[PATCH v2 04/11] soc: mediatek: add new flow for mtcmos power.

Nicolas Boichat
2018-11-27T05:57:52Z

On Tue, Nov 27, 2018 at 11:43 AM Weiyi Lu <weiyi.lu@mediatek.com> wrote:
>
> From: Owen Chen <owen.chen@mediatek.com>
>
> 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 <owen.chen@mediatek.com>
> Signed-off-by: Mars Cheng <mars.cheng@mediatek.com>
> Signed-off-by: Weiyi Lu <weiyi.lu@mediatek.com>
> ---
> drivers/soc/mediatek/Makefile | 2 +-
> drivers/soc/mediatek/mtk-scpsys-ext.c | 99 +++++++
> drivers/soc/mediatek/mtk-scpsys.c | 379 +++++++++++++++++++-----
> include/linux/soc/mediatek/scpsys-ext.h | 39 +++
> 4 files changed, 448 insertions(+), 71 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 <Owen.Chen@mediatek.com>
> + */
> +#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..80be2e05e4e0 100644
> --- a/drivers/soc/mediatek/mtk-scpsys.c
> +++ b/drivers/soc/mediatek/mtk-scpsys.c
> @@ -1,3 +1,4 @@
> +// SPDX-License-Identifier: GPL-2.0

If you add the SPDX header, should you remove the licence boilerplate below?

> /*
> * Copyright (c) 2015 Pengutronix, Sascha Hauer <kernel@pengutronix.de>
> *
> @@ -20,6 +21,7 @@
> #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 +66,8 @@
> #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 +119,38 @@ 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 rathan than clk_id.

*rather

> + * @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 +159,7 @@ 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 +175,7 @@ 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;
> };
> @@ -188,20 +216,26 @@ static int scpsys_domain_is_on(struct scp_domain *scpd)
> return -EINVAL;
> }
>
> -static int scpsys_power_on(struct generic_pm_domain *genpd)
> +static int scpsys_regulator_onoff(struct scp_domain *scpd, bool on)

This function is so simple that I'm not sure why it was added.
Wouldn't be generally simpler to just call
regulator_enable/disable(scpd->supply) in the code below? (as was done
before this refactoring)

> {
> - 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;
> + struct regulator *s = scpd->supply;
> +
> + if (!s)
> + return 0;
> +
> + return on ? regulator_enable(s) : regulator_disable(s);
> +}
> +
> +static int scpsys_basic_clk_onoff(struct scp_domain *scpd, bool on)

I don't find this pattern particularly nice:
int func_onoff(bool on) {
if (on) enable();
else disable();
}

Especially give that you always call func_onoff with either hard-coded
true or false parameter.

I think 2 sets of functions (func_enable and func_disable) is probably
better in this case.

> +{
> + int ret = 0;
> int i;
>
> - if (scpd->supply) {
> - ret = regulator_enable(scpd->supply);
> - if (ret)
> - return ret;
> + if (!on) {
> + for (i = 0; i < MAX_CLKS && scpd->clk[i]; i++)
> + clk_disable_unprepare(scpd->clk[i]);
> +
> + return ret;
> }
>
> for (i = 0; i < MAX_CLKS && scpd->clk[i]; i++) {
> @@ -210,10 +244,147 @@ static int scpsys_power_on(struct generic_pm_domain *genpd)
> for (--i; i >= 0; i--)
> clk_disable_unprepare(scpd->clk[i]);
>
> - goto err_clk;
> + break;
> }
> }
>
> + return ret;
> +}
> +
> +static int scpsys_sram_onoff(struct scp_domain *scpd, void __iomem *ctl_addr,
> + bool on)

This one is a little more borderline, but IMHO enable/disable would
still be more readable.

> +{
> + u32 val, ack;
> + int tmp;
> + int ret = 0;
> + u32 pdn_ack = scpd->data->sram_pdn_ack_bits;
> +
> + if (!on && 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);
> + if (on) {
> + val &= ~scpd->data->sram_pdn_bits;
> + ack = 0;
> + } else {
> + val |= scpd->data->sram_pdn_bits;
> + ack = pdn_ack;
> + }
> + writel(val, ctl_addr);
> +
> + /* Either wait until SRAM_PDN_ACK all 0 or have a force wait */
> + if (on && 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) == ack,
> + MTK_POLL_DELAY_US, MTK_POLL_TIMEOUT);
> +
> + if (on && scpd->data->sram_iso_ctrl) {
> + val = readl(ctl_addr);
> + val |= 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_subsys_clk_onoff(struct scp_domain *scpd, bool on)

enable/disable for this one.

