[PATCH v6 net-next 00/17] net: qualcomm: add QCA7000 UART driver

[PATCH v6 net-next 00/17] net: qualcomm: add QCA7000 UART driver

[Stefan Wahren]

The Qualcomm QCA7000 HomePlug GreenPHY supports two interfaces:
UART and SPI. This patch series adds the missing support for UART.

This driver based on the Qualcomm code [1], but contains some changes:
* use random MAC address per default
* use net_device_stats from device
* share frame decoding between SPI and UART driver
* improve error handling
* reimplement tty_wakeup with work queue (based on slcan)
* use new serial device bus instead of ldisc

The patches 1 - 3 are just for clean up and are not related to
the UART support. Patch 4 adds SET_NETDEV_DEV() to qca_spi.
Patches 5 - 16 prepare the existing QCA7000 code for UART support.
The last patch contains the new driver.

The code itself has been tested on a Freescale i.MX28 board and
a Raspberry Pi Zero.

Changes in v6:
  * rebase to current linux-next
  * use SET_NETDEV_DEV() for qca_spi and qca_uart
  * rename binding to qca,qca7000.txt
  * use qca,qca7000 compatible for both driver
  * handle error cases in qca_uart_probe properly
  * fix skb leak in error path of qcauart_netdev_init
  * use dev_kfree_skb_any instead of kfree_skb
  * take care of tx_work on close / remove
  * use devm_kmalloc for tx buffer
  * minor cleanups

Changes in v5:
  * rebase to current linux-next
  * fix alignment issues in rx path
  * fix buffer overrun with big ethernet frames
  * fix init of UART decoding fsm
  * add device UART settings to Kconfig help
  * add current-speed to slave-device binding
  * merge SPI and UART binding document
  * rename qca_common to qca_7k_common
  * drop patch for retrieving UART settings
  * several cleanups

Changes in v4:
  * rebase to current linux-next
  * use parameter -M for git format-patch
  * change order of local variables where possible
  * implement basic serdev support (without hardware flow control)

Changes in v3:
  * rebase to current net-next

Changes in v2:
  * fix build issue by using netif_trans_update() and dev_trans_start()

[1] - https://github.com/IoE/qca7000

Stefan Wahren (17):
  net: qualcomm: remove unnecessary includes
  net: qca_framing: use u16 for frame offset
  net: qca_7k: Use BIT macro
  net: qca_spi: Use SET_NETDEV_DEV()
  net: qualcomm: use net_device_ops instead of direct call
  net: qualcomm: Improve readability of length defines
  net: qca_spi: remove QCASPI_MTU
  net: qualcomm: move qcaspi_tx_cmd to qca_spi.c
  net: qca_spi: Clarify MODULE_DESCRIPTION
  net: qualcomm: rename qca_framing.c to qca_7k_common.c
  net: qualcomm: prepare frame decoding for UART driver
  net: qualcomm: make qca_7k_common a separate kernel module
  dt-bindings: qca7000-spi: Rework binding
  dt-bindings: qca7000: rename binding
  dt-bindings: slave-device: add current-speed property
  dt-bindings: qca7000: append UART interface to binding
  net: qualcomm: add QCA7000 UART driver

 .../devicetree/bindings/net/qca,qca7000.txt        |  88 +++++
 .../devicetree/bindings/net/qca-qca7000-spi.txt    |  47 ---
 .../devicetree/bindings/serial/slave-device.txt    |   9 +
 drivers/net/ethernet/qualcomm/Kconfig              |  24 +-
 drivers/net/ethernet/qualcomm/Makefile             |   7 +-
 drivers/net/ethernet/qualcomm/qca_7k.c             |  28 --
 drivers/net/ethernet/qualcomm/qca_7k.h             |  15 +-
 .../qualcomm/{qca_framing.c => qca_7k_common.c}    |  26 +-
 .../qualcomm/{qca_framing.h => qca_7k_common.h}    |  24 +-
 drivers/net/ethernet/qualcomm/qca_debug.c          |   5 +-
 drivers/net/ethernet/qualcomm/qca_spi.c            |  48 ++-
 drivers/net/ethernet/qualcomm/qca_spi.h            |   5 +-
 drivers/net/ethernet/qualcomm/qca_uart.c           | 423 +++++++++++++++++++++
 13 files changed, 630 insertions(+), 119 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/net/qca,qca7000.txt
 delete mode 100644 Documentation/devicetree/bindings/net/qca-qca7000-spi.txt
 rename drivers/net/ethernet/qualcomm/{qca_framing.c => qca_7k_common.c} (85%)
 rename drivers/net/ethernet/qualcomm/{qca_framing.h => qca_7k_common.h} (86%)
 create mode 100644 drivers/net/ethernet/qualcomm/qca_uart.c

-- 
2.1.4

[PATCH v6 net-next 01/17] net: qualcomm: remove unnecessary includes

[Stefan Wahren]

Most of the includes in qca_7k.c are unnecessary so we better remove them.

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
---
 drivers/net/ethernet/qualcomm/qca_7k.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/drivers/net/ethernet/qualcomm/qca_7k.c b/drivers/net/ethernet/qualcomm/qca_7k.c
index f0066fb..557d53c 100644
--- a/drivers/net/ethernet/qualcomm/qca_7k.c
+++ b/drivers/net/ethernet/qualcomm/qca_7k.c
@@ -23,11 +23,7 @@
  *   kernel-based SPI device.
  */
 
-#include <linux/init.h>
-#include <linux/module.h>
-#include <linux/moduleparam.h>
 #include <linux/spi/spi.h>
-#include <linux/version.h>
 
 #include "qca_7k.h"
 
-- 
2.1.4

Re: [PATCH v6 net-next 01/17] net: qualcomm: remove unnecessary includes

[David Miller]

From: Stefan Wahren <stefan.wahren@i2se.com>
Date: Tue, 23 May 2017 15:12:37 +0200

> Most of the includes in qca_7k.c are unnecessary so we better remove them.
> 
> Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
> ---
>  drivers/net/ethernet/qualcomm/qca_7k.c | 4 ----
>  1 file changed, 4 deletions(-)
> 
> diff --git a/drivers/net/ethernet/qualcomm/qca_7k.c b/drivers/net/ethernet/qualcomm/qca_7k.c
> index f0066fb..557d53c 100644
> --- a/drivers/net/ethernet/qualcomm/qca_7k.c
> +++ b/drivers/net/ethernet/qualcomm/qca_7k.c
> @@ -23,11 +23,7 @@
>   *   kernel-based SPI device.
>   */
>  
> -#include <linux/init.h>
> -#include <linux/module.h>
> -#include <linux/moduleparam.h>
>  #include <linux/spi/spi.h>
> -#include <linux/version.h>
>  
>  #include "qca_7k.h"
>  
> -- 
> 2.1.4
> 

Changes like this drive me crazy.

The only reason you can remove those headers is because you are obtaining
things indirectly via qca_7k.h

And if that is indeed the case, you are also getting qca_spi.h which
in turn includes linux/spi/spi.h

So you could have removed that as well.

But seriously, it is so much harder to understand a driver and what
interfaces it needs via header files when you hide _all_ of it behind
these local private header files which just include _everything_
and then _every_ foo.c file in your driver gets _all_ of those kernel
headers whether they need it or not.

So if just one foo.c file needs 20 extra kernel headers than the rest
of the files in the driver, every foo.c file eats that cost of
including them.

I really don't like when drivers move in this direction for that
reason.  And at best, as described at the beginning of my response,
this change is incomplete.

Re: [PATCH v6 net-next 01/17] net: qualcomm: remove unnecessary includes

[David Miller]

From: Stefan Wahren <stefan.wahren-eS4NqCHxEME@public.gmane.org>
Date: Tue, 23 May 2017 15:12:37 +0200

> Most of the includes in qca_7k.c are unnecessary so we better remove them.
> 
> Signed-off-by: Stefan Wahren <stefan.wahren-eS4NqCHxEME@public.gmane.org>
> ---
>  drivers/net/ethernet/qualcomm/qca_7k.c | 4 ----
>  1 file changed, 4 deletions(-)
> 
> diff --git a/drivers/net/ethernet/qualcomm/qca_7k.c b/drivers/net/ethernet/qualcomm/qca_7k.c
> index f0066fb..557d53c 100644
> --- a/drivers/net/ethernet/qualcomm/qca_7k.c
> +++ b/drivers/net/ethernet/qualcomm/qca_7k.c
> @@ -23,11 +23,7 @@
>   *   kernel-based SPI device.
>   */
>  
> -#include <linux/init.h>
> -#include <linux/module.h>
> -#include <linux/moduleparam.h>
>  #include <linux/spi/spi.h>
> -#include <linux/version.h>
>  
>  #include "qca_7k.h"
>  
> -- 
> 2.1.4
> 

Changes like this drive me crazy.

The only reason you can remove those headers is because you are obtaining
things indirectly via qca_7k.h

And if that is indeed the case, you are also getting qca_spi.h which
in turn includes linux/spi/spi.h

So you could have removed that as well.

But seriously, it is so much harder to understand a driver and what
interfaces it needs via header files when you hide _all_ of it behind
these local private header files which just include _everything_
and then _every_ foo.c file in your driver gets _all_ of those kernel
headers whether they need it or not.

So if just one foo.c file needs 20 extra kernel headers than the rest
of the files in the driver, every foo.c file eats that cost of
including them.

I really don't like when drivers move in this direction for that
reason.  And at best, as described at the beginning of my response,
this change is incomplete.

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Re: [PATCH v6 net-next 01/17] net: qualcomm: remove unnecessary includes

[Stefan Wahren]

> David Miller <davem@davemloft.net> hat am 24. Mai 2017 um 21:41 geschrieben:
> 
> 
> From: Stefan Wahren <stefan.wahren@i2se.com>
> Date: Tue, 23 May 2017 15:12:37 +0200
> 
> > Most of the includes in qca_7k.c are unnecessary so we better remove them.
> > 
> > Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
> > ---
> >  drivers/net/ethernet/qualcomm/qca_7k.c | 4 ----
> >  1 file changed, 4 deletions(-)
> > 
> > diff --git a/drivers/net/ethernet/qualcomm/qca_7k.c b/drivers/net/ethernet/qualcomm/qca_7k.c
> > index f0066fb..557d53c 100644
> > --- a/drivers/net/ethernet/qualcomm/qca_7k.c
> > +++ b/drivers/net/ethernet/qualcomm/qca_7k.c
> > @@ -23,11 +23,7 @@
> >   *   kernel-based SPI device.
> >   */
> >  
> > -#include <linux/init.h>
> > -#include <linux/module.h>
> > -#include <linux/moduleparam.h>
> >  #include <linux/spi/spi.h>
> > -#include <linux/version.h>
> >  
> >  #include "qca_7k.h"
> >  
> > -- 
> > 2.1.4
> > 
> 
> Changes like this drive me crazy.
> 
> The only reason you can remove those headers is because you are obtaining
> things indirectly via qca_7k.h
> 
> And if that is indeed the case, you are also getting qca_spi.h which
> in turn includes linux/spi/spi.h
> 
> So you could have removed that as well.
> 
> But seriously, it is so much harder to understand a driver and what
> interfaces it needs via header files when you hide _all_ of it behind
> these local private header files which just include _everything_
> and then _every_ foo.c file in your driver gets _all_ of those kernel
> headers whether they need it or not.
> 
> So if just one foo.c file needs 20 extra kernel headers than the rest
> of the files in the driver, every foo.c file eats that cost of
> including them.
> 
> I really don't like when drivers move in this direction for that
> reason.  And at best, as described at the beginning of my response,
> this change is incomplete.
>

The intension of this change wasn't to hide the includes into qca_7k.h

AFAIK these ones above aren't necessary (no init, no kernel module, no kernel parameter, no kernel version) for this C file. So i will double check it.

Re: [PATCH v6 net-next 01/17] net: qualcomm: remove unnecessary includes

[David Miller]

From: Stefan Wahren <stefan.wahren@i2se.com>
Date: Wed, 24 May 2017 22:05:26 +0200 (CEST)

> AFAIK these ones above aren't necessary (no init, no kernel module,
> no kernel parameter, no kernel version) for this C file. So i will
> double check it.

You need the endianness translators like cpu_to_be32() or whatever,
so you need to figure out where you are getting that once these
explicit headers are removed.

And see, it's probably hidden inside of the private header's includes.

So we can't tell.

[PATCH v6 net-next 02/17] net: qca_framing: use u16 for frame offset

[Stefan Wahren]

It doesn't make sense to use a signed variable for offset here, so
fix it up.

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
---
 drivers/net/ethernet/qualcomm/qca_framing.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/qualcomm/qca_framing.h b/drivers/net/ethernet/qualcomm/qca_framing.h
index d5e795d..8b385e6 100644
--- a/drivers/net/ethernet/qualcomm/qca_framing.h
+++ b/drivers/net/ethernet/qualcomm/qca_framing.h
@@ -103,7 +103,7 @@ struct qcafrm_handle {
 	enum qcafrm_state state;
 
 	/* Offset in buffer (borrowed for length too) */
-	s16 offset;
+	u16 offset;
 
 	/* Frame length as kept by this module */
 	u16 len;
-- 
2.1.4

[PATCH v6 net-next 03/17] net: qca_7k: Use BIT macro

[Stefan Wahren]

Use the BIT macro for the CONFIG and INT register values.

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
---
 drivers/net/ethernet/qualcomm/qca_7k.h | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/qualcomm/qca_7k.h b/drivers/net/ethernet/qualcomm/qca_7k.h
index 1cad851..4047f0a 100644
--- a/drivers/net/ethernet/qualcomm/qca_7k.h
+++ b/drivers/net/ethernet/qualcomm/qca_7k.h
@@ -54,15 +54,15 @@
 #define SPI_REG_ACTION_CTRL     0x1B00
 
 /*   SPI_CONFIG register definition;             */
-#define QCASPI_SLAVE_RESET_BIT (1 << 6)
+#define QCASPI_SLAVE_RESET_BIT  BIT(6)
 
 /*   INTR_CAUSE/ENABLE register definition.      */
-#define SPI_INT_WRBUF_BELOW_WM (1 << 10)
-#define SPI_INT_CPU_ON         (1 << 6)
-#define SPI_INT_ADDR_ERR       (1 << 3)
-#define SPI_INT_WRBUF_ERR      (1 << 2)
-#define SPI_INT_RDBUF_ERR      (1 << 1)
-#define SPI_INT_PKT_AVLBL      (1 << 0)
+#define SPI_INT_WRBUF_BELOW_WM  BIT(10)
+#define SPI_INT_CPU_ON          BIT(6)
+#define SPI_INT_ADDR_ERR        BIT(3)
+#define SPI_INT_WRBUF_ERR       BIT(2)
+#define SPI_INT_RDBUF_ERR       BIT(1)
+#define SPI_INT_PKT_AVLBL       BIT(0)
 
 void qcaspi_spi_error(struct qcaspi *qca);
 int qcaspi_read_register(struct qcaspi *qca, u16 reg, u16 *result);
-- 
2.1.4

[PATCH v6 net-next 04/17] net: qca_spi: Use SET_NETDEV_DEV()

[Stefan Wahren]

Use SET_NETDEV_DEV() in qca_spi to create the "/sys/class/net/<if>/device"
symlink.

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
---
 drivers/net/ethernet/qualcomm/qca_spi.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/ethernet/qualcomm/qca_spi.c b/drivers/net/ethernet/qualcomm/qca_spi.c
index 24ca7df..0c3fdee 100644
--- a/drivers/net/ethernet/qualcomm/qca_spi.c
+++ b/drivers/net/ethernet/qualcomm/qca_spi.c
@@ -894,6 +894,7 @@ qca_spi_probe(struct spi_device *spi)
 		return -ENOMEM;
 
 	qcaspi_netdev_setup(qcaspi_devs);
+	SET_NETDEV_DEV(qcaspi_devs, &spi->dev);
 
 	qca = netdev_priv(qcaspi_devs);
 	if (!qca) {
-- 
2.1.4

[PATCH v6 net-next 05/17] net: qualcomm: use net_device_ops instead of direct call

[Stefan Wahren]

There is no need to export qcaspi_netdev_open and qcaspi_netdev_close
because they are also accessible via the net_device_ops.

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
---
 drivers/net/ethernet/qualcomm/qca_debug.c | 5 +++--
 drivers/net/ethernet/qualcomm/qca_spi.c   | 4 ++--
 drivers/net/ethernet/qualcomm/qca_spi.h   | 3 ---
 3 files changed, 5 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/qualcomm/qca_debug.c b/drivers/net/ethernet/qualcomm/qca_debug.c
index d145df9..92b6be9 100644
--- a/drivers/net/ethernet/qualcomm/qca_debug.c
+++ b/drivers/net/ethernet/qualcomm/qca_debug.c
@@ -275,6 +275,7 @@ qcaspi_get_ringparam(struct net_device *dev, struct ethtool_ringparam *ring)
 static int
 qcaspi_set_ringparam(struct net_device *dev, struct ethtool_ringparam *ring)
 {
+	const struct net_device_ops *ops = dev->netdev_ops;
 	struct qcaspi *qca = netdev_priv(dev);
 
 	if ((ring->rx_pending) ||
@@ -283,13 +284,13 @@ qcaspi_set_ringparam(struct net_device *dev, struct ethtool_ringparam *ring)
 		return -EINVAL;
 
 	if (netif_running(dev))
-		qcaspi_netdev_close(dev);
+		ops->ndo_stop(dev);
 
 	qca->txr.count = max_t(u32, ring->tx_pending, TX_RING_MIN_LEN);
 	qca->txr.count = min_t(u16, qca->txr.count, TX_RING_MAX_LEN);
 
 	if (netif_running(dev))
-		qcaspi_netdev_open(dev);
+		ops->ndo_open(dev);
 
 	return 0;
 }
diff --git a/drivers/net/ethernet/qualcomm/qca_spi.c b/drivers/net/ethernet/qualcomm/qca_spi.c
index 0c3fdee..7e039e3 100644
--- a/drivers/net/ethernet/qualcomm/qca_spi.c
+++ b/drivers/net/ethernet/qualcomm/qca_spi.c
@@ -603,7 +603,7 @@ qcaspi_intr_handler(int irq, void *data)
 	return IRQ_HANDLED;
 }
 
-int
+static int
 qcaspi_netdev_open(struct net_device *dev)
 {
 	struct qcaspi *qca = netdev_priv(dev);
@@ -640,7 +640,7 @@ qcaspi_netdev_open(struct net_device *dev)
 	return 0;
 }
 
-int
+static int
 qcaspi_netdev_close(struct net_device *dev)
 {
 	struct qcaspi *qca = netdev_priv(dev);
diff --git a/drivers/net/ethernet/qualcomm/qca_spi.h b/drivers/net/ethernet/qualcomm/qca_spi.h
index 6e31a0e..064853d 100644
--- a/drivers/net/ethernet/qualcomm/qca_spi.h
+++ b/drivers/net/ethernet/qualcomm/qca_spi.h
@@ -108,7 +108,4 @@ struct qcaspi {
 	u16 burst_len;
 };
 
-int qcaspi_netdev_open(struct net_device *dev);
-int qcaspi_netdev_close(struct net_device *dev);
-
 #endif /* _QCA_SPI_H */
-- 
2.1.4

[PATCH v6 net-next 06/17] net: qualcomm: Improve readability of length defines

[Stefan Wahren]

In order to avoid mixing things up, make the MTU and frame length
defines easier to read.

