public inbox for linux-i3c@lists.infradead.org
 help / color / mirror / Atom feed
* [PATCH 1/1] i3c: master: svc: add support for read len bigger than 255
@ 2024-01-17 22:50 Frank Li
  2024-01-18 20:14 ` Frank Li
  0 siblings, 1 reply; 2+ messages in thread
From: Frank Li @ 2024-01-17 22:50 UTC (permalink / raw)
  To: imx, Miquel Raynal, Conor Culhane, Alexandre Belloni,
	moderated list:SILVACO I3C DUAL-ROLE MASTER, open list

RDTERM is 8bit. Only support max 255 read transfer for auto terminate. Use
manual terminate when read len bigger than 255.

When left data length is FIFO size + 1, issue terminate
(RDTERM(1) | REQUEST_NONE). So hardware will stop fetch data after next
data.
	│ ◄──────────  buff length     ────────►│
	│                                       │
	│                       ┌─┬─────────────┤
	│                       │ │  FIFO SIZE  │
	│                       └─┴─────────────┘
	                        ▲
	                        │
	                  Wait FIFO Full and Issue read termniate here!!

Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
 drivers/i3c/master/svc-i3c-master.c | 76 ++++++++++++++++++++++++-----
 1 file changed, 64 insertions(+), 12 deletions(-)

diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c
index 5ee4db68988e2..58047ad357791 100644
--- a/drivers/i3c/master/svc-i3c-master.c
+++ b/drivers/i3c/master/svc-i3c-master.c
@@ -977,7 +977,7 @@ static int svc_i3c_master_do_daa(struct i3c_master_controller *m)
 }
 
 static int svc_i3c_master_read(struct svc_i3c_master *master,
-			       u8 *in, unsigned int len)
+			       u8 *in, unsigned int len, bool auto_term)
 {
 	int offset = 0, i;
 	u32 mdctrl, mstatus;
@@ -995,16 +995,60 @@ static int svc_i3c_master_read(struct svc_i3c_master *master,
 			return -ETIMEDOUT;
 		}
 
-		mdctrl = readl(master->regs + SVC_I3C_MDATACTRL);
-		count = SVC_I3C_MDATACTRL_RXCOUNT(mdctrl);
-		if (offset + count > len) {
-			dev_err(master->dev, "I3C receive length too long!\n");
-			return -EINVAL;
-		}
-		for (i = 0; i < count; i++)
-			in[offset + i] = readl(master->regs + SVC_I3C_MRDATAB);
+		if (auto_term || completed) {
+			/* auto termate or early termate by target */
+			mdctrl = readl(master->regs + SVC_I3C_MDATACTRL);
+			count = SVC_I3C_MDATACTRL_RXCOUNT(mdctrl);
+			if (offset + count > len) {
+				dev_err(master->dev, "I3C receive length too long!\n");
+				return -EINVAL;
+			}
+			for (i = 0; i < count; i++)
+				in[offset + i] = readl(master->regs + SVC_I3C_MRDATAB);
+
+			offset += count;
 
-		offset += count;
+		} else {
+			/*
+			 * Controller will fill whole RX FIFO in manual mode. FIFO full can prevent
+			 * controller continue fetch data from target.
+			 *
+			 * When left data length is FIFO size + 1, issue terminate
+			 * (RDTERM(1) | REQUEST_NONE). So hardware will stop fetch data after next
+			 * data.
+			 *
+			 * │ ◄──────────  buff length     ────────►│
+			 * │                                       │
+			 * │                       ┌─┬─────────────┤
+			 * │                       │ │  FIFO SIZE  │
+			 * │                       └─┴─────────────┘
+			 *                         ▲
+			 *                         │
+			 *                         Wait FIFO Full and Issue read termniate here!!
+			 */
+			mdctrl = readl_relaxed(master->regs + SVC_I3C_MDATACTRL);
+			count = SVC_I3C_MDATACTRL_RXCOUNT(mdctrl);
+
+			if (offset + count + SVC_I3C_FIFO_SIZE < len) {
+				for (i = 0; i < count; i++) {
+					in[offset] = readl_relaxed(master->regs + SVC_I3C_MRDATAB);
+					offset++;
+				}
+			} else {
+				if (count != SVC_I3C_FIFO_SIZE)
+					continue;
+
+				/* Issue manual read terminate at next data */
+				if (offset + SVC_I3C_FIFO_SIZE == len - 1)
+					writel_relaxed(SVC_I3C_MCTRL_REQUEST_NONE |
+						       SVC_I3C_MCTRL_DIR(1) |
+						       SVC_I3C_MCTRL_RDTERM(1),
+						       master->regs + SVC_I3C_MCTRL);
+
+				in[offset] = readl_relaxed(master->regs + SVC_I3C_MRDATAB);
+				offset++;
+			}
+		}
 	}
 
 	return offset;
@@ -1042,9 +1086,17 @@ static int svc_i3c_master_xfer(struct svc_i3c_master *master,
 			       u8 *in, const u8 *out, unsigned int xfer_len,
 			       unsigned int *actual_len, bool continued)
 {
+	int rdterm = 0;
 	u32 reg;
 	int ret;
 
