ARM: shmobile: r8a7740: Add D4 pm domain support

Add support for the D4 power domain.
This domain contains the Coresight-ETM hardware block.

As long as the ARM debug/perf code doesn't use resource management with
runtime PM support, the D4 power domain must be kept powered to avoid a
crash during resume from s2ram (dbg_cpu_pm_notify() calls
reset_ctrl_regs() unconditionally, causing an undefined instruction
oops).

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

diff --git a/arch/arm/mach-shmobile/pm-r8a7740.c b/arch/arm/mach-shmobile/pm-r8a7740.c
index 081a4f9726a0c909b35462fffc99f38d5bb7f698..8b1af2a585ab99d41f0bdbf465b16a94f7eced2b 100644 (file)
--- a/arch/arm/mach-shmobile/pm-r8a7740.c
+++ b/arch/arm/mach-shmobile/pm-r8a7740.c
@@ -32,6 +32,16 @@ static int r8a7740_pd_a3sp_suspend(void)
        return console_suspend_enabled ? 0 : -EBUSY;
 }
 
+static int r8a7740_pd_d4_suspend(void)
+{
+       /*
+        * The D4 domain contains the Coresight-ETM hardware block and
+        * therefore it should only be turned off if the debug module is
+        * not in use.
+        */
+       return -EBUSY;
+}
+
 static struct rmobile_pm_domain r8a7740_pm_domains[] = {
        {
                .genpd.name     = "A4LC",
@@ -39,6 +49,11 @@ static struct rmobile_pm_domain r8a7740_pm_domains[] = {
        }, {
                .genpd.name     = "A4MP",
                .bit_shift      = 2,
+       }, {
+               .genpd.name     = "D4",
+               .bit_shift      = 3,
+               .gov            = &pm_domain_always_on_gov,
+               .suspend        = r8a7740_pd_d4_suspend,
        }, {
                .genpd.name     = "A3RV",
                .bit_shift      = 6,