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
---
 drivers/net/ethernet/qualcomm/qca_framing.c |  2 +-
 drivers/net/ethernet/qualcomm/qca_framing.h |  8 ++++----
 drivers/net/ethernet/qualcomm/qca_spi.c     | 12 ++++++------
 3 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/drivers/net/ethernet/qualcomm/qca_framing.c b/drivers/net/ethernet/qualcomm/qca_framing.c
index faa924c..2341f2b 100644
--- a/drivers/net/ethernet/qualcomm/qca_framing.c
+++ b/drivers/net/ethernet/qualcomm/qca_framing.c
@@ -117,7 +117,7 @@ qcafrm_fsm_decode(struct qcafrm_handle *handle, u8 *buf, u16 buf_len, u8 recv_by
 		break;
 	case QCAFRM_WAIT_RSVD_BYTE2:
 		len = handle->offset;
-		if (len > buf_len || len < QCAFRM_ETHMINLEN) {
+		if (len > buf_len || len < QCAFRM_MIN_LEN) {
 			ret = QCAFRM_INVLEN;
 			handle->state = QCAFRM_HW_LEN0;
 		} else {
diff --git a/drivers/net/ethernet/qualcomm/qca_framing.h b/drivers/net/ethernet/qualcomm/qca_framing.h
index 8b385e6..5df7c65 100644
--- a/drivers/net/ethernet/qualcomm/qca_framing.h
+++ b/drivers/net/ethernet/qualcomm/qca_framing.h
@@ -44,12 +44,12 @@
 #define QCAFRM_INVFRAME (QCAFRM_ERR_BASE - 4)
 
 /* Min/Max Ethernet MTU: 46/1500 */
-#define QCAFRM_ETHMINMTU (ETH_ZLEN - ETH_HLEN)
-#define QCAFRM_ETHMAXMTU ETH_DATA_LEN
+#define QCAFRM_MIN_MTU (ETH_ZLEN - ETH_HLEN)
+#define QCAFRM_MAX_MTU ETH_DATA_LEN
 
 /* Min/Max frame lengths */
-#define QCAFRM_ETHMINLEN (QCAFRM_ETHMINMTU + ETH_HLEN)
-#define QCAFRM_ETHMAXLEN (QCAFRM_ETHMAXMTU + VLAN_ETH_HLEN)
+#define QCAFRM_MIN_LEN (QCAFRM_MIN_MTU + ETH_HLEN)
+#define QCAFRM_MAX_LEN (QCAFRM_MAX_MTU + VLAN_ETH_HLEN)
 
 /* QCA7K header len */
 #define QCAFRM_HEADER_LEN 8
diff --git a/drivers/net/ethernet/qualcomm/qca_spi.c b/drivers/net/ethernet/qualcomm/qca_spi.c
index 7e039e3..f155548 100644
--- a/drivers/net/ethernet/qualcomm/qca_spi.c
+++ b/drivers/net/ethernet/qualcomm/qca_spi.c
@@ -69,7 +69,7 @@ static int qcaspi_pluggable = QCASPI_PLUGGABLE_MIN;
 module_param(qcaspi_pluggable, int, 0);
 MODULE_PARM_DESC(qcaspi_pluggable, "Pluggable SPI connection (yes/no).");
 
-#define QCASPI_MTU QCAFRM_ETHMAXMTU
+#define QCASPI_MTU QCAFRM_MAX_MTU
 #define QCASPI_TX_TIMEOUT (1 * HZ)
 #define QCASPI_QCA7K_REBOOT_TIME_MS 1000
 
@@ -403,7 +403,7 @@ qcaspi_tx_ring_has_space(struct tx_ring *txr)
 	if (txr->skb[txr->tail])
 		return 0;
 
-	return (txr->size + QCAFRM_ETHMAXLEN < QCASPI_HW_BUF_LEN) ? 1 : 0;
+	return (txr->size + QCAFRM_MAX_LEN < QCASPI_HW_BUF_LEN) ? 1 : 0;
 }
 
 /*   Flush the tx ring. This function is only safe to
@@ -667,8 +667,8 @@ qcaspi_netdev_xmit(struct sk_buff *skb, struct net_device *dev)
 	struct sk_buff *tskb;
 	u8 pad_len = 0;
 
-	if (skb->len < QCAFRM_ETHMINLEN)
-		pad_len = QCAFRM_ETHMINLEN - skb->len;
+	if (skb->len < QCAFRM_MIN_LEN)
+		pad_len = QCAFRM_MIN_LEN - skb->len;
 
 	if (qca->txr.skb[qca->txr.tail]) {
 		netdev_warn(qca->net_dev, "queue was unexpectedly full!\n");
@@ -805,8 +805,8 @@ qcaspi_netdev_setup(struct net_device *dev)
 	dev->tx_queue_len = 100;
 
 	/* MTU range: 46 - 1500 */
-	dev->min_mtu = QCAFRM_ETHMINMTU;
-	dev->max_mtu = QCAFRM_ETHMAXMTU;
+	dev->min_mtu = QCAFRM_MIN_MTU;
+	dev->max_mtu = QCAFRM_MAX_MTU;
 
 	qca = netdev_priv(dev);
 	memset(qca, 0, sizeof(struct qcaspi));
-- 
2.1.4

[PATCH v6 net-next 07/17] net: qca_spi: remove QCASPI_MTU

[Stefan Wahren]

There is no need for an additional MTU define.

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
---
 drivers/net/ethernet/qualcomm/qca_spi.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/qualcomm/qca_spi.c b/drivers/net/ethernet/qualcomm/qca_spi.c
index f155548..7464628 100644
--- a/drivers/net/ethernet/qualcomm/qca_spi.c
+++ b/drivers/net/ethernet/qualcomm/qca_spi.c
@@ -69,7 +69,6 @@ static int qcaspi_pluggable = QCASPI_PLUGGABLE_MIN;
 module_param(qcaspi_pluggable, int, 0);
 MODULE_PARM_DESC(qcaspi_pluggable, "Pluggable SPI connection (yes/no).");
 
-#define QCASPI_MTU QCAFRM_MAX_MTU
 #define QCASPI_TX_TIMEOUT (1 * HZ)
 #define QCASPI_QCA7K_REBOOT_TIME_MS 1000
 
@@ -746,7 +745,7 @@ qcaspi_netdev_init(struct net_device *dev)
 {
 	struct qcaspi *qca = netdev_priv(dev);
 
-	dev->mtu = QCASPI_MTU;
+	dev->mtu = QCAFRM_MAX_MTU;
 	dev->type = ARPHRD_ETHER;
 	qca->clkspeed = qcaspi_clkspeed;
 	qca->burst_len = qcaspi_burst_len;
-- 
2.1.4

[PATCH v6 net-next 08/17] net: qualcomm: move qcaspi_tx_cmd to qca_spi.c

[Stefan Wahren]

The function qcaspi_tx_cmd() is only called from qca_spi.c. So we better
move it there.

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
---
 drivers/net/ethernet/qualcomm/qca_7k.c  | 24 ------------------------
 drivers/net/ethernet/qualcomm/qca_7k.h  |  1 -
 drivers/net/ethernet/qualcomm/qca_spi.c | 24 ++++++++++++++++++++++++
 3 files changed, 24 insertions(+), 25 deletions(-)

diff --git a/drivers/net/ethernet/qualcomm/qca_7k.c b/drivers/net/ethernet/qualcomm/qca_7k.c
index 557d53c..aa90a1d 100644
--- a/drivers/net/ethernet/qualcomm/qca_7k.c
+++ b/drivers/net/ethernet/qualcomm/qca_7k.c
@@ -119,27 +119,3 @@ qcaspi_write_register(struct qcaspi *qca, u16 reg, u16 value)
 
 	return ret;
 }
-
-int
-qcaspi_tx_cmd(struct qcaspi *qca, u16 cmd)
-{
-	__be16 tx_data;
-	struct spi_message *msg = &qca->spi_msg1;
-	struct spi_transfer *transfer = &qca->spi_xfer1;
-	int ret;
-
-	tx_data = cpu_to_be16(cmd);
-	transfer->len = sizeof(tx_data);
-	transfer->tx_buf = &tx_data;
-	transfer->rx_buf = NULL;
-
-	ret = spi_sync(qca->spi_dev, msg);
-
-	if (!ret)
-		ret = msg->status;
-
-	if (ret)
-		qcaspi_spi_error(qca);
-
-	return ret;
-}
diff --git a/drivers/net/ethernet/qualcomm/qca_7k.h b/drivers/net/ethernet/qualcomm/qca_7k.h
index 4047f0a..27124c2 100644
--- a/drivers/net/ethernet/qualcomm/qca_7k.h
+++ b/drivers/net/ethernet/qualcomm/qca_7k.h
@@ -67,6 +67,5 @@
 void qcaspi_spi_error(struct qcaspi *qca);
 int qcaspi_read_register(struct qcaspi *qca, u16 reg, u16 *result);
 int qcaspi_write_register(struct qcaspi *qca, u16 reg, u16 value);
-int qcaspi_tx_cmd(struct qcaspi *qca, u16 cmd);
 
 #endif /* _QCA_7K_H */
diff --git a/drivers/net/ethernet/qualcomm/qca_spi.c b/drivers/net/ethernet/qualcomm/qca_spi.c
index 7464628..50adc4f 100644
--- a/drivers/net/ethernet/qualcomm/qca_spi.c
+++ b/drivers/net/ethernet/qualcomm/qca_spi.c
@@ -192,6 +192,30 @@ qcaspi_read_legacy(struct qcaspi *qca, u8 *dst, u32 len)
 }
 
 static int
+qcaspi_tx_cmd(struct qcaspi *qca, u16 cmd)
+{
+	__be16 tx_data;
+	struct spi_message *msg = &qca->spi_msg1;
+	struct spi_transfer *transfer = &qca->spi_xfer1;
+	int ret;
+
+	tx_data = cpu_to_be16(cmd);
+	transfer->len = sizeof(tx_data);
+	transfer->tx_buf = &tx_data;
+	transfer->rx_buf = NULL;
+
+	ret = spi_sync(qca->spi_dev, msg);
+
+	if (!ret)
+		ret = msg->status;
+
+	if (ret)
+		qcaspi_spi_error(qca);
+
+	return ret;
+}
+
+static int
 qcaspi_tx_frame(struct qcaspi *qca, struct sk_buff *skb)
 {
 	u32 count;
-- 
2.1.4

[PATCH v6 net-next 09/17] net: qca_spi: Clarify MODULE_DESCRIPTION

[Stefan Wahren]

Since this driver is specific to the QCA7000, we should make the module
description more precisely.

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
---
 drivers/net/ethernet/qualcomm/qca_spi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/qualcomm/qca_spi.c b/drivers/net/ethernet/qualcomm/qca_spi.c
index 50adc4f..ee90af3 100644
--- a/drivers/net/ethernet/qualcomm/qca_spi.c
+++ b/drivers/net/ethernet/qualcomm/qca_spi.c
@@ -999,7 +999,7 @@ static struct spi_driver qca_spi_driver = {
 };
 module_spi_driver(qca_spi_driver);
 
-MODULE_DESCRIPTION("Qualcomm Atheros SPI Driver");
+MODULE_DESCRIPTION("Qualcomm Atheros QCA7000 SPI Driver");
 MODULE_AUTHOR("Qualcomm Atheros Communications");
 MODULE_AUTHOR("Stefan Wahren <stefan.wahren@i2se.com>");
 MODULE_LICENSE("Dual BSD/GPL");
-- 
2.1.4

[PATCH v6 net-next 10/17] net: qualcomm: rename qca_framing.c to qca_7k_common.c

[Stefan Wahren]

As preparation for the upcoming UART driver we need a module
which contains common functions for both interfaces. The module
qca_framing is a good candidate but renaming to qca_7k_common would
make it clear.

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
---
 drivers/net/ethernet/qualcomm/Makefile                           | 2 +-
 drivers/net/ethernet/qualcomm/{qca_framing.c => qca_7k_common.c} | 2 +-
 drivers/net/ethernet/qualcomm/{qca_framing.h => qca_7k_common.h} | 0
 drivers/net/ethernet/qualcomm/qca_spi.c                          | 2 +-
 drivers/net/ethernet/qualcomm/qca_spi.h                          | 2 +-
 5 files changed, 4 insertions(+), 4 deletions(-)
 rename drivers/net/ethernet/qualcomm/{qca_framing.c => qca_7k_common.c} (99%)
 rename drivers/net/ethernet/qualcomm/{qca_framing.h => qca_7k_common.h} (100%)

diff --git a/drivers/net/ethernet/qualcomm/Makefile b/drivers/net/ethernet/qualcomm/Makefile
index aacb0a5..5e17bf1 100644
--- a/drivers/net/ethernet/qualcomm/Makefile
+++ b/drivers/net/ethernet/qualcomm/Makefile
@@ -3,6 +3,6 @@
 #
 
 obj-$(CONFIG_QCA7000) += qcaspi.o
-qcaspi-objs := qca_spi.o qca_framing.o qca_7k.o qca_debug.o
+qcaspi-objs := qca_spi.o qca_7k_common.o qca_7k.o qca_debug.o
 
 obj-y += emac/
diff --git a/drivers/net/ethernet/qualcomm/qca_framing.c b/drivers/net/ethernet/qualcomm/qca_7k_common.c
similarity index 99%
rename from drivers/net/ethernet/qualcomm/qca_framing.c
rename to drivers/net/ethernet/qualcomm/qca_7k_common.c
index 2341f2b..6d17fbd 100644
--- a/drivers/net/ethernet/qualcomm/qca_framing.c
+++ b/drivers/net/ethernet/qualcomm/qca_7k_common.c
@@ -23,7 +23,7 @@
 
 #include <linux/kernel.h>
 
-#include "qca_framing.h"
+#include "qca_7k_common.h"
 
 u16
 qcafrm_create_header(u8 *buf, u16 length)
diff --git a/drivers/net/ethernet/qualcomm/qca_framing.h b/drivers/net/ethernet/qualcomm/qca_7k_common.h
similarity index 100%
rename from drivers/net/ethernet/qualcomm/qca_framing.h
rename to drivers/net/ethernet/qualcomm/qca_7k_common.h
diff --git a/drivers/net/ethernet/qualcomm/qca_spi.c b/drivers/net/ethernet/qualcomm/qca_spi.c
index ee90af3..43cc7de 100644
--- a/drivers/net/ethernet/qualcomm/qca_spi.c
+++ b/drivers/net/ethernet/qualcomm/qca_spi.c
@@ -43,8 +43,8 @@
 #include <linux/types.h>
 
 #include "qca_7k.h"
+#include "qca_7k_common.h"
 #include "qca_debug.h"
-#include "qca_framing.h"
 #include "qca_spi.h"
 
 #define MAX_DMA_BURST_LEN 5000
diff --git a/drivers/net/ethernet/qualcomm/qca_spi.h b/drivers/net/ethernet/qualcomm/qca_spi.h
index 064853d..fc4beb1 100644
--- a/drivers/net/ethernet/qualcomm/qca_spi.h
+++ b/drivers/net/ethernet/qualcomm/qca_spi.h
@@ -32,7 +32,7 @@
 #include <linux/spi/spi.h>
 #include <linux/types.h>
 
-#include "qca_framing.h"
+#include "qca_7k_common.h"
 
 #define QCASPI_DRV_VERSION "0.2.7-i"
 #define QCASPI_DRV_NAME    "qcaspi"
-- 
2.1.4

[PATCH v6 net-next 11/17] net: qualcomm: prepare frame decoding for UART driver

[Stefan Wahren]

Unfortunately the frame format is not exactly identical between SPI
and UART. In case of SPI there is an additional HW length at the
beginning. So store the initial state to make the decoding state machine
more flexible and easy to extend for UART support.

