[V2,08/14] net: ks8851: Use 16-bit writes to program MAC address
diff mbox series

Message ID 20200325150543.78569-9-marex@denx.de
State Superseded
Delegated to: David Miller
Headers show
Series
  • net: ks8851: Unify KS8851 SPI and MLL drivers
Related show

Commit Message

Marek Vasut March 25, 2020, 3:05 p.m. UTC
On the SPI variant of KS8851, the MAC address can be programmed with
either 8/16/32-bit writes. To make it easier to support the 16-bit
parallel option of KS8851 too, switch both the MAC address programming
and readout to 16-bit operations.

Remove ks8851_wrreg8() as it is not used anywhere anymore.

There should be no functional change.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: David S. Miller <davem@davemloft.net>
Cc: Lukas Wunner <lukas@wunner.de>
Cc: Petr Stetiar <ynezz@true.cz>
Cc: YueHaibing <yuehaibing@huawei.com>
---
V2: Get rid of the KS_MAR(i + 1) by adjusting KS_MAR(x) macro
---
 drivers/net/ethernet/micrel/ks8851.c | 47 ++++++++--------------------
 drivers/net/ethernet/micrel/ks8851.h |  2 +-
 2 files changed, 14 insertions(+), 35 deletions(-)

Comments

Michal Kubecek March 25, 2020, 4:56 p.m. UTC | #1
On Wed, Mar 25, 2020 at 04:05:37PM +0100, Marek Vasut wrote:
> On the SPI variant of KS8851, the MAC address can be programmed with
> either 8/16/32-bit writes. To make it easier to support the 16-bit
> parallel option of KS8851 too, switch both the MAC address programming
> and readout to 16-bit operations.
> 
> Remove ks8851_wrreg8() as it is not used anywhere anymore.
> 
> There should be no functional change.
> 
> Signed-off-by: Marek Vasut <marex@denx.de>
> Cc: David S. Miller <davem@davemloft.net>
> Cc: Lukas Wunner <lukas@wunner.de>
> Cc: Petr Stetiar <ynezz@true.cz>
> Cc: YueHaibing <yuehaibing@huawei.com>
> ---
> V2: Get rid of the KS_MAR(i + 1) by adjusting KS_MAR(x) macro
> ---
[...]
> @@ -358,8 +329,12 @@ static int ks8851_write_mac_addr(struct net_device *dev)
>  	 * the first write to the MAC address does not take effect.
>  	 */
>  	ks8851_set_powermode(ks, PMECR_PM_NORMAL);
> -	for (i = 0; i < ETH_ALEN; i++)
> -		ks8851_wrreg8(ks, KS_MAR(i), dev->dev_addr[i]);
> +
> +	for (i = 0; i < ETH_ALEN; i += 2) {
> +		val = (dev->dev_addr[i] << 8) | dev->dev_addr[i + 1];
> +		ks8851_wrreg16(ks, KS_MAR(i), val);
> +	}
> +
>  	if (!netif_running(dev))
>  		ks8851_set_powermode(ks, PMECR_PM_SOFTDOWN);
>  
> @@ -377,12 +352,16 @@ static int ks8851_write_mac_addr(struct net_device *dev)
>  static void ks8851_read_mac_addr(struct net_device *dev)
>  {
>  	struct ks8851_net *ks = netdev_priv(dev);
> +	u16 reg;
>  	int i;
>  
>  	mutex_lock(&ks->lock);
>  
> -	for (i = 0; i < ETH_ALEN; i++)
> -		dev->dev_addr[i] = ks8851_rdreg8(ks, KS_MAR(i));
> +	for (i = 0; i < ETH_ALEN; i += 2) {
> +		reg = ks8851_rdreg16(ks, KS_MAR(i));
> +		dev->dev_addr[i] = reg & 0xff;
> +		dev->dev_addr[i + 1] = reg >> 8;
> +	}
>  
>  	mutex_unlock(&ks->lock);
>  }

It seems my question from v1 went unnoticed and the inconsistency still
seems to be there so let me ask again: when writing, you put addr[i]
into upper part of the 16-bit value and addr[i+1] into lower but when 
reading, you do the opposite. Is it correct?

