blob: 3147123bba878093d91d91547faacf067ecb628a [file] [log] [blame]
/*
* 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 << 3)
#define SH_IC_TACK (1 << 2)
#define SH_IC_WAIT (1 << 1)
#define SH_IC_DTE (1 << 0)
static u8 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, &base->iccl);
writeb(icch, &base->icch);
writeb(0, &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;
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;
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 = (u8)((num/denom) + 1);
else
iccl = (u8)(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 = (u8)((num/denom) + 1);
else
icch = (u8)(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;
}