diff mbox

[2/4] soc: Mediatek: Add SCPSYS power domain driver

Message ID 1431349882-12260-3-git-send-email-s.hauer@pengutronix.de
State New, archived
Headers show

Commit Message

Sascha Hauer May 11, 2015, 1:11 p.m. UTC
This adds a power domain driver for the Mediatek SCPSYS unit.

The System Control Processor System (SCPSYS) has several power
management related tasks in the system. The tasks include thermal
measurement, dynamic voltage frequency scaling (DVFS), interrupt
filter and lowlevel sleep control. The System Power Manager (SPM)
inside the SCPSYS is for the MTCMOS power domain control.

For now this driver only adds power domain support, the more
advanced features are not yet supported. The driver implements
the generic PM domain device tree bindings, the first user will
most likely be the Mediatek AFE audio driver.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 drivers/soc/mediatek/Kconfig             |   6 +
 drivers/soc/mediatek/Makefile            |   1 +
 drivers/soc/mediatek/mtk-scpsys.c        | 345 +++++++++++++++++++++++++++++++
 include/dt-bindings/power/mt8173-power.h |  15 ++
 4 files changed, 367 insertions(+)
 create mode 100644 drivers/soc/mediatek/mtk-scpsys.c
 create mode 100644 include/dt-bindings/power/mt8173-power.h

Comments

Kevin Hilman May 26, 2015, 10:35 p.m. UTC | #1
Sascha Hauer <s.hauer@pengutronix.de> writes:

> This adds a power domain driver for the Mediatek SCPSYS unit.
>
> The System Control Processor System (SCPSYS) has several power
> management related tasks in the system. The tasks include thermal
> measurement, dynamic voltage frequency scaling (DVFS), interrupt
> filter and lowlevel sleep control. The System Power Manager (SPM)
> inside the SCPSYS is for the MTCMOS power domain control.
>
> For now this driver only adds power domain support, the more
> advanced features are not yet supported. The driver implements
> the generic PM domain device tree bindings, the first user will
> most likely be the Mediatek AFE audio driver.
>
> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
> ---
>  drivers/soc/mediatek/Kconfig             |   6 +
>  drivers/soc/mediatek/Makefile            |   1 +
>  drivers/soc/mediatek/mtk-scpsys.c        | 345 +++++++++++++++++++++++++++++++
>  include/dt-bindings/power/mt8173-power.h |  15 ++
>  4 files changed, 367 insertions(+)
>  create mode 100644 drivers/soc/mediatek/mtk-scpsys.c
>  create mode 100644 include/dt-bindings/power/mt8173-power.h
>
> diff --git a/drivers/soc/mediatek/Kconfig b/drivers/soc/mediatek/Kconfig
> index bcdb22d..1d34819 100644
> --- a/drivers/soc/mediatek/Kconfig
> +++ b/drivers/soc/mediatek/Kconfig
> @@ -9,3 +9,9 @@ config MTK_PMIC_WRAP
>  	  Say yes here to add support for MediaTek PMIC Wrapper found
>  	  on different MediaTek SoCs. The PMIC wrapper is a proprietary
>  	  hardware to connect the PMIC.
> +
> +config MTK_SCPSYS
> +	tristate "MediaTek SCPSYS Support"

depends on ARCH_MEDIATEK ?

> +	help
> +	  Say yes here to add support for the MediaTek SCPSYS power domain
> +	  driver.

[...]

> +static int scpsys_probe(struct platform_device *pdev)
> +{
> +	struct genpd_onecell_data *pd_data;
> +	struct resource *res;
> +	int i;
> +	struct scp *scp;
> +
> +	scp = devm_kzalloc(&pdev->dev, sizeof(*scp), GFP_KERNEL);
> +	if (!scp)
> +		return -ENOMEM;
> +
> +	scp->dev = &pdev->dev;
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	scp->base = devm_ioremap_resource(&pdev->dev, res);
> +	if (IS_ERR(scp->base))
> +		return PTR_ERR(scp->base);
> +
> +	pd_data = &scp->pd_data;
> +
> +	pd_data->domains = scp->pmd;
> +	pd_data->num_domains = NUM_DOMAINS;
> +
> +	for (i = 0; i < NUM_DOMAINS; i++) {
> +		struct scp_domain *scpd = &scp->domains[i];
> +		struct generic_pm_domain *pmd = &scpd->pmd;
> +
> +		scp->pmd[i] = pmd;
> +		scpd->data = &scp_domain_data[i];
> +		scpd->scp = scp;
> +
> +		pmd->name = scp_domain_data[i].name;
> +		pmd->power_off = scpsys_power_off;
> +		pmd->power_on = scpsys_power_on;
> +		pmd->power_off_latency_ns = 20000;
> +		pmd->power_on_latency_ns = 20000;

I think I mentioned this before... are these numbers really identical
for all domains?  I suggest you make these each a field in the domain
data so they can be different for each domain, and eventually come from
DT data.

