Subject: [PATCH v3 1/3] soc: zte: pm_domains: Prepare for supporting ARMv8 2967 family

From: [email-masked] (Shawn Guo)
Date: Wed, 7 Dec 2016 20:41:32 +0800

On Wed, Dec 07, 2016 at 02:13:22PM +0800, Baoyou Xie wrote:
> The ARMv8 2967 family (296718, 296716 etc) uses different value
> for controlling the power domain on/off registers, Choose the
> value depending on the compatible.
> 
> Multiple domains are prepared for the family, this patch prepares
> the common functions.
> 
> Signed-off-by: Baoyou Xie <[email-masked]>
> ---
>  drivers/soc/Kconfig          |   1 +
>  drivers/soc/Makefile         |   1 +
>  drivers/soc/zte/Kconfig      |  13 ++++
>  drivers/soc/zte/Makefile     |   4 ++
>  drivers/soc/zte/pm_domains.c | 150 +++++++++++++++++++++++++++++++++++++++++++
>  drivers/soc/zte/pm_domains.h |  48 ++++++++++++++
>  6 files changed, 217 insertions(+)
>  create mode 100644 drivers/soc/zte/Kconfig
>  create mode 100644 drivers/soc/zte/Makefile
>  create mode 100644 drivers/soc/zte/pm_domains.c
>  create mode 100644 drivers/soc/zte/pm_domains.h
> 
> diff --git a/drivers/soc/Kconfig b/drivers/soc/Kconfig
> index f31bceb..f09023f 100644
> --- a/drivers/soc/Kconfig
> +++ b/drivers/soc/Kconfig
> @@ -11,5 +11,6 @@ source "drivers/soc/tegra/Kconfig"
>  source "drivers/soc/ti/Kconfig"
>  source "drivers/soc/ux500/Kconfig"
>  source "drivers/soc/versatile/Kconfig"
> +source "drivers/soc/zte/Kconfig"
>  
>  endmenu
> diff --git a/drivers/soc/Makefile b/drivers/soc/Makefile
> index 50c23d0..05eae52 100644
> --- a/drivers/soc/Makefile
> +++ b/drivers/soc/Makefile
> @@ -16,3 +16,4 @@ obj-$(CONFIG_ARCH_TEGRA)	+= tegra/
>  obj-$(CONFIG_SOC_TI)		+= ti/
>  obj-$(CONFIG_ARCH_U8500)	+= ux500/
>  obj-$(CONFIG_PLAT_VERSATILE)	+= versatile/
> +obj-$(CONFIG_ARCH_ZX)		+= zte/
> diff --git a/drivers/soc/zte/Kconfig b/drivers/soc/zte/Kconfig
> new file mode 100644
> index 0000000..4953c3fa
> --- /dev/null
> +++ b/drivers/soc/zte/Kconfig
> @@ -0,0 +1,13 @@
> +#
> +# zx SoC drivers
> +#
> +menuconfig SOC_ZX

Can we use SOC_ZTE to reflect the folder name 'zte'?  If we take
drivers/soc/samsung/Kconfig as example, SAMSUNG is like ZTE, while
EXYNOS is like ZX, I guess.

> +        bool "zx SoC driver support"
> +
> +if SOC_ZX
> +
> +config ZX_PM_DOMAINS
> +        bool "zx PM domains"
> +        depends on PM_GENERIC_DOMAINS
> +
> +endif
> diff --git a/drivers/soc/zte/Makefile b/drivers/soc/zte/Makefile
> new file mode 100644
> index 0000000..97ac8ea
> --- /dev/null
> +++ b/drivers/soc/zte/Makefile
> @@ -0,0 +1,4 @@
> +#
> +# zx SOC drivers
> +#
> +obj-$(CONFIG_ZX_PM_DOMAINS) += pm_domains.o
> diff --git a/drivers/soc/zte/pm_domains.c b/drivers/soc/zte/pm_domains.c
> new file mode 100644
> index 0000000..e4d1235
> --- /dev/null
> +++ b/drivers/soc/zte/pm_domains.c
> @@ -0,0 +1,150 @@
> +/*
> + * Copyright (C) 2015 ZTE Ltd.

Do we at least need year 2016?

> + *
> + * Author: Baoyou Xie <[email-masked]>
> + * License terms: GNU General Public License (GPL) version 2

I see drivers/soc/zte/pm_domains.h use a different licence format.  Can
we make them unified?

