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From: Manikanta Guntupalli <manikanta.guntupalli@amd.com>
To: <michal.simek@xilinx.com>, <michal.simek@amd.com>,
	<devicetree@vger.kernel.org>, <andrew@lunn.ch>,
	<robh+dt@kernel.org>, <krzysztof.kozlowski+dt@linaro.org>,
	<linux-arm-kernel@lists.infradead.org>,
	<linux-i2c@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Cc: <git@amd.com>, <manikanta.guntupalli@amd.com>,
	<srinivas.goud@amd.com>, <shubhrajyoti.datta@amd.com>,
	<manion05gk@gmail.com>,
	Raviteja Narayanam <raviteja.narayanam@xilinx.com>
Subject: [PATCH V4 4/9] i2c: xiic: Add wait for FIFO empty in send_tx
Date: Thu, 2 Feb 2023 15:11:33 +0530	[thread overview]
Message-ID: <1675330898-563-5-git-send-email-manikanta.guntupalli@amd.com> (raw)
In-Reply-To: <1675330898-563-1-git-send-email-manikanta.guntupalli@amd.com>

From: Raviteja Narayanam <raviteja.narayanam@xilinx.com>

If the tx_half_empty interrupt comes first instead of tx_empty,
STOP bit is generated even before all the bytes are transmitted
out on the bus.
STOP bit should be sent only after all the bytes in the FIFO are
transmitted out of the FIFO. So wait until FIFO is empty before sending
the STOP bit.

Signed-off-by: Raviteja Narayanam <raviteja.narayanam@xilinx.com>
Signed-off-by: Manikanta Guntupalli <manikanta.guntupalli@amd.com>
Acked-by: Michal Simek <michal.simek@amd.com>
---
 drivers/i2c/busses/i2c-xiic.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/i2c/busses/i2c-xiic.c b/drivers/i2c/busses/i2c-xiic.c
index edc64b79e293..57084696429c 100644
--- a/drivers/i2c/busses/i2c-xiic.c
+++ b/drivers/i2c/busses/i2c-xiic.c
@@ -436,6 +436,13 @@ static void xiic_fill_tx_fifo(struct xiic_i2c *i2c)
 				data |= XIIC_TX_DYN_STOP_MASK;
 			} else {
 				u8 cr;
+				int status;
+
+				/* Wait till FIFO is empty so STOP is sent last */
+				status = xiic_wait_tx_empty(i2c);
+				if (status)
+					return;
+
 				/* Write to CR to stop */
 				cr = xiic_getreg8(i2c, XIIC_CR_REG_OFFSET);
 				xiic_setreg8(i2c, XIIC_CR_REG_OFFSET, cr &
-- 
2.25.1


WARNING: multiple messages have this Message-ID (diff)
From: Manikanta Guntupalli <manikanta.guntupalli@amd.com>
To: <michal.simek@xilinx.com>, <michal.simek@amd.com>,
	<devicetree@vger.kernel.org>, <andrew@lunn.ch>,
	<robh+dt@kernel.org>, <krzysztof.kozlowski+dt@linaro.org>,
	<linux-arm-kernel@lists.infradead.org>,
	<linux-i2c@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Cc: <git@amd.com>, <manikanta.guntupalli@amd.com>,
	<srinivas.goud@amd.com>, <shubhrajyoti.datta@amd.com>,
	<manion05gk@gmail.com>,
	Raviteja Narayanam <raviteja.narayanam@xilinx.com>
Subject: [PATCH V4 4/9] i2c: xiic: Add wait for FIFO empty in send_tx
Date: Thu, 2 Feb 2023 15:11:33 +0530	[thread overview]
Message-ID: <1675330898-563-5-git-send-email-manikanta.guntupalli@amd.com> (raw)
In-Reply-To: <1675330898-563-1-git-send-email-manikanta.guntupalli@amd.com>

From: Raviteja Narayanam <raviteja.narayanam@xilinx.com>

If the tx_half_empty interrupt comes first instead of tx_empty,
STOP bit is generated even before all the bytes are transmitted
out on the bus.
STOP bit should be sent only after all the bytes in the FIFO are
transmitted out of the FIFO. So wait until FIFO is empty before sending
the STOP bit.

