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References: <20210612133134.2738-1-peng.fan@oss.nxp.com> <20210612133134.2738-4-peng.fan@oss.nxp.com>
In-Reply-To: <20210612133134.2738-4-peng.fan@oss.nxp.com>
From:   Adam Ford <aford173@gmail.com>
Date:   Mon, 14 Jun 2021 14:43:19 -0500
Message-ID: <CAHCN7xLskx8RnW6ZjDapv3wa4VbFq9a=07KkdkuLRsSNrfejRg@mail.gmail.com>
Subject: Re: [PATCH V7 3/4] soc: imx: Add generic blk-ctl driver
To:     "Peng Fan (OSS)" <peng.fan@oss.nxp.com>
Cc:     Rob Herring <robh+dt@kernel.org>, Shawn Guo <shawnguo@kernel.org>,
        Sascha Hauer <s.hauer@pengutronix.de>,
        Sascha Hauer <kernel@pengutronix.de>,
        Fabio Estevam <festevam@gmail.com>,
        NXP Linux Team <linux-imx@nxp.com>,
        Philipp Zabel <p.zabel@pengutronix.de>,
        Lucas Stach <l.stach@pengutronix.de>,
        Krzysztof Kozlowski <krzk@kernel.org>,
        =?UTF-8?Q?Guido_G=C3=BCnther?= <agx@sigxcpu.org>,
        Marek Vasut <marex@denx.de>,
        Andrey Smirnov <andrew.smirnov@gmail.com>,
        devicetree <devicetree@vger.kernel.org>,
        arm-soc <linux-arm-kernel@lists.infradead.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Jacky Bai <ping.bai@nxp.com>,
        Schrempf Frieder <frieder.schrempf@kontron.de>,
        Abel Vesa <abel.vesa@nxp.com>, Peng Fan <peng.fan@nxp.com>
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

On Sat, Jun 12, 2021 at 7:58 AM Peng Fan (OSS) <peng.fan@oss.nxp.com> wrote:
>
> From: Peng Fan <peng.fan@nxp.com>
>
> The i.MX8MM introduces an IP named BLK_CTL and usually is comprised of
> some GPRs.
>
> The GPRs has some clock bits and reset bits, but here we take it
> as virtual PDs, because of the clock and power domain A/B lock issue
> when taking it as a clock controller.
>
> For some bits, it might be good to also make it as a reset controller,
> but to i.MX8MM, we not add that support for now.
>
> Signed-off-by: Peng Fan <peng.fan@nxp.com>
> ---
>  drivers/soc/imx/Makefile  |   2 +-
>  drivers/soc/imx/blk-ctl.c | 325 ++++++++++++++++++++++++++++++++++++++
>  drivers/soc/imx/blk-ctl.h |  85 ++++++++++
>  3 files changed, 411 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/soc/imx/blk-ctl.c
>  create mode 100644 drivers/soc/imx/blk-ctl.h
>
> diff --git a/drivers/soc/imx/Makefile b/drivers/soc/imx/Makefile
> index 078dc918f4f3..d3d2b49a386c 100644
> --- a/drivers/soc/imx/Makefile
> +++ b/drivers/soc/imx/Makefile
> @@ -4,4 +4,4 @@ obj-$(CONFIG_ARCH_MXC) += soc-imx.o
>  endif
>  obj-$(CONFIG_HAVE_IMX_GPC) += gpc.o
>  obj-$(CONFIG_IMX_GPCV2_PM_DOMAINS) += gpcv2.o
> -obj-$(CONFIG_SOC_IMX8M) += soc-imx8m.o
> +obj-$(CONFIG_SOC_IMX8M) += soc-imx8m.o blk-ctl.o
> diff --git a/drivers/soc/imx/blk-ctl.c b/drivers/soc/imx/blk-ctl.c
> new file mode 100644
> index 000000000000..3464e4cf7fe6
> --- /dev/null
> +++ b/drivers/soc/imx/blk-ctl.c
> @@ -0,0 +1,325 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright 2021 NXP.
