/*
 * ADMTEK Adm6996 switch configuration module
 *
 * Copyright (C) 2005 Felix Fietkau <nbd@nbd.name>
 * 
 * Partially based on Broadcom Home Networking Division 10/100 Mbit/s
 * Ethernet Device Driver (from Montavista 2.4.20_mvl31 Kernel).
 * Copyright (C) 2004 Broadcom Corporation
 *
 * adm_rreg function from adm6996
 * Copyright (C) 2004 Nikki Chumakov <nikki@gattaca.ru>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that 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 Street, Fifth Floor, Boston, MA  
 * 02110-1301, USA.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/if.h>
#include <linux/if_arp.h>
#include <linux/sockios.h>
#include <linux/delay.h>
#include <asm/uaccess.h>

#include "switch-core.h"
#include "gpio.h"

#define DRIVER_NAME "adm6996"
#define DRIVER_VERSION "0.01"

static int eecs = 0;
static int eesk = 0;
static int eedi = 0;
static int eerc = 0;
static int force = 0;

MODULE_AUTHOR("Felix Fietkau <openwrt@nbd.name>");
MODULE_LICENSE("GPL");
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,5,52)
module_param(eecs, int, 0);
module_param(eesk, int, 0);
module_param(eedi, int, 0);
module_param(eerc, int, 0);
module_param(force, int, 0);
#else
MODULE_PARM(eecs, "i");
MODULE_PARM(eesk, "i");
MODULE_PARM(eedi, "i");
MODULE_PARM(eerc, "i");
MODULE_PARM(force, "i");
#endif

/* Minimum timing constants */
#define EECK_EDGE_TIME  3   /* 3us - max(adm 2.5us, 93c 1us) */
#define EEDI_SETUP_TIME 1   /* 1us - max(adm 10ns, 93c 400ns) */
#define EECS_SETUP_TIME 1   /* 1us - max(adm no, 93c 200ns) */

/* Handy macros for writing fixed length values */
#define adm_write8(cs, b) { __u8 val = (__u8) (b); adm_write(cs, &val, sizeof(val)*8); }
#define adm_write16(cs, w) { __u16 val = hton16(w); adm_write(cs, (__u8 *)&val, sizeof(val)*8); }
#define adm_write32(cs, i) { uint32 val = hton32(i); adm_write(cs, (__u8 *)&val, sizeof(val)*8); }

#define atoi(str) simple_strtoul(((str != NULL) ? str : ""), NULL, 0)

#ifdef BROADCOM
extern char *nvram_get(char *name);

/* Return gpio pin number assigned to the named pin */
/*
* Variable should be in format:
*
*	gpio<N>=pin_name
*
* 'def_pin' is returned if there is no such variable found.
*/
static unsigned int get_gpiopin(char *pin_name, unsigned int def_pin)
{
	char name[] = "gpioXXXX";
	char *val;
	unsigned int pin;

	/* Go thru all possibilities till a match in pin name */
	for (pin = 0; pin < 16; pin ++) {
		sprintf(name, "gpio%d", pin);
		val = nvram_get(name);
		if (val && !strcmp(val, pin_name))
			return pin;
	}
	return def_pin;
}
#endif


static void adm_write(int cs, char *buf, unsigned int bits)
{
	int i, len = (bits + 7) / 8;
	__u8 mask;

	gpio_out(eecs, (cs ? eecs : 0));
	udelay(EECK_EDGE_TIME);

	/* Byte assemble from MSB to LSB */
	for (i = 0; i < len; i++) {
		/* Bit bang from MSB to LSB */
		for (mask = 0x80; mask && bits > 0; mask >>= 1, bits --) {
			/* Clock low */
			gpio_out(eesk, 0);
			udelay(EECK_EDGE_TIME);

			/* Output on rising edge */
			gpio_out(eedi, ((mask & buf[i]) ? eedi : 0));
			udelay(EEDI_SETUP_TIME);

			/* Clock high */
			gpio_out(eesk, eesk);
			udelay(EECK_EDGE_TIME);
		}
	}

	/* Clock low */
	gpio_out(eesk, 0);
	udelay(EECK_EDGE_TIME);

	if (cs)
		gpio_out(eecs, 0);
}


static void adm_read(int cs, char *buf, unsigned int bits)
{
	int i, len = (bits + 7) / 8;
	__u8 mask;

	gpio_out(eecs, (cs ? eecs : 0));
	udelay(EECK_EDGE_TIME);

