diff mbox

[3/5] soc: Mediatek: Add SCPSYS power domain driver

Message ID 1433839623-10804-4-git-send-email-s.hauer@pengutronix.de (mailing list archive)
State New, archived
Headers show

Commit Message

Sascha Hauer June 9, 2015, 8:47 a.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             |   9 +
 drivers/soc/mediatek/Makefile            |   1 +
 drivers/soc/mediatek/mtk-scpsys.c        | 490 +++++++++++++++++++++++++++++++
 include/dt-bindings/power/mt8173-power.h |  15 +
 4 files changed, 515 insertions(+)
 create mode 100644 drivers/soc/mediatek/mtk-scpsys.c
 create mode 100644 include/dt-bindings/power/mt8173-power.h

Comments

Matthias Brugger June 10, 2015, 12:03 p.m. UTC | #1
2015-06-09 10:47 GMT+02:00 Sascha Hauer <s.hauer@pengutronix.de>:
> 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             |   9 +
>  drivers/soc/mediatek/Makefile            |   1 +
>  drivers/soc/mediatek/mtk-scpsys.c        | 490 +++++++++++++++++++++++++++++++
>  include/dt-bindings/power/mt8173-power.h |  15 +
>  4 files changed, 515 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 e4f37a3..9a61b54 100644
> --- a/drivers/soc/mediatek/Kconfig
> +++ b/drivers/soc/mediatek/Kconfig
> @@ -18,3 +18,12 @@ 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
> +       bool "MediaTek SCPSYS Support"
> +       depends on ARCH_MEDIATEK || COMPILE_TEST
> +       select REGMAP
> +       select MTK_INFRACFG
> +       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 3fa940f..12998b0 100644
> --- a/drivers/soc/mediatek/Makefile
> +++ b/drivers/soc/mediatek/Makefile
> @@ -1,2 +1,3 @@
>  obj-$(CONFIG_MTK_INFRACFG) += mtk-infracfg.o
>  obj-$(CONFIG_MTK_PMIC_WRAP) += mtk-pmic-wrap.o
> +obj-$(CONFIG_MTK_SCPSYS) += mtk-scpsys.o
> diff --git a/drivers/soc/mediatek/mtk-scpsys.c b/drivers/soc/mediatek/mtk-scpsys.c
> new file mode 100644
> index 0000000..b9eed37
> --- /dev/null
> +++ b/drivers/soc/mediatek/mtk-scpsys.c
> @@ -0,0 +1,490 @@
> +/*
> + * 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/delay.h>
> +#include <linux/io.h>
> +#include <linux/kernel.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/of_device.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_domain.h>
> +#include <linux/regmap.h>
> +#include <linux/soc/mediatek/infracfg.h>
> +#include <dt-bindings/power/mt8173-power.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 PWR_STATUS_DISP                        BIT(3)
> +#define PWR_STATUS_MFG                 BIT(4)
> +#define PWR_STATUS_ISP                 BIT(5)
> +#define PWR_STATUS_VDEC                        BIT(7)
> +#define PWR_STATUS_VENC_LT             BIT(20)
> +#define PWR_STATUS_VENC                        BIT(21)
> +#define PWR_STATUS_MFG_2D              BIT(22)
> +#define PWR_STATUS_MFG_ASYNC           BIT(23)
> +#define PWR_STATUS_AUDIO               BIT(24)
> +#define PWR_STATUS_USB                 BIT(25)
> +
> +enum clk_id {
> +       MT8173_CLK_NONE,
> +       MT8173_CLK_MM,
> +       MT8173_CLK_MFG,
> +       MT8173_CLK_MAX = MT8173_CLK_MFG,
> +};
> +
> +struct scp_domain_data {
> +       const char *name;
> +       u32 sta_mask;
> +       int ctl_offs;
> +       u32 sram_pdn_bits;
> +       u32 sram_pdn_ack_bits;
> +       u32 bus_prot_mask;
> +       enum clk_id clk_id;
> +};
> +
> +static const struct scp_domain_data scp_domain_data[] __initconst = {
> +       [MT8173_POWER_DOMAIN_VDEC] = {
> +               .name = "vdec",
> +               .sta_mask = PWR_STATUS_VDEC,
> +               .ctl_offs = SPM_VDE_PWR_CON,
> +               .sram_pdn_bits = GENMASK(11, 8),
> +               .sram_pdn_ack_bits = GENMASK(12, 12),
> +               .clk_id = MT8173_CLK_MM,
> +       },
> +       [MT8173_POWER_DOMAIN_VENC] = {
> +               .name = "venc",
> +               .sta_mask = PWR_STATUS_VENC,
> +               .ctl_offs = SPM_VEN_PWR_CON,
> +               .sram_pdn_bits = GENMASK(11, 8),
> +               .sram_pdn_ack_bits = GENMASK(15, 12),
> +               .clk_id = MT8173_CLK_MM,
> +       },
> +       [MT8173_POWER_DOMAIN_ISP] = {
> +               .name = "isp",
> +               .sta_mask = PWR_STATUS_ISP,
> +               .ctl_offs = SPM_ISP_PWR_CON,
> +               .sram_pdn_bits = GENMASK(11, 8),
> +               .sram_pdn_ack_bits = GENMASK(13, 12),
> +               .clk_id = MT8173_CLK_MM,
> +       },
> +       [MT8173_POWER_DOMAIN_MM] = {
> +               .name = "mm",
> +               .sta_mask = PWR_STATUS_DISP,
> +               .ctl_offs = SPM_DIS_PWR_CON,
> +               .sram_pdn_bits = GENMASK(11, 8),
> +               .sram_pdn_ack_bits = GENMASK(12, 12),
> +               .clk_id = MT8173_CLK_MM,
> +               .bus_prot_mask = MT8173_TOP_AXI_PROT_EN_MM_M0 |
> +                       MT8173_TOP_AXI_PROT_EN_MM_M1,
> +       },
> +       [MT8173_POWER_DOMAIN_VENC_LT] = {
> +               .name = "venc_lt",
> +               .sta_mask = PWR_STATUS_VENC_LT,
> +               .ctl_offs = SPM_VEN2_PWR_CON,
> +               .sram_pdn_bits = GENMASK(11, 8),
> +               .sram_pdn_ack_bits = GENMASK(15, 12),
> +               .clk_id = MT8173_CLK_MM,
> +       },
> +       [MT8173_POWER_DOMAIN_AUDIO] = {
> +               .name = "audio",
> +               .sta_mask = PWR_STATUS_AUDIO,
> +               .ctl_offs = SPM_AUDIO_PWR_CON,
> +               .sram_pdn_bits = GENMASK(11, 8),
> +               .sram_pdn_ack_bits = GENMASK(15, 12),
> +               .clk_id = MT8173_CLK_NONE,
> +       },
> +       [MT8173_POWER_DOMAIN_USB] = {
> +               .name = "usb",
> +               .sta_mask = PWR_STATUS_USB,
> +               .ctl_offs = SPM_USB_PWR_CON,
> +               .sram_pdn_bits = GENMASK(11, 8),
> +               .sram_pdn_ack_bits = GENMASK(15, 12),
> +               .clk_id = MT8173_CLK_NONE,
> +       },
> +       [MT8173_POWER_DOMAIN_MFG_ASYNC] = {
> +               .name = "mfg_async",
> +               .sta_mask = PWR_STATUS_MFG_ASYNC,
> +               .ctl_offs = SPM_MFG_ASYNC_PWR_CON,
> +               .sram_pdn_bits = GENMASK(11, 8),
> +               .sram_pdn_ack_bits = 0,
> +               .clk_id = MT8173_CLK_MFG,
> +       },
> +       [MT8173_POWER_DOMAIN_MFG_2D] = {
> +               .name = "mfg_2d",
> +               .sta_mask = PWR_STATUS_MFG_2D,
> +               .ctl_offs = SPM_MFG_2D_PWR_CON,
> +               .sram_pdn_bits = GENMASK(11, 8),
> +               .sram_pdn_ack_bits = GENMASK(13, 12),
> +               .clk_id = MT8173_CLK_NONE,
> +       },
> +       [MT8173_POWER_DOMAIN_MFG] = {
> +               .name = "mfg",
> +               .sta_mask = PWR_STATUS_MFG,
> +               .ctl_offs = SPM_MFG_PWR_CON,
> +               .sram_pdn_bits = GENMASK(13, 8),
> +               .sram_pdn_ack_bits = GENMASK(21, 16),
> +               .clk_id = MT8173_CLK_NONE,
> +               .bus_prot_mask = MT8173_TOP_AXI_PROT_EN_MFG_S |
> +                       MT8173_TOP_AXI_PROT_EN_MFG_M0 |
> +                       MT8173_TOP_AXI_PROT_EN_MFG_M1 |
> +                       MT8173_TOP_AXI_PROT_EN_MFG_SNOOP_OUT,
> +       },
> +};
> +
> +#define NUM_DOMAINS    ARRAY_SIZE(scp_domain_data)
> +
> +struct scp;
> +
> +struct scp_domain {
> +       struct generic_pm_domain genpd;
> +       struct scp *scp;
> +       struct clk *clk;
> +       u32 sta_mask;
> +       void __iomem *ctl_addr;
> +       u32 sram_pdn_bits;
> +       u32 sram_pdn_ack_bits;
> +       u32 bus_prot_mask;
> +};
> +
> +struct scp {
> +       struct scp_domain domains[NUM_DOMAINS];
> +       struct genpd_onecell_data pd_data;
> +       struct device *dev;
> +       void __iomem *base;
> +       struct regmap *infracfg;
> +       struct clk *clk[MT8173_CLK_MAX];
> +};
> +
> +static int scpsys_domain_is_on(struct scp_domain *scpd)
> +{
> +       struct scp *scp = scpd->scp;
> +
> +       u32 status = readl(scp->base + SPM_PWR_STATUS) & scpd->sta_mask;
> +       u32 status2 = readl(scp->base + SPM_PWR_STATUS_2ND) & scpd->sta_mask;
> +
> +       /*
> +        * A domain is on when both status bits are set. If only one is set
> +        * return an error. This happens while powering up a domain
> +        */
> +
> +       if (status && status2)
> +               return true;
