From 6ee608c1c9ce2b11ef90873b841ca380e7142007 Mon Sep 17 00:00:00 2001 From: Ray Jui Date: Fri, 12 Feb 2016 13:10:41 -0800 Subject: [PATCH] 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 Signed-off-by: Ray Jui Tested-by: Icarus Chau Reviewed-by: Scott Branden [wsa: whitespace fixes] Signed-off-by: Wolfram Sang --- 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 0419f5284609..709b56af0676 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; -- 2.11.4.GIT