diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-altera.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-altera.c | 21 |
1 files changed, 14 insertions, 7 deletions
diff --git a/drivers/i2c/busses/i2c-altera.c b/drivers/i2c/busses/i2c-altera.c index 5255d3755411..a60042431370 100644 --- a/drivers/i2c/busses/i2c-altera.c +++ b/drivers/i2c/busses/i2c-altera.c @@ -70,6 +70,7 @@ * @isr_mask: cached copy of local ISR enables. * @isr_status: cached copy of local ISR status. * @lock: spinlock for IRQ synchronization. + * @isr_mutex: mutex for IRQ thread. */ struct altr_i2c_dev { void __iomem *base; @@ -86,6 +87,7 @@ struct altr_i2c_dev { u32 isr_mask; u32 isr_status; spinlock_t lock; /* IRQ synchronization */ + struct mutex isr_mutex; }; static void @@ -171,7 +173,7 @@ static void altr_i2c_init(struct altr_i2c_dev *idev) /* SCL Low Time */ writel(t_low, idev->base + ALTR_I2C_SCL_LOW); /* SDA Hold Time, 300ns */ - writel(div_u64(300 * clk_mhz, 1000), idev->base + ALTR_I2C_SDA_HOLD); + writel(3 * clk_mhz / 10, idev->base + ALTR_I2C_SDA_HOLD); /* Mask all master interrupt bits */ altr_i2c_int_enable(idev, ALTR_I2C_ALL_IRQ, false); @@ -245,10 +247,11 @@ static irqreturn_t altr_i2c_isr(int irq, void *_dev) struct altr_i2c_dev *idev = _dev; u32 status = idev->isr_status; + mutex_lock(&idev->isr_mutex); if (!idev->msg) { dev_warn(idev->dev, "unexpected interrupt\n"); altr_i2c_int_clear(idev, ALTR_I2C_ALL_IRQ); - return IRQ_HANDLED; + goto out; } read = (idev->msg->flags & I2C_M_RD) != 0; @@ -301,6 +304,8 @@ static irqreturn_t altr_i2c_isr(int irq, void *_dev) complete(&idev->msg_complete); dev_dbg(idev->dev, "Message Complete\n"); } +out: + mutex_unlock(&idev->isr_mutex); return IRQ_HANDLED; } @@ -312,6 +317,7 @@ static int altr_i2c_xfer_msg(struct altr_i2c_dev *idev, struct i2c_msg *msg) u32 value; u8 addr = i2c_8bit_addr_from_msg(msg); + mutex_lock(&idev->isr_mutex); idev->msg = msg; idev->msg_len = msg->len; idev->buf = msg->buf; @@ -336,6 +342,7 @@ static int altr_i2c_xfer_msg(struct altr_i2c_dev *idev, struct i2c_msg *msg) altr_i2c_int_enable(idev, imask, true); altr_i2c_fill_tx_fifo(idev); } + mutex_unlock(&idev->isr_mutex); time_left = wait_for_completion_timeout(&idev->msg_complete, ALTR_I2C_XFER_TIMEOUT); @@ -384,7 +391,6 @@ static int altr_i2c_probe(struct platform_device *pdev) struct altr_i2c_dev *idev = NULL; struct resource *res; int irq, ret; - u32 val; idev = devm_kzalloc(&pdev->dev, sizeof(*idev), GFP_KERNEL); if (!idev) @@ -410,18 +416,19 @@ static int altr_i2c_probe(struct platform_device *pdev) idev->dev = &pdev->dev; init_completion(&idev->msg_complete); spin_lock_init(&idev->lock); + mutex_init(&idev->isr_mutex); - val = device_property_read_u32(idev->dev, "fifo-size", + ret = device_property_read_u32(idev->dev, "fifo-size", &idev->fifo_size); - if (val) { + if (ret) { dev_err(&pdev->dev, "FIFO size set to default of %d\n", ALTR_I2C_DFLT_FIFO_SZ); idev->fifo_size = ALTR_I2C_DFLT_FIFO_SZ; } - val = device_property_read_u32(idev->dev, "clock-frequency", + ret = device_property_read_u32(idev->dev, "clock-frequency", &idev->bus_clk_rate); - if (val) { + if (ret) { dev_err(&pdev->dev, "Default to 100kHz\n"); idev->bus_clk_rate = 100000; /* default clock rate */ } |