RE: [PATCH V2 3/4] soc: imx: Add generic blk-ctl driver
From: Peng Fan (OSS)
Date: Tue May 04 2021 - 07:25:20 EST
> Subject: Re: [PATCH V2 3/4] soc: imx: Add generic blk-ctl driver
>
> On 30.04.21 07:27, Peng Fan (OSS) wrote:
> > From: Peng Fan <peng.fan@xxxxxxx>
> >
> > 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@xxxxxxx>
> > ---
> > drivers/soc/imx/Makefile | 2 +-
> > drivers/soc/imx/blk-ctl.c | 303
> ++++++++++++++++++++++++++++++++++++++
> > drivers/soc/imx/blk-ctl.h | 76 ++++++++++
> > 3 files changed, 380 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..1f764dfd308d
> > --- /dev/null
> > +++ b/drivers/soc/imx/blk-ctl.c
> > @@ -0,0 +1,303 @@
> > +// 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/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>
> > +
> > +#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, pd); }
> > +
> > +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;
> > +
> > +
>
> Only one blank line here.
Fix in V3.
>
> > + if (hw->flags & IMX_BLK_CTL_PD_RESET)
> > + ret = regmap_update_bits(regmap, hw->rst_offset, hw->rst_mask,
> > +hw->rst_mask);
>
> The return value above gets discarded.
Fix in V3.
>
> > +
> > + ret = regmap_update_bits(regmap, hw->offset, hw->mask, hw->mask);
> > +
> > + /* Wait for handshake */
> > + udelay(5);
> > +
> > + return ret;
> > +}
> > +
> > +int imx_blk_ctl_power_off(struct generic_pm_domain *domain) {
> > + struct imx_blk_ctl_domain *pd;
> > + struct imx_blk_ctl *blk_ctl;
> > + const struct imx_blk_ctl_hw *hw;
> > + struct regmap *regmap;
> > + int ret;
> > +
> > + pd = to_imx_blk_ctl_pd(domain);
> > + blk_ctl = pd->blk_ctl;
> > + regmap = blk_ctl->regmap;
> > + hw = &blk_ctl->dev_data->pds[pd->id];
>
> You could include the assignments above in the declarations.
Fix in V3.
>
> > +
> > + ret = clk_bulk_prepare_enable(blk_ctl->num_clks, blk_ctl->clks);
> > + if (ret)
> > + return ret;
> > +
> > + ret = regmap_update_bits(regmap, hw->offset, hw->mask, 0);
>
> You could use regmap_clear_bits() here.
Fix in V3.
>
> > + if (ret)
> > + goto hsk_fail;
> > +
> > + if (hw->flags & IMX_BLK_CTL_PD_RESET)
> > + ret = regmap_update_bits(regmap, hw->rst_offset, hw->rst_mask,
> 0);
>
> You could use regmap_clear_bits() here.
> And the return value of regmap_update_bits() potentially gets discarded.
Fix in V3.
>
> > +
> > + if (atomic_dec_and_test(&blk_ctl->power_count)) {
> > + ret = imx_blk_ctl_enable_hsk(blk_ctl->dev);
> > + if (ret) {
> > + dev_err(blk_ctl->dev, "Hankshake fail\n");
>
> s/Hankshake fail/Handshake failed/
Fix in V3.
>
> > + goto hsk_fail;
>
> This goto is redundant.
Fix in V3.
>
> > + }
> > + }
> > +
> > +hsk_fail:
> > + clk_bulk_disable_unprepare(blk_ctl->num_clks, blk_ctl->clks);
> > +
> > + return ret;
> > +}
> > +
> > +int imx_blk_ctl_power_on(struct generic_pm_domain *domain) {
> > + struct imx_blk_ctl_domain *pd;
> > + struct regmap *regmap;
> > + const struct imx_blk_ctl_hw *hw;
> > + int ret;
> > + struct imx_blk_ctl *blk_ctl;
> > +
> > + pd = to_imx_blk_ctl_pd(domain);
> > + blk_ctl = pd->blk_ctl;
> > + regmap = blk_ctl->regmap;
> > + hw = &blk_ctl->dev_data->pds[pd->id];
>
> You could include the assignments above in the declarations.
>
> > +
> > + ret = clk_bulk_prepare_enable(blk_ctl->num_clks, blk_ctl->clks);
> > + if (ret)
> > + return ret;
> > +
> > + if ((atomic_read(&blk_ctl->power_count) == 0)) {
> > + ret = imx_blk_ctl_enable_hsk(blk_ctl->dev);
> > + if (ret) {
> > + dev_err(blk_ctl->dev, "Hankshake fail\n");
>
> s/Hankshake fail/Handshake failed/
Fix in v3.
