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SubjectRe: [PATCH 2/4] net: hix5hd2_gmac: add reset control and clock signals
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Hi Rob,

On 2016/8/13 2:48, Rob Herring wrote:
> On Thu, Aug 11, 2016 at 05:01:53PM +0800, Dongpo Li wrote:
>> From: Li Dongpo <lidongpo@hisilicon.com>
>>
>> Add three reset control signals, "mac_core_rst", "mac_ifc_rst" and
>> "phy_rst".
>> The following diagram explained how the reset signals work.
>>
>> SoC
>> |-----------------------------------------------------
>> | ------ |
>> | | cpu | |
>> | ------ |
>> | | |
>> | ------------ AMBA bus |
>> | GMAC | |
>> | ---------------------- |
>> | ------------- mac_core_rst | -------------- | |
>> | |clock and |-------------->| mac core | | |
>> | |reset | | -------------- | |
>> | |generator |---- | | | |
>> | ------------- | | ---------------- | |
>> | | ---------->| mac interface | | |
>> | | mac_ifc_rst | ---------------- | |
>> | | | | | |
>> | | | ------------------ | |
>> | |phy_rst | | RGMII interface | | |
>> | | | ------------------ | |
>> | | ---------------------- |
>> |----------|------------------------------------------|
>> | |
>> | ----------
>> |--------------------- |PHY chip |
>> ----------
>>
>> The "mac_core_rst" represents "mac core reset signal", it resets
>> the mac core including packet processing unit, descriptor processing unit,
>> tx engine, rx engine, control unit.
>> The "mac_ifc_rst" represents "mac interface reset signal", it resets
>> the mac interface. The mac interface unit connects mac core and
>> data interface like MII/RMII/RGMII. After we set a new value of
>> interface mode, we must reset mac interface to reload the new mode value.
>> The "phy_rst" represents "phy reset signal", it does a hardware reset
>> on the PHY chip. This reset signal is optinal if the PHY can work well
>> without the hardware reset.
>>
>> Add one more clock signal, the existing is MAC core clock,
>> and the new one is MAC interface clock.
>>
>> Signed-off-by: Dongpo Li <lidongpo@hisilicon.com>
>> ---
>> .../bindings/net/hisilicon-hix5hd2-gmac.txt | 16 ++-
>> drivers/net/ethernet/hisilicon/hix5hd2_gmac.c | 140 +++++++++++++++++++--
>> 2 files changed, 143 insertions(+), 13 deletions(-)
>
>
>>
>> @@ -807,16 +829,26 @@ static int hix5hd2_net_open(struct net_device *dev)
>> struct phy_device *phy;
>> int ret;
>>
>> - ret = clk_prepare_enable(priv->clk);
>> + ret = clk_prepare_enable(priv->mac_core_clk);
>> + if (ret < 0) {
>> + netdev_err(dev, "failed to enable mac core clk %d\n", ret);
>> + return ret;
>> + }
>> +
>> + ret = clk_prepare_enable(priv->mac_ifc_clk);
>> if (ret < 0) {
>> - netdev_err(dev, "failed to enable clk %d\n", ret);
>> + clk_disable_unprepare(priv->mac_core_clk);
>> + netdev_err(dev, "failed to enable mac ifc clk %d\n", ret);
>
> This change will break with existing DTs. The mac_ifc_clk should be
> optional.
>
The mac_ifc_clk has existed in the existing hix5hd2. It's not implemented in the MAC driver
because the CLOCK driver implements a "complex" ethernet clock type.
So [PATCH 3/4] and [PATCH 4/4] are following this patch to change the CLOCK driver and existing DTs
at the same time.

> Rob
>
>> return ret;
>> }
>
> .
>


Regards,
Dongpo

.

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