+	if (rnw)
+		rdterm = xfer_len;
+
+	/* If read length > max RDTERM in MCTRL, using manual terminate */
+	if (xfer_len > 255)
+		rdterm = 0;
+
 	/* clean SVC_I3C_MINT_IBIWON w1c bits */
 	writel(SVC_I3C_MINT_IBIWON, master->regs + SVC_I3C_MSTATUS);
 
@@ -1053,7 +1105,7 @@ static int svc_i3c_master_xfer(struct svc_i3c_master *master,
 	       SVC_I3C_MCTRL_IBIRESP_NACK |
 	       SVC_I3C_MCTRL_DIR(rnw) |
 	       SVC_I3C_MCTRL_ADDR(addr) |
-	       SVC_I3C_MCTRL_RDTERM(*actual_len),
+	       SVC_I3C_MCTRL_RDTERM(rdterm),
 	       master->regs + SVC_I3C_MCTRL);
 
 	ret = readl_poll_timeout(master->regs + SVC_I3C_MSTATUS, reg,
@@ -1086,7 +1138,7 @@ static int svc_i3c_master_xfer(struct svc_i3c_master *master,
 	}
 
 	if (rnw)
-		ret = svc_i3c_master_read(master, in, xfer_len);
+		ret = svc_i3c_master_read(master, in, xfer_len, !!rdterm);
 	else
 		ret = svc_i3c_master_write(master, out, xfer_len);
 	if (ret < 0)
-- 
2.34.1


-- 
linux-i3c mailing list
linux-i3c@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-i3c

^ permalink raw reply related	[flat|nested] 2+ messages in thread
* Re: [PATCH 1/1] i3c: master: svc: add support for read len bigger than 255
  2024-01-17 22:50 [PATCH 1/1] i3c: master: svc: add support for read len bigger than 255 Frank Li
@ 2024-01-18 20:14 ` Frank Li
  0 siblings, 0 replies; 2+ messages in thread
From: Frank Li @ 2024-01-18 20:14 UTC (permalink / raw)
  To: imx, Miquel Raynal, Conor Culhane, Alexandre Belloni,
	moderated list:SILVACO I3C DUAL-ROLE MASTER, open list

On Wed, Jan 17, 2024 at 05:50:09PM -0500, Frank Li wrote:
> RDTERM is 8bit. Only support max 255 read transfer for auto terminate. Use
> manual terminate when read len bigger than 255.
> 
> When left data length is FIFO size + 1, issue terminate
> (RDTERM(1) | REQUEST_NONE). So hardware will stop fetch data after next
> data.
> 	│ ◄──────────  buff length     ────────►│
> 	│                                       │
> 	│                       ┌─┬─────────────┤
> 	│                       │ │  FIFO SIZE  │
> 	│                       └─┴─────────────┘
> 	                        ▲
> 	                        │
> 	                  Wait FIFO Full and Issue read termniate here!!
> 
> Signed-off-by: Frank Li <Frank.Li@nxp.com>

Sorry, please hold. I found failure at corner case.
will improve and send next version later.