> +		pd_data->domains[i] = pmd;
> +		pm_genpd_init(pmd, NULL, 1);
> +
> +		/*
> +		 * If PM is disabled turn on all domains by default so that
> +		 * consumers can work.
> +		 */
> +		if (!IS_ENABLED(CONFIG_PM))
> +			pmd->power_on(pmd);
> +	}
> +
> +	return of_genpd_add_provider_onecell(pdev->dev.of_node, pd_data);
> +}

Kevin
Sascha Hauer May 27, 2015, 6:24 a.m. UTC | #2
On Tue, May 26, 2015 at 03:35:14PM -0700, Kevin Hilman wrote:
> Sascha Hauer <s.hauer@pengutronix.de> writes:
> 
> > This adds a power domain driver for the Mediatek SCPSYS unit.
> >
> > The System Control Processor System (SCPSYS) has several power
> > management related tasks in the system. The tasks include thermal
> > measurement, dynamic voltage frequency scaling (DVFS), interrupt
> > filter and lowlevel sleep control. The System Power Manager (SPM)
> > inside the SCPSYS is for the MTCMOS power domain control.
> >
> > For now this driver only adds power domain support, the more
> > advanced features are not yet supported. The driver implements
> > the generic PM domain device tree bindings, the first user will
> > most likely be the Mediatek AFE audio driver.
> >
> > Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
> > ---
> >  drivers/soc/mediatek/Kconfig             |   6 +
> >  drivers/soc/mediatek/Makefile            |   1 +
> >  drivers/soc/mediatek/mtk-scpsys.c        | 345 +++++++++++++++++++++++++++++++
> >  include/dt-bindings/power/mt8173-power.h |  15 ++
> >  4 files changed, 367 insertions(+)
> >  create mode 100644 drivers/soc/mediatek/mtk-scpsys.c
> >  create mode 100644 include/dt-bindings/power/mt8173-power.h
> >
> > diff --git a/drivers/soc/mediatek/Kconfig b/drivers/soc/mediatek/Kconfig
> > index bcdb22d..1d34819 100644
> > --- a/drivers/soc/mediatek/Kconfig
> > +++ b/drivers/soc/mediatek/Kconfig
> > @@ -9,3 +9,9 @@ config MTK_PMIC_WRAP
> >  	  Say yes here to add support for MediaTek PMIC Wrapper found
> >  	  on different MediaTek SoCs. The PMIC wrapper is a proprietary
> >  	  hardware to connect the PMIC.
> > +
> > +config MTK_SCPSYS
> > +	tristate "MediaTek SCPSYS Support"
> 
> depends on ARCH_MEDIATEK ?

You are reviewing v2 of this series. This is already fixed in v3 sent
out last wednesday.

> > +	for (i = 0; i < NUM_DOMAINS; i++) {
> > +		struct scp_domain *scpd = &scp->domains[i];
> > +		struct generic_pm_domain *pmd = &scpd->pmd;
> > +
> > +		scp->pmd[i] = pmd;
> > +		scpd->data = &scp_domain_data[i];
> > +		scpd->scp = scp;
> > +
> > +		pmd->name = scp_domain_data[i].name;
> > +		pmd->power_off = scpsys_power_off;
> > +		pmd->power_on = scpsys_power_on;
> > +		pmd->power_off_latency_ns = 20000;
> > +		pmd->power_on_latency_ns = 20000;
> 
> I think I mentioned this before... are these numbers really identical
> for all domains?  I suggest you make these each a field in the domain
> data so they can be different for each domain, and eventually come from
> DT data.

