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i2c: 'fixed bug: set scl clk' and 'warning if scl is hold by slave'

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This commit is contained in:
kfx
2013-06-28 10:38:35 +08:00
parent 392faa8e4b
commit 9ca853a25d
1 changed files with 25 additions and 6 deletions
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31
drivers/i2c/busses/i2c-rk30-adapter.c Executable file → Normal file
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@@ -76,6 +76,8 @@ enum{
#define I2C_STARTIPD (1 << 4)
#define I2C_STOPIPD (1 << 5)
#define I2C_NAKRCVIPD (1 << 6)
#define I2C_HOLD_SCL (1 << 7)
#define I2C_IPD_ALL_CLEAN 0x7f
/* finished count */
@@ -209,22 +211,36 @@ static inline void rk30_i2c_enable_irq(struct rk30_i2c *i2c)
{
i2c_writel(IRQ_MST_ENABLE, i2c->regs + I2C_IEN);
}
/* SCL Divisor = 8 * (CLKDIVL + CLKDIVH)
static void rk30_get_div(int div, int *divh, int *divl)
{
if(div % 2 == 0){
*divh = div/2;
*divl = div/2;
}else{
*divh = rk30_ceil(div, 2);
*divl = div/2;
}
}
/* SCL Divisor = 8 * (CLKDIVL+1 + CLKDIVH+1)
* SCL = i2c_rate/ SCLK Divisor
*/
static void rk30_i2c_set_clk(struct rk30_i2c *i2c, unsigned long scl_rate)
{
unsigned long i2c_rate = clk_get_rate(i2c->clk);
unsigned int div, divl, divh;
int div, divl, divh;
if((scl_rate == i2c->scl_rate) && (i2c_rate == i2c->i2c_rate))
return;
i2c->i2c_rate = i2c_rate;
i2c->scl_rate = scl_rate;
div = rk30_ceil(i2c_rate, scl_rate * 8);
divh = divl = rk30_ceil(div, 2);
div = rk30_ceil(i2c_rate, (scl_rate * 8)) - 2;
if(unlikely(div < 0)){
dev_warn(i2c->dev, "Divisor(%d) is negative, set divl = divh = 0\n", div);
divh =divl = 0;
}else{
rk30_get_div(div, &divh, &divl);
}
i2c_writel(I2C_CLKDIV_VAL(divl, divh), i2c->regs + I2C_CLKDIV);
i2c_dbg(i2c->dev, "set clk(I2C_CLKDIV: 0x%08x)\n", i2c_readl(i2c->regs + I2C_CLKDIV));
return;
@@ -572,11 +588,14 @@ static int rk30_i2c_doxfer(struct rk30_i2c *i2c,
spin_unlock_irqrestore(&i2c->lock, flags);
if (timeout == 0){
unsigned int ipd = i2c_readl(i2c->regs + I2C_IPD);
if(error < 0)
i2c_dbg(i2c->dev, "error = %d\n", error);
else if((i2c->complete_what !=COMPLETE_READ && i2c->complete_what != COMPLETE_WRITE)){
if(ipd & I2C_HOLD_SCL)
dev_err(i2c->dev, "SCL was hold by slave\n");
dev_err(i2c->dev, "Addr[0x%04x] wait event timeout, state: %d, is_busy: %d, error: %d, complete_what: 0x%x, ipd: 0x%x\n",
msgs[0].addr, i2c->state, i2c->is_busy, error, i2c->complete_what, i2c_readl(i2c->regs + I2C_IPD));
msgs[0].addr, i2c->state, i2c->is_busy, error, i2c->complete_what, ipd);
//rk30_show_regs(i2c);
error = -ETIMEDOUT;
if(in_atomic())