Frank
> ---
>  drivers/i3c/master/svc-i3c-master.c | 76 ++++++++++++++++++++++++-----
>  1 file changed, 64 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/i3c/master/svc-i3c-master.c b/drivers/i3c/master/svc-i3c-master.c
> index 5ee4db68988e2..58047ad357791 100644
> --- a/drivers/i3c/master/svc-i3c-master.c
> +++ b/drivers/i3c/master/svc-i3c-master.c
> @@ -977,7 +977,7 @@ static int svc_i3c_master_do_daa(struct i3c_master_controller *m)
>  }
>  
>  static int svc_i3c_master_read(struct svc_i3c_master *master,
> -			       u8 *in, unsigned int len)
> +			       u8 *in, unsigned int len, bool auto_term)
>  {
>  	int offset = 0, i;
>  	u32 mdctrl, mstatus;
> @@ -995,16 +995,60 @@ static int svc_i3c_master_read(struct svc_i3c_master *master,
>  			return -ETIMEDOUT;
>  		}
>  
> -		mdctrl = readl(master->regs + SVC_I3C_MDATACTRL);
> -		count = SVC_I3C_MDATACTRL_RXCOUNT(mdctrl);
> -		if (offset + count > len) {
> -			dev_err(master->dev, "I3C receive length too long!\n");
> -			return -EINVAL;
> -		}
> -		for (i = 0; i < count; i++)
> -			in[offset + i] = readl(master->regs + SVC_I3C_MRDATAB);
> +		if (auto_term || completed) {
> +			/* auto termate or early termate by target */
> +			mdctrl = readl(master->regs + SVC_I3C_MDATACTRL);
> +			count = SVC_I3C_MDATACTRL_RXCOUNT(mdctrl);
> +			if (offset + count > len) {
> +				dev_err(master->dev, "I3C receive length too long!\n");
> +				return -EINVAL;
> +			}
> +			for (i = 0; i < count; i++)
> +				in[offset + i] = readl(master->regs + SVC_I3C_MRDATAB);
> +
> +			offset += count;
>  
> -		offset += count;
> +		} else {
> +			/*
> +			 * Controller will fill whole RX FIFO in manual mode. FIFO full can prevent
> +			 * controller continue fetch data from target.
> +			 *
> +			 * When left data length is FIFO size + 1, issue terminate
> +			 * (RDTERM(1) | REQUEST_NONE). So hardware will stop fetch data after next
> +			 * data.
> +			 *
> +			 * │ ◄──────────  buff length     ────────►│
> +			 * │                                       │
> +			 * │                       ┌─┬─────────────┤
> +			 * │                       │ │  FIFO SIZE  │
> +			 * │                       └─┴─────────────┘
> +			 *                         ▲
> +			 *                         │
> +			 *                         Wait FIFO Full and Issue read termniate here!!
> +			 */
> +			mdctrl = readl_relaxed(master->regs + SVC_I3C_MDATACTRL);
> +			count = SVC_I3C_MDATACTRL_RXCOUNT(mdctrl);
> +
> +			if (offset + count + SVC_I3C_FIFO_SIZE < len) {
> +				for (i = 0; i < count; i++) {
> +					in[offset] = readl_relaxed(master->regs + SVC_I3C_MRDATAB);
> +					offset++;
> +				}
> +			} else {
> +				if (count != SVC_I3C_FIFO_SIZE)
> +					continue;
> +
> +				/* Issue manual read terminate at next data */
> +				if (offset + SVC_I3C_FIFO_SIZE == len - 1)
> +					writel_relaxed(SVC_I3C_MCTRL_REQUEST_NONE |
> +						       SVC_I3C_MCTRL_DIR(1) |
> +						       SVC_I3C_MCTRL_RDTERM(1),
> +						       master->regs + SVC_I3C_MCTRL);
> +
> +				in[offset] = readl_relaxed(master->regs + SVC_I3C_MRDATAB);
> +				offset++;
> +			}
> +		}
>  	}
>  
>  	return offset;
> @@ -1042,9 +1086,17 @@ static int svc_i3c_master_xfer(struct svc_i3c_master *master,
>  			       u8 *in, const u8 *out, unsigned int xfer_len,
>  			       unsigned int *actual_len, bool continued)
>  {
> +	int rdterm = 0;
>  	u32 reg;
>  	int ret;
>  
> +	if (rnw)
> +		rdterm = xfer_len;
> +
> +	/* If read length > max RDTERM in MCTRL, using manual terminate */
> +	if (xfer_len > 255)
> +		rdterm = 0;
> +
>  	/* clean SVC_I3C_MINT_IBIWON w1c bits */
>  	writel(SVC_I3C_MINT_IBIWON, master->regs + SVC_I3C_MSTATUS);
>  
> @@ -1053,7 +1105,7 @@ static int svc_i3c_master_xfer(struct svc_i3c_master *master,
>  	       SVC_I3C_MCTRL_IBIRESP_NACK |
>  	       SVC_I3C_MCTRL_DIR(rnw) |
>  	       SVC_I3C_MCTRL_ADDR(addr) |
> -	       SVC_I3C_MCTRL_RDTERM(*actual_len),
> +	       SVC_I3C_MCTRL_RDTERM(rdterm),
>  	       master->regs + SVC_I3C_MCTRL);
>  
>  	ret = readl_poll_timeout(master->regs + SVC_I3C_MSTATUS, reg,
> @@ -1086,7 +1138,7 @@ static int svc_i3c_master_xfer(struct svc_i3c_master *master,
>  	}
>  
>  	if (rnw)
> -		ret = svc_i3c_master_read(master, in, xfer_len);
> +		ret = svc_i3c_master_read(master, in, xfer_len, !!rdterm);
>  	else
>  		ret = svc_i3c_master_write(master, out, xfer_len);
>  	if (ret < 0)
> -- 
> 2.34.1
> 

-- 
linux-i3c mailing list
linux-i3c@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-i3c

^ permalink raw reply	[flat|nested] 2+ messages in thread
end of thread, other threads:[~2024-01-18 20:14 UTC | newest]

Thread overview: 2+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2024-01-17 22:50 [PATCH 1/1] i3c: master: svc: add support for read len bigger than 255 Frank Li
2024-01-18 20:14 ` Frank Li

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox