The imx5 idle code that existed in mm-imx5.c is moved to pm-imx5.c. The imx5_pm_init call is now exported and called during the MACHINE_START late_init in supported imx5 platforms.
Remove various enabling/disabling of the gpc_dvfs clock and enable it once during initialization. This is a very low power clock that must be enabled during low power operations.
There are only two "suspend_state_t" imx5 low power modes ever used. STOP_POWER_OFF for suspend to mem and WAIT_UNCLOCKED_POWER_OFF for idle and suspend to standby. The latter mode only requires 500 nanoseconds of extra hardware exit time beyond a basic WFI operation (WAIT_CLOCKED mode) so no other idle mode is necessary. Given this information, it is more efficient to keep the registers in the often used WAIT_UNCLOCKED_POWER_OFF state and only to and from the STOP_POWER_OFF register state as needed when suspend to mem is required.
Signed-off-by: Robert Lee rob.lee@linaro.org --- arch/arm/mach-imx/mm-imx5.c | 21 +--------- arch/arm/mach-imx/pm-imx5.c | 67 +++++++++++++++++++------------ arch/arm/plat-mxc/include/mach/common.h | 3 +- 3 files changed, 44 insertions(+), 47 deletions(-)
diff --git a/arch/arm/mach-imx/mm-imx5.c b/arch/arm/mach-imx/mm-imx5.c index 3fb4d56..ff7fa61 100644 --- a/arch/arm/mach-imx/mm-imx5.c +++ b/arch/arm/mach-imx/mm-imx5.c @@ -15,7 +15,6 @@ #include <linux/init.h> #include <linux/clk.h>
-#include <asm/system_misc.h> #include <asm/mach/map.h>
#include <mach/hardware.h> @@ -23,24 +22,6 @@ #include <mach/devices-common.h> #include <mach/iomux-v3.h>
-static struct clk *gpc_dvfs_clk; - -static void imx5_idle(void) -{ - /* gpc clock is needed for SRPG */ - if (gpc_dvfs_clk == NULL) { - gpc_dvfs_clk = clk_get(NULL, "gpc_dvfs"); - if (IS_ERR(gpc_dvfs_clk)) - return; - clk_prepare(gpc_dvfs_clk); - } - clk_enable(gpc_dvfs_clk); - mx5_cpu_lp_set(WAIT_UNCLOCKED_POWER_OFF); - if (!tzic_enable_wake()) - cpu_do_idle(); - clk_disable(gpc_dvfs_clk); -} - /* * Define the MX50 memory map. */ @@ -104,7 +85,6 @@ void __init imx51_init_early(void) mxc_set_cpu_type(MXC_CPU_MX51); mxc_iomux_v3_init(MX51_IO_ADDRESS(MX51_IOMUXC_BASE_ADDR)); mxc_arch_reset_init(MX51_IO_ADDRESS(MX51_WDOG1_BASE_ADDR)); - arm_pm_idle = imx5_idle; }
void __init imx53_init_early(void) @@ -239,4 +219,5 @@ void __init imx53_soc_init(void) void __init imx51_init_late(void) { mx51_neon_fixup(); + imx51_pm_init(); } diff --git a/arch/arm/mach-imx/pm-imx5.c b/arch/arm/mach-imx/pm-imx5.c index e26a9cb..baf9321 100644 --- a/arch/arm/mach-imx/pm-imx5.c +++ b/arch/arm/mach-imx/pm-imx5.c @@ -13,18 +13,27 @@ #include <linux/io.h> #include <linux/err.h> #include <asm/cacheflush.h> +#include <asm/system_misc.h> #include <asm/tlbflush.h> #include <mach/common.h> #include <mach/hardware.h> #include "crm-regs-imx5.h"
-static struct clk *gpc_dvfs_clk; +/* + * The WAIT_UNCLOCKED_POWER_OFF state only requires <= 500ns to exit. + * This is also the lowest power state possible without affecting + * non-cpu parts of the system. For these reasons, imx5 should default + * to always using this state for cpu idling. The PM_SUSPEND_STANDBY also + * uses this state and needs to take no action when registers remain confgiured + * for this state. + */ +#define IMX5_DEFAULT_CPU_IDLE_STATE WAIT_UNCLOCKED_POWER_OFF