> +       if (!status && !status2)
> +               return false;
> +
> +       return -EINVAL;
> +}
> +
> +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;
> +       unsigned long timeout;
> +       bool expired;
> +       void __iomem *ctl_addr = scpd->ctl_addr;
> +       u32 sram_pdn_ack = scpd->sram_pdn_ack_bits;
> +       u32 val;
> +       int ret;
> +
> +       if (scpd->clk) {
> +               ret = clk_prepare_enable(scpd->clk);
> +               if (ret)
> +                       return 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 */
> +       timeout = jiffies + HZ;
> +       expired = false;
> +       while (1) {
> +               ret = scpsys_domain_is_on(scpd);
> +               if (ret > 0)
> +                       break;
> +
> +               if (expired) {
> +                       ret = -ETIMEDOUT;
> +                       goto out;
> +               }
> +
> +               cpu_relax();
> +
> +               if (time_after(jiffies, timeout))
> +                       expired = true;
> +       }
> +
> +       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 &= ~scpd->sram_pdn_bits;
> +       writel(val, ctl_addr);
> +
> +       /* wait until SRAM_PDN_ACK all 0 */
> +       timeout = jiffies + HZ;
> +       expired = false;
> +       while (sram_pdn_ack && (readl(ctl_addr) & sram_pdn_ack)) {
> +
> +               if (expired) {
> +                       ret = -ETIMEDOUT;
> +                       goto out;
> +               }
> +
> +               cpu_relax();
> +
> +               if (time_after(jiffies, timeout))
> +                       expired = true;
> +       }
> +
> +       if (scpd->bus_prot_mask) {
> +               ret = mtk_infracfg_clear_bus_protection(scp->infracfg,
> +                               scpd->bus_prot_mask);
> +               if (ret)
> +                       return ret;
> +       }
> +
> +       return 0;
> +out:
> +       dev_err(scp->dev, "Failed to power on domain %s\n", genpd->name);
> +
> +       return ret;
> +}
> +
> +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;
> +       unsigned long timeout;
> +       bool expired;
> +       void __iomem *ctl_addr = scpd->ctl_addr;
> +       u32 pdn_ack = scpd->sram_pdn_ack_bits;
> +       u32 val;
> +       int ret;
> +
> +       if (scpd->bus_prot_mask) {
> +               ret = mtk_infracfg_set_bus_protection(scp->infracfg,
> +                               scpd->bus_prot_mask);
> +               if (ret)
> +                       return ret;
> +       }
> +
> +       val = readl(ctl_addr);
> +       val |= scpd->sram_pdn_bits;
> +       writel(val, ctl_addr);
> +
> +       /* wait until SRAM_PDN_ACK all 1 */
> +       timeout = jiffies + HZ;
> +       expired = false;
> +       while (pdn_ack && (readl(ctl_addr) & pdn_ack) != pdn_ack) {
> +               if (expired) {
> +                       ret = -ETIMEDOUT;
> +                       goto out;
> +               }
> +
> +               cpu_relax();
> +
> +               if (time_after(jiffies, timeout))
> +                       expired = true;
> +       }
> +
> +       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 */
> +       timeout = jiffies + HZ;
> +       expired = false;
> +       while (1) {
> +               ret = scpsys_domain_is_on(scpd);
> +               if (ret == 0)
> +                       break;
> +
> +               if (expired) {
> +                       ret = -ETIMEDOUT;
> +                       goto out;
> +               }
> +
> +               cpu_relax();
> +
> +               if (time_after(jiffies, timeout))
> +                       expired = true;
> +       }
> +
> +       if (scpd->clk)
> +               clk_disable_unprepare(scpd->clk);
> +
> +       return 0;
> +
> +out:
> +       dev_err(scp->dev, "Failed to power off domain %s\n", genpd->name);
> +
> +       return ret;
> +}
> +
> +static int __init scpsys_probe(struct platform_device *pdev)
> +{
> +       struct genpd_onecell_data *pd_data;
> +       struct resource *res;
> +       int i, ret;
> +       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 = devm_kzalloc(&pdev->dev,
> +                       sizeof(*pd_data->domains) * NUM_DOMAINS, GFP_KERNEL);
> +       if (!pd_data->domains)
> +               return -ENOMEM;
> +
> +       scp->clk[MT8173_CLK_MM] = devm_clk_get(&pdev->dev, "mm");
> +       if (IS_ERR(scp->clk[MT8173_CLK_MM])) {
> +               dev_err(&pdev->dev, "Failed to get mm clk: %ld\n",
> +                               PTR_ERR(scp->clk[MT8173_CLK_MM]));
> +               return PTR_ERR(scp->clk[MT8173_CLK_MM]);
> +       }
> +
> +       scp->clk[MT8173_CLK_MFG] = devm_clk_get(&pdev->dev, "mfg");
> +       if (IS_ERR(scp->clk[MT8173_CLK_MFG])) {
> +               dev_err(&pdev->dev, "Failed to get mfg clk: %ld\n",
> +                               PTR_ERR(scp->clk[MT8173_CLK_MFG]));
> +               return PTR_ERR(scp->clk[MT8173_CLK_MFG]);
> +       }
> +
> +       scp->infracfg = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
> +                       "infracfg");
> +       if (IS_ERR(scp->infracfg)) {
> +               dev_err(&pdev->dev, "Cannot find infracfg controller: %ld\n",
> +                               PTR_ERR(scp->infracfg));
> +               return PTR_ERR(scp->infracfg);
> +       }
> +
> +       pd_data->num_domains = NUM_DOMAINS;
> +
> +       for (i = 0; i < NUM_DOMAINS; i++) {
> +               struct scp_domain *scpd = &scp->domains[i];
> +               struct generic_pm_domain *genpd = &scpd->genpd;
> +               const struct scp_domain_data *data = &scp_domain_data[i];
> +
> +               pd_data->domains[i] = genpd;
> +               scpd->scp = scp;
> +
> +               scpd->sta_mask = data->sta_mask;
> +               scpd->ctl_addr = scp->base + data->ctl_offs;
> +               scpd->sram_pdn_bits = data->sram_pdn_bits;
> +               scpd->sram_pdn_ack_bits = data->sram_pdn_ack_bits;
> +               scpd->bus_prot_mask = data->bus_prot_mask;
> +               if (data->clk_id != MT8173_CLK_NONE)
> +                       scpd->clk = scp->clk[data->clk_id];
> +
> +               genpd->name = data->name;
> +               genpd->power_off = scpsys_power_off;
> +               genpd->power_on = scpsys_power_on;
> +
> +               /*
> +                * Initially turn on all domains to make the domains usable
> +                * with !CONFIG_PM and to get the hardware in sync with the
> +                * software.  The unused domains will be switched off during
> +                * late_init time.
> +                */
> +               genpd->power_on(genpd);
> +
> +               pm_genpd_init(genpd, NULL, false);
> +       }
> +
> +       /*
> +        * We are not allowed to fail here since there is no way to unregister
> +        * a power domain. Once registered above we have to keep the domains
> +        * valid.
> +        */
> +
> +       ret = pm_genpd_add_subdomain(pd_data->domains[MT8173_POWER_DOMAIN_MFG_ASYNC],
> +               pd_data->domains[MT8173_POWER_DOMAIN_MFG_2D]);
> +       if (ret && IS_ENABLED(CONFIG_PM))
> +               dev_err(&pdev->dev, "Failed to add subdomain: %d\n", ret);
> +
> +       ret = pm_genpd_add_subdomain(pd_data->domains[MT8173_POWER_DOMAIN_MFG_2D],
> +               pd_data->domains[MT8173_POWER_DOMAIN_MFG]);
> +       if (ret && IS_ENABLED(CONFIG_PM))
> +               dev_err(&pdev->dev, "Failed to add subdomain: %d\n", ret);
> +
> +       ret = of_genpd_add_provider_onecell(pdev->dev.of_node, pd_data);
> +       if (ret)
> +               dev_err(&pdev->dev, "Failed to add OF provider: %d\n", ret);
> +
> +       return 0;
> +}
> +
> +static const struct of_device_id of_scpsys_match_tbl[] = {
> +       {
> +               .compatible = "mediatek,mt8173-scpsys",
> +       }, {
> +               /* sentinel */
> +       }
> +};
> +
> +static struct platform_driver scpsys_drv = {
> +       .driver = {
> +               .name = "mtk-scpsys",
> +               .owner = THIS_MODULE,
> +               .of_match_table = of_match_ptr(of_scpsys_match_tbl),
> +       },
> +};
> +
> +module_platform_driver_probe(scpsys_drv, scpsys_probe);

