From: Ray Jui <rjui@xxxxxxxxxxxx>
Add proper recovery mechanism to the iProc I2C driver in error cases
Signed-off-by: Icarus Chau <ichau@xxxxxxxxxxxx>
Signed-off-by: Ray Jui <rjui@xxxxxxxxxxxx>
Tested-by: Icarus Chau <ichau@xxxxxxxxxxxx>
Reviewed-by: Scott Branden <sbranden@xxxxxxxxxxxx>
---
drivers/i2c/busses/i2c-bcm-iproc.c | 91 ++++++++++++++++++++------------------
1 file changed, 48 insertions(+), 43 deletions(-)
diff --git a/drivers/i2c/busses/i2c-bcm-iproc.c b/drivers/i2c/busses/i2c-bcm-iproc.c
index 0419f52..ce062d3 100644
--- 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;
--
1.9.1
--
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