Commit 797047f8 authored by Marek Vasut's avatar Marek Vasut Committed by David S. Miller
Browse files

net: ks8851: Implement Parallel bus operations 



Implement accessors for KS8851-16MLL/MLLI/MLLU parallel bus variant of
the KS8851. This is based off the ks8851_mll.c , which is a driver for
exactly the same hardware, however the ks8851.c code is much higher
quality. Hence, this patch pulls out the relevant information from the
ks8851_mll.c on how to access the bus, but uses the common ks8851.c
code. To make this patch reviewable, instead of rewriting ks8851_mll.c,
ks8851_mll.c is removed in a separate subsequent patch.

Signed-off-by: default avatarMarek Vasut <marex@denx.de>
Cc: David S. Miller <davem@davemloft.net>
Cc: Lukas Wunner <lukas@wunner.de>
Cc: Petr Stetiar <ynezz@true.cz>
Cc: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: default avatarAndrew Lunn <andrew@lunn.ch>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent b07f987a

drivers/net/ethernet/micrel/Kconfig

+2 −0
Original line number Diff line number Diff line
@@ -38,6 +38,8 @@ config KS8851_MLL 
	tristate "Micrel KS8851 MLL"

	depends on HAS_IOMEM

	select MII

	select CRC32

	select EEPROM_93CX6

	---help---

	  This platform driver is for Micrel KS8851 Address/data bus

	  multiplexed network chip.

drivers/net/ethernet/micrel/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -7,4 +7,5 @@ obj-$(CONFIG_KS8842) += ks8842.o 
obj-$(CONFIG_KS8851) += ks8851.o

ks8851-objs = ks8851_common.o ks8851_spi.o

obj-$(CONFIG_KS8851_MLL) += ks8851_mll.o

ks8851_mll-objs = ks8851_common.o ks8851_par.o

obj-$(CONFIG_KSZ884X_PCI) += ksz884x.o

drivers/net/ethernet/micrel/ks8851_par.c

0 → 100644
+357 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-only

/* drivers/net/ethernet/micrel/ks8851.c

 *

 * Copyright 2009 Simtec Electronics

 *	http://www.simtec.co.uk/

 *	Ben Dooks <ben@simtec.co.uk>

 */



#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt



#define DEBUG



#include <linux/interrupt.h>

#include <linux/module.h>

#include <linux/kernel.h>

#include <linux/netdevice.h>

#include <linux/etherdevice.h>

#include <linux/ethtool.h>

#include <linux/iopoll.h>

#include <linux/mii.h>



#include <linux/platform_device.h>

#include <linux/of_net.h>



#include "ks8851.h"



static int msg_enable;



#define BE3             0x8000      /* Byte Enable 3 */

#define BE2             0x4000      /* Byte Enable 2 */

#define BE1             0x2000      /* Byte Enable 1 */

#define BE0             0x1000      /* Byte Enable 0 */



/**

 * struct ks8851_net_par - KS8851 Parallel driver private data

 * @ks8851: KS8851 driver common private data

 * @lock: Lock to ensure that the device is not accessed when busy.

 * @hw_addr	: start address of data register.

 * @hw_addr_cmd	: start address of command register.

 * @cmd_reg_cache	: command register cached.

 *

 * The @lock ensures that the chip is protected when certain operations are

 * in progress. When the read or write packet transfer is in progress, most

 * of the chip registers are not accessible until the transfer is finished

 * and the DMA has been de-asserted.

 */

struct ks8851_net_par {

	struct ks8851_net	ks8851;

	spinlock_t		lock;

	void __iomem		*hw_addr;

	void __iomem		*hw_addr_cmd;

	u16			cmd_reg_cache;

};



#define to_ks8851_par(ks) container_of((ks), struct ks8851_net_par, ks8851)



/**

 * ks8851_lock_par - register access lock

 * @ks: The chip state

 * @flags: Spinlock flags

 *

 * Claim chip register access lock

 */

static void ks8851_lock_par(struct ks8851_net *ks, unsigned long *flags)

{

	struct ks8851_net_par *ksp = to_ks8851_par(ks);



	spin_lock_irqsave(&ksp->lock, *flags);

}



/**

 * ks8851_unlock_par - register access unlock

 * @ks: The chip state

 * @flags: Spinlock flags

 *

 * Release chip register access lock

 */

static void ks8851_unlock_par(struct ks8851_net *ks, unsigned long *flags)

{

	struct ks8851_net_par *ksp = to_ks8851_par(ks);



	spin_unlock_irqrestore(&ksp->lock, *flags);

}



/**

 * ks_check_endian - Check whether endianness of the bus is correct

 * @ks	  : The chip information

 *

 * The KS8851-16MLL EESK pin allows selecting the endianness of the 16bit

 * bus. To maintain optimum performance, the bus endianness should be set

 * such that it matches the endianness of the CPU.

