Re: [RFC PATCH 2/2] clk: mediatek: Add frequency hopping support

[AngeloGioacchino Del Regno]

Il 12/06/22 15:54, Johnson Wang ha scritto:
> Add frequency hopping support and spread spectrum clocking
> control for MT8186.
>
> Signed-off-by: Edward-JW Yang <edward-jw.yang@xxxxxxxxxxxx>
> Signed-off-by: Johnson Wang <johnson.wang@xxxxxxxxxxxx>

Before going on with the review, there's one important consideration:
the Frequency Hopping control is related to PLLs only (so, no other clock
types get in the mix).

Checking the code, the *main* thing that we do here is initializing the
FHCTL by setting some registers, and we're performing the actual frequency
hopping operation in clk-pll, which is right but, at this point, I think
that the best way to proceed is to add the "FHCTL superpowers" to clk-pll
itself, instead of adding multiple new files and devicetree bindings that
are specific to the FHCTL itself.

This would mean that the `fh-id` and `perms` params that you're setting in
the devicetree get transferred to clk-mt8186 (and hardcoded there), as to
extend the PLL declarations to include these two: that will also simplify
the driver so that you won't have to match names here and there.

Just an example:

	PLL(CLK_APMIXED_CCIPLL, "ccipll", 0x0224, 0x0230, 0,

	    PLL_AO, 0, 22, 0x0228, 24, 0, 0, 0, 0x0228, 2, FHCTL_PERM_DBG_DUMP),

Besides, there are another couple of reasons why you should do that instead,
of which:
 - The devicetree should be "generic enough", we shall not see the direct value
   to write to the registers in there (yet, perms assigns exactly that)
 - These values won't change on a per-device basis, I believe? They're SoC-related,
   not board-related, right?

In case they're board related (and/or related to TZ permissions), we can always add
a bool property to the apmixedsys to advertise that board X needs to use an
alternative permission (ex.: `mediatek,secure-fhctl`).

In any case, to speed up development (I believe that transferring this in clk-pll
means that the code will still be more or less the same), I've performed a review
on the code; check below.

> ---
>   drivers/clk/mediatek/Kconfig          |   8 +
>   drivers/clk/mediatek/Makefile         |   2 +
>   drivers/clk/mediatek/clk-fhctl-ap.c   | 347 ++++++++++++++++++++++++++
>   drivers/clk/mediatek/clk-fhctl-pll.c  | 209 ++++++++++++++++
>   drivers/clk/mediatek/clk-fhctl-pll.h  |  74 ++++++
>   drivers/clk/mediatek/clk-fhctl-util.h |  24 ++
>   drivers/clk/mediatek/clk-fhctl.c      | 191 ++++++++++++++
>   drivers/clk/mediatek/clk-fhctl.h      |  45 ++++
>   drivers/clk/mediatek/clk-pll.c        |   5 +-
>   drivers/clk/mediatek/clk-pll.h        |   5 +
>   10 files changed, 909 insertions(+), 1 deletion(-)
>   create mode 100644 drivers/clk/mediatek/clk-fhctl-ap.c
>   create mode 100644 drivers/clk/mediatek/clk-fhctl-pll.c
>   create mode 100644 drivers/clk/mediatek/clk-fhctl-pll.h
>   create mode 100644 drivers/clk/mediatek/clk-fhctl-util.h
>   create mode 100644 drivers/clk/mediatek/clk-fhctl.c
>   create mode 100644 drivers/clk/mediatek/clk-fhctl.h
>
> diff --git a/drivers/clk/mediatek/Kconfig b/drivers/clk/mediatek/Kconfig
> index d5936cfb3bee..fd887c537a91 100644
> --- a/drivers/clk/mediatek/Kconfig
> +++ b/drivers/clk/mediatek/Kconfig
> @@ -622,4 +622,12 @@ config COMMON_CLK_MT8516_AUDSYS
>   	help
>   	  This driver supports MediaTek MT8516 audsys clocks.
>   
> +config COMMON_CLK_MTK_FREQ_HOPPING
> +	tristate "MediaTek frequency hopping driver"

If this goes inside of clk-pll, this configuration option can be safely removed.

