[PATCH 5.4 183/314] mfd: stmfx: Reset chip on resume as supply was disabled

[Greg Kroah-Hartman]

From: Amelie Delaunay <amelie.delau...@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.delau...@st.com>
Signed-off-by: Lee Jones <lee.jo...@linaro.org>
Signed-off-by: Sasha Levin <sas...@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 857991cb3cbb8..fde6541e347c8 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