[v3,04/12] soc: mediatek: add new flow for mtcmos power.

Commit Message

Weiyi Lu Dec. 10, 2018, 7:32 a.m. UTC

From: Owen Chen <[e-mail]>

Both MT8183 & MT6765 add more bus protect node than previous project,
therefore we add two more register for setup bus protect, which reside
at INFRA_CFG & SMI_COMMON.

With the following change
1. bus protect need not only infracfg but smi_common registers involved
   to setup. Therefore we add a set/clr APIs with more customize arguments.

The second change is that we also add subsys CG control flow before/after
the bus protect/sram control, due to bus protect need SMI bus relative CGs
enable to feed-back its ack, and some master's sram control need CG enable
to on/off its resource sequentially.

With the following change
1. turn on subsys CG before sram pwron and release bus protect.
2. turn off subsys CG after the process of set bus protect/receive
   ack/disable sram.

The last change is for some power domains like vpu_core on MT8183 whose
sram need to do clock and internal isolation while power on/off sram.
We add a flag "sram_iso_ctrl" in scp_domain_data to judge if we need to
do the extra sram isolation control or not.

Signed-off-by: Owen Chen <[e-mail]>
Signed-off-by: Mars Cheng <[e-mail]>
Signed-off-by: Weiyi Lu <[e-mail]>
---
 drivers/soc/mediatek/Makefile           |   2 +-
 drivers/soc/mediatek/mtk-scpsys-ext.c   |  99 ++++++
 drivers/soc/mediatek/mtk-scpsys.c       | 390 ++++++++++++++++++------
 include/linux/soc/mediatek/scpsys-ext.h |  39 +++
 4 files changed, 443 insertions(+), 87 deletions(-)
 create mode 100644 drivers/soc/mediatek/mtk-scpsys-ext.c
 create mode 100644 include/linux/soc/mediatek/scpsys-ext.h

Comments

Nicolas Boichat Dec. 10, 2018, 12:52 p.m. UTC | #1

On Mon, Dec 10, 2018 at 3:33 PM Weiyi Lu <[e-mail]> wrote:
>
> From: Owen Chen <[e-mail]>
>
> Both MT8183 & MT6765 add more bus protect node than previous project,
> therefore we add two more register for setup bus protect, which reside
> at INFRA_CFG & SMI_COMMON.
>
> With the following change
> 1. bus protect need not only infracfg but smi_common registers involved
>    to setup. Therefore we add a set/clr APIs with more customize arguments.
>
> The second change is that we also add subsys CG control flow before/after
> the bus protect/sram control, due to bus protect need SMI bus relative CGs
> enable to feed-back its ack, and some master's sram control need CG enable
> to on/off its resource sequentially.
>
> With the following change
> 1. turn on subsys CG before sram pwron and release bus protect.
> 2. turn off subsys CG after the process of set bus protect/receive
>    ack/disable sram.
>
> The last change is for some power domains like vpu_core on MT8183 whose
> sram need to do clock and internal isolation while power on/off sram.
> We add a flag "sram_iso_ctrl" in scp_domain_data to judge if we need to
> do the extra sram isolation control or not.
>
> Signed-off-by: Owen Chen <[e-mail]>
> Signed-off-by: Mars Cheng <[e-mail]>
> Signed-off-by: Weiyi Lu <[e-mail]>
> ---
>  drivers/soc/mediatek/Makefile           |   2 +-
>  drivers/soc/mediatek/mtk-scpsys-ext.c   |  99 ++++++
>  drivers/soc/mediatek/mtk-scpsys.c       | 390 ++++++++++++++++++------
>  include/linux/soc/mediatek/scpsys-ext.h |  39 +++
>  4 files changed, 443 insertions(+), 87 deletions(-)
>  create mode 100644 drivers/soc/mediatek/mtk-scpsys-ext.c
>  create mode 100644 include/linux/soc/mediatek/scpsys-ext.h
>
> diff --git a/drivers/soc/mediatek/Makefile b/drivers/soc/mediatek/Makefile
> index 12998b08819e..9dc6670c19cb 100644
> --- a/drivers/soc/mediatek/Makefile
> +++ b/drivers/soc/mediatek/Makefile
> @@ -1,3 +1,3 @@
> -obj-$(CONFIG_MTK_INFRACFG) += mtk-infracfg.o
> +obj-$(CONFIG_MTK_INFRACFG) += mtk-infracfg.o mtk-scpsys-ext.o
>  obj-$(CONFIG_MTK_PMIC_WRAP) += mtk-pmic-wrap.o
>  obj-$(CONFIG_MTK_SCPSYS) += mtk-scpsys.o
> diff --git a/drivers/soc/mediatek/mtk-scpsys-ext.c b/drivers/soc/mediatek/mtk-scpsys-ext.c
> new file mode 100644
> index 000000000000..54df42db2a8f
> --- /dev/null
> +++ b/drivers/soc/mediatek/mtk-scpsys-ext.c
> @@ -0,0 +1,99 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2018 MediaTek Inc.
> + * Author: Owen Chen <[e-mail]>
> + */
> +#include <linux/ktime.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/of_device.h>
> +#include <linux/regmap.h>
> +#include <linux/soc/mediatek/scpsys-ext.h>
> +
> +#define MTK_POLL_DELAY_US   10
> +#define MTK_POLL_TIMEOUT    (jiffies_to_usecs(HZ))

That's just USEC_PER_SEC.