For the record, here are the numbers I just measured:

mtk-scpsys 10006000.scpsys:       vdec on: 31000 off: 10769
mtk-scpsys 10006000.scpsys:       venc on:  6000 off:  5923
mtk-scpsys 10006000.scpsys:        isp on:  5923 off:  5923
mtk-scpsys 10006000.scpsys:         mm on:  7616 off:  7692
mtk-scpsys 10006000.scpsys:    venc_lt on:  5924 off:  6000
mtk-scpsys 10006000.scpsys:      audio on:  5462 off:  5615
mtk-scpsys 10006000.scpsys:        usb on:  5461 off:  5462
mtk-scpsys 10006000.scpsys:  mfg_async on: 29923 off: 11077
mtk-scpsys 10006000.scpsys:     mfg_2d on:  5923 off:  5616
mtk-scpsys 10006000.scpsys:        mfg on: 11231 off: 16153

Anyway, the pm domain core measures these times itself, so there
should not be a need to fill in anything here. I was irritated by the
warning message I got each time when the times were exceeded. This
message seemed to imply that something was wrong and I had to fill
in sane values in the latency fields. Since we now have [1] I'll just
drop the initialisation of these fields.

Sascha

[1]

commit 6d7d5c3266aa946b2049d9fed02186c1a378621b
Author: Russell King <rmk+kernel@arm.linux.org.uk>
Date:   Fri Mar 20 17:20:28 2015 +0000

    PM / domains: quieten down generic pm domains
Kevin Hilman May 28, 2015, 5:22 p.m. UTC | #3
Sascha Hauer <s.hauer@pengutronix.de> writes:

> On Tue, May 26, 2015 at 03:35:14PM -0700, Kevin Hilman wrote:
>> Sascha Hauer <s.hauer@pengutronix.de> writes:
>> 
>> > This adds a power domain driver for the Mediatek SCPSYS unit.
>> >
>> > The System Control Processor System (SCPSYS) has several power
>> > management related tasks in the system. The tasks include thermal
>> > measurement, dynamic voltage frequency scaling (DVFS), interrupt
>> > filter and lowlevel sleep control. The System Power Manager (SPM)
>> > inside the SCPSYS is for the MTCMOS power domain control.
>> >
>> > For now this driver only adds power domain support, the more
>> > advanced features are not yet supported. The driver implements
>> > the generic PM domain device tree bindings, the first user will
>> > most likely be the Mediatek AFE audio driver.
>> >
>> > Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
>> > ---
>> >  drivers/soc/mediatek/Kconfig             |   6 +
>> >  drivers/soc/mediatek/Makefile            |   1 +
>> >  drivers/soc/mediatek/mtk-scpsys.c        | 345 +++++++++++++++++++++++++++++++
>> >  include/dt-bindings/power/mt8173-power.h |  15 ++
>> >  4 files changed, 367 insertions(+)
>> >  create mode 100644 drivers/soc/mediatek/mtk-scpsys.c
>> >  create mode 100644 include/dt-bindings/power/mt8173-power.h
>> >
>> > diff --git a/drivers/soc/mediatek/Kconfig b/drivers/soc/mediatek/Kconfig
>> > index bcdb22d..1d34819 100644
>> > --- a/drivers/soc/mediatek/Kconfig
>> > +++ b/drivers/soc/mediatek/Kconfig
>> > @@ -9,3 +9,9 @@ config MTK_PMIC_WRAP
>> >  	  Say yes here to add support for MediaTek PMIC Wrapper found
>> >  	  on different MediaTek SoCs. The PMIC wrapper is a proprietary
>> >  	  hardware to connect the PMIC.
>> > +
>> > +config MTK_SCPSYS
>> > +	tristate "MediaTek SCPSYS Support"
>> 
>> depends on ARCH_MEDIATEK ?
>
> You are reviewing v2 of this series. This is already fixed in v3 sent
> out last wednesday.

Yeah, sorry about that.  I noticed that after sending.

