From: Wolfram Sang <wsa@the-dreams.de>
To: linux-i2c@vger.kernel.org
Cc: linux-renesas-soc@vger.kernel.org,
Phil Reid <preid@electromag.com.au>,
Wolfram Sang <wsa+renesas@sang-engineering.com>
Subject: [PATCH v2 5/6] i2c: send STOP after successful bus recovery
Date: Tue, 9 Jan 2018 14:58:58 +0100 [thread overview]
Message-ID: <20180109135859.20771-6-wsa@the-dreams.de> (raw)
In-Reply-To: <20180109135859.20771-1-wsa@the-dreams.de>
From: Wolfram Sang <wsa+renesas@sang-engineering.com>
If we managed to get a client release SDA again, send a STOP afterwards
to make sure we have a consistent state on the bus again.
Tested-by: Phil Reid <preid@electromag.com.au>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---
drivers/i2c/i2c-core-base.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index 54cef80990a11a..23f353630db32f 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -199,6 +199,18 @@ int i2c_generic_scl_recovery(struct i2c_adapter *adap)
if (bri->get_sda && !bri->get_sda(adap))
ret = -EBUSY;
+ /* If all went well, send STOP for a sane bus state. */
+ if (ret == 0 && bri->set_sda) {
+ bri->set_scl(adap, 0);
+ ndelay(RECOVERY_NDELAY / 2);
+ bri->set_sda(adap, 0);
+ ndelay(RECOVERY_NDELAY / 2);
+ bri->set_scl(adap, 1);
+ ndelay(RECOVERY_NDELAY / 2);
+ bri->set_sda(adap, 1);
+ ndelay(RECOVERY_NDELAY / 2);
+ }
+
if (bri->unprepare_recovery)
bri->unprepare_recovery(adap);
--
2.11.0
next prev parent reply other threads:[~2018-01-09 13:58 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-09 13:58 [PATCH v2 0/6] i2c: send STOP after recovery; use it for i2c-rcar Wolfram Sang
2018-01-09 13:58 ` [PATCH v2 1/6] i2c: make kerneldoc about bus recovery more precise Wolfram Sang
2018-01-09 13:58 ` [PATCH v2 2/6] i2c: add identifier in declarations for i2c_bus_recovery Wolfram Sang
2018-01-09 13:58 ` [PATCH v2 3/6] i2c: add 'set_sda' to bus_recovery_info Wolfram Sang
2018-01-10 13:43 ` Linus Walleij
2018-01-09 13:58 ` [PATCH v2 4/6] i2c: ensure SDA is released in recovery if SDA is controllable Wolfram Sang
2018-01-09 13:58 ` Wolfram Sang [this message]
2018-01-09 13:58 ` [PATCH v2 6/6] i2c: rcar: implement bus recovery Wolfram Sang
2018-01-15 23:08 ` [PATCH v2 0/6] i2c: send STOP after recovery; use it for i2c-rcar Wolfram Sang
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