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From: Tero Kristo <t-kristo@ti.com>
To: <ssantosh@kernel.org>, <linux-arm-kernel@lists.infradead.org>,
	<linux-omap@vger.kernel.org>, <robh+dt@kernel.org>
Cc: tony@atomide.com, devicetree@vger.kernel.org
Subject: [PATCH 3/8] soc: ti: omap-prm: poll for reset complete during de-assert
Date: Wed, 7 Aug 2019 10:48:54 +0300	[thread overview]
Message-ID: <1565164139-21886-4-git-send-email-t-kristo@ti.com> (raw)
In-Reply-To: <1565164139-21886-1-git-send-email-t-kristo@ti.com>

Poll for reset completion status during de-assertion of reset, otherwise
the IP in question might be accessed before it has left reset properly.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
---
 drivers/soc/ti/omap_prm.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/drivers/soc/ti/omap_prm.c b/drivers/soc/ti/omap_prm.c
index 7c89eb8..d412af3 100644
--- a/drivers/soc/ti/omap_prm.c
+++ b/drivers/soc/ti/omap_prm.c
@@ -107,6 +107,7 @@ static int omap_reset_deassert(struct reset_controller_dev *rcdev,
 	u32 v;
 	int st_bit = id;
 	bool has_rstst;
+	int timeout = 0;
 
 	/* check the current status to avoid de-asserting the line twice */
 	v = readl_relaxed(reset->prm->base + reset->prm->data->rstctl);
@@ -129,6 +130,22 @@ static int omap_reset_deassert(struct reset_controller_dev *rcdev,
 	v &= ~(1 << id);
 	writel_relaxed(v, reset->prm->base + reset->prm->data->rstctl);
 
+	if (!has_rstst)
+		return 0;
+
+	/* wait for the status to be set */
+	while (1) {
+		v = readl_relaxed(reset->prm->base + reset->prm->data->rstst);
+		v &= 1 << st_bit;
+		if (v)
+			break;
+		timeout++;
+		if (timeout > OMAP_RESET_MAX_WAIT)
+			return -EBUSY;
+
+		udelay(1);
+	}
+
 	return 0;
 }
 
-- 
1.9.1

--
Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki

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  parent reply	other threads:[~2019-08-07  7:50 UTC|newest]

Thread overview: 41+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-07  7:48 [PATCH 0/8] soc: ti: Add OMAP PRM driver Tero Kristo
2019-08-07  7:48 ` [PATCH 1/8] dt-bindings: omap: add new binding for PRM instances Tero Kristo
2019-08-08  4:35   ` Keerthy
2019-08-19  9:28     ` Tero Kristo
2019-08-19 21:28       ` Suman Anna
2019-08-20  7:45         ` Tero Kristo
2019-08-07  7:48 ` [PATCH 2/8] soc: ti: add initial PRM driver with reset control support Tero Kristo
2019-08-08  5:26   ` Keerthy
2019-08-19  9:32     ` Tero Kristo
2019-08-19 23:01       ` Suman Anna
2019-08-20  7:37         ` Tero Kristo
2019-08-20 16:47           ` Suman Anna
2019-08-21 15:10             ` Philipp Zabel
2019-08-21 15:45               ` Suman Anna
2019-08-21 18:15                 ` Tero Kristo
2019-08-23  8:50                   ` Philipp Zabel
2019-08-23 11:27                     ` Tero Kristo
2019-08-07  7:48 ` Tero Kristo [this message]
2019-08-07  7:48 ` [PATCH 4/8] soc: ti: omap-prm: add support for denying idle for reset clockdomain Tero Kristo
2019-08-19 23:16   ` Suman Anna
2019-08-20  7:51     ` Tero Kristo
2019-08-07  7:48 ` [PATCH 5/8] soc: ti: omap-prm: add omap4 PRM data Tero Kristo
2019-08-08  5:30   ` Keerthy
2019-08-19  9:32     ` Tero Kristo
2019-08-19 23:08   ` Suman Anna
2019-08-20  7:52     ` Tero Kristo
2019-08-20 17:23       ` Suman Anna
2019-08-21  6:38         ` Tero Kristo
2019-08-07  7:48 ` [PATCH 6/8] soc: ti: omap_prm: add data for am33xx Tero Kristo
2019-08-19 23:11   ` Suman Anna
2019-08-20 18:48   ` Suman Anna
2019-08-21  7:23     ` Tero Kristo
2019-08-21 15:49       ` Suman Anna
2019-08-07  7:48 ` [PATCH 7/8] soc: ti: omap-prm: add dra7 PRM data Tero Kristo
2019-08-19 23:12   ` Suman Anna
2019-08-20 19:03   ` Suman Anna
2019-08-21  7:36     ` Tero Kristo
2019-08-07  7:48 ` [PATCH 8/8] ARM: OMAP2+: pdata-quirks: add PRM data for reset support Tero Kristo
2019-08-19 23:20 ` [PATCH 0/8] soc: ti: Add OMAP PRM driver Suman Anna
2019-08-20  7:54   ` Tero Kristo
2019-08-20 16:51     ` Suman Anna

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