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

From: Andreas FÃrber
Date: Mon Jun 05 2017 - 20:57:04 EST


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

Signed-off-by: Andreas FÃrber <afaerber@xxxxxxx>
---
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