>> > +	for (i = 0; i < NUM_DOMAINS; i++) {
>> > +		struct scp_domain *scpd = &scp->domains[i];
>> > +		struct generic_pm_domain *pmd = &scpd->pmd;
>> > +
>> > +		scp->pmd[i] = pmd;
>> > +		scpd->data = &scp_domain_data[i];
>> > +		scpd->scp = scp;
>> > +
>> > +		pmd->name = scp_domain_data[i].name;
>> > +		pmd->power_off = scpsys_power_off;
>> > +		pmd->power_on = scpsys_power_on;
>> > +		pmd->power_off_latency_ns = 20000;
>> > +		pmd->power_on_latency_ns = 20000;
>> 
>> I think I mentioned this before... are these numbers really identical
>> for all domains?  I suggest you make these each a field in the domain
>> data so they can be different for each domain, and eventually come from
>> DT data.
>
> For the record, here are the numbers I just measured:
>
> mtk-scpsys 10006000.scpsys:       vdec on: 31000 off: 10769
> mtk-scpsys 10006000.scpsys:       venc on:  6000 off:  5923
> mtk-scpsys 10006000.scpsys:        isp on:  5923 off:  5923
> mtk-scpsys 10006000.scpsys:         mm on:  7616 off:  7692
> mtk-scpsys 10006000.scpsys:    venc_lt on:  5924 off:  6000
> mtk-scpsys 10006000.scpsys:      audio on:  5462 off:  5615
> mtk-scpsys 10006000.scpsys:        usb on:  5461 off:  5462
> mtk-scpsys 10006000.scpsys:  mfg_async on: 29923 off: 11077
> mtk-scpsys 10006000.scpsys:     mfg_2d on:  5923 off:  5616
> mtk-scpsys 10006000.scpsys:        mfg on: 11231 off: 16153
>
> Anyway, the pm domain core measures these times itself, so there
> should not be a need to fill in anything here. I was irritated by the
> warning message I got each time when the times were exceeded. This
> message seemed to imply that something was wrong and I had to fill
> in sane values in the latency fields. Since we now have [1] I'll just
> drop the initialisation of these fields.

OK.

However, I suspect you will still want these numbers on a per-domain
basis eventually when you consider having genpd governors that want
to make decisions.  But that can always be added later also.