	/* Byte assemble from MSB to LSB */
	for (i = 0; i < len; i++) {
		__u8 byte;

		/* Bit bang from MSB to LSB */
		for (mask = 0x80, byte = 0; mask && bits > 0; mask >>= 1, bits --) {
			__u8 gp;

			/* Clock low */
			gpio_out(eesk, 0);
			udelay(EECK_EDGE_TIME);

			/* Input on rising edge */
			gp = gpio_in();
			if (gp & eedi)
				byte |= mask;

			/* Clock high */
			gpio_out(eesk, eesk);
			udelay(EECK_EDGE_TIME);
		}

		*buf++ = byte;
	}

	/* Clock low */
	gpio_out(eesk, 0);
	udelay(EECK_EDGE_TIME);

	if (cs)
		gpio_out(eecs, 0);
}


/* Enable outputs with specified value to the chip */
static void adm_enout(__u8 pins, __u8 val)
{   
	/* Prepare GPIO output value */
	gpio_out(pins, val);
	
	/* Enable GPIO outputs */
	gpio_outen(pins, pins);
	udelay(EECK_EDGE_TIME);
}


/* Disable outputs to the chip */
static void adm_disout(__u8 pins)
{   
	/* Disable GPIO outputs */
	gpio_outen(pins, 0);
	udelay(EECK_EDGE_TIME);
}


/* Advance clock(s) */
static void adm_adclk(int clocks)
{
	int i;
	for (i = 0; i < clocks; i++) {
		/* Clock high */
		gpio_out(eesk, eesk);
		udelay(EECK_EDGE_TIME);

		/* Clock low */
		gpio_out(eesk, 0);
		udelay(EECK_EDGE_TIME);
	}
}

static __u32 adm_rreg(__u8 table, __u8 addr)
{
	/* cmd: 01 10 T DD R RRRRRR */
	__u8 bits[6] = {
		0xFF, 0xFF, 0xFF, 0xFF,
		(0x06 << 4) | ((table & 0x01) << 3 | (addr&64)>>6),
		((addr&63)<<2)
	};

	__u8 rbits[4];

	/* Enable GPIO outputs with all pins to 0 */
	adm_enout((__u8)(eecs | eesk | eedi), 0);

	adm_write(0, bits, 46);
	adm_disout((__u8)(eedi));
	adm_adclk(2);
	adm_read (0, rbits, 32);

	/* Extra clock(s) required per datasheet */
	adm_adclk(2);

	/* Disable GPIO outputs */
	adm_disout((__u8)(eecs | eesk));

	if (!table) /* EEPROM has 16-bit registers, but pumps out two registers in one request */
		return (addr & 0x01 ?  (rbits[0]<<8) | rbits[1] : (rbits[2]<<8) | (rbits[3]));
	else
		return (rbits[0]<<24) | (rbits[1]<<16) | (rbits[2]<<8) | rbits[3];
}



/* Write chip configuration register */
/* Follow 93c66 timing and chip's min EEPROM timing requirement */
void
adm_wreg(__u8 addr, __u16 val)
{
	/* cmd(27bits): sb(1) + opc(01) + addr(bbbbbbbb) + data(bbbbbbbbbbbbbbbb) */
	__u8 bits[4] = {
		(0x05 << 5) | (addr >> 3),
		(addr << 5) | (__u8)(val >> 11),
		(__u8)(val >> 3),
		(__u8)(val << 5)
	};

	/* Enable GPIO outputs with all pins to 0 */
	adm_enout((__u8)(eecs | eesk | eedi), 0);

	/* Write cmd. Total 27 bits */
	adm_write(1, bits, 27);

	/* Extra clock(s) required per datasheet */
	adm_adclk(2);

	/* Disable GPIO outputs */
	adm_disout((__u8)(eecs | eesk | eedi));
}


/* Port configuration registers */
static int port_conf[] = { 0x01, 0x03, 0x05, 0x07, 0x08, 0x09 };

/* Bits in VLAN port mapping */
static int vlan_ports[] = { 1 << 0, 1 << 2, 1 << 4, 1 << 6, 1 << 7, 1 << 8 };

static int handle_vlan_port_read(void *driver, char *buf, int nr)
{
	int ports, i, c, len = 0;
			
	if ((nr < 0) || (nr > 15))
		return 0;