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/err.h>
> +#include <linux/io.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/of.h>
> +#include <linux/of_address.h>
> +#include <linux/of_device.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> +#include <linux/pm_domain.h>
> +#include <linux/regmap.h>
> +#include <linux/slab.h>
> +
> +#include "blk-ctl.h"
> +
> +static inline struct imx_blk_ctl_domain *to_imx_blk_ctl_pd(struct generic_pm_domain *genpd)
> +{
> +       return container_of(genpd, struct imx_blk_ctl_domain, genpd);
> +}
> +
> +static int imx_blk_ctl_enable_hsk(struct device *dev)
> +{
> +       struct imx_blk_ctl *blk_ctl = dev_get_drvdata(dev);
> +       const struct imx_blk_ctl_hw *hw = blk_ctl->dev_data->hw_hsk;
> +       struct regmap *regmap = blk_ctl->regmap;
> +       int ret;
> +
> +       if (hw->flags & IMX_BLK_CTL_PD_RESET) {
> +               ret = regmap_update_bits(regmap, hw->rst_offset, hw->rst_mask, hw->rst_mask);
> +               if (ret)
> +                       return ret;
> +       }
> +
> +       ret = regmap_update_bits(regmap, hw->offset, hw->mask, hw->mask);
> +
> +       /* Wait for handshake */
> +       udelay(5);
> +
> +       return ret;
> +}
> +
> +static int imx_blk_ctl_power_on(struct generic_pm_domain *domain)
> +{
> +       struct imx_blk_ctl_domain *pd = to_imx_blk_ctl_pd(domain);
> +       struct imx_blk_ctl *blk_ctl = pd->blk_ctl;
> +       struct regmap *regmap = blk_ctl->regmap;
> +       const struct imx_blk_ctl_hw *hw = &blk_ctl->dev_data->pds[pd->id];
> +       int ret;
> +
> +       mutex_lock(&blk_ctl->lock);
> +
> +       ret = clk_bulk_prepare_enable(blk_ctl->num_clks, blk_ctl->clks);
> +       if (ret) {
> +               mutex_unlock(&blk_ctl->lock);
> +               return ret;
> +       }
> +
> +       if (hw->flags & IMX_BLK_CTL_PD_HANDSHAKE) {
> +               ret = imx_blk_ctl_enable_hsk(blk_ctl->dev);
> +               if (ret) {
> +                       dev_err(blk_ctl->dev, "Hankshake failed when power on\n");

handshake

> +                       goto disable_clk;
> +               }
> +       }
> +
> +       if (hw->flags & IMX_BLK_CTL_PD_RESET) {
> +               ret = regmap_clear_bits(regmap, hw->rst_offset, hw->rst_mask);
> +               if (ret)
> +                       goto disable_clk;
> +
> +               /* Wait for reset propagate */
> +               udelay(5);
> +
> +               ret = regmap_update_bits(regmap, hw->rst_offset, hw->rst_mask, hw->rst_mask);
> +               if (ret)
> +                       goto disable_clk;
> +       }
> +
> +       ret = regmap_update_bits(regmap, hw->offset, hw->mask, hw->mask);
> +
> +disable_clk:
> +       clk_bulk_disable_unprepare(blk_ctl->num_clks, blk_ctl->clks);
> +
> +       mutex_unlock(&blk_ctl->lock);
> +
> +       return ret;
> +}
> +
> +static int imx_blk_ctl_power_off(struct generic_pm_domain *domain)
> +{
> +       struct imx_blk_ctl_domain *pd = to_imx_blk_ctl_pd(domain);
> +       struct imx_blk_ctl *blk_ctl = pd->blk_ctl;
> +       struct regmap *regmap = blk_ctl->regmap;
> +       const struct imx_blk_ctl_hw *hw = &blk_ctl->dev_data->pds[pd->id];
> +       int ret;
> +
> +       mutex_lock(&blk_ctl->lock);
> +
> +       ret = clk_bulk_prepare_enable(blk_ctl->num_clks, blk_ctl->clks);
> +       if (ret) {
> +               mutex_unlock(&blk_ctl->lock);
> +               return ret;
> +       }
> +
> +       if (!(hw->flags & IMX_BLK_CTL_PD_HANDSHAKE)) {
> +               ret = regmap_clear_bits(regmap, hw->offset, hw->mask);
> +               if (ret)
> +                       goto disable_clk;
> +
> +               if (hw->flags & IMX_BLK_CTL_PD_RESET) {
> +                       ret = regmap_clear_bits(regmap, hw->rst_offset, hw->rst_mask);
