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Date:   Mon, 1 Aug 2022 09:24:49 +0200
From:   Daniel =?iso-8859-1?Q?Gl=F6ckner?= <dg@emlix.com>
To:     Ivan Bornyakov <i.bornyakov@metrotek.ru>
Cc:     mdf@kernel.org, hao.wu@intel.com, yilun.xu@intel.com,
        trix@redhat.com, robh+dt@kernel.org,
        krzysztof.kozlowski+dt@linaro.org, linux-fpga@vger.kernel.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
        system@metrotek.ru
Subject: Re: [PATCH v5 1/2] fpga: ecp5-spi: add Lattice ECP5 FPGA manager
Message-ID: <20220801072448.GA11993@homes.emlix.com>
References: <20220719112335.9528-1-i.bornyakov@metrotek.ru>
 <20220719112335.9528-2-i.bornyakov@metrotek.ru>
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In-Reply-To: <20220719112335.9528-2-i.bornyakov@metrotek.ru>
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Hi,

On Tue, Jul 19, 2022 at 02:23:34PM +0300, Ivan Bornyakov wrote:
> +	/* Enter init mode */
> +	gpiod_set_value(priv->program, 1);
> +
> +	ret = ecp5_poll_gpio(priv->init, true);
> +	if (!ret)
> +		ret = ecp5_poll_gpio(priv->done, false);
> +
> +	if (ret) {
> +		dev_err(dev, "Failed to go to initialization mode\n");
> +		return ret;
> +	}

To me the documentation looks like the chip will deassert INITN after
tINITL regardless of the PROGRAMN signal. At 55ns max tINITL is too
short to reliably sample INITN while it is asserted when we have
interrupts enabled. Can you confirm that INITN stays asserted as long
as PROGRAMN is asserted?

Best regards,

  Daniel