RE: [PATCH v4 10/11] ARM: EXYNOS: Add platform driver support for Exynos PMU.

Pankaj Dubey
2014-06-24T11:27:35Z

Hi Tomasz,

On Tuesday, June 17 2014, Tomasz Figa wrote:
> Hi Pankaj,
>
> [dropping Young-Gun Jang <yg1004.jang@samsung.com>, as my mailer denies to
> send to this address]
>

Yes, we can drop Young-Gun Jang's email id as it's no more valid.

> Please see my comments inline. I have skipped comments for changed related
to
> regmap, as according to our previous discussion they will be dropped in
next version.
>
> On 10.05.2014 08:56, Pankaj Dubey wrote:
> > This patch modifies Exynos Power Management Unit (PMU) initialization
> > implementation in following way:
> >
> > - Added platform_device support by registering static platform device.
> > - Added platform struct exynos_pmu_data to hold platform specific data.
> > - For each SoC's PMU support now we can add platform data and statically
> > bind PMU configuration and SoC specific initialization function.
> > - Probe function will scan DT and based on matching PMU compatibility
> > string initialize pmu_context which will be platform_data for driver.
> > - Obtain PMU regmap handle using "syscon_regmap_lookup_by_phandle" so
> > that we can reduce dependency over machine header files.
> > - Separate each SoC's PMU initialization function and make it as part of
> > platform data.
> > - It also removes uses of soc_is_exynosXYZ() thus making PMU
implementation
> > independent of "plat/cpu.h".
> >
> > Signed-off-by: Pankaj Dubey <pankaj.dubey@samsung.com>
> > Signed-off-by: Young-Gun Jang <yg1004.jang@samsung.com>
> > ---
> > arch/arm/mach-exynos/pmu.c | 266
> > ++++++++++++++++++++++++++++++++++----------
> > 1 file changed, 210 insertions(+), 56 deletions(-)
> >
> > diff --git a/arch/arm/mach-exynos/pmu.c b/arch/arm/mach-exynos/pmu.c
> > index 67116a5..6a7fa8e 100644
> > --- a/arch/arm/mach-exynos/pmu.c
> > +++ b/arch/arm/mach-exynos/pmu.c
> > @@ -1,5 +1,5 @@
> > /*
> > - * Copyright (c) 2011-2012 Samsung Electronics Co., Ltd.
> > + * Copyright (c) 2011-2014 Samsung Electronics Co., Ltd.
> > * http://www.samsung.com/
> > *
> > * EXYNOS - CPU PMU(Power Management Unit) support @@ -9,20 +9,33
> @@
> > * published by the Free Software Foundation.
> > */
> >
> > -#include <linux/io.h>
> > -#include <linux/kernel.h>
> > +#include <linux/module.h>
> > #include <linux/regmap.h>
> > -
> > -#include <plat/cpu.h>
> > +#include <linux/of.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/slab.h>
> > +#include <linux/mfd/syscon.h>
> >
> > #include "common.h"
> > #include "regs-pmu.h"
> >
> > -static const struct exynos_pmu_conf *exynos_pmu_config; -static
> > struct regmap *pmu_regmap;
> > +struct exynos_pmu_data {
> > + const struct exynos_pmu_conf *pmu_config;
> > + const struct exynos_pmu_conf *pmu_config_extra;
> > + void (*pmu_init)(void);
> > + void (*powerdown_conf)(enum sys_powerdown); };
> > +
> > +struct exynos_pmu_context {
> > + struct device *dev;
> > + struct exynos_pmu_data *pmu_data;
> > + struct regmap *pmu_regmap;
> > +};
> > +
> > +static struct exynos_pmu_context *pmu_context;
> >
> > static const struct exynos_pmu_conf exynos4210_pmu_config[] = {
> > - /* { .reg = address, .val = { AFTR, LPA, SLEEP } */
> > + /* { .offset = address, .val = { AFTR, LPA, SLEEP } */
>
> AFAICT those have changed already in patch 08/11.
>

Will correct this.

> > { S5P_ARM_CORE0_LOWPWR, { 0x0, 0x0, 0x2 } },
> > { S5P_DIS_IRQ_CORE0, { 0x0, 0x0, 0x0 } },
> > { S5P_DIS_IRQ_CENTRAL0, { 0x0, 0x0, 0x0 } },
> > @@ -216,7 +229,7 @@ static const struct exynos_pmu_conf
> > exynos4412_pmu_config[] = { };
> >
> > static const struct exynos_pmu_conf exynos5250_pmu_config[] = {
> > - /* { .reg = address, .val = { AFTR, LPA, SLEEP } */
> > + /* { .offset = address, .val = { AFTR, LPA, SLEEP } */
>
> Ditto.
>
> > { EXYNOS5_ARM_CORE0_SYS_PWR_REG, { 0x0, 0x0, 0x2}
> },
> > { EXYNOS5_DIS_IRQ_ARM_CORE0_LOCAL_SYS_PWR_REG, {
> 0x0, 0x0, 0x0} },
> > { EXYNOS5_DIS_IRQ_ARM_CORE0_CENTRAL_SYS_PWR_REG, {
> 0x0, 0x0, 0x0} },
> > @@ -339,7 +352,7 @@ static unsigned int const
exynos5_list_diable_wfi_wfe[] =
> {
> > EXYNOS5_ISP_ARM_OPTION,
> > };
> >
> > -static void exynos5_init_pmu(void)
> > +void exynos5_powerdown_conf(enum sys_powerdown mode)
>
> static
>

OK.