> +	depends on ARCH_MEDIATEK || COMPILE_TEST
> +	select COMMON_CLK_MEDIATEK
> +	help
> +	  This driver supports frequency hopping and spread spectrum clocking
> +	  control for some MediaTek SoCs.
> +
>   endmenu
> diff --git a/drivers/clk/mediatek/Makefile b/drivers/clk/mediatek/Makefile
> index caf2ce93d666..3c0e9bd3978b 100644
> --- a/drivers/clk/mediatek/Makefile
> +++ b/drivers/clk/mediatek/Makefile
> @@ -99,3 +99,5 @@ obj-$(CONFIG_COMMON_CLK_MT8195) += clk-mt8195-apmixedsys.o clk-mt8195-topckgen.o
>   				   clk-mt8195-apusys_pll.o
>   obj-$(CONFIG_COMMON_CLK_MT8516) += clk-mt8516.o
>   obj-$(CONFIG_COMMON_CLK_MT8516_AUDSYS) += clk-mt8516-aud.o
> +obj-$(CONFIG_COMMON_CLK_MTK_FREQ_HOPPING) += fhctl.o
> +fhctl-objs += clk-fhctl.o clk-fhctl-ap.o clk-fhctl-pll.o
> diff --git a/drivers/clk/mediatek/clk-fhctl-ap.c b/drivers/clk/mediatek/clk-fhctl-ap.c
> new file mode 100644
> index 000000000000..9e3226a9c1ca
> --- /dev/null
> +++ b/drivers/clk/mediatek/clk-fhctl-ap.c
> @@ -0,0 +1,347 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2022 MediaTek Inc.
> + */
> +
> +#include <linux/device.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_address.h>
> +#include <linux/of_device.h>
> +#include <linux/platform_device.h>
> +#include <linux/string.h>
> +#include <linux/slab.h>
> +#include "clk-fhctl.h"
> +#include "clk-fhctl-pll.h"
> +#include "clk-fhctl-util.h"
> +
> +#define FHCTL_TARGET FHCTL_AP
> +
> +#define PERCENT_TO_DDSLMT(dds, percent_m10) \
> +	((((dds) * (percent_m10)) >> 5) / 100)
> +
> +struct fh_ap_match {
> +	char *name;
> +	struct fh_hdlr *hdlr;
> +	int (*init)(struct pll_dts *array, struct fh_ap_match *match);
> +};
> +
> +struct hdlr_data {
> +	struct pll_dts *array;
> +	struct fh_pll_domain *domain;
> +	spinlock_t *lock;
> +};
> +
> +static int fhctl_set_ssc_regs(struct fh_pll_regs *regs,
> +			      struct fh_pll_data *data,
> +			      int fh_id, int rate)
> +{
> +	unsigned int updnlmt_val;
> +
> +	if (rate > 0) {
> +		fh_set_field(regs->reg_cfg, data->frddsx_en, 0);
> +		fh_set_field(regs->reg_cfg, data->sfstrx_en, 0);
> +		fh_set_field(regs->reg_cfg, data->fhctlx_en, 0);

Are all of these writes to be performed with a barrier?
Can't we use writel_relaxed() for some, with a "final" writel() where ordering
*really* matters?

Also, at least these three field settings are common between (rate > 0) and
(rate <= 0), so they can go outside of the conditional.

