[PATCH 11/12] net: macb: add SiFive support

[Sascha Hauer]

On Tue, Apr 27, 2021 at 10:23:08PM +0200, Ahmad Fatoum wrote:
> The Ethernet controller on the SiFive SoCs needs some special TX clock
> setup. Port the relevant Linux v5.12 bits to enable it.
> 
> Tested on qemu-system-riscv64 -M sifive_u with dhcp.
> 
> Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
> ---
>  drivers/net/macb.c | 113 +++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 113 insertions(+)
> 
> diff --git a/drivers/net/macb.c b/drivers/net/macb.c
> index 14a0b45322bf..9c4fdbd5bc4f 100644
> --- a/drivers/net/macb.c
> +++ b/drivers/net/macb.c
> @@ -52,6 +52,17 @@
>  #define TX_RING_BYTES		(sizeof(struct macb_dma_desc) * TX_RING_SIZE)
>  #define GEM_Q1_DESC_BYTES	(sizeof(struct macb_dma_desc) * GEM_Q1_DESCS)
>  
> +/* This structure is only used for MACB on SiFive FU540 devices */
> +struct sifive_fu540_macb_mgmt {
> +	void __iomem *reg;
> +	unsigned long rate;
> +	struct clk clk;
> +};
> +
> +struct macb_config {
> +	int (*txclk_init)(struct device_d *dev, struct clk **tx_clk);
> +};
> +
>  struct macb_device {
>  	void			__iomem *regs;
>  
> @@ -666,12 +677,101 @@ static void macb_init_rx_buffer_size(struct macb_device *bp, size_t size)
>  		   size, bp->rx_buffer_size);
>  }
>  
> +static struct sifive_fu540_macb_mgmt *mgmt;
> +
> +static unsigned long fu540_macb_tx_recalc_rate(struct clk *clk,
> +					       unsigned long parent_rate)
> +{
> +	return mgmt->rate;
> +}

Unfortunately I had to drop this one. The macb driver is used by some of
the old at91 configs which have their own clk implementation. Among
other things there is no recalc_rate hook.

Can we place the clk code inside a #ifdef CONFIG_COMMON_CLK?

Sascha

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