Re: [PATCH 10/10 v6] ARM / shmobile: Support for I/O power domains for SH7372 (v8)

["Rafael J. Wysocki" <rjw@sisk.pl>]

On Tuesday, June 28, 2011, Magnus Damm wrote:
> On Tue, Jun 28, 2011 at 4:25 AM, Rafael J. Wysocki <rjw@sisk.pl> wrote:
> > On Monday, June 27, 2011, Magnus Damm wrote:
> >> On Sun, Jun 26, 2011 at 6:31 AM, Rafael J. Wysocki <rjw@sisk.pl> wrote:
> >> > From: Rafael J. Wysocki <rjw@sisk.pl>
> >> >
> >> > Use the generic power domains support introduced by the previous
> >> > patch to implement support for power domains on SH7372.
> >> >
> >> > Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
> >> > Acked-by: Paul Mundt <lethal@linux-sh.org>
> >> > ---
> >>
> >> Hi Rafael,
> >>
> >> Thanks for your work on this. I've been working on up-porting my A3RV
> >> prototype, and I came across these minor details:
> >>
> >> > --- linux-2.6.orig/arch/arm/mach-shmobile/board-mackerel.c
> >> > +++ linux-2.6/arch/arm/mach-shmobile/board-mackerel.c
> >> > @@ -1582,6 +1582,10 @@ static void __init mackerel_init(void)
> >> >
> >> >        platform_add_devices(mackerel_devices, ARRAY_SIZE(mackerel_devices));
> >> >
> >> > +       sh7372_init_pm_domain(SH7372_A4LC);
> >> > +       sh7372_add_device_to_domain(SH7372_A4LC, &lcdc_device);
> >> > +       sh7372_add_device_to_domain(SH7372_A4LC, &hdmi_lcdc_device);
> >> > +
> >> >        hdmi_init_pm_clock();
> >> >        sh7372_pm_init();
> >> >  }
> >> > Index: linux-2.6/arch/arm/mach-shmobile/include/mach/sh7372.h
> >> > =================================> >> > --- linux-2.6.orig/arch/arm/mach-shmobile/include/mach/sh7372.h
> >> > +++ linux-2.6/arch/arm/mach-shmobile/include/mach/sh7372.h
> >> > @@ -12,6 +12,7 @@
> >> >  #define __ASM_SH7372_H__
> >> >
> >> >  #include <linux/sh_clk.h>
> >> > +#include <linux/pm_domain.h>
> >> >
> >> >  /*
> >> >  * Pin Function Controller:
> >> > @@ -470,4 +471,31 @@ extern struct clk sh7372_fsibck_clk;
> >> >  extern struct clk sh7372_fsidiva_clk;
> >> >  extern struct clk sh7372_fsidivb_clk;
> >> >
> >> > +struct platform_device;
> >> > +
> >> > +struct sh7372_pm_domain {
> >> > +       struct generic_pm_domain genpd;
> >> > +       unsigned int bit_shift;
> >> > +};
> >> > +
> >> > +static inline struct sh7372_pm_domain *to_sh7372_pd(struct generic_pm_domain *d)
> >> > +{
> >> > +       return container_of(d, struct sh7372_pm_domain, genpd);
> >> > +}
> >> > +
> >> > +#ifdef CONFIG_PM
> >> > +extern struct sh7372_pm_domain sh7372_a4lc_domain;
> >> > +#define SH7372_A4LC    (&sh7372_a4lc_domain)
> >> > +
> >> > +extern void sh7372_init_pm_domain(struct sh7372_pm_domain *sh7372_pd);
> >> > +extern void sh7372_add_device_to_domain(struct sh7372_pm_domain *sh7372_pd,
> >> > +                                       struct platform_device *pdev);
> >> > +#else
> >> > +#define SH7372_A4LC    NULL
> >> > +
> >> > +static inline void sh7372_init_pm_domain(struct sh7372_pm_domain *sh7372_pd) {}
> >> > +static inline void sh7372_add_device_to_domain(struct sh7372_pm_domain *pd,
> >> > +                                              struct platform_device *pdev) {}
> >> > +#endif /* CONFIG_PM */
> >> > +
> >> >  #endif /* __ASM_SH7372_H__ */
> >>
> >> Wouldn't it be easier to simply get rid of SH7372_A4LC?
> >
> > Not really, because the code won't build for both CONFIG_PM_RUNTIME and
> > CONFIG_SUSPEND unset (resulting in CONFIG_PM unset).
> >
> >> Perhaps you have some special intention behind your #define, but for me the
> >> following change is working just fine:
> >
> > Well, if CONFIG_PM is unset, sh7372_a4lc is not defined.
> 
> True, but in the CONFIG_PM=n case sh7372_a4lc is never used by
> sh7372_init_pm_domain() or sh7372_add_device_to_domain().
> 
> How about letting the preprocessor do the work for us instead? This
> certainly builds without SH7372_A4LC in case of CONFIG_PM=n:
> 
> #else
> #define sh7372_init_pm_domain(pd) do { } while(0)
> #define sh7372_add_device_to_domain(pd, pdev) do { } while(0)
> #endif /* CONFIG_PM */

