2019-12-13 03:10:07

by Dave Gerlach

[permalink] [raw]
Subject: [PATCH 4/5] soc: ti: pm33xx: Add base cpuidle support

Some cpuidle C-states supported on am335x and am437x, like C1 on am335x,
require the use of the wkup_m3_ipc driver, and all C-states beyond C0 on
both platforms require the use of the SRAM sleep code.

Pass am33xx_do_sram_idle as the idle function to the platform pm core to
be used by the cpuidle-arm driver when entering cpuidle states.
am33xx_do_sram_idle will detect when the wkup_m3 is needed and ping it
if necessary before calling the final cpu_suspend op which will execute
the SRAM code to put the cpu into idle.

Finally, use the begin_suspend and finish_suspend platform ops to be
called at the beginning and end of suspend path to allow use of
cpu_idle_poll_ctrl.

This prevents races between cpuidle and suspend paths trying to
communicate with the wkup_m3, as during suspend we only want it
configured for entry to suspend.

Signed-off-by: Dave Gerlach <[email protected]>
---
drivers/soc/ti/pm33xx.c | 21 ++++++++++++++++++++-
1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/drivers/soc/ti/pm33xx.c b/drivers/soc/ti/pm33xx.c
index 19bdcaca1f21..de0123ec8ad6 100644
--- a/drivers/soc/ti/pm33xx.c
+++ b/drivers/soc/ti/pm33xx.c
@@ -130,6 +130,19 @@ static int am33xx_push_sram_idle(void)
return 0;
}

+static int am33xx_do_sram_idle(u32 wfi_flags)
+{
+ int ret = 0;
+
+ if (!m3_ipc || !pm_ops)
+ return 0;
+
+ if (wfi_flags & WFI_FLAG_WAKE_M3)
+ ret = m3_ipc->ops->prepare_low_power(m3_ipc, WKUP_M3_IDLE);
+
+ return pm_ops->cpu_suspend(am33xx_do_wfi_sram, wfi_flags);
+}
+
static int __init am43xx_map_gic(void)
{
gic_dist_base = ioremap(AM43XX_GIC_DIST_BASE, SZ_4K);
@@ -260,6 +273,8 @@ static int am33xx_pm_begin(suspend_state_t state)
rtc_only_idle = 0;
}

+ pm_ops->begin_suspend();
+
switch (state) {
case PM_SUSPEND_MEM:
ret = m3_ipc->ops->prepare_low_power(m3_ipc, WKUP_M3_DEEPSLEEP);
@@ -301,6 +316,8 @@ static void am33xx_pm_end(void)
}

rtc_only_idle = 0;
+
+ pm_ops->finish_suspend();
}

static int am33xx_pm_valid(suspend_state_t state)
@@ -503,7 +520,7 @@ static int am33xx_pm_probe(struct platform_device *pdev)
suspend_wfi_flags |= WFI_FLAG_WAKE_M3;
#endif /* CONFIG_SUSPEND */

- ret = pm_ops->init(NULL);
+ ret = pm_ops->init(am33xx_do_sram_idle);
if (ret) {
dev_err(dev, "Unable to call core pm init!\n");
ret = -ENODEV;
@@ -522,6 +539,8 @@ static int am33xx_pm_probe(struct platform_device *pdev)

static int am33xx_pm_remove(struct platform_device *pdev)
{
+ if (pm_ops->deinit)
+ pm_ops->deinit();
suspend_set_ops(NULL);
wkup_m3_ipc_put(m3_ipc);
am33xx_pm_free_sram();
--
2.20.1