Re: [PATCH v3 2/3] can: rcar_canfd: Add support for RZ/G2L family
From: Geert Uytterhoeven
Date: Mon Jul 26 2021 - 05:53:22 EST
Hi Prabhakar,
On Wed, Jul 21, 2021 at 9:50 PM Lad Prabhakar
<prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx> wrote:
> CANFD block on RZ/G2L SoC is almost identical to one found on
> R-Car Gen3 SoC's. On RZ/G2L SoC interrupt sources for each channel
> are split into different sources and the IP doesn't divide (1/2)
> CANFD clock within the IP.
>
> This patch adds compatible string for RZ/G2L family and registers
> the irq handlers required for CANFD operation. IRQ numbers are now
> fetched based on names instead of indices. For backward compatibility
> on non RZ/G2L SoC's we fallback reading based on indices.
>
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
Thanks for the update!
I think you misunderstood my comment on v1 about the interrupt
handlers, cfr. below.
> --- a/drivers/net/can/rcar/rcar_canfd.c
> +++ b/drivers/net/can/rcar/rcar_canfd.c
> @@ -1577,6 +1586,53 @@ static int rcar_canfd_channel_probe(struct rcar_canfd_global *gpriv, u32 ch,
> priv->can.clock.freq = fcan_freq;
> dev_info(&pdev->dev, "can_clk rate is %u\n", priv->can.clock.freq);
>
> + if (gpriv->chip_id == RENESAS_RZG2L) {
> + char *irq_name;
> + int err_irq;
> + int tx_irq;
> +
> + err_irq = platform_get_irq_byname(pdev, ch == 0 ? "ch0_err" : "ch1_err");
> + if (err_irq < 0) {
> + err = err_irq;
> + goto fail;
> + }
> +
> + tx_irq = platform_get_irq_byname(pdev, ch == 0 ? "ch0_trx" : "ch1_trx");
> + if (tx_irq < 0) {
> + err = tx_irq;
> + goto fail;
> + }
> +
> + irq_name = devm_kasprintf(&pdev->dev, GFP_KERNEL,
> + "canfd.ch%d_err", ch);
> + if (!irq_name) {
> + err = -ENOMEM;
> + goto fail;
> + }
> + err = devm_request_irq(&pdev->dev, err_irq,
> + rcar_canfd_channel_interrupt, 0,
This is the same interrupt handler...
> + irq_name, gpriv);
> + if (err) {
> + dev_err(&pdev->dev, "devm_request_irq CH Err(%d) failed, error %d\n",
> + err_irq, err);
> + goto fail;
> + }
> + irq_name = devm_kasprintf(&pdev->dev, GFP_KERNEL,
> + "canfd.ch%d_trx", ch);
> + if (!irq_name) {
> + err = -ENOMEM;
> + goto fail;
> + }
> + err = devm_request_irq(&pdev->dev, tx_irq,
> + rcar_canfd_channel_interrupt, 0,
... as this one.
> + irq_name, gpriv);
> + if (err) {
> + dev_err(&pdev->dev, "devm_request_irq Tx (%d) failed, error %d\n",
> + tx_irq, err);
> + goto fail;
> + }
> + }
> +
> if (gpriv->fdmode) {
> priv->can.bittiming_const = &rcar_canfd_nom_bittiming_const;
> priv->can.data_bittiming_const =
> @@ -1711,20 +1798,51 @@ static int rcar_canfd_probe(struct platform_device *pdev)
> gpriv->base = addr;
>
> /* Request IRQ that's common for both channels */
> - err = devm_request_irq(&pdev->dev, ch_irq,
> - rcar_canfd_channel_interrupt, 0,
> - "canfd.chn", gpriv);
> - if (err) {
> - dev_err(&pdev->dev, "devm_request_irq(%d) failed, error %d\n",
> - ch_irq, err);
> - goto fail_dev;
> + if (gpriv->chip_id == RENESAS_RCAR_GEN3) {
> + err = devm_request_irq(&pdev->dev, ch_irq,
> + rcar_canfd_channel_interrupt, 0,
> + "canfd.ch_int", gpriv);
> + if (err) {
> + dev_err(&pdev->dev, "devm_request_irq(%d) failed, error %d\n",
> + ch_irq, err);
> + goto fail_dev;
> + }
> +
> + err = devm_request_irq(&pdev->dev, g_irq,
> + rcar_canfd_global_interrupt, 0,
> + "canfd.g_int", gpriv);
> + if (err) {
> + dev_err(&pdev->dev, "devm_request_irq(%d) failed, error %d\n",
> + g_irq, err);
> + goto fail_dev;
> + }
> + } else {
> + err = devm_request_irq(&pdev->dev, g_recc_irq,
> + rcar_canfd_global_interrupt, 0,
This is the same interrupt handler...
> + "canfd.g_recc", gpriv);
> +
> + if (err) {
> + dev_err(&pdev->dev, "devm_request_irq(%d) failed, error %d\n",
> + g_recc_irq, err);
> + goto fail_dev;
> + }
> +
> + err = devm_request_irq(&pdev->dev, g_err_irq,
> + rcar_canfd_global_interrupt, 0,
... as this one.
> + "canfd.g_err", gpriv);
> + if (err) {
> + dev_err(&pdev->dev, "devm_request_irq(%d) failed, error %d\n",
> + g_err_irq, err);
> + goto fail_dev;
> + }
> }
> - err = devm_request_irq(&pdev->dev, g_irq,
> - rcar_canfd_global_interrupt, 0,
> - "canfd.gbl", gpriv);
> +
> + err = reset_control_reset(gpriv->rstc1);
> + if (err)
> + goto fail_dev;
> + err = reset_control_reset(gpriv->rstc2);
> if (err) {
> - dev_err(&pdev->dev, "devm_request_irq(%d) failed, error %d\n",
> - g_irq, err);
> + reset_control_assert(gpriv->rstc1);
> goto fail_dev;
> }
I did not object to having fine-grained interrupt handlers on RZ/G2L.
I did object to duplicating code in global and fine-grained interrupt
handlers.
The trick to have both is to let the global interrupt handlers call
(conditionally) into the fine-grained handlers. In pseudo-code:
global_interrupt_handler()
{
if (...)
fine_grained_handler1();
if (...)
fine_grained_handler2();
...
}
On R-Car Gen3, you register the global interrupt handlers, as before.
On RZ/G2L, you register the fine-grained interrupt handlers instead.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds