Re: [PATCH] ARM: dts: Add am335x mcasp with l3 data port ranges

[Tony Lindgren <tony@atomide.com>]

* Tony Lindgren <tony@atomide.com> [181210 14:49]:
> * Peter Ujfalusi <peter.ujfalusi@ti.com> [181210 09:52]:
> > On 10/12/2018 9.05, Peter Ujfalusi wrote:
> > > Works fine on bbb + audio cape.
> > > For some reason my am335x-evm-sk is not booting up at all w/ linux-next,
> > > but I believe it is not related to this (disabled audio and still not
> > > booting).
> > 
> > bisect on next-20181207 (am335x-evm-sk) points to:
> > Author: Tony Lindgren <tony@atomide.com>
> > 87fc89ced3a78f7f0845afab1934d509ef4ad0f2
> > ARM: dts: am335x: Move l4 child devices to probe them with ti-sysc
> > 
> > when looking for the non booting of am335x-evm-sk (nothing printed on
> > serial after stating kernel).
> 
> OK I'm pretty sure this is because we now need to move the gpio1
> ti,no-reset-on-init up to the module level because of the DDR being
> GPIO controlled. I'll send a patch out shortly for that.
> 
> It might be also worth adding a check for having ti,no-reset-on-init
> at the child level to ti-sysc driver too.

Looks like we have quite a few boards variants with probably
DDR powered by a gpio1 pin. So let's fix the ti-sysc driver first,
care to try the following patch?

Regards,

Tony

8< ---------------------------
>From tony Mon Sep 17 00:00:00 2001
From: Tony Lindgren <tony@atomide.com>
Date: Mon, 10 Dec 2018 07:26:04 -0800
Subject: [PATCH] bus: ti-sysc: Check for no-reset and no-idle flags at the
 child level

With ti-sysc, we need to now have the device tree properties for
ti,no-reset-on-idle and ti,no-idle-on-init at the module level instead
of the child device level.

Let's check for these properties at the child device level to enable
quirks, and warn about moving the properties to the module level.

Otherwise am335x-evm based boards tagging gpio1 with ti,no-reset-on-init
will have their DDR power disabled if wired up in such a tricky way.

Note that this should not be an issue for earlier kernels as we don't
rely on this until the dts files have been updated to probe with ti-sysc
interconnect target driver.

Cc: Peter Ujfalusi <peter.ujfalusi@ti.com>
Reported-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
---
 drivers/bus/ti-sysc.c | 32 +++++++++++++++++++++++++-------
 1 file changed, 25 insertions(+), 7 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
@@ -91,6 +91,9 @@ struct sysc {
 	struct delayed_work idle_work;
 };
 
+static void sysc_parse_dts_quirks(struct sysc *ddata, struct device_node *np,
+				  bool is_child);
+
 void sysc_write(struct sysc *ddata, int offset, u32 value)
 {
 	writel_relaxed(value, ddata->module_va + offset);
@@ -379,6 +382,7 @@ static int sysc_check_one_child(struct sysc *ddata,
 		dev_warn(ddata->dev, "really a child ti,hwmods property?");
 
 	sysc_check_quirk_stdout(ddata, np);
+	sysc_parse_dts_quirks(ddata, np, true);
 
 	return 0;
 }
@@ -1279,23 +1283,37 @@ static const struct sysc_dts_quirk sysc_dts_quirks[] = {
 	  .mask = SYSC_QUIRK_NO_RESET_ON_INIT, },
 };
 
-static int sysc_init_dts_quirks(struct sysc *ddata)
+static void sysc_parse_dts_quirks(struct sysc *ddata, struct device_node *np,
+				  bool is_child)
 {
-	struct device_node *np = ddata->dev->of_node;
 	const struct property *prop;
-	int i, len, error;
-	u32 val;
-
-	ddata->legacy_mode = of_get_property(np, "ti,hwmods", NULL);
+	int i, len;
 
 	for (i = 0; i < ARRAY_SIZE(sysc_dts_quirks); i++) {
-		prop = of_get_property(np, sysc_dts_quirks[i].name, &len);
+		const char *name = sysc_dts_quirks[i].name;
+
+		prop = of_get_property(np, name, &len);
 		if (!prop)
 			continue;
 
 		ddata->cfg.quirks |= sysc_dts_quirks[i].mask;
+		if (is_child) {
+			dev_warn(ddata->dev,
+				 "dts flag should be at module level for %s\n",
+				 name);
+		}
 	}
+}
+
+static int sysc_init_dts_quirks(struct sysc *ddata)
+{
+	struct device_node *np = ddata->dev->of_node;
+	int error;
+	u32 val;
+
+	ddata->legacy_mode = of_get_property(np, "ti,hwmods", NULL);
 
+	sysc_parse_dts_quirks(ddata, np, false);
 	error = of_property_read_u32(np, "ti,sysc-delay-us", &val);
 	if (!error) {
 		if (val > 255) {
-- 
2.19.2