> +
> +		/* Set the relative parameter registers (dt/df/upbnd/downbnd) */
> +		fh_set_field(regs->reg_cfg, data->msk_frddsx_dys, data->df_val);
> +		fh_set_field(regs->reg_cfg, data->msk_frddsx_dts, data->dt_val);
> +
> +		writel((readl(regs->reg_con_pcw) & data->dds_mask) |
> +			data->tgl_org, regs->reg_dds);
> +
> +		/* Calculate UPDNLMT */
> +		updnlmt_val = PERCENT_TO_DDSLMT((readl(regs->reg_dds) &
> +						 data->dds_mask), rate) <<
> +						 data->updnlmt_shft;
> +
> +		writel(updnlmt_val, regs->reg_updnlmt);
> +
> +		fh_set_field(regs->reg_hp_en, BIT(fh_id), 1);
> +
> +		/* Enable SSC */
> +		fh_set_field(regs->reg_cfg, data->frddsx_en, 1);
> +		/* Enable Hopping control */
> +		fh_set_field(regs->reg_cfg, data->fhctlx_en, 1);
> +
> +	} else {
> +		fh_set_field(regs->reg_cfg, data->frddsx_en, 0);
> +		fh_set_field(regs->reg_cfg, data->sfstrx_en, 0);
> +		fh_set_field(regs->reg_cfg, data->fhctlx_en, 0);
> +
> +		/* Switch to APMIXEDSYS control */
> +		fh_set_field(regs->reg_hp_en, BIT(fh_id), 0);
> +
> +		/* Wait for DDS to be stable */
> +		udelay(30);
> +	}
> +
> +	return 0;
> +}
> +
> +static int hopping_hw_flow(void *priv_data, char *domain_name, int fh_id,
> +			   unsigned int new_dds, int postdiv)
> +{
> +	struct fh_pll_domain *domain;
> +	struct fh_pll_regs *regs;
> +	struct fh_pll_data *data;
> +	unsigned int dds_mask;
> +	unsigned int mon_dds = 0;
> +	int ret = 0;
> +	unsigned int con_pcw_tmp;
> +	struct hdlr_data *d = (struct hdlr_data *)priv_data;
> +	struct pll_dts *array = d->array;
> +
> +	domain = d->domain;
> +	regs = &domain->regs[fh_id];
> +	data = &domain->data[fh_id];
> +	dds_mask = data->dds_mask;

Just perform these assignments in the variable declarations... with some
reordering as well, and drop the zero assignment to ret.

In few words:

	struct hdlr_data *d = (struct hdlr_data *)priv_data;

	struct fh_pll_domain *domain = d->domain;

	struct fh_pll_regs *regs = &domain->regs[fh_id];

	struct fh_pll_data *data = &domain->data[fh_id];

	struct pll_dts *array = d->array;

	u32 con_pcw_tmp, dds_mask;

	u32 mon_dds = 0;

	int ret;

This comment is valid for some other functions as well - I won't repeat
this for every instance... :-)

> +
> +	if (array->ssc_rate)
> +		fhctl_set_ssc_regs(regs, data, fh_id, 0);
> +
> +	writel((readl(regs->reg_con_pcw) & dds_mask) |
> +		data->tgl_org, regs->reg_dds);
> +
> +	fh_set_field(regs->reg_cfg, data->sfstrx_en, 1);
> +	fh_set_field(regs->reg_cfg, data->fhctlx_en, 1);
> +	writel(data->slope0_value, regs->reg_slope0);
> +	writel(data->slope1_value, regs->reg_slope1);
> +
> +	fh_set_field(regs->reg_hp_en, BIT(fh_id), 1);
> +	writel((new_dds) | (data->dvfs_tri), regs->reg_dvfs);
> +
> +	/* Wait 1000 us until DDS stable */
> +	ret = readl_poll_timeout_atomic(regs->reg_mon, mon_dds,
> +				(mon_dds & dds_mask) == new_dds, 10, 1000);

Why are you writing to CON_PCW even when this returns en error?
Please add a comment explaining the reasons.

> +
> +	con_pcw_tmp = readl(regs->reg_con_pcw) & (~dds_mask);
> +	con_pcw_tmp = (con_pcw_tmp | (readl(regs->reg_mon) & dds_mask) |
> +		       data->pcwchg);
> +
> +	writel(con_pcw_tmp, regs->reg_con_pcw);
> +
> +	fh_set_field(regs->reg_hp_en, BIT(fh_id), 0);
> +
> +	if (array->ssc_rate)
> +		fhctl_set_ssc_regs(regs, data, fh_id, array->ssc_rate);
> +
> +	return ret;
> +}
> +
> +static unsigned int __get_postdiv(struct fh_pll_regs *regs,
> +				  struct fh_pll_data *data)
> +{
> +	unsigned int regval;
> +
> +	regval = (readl(regs->reg_con_postdiv) & data->postdiv_mask)
> +		  >> data->postdiv_offset;
> +
> +	return data->postdiv_table[regval];

Can we instead simply reuse `struct clk_div_table` from clk-provider.h?

