* Tony Lindgren <tony@xxxxxxxxxxx> [190325 22:00]:
> We should not do the reset until the clocks are enabled. Let's only init
> restctrl in sysc_init_resets() and do the reset later on in sysc_reset().
...
> static int sysc_reset(struct sysc *ddata)
> {
> int offset = ddata->offsets[SYSC_SYSCONFIG];
> - int val;
> + int error, val;
>
> if (ddata->legacy_mode || offset < 0 ||
> ddata->cfg.quirks & SYSC_QUIRK_NO_RESET_ON_INIT)
> - return 0;
> + return sysc_rstctrl_reset_deassert(ddata, false);
> +
> + error = sysc_rstctrl_reset_deassert(ddata, true);
> + if (error)
> + return error;
This change is wrong, we need to deassert rstctrl reset before
we enable clocks, not after. Updated version below.
Regards,
Tony
8< --------------------
>From tony Mon Sep 17 00:00:00 2001
From: Tony Lindgren <tony@xxxxxxxxxxx>
Date: Thu, 21 Mar 2019 11:00:21 -0700
Subject: [PATCH] bus: ti-sysc: Move rstctrl reset to happen later
We can do the rsstctrl a bit later, but need to deassert rstctrl reset
before the clocks are enabled if asserted. Let's only init restctrl
in sysc_init_resets() and do the reset later on just before we enable
the device clocks.
Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>
---
drivers/bus/ti-sysc.c | 61 +++++++++++++++++++++++++++----------------
1 file changed, 39 insertions(+), 22 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
@@ -339,38 +339,18 @@ static void sysc_disable_opt_clocks(struct sysc *ddata)
}
/**
- * sysc_init_resets - reset module on init
+ * sysc_init_resets - init rstctrl reset line if configured
* @ddata: device driver data
*
- * A module can have both OCP softreset control and external rstctrl.
- * If more complicated rstctrl resets are needed, please handle these
- * directly from the child device driver and map only the module reset
- * for the parent interconnect target module device.
- *
- * Automatic reset of the module on init can be skipped with the
- * "ti,no-reset-on-init" device tree property.
+ * See sysc_rstctrl_reset_deassert().
*/
static int sysc_init_resets(struct sysc *ddata)
{
- int error;
-
ddata->rsts =
devm_reset_control_array_get_optional_exclusive(ddata->dev);
if (IS_ERR(ddata->rsts))
return PTR_ERR(ddata->rsts);
- if (ddata->cfg.quirks & SYSC_QUIRK_NO_RESET_ON_INIT)
- goto deassert;
-
- error = reset_control_assert(ddata->rsts);
- if (error)
- return error;
-
-deassert:
- error = reset_control_deassert(ddata->rsts);
- if (error)
- return error;
-
return 0;
}
@@ -1031,6 +1011,35 @@ static int sysc_legacy_init(struct sysc *ddata)
return error;
}
+/**
+ * sysc_rstctrl_reset_deassert - deassert rstctrl reset
+ * @ddata: device driver data
+ * @reset: reset before deassert
+ *
+ * A module can have both OCP softreset control and external rstctrl.
+ * If more complicated rstctrl resets are needed, please handle these
+ * directly from the child device driver and map only the module reset
+ * for the parent interconnect target module device.
+ *
+ * Automatic reset of the module on init can be skipped with the
+ * "ti,no-reset-on-init" device tree property.
+ */
+static int sysc_rstctrl_reset_deassert(struct sysc *ddata, bool reset)
+{
+ int error;
+
+ if (!ddata->rsts)
+ return 0;
+
+ if (reset) {
+ error = reset_control_assert(ddata->rsts);
+ if (error)
+ return error;
+ }
+
+ return reset_control_deassert(ddata->rsts);
+}
+
static int sysc_reset(struct sysc *ddata)
{
int offset = ddata->offsets[SYSC_SYSCONFIG];
@@ -1071,6 +1080,14 @@ static int sysc_init_module(struct sysc *ddata)
{
int error = 0;
bool manage_clocks = true;
+ bool reset = true;
+
+ if (ddata->cfg.quirks & SYSC_QUIRK_NO_RESET_ON_INIT)
+ reset = false;
+
+ error = sysc_rstctrl_reset_deassert(ddata, reset);
+ if (error)
+ return error;
if (ddata->cfg.quirks &
(SYSC_QUIRK_NO_IDLE | SYSC_QUIRK_NO_IDLE_ON_INIT))
--
2.21.0
