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  • /*
     * Copyright (C) 2011 Renesas Solutions Corp.
     * Copyright (C) 2011 Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
     *
     * 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., 59 Temple Place, Suite 330, Boston,
     * MA 02111-1307 USA
     */
    
    #include <common.h>
    #include <asm/io.h>
    
    /* Every register is 32bit aligned, but only 8bits in size */
    #define ureg(name) u8 name; u8 __pad_##name##0; u16 __pad_##name##1;
    struct sh_i2c {
    	ureg(icdr);
    	ureg(iccr);
    	ureg(icsr);
    	ureg(icic);
    	ureg(iccl);
    	ureg(icch);
    };
    #undef ureg
    
    static struct sh_i2c *base;
    
    /* ICCR */
    #define SH_I2C_ICCR_ICE		(1 << 7)
    #define SH_I2C_ICCR_RACK	(1 << 6)
    #define SH_I2C_ICCR_RTS		(1 << 4)
    #define SH_I2C_ICCR_BUSY	(1 << 2)
    #define SH_I2C_ICCR_SCP		(1 << 0)
    
    /* ICSR / ICIC */
    
    #define SH_IC_BUSY	(1 << 4)
    
    #define SH_IC_TACK	(1 << 2)
    #define SH_IC_WAIT	(1 << 1)
    #define SH_IC_DTE	(1 << 0)
    
    
    #ifdef CONFIG_SH_I2C_8BIT
    /* store 8th bit of iccl and icch in ICIC register */
    #define SH_I2C_ICIC_ICCLB8	(1 << 7)
    #define SH_I2C_ICIC_ICCHB8	(1 << 6)
    #endif
    
    static u16 iccl, icch;
    
    
    #define IRQ_WAIT 1000
    
    static void irq_dte(struct sh_i2c *base)
    {
    	int i;
    
    	for (i = 0 ; i < IRQ_WAIT ; i++) {
    		if (SH_IC_DTE & readb(&base->icsr))
    			break;
    		udelay(10);
    	}
    }
    
    static void irq_busy(struct sh_i2c *base)
    {
    	int i;
    
    	for (i = 0 ; i < IRQ_WAIT ; i++) {
    		if (!(SH_IC_BUSY & readb(&base->icsr)))
    			break;
    		udelay(10);
    	}
    }
    
    static void i2c_set_addr(struct sh_i2c *base, u8 id, u8 reg, int stop)
    {
    
    	writeb(readb(&base->iccr) & ~SH_I2C_ICCR_ICE, &base->iccr);
    	writeb(readb(&base->iccr) | SH_I2C_ICCR_ICE, &base->iccr);
    
    
    	writeb(iccl & 0xff, &base->iccl);
    	writeb(icch & 0xff, &base->icch);
    #ifdef CONFIG_SH_I2C_8BIT
    	if (iccl > 0xff)
    		icic |= SH_I2C_ICIC_ICCLB8;
    	if (icch > 0xff)
    		icic |= SH_I2C_ICIC_ICCHB8;
    #endif
    	writeb(icic, &base->icic);
    
    
    	writeb((SH_I2C_ICCR_ICE|SH_I2C_ICCR_RTS|SH_I2C_ICCR_BUSY), &base->iccr);
    	irq_dte(base);
    
    	writeb(id << 1, &base->icdr);
    	irq_dte(base);
    
    	writeb(reg, &base->icdr);
    	if (stop)
    		writeb((SH_I2C_ICCR_ICE|SH_I2C_ICCR_RTS), &base->iccr);
    
    	irq_dte(base);
    }
    
    static void i2c_finish(struct sh_i2c *base)
    {
    	writeb(0, &base->icsr);
    	writeb(readb(&base->iccr) & ~SH_I2C_ICCR_ICE, &base->iccr);
    }
    
    static void i2c_raw_write(struct sh_i2c *base, u8 id, u8 reg, u8 val)
    {
    	i2c_set_addr(base, id, reg, 0);
    	udelay(10);
    
    	writeb(val, &base->icdr);
    	irq_dte(base);
    
    	writeb((SH_I2C_ICCR_ICE | SH_I2C_ICCR_RTS), &base->iccr);
    	irq_dte(base);
    	irq_busy(base);
    
    	i2c_finish(base);
    }
    
    static u8 i2c_raw_read(struct sh_i2c *base, u8 id, u8 reg)
    {
    	u8 ret;
    
    
    #if defined(CONFIG_SH73A0)
    	i2c_set_addr(base, id, reg, 0);
    #else
    
    	i2c_set_addr(base, id, reg, 1);
    	udelay(100);
    
    
    	writeb((SH_I2C_ICCR_ICE|SH_I2C_ICCR_RTS|SH_I2C_ICCR_BUSY), &base->iccr);
    	irq_dte(base);
    
    	writeb(id << 1 | 0x01, &base->icdr);
    	irq_dte(base);
    
    	writeb((SH_I2C_ICCR_ICE|SH_I2C_ICCR_SCP), &base->iccr);
    	irq_dte(base);
    
    	ret = readb(&base->icdr);
    
    	writeb((SH_I2C_ICCR_ICE|SH_I2C_ICCR_RACK), &base->iccr);
    	readb(&base->icdr); /* Dummy read */
    	irq_busy(base);
    
    	i2c_finish(base);
    
    	return ret;
    }
    
    #ifdef CONFIG_I2C_MULTI_BUS
    static unsigned int current_bus;
    
