Messages in this thread |  | | Subject | Re: [PATCH 03/14] ASoC: sun4i-i2s: Add apb reset | From | Mylene Josserand <> | Date | Wed, 5 Oct 2016 11:43:10 +0200 |
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Hello,
On 04/10/2016 17:42, Maxime Ripard wrote: > Hi, > > On Tue, Oct 04, 2016 at 02:15:16PM +0200, Thomas Petazzoni wrote: >> Hello, >> >> On Tue, 4 Oct 2016 11:46:16 +0200, Mylène Josserand wrote: >> >>> #include <sound/dmaengine_pcm.h> >>> #include <sound/pcm_params.h> >>> @@ -589,6 +590,7 @@ static int sun4i_i2s_probe(struct platform_device *pdev) >>> { >>> struct sun4i_i2s *i2s; >>> struct resource *res; >>> + struct reset_control *reset_apb; >>> void __iomem *regs; >>> int irq, ret; >>> >>> @@ -626,7 +628,19 @@ static int sun4i_i2s_probe(struct platform_device *pdev) >>> dev_err(&pdev->dev, "Can't get our mod clock\n"); >>> return PTR_ERR(i2s->mod_clk); >>> } >>> - >>> + >>> + reset_apb = devm_reset_control_get(&pdev->dev, "apb_reset"); >> >> I believe this is a change in the Device Tree binding, since you're >> adding support for a new resource. Perhaps the Device Tree binding >> documentation should be updated accordingly? > > Indeed. > > You have two solutions to do that: > - Either mark it as optional and use reset_control_get_optional > (because here, you broke the other SoCs that have that controller > but no reset line) > - Or introduce a new compatible, and make the reset property > mandatory for that new compatible. > > I prefer the latter, since you get a stricter error check, and you > cannot end up in a situation where your driver probes but is > useless. But you'll find both in our drivers. >
Okay, thank you for the hints!
>>> + } >>> + >>> + ret = reset_control_deassert(reset_apb); >>> + if (ret < 0) { >>> + dev_err(&pdev->dev, "Can't deassert apb reset (%d)\n", ret); >>> + return ret; >>> + } >> >> Do you need to re-assert the reset line in the ->remove() hook? > > Even better, you can add it to the runtime_pm hooks! :)
I will have a look to runtime_pm and update it for a V2.
-- Mylène Josserand, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com
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