Yes, we can do that too, if you prefer it.

Update patch is appended.

Thanks,
Rafael

---
From: Rafael J. Wysocki <rjw@sisk.pl>
Subject: ARM / shmobile: Support for I/O power domains for SH7372 (v9)

Use the generic power domains support introduced by the previous
patch to implement support for power domains on SH7372.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Paul Mundt <lethal@linux-sh.org>
---
 arch/arm/Kconfig                             |    1 
 arch/arm/mach-shmobile/board-mackerel.c      |    4 +
 arch/arm/mach-shmobile/include/mach/sh7372.h |   24 ++++++
 arch/arm/mach-shmobile/pm-sh7372.c           |   96 +++++++++++++++++++++++++++
 4 files changed, 125 insertions(+)

Index: linux-2.6/arch/arm/mach-shmobile/board-mackerel.c
=================================--- linux-2.6.orig/arch/arm/mach-shmobile/board-mackerel.c
+++ linux-2.6/arch/arm/mach-shmobile/board-mackerel.c
@@ -1582,6 +1582,10 @@ static void __init mackerel_init(void)
 
 	platform_add_devices(mackerel_devices, ARRAY_SIZE(mackerel_devices));
 
+	sh7372_init_pm_domain(&sh7372_a4lc);
+	sh7372_add_device_to_domain(&sh7372_a4lc, &lcdc_device);
+	sh7372_add_device_to_domain(&sh7372_a4lc, &hdmi_lcdc_device);
+
 	hdmi_init_pm_clock();
 	sh7372_pm_init();
 }
Index: linux-2.6/arch/arm/mach-shmobile/include/mach/sh7372.h
=================================--- linux-2.6.orig/arch/arm/mach-shmobile/include/mach/sh7372.h
+++ linux-2.6/arch/arm/mach-shmobile/include/mach/sh7372.h
@@ -12,6 +12,7 @@
 #define __ASM_SH7372_H__
 
 #include <linux/sh_clk.h>
+#include <linux/pm_domain.h>
 
 /*
  * Pin Function Controller:
@@ -470,4 +471,27 @@ extern struct clk sh7372_fsibck_clk;
 extern struct clk sh7372_fsidiva_clk;
 extern struct clk sh7372_fsidivb_clk;
 
+struct platform_device;
+
+struct sh7372_pm_domain {
+	struct generic_pm_domain genpd;
+	unsigned int bit_shift;
+};
+
+static inline struct sh7372_pm_domain *to_sh7372_pd(struct generic_pm_domain *d)
+{
+	return container_of(d, struct sh7372_pm_domain, genpd);
+}
+
+#ifdef CONFIG_PM
+extern struct sh7372_pm_domain sh7372_a4lc;
+
+extern void sh7372_init_pm_domain(struct sh7372_pm_domain *sh7372_pd);
+extern void sh7372_add_device_to_domain(struct sh7372_pm_domain *sh7372_pd,
+					struct platform_device *pdev);
+#else
+#define sh7372_init_pm_domain(pd) do { } while(0)
+#define sh7372_add_device_to_domain(pd, pdev) do { } while(0)
+#endif /* CONFIG_PM */
+
 #endif /* __ASM_SH7372_H__ */
Index: linux-2.6/arch/arm/mach-shmobile/pm-sh7372.c
=================================--- linux-2.6.orig/arch/arm/mach-shmobile/pm-sh7372.c
+++ linux-2.6/arch/arm/mach-shmobile/pm-sh7372.c
@@ -15,16 +15,112 @@
 #include <linux/list.h>
 #include <linux/err.h>
 #include <linux/slab.h>
+#include <linux/pm_runtime.h>
+#include <linux/platform_device.h>
+#include <linux/delay.h>
 #include <asm/system.h>
 #include <asm/io.h>
 #include <asm/tlbflush.h>
 #include <mach/common.h>
+#include <mach/sh7372.h>
 
