Re: [PATCH] drivers/iio/adc/at91_adc.c: use devm_ functions

From: Jonathan Cameron
Date: Tue Aug 14 2012 - 16:32:44 EST


Lars-Peter,

Are you happy with this updated version? Can't immediately find any response
from you to it.

Jonathan
> From: Julia Lawall <Julia.Lawall@xxxxxxx>
>
> The various devm_ functions allocate memory that is released when a driver
> detaches. This patch uses these functions for data that is allocated in
> the probe function of a platform device and is only freed in the remove
> function.
>
> The call to platform_get_resource(pdev, IORESOURCE_MEM, 0) is moved coser
> to the call to devm_request_and_ioremap, which is th first use of the
> result of platform_get_resource.
>
> This does not use devm_request_irq to ensure that free_irq is executed
> before its idev argument is freed.
>
> Signed-off-by: Julia Lawall <Julia.Lawall@xxxxxxx>
>
> ---
> drivers/iio/adc/at91_adc.c | 41 ++++++++---------------------------------
> 1 file changed, 8 insertions(+), 33 deletions(-)
>
> diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c
> index f61780a..3506e3d 100644
> --- a/drivers/iio/adc/at91_adc.c
> +++ b/drivers/iio/adc/at91_adc.c
> @@ -545,13 +545,6 @@ static int __devinit at91_adc_probe(struct platform_device *pdev)
> goto error_free_device;
> }
>
> - res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> - if (!res) {
> - dev_err(&pdev->dev, "No resource defined\n");
> - ret = -ENXIO;
> - goto error_ret;
> - }
> -
> platform_set_drvdata(pdev, idev);
>
> idev->dev.parent = &pdev->dev;
> @@ -566,18 +559,13 @@ static int __devinit at91_adc_probe(struct platform_device *pdev)
> goto error_free_device;
> }
>
> - if (!request_mem_region(res->start, resource_size(res),
> - "AT91 adc registers")) {
> - dev_err(&pdev->dev, "Resources are unavailable.\n");
> - ret = -EBUSY;
> - goto error_free_device;
> - }
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>
> - st->reg_base = ioremap(res->start, resource_size(res));
> + st->reg_base = devm_request_and_ioremap(&pdev->dev, res);
> if (!st->reg_base) {
> dev_err(&pdev->dev, "Failed to map registers.\n");
> ret = -ENOMEM;
> - goto error_release_mem;
> + goto error_free_device;
> }
>
> /*
> @@ -592,10 +580,10 @@ static int __devinit at91_adc_probe(struct platform_device *pdev)
> idev);
> if (ret) {
> dev_err(&pdev->dev, "Failed to allocate IRQ.\n");
> - goto error_unmap_reg;
> + goto error_free_device;
> }
>
> - st->clk = clk_get(&pdev->dev, "adc_clk");
> + st->clk = devm_clk_get(&pdev->dev, "adc_clk");
> if (IS_ERR(st->clk)) {
> dev_err(&pdev->dev, "Failed to get the clock.\n");
> ret = PTR_ERR(st->clk);
> @@ -605,7 +593,7 @@ static int __devinit at91_adc_probe(struct platform_device *pdev)
> ret = clk_prepare(st->clk);
> if (ret) {
> dev_err(&pdev->dev, "Could not prepare the clock.\n");
> - goto error_free_clk;
> + goto error_free_irq;
> }
>
> ret = clk_enable(st->clk);
> @@ -614,7 +602,7 @@ static int __devinit at91_adc_probe(struct platform_device *pdev)
> goto error_unprepare_clk;
> }
>
> - st->adc_clk = clk_get(&pdev->dev, "adc_op_clk");
> + st->adc_clk = devm_clk_get(&pdev->dev, "adc_op_clk");
> if (IS_ERR(st->adc_clk)) {
> dev_err(&pdev->dev, "Failed to get the ADC clock.\n");
> ret = PTR_ERR(st->clk);
> @@ -624,7 +612,7 @@ static int __devinit at91_adc_probe(struct platform_device *pdev)
> ret = clk_prepare(st->adc_clk);
> if (ret) {
> dev_err(&pdev->dev, "Could not prepare the ADC clock.\n");
> - goto error_free_adc_clk;
> + goto error_disable_clk;
> }
>
> ret = clk_enable(st->adc_clk);
> @@ -697,20 +685,12 @@ error_disable_adc_clk:
> clk_disable(st->adc_clk);
> error_unprepare_adc_clk:
> clk_unprepare(st->adc_clk);
> -error_free_adc_clk:
> - clk_put(st->adc_clk);
> error_disable_clk:
> clk_disable(st->clk);
> error_unprepare_clk:
> clk_unprepare(st->clk);
> -error_free_clk:
> - clk_put(st->clk);
> error_free_irq:
> free_irq(st->irq, idev);
> -error_unmap_reg:
> - iounmap(st->reg_base);
> -error_release_mem:
> - release_mem_region(res->start, resource_size(res));
> error_free_device:
> iio_device_free(idev);
> error_ret:
> @@ -720,20 +700,15 @@ error_ret:
> static int __devexit at91_adc_remove(struct platform_device *pdev)
> {
> struct iio_dev *idev = platform_get_drvdata(pdev);
> - struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> struct at91_adc_state *st = iio_priv(idev);
>
> iio_device_unregister(idev);
> at91_adc_trigger_remove(idev);
> at91_adc_buffer_remove(idev);
> clk_disable_unprepare(st->adc_clk);
> - clk_put(st->adc_clk);
> clk_disable(st->clk);
> clk_unprepare(st->clk);
> - clk_put(st->clk);
> free_irq(st->irq, idev);
> - iounmap(st->reg_base);
> - release_mem_region(res->start, resource_size(res));
> iio_device_free(idev);
>
> return 0;
>
--
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