Re: [PATCH 1/4] ARM: EXYNOS4: Support for generic I/O power domains on EXYNOS4210

[Sylwester Nawrocki <snjw23@gmail.com>]

Hi Chanwoo,

a few minor comments below...
 
On 08/11/2011 06:55 AM, Chanwoo Choi wrote:
> Use the generic power domains support to implement support for
> power domain on EXYNOS4210.
> 
> I refer to the following patch to implement what configure
> the clock-gating control register for block to turn off/on:
> http://git.infradead.org/users/kmpark/linux-2.6-samsung/commit/39a81876d034dcbdc2a4c4c4b847b3b49e38870c
> 
> Signed-off-by: Chanwoo Choi<cw00.choi@samsung.com>
> Signed-off-by: Kyungmin Park<kyungmin.park@samsung.com>
> ---
>   arch/arm/mach-exynos4/Kconfig                      |    1 +
>   arch/arm/mach-exynos4/Makefile                     |    1 +
>   arch/arm/mach-exynos4/include/mach/pm-exynos4210.h |   52 ++++++
>   arch/arm/mach-exynos4/include/mach/regs-clock.h    |    8 +
>   arch/arm/mach-exynos4/pm-exynos4210.c              |  189 ++++++++++++++++++++
>   5 files changed, 251 insertions(+), 0 deletions(-)
>   create mode 100644 arch/arm/mach-exynos4/include/mach/pm-exynos4210.h
>   create mode 100644 arch/arm/mach-exynos4/pm-exynos4210.c
> 
> diff --git a/arch/arm/mach-exynos4/Kconfig b/arch/arm/mach-exynos4/Kconfig
> index 64baca7..8d5e876 100644
> --- a/arch/arm/mach-exynos4/Kconfig
> +++ b/arch/arm/mach-exynos4/Kconfig
> @@ -12,6 +12,7 @@ if ARCH_EXYNOS4
>   config CPU_EXYNOS4210
>   	bool
>   	select S3C_PL330_DMA
> +	select PM_GENERIC_DOMAINS if PM
>   	help
>   	  Enable EXYNOS4210 CPU support
> 
> diff --git a/arch/arm/mach-exynos4/Makefile b/arch/arm/mach-exynos4/Makefile
> index b7fe1d7..97c31ce 100644
> --- a/arch/arm/mach-exynos4/Makefile
> +++ b/arch/arm/mach-exynos4/Makefile
> @@ -16,6 +16,7 @@ obj-$(CONFIG_CPU_EXYNOS4210)	+= cpu.o init.o clock.o irq-combiner.o
>   obj-$(CONFIG_CPU_EXYNOS4210)	+= setup-i2c0.o irq-eint.o dma.o pmu.o
>   obj-$(CONFIG_PM)		+= pm.o sleep.o
>   obj-$(CONFIG_CPU_IDLE)		+= cpuidle.o
> +obj-$(CONFIG_CPU_EXYNOS4210)	+= pm-exynos4210.o
> 
>   obj-$(CONFIG_SMP)		+= platsmp.o headsmp.o
> 
> diff --git a/arch/arm/mach-exynos4/include/mach/pm-exynos4210.h b/arch/arm/mach-exynos4/include/mach/pm-exynos4210.h
> new file mode 100644
> index 0000000..e36425a
> --- /dev/null
> +++ b/arch/arm/mach-exynos4/include/mach/pm-exynos4210.h
> @@ -0,0 +1,52 @@
> +/* linux/arch/arm/mach-exynos4/include/mach/pm-exynos4210.h
> + *
> + * Exynos4210 Power management support
> + *
> + * Copyright (c) 2011 Samsung Electronics Co., Ltd.
> + *		http://www.samsung.com
> + *
> + * 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 PM_EXYNOS4210_H
> +#define PM_EXYNOS4210_H
> +
> +#include<linux/pm_domain.h>
> +
> +struct platform_device;
> +
> +struct exynos4210_pm_domain {

I wonder whether it isn't worth to start with 'struct exynos_pm_domain' as we're
consolidating the code for various exynos variants.

