/*******************************************************************************
  This is the driver for the MAC 10/100 on-chip Ethernet controller
  currently tested on all the ST boards based on STb7109 and stx7200 SoCs.

  DWC Ether MAC 10/100 Universal version 4.0 has been used for developing
  this code.

  Copyright (C) 2007-2009  STMicroelectronics Ltd

  This program is free software; you can redistribute it and/or modify it
  under the terms and conditions of the GNU General Public License,
  version 2, as published by the Free Software Foundation.

  This program is distributed in the hope it will be useful, but WITHOUT
  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  more details.

  You should have received a copy of the GNU General Public License along with
  this program; if not, write to the Free Software Foundation, Inc.,
  51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.

  The full GNU General Public License is included in this distribution in
  the file called "COPYING".

  Author: Giuseppe Cavallaro <peppe.cavallaro@st.com>
*******************************************************************************/

#include <linux/netdevice.h>
#include <linux/crc32.h>
#include <linux/mii.h>
#include <linux/phy.h>

#include "common.h"
#include "mac100.h"

#undef MAC100_DEBUG
/*#define MAC100_DEBUG*/
#ifdef MAC100_DEBUG
#define DBG(fmt, args...)  printk(fmt, ## args)
#else
#define DBG(fmt, args...)  do { } while (0)
#endif

static void mac100_core_init(unsigned long ioaddr)
{
	u32 value = readl(ioaddr + MAC_CONTROL);

	writel((value | MAC_CORE_INIT), ioaddr + MAC_CONTROL);

#ifdef STMMAC_VLAN_TAG_USED
	writel(ETH_P_8021Q, ioaddr + MAC_VLAN1);
#endif
	return;
}

static void mac100_dump_mac_regs(unsigned long ioaddr)
{
	pr_info("\t----------------------------------------------\n"
	       "\t  MAC100 CSR (base addr = 0x%8x)\n"
	       "\t----------------------------------------------\n",
	       (unsigned int)ioaddr);
	pr_info("\tcontrol reg (offset 0x%x): 0x%08x\n", MAC_CONTROL,
	       readl(ioaddr + MAC_CONTROL));
	pr_info("\taddr HI (offset 0x%x): 0x%08x\n ", MAC_ADDR_HIGH,
	       readl(ioaddr + MAC_ADDR_HIGH));
	pr_info("\taddr LO (offset 0x%x): 0x%08x\n", MAC_ADDR_LOW,
	       readl(ioaddr + MAC_ADDR_LOW));
	pr_info("\tmulticast hash HI (offset 0x%x): 0x%08x\n",
			MAC_HASH_HIGH, readl(ioaddr + MAC_HASH_HIGH));
	pr_info("\tmulticast hash LO (offset 0x%x): 0x%08x\n",
			MAC_HASH_LOW, readl(ioaddr + MAC_HASH_LOW));
	pr_info("\tflow control (offset 0x%x): 0x%08x\n",
		MAC_FLOW_CTRL, readl(ioaddr + MAC_FLOW_CTRL));
	pr_info("\tVLAN1 tag (offset 0x%x): 0x%08x\n", MAC_VLAN1,
	       readl(ioaddr + MAC_VLAN1));
	pr_info("\tVLAN2 tag (offset 0x%x): 0x%08x\n", MAC_VLAN2,
	       readl(ioaddr + MAC_VLAN2));
	pr_info("\n\tMAC management counter registers\n");
	pr_info("\t MMC crtl (offset 0x%x): 0x%08x\n",
	       MMC_CONTROL, readl(ioaddr + MMC_CONTROL));
	pr_info("\t MMC High Interrupt (offset 0x%x): 0x%08x\n",
	       MMC_HIGH_INTR, readl(ioaddr + MMC_HIGH_INTR));
	pr_info("\t MMC Low Interrupt (offset 0x%x): 0x%08x\n",
	       MMC_LOW_INTR, readl(ioaddr + MMC_LOW_INTR));
	pr_info("\t MMC High Interrupt Mask (offset 0x%x): 0x%08x\n",
	       MMC_HIGH_INTR_MASK, readl(ioaddr + MMC_HIGH_INTR_MASK));
	pr_info("\t MMC Low Interrupt Mask (offset 0x%x): 0x%08x\n",
	       MMC_LOW_INTR_MASK, readl(ioaddr + MMC_LOW_INTR_MASK));
	return;
}