    /**
     * i2c_set_bus_num - change active I2C bus
     *	@bus: bus index, zero based
     *	@returns: 0 on success, non-0 on failure
     */
    int i2c_set_bus_num(unsigned int bus)
    {
    	if ((bus < 0) || (bus >= CONFIG_SYS_MAX_I2C_BUS)) {
    		printf("Bad bus: %d\n", bus);
    		return -1;
    	}
    
    	switch (bus) {
    	case 0:
    		base = (void *)CONFIG_SH_I2C_BASE0;
    		break;
    	case 1:
    		base = (void *)CONFIG_SH_I2C_BASE1;
    		break;
    
    #ifdef CONFIG_SH_I2C_BASE2
    	case 2:
    		base = (void *)CONFIG_SH_I2C_BASE2;
    		break;
    #endif
    #ifdef CONFIG_SH_I2C_BASE3
    	case 3:
    		base = (void *)CONFIG_SH_I2C_BASE3;
    		break;
    #endif
    #ifdef CONFIG_SH_I2C_BASE4
    	case 4:
    		base = (void *)CONFIG_SH_I2C_BASE4;
    		break;
    #endif
    
    	default:
    		return -1;
    	}
    	current_bus = bus;
    
    	return 0;
    }
    
    /**
     * i2c_get_bus_num - returns index of active I2C bus
     */
    unsigned int i2c_get_bus_num(void)
    {
    	return current_bus;
    }
    #endif
    
    #define SH_I2C_ICCL_CALC(clk, date, t_low, t_high) \
    		((clk / rate) * (t_low / t_low + t_high))
    #define SH_I2C_ICCH_CALC(clk, date, t_low, t_high) \
    		((clk / rate) * (t_high / t_low + t_high))
    
    void i2c_init(int speed, int slaveaddr)
    {
    	int num, denom, tmp;
    
    #ifdef CONFIG_I2C_MULTI_BUS
    	current_bus = 0;
    #endif
    	base = (struct sh_i2c *)CONFIG_SH_I2C_BASE0;
    
    	/*
    	 * Calculate the value for iccl. From the data sheet:
    	 * iccl = (p-clock / transfer-rate) * (L / (L + H))
    	 * where L and H are the SCL low and high ratio.
    	 */
    	num = CONFIG_SH_I2C_CLOCK * CONFIG_SH_I2C_DATA_LOW;
    	denom = speed * (CONFIG_SH_I2C_DATA_HIGH + CONFIG_SH_I2C_DATA_LOW);
    	tmp = num * 10 / denom;
    	if (tmp % 10 >= 5)
    
    		iccl = (u16)((num/denom) + 1);
    
    		iccl = (u16)(num/denom);
    
    
    	/* Calculate the value for icch. From the data sheet:
    	   icch = (p clock / transfer rate) * (H / (L + H)) */
    	num = CONFIG_SH_I2C_CLOCK * CONFIG_SH_I2C_DATA_HIGH;
    	tmp = num * 10 / denom;
    	if (tmp % 10 >= 5)
    
    		icch = (u16)((num/denom) + 1);
    
    		icch = (u16)(num/denom);
    
    }
    
    /*
     * i2c_read: - Read multiple bytes from an i2c device
     *
     * The higher level routines take into account that this function is only
     * called with len < page length of the device (see configuration file)
     *
     * @chip:   address of the chip which is to be read
     * @addr:   i2c data address within the chip
     * @alen:   length of the i2c data address (1..2 bytes)
     * @buffer: where to write the data
     * @len:    how much byte do we want to read
     * @return: 0 in case of success
     */
    int i2c_read(u8 chip, u32 addr, int alen, u8 *buffer, int len)
    {
    	int i = 0;
    	for (i = 0 ; i < len ; i++)
    		buffer[i] = i2c_raw_read(base, chip, addr + i);
    
    	return 0;
    }
    
    /*
     * i2c_write: -  Write multiple bytes to an i2c device
     *
     * The higher level routines take into account that this function is only
     * called with len < page length of the device (see configuration file)
     *
     * @chip:   address of the chip which is to be written
     * @addr:   i2c data address within the chip
     * @alen:   length of the i2c data address (1..2 bytes)
     * @buffer: where to find the data to be written
     * @len:    how much byte do we want to read
     * @return: 0 in case of success
     */
    int i2c_write(u8 chip, u32 addr, int alen, u8 *buffer, int len)
    {
    	int i = 0;
    	for (i = 0; i < len ; i++)
    		i2c_raw_write(base, chip, addr + i, buffer[i]);
    
    	return 0;
    }
    
    /*
     * i2c_probe: - Test if a chip answers for a given i2c address
     *
     * @chip:   address of the chip which is searched for
     * @return: 0 if a chip was found, -1 otherwhise
     */
    int i2c_probe(u8 chip)
    {
    	return 0;
    }