Re: [PATCH 1/3] mailbox: add support for APM X-Gene platform mailbox driver

[Feng Kan <fkan@apm.com>]

On Tue, Apr 21, 2015 at 12:42 AM, Jassi Brar <jassisinghbrar@gmail.com> wrote:
> On Wed, Feb 18, 2015 at 8:40 AM, Feng Kan <fkan@apm.com> wrote:
>
>> +#define MBOX_CON_NAME                  "slimpro-mbox"
>> +#define MBOX_REG_SET_OFFSET            0x1000
>> +#define MBOX_CNT                       8
>> +#define MBOX_STATUS_AVAIL_MASK         0x00010000
>> +#define MBOX_STATUS_ACK_MASK           0x00000001
>>
> Nit: BIT(16) and BIT(0) is more readable
will fix
>
>> +/* Configuration and Status Registers */
>> +struct slimpro_mbox_reg {
>> +       u32 in;
>> +       u32 din0;
>> +       u32 din1;
>> +       u32 rsvd1;
>> +       u32 out;
>> +       u32 dout0;
>> +       u32 dout1;
>> +       u32 rsvd2;
>> +       u32 status;
>> +       u32 statusmask;
>> +};
>> +
> Why not the normal way of defining offset macros, like most drivers do?
I personally don't prefer one way over another, let me know if you want me
to change to use defines.
>
>> +struct slimpro_mbox_chan {
>> +       struct device *dev;
>> +       struct mbox_chan *chan;
>> +       struct slimpro_mbox_reg __iomem *reg;
>> +       int id;
>> +       int irq;
>> +       u32 rx_msg[3];
>> +};
>> +
>> +struct slimpro_mbox {
>> +       struct mbox_controller mb_ctrl;
>> +       struct slimpro_mbox_chan mc[MBOX_CNT];
>> +       struct mbox_chan chans[MBOX_CNT];
>> +};
>> +
>> +static struct slimpro_mbox_chan *to_slimpro_mbox_chan(struct mbox_chan *chan)
>> +{
>> +       if (!chan || !chan->con_priv)
>> +               return NULL;
> This seems un-necessary. Anyway you don't care for NULL returned :)
> Probably just kill this function?
done
>
>> +
>> +       return (struct slimpro_mbox_chan *)chan->con_priv;
>> +}
>> +
>> +static void mb_chan_send_msg(struct slimpro_mbox_chan *mb_chan, u32 *msg)
>> +{
>> +       writel(msg[1], &mb_chan->reg->dout0);
>> +       writel(msg[2], &mb_chan->reg->dout1);
>> +       writel(msg[0], &mb_chan->reg->out);
>> +}
>> +
>> +static void mb_chan_recv_msg(struct slimpro_mbox_chan *mb_chan)
>> +{
>> +       mb_chan->rx_msg[1] = readl(&mb_chan->reg->din0);
>> +       mb_chan->rx_msg[2] = readl(&mb_chan->reg->din1);
>> +       mb_chan->rx_msg[0] = readl(&mb_chan->reg->in);
>> +}
>> +
> maybe move the send/recv function inline the caller?
done
>
>> +static void mb_chan_enable_int(struct slimpro_mbox_chan *mb_chan, u32 mask)
>> +{
>> +       u32 val = readl(&mb_chan->reg->statusmask);
>> +
>> +       val &= ~mask;
>> +
>> +       writel(val, &mb_chan->reg->statusmask);
>> +}
>> +
>> +static void mb_chan_disable_int(struct slimpro_mbox_chan *mb_chan, u32 mask)
>> +{
>> +       u32 val = readl(&mb_chan->reg->statusmask);
>> +
>> +       val |= mask;
>> +
>> +       writel(val, &mb_chan->reg->statusmask);
>> +}
>> +
>> +static int mb_chan_status_ack(struct slimpro_mbox_chan *mb_chan)
>> +{
>> +       u32 val = readl(&mb_chan->reg->status);
>> +
>> +       if (val & MBOX_STATUS_ACK_MASK) {
>> +               writel(MBOX_STATUS_ACK_MASK, &mb_chan->reg->status);
>> +               return 1;
>> +       }
>> +       return 0;
>> +}
>> +
>> +static int mb_chan_status_avail(struct slimpro_mbox_chan *mb_chan)
>> +{
>> +       u32 val = readl(&mb_chan->reg->status);
>> +
