Re: [PATCH v5 3/5] clk: spacemit: Add clock support for Spacemit K1 SoC

[Haylen Chu <heylenay@4d2.org>]

On Fri, Mar 07, 2025 at 12:51:49AM +0000, Yixun Lan wrote:
> On 17:57 Thu 06 Mar     , Haylen Chu wrote:
> > The clock tree of K1 SoC contains three main types of clock hardware
> > (PLL/DDN/MIX) and has control registers split into several multifunction
> > devices: APBS (PLLs), MPMU, APBC and APMU.
> > 
> > All register operations are done through regmap to ensure atomiciy
> > between concurrent operations of clock driver and reset,
> > power-domain driver that will be introduced in the future.
> > 
> > Signed-off-by: Haylen Chu <heylenay@4d2.org>
> > ---
> >  drivers/clk/Kconfig               |    1 +
> >  drivers/clk/Makefile              |    1 +
> >  drivers/clk/spacemit/Kconfig      |   20 +
> >  drivers/clk/spacemit/Makefile     |    5 +
> >  drivers/clk/spacemit/ccu-k1.c     | 1714 +++++++++++++++++++++++++++++
> >  drivers/clk/spacemit/ccu_common.h |   47 +
> >  drivers/clk/spacemit/ccu_ddn.c    |   80 ++
> >  drivers/clk/spacemit/ccu_ddn.h    |   48 +
> >  drivers/clk/spacemit/ccu_mix.c    |  284 +++++
> >  drivers/clk/spacemit/ccu_mix.h    |  246 +++++
> >  drivers/clk/spacemit/ccu_pll.c    |  146 +++
> >  drivers/clk/spacemit/ccu_pll.h    |   76 ++
> >  12 files changed, 2668 insertions(+)
> >  create mode 100644 drivers/clk/spacemit/Kconfig
> >  create mode 100644 drivers/clk/spacemit/Makefile
> >  create mode 100644 drivers/clk/spacemit/ccu-k1.c
> >  create mode 100644 drivers/clk/spacemit/ccu_common.h
> >  create mode 100644 drivers/clk/spacemit/ccu_ddn.c
> >  create mode 100644 drivers/clk/spacemit/ccu_ddn.h
> >  create mode 100644 drivers/clk/spacemit/ccu_mix.c
> >  create mode 100644 drivers/clk/spacemit/ccu_mix.h
> >  create mode 100644 drivers/clk/spacemit/ccu_pll.c
> >  create mode 100644 drivers/clk/spacemit/ccu_pll.h
> > 
> ..
> > +static int k1_ccu_probe(struct platform_device *pdev)
> > +{
> > +	struct regmap *base_regmap, *lock_regmap = NULL;
> > +	struct device *dev = &pdev->dev;
> > +	int ret;
> > +
> > +	base_regmap = device_node_to_regmap(dev->of_node);
> > +	if (IS_ERR(base_regmap))
> > +		return dev_err_probe(dev, PTR_ERR(base_regmap),
> > +				     "failed to get regmap\n");
> > +
> > +	if (of_device_is_compatible(dev->of_node, "spacemit,k1-pll")) {
> ..
> > +		struct device_node *mpmu = of_parse_phandle(dev->of_node,
> > +							    "spacemit,mpmu", 0);
> > +		if (!mpmu)
> > +			return dev_err_probe(dev, -ENODEV,
> > +					     "Cannot parse MPMU region\n");
> > +
> > +		lock_regmap = device_node_to_regmap(mpmu);
> > +		of_node_put(mpmu);
> > +
> you can simplify above with syscon_regmap_lookup_by_phandle(), which
> would save a few lines
> 
> or further, just call syscon_regmap_lookup_by_compatible()? then
> won't be necessary to introduce the "spacemit,mpmu" property..
> 

These syscon_* functions differ a little from device_node_to_regmap():
they get and enable the first item in "clocks" property when
instantiating a regmap, which isn't desired for a clock controller.

> > +		if (IS_ERR(lock_regmap))
> > +			return dev_err_probe(dev, PTR_ERR(lock_regmap),
> > +					     "failed to get lock regmap\n");
> > +	}
> > +
> > +	ret = spacemit_ccu_register(dev, base_regmap, lock_regmap,
> > +				    of_device_get_match_data(dev));
> > +	if (ret)
> > +		return dev_err_probe(dev, ret, "failed to register clocks\n");
> > +
> > +	return 0;
> > +}
> > +
> > +static const struct of_device_id of_k1_ccu_match[] = {
> > +	{
> > +		.compatible	= "spacemit,k1-pll",
> > +		.data		= k1_ccu_apbs_clks,
> > +	},
> > +	{
> > +		.compatible	= "spacemit,k1-syscon-mpmu",
> > +		.data		= k1_ccu_mpmu_clks,
> > +	},
> > +	{
> > +		.compatible	= "spacemit,k1-syscon-apbc",
> > +		.data		= k1_ccu_apbc_clks,
> > +	},
> > +	{
> > +		.compatible	= "spacemit,k1-syscon-apmu",
> > +		.data		= k1_ccu_apmu_clks,
> > +	},
> > +	{ }
> > +};
> > +MODULE_DEVICE_TABLE(of, of_k1_ccu_match);
> > +
> > +static struct platform_driver k1_ccu_driver = {
> > +	.driver = {
> > +		.name		= "spacemit,k1-ccu",
> > +		.of_match_table = of_k1_ccu_match,
> > +	},
> > +	.probe	= k1_ccu_probe,
> > +};
> > +module_platform_driver(k1_ccu_driver);
> > +
> > +MODULE_DESCRIPTION("Spacemit K1 CCU driver");
> > +MODULE_AUTHOR("Haylen Chu <heylenay@4d2.org>");
> > +MODULE_LICENSE("GPL");
> 

...

> -- 
> Yixun Lan (dlan)
> Gentoo Linux Developer
> GPG Key ID AABEFD55

Best regards,
Haylen Chu