From: Hugo Villeneuve <hugo@hugovil.com>
To: gregkh@linuxfoundation.org, robh+dt@kernel.org,
krzysztof.kozlowski+dt@linaro.org, conor+dt@kernel.org,
jirislaby@kernel.org, jringle@gridpoint.com,
tomasz.mon@camlingroup.com, l.perczak@camlintechnologies.com
Cc: linux-serial@vger.kernel.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org, hugo@hugovil.com,
linux-gpio@vger.kernel.org,
Hugo Villeneuve <hvilleneuve@dimonoff.com>,
Lech Perczak <lech.perczak@camlingroup.com>
Subject: [PATCH v6 8/9] serial: sc16is7xx: add post reset delay
Date: Thu, 1 Jun 2023 16:18:43 -0400 [thread overview]
Message-ID: <20230601201844.3739926-9-hugo@hugovil.com> (raw)
In-Reply-To: <20230601201844.3739926-1-hugo@hugovil.com>
From: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Make sure we wait at least 3us before initiating communication with
the device after reset.
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Reviewed-by: Lech Perczak <lech.perczak@camlingroup.com>
Tested-by: Lech Perczak <lech.perczak@camlingroup.com>
---
drivers/tty/serial/sc16is7xx.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
index 388c1d490853..9b2d58023c55 100644
--- a/drivers/tty/serial/sc16is7xx.c
+++ b/drivers/tty/serial/sc16is7xx.c
@@ -1521,6 +1521,12 @@ static int sc16is7xx_probe(struct device *dev,
regmap_write(s->regmap, SC16IS7XX_IOCONTROL_REG << SC16IS7XX_REG_SHIFT,
SC16IS7XX_IOCONTROL_SRESET_BIT);
+ /*
+ * After reset, the host must wait at least 3us before initializing a
+ * communication with the device.
+ */
+ usleep_range(5, 10);
+
for (i = 0; i < devtype->nr_uart; ++i) {
s->p[i].line = i;
/* Initialize port data */
--
2.30.2
next prev parent reply other threads:[~2023-06-01 20:19 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-01 20:18 [PATCH v6 0/9] serial: sc16is7xx: fix GPIO regression and rs485 improvements Hugo Villeneuve
2023-06-01 20:18 ` [PATCH v6 1/9] serial: sc16is7xx: fix broken port 0 uart init Hugo Villeneuve
2023-06-01 20:18 ` [PATCH v6 2/9] serial: sc16is7xx: mark IOCONTROL register as volatile Hugo Villeneuve
2023-06-01 20:18 ` [PATCH v6 3/9] serial: sc16is7xx: refactor GPIO controller registration Hugo Villeneuve
2023-06-01 20:18 ` [PATCH v6 4/9] dt-bindings: sc16is7xx: Add property to change GPIO function Hugo Villeneuve
2023-06-01 20:18 ` [PATCH v6 5/9] serial: sc16is7xx: fix regression with GPIO configuration Hugo Villeneuve
2023-06-01 21:30 ` andy.shevchenko
2023-06-02 0:41 ` Hugo Villeneuve
2023-06-02 1:25 ` Hugo Villeneuve
2023-06-02 12:58 ` Andy Shevchenko
2023-06-02 13:06 ` Hugo Villeneuve
2023-06-01 20:18 ` [PATCH v6 6/9] serial: sc16is7xx: fix bug when first setting GPIO direction Hugo Villeneuve
2023-06-01 20:18 ` [PATCH v6 7/9] serial: sc16is7xx: add call to get rs485 DT flags and properties Hugo Villeneuve
2023-06-01 20:18 ` Hugo Villeneuve [this message]
2023-06-01 20:18 ` [PATCH v6 9/9] serial: sc16is7xx: improve comments about variants Hugo Villeneuve
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