linux-kernel - [PATCH] remoteproc: stm32: clear MCU PDDS at firmware start

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Date:   Mon, 26 Aug 2019 17:38:06 +0200
From:   Fabien Dessenne <fabien.dessenne@...com>
To:     Maxime Coquelin <mcoquelin.stm32@...il.com>,
        Alexandre Torgue <alexandre.torgue@...com>,
        Ohad Ben-Cohen <ohad@...ery.com>,
        Bjorn Andersson <bjorn.andersson@...aro.org>,
        <linux-stm32@...md-mailman.stormreply.com>,
        <linux-arm-kernel@...ts.infradead.org>,
        <linux-kernel@...r.kernel.org>, <linux-remoteproc@...r.kernel.org>
CC:     Fabien Dessenne <fabien.dessenne@...com>,
        Loic Pallardy <loic.pallardy@...com>,
        Arnaud Pouliquen <arnaud.pouliquen@...com>
Subject: [PATCH] remoteproc: stm32: clear MCU PDDS at firmware start

When remoteproc stops a firmware, it sets the MCU PDDS flag, allowing
the platform to reach the Standby power mode if needed.
Symmetrically, clear this flag before running a firmware.
This fixes the issue where the system goes to Standby mode when the
MCU crashes while MPU is in CSTOP mode.

Signed-off-by: Fabien Dessenne <fabien.dessenne@...com>
---
 drivers/remoteproc/stm32_rproc.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/remoteproc/stm32_rproc.c b/drivers/remoteproc/stm32_rproc.c
index e2da719..1c95913 100644
--- a/drivers/remoteproc/stm32_rproc.c
+++ b/drivers/remoteproc/stm32_rproc.c
@@ -383,10 +383,21 @@ static void stm32_rproc_add_coredump_trace(struct rproc *rproc)
 
 static int stm32_rproc_start(struct rproc *rproc)
 {
+	struct stm32_rproc *ddata = rproc->priv;
 	int err;
 
 	stm32_rproc_add_coredump_trace(rproc);
 
+	/* clear remote proc Deep Sleep */
+	if (ddata->pdds.map) {
+		err = regmap_update_bits(ddata->pdds.map, ddata->pdds.reg,
+					 ddata->pdds.mask, 0);
+		if (err) {
+			dev_err(&rproc->dev, "failed to clear pdds\n");
+			return err;
+		}
+	}
+
 	err = stm32_rproc_set_hold_boot(rproc, false);
 	if (err)
 		return err;
-- 
2.7.4