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* [PATCH 1/2] i2c: mv64xxx: add software delays
@ 2017-02-23 16:34 Bastian Stender
  2017-02-23 16:34 ` [PATCH 2/2] i2c: mv64xxx: simplify mv64xxx_i2c_wait_for_completion Bastian Stender
  2017-02-24  7:24 ` [PATCH 1/2] i2c: mv64xxx: add software delays Sascha Hauer
  0 siblings, 2 replies; 3+ messages in thread
From: Bastian Stender @ 2017-02-23 16:34 UTC (permalink / raw)
  To: barebox; +Cc: Bastian Stender

As stated in Marvell's Functional Specifications in MV-S107021-U0 Rev. A
on page 420 ff. software delays are needed. "SW delay represent a delay
of at least 2 internal clock cycles". These delays are hereby
implemented.

The original kernel driver compensates the needed software delays with
the time the interrupts take.

Signed-off-by: Bastian Stender <bst@pengutronix.de>
---
 drivers/i2c/busses/i2c-mv64xxx.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/i2c/busses/i2c-mv64xxx.c b/drivers/i2c/busses/i2c-mv64xxx.c
index 9b9e6c953f..45d5a2b6dc 100644
--- a/drivers/i2c/busses/i2c-mv64xxx.c
+++ b/drivers/i2c/busses/i2c-mv64xxx.c
@@ -270,6 +270,7 @@ mv64xxx_i2c_fsm(struct mv64xxx_i2c_data *drv_data, u32 status)
 		}
 		/* FALLTHRU */
 	case STATUS_MAST_RD_DATA_ACK: /* 0x50 */
+		udelay(2);
 		if (status != STATUS_MAST_RD_DATA_ACK)
 			drv_data->action = ACTION_CONTINUE;
 		else {
@@ -280,6 +281,7 @@ mv64xxx_i2c_fsm(struct mv64xxx_i2c_data *drv_data, u32 status)
 
 		if (drv_data->bytes_left == 1)
 			drv_data->cntl_bits &= ~REG_CONTROL_ACK;
+			udelay(2);
 		break;
 
 	case STATUS_MAST_RD_DATA_NO_ACK: /* 0x58 */
@@ -318,6 +320,8 @@ static void mv64xxx_i2c_send_start(struct mv64xxx_i2c_data *drv_data)
 	mv64xxx_i2c_prepare_for_io(drv_data, drv_data->msgs);
 	mv64xxx_write(drv_data, drv_data->cntl_bits | REG_CONTROL_START,
 		drv_data->reg_offsets.control);
+
+	udelay(2);
 }
 
 static void
@@ -333,7 +337,7 @@ mv64xxx_i2c_do_action(struct mv64xxx_i2c_data *drv_data)
 		mv64xxx_i2c_send_start(drv_data);
 
 		if (drv_data->errata_delay)
-			udelay(5);
+			udelay(3);
 
 		/*
 		 * We're never at the start of the message here, and by this
@@ -349,6 +353,7 @@ mv64xxx_i2c_do_action(struct mv64xxx_i2c_data *drv_data)
 		break;
 
 	case ACTION_SEND_ADDR_1:
+		udelay(2);
 		mv64xxx_write(drv_data, drv_data->addr1,
 			drv_data->reg_offsets.data);
 		mv64xxx_write(drv_data, drv_data->cntl_bits,
@@ -360,9 +365,11 @@ mv64xxx_i2c_do_action(struct mv64xxx_i2c_data *drv_data)
 			drv_data->reg_offsets.data);
 		mv64xxx_write(drv_data, drv_data->cntl_bits,
 			drv_data->reg_offsets.control);
+		udelay(2);
 		break;
 
 	case ACTION_SEND_DATA:
+		udelay(2);
 		mv64xxx_write(drv_data, drv_data->msg->buf[drv_data->byte_posn++],
 			drv_data->reg_offsets.data);
 		mv64xxx_write(drv_data, drv_data->cntl_bits,
@@ -383,8 +390,9 @@ mv64xxx_i2c_do_action(struct mv64xxx_i2c_data *drv_data)
 		mv64xxx_write(drv_data, drv_data->cntl_bits | REG_CONTROL_STOP,
 			drv_data->reg_offsets.control);
 		drv_data->block = false;
+		udelay(2);
 		if (drv_data->errata_delay)
-			udelay(5);
+			udelay(3);
 
 		break;
 