> > {
> > unsigned int i;
> > unsigned int tmp;
> > @@ -348,81 +361,222 @@ static void exynos5_init_pmu(void)
> > * Enable both SC_FEEDBACK and SC_COUNTER
> > */
> > for (i = 0 ; i < ARRAY_SIZE(exynos5_list_both_cnt_feed) ; i++) {
> > - regmap_read(pmu_regmap, exynos5_list_both_cnt_feed[i],
&tmp);
> > + regmap_read(pmu_context->pmu_regmap,
> > + exynos5_list_both_cnt_feed[i], &tmp);
> > tmp |= (EXYNOS5_USE_SC_FEEDBACK |
> > EXYNOS5_USE_SC_COUNTER);
> > - regmap_write(pmu_regmap, exynos5_list_both_cnt_feed[i],
tmp);
> > + regmap_write(pmu_context->pmu_regmap,
> > + exynos5_list_both_cnt_feed[i], tmp);
> > }
> >
> > /*
> > * SKIP_DEACTIVATE_ACEACP_IN_PWDN_BITFIELD Enable
> > */
> > - regmap_read(pmu_regmap, EXYNOS5_ARM_COMMON_OPTION,
> &tmp);
> > + regmap_read(pmu_context->pmu_regmap,
> EXYNOS5_ARM_COMMON_OPTION,
> > +&tmp);
> > tmp |= EXYNOS5_SKIP_DEACTIVATE_ACEACP_IN_PWDN;
> > - regmap_write(pmu_regmap, EXYNOS5_ARM_COMMON_OPTION, tmp);
> > + regmap_write(pmu_context->pmu_regmap,
> EXYNOS5_ARM_COMMON_OPTION,
> > +tmp);
> >
> > /*
> > * Disable WFI/WFE on XXX_OPTION
> > */
> > for (i = 0 ; i < ARRAY_SIZE(exynos5_list_diable_wfi_wfe) ; i++) {
> > - tmp = regmap_read(pmu_regmap,
exynos5_list_diable_wfi_wfe[i],
> > - &tmp);
> > + tmp = regmap_read(pmu_context->pmu_regmap,
> > + exynos5_list_diable_wfi_wfe[i], &tmp);
> > tmp &= ~(EXYNOS5_OPTION_USE_STANDBYWFE |
> > EXYNOS5_OPTION_USE_STANDBYWFI);
> > - regmap_write(pmu_regmap, exynos5_list_diable_wfi_wfe[i],
tmp);
> > + regmap_write(pmu_context->pmu_regmap,
> > + exynos5_list_diable_wfi_wfe[i], tmp);
> > }
> > }
> >
> > void exynos_sys_powerdown_conf(enum sys_powerdown mode) {
> > unsigned int i;
> > + struct exynos_pmu_data *pmu_data = pmu_context->pmu_data;
> > +
> > + if (pmu_data->powerdown_conf)
> > + pmu_data->powerdown_conf(mode);
> > +
> > + if (pmu_data->pmu_config) {
> > + for (i = 0; (pmu_data->pmu_config[i].offset !=
PMU_TABLE_END)
> ; i++)
> > + regmap_write(pmu_context->pmu_regmap,
> > + pmu_data->pmu_config[i].offset,
> > + pmu_data->pmu_config[i].val[mode]);
> > + }
> > +
> > + if (pmu_data->pmu_config_extra) {
> > + for (i = 0; pmu_data->pmu_config_extra[i].offset !=
> PMU_TABLE_END; i++)
> > + regmap_write(pmu_context->pmu_regmap,
> > +
pmu_data->pmu_config_extra[i].offset,
> > +
pmu_data->pmu_config_extra[i].val[mode]);
> > + }
> > +}
> > +
> > +static void exynos5250_pmu_init(void) {
> > + unsigned int tmp;
> > + struct regmap *pmu_regmap = pmu_context->pmu_regmap;
> > + /*
> > + * When SYS_WDTRESET is set, watchdog timer reset request
> > + * is ignored by power management unit.
> > + */
> > + regmap_read(pmu_regmap, EXYNOS5_AUTO_WDTRESET_DISABLE,
> &tmp);
> > + tmp &= ~EXYNOS5_SYS_WDTRESET;
> > + regmap_write(pmu_regmap, EXYNOS5_AUTO_WDTRESET_DISABLE,
> tmp);
> > +
> > + regmap_read(pmu_regmap, EXYNOS5_MASK_WDTRESET_REQUEST,
> &tmp);
> > + tmp &= ~EXYNOS5_SYS_WDTRESET;
> > + regmap_write(pmu_regmap, EXYNOS5_MASK_WDTRESET_REQUEST,
> tmp); }
> > +
> > +static struct exynos_pmu_data exynos4210_pmu_data = {
> > + .pmu_config = exynos4210_pmu_config,
> > +};
> > +
> > +static struct exynos_pmu_data exynos4x12_pmu_data = {
>
> Should be probably called exynos4212_pmu_data.
>

