Re: [Update][PATCH 8/8] ARM / shmobile: Support for I/O power domains for SH7372 (v6)
From: Paul Mundt <hidden>
Date: 2011-06-20 02:01:32
On Mon, Jun 20, 2011 at 12:07:47AM +0200, Rafael J. Wysocki wrote:
quoted hunk
+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.