[PATCH 08/12] bus: ti-sysc: Add support for disabling module without legacy mode

From: Tony Lindgren
Date: Mon May 27 2019 - 08:17:42 EST


We must not assert reset for modules with no child device drivers
until in runtime_suspend. Otherwise register access will fail without
legacy mode helping us.

Let's add a flag for disable_on_idle and move the reset driver
handling to runtime suspend and resume. We can then also use the
disable_on_idle flag to reconfigure sysconfig register for PM
modes requesting it.

Let's also make the other flags use bitfield while at it instead of
bool.

Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>
---
drivers/bus/ti-sysc.c | 21 +++++++++++++++++----
1 file changed, 17 insertions(+), 4 deletions(-)

diff --git a/drivers/bus/ti-sysc.c b/drivers/bus/ti-sysc.c
--- a/drivers/bus/ti-sysc.c
+++ b/drivers/bus/ti-sysc.c
@@ -89,9 +89,10 @@ struct sysc {
struct ti_sysc_cookie cookie;
const char *name;
u32 revision;
- bool enabled;
- bool needs_resume;
- bool child_needs_resume;
+ unsigned int enabled:1;
+ unsigned int needs_resume:1;
+ unsigned int child_needs_resume:1;
+ unsigned int disable_on_idle:1;
struct delayed_work idle_work;
};

@@ -1007,6 +1008,9 @@ static int __maybe_unused sysc_runtime_suspend_legacy(struct device *dev,
dev_err(dev, "%s: could not idle: %i\n",
__func__, error);

+ if (ddata->disable_on_idle)
+ reset_control_assert(ddata->rsts);
+
return 0;
}

@@ -1016,6 +1020,9 @@ static int __maybe_unused sysc_runtime_resume_legacy(struct device *dev,
struct ti_sysc_platform_data *pdata;
int error;

+ if (ddata->disable_on_idle)
+ reset_control_deassert(ddata->rsts);
+
pdata = dev_get_platdata(ddata->dev);
if (!pdata)
return 0;
@@ -1063,6 +1070,9 @@ static int __maybe_unused sysc_runtime_suspend(struct device *dev)
err_allow_idle:
sysc_clkdm_allow_idle(ddata);

+ if (ddata->disable_on_idle)
+ reset_control_assert(ddata->rsts);
+
return error;
}

@@ -1076,6 +1086,9 @@ static int __maybe_unused sysc_runtime_resume(struct device *dev)
if (ddata->enabled)
return 0;

+ if (ddata->disable_on_idle)
+ reset_control_deassert(ddata->rsts);
+
sysc_clkdm_deny_idle(ddata);

if (sysc_opt_clks_needed(ddata)) {
@@ -2293,7 +2306,7 @@ static int sysc_probe(struct platform_device *pdev)
}

if (!of_get_available_child_count(ddata->dev->of_node))
- reset_control_assert(ddata->rsts);
+ ddata->disable_on_idle = true;

return 0;

--
2.21.0