OK, will update this.

> > + .pmu_config = exynos4x12_pmu_config,
> > +};
> > +
> > +static struct exynos_pmu_data exynos4412_pmu_data = {
> > + .pmu_config = exynos4x12_pmu_config,
> > + .pmu_config_extra = exynos4412_pmu_config,
> > +};
> > +
> > +static struct exynos_pmu_data exynos5250_pmu_data = {
> > + .pmu_config = exynos5250_pmu_config,
> > + .pmu_init = exynos5250_pmu_init,
> > + .powerdown_conf = exynos5_powerdown_conf,
> > +};
> > +
> > +/*
> > + * PMU platform driver and devicetree bindings.
> > + */
> > +static struct of_device_id exynos_pmu_of_device_ids[] = {
> > + {
> > + .compatible = "samsung,exynos4210-pmu",
> > + .data = (void *)&exynos4210_pmu_data,
> > + },
> > + {
> > + .compatible = "samsung,exynos4212-pmu",
> > + .data = (void *)&exynos4x12_pmu_data,
> > + },
> > + {
> > + .compatible = "samsung,exynos4412-pmu",
> > + .data = (void *)&exynos4412_pmu_data,
> > + },
> > + {
> > + .compatible = "samsung,exynos5250-pmu",
> > + .data = (void *)&exynos5250_pmu_data,
> > + },
> > + {},
> > +};
> > +
> > +static int exynos_pmu_probe(struct platform_device *pdev) {
> > + struct device_node *np;
> > + const struct of_device_id *match;
> > + struct device *dev = &pdev->dev;
> >
> > - if (soc_is_exynos5250())
> > - exynos5_init_pmu();
> > + pmu_context = devm_kzalloc(&pdev->dev,
> > + sizeof(struct exynos_pmu_context),
> > + GFP_KERNEL);
> > + if (pmu_context == NULL) {
> > + dev_err(dev, "Cannot allocate memory.\n");
> > + return -ENOMEM;
> > + }
> > +
> > + np = of_find_matching_node_and_match(NULL,
> > + exynos_pmu_of_device_ids, &match);
> > + if (!np) {
> > + pr_warn("%s, failed to find PMU node\n", __func__);
> > + return -ENODEV;
> > + }
> >
> > - for (i = 0; (exynos_pmu_config[i].offset != PMU_TABLE_END) ; i++)
> > - regmap_write(pmu_regmap, exynos_pmu_config[i].offset,
> > - exynos_pmu_config[i].val[mode]);
> > + pmu_context->pmu_data = (struct exynos_pmu_data *) match->data;
> > + pmu_context->pmu_regmap = syscon_regmap_lookup_by_phandle(np,
> NULL);
> >
> > - if (soc_is_exynos4412()) {
> > - for (i = 0; exynos4412_pmu_config[i].offset !=
PMU_TABLE_END;
> i++)
> > - regmap_write(pmu_regmap,
exynos4412_pmu_config[i].offset,
> > - exynos4412_pmu_config[i].val[mode]);
> > + if (IS_ERR(pmu_context->pmu_regmap)) {
> > + pr_err("failed to find exynos_pmu_regmap\n");
> > + return PTR_ERR(pmu_context->pmu_regmap);
> > }
> > +
> > + if (pmu_context->pmu_data->pmu_init)
> > + pmu_context->pmu_data->pmu_init();
> > +
> > + pmu_context->dev = dev;
> > +
> > + platform_set_drvdata(pdev, pmu_context);
> > +
> > + pr_info("Exynos PMU Driver probe done!!!\n");
> > + return 0;
> > +}
> > +
> > +static int exynos_pmu_suspend(struct device *dev) {
> > + /* ToDo: */
> > + return 0;
> > +}
> > +
> > +static int exynos_pmu_resume(struct device *dev) {
> > + /* ToDo: */
> > + return 0;
> > }
>
> No need to add those if unused.
>

OK, will remove this.