static int mac100_dma_init(unsigned long ioaddr, int pbl, u32 dma_tx,
			   u32 dma_rx)
{
	u32 value = readl(ioaddr + DMA_BUS_MODE);
	/* DMA SW reset */
	value |= DMA_BUS_MODE_SFT_RESET;
	writel(value, ioaddr + DMA_BUS_MODE);
	do {} while ((readl(ioaddr + DMA_BUS_MODE) & DMA_BUS_MODE_SFT_RESET));

	/* Enable Application Access by writing to DMA CSR0 */
	writel(DMA_BUS_MODE_DEFAULT | (pbl << DMA_BUS_MODE_PBL_SHIFT),
	       ioaddr + DMA_BUS_MODE);

	/* Mask interrupts by writing to CSR7 */
	writel(DMA_INTR_DEFAULT_MASK, ioaddr + DMA_INTR_ENA);

	/* The base address of the RX/TX descriptor lists must be written into
	 * DMA CSR3 and CSR4, respectively. */
	writel(dma_tx, ioaddr + DMA_TX_BASE_ADDR);
	writel(dma_rx, ioaddr + DMA_RCV_BASE_ADDR);

	return 0;
}

/* Store and Forward capability is not used at all..
 * The transmit threshold can be programmed by
 * setting the TTC bits in the DMA control register.*/
static void mac100_dma_operation_mode(unsigned long ioaddr, int txmode,
				      int rxmode)
{
	u32 csr6 = readl(ioaddr + DMA_CONTROL);

	if (txmode <= 32)
		csr6 |= DMA_CONTROL_TTC_32;
	else if (txmode <= 64)
		csr6 |= DMA_CONTROL_TTC_64;
	else
		csr6 |= DMA_CONTROL_TTC_128;

	writel(csr6, ioaddr + DMA_CONTROL);

	return;
}

static void mac100_dump_dma_regs(unsigned long ioaddr)
{
	int i;

	DBG(KERN_DEBUG "MAC100 DMA CSR \n");
	for (i = 0; i < 9; i++)
		pr_debug("\t CSR%d (offset 0x%x): 0x%08x\n", i,
		       (DMA_BUS_MODE + i * 4),
		       readl(ioaddr + DMA_BUS_MODE + i * 4));
	DBG(KERN_DEBUG "\t CSR20 (offset 0x%x): 0x%08x\n",
	    DMA_CUR_TX_BUF_ADDR, readl(ioaddr + DMA_CUR_TX_BUF_ADDR));
	DBG(KERN_DEBUG "\t CSR21 (offset 0x%x): 0x%08x\n",
	    DMA_CUR_RX_BUF_ADDR, readl(ioaddr + DMA_CUR_RX_BUF_ADDR));
	return;
}

/* DMA controller has two counters to track the number of
   the receive missed frames. */
static void mac100_dma_diagnostic_fr(void *data, struct stmmac_extra_stats *x,
				     unsigned long ioaddr)
{
	struct net_device_stats *stats = (struct net_device_stats *)data;
	u32 csr8 = readl(ioaddr + DMA_MISSED_FRAME_CTR);

	if (unlikely(csr8)) {
		if (csr8 & DMA_MISSED_FRAME_OVE) {
			stats->rx_over_errors += 0x800;
			x->rx_overflow_cntr += 0x800;
		} else {
			unsigned int ove_cntr;
			ove_cntr = ((csr8 & DMA_MISSED_FRAME_OVE_CNTR) >> 17);
			stats->rx_over_errors += ove_cntr;
			x->rx_overflow_cntr += ove_cntr;
		}

		if (csr8 & DMA_MISSED_FRAME_OVE_M) {
			stats->rx_missed_errors += 0xffff;
			x->rx_missed_cntr += 0xffff;
		} else {
			unsigned int miss_f = (csr8 & DMA_MISSED_FRAME_M_CNTR);
			stats->rx_missed_errors += miss_f;
			x->rx_missed_cntr += miss_f;
		}
	}
	return;
}

