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From: Jan Glauber <jglauber@cavium.com>
To: Wolfram Sang <wsa@the-dreams.de>
Cc: linux-kernel@vger.kernel.org, linux-i2c@vger.kernel.org,
	David Daney <ddaney@caviumnetworks.com>,
	Peter Swain <pswain@cavium.com>,
	Jan Glauber <jglauber@cavium.com>
Subject: [PATCH v3 09/14] i2c-octeon: Flush TWSI writes with readback
Date: Mon,  7 Mar 2016 16:10:52 +0100	[thread overview]
Message-ID: <b12605dbe864ee6302d0c112d2fad11e0b206427.1457362545.git.jglauber@cavium.com> (raw)
In-Reply-To: <cover.1457362545.git.jglauber@cavium.com>
In-Reply-To: <cover.1457362545.git.jglauber@cavium.com>

From: Peter Swain <pswain@cavium.com>

Signed-off-by: Peter Swain <pswain@cavium.com>
Signed-off-by: Jan Glauber <jglauber@cavium.com>
Acked-by: David Daney <ddaney@caviumnetworks.com>
---
 drivers/i2c/busses/i2c-octeon.c | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/drivers/i2c/busses/i2c-octeon.c b/drivers/i2c/busses/i2c-octeon.c
index b76ccd5..a8a56a0 100644
--- a/drivers/i2c/busses/i2c-octeon.c
+++ b/drivers/i2c/busses/i2c-octeon.c
@@ -126,6 +126,12 @@ static int timeout = 2;
 module_param(timeout, int, 0444);
 MODULE_PARM_DESC(timeout, "Low-level device timeout (ms)");
 
+static void writeqflush(u64 val, void __iomem *addr)
+{
+	__raw_writeq(val, addr);
+	__raw_readq(addr);	/* wait for write to land */
+}
+
 /**
  * octeon_i2c_write_sw - write an I2C core register
  * @i2c: The struct octeon_i2c
@@ -186,8 +192,7 @@ static u8 octeon_i2c_read_sw(struct octeon_i2c *i2c, u64 eop_reg)
  */
 static void octeon_i2c_write_int(struct octeon_i2c *i2c, u64 data)
 {
-	__raw_writeq(data, i2c->twsi_base + TWSI_INT);
-	__raw_readq(i2c->twsi_base + TWSI_INT);
+	writeqflush(data, i2c->twsi_base + TWSI_INT);
 }
 
 /**
@@ -573,10 +578,10 @@ static int octeon_i2c_simple_write(struct octeon_i2c *i2c, struct i2c_msg *msgs)
 
 		for (i = 0; i < msgs[0].len - 4 && i < 4; i++, j--)
 			ext |= (u64) msgs[0].buf[j] << (8 * i);
-		__raw_writeq(ext, i2c->twsi_base + SW_TWSI_EXT);
+		writeqflush(ext, i2c->twsi_base + SW_TWSI_EXT);
 	}
 
-	__raw_writeq(cmd, i2c->twsi_base + SW_TWSI);
+	writeqflush(cmd, i2c->twsi_base + SW_TWSI);
 
 	ret = octeon_i2c_hlc_wait(i2c);
 	if (ret)
@@ -622,7 +627,7 @@ static int octeon_i2c_ia_read(struct octeon_i2c *i2c, struct i2c_msg *msgs)
 		cmd |= (u64) msgs[0].buf[0] << SW_TWSI_IA_SHIFT;
 
 	octeon_i2c_hlc_int_clear(i2c);
-	__raw_writeq(cmd, i2c->twsi_base + SW_TWSI);
+	writeqflush(cmd, i2c->twsi_base + SW_TWSI);
 
 	ret = octeon_i2c_hlc_wait(i2c);
 	if (ret)
@@ -682,10 +687,10 @@ static int octeon_i2c_ia_write(struct octeon_i2c *i2c, struct i2c_msg *msgs)
 		set_ext = true;
 	}
 	if (set_ext)
-		__raw_writeq(ext, i2c->twsi_base + SW_TWSI_EXT);
+		writeqflush(ext, i2c->twsi_base + SW_TWSI_EXT);
 
 	octeon_i2c_hlc_int_clear(i2c);
-	__raw_writeq(cmd, i2c->twsi_base + SW_TWSI);
+	writeqflush(cmd, i2c->twsi_base + SW_TWSI);
 
 	ret = octeon_i2c_hlc_wait(i2c);
 	if (ret)
-- 
1.9.1

  parent reply	other threads:[~2016-03-07 15:13 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-03-07 15:10 [PATCH v3 00/14] i2c-octeon and i2c-thunderx drivers Jan Glauber
2016-03-07 15:10 ` [PATCH v3 01/14] i2c-octeon: Cleanup kerneldoc comments Jan Glauber
2016-03-12 15:35   ` Wolfram Sang
2016-03-07 15:10 ` [PATCH v3 02/14] i2c-octeon: Cleanup i2c-octeon driver Jan Glauber
2016-03-12 15:35   ` Wolfram Sang
2016-03-14  8:52     ` Jan Glauber
2016-03-07 15:10 ` [PATCH v3 03/14] i2c-octeon: Cleanup resource allocation code Jan Glauber
2016-03-12 15:37   ` Wolfram Sang
2016-03-14  9:21     ` Jan Glauber
2016-03-07 15:10 ` [PATCH v3 04/14] i2c-octeon: Support I2C_M_RECV_LEN Jan Glauber
2016-03-12 15:44   ` Wolfram Sang
2016-03-07 15:10 ` [PATCH v3 05/14] i2c-octeon: Make adapter timeout tunable Jan Glauber
2016-03-12 15:46   ` Wolfram Sang
2016-03-14 12:45     ` Jan Glauber
2016-03-14 17:21       ` Swain, Peter
2016-03-07 15:10 ` [PATCH v3 06/14] i2c-octeon: Enable high-level controller and improve on bus contention Jan Glauber
2016-03-07 15:10 ` [PATCH v3 07/14] dt-bindings: i2c: Add Octeon cn78xx TWSI Jan Glauber
2016-03-07 15:10 ` [PATCH v3 08/14] i2c-octeon: Add support for cn78XX chips Jan Glauber
2016-03-07 15:10 ` Jan Glauber [this message]
2016-03-07 15:10 ` [PATCH v3 10/14] i2c-octeon: Faster operation when IFLG signals late Jan Glauber
2016-03-07 15:10 ` [PATCH v3 11/14] i2c-octeon: Add workaround for broken irqs on CN3860 Jan Glauber
2016-03-07 15:10 ` [PATCH v3 12/14] i2c-octeon: Split the driver into two parts Jan Glauber
2016-03-07 15:10 ` [PATCH v3 13/14] i2c-thunderx: Add i2c driver for ThunderX SOC Jan Glauber
2016-03-07 15:10 ` [PATCH v3 14/14] i2c-thunderx: Add smbus support Jan Glauber

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