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path: root/drivers/i2c/busses/i2c-mpc.c
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Diffstat (limited to 'drivers/i2c/busses/i2c-mpc.c')
-rw-r--r--drivers/i2c/busses/i2c-mpc.c26
1 files changed, 25 insertions, 1 deletions
diff --git a/drivers/i2c/busses/i2c-mpc.c b/drivers/i2c/busses/i2c-mpc.c
index c6b6898592b..851c3ed513d 100644
--- a/drivers/i2c/busses/i2c-mpc.c
+++ b/drivers/i2c/busses/i2c-mpc.c
@@ -74,6 +74,25 @@ static irqreturn_t mpc_i2c_isr(int irq, void *dev_id)
return IRQ_HANDLED;
}
+/* Sometimes 9th clock pulse isn't generated, and slave doesn't release
+ * the bus, because it wants to send ACK.
+ * Following sequence of enabling/disabling and sending start/stop generates
+ * the pulse, so it's all OK.
+ */
+static void mpc_i2c_fixup(struct mpc_i2c *i2c)
+{
+ writeccr(i2c, 0);
+ udelay(30);
+ writeccr(i2c, CCR_MEN);
+ udelay(30);
+ writeccr(i2c, CCR_MSTA | CCR_MTX);
+ udelay(30);
+ writeccr(i2c, CCR_MSTA | CCR_MTX | CCR_MEN);
+ udelay(30);
+ writeccr(i2c, CCR_MEN);
+ udelay(30);
+}
+
static int i2c_wait(struct mpc_i2c *i2c, unsigned timeout, int writing)
{
unsigned long orig_jiffies = jiffies;
@@ -153,6 +172,7 @@ static void mpc_i2c_start(struct mpc_i2c *i2c)
static void mpc_i2c_stop(struct mpc_i2c *i2c)
{
writeccr(i2c, CCR_MEN);
+ writeccr(i2c, 0);
}
static int mpc_write(struct mpc_i2c *i2c, int target,
@@ -245,6 +265,9 @@ static int mpc_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
}
if (time_after(jiffies, orig_jiffies + HZ)) {
pr_debug("I2C: timeout\n");
+ if (readb(i2c->base + MPC_I2C_SR) ==
+ (CSR_MCF | CSR_MBB | CSR_RXAK))
+ mpc_i2c_fixup(i2c);
return -EIO;
}
schedule();
@@ -327,9 +350,10 @@ static int fsl_i2c_probe(struct platform_device *pdev)
platform_set_drvdata(pdev, i2c);
i2c->adap = mpc_ops;
+ i2c->adap.nr = pdev->id;
i2c_set_adapdata(&i2c->adap, i2c);
i2c->adap.dev.parent = &pdev->dev;
- if ((result = i2c_add_adapter(&i2c->adap)) < 0) {
+ if ((result = i2c_add_numbered_adapter(&i2c->adap)) < 0) {
printk(KERN_ERR "i2c-mpc - failed to add adapter\n");
goto fail_add;
}