I saw builtin_platform_driver_probe() is in linux-next, so I suppose
it is fine to change this.
Apart from that the series look good to me.

Thanks,
Matthias
Ulf Hansson June 10, 2015, 2:47 p.m. UTC | #2
On 9 June 2015 at 10:47, Sascha Hauer <s.hauer@pengutronix.de> wrote:
> 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             |   9 +
>  drivers/soc/mediatek/Makefile            |   1 +
>  drivers/soc/mediatek/mtk-scpsys.c        | 490 +++++++++++++++++++++++++++++++
>  include/dt-bindings/power/mt8173-power.h |  15 +
>  4 files changed, 515 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 e4f37a3..9a61b54 100644
> --- a/drivers/soc/mediatek/Kconfig
> +++ b/drivers/soc/mediatek/Kconfig
> @@ -18,3 +18,12 @@ 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
> +       bool "MediaTek SCPSYS Support"
> +       depends on ARCH_MEDIATEK || COMPILE_TEST

How about also depending on "PM" and selecting PM_GENERIC_DOMAINS,
would that work?

> +       select REGMAP
> +       select MTK_INFRACFG
> +       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 3fa940f..12998b0 100644
> --- a/drivers/soc/mediatek/Makefile
> +++ b/drivers/soc/mediatek/Makefile
> @@ -1,2 +1,3 @@
>  obj-$(CONFIG_MTK_INFRACFG) += mtk-infracfg.o
>  obj-$(CONFIG_MTK_PMIC_WRAP) += mtk-pmic-wrap.o
> +obj-$(CONFIG_MTK_SCPSYS) += mtk-scpsys.o
> diff --git a/drivers/soc/mediatek/mtk-scpsys.c b/drivers/soc/mediatek/mtk-scpsys.c
> new file mode 100644
> index 0000000..b9eed37
> --- /dev/null
> +++ b/drivers/soc/mediatek/mtk-scpsys.c
> @@ -0,0 +1,490 @@
> +/*
> + * 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/delay.h>
> +#include <linux/io.h>
> +#include <linux/kernel.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/of_device.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_domain.h>
> +#include <linux/regmap.h>
> +#include <linux/soc/mediatek/infracfg.h>
> +#include <dt-bindings/power/mt8173-power.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 PWR_STATUS_DISP                        BIT(3)
> +#define PWR_STATUS_MFG                 BIT(4)
> +#define PWR_STATUS_ISP                 BIT(5)
> +#define PWR_STATUS_VDEC                        BIT(7)
> +#define PWR_STATUS_VENC_LT             BIT(20)
> +#define PWR_STATUS_VENC                        BIT(21)
> +#define PWR_STATUS_MFG_2D              BIT(22)
> +#define PWR_STATUS_MFG_ASYNC           BIT(23)
> +#define PWR_STATUS_AUDIO               BIT(24)
> +#define PWR_STATUS_USB                 BIT(25)
> +
> +enum clk_id {
> +       MT8173_CLK_NONE,
> +       MT8173_CLK_MM,
> +       MT8173_CLK_MFG,
> +       MT8173_CLK_MAX = MT8173_CLK_MFG,
> +};
> +
> +struct scp_domain_data {
> +       const char *name;
> +       u32 sta_mask;
> +       int ctl_offs;
> +       u32 sram_pdn_bits;
> +       u32 sram_pdn_ack_bits;
> +       u32 bus_prot_mask;
> +       enum clk_id clk_id;
> +};
> +
> +static const struct scp_domain_data scp_domain_data[] __initconst = {
> +       [MT8173_POWER_DOMAIN_VDEC] = {
> +               .name = "vdec",
> +               .sta_mask = PWR_STATUS_VDEC,
> +               .ctl_offs = SPM_VDE_PWR_CON,
> +               .sram_pdn_bits = GENMASK(11, 8),
> +               .sram_pdn_ack_bits = GENMASK(12, 12),
> +               .clk_id = MT8173_CLK_MM,
> +       },
> +       [MT8173_POWER_DOMAIN_VENC] = {
> +               .name = "venc",
> +               .sta_mask = PWR_STATUS_VENC,
> +               .ctl_offs = SPM_VEN_PWR_CON,
> +               .sram_pdn_bits = GENMASK(11, 8),
> +               .sram_pdn_ack_bits = GENMASK(15, 12),
> +               .clk_id = MT8173_CLK_MM,
> +       },
> +       [MT8173_POWER_DOMAIN_ISP] = {
> +               .name = "isp",
> +               .sta_mask = PWR_STATUS_ISP,
> +               .ctl_offs = SPM_ISP_PWR_CON,
> +               .sram_pdn_bits = GENMASK(11, 8),
> +               .sram_pdn_ack_bits = GENMASK(13, 12),
> +               .clk_id = MT8173_CLK_MM,
> +       },
> +       [MT8173_POWER_DOMAIN_MM] = {
> +               .name = "mm",
> +               .sta_mask = PWR_STATUS_DISP,
> +               .ctl_offs = SPM_DIS_PWR_CON,
> +               .sram_pdn_bits = GENMASK(11, 8),
> +               .sram_pdn_ack_bits = GENMASK(12, 12),
> +               .clk_id = MT8173_CLK_MM,
> +               .bus_prot_mask = MT8173_TOP_AXI_PROT_EN_MM_M0 |
> +                       MT8173_TOP_AXI_PROT_EN_MM_M1,
> +       },
> +       [MT8173_POWER_DOMAIN_VENC_LT] = {
> +               .name = "venc_lt",
> +               .sta_mask = PWR_STATUS_VENC_LT,
> +               .ctl_offs = SPM_VEN2_PWR_CON,
> +               .sram_pdn_bits = GENMASK(11, 8),
> +               .sram_pdn_ack_bits = GENMASK(15, 12),
> +               .clk_id = MT8173_CLK_MM,
> +       },
> +       [MT8173_POWER_DOMAIN_AUDIO] = {
> +               .name = "audio",
> +               .sta_mask = PWR_STATUS_AUDIO,
> +               .ctl_offs = SPM_AUDIO_PWR_CON,
> +               .sram_pdn_bits = GENMASK(11, 8),
> +               .sram_pdn_ack_bits = GENMASK(15, 12),
> +               .clk_id = MT8173_CLK_NONE,
> +       },
> +       [MT8173_POWER_DOMAIN_USB] = {
> +               .name = "usb",
> +               .sta_mask = PWR_STATUS_USB,
> +               .ctl_offs = SPM_USB_PWR_CON,
> +               .sram_pdn_bits = GENMASK(11, 8),
> +               .sram_pdn_ack_bits = GENMASK(15, 12),
> +               .clk_id = MT8173_CLK_NONE,
> +       },
> +       [MT8173_POWER_DOMAIN_MFG_ASYNC] = {
> +               .name = "mfg_async",
> +               .sta_mask = PWR_STATUS_MFG_ASYNC,
> +               .ctl_offs = SPM_MFG_ASYNC_PWR_CON,
> +               .sram_pdn_bits = GENMASK(11, 8),
> +               .sram_pdn_ack_bits = 0,
> +               .clk_id = MT8173_CLK_MFG,
> +       },
> +       [MT8173_POWER_DOMAIN_MFG_2D] = {
> +               .name = "mfg_2d",