> +}
> +
> +static void __set_postdiv(struct fh_pll_regs *regs, struct fh_pll_data *data,
> +			  int postdiv)
> +{
> +	unsigned int regval, temp;
> +
> +	for (regval = 0 ; regval < data->postdiv_table_size ; regval++) {
> +		if (data->postdiv_table[regval] > postdiv) {
> +			regval--;
> +			break;
> +		}
> +	}
> +
> +	temp = (readl(regs->reg_con_postdiv)) & ~(data->postdiv_mask);
> +	temp |= regval << data->postdiv_offset;
> +	writel(temp, regs->reg_con_postdiv);
> +}
> +
> +static int fhctl_ap_hopping(void *priv_data, char *domain_name, int fh_id,
> +			    unsigned int new_dds, int postdiv)
> +{
> +	struct fh_pll_domain *domain;
> +	struct fh_pll_regs *regs;
> +	struct fh_pll_data *data;
> +	int ret = 0;
> +	struct hdlr_data *d = (struct hdlr_data *)priv_data;
> +	spinlock_t *lock = d->lock;
> +	unsigned long flags = 0;
> +	unsigned int pll_postdiv;
> +
> +	domain = d->domain;
> +	regs = &domain->regs[fh_id];
> +	data = &domain->data[fh_id];
> +
> +	if (postdiv > 0) {
> +		pll_postdiv = __get_postdiv(regs, data);
> +
> +		if (postdiv > pll_postdiv)
> +			__set_postdiv(regs, data, postdiv);
> +	}
> +
> +	spin_lock_irqsave(lock, flags);
> +
> +	ret = hopping_hw_flow(priv_data, domain_name, fh_id, new_dds, postdiv);
> +
> +	spin_unlock_irqrestore(lock, flags);
> +
> +	if (postdiv > 0) {
> +		if (postdiv < pll_postdiv)
> +			__set_postdiv(regs, data, postdiv);
> +	}
> +
> +	return ret;
> +}
> +
> +static int fhctl_ap_ssc_enable(void *priv_data, char *domain_name,
> +			       int fh_id, int rate)
> +{
> +	struct fh_pll_domain *domain;
> +	struct fh_pll_regs *regs;
> +	struct fh_pll_data *data;
> +	struct hdlr_data *d = (struct hdlr_data *)priv_data;
> +	spinlock_t *lock = d->lock;
> +	struct pll_dts *array = d->array;
> +	unsigned long flags = 0;
> +
> +	spin_lock_irqsave(lock, flags);
> +
> +	domain = d->domain;
> +	regs = &domain->regs[fh_id];
> +	data = &domain->data[fh_id];
> +
> +	fhctl_set_ssc_regs(regs, data, fh_id, rate);
> +
> +	array->ssc_rate = rate;
> +
> +	spin_unlock_irqrestore(lock, flags);
> +
> +	return 0;
> +}
> +
> +static int fhctl_ap_ssc_disable(void *priv_data, char *domain_name, int fh_id)
> +{
> +	struct fh_pll_domain *domain;
> +	struct fh_pll_regs *regs;
> +	struct fh_pll_data *data;
> +	struct hdlr_data *d = (struct hdlr_data *)priv_data;
> +	spinlock_t *lock = d->lock;
> +	struct pll_dts *array = d->array;
> +	unsigned long flags = 0;
> +
> +	spin_lock_irqsave(lock, flags);
> +
> +	domain = d->domain;
> +	regs = &domain->regs[fh_id];
> +	data = &domain->data[fh_id];
> +
> +	fhctl_set_ssc_regs(regs, data, fh_id, 0);
> +
> +	array->ssc_rate = 0;
> +
> +	spin_unlock_irqrestore(lock, flags);
> +
> +	return 0;
> +}


Just commonize these two...

static int __fhctl_ap_ssc_enable(struct hdlr_data *d, int fh_id, int rate)
{
	struct fh_pll_domain *domain = d->domain;

	struct fh_pll_regs *regs = &domain->regs[fh_id];

	struct fh_pll_data *data = &domain->data[fh_id];

	struct pll_dts *array = d->array;

	spinlock_t *lock = d->lock;

	unsigned long flags = 0;



	spin_lock_irqsave(lock, flags);



	fhctl_set_ssc_regs(regs, data, fh_id, rate);



	array->ssc_rate = rate;



	spin_unlock_irqrestore(lock, flags);



	return 0;
}

static int fhctl_ap_ssc_enable(void *priv_data, char *domain_name, int fh_id, int rate)
{
	return __fhctl_ap_ssc_enable((struct hdlr_data *)priv_data, domain_name,
				     fh_id, rate);
}

static int fhctl_ap_ssc_disable(void *priv_data, char *domain_name, int fh_id)
{
	return __fhctl_ap_ssc_enable((struct hdlr_data *)priv_data, domain_name,
				     fh_id, 0);
}


