[i2c] [PATCH 2/2] S3C24XX: fix bug in releasing driver

[Ben Dooks]

When compiled as a module, the i2c driver does not
free either the IRQ or the i2c adapter it attached
to the system.

As part of this fix, move to the usual kernel style
of freeing items as part of the probe error path
making the remove process easier.

Signed-off-by: Ben Dooks <ben-linux at fluff.org>

diff -urpN -X linux-2.6.21-rc6-i2cfix1/Documentation/dontdiff linux-2.6.21-rc6-i2cfix1/drivers/i2c/busses/i2c-s3c2410.c linux-2.6.21-rc6-i2cfix2/drivers/i2c/busses/i2c-s3c2410.c
--- linux-2.6.21-rc6-i2cfix1/drivers/i2c/busses/i2c-s3c2410.c	2007-04-17 23:35:22.000000000 +0100
+++ linux-2.6.21-rc6-i2cfix2/drivers/i2c/busses/i2c-s3c2410.c	2007-04-17 23:49:29.000000000 +0100
@@ -745,26 +745,6 @@ static int s3c24xx_i2c_init(struct s3c24
 	return 0;
 }
 
-static void s3c24xx_i2c_free(struct s3c24xx_i2c *i2c)
-{
-	if (i2c->clk != NULL && !IS_ERR(i2c->clk)) {
-		clk_disable(i2c->clk);
-		clk_put(i2c->clk);
-		i2c->clk = NULL;
-	}
-
-	if (i2c->regs != NULL) {
-		iounmap(i2c->regs);
-		i2c->regs = NULL;
-	}
-
-	if (i2c->ioarea != NULL) {
-		release_resource(i2c->ioarea);
-		kfree(i2c->ioarea);
-		i2c->ioarea = NULL;
-	}
-}
-
 /* s3c24xx_i2c_probe
  *
  * called by the bus driver when a suitable device is found
@@ -783,7 +763,7 @@ static int s3c24xx_i2c_probe(struct plat
 	if (IS_ERR(i2c->clk)) {
 		dev_err(&pdev->dev, "cannot get clock\n");
 		ret = -ENOENT;
-		goto out;
+		goto err_noclk;
 	}
 
 	dev_dbg(&pdev->dev, "clock source %p\n", i2c->clk);
@@ -796,7 +776,7 @@ static int s3c24xx_i2c_probe(struct plat
 	if (res == NULL) {
 		dev_err(&pdev->dev, "cannot find IO resource\n");
 		ret = -ENOENT;
-		goto out;
+		goto err_clk;
 	}
 
 	i2c->ioarea = request_mem_region(res->start, (res->end-res->start)+1,
@@ -805,7 +785,7 @@ static int s3c24xx_i2c_probe(struct plat
 	if (i2c->ioarea == NULL) {
 		dev_err(&pdev->dev, "cannot request IO\n");
 		ret = -ENXIO;
-		goto out;
+		goto err_clk;
 	}
 
 	i2c->regs = ioremap(res->start, (res->end-res->start)+1);
@@ -813,7 +793,7 @@ static int s3c24xx_i2c_probe(struct plat
 	if (i2c->regs == NULL) {
 		dev_err(&pdev->dev, "cannot map IO\n");
 		ret = -ENXIO;
-		goto out;
+		goto err_ioarea;
 	}
 
 	dev_dbg(&pdev->dev, "registers %p (%p, %p)\n", i2c->regs, i2c->ioarea, res);
@@ -827,7 +807,7 @@ static int s3c24xx_i2c_probe(struct plat
 
 	ret = s3c24xx_i2c_init(i2c);
 	if (ret != 0)
-		goto out;
+		goto err_iomap;
 
 	/* find the IRQ for this unit (note, this relies on the init call to
 	 * ensure no current IRQs pending 
@@ -837,7 +817,7 @@ static int s3c24xx_i2c_probe(struct plat
 	if (res == NULL) {
 		dev_err(&pdev->dev, "cannot find IRQ\n");
 		ret = -ENOENT;
-		goto out;
+		goto err_iomap;
 	}
 
 	ret = request_irq(res->start, s3c24xx_i2c_irq, IRQF_DISABLED,
@@ -845,7 +825,7 @@ static int s3c24xx_i2c_probe(struct plat
 
 	if (ret != 0) {
 		dev_err(&pdev->dev, "cannot claim IRQ\n");
-		goto out;
+		goto err_iomap;
 	}
 
 	i2c->irq = res;
@@ -855,17 +835,29 @@ static int s3c24xx_i2c_probe(struct plat
 	ret = i2c_add_adapter(&i2c->adap);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "failed to add bus to i2c core\n");
-		goto out;
+		goto err_irq;
 	}
 
 	platform_set_drvdata(pdev, i2c);
 
 	dev_info(&pdev->dev, "%s: S3C I2C adapter\n", i2c->adap.dev.bus_id);
+	return 0;
 
- out:
-	if (ret < 0)
-		s3c24xx_i2c_free(i2c);
+ err_irq:
+	free_irq(i2c->irq->start, i2c);
 
+ err_iomap:
+	iounmap(i2c->regs);
+
+ err_ioarea:
+	release_resource(i2c->ioarea);
+	kfree(i2c->ioarea);
+
+ err_clk:
+	clk_disable(i2c->clk);
+	clk_put(i2c->clk);
+
+ err_noclk:
 	return ret;
 }
 
@@ -877,11 +869,17 @@ static int s3c24xx_i2c_probe(struct plat
 static int s3c24xx_i2c_remove(struct platform_device *pdev)
 {
 	struct s3c24xx_i2c *i2c = platform_get_drvdata(pdev);
-	
-	if (i2c != NULL) {
-		s3c24xx_i2c_free(i2c);
-		platform_set_drvdata(pdev, NULL);
-	}
+
+	i2c_del_adapter(&i2c->adap);	
+	free_irq(i2c->irq->start, i2c);
+
+	clk_disable(i2c->clk);
+	clk_put(i2c->clk);
+
+	iounmap(i2c->regs);
+
+	release_resource(i2c->ioarea);
+	kfree(i2c->ioarea);
 
 	return 0;
 }