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i2c: sh_i2c: enable i2c_probe

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Before this patch i2c_probe() always returned 0 and "i2c probe" command did not work properly.

Modify i2c_set_addr() to check TACK when waiting DTE and make i2c_probe() call this function.

Acked-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
Signed-off-by: Tetsuyuki Kobayashi <koba@kmckk.co.jp>
This commit is contained in:
Tetsuyuki Kobayashi 2012-09-13 19:08:00 +00:00 • committed by Heiko Schocher
parent 020ec727a6
commit d042d7121b
1 changed files with 27 additions and 5 deletions
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32
drivers/i2c/sh_i2c.c
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@ -69,6 +69,20 @@ static void irq_dte(struct sh_i2c *base)
} }
} }
static int irq_dte_with_tack(struct sh_i2c *base)
{
int i;
for (i = 0 ; i < IRQ_WAIT ; i++) {
if (SH_IC_DTE & readb(&base->icsr))
break;
if (SH_IC_TACK & readb(&base->icsr))
return -1;
udelay(10);
}
return 0;
}
static void irq_busy(struct sh_i2c *base) static void irq_busy(struct sh_i2c *base)
{ {
int i; int i;
@ -80,9 +94,9 @@ static void irq_busy(struct sh_i2c *base)
} }
} }
static void i2c_set_addr(struct sh_i2c *base, u8 id, u8 reg, int stop) static int i2c_set_addr(struct sh_i2c *base, u8 id, u8 reg, int stop)
{ {
u8 icic = 0; u8 icic = SH_IC_TACK;
writeb(readb(&base->iccr) & ~SH_I2C_ICCR_ICE, &base->iccr); writeb(readb(&base->iccr) & ~SH_I2C_ICCR_ICE, &base->iccr);
writeb(readb(&base->iccr) | SH_I2C_ICCR_ICE, &base->iccr); writeb(readb(&base->iccr) | SH_I2C_ICCR_ICE, &base->iccr);
@ -100,14 +114,18 @@ static void i2c_set_addr(struct sh_i2c *base, u8 id, u8 reg, int stop)
writeb((SH_I2C_ICCR_ICE|SH_I2C_ICCR_RTS|SH_I2C_ICCR_BUSY), &base->iccr); writeb((SH_I2C_ICCR_ICE|SH_I2C_ICCR_RTS|SH_I2C_ICCR_BUSY), &base->iccr);
irq_dte(base); irq_dte(base);
writeb(readb(&base->icsr) & ~SH_IC_TACK, &base->icsr);
writeb(id << 1, &base->icdr); writeb(id << 1, &base->icdr);
irq_dte(base); if (irq_dte_with_tack(base) != 0)
return -1;
writeb(reg, &base->icdr); writeb(reg, &base->icdr);
if (stop) if (stop)
writeb((SH_I2C_ICCR_ICE|SH_I2C_ICCR_RTS), &base->iccr); writeb((SH_I2C_ICCR_ICE|SH_I2C_ICCR_RTS), &base->iccr);
irq_dte(base); if (irq_dte_with_tack(base) != 0)
return -1;
return 0;
} }
static void i2c_finish(struct sh_i2c *base) static void i2c_finish(struct sh_i2c *base)
@ -305,5 +323,9 @@ int i2c_write(u8 chip, u32 addr, int alen, u8 *buffer, int len)
*/ */
int i2c_probe(u8 chip) int i2c_probe(u8 chip)
{ {
return 0; int ret;
ret = i2c_set_addr(base, chip, 0, 1);
i2c_finish(base);
return ret;
} }