static int start_ch(struct sh_mobile_i2c_data *pd, struct i2c_msg *usr_msg)
{
if (usr_msg->len == 0 && (usr_msg->flags & I2C_M_RD)) {
dev_err(pd->dev, "Unsupported zero length i2c read\n");
return -EIO;
}
/* Initialize channel registers */
iic_set_clr(pd, ICCR, 0, ICCR_ICE);
/* Enable channel and configure rx ack */
iic_set_clr(pd, ICCR, ICCR_ICE, 0);
/* Set the clock */
iic_wr(pd, ICCL, pd->iccl);
iic_wr(pd, ICCH, pd->icch);
pd->msg = usr_msg;
pd->pos = -1;
pd->sr = 0;
/* Enable all interrupts to begin with */
iic_wr(pd, ICIC, ICIC_DTEE | ICIC_WAITE | ICIC_ALE | ICIC_TACKE);
return 0;
}
//8 bits register address only
static int write_eeprom(U8 slvAddr, U8 addr, U8 data)
{
int i;
U8 ch[3];
ch[1] = addr;
ch[2] = data;
rIICDS = slvAddr;
rIICSTAT = 0xf0; //MasTx,Start
for(i=0; i<3; i++)
if(iic_wr(ch[i], i))
break;
rIICSTAT = 0xd0; //Stop MasTx condition
if(i<3)
return -1;
i = 200; //200ms
while(i--) {
Delay(1);
rIICDS = slvAddr;
rIICSTAT = 0xf0;
if(!iic_wr(0, 0))
break;
}
rIICSTAT = 0xd0;
return i?0:-1;
}
static irqreturn_t sh_mobile_i2c_isr(int irq, void *dev_id)
{
struct platform_device *dev = dev_id;
struct sh_mobile_i2c_data *pd = platform_get_drvdata(dev);
unsigned char sr;
int wakeup;
sr = iic_rd(pd, ICSR);
pd->sr |= sr; /* remember state */
dev_dbg(pd->dev, "i2c_isr 0x%02x 0x%02x %s %d %d!\n", sr, pd->sr,
(pd->msg->flags & I2C_M_RD) ? "read" : "write",
pd->pos, pd->msg->len);
if (sr & (ICSR_AL | ICSR_TACK)) {
/* don't interrupt transaction - continue to issue stop */
iic_wr(pd, ICSR, sr & ~(ICSR_AL | ICSR_TACK));
wakeup = 0;
} else if (pd->msg->flags & I2C_M_RD)
wakeup = sh_mobile_i2c_isr_rx(pd);
else
wakeup = sh_mobile_i2c_isr_tx(pd);
if (sr & ICSR_WAIT) /* TODO: add delay here to support slow acks */
iic_wr(pd, ICSR, sr & ~ICSR_WAIT);
if (wakeup) {
pd->sr |= SW_DONE;
wake_up(&pd->wait);
}
return IRQ_HANDLED;
}
static void start_ch(struct sh_mobile_i2c_data *pd, struct i2c_msg *usr_msg,
bool do_init)
{
if (do_init) {
/* Initialize channel registers */
iic_wr(pd, ICCR, ICCR_SCP);
/* Enable channel and configure rx ack */
iic_wr(pd, ICCR, ICCR_ICE | ICCR_SCP);
/* Set the clock */
iic_wr(pd, ICCL, pd->iccl & 0xff);
iic_wr(pd, ICCH, pd->icch & 0xff);
}
pd->msg = usr_msg;
pd->pos = -1;
pd->sr = 0;
pd->dma_buf = i2c_get_dma_safe_msg_buf(pd->msg, 8);
if (pd->dma_buf)
sh_mobile_i2c_xfer_dma(pd);
/* Enable all interrupts to begin with */
iic_wr(pd, ICIC, ICIC_DTEE | ICIC_WAITE | ICIC_ALE | ICIC_TACKE);
}
//8 bits register address only
static int read_eeprom(U8 slvAddr, U8 addr, U8 *pBuf)
{
int i;
U8 ch[2];
ch[1] = addr;
rIICDS = slvAddr;
rIICSTAT = 0xf0; //MasTx,Start
for(i=0; i<2; i++)
if(iic_wr(ch[i], i))
break;
if(i<2) {
rIICSTAT = 0xd0; //Stop MasTx condition
return -1;
}
rIICDS = slvAddr;
rIICSTAT = 0xb0; //Master Rx,Start
if(!iic_wr(0, 0)) //wait ack
i = iic_rd(pBuf);
rIICSTAT = 0x90; //Stop MaxRx condition
return i;
}
static void deactivate_ch(struct sh_mobile_i2c_data *pd)
{
/* Clear/disable interrupts */
iic_wr(pd, ICSR, 0);
iic_wr(pd, ICIC, 0);
/* Disable channel */
iic_set_clr(pd, ICCR, 0, ICCR_ICE);
/* Disable clock and mark device as idle */
clk_disable(pd->clk);
pm_runtime_put_sync(pd->dev);
}
