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From: Tudor Ambarus <tudor.ambarus@microchip.com>
To: wsa@the-dreams.de, ludovic.desroches@microchip.com,
	nicolas.ferre@microchip.com, alexandre.belloni@bootlin.com,
	linux-i2c@vger.kernel.org, linux-arm-kernel@lists.infradead.org
Cc: Tudor Ambarus <tudor.ambarus@microchip.com>
Subject: [RFC PATCH 1/2] i2c: add bus_freq_hz in i2c_adapter
Date: Mon, 26 Mar 2018 14:19:26 +0300	[thread overview]
Message-ID: <20180326111927.16040-1-tudor.ambarus@microchip.com> (raw)

The clock-frequency property is not mandatory for the i2c buses. If it's
not present in device tree, the buses usually asume that it is 100kHZ.
There are i2c clients that need to know the i2c bus frequency in order to
compute their wake token. Spare the clients of making (wrong) assumptions
and save the bus frequency in the i2c_adapter structure.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
---
 include/linux/i2c.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index 44ad14e..7a1f26e 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -671,6 +671,7 @@ struct i2c_adapter {
 	struct rt_mutex bus_lock;
 	struct rt_mutex mux_lock;
 
+	u32 bus_freq_hz;
 	int timeout;			/* in jiffies */
 	int retries;
 	struct device dev;		/* the adapter device */
-- 
2.9.4

             reply	other threads:[~2018-03-26 11:19 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-03-26 11:19 Tudor Ambarus [this message]
2018-03-26 11:19 ` [RFC PATCH 2/2] i2c: at91: provide bus_freq_hz Tudor Ambarus
2018-04-04 15:34   ` Ludovic Desroches
2018-04-18  7:59 ` [RFC PATCH 1/2] i2c: add bus_freq_hz in i2c_adapter Tudor Ambarus

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