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
---
 drivers/net/ethernet/qualcomm/qca_7k_common.c | 12 ++++++------
 drivers/net/ethernet/qualcomm/qca_7k_common.h |  8 ++++++--
 drivers/net/ethernet/qualcomm/qca_spi.c       |  2 +-
 3 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ethernet/qualcomm/qca_7k_common.c b/drivers/net/ethernet/qualcomm/qca_7k_common.c
index 6d17fbd..0d3daa9 100644
--- a/drivers/net/ethernet/qualcomm/qca_7k_common.c
+++ b/drivers/net/ethernet/qualcomm/qca_7k_common.c
@@ -83,7 +83,7 @@ qcafrm_fsm_decode(struct qcafrm_handle *handle, u8 *buf, u16 buf_len, u8 recv_by
 
 		if (recv_byte != 0x00) {
 			/* first two bytes of length must be 0 */
-			handle->state = QCAFRM_HW_LEN0;
+			handle->state = handle->init;
 		}
 		break;
 	case QCAFRM_HW_LEN2:
@@ -97,7 +97,7 @@ qcafrm_fsm_decode(struct qcafrm_handle *handle, u8 *buf, u16 buf_len, u8 recv_by
 	case QCAFRM_WAIT_AA4:
 		if (recv_byte != 0xAA) {
 			ret = QCAFRM_NOHEAD;
-			handle->state = QCAFRM_HW_LEN0;
+			handle->state = handle->init;
 		} else {
 			handle->state--;
 		}
@@ -119,7 +119,7 @@ qcafrm_fsm_decode(struct qcafrm_handle *handle, u8 *buf, u16 buf_len, u8 recv_by
 		len = handle->offset;
 		if (len > buf_len || len < QCAFRM_MIN_LEN) {
 			ret = QCAFRM_INVLEN;
-			handle->state = QCAFRM_HW_LEN0;
+			handle->state = handle->init;
 		} else {
 			handle->state = (enum qcafrm_state)(len + 1);
 			/* Remaining number of bytes. */
@@ -135,7 +135,7 @@ qcafrm_fsm_decode(struct qcafrm_handle *handle, u8 *buf, u16 buf_len, u8 recv_by
 	case QCAFRM_WAIT_551:
 		if (recv_byte != 0x55) {
 			ret = QCAFRM_NOTAIL;
-			handle->state = QCAFRM_HW_LEN0;
+			handle->state = handle->init;
 		} else {
 			handle->state = QCAFRM_WAIT_552;
 		}
@@ -143,11 +143,11 @@ qcafrm_fsm_decode(struct qcafrm_handle *handle, u8 *buf, u16 buf_len, u8 recv_by
 	case QCAFRM_WAIT_552:
 		if (recv_byte != 0x55) {
 			ret = QCAFRM_NOTAIL;
-			handle->state = QCAFRM_HW_LEN0;
+			handle->state = handle->init;
 		} else {
 			ret = handle->offset;
 			/* Frame is fully received. */
-			handle->state = QCAFRM_HW_LEN0;
+			handle->state = handle->init;
 		}
 		break;
 	}
diff --git a/drivers/net/ethernet/qualcomm/qca_7k_common.h b/drivers/net/ethernet/qualcomm/qca_7k_common.h
index 5df7c65..07bdd6c 100644
--- a/drivers/net/ethernet/qualcomm/qca_7k_common.h
+++ b/drivers/net/ethernet/qualcomm/qca_7k_common.h
@@ -61,6 +61,7 @@
 #define QCAFRM_ERR_BASE -1000
 
 enum qcafrm_state {
+	/* HW length is only available on SPI */
 	QCAFRM_HW_LEN0 = 0x8000,
 	QCAFRM_HW_LEN1 = QCAFRM_HW_LEN0 - 1,
 	QCAFRM_HW_LEN2 = QCAFRM_HW_LEN1 - 1,
@@ -101,6 +102,8 @@ enum qcafrm_state {
 struct qcafrm_handle {
 	/*  Current decoding state */
 	enum qcafrm_state state;
+	/* Initial state depends on connection type */
+	enum qcafrm_state init;
 
 	/* Offset in buffer (borrowed for length too) */
 	u16 offset;
@@ -113,9 +116,10 @@ u16 qcafrm_create_header(u8 *buf, u16 len);
 
 u16 qcafrm_create_footer(u8 *buf);
 
-static inline void qcafrm_fsm_init(struct qcafrm_handle *handle)
+static inline void qcafrm_fsm_init_spi(struct qcafrm_handle *handle)
 {
-	handle->state = QCAFRM_HW_LEN0;
+	handle->init = QCAFRM_HW_LEN0;
+	handle->state = handle->init;
 }
 
 /*   Gather received bytes and try to extract a full Ethernet frame
diff --git a/drivers/net/ethernet/qualcomm/qca_spi.c b/drivers/net/ethernet/qualcomm/qca_spi.c
index 43cc7de..de78f60 100644
--- a/drivers/net/ethernet/qualcomm/qca_spi.c
+++ b/drivers/net/ethernet/qualcomm/qca_spi.c
@@ -638,7 +638,7 @@ qcaspi_netdev_open(struct net_device *dev)
 	qca->intr_req = 1;
 	qca->intr_svc = 0;
 	qca->sync = QCASPI_SYNC_UNKNOWN;
-	qcafrm_fsm_init(&qca->frm_handle);
+	qcafrm_fsm_init_spi(&qca->frm_handle);
 
 	qca->spi_thread = kthread_run((void *)qcaspi_spi_thread,
 				      qca, "%s", dev->name);
-- 
2.1.4

[PATCH v6 net-next 12/17] net: qualcomm: make qca_7k_common a separate kernel module

[Stefan Wahren]

In order to share common functions between QCA7000 SPI and UART protocol
driver the qca_7k_common needs to be a separate kernel module.

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
---
 drivers/net/ethernet/qualcomm/Kconfig         |  8 +++++++-
 drivers/net/ethernet/qualcomm/Makefile        |  5 +++--
 drivers/net/ethernet/qualcomm/qca_7k_common.c | 10 ++++++++++
 3 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/qualcomm/Kconfig b/drivers/net/ethernet/qualcomm/Kconfig
index d7720bf..b4c369d 100644
--- a/drivers/net/ethernet/qualcomm/Kconfig
+++ b/drivers/net/ethernet/qualcomm/Kconfig
@@ -16,7 +16,13 @@ config NET_VENDOR_QUALCOMM
 if NET_VENDOR_QUALCOMM
 
 config QCA7000
-	tristate "Qualcomm Atheros QCA7000 support"
+	tristate
+	help
+	  This enables support for the Qualcomm Atheros QCA7000.
+
+config QCA7000_SPI
+	tristate "Qualcomm Atheros QCA7000 SPI support"
+	select QCA7000
 	depends on SPI_MASTER && OF
 	---help---
 	  This SPI protocol driver supports the Qualcomm Atheros QCA7000.
diff --git a/drivers/net/ethernet/qualcomm/Makefile b/drivers/net/ethernet/qualcomm/Makefile
index 5e17bf1..65556ca 100644
--- a/drivers/net/ethernet/qualcomm/Makefile
+++ b/drivers/net/ethernet/qualcomm/Makefile
@@ -2,7 +2,8 @@
 # Makefile for the Qualcomm network device drivers.
 #
 
-obj-$(CONFIG_QCA7000) += qcaspi.o
-qcaspi-objs := qca_spi.o qca_7k_common.o qca_7k.o qca_debug.o
+obj-$(CONFIG_QCA7000) += qca_7k_common.o
+obj-$(CONFIG_QCA7000_SPI) += qcaspi.o
+qcaspi-objs := qca_7k.o qca_debug.o qca_spi.o
 
 obj-y += emac/
diff --git a/drivers/net/ethernet/qualcomm/qca_7k_common.c b/drivers/net/ethernet/qualcomm/qca_7k_common.c
index 0d3daa9..6b511f0 100644
--- a/drivers/net/ethernet/qualcomm/qca_7k_common.c
+++ b/drivers/net/ethernet/qualcomm/qca_7k_common.c
@@ -21,7 +21,9 @@
  *   by an atheros frame while transmitted over a serial channel;
  */
 
+#include <linux/init.h>
 #include <linux/kernel.h>
+#include <linux/module.h>
 
 #include "qca_7k_common.h"
 
@@ -46,6 +48,7 @@ qcafrm_create_header(u8 *buf, u16 length)
 
 	return QCAFRM_HEADER_LEN;
 }
+EXPORT_SYMBOL_GPL(qcafrm_create_header);
 
 u16
 qcafrm_create_footer(u8 *buf)
@@ -57,6 +60,7 @@ qcafrm_create_footer(u8 *buf)
 	buf[1] = 0x55;
 	return QCAFRM_FOOTER_LEN;
 }
+EXPORT_SYMBOL_GPL(qcafrm_create_footer);
 
 /*   Gather received bytes and try to extract a full ethernet frame by
  *   following a simple state machine.
@@ -154,3 +158,9 @@ qcafrm_fsm_decode(struct qcafrm_handle *handle, u8 *buf, u16 buf_len, u8 recv_by
 
 	return ret;
 }
+EXPORT_SYMBOL_GPL(qcafrm_fsm_decode);
+
+MODULE_DESCRIPTION("Qualcomm Atheros QCA7000 common");
+MODULE_AUTHOR("Qualcomm Atheros Communications");
+MODULE_AUTHOR("Stefan Wahren <stefan.wahren@i2se.com>");
+MODULE_LICENSE("Dual BSD/GPL");
-- 
2.1.4

[PATCH v6 net-next 13/17] dt-bindings: qca7000-spi: Rework binding

[Stefan Wahren]

In preparation for the QCA7000 UART binding rework the binding document.

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
---
 .../devicetree/bindings/net/qca-qca7000-spi.txt    | 49 +++++++++++++---------
 1 file changed, 29 insertions(+), 20 deletions(-)

diff --git a/Documentation/devicetree/bindings/net/qca-qca7000-spi.txt b/Documentation/devicetree/bindings/net/qca-qca7000-spi.txt
index c74989c..a37f656 100644
--- a/Documentation/devicetree/bindings/net/qca-qca7000-spi.txt
+++ b/Documentation/devicetree/bindings/net/qca-qca7000-spi.txt
@@ -1,29 +1,38 @@
-* Qualcomm QCA7000 (Ethernet over SPI protocol)
+* Qualcomm QCA7000
 
-Note: The QCA7000 is useable as a SPI device. In this case it must be defined
-as a child of a SPI master in the device tree.
+The QCA7000 is a serial-to-powerline bridge with a host interface which could
+be configured either as SPI or UART slave. This configuration is done by
+the QCA7000 firmware.
+
+(a) Ethernet over SPI
+
+In order to use the QCA7000 as SPI device it must be defined as a child of a
+SPI master in the device tree.
 
 Required properties:
-- compatible : Should be "qca,qca7000"
-- reg : Should specify the SPI chip select
-- interrupts : The first cell should specify the index of the source interrupt
-  and the second cell should specify the trigger type as rising edge
-- spi-cpha : Must be set
-- spi-cpol: Must be set
+- compatible	    : Should be "qca,qca7000"
+- reg		    : Should specify the SPI chip select
+- interrupts	    : The first cell should specify the index of the source
+		      interrupt and the second cell should specify the trigger
+		      type as rising edge
+- spi-cpha	    : Must be set
+- spi-cpol	    : Must be set
 
 Optional properties:
-- interrupt-parent : Specify the pHandle of the source interrupt
+- interrupt-parent  : Specify the pHandle of the source interrupt
 - spi-max-frequency : Maximum frequency of the SPI bus the chip can operate at.
-  Numbers smaller than 1000000 or greater than 16000000 are invalid. Missing
-  the property will set the SPI frequency to 8000000 Hertz.
-- local-mac-address: 6 bytes, MAC address
-- qca,legacy-mode : Set the SPI data transfer of the QCA7000 to legacy mode.
-  In this mode the SPI master must toggle the chip select between each data
-  word. In burst mode these gaps aren't necessary, which is faster.
-  This setting depends on how the QCA7000 is setup via GPIO pin strapping.
-  If the property is missing the driver defaults to burst mode.
-
-Example:
+		      Numbers smaller than 1000000 or greater than 16000000
+		      are invalid. Missing the property will set the SPI
+		      frequency to 8000000 Hertz.
+- local-mac-address : see ./ethernet.txt
+- qca,legacy-mode   : Set the SPI data transfer of the QCA7000 to legacy mode.
+		      In this mode the SPI master must toggle the chip select
+		      between each data word. In burst mode these gaps aren't
+		      necessary, which is faster. This setting depends on how
+		      the QCA7000 is setup via GPIO pin strapping. If the
+		      property is missing the driver defaults to burst mode.
+
+SPI Example:
 
 /* Freescale i.MX28 SPI master*/
 ssp2: spi@80014000 {
-- 
2.1.4

[PATCH v6 net-next 14/17] dt-bindings: qca7000: rename binding

[Stefan Wahren]

Before we can merge the QCA7000 UART binding the document needs to be
renamed.

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
---
 .../devicetree/bindings/net/{qca-qca7000-spi.txt => qca,qca7000.txt}      | 0
 1 file changed, 0 insertions(+), 0 deletions(-)
 rename Documentation/devicetree/bindings/net/{qca-qca7000-spi.txt => qca,qca7000.txt} (100%)

diff --git a/Documentation/devicetree/bindings/net/qca-qca7000-spi.txt b/Documentation/devicetree/bindings/net/qca,qca7000.txt
similarity index 100%
rename from Documentation/devicetree/bindings/net/qca-qca7000-spi.txt
rename to Documentation/devicetree/bindings/net/qca,qca7000.txt
-- 
2.1.4

[PATCH v6 net-next 15/17] dt-bindings: slave-device: add current-speed property

[Stefan Wahren]

This adds a new DT property to define the current baud rate of the
slave device.

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Reviewed-by: Rob Herring <robh@kernel.org>
---
 Documentation/devicetree/bindings/serial/slave-device.txt | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/Documentation/devicetree/bindings/serial/slave-device.txt b/Documentation/devicetree/bindings/serial/slave-device.txt
index f660379..40110e0 100644
--- a/Documentation/devicetree/bindings/serial/slave-device.txt
+++ b/Documentation/devicetree/bindings/serial/slave-device.txt
@@ -21,6 +21,15 @@ Optional Properties:
 		  can support. For example, a particular board has some signal
 		  quality issue or the host processor can't support higher
 		  baud rates.
+- current-speed	: The current baud rate the device operates at. This should
+		  only be present in case a driver has no chance to know
+		  the baud rate of the slave device.
+		  Examples:
+		    * device supports auto-baud
+		    * the rate is setup by a bootloader and there is no
+		      way to reset the device
+		    * device baud rate is configured by its firmware but
+		      there is no way to request the actual settings
 
 Example:
 
-- 
2.1.4

[PATCH v6 net-next 16/17] dt-bindings: qca7000: append UART interface to binding

[Stefan Wahren]

This merges the serdev binding for the QCA7000 UART driver (Ethernet over
UART) into the existing document.

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
---
 .../devicetree/bindings/net/qca,qca7000.txt        | 32 ++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/Documentation/devicetree/bindings/net/qca,qca7000.txt b/Documentation/devicetree/bindings/net/qca,qca7000.txt
index a37f656..6d9efb2 100644
--- a/Documentation/devicetree/bindings/net/qca,qca7000.txt
+++ b/Documentation/devicetree/bindings/net/qca,qca7000.txt
@@ -54,3 +54,35 @@ ssp2: spi@80014000 {
 		local-mac-address = [ A0 B0 C0 D0 E0 F0 ];
 	};
 };
+
+(b) Ethernet over UART
+
+In order to use the QCA7000 as UART slave it must be defined as a child of a
+UART master in the device tree. It is possible to preconfigure the UART
+settings of the QCA7000 firmware, but it's not possible to change them during
+runtime.
+
+Required properties:
+- compatible        : Should be "qca,qca7000"
+
+Optional properties:
+- local-mac-address : see ./ethernet.txt
+- current-speed     : current baud rate of QCA7000 which defaults to 115200
+		      if absent, see also ../serial/slave-device.txt
+
+UART Example:
+
+/* Freescale i.MX28 UART */
+auart0: serial@8006a000 {
+	compatible = "fsl,imx28-auart", "fsl,imx23-auart";
+	reg = <0x8006a000 0x2000>;
+	pinctrl-names = "default";
+	pinctrl-0 = <&auart0_2pins_a>;
+	status = "okay";
+
+	qca7000: ethernet {
+		compatible = "qca,qca7000";
+		local-mac-address = [ A0 B0 C0 D0 E0 F0 ];
+		current-speed = <38400>;
+	};
+};
-- 
2.1.4

[PATCH v6 net-next 16/17] dt-bindings: qca7000: append UART interface to binding

[Stefan Wahren]

This merges the serdev binding for the QCA7000 UART driver (Ethernet over
UART) into the existing document.

Signed-off-by: Stefan Wahren <stefan.wahren-eS4NqCHxEME@public.gmane.org>
---
 .../devicetree/bindings/net/qca,qca7000.txt        | 32 ++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/Documentation/devicetree/bindings/net/qca,qca7000.txt b/Documentation/devicetree/bindings/net/qca,qca7000.txt
index a37f656..6d9efb2 100644
--- a/Documentation/devicetree/bindings/net/qca,qca7000.txt
+++ b/Documentation/devicetree/bindings/net/qca,qca7000.txt
@@ -54,3 +54,35 @@ ssp2: spi@80014000 {
 		local-mac-address = [ A0 B0 C0 D0 E0 F0 ];
 	};
 };
+
+(b) Ethernet over UART
+
+In order to use the QCA7000 as UART slave it must be defined as a child of a
+UART master in the device tree. It is possible to preconfigure the UART
+settings of the QCA7000 firmware, but it's not possible to change them during
+runtime.
+
+Required properties:
+- compatible        : Should be "qca,qca7000"
+
+Optional properties:
+- local-mac-address : see ./ethernet.txt
+- current-speed     : current baud rate of QCA7000 which defaults to 115200
+		      if absent, see also ../serial/slave-device.txt
+
+UART Example:
+
+/* Freescale i.MX28 UART */
+auart0: serial@8006a000 {
+	compatible = "fsl,imx28-auart", "fsl,imx23-auart";
+	reg = <0x8006a000 0x2000>;
+	pinctrl-names = "default";
+	pinctrl-0 = <&auart0_2pins_a>;
+	status = "okay";
+
+	qca7000: ethernet {
+		compatible = "qca,qca7000";
+		local-mac-address = [ A0 B0 C0 D0 E0 F0 ];
+		current-speed = <38400>;
+	};
+};
-- 
2.1.4

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[PATCH v6 net-next 17/17] net: qualcomm: add QCA7000 UART driver

[Stefan Wahren]

This patch adds the Ethernet over UART driver for the
Qualcomm QCA7000 HomePlug GreenPHY.

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
---
 drivers/net/ethernet/qualcomm/Kconfig         |  16 +
 drivers/net/ethernet/qualcomm/Makefile        |   2 +
 drivers/net/ethernet/qualcomm/qca_7k_common.h |   6 +
 drivers/net/ethernet/qualcomm/qca_uart.c      | 423 ++++++++++++++++++++++++++
 4 files changed, 447 insertions(+)
 create mode 100644 drivers/net/ethernet/qualcomm/qca_uart.c

diff --git a/drivers/net/ethernet/qualcomm/Kconfig b/drivers/net/ethernet/qualcomm/Kconfig
index b4c369d..877675a 100644
--- a/drivers/net/ethernet/qualcomm/Kconfig
+++ b/drivers/net/ethernet/qualcomm/Kconfig
@@ -30,6 +30,22 @@ config QCA7000_SPI
 	  To compile this driver as a module, choose M here. The module
 	  will be called qcaspi.
 