Michal Kubecek
Marek Vasut March 25, 2020, 5:05 p.m. UTC | #2
On 3/25/20 5:56 PM, Michal Kubecek wrote:
> On Wed, Mar 25, 2020 at 04:05:37PM +0100, Marek Vasut wrote:
>> On the SPI variant of KS8851, the MAC address can be programmed with
>> either 8/16/32-bit writes. To make it easier to support the 16-bit
>> parallel option of KS8851 too, switch both the MAC address programming
>> and readout to 16-bit operations.
>>
>> Remove ks8851_wrreg8() as it is not used anywhere anymore.
>>
>> There should be no functional change.
>>
>> Signed-off-by: Marek Vasut <marex@denx.de>
>> Cc: David S. Miller <davem@davemloft.net>
>> Cc: Lukas Wunner <lukas@wunner.de>
>> Cc: Petr Stetiar <ynezz@true.cz>
>> Cc: YueHaibing <yuehaibing@huawei.com>
>> ---
>> V2: Get rid of the KS_MAR(i + 1) by adjusting KS_MAR(x) macro
>> ---
> [...]
>> @@ -358,8 +329,12 @@ static int ks8851_write_mac_addr(struct net_device *dev)
>>  	 * the first write to the MAC address does not take effect.
>>  	 */
>>  	ks8851_set_powermode(ks, PMECR_PM_NORMAL);
>> -	for (i = 0; i < ETH_ALEN; i++)
>> -		ks8851_wrreg8(ks, KS_MAR(i), dev->dev_addr[i]);
>> +
>> +	for (i = 0; i < ETH_ALEN; i += 2) {
>> +		val = (dev->dev_addr[i] << 8) | dev->dev_addr[i + 1];
>> +		ks8851_wrreg16(ks, KS_MAR(i), val);
>> +	}
>> +
>>  	if (!netif_running(dev))
>>  		ks8851_set_powermode(ks, PMECR_PM_SOFTDOWN);
>>  
>> @@ -377,12 +352,16 @@ static int ks8851_write_mac_addr(struct net_device *dev)
>>  static void ks8851_read_mac_addr(struct net_device *dev)
>>  {
>>  	struct ks8851_net *ks = netdev_priv(dev);
>> +	u16 reg;
>>  	int i;
>>  
>>  	mutex_lock(&ks->lock);
>>  
>> -	for (i = 0; i < ETH_ALEN; i++)
>> -		dev->dev_addr[i] = ks8851_rdreg8(ks, KS_MAR(i));
>> +	for (i = 0; i < ETH_ALEN; i += 2) {
>> +		reg = ks8851_rdreg16(ks, KS_MAR(i));
>> +		dev->dev_addr[i] = reg & 0xff;
>> +		dev->dev_addr[i + 1] = reg >> 8;
>> +	}
>>  
>>  	mutex_unlock(&ks->lock);
>>  }
> 
> It seems my question from v1 went unnoticed and the inconsistency still
> seems to be there so let me ask again: when writing, you put addr[i]
> into upper part of the 16-bit value and addr[i+1] into lower but when 
> reading, you do the opposite. Is it correct?