static int mac100_get_tx_frame_status(void *data, struct stmmac_extra_stats *x,
				      struct dma_desc *p, unsigned long ioaddr)
{
	int ret = 0;
	struct net_device_stats *stats = (struct net_device_stats *)data;

	if (unlikely(p->des01.tx.error_summary)) {
		if (unlikely(p->des01.tx.underflow_error)) {
			x->tx_underflow++;
			stats->tx_fifo_errors++;
		}
		if (unlikely(p->des01.tx.no_carrier)) {
			x->tx_carrier++;
			stats->tx_carrier_errors++;
		}
		if (unlikely(p->des01.tx.loss_carrier)) {
			x->tx_losscarrier++;
			stats->tx_carrier_errors++;
		}
		if (unlikely((p->des01.tx.excessive_deferral) ||
			     (p->des01.tx.excessive_collisions) ||
			     (p->des01.tx.late_collision)))
			stats->collisions += p->des01.tx.collision_count;
		ret = -1;
	}
	if (unlikely(p->des01.tx.heartbeat_fail)) {
		x->tx_heartbeat++;
		stats->tx_heartbeat_errors++;
		ret = -1;
	}
	if (unlikely(p->des01.tx.deferred))
		x->tx_deferred++;

	return ret;
}

static int mac100_get_tx_len(struct dma_desc *p)
{
	return p->des01.tx.buffer1_size;
}

/* This function verifies if each incoming frame has some errors
 * and, if required, updates the multicast statistics.
 * In case of success, it returns csum_none becasue the device
 * is not able to compute the csum in HW. */
static int mac100_get_rx_frame_status(void *data, struct stmmac_extra_stats *x,
				      struct dma_desc *p)
{
	int ret = csum_none;
	struct net_device_stats *stats = (struct net_device_stats *)data;

	if (unlikely(p->des01.rx.last_descriptor == 0)) {
		pr_warning("mac100 Error: Oversized Ethernet "
			   "frame spanned multiple buffers\n");
		stats->rx_length_errors++;
		return discard_frame;
	}

	if (unlikely(p->des01.rx.error_summary)) {
		if (unlikely(p->des01.rx.descriptor_error))
			x->rx_desc++;
		if (unlikely(p->des01.rx.partial_frame_error))
			x->rx_partial++;
		if (unlikely(p->des01.rx.run_frame))
			x->rx_runt++;
		if (unlikely(p->des01.rx.frame_too_long))
			x->rx_toolong++;
		if (unlikely(p->des01.rx.collision)) {
			x->rx_collision++;
			stats->collisions++;
		}
		if (unlikely(p->des01.rx.crc_error)) {
			x->rx_crc++;
			stats->rx_crc_errors++;
		}
		ret = discard_frame;
	}
	if (unlikely(p->des01.rx.dribbling))
		ret = discard_frame;

	if (unlikely(p->des01.rx.length_error)) {
		x->rx_lenght++;
		ret = discard_frame;
	}
	if (unlikely(p->des01.rx.mii_error)) {
		x->rx_mii++;
		ret = discard_frame;
	}
	if (p->des01.rx.multicast_frame) {
		x->rx_multicast++;
		stats->multicast++;
	}
	return ret;
}

static void mac100_irq_status(unsigned long ioaddr)
{
	return;
}

static void mac100_set_umac_addr(unsigned long ioaddr, unsigned char *addr,
			  unsigned int reg_n)
{
	stmmac_set_mac_addr(ioaddr, addr, MAC_ADDR_HIGH, MAC_ADDR_LOW);
}

static void mac100_get_umac_addr(unsigned long ioaddr, unsigned char *addr,
			  unsigned int reg_n)
{
	stmmac_get_mac_addr(ioaddr, addr, MAC_ADDR_HIGH, MAC_ADDR_LOW);
}

static void mac100_set_filter(struct net_device *dev)
{
	unsigned long ioaddr = dev->base_addr;
	u32 value = readl(ioaddr + MAC_CONTROL);