-- 
2.11.0


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^ permalink raw reply	[flat|nested] 3+ messages in thread
* [PATCH 2/2] i2c: mv64xxx: simplify mv64xxx_i2c_wait_for_completion
  2017-02-23 16:34 [PATCH 1/2] i2c: mv64xxx: add software delays Bastian Stender
@ 2017-02-23 16:34 ` Bastian Stender
  2017-02-24  7:24 ` [PATCH 1/2] i2c: mv64xxx: add software delays Sascha Hauer
  1 sibling, 0 replies; 3+ messages in thread
From: Bastian Stender @ 2017-02-23 16:34 UTC (permalink / raw)
  To: barebox; +Cc: Bastian Stender

Two nested while loops are not necessary here, so integrate the read,
i2c_fsm and i2c_do_action calls into mv64xxx_i2c_wait_for_completion()
and remove the obsolete interrupt remains.

Signed-off-by: Bastian Stender <bst@pengutronix.de>
---
 drivers/i2c/busses/i2c-mv64xxx.c | 29 ++++++++---------------------
 1 file changed, 8 insertions(+), 21 deletions(-)

diff --git a/drivers/i2c/busses/i2c-mv64xxx.c b/drivers/i2c/busses/i2c-mv64xxx.c
index 45d5a2b6dc..caece3b78e 100644
--- a/drivers/i2c/busses/i2c-mv64xxx.c
+++ b/drivers/i2c/busses/i2c-mv64xxx.c
@@ -414,26 +414,6 @@ mv64xxx_i2c_do_action(struct mv64xxx_i2c_data *drv_data)
 	}
 }
 
-static void mv64xxx_i2c_intr(struct mv64xxx_i2c_data *drv_data)
-{
-	u32 status;
-	uint64_t start;
-
-	start = get_time_ns();
-
-	while (mv64xxx_read(drv_data, drv_data->reg_offsets.control) &
-						REG_CONTROL_IFLG) {
-		status = mv64xxx_read(drv_data, drv_data->reg_offsets.status);
-		mv64xxx_i2c_fsm(drv_data, status);
-		mv64xxx_i2c_do_action(drv_data);
-
-		if (is_timeout_non_interruptible(start, 3 * SECOND)) {
-			drv_data->rc = -EIO;
-			break;
-		}
-	}
-}
-
 /*
  *****************************************************************************
  *
@@ -444,8 +424,15 @@ static void mv64xxx_i2c_intr(struct mv64xxx_i2c_data *drv_data)
 static void
 mv64xxx_i2c_wait_for_completion(struct mv64xxx_i2c_data *drv_data)
 {
+	u32 status;
 	do {
-		mv64xxx_i2c_intr(drv_data);
+		if (mv64xxx_read(drv_data, drv_data->reg_offsets.control) &
+							REG_CONTROL_IFLG) {
+			status = mv64xxx_read(drv_data,
+					      drv_data->reg_offsets.status);
+			mv64xxx_i2c_fsm(drv_data, status);
+			mv64xxx_i2c_do_action(drv_data);
+		}
 		if (drv_data->rc) {
 			drv_data->state = STATE_IDLE;
 			dev_err(&drv_data->adapter.dev, "I2C bus error\n");
-- 
2.11.0


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^ permalink raw reply	[flat|nested] 3+ messages in thread
* Re: [PATCH 1/2] i2c: mv64xxx: add software delays
  2017-02-23 16:34 [PATCH 1/2] i2c: mv64xxx: add software delays Bastian Stender
  2017-02-23 16:34 ` [PATCH 2/2] i2c: mv64xxx: simplify mv64xxx_i2c_wait_for_completion Bastian Stender
@ 2017-02-24  7:24 ` Sascha Hauer
  1 sibling, 0 replies; 3+ messages in thread
From: Sascha Hauer @ 2017-02-24  7:24 UTC (permalink / raw)
  To: Bastian Stender; +Cc: barebox

On Thu, Feb 23, 2017 at 05:34:49PM +0100, Bastian Stender wrote:
> As stated in Marvell's Functional Specifications in MV-S107021-U0 Rev. A
> on page 420 ff. software delays are needed. "SW delay represent a delay
> of at least 2 internal clock cycles". These delays are hereby
> implemented.
> 
> The original kernel driver compensates the needed software delays with
> the time the interrupts take.
> 
> Signed-off-by: Bastian Stender <bst@pengutronix.de>

