/*++
 * linux/drivers/video/wmt/sw_i2c.c
 * WonderMedia video post processor (VPP) driver
 *
 * Copyright c 2013  WonderMedia  Technologies, Inc.
 *
 * 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, see <http://www.gnu.org/licenses/>.
 *
 * WonderMedia Technologies, Inc.
 * 4F, 533, Chung-Cheng Road, Hsin-Tien, Taipei 231, R.O.C
--*/

#include "vpp-osif.h"
#include "sw_i2c.h"

#define   SPEED			50	/* 5000000 */

#define delay_time 30

struct swi2c_reg_bk_t {
	unsigned int gpio_en;
	unsigned int out_en;
	unsigned int data_out;
	unsigned int pull_en;
};

#ifdef __KERNEL__
static DEFINE_SPINLOCK(swi2c_irqlock);
unsigned long swi2c_irqlock_flags;
#endif
void wmt_swi2c_lock(int lock)
{
#ifdef __KERNEL__
	if (lock)
		spin_lock_irqsave(&swi2c_irqlock, swi2c_irqlock_flags);
	else
		spin_unlock_irqrestore(&swi2c_irqlock, swi2c_irqlock_flags);
#endif
}

swi2c_reg_t *swi2c_scl, *swi2c_sda;

void wmt_swi2c_delay(unsigned int time)
{
	udelay(time);
}

void wmt_swi2c_SetSDAInput(void)
{
	REG16_VAL(swi2c_sda->gpio_en) |= swi2c_sda->bit_mask;
	REG16_VAL(swi2c_sda->out_en) &= ~swi2c_sda->bit_mask;
}


void wmt_swi2c_SetSDAOutput(void)
{
	REG16_VAL(swi2c_sda->gpio_en) |= swi2c_sda->bit_mask;
	REG16_VAL(swi2c_sda->out_en) |= swi2c_sda->bit_mask;
}

bool wmt_swi2c_GetSDA(void) /* bit */
{
	if (*(volatile unsigned short *)(swi2c_sda->data_in) &
		swi2c_sda->bit_mask)
#ifdef CFG_LOADER
		return 1;
	return 0;
#else
		return (volatile bool) 1;
	return (volatile bool) 0;
#endif
}

bool wmt_swi2c_GetSCL(void) /* bit */
{
	if (*(volatile unsigned short *)(swi2c_scl->data_in) &
		swi2c_scl->bit_mask)
#ifdef CFG_LOADER
		return 1;
	return 0;
#else
		return (volatile bool) 1;
	return (volatile bool) 0;
#endif
}

void wmt_swi2c_SetSDA(int high)
{
	if (high) {
		/* set to GPI and pull high */
		REG16_VAL(swi2c_sda->gpio_en) |= swi2c_sda->bit_mask;
		REG16_VAL(swi2c_sda->out_en) &= ~swi2c_sda->bit_mask;
		if (swi2c_sda->pull_en)
			REG16_VAL(swi2c_sda->pull_en) &=
					~swi2c_sda->pull_en_bit_mask;
	} else {
		REG16_VAL(swi2c_sda->gpio_en) |= swi2c_sda->bit_mask;
		REG16_VAL(swi2c_sda->out_en) |= swi2c_sda->bit_mask;
		REG16_VAL(swi2c_sda->data_out) &= ~swi2c_sda->bit_mask;
	}
}

void wmt_swi2c_SetSCL(int high)
{
	if (high) {
		REG16_VAL(swi2c_scl->gpio_en) |= swi2c_scl->bit_mask;
		REG16_VAL(swi2c_scl->out_en) &= ~swi2c_scl->bit_mask;
		if (swi2c_scl->pull_en)
			REG16_VAL(swi2c_scl->pull_en) &=
					~swi2c_scl->pull_en_bit_mask;
	} else {
		REG16_VAL(swi2c_scl->gpio_en) |= swi2c_scl->bit_mask;
		REG16_VAL(swi2c_scl->out_en) |= swi2c_scl->bit_mask;
		REG16_VAL(swi2c_scl->data_out) &= ~swi2c_scl->bit_mask;
	}
}

int wmt_swi2c_SetData(int high)
{
	unsigned int wait = 1;

	wmt_swi2c_SetSDA(high);
	do {
		if (wmt_swi2c_GetSDA() == ((high) ? 1 : 0))
			return 0;
	} while (wait++ < SPEED);
	return 1;
}

int wmt_swi2c_SetClock(int high)
{
	unsigned int wait = 1;

