From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Rafael J. Wysocki" Subject: Re: [Update][PATCH 8/8] ARM / shmobile: Support for I/O power domains for SH7372 (v6) Date: Tue, 21 Jun 2011 13:57:08 +0200 Message-ID: <201106211357.09202.rjw__32985.0028422245$1308657434$gmane$org@sisk.pl> References: <201106112223.04972.rjw@sisk.pl> <20110620020125.GA26125@linux-sh.org> <201106210030.01922.rjw@sisk.pl> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <201106210030.01922.rjw@sisk.pl> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-pm-bounces@lists.linux-foundation.org Errors-To: linux-pm-bounces@lists.linux-foundation.org To: Paul Mundt Cc: linux-sh@vger.kernel.org, Greg Kroah-Hartman , LKML , Linux PM mailing list List-Id: linux-pm@vger.kernel.org On Tuesday, June 21, 2011, Rafael J. Wysocki wrote: > On Monday, June 20, 2011, Paul Mundt wrote: > > On Mon, Jun 20, 2011 at 12:07:47AM +0200, Rafael J. Wysocki wrote: > > > +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) { > > > + __raw_writel(mask, SPDCR); > > > + > > > + while (__raw_readl(SPDCR) & mask) > > > + 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; > > > + > > > + if (!(__raw_readl(PSTR) & mask)) { > > > + __raw_writel(mask, SWUCR); > > > + > > > + while (__raw_readl(SWUCR) & mask) > > > + cpu_relax(); > > > + > > > + pr_debug("sh7372 power domain up 0x%08x -> PSTR = 0x%08x\n", > > > + mask, __raw_readl(PSTR)); > > > + } > > > + > > > + return 0; > > > +} > > > + > > Given that these functions can return errors, it's probably more prudent > > to implement some timeout logic on top of the busy loop. Hardware does > > get stuck, after all. > > Yes, it does, but we don't really know what timeout value to use in there. > > In fact, failures of pd_power_down() don't really matter (at worst the power > domain won't be powered off really) and pd_power_up() should only return error > code if the error is known to be unrecoverable. > > So, what about this: repeat certain number of times (I verified that it took > several iterations of the loop until the new value settled on my hardware) > and then return from pd_power_down() or go to sleep for a short time and repeat > in pd_power_up()? Having discussed that with Magnus I changed pd_power_down() to use a timeout. Specifically, it will bail out if the state doesn't change after approximately 1 ms. Updated patch is appended. Thanks, Rafael --- From: Rafael J. Wysocki Subject: ARM / shmobile: Support for I/O power domains for SH7372 (v7) 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 --- arch/arm/Kconfig | 1 arch/arm/mach-shmobile/Makefile | 4 + arch/arm/mach-shmobile/board-mackerel.c | 4 + arch/arm/mach-shmobile/include/mach/sh7372.h | 28 ++++++++ arch/arm/mach-shmobile/pm-sh7372.c | 92 +++++++++++++++++++++++++++ 5 files changed, 129 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_domain); + 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 +#include /* * 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__ */ Index: linux-2.6/arch/arm/mach-shmobile/Makefile =================================================================== --- linux-2.6.orig/arch/arm/mach-shmobile/Makefile +++ linux-2.6/arch/arm/mach-shmobile/Makefile @@ -42,6 +42,10 @@ obj-$(CONFIG_MACH_AP4EVB) += board-ap4ev obj-$(CONFIG_MACH_AG5EVM) += board-ag5evm.o obj-$(CONFIG_MACH_MACKEREL) += board-mackerel.o +# PM objects +pm-$(CONFIG_ARCH_SH7372) += pm-sh7372.o + # Framework support obj-$(CONFIG_SMP) += $(smp-y) obj-$(CONFIG_GENERIC_GPIO) += $(pfc-y) +obj-$(CONFIG_PM) += $(pm-y) 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 +15,108 @@ #include #include #include +#include +#include +#include #include #include #include #include +#include #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 + +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_runtime_clk_suspend; + genpd->start_device = pm_runtime_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_runtime_clk_init(dev); + pm_runtime_clk_add(dev, NULL); + } + pm_genpd_add_device(&sh7372_pd->genpd, dev); +} + +struct sh7372_pm_domain sh7372_a4lc_domain = { + .bit_shift = 1, +}; + 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 help Support for Renesas's SH-Mobile and R-Mobile ARM platforms.