	if (dev->flags & IFF_PROMISC) {
		value |= MAC_CONTROL_PR;
		value &= ~(MAC_CONTROL_PM | MAC_CONTROL_IF | MAC_CONTROL_HO |
			   MAC_CONTROL_HP);
	} else if ((dev->mc_count > HASH_TABLE_SIZE)
		   || (dev->flags & IFF_ALLMULTI)) {
		value |= MAC_CONTROL_PM;
		value &= ~(MAC_CONTROL_PR | MAC_CONTROL_IF | MAC_CONTROL_HO);
		writel(0xffffffff, ioaddr + MAC_HASH_HIGH);
		writel(0xffffffff, ioaddr + MAC_HASH_LOW);
	} else if (dev->mc_count == 0) {	/* no multicast */
		value &= ~(MAC_CONTROL_PM | MAC_CONTROL_PR | MAC_CONTROL_IF |
			   MAC_CONTROL_HO | MAC_CONTROL_HP);
	} else {
		int i;
		u32 mc_filter[2];
		struct dev_mc_list *mclist;

		/* Perfect filter mode for physical address and Hash
		   filter for multicast */
		value |= MAC_CONTROL_HP;
		value &= ~(MAC_CONTROL_PM | MAC_CONTROL_PR | MAC_CONTROL_IF
			   | MAC_CONTROL_HO);

		memset(mc_filter, 0, sizeof(mc_filter));
		for (i = 0, mclist = dev->mc_list;
		     mclist && i < dev->mc_count; i++, mclist = mclist->next) {
			/* The upper 6 bits of the calculated CRC are used to
			 * index the contens of the hash table */
			int bit_nr =
			    ether_crc(ETH_ALEN, mclist->dmi_addr) >> 26;
			/* The most significant bit determines the register to
			 * use (H/L) while the other 5 bits determine the bit
			 * within the register. */
			mc_filter[bit_nr >> 5] |= 1 << (bit_nr & 31);
		}
		writel(mc_filter[0], ioaddr + MAC_HASH_LOW);
		writel(mc_filter[1], ioaddr + MAC_HASH_HIGH);
	}

	writel(value, ioaddr + MAC_CONTROL);

	DBG(KERN_INFO "%s: CTRL reg: 0x%08x Hash regs: "
	    "HI 0x%08x, LO 0x%08x\n",
	    __func__, readl(ioaddr + MAC_CONTROL),
	    readl(ioaddr + MAC_HASH_HIGH), readl(ioaddr + MAC_HASH_LOW));
	return;
}

static void mac100_flow_ctrl(unsigned long ioaddr, unsigned int duplex,
			     unsigned int fc, unsigned int pause_time)
{
	unsigned int flow = MAC_FLOW_CTRL_ENABLE;

	if (duplex)
		flow |= (pause_time << MAC_FLOW_CTRL_PT_SHIFT);
	writel(flow, ioaddr + MAC_FLOW_CTRL);

	return;
}

/* No PMT module supported in our SoC  for the Ethernet Controller. */
static void mac100_pmt(unsigned long ioaddr, unsigned long mode)
{
	return;
}

static void mac100_init_rx_desc(struct dma_desc *p, unsigned int ring_size,
				int disable_rx_ic)
{
	int i;
	for (i = 0; i < ring_size; i++) {
		p->des01.rx.own = 1;
		p->des01.rx.buffer1_size = BUF_SIZE_2KiB - 1;
		if (i == ring_size - 1)
			p->des01.rx.end_ring = 1;
		if (disable_rx_ic)
			p->des01.rx.disable_ic = 1;
		p++;
	}
	return;
}

static void mac100_init_tx_desc(struct dma_desc *p, unsigned int ring_size)
{
	int i;
	for (i = 0; i < ring_size; i++) {
		p->des01.tx.own = 0;
		if (i == ring_size - 1)
			p->des01.tx.end_ring = 1;
		p++;
	}
	return;
}

static int mac100_get_tx_owner(struct dma_desc *p)
{
	return p->des01.tx.own;
}

static int mac100_get_rx_owner(struct dma_desc *p)
{
	return p->des01.rx.own;
}

static void mac100_set_tx_owner(struct dma_desc *p)
{
	p->des01.tx.own = 1;
}

static void mac100_set_rx_owner(struct dma_desc *p)
{
	p->des01.rx.own = 1;
}

static int mac100_get_tx_ls(struct dma_desc *p)
{
	return p->des01.tx.last_segment;
}

static void mac100_release_tx_desc(struct dma_desc *p)
{
	int ter = p->des01.tx.end_ring;