> +                       if (ret)
> +                               goto disable_clk;
> +               }
> +       }
> +
> +       if (hw->flags & IMX_BLK_CTL_PD_HANDSHAKE) {
> +               ret = imx_blk_ctl_enable_hsk(blk_ctl->dev);
> +               if (ret)
> +                       dev_err(blk_ctl->dev, "Hankshake failed when power off\n");

handshake

> +       }
> +
> +disable_clk:
> +       clk_bulk_disable_unprepare(blk_ctl->num_clks, blk_ctl->clks);
> +
> +       mutex_unlock(&blk_ctl->lock);
> +
> +       return ret;
> +}
> +
> +static int imx_blk_ctl_probe(struct platform_device *pdev)
> +{
> +       struct imx_blk_ctl_domain *domain = pdev->dev.platform_data;
> +       struct imx_blk_ctl *blk_ctl = domain->blk_ctl;
> +       struct generic_pm_domain *parent_genpd;
> +       struct device *dev = &pdev->dev;
> +       struct device *active_pd;
> +       int ret;
> +
> +       pdev->dev.of_node = blk_ctl->dev->of_node;
> +
> +       if (domain->hw->active_pd_name) {
> +               active_pd = dev_pm_domain_attach_by_name(dev, domain->hw->active_pd_name);
> +               if (IS_ERR_OR_NULL(active_pd)) {
> +                       ret = PTR_ERR(active_pd) ? : -ENODATA;
> +                       pdev->dev.of_node = NULL;
> +                       return ret;
> +               }
> +
> +               domain->active_pd = active_pd;
> +       } else {
> +               if (!blk_ctl->bus_domain) {
> +                       pdev->dev.of_node = NULL;
> +                       return -EPROBE_DEFER;
> +               }
> +       }
> +
> +       if (domain->hw->active_pd_name)
> +               parent_genpd = pd_to_genpd(active_pd->pm_domain);
> +       else
> +               parent_genpd = blk_ctl->bus_domain;
> +
> +       if (pm_genpd_add_subdomain(parent_genpd, &domain->genpd)) {
> +               dev_warn(dev, "failed to add subdomain: %s\n", domain->genpd.name);
> +       } else {
> +               mutex_lock(&blk_ctl->lock);
> +               domain->hooked = true;
> +               mutex_unlock(&blk_ctl->lock);
> +       }
> +
> +       return 0;
> +}
> +
> +static int imx_blk_ctl_remove(struct platform_device *pdev)
> +{
> +       struct imx_blk_ctl_domain *domain = pdev->dev.platform_data;
> +       struct imx_blk_ctl *blk_ctl = domain->blk_ctl;
> +       struct generic_pm_domain *parent_genpd;
> +       struct device *active_pd;
> +
> +       if (domain->hw->active_pd_name)
> +               parent_genpd = pd_to_genpd(active_pd->pm_domain);
> +       else
> +               parent_genpd = blk_ctl->bus_domain;
> +
> +       pm_genpd_remove_subdomain(parent_genpd, &domain->genpd);
> +
> +       mutex_lock(&blk_ctl->lock);
> +       domain->hooked = false;
> +       mutex_unlock(&blk_ctl->lock);
> +
> +       if (domain->hw->active_pd_name)
> +               dev_pm_domain_detach(domain->active_pd, false);
> +
> +       return 0;
> +}
> +
> +static const struct platform_device_id imx_blk_ctl_id[] = {
> +       { "imx-vpumix-blk-ctl", },
> +       { "imx-dispmix-blk-ctl", },
> +       { },
> +};
> +
> +static struct platform_driver imx_blk_ctl_driver = {
> +       .driver = {
> +               .name = "imx-blk-ctl",
> +       },
> +       .probe    = imx_blk_ctl_probe,
> +       .remove   = imx_blk_ctl_remove,
> +       .id_table = imx_blk_ctl_id,
> +};
> +builtin_platform_driver(imx_blk_ctl_driver)
> +
> +static struct generic_pm_domain *imx_blk_ctl_genpd_xlate(struct of_phandle_args *genpdspec,
> +                                                        void *data)
> +{
> +       struct genpd_onecell_data *genpd_data = data;
> +       unsigned int idx = genpdspec->args[0];
> +       struct imx_blk_ctl_domain *domain;