> +
> +static int fhctl_ap_hw_init(struct pll_dts *array, struct fh_ap_match *match)
> +{
> +	static DEFINE_SPINLOCK(lock);
> +	struct hdlr_data *priv_data;
> +	struct fh_hdlr *hdlr;
> +	struct fh_pll_domain *domain;
> +	int fh_id = array->fh_id;
> +	struct fh_pll_regs *regs;
> +	struct fh_pll_data *data;
> +	int mask = BIT(fh_id);
> +
> +	priv_data = kzalloc(sizeof(*priv_data), GFP_KERNEL);
> +	hdlr = kzalloc(sizeof(*hdlr), GFP_KERNEL);
> +	init_fh_domain(array->domain, array->comp, array->fhctl_base,
> +		       array->apmixed_base);
> +
> +	priv_data->array = array;
> +	priv_data->lock = &lock;
> +	priv_data->domain = get_fh_domain(array->domain);
> +
> +	/* do HW init */
> +	domain = priv_data->domain;
> +	regs = &domain->regs[fh_id];
> +	data = &domain->data[fh_id];
> +
> +	fh_set_field(regs->reg_clk_con, mask, 1);
> +	fh_set_field(regs->reg_rst_con, mask, 0);
> +	fh_set_field(regs->reg_rst_con, mask, 1);
> +	writel(0x0, regs->reg_cfg);
> +	writel(0x0, regs->reg_updnlmt);
> +	writel(0x0, regs->reg_dds);
> +
> +	/* hook to array */
> +	hdlr->data = priv_data;
> +	hdlr->ops = match->hdlr->ops;
> +	/* hook hdlr to array is the last step */
> +	mb();

I really don't think that you need this barrier here - if there's something that
I have misunderstood about that, please provide an extensive explanation.