>
> > + goto disable_clk;
> > + }
> > + }
> > +
> > + if (hw->flags & IMX_BLK_CTL_PD_RESET)
> > + ret = regmap_update_bits(regmap, hw->rst_offset, hw->rst_mask,
> 0);
>
> You could use regmap_clear_bits() here.
> And the return value of regmap_update_bits() gets discarded.
Fix in v3.
>
> > +
> > + /* Wait for reset propagate */
> > + udelay(5);
> > +
> > + if (hw->flags & IMX_BLK_CTL_PD_RESET)
> > + ret = regmap_update_bits(regmap, hw->rst_offset, hw->rst_mask,
> > +hw->rst_mask);
>
> The return value above gets discarded.
Fix in V3.
>
> > +
> > + ret = regmap_update_bits(regmap, hw->offset, hw->mask, hw->mask);
> > + if (ret)
> > + goto disable_clk;
> > +
> > + atomic_inc(&blk_ctl->power_count);
> > +
> > +disable_clk:
> > + clk_bulk_disable_unprepare(blk_ctl->num_clks, blk_ctl->clks);
> > +
> > + return ret;
> > +}
> > +
> > +static int imx_blk_ctl_attach_pd(struct device *dev, struct device **devs,
> char **pd_names,
> > + u32 num_pds)
> > +{
> > + int i, ret;
> > +
> > + if (!pd_names)
> > + return 0;
> > +
> > + if (dev->pm_domain) {
> > + devs[0] = dev;
> > + pm_runtime_enable(dev);
> > + return 0;
> > + }
> > +
> > + for (i = 0; i < num_pds; i++) {
> > + devs[i] = dev_pm_domain_attach_by_name(dev, pd_names[i]);
> > + if (IS_ERR_OR_NULL(devs[i])) {
> > + ret = PTR_ERR(devs[i]) ? : -ENODATA;
> > + goto detach_pm;
> > + }
> > + }
> > +
> > + return 0;
> > +
> > +detach_pm:
> > + for (i--; i >= 0; i--)
> > + dev_pm_domain_detach(devs[i], false);
>
> It looks like you should add pm_runtime_disable() in this error path to not
> leave the pm_runtime_enable() unmatched.
I might need to remove pm runtime, since no the ops callback here does nothing.
>
> > +
> > + return ret;
> > +}
> > +
> > +static int imx_blk_ctl_register_pd(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;
> > + int i, ret;
> > +
> > + blk_ctl->onecell_data.num_domains = num;
> > + 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 = devm_kzalloc(dev, sizeof(*domain), GFP_KERNEL);
> > + if (!domain) {
> > + ret = -ENOMEM;
> > + goto remove_genpd;
> > + }
> > + domain->pd.name = dev_data->pds[i].name;
> > + domain->pd.power_off = imx_blk_ctl_power_off;
> > + domain->pd.power_on = imx_blk_ctl_power_on;
> > + domain->blk_ctl = blk_ctl;
> > + domain->id = i;
> > +
> > + ret = pm_genpd_init(&domain->pd, NULL, true);
> > + if (ret)
> > + return ret;
>
> Looks like you should use the error path here and "goto remove_genpd"
> instead of return.
Fix in V3.
>
> > +
> > + blk_ctl->onecell_data.domains[i] = &domain->pd;
> > + }
> > +
> > + return 0;
> > +
> > +remove_genpd:
> > + for (i = i - 1; i >= 0; i--)
> > + pm_genpd_remove(blk_ctl->onecell_data.domains[i]);
> > +
> > + return ret;
> > +}
> > +
> > +static int imx_blk_ctl_hook_pd(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;
> > + const struct imx_blk_ctl_hw *pds = dev_data->pds;
> > + int num_active_pd = dev_data->num_active_pd;
> > + int num = dev_data->pds_num;
> > + struct generic_pm_domain *genpd, *child_genpd;
> > + int ret;
> > + int i, j;
> > +
> > + blk_ctl->active_pds = devm_kcalloc(dev, num_active_pd, sizeof(struct
> device *), GFP_KERNEL);
> > + if (!blk_ctl->active_pds)
> > + return -ENOMEM;
> > +
> > + ret = imx_blk_ctl_attach_pd(dev, blk_ctl->active_pds,
> dev_data->active_pd_names,
> > + num_active_pd);
> > + if (ret) {
> > + if (ret == -EPROBE_DEFER)
> > + return ret;
> > + dev_err(dev, "Failed to attach active pd: %d\n", ret);
> > + return ret;
>
> I think it would be better to do it the other way round:
Fix in V3.