+config QCA7000_UART
+	tristate "Qualcomm Atheros QCA7000 UART support"
+	select QCA7000
+	depends on SERIAL_DEV_BUS && OF
+	---help---
+	  This UART protocol driver supports the Qualcomm Atheros QCA7000.
+
+	  Currently the driver assumes these device UART settings:
+	    Data bits: 8
+	    Parity: None
+	    Stop bits: 1
+	    Flow control: None
+
+	  To compile this driver as a module, choose M here. The module
+	  will be called qcauart.
+
 config QCOM_EMAC
 	tristate "Qualcomm Technologies, Inc. EMAC Gigabit Ethernet support"
 	depends on HAS_DMA && HAS_IOMEM
diff --git a/drivers/net/ethernet/qualcomm/Makefile b/drivers/net/ethernet/qualcomm/Makefile
index 65556ca..92fa7c4 100644
--- a/drivers/net/ethernet/qualcomm/Makefile
+++ b/drivers/net/ethernet/qualcomm/Makefile
@@ -5,5 +5,7 @@
 obj-$(CONFIG_QCA7000) += qca_7k_common.o
 obj-$(CONFIG_QCA7000_SPI) += qcaspi.o
 qcaspi-objs := qca_7k.o qca_debug.o qca_spi.o
+obj-$(CONFIG_QCA7000_UART) += qcauart.o
+qcauart-objs := qca_uart.o
 
 obj-y += emac/
diff --git a/drivers/net/ethernet/qualcomm/qca_7k_common.h b/drivers/net/ethernet/qualcomm/qca_7k_common.h
index 07bdd6c..928554f 100644
--- a/drivers/net/ethernet/qualcomm/qca_7k_common.h
+++ b/drivers/net/ethernet/qualcomm/qca_7k_common.h
@@ -122,6 +122,12 @@ static inline void qcafrm_fsm_init_spi(struct qcafrm_handle *handle)
 	handle->state = handle->init;
 }
 
+static inline void qcafrm_fsm_init_uart(struct qcafrm_handle *handle)
+{
+	handle->init = QCAFRM_WAIT_AA1;
+	handle->state = handle->init;
+}
+
 /*   Gather received bytes and try to extract a full Ethernet frame
  *   by following a simple state machine.
  *
diff --git a/drivers/net/ethernet/qualcomm/qca_uart.c b/drivers/net/ethernet/qualcomm/qca_uart.c
new file mode 100644
index 0000000..43d91ba
--- /dev/null
+++ b/drivers/net/ethernet/qualcomm/qca_uart.c
@@ -0,0 +1,423 @@
+/*
+ *   Copyright (c) 2011, 2012, Qualcomm Atheros Communications Inc.
+ *   Copyright (c) 2017, I2SE GmbH
+ *
+ *   Permission to use, copy, modify, and/or distribute this software
+ *   for any purpose with or without fee is hereby granted, provided
+ *   that the above copyright notice and this permission notice appear
+ *   in all copies.
+ *
+ *   THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
+ *   WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
+ *   WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
+ *   THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR
+ *   CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ *   LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
+ *   NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ *   CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*   This module implements the Qualcomm Atheros UART protocol for
+ *   kernel-based UART device; it is essentially an Ethernet-to-UART
+ *   serial converter;
+ */
+
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/etherdevice.h>
+#include <linux/if_arp.h>
+#include <linux/if_ether.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_net.h>
+#include <linux/sched.h>
+#include <linux/serdev.h>
+#include <linux/skbuff.h>
+#include <linux/types.h>
+
+#include "qca_7k_common.h"
+
+#define QCAUART_DRV_VERSION "0.1.0"
+#define QCAUART_DRV_NAME "qcauart"
+#define QCAUART_TX_TIMEOUT (1 * HZ)
+
+struct qcauart {
+	struct net_device *net_dev;
+	spinlock_t lock;			/* transmit lock */
+	struct work_struct tx_work;		/* Flushes transmit buffer   */
+
+	struct serdev_device *serdev;
+	struct qcafrm_handle frm_handle;
+	struct sk_buff *rx_skb;
+
+	unsigned char *tx_head;			/* pointer to next XMIT byte */
+	int tx_left;				/* bytes left in XMIT queue  */
+	unsigned char *tx_buffer;
+};
+
+static int
+qca_tty_receive(struct serdev_device *serdev, const unsigned char *data,
+		size_t count)
+{
+	struct qcauart *qca = serdev_device_get_drvdata(serdev);
+	struct net_device *netdev = qca->net_dev;
+	struct net_device_stats *n_stats = &netdev->stats;
+	size_t i;
+
+	if (!qca->rx_skb) {
+		qca->rx_skb = netdev_alloc_skb_ip_align(netdev,
+							netdev->mtu +
+							VLAN_ETH_HLEN);
+		if (!qca->rx_skb) {
+			n_stats->rx_errors++;
+			n_stats->rx_dropped++;
+			return 0;
+		}
+	}
+
+	for (i = 0; i < count; i++) {
+		s32 retcode;
+
+		retcode = qcafrm_fsm_decode(&qca->frm_handle,
+					    qca->rx_skb->data,
+					    skb_tailroom(qca->rx_skb),
+					    data[i]);
+
+		switch (retcode) {
+		case QCAFRM_GATHER:
+		case QCAFRM_NOHEAD:
+			break;
+		case QCAFRM_NOTAIL:
+			netdev_dbg(netdev, "recv: no RX tail\n");
+			n_stats->rx_errors++;
+			n_stats->rx_dropped++;
+			break;
+		case QCAFRM_INVLEN:
+			netdev_dbg(netdev, "recv: invalid RX length\n");
+			n_stats->rx_errors++;
+			n_stats->rx_dropped++;
+			break;
+		default:
+			n_stats->rx_packets++;
+			n_stats->rx_bytes += retcode;
+			skb_put(qca->rx_skb, retcode);
+			qca->rx_skb->protocol = eth_type_trans(
+						qca->rx_skb, qca->rx_skb->dev);
+			qca->rx_skb->ip_summed = CHECKSUM_UNNECESSARY;
+			netif_rx_ni(qca->rx_skb);
+			qca->rx_skb = netdev_alloc_skb_ip_align(netdev,
+								netdev->mtu +
+								VLAN_ETH_HLEN);
+			if (!qca->rx_skb) {
+				netdev_dbg(netdev, "recv: out of RX resources\n");
+				n_stats->rx_errors++;
+				return i;
+			}
+		}
+	}
+
+	return i;
+}
+
+/* Write out any remaining transmit buffer. Scheduled when tty is writable */
+static void qcauart_transmit(struct work_struct *work)
+{
+	struct qcauart *qca = container_of(work, struct qcauart, tx_work);
+	struct net_device_stats *n_stats = &qca->net_dev->stats;
+	int written;
+
+	spin_lock_bh(&qca->lock);
+
+	/* First make sure we're connected. */
+	if (!netif_running(qca->net_dev)) {
+		spin_unlock_bh(&qca->lock);
+		return;
+	}
+
+	if (qca->tx_left <= 0)  {
+		/* Now serial buffer is almost free & we can start
+		 * transmission of another packet
+		 */
+		n_stats->tx_packets++;
+		spin_unlock_bh(&qca->lock);
+		netif_wake_queue(qca->net_dev);
+		return;
+	}
+
+	written = serdev_device_write_buf(qca->serdev, qca->tx_head,
+					  qca->tx_left);
+	if (written > 0) {
+		qca->tx_left -= written;
+		qca->tx_head += written;
+	}
+	spin_unlock_bh(&qca->lock);
+}
+
+/* Called by the driver when there's room for more data.
+ * Schedule the transmit.
+ */
+static void qca_tty_wakeup(struct serdev_device *serdev)
+{
+	struct qcauart *qca = serdev_device_get_drvdata(serdev);
+
+	schedule_work(&qca->tx_work);
+}
+
+static struct serdev_device_ops qca_serdev_ops = {
+	.receive_buf = qca_tty_receive,
+	.write_wakeup = qca_tty_wakeup,
+};
+
+static int qcauart_netdev_open(struct net_device *dev)
+{
+	struct qcauart *qca = netdev_priv(dev);
+
+	netif_start_queue(qca->net_dev);
+
+	return 0;
+}
+
+static int qcauart_netdev_close(struct net_device *dev)
+{
+	struct qcauart *qca = netdev_priv(dev);
+
+	netif_stop_queue(dev);
+	flush_work(&qca->tx_work);
+
+	spin_lock_bh(&qca->lock);
+	qca->tx_left = 0;
+	spin_unlock_bh(&qca->lock);
+
+	return 0;
+}
+
+static netdev_tx_t
+qcauart_netdev_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	struct net_device_stats *n_stats = &dev->stats;
+	struct qcauart *qca = netdev_priv(dev);
+	u8 pad_len = 0;
+	int written;
+	u8 *pos;
+
+	spin_lock(&qca->lock);
+
+	WARN_ON(qca->tx_left);
+
+	if (!netif_running(dev))  {
+		spin_unlock(&qca->lock);
+		netdev_warn(qca->net_dev, "xmit: iface is down\n");
+		goto out;
+	}
+
+	pos = qca->tx_buffer;
+
+	if (skb->len < QCAFRM_MIN_LEN)
+		pad_len = QCAFRM_MIN_LEN - skb->len;
+
+	pos += qcafrm_create_header(pos, skb->len + pad_len);
+
+	memcpy(pos, skb->data, skb->len);
+	pos += skb->len;
+
+	if (pad_len) {
+		memset(pos, 0, pad_len);
+		pos += pad_len;
+	}
+
+	pos += qcafrm_create_footer(pos);
+
+	netif_stop_queue(qca->net_dev);
+
+	written = serdev_device_write_buf(qca->serdev, qca->tx_buffer,
+					  pos - qca->tx_buffer);
+	if (written > 0) {
+		qca->tx_left = (pos - qca->tx_buffer) - written;
+		qca->tx_head = qca->tx_buffer + written;
+		n_stats->tx_bytes += written;
+	}
+	spin_unlock(&qca->lock);
+
+	netif_trans_update(dev);
+out:
+	dev_kfree_skb_any(skb);
+	return NETDEV_TX_OK;
+}
+
+static void qcauart_netdev_tx_timeout(struct net_device *dev)
+{
+	struct qcauart *qca = netdev_priv(dev);
+
+	netdev_info(qca->net_dev, "Transmit timeout at %ld, latency %ld\n",
+		    jiffies, dev_trans_start(dev));
+	dev->stats.tx_errors++;
+	dev->stats.tx_dropped++;
+}
+
+static int qcauart_netdev_init(struct net_device *dev)
+{
+	struct qcauart *qca = netdev_priv(dev);
+	size_t len;
+
+	/* Finish setting up the device info. */
+	dev->mtu = QCAFRM_MAX_MTU;
+	dev->type = ARPHRD_ETHER;
+
+	len = QCAFRM_HEADER_LEN + QCAFRM_MAX_LEN + QCAFRM_FOOTER_LEN;
+	qca->tx_buffer = devm_kmalloc(&qca->serdev->dev, len, GFP_KERNEL);
+	if (!qca->tx_buffer)
+		return -ENOMEM;
+
+	qca->rx_skb = netdev_alloc_skb_ip_align(qca->net_dev,
+						qca->net_dev->mtu +
+						VLAN_ETH_HLEN);
+	if (!qca->rx_skb)
+		return -ENOBUFS;
+
+	return 0;
+}
+
+static void qcauart_netdev_uninit(struct net_device *dev)
+{
+	struct qcauart *qca = netdev_priv(dev);
+
+	if (qca->rx_skb)
+		dev_kfree_skb(qca->rx_skb);
+}
+
+static const struct net_device_ops qcauart_netdev_ops = {
+	.ndo_init = qcauart_netdev_init,
+	.ndo_uninit = qcauart_netdev_uninit,
+	.ndo_open = qcauart_netdev_open,
+	.ndo_stop = qcauart_netdev_close,
+	.ndo_start_xmit = qcauart_netdev_xmit,
+	.ndo_set_mac_address = eth_mac_addr,
+	.ndo_tx_timeout = qcauart_netdev_tx_timeout,
+	.ndo_validate_addr = eth_validate_addr,
+};
+
+static void qcauart_netdev_setup(struct net_device *dev)
+{
+	dev->netdev_ops = &qcauart_netdev_ops;
+	dev->watchdog_timeo = QCAUART_TX_TIMEOUT;
+	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
+	dev->tx_queue_len = 100;
+
+	/* MTU range: 46 - 1500 */
+	dev->min_mtu = QCAFRM_MIN_MTU;
+	dev->max_mtu = QCAFRM_MAX_MTU;
+}
+
+static const struct of_device_id qca_uart_of_match[] = {
+	{
+	 .compatible = "qca,qca7000",
+	},
+	{}
+};
+MODULE_DEVICE_TABLE(of, qca_uart_of_match);
+
+static int qca_uart_probe(struct serdev_device *serdev)
+{
+	struct net_device *qcauart_dev = alloc_etherdev(sizeof(struct qcauart));
+	struct qcauart *qca;
+	const char *mac;
+	u32 speed = 115200;
+	int ret;
+
+	if (!qcauart_dev)
+		return -ENOMEM;
+
+	qcauart_netdev_setup(qcauart_dev);
+	SET_NETDEV_DEV(qcauart_dev, &serdev->dev);
+
+	qca = netdev_priv(qcauart_dev);
+	if (!qca) {
+		pr_err("qca_uart: Fail to retrieve private structure\n");
+		ret = -ENOMEM;
+		goto free;
+	}
+	qca->net_dev = qcauart_dev;
+	qca->serdev = serdev;
+	qcafrm_fsm_init_uart(&qca->frm_handle);
+
+	spin_lock_init(&qca->lock);
+	INIT_WORK(&qca->tx_work, qcauart_transmit);
+
+	of_property_read_u32(serdev->dev.of_node, "current-speed", &speed);
+
+	mac = of_get_mac_address(serdev->dev.of_node);
+
+	if (mac)
+		ether_addr_copy(qca->net_dev->dev_addr, mac);
+
+	if (!is_valid_ether_addr(qca->net_dev->dev_addr)) {
+		eth_hw_addr_random(qca->net_dev);
+		dev_info(&serdev->dev, "Using random MAC address: %pM\n",
+			 qca->net_dev->dev_addr);
+	}
+
+	netif_carrier_on(qca->net_dev);
+	serdev_device_set_drvdata(serdev, qca);
+	serdev_device_set_client_ops(serdev, &qca_serdev_ops);
+
+	ret = serdev_device_open(serdev);
+	if (ret) {
+		dev_err(&serdev->dev, "Unable to open device %s\n",
+			qcauart_dev->name);
+		goto free;
+	}
+
+	speed = serdev_device_set_baudrate(serdev, speed);
+	dev_info(&serdev->dev, "Using baudrate: %u\n", speed);
+
+	serdev_device_set_flow_control(serdev, false);
+
+	ret = register_netdev(qcauart_dev);
+	if (ret) {
+		dev_err(&serdev->dev, "Unable to register net device %s\n",
+			qcauart_dev->name);
+		serdev_device_close(serdev);
+		goto free;
+	}
+
+	return 0;
+
+free:
+	free_netdev(qcauart_dev);
+	return ret;
+}
+
+static void qca_uart_remove(struct serdev_device *serdev)
+{
+	struct qcauart *qca = serdev_device_get_drvdata(serdev);
+
+	netif_carrier_off(qca->net_dev);
+	cancel_work_sync(&qca->tx_work);
+	unregister_netdev(qca->net_dev);
+
+	/* Flush any pending characters in the driver. */
+	serdev_device_close(serdev);
+
+	free_netdev(qca->net_dev);
+}
+
+static struct serdev_device_driver qca_uart_driver = {
+	.probe = qca_uart_probe,
+	.remove = qca_uart_remove,
+	.driver = {
+		.name = QCAUART_DRV_NAME,
+		.of_match_table = of_match_ptr(qca_uart_of_match),
+	},
+};
+
+module_serdev_device_driver(qca_uart_driver);
+
+MODULE_DESCRIPTION("Qualcomm Atheros QCA7000 UART Driver");
+MODULE_AUTHOR("Qualcomm Atheros Communications");
+MODULE_AUTHOR("Stefan Wahren <stefan.wahren@i2se.com>");
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_VERSION(QCAUART_DRV_VERSION);
-- 
2.1.4

[PATCH v6 net-next 17/17] net: qualcomm: add QCA7000 UART driver

[Stefan Wahren]

This patch adds the Ethernet over UART driver for the
Qualcomm QCA7000 HomePlug GreenPHY.

Signed-off-by: Stefan Wahren <stefan.wahren-eS4NqCHxEME@public.gmane.org>
---
 drivers/net/ethernet/qualcomm/Kconfig         |  16 +
 drivers/net/ethernet/qualcomm/Makefile        |   2 +
 drivers/net/ethernet/qualcomm/qca_7k_common.h |   6 +
 drivers/net/ethernet/qualcomm/qca_uart.c      | 423 ++++++++++++++++++++++++++
 4 files changed, 447 insertions(+)
 create mode 100644 drivers/net/ethernet/qualcomm/qca_uart.c

diff --git a/drivers/net/ethernet/qualcomm/Kconfig b/drivers/net/ethernet/qualcomm/Kconfig
index b4c369d..877675a 100644
--- a/drivers/net/ethernet/qualcomm/Kconfig
+++ b/drivers/net/ethernet/qualcomm/Kconfig
@@ -30,6 +30,22 @@ config QCA7000_SPI
 	  To compile this driver as a module, choose M here. The module
 	  will be called qcaspi.
 
+config QCA7000_UART
+	tristate "Qualcomm Atheros QCA7000 UART support"
+	select QCA7000
+	depends on SERIAL_DEV_BUS && OF
+	---help---
+	  This UART protocol driver supports the Qualcomm Atheros QCA7000.
+
+	  Currently the driver assumes these device UART settings:
+	    Data bits: 8
+	    Parity: None
+	    Stop bits: 1
+	    Flow control: None
+
+	  To compile this driver as a module, choose M here. The module
+	  will be called qcauart.
+
 config QCOM_EMAC
 	tristate "Qualcomm Technologies, Inc. EMAC Gigabit Ethernet support"
 	depends on HAS_DMA && HAS_IOMEM
diff --git a/drivers/net/ethernet/qualcomm/Makefile b/drivers/net/ethernet/qualcomm/Makefile
index 65556ca..92fa7c4 100644
--- a/drivers/net/ethernet/qualcomm/Makefile
+++ b/drivers/net/ethernet/qualcomm/Makefile
@@ -5,5 +5,7 @@
 obj-$(CONFIG_QCA7000) += qca_7k_common.o
 obj-$(CONFIG_QCA7000_SPI) += qcaspi.o
 qcaspi-objs := qca_7k.o qca_debug.o qca_spi.o
+obj-$(CONFIG_QCA7000_UART) += qcauart.o
+qcauart-objs := qca_uart.o
 
 obj-y += emac/
diff --git a/drivers/net/ethernet/qualcomm/qca_7k_common.h b/drivers/net/ethernet/qualcomm/qca_7k_common.h
index 07bdd6c..928554f 100644
--- a/drivers/net/ethernet/qualcomm/qca_7k_common.h
+++ b/drivers/net/ethernet/qualcomm/qca_7k_common.h
@@ -122,6 +122,12 @@ static inline void qcafrm_fsm_init_spi(struct qcafrm_handle *handle)
 	handle->state = handle->init;
 }
 
+static inline void qcafrm_fsm_init_uart(struct qcafrm_handle *handle)
+{
+	handle->init = QCAFRM_WAIT_AA1;
+	handle->state = handle->init;
+}
+
 /*   Gather received bytes and try to extract a full Ethernet frame
  *   by following a simple state machine.
  *
diff --git a/drivers/net/ethernet/qualcomm/qca_uart.c b/drivers/net/ethernet/qualcomm/qca_uart.c
new file mode 100644
index 0000000..43d91ba
--- /dev/null
+++ b/drivers/net/ethernet/qualcomm/qca_uart.c
@@ -0,0 +1,423 @@
+/*
+ *   Copyright (c) 2011, 2012, Qualcomm Atheros Communications Inc.
+ *   Copyright (c) 2017, I2SE GmbH
+ *
+ *   Permission to use, copy, modify, and/or distribute this software
+ *   for any purpose with or without fee is hereby granted, provided
+ *   that the above copyright notice and this permission notice appear
+ *   in all copies.
+ *
+ *   THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
+ *   WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
+ *   WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
+ *   THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR
+ *   CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ *   LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
+ *   NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ *   CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*   This module implements the Qualcomm Atheros UART protocol for
+ *   kernel-based UART device; it is essentially an Ethernet-to-UART
+ *   serial converter;
+ */
+
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/etherdevice.h>
+#include <linux/if_arp.h>
+#include <linux/if_ether.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_net.h>
+#include <linux/sched.h>
+#include <linux/serdev.h>
+#include <linux/skbuff.h>
+#include <linux/types.h>
+
+#include "qca_7k_common.h"
+
+#define QCAUART_DRV_VERSION "0.1.0"
+#define QCAUART_DRV_NAME "qcauart"
+#define QCAUART_TX_TIMEOUT (1 * HZ)
+
+struct qcauart {
+	struct net_device *net_dev;
+	spinlock_t lock;			/* transmit lock */
+	struct work_struct tx_work;		/* Flushes transmit buffer   */
+
+	struct serdev_device *serdev;
+	struct qcafrm_handle frm_handle;
+	struct sk_buff *rx_skb;
+
+	unsigned char *tx_head;			/* pointer to next XMIT byte */
+	int tx_left;				/* bytes left in XMIT queue  */
+	unsigned char *tx_buffer;
+};
+
+static int
+qca_tty_receive(struct serdev_device *serdev, const unsigned char *data,
+		size_t count)
+{
+	struct qcauart *qca = serdev_device_get_drvdata(serdev);
+	struct net_device *netdev = qca->net_dev;
+	struct net_device_stats *n_stats = &netdev->stats;
+	size_t i;
+
+	if (!qca->rx_skb) {
+		qca->rx_skb = netdev_alloc_skb_ip_align(netdev,
+							netdev->mtu +
+							VLAN_ETH_HLEN);
+		if (!qca->rx_skb) {
+			n_stats->rx_errors++;
+			n_stats->rx_dropped++;
+			return 0;
+		}
+	}
+
+	for (i = 0; i < count; i++) {
+		s32 retcode;
+
+		retcode = qcafrm_fsm_decode(&qca->frm_handle,
+					    qca->rx_skb->data,
+					    skb_tailroom(qca->rx_skb),
+					    data[i]);
+
+		switch (retcode) {
+		case QCAFRM_GATHER:
+		case QCAFRM_NOHEAD:
+			break;
+		case QCAFRM_NOTAIL:
+			netdev_dbg(netdev, "recv: no RX tail\n");
+			n_stats->rx_errors++;
+			n_stats->rx_dropped++;
+			break;
+		case QCAFRM_INVLEN:
+			netdev_dbg(netdev, "recv: invalid RX length\n");
+			n_stats->rx_errors++;
+			n_stats->rx_dropped++;
+			break;
+		default:
+			n_stats->rx_packets++;
+			n_stats->rx_bytes += retcode;
+			skb_put(qca->rx_skb, retcode);
+			qca->rx_skb->protocol = eth_type_trans(
+						qca->rx_skb, qca->rx_skb->dev);
+			qca->rx_skb->ip_summed = CHECKSUM_UNNECESSARY;
+			netif_rx_ni(qca->rx_skb);
+			qca->rx_skb = netdev_alloc_skb_ip_align(netdev,
+								netdev->mtu +
+								VLAN_ETH_HLEN);
+			if (!qca->rx_skb) {
+				netdev_dbg(netdev, "recv: out of RX resources\n");
+				n_stats->rx_errors++;
+				return i;
+			}
+		}
+	}
+
+	return i;
+}
+
+/* Write out any remaining transmit buffer. Scheduled when tty is writable */
+static void qcauart_transmit(struct work_struct *work)
+{
+	struct qcauart *qca = container_of(work, struct qcauart, tx_work);
+	struct net_device_stats *n_stats = &qca->net_dev->stats;
+	int written;
+
+	spin_lock_bh(&qca->lock);
+
+	/* First make sure we're connected. */
+	if (!netif_running(qca->net_dev)) {
+		spin_unlock_bh(&qca->lock);
+		return;
+	}
+
+	if (qca->tx_left <= 0)  {
+		/* Now serial buffer is almost free & we can start
+		 * transmission of another packet
+		 */
+		n_stats->tx_packets++;
+		spin_unlock_bh(&qca->lock);
+		netif_wake_queue(qca->net_dev);
+		return;
+	}
+
+	written = serdev_device_write_buf(qca->serdev, qca->tx_head,
+					  qca->tx_left);
+	if (written > 0) {
+		qca->tx_left -= written;
+		qca->tx_head += written;
+	}
+	spin_unlock_bh(&qca->lock);
+}
+
+/* Called by the driver when there's room for more data.
+ * Schedule the transmit.
+ */
+static void qca_tty_wakeup(struct serdev_device *serdev)
+{
+	struct qcauart *qca = serdev_device_get_drvdata(serdev);
+
+	schedule_work(&qca->tx_work);
+}
+
+static struct serdev_device_ops qca_serdev_ops = {
+	.receive_buf = qca_tty_receive,
+	.write_wakeup = qca_tty_wakeup,
+};
+
+static int qcauart_netdev_open(struct net_device *dev)
+{
+	struct qcauart *qca = netdev_priv(dev);
+
+	netif_start_queue(qca->net_dev);
+
+	return 0;
+}
+
+static int qcauart_netdev_close(struct net_device *dev)
+{
+	struct qcauart *qca = netdev_priv(dev);
+
+	netif_stop_queue(dev);
+	flush_work(&qca->tx_work);
+
+	spin_lock_bh(&qca->lock);
+	qca->tx_left = 0;
+	spin_unlock_bh(&qca->lock);
+
+	return 0;
+}
+
+static netdev_tx_t
+qcauart_netdev_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	struct net_device_stats *n_stats = &dev->stats;
+	struct qcauart *qca = netdev_priv(dev);
+	u8 pad_len = 0;
+	int written;
+	u8 *pos;
+
+	spin_lock(&qca->lock);
+
+	WARN_ON(qca->tx_left);
+
+	if (!netif_running(dev))  {
+		spin_unlock(&qca->lock);
+		netdev_warn(qca->net_dev, "xmit: iface is down\n");
+		goto out;
+	}
+
+	pos = qca->tx_buffer;
+
+	if (skb->len < QCAFRM_MIN_LEN)
+		pad_len = QCAFRM_MIN_LEN - skb->len;
+
+	pos += qcafrm_create_header(pos, skb->len + pad_len);
+
+	memcpy(pos, skb->data, skb->len);
+	pos += skb->len;
+
+	if (pad_len) {
+		memset(pos, 0, pad_len);
+		pos += pad_len;
+	}
+
+	pos += qcafrm_create_footer(pos);
+
+	netif_stop_queue(qca->net_dev);
+
+	written = serdev_device_write_buf(qca->serdev, qca->tx_buffer,
+					  pos - qca->tx_buffer);
+	if (written > 0) {
+		qca->tx_left = (pos - qca->tx_buffer) - written;
+		qca->tx_head = qca->tx_buffer + written;
+		n_stats->tx_bytes += written;
+	}
+	spin_unlock(&qca->lock);
+
+	netif_trans_update(dev);
+out:
+	dev_kfree_skb_any(skb);
+	return NETDEV_TX_OK;
+}
+
+static void qcauart_netdev_tx_timeout(struct net_device *dev)
+{
+	struct qcauart *qca = netdev_priv(dev);
+
+	netdev_info(qca->net_dev, "Transmit timeout at %ld, latency %ld\n",
+		    jiffies, dev_trans_start(dev));
+	dev->stats.tx_errors++;
+	dev->stats.tx_dropped++;
+}
+
+static int qcauart_netdev_init(struct net_device *dev)
+{
+	struct qcauart *qca = netdev_priv(dev);
+	size_t len;
+
+	/* Finish setting up the device info. */
+	dev->mtu = QCAFRM_MAX_MTU;
+	dev->type = ARPHRD_ETHER;
+
+	len = QCAFRM_HEADER_LEN + QCAFRM_MAX_LEN + QCAFRM_FOOTER_LEN;
+	qca->tx_buffer = devm_kmalloc(&qca->serdev->dev, len, GFP_KERNEL);
+	if (!qca->tx_buffer)
+		return -ENOMEM;
+
+	qca->rx_skb = netdev_alloc_skb_ip_align(qca->net_dev,
+						qca->net_dev->mtu +
+						VLAN_ETH_HLEN);
+	if (!qca->rx_skb)
+		return -ENOBUFS;
+
+	return 0;
+}
+
+static void qcauart_netdev_uninit(struct net_device *dev)
+{
+	struct qcauart *qca = netdev_priv(dev);
+
+	if (qca->rx_skb)
+		dev_kfree_skb(qca->rx_skb);
+}
+
+static const struct net_device_ops qcauart_netdev_ops = {
+	.ndo_init = qcauart_netdev_init,
+	.ndo_uninit = qcauart_netdev_uninit,
+	.ndo_open = qcauart_netdev_open,
+	.ndo_stop = qcauart_netdev_close,
+	.ndo_start_xmit = qcauart_netdev_xmit,
+	.ndo_set_mac_address = eth_mac_addr,
+	.ndo_tx_timeout = qcauart_netdev_tx_timeout,
+	.ndo_validate_addr = eth_validate_addr,
+};
+
+static void qcauart_netdev_setup(struct net_device *dev)
+{
+	dev->netdev_ops = &qcauart_netdev_ops;
+	dev->watchdog_timeo = QCAUART_TX_TIMEOUT;
+	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
+	dev->tx_queue_len = 100;
+
+	/* MTU range: 46 - 1500 */
+	dev->min_mtu = QCAFRM_MIN_MTU;
+	dev->max_mtu = QCAFRM_MAX_MTU;
+}
+
+static const struct of_device_id qca_uart_of_match[] = {
+	{
+	 .compatible = "qca,qca7000",
+	},
+	{}
+};
+MODULE_DEVICE_TABLE(of, qca_uart_of_match);
+
+static int qca_uart_probe(struct serdev_device *serdev)
+{
+	struct net_device *qcauart_dev = alloc_etherdev(sizeof(struct qcauart));
+	struct qcauart *qca;
+	const char *mac;
+	u32 speed = 115200;
+	int ret;
+
+	if (!qcauart_dev)
+		return -ENOMEM;
+
+	qcauart_netdev_setup(qcauart_dev);
+	SET_NETDEV_DEV(qcauart_dev, &serdev->dev);
+
+	qca = netdev_priv(qcauart_dev);
+	if (!qca) {
+		pr_err("qca_uart: Fail to retrieve private structure\n");
+		ret = -ENOMEM;
+		goto free;
+	}
+	qca->net_dev = qcauart_dev;
+	qca->serdev = serdev;
+	qcafrm_fsm_init_uart(&qca->frm_handle);
+
+	spin_lock_init(&qca->lock);
+	INIT_WORK(&qca->tx_work, qcauart_transmit);
+
+	of_property_read_u32(serdev->dev.of_node, "current-speed", &speed);
+
+	mac = of_get_mac_address(serdev->dev.of_node);
+
+	if (mac)
+		ether_addr_copy(qca->net_dev->dev_addr, mac);
+
+	if (!is_valid_ether_addr(qca->net_dev->dev_addr)) {
+		eth_hw_addr_random(qca->net_dev);
+		dev_info(&serdev->dev, "Using random MAC address: %pM\n",
+			 qca->net_dev->dev_addr);
+	}
+
+	netif_carrier_on(qca->net_dev);
+	serdev_device_set_drvdata(serdev, qca);
+	serdev_device_set_client_ops(serdev, &qca_serdev_ops);
+
+	ret = serdev_device_open(serdev);
+	if (ret) {
+		dev_err(&serdev->dev, "Unable to open device %s\n",
+			qcauart_dev->name);
+		goto free;
+	}
+
+	speed = serdev_device_set_baudrate(serdev, speed);
+	dev_info(&serdev->dev, "Using baudrate: %u\n", speed);
+
+	serdev_device_set_flow_control(serdev, false);
+
+	ret = register_netdev(qcauart_dev);
+	if (ret) {
+		dev_err(&serdev->dev, "Unable to register net device %s\n",
+			qcauart_dev->name);
+		serdev_device_close(serdev);
+		goto free;
+	}
+
+	return 0;
+
+free:
+	free_netdev(qcauart_dev);
+	return ret;
+}
+
+static void qca_uart_remove(struct serdev_device *serdev)
+{
+	struct qcauart *qca = serdev_device_get_drvdata(serdev);
+
+	netif_carrier_off(qca->net_dev);
+	cancel_work_sync(&qca->tx_work);
+	unregister_netdev(qca->net_dev);
+
+	/* Flush any pending characters in the driver. */
+	serdev_device_close(serdev);
+
+	free_netdev(qca->net_dev);
+}
+
+static struct serdev_device_driver qca_uart_driver = {
+	.probe = qca_uart_probe,
+	.remove = qca_uart_remove,
+	.driver = {
+		.name = QCAUART_DRV_NAME,
+		.of_match_table = of_match_ptr(qca_uart_of_match),
+	},
+};
+
+module_serdev_device_driver(qca_uart_driver);
+
+MODULE_DESCRIPTION("Qualcomm Atheros QCA7000 UART Driver");
+MODULE_AUTHOR("Qualcomm Atheros Communications");
+MODULE_AUTHOR("Stefan Wahren <stefan.wahren-eS4NqCHxEME@public.gmane.org>");
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_VERSION(QCAUART_DRV_VERSION);
-- 
2.1.4

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Re: [PATCH v6 net-next 17/17] net: qualcomm: add QCA7000 UART driver

[Lino Sanfilippo]

Hi,

On 23.05.2017 15:12, Stefan Wahren wrote:


> +}
> +
> +static void qca_uart_remove(struct serdev_device *serdev)
> +{
> +	struct qcauart *qca = serdev_device_get_drvdata(serdev);
> +
> +	netif_carrier_off(qca->net_dev);
> +	cancel_work_sync(&qca->tx_work);
> +	unregister_netdev(qca->net_dev);

Note that it is still possible that the tx work is queued right after cancel_work_sync()
returned and before the net device is unregistered (and thus the check for the net device
being up at the beginning of the tx work function is passed and the function is executed).
I suggest to avoid this possible race by first unregistering the netdevice and then 
calling cancel_work_sync().

Regards,
Lino 

Re: [PATCH v6 net-next 17/17] net: qualcomm: add QCA7000 UART driver

[Stefan Wahren]

> Lino Sanfilippo <LinoSanfilippo@gmx.de> hat am 23. Mai 2017 um 20:16 geschrieben:
> 
> 
> Hi,
> 
> On 23.05.2017 15:12, Stefan Wahren wrote:
> 
> 
> > +}
> > +
> > +static void qca_uart_remove(struct serdev_device *serdev)
> > +{
> > +	struct qcauart *qca = serdev_device_get_drvdata(serdev);
> > +
> > +	netif_carrier_off(qca->net_dev);
> > +	cancel_work_sync(&qca->tx_work);
> > +	unregister_netdev(qca->net_dev);
> 
> Note that it is still possible that the tx work is queued right after cancel_work_sync()
> returned and before the net device is unregistered (and thus the check for the net device
> being up at the beginning of the tx work function is passed and the function is executed).

Even if the carrier is off? Since i see this pattern in some drivers, can you please point me to a reference like a thread or something else?

> I suggest to avoid this possible race by first unregistering the netdevice and then 
> calling cancel_work_sync().

What makes you sure that's safe to unregister the netdev while the tx work queue is possibly active?

> Regards,
> Lino 
>

Re: [PATCH v6 net-next 17/17] net: qualcomm: add QCA7000 UART driver

[Lino Sanfilippo]

On 23.05.2017 21:38, Stefan Wahren wrote:
> 
>> Lino Sanfilippo <LinoSanfilippo@gmx.de> hat am 23. Mai 2017 um 20:16 geschrieben:
>>
>>
>> Hi,
>>
>> On 23.05.2017 15:12, Stefan Wahren wrote:
>>
>>
>>> +}
>>> +
>>> +static void qca_uart_remove(struct serdev_device *serdev)
>>> +{
>>> +	struct qcauart *qca = serdev_device_get_drvdata(serdev);
>>> +
>>> +	netif_carrier_off(qca->net_dev);
>>> +	cancel_work_sync(&qca->tx_work);
>>> +	unregister_netdev(qca->net_dev);
>>
>> Note that it is still possible that the tx work is queued right after cancel_work_sync()
>> returned and before the net device is unregistered (and thus the check for the net device
>> being up at the beginning of the tx work function is passed and the function is executed).
> 
> Even if the carrier is off? Since i see this pattern in some drivers, can you please point me to a reference like a thread or something else?
> 

The check in the tx work function is against the "running" state not against the carrier. So why should 
the carrier matter in this case? 


>> I suggest to avoid this possible race by first unregistering the netdevice and then 
>> calling cancel_work_sync().
> 
> What makes you sure that's safe to unregister the netdev while the tx work queue is possibly active?

unregister_netdevice() calls netdev_close() if the interface is still up. netdev_close() calls flush_work()
so the unregistration is delayed until the tx work function is finished. Furthermore both close() and
tx work are synchronized by means of the qca->lock which also guarantees that unregister_netdevice() wont
be finished until the tx work is done.

But I may have missed something and if unregistering the device while the tx work could be running worries you,
we could first close and later unregister the device like in the following sequence:


dev_close();
/* the tx work wont be scheduled any more now, however we have to wait for a potentially
   earlier scheduled work */ 
cancel_work_sync(&qca->tx_work);
/* we can be sure that the tx work will neither be running nor be started again, so 
   it is safe to unregister the netdev */
unregister_netdev(qca->net_dev);
serdev_device_close(serdev);
free_netdev(qca->net_dev);
 
What do you think?

Regards,
Lino

Re: [PATCH v6 net-next 17/17] net: qualcomm: add QCA7000 UART driver

[Stefan Wahren]

Am 23.05.2017 um 23:01 schrieb Lino Sanfilippo:
> On 23.05.2017 21:38, Stefan Wahren wrote:
>>> Lino Sanfilippo <LinoSanfilippo@gmx.de> hat am 23. Mai 2017 um 20:16 geschrieben:
>>>
>>> I suggest to avoid this possible race by first unregistering the netdevice and then 
>>> calling cancel_work_sync().
>> What makes you sure that's safe to unregister the netdev while the tx work queue is possibly active?
> unregister_netdevice() calls netdev_close() if the interface is still up. netdev_close() calls flush_work()
> so the unregistration is delayed until the tx work function is finished. Furthermore both close() and
> tx work are synchronized by means of the qca->lock which also guarantees that unregister_netdevice() wont
> be finished until the tx work is done.
>

Thanks for the explanation. I suspect there could be the same race
between serdev_device_close() and the tx work queue.

So i would propose a variant of your original suggestion:

unregister_netdev(qca->net_dev);

/* Flush any pending characters in the driver. */
serdev_device_close(serdev);
cancel_work_sync(&qca->tx_work);

Since we have the same pattern in the error path of the probe function,
the same applies there.

