[PATCHv5 2/2] mailbox: Adding driver for Xilinx LogiCORE IP mailbox.
Josh Cartwright
joshc at ni.com
Tue Jun 23 11:51:10 PDT 2015
Hey Moritz-
Just a couple more nits, nothing big. Looks pretty clean!
On Tue, Jun 23, 2015 at 11:00:02AM -0700, Moritz Fischer wrote:
> The Xilinx LogiCORE IP mailbox is a FPGA core that allows for
> interprocessor communication via AXI4 memory mapped / AXI4 stream
> interfaces.
>
> It is single channel per core and allows for transmit and receive.
>
> Changes from v4:
> - Have separate mbox_ops structs for polling / irq mode
> - Moved clk handling to startup / shutdown
> - Embedded struct mbox_chan in struct xilinx_mbox
> - Misc stylistic issues
>
> Changes from v3:
> - Stylistic
>
> Changes from v2:
> - Fixed error handling for IRQ from >= 0 to > 0
> - Fixed error handling for clock enabling
> - Addressed Michal's stylistic comments
>
> Changes from v1:
> - Added common clock framework support
> - Deal with IRQs that happend before driver load,
> since HW will not let us know about them when we enable IRQs
>
> Changes from v0:
> - Several stylistic issues
> - Dropped superfluous intr_mode member
> - Really masking the IRQs on mailbox_shutdown
> - No longer using polling by accident in non-IRQ mode
> - Swapped doc and driver commits
>
> Signed-off-by: Moritz Fischer <moritz.fischer at ettus.com>
> Acked-by: Michal Simek <michal.simek at xilinx.com>
>
> mailbox: Address some feedback, make ops const.
>
> Signed-off-by: Moritz Fischer <moritz.fischer at ettus.com>
>
> mailbox: xilinx-mailbox: Addressed more of Josh's feedback.
>
> Signed-off-by: Moritz Fischer <moritz.fischer at ettus.com>
Did you intend for this intermediate history to exist? Seems verbose,
doesn't provide any meaningful detail?
[..]
> +++ b/drivers/mailbox/mailbox-xilinx.c
[..]
> +static int xilinx_mbox_poll_startup(struct mbox_chan *chan)
> +{
> + struct xilinx_mbox *mbox = mbox_chan_to_xilinx_mbox(chan);
> +
> + /* prep and enable the clock */
Nit: Is this comment conveying anything useful?
> + clk_prepare_enable(mbox->clk);
> +
> + /* setup polling timer */
Nit: Same here.
> + setup_timer(&mbox->rxpoll_timer, xilinx_mbox_poll_rx,
> + (unsigned long)chan);
setup_timer() could conceivably be done in probe().
[..]
> +static int xilinx_mbox_poll_send_data(struct mbox_chan *chan, void *data)
> +{
> + struct xilinx_mbox *mbox = mbox_chan_to_xilinx_mbox(chan);
> + u32 *udata = data;
> +
> + if (!mbox || !data)
Nit: How could this happen?
> + return -EINVAL;
> +
> + if (xilinx_mbox_full(mbox))
> + return -EBUSY;
> +
> + writel_relaxed(*udata, mbox->mbox_base + MAILBOX_REG_WRDATA);
> +
> + return 0;
> +}
[..]
> +static struct mbox_chan_ops xilinx_mbox_irq_ops = {
const?
> + .send_data = xilinx_mbox_irq_send_data,
> + .startup = xilinx_mbox_irq_startup,
> + .shutdown = xilinx_mbox_irq_shutdown,
> + .last_tx_done = xilinx_mbox_last_tx_done,
> + .peek_data = xilinx_mbox_peek_data,
> +};
> +
> +static struct mbox_chan_ops xilinx_mbox_poll_ops = {
const?
> + .send_data = xilinx_mbox_poll_send_data,
> + .startup = xilinx_mbox_poll_startup,
> + .shutdown = xilinx_mbox_poll_shutdown,
> + .last_tx_done = xilinx_mbox_last_tx_done,
> + .peek_data = xilinx_mbox_peek_data,
> +};
Splitting up the ops seemed to clean things up quite a bit!
> +
> +static int xilinx_mbox_probe(struct platform_device *pdev)
> +{
> + struct xilinx_mbox *mbox;
> + struct resource *regs;
> + int ret;
> +
> + mbox = devm_kzalloc(&pdev->dev, sizeof(*mbox), GFP_KERNEL);
> + if (!mbox)
> + return -ENOMEM;
> +
> + /* get clk and enable */
> + mbox->clk = devm_clk_get(&pdev->dev, "mbox");
> + if (IS_ERR(mbox->clk)) {
> + dev_err(&pdev->dev, "Couldn't get clk.\n");
> + return PTR_ERR(mbox->clk);
> + }
> +
> + regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +
> + mbox->mbox_base = devm_ioremap_resource(&pdev->dev, regs);
> + if (IS_ERR(mbox->mbox_base))
> + return PTR_ERR(mbox->mbox_base);
> +
> + mbox->irq = platform_get_irq(pdev, 0);
> + /* if irq is present, we can use it, otherwise, poll */
> + if (mbox->irq > 0) {
> + mbox->controller.txdone_irq = true;
> + } else {
> + dev_info(&pdev->dev, "IRQ not found, fallback to polling.\n");
> + mbox->controller.txdone_poll = true;
> + mbox->controller.txpoll_period = MBOX_POLLING_MS;
> + }
> +
> + mbox->dev = &pdev->dev;
> +
> + /* hardware supports only one channel. */
> + mbox->controller.dev = mbox->dev;
> + mbox->controller.num_chans = 1;
> + mbox->controller.chans = &mbox->chan;
> +
> + if (mbox->irq > 0)
> + mbox->controller.ops = &xilinx_mbox_irq_ops;
> + else
> + mbox->controller.ops = &xilinx_mbox_poll_ops;
Nit: you're already checking this above, seems like you can just move
the .ops assignment there.
Josh
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