>> +       if (val & MBOX_STATUS_AVAIL_MASK) {
>> +               mb_chan_recv_msg(mb_chan);
>> +               writel(MBOX_STATUS_AVAIL_MASK, &mb_chan->reg->status);
>> +               return 1;
>> +       }
>> +       return 0;
>> +}
>> +
>> +static irqreturn_t slimpro_mbox_irq(int irq, void *id)
>> +{
>> +       struct slimpro_mbox_chan *mb_chan = id;
>> +
>> +       if (mb_chan_status_ack(mb_chan))
>> +               mbox_chan_txdone(mb_chan->chan, 0);
>> +
>> +       if (mb_chan_status_avail(mb_chan)) {
>> +               mb_chan_recv_msg(mb_chan)
>>
> you already did this in mb_chan_status_avail()  is it needed?
removed
>
>> +               mbox_chan_received_data(mb_chan->chan, mb_chan->rx_msg);
>> +       }
>> +
>> +       return IRQ_HANDLED;
>> +}
>> +
>> +static int slimpro_mbox_send_data(struct mbox_chan *chan, void *msg)
>> +{
>> +       struct slimpro_mbox_chan *mb_chan = to_slimpro_mbox_chan(chan);
>> +
>> +       mb_chan_send_msg(mb_chan, msg);
>> +       return 0;
>> +}
>> +
>> +static int slimpro_mbox_startup(struct mbox_chan *chan)
>> +{
>> +       struct slimpro_mbox_chan *mb_chan = to_slimpro_mbox_chan(chan);
>> +       int rc;
>> +
>> +       rc = devm_request_irq(mb_chan->dev, mb_chan->irq, slimpro_mbox_irq, 0,
>> +                             MBOX_CON_NAME, mb_chan);
>>
> You may want to use IRQF_SHARED flag here and make slimpro_mbox_irq()
> aware of that -- some platforms tie together irq lines of all
> instances of a resource, like dma, mbox, so they may share the same
> irq line.
this is an internal dedicated irq line.
>
>
>> +static int __init slimpro_mbox_probe(struct platform_device *pdev)
>> +{
>> +       struct slimpro_mbox *ctx;
>> +       struct resource *regs;
>> +       void __iomem *mb_base;
>> +       int rc;
>> +       int i;
>> +
>> +       ctx = devm_kzalloc(&pdev->dev, sizeof(struct slimpro_mbox), GFP_KERNEL);
>> +       if (IS_ERR(ctx))
>> +               return PTR_ERR(ctx);
>> +
>> +       platform_set_drvdata(pdev, ctx);
>> +
>> +       regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> +       mb_base = devm_ioremap_resource(&pdev->dev, regs);
>> +       if (IS_ERR(mb_base))
>> +               return PTR_ERR(mb_base);
>> +
>> +       /* Setup mailbox links */
>> +       for (i = 0; i < MBOX_CNT; i++) {
>> +               ctx->mc[i].irq = platform_get_irq(pdev, i);
>> +               if (ctx->mc[i].irq < 0) {
>> +                       dev_err(&pdev->dev, "no IRQ at index %d\n",
>> +                               ctx->mc[i].irq);
>> +                       return -ENODEV;
>> +               }
>> +
>> +               ctx->mc[i].dev = &pdev->dev;
>> +               ctx->mc[i].reg = mb_base + i * MBOX_REG_SET_OFFSET;
>> +               ctx->mc[i].id = i;
>> +               ctx->mc[i].chan = &ctx->chans[i];
>> +               ctx->chans[i].con_priv = &ctx->mc[i];
>>
> Note to self: Maybe we should make it possible to populate a channel
> during request/of_xlate.
>
>> +
>> +static int __init slimpro_mbox_init(void)
>> +{
>> +       return platform_driver_register(&slimpro_mbox_driver);
>> +}
>> +
>> +static void __exit slimpro_mbox_exit(void)
>> +{
>> +}
>> +
>> +subsys_initcall(slimpro_mbox_init);
>> +module_exit(slimpro_mbox_exit);
will remove
> Why empty module_exit?
>
> regards.

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