Kevin
diff mbox

Patch

diff --git a/drivers/soc/mediatek/Kconfig b/drivers/soc/mediatek/Kconfig
index bcdb22d..1d34819 100644
--- a/drivers/soc/mediatek/Kconfig
+++ b/drivers/soc/mediatek/Kconfig
@@ -9,3 +9,9 @@  config MTK_PMIC_WRAP
 	  Say yes here to add support for MediaTek PMIC Wrapper found
 	  on different MediaTek SoCs. The PMIC wrapper is a proprietary
 	  hardware to connect the PMIC.
+
+config MTK_SCPSYS
+	tristate "MediaTek SCPSYS Support"
+	help
+	  Say yes here to add support for the MediaTek SCPSYS power domain
+	  driver.
diff --git a/drivers/soc/mediatek/Makefile b/drivers/soc/mediatek/Makefile
index ecaf4de..ce88693 100644
--- a/drivers/soc/mediatek/Makefile
+++ b/drivers/soc/mediatek/Makefile
@@ -1 +1,2 @@ 
 obj-$(CONFIG_MTK_PMIC_WRAP) += mtk-pmic-wrap.o
+obj-$(CONFIG_MTK_SCPSYS) += mtk-scpsys.o
diff --git a/drivers/soc/mediatek/mtk-scpsys.c b/drivers/soc/mediatek/mtk-scpsys.c
new file mode 100644
index 0000000..a72ac51
--- /dev/null
+++ b/drivers/soc/mediatek/mtk-scpsys.c
@@ -0,0 +1,345 @@ 
+/*
+ * Copyright (c) 2015 Pengutronix, Sascha Hauer <kernel@pengutronix.de>
+ *
+ * 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.
+ */
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/pm_domain.h>
+#include <linux/delay.h>
+#include <dt-bindings/power/mt8173-power.h>
+#include <linux/mfd/syscon.h>
+
+#define SPM_VDE_PWR_CON			0x0210
+#define SPM_MFG_PWR_CON			0x0214
+#define SPM_VEN_PWR_CON			0x0230
+#define SPM_ISP_PWR_CON			0x0238
+#define SPM_DIS_PWR_CON			0x023c
+#define SPM_VEN2_PWR_CON		0x0298
+#define SPM_AUDIO_PWR_CON		0x029c
+#define SPM_MFG_2D_PWR_CON		0x02c0
+#define SPM_MFG_ASYNC_PWR_CON		0x02c4
+#define SPM_USB_PWR_CON			0x02cc
+#define SPM_PWR_STATUS			0x060c
+#define SPM_PWR_STATUS_2ND		0x0610
+
+#define PWR_RST_B_BIT			BIT(0)
+#define PWR_ISO_BIT			BIT(1)
+#define PWR_ON_BIT			BIT(2)
+#define PWR_ON_2ND_BIT			BIT(3)
+#define PWR_CLK_DIS_BIT			BIT(4)
+
+#define DIS_PWR_STA_MASK		BIT(3)
+#define MFG_PWR_STA_MASK		BIT(4)
+#define ISP_PWR_STA_MASK		BIT(5)
+#define VDE_PWR_STA_MASK		BIT(7)
+#define VEN2_PWR_STA_MASK		BIT(20)
+#define VEN_PWR_STA_MASK		BIT(21)
+#define MFG_2D_PWR_STA_MASK		BIT(22)
+#define MFG_ASYNC_PWR_STA_MASK		BIT(23)
+#define AUDIO_PWR_STA_MASK		BIT(24)
+#define USB_PWR_STA_MASK		BIT(25)
+
+struct scp_domain_data {
+	const char *name;
+	u32 sta_mask;
+	int ctl_offs;
+	u32 sram_pdn_bits;
+	u32 sram_pdn_ack_bits;
+	int id;
+};
+
+static struct scp_domain_data scp_domain_data[] = {
+	{
+		.id = MT8173_POWER_DOMAIN_VDE,
+		.name = "vde",
+		.sta_mask = VDE_PWR_STA_MASK,
+		.ctl_offs = SPM_VDE_PWR_CON,
+		.sram_pdn_bits = GENMASK(11, 8),
+		.sram_pdn_ack_bits = GENMASK(12, 12),
+	}, {
+		.id = MT8173_POWER_DOMAIN_MFG,
+		.name = "mfg",
+		.sta_mask = MFG_PWR_STA_MASK,
+		.ctl_offs = SPM_MFG_PWR_CON,
+		.sram_pdn_bits = GENMASK(13, 8),
+		.sram_pdn_ack_bits = GENMASK(21, 16),
+	}, {
+		.id = MT8173_POWER_DOMAIN_VEN,
+		.name = "ven",
+		.sta_mask = VEN_PWR_STA_MASK,
+		.ctl_offs = SPM_VEN_PWR_CON,
+		.sram_pdn_bits = GENMASK(11, 8),
+		.sram_pdn_ack_bits = GENMASK(15, 12),
+	}, {
+		.id = MT8173_POWER_DOMAIN_ISP,
+		.name = "isp",
+		.sta_mask = ISP_PWR_STA_MASK,
+		.ctl_offs = SPM_ISP_PWR_CON,
+		.sram_pdn_bits = GENMASK(11, 8),
+		.sram_pdn_ack_bits = GENMASK(13, 12),
+	}, {
+		.id = MT8173_POWER_DOMAIN_DIS,
+		.name = "dis",
