i2c: sh_i2c: enable i2c_probe

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>

diff --git a/drivers/i2c/sh_i2c.c b/drivers/i2c/sh_i2c.c
index d50c8eca6d320f85fe172d23db07f2ba949f8622..a7204cc1d010b4a626fa63ac4309cb5eda8cd35a 100644 (file)
--- a/drivers/i2c/sh_i2c.c
+++ b/drivers/i2c/sh_i2c.c
@@ -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)
 {
        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);
@@ -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);
        irq_dte(base);
 
+       writeb(readb(&base->icsr) & ~SH_IC_TACK, &base->icsr);
        writeb(id << 1, &base->icdr);
-       irq_dte(base);
+       if (irq_dte_with_tack(base) != 0)
+               return -1;
 
        writeb(reg, &base->icdr);
        if (stop)
                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)
@@ -305,5 +323,9 @@ int i2c_write(u8 chip, u32 addr, int alen, u8 *buffer, int len)
  */
 int i2c_probe(u8 chip)
 {
-       return 0;
+       int ret;
+
+       ret = i2c_set_addr(base, chip, 0, 1);
+       i2c_finish(base);
+       return ret;
 }