Messages in this thread | | | Date | Fri, 09 Nov 2012 10:16:03 -0700 | From | Stephen Warren <> | Subject | Re: [PATCH v2] pinctrl/nomadik: make independent of prcmu driver |
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On 11/09/2012 03:28 AM, Linus Walleij wrote: > From: Jonas Aaberg <jonas.aberg@stericsson.com> > > Currently there are some unnecessary criss-cross > dependencies between the PRCMU driver in MFD and a lot of > other drivers, mainly because other drivers need to poke > around in the PRCM register range. > > In cases like this there are actually just a few select > registers that the pinctrl driver need to read/modify/write, > and it turns out that no other driver is actually using > these registers, so there are no concurrency issues > whatsoever. > > So: don't let the location of the register range complicate > things, just poke into these registers directly and skip > a layer of indirection. > > Take this opportunity to add kerneldoc to the pinctrl > state container.
> diff --git a/drivers/pinctrl/pinctrl-nomadik.c b/drivers/pinctrl/pinctrl-nomadik.c
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + if (res) { > + npct->prcm_base = devm_ioremap(&pdev->dev, res->start, > + resource_size(res)); > + if (!npct->prcm_base) { > + dev_err(&pdev->dev, > + "failed to ioremap PRCM registers\n"); > + return -ENOMEM; > + } > + } else { > + dev_info(&pdev->dev, > + "No PRCM base, assume no ALT-Cx control is available\n"); > + }
Where is "assume no ALT-Cx control is available" implemented; I don't see anything that uses npct->prcm_base to conditionally enable/block any features. Is it just assumed that the DT won't contain any entries that trigger writes to the PRCM registers? That seems fragile; it could cause a "user"-triggered kernel crash.
Aside from that, this seems fine. Much smaller than V1:-)
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