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

Haylen Chu
2025-03-07T06:42:17Z

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