From mboxrd@z Thu Jan 1 00:00:00 1970 From: ezequiel.garcia@free-electrons.com (Ezequiel Garcia) Date: Fri, 30 Aug 2013 20:10:04 -0300 Subject: [PATCH v3 2/2] ARM: kirkwood: Add standby support In-Reply-To: <1377186547-14284-3-git-send-email-ezequiel.garcia@free-electrons.com> References: <1377186547-14284-1-git-send-email-ezequiel.garcia@free-electrons.com> <1377186547-14284-3-git-send-email-ezequiel.garcia@free-electrons.com> Message-ID: <20130830231003.GA2398@localhost> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, Aug 22, 2013 at 12:49:07PM -0300, Ezequiel Garcia wrote: > Implements standby support for Kirkwood SoC. When the SoC enters > standby state the memory PM units are disabled, the DDR is set > in self-refresh mode, and the CPU is set in WFI. > > At this point there's no clock gating, as that is considered each > driver's task. > > Signed-off-by: Simon Guinot > Signed-off-by: Ezequiel Garcia > --- > arch/arm/mach-kirkwood/Makefile | 2 + > arch/arm/mach-kirkwood/board-dt.c | 1 + > arch/arm/mach-kirkwood/common.c | 1 + > arch/arm/mach-kirkwood/common.h | 6 ++ > arch/arm/mach-kirkwood/include/mach/bridge-regs.h | 2 + > arch/arm/mach-kirkwood/pm.c | 73 +++++++++++++++++++++++ > 6 files changed, 85 insertions(+) > create mode 100644 arch/arm/mach-kirkwood/pm.c > > diff --git a/arch/arm/mach-kirkwood/Makefile b/arch/arm/mach-kirkwood/Makefile > index ac4cd75..ac78dcc 100644 > --- a/arch/arm/mach-kirkwood/Makefile > +++ b/arch/arm/mach-kirkwood/Makefile > @@ -1,4 +1,6 @@ > obj-y += common.o irq.o pcie.o mpp.o > +obj-$(CONFIG_PM) += pm.o > + > > obj-$(CONFIG_MACH_D2NET_V2) += d2net_v2-setup.o lacie_v2-common.o > obj-$(CONFIG_MACH_DOCKSTAR) += dockstar-setup.o > diff --git a/arch/arm/mach-kirkwood/board-dt.c b/arch/arm/mach-kirkwood/board-dt.c > index 6e122ed..2d4a4aa 100644 > --- a/arch/arm/mach-kirkwood/board-dt.c > +++ b/arch/arm/mach-kirkwood/board-dt.c > @@ -96,6 +96,7 @@ static void __init kirkwood_dt_init(void) > /* Setup root of clk tree */ > kirkwood_of_clk_init(); > > + kirkwood_pm_init(); > kirkwood_cpuidle_init(); > > #ifdef CONFIG_KEXEC > diff --git a/arch/arm/mach-kirkwood/common.c b/arch/arm/mach-kirkwood/common.c > index e9238b5..aceb68a 100644 > --- a/arch/arm/mach-kirkwood/common.c > +++ b/arch/arm/mach-kirkwood/common.c > @@ -717,6 +717,7 @@ void __init kirkwood_init(void) > kirkwood_xor1_init(); > kirkwood_crypto_init(); > > + kirkwood_pm_init(); > kirkwood_cpuidle_init(); > #ifdef CONFIG_KEXEC > kexec_reinit = kirkwood_enable_pcie; > diff --git a/arch/arm/mach-kirkwood/common.h b/arch/arm/mach-kirkwood/common.h > index fcf3ba6..2be1226 100644 > --- a/arch/arm/mach-kirkwood/common.h > +++ b/arch/arm/mach-kirkwood/common.h > @@ -58,6 +58,12 @@ void kirkwood_cpufreq_init(void); > void kirkwood_restart(enum reboot_mode, const char *); > void kirkwood_clk_init(void); > > +#ifdef CONFIG_PM > +void kirkwood_pm_init(void); > +#else > +static inline void kirkwood_pm_init(void) {}; > +#endif > + > /* board init functions for boards not fully converted to fdt */ > #ifdef CONFIG_MACH_DREAMPLUG_DT > void dreamplug_init(void); > diff --git a/arch/arm/mach-kirkwood/include/mach/bridge-regs.h b/arch/arm/mach-kirkwood/include/mach/bridge-regs.h > index 91242c9..8b9d1c9 100644 > --- a/arch/arm/mach-kirkwood/include/mach/bridge-regs.h > +++ b/arch/arm/mach-kirkwood/include/mach/bridge-regs.h > @@ -78,4 +78,6 @@ > #define CGC_TDM (1 << 20) > #define CGC_RESERVED (0x6 << 21) > > +#define MEMORY_PM_CTRL (BRIDGE_VIRT_BASE + 0x118) > + > #endif > diff --git a/arch/arm/mach-kirkwood/pm.c b/arch/arm/mach-kirkwood/pm.c > new file mode 100644 > index 0000000..8783a71 > --- /dev/null > +++ b/arch/arm/mach-kirkwood/pm.c > @@ -0,0 +1,73 @@ > +/* > + * Power Management driver for Marvell Kirkwood SoCs > + * > + * Copyright (C) 2013 Ezequiel Garcia > + * Copyright (C) 2010 Simon Guinot > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License, > + * version 2 of the License. > + * > + * This program is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + */ > + > +#include > +#include > +#include > +#include > + > +static void __iomem *ddr_operation_base; > + > +static void kirkwood_low_power(void) > +{ > + u32 mem_pm_ctrl; > + > + mem_pm_ctrl = readl(MEMORY_PM_CTRL); > + > + /* Set peripherals to low-power mode */ > + writel_relaxed(~0, MEMORY_PM_CTRL); > + > + /* Set DDR in self-refresh */ > + writel_relaxed(0x7, ddr_operation_base); > + > + /* > + * Set CPU in wait-for-interrupt state. > + * This disables the CPU core clocks, > + * the array clocks, and also the L2 controller. > + */ > + cpu_do_idle(); > + > + writel_relaxed(mem_pm_ctrl, MEMORY_PM_CTRL); > +} > + > +static int kirkwood_suspend_enter(suspend_state_t state) > +{ > + switch (state) { > + case PM_SUSPEND_STANDBY: > + kirkwood_low_power(); > + break; > + default: > + return -EINVAL; > + } > + return 0; > +} > + > +static int kirkwood_pm_valid_standby(suspend_state_t state) > +{ > + return state == PM_SUSPEND_STANDBY; > +} > + > +static const struct platform_suspend_ops kirkwood_suspend_ops = { > + .enter = kirkwood_suspend_enter, > + .valid = kirkwood_pm_valid_standby, > +}; > + > +int __init kirkwood_pm_init(void) > +{ > + ddr_operation_base = ioremap(DDR_OPERATION_BASE, 4); > + suspend_set_ops(&kirkwood_suspend_ops); > + return 0; > +} > -- > 1.8.1.5 > Any comments on this? -- Ezequiel Garc?a, Free Electrons Embedded Linux, Kernel and Android Engineering http://free-electrons.com