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 --- Changes for v2: - new Changes for v3: - call i2c_finish before returning i2c_probe.
drivers/i2c/sh_i2c.c | 32 +++++++++++++++++++++++++++----- 1 file changed, 27 insertions(+), 5 deletions(-)
diff --git a/drivers/i2c/sh_i2c.c b/drivers/i2c/sh_i2c.c index d524619..1f5104c 100644 --- a/drivers/i2c/sh_i2c.c +++ b/drivers/i2c/sh_i2c.c @@ -85,6 +85,20 @@ 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; @@ -96,9 +110,9 @@ 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); @@ -116,14 +130,18 @@ 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) @@ -321,5 +339,9 @@ 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; }