qca_7k: Replace BSD boilerplate with SPDX

According to MODULE_LICENSE the driver is under a dual license.
So replace the BSD license text with the proper SPDX tag.

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

qca_spi: Introduce QCASPI_RX_MAX_FRAMES

Currently qca_spi reserves enough space for 4 complete Ethernet over SPI
frames in the receive buffer. Unfortunately this is hidden under a magic
number. So replace it with a more self explaining define.

Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

qca_spi: Add QCASPI prefix to ring defines

All defines in qca_spi.h except of the two ring limit defines have
a QCASPI prefix. Since the name is quite generic add the QCASPI prefix
to avoid possible name conflicts.

Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: qca_spi: Introduce stat about bad signature

In order to identify significant signature issues add a new stat counter,
which increases on bad signature values that causes a sync loss.

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: qca_spi: Move reset_count to struct qcaspi

The reset counter is specific for every QCA700x chip. So move this
into the private driver struct. Otherwise we get unpredictable reset
behavior in setups with multiple QCA700x chips.

Fixes: 291ab06ecf67 (net: qualcomm: new Ethernet over SPI driver for QCA7000)
Signed-off-by: Stefan Wahren <stefan.wahren@in-tech.com>
Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: qca_spi: Add available buffer space verification

Interferences on the SPI line could distort the response of
available buffer space. So at least we should check that the
response doesn't exceed the maximum available buffer space.
In error case increase a new error counter and retry it later.
This behavior avoids buffer errors in the QCA7000, which
results in an unnecessary chip reset including packet loss.

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: qca_spi: Introduce write register verification

The SPI protocol for the QCA7000 doesn't have any fault detection.
In order to increase the drivers reliability in noisy environments,
we could implement a write verification inspired by the enc28j60.
This should avoid situations were the driver wrongly assumes the
receive interrupt is enabled and miss all incoming packets.

This function is disabled per default and can be controlled via module
parameter wr_verify.

Signed-off-by: Michael Heimpold <michael.heimpold@i2se.com>
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: qca_spi: Fix race condition in spi transfers

With performance optimization the spi transfer and messages of basic
register operations like qcaspi_read_register moved into the private
driver structure. But they weren't protected against mutual access
(e.g. between driver kthread and ethtool). So dumping the QCA7000
registers via ethtool during network traffic could make spi_sync
hang forever, because the completion in spi_message is overwritten.

So revert the optimization completely.

Fixes: 291ab06ecf676 ("net: qualcomm: new Ethernet over SPI driver for QCA700")
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: qualcomm: rename qca_framing.c to qca_7k_common.c

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>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: qualcomm: use net_device_ops instead of direct call

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>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: qualcomm: new Ethernet over SPI driver for QCA7000

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

Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: David S. Miller <davem@davemloft.net>