Re: [PATCH v4 3/5] net: ax88796c: ASIX AX88796C SPI Ethernet Adapter Driver

[Marc Kleine-Budde]

On 10/28/20 10:40 PM, Łukasz Stelmach wrote:
> ASIX AX88796[1] is a versatile ethernet adapter chip, that can be
> connected to a CPU with a 8/16-bit bus or with an SPI. This driver
> supports SPI connection.
> 
> The driver has been ported from the vendor kernel for ARTIK5[2]
> boards. Several changes were made to adapt it to the current kernel
> which include:
> 
> + updated DT configuration,
> + clock configuration moved to DT,
> + new timer, ethtool and gpio APIs,
> + dev_* instead of pr_* and custom printk() wrappers,
> + removed awkward vendor power managemtn.
> 
> [1] https://www.asix.com.tw/products.php?op=pItemdetail&PItemID=104;65;86&PLine=65
> [2] https://git.tizen.org/cgit/profile/common/platform/kernel/linux-3.10-artik/
> 
> The other ax88796 driver is for NE2000 compatible AX88796L chip. These
> chips are not compatible. Hence, two separate drivers are required.
> 
> Signed-off-by: Łukasz Stelmach <l.stelmach@xxxxxxxxxxx>
> ---
>  MAINTAINERS                                |    6 +
>  drivers/net/ethernet/Kconfig               |    1 +
>  drivers/net/ethernet/Makefile              |    1 +
>  drivers/net/ethernet/asix/Kconfig          |   22 +
>  drivers/net/ethernet/asix/Makefile         |    6 +
>  drivers/net/ethernet/asix/ax88796c_ioctl.c |  197 ++++
>  drivers/net/ethernet/asix/ax88796c_ioctl.h |   26 +
>  drivers/net/ethernet/asix/ax88796c_main.c  | 1144 ++++++++++++++++++++
>  drivers/net/ethernet/asix/ax88796c_main.h  |  578 ++++++++++
>  drivers/net/ethernet/asix/ax88796c_spi.c   |  111 ++
>  drivers/net/ethernet/asix/ax88796c_spi.h   |   69 ++
>  11 files changed, 2161 insertions(+)
>  create mode 100644 drivers/net/ethernet/asix/Kconfig
>  create mode 100644 drivers/net/ethernet/asix/Makefile
>  create mode 100644 drivers/net/ethernet/asix/ax88796c_ioctl.c
>  create mode 100644 drivers/net/ethernet/asix/ax88796c_ioctl.h
>  create mode 100644 drivers/net/ethernet/asix/ax88796c_main.c
>  create mode 100644 drivers/net/ethernet/asix/ax88796c_main.h
>  create mode 100644 drivers/net/ethernet/asix/ax88796c_spi.c
>  create mode 100644 drivers/net/ethernet/asix/ax88796c_spi.h

[...]

> +enum watchdog_state {
> +	chk_link = 0,
> +	chk_cable,
> +	ax_nop,
> +};
> +
> +struct ax88796c_device {
> +	struct resource		*addr_res;   /* resources found */
> +	struct resource		*addr_req;   /* resources requested */
> +	struct resource		*irq_res;
> +
> +	struct spi_device	*spi;
> +	struct net_device	*ndev;
> +	struct net_device_stats	stats;
> +
> +	struct timer_list	watchdog;
> +	enum watchdog_state	w_state;
> +	size_t			w_ticks;

are these used?

> +
> +	struct work_struct	ax_work;
> +
> +	struct mutex		spi_lock; /* device access */
> +
> +	struct sk_buff_head	tx_wait_q;
> +
> +	struct axspi_data	ax_spi;
> +
> +	struct mii_bus		*mdiobus;
> +	struct phy_device	*phydev;
> +
> +	int			msg_enable;
> +
> +	u16			seq_num;
> +
> +	u8			multi_filter[AX_MCAST_FILTER_SIZE];
> +
> +	int			link;
> +	int			speed;
> +	int			duplex;
> +	int			pause;
> +	int			asym_pause;
> +	int			flowctrl;
> +		#define AX_FC_NONE		0
> +		#define AX_FC_RX		BIT(0)
> +		#define AX_FC_TX		BIT(1)
> +		#define AX_FC_ANEG		BIT(2)
> +
> +	unsigned long		capabilities;
> +		#define AX_CAP_DMA		BIT(0)
> +		#define AX_CAP_COMP		BIT(1)
> +		#define AX_CAP_BIDIR		BIT(2)
> +
> +	u8			plat_endian;
> +		#define PLAT_LITTLE_ENDIAN	0
> +		#define PLAT_BIG_ENDIAN		1
> +
> +	unsigned long		flags;
> +		#define EVENT_INTR		BIT(0)
> +		#define EVENT_TX		BIT(1)
> +		#define EVENT_SET_MULTI		BIT(2)
> +
> +};
> +
> +#define to_ax88796c_device(ndev) ((struct ax88796c_device *)netdev_priv(ndev))
> +
> +enum skb_state {
> +	illegal = 0,
> +	tx_done,
> +	rx_done,
> +	rx_err,
> +};
> +
> +struct skb_data {
> +	enum skb_state state;
> +	struct net_device *ndev;
> +	struct sk_buff *skb;
> +	size_t len;
> +	dma_addr_t phy_addr;

unused?