	/* Get VLAN port map */
	ports = adm_rreg(0, 0x13 + nr);
	
	for (i = 0; i <= 5; i++) {
		if (ports & vlan_ports[i]) {
			c = adm_rreg(0, port_conf[i]);
			
			len += sprintf(buf + len, "%d", i);
			if (c & (1 << 4)) {
				buf[len++] = 't';
				if (((c & (0xf << 10)) >> 10) == nr)
					buf[len++] = '*';
			} else if (i == 5)
				buf[len++] = 'u';

			buf[len++] = '\t';
		}
	}
	len += sprintf(buf + len, "\n");

	return len;
}

static int handle_vlan_port_write(void *driver, char *buf, int nr)
{
	int i, cfg, ports;
	switch_driver *d = (switch_driver *) driver;
	switch_vlan_config *c = switch_parse_vlan(d, buf);

	if (c == NULL)
		return -1;

	ports = adm_rreg(0, 0x13 + nr);
	for (i = 0; i < d->ports; i++) {
		if (c->port & (1 << i)) {
			ports |= vlan_ports[i];

			cfg = adm_rreg(0, port_conf[i]);
			
			/* Tagging */
			if (c->untag & (1 << i))
				cfg &= ~(1 << 4);
			else
				cfg |= (1 << 4);
			
			if ((c->untag | c->pvid) & (1 << i)) {
				cfg = (cfg & ~(0xf << 10)) | (nr << 10);
			}
			
			adm_wreg(port_conf[i], (__u16) cfg);
		} else {
			ports &= ~(vlan_ports[i]);
		}
	}
	adm_wreg(0x13 + nr, (__u16) ports);

	return 0;
}

static int handle_port_enable_read(void *driver, char *buf, int nr)
{
	return sprintf(buf, "%d\n", ((adm_rreg(0, port_conf[nr]) & (1 << 5)) ? 0 : 1));
}

static int handle_port_enable_write(void *driver, char *buf, int nr)
{
	int reg = adm_rreg(0, port_conf[nr]);
	
	if (buf[0] == '0')
		reg |= (1 << 5);
	else if (buf[0] == '1')
		reg &= ~(1 << 5);
	else return -1;

	adm_wreg(port_conf[nr], (__u16) reg);
	return 0;
}

static int handle_port_media_read(void *driver, char *buf, int nr)
{
	int len;
	int media = 0;
	int reg = adm_rreg(0, port_conf[nr]);

	if (reg & (1 << 1))
		media |= SWITCH_MEDIA_AUTO;
	if (reg & (1 << 2))
		media |= SWITCH_MEDIA_100;
	if (reg & (1 << 3))
		media |= SWITCH_MEDIA_FD;

	len = switch_print_media(buf, media);
	return len + sprintf(buf + len, "\n");
}

static int handle_port_media_write(void *driver, char *buf, int nr)
{
	int media = switch_parse_media(buf);
	int reg = adm_rreg(0, port_conf[nr]);

	if (media < 0)
		return -1;
	
	reg &= ~((1 << 1) | (1 << 2) | (1 << 3));
	if (media & SWITCH_MEDIA_AUTO)
		reg |= 1 << 1;
	if (media & SWITCH_MEDIA_100)
		reg |= 1 << 2;
	if (media & SWITCH_MEDIA_FD)
		reg |= 1 << 3;

	adm_wreg(port_conf[nr], reg);
	
	return 0;
}

static int handle_vlan_enable_read(void *driver, char *buf, int nr)
{
	return sprintf(buf, "%d\n", ((adm_rreg(0, 0x11) & (1 << 5)) ? 1 : 0));
}

static int handle_vlan_enable_write(void *driver, char *buf, int nr)
{
	int reg = adm_rreg(0, 0x11);
	
	if (buf[0] == '1')
		reg |= (1 << 5);
	else if (buf[0] == '0')
		reg &= ~(1 << 5);
	else return -1;

	adm_wreg(0x11, (__u16) reg);
	return 0;
}

static int handle_reset(void *driver, char *buf, int nr)
{
	int i;
	u32 cfg;

