OMAP4: powerdomain: Add pwrdm_clear_all_prev_pwrst

Like OMAP3, OMAP4430 ES2 has additional bitfields in PWRSTST register
which help identify the previous power state entered by the
powerdomain.  Add pwrdm_clear_all_prev_pwrst to the OMAP4 powerdomains
implementation to support this.
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Rajendra Nayak <rnayak@ti.com>
[paul@pwsan.com: clarified commit message]
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Benoit Cousson <b-cousson@ti.com>
Cc: Kevin Hilman <khilman@deeprootsystems.com>
Reviewed-by: Kevin Hilman <khilman@deeprootsystems.com>
Tested-by: Kevin Hilman <khilman@deeprootsystems.com>
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Rajendra Nayak <rnayak@ti.com>

arch/arm/mach-omap2/powerdomain44xx.c

@@ -55,6 +55,14 @@ static int omap4_pwrdm_set_lowpwrstchange(struct powerdomain *pwrdm)
 	return 0;
 }
 
+static int omap4_pwrdm_clear_all_prev_pwrst(struct powerdomain *pwrdm)
+{
+	prm_rmw_mod_reg_bits(OMAP4430_LASTPOWERSTATEENTERED_MASK,
+				OMAP4430_LASTPOWERSTATEENTERED_MASK,
+				pwrdm->prcm_offs, OMAP4_PM_PWSTST);
+	return 0;
+}
+
 static int omap4_pwrdm_set_logic_retst(struct powerdomain *pwrdm, u8 pwrst)
 {
 	u32 v;
@@ -155,6 +163,7 @@ struct pwrdm_ops omap4_pwrdm_operations = {
 	.pwrdm_read_pwrst	= omap4_pwrdm_read_pwrst,
 	.pwrdm_read_prev_pwrst	= omap4_pwrdm_read_prev_pwrst,
 	.pwrdm_set_lowpwrstchange	= omap4_pwrdm_set_lowpwrstchange,
+	.pwrdm_clear_all_prev_pwrst	= omap4_pwrdm_clear_all_prev_pwrst,
 	.pwrdm_set_logic_retst	= omap4_pwrdm_set_logic_retst,
 	.pwrdm_read_logic_pwrst	= omap4_pwrdm_read_logic_pwrst,
 	.pwrdm_read_logic_retst	= omap4_pwrdm_read_logic_retst,