	/* clean field used within the xmit */
	p->des01.tx.first_segment = 0;
	p->des01.tx.last_segment = 0;
	p->des01.tx.buffer1_size = 0;

	/* clean status reported */
	p->des01.tx.error_summary = 0;
	p->des01.tx.underflow_error = 0;
	p->des01.tx.no_carrier = 0;
	p->des01.tx.loss_carrier = 0;
	p->des01.tx.excessive_deferral = 0;
	p->des01.tx.excessive_collisions = 0;
	p->des01.tx.late_collision = 0;
	p->des01.tx.heartbeat_fail = 0;
	p->des01.tx.deferred = 0;

	/* set termination field */
	p->des01.tx.end_ring = ter;

	return;
}

static void mac100_prepare_tx_desc(struct dma_desc *p, int is_fs, int len,
				   int csum_flag)
{
	p->des01.tx.first_segment = is_fs;
	p->des01.tx.buffer1_size = len;
}

static void mac100_clear_tx_ic(struct dma_desc *p)
{
	p->des01.tx.interrupt = 0;
}

static void mac100_close_tx_desc(struct dma_desc *p)
{
	p->des01.tx.last_segment = 1;
	p->des01.tx.interrupt = 1;
}

static int mac100_get_rx_frame_len(struct dma_desc *p)
{
	return p->des01.rx.frame_length;
}

struct stmmac_ops mac100_driver = {
	.core_init = mac100_core_init,
	.dump_mac_regs = mac100_dump_mac_regs,
	.dma_init = mac100_dma_init,
	.dump_dma_regs = mac100_dump_dma_regs,
	.dma_mode = mac100_dma_operation_mode,
	.dma_diagnostic_fr = mac100_dma_diagnostic_fr,
	.tx_status = mac100_get_tx_frame_status,
	.rx_status = mac100_get_rx_frame_status,
	.get_tx_len = mac100_get_tx_len,
	.set_filter = mac100_set_filter,
	.flow_ctrl = mac100_flow_ctrl,
	.pmt = mac100_pmt,
	.init_rx_desc = mac100_init_rx_desc,
	.init_tx_desc = mac100_init_tx_desc,
	.get_tx_owner = mac100_get_tx_owner,
	.get_rx_owner = mac100_get_rx_owner,
	.release_tx_desc = mac100_release_tx_desc,
	.prepare_tx_desc = mac100_prepare_tx_desc,
	.clear_tx_ic = mac100_clear_tx_ic,
	.close_tx_desc = mac100_close_tx_desc,
	.get_tx_ls = mac100_get_tx_ls,
	.set_tx_owner = mac100_set_tx_owner,
	.set_rx_owner = mac100_set_rx_owner,
	.get_rx_frame_len = mac100_get_rx_frame_len,
	.host_irq_status = mac100_irq_status,
	.set_umac_addr = mac100_set_umac_addr,
	.get_umac_addr = mac100_get_umac_addr,
};

struct mac_device_info *mac100_setup(unsigned long ioaddr)
{
	struct mac_device_info *mac;

	mac = kzalloc(sizeof(const struct mac_device_info), GFP_KERNEL);

	pr_info("\tMAC 10/100\n");

	mac->ops = &mac100_driver;
	mac->hw.pmt = PMT_NOT_SUPPORTED;
	mac->hw.link.port = MAC_CONTROL_PS;
	mac->hw.link.duplex = MAC_CONTROL_F;
	mac->hw.link.speed = 0;
	mac->hw.mii.addr = MAC_MII_ADDR;
	mac->hw.mii.data = MAC_MII_DATA;

	return mac;
}