From: Anders Berg <anders.b...@avagotech.com>
If the device tree does not specify an interrupt property, the device falls
back to polling the controller status. This is needed to support simulator
models without interrupt capabilities.
Signed-off-by: Anders Berg <anders.b...@avagotech.com>
---
drivers/i2c/busses/i2c-axxia.c | 82 +++++++++++++++++++++++-----------------
1 file changed, 48 insertions(+), 34 deletions(-)
diff --git a/drivers/i2c/busses/i2c-axxia.c b/drivers/i2c/busses/i2c-axxia.c
index 4721d3c..93f73ec 100644
--- a/drivers/i2c/busses/i2c-axxia.c
+++ b/drivers/i2c/busses/i2c-axxia.c
@@ -123,6 +123,8 @@ struct axxia_i2c_dev {
size_t msg_xfrd;
/* error code for completed message */
int msg_err;
+ /* IRQ number (or 0 if not using interrupt) */
+ int irq;
/* current i2c bus clock rate */
u32 bus_clk_rate;
};
@@ -327,15 +329,11 @@ status_str(u32 status)
return buf;
}
-static irqreturn_t
-axxia_i2c_isr(int irq, void *_dev)
+static void
+axxia_i2c_service_irq(struct axxia_i2c_dev *idev)
{
- struct axxia_i2c_dev *idev = _dev;
u32 status = readl(&idev->regs->mst_int_status);
- /* Clear interrupt */
- writel(0x01, &idev->regs->interrupt_status);
-
/* RX FIFO needs service? */
if (i2c_m_rd(idev->msg) && (status & MST_STATUS_RFL))
axxia_i2c_empty_rx_fifo(idev);
@@ -370,6 +368,23 @@ axxia_i2c_isr(int irq, void *_dev)
readl(&idev->regs->mst_tx_xfer));
complete(&idev->msg_complete);
}
+}
+
+static irqreturn_t
+axxia_i2c_isr(int irq, void *_dev)
+{
+ struct axxia_i2c_dev *idev = _dev;
+
+ if ((readl(&idev->regs->interrupt_status) & 0x1) == 0)
+ return IRQ_NONE;
+
+ if (!idev->msg)
+ return IRQ_NONE;
+
+ axxia_i2c_service_irq(idev);
+
+ /* Clear interrupt */
+ writel(0x01, &idev->regs->interrupt_status);
return IRQ_HANDLED;
}
@@ -436,14 +451,21 @@ axxia_i2c_xfer_msg(struct axxia_i2c_dev *idev, struct
i2c_msg *msg)
/* Start manual mode */
writel(0x8, &idev->regs->mst_command);
- i2c_int_enable(idev, int_mask);
-
- ret = wait_for_completion_timeout(&idev->msg_complete,
- I2C_XFER_TIMEOUT);
-
- i2c_int_disable(idev, int_mask);
+ if (idev->irq > 0) {
+ i2c_int_enable(idev, int_mask);
+ ret = wait_for_completion_timeout(&idev->msg_complete,
+ I2C_XFER_TIMEOUT);
+ i2c_int_disable(idev, int_mask);
+ WARN_ON(readl(&idev->regs->mst_command) & 0x8);
+ } else {
+ unsigned long tmo = jiffies + I2C_XFER_TIMEOUT;
- WARN_ON(readl(&idev->regs->mst_command) & 0x8);
+ do {
+ /* Poll interrupt status */
+ axxia_i2c_service_irq(idev);
+ ret = try_wait_for_completion(&idev->msg_complete);
+ } while (!ret && time_before(jiffies, tmo));
+ }
if (ret == 0) {
dev_warn(idev->dev, "xfer timeout (%#x)\n", msg->addr);
@@ -518,7 +540,6 @@ axxia_i2c_probe(struct platform_device *pdev)
struct axxia_i2c_dev *idev = NULL;
struct resource *res;
void __iomem *base;
- int irq;
int ret = 0;
idev = devm_kzalloc(&pdev->dev, sizeof(*idev), GFP_KERNEL);
@@ -526,48 +547,41 @@ axxia_i2c_probe(struct platform_device *pdev)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- if (!res) {
- dev_err(&pdev->dev, "can't get device io-resource\n");
- return -ENOENT;
- }
-
- irq = platform_get_irq(pdev, 0);
- if (irq < 0) {
- dev_err(&pdev->dev, "can't get irq number\n");
- return -ENOENT;
- }
-
base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(base))
return PTR_ERR(base);
+ idev->irq = platform_get_irq(pdev, 0);
+ if (idev->irq < 0)
+ dev_info(&pdev->dev, "No IRQ specified, using polling mode\n");
+
idev->i2c_clk = devm_clk_get(&pdev->dev, "i2c");
if (IS_ERR(idev->i2c_clk)) {
dev_err(&pdev->dev, "missing I2C bus clock");
return PTR_ERR(idev->i2c_clk);
}
- idev->regs = (struct i2c_regs __iomem *) base;
- idev->dev = &pdev->dev;
+ idev->regs = (struct i2c_regs __iomem *) base;
+ idev->dev = &pdev->dev;
init_completion(&idev->msg_complete);
of_property_read_u32(np, "clock-frequency", &idev->bus_clk_rate);
if (idev->bus_clk_rate == 0)
idev->bus_clk_rate = 100000; /* default clock rate */
- platform_set_drvdata(pdev, idev);
-
ret = axxia_i2c_init(idev);
if (ret) {
dev_err(&pdev->dev, "Failed to initialize i2c controller");
return ret;
}
- ret = devm_request_irq(&pdev->dev, irq, axxia_i2c_isr, 0,
- pdev->name, idev);
- if (ret) {
- dev_err(&pdev->dev, "can't claim irq %d\n", irq);
- return ret;
+ if (idev->irq >= 0) {
+ ret = devm_request_irq(&pdev->dev, idev->irq, axxia_i2c_isr, 0,
+ pdev->name, idev);
+ if (ret) {
+ dev_err(&pdev->dev, "can't claim irq %d\n", idev->irq);
+ return ret;
+ }
}
clk_enable(idev->i2c_clk);
--
1.7.9.5
--
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