diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-mpc.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-mpc.c | 35 |
1 files changed, 31 insertions, 4 deletions
diff --git a/drivers/i2c/busses/i2c-mpc.c b/drivers/i2c/busses/i2c-mpc.c index c6b6898592b1..d8de4ac88b7d 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; @@ -86,6 +105,7 @@ static int i2c_wait(struct mpc_i2c *i2c, unsigned timeout, int writing) schedule(); if (time_after(jiffies, orig_jiffies + timeout)) { pr_debug("I2C: timeout\n"); + writeccr(i2c, 0); result = -EIO; break; } @@ -97,10 +117,12 @@ static int i2c_wait(struct mpc_i2c *i2c, unsigned timeout, int writing) result = wait_event_interruptible_timeout(i2c->queue, (i2c->interrupt & CSR_MIF), timeout * HZ); - if (unlikely(result < 0)) + if (unlikely(result < 0)) { pr_debug("I2C: wait interrupted\n"); - else if (unlikely(!(i2c->interrupt & CSR_MIF))) { + writeccr(i2c, 0); + } else if (unlikely(!(i2c->interrupt & CSR_MIF))) { pr_debug("I2C: wait timeout\n"); + writeccr(i2c, 0); result = -ETIMEDOUT; } @@ -241,10 +263,14 @@ static int mpc_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) while (readb(i2c->base + MPC_I2C_SR) & CSR_MBB) { if (signal_pending(current)) { pr_debug("I2C: Interrupted\n"); + writeccr(i2c, 0); return -EINTR; } 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 +353,10 @@ 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; } @@ -338,7 +365,7 @@ static int fsl_i2c_probe(struct platform_device *pdev) fail_add: if (i2c->irq != 0) - free_irq(i2c->irq, NULL); + free_irq(i2c->irq, i2c); fail_irq: iounmap(i2c->base); fail_map: |