> +               .sta_mask = PWR_STATUS_MFG_2D,
> +               .ctl_offs = SPM_MFG_2D_PWR_CON,
> +               .sram_pdn_bits = GENMASK(11, 8),
> +               .sram_pdn_ack_bits = GENMASK(13, 12),
> +               .clk_id = MT8173_CLK_NONE,
> +       },
> +       [MT8173_POWER_DOMAIN_MFG] = {
> +               .name = "mfg",
> +               .sta_mask = PWR_STATUS_MFG,
> +               .ctl_offs = SPM_MFG_PWR_CON,
> +               .sram_pdn_bits = GENMASK(13, 8),
> +               .sram_pdn_ack_bits = GENMASK(21, 16),
> +               .clk_id = MT8173_CLK_NONE,
> +               .bus_prot_mask = MT8173_TOP_AXI_PROT_EN_MFG_S |
> +                       MT8173_TOP_AXI_PROT_EN_MFG_M0 |
> +                       MT8173_TOP_AXI_PROT_EN_MFG_M1 |
> +                       MT8173_TOP_AXI_PROT_EN_MFG_SNOOP_OUT,
> +       },
> +};
> +
> +#define NUM_DOMAINS    ARRAY_SIZE(scp_domain_data)
> +
> +struct scp;
> +
> +struct scp_domain {
> +       struct generic_pm_domain genpd;
> +       struct scp *scp;
> +       struct clk *clk;
> +       u32 sta_mask;
> +       void __iomem *ctl_addr;
> +       u32 sram_pdn_bits;
> +       u32 sram_pdn_ack_bits;
> +       u32 bus_prot_mask;
> +};
> +
> +struct scp {
> +       struct scp_domain domains[NUM_DOMAINS];
> +       struct genpd_onecell_data pd_data;
> +       struct device *dev;
> +       void __iomem *base;
> +       struct regmap *infracfg;
> +       struct clk *clk[MT8173_CLK_MAX];
> +};
> +
> +static int scpsys_domain_is_on(struct scp_domain *scpd)
> +{
> +       struct scp *scp = scpd->scp;
> +
> +       u32 status = readl(scp->base + SPM_PWR_STATUS) & scpd->sta_mask;
> +       u32 status2 = readl(scp->base + SPM_PWR_STATUS_2ND) & scpd->sta_mask;
> +
> +       /*
> +        * A domain is on when both status bits are set. If only one is set
> +        * return an error. This happens while powering up a domain
> +        */
> +
> +       if (status && status2)
> +               return true;
> +       if (!status && !status2)
> +               return false;
> +
> +       return -EINVAL;
> +}
> +
> +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;
> +       unsigned long timeout;
> +       bool expired;
> +       void __iomem *ctl_addr = scpd->ctl_addr;
> +       u32 sram_pdn_ack = scpd->sram_pdn_ack_bits;
> +       u32 val;
> +       int ret;
> +
> +       if (scpd->clk) {

Shouldn't you check for !IS_ERR(scpd->clk) instead?

> +               ret = clk_prepare_enable(scpd->clk);
> +               if (ret)
> +                       return 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 */
> +       timeout = jiffies + HZ;
> +       expired = false;
> +       while (1) {
> +               ret = scpsys_domain_is_on(scpd);
> +               if (ret > 0)
> +                       break;
> +
> +               if (expired) {
> +                       ret = -ETIMEDOUT;
> +                       goto out;
> +               }
> +
> +               cpu_relax();
> +
> +               if (time_after(jiffies, timeout))
> +                       expired = true;
> +       }
> +
> +       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 &= ~scpd->sram_pdn_bits;
> +       writel(val, ctl_addr);
> +
> +       /* wait until SRAM_PDN_ACK all 0 */
> +       timeout = jiffies + HZ;
> +       expired = false;
> +       while (sram_pdn_ack && (readl(ctl_addr) & sram_pdn_ack)) {
> +
> +               if (expired) {
> +                       ret = -ETIMEDOUT;
> +                       goto out;
> +               }
> +
> +               cpu_relax();
> +
> +               if (time_after(jiffies, timeout))
> +                       expired = true;
> +       }
> +
> +       if (scpd->bus_prot_mask) {
> +               ret = mtk_infracfg_clear_bus_protection(scp->infracfg,
> +                               scpd->bus_prot_mask);
> +               if (ret)
> +                       return ret;
> +       }
> +
> +       return 0;
> +out:

There are no error handling. Especially the clock should be gated.

> +       dev_err(scp->dev, "Failed to power on domain %s\n", genpd->name);
> +
> +       return ret;
> +}
> +
> +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;
> +       unsigned long timeout;
> +       bool expired;
> +       void __iomem *ctl_addr = scpd->ctl_addr;
> +       u32 pdn_ack = scpd->sram_pdn_ack_bits;
> +       u32 val;
> +       int ret;
> +
> +       if (scpd->bus_prot_mask) {
> +               ret = mtk_infracfg_set_bus_protection(scp->infracfg,
> +                               scpd->bus_prot_mask);
> +               if (ret)
> +                       return ret;
> +       }
> +
> +       val = readl(ctl_addr);
> +       val |= scpd->sram_pdn_bits;
> +       writel(val, ctl_addr);
> +
> +       /* wait until SRAM_PDN_ACK all 1 */
> +       timeout = jiffies + HZ;
> +       expired = false;
> +       while (pdn_ack && (readl(ctl_addr) & pdn_ack) != pdn_ack) {
> +               if (expired) {
> +                       ret = -ETIMEDOUT;
> +                       goto out;
> +               }
> +
> +               cpu_relax();
> +
> +               if (time_after(jiffies, timeout))
> +                       expired = true;
> +       }
> +
> +       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 */
> +       timeout = jiffies + HZ;
> +       expired = false;
> +       while (1) {
> +               ret = scpsys_domain_is_on(scpd);
> +               if (ret == 0)
> +                       break;
> +
> +               if (expired) {
> +                       ret = -ETIMEDOUT;
> +                       goto out;
> +               }
> +
> +               cpu_relax();
> +
> +               if (time_after(jiffies, timeout))
> +                       expired = true;
> +       }
> +
> +       if (scpd->clk)

Shouldn't you check for !IS_ERR(scpd->clk) instead?