> +
> +static int set_bus_protection(struct regmap *map, u32 mask, u32 ack_mask,
> +               u32 reg_set, u32 reg_sta, u32 reg_en)
> +{
> +       u32 val;
> +
> +       if (reg_set)
> +               regmap_write(map, reg_set, mask);
> +       else
> +               regmap_update_bits(map, reg_en, mask, mask);
> +
> +       return regmap_read_poll_timeout(map, reg_sta,
> +                       val, (val & ack_mask) == ack_mask,
> +                       MTK_POLL_DELAY_US, MTK_POLL_TIMEOUT);
> +}
> +
> +static int clear_bus_protection(struct regmap *map, u32 mask, u32 ack_mask,
> +               u32 reg_clr, u32 reg_sta, u32 reg_en)
> +{
> +       u32 val;
> +
> +       if (reg_clr)
> +               regmap_write(map, reg_clr, mask);
> +       else
> +               regmap_update_bits(map, reg_en, mask, 0);
> +
> +       return regmap_read_poll_timeout(map, reg_sta,
> +                       val, !(val & ack_mask),
> +                       MTK_POLL_DELAY_US, MTK_POLL_TIMEOUT);
> +}
> +
> +int mtk_scpsys_ext_set_bus_protection(const struct bus_prot *bp_table,
> +       struct regmap *infracfg, struct regmap *smi_common)
> +{
> +       int i;
> +
> +       for (i = 0; i < MAX_STEPS && bp_table[i].mask; i++) {
> +               struct regmap *map;
> +               int ret;
> +
> +               if (bp_table[i].type == IFR_TYPE)
> +                       map = infracfg;
> +               else if (bp_table[i].type == SMI_TYPE)
> +                       map = smi_common;
> +               else
> +                       return -EINVAL;
> +
> +               ret = set_bus_protection(map,
> +                               bp_table[i].mask, bp_table[i].mask,
> +                               bp_table[i].set_ofs, bp_table[i].sta_ofs,
> +                               bp_table[i].en_ofs);
> +
> +               if (ret)
> +                       return ret;
> +       }
> +
> +       return 0;
> +}
> +
> +int mtk_scpsys_ext_clear_bus_protection(const struct bus_prot *bp_table,
> +       struct regmap *infracfg, struct regmap *smi_common)
> +{
> +       int i;
> +
> +       for (i = MAX_STEPS - 1; i >= 0; i--) {
> +               struct regmap *map;
> +               int ret;
> +
> +               if (bp_table[i].type == IFR_TYPE)
> +                       map = infracfg;
> +               else if (bp_table[i].type == SMI_TYPE)
> +                       map = smi_common;
> +               else
> +                       return -EINVAL;
> +
> +               ret = clear_bus_protection(map,
> +                               bp_table[i].mask, bp_table[i].clr_ack_mask,
> +                               bp_table[i].clr_ofs, bp_table[i].sta_ofs,
> +                               bp_table[i].en_ofs);
> +
> +               if (ret)
> +                       return ret;
> +       }
> +
> +       return 0;
> +}
> diff --git a/drivers/soc/mediatek/mtk-scpsys.c b/drivers/soc/mediatek/mtk-scpsys.c
> index 5b24bb4bfbf6..98ccef566ce1 100644
> --- a/drivers/soc/mediatek/mtk-scpsys.c
> +++ b/drivers/soc/mediatek/mtk-scpsys.c
> @@ -1,15 +1,8 @@
> -/*
> - * Copyright (c) 2015 Pengutronix, Sascha Hauer <[e-mail]>
> - *
> - * This program is free software; you can redistribute it and/or modify
> - * it under the terms of the GNU General Public License version 2 as
> - * published by the Free Software Foundation.
> - *
> - * This program is distributed in the hope that it will be useful,
> - * but WITHOUT ANY WARRANTY; without even the implied warranty of
> - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> - * GNU General Public License for more details.
> - */
> +// SPDX-License-Identifier: GPL-2.0
> +//
> +// Copyright (c) 2015 Pengutronix
> +// Author: Sascha Hauer <[e-mail]>

I'm not super familiar with copyright rules in Germany, but I would
not change this line. I.e., I'd keep:
// Copyright (c) 2015 Pengutronix, Sascha Hauer <[e-mail]>

> +
>  #include <linux/clk.h>
>  #include <linux/init.h>
>  #include <linux/io.h>
> @@ -20,6 +13,7 @@
>  #include <linux/pm_domain.h>
>  #include <linux/regulator/consumer.h>
>  #include <linux/soc/mediatek/infracfg.h>
> +#include <linux/soc/mediatek/scpsys-ext.h>
>
>  #include <dt-bindings/power/mt2701-power.h>
>  #include <dt-bindings/power/mt2712-power.h>
> @@ -64,6 +58,8 @@
>  #define PWR_ON_BIT                     BIT(2)
>  #define PWR_ON_2ND_BIT                 BIT(3)
>  #define PWR_CLK_DIS_BIT                        BIT(4)
> +#define PWR_SRAM_CLKISO_BIT            BIT(5)
> +#define PWR_SRAM_ISOINT_B_BIT          BIT(6)
>
>  #define PWR_STATUS_CONN                        BIT(1)
>  #define PWR_STATUS_DISP                        BIT(3)
> @@ -115,16 +111,38 @@ static const char * const clk_names[] = {
>  };
>
>  #define MAX_CLKS       3
> -
> +#define MAX_SUBSYS_CLKS 10
> +
> +/**
> + * struct scp_domain_data - scp domain data for power on/off flow
> + * @name: The domain name.
> + * @sta_mask: The mask for power on/off status bit.
> + * @ctl_offs: The offset for main power control register.

Thanks for adding documentation, but @sram_iso_ctrl is missing here.

> + * @sram_pdn_bits: The mask for sram power control bits.
> + * @sram_pdn_ack_bits: The mask for sram power control acked bits.
> + * @bus_prot_mask: The mask for single step bus protection.
> + * @clk_id: The basic clock needs to be enabled before enabling certain
> + *          power domains.
> + * @basic_clk_name: provide the same purpose with field "clk_id"
> + *                  by declaring basic clock prefix name rather than clk_id.
> + * @subsys_clk_prefix: The prefix name of the clocks need to be enabled
> + *                     before releasing bus protection.
> + * @caps: The flag for active wake-up action.
> + * @bp_table: The mask table for multiple step bus protection.
> + */
>  struct scp_domain_data {
>         const char *name;
>         u32 sta_mask;
>         int ctl_offs;
> +       bool sram_iso_ctrl;
>         u32 sram_pdn_bits;
>         u32 sram_pdn_ack_bits;
>         u32 bus_prot_mask;
>         enum clk_id clk_id[MAX_CLKS];
> +       const char *basic_clk_name[MAX_CLKS];
> +       const char *subsys_clk_prefix;
>         u8 caps;
> +       struct bus_prot bp_table[MAX_STEPS];
>  };
>
>  struct scp;
> @@ -133,6 +151,7 @@ struct scp_domain {
>         struct generic_pm_domain genpd;
>         struct scp *scp;
>         struct clk *clk[MAX_CLKS];
> +       struct clk *subsys_clk[MAX_SUBSYS_CLKS];
>         const struct scp_domain_data *data;
>         struct regulator *supply;
>  };
> @@ -148,6 +167,7 @@ struct scp {
>         struct device *dev;
>         void __iomem *base;
>         struct regmap *infracfg;
> +       struct regmap *smi_common;
>         struct scp_ctrl_reg ctrl_reg;
>         bool bus_prot_reg_update;
>  };
> @@ -188,32 +208,166 @@ static int scpsys_domain_is_on(struct scp_domain *scpd)
>         return -EINVAL;
>  }
>
> +static int scpsys_regulator_enable(struct scp_domain *scpd)
> +{
> +       if (!scpd->supply)
> +               return 0;
> +       else

nit: Else branch not strictly needed.

> +               return regulator_enable(scpd->supply);
> +}
> +
> +static int scpsys_regulator_disable(struct scp_domain *scpd)
> +{
> +       if (!scpd->supply)
> +               return 0;
> +       else
> +               return regulator_disable(scpd->supply);
> +}
> +
> +static int scpsys_clk_enable(struct clk *clk[], int max_num)
> +{
> +       int i, ret = 0;
> +
> +       for (i = 0; i < max_num && clk[i]; i++) {
> +               ret = clk_prepare_enable(clk[i]);
> +               if (ret) {
> +                       for (--i; i >= 0; i--)
> +                               clk_disable_unprepare(clk[i]);
> +
> +                       break;
> +               }
> +       }
> +
> +       return ret;
> +}
> +
> +static int scpsys_clk_disable(struct clk *clk[], int max_num)
> +{
> +       int i;
> +
> +       for (i = max_num - 1; i >= 0; i--) {
> +               if (clk[i])
> +                       clk_disable_unprepare(clk[i]);
> +       }
> +
> +       return 0;
> +}
> +
> +static int scpsys_sram_enable(struct scp_domain *scpd, void __iomem *ctl_addr)
> +{
> +       u32 val;
> +       u32 pdn_ack = scpd->data->sram_pdn_ack_bits;
> +       int tmp, ret = 0;
> +
> +       val = readl(ctl_addr) & ~scpd->data->sram_pdn_bits;
> +       writel(val, ctl_addr);
> +
> +       /* Either wait until SRAM_PDN_ACK all 0 or have a force wait */
> +       if (MTK_SCPD_CAPS(scpd, MTK_SCPD_FWAIT_SRAM)) {
> +               /*
> +                * Currently, MTK_SCPD_FWAIT_SRAM is necessary only for
> +                * MT7622_POWER_DOMAIN_WB and thus just a trivial setup
> +                * is applied here.
> +                */
> +               usleep_range(12000, 12100);
> +       } else {
> +               /* Either wait until SRAM_PDN_ACK all 1 or 0 */
> +               ret = readl_poll_timeout(ctl_addr, tmp,
> +                               (tmp & pdn_ack) == 0,
> +                               MTK_POLL_DELAY_US, MTK_POLL_TIMEOUT);
> +       }
> +
> +       if (scpd->data->sram_iso_ctrl)  {