 */

static int ks_check_endian(struct ks8851_net *ks)

{

	struct ks8851_net_par *ksp = to_ks8851_par(ks);

	u16 cider;



	/*

	 * Read CIDER register first, however read it the "wrong" way around.

	 * If the endian strap on the KS8851-16MLL in incorrect and the chip

	 * is operating in different endianness than the CPU, then the meaning

	 * of BE[3:0] byte-enable bits is also swapped such that:

	 *    BE[3,2,1,0] becomes BE[1,0,3,2]

	 *

	 * Luckily for us, the byte-enable bits are the top four MSbits of

	 * the address register and the CIDER register is at offset 0xc0.

	 * Hence, by reading address 0xc0c0, which is not impacted by endian

	 * swapping, we assert either BE[3:2] or BE[1:0] while reading the

	 * CIDER register.

	 *

	 * If the bus configuration is correct, reading 0xc0c0 asserts

	 * BE[3:2] and this read returns 0x0000, because to read register

	 * with bottom two LSbits of address set to 0, BE[1:0] must be

	 * asserted.

	 *

	 * If the bus configuration is NOT correct, reading 0xc0c0 asserts

	 * BE[1:0] and this read returns non-zero 0x8872 value.

	 */

	iowrite16(BE3 | BE2 | KS_CIDER, ksp->hw_addr_cmd);

	cider = ioread16(ksp->hw_addr);

	if (!cider)

		return 0;



	netdev_err(ks->netdev, "incorrect EESK endian strap setting\n");



	return -EINVAL;

}



/**

 * ks8851_wrreg16_par - write 16bit register value to chip

 * @ks: The chip state

 * @reg: The register address

 * @val: The value to write

 *

 * Issue a write to put the value @val into the register specified in @reg.

 */

static void ks8851_wrreg16_par(struct ks8851_net *ks, unsigned int reg,

			       unsigned int val)

{

	struct ks8851_net_par *ksp = to_ks8851_par(ks);



	ksp->cmd_reg_cache = (u16)reg | ((BE1 | BE0) << (reg & 0x02));

	iowrite16(ksp->cmd_reg_cache, ksp->hw_addr_cmd);

	iowrite16(val, ksp->hw_addr);

}



/**

 * ks8851_rdreg16_par - read 16 bit register from chip

 * @ks: The chip information

 * @reg: The register address

 *

 * Read a 16bit register from the chip, returning the result

 */

static unsigned int ks8851_rdreg16_par(struct ks8851_net *ks, unsigned int reg)

{

	struct ks8851_net_par *ksp = to_ks8851_par(ks);



	ksp->cmd_reg_cache = (u16)reg | ((BE1 | BE0) << (reg & 0x02));

	iowrite16(ksp->cmd_reg_cache, ksp->hw_addr_cmd);

	return ioread16(ksp->hw_addr);

}



/**

 * ks8851_rdfifo_par - read data from the receive fifo

 * @ks: The device state.

 * @buff: The buffer address

 * @len: The length of the data to read

 *

 * Issue an RXQ FIFO read command and read the @len amount of data from

 * the FIFO into the buffer specified by @buff.

 */

static void ks8851_rdfifo_par(struct ks8851_net *ks, u8 *buff, unsigned int len)

{

	struct ks8851_net_par *ksp = to_ks8851_par(ks);



	netif_dbg(ks, rx_status, ks->netdev,

		  "%s: %d@%p\n", __func__, len, buff);



	ioread16_rep(ksp->hw_addr, (u16 *)buff + 1, len / 2);

}



/**

 * ks8851_wrfifo_par - write packet to TX FIFO

 * @ks: The device state.

 * @txp: The sk_buff to transmit.

 * @irq: IRQ on completion of the packet.

 *

 * Send the @txp to the chip. This means creating the relevant packet header

 * specifying the length of the packet and the other information the chip

 * needs, such as IRQ on completion. Send the header and the packet data to

 * the device.

 */

static void ks8851_wrfifo_par(struct ks8851_net *ks, struct sk_buff *txp,

			      bool irq)

{

	struct ks8851_net_par *ksp = to_ks8851_par(ks);

	unsigned int len = ALIGN(txp->len, 4);

	unsigned int fid = 0;



	netif_dbg(ks, tx_queued, ks->netdev, "%s: skb %p, %d@%p, irq %d\n",

		  __func__, txp, txp->len, txp->data, irq);



	fid = ks->fid++;

	fid &= TXFR_TXFID_MASK;



	if (irq)

		fid |= TXFR_TXIC;	/* irq on completion */



	iowrite16(fid, ksp->hw_addr);

	iowrite16(txp->len, ksp->hw_addr);



	iowrite16_rep(ksp->hw_addr, txp->data, len / 2);

}



/**

 * ks8851_rx_skb_par - receive skbuff

 * @ks: The device state.