> +               clk_disable_unprepare(scpd->clk);
> +
> +       return 0;
> +
> +out:

There are no error handling, isn't that needed?

> +       dev_err(scp->dev, "Failed to power off domain %s\n", genpd->name);
> +
> +       return ret;
> +}
> +
> +static int __init scpsys_probe(struct platform_device *pdev)
> +{
> +       struct genpd_onecell_data *pd_data;
> +       struct resource *res;
> +       int i, ret;
> +       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 = devm_kzalloc(&pdev->dev,
> +                       sizeof(*pd_data->domains) * NUM_DOMAINS, GFP_KERNEL);
> +       if (!pd_data->domains)
> +               return -ENOMEM;
> +
> +       scp->clk[MT8173_CLK_MM] = devm_clk_get(&pdev->dev, "mm");
> +       if (IS_ERR(scp->clk[MT8173_CLK_MM])) {
> +               dev_err(&pdev->dev, "Failed to get mm clk: %ld\n",
> +                               PTR_ERR(scp->clk[MT8173_CLK_MM]));

I think a similar error message is already printed by the common clk framework!?

> +               return PTR_ERR(scp->clk[MT8173_CLK_MM]);
> +       }
> +
> +       scp->clk[MT8173_CLK_MFG] = devm_clk_get(&pdev->dev, "mfg");
> +       if (IS_ERR(scp->clk[MT8173_CLK_MFG])) {
> +               dev_err(&pdev->dev, "Failed to get mfg clk: %ld\n",
> +                               PTR_ERR(scp->clk[MT8173_CLK_MFG]));

I think a similar error message is already printed by the common clk framework!?

> +               return PTR_ERR(scp->clk[MT8173_CLK_MFG]);
> +       }
> +
> +       scp->infracfg = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
> +                       "infracfg");
> +       if (IS_ERR(scp->infracfg)) {
> +               dev_err(&pdev->dev, "Cannot find infracfg controller: %ld\n",
> +                               PTR_ERR(scp->infracfg));
> +               return PTR_ERR(scp->infracfg);
> +       }
> +
> +       pd_data->num_domains = NUM_DOMAINS;
> +
> +       for (i = 0; i < NUM_DOMAINS; i++) {
> +               struct scp_domain *scpd = &scp->domains[i];
> +               struct generic_pm_domain *genpd = &scpd->genpd;
> +               const struct scp_domain_data *data = &scp_domain_data[i];
> +
> +               pd_data->domains[i] = genpd;
> +               scpd->scp = scp;
> +
> +               scpd->sta_mask = data->sta_mask;
> +               scpd->ctl_addr = scp->base + data->ctl_offs;
> +               scpd->sram_pdn_bits = data->sram_pdn_bits;
> +               scpd->sram_pdn_ack_bits = data->sram_pdn_ack_bits;
> +               scpd->bus_prot_mask = data->bus_prot_mask;
> +               if (data->clk_id != MT8173_CLK_NONE)
> +                       scpd->clk = scp->clk[data->clk_id];

This seems odd. Why do you need to have an array of clocks to deal
with this assignment?

I don't find that the struct scp->clk pointer is used but from this
place. Couldn't you just fetch a reference to the clock to a local
struct *clk, without caching it in the struct scp->clk?

> +
> +               genpd->name = data->name;
> +               genpd->power_off = scpsys_power_off;
> +               genpd->power_on = scpsys_power_on;
> +
> +               /*
> +                * Initially turn on all domains to make the domains usable
> +                * with !CONFIG_PM and to get the hardware in sync with the
> +                * software.  The unused domains will be switched off during
> +                * late_init time.
> +                */
> +               genpd->power_on(genpd);
> +
> +               pm_genpd_init(genpd, NULL, false);
> +       }
> +
> +       /*
> +        * We are not allowed to fail here since there is no way to unregister
> +        * a power domain. Once registered above we have to keep the domains
> +        * valid.
> +        */
> +
> +       ret = pm_genpd_add_subdomain(pd_data->domains[MT8173_POWER_DOMAIN_MFG_ASYNC],
> +               pd_data->domains[MT8173_POWER_DOMAIN_MFG_2D]);
> +       if (ret && IS_ENABLED(CONFIG_PM))
> +               dev_err(&pdev->dev, "Failed to add subdomain: %d\n", ret);
> +
> +       ret = pm_genpd_add_subdomain(pd_data->domains[MT8173_POWER_DOMAIN_MFG_2D],
> +               pd_data->domains[MT8173_POWER_DOMAIN_MFG]);
> +       if (ret && IS_ENABLED(CONFIG_PM))
> +               dev_err(&pdev->dev, "Failed to add subdomain: %d\n", ret);
> +
> +       ret = of_genpd_add_provider_onecell(pdev->dev.of_node, pd_data);
> +       if (ret)
> +               dev_err(&pdev->dev, "Failed to add OF provider: %d\n", ret);
> +
> +       return 0;
> +}
> +
> +static const struct of_device_id of_scpsys_match_tbl[] = {
> +       {
> +               .compatible = "mediatek,mt8173-scpsys",
> +       }, {
> +               /* sentinel */
> +       }
> +};
> +
> +static struct platform_driver scpsys_drv = {
> +       .driver = {
> +               .name = "mtk-scpsys",
> +               .owner = THIS_MODULE,
> +               .of_match_table = of_match_ptr(of_scpsys_match_tbl),
> +       },
> +};
> +
> +module_platform_driver_probe(scpsys_drv, scpsys_probe);
> diff --git a/include/dt-bindings/power/mt8173-power.h b/include/dt-bindings/power/mt8173-power.h
> new file mode 100644
> index 0000000..b34cee9
> --- /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_VDEC       0
> +#define MT8173_POWER_DOMAIN_VENC       1
> +#define MT8173_POWER_DOMAIN_ISP                2
> +#define MT8173_POWER_DOMAIN_MM         3
> +#define MT8173_POWER_DOMAIN_VENC_LT    4
> +#define MT8173_POWER_DOMAIN_AUDIO      5
> +#define MT8173_POWER_DOMAIN_USB                6
> +#define MT8173_POWER_DOMAIN_MFG_ASYNC  7
> +#define MT8173_POWER_DOMAIN_MFG_2D     8
> +#define MT8173_POWER_DOMAIN_MFG                9
> +
> +#endif /* _DT_BINDINGS_POWER_MT8183_POWER_H */
> --
> 2.1.4

Kind regards
Uffe
Sascha Hauer June 15, 2015, 7:45 a.m. UTC | #3
Hi Ulf,

On Wed, Jun 10, 2015 at 04:47:01PM +0200, Ulf Hansson wrote:
> On 9 June 2015 at 10:47, Sascha Hauer <s.hauer@pengutronix.de> wrote:
> > 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             |   9 +
> >  drivers/soc/mediatek/Makefile            |   1 +
> >  drivers/soc/mediatek/mtk-scpsys.c        | 490 +++++++++++++++++++++++++++++++
> >  include/dt-bindings/power/mt8173-power.h |  15 +
> >  4 files changed, 515 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 e4f37a3..9a61b54 100644
> > --- a/drivers/soc/mediatek/Kconfig
> > +++ b/drivers/soc/mediatek/Kconfig
> > @@ -18,3 +18,12 @@ 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
> > +       bool "MediaTek SCPSYS Support"
> > +       depends on ARCH_MEDIATEK || COMPILE_TEST
> 
> How about also depending on "PM" and selecting PM_GENERIC_DOMAINS,
> would that work?

