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

Tomasz Figa
2014-06-17T17:13:21Z

Hi Pankaj,

[dropping Young-Gun Jang <yg1004.jang@samsung.com>, as my mailer denies
to send to this address]

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.

> { 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

> {
> 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.

> + .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.

>
> -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.

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

This function as well.

> +
> +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.

> +
> + 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?

> +
> +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.

> +
> +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.

--
Best regards,
Tomasz