 * @skb: The skbuff

 */

static void ks8851_rx_skb_par(struct ks8851_net *ks, struct sk_buff *skb)

{

	netif_rx(skb);

}



static unsigned int ks8851_rdreg16_par_txqcr(struct ks8851_net *ks)

{

	return ks8851_rdreg16_par(ks, KS_TXQCR);

}



/**

 * ks8851_start_xmit_par - transmit packet

 * @skb: The buffer to transmit

 * @dev: The device used to transmit the packet.

 *

 * Called by the network layer to transmit the @skb. Queue the packet for

 * the device and schedule the necessary work to transmit the packet when

 * it is free.

 *

 * We do this to firstly avoid sleeping with the network device locked,

 * and secondly so we can round up more than one packet to transmit which

 * means we can try and avoid generating too many transmit done interrupts.

 */

static netdev_tx_t ks8851_start_xmit_par(struct sk_buff *skb,

					 struct net_device *dev)

{

	struct ks8851_net *ks = netdev_priv(dev);

	netdev_tx_t ret = NETDEV_TX_OK;

	unsigned long flags;

	unsigned int txqcr;

	u16 txmir;

	int err;



	netif_dbg(ks, tx_queued, ks->netdev,

		  "%s: skb %p, %d@%p\n", __func__, skb, skb->len, skb->data);



	ks8851_lock_par(ks, &flags);



	txmir = ks8851_rdreg16_par(ks, KS_TXMIR) & 0x1fff;



	if (likely(txmir >= skb->len + 12)) {

		ks8851_wrreg16_par(ks, KS_RXQCR, ks->rc_rxqcr | RXQCR_SDA);

		ks8851_wrfifo_par(ks, skb, false);

		ks8851_wrreg16_par(ks, KS_RXQCR, ks->rc_rxqcr);

		ks8851_wrreg16_par(ks, KS_TXQCR, TXQCR_METFE);



		err = readx_poll_timeout_atomic(ks8851_rdreg16_par_txqcr, ks,

						txqcr, !(txqcr & TXQCR_METFE),

						5, 1000000);

		if (err)

			ret = NETDEV_TX_BUSY;



		ks8851_done_tx(ks, skb);

	} else {

		ret = NETDEV_TX_BUSY;

	}



	ks8851_unlock_par(ks, &flags);



	return ret;

}



static int ks8851_probe_par(struct platform_device *pdev)

{

	struct device *dev = &pdev->dev;

	struct ks8851_net_par *ksp;

	struct net_device *netdev;

	struct ks8851_net *ks;

	int ret;



	netdev = devm_alloc_etherdev(dev, sizeof(struct ks8851_net_par));

	if (!netdev)

		return -ENOMEM;



	ks = netdev_priv(netdev);



	ks->lock = ks8851_lock_par;

	ks->unlock = ks8851_unlock_par;

	ks->rdreg16 = ks8851_rdreg16_par;

	ks->wrreg16 = ks8851_wrreg16_par;

	ks->rdfifo = ks8851_rdfifo_par;

	ks->wrfifo = ks8851_wrfifo_par;

	ks->start_xmit = ks8851_start_xmit_par;

	ks->rx_skb = ks8851_rx_skb_par;



#define STD_IRQ (IRQ_LCI |	/* Link Change */	\

		 IRQ_RXI |	/* RX done */		\

		 IRQ_RXPSI)	/* RX process stop */

	ks->rc_ier = STD_IRQ;



	ksp = to_ks8851_par(ks);

	spin_lock_init(&ksp->lock);



	ksp->hw_addr = devm_platform_ioremap_resource(pdev, 0);

	if (IS_ERR(ksp->hw_addr))

		return PTR_ERR(ksp->hw_addr);



	ksp->hw_addr_cmd = devm_platform_ioremap_resource(pdev, 1);

	if (IS_ERR(ksp->hw_addr_cmd))

		return PTR_ERR(ksp->hw_addr_cmd);



	ret = ks_check_endian(ks);

	if (ret)

		return ret;



	netdev->irq = platform_get_irq(pdev, 0);



	return ks8851_probe_common(netdev, dev, msg_enable);

}



static int ks8851_remove_par(struct platform_device *pdev)

{

	return ks8851_remove_common(&pdev->dev);

}



static const struct of_device_id ks8851_match_table[] = {

	{ .compatible = "micrel,ks8851-mll" },

	{ }

};

MODULE_DEVICE_TABLE(of, ks8851_match_table);



static struct platform_driver ks8851_driver = {

	.driver = {

		.name = "ks8851",

		.of_match_table = ks8851_match_table,

		.pm = &ks8851_pm_ops,

	},

	.probe = ks8851_probe_par,

	.remove = ks8851_remove_par,

};

module_platform_driver(ks8851_driver);



MODULE_DESCRIPTION("KS8851 Network driver");

MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");

MODULE_LICENSE("GPL");



module_param_named(message, msg_enable, int, 0);

MODULE_PARM_DESC(message, "Message verbosity level (0=none, 31=all)");

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