Stefan

[PATCH v7 net-next 17/17] net: qualcomm: add QCA7000 UART driver

[Stefan Wahren]

This patch adds the Ethernet over UART driver for the
Qualcomm QCA7000 HomePlug GreenPHY.

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
---
 drivers/net/ethernet/qualcomm/Kconfig         |  16 +
 drivers/net/ethernet/qualcomm/Makefile        |   2 +
 drivers/net/ethernet/qualcomm/qca_7k_common.h |   6 +
 drivers/net/ethernet/qualcomm/qca_uart.c      | 423 ++++++++++++++++++++++++++
 4 files changed, 447 insertions(+)
 create mode 100644 drivers/net/ethernet/qualcomm/qca_uart.c

diff --git a/drivers/net/ethernet/qualcomm/Kconfig b/drivers/net/ethernet/qualcomm/Kconfig
index b4c369d..877675a 100644
--- a/drivers/net/ethernet/qualcomm/Kconfig
+++ b/drivers/net/ethernet/qualcomm/Kconfig
@@ -30,6 +30,22 @@ config QCA7000_SPI
 	  To compile this driver as a module, choose M here. The module
 	  will be called qcaspi.
 
+config QCA7000_UART
+	tristate "Qualcomm Atheros QCA7000 UART support"
+	select QCA7000
+	depends on SERIAL_DEV_BUS && OF
+	---help---
+	  This UART protocol driver supports the Qualcomm Atheros QCA7000.
+
+	  Currently the driver assumes these device UART settings:
+	    Data bits: 8
+	    Parity: None
+	    Stop bits: 1
+	    Flow control: None
+
+	  To compile this driver as a module, choose M here. The module
+	  will be called qcauart.
+
 config QCOM_EMAC
 	tristate "Qualcomm Technologies, Inc. EMAC Gigabit Ethernet support"
 	depends on HAS_DMA && HAS_IOMEM
diff --git a/drivers/net/ethernet/qualcomm/Makefile b/drivers/net/ethernet/qualcomm/Makefile
index 65556ca..92fa7c4 100644
--- a/drivers/net/ethernet/qualcomm/Makefile
+++ b/drivers/net/ethernet/qualcomm/Makefile
@@ -5,5 +5,7 @@
 obj-$(CONFIG_QCA7000) += qca_7k_common.o
 obj-$(CONFIG_QCA7000_SPI) += qcaspi.o
 qcaspi-objs := qca_7k.o qca_debug.o qca_spi.o
+obj-$(CONFIG_QCA7000_UART) += qcauart.o
+qcauart-objs := qca_uart.o
 
 obj-y += emac/
diff --git a/drivers/net/ethernet/qualcomm/qca_7k_common.h b/drivers/net/ethernet/qualcomm/qca_7k_common.h
index 07bdd6c..928554f 100644
--- a/drivers/net/ethernet/qualcomm/qca_7k_common.h
+++ b/drivers/net/ethernet/qualcomm/qca_7k_common.h
@@ -122,6 +122,12 @@ static inline void qcafrm_fsm_init_spi(struct qcafrm_handle *handle)
 	handle->state = handle->init;
 }
 
+static inline void qcafrm_fsm_init_uart(struct qcafrm_handle *handle)
+{
+	handle->init = QCAFRM_WAIT_AA1;
+	handle->state = handle->init;
+}
+
 /*   Gather received bytes and try to extract a full Ethernet frame
  *   by following a simple state machine.
  *
diff --git a/drivers/net/ethernet/qualcomm/qca_uart.c b/drivers/net/ethernet/qualcomm/qca_uart.c
new file mode 100644
index 0000000..db6068c
--- /dev/null
+++ b/drivers/net/ethernet/qualcomm/qca_uart.c
@@ -0,0 +1,423 @@
+/*
+ *   Copyright (c) 2011, 2012, Qualcomm Atheros Communications Inc.
+ *   Copyright (c) 2017, I2SE GmbH
+ *
+ *   Permission to use, copy, modify, and/or distribute this software
+ *   for any purpose with or without fee is hereby granted, provided
+ *   that the above copyright notice and this permission notice appear
+ *   in all copies.
+ *
+ *   THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
+ *   WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
+ *   WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
+ *   THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR
+ *   CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ *   LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
+ *   NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ *   CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*   This module implements the Qualcomm Atheros UART protocol for
+ *   kernel-based UART device; it is essentially an Ethernet-to-UART
+ *   serial converter;
+ */
+
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/etherdevice.h>
+#include <linux/if_arp.h>
+#include <linux/if_ether.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_net.h>
+#include <linux/sched.h>
+#include <linux/serdev.h>
+#include <linux/skbuff.h>
+#include <linux/types.h>
+
+#include "qca_7k_common.h"
+
+#define QCAUART_DRV_VERSION "0.1.0"
+#define QCAUART_DRV_NAME "qcauart"
+#define QCAUART_TX_TIMEOUT (1 * HZ)
+
+struct qcauart {
+	struct net_device *net_dev;
+	spinlock_t lock;			/* transmit lock */
+	struct work_struct tx_work;		/* Flushes transmit buffer   */
+
+	struct serdev_device *serdev;
+	struct qcafrm_handle frm_handle;
+	struct sk_buff *rx_skb;
+
+	unsigned char *tx_head;			/* pointer to next XMIT byte */
+	int tx_left;				/* bytes left in XMIT queue  */
+	unsigned char *tx_buffer;
+};
+
+static int
+qca_tty_receive(struct serdev_device *serdev, const unsigned char *data,
+		size_t count)
+{
+	struct qcauart *qca = serdev_device_get_drvdata(serdev);
+	struct net_device *netdev = qca->net_dev;
+	struct net_device_stats *n_stats = &netdev->stats;
+	size_t i;
+
+	if (!qca->rx_skb) {
+		qca->rx_skb = netdev_alloc_skb_ip_align(netdev,
+							netdev->mtu +
+							VLAN_ETH_HLEN);
+		if (!qca->rx_skb) {
+			n_stats->rx_errors++;
+			n_stats->rx_dropped++;
+			return 0;
+		}
+	}
+
+	for (i = 0; i < count; i++) {
+		s32 retcode;
+
+		retcode = qcafrm_fsm_decode(&qca->frm_handle,
+					    qca->rx_skb->data,
+					    skb_tailroom(qca->rx_skb),
+					    data[i]);
+
+		switch (retcode) {
+		case QCAFRM_GATHER:
+		case QCAFRM_NOHEAD:
+			break;
+		case QCAFRM_NOTAIL:
+			netdev_dbg(netdev, "recv: no RX tail\n");
+			n_stats->rx_errors++;
+			n_stats->rx_dropped++;
+			break;
+		case QCAFRM_INVLEN:
+			netdev_dbg(netdev, "recv: invalid RX length\n");
+			n_stats->rx_errors++;
+			n_stats->rx_dropped++;
+			break;
+		default:
+			n_stats->rx_packets++;
+			n_stats->rx_bytes += retcode;
+			skb_put(qca->rx_skb, retcode);
+			qca->rx_skb->protocol = eth_type_trans(
+						qca->rx_skb, qca->rx_skb->dev);
+			qca->rx_skb->ip_summed = CHECKSUM_UNNECESSARY;
+			netif_rx_ni(qca->rx_skb);
+			qca->rx_skb = netdev_alloc_skb_ip_align(netdev,
+								netdev->mtu +
+								VLAN_ETH_HLEN);
+			if (!qca->rx_skb) {
+				netdev_dbg(netdev, "recv: out of RX resources\n");
+				n_stats->rx_errors++;
+				return i;
+			}
+		}
+	}
+
+	return i;
+}
+
+/* Write out any remaining transmit buffer. Scheduled when tty is writable */
+static void qcauart_transmit(struct work_struct *work)
+{
+	struct qcauart *qca = container_of(work, struct qcauart, tx_work);
+	struct net_device_stats *n_stats = &qca->net_dev->stats;
+	int written;
+
+	spin_lock_bh(&qca->lock);
+
+	/* First make sure we're connected. */
+	if (!netif_running(qca->net_dev)) {
+		spin_unlock_bh(&qca->lock);
+		return;
+	}
+
+	if (qca->tx_left <= 0)  {
+		/* Now serial buffer is almost free & we can start
+		 * transmission of another packet
+		 */
+		n_stats->tx_packets++;
+		spin_unlock_bh(&qca->lock);
+		netif_wake_queue(qca->net_dev);
+		return;
+	}
+
+	written = serdev_device_write_buf(qca->serdev, qca->tx_head,
+					  qca->tx_left);
+	if (written > 0) {
+		qca->tx_left -= written;
+		qca->tx_head += written;
+	}
+	spin_unlock_bh(&qca->lock);
+}
+
+/* Called by the driver when there's room for more data.
+ * Schedule the transmit.
+ */
+static void qca_tty_wakeup(struct serdev_device *serdev)
+{
+	struct qcauart *qca = serdev_device_get_drvdata(serdev);
+
+	schedule_work(&qca->tx_work);
+}
+
+static struct serdev_device_ops qca_serdev_ops = {
+	.receive_buf = qca_tty_receive,
+	.write_wakeup = qca_tty_wakeup,
+};
+
+static int qcauart_netdev_open(struct net_device *dev)
+{
+	struct qcauart *qca = netdev_priv(dev);
+
+	netif_start_queue(qca->net_dev);
+
+	return 0;
+}
+
+static int qcauart_netdev_close(struct net_device *dev)
+{
+	struct qcauart *qca = netdev_priv(dev);
+
+	netif_stop_queue(dev);
+	flush_work(&qca->tx_work);
+
+	spin_lock_bh(&qca->lock);
+	qca->tx_left = 0;
+	spin_unlock_bh(&qca->lock);
+
+	return 0;
+}
+
+static netdev_tx_t
+qcauart_netdev_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	struct net_device_stats *n_stats = &dev->stats;
+	struct qcauart *qca = netdev_priv(dev);
+	u8 pad_len = 0;
+	int written;
+	u8 *pos;
+
+	spin_lock(&qca->lock);
+
+	WARN_ON(qca->tx_left);
+
+	if (!netif_running(dev))  {
+		spin_unlock(&qca->lock);
+		netdev_warn(qca->net_dev, "xmit: iface is down\n");
+		goto out;
+	}
+
+	pos = qca->tx_buffer;
+
+	if (skb->len < QCAFRM_MIN_LEN)
+		pad_len = QCAFRM_MIN_LEN - skb->len;
+
+	pos += qcafrm_create_header(pos, skb->len + pad_len);
+
+	memcpy(pos, skb->data, skb->len);
+	pos += skb->len;
+
+	if (pad_len) {
+		memset(pos, 0, pad_len);
+		pos += pad_len;
+	}
+
+	pos += qcafrm_create_footer(pos);
+
+	netif_stop_queue(qca->net_dev);
+
+	written = serdev_device_write_buf(qca->serdev, qca->tx_buffer,
+					  pos - qca->tx_buffer);
+	if (written > 0) {
+		qca->tx_left = (pos - qca->tx_buffer) - written;
+		qca->tx_head = qca->tx_buffer + written;
+		n_stats->tx_bytes += written;
+	}
+	spin_unlock(&qca->lock);
+
+	netif_trans_update(dev);
+out:
+	dev_kfree_skb_any(skb);
+	return NETDEV_TX_OK;
+}
+
+static void qcauart_netdev_tx_timeout(struct net_device *dev)
+{
+	struct qcauart *qca = netdev_priv(dev);
+
+	netdev_info(qca->net_dev, "Transmit timeout at %ld, latency %ld\n",
+		    jiffies, dev_trans_start(dev));
+	dev->stats.tx_errors++;
+	dev->stats.tx_dropped++;
+}
+
+static int qcauart_netdev_init(struct net_device *dev)
+{
+	struct qcauart *qca = netdev_priv(dev);
+	size_t len;
+
+	/* Finish setting up the device info. */
+	dev->mtu = QCAFRM_MAX_MTU;
+	dev->type = ARPHRD_ETHER;
+
+	len = QCAFRM_HEADER_LEN + QCAFRM_MAX_LEN + QCAFRM_FOOTER_LEN;
+	qca->tx_buffer = devm_kmalloc(&qca->serdev->dev, len, GFP_KERNEL);
+	if (!qca->tx_buffer)
+		return -ENOMEM;
+
+	qca->rx_skb = netdev_alloc_skb_ip_align(qca->net_dev,
+						qca->net_dev->mtu +
+						VLAN_ETH_HLEN);
+	if (!qca->rx_skb)
+		return -ENOBUFS;
+
+	return 0;
+}
+
+static void qcauart_netdev_uninit(struct net_device *dev)
+{
+	struct qcauart *qca = netdev_priv(dev);
+
+	if (qca->rx_skb)
+		dev_kfree_skb(qca->rx_skb);
+}
+
+static const struct net_device_ops qcauart_netdev_ops = {
+	.ndo_init = qcauart_netdev_init,
+	.ndo_uninit = qcauart_netdev_uninit,
+	.ndo_open = qcauart_netdev_open,
+	.ndo_stop = qcauart_netdev_close,
+	.ndo_start_xmit = qcauart_netdev_xmit,
+	.ndo_set_mac_address = eth_mac_addr,
+	.ndo_tx_timeout = qcauart_netdev_tx_timeout,
+	.ndo_validate_addr = eth_validate_addr,
+};
+
+static void qcauart_netdev_setup(struct net_device *dev)
+{
+	dev->netdev_ops = &qcauart_netdev_ops;
+	dev->watchdog_timeo = QCAUART_TX_TIMEOUT;
+	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
+	dev->tx_queue_len = 100;
+
+	/* MTU range: 46 - 1500 */
+	dev->min_mtu = QCAFRM_MIN_MTU;
+	dev->max_mtu = QCAFRM_MAX_MTU;
+}
+
+static const struct of_device_id qca_uart_of_match[] = {
+	{
+	 .compatible = "qca,qca7000",
+	},
+	{}
+};
+MODULE_DEVICE_TABLE(of, qca_uart_of_match);
+
+static int qca_uart_probe(struct serdev_device *serdev)
+{
+	struct net_device *qcauart_dev = alloc_etherdev(sizeof(struct qcauart));
+	struct qcauart *qca;
+	const char *mac;
+	u32 speed = 115200;
+	int ret;
+
+	if (!qcauart_dev)
+		return -ENOMEM;
+
+	qcauart_netdev_setup(qcauart_dev);
+	SET_NETDEV_DEV(qcauart_dev, &serdev->dev);
+
+	qca = netdev_priv(qcauart_dev);
+	if (!qca) {
+		pr_err("qca_uart: Fail to retrieve private structure\n");
+		ret = -ENOMEM;
+		goto free;
+	}
+	qca->net_dev = qcauart_dev;
+	qca->serdev = serdev;
+	qcafrm_fsm_init_uart(&qca->frm_handle);
+
+	spin_lock_init(&qca->lock);
+	INIT_WORK(&qca->tx_work, qcauart_transmit);
+
+	of_property_read_u32(serdev->dev.of_node, "current-speed", &speed);
+
+	mac = of_get_mac_address(serdev->dev.of_node);
+
+	if (mac)
+		ether_addr_copy(qca->net_dev->dev_addr, mac);
+
+	if (!is_valid_ether_addr(qca->net_dev->dev_addr)) {
+		eth_hw_addr_random(qca->net_dev);
+		dev_info(&serdev->dev, "Using random MAC address: %pM\n",
+			 qca->net_dev->dev_addr);
+	}
+
+	netif_carrier_on(qca->net_dev);
+	serdev_device_set_drvdata(serdev, qca);
+	serdev_device_set_client_ops(serdev, &qca_serdev_ops);
+
+	ret = serdev_device_open(serdev);
+	if (ret) {
+		dev_err(&serdev->dev, "Unable to open device %s\n",
+			qcauart_dev->name);
+		goto free;
+	}
+
+	speed = serdev_device_set_baudrate(serdev, speed);
+	dev_info(&serdev->dev, "Using baudrate: %u\n", speed);
+
+	serdev_device_set_flow_control(serdev, false);
+
+	ret = register_netdev(qcauart_dev);
+	if (ret) {
+		dev_err(&serdev->dev, "Unable to register net device %s\n",
+			qcauart_dev->name);
+		serdev_device_close(serdev);
+		cancel_work_sync(&qca->tx_work);
+		goto free;
+	}
+
+	return 0;
+
+free:
+	free_netdev(qcauart_dev);
+	return ret;
+}
+
+static void qca_uart_remove(struct serdev_device *serdev)
+{
+	struct qcauart *qca = serdev_device_get_drvdata(serdev);
+
+	unregister_netdev(qca->net_dev);
+
+	/* Flush any pending characters in the driver. */
+	serdev_device_close(serdev);
+	cancel_work_sync(&qca->tx_work);
+
+	free_netdev(qca->net_dev);
+}
+
+static struct serdev_device_driver qca_uart_driver = {
+	.probe = qca_uart_probe,
+	.remove = qca_uart_remove,
+	.driver = {
+		.name = QCAUART_DRV_NAME,
+		.of_match_table = of_match_ptr(qca_uart_of_match),
+	},
+};
+
+module_serdev_device_driver(qca_uart_driver);
+
+MODULE_DESCRIPTION("Qualcomm Atheros QCA7000 UART Driver");
+MODULE_AUTHOR("Qualcomm Atheros Communications");
+MODULE_AUTHOR("Stefan Wahren <stefan.wahren@i2se.com>");
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_VERSION(QCAUART_DRV_VERSION);
-- 
2.1.4

[PATCH v7 net-next 17/17] net: qualcomm: add QCA7000 UART driver

[Stefan Wahren]

This patch adds the Ethernet over UART driver for the
Qualcomm QCA7000 HomePlug GreenPHY.

Signed-off-by: Stefan Wahren <stefan.wahren-eS4NqCHxEME@public.gmane.org>
---
 drivers/net/ethernet/qualcomm/Kconfig         |  16 +
 drivers/net/ethernet/qualcomm/Makefile        |   2 +
 drivers/net/ethernet/qualcomm/qca_7k_common.h |   6 +
 drivers/net/ethernet/qualcomm/qca_uart.c      | 423 ++++++++++++++++++++++++++
 4 files changed, 447 insertions(+)
 create mode 100644 drivers/net/ethernet/qualcomm/qca_uart.c

diff --git a/drivers/net/ethernet/qualcomm/Kconfig b/drivers/net/ethernet/qualcomm/Kconfig
index b4c369d..877675a 100644
--- a/drivers/net/ethernet/qualcomm/Kconfig
+++ b/drivers/net/ethernet/qualcomm/Kconfig
@@ -30,6 +30,22 @@ config QCA7000_SPI
 	  To compile this driver as a module, choose M here. The module
 	  will be called qcaspi.
 
