Re: [PATCH 3/4] soc: Mediatek: Add SCPSYS power domain driver

From: Daniel Kurtz
Date: Mon Jun 22 2015 - 09:54:33 EST

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In reply to: Sascha Hauer: "[PATCH 3/4] soc: Mediatek: Add SCPSYS power domain driver"
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On Mon, Jun 22, 2015 at 2:35 PM, Sascha Hauer <s.hauer@xxxxxxxxxxxxxx> 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@xxxxxxxxxxxxxx>
> ---
> drivers/soc/mediatek/Kconfig | 10 +
> drivers/soc/mediatek/Makefile | 1 +
> drivers/soc/mediatek/mtk-scpsys.c | 487 +++++++++++++++++++++++++++++++
> include/dt-bindings/power/mt8173-power.h | 15 +
> 4 files changed, 513 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..32eff1b 100644
> --- a/drivers/soc/mediatek/Kconfig
> +++ b/drivers/soc/mediatek/Kconfig
> @@ -18,3 +18,13 @@ 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
> + select PM_GENERIC_DOMAINS if PM
> + 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..84c306a
> --- /dev/null
> +++ b/drivers/soc/mediatek/mtk-scpsys.c
> @@ -0,0 +1,487 @@
> +/*
> + * Copyright (c) 2015 Pengutronix, Sascha Hauer <kernel@xxxxxxxxxxxxxx>
> + *
> + * 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,

This sets MT8173_CLK_MAX = 2 ...

> +};
> +
> +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;
> +};
> +
> +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)
> + goto err_clk;
> + }
> +
> + 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 err_pwr_ack;
> + }
> +
> + 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 err_pwr_ack;
> + }
> +
> + 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)
> + goto err_pwr_ack;
> + }
> +
> + return 0;
> +
> +err_pwr_ack:
> + clk_disable_unprepare(scpd->clk);
> +err_clk:
> + 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)
> + goto out;
> + }
> +
> + 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;
> + struct clk *clk[MT8173_CLK_MAX];

So ARRAY_SIZE(clk) == 2 ...

> +
> + 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;
> +
> + clk[MT8173_CLK_MM] = devm_clk_get(&pdev->dev, "mm");

here we want to access:
clk[MT8173_CLK_MM] == clk[1]

> + if (IS_ERR(clk[MT8173_CLK_MM]))
> + return PTR_ERR(clk[MT8173_CLK_MM]);
> +
> + clk[MT8173_CLK_MFG] = devm_clk_get(&pdev->dev, "mfg");

and here...
clk[MT8173_CLK_MFG] == clk[2]

oops.

> + if (IS_ERR(clk[MT8173_CLK_MFG]))
> + return PTR_ERR(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 = clk[data->clk_id];

(and here)

-Dan

> +
> + 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
>
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