[...]

> diff --git a/drivers/net/ethernet/asix/ax88796c_spi.c b/drivers/net/ethernet/asix/ax88796c_spi.c
> new file mode 100644
> index 000000000000..1a20bbeb4dc1
> --- /dev/null
> +++ b/drivers/net/ethernet/asix/ax88796c_spi.c
> @@ -0,0 +1,111 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2010 ASIX Electronics Corporation
> + * Copyright (c) 2020 Samsung Electronics Co., Ltd.
> + *
> + * ASIX AX88796C SPI Fast Ethernet Linux driver
> + */
> +
> +#define pr_fmt(fmt)	"ax88796c: " fmt
> +
> +#include <linux/string.h>
> +#include <linux/spi/spi.h>
> +
> +#include "ax88796c_spi.h"
> +
> +/* driver bus management functions */
> +int axspi_wakeup(const struct axspi_data *ax_spi)
> +{
> +	u8 tx_buf;
> +	int ret;
> +
> +	tx_buf = AX_SPICMD_EXIT_PWD;	/* OP */
> +	ret = spi_write(ax_spi->spi, &tx_buf, 1);

spi_write() needs a DMA safe buffer.

> +	if (ret)
> +		dev_err(&ax_spi->spi->dev, "%s() failed: ret = %d\n", __func__, ret);
> +	return ret;
> +}
> +
> +int axspi_read_status(const struct axspi_data *ax_spi, struct spi_status *status)
> +{
> +	u8 tx_buf;
> +	int ret;
> +
> +	/* OP */
> +	tx_buf = AX_SPICMD_READ_STATUS;
> +	ret = spi_write_then_read(ax_spi->spi, &tx_buf, 1, (u8 *)&status, 3);
> +	if (ret)
> +		dev_err(&ax_spi->spi->dev, "%s() failed: ret = %d\n", __func__, ret);
> +	else
> +		le16_to_cpus(&status->isr);
> +
> +	return ret;
> +}
> +
> +int axspi_read_rxq(struct axspi_data *ax_spi, void *data, int len)
> +{
> +	struct spi_transfer *xfer = ax_spi->spi_rx_xfer;
> +	int ret;
> +
> +	memcpy(ax_spi->cmd_buf, rx_cmd_buf, 5);
> +
> +	xfer->tx_buf = ax_spi->cmd_buf;
> +	xfer->rx_buf = NULL;
> +	xfer->len = ax_spi->comp ? 2 : 5;
> +	xfer->bits_per_word = 8;
> +	spi_message_add_tail(xfer, &ax_spi->rx_msg);
> +
> +	xfer++;
> +	xfer->rx_buf = data;
> +	xfer->tx_buf = NULL;
> +	xfer->len = len;
> +	xfer->bits_per_word = 8;
> +	spi_message_add_tail(xfer, &ax_spi->rx_msg);
> +	ret = spi_sync(ax_spi->spi, &ax_spi->rx_msg);
> +	if (ret)
> +		dev_err(&ax_spi->spi->dev, "%s() failed: ret = %d\n", __func__, ret);
> +
> +	return ret;
> +}
> +
> +int axspi_write_txq(const struct axspi_data *ax_spi, void *data, int len)
> +{
> +	return spi_write(ax_spi->spi, data, len);
> +}
> +
> +u16 axspi_read_reg(const struct axspi_data *ax_spi, u8 reg)
> +{
> +	u8 tx_buf[4];
> +	u16 rx_buf = 0;
> +	int ret;
> +	int len = ax_spi->comp ? 3 : 4;
> +
> +	tx_buf[0] = 0x03;	/* OP code read register */
> +	tx_buf[1] = reg;	/* register address */
> +	tx_buf[2] = 0xFF;	/* dumy cycle */
> +	tx_buf[3] = 0xFF;	/* dumy cycle */
> +	ret = spi_write_then_read(ax_spi->spi, tx_buf, len, (u8 *)&rx_buf, 2);
> +	if (ret)
> +		dev_err(&ax_spi->spi->dev, "%s() failed: ret = %d\n", __func__, ret);
> +	else
> +		le16_to_cpus(&rx_buf);
> +
> +	return rx_buf;
> +}
> +
> +int axspi_write_reg(const struct axspi_data *ax_spi, u8 reg, u16 value)
> +{
> +	u8 tx_buf[4];
> +	int ret;
> +
> +	tx_buf[0] = AX_SPICMD_WRITE_REG;	/* OP code read register */
> +	tx_buf[1] = reg;			/* register address */
> +	tx_buf[2] = value;
> +	tx_buf[3] = value >> 8;
> +
> +	ret = spi_write(ax_spi->spi, tx_buf, 4);

I think you need DMA safe mem for spi_write().

Marc

-- 
Pengutronix e.K.                 | Marc Kleine-Budde           |
Embedded Linux                   | https://www.pengutronix.de  |
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