> +	struct generic_pm_domain genpd;
> +
> +	const char *name;
> +	void __iomem *base;
> +	u32 clkgate_mask;
> +	int boot_on;
> +};
> +
> +static inline struct exynos4210_pm_domain *to_exynos4210_pd(
> +		struct generic_pm_domain *pd)
> +{
> +	return container_of(pd, struct exynos4210_pm_domain, genpd);
> +}
> +
> +#ifdef CONFIG_PM
> +extern struct exynos4210_pm_domain exynos4210_pd_mfc;
> +extern struct exynos4210_pm_domain exynos4210_pd_g3d;
> +extern struct exynos4210_pm_domain exynos4210_pd_lcd0;
> +extern struct exynos4210_pm_domain exynos4210_pd_lcd1;
> +extern struct exynos4210_pm_domain exynos4210_pd_tv;
> +extern struct exynos4210_pm_domain exynos4210_pd_cam;
> +extern struct exynos4210_pm_domain exynos4210_pd_gps;
> +
> +extern void exynos4210_init_pm_domain(struct exynos4210_pm_domain *exynos4210_pd);

exynos_pd_init() ?

> +extern void exynos4210_add_device_to_domain(struct exynos4210_pm_domain *exynos4210_pd,

exynos_pd_add_device() ?

> +				struct platform_device *pdev);
> +#else
> +#define exynos4210_init_pm_domain(pd) do { } while(0)
> +#define exynos4210_add_device_to_domain(pd, pdev) do { } while(0)
> +#endif /* CONFIG_PM */
> +
> +#endif /* PM_EXYNOS4210_H */
> diff --git a/arch/arm/mach-exynos4/include/mach/regs-clock.h b/arch/arm/mach-exynos4/include/mach/regs-clock.h
> index d493fdb..0d1c9ec 100644
> --- a/arch/arm/mach-exynos4/include/mach/regs-clock.h
> +++ b/arch/arm/mach-exynos4/include/mach/regs-clock.h
> @@ -183,6 +183,14 @@
>   #define S5P_CLKDIV_BUS_GPLR_SHIFT	(4)

nit: don't need braces

>   #define S5P_CLKDIV_BUS_GPLR_MASK	(0x7<<  S5P_CLKDIV_BUS_GPLR_SHIFT)
> 
> +#define S5P_CLKGATE_BLOCK_CAM		(1<<  0)
> +#define S5P_CLKGATE_BLOCK_TV		(1<<  1)
> +#define S5P_CLKGATE_BLOCK_MFC		(1<<  2)
> +#define S5P_CLKGATE_BLOCK_G3D		(1<<  3)
> +#define S5P_CLKGATE_BLOCK_LCD0		(1<<  4)
> +#define S5P_CLKGATE_BLOCK_LCD1		(1<<  5)
> +#define S5P_CLKGATE_BLOCK_GPS		(1<<  7)
> +
>   /* Compatibility defines and inclusion */
> 
>   #include<mach/regs-pmu.h>
> diff --git a/arch/arm/mach-exynos4/pm-exynos4210.c b/arch/arm/mach-exynos4/pm-exynos4210.c
> new file mode 100644
> index 0000000..d43c37f
> --- /dev/null
> +++ b/arch/arm/mach-exynos4/pm-exynos4210.c
> @@ -0,0 +1,189 @@
> +/* linux/arch/arm/mach-exynos4/pm-exynos4210.c
> + *
> + * Exynos4210 Power management support
> + *
> + * Copyright (c) 2011 Samsung Electronics Co., Ltd.
> + *		http://www.samsung.com
> + *
> + * 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.
> + */
> +
> +#include<linux/pm.h>
> +#include<linux/module.h>
> +#include<linux/delay.h>
> +#include<linux/err.h>
> +#include<linux/slab.h>
> +#include<linux/pm_runtime.h>
> +#include<linux/platform_device.h>
> +#include<linux/pm_domain.h>
> +#include<linux/io.h>
> +
> +#include<mach/regs-clock.h>
> +#include<mach/pm-exynos4210.h>
> +
> +#ifdef CONFIG_PM
> +static DEFINE_SPINLOCK(clkgate_block_lock);
> +
> +static int pd_power_down(struct generic_pm_domain *genpd)