/* * set cpu low power mode before WFI instruction. This function is called * mx5 because it can be used for mx50, mx51, and mx53. */ -void mx5_cpu_lp_set(enum mxc_cpu_pwr_mode mode) +static void mx5_cpu_lp_set(enum mxc_cpu_pwr_mode mode) { u32 plat_lpc, arm_srpgcr, ccm_clpcr; u32 empgc0, empgc1; @@ -87,11 +96,6 @@ void mx5_cpu_lp_set(enum mxc_cpu_pwr_mode mode) } }
-static int mx5_suspend_prepare(void) -{ - return clk_prepare_enable(gpc_dvfs_clk); -} - static int mx5_suspend_enter(suspend_state_t state) { switch (state) { @@ -99,7 +103,7 @@ static int mx5_suspend_enter(suspend_state_t state) mx5_cpu_lp_set(STOP_POWER_OFF); break; case PM_SUSPEND_STANDBY: - mx5_cpu_lp_set(WAIT_UNCLOCKED_POWER_OFF); + /* DEFAULT_IDLE_STATE already configured */ break; default: return -EINVAL; @@ -114,12 +118,10 @@ static int mx5_suspend_enter(suspend_state_t state) __raw_writel(0, MXC_SRPG_EMPGC1_SRPGCR); } cpu_do_idle(); - return 0; -}
-static void mx5_suspend_finish(void) -{ - clk_disable_unprepare(gpc_dvfs_clk); + /* return registers to default idle state */ + mx5_cpu_lp_set(IMX5_DEFAULT_CPU_IDLE_STATE); + return 0; }
static int mx5_pm_valid(suspend_state_t state) @@ -129,25 +131,38 @@ static int mx5_pm_valid(suspend_state_t state)
static const struct platform_suspend_ops mx5_suspend_ops = { .valid = mx5_pm_valid, - .prepare = mx5_suspend_prepare, .enter = mx5_suspend_enter, - .finish = mx5_suspend_finish, };
-static int __init mx5_pm_init(void) +static void imx5_pm_idle(void) { - if (!cpu_is_mx51() && !cpu_is_mx53()) - return 0; + if (likely(!tzic_enable_wake())) + cpu_do_idle(); +} + +static int __init imx5_pm_common_init(void) +{ + int ret; + struct clk *gpc_dvfs_clk = clk_get(NULL, "gpc_dvfs"); + + if (IS_ERR(gpc_dvfs_clk)) + return PTR_ERR(gpc_dvfs_clk);
- if (gpc_dvfs_clk == NULL) - gpc_dvfs_clk = clk_get(NULL, "gpc_dvfs"); + ret = clk_prepare_enable(gpc_dvfs_clk); + if (ret) + return ret;
- if (!IS_ERR(gpc_dvfs_clk)) { - if (cpu_is_mx51()) - suspend_set_ops(&mx5_suspend_ops); - } else - return -EPERM; + arm_pm_idle = imx5_pm_idle; + + /* Set the registers to the default cpu idle state. */ + mx5_cpu_lp_set(IMX5_DEFAULT_CPU_IDLE_STATE);
return 0; } -device_initcall(mx5_pm_init); + +void __init imx51_pm_init(void) +{ + int ret = imx5_pm_common_init(); + if (!ret) + suspend_set_ops(&mx5_suspend_ops); +} diff --git a/arch/arm/plat-mxc/include/mach/common.h b/arch/arm/plat-mxc/include/mach/common.h index cf663d8..f65d068 100644 --- a/arch/arm/plat-mxc/include/mach/common.h +++ b/arch/arm/plat-mxc/include/mach/common.h @@ -95,7 +95,6 @@ enum mx3_cpu_pwr_mode { };
extern void mx3_cpu_lp_set(enum mx3_cpu_pwr_mode mode); -extern void mx5_cpu_lp_set(enum mxc_cpu_pwr_mode mode); extern void imx_print_silicon_rev(const char *cpu, int srev);
void avic_handle_irq(struct pt_regs *); @@ -146,8 +145,10 @@ extern void imx6q_clock_map_io(void);
#ifdef CONFIG_PM extern void imx6q_pm_init(void); +extern void imx51_pm_init(void); #else static inline void imx6q_pm_init(void) {} +static inline void imx51_pm_init(void) {} #endif
#ifdef CONFIG_NEON