> + */
> +#include <linux/delay.h>
> +#include <linux/err.h>
> +#include <linux/io.h>
> +#include <linux/of.h>
> +#include "pm_domains.h"
> +
> +#define PCU_DM_CLKEN(zpd)	((zpd)->reg_offset[REG_CLKEN])
> +#define PCU_DM_ISOEN(zpd)	((zpd)->reg_offset[REG_ISOEN])
> +#define PCU_DM_RSTEN(zpd)	((zpd)->reg_offset[REG_RSTEN])
> +#define PCU_DM_PWREN(zpd)	((zpd)->reg_offset[REG_PWREN])
> +#define PCU_DM_PWRDN(zpd)	((zpd)->reg_offset[REG_PWRDN])
> +#define PCU_DM_ACK_SYNC(zpd)	((zpd)->reg_offset[REG_ACK_SYNC])
> +
> +static void __iomem *pcubase;
> +
> +int zx_normal_power_on(struct generic_pm_domain *domain)

What does 'normal' in the function name mean?

> +{
> +	struct zx_pm_domain *zpd = (struct zx_pm_domain *)domain;
> +	unsigned long loop = 1000;
> +	u32 val;
> +
> +	if (zpd->polarity == PWREN) {
> +		val = readl_relaxed(pcubase + PCU_DM_PWREN(zpd));
> +		val |= BIT(zpd->bit);
> +		writel_relaxed(val, pcubase + PCU_DM_PWREN(zpd));
> +	} else {
> +		val = readl_relaxed(pcubase + PCU_DM_PWRDN(zpd));
> +		val &= ~BIT(zpd->bit);
> +		writel_relaxed(val, pcubase + PCU_DM_PWRDN(zpd));
> +	}
> +
> +	do {
> +		udelay(1);
> +		val = readl_relaxed(pcubase + PCU_DM_ACK_SYNC(zpd))
> +				   & BIT(zpd->bit);
> +	} while (--loop && !val);
> +
> +	if (!loop) {
> +		pr_err("Error: %s %s fail\n", __func__, domain->name);
> +		return -EIO;
> +	}
> +
> +	val = readl_relaxed(pcubase + PCU_DM_RSTEN(zpd));
> +	val &= ~BIT(zpd->bit);
> +	writel_relaxed(val | BIT(zpd->bit), pcubase + PCU_DM_RSTEN(zpd));

For a single bit setting, it can be as simple as the following, right?

	val = readl_relaxed(pcubase + PCU_DM_RSTEN(zpd));
	val |= BIT(zpd->bit);
	writel_relaxed(val, pcubase + PCU_DM_RSTEN(zpd));

> +	udelay(5);
> +
> +	val = readl_relaxed(pcubase + PCU_DM_ISOEN(zpd));
> +	val &= ~BIT(zpd->bit);
> +	writel_relaxed(val, pcubase + PCU_DM_ISOEN(zpd));
> +	udelay(5);
> +
> +	val = readl_relaxed(pcubase + PCU_DM_CLKEN(zpd));
> +	val &= ~BIT(zpd->bit);
> +	writel_relaxed(val | BIT(zpd->bit), pcubase + PCU_DM_CLKEN(zpd));

Ditto

> +	udelay(5);
> +
> +	pr_info("normal poweron %s\n", domain->name);

Do we really want to see a message on every single power domain on/off
function call?  A pr_debug is better?

> +
> +	return 0;
> +}
> +
> +int zx_normal_power_off(struct generic_pm_domain *domain)
> +{
> +	struct zx_pm_domain *zpd = (struct zx_pm_domain *)domain;
> +	unsigned long loop = 1000;
> +	u32 val;
> +
> +	val = readl_relaxed(pcubase + PCU_DM_CLKEN(zpd));
> +	val &= ~BIT(zpd->bit);
> +	writel_relaxed(val, pcubase + PCU_DM_CLKEN(zpd));
> +	udelay(5);
> +
> +	val = readl_relaxed(pcubase + PCU_DM_ISOEN(zpd));
> +	val &= ~BIT(zpd->bit);
> +	writel_relaxed(val | BIT(zpd->bit), pcubase + PCU_DM_ISOEN(zpd));

Same here.

