On Thursday 15 May 2014 11:41:00 Jassi Brar wrote:
> Introduce common framework for client/protocol drivers and
> controller drivers of Inter-Processor-Communication (IPC).
>
> Client driver developers should have a look at
> include/linux/mailbox_client.h to understand the part of
> the API exposed to client drivers.
> Similarly controller driver developers should have a look
> at include/linux/mailbox_controller.h
>
> Signed-off-by: Jassi Brar <jaswinder.si...@linaro.org>
I hadn't followed all the previous versions, but this looks very nice!
I only have comments about tiny details.
> new file mode 100644
> index 0000000..0eb2fb0
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mailbox/mailbox.txt
> @@ -0,0 +1,30 @@
> +* Generic Mailbox Controller and client driver bindings
> +
> +Generic binding to provide a way for Mailbox controller drivers to assign
> appropriate mailbox channel to client drivers.
> +
> +* MAILBOX Controller
Just formatting: wrap the lines after 70 characters, and don't use
capital letters for 'mailbox'.
> +
> +enum mbox_result {
> + MBOX_OK = 0,
> + MBOX_ERR,
> +};
How about using a standard error number?
> +/**
> + * struct mbox_client - User of a mailbox
> + * @dev: The client device
> + * @chan_name: The "controller:channel" this client wants
> + * @rx_callback: Atomic callback to provide client the data received
> + * @tx_done: Atomic callback to tell client of data transmission
> + * @tx_block: If the mbox_send_message should block until
> data is
> + * transmitted.
> + * @tx_tout: Max block period in ms before TX is assumed failure
> + * @knows_txdone: if the client could run the TX state machine. Usually
> + * if the client receives some ACK packet for transmission.
> + * Unused if the controller already has TX_Done/RTR IRQ.
> + */
> +struct mbox_client {
> + struct device *dev;
> + const char *chan_name;
> + void (*rx_callback)(struct mbox_client *cl, void *mssg);
> + void (*tx_done)(struct mbox_client *cl, void *mssg, enum mbox_result r);
> + bool tx_block;
> + unsigned long tx_tout;
> + bool knows_txdone;
> +};
> +
> +struct mbox_chan *mbox_request_channel(struct mbox_client *cl);
Is it possible to make the argument 'const'?
Maybe document how you expect an mbox_client to be allocated:
- static const definition in driver
- dynamically allocated and embedded in some client specific struct
- on the stack and discarded after mbox_request_channel()
> +/**
> + * struct mbox_controller - Controller of a class of communication chans
> + * @dev: Device backing this controller
> + * @controller_name: Literal name of the controller.
> + * @ops: Operators that work on each communication chan
> + * @chans: Null terminated array of chans.
> + * @txdone_irq: Indicates if the controller can report to API
> when
> + * the last transmitted data was read by the remote.
> + * Eg, if it has some TX ACK irq.
> + * @txdone_poll: If the controller can read but not report the TX
> + * done. Ex, some register shows the TX status but
> + * no interrupt rises. Ignored if 'txdone_irq' is set.
> + * @txpoll_period: If 'txdone_poll' is in effect, the API polls for
> + * last TX's status after these many millisecs
> + */
> +struct mbox_controller {
> + struct device *dev;
> + struct mbox_chan_ops *ops;
> + struct mbox_chan *chans;
> + int num_chans;
> + bool txdone_irq;
> + bool txdone_poll;
> + unsigned txpoll_period;
> + struct mbox_chan *(*of_xlate)(struct mbox_controller *mbox,
> + const struct of_phandle_args *sp);
> + /*
> + * If the controller supports only TXDONE_BY_POLL,
> + * this timer polls all the links for txdone.
> + */
> + struct timer_list poll;
> + unsigned period;
> + /* Hook to add to the global controller list */
> + struct list_head node;
> +} __aligned(32);
What is the __aligned(32) for?
Arnd
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