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i2c: bcm2835: Store pointer to bus clock

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The commit bebff81fb8 ("i2c: bcm2835: Model Divider in CCF") introduced
a NULL pointer dereference on driver unload. It seems that we can't fetch
the bus clock via devm_clk_get in bcm2835_i2c_remove. As an alternative
approach store a pointer to the bus clock in the private driver structure.

Fixes: bebff81fb8 ("i2c: bcm2835: Model Divider in CCF")
Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This commit is contained in:
Stefan Wahren 2020-01-04 16:13:20 +01:00 committed by Wolfram Sang
parent 42052d96ae
commit 3b722da667
1 changed files with 8 additions and 9 deletions
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17
drivers/i2c/busses/i2c-bcm2835.c
View file

@ -58,6 +58,7 @@ struct bcm2835_i2c_dev {
struct i2c_adapter adapter;
struct completion completion;
struct i2c_msg *curr_msg;
struct clk *bus_clk;
int num_msgs;
u32 msg_err;
u8 *msg_buf;
@ -404,7 +405,6 @@ static int bcm2835_i2c_probe(struct platform_device *pdev)
struct resource *mem, *irq;
int ret;
struct i2c_adapter *adap;
struct clk *bus_clk;
struct clk *mclk;
u32 bus_clk_rate;
@ -427,11 +427,11 @@ static int bcm2835_i2c_probe(struct platform_device *pdev)
return PTR_ERR(mclk);
}
bus_clk = bcm2835_i2c_register_div(&pdev->dev, mclk, i2c_dev);
i2c_dev->bus_clk = bcm2835_i2c_register_div(&pdev->dev, mclk, i2c_dev);
if (IS_ERR(bus_clk)) {
if (IS_ERR(i2c_dev->bus_clk)) {
dev_err(&pdev->dev, "Could not register clock\n");
return PTR_ERR(bus_clk);
return PTR_ERR(i2c_dev->bus_clk);
}
ret = of_property_read_u32(pdev->dev.of_node, "clock-frequency",
@ -442,13 +442,13 @@ static int bcm2835_i2c_probe(struct platform_device *pdev)
bus_clk_rate = 100000;
}
ret = clk_set_rate_exclusive(bus_clk, bus_clk_rate);
ret = clk_set_rate_exclusive(i2c_dev->bus_clk, bus_clk_rate);
if (ret < 0) {
dev_err(&pdev->dev, "Could not set clock frequency\n");
return ret;
}
ret = clk_prepare_enable(bus_clk);
ret = clk_prepare_enable(i2c_dev->bus_clk);
if (ret) {
dev_err(&pdev->dev, "Couldn't prepare clock");
return ret;
@ -491,10 +491,9 @@ static int bcm2835_i2c_probe(struct platform_device *pdev)
static int bcm2835_i2c_remove(struct platform_device *pdev)
{
struct bcm2835_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
struct clk *bus_clk = devm_clk_get(i2c_dev->dev, "div");
clk_rate_exclusive_put(bus_clk);
clk_disable_unprepare(bus_clk);
clk_rate_exclusive_put(i2c_dev->bus_clk);
clk_disable_unprepare(i2c_dev->bus_clk);
free_irq(i2c_dev->irq, i2c_dev);
i2c_del_adapter(&i2c_dev->adapter);