> +	array->hdlr = hdlr;
> +
> +	/* do SSC */
> +	if (array->ssc_rate) {
> +		struct fh_hdlr *hdlr = array->hdlr;
> +
> +		hdlr->ops->ssc_enable(hdlr->data, array->domain, array->fh_id,
> +				      array->ssc_rate);
> +	}
> +
> +	return 0;
> +}
> +
> +static struct fh_operation fhctl_ap_ops = {
> +	.hopping = fhctl_ap_hopping,
> +	.ssc_enable = fhctl_ap_ssc_enable,
> +	.ssc_disable = fhctl_ap_ssc_disable,
> +};
> +
> +static struct fh_hdlr mt8186_hdlr = {
> +	.ops = &fhctl_ap_ops,
> +};
> +
> +static struct fh_ap_match mt8186_match = {
> +	.name = "mediatek,mt8186-fhctl",
> +	.hdlr = &mt8186_hdlr,
> +	.init = &fhctl_ap_hw_init,
> +};
> +
> +static struct fh_ap_match *matches[] = {
> +	&mt8186_match,
> +	NULL,
> +};
> +
> +int fhctl_ap_init(struct pll_dts *array)
> +{
> +	int i;
> +	int num_pll = array->num_pll;
> +	struct fh_ap_match **match = matches;
> +
> +	/* find match by compatible */
> +	for (i = 0; i < ARRAY_SIZE(matches); i++) {
> +		char *comp = (*match)->name;
> +		char *target = array->comp;
> +
> +		if (!strcmp(comp, target))
> +			break;
> +		match++;
> +	}
> +
> +	if (*match == NULL)
> +		return -1;
> +
> +	/* init flow for every pll */
> +	for (i = 0; i < num_pll; i++, array++) {
> +		char *method = array->method;
> +
> +		if (!strcmp(method, FHCTL_TARGET))
> +			(*match)->init(array, *match);
> +	}
> +
> +	return 0;
> +}
> diff --git a/drivers/clk/mediatek/clk-fhctl-pll.c b/drivers/clk/mediatek/clk-fhctl-pll.c
> new file mode 100644
> index 000000000000..b3ccbbd04e1b
> --- /dev/null
> +++ b/drivers/clk/mediatek/clk-fhctl-pll.c
> @@ -0,0 +1,209 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2022 MediaTek Inc.
> + */
> +
> +#include <linux/device.h>
> +#include <linux/module.h>
> +#include "clk-fhctl-pll.h"
> +#include "clk-fhctl-util.h"
> +
> +#define REG_ADDR(base, x) ((void __iomem *)((unsigned long)base + (x)))
> +
> +struct fh_pll_match {
> +	char *compatible;
> +	struct fh_pll_domain **domain_list;
> +};
> +
> +static int fhctl_pll_init(struct fh_pll_domain *d, void __iomem *fhctl_base,
> +			  void __iomem *apmixed_base)
> +{
> +	struct fh_pll_data *data = d->data;
> +	struct fh_pll_offset *offset = d->offset;
> +	struct fh_pll_regs *regs = d->regs;
> +
> +	if (regs->reg_hp_en)
> +		return 0;
> +
> +	while (data->dds_mask != 0) {
> +		int regs_offset;
> +
> +		/* fhctl common part */
> +		regs->reg_hp_en = REG_ADDR(fhctl_base, offset->offset_hp_en);
> +		regs->reg_clk_con = REG_ADDR(fhctl_base,
> +					     offset->offset_clk_con);
> +		regs->reg_rst_con = REG_ADDR(fhctl_base,
> +					     offset->offset_rst_con);
> +		regs->reg_slope0 = REG_ADDR(fhctl_base, offset->offset_slope0);
> +		regs->reg_slope1 = REG_ADDR(fhctl_base, offset->offset_slope1);
> +
> +		/* fhctl pll part */
> +		regs_offset = offset->offset_fhctl + offset->offset_cfg;
> +		regs->reg_cfg = REG_ADDR(fhctl_base, regs_offset);
> +		regs->reg_updnlmt = REG_ADDR(regs->reg_cfg,
> +					     offset->offset_updnlmt);
> +		regs->reg_dds = REG_ADDR(regs->reg_cfg, offset->offset_dds);
> +		regs->reg_dvfs = REG_ADDR(regs->reg_cfg, offset->offset_dvfs);
> +		regs->reg_mon = REG_ADDR(regs->reg_cfg, offset->offset_mon);
> +
> +		/* apmixed part */
> +		regs->reg_con_pcw = REG_ADDR(apmixed_base,
> +					     offset->offset_con_pcw);
> +		regs->reg_con_postdiv = REG_ADDR(apmixed_base,
> +						 offset->offset_con_postdiv);
> +
> +		data++;
> +		offset++;
> +		regs++;
> +	}
> +
> +	return 0;
> +}
> +
> +static unsigned int __postdiv_pow_tbl[8] = {1, 2, 4, 8, 16, 1, 1, 1};
> +#define POSTDIV_TABLE_SIZE (sizeof(__postdiv_pow_tbl)\
> +	/sizeof(unsigned int))
> +
> +#define SIZE_8186_TOP (sizeof(mt8186_top_data)\
> +	/sizeof(struct fh_pll_data))
> +#define DATA_8186_TOP(_name) {						\

Is it just only about the name?
I mean, are there other SoCs for which each PLL needs different parameters?

If not, there are many ways to commonize these params instead of repeating
them over and over again...

