[PATCH v4 28/28] ARM: owl: smp: Implement SPS power-gating for CPU2 and CPU3

[Andreas Färber]

Bring up the two remaining CPUs by calling into PM domain code.

Signed-off-by: Andreas Färber <afaer...@suse.de>
---
 v3 -> v4:
 * Reused PM domain helper code to avoid code duplication
 
 v3: new
 
 arch/arm/mach-actions/Kconfig   |  1 +
 arch/arm/mach-actions/platsmp.c | 36 ++++++++++++++++++++++++++++++++++--
 2 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/arch/arm/mach-actions/Kconfig b/arch/arm/mach-actions/Kconfig
index 717adc1630a1..ad9c5c89c683 100644
--- a/arch/arm/mach-actions/Kconfig
+++ b/arch/arm/mach-actions/Kconfig
@@ -10,6 +10,7 @@ menuconfig ARCH_ACTIONS
        select GENERIC_IRQ_CHIP
        select HAVE_ARM_SCU if SMP
        select HAVE_ARM_TWD if SMP
+       select OWL_PM_DOMAINS_HELPER
        select OWL_TIMER
        help
          This enables support for the Actions Semiconductor S500 SoC family.
diff --git a/arch/arm/mach-actions/platsmp.c b/arch/arm/mach-actions/platsmp.c
index 9d3601ebe535..b4806ce0e9bb 100644
--- a/arch/arm/mach-actions/platsmp.c
+++ b/arch/arm/mach-actions/platsmp.c
@@ -19,6 +19,7 @@
 #include <linux/of.h>
 #include <linux/of_address.h>
 #include <linux/smp.h>
+#include <linux/soc/actions/owl-sps.h>
 #include <asm/cacheflush.h>
 #include <asm/smp_plat.h>
 #include <asm/smp_scu.h>
@@ -28,7 +29,13 @@
 
 #define OWL_CPUx_FLAG_BOOT     0x55aa
 
+#define OWL_SPS_PG_CTL_PWR_CPU2        BIT(5)
+#define OWL_SPS_PG_CTL_PWR_CPU3        BIT(6)
+#define OWL_SPS_PG_CTL_ACK_CPU2        BIT(21)
+#define OWL_SPS_PG_CTL_ACK_CPU3        BIT(22)
+
 static void __iomem *scu_base_addr;
+static void __iomem *sps_base_addr;
 static void __iomem *timer_base_addr;
 static int ncores;
 
@@ -58,14 +65,27 @@ void owl_secondary_startup(void);
 
 static int s500_wakeup_secondary(unsigned int cpu)
 {
+       int ret;
+
        if (cpu > 3)
                return -EINVAL;
 
+       /* The generic PM domain driver is not available this early. */
        switch (cpu) {
        case 2:
+               ret = owl_sps_set_pg(sps_base_addr,
+                                    OWL_SPS_PG_CTL_PWR_CPU2,
+                                    OWL_SPS_PG_CTL_ACK_CPU2, true);
+               if (ret)
+                       return ret;
+               break;
        case 3:
-               /* CPU2/3 are power-gated */
-               return -EINVAL;
+               ret = owl_sps_set_pg(sps_base_addr,
+                                    OWL_SPS_PG_CTL_PWR_CPU3,
+                                    OWL_SPS_PG_CTL_ACK_CPU3, true);
+               if (ret)
+                       return ret;
+               break;
        }
 
        /* wait for CPUx to run to WFE instruction */
@@ -133,6 +153,18 @@ static void __init s500_smp_prepare_cpus(unsigned int 
max_cpus)
                return;
        }
 
+       node = of_find_compatible_node(NULL, NULL, "actions,s500-sps");
+       if (!node) {
+               pr_err("%s: missing sps\n", __func__);
+               return;
+       }
+
+       sps_base_addr = of_iomap(node, 0);
+       if (!sps_base_addr) {
+               pr_err("%s: could not map sps registers\n", __func__);
+               return;
+       }
+
        if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A9) {
                node = of_find_compatible_node(NULL, NULL, "arm,cortex-a9-scu");
                if (!node) {
-- 
2.12.3