I believe so, and it works at least on the hardware I have here.
I need to wait for Lukas to verify that on KS8851 SPI edition tomorrow
(that's also why I sent out the V2, so he can test it out)
Michal Kubecek March 25, 2020, 5:30 p.m. UTC | #3
On Wed, Mar 25, 2020 at 06:05:30PM +0100, Marek Vasut wrote:
> On 3/25/20 5:56 PM, Michal Kubecek wrote:
> > On Wed, Mar 25, 2020 at 04:05:37PM +0100, Marek Vasut wrote:
> >> On the SPI variant of KS8851, the MAC address can be programmed with
> >> either 8/16/32-bit writes. To make it easier to support the 16-bit
> >> parallel option of KS8851 too, switch both the MAC address programming
> >> and readout to 16-bit operations.
> >>
> >> Remove ks8851_wrreg8() as it is not used anywhere anymore.
> >>
> >> There should be no functional change.
> >>
> >> Signed-off-by: Marek Vasut <marex@denx.de>
> >> Cc: David S. Miller <davem@davemloft.net>
> >> Cc: Lukas Wunner <lukas@wunner.de>
> >> Cc: Petr Stetiar <ynezz@true.cz>
> >> Cc: YueHaibing <yuehaibing@huawei.com>
> >> ---
> >> V2: Get rid of the KS_MAR(i + 1) by adjusting KS_MAR(x) macro
> >> ---
> > [...]
> >> @@ -358,8 +329,12 @@ static int ks8851_write_mac_addr(struct net_device *dev)
> >>  	 * the first write to the MAC address does not take effect.
> >>  	 */
> >>  	ks8851_set_powermode(ks, PMECR_PM_NORMAL);
> >> -	for (i = 0; i < ETH_ALEN; i++)
> >> -		ks8851_wrreg8(ks, KS_MAR(i), dev->dev_addr[i]);
> >> +
> >> +	for (i = 0; i < ETH_ALEN; i += 2) {
> >> +		val = (dev->dev_addr[i] << 8) | dev->dev_addr[i + 1];
> >> +		ks8851_wrreg16(ks, KS_MAR(i), val);
> >> +	}
> >> +
> >>  	if (!netif_running(dev))
> >>  		ks8851_set_powermode(ks, PMECR_PM_SOFTDOWN);
> >>  
> >> @@ -377,12 +352,16 @@ static int ks8851_write_mac_addr(struct net_device *dev)
> >>  static void ks8851_read_mac_addr(struct net_device *dev)
> >>  {
> >>  	struct ks8851_net *ks = netdev_priv(dev);
> >> +	u16 reg;
> >>  	int i;
> >>  
> >>  	mutex_lock(&ks->lock);
> >>  
> >> -	for (i = 0; i < ETH_ALEN; i++)
> >> -		dev->dev_addr[i] = ks8851_rdreg8(ks, KS_MAR(i));
> >> +	for (i = 0; i < ETH_ALEN; i += 2) {
> >> +		reg = ks8851_rdreg16(ks, KS_MAR(i));
> >> +		dev->dev_addr[i] = reg & 0xff;
> >> +		dev->dev_addr[i + 1] = reg >> 8;
> >> +	}
> >>  
> >>  	mutex_unlock(&ks->lock);
> >>  }
> > 
> > It seems my question from v1 went unnoticed and the inconsistency still
> > seems to be there so let me ask again: when writing, you put addr[i]
> > into upper part of the 16-bit value and addr[i+1] into lower but when 
> > reading, you do the opposite. Is it correct?
> 
> I believe so, and it works at least on the hardware I have here.
> I need to wait for Lukas to verify that on KS8851 SPI edition tomorrow
> (that's also why I sent out the V2, so he can test it out)

That's a bit surprising (and counterintuitive) as it means that if you do

  ks8851_wrreg16(ks, a, val);
  val = ks8851_rdreg16(ks, a);

you read a different value than you wrote. But I know nothing about the
hardware (I only noticed the strange inconsistency) so I can't say where
does it come from.