That's what patch 4/5 does. So far all drivers have this in
arch/arm/mach-*/Kconfig and so did I. However, they probably have it
under arch/ to have it next to the driver. I'll move it here and drop
4/5.

> > +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;
> > +       unsigned long timeout;
> > +       bool expired;
> > +       void __iomem *ctl_addr = scpd->ctl_addr;
> > +       u32 sram_pdn_ack = scpd->sram_pdn_ack_bits;
> > +       u32 val;
> > +       int ret;
> > +
> > +       if (scpd->clk) {
> 
> Shouldn't you check for !IS_ERR(scpd->clk) instead?

No. scpd->clk is initialized like this:

		if (data->clk_id != MT8173_CLK_NONE)
			scpd->clk = scp->clk[data->clk_id];

So scpd->clk will never be an ERR_PTR but always NULL if unset.

> 
> > +               ret = clk_prepare_enable(scpd->clk);
> > +               if (ret)
> > +                       return 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 */
> > +       timeout = jiffies + HZ;
> > +       expired = false;
> > +       while (1) {
> > +               ret = scpsys_domain_is_on(scpd);
> > +               if (ret > 0)
> > +                       break;
> > +
> > +               if (expired) {
> > +                       ret = -ETIMEDOUT;
> > +                       goto out;
> > +               }
> > +
> > +               cpu_relax();
> > +
> > +               if (time_after(jiffies, timeout))
> > +                       expired = true;
> > +       }
> > +
> > +       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 &= ~scpd->sram_pdn_bits;
> > +       writel(val, ctl_addr);
> > +
> > +       /* wait until SRAM_PDN_ACK all 0 */
> > +       timeout = jiffies + HZ;
> > +       expired = false;
> > +       while (sram_pdn_ack && (readl(ctl_addr) & sram_pdn_ack)) {
> > +
> > +               if (expired) {
> > +                       ret = -ETIMEDOUT;
> > +                       goto out;
> > +               }
> > +
> > +               cpu_relax();
> > +
> > +               if (time_after(jiffies, timeout))
> > +                       expired = true;
> > +       }
> > +
> > +       if (scpd->bus_prot_mask) {
> > +               ret = mtk_infracfg_clear_bus_protection(scp->infracfg,
> > +                               scpd->bus_prot_mask);
> > +               if (ret)
> > +                       return ret;
> > +       }
> > +
> > +       return 0;
> > +out:
> 
> There are no error handling. Especially the clock should be gated.

I'll disable the clock in the error path for the next round. Apart from
that I think I cannot implement a proper error handling without knowing
what actually went wrong. I mean I ask the hardware to do something
and then poll for a bit to get the ack from the hardware. If that ack
doesn't come I don't know what to do to recover from this state. A I2C
controller or such could probably be resetted in this situation, but a
power domain controller?

> > +       writel(val, ctl_addr);
> > +
> > +       /* wait until PWR_ACK = 0 */
> > +       timeout = jiffies + HZ;
> > +       expired = false;
> > +       while (1) {
> > +               ret = scpsys_domain_is_on(scpd);
> > +               if (ret == 0)
> > +                       break;
> > +
> > +               if (expired) {
> > +                       ret = -ETIMEDOUT;
> > +                       goto out;
> > +               }
> > +
> > +               cpu_relax();
> > +
> > +               if (time_after(jiffies, timeout))
> > +                       expired = true;
> > +       }
> > +
> > +       if (scpd->clk)
> 
> Shouldn't you check for !IS_ERR(scpd->clk) instead?

No, as above.

> > +               return -ENOMEM;
> > +
> > +       scp->clk[MT8173_CLK_MM] = devm_clk_get(&pdev->dev, "mm");
> > +       if (IS_ERR(scp->clk[MT8173_CLK_MM])) {
> > +               dev_err(&pdev->dev, "Failed to get mm clk: %ld\n",
> > +                               PTR_ERR(scp->clk[MT8173_CLK_MM]));
> 
> I think a similar error message is already printed by the common clk framework!?
> 
> > +               return PTR_ERR(scp->clk[MT8173_CLK_MM]);
> > +       }
> > +
> > +       scp->clk[MT8173_CLK_MFG] = devm_clk_get(&pdev->dev, "mfg");
> > +       if (IS_ERR(scp->clk[MT8173_CLK_MFG])) {
> > +               dev_err(&pdev->dev, "Failed to get mfg clk: %ld\n",
> > +                               PTR_ERR(scp->clk[MT8173_CLK_MFG]));
> 
> I think a similar error message is already printed by the common clk framework!?

Yes, will drop these messages.

> 
> > +               return PTR_ERR(scp->clk[MT8173_CLK_MFG]);
> > +       }
> > +
> > +       scp->infracfg = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
> > +                       "infracfg");
> > +       if (IS_ERR(scp->infracfg)) {
> > +               dev_err(&pdev->dev, "Cannot find infracfg controller: %ld\n",
> > +                               PTR_ERR(scp->infracfg));
> > +               return PTR_ERR(scp->infracfg);
> > +       }
> > +
> > +       pd_data->num_domains = NUM_DOMAINS;
> > +
> > +       for (i = 0; i < NUM_DOMAINS; i++) {
> > +               struct scp_domain *scpd = &scp->domains[i];
> > +               struct generic_pm_domain *genpd = &scpd->genpd;
> > +               const struct scp_domain_data *data = &scp_domain_data[i];
> > +
> > +               pd_data->domains[i] = genpd;
> > +               scpd->scp = scp;
> > +
> > +               scpd->sta_mask = data->sta_mask;
> > +               scpd->ctl_addr = scp->base + data->ctl_offs;
> > +               scpd->sram_pdn_bits = data->sram_pdn_bits;
> > +               scpd->sram_pdn_ack_bits = data->sram_pdn_ack_bits;
> > +               scpd->bus_prot_mask = data->bus_prot_mask;
> > +               if (data->clk_id != MT8173_CLK_NONE)
> > +                       scpd->clk = scp->clk[data->clk_id];
> 
> This seems odd. Why do you need to have an array of clocks to deal
> with this assignment?
> 
> I don't find that the struct scp->clk pointer is used but from this
> place. Couldn't you just fetch a reference to the clock to a local
> struct *clk, without caching it in the struct scp->clk?

Yes, will change.

Thanks for reviewing.