Are we ok with doing this even if readl_poll_timeout fails? Should we
return ret earlier?

> +               val = readl(ctl_addr) | PWR_SRAM_ISOINT_B_BIT;
> +               writel(val, ctl_addr);
> +               udelay(1);
> +               val &= ~PWR_SRAM_CLKISO_BIT;
> +               writel(val, ctl_addr);
> +       }
> +
> +       return ret;
> +}
> +
> +static int scpsys_sram_disable(struct scp_domain *scpd, void __iomem *ctl_addr)
> +{
> +       u32 val;
> +       u32 pdn_ack = scpd->data->sram_pdn_ack_bits;
> +       int tmp, ret = 0;

No need to init ret to 0.

> +
> +       if (scpd->data->sram_iso_ctrl)  {
> +               val = readl(ctl_addr);
> +               val |= PWR_SRAM_CLKISO_BIT;
> +               writel(val, ctl_addr);
> +               val &= ~PWR_SRAM_ISOINT_B_BIT;
> +               writel(val, ctl_addr);
> +               udelay(1);
> +       }
> +
> +       val = readl(ctl_addr) | scpd->data->sram_pdn_bits;
> +       writel(val, ctl_addr);
> +
> +       /* Either wait until SRAM_PDN_ACK all 1 or 0 */
> +       ret = readl_poll_timeout(ctl_addr, tmp,
> +                       (tmp & pdn_ack) == pdn_ack,
> +                       MTK_POLL_DELAY_US, MTK_POLL_TIMEOUT);
> +
> +       return ret;

Just return readl_poll_timeout.

> +}
> +
> +static int scpsys_bus_protect_enable(struct scp_domain *scpd)
> +{
> +       struct scp *scp = scpd->scp;
> +       int ret = 0;
> +
> +       if (scpd->data->bus_prot_mask) {
> +               ret = mtk_infracfg_set_bus_protection(scp->infracfg,
> +                               scpd->data->bus_prot_mask,
> +                               scp->bus_prot_reg_update);
> +       } else if (scpd->data->bp_table[0].mask) {
> +               ret = mtk_scpsys_ext_set_bus_protection(scpd->data->bp_table,
> +                               scp->infracfg,
> +                               scp->smi_common);
> +       }
> +
> +       return ret;

More simply:

       if (scpd->data->bus_prot_mask)
              return mtk_infracfg_set_bus_protection(scp->infracfg,
                               scpd->data->bus_prot_mask,
                               scp->bus_prot_reg_update);

      if (scpd->data->bp_table[0].mask)
               return mtk_scpsys_ext_set_bus_protection(scpd->data->bp_table,
                               scp->infracfg,
                               scp->smi_common);

       return 0;

(feel free to add else's, if you like that better)

> +}
> +
> +static int scpsys_bus_protect_disable(struct scp_domain *scpd)
> +{
> +       struct scp *scp = scpd->scp;
> +       int ret = 0;
> +
> +       if (scpd->data->bus_prot_mask) {
> +               ret = mtk_infracfg_clear_bus_protection(scp->infracfg,
> +                               scpd->data->bus_prot_mask,
> +                               scp->bus_prot_reg_update);
> +       } else if (scpd->data->bp_table[0].mask) {
> +               ret = mtk_scpsys_ext_clear_bus_protection(
> +                               scpd->data->bp_table,
> +                               scp->infracfg,
> +                               scp->smi_common);
> +       }
> +
> +       return ret;

