From: Wolfram Sang <wsa+renesas@sang-engineering.com>
To: linux-i2c@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, linux-renesas-soc@vger.kernel.org,
linux-iio@vger.kernel.org, linux-input@vger.kernel.org,
linux-media@vger.kernel.org, Mark Brown <broonie@kernel.org>,
Wolfram Sang <wsa+renesas@sang-engineering.com>
Subject: [PATCH v6 5/9] i2c: add i2c_master_{send|recv}_dmasafe
Date: Sat, 4 Nov 2017 21:20:05 +0100 [thread overview]
Message-ID: <20171104202009.3818-6-wsa+renesas@sang-engineering.com> (raw)
In-Reply-To: <20171104202009.3818-1-wsa+renesas@sang-engineering.com>
Use the new helper to create variants of i2c_master_{send|recv} which
mark their buffers as DMA safe.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---
include/linux/i2c.h | 31 +++++++++++++++++++++++++++++++
1 file changed, 31 insertions(+)
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index ef1a8791c1ae24..8c144e3cbfb261 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -81,6 +81,22 @@ static inline int i2c_master_recv(const struct i2c_client *client,
};
/**
+ * i2c_master_recv_dmasafe - issue a single I2C message in master receive mode
+ * using a DMA safe buffer
+ * @client: Handle to slave device
+ * @buf: Where to store data read from slave, must be safe to use with DMA
+ * @count: How many bytes to read, must be less than 64k since msg.len is u16
+ *
+ * Returns negative errno, or else the number of bytes read.
+ */
+static inline int i2c_master_recv_dmasafe(const struct i2c_client *client,
+ char *buf, int count)
+{
+ return i2c_transfer_buffer_flags(client, buf, count,
+ I2C_M_RD | I2C_M_DMA_SAFE);
+};
+
+/**
* i2c_master_send - issue a single I2C message in master transmit mode
* @client: Handle to slave device
* @buf: Data that will be written to the slave
@@ -93,6 +109,21 @@ static inline int i2c_master_send(const struct i2c_client *client,
{
return i2c_transfer_buffer_flags(client, (char *)buf, count, 0);
};
+/**
+ * i2c_master_send_dmasafe - issue a single I2C message in master transmit mode
+ * using a DMA safe buffer
+ * @client: Handle to slave device
+ * @buf: Data that will be written to the slave, must be safe to use with DMA
+ * @count: How many bytes to write, must be less than 64k since msg.len is u16
+ *
+ * Returns negative errno, or else the number of bytes written.
+ */
+static inline int i2c_master_send_dmasafe(const struct i2c_client *client,
+ const char *buf, int count)
+{
+ return i2c_transfer_buffer_flags(client, (char *)buf, count,
+ I2C_M_DMA_SAFE);
+};
/* Transfer num messages.
*/
--
2.11.0
next prev parent reply other threads:[~2017-11-04 20:23 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-04 20:20 [PATCH v6 0/9] i2c: document DMA handling and add helpers for it Wolfram Sang
2017-11-04 20:20 ` [PATCH v6 1/9] i2c: add a message flag for DMA safe buffers Wolfram Sang
2017-11-04 20:20 ` [PATCH v6 2/9] i2c: add helpers to ease DMA handling Wolfram Sang
2017-11-04 20:20 ` [PATCH v6 3/9] i2c: dev: mark RDWR buffers as DMA_SAFE Wolfram Sang
2017-11-04 20:20 ` [PATCH v6 4/9] i2c: refactor i2c_master_{send_recv} Wolfram Sang
2017-11-11 0:03 ` Jonathan Cameron
2017-11-04 20:20 ` Wolfram Sang [this message]
2017-11-11 0:08 ` [PATCH v6 5/9] i2c: add i2c_master_{send|recv}_dmasafe Jonathan Cameron
2017-11-04 20:20 ` [PATCH v6 6/9] i2c: smbus: use DMA safe buffers for emulated SMBus transactions Wolfram Sang
2017-11-11 0:13 ` Jonathan Cameron
2017-11-04 20:20 ` [PATCH v6 7/9] i2c: add docs to clarify DMA handling Wolfram Sang
2017-11-04 20:20 ` [PATCH v6 8/9] i2c: sh_mobile: use core helper to decide when to use DMA Wolfram Sang
2017-11-04 20:20 ` [PATCH v6 9/9] i2c: rcar: skip DMA if buffer is not safe Wolfram Sang
2017-11-08 22:50 ` [PATCH v6 0/9] i2c: document DMA handling and add helpers for it Mark Brown
2017-11-27 18:51 ` Wolfram Sang
2017-11-28 15:34 ` Mark Brown
2017-12-03 19:43 ` Wolfram Sang
2017-12-04 22:05 ` Mark Brown
2017-12-05 11:00 ` Jonathan Cameron
2017-12-04 21:25 ` Wolfram Sang
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