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Commit fd6b42a5 authored Jan 26, 2013 by Paul Walmsley

ARM: OMAP3xxx: CPUIdle: simplify the PER next-state code



The OMAP3xxx CPUIdle driver contains some code to place a lower bound
on the PER powerdomain's power state.  Convert this code to a data-driven
implementation to remove branches and to improve readability.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Kevin Hilman <khilman@deeprootsystems.com>

parent 8e1ff676

arch/arm/mach-omap2/cpuidle34xx.c

+22 −22

Original line number	Diff line number	Diff line
		@@ -36,40 +36,53 @@

		/* Mach specific information to be recorded in the C-state driver_data */
		struct omap3_idle_statedata {
		u32 mpu_state;
		u32 core_state;
		u8 mpu_state;
		u8 core_state;
		u8 per_min_state;
		};

		static struct powerdomain mpu_pd, core_pd, per_pd, cam_pd;

		/*
		* Prevent PER OFF if CORE is not in RETention or OFF as this would
		* disable PER wakeups completely.
		*/
		static struct omap3_idle_statedata omap3_idle_data[] = {
		{
		.mpu_state = PWRDM_POWER_ON,
		.core_state = PWRDM_POWER_ON,
		/* In C1 do not allow PER state lower than CORE state */
		.per_min_state = PWRDM_POWER_ON,
		},
		{
		.mpu_state = PWRDM_POWER_ON,
		.core_state = PWRDM_POWER_ON,
		.per_min_state = PWRDM_POWER_RET,
		},
		{
		.mpu_state = PWRDM_POWER_RET,
		.core_state = PWRDM_POWER_ON,
		.per_min_state = PWRDM_POWER_RET,
		},
		{
		.mpu_state = PWRDM_POWER_OFF,
		.core_state = PWRDM_POWER_ON,
		.per_min_state = PWRDM_POWER_RET,
		},
		{
		.mpu_state = PWRDM_POWER_RET,
		.core_state = PWRDM_POWER_RET,
		.per_min_state = PWRDM_POWER_OFF,
		},
		{
		.mpu_state = PWRDM_POWER_OFF,
		.core_state = PWRDM_POWER_RET,
		.per_min_state = PWRDM_POWER_OFF,
		},
		{
		.mpu_state = PWRDM_POWER_OFF,
		.core_state = PWRDM_POWER_OFF,
		.per_min_state = PWRDM_POWER_OFF,
		},
		};

		@@ -209,10 +222,9 @@ static int omap3_enter_idle_bm(struct cpuidle_device *dev,
		struct cpuidle_driver *drv,
		int index)
		{
		int new_state_idx;
		u32 core_next_state, per_next_state = 0, per_saved_state = 0;
		int new_state_idx, ret;
		u8 per_next_state, per_saved_state;
		struct omap3_idle_statedata *cx;
		int ret;

		/*
		* Use only C1 if CAM is active.
		@@ -233,25 +245,13 @@ static int omap3_enter_idle_bm(struct cpuidle_device *dev,

		/* Program PER state */
		cx = &omap3_idle_data[new_state_idx];
		core_next_state = cx->core_state;
		per_next_state = per_saved_state = pwrdm_read_next_pwrst(per_pd);
		if (new_state_idx == 0) {
		/* In C1 do not allow PER state lower than CORE state */
		if (per_next_state < core_next_state)
		per_next_state = core_next_state;
		} else {
		/*
		* Prevent PER OFF if CORE is not in RETention or OFF as this
		* would disable PER wakeups completely.
		*/
		if ((per_next_state == PWRDM_POWER_OFF) &&
		(core_next_state > PWRDM_POWER_RET))
		per_next_state = PWRDM_POWER_RET;
		}

		/* Are we changing PER target state? */
		if (per_next_state != per_saved_state)
		per_next_state = pwrdm_read_next_pwrst(per_pd);
		per_saved_state = per_next_state;
		if (per_next_state < cx->per_min_state) {
		per_next_state = cx->per_min_state;
		pwrdm_set_next_pwrst(per_pd, per_next_state);
		}

		ret = omap3_enter_idle(dev, drv, new_state_idx);