[PATCH] net: zynq: Add support for GEM reset

[Michal Simek]

On 11/21/21 20:12, Ramon Fried wrote:
> On Thu, Nov 18, 2021 at 2:08 PM Michal Simek <michal.simek at xilinx.com> wrote:
>>
>> Perform reset before core initialization.
> Does it fix any apparent issue ? How did it work before that ?

Standard flow which I would say close to 99% users are using getting all 
IPs out of reset that there is no need to reset IP again. This is 
because of all low level initialization is done in previous bootloader 
stage.
In SOM case which we are working on these IPs are not touched by 
previous bootloader stage that's why reset needs to be called before IP 
is accessed to make sure that it is in correct state.

Thanks,
Michal


>>
>> Signed-off-by: Michal Simek <michal.simek at xilinx.com>
>> ---
>>
>>   drivers/net/zynq_gem.c | 26 ++++++++++++++++++++++++++
>>   1 file changed, 26 insertions(+)
>>
>> diff --git a/drivers/net/zynq_gem.c b/drivers/net/zynq_gem.c
>> index 91957757727d..5cbe8d28304b 100644
>> --- a/drivers/net/zynq_gem.c
>> +++ b/drivers/net/zynq_gem.c
>> @@ -21,6 +21,7 @@
>>   #include <asm/cache.h>
>>   #include <asm/io.h>
>>   #include <phy.h>
>> +#include <reset.h>
>>   #include <miiphy.h>
>>   #include <wait_bit.h>
>>   #include <watchdog.h>
>> @@ -217,6 +218,7 @@ struct zynq_gem_priv {
>>          bool int_pcs;
>>          bool dma_64bit;
>>          u32 clk_en_info;
>> +       struct reset_ctl_bulk resets;
>>   };
>>
>>   static int phy_setup_op(struct zynq_gem_priv *priv, u32 phy_addr, u32 regnum,
>> @@ -688,12 +690,36 @@ static int zynq_gem_miiphy_write(struct mii_dev *bus, int addr, int devad,
>>          return phywrite(priv, addr, reg, value);
>>   }
>>
>> +static int zynq_gem_reset_init(struct udevice *dev)
>> +{
>> +       struct zynq_gem_priv *priv = dev_get_priv(dev);
>> +       int ret;
>> +
>> +       ret = reset_get_bulk(dev, &priv->resets);
>> +       if (ret == -ENOTSUPP || ret == -ENOENT)
>> +               return 0;
>> +       else if (ret)
>> +               return ret;
>> +
>> +       ret = reset_deassert_bulk(&priv->resets);
>> +       if (ret) {
>> +               reset_release_bulk(&priv->resets);
>> +               return ret;
>> +       }
>> +
>> +       return 0;
>> +}
>> +
>>   static int zynq_gem_probe(struct udevice *dev)
>>   {
>>          void *bd_space;
>>          struct zynq_gem_priv *priv = dev_get_priv(dev);
>>          int ret;
>>
>> +       ret = zynq_gem_reset_init(dev);
>> +       if (ret)
>> +               return ret;
>> +
>>          /* Align rxbuffers to ARCH_DMA_MINALIGN */
>>          priv->rxbuffers = memalign(ARCH_DMA_MINALIGN, RX_BUF * PKTSIZE_ALIGN);
>>          if (!priv->rxbuffers)
>> --
>> 2.33.1
>>