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: Marek Vasut <marex@denx.de>
Cc: David S. Miller <davem@davemloft.net>
Cc: Lukas Wunner <lukas@wunner.de>
Cc: Petr Stetiar <ynezz@true.cz>
Cc: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Marek Vasut 2020-05-29 00:21:45 +02:00 committed by David S. Miller
parent b07f987a8d
commit 797047f875
3 changed files with 360 additions and 0 deletions

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@ -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.

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@ -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

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@ -0,0 +1,357 @@
// 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)");