> >
> > -static int __init exynos_pmu_init(void)
> > +static const struct dev_pm_ops exynos_pmu_pm = {
> > + .suspend = exynos_pmu_suspend,
> > + .resume = exynos_pmu_resume,
> > +};
>
> You can drop this structure too.
>

OK.

> > +
> > +static int exynos_pmu_remove(struct platform_device *pdev) {
> > + /* nothing to do here */
> > + return 0;
> > +}
>
> This function as well.

OK.

>
> > +
> > +static struct platform_device *exynos_pmu_pdev;
> > +
> > +static struct platform_driver exynos_pmu_driver = {
> > + .driver = {
> > + .name = "exynos-pmu",
> > + .owner = THIS_MODULE,
> > + .pm = &exynos_pmu_pm,
> > + },
> > + .probe = exynos_pmu_probe,
> > + .remove = exynos_pmu_remove,
> > +};
> > +
> > +static int __init exynos_pmu_of_init(void)
> > {
> > - unsigned int value;
> > -
> > - exynos_pmu_config = exynos4210_pmu_config;
> > - pmu_regmap = get_exynos_pmuregmap();
> > -
> > - if (soc_is_exynos4210()) {
> > - exynos_pmu_config = exynos4210_pmu_config;
> > - pr_info("EXYNOS4210 PMU Initialize\n");
> > - } else if (soc_is_exynos4212() || soc_is_exynos4412()) {
> > - exynos_pmu_config = exynos4x12_pmu_config;
> > - pr_info("EXYNOS4x12 PMU Initialize\n");
> > - } else if (soc_is_exynos5250()) {
> > - /*
> > - * When SYS_WDTRESET is set, watchdog timer reset request
> > - * is ignored by power management unit.
> > - */
> > - regmap_read(pmu_regmap,
> EXYNOS5_AUTO_WDTRESET_DISABLE, &value);
> > - value &= ~EXYNOS5_SYS_WDTRESET;
> > - regmap_write(pmu_regmap,
> EXYNOS5_AUTO_WDTRESET_DISABLE, value);
> > -
> > - regmap_read(pmu_regmap,
> EXYNOS5_MASK_WDTRESET_REQUEST, &value);
> > - value &= ~EXYNOS5_SYS_WDTRESET;
> > - regmap_write(pmu_regmap,
> EXYNOS5_MASK_WDTRESET_REQUEST, value);
> > -
> > - exynos_pmu_config = exynos5250_pmu_config;
> > - pr_info("EXYNOS5250 PMU Initialize\n");
> > - } else {
> > - pr_info("EXYNOS: PMU not supported\n");
> > + int ret;
> > +
> > + ret = platform_driver_register(&exynos_pmu_driver);
> > + if (ret < 0)
> > + goto out;
> > +
> > + exynos_pmu_pdev = platform_device_register_simple("exynos-pmu", -1,
> > + NULL, 0);
>
> Hmm, I don't see the point of making this a platform driver only to
register respective
> platform device few lines below. If you take into account the patch for
syscon I
> posted as a reply to patch 06/11, you will be able to make this a normal
platform
> driver that binds to DT node directly and then register a syscon in probe
function
> above.
>

Well I updated PMU to be a syscon provider using your patch. It worked well.
I have following two points to mention here:

1: For making PMU a normal platform driver, other than making PMU a syscon
provider we need to change PMU's DT binding. Basically we need to remove
"syscon"
as second compatibility string. I hope this should not be an issue.

2: I can see for your syscon patch Arnd has some comments, hopefully we can
address
his concern.

> > +
> > + if (IS_ERR(exynos_pmu_pdev)) {
> > + ret = PTR_ERR(exynos_pmu_pdev);
> > + goto out1;
> > }
> >
> > return 0;
> > +out1:
> > + platform_driver_unregister(&exynos_pmu_driver);
> > +out:
> > + return ret;
> > }
> > -arch_initcall(exynos_pmu_init);
> > +arch_initcall(exynos_pmu_of_init);
>
> Is there a need to change the name?
>

No, I will keep same name.

> > +
> > +static void __exit exynos_pmu_exit(void) {
> > + platform_device_unregister(exynos_pmu_pdev);
> > + platform_driver_unregister(&exynos_pmu_driver);
> > +}
> > +module_exit(exynos_pmu_exit);
>
> No need for module_exit() in case of such low level code. It will be
always built-in.
>

OK, will remove this.

> > +
> > +MODULE_AUTHOR("Pankaj Dubey <pankaj.dubey@samsung.com");
> > +MODULE_LICENSE("GPL v2"); MODULE_DESCRIPTION("EXYNOS
> Power Management
> > +Unit Driver");
> >
>
> This driver will never be a module, so I don't think there is any need for
those.
>

OK.

> --
> Best regards,
> Tomasz

Thanks,
Pankaj Dubey