+config QCA7000_UART
+	tristate "Qualcomm Atheros QCA7000 UART support"
+	select QCA7000
+	depends on SERIAL_DEV_BUS && OF
+	---help---
+	  This UART protocol driver supports the Qualcomm Atheros QCA7000.
+
+	  Currently the driver assumes these device UART settings:
+	    Data bits: 8
+	    Parity: None
+	    Stop bits: 1
+	    Flow control: None
+
+	  To compile this driver as a module, choose M here. The module
+	  will be called qcauart.
+
 config QCOM_EMAC
 	tristate "Qualcomm Technologies, Inc. EMAC Gigabit Ethernet support"
 	depends on HAS_DMA && HAS_IOMEM
diff --git a/drivers/net/ethernet/qualcomm/Makefile b/drivers/net/ethernet/qualcomm/Makefile
index 65556ca..92fa7c4 100644
--- a/drivers/net/ethernet/qualcomm/Makefile
+++ b/drivers/net/ethernet/qualcomm/Makefile
@@ -5,5 +5,7 @@
 obj-$(CONFIG_QCA7000) += qca_7k_common.o
 obj-$(CONFIG_QCA7000_SPI) += qcaspi.o
 qcaspi-objs := qca_7k.o qca_debug.o qca_spi.o
+obj-$(CONFIG_QCA7000_UART) += qcauart.o
+qcauart-objs := qca_uart.o
 
 obj-y += emac/
diff --git a/drivers/net/ethernet/qualcomm/qca_7k_common.h b/drivers/net/ethernet/qualcomm/qca_7k_common.h
index 07bdd6c..928554f 100644
--- a/drivers/net/ethernet/qualcomm/qca_7k_common.h
+++ b/drivers/net/ethernet/qualcomm/qca_7k_common.h
@@ -122,6 +122,12 @@ static inline void qcafrm_fsm_init_spi(struct qcafrm_handle *handle)
 	handle->state = handle->init;
 }
 
+static inline void qcafrm_fsm_init_uart(struct qcafrm_handle *handle)
+{
+	handle->init = QCAFRM_WAIT_AA1;
+	handle->state = handle->init;
+}
+
 /*   Gather received bytes and try to extract a full Ethernet frame
  *   by following a simple state machine.
  *
diff --git a/drivers/net/ethernet/qualcomm/qca_uart.c b/drivers/net/ethernet/qualcomm/qca_uart.c
new file mode 100644
index 0000000..db6068c
--- /dev/null
+++ b/drivers/net/ethernet/qualcomm/qca_uart.c
@@ -0,0 +1,423 @@
+/*
+ *   Copyright (c) 2011, 2012, Qualcomm Atheros Communications Inc.
+ *   Copyright (c) 2017, I2SE GmbH
+ *
+ *   Permission to use, copy, modify, and/or distribute this software
+ *   for any purpose with or without fee is hereby granted, provided
+ *   that the above copyright notice and this permission notice appear
+ *   in all copies.
+ *
+ *   THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
+ *   WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
+ *   WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
+ *   THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR
+ *   CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ *   LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
+ *   NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ *   CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*   This module implements the Qualcomm Atheros UART protocol for
+ *   kernel-based UART device; it is essentially an Ethernet-to-UART
+ *   serial converter;
+ */
+
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/etherdevice.h>
+#include <linux/if_arp.h>
+#include <linux/if_ether.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_net.h>
+#include <linux/sched.h>
+#include <linux/serdev.h>
+#include <linux/skbuff.h>
+#include <linux/types.h>
+
+#include "qca_7k_common.h"
+
+#define QCAUART_DRV_VERSION "0.1.0"
+#define QCAUART_DRV_NAME "qcauart"
+#define QCAUART_TX_TIMEOUT (1 * HZ)
+
+struct qcauart {
+	struct net_device *net_dev;
+	spinlock_t lock;			/* transmit lock */
+	struct work_struct tx_work;		/* Flushes transmit buffer   */
+
+	struct serdev_device *serdev;
+	struct qcafrm_handle frm_handle;
+	struct sk_buff *rx_skb;
+
+	unsigned char *tx_head;			/* pointer to next XMIT byte */
+	int tx_left;				/* bytes left in XMIT queue  */
+	unsigned char *tx_buffer;
+};
+
+static int
+qca_tty_receive(struct serdev_device *serdev, const unsigned char *data,
+		size_t count)
+{
+	struct qcauart *qca = serdev_device_get_drvdata(serdev);
+	struct net_device *netdev = qca->net_dev;
+	struct net_device_stats *n_stats = &netdev->stats;
+	size_t i;
+
+	if (!qca->rx_skb) {
+		qca->rx_skb = netdev_alloc_skb_ip_align(netdev,
+							netdev->mtu +
+							VLAN_ETH_HLEN);
+		if (!qca->rx_skb) {
+			n_stats->rx_errors++;
+			n_stats->rx_dropped++;
+			return 0;
+		}
+	}
+
+	for (i = 0; i < count; i++) {
+		s32 retcode;
+
+		retcode = qcafrm_fsm_decode(&qca->frm_handle,
+					    qca->rx_skb->data,
+					    skb_tailroom(qca->rx_skb),
+					    data[i]);
+
+		switch (retcode) {
+		case QCAFRM_GATHER:
+		case QCAFRM_NOHEAD:
+			break;
+		case QCAFRM_NOTAIL:
+			netdev_dbg(netdev, "recv: no RX tail\n");
+			n_stats->rx_errors++;
+			n_stats->rx_dropped++;
+			break;
+		case QCAFRM_INVLEN:
+			netdev_dbg(netdev, "recv: invalid RX length\n");
+			n_stats->rx_errors++;
+			n_stats->rx_dropped++;
+			break;
+		default:
+			n_stats->rx_packets++;
+			n_stats->rx_bytes += retcode;
+			skb_put(qca->rx_skb, retcode);
+			qca->rx_skb->protocol = eth_type_trans(
+						qca->rx_skb, qca->rx_skb->dev);
+			qca->rx_skb->ip_summed = CHECKSUM_UNNECESSARY;
+			netif_rx_ni(qca->rx_skb);
+			qca->rx_skb = netdev_alloc_skb_ip_align(netdev,
+								netdev->mtu +
+								VLAN_ETH_HLEN);
+			if (!qca->rx_skb) {
+				netdev_dbg(netdev, "recv: out of RX resources\n");
+				n_stats->rx_errors++;
+				return i;
+			}
+		}
+	}
+
+	return i;
+}
+
+/* Write out any remaining transmit buffer. Scheduled when tty is writable */
+static void qcauart_transmit(struct work_struct *work)
+{
+	struct qcauart *qca = container_of(work, struct qcauart, tx_work);
+	struct net_device_stats *n_stats = &qca->net_dev->stats;
+	int written;
+
+	spin_lock_bh(&qca->lock);
+
+	/* First make sure we're connected. */
+	if (!netif_running(qca->net_dev)) {
+		spin_unlock_bh(&qca->lock);
+		return;
+	}
+
+	if (qca->tx_left <= 0)  {
+		/* Now serial buffer is almost free & we can start
+		 * transmission of another packet
+		 */
+		n_stats->tx_packets++;
+		spin_unlock_bh(&qca->lock);
+		netif_wake_queue(qca->net_dev);
+		return;
+	}
+
+	written = serdev_device_write_buf(qca->serdev, qca->tx_head,
+					  qca->tx_left);
+	if (written > 0) {
+		qca->tx_left -= written;
+		qca->tx_head += written;
+	}
+	spin_unlock_bh(&qca->lock);
+}
+
+/* Called by the driver when there's room for more data.
+ * Schedule the transmit.
+ */
+static void qca_tty_wakeup(struct serdev_device *serdev)
+{
+	struct qcauart *qca = serdev_device_get_drvdata(serdev);
+
+	schedule_work(&qca->tx_work);
+}
+
+static struct serdev_device_ops qca_serdev_ops = {
+	.receive_buf = qca_tty_receive,
+	.write_wakeup = qca_tty_wakeup,
+};
+
+static int qcauart_netdev_open(struct net_device *dev)
+{
+	struct qcauart *qca = netdev_priv(dev);
+
+	netif_start_queue(qca->net_dev);
+
+	return 0;
+}
+
+static int qcauart_netdev_close(struct net_device *dev)
+{
+	struct qcauart *qca = netdev_priv(dev);
+
+	netif_stop_queue(dev);
+	flush_work(&qca->tx_work);
+
+	spin_lock_bh(&qca->lock);
+	qca->tx_left = 0;
+	spin_unlock_bh(&qca->lock);
+
+	return 0;
+}
+
+static netdev_tx_t
+qcauart_netdev_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	struct net_device_stats *n_stats = &dev->stats;
+	struct qcauart *qca = netdev_priv(dev);
+	u8 pad_len = 0;
+	int written;
+	u8 *pos;
+
+	spin_lock(&qca->lock);
+
+	WARN_ON(qca->tx_left);
+
+	if (!netif_running(dev))  {
+		spin_unlock(&qca->lock);
+		netdev_warn(qca->net_dev, "xmit: iface is down\n");
+		goto out;
+	}
+
+	pos = qca->tx_buffer;
+
+	if (skb->len < QCAFRM_MIN_LEN)
+		pad_len = QCAFRM_MIN_LEN - skb->len;
+
+	pos += qcafrm_create_header(pos, skb->len + pad_len);
+
+	memcpy(pos, skb->data, skb->len);
+	pos += skb->len;
+
+	if (pad_len) {
+		memset(pos, 0, pad_len);
+		pos += pad_len;
+	}
+
+	pos += qcafrm_create_footer(pos);
+
+	netif_stop_queue(qca->net_dev);
+
+	written = serdev_device_write_buf(qca->serdev, qca->tx_buffer,
+					  pos - qca->tx_buffer);
+	if (written > 0) {
+		qca->tx_left = (pos - qca->tx_buffer) - written;
+		qca->tx_head = qca->tx_buffer + written;
+		n_stats->tx_bytes += written;
+	}
+	spin_unlock(&qca->lock);
+
+	netif_trans_update(dev);
+out:
+	dev_kfree_skb_any(skb);
+	return NETDEV_TX_OK;
+}
+
+static void qcauart_netdev_tx_timeout(struct net_device *dev)
+{
+	struct qcauart *qca = netdev_priv(dev);
+
+	netdev_info(qca->net_dev, "Transmit timeout at %ld, latency %ld\n",
+		    jiffies, dev_trans_start(dev));
+	dev->stats.tx_errors++;
+	dev->stats.tx_dropped++;
+}
+
+static int qcauart_netdev_init(struct net_device *dev)
+{
+	struct qcauart *qca = netdev_priv(dev);
+	size_t len;
+
+	/* Finish setting up the device info. */
+	dev->mtu = QCAFRM_MAX_MTU;
+	dev->type = ARPHRD_ETHER;
+
+	len = QCAFRM_HEADER_LEN + QCAFRM_MAX_LEN + QCAFRM_FOOTER_LEN;
+	qca->tx_buffer = devm_kmalloc(&qca->serdev->dev, len, GFP_KERNEL);
+	if (!qca->tx_buffer)
+		return -ENOMEM;
+
+	qca->rx_skb = netdev_alloc_skb_ip_align(qca->net_dev,
+						qca->net_dev->mtu +
+						VLAN_ETH_HLEN);
+	if (!qca->rx_skb)
+		return -ENOBUFS;
+
+	return 0;
+}
+
+static void qcauart_netdev_uninit(struct net_device *dev)
+{
+	struct qcauart *qca = netdev_priv(dev);
+
+	if (qca->rx_skb)
+		dev_kfree_skb(qca->rx_skb);
+}
+
+static const struct net_device_ops qcauart_netdev_ops = {
+	.ndo_init = qcauart_netdev_init,
+	.ndo_uninit = qcauart_netdev_uninit,
+	.ndo_open = qcauart_netdev_open,
+	.ndo_stop = qcauart_netdev_close,
+	.ndo_start_xmit = qcauart_netdev_xmit,
+	.ndo_set_mac_address = eth_mac_addr,
+	.ndo_tx_timeout = qcauart_netdev_tx_timeout,
+	.ndo_validate_addr = eth_validate_addr,
+};
+
+static void qcauart_netdev_setup(struct net_device *dev)
+{
+	dev->netdev_ops = &qcauart_netdev_ops;
+	dev->watchdog_timeo = QCAUART_TX_TIMEOUT;
+	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
+	dev->tx_queue_len = 100;
+
+	/* MTU range: 46 - 1500 */
+	dev->min_mtu = QCAFRM_MIN_MTU;
+	dev->max_mtu = QCAFRM_MAX_MTU;
+}
+
+static const struct of_device_id qca_uart_of_match[] = {
+	{
+	 .compatible = "qca,qca7000",
+	},
+	{}
+};
+MODULE_DEVICE_TABLE(of, qca_uart_of_match);
+
+static int qca_uart_probe(struct serdev_device *serdev)
+{
+	struct net_device *qcauart_dev = alloc_etherdev(sizeof(struct qcauart));
+	struct qcauart *qca;
+	const char *mac;
+	u32 speed = 115200;
+	int ret;
+
+	if (!qcauart_dev)
+		return -ENOMEM;
+
+	qcauart_netdev_setup(qcauart_dev);
+	SET_NETDEV_DEV(qcauart_dev, &serdev->dev);
+
+	qca = netdev_priv(qcauart_dev);
+	if (!qca) {
+		pr_err("qca_uart: Fail to retrieve private structure\n");
+		ret = -ENOMEM;
+		goto free;
+	}
+	qca->net_dev = qcauart_dev;
+	qca->serdev = serdev;
+	qcafrm_fsm_init_uart(&qca->frm_handle);
+
+	spin_lock_init(&qca->lock);
+	INIT_WORK(&qca->tx_work, qcauart_transmit);
+
+	of_property_read_u32(serdev->dev.of_node, "current-speed", &speed);
+
+	mac = of_get_mac_address(serdev->dev.of_node);
+
+	if (mac)
+		ether_addr_copy(qca->net_dev->dev_addr, mac);
+
+	if (!is_valid_ether_addr(qca->net_dev->dev_addr)) {
+		eth_hw_addr_random(qca->net_dev);
+		dev_info(&serdev->dev, "Using random MAC address: %pM\n",
+			 qca->net_dev->dev_addr);
+	}
+
+	netif_carrier_on(qca->net_dev);
+	serdev_device_set_drvdata(serdev, qca);
+	serdev_device_set_client_ops(serdev, &qca_serdev_ops);
+
+	ret = serdev_device_open(serdev);
+	if (ret) {
+		dev_err(&serdev->dev, "Unable to open device %s\n",
+			qcauart_dev->name);
+		goto free;
+	}
+
+	speed = serdev_device_set_baudrate(serdev, speed);
+	dev_info(&serdev->dev, "Using baudrate: %u\n", speed);
+
+	serdev_device_set_flow_control(serdev, false);
+
+	ret = register_netdev(qcauart_dev);
+	if (ret) {
+		dev_err(&serdev->dev, "Unable to register net device %s\n",
+			qcauart_dev->name);
+		serdev_device_close(serdev);
+		cancel_work_sync(&qca->tx_work);
+		goto free;
+	}
+
+	return 0;
+
+free:
+	free_netdev(qcauart_dev);
+	return ret;
+}
+
+static void qca_uart_remove(struct serdev_device *serdev)
+{
+	struct qcauart *qca = serdev_device_get_drvdata(serdev);
+
+	unregister_netdev(qca->net_dev);
+
+	/* Flush any pending characters in the driver. */
+	serdev_device_close(serdev);
+	cancel_work_sync(&qca->tx_work);
+
+	free_netdev(qca->net_dev);
+}
+
+static struct serdev_device_driver qca_uart_driver = {
+	.probe = qca_uart_probe,
+	.remove = qca_uart_remove,
+	.driver = {
+		.name = QCAUART_DRV_NAME,
+		.of_match_table = of_match_ptr(qca_uart_of_match),
+	},
+};
+
+module_serdev_device_driver(qca_uart_driver);
+
+MODULE_DESCRIPTION("Qualcomm Atheros QCA7000 UART Driver");
+MODULE_AUTHOR("Qualcomm Atheros Communications");
+MODULE_AUTHOR("Stefan Wahren <stefan.wahren-eS4NqCHxEME@public.gmane.org>");
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_VERSION(QCAUART_DRV_VERSION);
-- 
2.1.4

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Re: [PATCH v7 net-next 17/17] net: qualcomm: add QCA7000 UART driver

[David Miller]

When you submit a new version of a patch within a patch series, you must
always resubmit the entire series not just the patches which change.

Thank you.

[PATCH RESEND v7 net-next 17/17] net: qualcomm: add QCA7000 UART driver

[Stefan Wahren]

This patch adds the Ethernet over UART driver for the
Qualcomm QCA7000 HomePlug GreenPHY.

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
---
 drivers/net/ethernet/qualcomm/Kconfig         |  16 +
 drivers/net/ethernet/qualcomm/Makefile        |   2 +
 drivers/net/ethernet/qualcomm/qca_7k_common.h |   6 +
 drivers/net/ethernet/qualcomm/qca_uart.c      | 423 ++++++++++++++++++++++++++
 4 files changed, 447 insertions(+)
 create mode 100644 drivers/net/ethernet/qualcomm/qca_uart.c

Changes in v7:
* fix race between tx workqueue and device deregistration (reported by Lino)

diff --git a/drivers/net/ethernet/qualcomm/Kconfig b/drivers/net/ethernet/qualcomm/Kconfig
index b4c369d..877675a 100644
--- a/drivers/net/ethernet/qualcomm/Kconfig
+++ b/drivers/net/ethernet/qualcomm/Kconfig
@@ -30,6 +30,22 @@ config QCA7000_SPI
 	  To compile this driver as a module, choose M here. The module
 	  will be called qcaspi.
 
