ARM: OMAP2+: PM: clean up omap_set_pwrdm_state()

Clean up a few different parts of omap_set_pwrdm_state():

- Remove a superfluous call to pwrdm_state_switch().  Not needed
  unless LOWPOWERSTATECHANGE is used, because the state switch code is
  called by either clkdm_sleep() or clkdm_allow_idle().

- Add code to wait for the power state transition in the OMAP4+ low
  power state change.  This is speculative, so I would particularly
  appreciate feedback on this part.

- Remove a superfluous call to pwrdm_read_pwrst().

- Update variable names to be more meaningful (hopefully) and precise.

- Fix an error path bug that would not place the clockdomain back into
  hardware-supervised idle or sleep mode if the power state could not
  be programmed.

The documentation for this function still needs major improvements;
that's left for a later patch.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Rajendra Nayak <rnayak@ti.com>
Tested-by: Tero Kristo <t-kristo@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>

diff --git a/arch/arm/mach-omap2/pm.c b/arch/arm/mach-omap2/pm.c
index 00bff46..fa0c30a 100644 (file)
--- a/arch/arm/mach-omap2/pm.c
+++ b/arch/arm/mach-omap2/pm.c
@@ -72,28 +72,27 @@ static void omap2_init_processor_devices(void)
  * This sets pwrdm state (other than mpu & core. Currently only ON &
  * RET are supported.
  */
-int omap_set_pwrdm_state(struct powerdomain *pwrdm, u32 state)
+int omap_set_pwrdm_state(struct powerdomain *pwrdm, u32 pwrst)
 {
-       u32 cur_state;
-       int sleep_switch = -1;
-       int ret = 0;
-       int hwsup = 0;
+       u8 curr_pwrst, next_pwrst;
+       int sleep_switch = -1, ret = 0, hwsup = 0;
 
-       if (pwrdm == NULL || IS_ERR(pwrdm))
+       if (!pwrdm || IS_ERR(pwrdm))
                return -EINVAL;
 
-       while (!(pwrdm->pwrsts & (1 << state))) {
-               if (state == PWRDM_POWER_OFF)
+       while (!(pwrdm->pwrsts & (1 << pwrst))) {
+               if (pwrst == PWRDM_POWER_OFF)
                        return ret;
-               state--;
+               pwrst--;
        }
 
-       cur_state = pwrdm_read_next_pwrst(pwrdm);
-       if (cur_state == state)
+       next_pwrst = pwrdm_read_next_pwrst(pwrdm);
+       if (next_pwrst == pwrst)
                return ret;
 
-       if (pwrdm_read_pwrst(pwrdm) < PWRDM_POWER_ON) {
-               if ((pwrdm_read_pwrst(pwrdm) > state) &&
+       curr_pwrst = pwrdm_read_pwrst(pwrdm);
+       if (curr_pwrst < PWRDM_POWER_ON) {
+               if ((curr_pwrst > pwrst) &&
                        (pwrdm->flags & PWRDM_HAS_LOWPOWERSTATECHANGE)) {
                        sleep_switch = LOWPOWERSTATE_SWITCH;
                } else {
@@ -103,12 +102,10 @@ int omap_set_pwrdm_state(struct powerdomain *pwrdm, u32 state)
                }
        }
 
-       ret = pwrdm_set_next_pwrst(pwrdm, state);
-       if (ret) {
-               pr_err("%s: unable to set state of powerdomain: %s\n",
+       ret = pwrdm_set_next_pwrst(pwrdm, pwrst);
+       if (ret)
+               pr_err("%s: unable to set power state of powerdomain: %s\n",
                       __func__, pwrdm->name);
-               goto err;
-       }
 
        switch (sleep_switch) {
        case FORCEWAKEUP_SWITCH:
@@ -119,13 +116,11 @@ int omap_set_pwrdm_state(struct powerdomain *pwrdm, u32 state)
                break;
        case LOWPOWERSTATE_SWITCH:
                pwrdm_set_lowpwrstchange(pwrdm);
+               pwrdm_wait_transition(pwrdm);
+               pwrdm_state_switch(pwrdm);
                break;
-       default:
-               return ret;
        }
 
-       pwrdm_state_switch(pwrdm);
-err:
        return ret;
 }