static unsigned char i2c_op(struct sh_mobile_i2c_data *pd,
enum sh_mobile_i2c_op op, unsigned char data)
{
unsigned char ret = 0;
unsigned long flags;
dev_dbg(pd->dev, "op %d, data in 0x%02x\n", op, data);
spin_lock_irqsave(&pd->lock, flags);
switch (op) {
case OP_START: /* issue start and trigger DTE interrupt */
iic_wr(pd, ICCR, ICCR_ICE | ICCR_TRS | ICCR_BBSY);
break;
case OP_TX_FIRST: /* disable DTE interrupt and write data */
iic_wr(pd, ICIC, ICIC_WAITE | ICIC_ALE | ICIC_TACKE);
iic_wr(pd, ICDR, data);
break;
case OP_TX: /* write data */
iic_wr(pd, ICDR, data);
break;
case OP_TX_STOP: /* issue a stop (or rep_start) */
iic_wr(pd, ICCR, pd->send_stop ? ICCR_ICE | ICCR_TRS
: ICCR_ICE | ICCR_TRS | ICCR_BBSY);
break;
case OP_TX_TO_RX: /* select read mode */
iic_wr(pd, ICCR, ICCR_ICE | ICCR_SCP);
break;
case OP_RX: /* just read data */
ret = iic_rd(pd, ICDR);
break;
case OP_RX_STOP: /* enable DTE interrupt, issue stop */
iic_wr(pd, ICIC,
ICIC_DTEE | ICIC_WAITE | ICIC_ALE | ICIC_TACKE);
iic_wr(pd, ICCR, ICCR_ICE | ICCR_RACK);
break;
case OP_RX_STOP_DATA: /* enable DTE interrupt, read data, issue stop */
iic_wr(pd, ICIC,
ICIC_DTEE | ICIC_WAITE | ICIC_ALE | ICIC_TACKE);
ret = iic_rd(pd, ICDR);
iic_wr(pd, ICCR, ICCR_ICE | ICCR_RACK);
break;
}
spin_unlock_irqrestore(&pd->lock, flags);
dev_dbg(pd->dev, "op %d, data out 0x%02x\n", op, ret);
return ret;
}
static void activate_ch(struct sh_mobile_i2c_data *pd)
{
/* Wake up device and enable clock */
pm_runtime_get_sync(pd->dev);
clk_prepare_enable(pd->clk);
/* Enable channel and configure rx ack */
iic_set_clr(pd, ICCR, ICCR_ICE, 0);
/* Mask all interrupts */
iic_wr(pd, ICIC, 0);
/* Set the clock */
iic_wr(pd, ICCL, pd->iccl & 0xff);
iic_wr(pd, ICCH, pd->icch & 0xff);
}
static int sh_mobile_i2c_xfer(struct i2c_adapter *adapter,
struct i2c_msg *msgs,
int num)
{
struct sh_mobile_i2c_data *pd = i2c_get_adapdata(adapter);
struct i2c_msg *msg;
int err = 0;
int i;
long timeout;
/* Wake up device and enable clock */
pm_runtime_get_sync(pd->dev);
/* Process all messages */
for (i = 0; i < num; i++) {
bool do_start = pd->send_stop || !i;
msg = &msgs[i];
pd->send_stop = i == num - 1 || msg->flags & I2C_M_STOP;
pd->stop_after_dma = false;
start_ch(pd, msg, do_start);
if (do_start)
i2c_op(pd, OP_START, 0);
/* The interrupt handler takes care of the rest... */
timeout = wait_event_timeout(pd->wait,
pd->sr & (ICSR_TACK | SW_DONE),
adapter->timeout);
/* 'stop_after_dma' tells if DMA transfer was complete */
i2c_put_dma_safe_msg_buf(pd->dma_buf, pd->msg, pd->stop_after_dma);
if (!timeout) {
dev_err(pd->dev, "Transfer request timed out\n");
if (pd->dma_direction != DMA_NONE)
sh_mobile_i2c_cleanup_dma(pd);
err = -ETIMEDOUT;
break;
}
if (pd->send_stop)
err = poll_busy(pd);
else
err = poll_dte(pd);
if (err < 0)
break;
}
/* Disable channel */
iic_wr(pd, ICCR, ICCR_SCP);
/* Disable clock and mark device as idle */
pm_runtime_put_sync(pd->dev);
return err ?: num;
}
static irqreturn_t sh_mobile_i2c_isr(int irq, void *dev_id)
{
struct sh_mobile_i2c_data *pd = dev_id;
unsigned char sr;
int wakeup = 0;
sr = iic_rd(pd, ICSR);
pd->sr |= sr; /* remember state */
dev_dbg(pd->dev, "i2c_isr 0x%02x 0x%02x %s %d %d!\n", sr, pd->sr,