	/*
	 * Reset sequence: RC high->low(100ms)->high(30ms)
	 *
	 * WAR: Certain boards don't have the correct power on 
	 * reset logic therefore we must explicitly perform the
	 * sequence in software.
	 */
	if (eerc) {
		/* Keep RC high for at least 20ms */
		adm_enout(eerc, eerc);
		for (i = 0; i < 20; i ++)
			udelay(1000);
		/* Keep RC low for at least 100ms */
		adm_enout(eerc, 0);
		for (i = 0; i < 100; i++)
			udelay(1000);
		/* Set default configuration */
		adm_enout((__u8)(eesk | eedi), eesk);
		/* Keep RC high for at least 30ms */
		adm_enout(eerc, eerc);
		for (i = 0; i < 30; i++)
			udelay(1000);
		/* Leave RC high and disable GPIO outputs */
		adm_disout((__u8)(eecs | eesk | eedi));
	
	}

	/* set up initial configuration for cpu port */
	cfg = (0x8000 | /* Auto MDIX */
	      (0xf << 10) | /* PVID */
		  (1 << 4) | /* Tagging */
		  0xf); /* full duplex, 100Mbps, auto neg, flow ctrl */
	adm_wreg(port_conf[5], cfg);
	
	/* vlan mode select register (0x11): vlan on, mac clone */
	adm_wreg(0x11, 0xff30);

	return 0;
}

static int handle_registers(void *driver, char *buf, int nr)
{
	int i, len = 0;
	
	for (i = 0; i <= 0x33; i++) {
		len += sprintf(buf + len, "0x%02x: 0x%04x\n", i, adm_rreg(0, i));
	}

	return len;
}

static int handle_counters(void *driver, char *buf, int nr)
{
	int i, len = 0;

	for (i = 0; i <= 0x3c; i++) {
		len += sprintf(buf + len, "0x%02x: 0x%08x\n", i, adm_rreg(1, i));
	}

	return len;
}

static int detect_adm(void)
{
	int ret = 0;

#ifdef BROADCOM
	int boardflags = atoi(nvram_get("boardflags"));
        int boardnum = atoi(nvram_get("boardnum"));

	if ((boardnum == 44) && (boardflags == 0x0388)) {  /* Trendware TEW-411BRP+ */
		ret = 1;

		eecs = get_gpiopin("adm_eecs", 2);
		eesk = get_gpiopin("adm_eesk", 3);
		eedi = get_gpiopin("adm_eedi", 4);
		eerc = get_gpiopin("adm_rc", 5);

	} else if ((boardflags & 0x80) || force) {
		ret = 1;

		eecs = get_gpiopin("adm_eecs", 2);
		eesk = get_gpiopin("adm_eesk", 3);
		eedi = get_gpiopin("adm_eedi", 4);
		eerc = get_gpiopin("adm_rc", 0);

	} else if ((strcmp(nvram_get("boardtype") ?: "", "bcm94710dev") == 0) &&
			(strncmp(nvram_get("boardnum") ?: "", "42", 2) == 0)) {
		/* WRT54G v1.1 hack */
		eecs = 2;
		eesk = 3;
		eedi = 5;

		ret = 1;
	}

	if (eecs)
		eecs = (1 << eecs);
	if (eesk)
		eesk = (1 << eesk);
	if (eedi)
		eedi = (1 << eedi);
	if (eerc)
		eerc = (1 << eerc);
#else
	ret = 1;
#endif

	return ret;
}

static int __init adm_init(void)
{
	switch_config cfg[] = {
		{"registers", handle_registers, NULL},
		{"counters", handle_counters, NULL},
		{"reset", NULL, handle_reset},
		{"enable_vlan", handle_vlan_enable_read, handle_vlan_enable_write},
		{NULL, NULL, NULL}
	};
	switch_config port[] = {
		{"enable", handle_port_enable_read, handle_port_enable_write},
		{"media", handle_port_media_read, handle_port_media_write},
		{NULL, NULL, NULL}
	};
	switch_config vlan[] = {
		{"ports", handle_vlan_port_read, handle_vlan_port_write},
		{NULL, NULL, NULL}
	};
	switch_driver driver = {
		name: DRIVER_NAME,
		version: DRIVER_VERSION,
		interface: "eth0",
		ports: 6,
		cpuport: 5,
		vlans: 16,
		driver_handlers: cfg,
		port_handlers: port,
		vlan_handlers: vlan,
	};

	if (!detect_adm())
		return -ENODEV;

	return switch_register_driver(&driver);
}

static void __exit adm_exit(void)
{
	switch_unregister_driver(DRIVER_NAME);
}


module_init(adm_init);
module_exit(adm_exit);