesas,sh-eth";
>> +             interrupt-parent = <&intca>;
>> +             reg = <0xe9a00000 0x800>, <0xe9a01800 0x800>;
>> +             interrupts = <0x500>;
>> +             phy-mode = "mii";
>> +             sh-eth,register-type = "gigabit";
>> +             sh-eth,phy-id = <0>;
>> +     };
>> diff --git a/drivers/net/ethernet/renesas/sh_eth.c b/drivers/net/ethernet/renesas/sh_eth.c
>> index 3d70586..15e50b87 100644
>> --- a/drivers/net/ethernet/renesas/sh_eth.c
>> +++ b/drivers/net/ethernet/renesas/sh_eth.c
>> @@ -1,7 +1,7 @@
>>  /*
>>   *  SuperH Ethernet device driver
>>   *
>> - *  Copyright (C) 2006-2012 Nobuhiro Iwamatsu
>> + *  Copyright (C) 2006-2013 Nobuhiro Iwamatsu
>>   *  Copyright (C) 2008-2012 Renesas Solutions Corp.
>>   *
>>   *  This program is free software; you can redistribute it and/or modify it
>> @@ -31,6 +31,12 @@
>>  #include <linux/platform_device.h>
>>  #include <linux/mdio-bitbang.h>
>>  #include <linux/netdevice.h>
>> +#include <linux/of.h>
>> +#include <linux/of_device.h>
>> +#include <linux/of_platform.h>
>> +#include <linux/of_address.h>
>> +#include <linux/of_irq.h>
>> +#include <linux/of_net.h>
>>  #include <linux/phy.h>
>>  #include <linux/cache.h>
>>  #include <linux/io.h>
>> @@ -2347,26 +2353,109 @@ static const struct net_device_ops sh_eth_netdev_ops = {
>>       .ndo_change_mtu         = eth_change_mtu,
>>  };
>>
>> +#ifdef CONFIG_OF
>> +
>> +static int
>> +sh_eth_of_get_register_type(struct device_node *np)
>> +{
>> +     const char *of_str;
>> +     int ret = of_property_read_string(np, "sh-eth,register-type", &of_str);
>> +     if (ret)
>> +             return ret;
>> +
>> +     if (of_str && !strcmp(of_str, "gigabit"))
>> +             return SH_ETH_REG_GIGABIT;
>> +
>
> This line space between the if and the else should disappear.

OK, I will fix.

>
>> +     else if (of_str && !strcmp(of_str, "fast-sh4"))
>> +             return SH_ETH_REG_FAST_SH4;
>> +     else if (of_str && !strcmp(of_str, "fast-sh3-sh2"))
>> +             return SH_ETH_REG_FAST_SH3_SH2;
>> +     else
>> +             return -EINVAL;
>
> I think this block is better handled using a compatible string.

I see, I will fix and update document.

>
>> +}
>> +
>> +static struct sh_eth_plat_data *
>> +sh_eth_parse_dt(struct device *dev, struct net_device *ndev)
>> +{
>> +     int ret;
>> +     struct device_node *np = dev->of_node;
>> +     struct sh_eth_plat_data *pdata;
>> +
>> +     pdata = devm_kzalloc(dev, sizeof(struct sh_eth_plat_data),
>> +                                     GFP_KERNEL);
>> +     if (!pdata) {
>> +             dev_err(dev, "%s: failed to allocate config data\n", __func__);
>> +             return NULL;
>> +     }
>> +
>> +     pdata->phy_interface = of_get_phy_mode(np);
>> +
>> +     of_property_read_u32(np, "sh-eth,phy-id", &pdata->phy);
>
> No sanity checking required?
>
> Is there a maximum possible PHY id?
>

OK, I will add sanity checking.

>> +
>> +     if (of_find_property(np, "sh-eth,edmac-big-endian", NULL))
>> +             pdata->edmac_endian = EDMAC_BIG_ENDIAN;
>> +     else
>> +             pdata->edmac_endian = EDMAC_LITTLE_ENDIAN;
>
> You can use of_property_read_bool here.
>

OK, I will fix.

>> +
>> +     if (of_find_property(np, "sh-eth,no-ether-link", NULL))
>> +             pdata->no_ether_link = 1;
>> +     else
>> +             pdata->no_ether_link = 0;
>
> This can be:
>
> pdata->no_ether_link = of_property_read_bool(np, "sh-eth,no-ether-link");

OK, I will fix.

>
>> +
>> +     if (of_find_property(np, "sh-eth,ether-link-active-low", NULL))
>> +             pdata->ether_link_active_low = 1;
>> +     else
>> +             pdata->ether_link_active_low = 0;
>
> A similar thing can be done here.

and this too.

>
>> +
>> +     ret = sh_eth_of_get_register_type(np);
>> +     if (ret < 0)
>> +             goto error;
>> +     pdata->register_type = ret;
>
> This could be done using the compatible string and some auxdata.

OK, I will fix.

>
> [...]
>
> Thanks,
> Mark.
> _______________________________________________

Best regards,
  Nobuhiro



-- 
Nobuhiro Iwamatsu


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