> +       struct generic_pm_domain *genpd = ERR_PTR(-EPROBE_DEFER);
> +
> +       if (genpdspec->args_count != 1)
> +               return ERR_PTR(-EINVAL);
> +
> +       if (idx >= genpd_data->num_domains)
> +               return ERR_PTR(-EINVAL);
> +
> +       if (!genpd_data->domains[idx])
> +               return ERR_PTR(-ENOENT);
> +
> +       domain = to_imx_blk_ctl_pd(genpd_data->domains[idx]);
> +
> +       mutex_lock(&domain->blk_ctl->lock);
> +       if (domain->hooked)
> +               genpd = genpd_data->domains[idx];
> +       mutex_unlock(&domain->blk_ctl->lock);
> +
> +       return genpd;
> +}
> +
> +int imx_blk_ctl_register(struct device *dev)
> +{
> +       struct imx_blk_ctl *blk_ctl = dev_get_drvdata(dev);
> +       const struct imx_blk_ctl_dev_data *dev_data = blk_ctl->dev_data;
> +       int num = dev_data->pds_num;
> +       struct imx_blk_ctl_domain *domain;
> +       struct generic_pm_domain *genpd;
> +       struct platform_device *pd_pdev;
> +       int domain_index;
> +       int i, ret;
> +
> +       blk_ctl->onecell_data.num_domains = num;
> +       blk_ctl->onecell_data.xlate = imx_blk_ctl_genpd_xlate;
> +       blk_ctl->onecell_data.domains = devm_kcalloc(dev, num, sizeof(struct generic_pm_domain *),
> +                                                    GFP_KERNEL);
> +       if (!blk_ctl->onecell_data.domains)
> +               return -ENOMEM;
> +
> +       for (i = 0; i < num; i++) {
> +               domain_index = dev_data->pds[i].id;
> +               if (domain_index >= num) {
> +                       dev_warn(dev, "Domain index %d is out of bounds\n", domain_index);
> +                       continue;
> +               }
> +
> +               domain = devm_kzalloc(dev, sizeof(struct imx_blk_ctl_domain), GFP_KERNEL);
> +               if (!domain)
> +                       goto error;
> +
> +               pd_pdev = platform_device_alloc(dev_data->name, domain_index);
> +               if (!pd_pdev) {
> +                       dev_err(dev, "Failed to allocate platform device\n");
> +                       goto error;
> +               }
> +
> +               pd_pdev->dev.platform_data = domain;
> +
> +               domain->blk_ctl = blk_ctl;
> +               domain->hw = &dev_data->pds[i];
> +               domain->id = domain_index;
> +               domain->genpd.name = dev_data->pds[i].name;
> +               domain->genpd.power_off = imx_blk_ctl_power_off;
> +               domain->genpd.power_on = imx_blk_ctl_power_on;
> +               domain->dev = &pd_pdev->dev;
> +               domain->hooked = false;
> +
> +               ret = pm_genpd_init(&domain->genpd, NULL, true);
> +               pd_pdev->dev.parent = dev;
> +
> +               if (domain->hw->flags & IMX_BLK_CTL_PD_HANDSHAKE)
> +                       blk_ctl->bus_domain = &domain->genpd;
> +
> +               ret = platform_device_add(pd_pdev);
> +               if (ret) {
> +                       platform_device_put(pd_pdev);
> +                       goto error;
> +               }
> +               blk_ctl->onecell_data.domains[i] = &domain->genpd;
> +       }
> +
> +       return of_genpd_add_provider_onecell(dev->of_node, &blk_ctl->onecell_data);
> +
> +error:
> +       for (; i >= 0; i--) {
> +               genpd = blk_ctl->onecell_data.domains[i];
> +               if (!genpd)
> +                       continue;
> +               domain = to_imx_blk_ctl_pd(genpd);
> +               if (domain->dev)
> +                       platform_device_put(to_platform_device(domain->dev));
> +       }
> +       return ret;
> +}
> +EXPORT_SYMBOL_GPL(imx_blk_ctl_register);
> +
> +const struct dev_pm_ops imx_blk_ctl_pm_ops = {
> +       SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, pm_runtime_force_resume)