 #define SMFRAM 0xe6a70000
 #define SYSTBCR 0xe6150024
 #define SBAR 0xe6180020
 #define APARMBAREA 0xe6f10020
 
+#define SPDCR 0xe6180008
+#define SWUCR 0xe6180014
+#define PSTR 0xe6180080
+
+#define PSTR_RETRIES 100
+#define PSTR_DELAY_US 10
+
+#ifdef CONFIG_PM
+
+static int pd_power_down(struct generic_pm_domain *genpd)
+{
+	struct sh7372_pm_domain *sh7372_pd = to_sh7372_pd(genpd);
+	unsigned int mask = 1 << sh7372_pd->bit_shift;
+
+	if (__raw_readl(PSTR) & mask) {
+		unsigned int retry_count;
+
+		__raw_writel(mask, SPDCR);
+
+		for (retry_count = PSTR_RETRIES; retry_count; retry_count--) {
+			if (!(__raw_readl(SPDCR) & mask))
+				break;
+			cpu_relax();
+		}
+	}
+
+	pr_debug("sh7372 power domain down 0x%08x -> PSTR = 0x%08x\n",
+		 mask, __raw_readl(PSTR));
+
+	return 0;
+}
+
+static int pd_power_up(struct generic_pm_domain *genpd)
+{
+	struct sh7372_pm_domain *sh7372_pd = to_sh7372_pd(genpd);
+	unsigned int mask = 1 << sh7372_pd->bit_shift;
+	unsigned int retry_count;
+	int ret = 0;
+
+	if (__raw_readl(PSTR) & mask)
+		goto out;
+
+	__raw_writel(mask, SWUCR);
+
+	for (retry_count = 2 * PSTR_RETRIES; retry_count; retry_count--) {
+		if (!(__raw_readl(SWUCR) & mask))
+			goto out;
+		if (retry_count > PSTR_RETRIES)
+			udelay(PSTR_DELAY_US);
+		else
+			cpu_relax();
+	}
+	if (__raw_readl(SWUCR) & mask)
+		ret = -EIO;
+
+ out:
+	pr_debug("sh7372 power domain up 0x%08x -> PSTR = 0x%08x\n",
+		 mask, __raw_readl(PSTR));
+
+	return ret;
+}
+
+void sh7372_init_pm_domain(struct sh7372_pm_domain *sh7372_pd)
+{
+	struct generic_pm_domain *genpd = &sh7372_pd->genpd;
+
+	pm_genpd_init(genpd, NULL, false);
+	genpd->stop_device = pm_clk_suspend;
+	genpd->start_device = pm_clk_resume;
+	genpd->power_off = pd_power_down;
+	genpd->power_on = pd_power_up;
+	pd_power_up(&sh7372_pd->genpd);
+}
+
+void sh7372_add_device_to_domain(struct sh7372_pm_domain *sh7372_pd,
+				 struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+
+	if (!dev->power.subsys_data) {
+		pm_clk_init(dev);
+		pm_clk_add(dev, NULL);
+	}
+	pm_genpd_add_device(&sh7372_pd->genpd, dev);
+}
+
+struct sh7372_pm_domain sh7372_a4lc = {
+	.bit_shift = 1,
+};
+
+#endif /* CONFIG_PM */
+
 static void sh7372_enter_core_standby(void)
 {
 	void __iomem *smfram = (void __iomem *)SMFRAM;
Index: linux-2.6/arch/arm/Kconfig
=================================--- linux-2.6.orig/arch/arm/Kconfig
+++ linux-2.6/arch/arm/Kconfig
@@ -642,6 +642,7 @@ config ARCH_SHMOBILE
 	select NO_IOPORT
 	select SPARSE_IRQ
 	select MULTI_IRQ_HANDLER
+	select PM_GENERIC_DOMAINS if PM
 	help
 	  Support for Renesas's SH-Mobile and R-Mobile ARM platforms.