	udelay(5);	/* 3-100kHz, 5-80kHz */

	wmt_swi2c_SetSCL(high);
	do {
		if (wmt_swi2c_GetSCL() == ((high) ? 1 : 0))
			return 0;
	} while (wait++ < SPEED);
	return 1; /* fail */
}

int wmt_swi2c_StartI2C(void)
{
	if (wmt_swi2c_SetData(1))
		return 1;
	if (wmt_swi2c_SetClock(1))
		return 2;
	if (wmt_swi2c_SetData(0))
		return 3;
	wmt_swi2c_delay(0);
	if (wmt_swi2c_SetClock(0))
		return 4;
	return 0; /* success */
}

int wmt_swi2c_StopI2C(void)
{
	if (wmt_swi2c_SetData(0))
		return 1;
	if (wmt_swi2c_SetClock(0))
		return 1;
	if (wmt_swi2c_SetClock(1))
		return 1;
	wmt_swi2c_delay(0);
	if (wmt_swi2c_SetData(1))
		return 1;
	return 0; /* success */
}

int wmt_swi2c_WriteAck(unsigned char byte)
{
	int ret;
	int bit;

	for (bit = 7; bit >= 0; bit--) {
		wmt_swi2c_SetData(byte & 0x80);
		byte <<= 1;
		if (wmt_swi2c_SetClock(1))
			return 1;
		if (wmt_swi2c_SetClock(0))
			return 1;
	}
	ret = 0;
	wmt_swi2c_SetSDAInput();
	if (wmt_swi2c_SetClock(1))
		ret = 1;
	else if (wmt_swi2c_GetSDA())
		ret = (wmt_swi2c_SetClock(0)) ? 1 : 0;
	else if (wmt_swi2c_SetClock(0))
		ret = 1;
	wmt_swi2c_SetSDAOutput();
	return ret;
}

int wmt_swi2c_ReadAck(unsigned char *byte, int last)
{
	unsigned char i;
	unsigned char Data = 0;

	wmt_swi2c_SetSDAInput();

	for (i = 0; i < 8; i++) {
		if (wmt_swi2c_SetClock(1)) {
			wmt_swi2c_SetSDAOutput();
			return 1;
		}
		Data <<= 1;
		wmt_swi2c_delay(0);
		Data |= wmt_swi2c_GetSDA();
		if (wmt_swi2c_SetClock(0)) {
			wmt_swi2c_SetSDAOutput();
			return 1;
		}
	}

	*byte = Data;
	wmt_swi2c_SetSDAOutput();

	wmt_swi2c_delay(0);
	if (wmt_swi2c_SetData((last) ? 1 : 0))
		return 1;
	if (wmt_swi2c_SetClock(1))
		return 1;
	wmt_swi2c_delay(0);
	if (wmt_swi2c_SetClock(0))
		return 1;
	wmt_swi2c_delay(0);
	return 0;
}

int wmt_swi2c_tx(
	char addr,
	char *buf,
	int  cnt,
	int *ret_cnt
)
{
	int ret = 0;
	unsigned char i;

	wmt_swi2c_lock(1);

	ret |= wmt_swi2c_StartI2C();
	if (ret)
		goto tx_end;
	ret |= wmt_swi2c_WriteAck(addr);
	if (ret)
		goto tx_end;
	for (i = 0; i < cnt; i++) {
		ret |= wmt_swi2c_WriteAck(buf[i]);
		if (ret)
			goto tx_end;
	}
	ret |= wmt_swi2c_StopI2C();
tx_end:
	wmt_swi2c_lock(0);
	return ret;
}

int wmt_swi2c_rx(
	char addr,
	char *buf,
	int cnt,
	int *ret_cnt
)
{
	int ret = 0;
	int i;

	wmt_swi2c_lock(1);

	ret |= wmt_swi2c_StartI2C();
	if (ret)
		goto rx_end;
	ret |= wmt_swi2c_WriteAck(addr | 0x01);
	if (ret)
		goto rx_end;
	for (i = 0; i < cnt; i++) {
		ret |= wmt_swi2c_ReadAck((unsigned char *)&buf[i],
			(i == (cnt - 1)));
		if (ret)
			goto rx_end;
	}
	ret |= wmt_swi2c_StopI2C();
rx_end:
	wmt_swi2c_lock(0);
	return ret;
}

