i2c: iproc: Add recovery mechanism in error case

Add proper recovery mechanism to the iProc I2C driver in error cases.

Signed-off-by: Icarus Chau <ichau@broadcom.com>
Signed-off-by: Ray Jui <rjui@broadcom.com>
Tested-by: Icarus Chau <ichau@broadcom.com>
Reviewed-by: Scott Branden <sbranden@broadcom.com>
[wsa: whitespace fixes]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

diff --git a/drivers/i2c/busses/i2c-bcm-iproc.c b/drivers/i2c/busses/i2c-bcm-iproc.c
index 0419f52846094950b333c48675991a0a267c1e5a..709b56af0676a814e3ad68750af8923ba85be8f7 100644 (file)
--- a/drivers/i2c/busses/i2c-bcm-iproc.c
+++ b/drivers/i2c/busses/i2c-bcm-iproc.c
@@ -119,6 +119,48 @@ static irqreturn_t bcm_iproc_i2c_isr(int irq, void *data)
        return IRQ_HANDLED;
 }
 
+static int bcm_iproc_i2c_init(struct bcm_iproc_i2c_dev *iproc_i2c)
+{
+       u32 val;
+
+       /* put controller in reset */
+       val = readl(iproc_i2c->base + CFG_OFFSET);
+       val |= 1 << CFG_RESET_SHIFT;
+       val &= ~(1 << CFG_EN_SHIFT);
+       writel(val, iproc_i2c->base + CFG_OFFSET);
+
+       /* wait 100 usec per spec */
+       udelay(100);
+
+       /* bring controller out of reset */
+       val &= ~(1 << CFG_RESET_SHIFT);
+       writel(val, iproc_i2c->base + CFG_OFFSET);
+
+       /* flush TX/RX FIFOs and set RX FIFO threshold to zero */
+       val = (1 << M_FIFO_RX_FLUSH_SHIFT) | (1 << M_FIFO_TX_FLUSH_SHIFT);
+       writel(val, iproc_i2c->base + M_FIFO_CTRL_OFFSET);
+       /* disable all interrupts */
+       writel(0, iproc_i2c->base + IE_OFFSET);
+
+       /* clear all pending interrupts */
+       writel(0xffffffff, iproc_i2c->base + IS_OFFSET);
+
+       return 0;
+}
+
+static void bcm_iproc_i2c_enable_disable(struct bcm_iproc_i2c_dev *iproc_i2c,
+                                        bool enable)
+{
+       u32 val;
+
+       val = readl(iproc_i2c->base + CFG_OFFSET);
+       if (enable)
+               val |= BIT(CFG_EN_SHIFT);
+       else
+               val &= ~BIT(CFG_EN_SHIFT);
+       writel(val, iproc_i2c->base + CFG_OFFSET);
+}
+
 static int bcm_iproc_i2c_check_status(struct bcm_iproc_i2c_dev *iproc_i2c,
                                      struct i2c_msg *msg)
 {
@@ -149,6 +191,12 @@ static int bcm_iproc_i2c_check_status(struct bcm_iproc_i2c_dev *iproc_i2c,
 
        default:
                dev_dbg(iproc_i2c->device, "unknown error code=%d\n", val);
+
+               /* re-initialize i2c for recovery */
+               bcm_iproc_i2c_enable_disable(iproc_i2c, false);
+               bcm_iproc_i2c_init(iproc_i2c);
+               bcm_iproc_i2c_enable_disable(iproc_i2c, true);
+
                return -EIO;
        }
 }
@@ -321,49 +369,6 @@ static int bcm_iproc_i2c_cfg_speed(struct bcm_iproc_i2c_dev *iproc_i2c)
        return 0;
 }
 
-static int bcm_iproc_i2c_init(struct bcm_iproc_i2c_dev *iproc_i2c)
-{
-       u32 val;
-
-       /* put controller in reset */
-       val = readl(iproc_i2c->base + CFG_OFFSET);
-       val |= 1 << CFG_RESET_SHIFT;
-       val &= ~(1 << CFG_EN_SHIFT);
-       writel(val, iproc_i2c->base + CFG_OFFSET);
-
-       /* wait 100 usec per spec */
-       udelay(100);
-
-       /* bring controller out of reset */
-       val &= ~(1 << CFG_RESET_SHIFT);
-       writel(val, iproc_i2c->base + CFG_OFFSET);
-
-       /* flush TX/RX FIFOs and set RX FIFO threshold to zero */
-       val = (1 << M_FIFO_RX_FLUSH_SHIFT) | (1 << M_FIFO_TX_FLUSH_SHIFT);
-       writel(val, iproc_i2c->base + M_FIFO_CTRL_OFFSET);
-
-       /* disable all interrupts */
-       writel(0, iproc_i2c->base + IE_OFFSET);
-
-       /* clear all pending interrupts */
-       writel(0xffffffff, iproc_i2c->base + IS_OFFSET);
-
-       return 0;
-}
-
-static void bcm_iproc_i2c_enable_disable(struct bcm_iproc_i2c_dev *iproc_i2c,
-                                        bool enable)
-{
-       u32 val;
-
-       val = readl(iproc_i2c->base + CFG_OFFSET);
-       if (enable)
-               val |= BIT(CFG_EN_SHIFT);
-       else
-               val &= ~BIT(CFG_EN_SHIFT);
-       writel(val, iproc_i2c->base + CFG_OFFSET);
-}
-
 static int bcm_iproc_i2c_probe(struct platform_device *pdev)
 {
        int irq, ret = 0;