msm: acpuclock-krait: Disable secondary clock source gating during switches
To workaround a Krait errata on 8064, disable secondary clock source
gating during the MUX switch. This errata was already worked around
in msm-krait-l2-accessors.c in a different way, but that will soon
be removed in favor of this and some power-collapse changes.
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>
Change-Id: Iffe42ee7216c9b9c4a4e68ddfe80fbc03b0413b0
Signed-off-by: Neha Pandey <nehap@codeaurora.org>
diff --git a/arch/arm/mach-msm/acpuclock-krait.c b/arch/arm/mach-msm/acpuclock-krait.c
index c429eec..7b5aa23 100644
--- a/arch/arm/mach-msm/acpuclock-krait.c
+++ b/arch/arm/mach-msm/acpuclock-krait.c
@@ -43,6 +43,8 @@
#define PRI_SRC_SEL_HFPLL 1
#define PRI_SRC_SEL_HFPLL_DIV2 2
+#define SECCLKAGD BIT(4)
+
static DEFINE_MUTEX(driver_lock);
static DEFINE_SPINLOCK(l2_lock);
@@ -81,10 +83,20 @@
{
u32 regval;
+ /* 8064 Errata: disable sec_src clock gating during switch. */
regval = get_l2_indirect_reg(sc->l2cpmr_iaddr);
+ regval |= SECCLKAGD;
+ set_l2_indirect_reg(sc->l2cpmr_iaddr, regval);
+
+ /* Program the MUX */
regval &= ~(0x3 << 2);
regval |= ((sec_src_sel & 0x3) << 2);
set_l2_indirect_reg(sc->l2cpmr_iaddr, regval);
+
+ /* 8064 Errata: re-enabled sec_src clock gating. */
+ regval &= ~SECCLKAGD;
+ set_l2_indirect_reg(sc->l2cpmr_iaddr, regval);
+
/* Wait for switch to complete. */
mb();
udelay(1);