Sascha
diff mbox

Patch

diff --git a/drivers/soc/mediatek/Kconfig b/drivers/soc/mediatek/Kconfig
index e4f37a3..9a61b54 100644
--- a/drivers/soc/mediatek/Kconfig
+++ b/drivers/soc/mediatek/Kconfig
@@ -18,3 +18,12 @@  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
+	bool "MediaTek SCPSYS Support"
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	select REGMAP
+	select MTK_INFRACFG
+	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 3fa940f..12998b0 100644
--- a/drivers/soc/mediatek/Makefile
+++ b/drivers/soc/mediatek/Makefile
@@ -1,2 +1,3 @@ 
 obj-$(CONFIG_MTK_INFRACFG) += mtk-infracfg.o
 obj-$(CONFIG_MTK_PMIC_WRAP) += mtk-pmic-wrap.o
+obj-$(CONFIG_MTK_SCPSYS) += mtk-scpsys.o
diff --git a/drivers/soc/mediatek/mtk-scpsys.c b/drivers/soc/mediatek/mtk-scpsys.c
new file mode 100644
index 0000000..b9eed37
--- /dev/null
+++ b/drivers/soc/mediatek/mtk-scpsys.c
@@ -0,0 +1,490 @@ 
+/*
+ * 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/delay.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/mfd/syscon.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pm_domain.h>
+#include <linux/regmap.h>
+#include <linux/soc/mediatek/infracfg.h>
+#include <dt-bindings/power/mt8173-power.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 PWR_STATUS_DISP			BIT(3)
+#define PWR_STATUS_MFG			BIT(4)
+#define PWR_STATUS_ISP			BIT(5)
+#define PWR_STATUS_VDEC			BIT(7)
+#define PWR_STATUS_VENC_LT		BIT(20)
+#define PWR_STATUS_VENC			BIT(21)
+#define PWR_STATUS_MFG_2D		BIT(22)
+#define PWR_STATUS_MFG_ASYNC		BIT(23)
+#define PWR_STATUS_AUDIO		BIT(24)
+#define PWR_STATUS_USB			BIT(25)
+
+enum clk_id {
+	MT8173_CLK_NONE,
+	MT8173_CLK_MM,
+	MT8173_CLK_MFG,
+	MT8173_CLK_MAX = MT8173_CLK_MFG,
+};
+
+struct scp_domain_data {
+	const char *name;
+	u32 sta_mask;
+	int ctl_offs;
+	u32 sram_pdn_bits;
+	u32 sram_pdn_ack_bits;
+	u32 bus_prot_mask;
+	enum clk_id clk_id;
+};
+
+static const struct scp_domain_data scp_domain_data[] __initconst = {
+	[MT8173_POWER_DOMAIN_VDEC] = {
+		.name = "vdec",
+		.sta_mask = PWR_STATUS_VDEC,
+		.ctl_offs = SPM_VDE_PWR_CON,
+		.sram_pdn_bits = GENMASK(11, 8),
+		.sram_pdn_ack_bits = GENMASK(12, 12),
+		.clk_id = MT8173_CLK_MM,
+	},
+	[MT8173_POWER_DOMAIN_VENC] = {
+		.name = "venc",
+		.sta_mask = PWR_STATUS_VENC,
+		.ctl_offs = SPM_VEN_PWR_CON,
+		.sram_pdn_bits = GENMASK(11, 8),
+		.sram_pdn_ack_bits = GENMASK(15, 12),
+		.clk_id = MT8173_CLK_MM,
+	},
+	[MT8173_POWER_DOMAIN_ISP] = {
+		.name = "isp",
+		.sta_mask = PWR_STATUS_ISP,
+		.ctl_offs = SPM_ISP_PWR_CON,
+		.sram_pdn_bits = GENMASK(11, 8),
+		.sram_pdn_ack_bits = GENMASK(13, 12),
+		.clk_id = MT8173_CLK_MM,
+	},
+	[MT8173_POWER_DOMAIN_MM] = {
+		.name = "mm",
+		.sta_mask = PWR_STATUS_DISP,
+		.ctl_offs = SPM_DIS_PWR_CON,
+		.sram_pdn_bits = GENMASK(11, 8),
+		.sram_pdn_ack_bits = GENMASK(12, 12),
+		.clk_id = MT8173_CLK_MM,
+		.bus_prot_mask = MT8173_TOP_AXI_PROT_EN_MM_M0 |
+			MT8173_TOP_AXI_PROT_EN_MM_M1,
+	},
+	[MT8173_POWER_DOMAIN_VENC_LT] = {
+		.name = "venc_lt",
+		.sta_mask = PWR_STATUS_VENC_LT,
+		.ctl_offs = SPM_VEN2_PWR_CON,
+		.sram_pdn_bits = GENMASK(11, 8),
+		.sram_pdn_ack_bits = GENMASK(15, 12),
+		.clk_id = MT8173_CLK_MM,
+	},
+	[MT8173_POWER_DOMAIN_AUDIO] = {
+		.name = "audio",
+		.sta_mask = PWR_STATUS_AUDIO,
+		.ctl_offs = SPM_AUDIO_PWR_CON,
+		.sram_pdn_bits = GENMASK(11, 8),
+		.sram_pdn_ack_bits = GENMASK(15, 12),
+		.clk_id = MT8173_CLK_NONE,
+	},
+	[MT8173_POWER_DOMAIN_USB] = {
+		.name = "usb",
+		.sta_mask = PWR_STATUS_USB,
+		.ctl_offs = SPM_USB_PWR_CON,
+		.sram_pdn_bits = GENMASK(11, 8),
+		.sram_pdn_ack_bits = GENMASK(15, 12),
+		.clk_id = MT8173_CLK_NONE,
+	},
+	[MT8173_POWER_DOMAIN_MFG_ASYNC] = {
+		.name = "mfg_async",
+		.sta_mask = PWR_STATUS_MFG_ASYNC,
+		.ctl_offs = SPM_MFG_ASYNC_PWR_CON,
+		.sram_pdn_bits = GENMASK(11, 8),
+		.sram_pdn_ack_bits = 0,
+		.clk_id = MT8173_CLK_MFG,
+	},
+	[MT8173_POWER_DOMAIN_MFG_2D] = {
+		.name = "mfg_2d",
+		.sta_mask = PWR_STATUS_MFG_2D,
+		.ctl_offs = SPM_MFG_2D_PWR_CON,
+		.sram_pdn_bits = GENMASK(11, 8),
+		.sram_pdn_ack_bits = GENMASK(13, 12),
+		.clk_id = MT8173_CLK_NONE,
+	},
+	[MT8173_POWER_DOMAIN_MFG] = {
+		.name = "mfg",
+		.sta_mask = PWR_STATUS_MFG,
+		.ctl_offs = SPM_MFG_PWR_CON,
+		.sram_pdn_bits = GENMASK(13, 8),
+		.sram_pdn_ack_bits = GENMASK(21, 16),
+		.clk_id = MT8173_CLK_NONE,
+		.bus_prot_mask = MT8173_TOP_AXI_PROT_EN_MFG_S |
+			MT8173_TOP_AXI_PROT_EN_MFG_M0 |
+			MT8173_TOP_AXI_PROT_EN_MFG_M1 |
+			MT8173_TOP_AXI_PROT_EN_MFG_SNOOP_OUT,
+	},
+};
+
+#define NUM_DOMAINS	ARRAY_SIZE(scp_domain_data)
+
+struct scp;
+
+struct scp_domain {
+	struct generic_pm_domain genpd;
+	struct scp *scp;
+	struct clk *clk;
+	u32 sta_mask;
+	void __iomem *ctl_addr;
+	u32 sram_pdn_bits;
+	u32 sram_pdn_ack_bits;
+	u32 bus_prot_mask;
+};
+
+struct scp {
+	struct scp_domain domains[NUM_DOMAINS];
+	struct genpd_onecell_data pd_data;
+	struct device *dev;
+	void __iomem *base;
+	struct regmap *infracfg;
+	struct clk *clk[MT8173_CLK_MAX];
+};
+
+static int scpsys_domain_is_on(struct scp_domain *scpd)
+{
+	struct scp *scp = scpd->scp;
+
+	u32 status = readl(scp->base + SPM_PWR_STATUS) & scpd->sta_mask;
+	u32 status2 = readl(scp->base + SPM_PWR_STATUS_2ND) & scpd->sta_mask;
+
+	/*
+	 * A domain is on when both status bits are set. If only one is set
+	 * return an error. This happens while powering up a domain
+	 */
+
+	if (status && status2)
+		return true;
+	if (!status && !status2)
+		return false;
+
+	return -EINVAL;
+}
+
+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;
+	unsigned long timeout;
+	bool expired;
+	void __iomem *ctl_addr = scpd->ctl_addr;
+	u32 sram_pdn_ack = scpd->sram_pdn_ack_bits;
+	u32 val;
+	int ret;
+
+	if (scpd->clk) {
+		ret = clk_prepare_enable(scpd->clk);
+		if (ret)
+			return 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 */
+	timeout = jiffies + HZ;
+	expired = false;
+	while (1) {