> +	udelay(5);
> +
> +	val = readl_relaxed(pcubase + PCU_DM_RSTEN(zpd));
> +	val &= ~BIT(zpd->bit);
> +	writel_relaxed(val, pcubase + PCU_DM_RSTEN(zpd));
> +	udelay(5);
> +
> +	if (zpd->polarity == PWREN) {
> +		val = readl_relaxed(pcubase + PCU_DM_PWREN(zpd));
> +		val &= ~BIT(zpd->bit);
> +		writel_relaxed(val, pcubase + PCU_DM_PWREN(zpd));
> +	} else {
> +		val = readl_relaxed(pcubase + PCU_DM_PWRDN(zpd));
> +		val |= BIT(zpd->bit);
> +		writel_relaxed(val, pcubase + PCU_DM_PWRDN(zpd));
> +	}
> +
> +	do {
> +		udelay(1);
> +		val = readl_relaxed(pcubase + PCU_DM_ACK_SYNC(zpd))
> +				   & BIT(zpd->bit);
> +	} while (--loop && val);
> +
> +	if (!loop) {
> +		pr_err("Error: %s %s fail\n", __func__, domain->name);
> +		return -EIO;
> +	}
> +
> +	pr_info("normal poweroff %s\n", domain->name);

pr_debug

> +
> +	return 0;
> +}
> +
> +int
> +zx_pd_probe(struct platform_device *pdev,

I do not see the need to break above two lines.

> +	   struct generic_pm_domain **zx_pm_domains,
> +	   int domain_num)

As long as the line doesn't exceed column 80, we do not need to break
the line into two.

> +{
> +	struct genpd_onecell_data *genpd_data;
> +	struct resource *res;
> +	int i;
> +
> +	genpd_data = devm_kzalloc(&pdev->dev, sizeof(*genpd_data), GFP_KERNEL);
> +	if (!genpd_data)
> +		return -ENOMEM;
> +
> +	genpd_data->domains = zx_pm_domains;
> +	genpd_data->num_domains = domain_num;
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	if (!res) {
> +		dev_err(&pdev->dev, "no memory resource defined\n");
> +		return -ENODEV;
> +	}

The error check on 'res' is not really necessary, as
devm_ioremap_resource() will do that for you.

> +
> +	pcubase = devm_ioremap_resource(&pdev->dev, res);
> +	if (IS_ERR(pcubase)) {
> +		dev_err(&pdev->dev, "ioremap fail.\n");
> +		return -EIO;

PTR_ERR(pcubase) should be returned as error code here.

> +	}
> +
> +	for (i = 0; i < domain_num; ++i)
> +		pm_genpd_init(zx_pm_domains[i], NULL, false);
> +
> +	of_genpd_add_provider_onecell(pdev->dev.of_node, genpd_data);
> +	dev_info(&pdev->dev, "powerdomain init ok\n");
> +	return 0;
> +}
> diff --git a/drivers/soc/zte/pm_domains.h b/drivers/soc/zte/pm_domains.h
> new file mode 100644
> index 0000000..d3a52fd
> --- /dev/null
> +++ b/drivers/soc/zte/pm_domains.h
> @@ -0,0 +1,48 @@
> +/*
> + * Copyright (c) 2015 ZTE Co., Ltd.
> + *           http://www.zte.com.cn
> + *
> + * Header for ZTE's Power Domain Driver support
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#ifndef __ZTE_PM_DOMAIN_H
> +#define __ZTE_PM_DOMAIN_H
> +
> +#include <linux/platform_device.h>
> +#include <linux/pm_domain.h>
> +
> +enum {
> +	REG_CLKEN,
> +	REG_ISOEN,
> +	REG_RSTEN,
> +	REG_PWREN,
> +	REG_PWRDN,
> +	REG_ACK_SYNC,
> +
> +	/* The size of the array - must be last */
> +	REG_ARRAY_SIZE,
> +};
> +
> +enum zx_power_polarity {
> +	PWREN,
> +	PWRDN,
> +};
> +
> +struct zx_pm_domain {
> +	struct		generic_pm_domain dm;

You can chose to have more tabs between 'generic_pm_domain' and 'dm'
for indention, but there should always be one space between 'struct' and
'generic_pm_domain'.

> +	const u16	bit;
> +	const enum zx_power_polarity	polarity;
> +	const u16	*reg_offset;
> +};
> +
> +extern int zx_normal_power_on(struct generic_pm_domain *domain);
> +extern int zx_normal_power_off(struct generic_pm_domain *domain);
> +extern int
> +zx_pd_probe(struct platform_device *pdev,
> +	   struct generic_pm_domain **zx_pm_domains,
> +	   int domain_num);

We do not need to break it into so many lines.

> +#endif /* __ZTE_PM_DOMAIN_H */
> -- 
> 2.7.4
>