> +		.name = _name,						\
> +		.dds_mask = GENMASK(21, 0),				\
> +		.postdiv_mask = GENMASK(26, 24),			\
> +		.postdiv_offset = 24,					\
> +		.postdiv_table = __postdiv_pow_tbl,			\
> +		.postdiv_table_size = POSTDIV_TABLE_SIZE,		\
> +		.slope0_value = 0x6003c97,				\
> +		.slope1_value = 0x6003c97,				\
> +		.sfstrx_en = BIT(2),					\
> +		.frddsx_en = BIT(1),					\
> +		.fhctlx_en = BIT(0),					\
> +		.tgl_org = BIT(31),					\
> +		.dvfs_tri = BIT(31),					\
> +		.pcwchg = BIT(31),					\
> +		.dt_val = 0x0,						\
> +		.df_val = 0x9,						\
> +		.updnlmt_shft = 16,					\
> +		.msk_frddsx_dys = GENMASK(23, 20),			\
> +		.msk_frddsx_dts = GENMASK(19, 16),			\
> +	}
> +#define OFFSET_8186_TOP(_fhctl, _con_pcw) {				\
> +		.offset_fhctl = _fhctl,					\
> +		.offset_con_pcw = _con_pcw,				\
> +		.offset_con_postdiv = _con_pcw,				\
> +		.offset_hp_en = 0x0,					\
> +		.offset_clk_con = 0x8,					\
> +		.offset_rst_con = 0xc,					\
> +		.offset_slope0 = 0x10,					\
> +		.offset_slope1 = 0x14,					\
> +		.offset_cfg = 0x0,					\
> +		.offset_updnlmt = 0x4,					\
> +		.offset_dds = 0x8,					\
> +		.offset_dvfs = 0xc,					\
> +		.offset_mon = 0x10,					\
> +	}
> +static struct fh_pll_data mt8186_top_data[] = {
> +	DATA_8186_TOP("armpll_ll"),
> +	DATA_8186_TOP("armpll_bl"),
> +	DATA_8186_TOP("ccipll"),
> +	DATA_8186_TOP("mainpll"),
> +	DATA_8186_TOP("mmpll"),
> +	DATA_8186_TOP("tvdpll"),
> +	DATA_8186_TOP("mpll"),
> +	DATA_8186_TOP("adsppll"),
> +	DATA_8186_TOP("mfgpll"),
> +	DATA_8186_TOP("nnapll"),
> +	DATA_8186_TOP("nna2pll"),
> +	DATA_8186_TOP("msdcpll"),
> +	DATA_8186_TOP("mempll"),
> +	{}
> +};
> +static struct fh_pll_offset mt8186_top_offset[] = {
> +	OFFSET_8186_TOP(0x003C, 0x0208),
> +	OFFSET_8186_TOP(0x0050, 0x0218),
> +	OFFSET_8186_TOP(0x0064, 0x0228),
> +	OFFSET_8186_TOP(0x0078, 0x0248),
> +	OFFSET_8186_TOP(0x008C, 0x0258),
> +	OFFSET_8186_TOP(0x00A0, 0x0268),
> +	OFFSET_8186_TOP(0x00B4, 0x0278),
> +	OFFSET_8186_TOP(0x00C8, 0x0308),
> +	OFFSET_8186_TOP(0x00DC, 0x0318),
> +	OFFSET_8186_TOP(0x00F0, 0x0360),
> +	OFFSET_8186_TOP(0x0104, 0x0370),
> +	OFFSET_8186_TOP(0x0118, 0x0390),
> +	OFFSET_8186_TOP(0x012c, 0xdeb1),
> +	{}
> +};
> +static struct fh_pll_regs mt8186_top_regs[SIZE_8186_TOP];
> +static struct fh_pll_domain mt8186_top = {
> +	.name = "top",
> +	.data = (struct fh_pll_data *)&mt8186_top_data,
> +	.offset = (struct fh_pll_offset *)&mt8186_top_offset,
> +	.regs = (struct fh_pll_regs *)&mt8186_top_regs,
> +	.init = &fhctl_pll_init,
> +};
> +static struct fh_pll_domain *mt8186_domain[] = {
> +	&mt8186_top,
> +	NULL,
> +};
> +static struct fh_pll_match mt8186_match = {
> +	.compatible = "mediatek,mt8186-fhctl",
> +	.domain_list = (struct fh_pll_domain **)mt8186_domain,
> +};
> +
> +static const struct fh_pll_match *matches[] = {
> +	&mt8186_match,
> +	NULL
> +};
> +
> +
> +static struct fh_pll_domain **get_list(char *comp)
> +{
> +	struct fh_pll_match **match;
> +	static struct fh_pll_domain **list;
> +	int i;
> +
> +	match = (struct fh_pll_match **)matches;
> +
> +	/* name used only if !list */
> +	if (!list) {
> +		for (i = 0; i < ARRAY_SIZE(matches); i++) {
> +			if (!strcmp(comp, (*match)->compatible)) {
> +				list = (*match)->domain_list;
> +				break;
> +			}
> +			match++;
> +		}
> +	}
> +	return list;
> +}
> +void init_fh_domain(const char *domain, char *comp, void __iomem *fhctl_base,
> +		    void __iomem *apmixed_base)
> +{
> +	struct fh_pll_domain **list;
> +
> +	list = get_list(comp);
> +
> +	while (*list != NULL) {
> +		if (!strcmp(domain, (*list)->name)) {
> +			(*list)->init(*list, fhctl_base, apmixed_base);
> +			return;
> +		}
> +		list++;
> +	}
> +}
> +
> +struct fh_pll_domain *get_fh_domain(const char *domain)
> +{
> +	struct fh_pll_domain **list;
> +
> +	list = get_list(NULL);
> +
> +	/* find instance */
> +	while (*list != NULL) {
> +		if (!strcmp(domain, (*list)->name))
> +			return *list;
> +		list++;
> +	}
> +	return NULL;
> +}
> diff --git a/drivers/clk/mediatek/clk-fhctl-pll.h b/drivers/clk/mediatek/clk-fhctl-pll.h
> new file mode 100644
> index 000000000000..7f0f7577f7a5
> --- /dev/null
> +++ b/drivers/clk/mediatek/clk-fhctl-pll.h
> @@ -0,0 +1,74 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (c) 2022 MediaTek Inc.
> + */
> +
> +#ifndef __CLK_FHCTL_PLL_H
> +#define __CLK_FHCTL_PLL_H
> +#include <linux/types.h>
> +#include <linux/bitops.h>
> +#include <linux/iopoll.h>
> +
> +struct fh_pll_data {
> +	char *name;
> +	unsigned int dds_mask;
> +	unsigned int postdiv_mask;
> +	unsigned int postdiv_offset;
> +	unsigned int *postdiv_table;
> +	unsigned int postdiv_table_size;
> +	unsigned int slope0_value;
> +	unsigned int slope1_value;
> +	unsigned int sfstrx_en;
> +	unsigned int frddsx_en;
> +	unsigned int fhctlx_en;
> +	unsigned int tgl_org;
> +	unsigned int dvfs_tri;
> +	unsigned int pcwchg;
> +	unsigned int dt_val;
> +	unsigned int df_val;
> +	unsigned int updnlmt_shft;
> +	unsigned int msk_frddsx_dys;
> +	unsigned int msk_frddsx_dts;

