[v2,0/6] ARM: sunxi: Convert A20/A31 GMAC driver to use CCU

This serie converts Allwinner A20 and A31 GMAC driver to CCU
while still retaining compatibility with existing devicetrees.

This patchset touches 3 areas:
- sun7i and sun6i CCUs now set up regmap to allow dwmac-sunxi driver
to properly access the GMAC clock register.
- dwmac-sunxi can now handle syscon-based clock register to handle
clock itself.
- sun7i and sun6i devicetrees are converted to use the new syscon-based
access.

Changes since v1:
* Use CLK_OF_DECLARE_DRIVER to make it possible to probe again and set up
regmap using platform device probe.
* Clarify the meaning of "legacy" in dwmac-sunxi driver.
* Make sure we don't mess with the RX/TX delay settings when updating
clock registers.
* Update devicetree bindings
* Add sun6i-A31 support. (not tested due to lack of hardware)

Priit Laes (6):
  clk: sunxi-ng: a20: Register regmap for sun7i CCU
  clk: sunxi-ng: a31: Register regmap for sun6i CCU
  net: stmmac: dwmac-sunxi: Implement syscon-based clock handling
  dt-bindings: net: sun7i-gmac: Add syscon support
  ARM: dts: sun7i: Use syscon-based implementation for gmac
  ARM: dts: sun6i: Use syscon-based implementation for gmac

 .../net/allwinner,sun7i-a20-gmac.yaml         |  15 +-
 arch/arm/boot/dts/sun6i-a31.dtsi              |  35 +----
 arch/arm/boot/dts/sun7i-a20.dtsi              |  36 +----
 drivers/clk/sunxi-ng/ccu-sun4i-a10.c          |  60 +++++++-
 drivers/clk/sunxi-ng/ccu-sun6i-a31.c          |  60 +++++++-
 .../net/ethernet/stmicro/stmmac/dwmac-sunxi.c | 130 ++++++++++++++++--
 6 files changed, 258 insertions(+), 78 deletions(-)

On Wed, Apr 29, 2020 at 11:46:08PM +0300, Priit Laes wrote:

I somehow messed up this patch when preparing the patchset,
so I'll resend the fixed patch with v3.

> On sun6i, the gmac clock is handled by the dwmac-sunxi driver, but
> its configuration register is located in the CCU register range,
> requiring proper regmap setup.
> 
> In order to do that, we use CLK_OF_DECLARE_DRIVER to initialize
> sun7i ccu, which clears the OF_POPULATED flag, allowing the
> platform device to probe the same resource with device node.
> 
> Signed-off-by: Priit Laes <plaes@plaes.org>
> ---
>  drivers/clk/sunxi-ng/ccu-sun6i-a31.c | 60 +++++++++++++++++++++++++++-
>  1 file changed, 58 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/clk/sunxi-ng/ccu-sun6i-a31.c b/drivers/clk/sunxi-ng/ccu-sun6i-a31.c
> index 9b40d53266a3..086eb93a4efd 100644
> --- a/drivers/clk/sunxi-ng/ccu-sun6i-a31.c
> +++ b/drivers/clk/sunxi-ng/ccu-sun6i-a31.c
> @@ -1262,5 +1262,61 @@ static void __init sun6i_a31_ccu_setup(struct device_node *node)
>  	ccu_mux_notifier_register(pll_cpu_clk.common.hw.clk,
>  				  &sun6i_a31_cpu_nb);
>  }
> -CLK_OF_DECLARE(sun6i_a31_ccu, "allwinner,sun6i-a31-ccu",
> -	       sun6i_a31_ccu_setup);
> +CLK_OF_DECLARE_DRIVER(sun6i_a31_ccu, "allwinner,sun6i-a31-ccu",
> +		      sun6i_a31_ccu_setup);
> +
> +/*
> + * Regmap for the GMAC driver (dwmac-sunxi) to allow access to
> + * GMAC configuration register.
> + */
> +#define SUN6I_A31_GMAC_CFG_REG 0xD0
> +static bool sun6i_a31_ccu_regmap_accessible_reg(struct device *dev,
> +						unsigned int reg)
> +{
> +	if (reg == SUN6I_A31_GMAC_CFG_REG)
> +		return true;
> +	return false;
> +}
> +
> +static struct regmap_config sun6i_a31_ccu_regmap_config = {
> +	.reg_bits	= 32,
> +	.val_bits	= 32,
> +	.reg_stride	= 4,
> +	.max_register	= 0x308, /* clk_out_b */
> +
> +	.readable_reg	= sun6i_a31_ccu_regmap_accessible_reg,
> +	.writeable_reg	= sun6i_a31_ccu_regmap_accessible_reg,
> +};
> +
> +static int sun6i_a31_ccu_probe_regmap(struct platform_device *pdev)
> +{
> +	void __iomem *reg;
> +	struct resource *res;
> +	struct regmap *regmap;
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	reg = devm_ioremap(&pdev->dev, res->start, resource_size(res));
> +	if (IS_ERR(reg))
> +		return PTR_ERR(reg);
> +
> +	regmap = devm_regmap_init_mmio(&pdev->dev, reg,
> +				       &sun6i_a31_ccu_regmap_accessible_reg);
> +	if (IS_ERR(regmap))
> +		return PTR_ERR(regmap);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id sun6i_a31_ccu_ids[] = {
> +	{ .compatible = "allwinner,sun6i-a31-ccu"},
> +	{ }
> +};
> +
> +static struct platform_driver sun6i_a31_ccu_driver = {
> +	.probe = sun6i_a31_ccu_probe_regmap,
> +	.driver = {
> +		.name = "sun6i-a31-ccu",
> +		.of_match_table = sun6i_a31_ccu_ids,
> +	},
> +};
> +builtin_platform_driver(sun6i_a31_ccu_driver);
> -- 
> 2.26.2
>