by Peng Fan (OSS)

[permalink] [raw]

Subject: RE: [PATCH V6 3/4] soc: imx: Add generic blk-ctl driver

> Subject: Re: [PATCH V6 3/4] soc: imx: Add generic blk-ctl driver
>
> On Sat, May 22, 2021 at 09:42:48PM +0800, Peng Fan (OSS) wrote:
> > From: Peng Fan <[email protected]>
> >
> > 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 <[email protected]>
>
> I would like to see some Reviewed-by tags.

ok

>
> > ---
> > drivers/soc/imx/Makefile | 2 +-
> > drivers/soc/imx/blk-ctl.c | 334
> > ++++++++++++++++++++++++++++++++++++++
> > drivers/soc/imx/blk-ctl.h | 85 ++++++++++
> > 3 files changed, 420 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
>
> As it's a generic blk-ctl driver, should we have a dedicated Kconfig option for
> it?

I think no need a dedicated Kconfig option, It is almost a must have
driver for i.MX8M.

>
> > diff --git a/drivers/soc/imx/blk-ctl.c b/drivers/soc/imx/blk-ctl.c new
> > file mode 100644 index 000000000000..8e286b8ef1b3
> > --- /dev/null
> > +++ b/drivers/soc/imx/blk-ctl.c
> > @@ -0,0 +1,334 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Copyright 2021 NXP.
> > + */
> > +
> > +#include <linux/clk.h>
> > +#include <linux/completion.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/regmap.h>
> > +#include <linux/slab.h>
> > +#include <linux/string.h>
> > +#include <linux/types.h>
> > +#include <linux/pm_domain.h>
> > +#include <linux/reset-controller.h>
>
> Some of the includes are out of alphabetic order. Also please check if you
> need all of these headers.

Fix in V7.

>
> > +
> > +#include "blk-ctl.h"
> > +
> > +static inline struct imx_blk_ctl_domain *to_imx_blk_ctl_pd(struct
> > +generic_pm_domain *genpd)
>
> Did you run checkpatch on it? Isn't this line beyond 80 column?

Yes. I ran, kernel new rule has been 100 column as I know.

>
> > +{
> > + 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;
> > +}
> > +
> > +int imx_blk_ctl_power_on(struct generic_pm_domain *domain)
>
> static?

Fix in v7.

>
> > +{
> > + 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");
> > +
> > + goto disable_clk;
>
> Goto disable_clk regardless of the ret check?

Oh, this was introduced in v6, fix in V7.

>
> > + }
> > +
> > + 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);
>
> The delay will be there even when IMX_BLK_CTL_PD_RESET is not set.

Fix in V7.

>
> > +
> > + if (hw->flags & IMX_BLK_CTL_PD_RESET) {
> > + 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);
> > + if (ret)
> > + goto disable_clk;
>
> Useless goto.

Fix in V7.

>
> > +
> > +disable_clk:
> > + clk_bulk_disable_unprepare(blk_ctl->num_clks, blk_ctl->clks);
> > +
> > + mutex_unlock(&blk_ctl->lock);
> > +
> > + return ret;
> > +}
> > +
> > +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 hsk_fail;
> > +
> > + if (hw->flags & IMX_BLK_CTL_PD_RESET) {
> > + ret = regmap_clear_bits(regmap, hw->rst_offset,
> hw->rst_mask);
> > + if (ret)
> > + goto hsk_fail;
> > + }
> > + }
> > +
> > + 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");
> > + }
> > +
> > +hsk_fail:
>
> You use disable_clk in above function for the same code. Inconsistent
> labeling strategy.

Fix in V7.

>
> > + 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;
>
> Have a newline.

Fix in V7.

>
> > + 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;
>
> Why is this necessary?

This is to avoid blk-ctl match with is parent's device driver, if
it use same dt node.

>
> > + return ret;
> > + }
>
> Have a newline.
>
> > + 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)) {
> > + pr_warn("failed to add subdomain: %s\n", domain->genpd.name);
>
> dev_warn()?
>
> > + } 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;
> > +
> > + pdev->dev.of_node = blk_ctl->dev->of_node;
>
> Why is this needed for .remove?
Fix in v7.
>
> I stop right here. The patch really needs some level cross reviewing.

ok, we are almost done in V5, but have to introduce a new design in V6.
I'll try to invite someone to help review.

Thanks,
Peng.

>
> Shawn
>
> > + 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) {
> > + pr_err("%s: invalid domain index %u\n", __func__, idx);
> > + 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
> >