__exynos_pd_power_down() ?

> +{
> +	struct exynos4210_pm_domain *exynos4210_pd = to_exynos4210_pd(genpd);
> +	u32 timeout;
> +
> +	/* Disable the power of power-domain */
> +	__raw_writel(0, exynos4210_pd->base);
> +
> +	/* Wait max 1ms */
> +	timeout = 10;
> +	while (__raw_readl(exynos4210_pd->base + 0x4)&  S5P_INT_LOCAL_PWR_EN) {
> +		if (timeout == 0) {
> +			printk(KERN_ERR "Power domain %s disable failed.\n",
> +				exynos4210_pd->name);
> +			return -ETIMEDOUT;
> +		}
> +		timeout--;
> +		udelay(100);
> +	}
> +
> +	/* Configure the clock-gating control register for block to turn off */
> +	if (exynos4210_pd->clkgate_mask) {
> +		unsigned long flags;
> +		u32 reg;
> +
> +		spin_lock_irqsave(&clkgate_block_lock, flags);
> +		reg = __raw_readl(S5P_CLKGATE_BLOCK);
> +		reg&= ~exynos4210_pd->clkgate_mask;
> +		__raw_writel(reg, S5P_CLKGATE_BLOCK);
> +		spin_unlock_irqrestore(&clkgate_block_lock, flags);
> +	}
> +
> +	return 0;
> +}
> +
> +static int pd_power_up(struct generic_pm_domain *genpd)

__exynos_pd_power_up() ?

> +{
> +	struct exynos4210_pm_domain *exynos4210_pd = to_exynos4210_pd(genpd);
> +	u32 timeout;
> +
> +	/* Enable power domain */
> +	__raw_writel(S5P_INT_LOCAL_PWR_EN, exynos4210_pd->base);
> +
> +	/* Wait max 1ms */
> +	timeout = 10;
> +	while ((__raw_readl(exynos4210_pd->base + 0x4)&  S5P_INT_LOCAL_PWR_EN)
> +		!= S5P_INT_LOCAL_PWR_EN) {
> +		if (timeout == 0) {
> +			printk(KERN_ERR "Power domain %s enable failed.\n",
> +				exynos4210_pd->name);
> +			return -ETIMEDOUT;
> +		}
> +		timeout--;
> +		udelay(100);
> +	}
> +
> +	/* Configure the clock-gating control register for block to turn on */
> +	if (exynos4210_pd->clkgate_mask) {
> +		unsigned long flags;
> +		u32 reg;
> +
> +		spin_lock_irqsave(&clkgate_block_lock, flags);
> +		reg = __raw_readl(S5P_CLKGATE_BLOCK);
> +		reg |= exynos4210_pd->clkgate_mask;
> +		__raw_writel(reg, S5P_CLKGATE_BLOCK);
> +		spin_unlock_irqrestore(&clkgate_block_lock, flags);
> +	}
> +
> +	return 0;
> +}
> +
> +static bool pd_active_wakeup(struct device *dev)

__exynos_pd_active_wakeup() ?

> +{
> +	return true;
> +}
> +
> +void exynos4210_init_pm_domain(struct exynos4210_pm_domain *exynos4210_pd)
> +{
> +	struct generic_pm_domain *genpd;
> +
> +	if (!exynos4210_pd)
> +		return;
> +
> +	genpd =&exynos4210_pd->genpd;
> +
> +	pm_genpd_init(genpd, NULL, false);
> +	genpd->stop_device = pm_clk_suspend;
> +	genpd->start_device = pm_clk_resume;

Perhaps each driver has to be inspected before we can do this.
I guess it's better to leave these 2 ops uninitialized for now.

> +	genpd->active_wakeup = pd_active_wakeup;
> +	genpd->power_off = pd_power_down;
> +	genpd->power_on = pd_power_up;
> +
> +	if (exynos4210_pd->boot_on)
> +		pd_power_up(&exynos4210_pd->genpd);
> +}
> +
> +void exynos4210_add_device_to_domain(struct exynos4210_pm_domain *exynos4210_pd,
> +				struct platform_device *pdev)
> +{
> +	struct device *dev =&pdev->dev;
> +
> +	if (!exynos4210_pd || !pdev)
> +		return;
> +
> +	if (!dev->power.subsys_data) {
> +		pm_clk_init(dev);
> +		pm_clk_add(dev, NULL);

Same here, this won't work for many devices, some have multiple clocks associated
with them and non null con_id. It might be needed to separate the clocks addition 
and to handle individually for each device.

> +	}
> +	pm_genpd_add_device(&exynos4210_pd->genpd, dev);
> +}
> +

--
Regards,
Sylwester