> +{
> + int ret = 0;
> + int i;
> +
> + if (!on) {
> + for (i = MAX_SUBSYS_CLKS - 1; i >= 0; i--) {
> + struct clk *clk = scpd->subsys_clk[i];
> +
> + if (clk)
> + clk_disable_unprepare(clk);
> + }
> +
> + return ret;
> + }
> +
> + for (i = 0; i < MAX_SUBSYS_CLKS && scpd->subsys_clk[i]; i++) {
> + struct clk *clk = scpd->subsys_clk[i];
> +
> + ret = clk_prepare_enable(clk);
> + if (ret) {
> + for (--i; i >= 0; i--) {
> + struct clk *clk = scpd->subsys_clk[i];
> +
> + clk_disable_unprepare(clk);
> + }
> +
> + break;
> + }
> + }
> +
> + return ret;
> +}
> +
> +static int scpsys_bus_protect_onoff(struct scp_domain *scpd, bool on)

I'd also do an enable/disable pair of function, that could look very simple:

...
{
...
if (scpd->data->bus_prot_mask)
return mtk_infracfg_set_bus_protection(scp->infracfg,
scpd->data->bus_prot_mask,
scp->bus_prot_reg_update);
else
return mtk_scpsys_ext_set_bus_protection(
scpd->data->bp_table,
scp->infracfg,
scp->smi_common);
return 0;
}

> +{
> + struct scp *scp = scpd->scp;
> + int ret = 0;
> +
> + if (scpd->data->bus_prot_mask) {
> + if (on)
> + ret = mtk_infracfg_set_bus_protection(scp->infracfg,
> + scpd->data->bus_prot_mask,
> + scp->bus_prot_reg_update);
> + else
> + 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) {
> + if (on)
> + ret = mtk_scpsys_ext_set_bus_protection(
> + scpd->data->bp_table,
> + scp->infracfg,
> + scp->smi_common);
> + else
> + 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 val;
> + int ret, tmp;
> +
> + ret = scpsys_regulator_onoff(scpd, true);
> + if (ret < 0)
> + return ret;
> +
> + ret = scpsys_basic_clk_onoff(scpd, true);
> + if (ret)
> + goto err_clk;
> +
> + /* subsys power on */
> val = readl(ctl_addr);
> val |= PWR_ON_BIT;
> writel(val, ctl_addr);
> @@ -226,6 +397,7 @@ static int scpsys_power_on(struct generic_pm_domain *genpd)
> if (ret < 0)
> goto err_pwr_ack;
>
> +

This extra blank line still needs to be removed.

> val &= ~PWR_CLK_DIS_BIT;
> writel(val, ctl_addr);
>
> @@ -235,43 +407,26 @@ 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_subsys_clk_onoff(scpd, true);
> + 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_onoff(scpd, ctl_addr, true);
> + 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_onoff(scpd, false);
> + if (ret < 0)
> + goto err_sram;
>
> return 0;
>
> +err_sram:
> + scpsys_subsys_clk_onoff(scpd, false);
> err_pwr_ack:
> - for (i = MAX_CLKS - 1; i >= 0; i--) {
> - if (scpd->clk[i])
> - clk_disable_unprepare(scpd->clk[i]);
> - }
> + scpsys_basic_clk_onoff(scpd, false);
> err_clk:
> - if (scpd->supply)
> - regulator_disable(scpd->supply);
> + scpsys_regulator_onoff(scpd, false);
>
> dev_err(scp->dev, "Failed to power on domain %s\n", genpd->name);
>
> @@ -283,29 +438,21 @@ 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_onoff(scpd, true);
> + 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_onoff(scpd, ctl_addr, false);
> if (ret < 0)
> goto out;
>
> + ret = scpsys_subsys_clk_onoff(scpd, false);
> +
> + /* subsys power off */
> + val = readl(ctl_addr);
> val |= PWR_ISO_BIT;
> writel(val, ctl_addr);
>
> @@ -327,11 +474,9 @@ 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_basic_clk_onoff(scpd, false);
>
> - if (scpd->supply)
> - regulator_disable(scpd->supply);
> + scpsys_regulator_onoff(scpd, false);
>
> return 0;
>
> @@ -341,6 +486,69 @@ 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 sub_clk_cnt = 0;
> + u32 prefix_len = 0;
> + int str_sz = 0;

These last 2 don't need to be initialized to 0.

> + int clk_idx;
> + int ret = 0;

No need to initialize to 0.

> +
> + 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)
> + && (strchr(clk_name + prefix_len, '-')

Shouldn't this just be clk_name[prefix_len] == '-' ? At least that's
how it seems to work right now ("mm" matches "mm-0", "mm-1", etc.)

Also, I'm wondering if this prefix matching approach is best, but I'll
let other people comment.

> + != NULL)) {
> + 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 +604,17 @@ 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 +636,42 @@ 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 = 0;

No need to init to 0.

>
> 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",
> + scpd->clk[j] = c;
> + }
> + else if (data->basic_clk_name[0])

Please use brackets {} here, makes the code clearer (even though
technically there is only one statement below).

> + 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]);
> +
> + 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_CAST(c);
> + return ERR_PTR(clk_cnt);
> }
> -
> - scpd->clk[j] = c;
> }
>
> 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
>