+		.sta_mask = DIS_PWR_STA_MASK,
+		.ctl_offs = SPM_DIS_PWR_CON,
+		.sram_pdn_bits = GENMASK(11, 8),
+		.sram_pdn_ack_bits = GENMASK(12, 12),
+	}, {
+		.id = MT8173_POWER_DOMAIN_VEN2,
+		.name = "ven2",
+		.sta_mask = VEN2_PWR_STA_MASK,
+		.ctl_offs = SPM_VEN2_PWR_CON,
+		.sram_pdn_bits = GENMASK(11, 8),
+		.sram_pdn_ack_bits = GENMASK(15, 12),
+	}, {
+		.id = MT8173_POWER_DOMAIN_AUDIO,
+		.name = "audio",
+		.sta_mask = AUDIO_PWR_STA_MASK,
+		.ctl_offs = SPM_AUDIO_PWR_CON,
+		.sram_pdn_bits = GENMASK(11, 8),
+		.sram_pdn_ack_bits = GENMASK(15, 12),
+	}, {
+		.id = MT8173_POWER_DOMAIN_MFG_2D,
+		.name = "mfg_2d",
+		.sta_mask = MFG_2D_PWR_STA_MASK,
+		.ctl_offs = SPM_MFG_2D_PWR_CON,
+		.sram_pdn_bits = GENMASK(11, 8),
+		.sram_pdn_ack_bits = GENMASK(13, 12),
+	}, {
+		.id = MT8173_POWER_DOMAIN_MFG_ASYNC,
+		.name = "mfg_async",
+		.sta_mask = MFG_ASYNC_PWR_STA_MASK,
+		.ctl_offs = SPM_MFG_ASYNC_PWR_CON,
+		.sram_pdn_bits = GENMASK(11, 8),
+		.sram_pdn_ack_bits = 0,
+	}, {
+		.id = MT8173_POWER_DOMAIN_USB,
+		.name = "usb",
+		.sta_mask = USB_PWR_STA_MASK,
+		.ctl_offs = SPM_USB_PWR_CON,
+		.sram_pdn_bits = GENMASK(11, 8),
+		.sram_pdn_ack_bits = GENMASK(15, 12),
+	},
+};
+
+#define NUM_DOMAINS	ARRAY_SIZE(scp_domain_data)
+
+struct scp;
+
+struct scp_domain {
+	struct generic_pm_domain pmd;
+	struct scp_domain_data *data;
+	struct scp *scp;
+};
+
+struct scp {
+	struct scp_domain domains[NUM_DOMAINS];
+	struct generic_pm_domain *pmd[NUM_DOMAINS];
+	struct genpd_onecell_data pd_data;
+	struct device *dev;
+	void __iomem *base;
+};
+
+static int scpsys_power_on(struct generic_pm_domain *genpd)
+{
+	struct scp_domain *scpd = container_of(genpd, struct scp_domain, pmd);
+	struct scp *scp = scpd->scp;
+	struct scp_domain_data *data = scpd->data;
+	unsigned long expired;
+	void __iomem *ctl_addr = scpd->scp->base + data->ctl_offs;
+	u32 sram_pdn_ack = data->sram_pdn_ack_bits;
+	u32 val;
+	int ret;
+
+	val = readl(ctl_addr);
+	val |= PWR_ON_BIT;
+	writel(val, ctl_addr);
+	val |= PWR_ON_2ND_BIT;
+	writel(val, ctl_addr);
+
+	/* wait until PWR_ACK = 1 */
+	expired = jiffies + HZ;
+	while (!(readl(scp->base + SPM_PWR_STATUS) & data->sta_mask) ||
+			!(readl(scp->base + SPM_PWR_STATUS_2ND) & data->sta_mask)) {
+		cpu_relax();
+		if (time_after(jiffies, expired)) {
+			ret = -EIO;
+			goto out;
+		}
+	}
+
+	val &= ~PWR_CLK_DIS_BIT;
+	writel(val, ctl_addr);
+
+	val &= ~PWR_ISO_BIT;
+	writel(val, ctl_addr);
+
+	val |= PWR_RST_B_BIT;
+	writel(val, ctl_addr);
+
+	val &= ~data->sram_pdn_bits;
+	writel(val, ctl_addr);
+
+	/* wait until SRAM_PDN_ACK all 0 */
+	expired = jiffies + HZ;
+	while (sram_pdn_ack && (readl(ctl_addr) & sram_pdn_ack)) {
+		cpu_relax();
+		if (time_after(jiffies, expired)) {
+			ret = -EIO;
+			goto out;
+		}
+	}
+
+	return 0;
+out:
+	dev_err(scp->dev, "Failed to power on domain %s\n", scpd->data->name);
+
+	return ret;
+}
+
+static int scpsys_power_off(struct generic_pm_domain *genpd)
+{
+	struct scp_domain *scpd = container_of(genpd, struct scp_domain, pmd);
+	struct scp *scp = scpd->scp;
+	struct scp_domain_data *data = scpd->data;
+	unsigned long expired;
+	void __iomem *ctl_addr = scpd->scp->base + data->ctl_offs;
+	u32 sram_pdn_ack = data->sram_pdn_ack_bits;
+	u32 val;
+	int ret;
+
+	val = readl(ctl_addr);
+	val |= data->sram_pdn_bits;
+	writel(val, ctl_addr);
+
+	/* wait until SRAM_PDN_ACK all 1 */