(pd->msg->flags & I2C_M_RD) ? "read" : "write",
pd->pos, pd->msg->len);
/* Kick off TxDMA after preface was done */
if (pd->dma_direction == DMA_TO_DEVICE && pd->pos == 0)
iic_set_clr(pd, ICIC, ICIC_TDMAE, 0);
else if (sr & (ICSR_AL | ICSR_TACK))
/* don't interrupt transaction - continue to issue stop */
iic_wr(pd, ICSR, sr & ~(ICSR_AL | ICSR_TACK));
else if (pd->msg->flags & I2C_M_RD)
wakeup = sh_mobile_i2c_isr_rx(pd);
else
wakeup = sh_mobile_i2c_isr_tx(pd);
/* Kick off RxDMA after preface was done */
if (pd->dma_direction == DMA_FROM_DEVICE && pd->pos == 1)
iic_set_clr(pd, ICIC, ICIC_RDMAE, 0);
if (sr & ICSR_WAIT) /* TODO: add delay here to support slow acks */
iic_wr(pd, ICSR, sr & ~ICSR_WAIT);
if (wakeup) {
pd->sr |= SW_DONE;
wake_up(&pd->wait);
}
/* defeat write posting to avoid spurious WAIT interrupts */
iic_rd(pd, ICSR);
return IRQ_HANDLED;
}
/*
* r8a7740 chip has lasting errata on I2C I/O pad reset.
* this is work-around for it.
*/
static int sh_mobile_i2c_r8a7740_workaround(struct sh_mobile_i2c_data *pd)
{
iic_set_clr(pd, ICCR, ICCR_ICE, 0);
iic_rd(pd, ICCR); /* dummy read */
iic_set_clr(pd, ICSTART, ICSTART_ICSTART, 0);
iic_rd(pd, ICSTART); /* dummy read */
udelay(10);
iic_wr(pd, ICCR, ICCR_SCP);
iic_wr(pd, ICSTART, 0);
udelay(10);
iic_wr(pd, ICCR, ICCR_TRS);
udelay(10);
iic_wr(pd, ICCR, 0);
udelay(10);
iic_wr(pd, ICCR, ICCR_TRS);
udelay(10);
return sh_mobile_i2c_init(pd);
}
static int seek_iic_device(U8 slvAddr)
{
int i;
i = 40; //400ms
while(i--) {
rIICDS = slvAddr;
rIICSTAT = 0xf0; //MasTx,Start
if(!iic_wr(0, 0))
break;
Delay(10);
}
rIICSTAT = 0xd0; //Stop MasTx condition
return i<40;
}
static void activate_ch(struct sh_mobile_i2c_data *pd)
{
unsigned long i2c_clk;
u_int32_t num;
u_int32_t denom;
u_int32_t tmp;
/* Wake up device and enable clock */
pm_runtime_get_sync(pd->dev);
clk_enable(pd->clk);
/* Get clock rate after clock is enabled */
i2c_clk = clk_get_rate(pd->clk);
/* 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/high ratio (5/4 in this case).
* We also round off the result.
*/
num = i2c_clk * 5;
denom = NORMAL_SPEED * 9;
tmp = num * 10 / denom;
if (tmp % 10 >= 5)
pd->iccl = (u_int8_t)((num/denom) + 1);
else
pd->iccl = (u_int8_t)(num/denom);
/* one more bit of ICCL in ICIC */
if (pd->flags & IIC_FLAG_HAS_ICIC67) {
if ((num/denom) > 0xff)
pd->icic |= ICIC_ICCLB8;
else
pd->icic &= ~ICIC_ICCLB8;
}
/* Calculate the value for icch. From the data sheet:
icch = (p clock / transfer rate) * (H / (L + H)) */
num = i2c_clk * 4;
tmp = num * 10 / denom;
if (tmp % 10 >= 5)
pd->icch = (u_int8_t)((num/denom) + 1);
else
pd->icch = (u_int8_t)(num/denom);
/* one more bit of ICCH in ICIC */
if (pd->flags & IIC_FLAG_HAS_ICIC67) {
if ((num/denom) > 0xff)
pd->icic |= ICIC_ICCHB8;
else
pd->icic &= ~ICIC_ICCHB8;
}
/* Enable channel and configure rx ack */
iic_set_clr(pd, ICCR, ICCR_ICE, 0);
/* Mask all interrupts */
iic_wr(pd, ICIC, 0);
/* Set the clock */
iic_wr(pd, ICCL, pd->iccl);
iic_wr(pd, ICCH, pd->icch);
}
static void iic_set_clr(struct sh_mobile_i2c_data *pd, int offs,
unsigned char set, unsigned char clr)
{
iic_wr(pd, offs, (iic_rd(pd, offs) | set) & ~clr);
}