ditto

> +}
> +
>  static int scpsys_power_on(struct generic_pm_domain *genpd)
>  {
>         struct scp_domain *scpd = container_of(genpd, struct scp_domain, genpd);
>         struct scp *scp = scpd->scp;
>         void __iomem *ctl_addr = scp->base + scpd->data->ctl_offs;
> -       u32 pdn_ack = scpd->data->sram_pdn_ack_bits;
>         u32 val;
>         int ret, tmp;
> -       int i;
> -
> -       if (scpd->supply) {
> -               ret = regulator_enable(scpd->supply);
> -               if (ret)
> -                       return ret;
> -       }
>
> -       for (i = 0; i < MAX_CLKS && scpd->clk[i]; i++) {
> -               ret = clk_prepare_enable(scpd->clk[i]);
> -               if (ret) {
> -                       for (--i; i >= 0; i--)
> -                               clk_disable_unprepare(scpd->clk[i]);
> +       ret = scpsys_regulator_enable(scpd);
> +       if (ret < 0)
> +               return ret;
>
> -                       goto err_clk;
> -               }
> -       }
> +       ret = scpsys_clk_enable(scpd->clk, MAX_CLKS);
> +       if (ret)
> +               goto err_clk;
>
> +       /* subsys power on */
>         val = readl(ctl_addr);
>         val |= PWR_ON_BIT;
>         writel(val, ctl_addr);
> @@ -235,43 +389,26 @@ static int scpsys_power_on(struct generic_pm_domain *genpd)
>         val |= PWR_RST_B_BIT;
>         writel(val, ctl_addr);
>
> -       val &= ~scpd->data->sram_pdn_bits;
> -       writel(val, ctl_addr);
> -
> -       /* Either wait until SRAM_PDN_ACK all 0 or have a force wait */
> -       if (MTK_SCPD_CAPS(scpd, MTK_SCPD_FWAIT_SRAM)) {
> -               /*
> -                * Currently, MTK_SCPD_FWAIT_SRAM is necessary only for
> -                * MT7622_POWER_DOMAIN_WB and thus just a trivial setup is
> -                * applied here.
> -                */
> -               usleep_range(12000, 12100);
> +       ret = scpsys_clk_enable(scpd->subsys_clk, MAX_SUBSYS_CLKS);
> +       if (ret < 0)
> +               goto err_pwr_ack;
>
> -       } else {
> -               ret = readl_poll_timeout(ctl_addr, tmp, (tmp & pdn_ack) == 0,
> -                                        MTK_POLL_DELAY_US, MTK_POLL_TIMEOUT);
> -               if (ret < 0)
> -                       goto err_pwr_ack;
> -       }
> +       ret = scpsys_sram_enable(scpd, ctl_addr);
> +       if (ret < 0)
> +               goto err_sram;
>
> -       if (scpd->data->bus_prot_mask) {
> -               ret = mtk_infracfg_clear_bus_protection(scp->infracfg,
> -                               scpd->data->bus_prot_mask,
> -                               scp->bus_prot_reg_update);
> -               if (ret)
> -                       goto err_pwr_ack;
> -       }
> +       ret = scpsys_bus_protect_disable(scpd);
> +       if (ret < 0)
> +               goto err_sram;
>
>         return 0;
>
> +err_sram:
> +       scpsys_clk_disable(scpd->subsys_clk, MAX_SUBSYS_CLKS);
>  err_pwr_ack:
> -       for (i = MAX_CLKS - 1; i >= 0; i--) {
> -               if (scpd->clk[i])
> -                       clk_disable_unprepare(scpd->clk[i]);
> -       }
> +       scpsys_clk_disable(scpd->clk, MAX_CLKS);
>  err_clk:
> -       if (scpd->supply)
> -               regulator_disable(scpd->supply);
> +       scpsys_regulator_disable(scpd);
>
>         dev_err(scp->dev, "Failed to power on domain %s\n", genpd->name);
>
> @@ -283,29 +420,21 @@ static int scpsys_power_off(struct generic_pm_domain *genpd)
>         struct scp_domain *scpd = container_of(genpd, struct scp_domain, genpd);
>         struct scp *scp = scpd->scp;
>         void __iomem *ctl_addr = scp->base + scpd->data->ctl_offs;
> -       u32 pdn_ack = scpd->data->sram_pdn_ack_bits;
>         u32 val;
>         int ret, tmp;
> -       int i;
>
> -       if (scpd->data->bus_prot_mask) {
> -               ret = mtk_infracfg_set_bus_protection(scp->infracfg,
> -                               scpd->data->bus_prot_mask,
> -                               scp->bus_prot_reg_update);
> -               if (ret)
> -                       goto out;
> -       }
> -
> -       val = readl(ctl_addr);
> -       val |= scpd->data->sram_pdn_bits;
> -       writel(val, ctl_addr);
> +       ret = scpsys_bus_protect_enable(scpd);
> +       if (ret < 0)
> +               goto out;
>
> -       /* wait until SRAM_PDN_ACK all 1 */
> -       ret = readl_poll_timeout(ctl_addr, tmp, (tmp & pdn_ack) == pdn_ack,
> -                                MTK_POLL_DELAY_US, MTK_POLL_TIMEOUT);
> +       ret = scpsys_sram_disable(scpd, ctl_addr);
>         if (ret < 0)
>                 goto out;
>
> +       ret = scpsys_clk_disable(scpd->subsys_clk, MAX_SUBSYS_CLKS);
> +
> +       /* subsys power off */
> +       val = readl(ctl_addr);
>         val |= PWR_ISO_BIT;
>         writel(val, ctl_addr);
>
> @@ -327,11 +456,9 @@ static int scpsys_power_off(struct generic_pm_domain *genpd)
>         if (ret < 0)
>                 goto out;
>
> -       for (i = 0; i < MAX_CLKS && scpd->clk[i]; i++)
> -               clk_disable_unprepare(scpd->clk[i]);
> +       scpsys_clk_disable(scpd->clk, MAX_CLKS);
>
> -       if (scpd->supply)
> -               regulator_disable(scpd->supply);
> +       scpsys_regulator_disable(scpd);
>
>         return 0;
>
> @@ -341,6 +468,65 @@ static int scpsys_power_off(struct generic_pm_domain *genpd)
>         return ret;
>  }
>
> +static int init_subsys_clks(struct platform_device *pdev,
> +               const char *prefix, struct clk **clk)
> +{
> +       struct device_node *node = pdev->dev.of_node;
> +       u32 prefix_len, sub_clk_cnt = 0;
> +       int str_sz, clk_idx, ret;
> +
> +       if (!node) {
> +               dev_err(&pdev->dev, "Cannot find scpsys node: %ld\n",
> +                       PTR_ERR(node));
> +               return PTR_ERR(node);
> +       }
> +
> +       str_sz = of_property_count_strings(node, "clock-names");
> +       if (str_sz < 0) {
> +               dev_err(&pdev->dev, "Cannot get any subsys strings: %d\n",
> +                               str_sz);
> +               return str_sz;
> +       }

Would it be nicer to use of_property_for_each_string to iterate over
the clock-names?

