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From: Hugo Villeneuve <hugo@hugovil.com>
To: gregkh@linuxfoundation.org, jirislaby@kernel.org, kubakici@wp.pl,
	indrakanti_ram@hotmail.com, phil@raspberrypi.org
Cc: linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org,
	hugo@hugovil.com, Hugo Villeneuve <hvilleneuve@dimonoff.com>,
	stable@vger.kernel.org
Subject: [PATCH v2 03/16] serial: sc16is7xx: set safe default SPI clock frequency
Date: Thu, 21 Dec 2023 18:18:10 -0500	[thread overview]
Message-ID: <20231221231823.2327894-4-hugo@hugovil.com> (raw)
In-Reply-To: <20231221231823.2327894-1-hugo@hugovil.com>

From: Hugo Villeneuve <hvilleneuve@dimonoff.com>

15 MHz is supported only by 76x variants.

If the SPI clock frequency is not specified, use a safe default clock value
of 4 MHz that is supported by all variants.

Also use HZ_PER_MHZ macro to improve readability.

Fixes: 2c837a8a8f9f ("sc16is7xx: spi interface is added")
Cc: stable@vger.kernel.org
Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
---
 drivers/tty/serial/sc16is7xx.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
index 798fa115b28a..ced2446909a2 100644
--- a/drivers/tty/serial/sc16is7xx.c
+++ b/drivers/tty/serial/sc16is7xx.c
@@ -24,6 +24,7 @@
 #include <linux/tty_flip.h>
 #include <linux/spi/spi.h>
 #include <linux/uaccess.h>
+#include <linux/units.h>
 #include <uapi/linux/sched/types.h>
 
 #define SC16IS7XX_NAME			"sc16is7xx"
@@ -1738,7 +1739,7 @@ static int sc16is7xx_spi_probe(struct spi_device *spi)
 		return dev_err_probe(&spi->dev, -EINVAL, "Unsupported SPI mode\n");
 
 	spi->mode		= spi->mode ? : SPI_MODE_0;
-	spi->max_speed_hz	= spi->max_speed_hz ? : 15000000;
+	spi->max_speed_hz	= spi->max_speed_hz ? : 4 * HZ_PER_MHZ;
 	ret = spi_setup(spi);
 	if (ret)
 		return ret;
-- 
2.39.2


  parent reply	other threads:[~2023-12-21 23:18 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-12-21 23:18 [PATCH v2 00/16] serial: sc16is7xx: fixes, cleanups and improvements Hugo Villeneuve
2023-12-21 23:18 ` [PATCH v2 01/16] serial: sc16is7xx: fix invalid sc16is7xx_lines bitfield in case of probe error Hugo Villeneuve
2023-12-21 23:18 ` [PATCH v2 02/16] serial: sc16is7xx: add check for unsupported SPI modes during probe Hugo Villeneuve
2023-12-21 23:18 ` Hugo Villeneuve [this message]
2023-12-21 23:18 ` [PATCH v2 04/16] serial: sc16is7xx: remove obsolete loop in sc16is7xx_port_irq() Hugo Villeneuve
2023-12-21 23:18 ` [PATCH v2 05/16] serial: sc16is7xx: improve do/while loop in sc16is7xx_irq() Hugo Villeneuve
2023-12-21 23:18 ` [PATCH v2 06/16] serial: sc16is7xx: use DECLARE_BITMAP for sc16is7xx_lines bitfield Hugo Villeneuve
2023-12-21 23:18 ` [PATCH v2 07/16] serial: sc16is7xx: use spi_get_device_match_data() Hugo Villeneuve
2023-12-21 23:18 ` [PATCH v2 08/16] serial: sc16is7xx: use i2c_get_match_data() Hugo Villeneuve
2023-12-21 23:18 ` [PATCH v2 09/16] serial: sc16is7xx: add driver name to struct uart_driver Hugo Villeneuve
2023-12-21 23:18 ` [PATCH v2 10/16] serial: sc16is7xx: add macro for max number of UART ports Hugo Villeneuve
2023-12-21 23:18 ` [PATCH v2 11/16] serial: sc16is7xx: add explicit return for some switch default cases Hugo Villeneuve
2023-12-21 23:18 ` [PATCH v2 12/16] serial: sc16is7xx: replace hardcoded divisor value with BIT() macro Hugo Villeneuve
2023-12-21 23:18 ` [PATCH v2 13/16] serial: sc16is7xx: drop unneeded MODULE_ALIAS Hugo Villeneuve
2023-12-21 23:18 ` [PATCH v2 14/16] serial: sc16is7xx: refactor FIFO access functions to increase commonality Hugo Villeneuve
2023-12-21 23:18 ` [PATCH v2 15/16] serial: sc16is7xx: reorder code to remove prototype declarations Hugo Villeneuve
2023-12-21 23:18 ` [PATCH v2 16/16] serial: sc16is7xx: refactor EFR lock Hugo Villeneuve

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