+		ret = scpsys_domain_is_on(scpd);
+		if (ret > 0)
+			break;
+
+		if (expired) {
+			ret = -ETIMEDOUT;
+			goto out;
+		}
+
+		cpu_relax();
+
+		if (time_after(jiffies, timeout))
+			expired = true;
+	}
+
+	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 &= ~scpd->sram_pdn_bits;
+	writel(val, ctl_addr);
+
+	/* wait until SRAM_PDN_ACK all 0 */
+	timeout = jiffies + HZ;
+	expired = false;
+	while (sram_pdn_ack && (readl(ctl_addr) & sram_pdn_ack)) {
+
+		if (expired) {
+			ret = -ETIMEDOUT;
+			goto out;
+		}
+
+		cpu_relax();
+
+		if (time_after(jiffies, timeout))
+			expired = true;
+	}
+
+	if (scpd->bus_prot_mask) {
+		ret = mtk_infracfg_clear_bus_protection(scp->infracfg,
+				scpd->bus_prot_mask);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+out:
+	dev_err(scp->dev, "Failed to power on domain %s\n", genpd->name);
+
+	return ret;
+}
+
+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;
+	unsigned long timeout;
+	bool expired;
+	void __iomem *ctl_addr = scpd->ctl_addr;
+	u32 pdn_ack = scpd->sram_pdn_ack_bits;
+	u32 val;
+	int ret;
+
+	if (scpd->bus_prot_mask) {
+		ret = mtk_infracfg_set_bus_protection(scp->infracfg,
+				scpd->bus_prot_mask);
+		if (ret)
+			return ret;
+	}
+
+	val = readl(ctl_addr);
+	val |= scpd->sram_pdn_bits;
+	writel(val, ctl_addr);
+
+	/* wait until SRAM_PDN_ACK all 1 */
+	timeout = jiffies + HZ;
+	expired = false;
+	while (pdn_ack && (readl(ctl_addr) & pdn_ack) != pdn_ack) {
+		if (expired) {
+			ret = -ETIMEDOUT;
+			goto out;
+		}
+
+		cpu_relax();
+
+		if (time_after(jiffies, timeout))
+			expired = true;
+	}
+
+	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 */
+	timeout = jiffies + HZ;
+	expired = false;
+	while (1) {
+		ret = scpsys_domain_is_on(scpd);
+		if (ret == 0)
+			break;
+
+		if (expired) {
+			ret = -ETIMEDOUT;
+			goto out;
+		}
+
+		cpu_relax();
+
+		if (time_after(jiffies, timeout))
+			expired = true;
+	}
+
+	if (scpd->clk)
+		clk_disable_unprepare(scpd->clk);
+
+	return 0;
+
+out:
+	dev_err(scp->dev, "Failed to power off domain %s\n", genpd->name);
+
+	return ret;
+}
+
+static int __init scpsys_probe(struct platform_device *pdev)
+{
+	struct genpd_onecell_data *pd_data;
+	struct resource *res;
+	int i, ret;
+	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 = devm_kzalloc(&pdev->dev,
+			sizeof(*pd_data->domains) * NUM_DOMAINS, GFP_KERNEL);
+	if (!pd_data->domains)
+		return -ENOMEM;
+
+	scp->clk[MT8173_CLK_MM] = devm_clk_get(&pdev->dev, "mm");
+	if (IS_ERR(scp->clk[MT8173_CLK_MM])) {
+		dev_err(&pdev->dev, "Failed to get mm clk: %ld\n",
+				PTR_ERR(scp->clk[MT8173_CLK_MM]));
+		return PTR_ERR(scp->clk[MT8173_CLK_MM]);
+	}
+
+	scp->clk[MT8173_CLK_MFG] = devm_clk_get(&pdev->dev, "mfg");
+	if (IS_ERR(scp->clk[MT8173_CLK_MFG])) {
+		dev_err(&pdev->dev, "Failed to get mfg clk: %ld\n",
+				PTR_ERR(scp->clk[MT8173_CLK_MFG]));
+		return PTR_ERR(scp->clk[MT8173_CLK_MFG]);
+	}
+
+	scp->infracfg = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
+			"infracfg");
+	if (IS_ERR(scp->infracfg)) {
+		dev_err(&pdev->dev, "Cannot find infracfg controller: %ld\n",
+				PTR_ERR(scp->infracfg));
+		return PTR_ERR(scp->infracfg);
+	}
+
+	pd_data->num_domains = NUM_DOMAINS;
+
+	for (i = 0; i < NUM_DOMAINS; i++) {
+		struct scp_domain *scpd = &scp->domains[i];
+		struct generic_pm_domain *genpd = &scpd->genpd;
+		const struct scp_domain_data *data = &scp_domain_data[i];
+
+		pd_data->domains[i] = genpd;
+		scpd->scp = scp;
+
+		scpd->sta_mask = data->sta_mask;
+		scpd->ctl_addr = scp->base + data->ctl_offs;
+		scpd->sram_pdn_bits = data->sram_pdn_bits;
+		scpd->sram_pdn_ack_bits = data->sram_pdn_ack_bits;
+		scpd->bus_prot_mask = data->bus_prot_mask;
+		if (data->clk_id != MT8173_CLK_NONE)
+			scpd->clk = scp->clk[data->clk_id];
+
+		genpd->name = data->name;
+		genpd->power_off = scpsys_power_off;
+		genpd->power_on = scpsys_power_on;
+
+		/*
+		 * Initially turn on all domains to make the domains usable
+		 * with !CONFIG_PM and to get the hardware in sync with the
+		 * software.  The unused domains will be switched off during
+		 * late_init time.
+		 */
+		genpd->power_on(genpd);
+
+		pm_genpd_init(genpd, NULL, false);
+	}
+
+	/*
+	 * We are not allowed to fail here since there is no way to unregister
+	 * a power domain. Once registered above we have to keep the domains
+	 * valid.
+	 */
+
+	ret = pm_genpd_add_subdomain(pd_data->domains[MT8173_POWER_DOMAIN_MFG_ASYNC],
+		pd_data->domains[MT8173_POWER_DOMAIN_MFG_2D]);
+	if (ret && IS_ENABLED(CONFIG_PM))
+		dev_err(&pdev->dev, "Failed to add subdomain: %d\n", ret);
+
+	ret = pm_genpd_add_subdomain(pd_data->domains[MT8173_POWER_DOMAIN_MFG_2D],
+		pd_data->domains[MT8173_POWER_DOMAIN_MFG]);
+	if (ret && IS_ENABLED(CONFIG_PM))
+		dev_err(&pdev->dev, "Failed to add subdomain: %d\n", ret);
+
+	ret = of_genpd_add_provider_onecell(pdev->dev.of_node, pd_data);
+	if (ret)
+		dev_err(&pdev->dev, "Failed to add OF provider: %d\n", ret);
+
+	return 0;
+}
+
+static const struct of_device_id of_scpsys_match_tbl[] = {
+	{
+		.compatible = "mediatek,mt8173-scpsys",
+	}, {
+		/* sentinel */
+	}
+};
+
+static struct platform_driver scpsys_drv = {
+	.driver = {
+		.name = "mtk-scpsys",
+		.owner = THIS_MODULE,
+		.of_match_table = of_match_ptr(of_scpsys_match_tbl),
+	},
+};
+
+module_platform_driver_probe(scpsys_drv, scpsys_probe);
diff --git a/include/dt-bindings/power/mt8173-power.h b/include/dt-bindings/power/mt8173-power.h
new file mode 100644
index 0000000..b34cee9
--- /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_VDEC	0
+#define MT8173_POWER_DOMAIN_VENC	1
+#define MT8173_POWER_DOMAIN_ISP		2
+#define MT8173_POWER_DOMAIN_MM		3
+#define MT8173_POWER_DOMAIN_VENC_LT	4
+#define MT8173_POWER_DOMAIN_AUDIO	5
+#define MT8173_POWER_DOMAIN_USB		6
+#define MT8173_POWER_DOMAIN_MFG_ASYNC	7
+#define MT8173_POWER_DOMAIN_MFG_2D	8
+#define MT8173_POWER_DOMAIN_MFG		9
+
+#endif /* _DT_BINDINGS_POWER_MT8183_POWER_H */