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



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