+	expired = jiffies + HZ;
+	while ((readl(ctl_addr) & sram_pdn_ack) != sram_pdn_ack) {
+		cpu_relax();
+		if (time_after(jiffies, expired)) {
+			ret = -EIO;
+			goto out;
+		}
+	}
+
+	val |= PWR_ISO_BIT;
+	writel(val, ctl_addr);
+
+	val &= ~PWR_RST_B_BIT;
+	writel(val, ctl_addr);
+
+	val |= PWR_CLK_DIS_BIT;
+	writel(val, ctl_addr);
+
+	val &= ~PWR_ON_BIT;
+	writel(val, ctl_addr);
+
+	val &= ~PWR_ON_2ND_BIT;
+	writel(val, ctl_addr);
+
+	/* wait until PWR_ACK = 0 */
+	expired = jiffies + HZ;
+	while ((readl(scp->base + SPM_PWR_STATUS) & data->sta_mask) ||
+			(readl(scp->base + SPM_PWR_STATUS_2ND) & data->sta_mask)) {
+		cpu_relax();
+		if (time_after(jiffies, expired)) {
+			ret = -EIO;
+			goto out;
+		}
+	}
+
+	return 0;
+
+out:
+	dev_err(scp->dev, "Failed to power on domain %s\n", scpd->data->name);
+
+	return ret;
+}
+
+static int scpsys_probe(struct platform_device *pdev)
+{
+	struct genpd_onecell_data *pd_data;
+	struct resource *res;
+	int i;
+	struct scp *scp;
+
+	scp = devm_kzalloc(&pdev->dev, sizeof(*scp), GFP_KERNEL);
+	if (!scp)
+		return -ENOMEM;
+
+	scp->dev = &pdev->dev;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	scp->base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(scp->base))
+		return PTR_ERR(scp->base);
+
+	pd_data = &scp->pd_data;
+
+	pd_data->domains = scp->pmd;
+	pd_data->num_domains = NUM_DOMAINS;
+
+	for (i = 0; i < NUM_DOMAINS; i++) {
+		struct scp_domain *scpd = &scp->domains[i];
+		struct generic_pm_domain *pmd = &scpd->pmd;
+
+		scp->pmd[i] = pmd;
+		scpd->data = &scp_domain_data[i];
+		scpd->scp = scp;
+
+		pmd->name = scp_domain_data[i].name;
+		pmd->power_off = scpsys_power_off;
+		pmd->power_on = scpsys_power_on;
+		pmd->power_off_latency_ns = 20000;
+		pmd->power_on_latency_ns = 20000;
+
+		pd_data->domains[i] = pmd;
+		pm_genpd_init(pmd, NULL, 1);
+
+		/*
+		 * If PM is disabled turn on all domains by default so that
+		 * consumers can work.
+		 */
+		if (!IS_ENABLED(CONFIG_PM))
+			pmd->power_on(pmd);
+	}
+
+	return of_genpd_add_provider_onecell(pdev->dev.of_node, pd_data);
+}
+
+static struct of_device_id of_scpsys_match_tbl[] = {
+	{
+		.compatible = "mediatek,mt8173-scpsys",
+	}, {
+		/* sentinel */
+	}
+};
+MODULE_DEVICE_TABLE(of, of_scpsys_match_tbl);
+
+static struct platform_driver scpsys_drv = {
+	.driver = {
+		.name = "mtk-scpsys",
+		.owner = THIS_MODULE,
+		.of_match_table = of_match_ptr(of_scpsys_match_tbl),
+	},
+	.probe = scpsys_probe,
+};
+
+module_platform_driver(scpsys_drv);
+
+MODULE_AUTHOR("Sascha Hauer, Pengutronix");
+MODULE_DESCRIPTION("MediaTek MT8173 scpsys driver");
+MODULE_LICENSE("GPL");
diff --git a/include/dt-bindings/power/mt8173-power.h b/include/dt-bindings/power/mt8173-power.h
new file mode 100644
index 0000000..88715f2
--- /dev/null
+++ b/include/dt-bindings/power/mt8173-power.h
@@ -0,0 +1,15 @@ 
+#ifndef _DT_BINDINGS_POWER_MT8183_POWER_H
+#define _DT_BINDINGS_POWER_MT8183_POWER_H
+
+#define MT8173_POWER_DOMAIN_VDE		0
+#define MT8173_POWER_DOMAIN_MFG		1
+#define MT8173_POWER_DOMAIN_VEN		2
+#define MT8173_POWER_DOMAIN_ISP		3
+#define MT8173_POWER_DOMAIN_DIS		4
+#define MT8173_POWER_DOMAIN_VEN2	5
+#define MT8173_POWER_DOMAIN_AUDIO	6
+#define MT8173_POWER_DOMAIN_MFG_2D	7
+#define MT8173_POWER_DOMAIN_MFG_ASYNC	8
+#define MT8173_POWER_DOMAIN_USB		9
+
+#endif /* _DT_BINDINGS_POWER_MT8183_POWER_H */