From: Peter Korsgaard <peter@korsgaard.com>
To: Sagar Shrikant Kadam <sagar.kadam@sifive.com>
Cc: andrew@lunn.ch, aou@eecs.berkeley.edu,
linux-kernel@vger.kernel.org, palmer@dabbelt.com,
linux-i2c@vger.kernel.org, paul.walmsley@sifive.com,
linux-riscv@lists.infradead.org
Subject: Re: [PATCH 1/1] i2c: ocores: fix polling mode workaround on FU540-C000 SoC
Date: Wed, 07 Oct 2020 13:40:26 +0200 [thread overview]
Message-ID: <87imbm4639.fsf@dell.be.48ers.dk> (raw)
In-Reply-To: <1602006796-273724-2-git-send-email-sagar.kadam@sifive.com> (Sagar Shrikant Kadam's message of "Tue, 6 Oct 2020 10:53:16 -0700")
>>>>> "Sagar" == Sagar Shrikant Kadam <sagar.kadam@sifive.com> writes:
> The FU540-C000 has a broken IRQ and support was added earlier
> so that it will operate in polling mode, but seems to work only
> in case interrupts property is missing from the i2c0 dt-node.
> This should not be the case and the driver should handle polling
> mode with the interrupt property present in i2c0 node of the
> device tree.
> So check if it's the FU540-C000 soc and enable polling mode master
> xfers, as the IRQ for this chip is broken.
> Fixes commit c45d4ba86731 ("i2c: ocores: add polling mode workaround
> for Sifive FU540-C000 SoC")
> Signed-off-by: Sagar Shrikant Kadam <sagar.kadam@sifive.com>
> ---
> drivers/i2c/busses/i2c-ocores.c | 22 +++++++++++++---------
> 1 file changed, 13 insertions(+), 9 deletions(-)
> diff --git a/drivers/i2c/busses/i2c-ocores.c b/drivers/i2c/busses/i2c-ocores.c
> index f5fc75b..4405244 100644
> --- a/drivers/i2c/busses/i2c-ocores.c
> +++ b/drivers/i2c/busses/i2c-ocores.c
> @@ -686,17 +686,21 @@ static int ocores_i2c_probe(struct platform_device *pdev)
> init_waitqueue_head(&i2c->wait);
> + /*
> + * Set OCORES_FLAG_BROKEN_IRQ to enable workaround for
> + * FU540-C000 SoC in polling mode.
> + * Since the SoC does have interrupt it's dt has the interrupt
> + * defined but it should be bypassed in driver as this SoC has
> + * a broken IRQ, hence update the master_xfer to use polling
> + * transfers.
> + */
> + match = of_match_node(ocores_i2c_match, pdev->dev.of_node);
> + if (match && (long)match->data == TYPE_SIFIVE_REV0)
> + i2c->flags |= OCORES_FLAG_BROKEN_IRQ;
> +
> irq = platform_get_irq(pdev, 0);
> - if (irq == -ENXIO) {
> + if (i2c->flags == OCORES_FLAG_BROKEN_IRQ || irq == -ENXIO) {
NIT: flags is a bitmask, so i2c->flags & OCORES_FLAG_BROKEN_IRQ would be
better, even if there currently doesn't exist any other flags.
TYPE_SIFIVE_REV0 is also set for two compatibles:
{
.compatible = "sifive,fu540-c000-i2c",
.data = (void *)TYPE_SIFIVE_REV0,
},
{
.compatible = "sifive,i2c0",
.data = (void *)TYPE_SIFIVE_REV0,
},
Are both affected by this issue? if not, we will need to extend the code
to handle them differently.
Other than that, it looks OK to me.
--
Bye, Peter Korsgaard
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next prev parent reply other threads:[~2020-10-07 11:40 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-06 17:53 [PATCH 0/1] fix i2c polling mode workaround for FU540-C000 SoC Sagar Shrikant Kadam
2020-10-06 17:53 ` [PATCH 1/1] i2c: ocores: fix polling mode workaround on " Sagar Shrikant Kadam
2020-10-07 11:40 ` Peter Korsgaard [this message]
2020-10-08 13:53 ` Sagar Kadam
2020-10-08 16:05 ` Peter Korsgaard
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