Applied, thanks

Sascha

> ---
>  drivers/i2c/busses/i2c-mv64xxx.c | 12 ++++++++++--
>  1 file changed, 10 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/i2c/busses/i2c-mv64xxx.c b/drivers/i2c/busses/i2c-mv64xxx.c
> index 9b9e6c953f..45d5a2b6dc 100644
> --- a/drivers/i2c/busses/i2c-mv64xxx.c
> +++ b/drivers/i2c/busses/i2c-mv64xxx.c
> @@ -270,6 +270,7 @@ mv64xxx_i2c_fsm(struct mv64xxx_i2c_data *drv_data, u32 status)
>  		}
>  		/* FALLTHRU */
>  	case STATUS_MAST_RD_DATA_ACK: /* 0x50 */
> +		udelay(2);
>  		if (status != STATUS_MAST_RD_DATA_ACK)
>  			drv_data->action = ACTION_CONTINUE;
>  		else {
> @@ -280,6 +281,7 @@ mv64xxx_i2c_fsm(struct mv64xxx_i2c_data *drv_data, u32 status)
>  
>  		if (drv_data->bytes_left == 1)
>  			drv_data->cntl_bits &= ~REG_CONTROL_ACK;
> +			udelay(2);
>  		break;
>  
>  	case STATUS_MAST_RD_DATA_NO_ACK: /* 0x58 */
> @@ -318,6 +320,8 @@ static void mv64xxx_i2c_send_start(struct mv64xxx_i2c_data *drv_data)
>  	mv64xxx_i2c_prepare_for_io(drv_data, drv_data->msgs);
>  	mv64xxx_write(drv_data, drv_data->cntl_bits | REG_CONTROL_START,
>  		drv_data->reg_offsets.control);
> +
> +	udelay(2);
>  }
>  
>  static void
> @@ -333,7 +337,7 @@ mv64xxx_i2c_do_action(struct mv64xxx_i2c_data *drv_data)
>  		mv64xxx_i2c_send_start(drv_data);
>  
>  		if (drv_data->errata_delay)
> -			udelay(5);
> +			udelay(3);
>  
>  		/*
>  		 * We're never at the start of the message here, and by this
> @@ -349,6 +353,7 @@ mv64xxx_i2c_do_action(struct mv64xxx_i2c_data *drv_data)
>  		break;
>  
>  	case ACTION_SEND_ADDR_1:
> +		udelay(2);
>  		mv64xxx_write(drv_data, drv_data->addr1,
>  			drv_data->reg_offsets.data);
>  		mv64xxx_write(drv_data, drv_data->cntl_bits,
> @@ -360,9 +365,11 @@ mv64xxx_i2c_do_action(struct mv64xxx_i2c_data *drv_data)
>  			drv_data->reg_offsets.data);
>  		mv64xxx_write(drv_data, drv_data->cntl_bits,
>  			drv_data->reg_offsets.control);
> +		udelay(2);
>  		break;
>  
>  	case ACTION_SEND_DATA:
> +		udelay(2);
>  		mv64xxx_write(drv_data, drv_data->msg->buf[drv_data->byte_posn++],
>  			drv_data->reg_offsets.data);
>  		mv64xxx_write(drv_data, drv_data->cntl_bits,
> @@ -383,8 +390,9 @@ mv64xxx_i2c_do_action(struct mv64xxx_i2c_data *drv_data)
>  		mv64xxx_write(drv_data, drv_data->cntl_bits | REG_CONTROL_STOP,
>  			drv_data->reg_offsets.control);
>  		drv_data->block = false;
> +		udelay(2);
>  		if (drv_data->errata_delay)
> -			udelay(5);
> +			udelay(3);
>  
>  		break;
>  
> -- 
> 2.11.0
> 
> 
> _______________________________________________
> barebox mailing list
> barebox@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/barebox
> 

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^ permalink raw reply	[flat|nested] 3+ messages in thread
end of thread, other threads:[~2017-02-24  7:24 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-02-23 16:34 [PATCH 1/2] i2c: mv64xxx: add software delays Bastian Stender
2017-02-23 16:34 ` [PATCH 2/2] i2c: mv64xxx: simplify mv64xxx_i2c_wait_for_completion Bastian Stender
2017-02-24  7:24 ` [PATCH 1/2] i2c: mv64xxx: add software delays Sascha Hauer

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