> +};
> +EXPORT_SYMBOL_GPL(imx_blk_ctl_pm_ops);
> diff --git a/drivers/soc/imx/blk-ctl.h b/drivers/soc/imx/blk-ctl.h
> new file mode 100644
> index 000000000000..6780d00ec8c5
> --- /dev/null
> +++ b/drivers/soc/imx/blk-ctl.h
> @@ -0,0 +1,85 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef __SOC_IMX_BLK_CTL_H
> +#define __SOC_IMX_BLK_CTL_H
> +
> +enum imx_blk_ctl_pd_type {
> +       BLK_CTL_PD,
> +};
> +
> +struct imx_blk_ctl_hw {
> +       int type;
> +       char *name;
> +       char *active_pd_name;
> +       u32 offset;
> +       u32 mask;
> +       u32 flags;
> +       u32 id;
> +       u32 rst_offset;
> +       u32 rst_mask;
> +       u32 errata;
> +};
> +
> +struct imx_blk_ctl_domain {
> +       struct generic_pm_domain genpd;
> +       struct device *active_pd;
> +       struct imx_blk_ctl *blk_ctl;
> +       struct imx_blk_ctl_hw *hw;
> +       struct device *dev;
> +       bool hooked;
> +       u32 id;
> +};
> +
> +struct imx_blk_ctl_dev_data {
> +       struct regmap_config config;
> +       struct imx_blk_ctl_hw *pds;
> +       struct imx_blk_ctl_hw *hw_hsk;
> +       u32 pds_num;
> +       u32 max_num;
> +       char *name;
> +};
> +
> +struct imx_blk_ctl {
> +       struct device *dev;
> +       struct regmap *regmap;
> +       struct genpd_onecell_data onecell_data;
> +       const struct imx_blk_ctl_dev_data *dev_data;
> +       struct clk_bulk_data *clks;
> +       u32 num_clks;
> +       struct generic_pm_domain *bus_domain;
> +
> +       struct mutex lock;
> +};
> +
> +#define IMX_BLK_CTL(_type, _name, _active_pd, _id, _offset, _mask, _rst_offset, _rst_mask,     \
> +                   _flags, _errata)                                                            \
> +       {                                                                                       \
> +               .type = _type,                                                                  \
> +               .name = _name,                                                                  \
> +               .active_pd_name = _active_pd,                                                   \
> +               .id = _id,                                                                      \
> +               .offset = _offset,                                                              \
> +               .mask = _mask,                                                                  \
> +               .flags = _flags,                                                                \
> +               .rst_offset = _rst_offset,                                                      \
> +               .rst_mask = _rst_mask,                                                          \
> +               .errata = _errata,                                                              \
> +       }
> +
> +#define IMX_BLK_CTL_PD(_name, _active_pd, _id, _offset, _mask, _rst_offset, _rst_mask, _flags) \
> +       IMX_BLK_CTL(BLK_CTL_PD, _name, _active_pd, _id, _offset, _mask, _rst_offset,            \
> +                   _rst_mask, _flags, 0)
> +
> +#define IMX_BLK_CTL_PD_ERRATA(_name, _active_pd, _id, _offset, _mask, _rst_offset, _rst_mask,  \
> +                             _flags, _errata)                                                  \
> +       IMX_BLK_CTL(BLK_CTL_PD, _name, _active_pd, _id, _offset, _mask, _rst_offset,            \
> +                   _rst_mask, _flags, _errata)
> +
> +int imx_blk_ctl_register(struct device *dev);
> +
> +#define IMX_BLK_CTL_PD_HANDSHAKE       BIT(0)
> +#define IMX_BLK_CTL_PD_RESET           BIT(1)
> +#define IMX_BLK_CTL_PD_BUS             BIT(2)
> +
> +const extern struct dev_pm_ops imx_blk_ctl_pm_ops;
> +
> +#endif
> --
> 2.30.0
>