void wmt_swi2c_reg_bk(swi2c_reg_t *reg_p, struct swi2c_reg_bk_t *reg_bk,
	int bk)
{
	if (bk) {
		reg_bk->gpio_en = REG16_VAL(reg_p->gpio_en);
		reg_bk->out_en = REG16_VAL(reg_p->out_en);
		reg_bk->data_out = REG16_VAL(reg_p->data_out);
		reg_bk->pull_en = REG16_VAL(reg_p->pull_en);
	} else {
		REG16_VAL(reg_p->gpio_en) = reg_bk->gpio_en;
		REG16_VAL(reg_p->out_en) = reg_bk->out_en;
		REG16_VAL(reg_p->data_out) = reg_bk->data_out;
		REG16_VAL(reg_p->pull_en) = reg_bk->pull_en;
	}
}

int wmt_swi2c_read(
	swi2c_handle_t *handle,
	char addr,
	char index,
	char *buf,
	int cnt
)
{
	int ret = 0;
	char buffer[24];
	int temp = 0;
	struct swi2c_reg_bk_t scl_bk, sda_bk;

	swi2c_scl = handle->scl_reg;
	swi2c_sda = handle->sda_reg;

	wmt_swi2c_reg_bk(swi2c_scl, &scl_bk, 1);
	wmt_swi2c_reg_bk(swi2c_sda, &sda_bk, 1);

	buffer[0] = index;
	ret = wmt_swi2c_tx(addr, buffer, 1, &temp);
	if (ret) {
		DPRINT("[SWI2C] *E* tx fail\n");
		goto exit;
	}
	ret = wmt_swi2c_rx(addr, buf, cnt, &temp);
	if (ret) {
		DPRINT("[SWI2C] *E* rx fail\n");
		goto exit;
	}
exit:
	wmt_swi2c_reg_bk(swi2c_scl, &scl_bk, 0);
	wmt_swi2c_reg_bk(swi2c_sda, &sda_bk, 0);
	return ret;
}
EXPORT_SYMBOL(wmt_swi2c_read);

int wmt_swi2c_write(
	swi2c_handle_t *handle,
	char addr,
	char index,
	char *buf,
	int cnt
)
{
	int ret = 0;
	char buffer[24];
	int temp;
	struct swi2c_reg_bk_t scl_bk, sda_bk;

	swi2c_scl = handle->scl_reg;
	swi2c_sda = handle->sda_reg;

	wmt_swi2c_reg_bk(swi2c_scl, &scl_bk, 1);
	wmt_swi2c_reg_bk(swi2c_sda, &sda_bk, 1);

	buffer[0] = index;
	buffer[1] = *buf;
	ret = wmt_swi2c_tx(addr, buffer, cnt, &temp);
	if (ret) {
		DPRINT("[SWI2C] *E* tx fail\n");
		goto exit;
	}
exit:
	wmt_swi2c_reg_bk(swi2c_scl, &scl_bk, 0);
	wmt_swi2c_reg_bk(swi2c_sda, &sda_bk, 0);
	return ret;
}
EXPORT_SYMBOL(wmt_swi2c_write);

int wmt_swi2c_check(swi2c_handle_t *handle)
{
	int ret = 0;
#if 0
	swi2c_reg_t *reg_p;
	struct swi2c_reg_bk_t scl_bk, sda_bk;

	swi2c_scl = handle->scl_reg;
	swi2c_sda = handle->sda_reg;

	wmt_swi2c_reg_bk(swi2c_scl, &scl_bk, 1);
	wmt_swi2c_reg_bk(swi2c_sda, &sda_bk, 1);
	reg_p = handle->scl_reg;
	do {
		REG16_VAL(reg_p->gpio_en) |= reg_p->bit_mask;
		REG16_VAL(reg_p->out_en) |= reg_p->bit_mask;
		REG16_VAL(reg_p->data_out) &= ~reg_p->bit_mask;

		REG16_VAL(reg_p->out_en) &= ~reg_p->bit_mask;
		if (reg_p->pull_en)
			REG16_VAL(reg_p->pull_en) &= ~reg_p->pull_en_bit_mask;
		if (*(volatile unsigned short *)(reg_p->data_in) &
			reg_p->bit_mask) {
			if (reg_p == handle->sda_reg)
				break;
			reg_p = handle->sda_reg;
		} else {
			ret = 1;
			break;
		}
	} while (1);
	wmt_swi2c_reg_bk(swi2c_scl, &scl_bk, 0);
	wmt_swi2c_reg_bk(swi2c_sda, &sda_bk, 0);
	DPRINT("[SWI2C] %s exist\n", (ret) ? "not" : "");
#endif
	return ret;
}
EXPORT_SYMBOL(wmt_swi2c_check);