+config QCA7000_UART
+	tristate "Qualcomm Atheros QCA7000 UART support"
+	select QCA7000
+	depends on SERIAL_DEV_BUS && OF
+	---help---
+	  This UART protocol driver supports the Qualcomm Atheros QCA7000.
+
+	  Currently the driver assumes these device UART settings:
+	    Data bits: 8
+	    Parity: None
+	    Stop bits: 1
+	    Flow control: None
+
+	  To compile this driver as a module, choose M here. The module
+	  will be called qcauart.
+
 config QCOM_EMAC
 	tristate "Qualcomm Technologies, Inc. EMAC Gigabit Ethernet support"
 	depends on HAS_DMA && HAS_IOMEM
diff --git a/drivers/net/ethernet/qualcomm/Makefile b/drivers/net/ethernet/qualcomm/Makefile
index 65556ca..92fa7c4 100644
--- a/drivers/net/ethernet/qualcomm/Makefile
+++ b/drivers/net/ethernet/qualcomm/Makefile
@@ -5,5 +5,7 @@
 obj-$(CONFIG_QCA7000) += qca_7k_common.o
 obj-$(CONFIG_QCA7000_SPI) += qcaspi.o
 qcaspi-objs := qca_7k.o qca_debug.o qca_spi.o
+obj-$(CONFIG_QCA7000_UART) += qcauart.o
+qcauart-objs := qca_uart.o
 
 obj-y += emac/
diff --git a/drivers/net/ethernet/qualcomm/qca_7k_common.h b/drivers/net/ethernet/qualcomm/qca_7k_common.h
index 07bdd6c..928554f 100644
--- a/drivers/net/ethernet/qualcomm/qca_7k_common.h
+++ b/drivers/net/ethernet/qualcomm/qca_7k_common.h
@@ -122,6 +122,12 @@ static inline void qcafrm_fsm_init_spi(struct qcafrm_handle *handle)
 	handle->state = handle->init;
 }
 
+static inline void qcafrm_fsm_init_uart(struct qcafrm_handle *handle)
+{
+	handle->init = QCAFRM_WAIT_AA1;
+	handle->state = handle->init;
+}
+
 /*   Gather received bytes and try to extract a full Ethernet frame
  *   by following a simple state machine.
  *
diff --git a/drivers/net/ethernet/qualcomm/qca_uart.c b/drivers/net/ethernet/qualcomm/qca_uart.c
new file mode 100644
index 0000000..db6068c
--- /dev/null
+++ b/drivers/net/ethernet/qualcomm/qca_uart.c
@@ -0,0 +1,423 @@
+/*
+ *   Copyright (c) 2011, 2012, Qualcomm Atheros Communications Inc.
+ *   Copyright (c) 2017, I2SE GmbH
+ *
+ *   Permission to use, copy, modify, and/or distribute this software
+ *   for any purpose with or without fee is hereby granted, provided
+ *   that the above copyright notice and this permission notice appear
+ *   in all copies.
+ *
+ *   THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
+ *   WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
+ *   WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
+ *   THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR
+ *   CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ *   LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
+ *   NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ *   CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*   This module implements the Qualcomm Atheros UART protocol for
+ *   kernel-based UART device; it is essentially an Ethernet-to-UART
+ *   serial converter;
+ */
+
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/etherdevice.h>
+#include <linux/if_arp.h>
+#include <linux/if_ether.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_net.h>
+#include <linux/sched.h>
+#include <linux/serdev.h>
+#include <linux/skbuff.h>
+#include <linux/types.h>
+
+#include "qca_7k_common.h"
+
+#define QCAUART_DRV_VERSION "0.1.0"
+#define QCAUART_DRV_NAME "qcauart"
+#define QCAUART_TX_TIMEOUT (1 * HZ)
+
+struct qcauart {
+	struct net_device *net_dev;
+	spinlock_t lock;			/* transmit lock */
+	struct work_struct tx_work;		/* Flushes transmit buffer   */
+
+	struct serdev_device *serdev;
+	struct qcafrm_handle frm_handle;
+	struct sk_buff *rx_skb;
+
+	unsigned char *tx_head;			/* pointer to next XMIT byte */
+	int tx_left;				/* bytes left in XMIT queue  */
+	unsigned char *tx_buffer;
+};
+
+static int
+qca_tty_receive(struct serdev_device *serdev, const unsigned char *data,
+		size_t count)
+{
+	struct qcauart *qca = serdev_device_get_drvdata(serdev);
+	struct net_device *netdev = qca->net_dev;
+	struct net_device_stats *n_stats = &netdev->stats;
+	size_t i;
+
+	if (!qca->rx_skb) {
+		qca->rx_skb = netdev_alloc_skb_ip_align(netdev,
+							netdev->mtu +
+							VLAN_ETH_HLEN);
+		if (!qca->rx_skb) {
+			n_stats->rx_errors++;
+			n_stats->rx_dropped++;
+			return 0;
+		}
+	}
+
+	for (i = 0; i < count; i++) {
+		s32 retcode;
+
+		retcode = qcafrm_fsm_decode(&qca->frm_handle,
+					    qca->rx_skb->data,
+					    skb_tailroom(qca->rx_skb),
+					    data[i]);
+
+		switch (retcode) {
+		case QCAFRM_GATHER:
+		case QCAFRM_NOHEAD:
+			break;
+		case QCAFRM_NOTAIL:
+			netdev_dbg(netdev, "recv: no RX tail\n");
+			n_stats->rx_errors++;
+			n_stats->rx_dropped++;
+			break;
+		case QCAFRM_INVLEN:
+			netdev_dbg(netdev, "recv: invalid RX length\n");
+			n_stats->rx_errors++;
+			n_stats->rx_dropped++;
+			break;
+		default:
+			n_stats->rx_packets++;
+			n_stats->rx_bytes += retcode;
+			skb_put(qca->rx_skb, retcode);
+			qca->rx_skb->protocol = eth_type_trans(
+						qca->rx_skb, qca->rx_skb->dev);
+			qca->rx_skb->ip_summed = CHECKSUM_UNNECESSARY;
+			netif_rx_ni(qca->rx_skb);
+			qca->rx_skb = netdev_alloc_skb_ip_align(netdev,
+								netdev->mtu +
+								VLAN_ETH_HLEN);
+			if (!qca->rx_skb) {
+				netdev_dbg(netdev, "recv: out of RX resources\n");
+				n_stats->rx_errors++;
+				return i;
+			}
+		}
+	}
+
+	return i;
+}
+
+/* Write out any remaining transmit buffer. Scheduled when tty is writable */
+static void qcauart_transmit(struct work_struct *work)
+{
+	struct qcauart *qca = container_of(work, struct qcauart, tx_work);
+	struct net_device_stats *n_stats = &qca->net_dev->stats;
+	int written;
+
+	spin_lock_bh(&qca->lock);
+
+	/* First make sure we're connected. */
+	if (!netif_running(qca->net_dev)) {
+		spin_unlock_bh(&qca->lock);
+		return;
+	}
+
+	if (qca->tx_left <= 0)  {
+		/* Now serial buffer is almost free & we can start
+		 * transmission of another packet
+		 */
+		n_stats->tx_packets++;
+		spin_unlock_bh(&qca->lock);
+		netif_wake_queue(qca->net_dev);
+		return;
+	}
+
+	written = serdev_device_write_buf(qca->serdev, qca->tx_head,
+					  qca->tx_left);
+	if (written > 0) {
+		qca->tx_left -= written;
+		qca->tx_head += written;
+	}
+	spin_unlock_bh(&qca->lock);
+}
+
+/* Called by the driver when there's room for more data.
+ * Schedule the transmit.
+ */
+static void qca_tty_wakeup(struct serdev_device *serdev)
+{
+	struct qcauart *qca = serdev_device_get_drvdata(serdev);
+
+	schedule_work(&qca->tx_work);
+}
+
+static struct serdev_device_ops qca_serdev_ops = {
+	.receive_buf = qca_tty_receive,
+	.write_wakeup = qca_tty_wakeup,
+};
+
+static int qcauart_netdev_open(struct net_device *dev)
+{
+	struct qcauart *qca = netdev_priv(dev);
+
+	netif_start_queue(qca->net_dev);
+
+	return 0;
+}
+
+static int qcauart_netdev_close(struct net_device *dev)
+{
+	struct qcauart *qca = netdev_priv(dev);
+
+	netif_stop_queue(dev);
+	flush_work(&qca->tx_work);
+
+	spin_lock_bh(&qca->lock);
+	qca->tx_left = 0;
+	spin_unlock_bh(&qca->lock);
+
+	return 0;
+}
+
+static netdev_tx_t
+qcauart_netdev_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	struct net_device_stats *n_stats = &dev->stats;
+	struct qcauart *qca = netdev_priv(dev);
+	u8 pad_len = 0;
+	int written;
+	u8 *pos;
+
+	spin_lock(&qca->lock);
+
+	WARN_ON(qca->tx_left);
+
+	if (!netif_running(dev))  {
+		spin_unlock(&qca->lock);
+		netdev_warn(qca->net_dev, "xmit: iface is down\n");
+		goto out;
+	}
+
+	pos = qca->tx_buffer;
+
+	if (skb->len < QCAFRM_MIN_LEN)
+		pad_len = QCAFRM_MIN_LEN - skb->len;
+
+	pos += qcafrm_create_header(pos, skb->len + pad_len);
+
+	memcpy(pos, skb->data, skb->len);
+	pos += skb->len;
+
+	if (pad_len) {
+		memset(pos, 0, pad_len);
+		pos += pad_len;
+	}
+
+	pos += qcafrm_create_footer(pos);
+
+	netif_stop_queue(qca->net_dev);
+
+	written = serdev_device_write_buf(qca->serdev, qca->tx_buffer,
+					  pos - qca->tx_buffer);
+	if (written > 0) {
+		qca->tx_left = (pos - qca->tx_buffer) - written;
+		qca->tx_head = qca->tx_buffer + written;
+		n_stats->tx_bytes += written;
+	}
+	spin_unlock(&qca->lock);
+
+	netif_trans_update(dev);
+out:
+	dev_kfree_skb_any(skb);
+	return NETDEV_TX_OK;
+}
+
+static void qcauart_netdev_tx_timeout(struct net_device *dev)
+{
+	struct qcauart *qca = netdev_priv(dev);
+
+	netdev_info(qca->net_dev, "Transmit timeout at %ld, latency %ld\n",
+		    jiffies, dev_trans_start(dev));
+	dev->stats.tx_errors++;
+	dev->stats.tx_dropped++;
+}
+
+static int qcauart_netdev_init(struct net_device *dev)
+{
+	struct qcauart *qca = netdev_priv(dev);
+	size_t len;
+
+	/* Finish setting up the device info. */
+	dev->mtu = QCAFRM_MAX_MTU;
+	dev->type = ARPHRD_ETHER;
+
+	len = QCAFRM_HEADER_LEN + QCAFRM_MAX_LEN + QCAFRM_FOOTER_LEN;
+	qca->tx_buffer = devm_kmalloc(&qca->serdev->dev, len, GFP_KERNEL);
+	if (!qca->tx_buffer)
+		return -ENOMEM;
+
+	qca->rx_skb = netdev_alloc_skb_ip_align(qca->net_dev,
+						qca->net_dev->mtu +
+						VLAN_ETH_HLEN);
+	if (!qca->rx_skb)
+		return -ENOBUFS;
+
+	return 0;
+}
+
+static void qcauart_netdev_uninit(struct net_device *dev)
+{
+	struct qcauart *qca = netdev_priv(dev);
+
+	if (qca->rx_skb)
+		dev_kfree_skb(qca->rx_skb);
+}
+
+static const struct net_device_ops qcauart_netdev_ops = {
+	.ndo_init = qcauart_netdev_init,
+	.ndo_uninit = qcauart_netdev_uninit,
+	.ndo_open = qcauart_netdev_open,
+	.ndo_stop = qcauart_netdev_close,
+	.ndo_start_xmit = qcauart_netdev_xmit,
+	.ndo_set_mac_address = eth_mac_addr,
+	.ndo_tx_timeout = qcauart_netdev_tx_timeout,
+	.ndo_validate_addr = eth_validate_addr,
+};
+
+static void qcauart_netdev_setup(struct net_device *dev)
+{
+	dev->netdev_ops = &qcauart_netdev_ops;
+	dev->watchdog_timeo = QCAUART_TX_TIMEOUT;
+	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
+	dev->tx_queue_len = 100;
+
+	/* MTU range: 46 - 1500 */
+	dev->min_mtu = QCAFRM_MIN_MTU;
+	dev->max_mtu = QCAFRM_MAX_MTU;
+}
+
+static const struct of_device_id qca_uart_of_match[] = {
+	{
+	 .compatible = "qca,qca7000",
+	},
+	{}
+};
+MODULE_DEVICE_TABLE(of, qca_uart_of_match);
+
+static int qca_uart_probe(struct serdev_device *serdev)
+{
+	struct net_device *qcauart_dev = alloc_etherdev(sizeof(struct qcauart));
+	struct qcauart *qca;
+	const char *mac;
+	u32 speed = 115200;
+	int ret;
+
+	if (!qcauart_dev)
+		return -ENOMEM;
+
+	qcauart_netdev_setup(qcauart_dev);
+	SET_NETDEV_DEV(qcauart_dev, &serdev->dev);
+
+	qca = netdev_priv(qcauart_dev);
+	if (!qca) {
+		pr_err("qca_uart: Fail to retrieve private structure\n");
+		ret = -ENOMEM;
+		goto free;
+	}
+	qca->net_dev = qcauart_dev;
+	qca->serdev = serdev;
+	qcafrm_fsm_init_uart(&qca->frm_handle);
+
+	spin_lock_init(&qca->lock);
+	INIT_WORK(&qca->tx_work, qcauart_transmit);
+
+	of_property_read_u32(serdev->dev.of_node, "current-speed", &speed);
+
+	mac = of_get_mac_address(serdev->dev.of_node);
+
+	if (mac)
+		ether_addr_copy(qca->net_dev->dev_addr, mac);
+
+	if (!is_valid_ether_addr(qca->net_dev->dev_addr)) {
+		eth_hw_addr_random(qca->net_dev);
+		dev_info(&serdev->dev, "Using random MAC address: %pM\n",
+			 qca->net_dev->dev_addr);
+	}
+
+	netif_carrier_on(qca->net_dev);
+	serdev_device_set_drvdata(serdev, qca);
+	serdev_device_set_client_ops(serdev, &qca_serdev_ops);
+
+	ret = serdev_device_open(serdev);
+	if (ret) {
+		dev_err(&serdev->dev, "Unable to open device %s\n",
+			qcauart_dev->name);
+		goto free;
+	}
+
+	speed = serdev_device_set_baudrate(serdev, speed);
+	dev_info(&serdev->dev, "Using baudrate: %u\n", speed);
+
+	serdev_device_set_flow_control(serdev, false);
+
+	ret = register_netdev(qcauart_dev);
+	if (ret) {
+		dev_err(&serdev->dev, "Unable to register net device %s\n",
+			qcauart_dev->name);
+		serdev_device_close(serdev);
+		cancel_work_sync(&qca->tx_work);
+		goto free;
+	}
+
+	return 0;
+
+free:
+	free_netdev(qcauart_dev);
+	return ret;
+}
+
+static void qca_uart_remove(struct serdev_device *serdev)
+{
+	struct qcauart *qca = serdev_device_get_drvdata(serdev);
+
+	unregister_netdev(qca->net_dev);
+
+	/* Flush any pending characters in the driver. */
+	serdev_device_close(serdev);
+	cancel_work_sync(&qca->tx_work);
+
+	free_netdev(qca->net_dev);
+}
+
+static struct serdev_device_driver qca_uart_driver = {
+	.probe = qca_uart_probe,
+	.remove = qca_uart_remove,
+	.driver = {
+		.name = QCAUART_DRV_NAME,
+		.of_match_table = of_match_ptr(qca_uart_of_match),
+	},
+};
+
+module_serdev_device_driver(qca_uart_driver);
+
+MODULE_DESCRIPTION("Qualcomm Atheros QCA7000 UART Driver");
+MODULE_AUTHOR("Qualcomm Atheros Communications");
+MODULE_AUTHOR("Stefan Wahren <stefan.wahren@i2se.com>");
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_VERSION(QCAUART_DRV_VERSION);
-- 
2.1.4

Re: [PATCH RESEND v7 net-next 17/17] net: qualcomm: add QCA7000 UART driver

[Lino Sanfilippo]

Hi,


> This patch adds the Ethernet over UART driver for the
> Qualcomm QCA7000 HomePlug GreenPHY.
> 
> Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
> ---

Reviewed-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>

Regards,
Lino

Re: [PATCH RESEND v7 net-next 17/17] net: qualcomm: add QCA7000 UART driver

[Lino Sanfilippo]

Hi,


> This patch adds the Ethernet over UART driver for the
> Qualcomm QCA7000 HomePlug GreenPHY.
> 
> Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
> ---

Reviewed-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>

Regards,
Lino

Re: [PATCH RESEND v7 net-next 17/17] net: qualcomm: add QCA7000 UART driver

[Stefan Wahren]

Am 24.05.2017 um 16:21 schrieb Lino Sanfilippo:
> Hi,
>
>
>> This patch adds the Ethernet over UART driver for the
>> Qualcomm QCA7000 HomePlug GreenPHY.
>>
>> Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
>> ---
> Reviewed-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
>

Thanks
Stefan

Re: [PATCH RESEND v7 net-next 17/17] net: qualcomm: add QCA7000 UART driver

[Stefan Wahren]

Am 24.05.2017 um 16:21 schrieb Lino Sanfilippo:
> Hi,
>
>
>> This patch adds the Ethernet over UART driver for the
>> Qualcomm QCA7000 HomePlug GreenPHY.
>>
>> Signed-off-by: Stefan Wahren <stefan.wahren-eS4NqCHxEME@public.gmane.org>
>> ---
> Reviewed-by: Lino Sanfilippo <LinoSanfilippo-Mmb7MZpHnFY@public.gmane.org>
>

Thanks
Stefan
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Aw: Re: [PATCH v6 net-next 17/17] net: qualcomm: add QCA7000 UART driver

[Lino Sanfilippo]

Hi,

> Gesendet: Mittwoch, 24. Mai 2017 um 11:06 Uhr
> Von: "Stefan Wahren" <stefan.wahren@i2se.com>
> An: "Lino Sanfilippo" <LinoSanfilippo@gmx.de>, "Rob Herring" <robh+dt@kernel.org>, "Mark Rutland" <mark.rutland@arm.com>, "David S. Miller" <davem@davemloft.net>
> Cc: linux-serial@vger.kernel.org, "Jiri Slaby" <jslaby@suse.com>, "Greg Kroah-Hartman" <gregkh@linuxfoundation.org>, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, "Jakub Kicinski" <kubakici@wp.pl>, devicetree@vger.kernel.org
> Betreff: Re: [PATCH v6 net-next 17/17] net: qualcomm: add QCA7000 UART driver
>
> Am 23.05.2017 um 23:01 schrieb Lino Sanfilippo:
> > On 23.05.2017 21:38, Stefan Wahren wrote:
> >>> Lino Sanfilippo <LinoSanfilippo@gmx.de> hat am 23. Mai 2017 um 20:16 geschrieben:
> >>>
> >>> I suggest to avoid this possible race by first unregistering the netdevice and then 
> >>> calling cancel_work_sync().
> >> What makes you sure that's safe to unregister the netdev while the tx work queue is possibly active?
> > unregister_netdevice() calls netdev_close() if the interface is still up. netdev_close() calls flush_work()
> > so the unregistration is delayed until the tx work function is finished. Furthermore both close() and
> > tx work are synchronized by means of the qca->lock which also guarantees that unregister_netdevice() wont
> > be finished until the tx work is done.
> >
> 
> Thanks for the explanation. I suspect there could be the same race
> between serdev_device_close() and the tx work queue.
> 
> So i would propose a variant of your original suggestion:
> 
> unregister_netdev(qca->net_dev);
> 
> /* Flush any pending characters in the driver. */
> serdev_device_close(serdev);
> cancel_work_sync(&qca->tx_work);
> 
> Since we have the same pattern in the error path of the probe function,
> the same applies there.

Agreed, it is much cleaner to have the same cleanup pattern in remove() as
we have in (error case of) probe().

Regards,
Lino