Signed-off-by: Raviteja Narayanam <raviteja.narayanam@xilinx.com>
Signed-off-by: Manikanta Guntupalli <manikanta.guntupalli@amd.com>
Acked-by: Michal Simek <michal.simek@amd.com>
---
 drivers/i2c/busses/i2c-xiic.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/i2c/busses/i2c-xiic.c b/drivers/i2c/busses/i2c-xiic.c
index edc64b79e293..57084696429c 100644
--- a/drivers/i2c/busses/i2c-xiic.c
+++ b/drivers/i2c/busses/i2c-xiic.c
@@ -436,6 +436,13 @@ static void xiic_fill_tx_fifo(struct xiic_i2c *i2c)
 				data |= XIIC_TX_DYN_STOP_MASK;
 			} else {
 				u8 cr;
+				int status;
+
+				/* Wait till FIFO is empty so STOP is sent last */
+				status = xiic_wait_tx_empty(i2c);
+				if (status)
+					return;
+
 				/* Write to CR to stop */
 				cr = xiic_getreg8(i2c, XIIC_CR_REG_OFFSET);
 				xiic_setreg8(i2c, XIIC_CR_REG_OFFSET, cr &
-- 
2.25.1


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  parent reply	other threads:[~2023-02-02  9:44 UTC|newest]

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-02-02  9:41 [PATCH V4 0/9] Added Standard mode and SMBus support Manikanta Guntupalli
2023-02-02  9:41 ` Manikanta Guntupalli
2023-02-02  9:41 ` [PATCH V4 1/9] i2c: xiic: Add standard mode support for > 255 byte Manikanta Guntupalli
2023-02-02  9:41   ` Manikanta Guntupalli
2023-02-03 16:35   ` Wolfram Sang
2023-02-03 16:35     ` Wolfram Sang
2023-02-02  9:41 ` [PATCH V4 2/9] i2c: xiic: Fix Rx and Tx paths in standard mode Manikanta Guntupalli
2023-02-02  9:41   ` Manikanta Guntupalli
2023-02-03 16:35   ` Wolfram Sang
2023-02-03 16:35     ` Wolfram Sang
2023-02-02  9:41 ` [PATCH V4 3/9] i2c: xiic: Switch to Xiic standard mode for i2c-read Manikanta Guntupalli
2023-02-02  9:41   ` Manikanta Guntupalli
2023-02-03 16:35   ` Wolfram Sang
2023-02-03 16:35     ` Wolfram Sang
2023-02-02  9:41 ` Manikanta Guntupalli [this message]
2023-02-02  9:41   ` [PATCH V4 4/9] i2c: xiic: Add wait for FIFO empty in send_tx Manikanta Guntupalli
2023-02-03 16:35   ` Wolfram Sang
2023-02-03 16:35     ` Wolfram Sang
2023-02-02  9:41 ` [PATCH V4 5/9] i2c: xiic: Add smbus_block_read functionality Manikanta Guntupalli
2023-02-02  9:41   ` Manikanta Guntupalli
2023-02-03 16:37   ` Wolfram Sang
2023-02-03 16:37     ` Wolfram Sang
2023-02-02  9:41 ` [PATCH V4 6/9] i2c: xiic: Remove interrupt enable/disable in Rx path Manikanta Guntupalli
2023-02-02  9:41   ` Manikanta Guntupalli
2023-02-03 16:37   ` Wolfram Sang
2023-02-03 16:37     ` Wolfram Sang
2023-02-02  9:41 ` [PATCH V4 7/9] dt-bindings: i2c: xiic: Add 'xlnx,axi-iic-2.1' to Manikanta Guntupalli
2023-02-02  9:41   ` Manikanta Guntupalli
2023-02-02  9:46   ` Krzysztof Kozlowski
2023-02-02  9:46     ` Krzysztof Kozlowski
2023-02-02  9:41 ` [PATCH V4 8/9] i2c: xiic: Update compatible with new IP version Manikanta Guntupalli
2023-02-02  9:41   ` Manikanta Guntupalli
2023-02-02  9:41 ` [PATCH V4 9/9] i2c: xiic: Add SCL frequency configuration support Manikanta Guntupalli
2023-02-02  9:41   ` Manikanta Guntupalli

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