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From:   Sasha Levin <sashal@kernel.org>
To:     linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc:     Amelie Delaunay <amelie.delaunay@st.com>,
        Lee Jones <lee.jones@linaro.org>,
        Sasha Levin <sashal@kernel.org>,
        linux-stm32@st-md-mailman.stormreply.com,
        linux-arm-kernel@lists.infradead.org
Subject: [PATCH AUTOSEL 5.7 273/388] mfd: stmfx: Reset chip on resume as supply was disabled
Date:   Wed, 17 Jun 2020 21:06:10 -0400
Message-Id: <20200618010805.600873-273-sashal@kernel.org>
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From: Amelie Delaunay <amelie.delaunay@st.com>

[ Upstream commit e583649d87ec090444aa5347af0927cd6e8581ae ]

STMFX supply is disabled during suspend. To avoid a too early access to
the STMFX firmware on resume, reset the chip and wait for its firmware to
be loaded.

Fixes: 06252ade9156 ("mfd: Add ST Multi-Function eXpander (STMFX) core driver")
Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/mfd/stmfx.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/mfd/stmfx.c b/drivers/mfd/stmfx.c
index 857991cb3cbb..fde6541e347c 100644
--- a/drivers/mfd/stmfx.c
+++ b/drivers/mfd/stmfx.c
@@ -501,6 +501,13 @@ static int stmfx_resume(struct device *dev)
 		}
 	}
 
+	/* Reset STMFX - supply has been stopped during suspend */
+	ret = stmfx_chip_reset(stmfx);
+	if (ret) {
+		dev_err(stmfx->dev, "Failed to reset chip: %d\n", ret);
+		return ret;
+	}
+
 	ret = regmap_raw_write(stmfx->map, STMFX_REG_SYS_CTRL,
 			       &stmfx->bkp_sysctrl, sizeof(stmfx->bkp_sysctrl));
 	if (ret)
-- 
2.25.1