[PATCH 05/10] ARM: bcm2835: Add the mailbox power channel driver.
eric at anholt.net
Mon Mar 2 14:02:18 PST 2015
Arnd Bergmann <arnd at arndb.de> writes:
> On Monday 02 March 2015 12:54:39 Eric Anholt wrote:
>> + * Submits a set of concatenated tags to the VPU firmware through the
>> + * mailbox power interface.
>> + *
>> + * The buffer header and the ending tag are added by this function and
>> + * don't need to be supplied, just the actual tags for your operation.
>> + * See struct bcm_mbox_power_tag_header for the per-tag structure.
>> + */
>> +static int bcm_mbox_set_power(uint32_t power_enables)
>> + int ret;
>> + reinit_completion(&mbox_power->c);
>> + ret = mbox_send_message(mbox_power->chan,
>> + (void *)(power_enables << BCM_MBOX_DATA_SHIFT));
>> + if (ret >= 0)
>> + wait_for_completion(&mbox_power->c);
>> + return ret;
> Please don't abuse the pointer argument to send an integer.
> Instead, pass a pointer to the data argument as intended. As this
> is a recurring problem, we may want to add a different interface
> to pass fixed-length inline data, maybe
> mbox_send_message_u32(struct mbox_chan *chan, u32 msg);
> and possibly add a length argument to the existing mbox_send_message.
Good point. I've adjusted this code to do this (and to use "msg"
instead of "mssg" -- is "mssg" supposed to mean something besides an
unusual abbreviation of "message"?), and since it was the same number of
lines of code, I don't think it makes sense to define a new API. I
suspect this awkward style just arose from following the lead of the
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