Re: [PATCH net-next v5 03/14] net: ethernet: qualcomm: Add PPE driver for IPQ9574 SoC

[Luo Jie]

On 6/28/2025 12:21 AM, Konrad Dybcio wrote:
> On 6/26/25 4:31 PM, Luo Jie wrote:
> > The PPE (Packet Process Engine) hardware block is available on Qualcomm
> > IPQ SoC that support PPE architecture, such as IPQ9574.
> >
> > The PPE in IPQ9574 includes six integrated ethernet MAC for 6 PPE ports,
> > buffer management, queue management and scheduler functions. The MACs
> > can connect with the external PHY or switch devices using the UNIPHY PCS
> > block available in the SoC.
> >
> > The PPE also includes various packet processing offload capabilities
> > such as L3 routing and L2 bridging, VLAN and tunnel processing offload.
> > It also includes Ethernet DMA function for transferring packets between
> > ARM cores and PPE ethernet ports.
> >
> > This patch adds the base source files and Makefiles for the PPE driver
> > such as platform driver registration, clock initialization, and PPE
> > reset routines.
> >
> > Signed-off-by: Luo Jie <quic_luoj@xxxxxxxxxxx>
> > ---
>
> [...]
>
> > +static int ppe_clock_init_and_reset(struct ppe_device *ppe_dev)
> > +{
> > +	unsigned long ppe_rate = ppe_dev->clk_rate;
> > +	struct device *dev = ppe_dev->dev;
> > +	struct reset_control *rstc;
> > +	struct clk_bulk_data *clks;
> > +	struct clk *clk;
> > +	int ret, i;
> > +
> > +	for (i = 0; i < ppe_dev->num_icc_paths; i++) {
> > +		ppe_dev->icc_paths[i].name = ppe_icc_data[i].name;
> > +		ppe_dev->icc_paths[i].avg_bw = ppe_icc_data[i].avg_bw ? :
> > +					       Bps_to_icc(ppe_rate);
> > +		ppe_dev->icc_paths[i].peak_bw = ppe_icc_data[i].peak_bw ? :
> > +						Bps_to_icc(ppe_rate);
> > +	}
>
> Can you not just set ppe_dev->icc_paths to ppe_icc_data?
>
> Konrad

The `avg_bw` and `peak_bw` for two of the PPE ICC clocks ('ppe' and
'ppe_cfg') vary across different SoCs and they need to be read from
platform data. They are not pre-defined in `ppe_icc_data` array.
Therefore, we use this format to assign `icc_paths`, allowing us to
accommodate cases where `avg_bw` and `peak_bw` are not predefined.
Hope this is fine. Thanks.