>
> if (ret != -EPROBE_DEFER)
> dev_err(dev, "Failed to attach active pd: %d\n", ret);
> return ret;
>
> > + }
> > +
> > + for (i = 0; i < num; i++) {
> > + for (j = 0; j < num_active_pd; j++) {
> > + genpd = pd_to_genpd(blk_ctl->active_pds[j]->pm_domain);
> > + if (!strcmp(genpd->name, pds[i].parent_name))
> > + break;
> > + }
> > +
> > + child_genpd = blk_ctl->onecell_data.domains[i];
> > + if (pm_genpd_add_subdomain(genpd, child_genpd))
> > + pr_warn("failed to add subdomain:\n");
>
> Remove the colon add the end of the warning message or add something after
> it.
Fix in V3.
Thanks,
Peng.
>
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +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;
> > + int i, ret;
> > +
> > + if (!blk_ctl)
> > + return -ENODEV;
> > +
> > + ret = imx_blk_ctl_register_pd(dev);
> > + if (ret)
> > + return ret;
> > +
> > + ret = imx_blk_ctl_hook_pd(dev);
> > + if (ret)
> > + goto unregister_pd;
> > +
> > + ret = of_genpd_add_provider_onecell(dev->of_node,
> &blk_ctl->onecell_data);
> > + if (ret)
> > + goto detach_pd;
> > +
> > + pm_runtime_get_noresume(dev);
> > + pm_runtime_set_active(dev);
> > + pm_runtime_enable(dev);
> > +
> > + pm_runtime_put(dev);
> > +
> > + return 0;
> > +
> > +detach_pd:
> > + for (i = blk_ctl->dev_data->num_active_pd; i >= 0; i--)
> > + dev_pm_domain_detach(blk_ctl->active_pds[i], false);
> > +unregister_pd:
> > + for (i = num - 1; i >= 0; i--)
> > + pm_genpd_remove(blk_ctl->onecell_data.domains[i]);
> > +
> > + return ret;
> > +}
> > +EXPORT_SYMBOL_GPL(imx_blk_ctl_register);
> > +
> > +static int __maybe_unused imx_blk_ctl_runtime_suspend(struct device
> > +*dev) {
> > + return 0;
> > +}
> > +
> > +static int __maybe_unused imx_blk_ctl_runtime_resume(struct device
> > +*dev) {
> > + return 0;
> > +}
> > +
> > +const struct dev_pm_ops imx_blk_ctl_pm_ops = {
> > + SET_RUNTIME_PM_OPS(imx_blk_ctl_runtime_suspend,
> > + imx_blk_ctl_runtime_resume, NULL)
> > + 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..e736369406a1
> > --- /dev/null
> > +++ b/drivers/soc/imx/blk-ctl.h
> > @@ -0,0 +1,76 @@
> > +/* 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 *parent_name;
> > + u32 offset;
> > + u32 mask;
> > + u32 flags;
> > + u32 id;
> > + u32 rst_offset;
> > + u32 rst_mask;
> > +};
> > +
> > +struct imx_blk_ctl_domain {
> > + struct generic_pm_domain pd;
> > + struct imx_blk_ctl *blk_ctl;
> > + 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;
> > + char **active_pd_names;
> > + u32 num_active_pd;
> > +};
> > +
> > +struct imx_blk_ctl {
> > + struct device *dev;
> > + struct regmap *regmap;
> > + struct device **active_pds;
> > + u32 pds_num;
> > + u32 active_pd_count;
> > + struct genpd_onecell_data onecell_data;
> > + const struct imx_blk_ctl_dev_data *dev_data;
> > + struct clk_bulk_data *clks;
> > + u32 num_clks;
> > +
> > + atomic_t power_count;
> > +};
> > +
> > +#define IMX_BLK_CTL(_type, _name, _parent_name, _id, _offset, _mask,
> _rst_offset, _rst_mask, \
> > + _flags) \
> > + { \
> > + .type = _type, \
> > + .name = _name, \
> > + .parent_name = _parent_name, \
> > + .id = _id, \
> > + .offset = _offset, \
> > + .mask = _mask, \
> > + .flags = _flags, \
> > + .rst_offset = _rst_offset, \
> > + .rst_mask = _rst_mask, \
> > + }
> > +
> > +#define IMX_BLK_CTL_PD(_name, _parent_name, _id, _offset, _mask,
> _rst_offset, _rst_mask, _flags) \
> > + IMX_BLK_CTL(BLK_CTL_PD, _name, _parent_name, _id, _offset, _mask,
> _rst_offset, \
> > + _rst_mask, _flags)
> > +
> > +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
> >