Michal Kubecek
Marek Vasut March 27, 2020, 6:16 p.m. UTC | #4
On 3/25/20 6:30 PM, Michal Kubecek wrote:
> On Wed, Mar 25, 2020 at 06:05:30PM +0100, Marek Vasut wrote:
>> On 3/25/20 5:56 PM, Michal Kubecek wrote:
>>> On Wed, Mar 25, 2020 at 04:05:37PM +0100, Marek Vasut wrote:
>>>> On the SPI variant of KS8851, the MAC address can be programmed with
>>>> either 8/16/32-bit writes. To make it easier to support the 16-bit
>>>> parallel option of KS8851 too, switch both the MAC address programming
>>>> and readout to 16-bit operations.
>>>>
>>>> Remove ks8851_wrreg8() as it is not used anywhere anymore.
>>>>
>>>> There should be no functional change.
>>>>
>>>> Signed-off-by: Marek Vasut <marex@denx.de>
>>>> Cc: David S. Miller <davem@davemloft.net>
>>>> Cc: Lukas Wunner <lukas@wunner.de>
>>>> Cc: Petr Stetiar <ynezz@true.cz>
>>>> Cc: YueHaibing <yuehaibing@huawei.com>
>>>> ---
>>>> V2: Get rid of the KS_MAR(i + 1) by adjusting KS_MAR(x) macro
>>>> ---
>>> [...]
>>>> @@ -358,8 +329,12 @@ static int ks8851_write_mac_addr(struct net_device *dev)
>>>>  	 * the first write to the MAC address does not take effect.
>>>>  	 */
>>>>  	ks8851_set_powermode(ks, PMECR_PM_NORMAL);
>>>> -	for (i = 0; i < ETH_ALEN; i++)
>>>> -		ks8851_wrreg8(ks, KS_MAR(i), dev->dev_addr[i]);
>>>> +
>>>> +	for (i = 0; i < ETH_ALEN; i += 2) {
>>>> +		val = (dev->dev_addr[i] << 8) | dev->dev_addr[i + 1];
>>>> +		ks8851_wrreg16(ks, KS_MAR(i), val);
>>>> +	}
>>>> +
>>>>  	if (!netif_running(dev))
>>>>  		ks8851_set_powermode(ks, PMECR_PM_SOFTDOWN);
>>>>  
>>>> @@ -377,12 +352,16 @@ static int ks8851_write_mac_addr(struct net_device *dev)
>>>>  static void ks8851_read_mac_addr(struct net_device *dev)
>>>>  {
>>>>  	struct ks8851_net *ks = netdev_priv(dev);
>>>> +	u16 reg;
>>>>  	int i;
>>>>  
>>>>  	mutex_lock(&ks->lock);
>>>>  
>>>> -	for (i = 0; i < ETH_ALEN; i++)
>>>> -		dev->dev_addr[i] = ks8851_rdreg8(ks, KS_MAR(i));
>>>> +	for (i = 0; i < ETH_ALEN; i += 2) {
>>>> +		reg = ks8851_rdreg16(ks, KS_MAR(i));
>>>> +		dev->dev_addr[i] = reg & 0xff;
>>>> +		dev->dev_addr[i + 1] = reg >> 8;
>>>> +	}
>>>>  
>>>>  	mutex_unlock(&ks->lock);
>>>>  }
>>>
>>> It seems my question from v1 went unnoticed and the inconsistency still
>>> seems to be there so let me ask again: when writing, you put addr[i]
>>> into upper part of the 16-bit value and addr[i+1] into lower but when 
>>> reading, you do the opposite. Is it correct?
>>
>> I believe so, and it works at least on the hardware I have here.
>> I need to wait for Lukas to verify that on KS8851 SPI edition tomorrow
>> (that's also why I sent out the V2, so he can test it out)
> 
> That's a bit surprising (and counterintuitive) as it means that if you do
> 
>   ks8851_wrreg16(ks, a, val);
>   val = ks8851_rdreg16(ks, a);
> 
> you read a different value than you wrote. But I know nothing about the
> hardware (I only noticed the strange inconsistency) so I can't say where
> does it come from.

So this really does need fixing.