That's describing some hardware, so... you should really use `u32` here
as that would be more descriptive.

> +};
> +struct fh_pll_offset {
> +	int offset_fhctl;
> +	int offset_con_pcw;
> +	int offset_con_postdiv;
> +	int offset_hp_en;
> +	int offset_clk_con;
> +	int offset_rst_con;
> +	int offset_slope0;
> +	int offset_slope1;
> +	int offset_cfg;
> +	int offset_updnlmt;
> +	int offset_dds;
> +	int offset_dvfs;
> +	int offset_mon;

These also seem to be describing HW registers, and I don't think that
we'll ever see a negative offset for any of these?

> +};
> +struct fh_pll_regs {
> +	void __iomem *reg_hp_en;
> +	void __iomem *reg_clk_con;
> +	void __iomem *reg_rst_con;
> +	void __iomem *reg_slope0;
> +	void __iomem *reg_slope1;
> +	void __iomem *reg_cfg;
> +	void __iomem *reg_updnlmt;
> +	void __iomem *reg_dds;
> +	void __iomem *reg_dvfs;
> +	void __iomem *reg_mon;
> +	void __iomem *reg_con_pcw;
> +	void __iomem *reg_con_postdiv;
> +};
> +struct fh_pll_domain {
> +	char *name;
> +	struct fh_pll_data *data;
> +	struct fh_pll_offset *offset;
> +	struct fh_pll_regs *regs;
> +	int (*init)(struct fh_pll_domain *d, void __iomem *fhctl_base,
> +		    void __iomem *apmixed_base);
> +};
> +extern struct fh_pll_domain *get_fh_domain(const char *name);
> +extern void init_fh_domain(const char *domain_name, char *comp_name,
> +			   void __iomem *fhctl_base,
> +			   void __iomem *apmixed_base);
> +#endif

...and I think this covers enough of the code that may be transferred to clk-pll.

Excited to see the next iteration of this one!

Cheers,
Angelo