Thread (1 message) 1 message, 1 author, 2012-09-19

Re: [PATCH] i2c: i2c-gpio: fix issue when DT node greater than 1

From: Bo Shen <hidden>
Date: 2012-09-19 01:15:08
Also in: linux-arm-kernel, linux-i2c

Hi Stephen Warren,

On 9/18/2012 22:51, Stephen Warren wrote:
On 09/18/2012 03:02 AM, Bo Shen wrote:
quoted
When i2c-gpio node number is greater than 1, the second can not sucessfully
regiter

Using alias method to get the pdev->id, or else the second device will use
the same id which will cause fail to register
pdev->id shouldn't be used at all with device tree. Why does
registration fail without this change?
I add the debug info, and it give the following error without this patch.

--<8----------------------------------
adap->name = i2c-gpio-1
i2c-gpio i2c.2: using pins 30 (SDA) and 31 (SCL)
adap->name = i2c-gpio-1
i2c-gpio: probe of i2c.3 failed with error -16
-->8----------------------------------

With this patch, it successfully registered.
--<8----------------------------------
adap->name = i2c-gpio0
i2c-gpio i2c.2: using pins 30 (SDA) and 31 (SCL)
adap->name = i2c-gpio1
i2c-gpio i2c.3: using pins 90 (SDA) and 91 (SCL)
-->8----------------------------------
quoted
diff --git a/drivers/i2c/busses/i2c-gpio.c b/drivers/i2c/busses/i2c-gpio.c
index e62d2d9..051fbb3 100644
--- a/drivers/i2c/busses/i2c-gpio.c
+++ b/drivers/i2c/busses/i2c-gpio.c
@@ -136,6 +136,7 @@ static int __devinit i2c_gpio_probe(struct platform_device *pdev)
  		ret = of_i2c_gpio_probe(pdev->dev.of_node, pdata);
  		if (ret)
  			return ret;
+		pdev->id = of_alias_get_id(pdev->dev.of_node, "i2c-gpio");
  	} else {
  		if (!pdev->dev.platform_data)
  			return -ENXIO;
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