Patch
diff mbox series

diff --git a/drivers/net/ethernet/micrel/ks8851.c b/drivers/net/ethernet/micrel/ks8851.c
index 8f1cc05dc3c8..6f3ecf980514 100644
--- a/drivers/net/ethernet/micrel/ks8851.c
+++ b/drivers/net/ethernet/micrel/ks8851.c
@@ -185,36 +185,6 @@  static void ks8851_wrreg16(struct ks8851_net *ks, unsigned reg, unsigned val)
 		netdev_err(ks->netdev, "spi_sync() failed\n");
 }
 
-/**
- * ks8851_wrreg8 - write 8bit register value to chip
- * @ks: The chip state
- * @reg: The register address
- * @val: The value to write
- *
- * Issue a write to put the value @val into the register specified in @reg.
- */
-static void ks8851_wrreg8(struct ks8851_net *ks, unsigned reg, unsigned val)
-{
-	struct spi_transfer *xfer = &ks->spi_xfer1;
-	struct spi_message *msg = &ks->spi_msg1;
-	__le16 txb[2];
-	int ret;
-	int bit;
-
-	bit = 1 << (reg & 3);
-
-	txb[0] = cpu_to_le16(MK_OP(bit, reg) | KS_SPIOP_WR);
-	txb[1] = val;
-
-	xfer->tx_buf = txb;
-	xfer->rx_buf = NULL;
-	xfer->len = 3;
-
-	ret = spi_sync(ks->spidev, msg);
-	if (ret < 0)
-		netdev_err(ks->netdev, "spi_sync() failed\n");
-}
-
 /**
  * ks8851_rdreg - issue read register command and return the data
  * @ks: The device state
@@ -349,6 +319,7 @@  static void ks8851_set_powermode(struct ks8851_net *ks, unsigned pwrmode)
 static int ks8851_write_mac_addr(struct net_device *dev)
 {
 	struct ks8851_net *ks = netdev_priv(dev);
+	u16 val;
 	int i;
 
 	mutex_lock(&ks->lock);
@@ -358,8 +329,12 @@  static int ks8851_write_mac_addr(struct net_device *dev)
 	 * the first write to the MAC address does not take effect.
 	 */
 	ks8851_set_powermode(ks, PMECR_PM_NORMAL);
-	for (i = 0; i < ETH_ALEN; i++)
-		ks8851_wrreg8(ks, KS_MAR(i), dev->dev_addr[i]);
+
+	for (i = 0; i < ETH_ALEN; i += 2) {
+		val = (dev->dev_addr[i] << 8) | dev->dev_addr[i + 1];
+		ks8851_wrreg16(ks, KS_MAR(i), val);
+	}
+
 	if (!netif_running(dev))
 		ks8851_set_powermode(ks, PMECR_PM_SOFTDOWN);
 
@@ -377,12 +352,16 @@  static int ks8851_write_mac_addr(struct net_device *dev)
 static void ks8851_read_mac_addr(struct net_device *dev)
 {
 	struct ks8851_net *ks = netdev_priv(dev);
+	u16 reg;
 	int i;
 
 	mutex_lock(&ks->lock);
 
-	for (i = 0; i < ETH_ALEN; i++)
-		dev->dev_addr[i] = ks8851_rdreg8(ks, KS_MAR(i));
+	for (i = 0; i < ETH_ALEN; i += 2) {
+		reg = ks8851_rdreg16(ks, KS_MAR(i));
+		dev->dev_addr[i] = reg & 0xff;
+		dev->dev_addr[i + 1] = reg >> 8;
+	}
 
 	mutex_unlock(&ks->lock);
 }
diff --git a/drivers/net/ethernet/micrel/ks8851.h b/drivers/net/ethernet/micrel/ks8851.h
index 8f834aef8e32..f210d18a10b5 100644
--- a/drivers/net/ethernet/micrel/ks8851.h
+++ b/drivers/net/ethernet/micrel/ks8851.h
@@ -19,7 +19,7 @@ 
 #define CCR_32PIN				(1 << 0)    /* KSZ8851SNL    */
 
 /* MAC address registers */
-#define KS_MAR(_m)				(0x15 - (_m))
+#define KS_MAR(_m)				(0x14 - (_m))
 #define KS_MARL					0x10
 #define KS_MARM					0x12
 #define KS_MARH					0x14