> +
> +       prefix_len = strlen(prefix);
> +
> +       for (clk_idx = 0; clk_idx < str_sz; clk_idx++) {
> +               const char *clk_name;
> +
> +               ret = of_property_read_string_index(node, "clock-names",
> +                                       clk_idx, &clk_name);
> +               if (ret < 0) {
> +                       dev_err(&pdev->dev,
> +                                       "Cannot read subsys string[%d]: %d\n",
> +                                       clk_idx, ret);
> +                       return ret;
> +               }
> +
> +               if (!strncmp(clk_name, prefix, prefix_len) &&
> +                               (clk_name[prefix_len] == '-')) {
> +                       if (sub_clk_cnt >= MAX_SUBSYS_CLKS) {
> +                               dev_err(&pdev->dev,
> +                                       "subsys clk out of range %d\n",
> +                                       sub_clk_cnt);
> +                               return -ENOMEM;
> +                       }
> +
> +                       clk[sub_clk_cnt] = devm_clk_get(&pdev->dev,
> +                                               clk_name);
> +
> +                       if (IS_ERR(clk)) {
> +                               dev_err(&pdev->dev,
> +                                       "Subsys clk read fail %ld\n",
> +                                       PTR_ERR(clk));
> +                               return PTR_ERR(clk);
> +                       }
> +                       sub_clk_cnt++;
> +               }
> +       }
> +
> +       return sub_clk_cnt;
> +}
> +
>  static void init_clks(struct platform_device *pdev, struct clk **clk)
>  {
>         int i;
> @@ -396,6 +582,17 @@ static struct scp *init_scp(struct platform_device *pdev,
>                 return ERR_CAST(scp->infracfg);
>         }
>
> +       scp->smi_common = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
> +                       "smi_comm");
> +
> +       if (scp->smi_common == ERR_PTR(-ENODEV)) {
> +               scp->smi_common = NULL;
> +       } else if (IS_ERR(scp->smi_common)) {
> +               dev_err(&pdev->dev, "Cannot find smi_common controller: %ld\n",
> +                               PTR_ERR(scp->smi_common));
> +               return ERR_CAST(scp->smi_common);
> +       }
> +
>         for (i = 0; i < num; i++) {
>                 struct scp_domain *scpd = &scp->domains[i];
>                 const struct scp_domain_data *data = &scp_domain_data[i];
> @@ -417,22 +614,43 @@ static struct scp *init_scp(struct platform_device *pdev,
>                 struct scp_domain *scpd = &scp->domains[i];
>                 struct generic_pm_domain *genpd = &scpd->genpd;
>                 const struct scp_domain_data *data = &scp_domain_data[i];
> +               int clk_cnt;
>
>                 pd_data->domains[i] = genpd;
>                 scpd->scp = scp;
>
>                 scpd->data = data;
>
> -               for (j = 0; j < MAX_CLKS && data->clk_id[j]; j++) {
> -                       struct clk *c = clk[data->clk_id[j]];
> +               if (data->clk_id[0]) {
> +                       for (j = 0; j < MAX_CLKS && data->clk_id[j]; j++) {
> +                               struct clk *c = clk[data->clk_id[j]];
>
> -                       if (IS_ERR(c)) {
> -                               dev_err(&pdev->dev, "%s: clk unavailable\n",
> -                                       data->name);
> -                               return ERR_CAST(c);
> +                               if (IS_ERR(c)) {
> +                                       dev_err(&pdev->dev,
> +                                               "%s: clk unavailable\n",
> +                                               data->name);
> +                                       return ERR_CAST(c);
> +                               }
> +
> +                               scpd->clk[j] = c;
>                         }
> +               } else if (data->basic_clk_name[0]) {
> +                       for (j = 0; j < MAX_CLKS &&
> +                                       data->basic_clk_name[j]; j++)
> +                               scpd->clk[j] = devm_clk_get(&pdev->dev,
> +                                               data->basic_clk_name[j]);
> +               }
>
> -                       scpd->clk[j] = c;
> +               if (data->subsys_clk_prefix) {
> +                       clk_cnt = init_subsys_clks(pdev,
> +                                       data->subsys_clk_prefix,
> +                                       scpd->subsys_clk);
> +                       if (clk_cnt < 0) {
> +                               dev_err(&pdev->dev,
> +                                       "%s: subsys clk unavailable\n",
> +                                       data->name);
> +                               return ERR_PTR(clk_cnt);
> +                       }
>                 }
>
>                 genpd->name = data->name;
> diff --git a/include/linux/soc/mediatek/scpsys-ext.h b/include/linux/soc/mediatek/scpsys-ext.h
> new file mode 100644
> index 000000000000..d0ed295c88a7
> --- /dev/null
> +++ b/include/linux/soc/mediatek/scpsys-ext.h
> @@ -0,0 +1,39 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef __SOC_MEDIATEK_SCPSYS_EXT_H
> +#define __SOC_MEDIATEK_SCPSYS_EXT_H
> +
> +#define MAX_STEPS      4
> +
> +#define BUS_PROT(_type, _set_ofs, _clr_ofs,                    \
> +               _en_ofs, _sta_ofs, _mask, _clr_ack_mask) {      \
> +               .type = _type,                                  \
> +               .set_ofs = _set_ofs,                            \
> +               .clr_ofs = _clr_ofs,                            \
> +               .en_ofs = _en_ofs,                              \
> +               .sta_ofs = _sta_ofs,                            \
> +               .mask = _mask,                                  \
> +               .clr_ack_mask = _clr_ack_mask,                  \
> +       }
> +
> +enum regmap_type {
> +       IFR_TYPE,
> +       SMI_TYPE,
> +       MAX_REGMAP_TYPE,
> +};
> +
> +struct bus_prot {
> +       enum regmap_type type;
> +       u32 set_ofs;
> +       u32 clr_ofs;
> +       u32 en_ofs;
> +       u32 sta_ofs;
> +       u32 mask;
> +       u32 clr_ack_mask;
> +};
> +
> +int mtk_scpsys_ext_set_bus_protection(const struct bus_prot *bp_table,
> +       struct regmap *infracfg, struct regmap *smi_common);
> +int mtk_scpsys_ext_clear_bus_protection(const struct bus_prot *bp_table,
> +       struct regmap *infracfg, struct regmap *smi_common);
> +
> +#endif /* __SOC_MEDIATEK_SCPSYS_EXT_H */
> --
> 2.18.0
>

Patch

diff --git a/drivers/soc/mediatek/Makefile b/drivers/soc/mediatek/Makefile
index 12998b08819e..9dc6670c19cb 100644
--- a/drivers/soc/mediatek/Makefile
+++ b/drivers/soc/mediatek/Makefile
@@ -1,3 +1,3 @@ 
-obj-$(CONFIG_MTK_INFRACFG) += mtk-infracfg.o
+obj-$(CONFIG_MTK_INFRACFG) += mtk-infracfg.o mtk-scpsys-ext.o
 obj-$(CONFIG_MTK_PMIC_WRAP) += mtk-pmic-wrap.o
 obj-$(CONFIG_MTK_SCPSYS) += mtk-scpsys.o
diff --git a/drivers/soc/mediatek/mtk-scpsys-ext.c b/drivers/soc/mediatek/mtk-scpsys-ext.c
new file mode 100644
index 000000000000..54df42db2a8f
--- /dev/null
+++ b/drivers/soc/mediatek/mtk-scpsys-ext.c
@@ -0,0 +1,99 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2018 MediaTek Inc.
+ * Author: Owen Chen <[e-mail]>
+ */
+#include <linux/ktime.h>
+#include <linux/mfd/syscon.h>
+#include <linux/of_device.h>
+#include <linux/regmap.h>
+#include <linux/soc/mediatek/scpsys-ext.h>
+
+#define MTK_POLL_DELAY_US   10
+#define MTK_POLL_TIMEOUT    (jiffies_to_usecs(HZ))
+
+static int set_bus_protection(struct regmap *map, u32 mask, u32 ack_mask,
+		u32 reg_set, u32 reg_sta, u32 reg_en)
+{
+	u32 val;
+
+	if (reg_set)
+		regmap_write(map, reg_set, mask);
+	else
+		regmap_update_bits(map, reg_en, mask, mask);
+
+	return regmap_read_poll_timeout(map, reg_sta,
+			val, (val & ack_mask) == ack_mask,
+			MTK_POLL_DELAY_US, MTK_POLL_TIMEOUT);
+}
+
+static int clear_bus_protection(struct regmap *map, u32 mask, u32 ack_mask,
+		u32 reg_clr, u32 reg_sta, u32 reg_en)
+{
+	u32 val;
+
+	if (reg_clr)
+		regmap_write(map, reg_clr, mask);
+	else
+		regmap_update_bits(map, reg_en, mask, 0);
+
+	return regmap_read_poll_timeout(map, reg_sta,
+			val, !(val & ack_mask),
+			MTK_POLL_DELAY_US, MTK_POLL_TIMEOUT);
+}
+
+int mtk_scpsys_ext_set_bus_protection(const struct bus_prot *bp_table,
+	struct regmap *infracfg, struct regmap *smi_common)
+{
+	int i;
+
+	for (i = 0; i < MAX_STEPS && bp_table[i].mask; i++) {
+		struct regmap *map;
+		int ret;
+
+		if (bp_table[i].type == IFR_TYPE)
+			map = infracfg;
+		else if (bp_table[i].type == SMI_TYPE)
+			map = smi_common;
+		else
+			return -EINVAL;
+
+		ret = set_bus_protection(map,
+				bp_table[i].mask, bp_table[i].mask,
+				bp_table[i].set_ofs, bp_table[i].sta_ofs,
+				bp_table[i].en_ofs);
+
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+int mtk_scpsys_ext_clear_bus_protection(const struct bus_prot *bp_table,
+	struct regmap *infracfg, struct regmap *smi_common)
+{
+	int i;
+
+	for (i = MAX_STEPS - 1; i >= 0; i--) {
+		struct regmap *map;
+		int ret;
+
+		if (bp_table[i].type == IFR_TYPE)
+			map = infracfg;
+		else if (bp_table[i].type == SMI_TYPE)
+			map = smi_common;
+		else
+			return -EINVAL;
+
+		ret = clear_bus_protection(map,
+				bp_table[i].mask, bp_table[i].clr_ack_mask,
+				bp_table[i].clr_ofs, bp_table[i].sta_ofs,
+				bp_table[i].en_ofs);
+
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
diff --git a/drivers/soc/mediatek/mtk-scpsys.c b/drivers/soc/mediatek/mtk-scpsys.c
index 5b24bb4bfbf6..98ccef566ce1 100644
--- a/drivers/soc/mediatek/mtk-scpsys.c
+++ b/drivers/soc/mediatek/mtk-scpsys.c
@@ -1,15 +1,8 @@ 
-/*
- * Copyright (c) 2015 Pengutronix, Sascha Hauer <[e-mail]>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- */
+// SPDX-License-Identifier: GPL-2.0
+//
+// Copyright (c) 2015 Pengutronix
+// Author: Sascha Hauer <[e-mail]>
+
 #include <linux/clk.h>
 #include <linux/init.h>
 #include <linux/io.h>
@@ -20,6 +13,7 @@ 
 #include <linux/pm_domain.h>
 #include <linux/regulator/consumer.h>
 #include <linux/soc/mediatek/infracfg.h>
+#include <linux/soc/mediatek/scpsys-ext.h>
 
 #include <dt-bindings/power/mt2701-power.h>
 #include <dt-bindings/power/mt2712-power.h>
@@ -64,6 +58,8 @@ 
 #define PWR_ON_BIT			BIT(2)
 #define PWR_ON_2ND_BIT			BIT(3)
 #define PWR_CLK_DIS_BIT			BIT(4)
+#define PWR_SRAM_CLKISO_BIT		BIT(5)
+#define PWR_SRAM_ISOINT_B_BIT		BIT(6)
 
 #define PWR_STATUS_CONN			BIT(1)
 #define PWR_STATUS_DISP			BIT(3)
@@ -115,16 +111,38 @@  static const char * const clk_names[] = {
 };
 
 #define MAX_CLKS	3
-
+#define MAX_SUBSYS_CLKS 10
+
+/**
+ * struct scp_domain_data - scp domain data for power on/off flow
+ * @name: The domain name.
+ * @sta_mask: The mask for power on/off status bit.
+ * @ctl_offs: The offset for main power control register.
+ * @sram_pdn_bits: The mask for sram power control bits.
+ * @sram_pdn_ack_bits: The mask for sram power control acked bits.
+ * @bus_prot_mask: The mask for single step bus protection.
+ * @clk_id: The basic clock needs to be enabled before enabling certain
+ *          power domains.
+ * @basic_clk_name: provide the same purpose with field "clk_id"
+ *                  by declaring basic clock prefix name rather than clk_id.
+ * @subsys_clk_prefix: The prefix name of the clocks need to be enabled
+ *                     before releasing bus protection.
+ * @caps: The flag for active wake-up action.
+ * @bp_table: The mask table for multiple step bus protection.
+ */
 struct scp_domain_data {
 	const char *name;
 	u32 sta_mask;
 	int ctl_offs;
+	bool sram_iso_ctrl;
 	u32 sram_pdn_bits;
 	u32 sram_pdn_ack_bits;
 	u32 bus_prot_mask;
 	enum clk_id clk_id[MAX_CLKS];
+	const char *basic_clk_name[MAX_CLKS];
+	const char *subsys_clk_prefix;
 	u8 caps;
+	struct bus_prot bp_table[MAX_STEPS];
 };
 
 struct scp;
@@ -133,6 +151,7 @@  struct scp_domain {
 	struct generic_pm_domain genpd;
 	struct scp *scp;
 	struct clk *clk[MAX_CLKS];
+	struct clk *subsys_clk[MAX_SUBSYS_CLKS];
 	const struct scp_domain_data *data;
 	struct regulator *supply;
 };
@@ -148,6 +167,7 @@  struct scp {
 	struct device *dev;
 	void __iomem *base;
 	struct regmap *infracfg;
+	struct regmap *smi_common;
 	struct scp_ctrl_reg ctrl_reg;
 	bool bus_prot_reg_update;
 };
@@ -188,32 +208,166 @@  static int scpsys_domain_is_on(struct scp_domain *scpd)
 	return -EINVAL;
 }
 
+static int scpsys_regulator_enable(struct scp_domain *scpd)
+{
+	if (!scpd->supply)
+		return 0;
+	else
+		return regulator_enable(scpd->supply);
+}
+
+static int scpsys_regulator_disable(struct scp_domain *scpd)
+{
+	if (!scpd->supply)
+		return 0;
+	else
+		return regulator_disable(scpd->supply);
+}
+
+static int scpsys_clk_enable(struct clk *clk[], int max_num)
+{
+	int i, ret = 0;
+
+	for (i = 0; i < max_num && clk[i]; i++) {
+		ret = clk_prepare_enable(clk[i]);
+		if (ret) {
+			for (--i; i >= 0; i--)
+				clk_disable_unprepare(clk[i]);
+
+			break;
+		}
+	}
+
+	return ret;
+}
+
+static int scpsys_clk_disable(struct clk *clk[], int max_num)
+{
+	int i;
+
+	for (i = max_num - 1; i >= 0; i--) {
+		if (clk[i])
+			clk_disable_unprepare(clk[i]);
+	}
+
+	return 0;
+}
+
+static int scpsys_sram_enable(struct scp_domain *scpd, void __iomem *ctl_addr)
+{
+	u32 val;
+	u32 pdn_ack = scpd->data->sram_pdn_ack_bits;
+	int tmp, ret = 0;
+
+	val = readl(ctl_addr) & ~scpd->data->sram_pdn_bits;
+	writel(val, ctl_addr);
+
+	/* Either wait until SRAM_PDN_ACK all 0 or have a force wait */
+	if (MTK_SCPD_CAPS(scpd, MTK_SCPD_FWAIT_SRAM)) {
+		/*
+		 * Currently, MTK_SCPD_FWAIT_SRAM is necessary only for
+		 * MT7622_POWER_DOMAIN_WB and thus just a trivial setup
+		 * is applied here.
+		 */
+		usleep_range(12000, 12100);
+	} else {
+		/* Either wait until SRAM_PDN_ACK all 1 or 0 */
+		ret = readl_poll_timeout(ctl_addr, tmp,
+				(tmp & pdn_ack) == 0,
+				MTK_POLL_DELAY_US, MTK_POLL_TIMEOUT);
+	}
+
+	if (scpd->data->sram_iso_ctrl)	{
+		val = readl(ctl_addr) | PWR_SRAM_ISOINT_B_BIT;
+		writel(val, ctl_addr);
+		udelay(1);
+		val &= ~PWR_SRAM_CLKISO_BIT;
+		writel(val, ctl_addr);
+	}
+
+	return ret;
+}
+
+static int scpsys_sram_disable(struct scp_domain *scpd, void __iomem *ctl_addr)
+{
+	u32 val;
+	u32 pdn_ack = scpd->data->sram_pdn_ack_bits;
+	int tmp, ret = 0;
+
+	if (scpd->data->sram_iso_ctrl)	{
+		val = readl(ctl_addr);
+		val |= PWR_SRAM_CLKISO_BIT;
+		writel(val, ctl_addr);
+		val &= ~PWR_SRAM_ISOINT_B_BIT;
+		writel(val, ctl_addr);
+		udelay(1);
+	}
+
+	val = readl(ctl_addr) | scpd->data->sram_pdn_bits;
+	writel(val, ctl_addr);
+
+	/* Either wait until SRAM_PDN_ACK all 1 or 0 */
+	ret = readl_poll_timeout(ctl_addr, tmp,
+			(tmp & pdn_ack) == pdn_ack,
+			MTK_POLL_DELAY_US, MTK_POLL_TIMEOUT);
+
+	return ret;
+}
+
+static int scpsys_bus_protect_enable(struct scp_domain *scpd)
+{
+	struct scp *scp = scpd->scp;
+	int ret = 0;
+
+	if (scpd->data->bus_prot_mask) {
+		ret = mtk_infracfg_set_bus_protection(scp->infracfg,
+				scpd->data->bus_prot_mask,
+				scp->bus_prot_reg_update);
+	} else if (scpd->data->bp_table[0].mask) {
+		ret = mtk_scpsys_ext_set_bus_protection(scpd->data->bp_table,
+				scp->infracfg,
+				scp->smi_common);
+	}
+
+	return ret;
+}
+
+static int scpsys_bus_protect_disable(struct scp_domain *scpd)
+{
+	struct scp *scp = scpd->scp;
+	int ret = 0;
+
+	if (scpd->data->bus_prot_mask) {
+		ret = mtk_infracfg_clear_bus_protection(scp->infracfg,
+				scpd->data->bus_prot_mask,
+				scp->bus_prot_reg_update);
+	} else if (scpd->data->bp_table[0].mask) {
+		ret = mtk_scpsys_ext_clear_bus_protection(
+				scpd->data->bp_table,
+				scp->infracfg,
+				scp->smi_common);
+	}
+
+	return ret;
+}
+
 static int scpsys_power_on(struct generic_pm_domain *genpd)
 {
 	struct scp_domain *scpd = container_of(genpd, struct scp_domain, genpd);
 	struct scp *scp = scpd->scp;
 	void __iomem *ctl_addr = scp->base + scpd->data->ctl_offs;
-	u32 pdn_ack = scpd->data->sram_pdn_ack_bits;
 	u32 val;
 	int ret, tmp;
-	int i;
-
-	if (scpd->supply) {
-		ret = regulator_enable(scpd->supply);
-		if (ret)
-			return ret;
-	}
 
-	for (i = 0; i < MAX_CLKS && scpd->clk[i]; i++) {
-		ret = clk_prepare_enable(scpd->clk[i]);
-		if (ret) {
-			for (--i; i >= 0; i--)
-				clk_disable_unprepare(scpd->clk[i]);
+	ret = scpsys_regulator_enable(scpd);
+	if (ret < 0)
+		return ret;
 
-			goto err_clk;
-		}
-	}
+	ret = scpsys_clk_enable(scpd->clk, MAX_CLKS);
+	if (ret)
+		goto err_clk;
 
+	/* subsys power on */
 	val = readl(ctl_addr);
 	val |= PWR_ON_BIT;
 	writel(val, ctl_addr);
@@ -235,43 +389,26 @@  static int scpsys_power_on(struct generic_pm_domain *genpd)
 	val |= PWR_RST_B_BIT;
 	writel(val, ctl_addr);
 
-	val &= ~scpd->data->sram_pdn_bits;
-	writel(val, ctl_addr);
-
-	/* Either wait until SRAM_PDN_ACK all 0 or have a force wait */
-	if (MTK_SCPD_CAPS(scpd, MTK_SCPD_FWAIT_SRAM)) {
-		/*
-		 * Currently, MTK_SCPD_FWAIT_SRAM is necessary only for
-		 * MT7622_POWER_DOMAIN_WB and thus just a trivial setup is
-		 * applied here.
-		 */
-		usleep_range(12000, 12100);
+	ret = scpsys_clk_enable(scpd->subsys_clk, MAX_SUBSYS_CLKS);
+	if (ret < 0)
+		goto err_pwr_ack;
 
-	} else {
-		ret = readl_poll_timeout(ctl_addr, tmp, (tmp & pdn_ack) == 0,
-					 MTK_POLL_DELAY_US, MTK_POLL_TIMEOUT);
-		if (ret < 0)
-			goto err_pwr_ack;
-	}
+	ret = scpsys_sram_enable(scpd, ctl_addr);
+	if (ret < 0)
+		goto err_sram;
 
-	if (scpd->data->bus_prot_mask) {
-		ret = mtk_infracfg_clear_bus_protection(scp->infracfg,
-				scpd->data->bus_prot_mask,
-				scp->bus_prot_reg_update);
-		if (ret)
-			goto err_pwr_ack;
-	}
+	ret = scpsys_bus_protect_disable(scpd);
+	if (ret < 0)
+		goto err_sram;
 
 	return 0;
 
+err_sram:
+	scpsys_clk_disable(scpd->subsys_clk, MAX_SUBSYS_CLKS);
 err_pwr_ack:
-	for (i = MAX_CLKS - 1; i >= 0; i--) {
-		if (scpd->clk[i])
-			clk_disable_unprepare(scpd->clk[i]);
-	}
+	scpsys_clk_disable(scpd->clk, MAX_CLKS);
 err_clk:
-	if (scpd->supply)
-		regulator_disable(scpd->supply);
+	scpsys_regulator_disable(scpd);
 
 	dev_err(scp->dev, "Failed to power on domain %s\n", genpd->name);
 
@@ -283,29 +420,21 @@  static int scpsys_power_off(struct generic_pm_domain *genpd)
 	struct scp_domain *scpd = container_of(genpd, struct scp_domain, genpd);
 	struct scp *scp = scpd->scp;
 	void __iomem *ctl_addr = scp->base + scpd->data->ctl_offs;
-	u32 pdn_ack = scpd->data->sram_pdn_ack_bits;
 	u32 val;
 	int ret, tmp;
-	int i;
 
-	if (scpd->data->bus_prot_mask) {
-		ret = mtk_infracfg_set_bus_protection(scp->infracfg,
-				scpd->data->bus_prot_mask,
-				scp->bus_prot_reg_update);
-		if (ret)
-			goto out;
-	}
-
-	val = readl(ctl_addr);
-	val |= scpd->data->sram_pdn_bits;
-	writel(val, ctl_addr);
+	ret = scpsys_bus_protect_enable(scpd);
+	if (ret < 0)
+		goto out;
 
-	/* wait until SRAM_PDN_ACK all 1 */
-	ret = readl_poll_timeout(ctl_addr, tmp, (tmp & pdn_ack) == pdn_ack,
-				 MTK_POLL_DELAY_US, MTK_POLL_TIMEOUT);
+	ret = scpsys_sram_disable(scpd, ctl_addr);
 	if (ret < 0)
 		goto out;
 
+	ret = scpsys_clk_disable(scpd->subsys_clk, MAX_SUBSYS_CLKS);
+
+	/* subsys power off */
+	val = readl(ctl_addr);
 	val |= PWR_ISO_BIT;
 	writel(val, ctl_addr);
 
@@ -327,11 +456,9 @@  static int scpsys_power_off(struct generic_pm_domain *genpd)
 	if (ret < 0)
 		goto out;
 
-	for (i = 0; i < MAX_CLKS && scpd->clk[i]; i++)
-		clk_disable_unprepare(scpd->clk[i]);
+	scpsys_clk_disable(scpd->clk, MAX_CLKS);
 
-	if (scpd->supply)
-		regulator_disable(scpd->supply);
+	scpsys_regulator_disable(scpd);
 
 	return 0;
 
@@ -341,6 +468,65 @@  static int scpsys_power_off(struct generic_pm_domain *genpd)
 	return ret;
 }
 
+static int init_subsys_clks(struct platform_device *pdev,
+		const char *prefix, struct clk **clk)
+{
+	struct device_node *node = pdev->dev.of_node;
+	u32 prefix_len, sub_clk_cnt = 0;
+	int str_sz, clk_idx, ret;
+
+	if (!node) {
+		dev_err(&pdev->dev, "Cannot find scpsys node: %ld\n",
+			PTR_ERR(node));
+		return PTR_ERR(node);
+	}
+
+	str_sz = of_property_count_strings(node, "clock-names");
+	if (str_sz < 0) {
+		dev_err(&pdev->dev, "Cannot get any subsys strings: %d\n",
+				str_sz);
+		return str_sz;
+	}
+
+	prefix_len = strlen(prefix);
+
+	for (clk_idx = 0; clk_idx < str_sz; clk_idx++) {
+		const char *clk_name;
+
+		ret = of_property_read_string_index(node, "clock-names",
+					clk_idx, &clk_name);
+		if (ret < 0) {
+			dev_err(&pdev->dev,
+					"Cannot read subsys string[%d]: %d\n",
+					clk_idx, ret);
+			return ret;
+		}
+
+		if (!strncmp(clk_name, prefix, prefix_len) &&
+				(clk_name[prefix_len] == '-')) {
+			if (sub_clk_cnt >= MAX_SUBSYS_CLKS) {
+				dev_err(&pdev->dev,
+					"subsys clk out of range %d\n",
+					sub_clk_cnt);
+				return -ENOMEM;
+			}
+
+			clk[sub_clk_cnt] = devm_clk_get(&pdev->dev,
+						clk_name);
+
+			if (IS_ERR(clk)) {
+				dev_err(&pdev->dev,
+					"Subsys clk read fail %ld\n",
+					PTR_ERR(clk));
+				return PTR_ERR(clk);
+			}
+			sub_clk_cnt++;
+		}
+	}
+
+	return sub_clk_cnt;
+}
+
 static void init_clks(struct platform_device *pdev, struct clk **clk)
 {
 	int i;
@@ -396,6 +582,17 @@  static struct scp *init_scp(struct platform_device *pdev,
 		return ERR_CAST(scp->infracfg);
 	}
 
+	scp->smi_common = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
+			"smi_comm");
+
+	if (scp->smi_common == ERR_PTR(-ENODEV)) {
+		scp->smi_common = NULL;
+	} else if (IS_ERR(scp->smi_common)) {
+		dev_err(&pdev->dev, "Cannot find smi_common controller: %ld\n",
+				PTR_ERR(scp->smi_common));
+		return ERR_CAST(scp->smi_common);
+	}
+
 	for (i = 0; i < num; i++) {
 		struct scp_domain *scpd = &scp->domains[i];
 		const struct scp_domain_data *data = &scp_domain_data[i];
@@ -417,22 +614,43 @@  static struct scp *init_scp(struct platform_device *pdev,
 		struct scp_domain *scpd = &scp->domains[i];
 		struct generic_pm_domain *genpd = &scpd->genpd;
 		const struct scp_domain_data *data = &scp_domain_data[i];
+		int clk_cnt;
 
 		pd_data->domains[i] = genpd;
 		scpd->scp = scp;
 
 		scpd->data = data;
 
-		for (j = 0; j < MAX_CLKS && data->clk_id[j]; j++) {
-			struct clk *c = clk[data->clk_id[j]];
+		if (data->clk_id[0]) {
+			for (j = 0; j < MAX_CLKS && data->clk_id[j]; j++) {
+				struct clk *c = clk[data->clk_id[j]];
 
-			if (IS_ERR(c)) {
-				dev_err(&pdev->dev, "%s: clk unavailable\n",
-					data->name);
-				return ERR_CAST(c);
+				if (IS_ERR(c)) {
+					dev_err(&pdev->dev,
+						"%s: clk unavailable\n",
+						data->name);
+					return ERR_CAST(c);
+				}
+
+				scpd->clk[j] = c;
 			}
+		} else if (data->basic_clk_name[0]) {
+			for (j = 0; j < MAX_CLKS &&
+					data->basic_clk_name[j]; j++)
+				scpd->clk[j] = devm_clk_get(&pdev->dev,
+						data->basic_clk_name[j]);
+		}
 
-			scpd->clk[j] = c;
+		if (data->subsys_clk_prefix) {
+			clk_cnt = init_subsys_clks(pdev,
+					data->subsys_clk_prefix,
+					scpd->subsys_clk);
+			if (clk_cnt < 0) {
+				dev_err(&pdev->dev,
+					"%s: subsys clk unavailable\n",
+					data->name);
+				return ERR_PTR(clk_cnt);
+			}
 		}
 
 		genpd->name = data->name;
diff --git a/include/linux/soc/mediatek/scpsys-ext.h b/include/linux/soc/mediatek/scpsys-ext.h
new file mode 100644
index 000000000000..d0ed295c88a7
--- /dev/null
+++ b/include/linux/soc/mediatek/scpsys-ext.h
@@ -0,0 +1,39 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __SOC_MEDIATEK_SCPSYS_EXT_H
+#define __SOC_MEDIATEK_SCPSYS_EXT_H
+
+#define MAX_STEPS	4
+
+#define BUS_PROT(_type, _set_ofs, _clr_ofs,			\
+		_en_ofs, _sta_ofs, _mask, _clr_ack_mask) {	\
+		.type = _type,					\
+		.set_ofs = _set_ofs,				\
+		.clr_ofs = _clr_ofs,				\
+		.en_ofs = _en_ofs,				\
+		.sta_ofs = _sta_ofs,				\
+		.mask = _mask,					\
+		.clr_ack_mask = _clr_ack_mask,			\
+	}
+
+enum regmap_type {
+	IFR_TYPE,
+	SMI_TYPE,
+	MAX_REGMAP_TYPE,
+};
+
+struct bus_prot {
+	enum regmap_type type;
+	u32 set_ofs;
+	u32 clr_ofs;
+	u32 en_ofs;
+	u32 sta_ofs;
+	u32 mask;
+	u32 clr_ack_mask;
+};
+
+int mtk_scpsys_ext_set_bus_protection(const struct bus_prot *bp_table,
+	struct regmap *infracfg, struct regmap *smi_common);
+int mtk_scpsys_ext_clear_bus_protection(const struct bus_prot *bp_table,
+	struct regmap *infracfg, struct regmap *smi_common);
+
+#endif /* __SOC_MEDIATEK_SCPSYS_EXT_H */