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Date:   Sat, 27 Aug 2022 01:12:33 +0300
From:   Serge Semin <fancer.lancer@gmail.com>
To:     Sudip Mukherjee <sudip.mukherjee@sifive.com>
Cc:     Serge Semin <Sergey.Semin@baikalelectronics.ru>,
        Mark Brown <broonie@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        greentime.hu@sifive.com, jude.onyenegecha@sifive.com,
        william.salmon@sifive.com, adnan.chowdhury@sifive.com,
        ben.dooks@sifive.com, linux-spi@vger.kernel.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
        jeegar.lakhani@sifive.com
Subject: Re: [PATCH 04/11] spi: dw: use TMOD_RO to read in enhanced spi modes
Message-ID: <20220826221233.3czezp7rcvk4ya6u@mobilestation>
References: <20220802175755.6530-1-sudip.mukherjee@sifive.com>
 <20220802175755.6530-5-sudip.mukherjee@sifive.com>
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On Tue, Aug 02, 2022 at 06:57:48PM +0100, Sudip Mukherjee wrote:
> When we are using the enhanced spi modes we can not use EEPROM Read.
> The Synopsys datasheet mentions EEPROM Read is not applicable in
> enhanced SPI modes. We will need to use Receive only mode.
> 
> Signed-off-by: Sudip Mukherjee <sudip.mukherjee@sifive.com>
> ---
>  drivers/spi/spi-dw-core.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/spi/spi-dw-core.c b/drivers/spi/spi-dw-core.c
> index 8c84a2e991b5..8e624620864f 100644
> --- a/drivers/spi/spi-dw-core.c
> +++ b/drivers/spi/spi-dw-core.c
> @@ -727,7 +727,10 @@ static int dw_spi_exec_mem_op(struct spi_mem *mem, const struct spi_mem_op *op)
>  	cfg.dfs = 8;
>  	cfg.freq = clamp(mem->spi->max_speed_hz, 0U, dws->max_mem_freq);
>  	if (op->data.dir == SPI_MEM_DATA_IN) {
> -		cfg.tmode = DW_SPI_CTRLR0_TMOD_EPROMREAD;

> +		if (enhanced_spi)
> +			cfg.tmode = DW_SPI_CTRLR0_TMOD_RO;
> +		else
> +			cfg.tmode = DW_SPI_CTRLR0_TMOD_EPROMREAD;

Just drop this modification and initialize the dw_spi_cfg structure
from scratch in the Enhanced SPI-specific method:
dw_spi_exec_enh_mem_op().

-Sergey

>  		cfg.ndf = op->data.nbytes;
>  	} else {
>  		cfg.tmode = DW_SPI_CTRLR0_TMOD_TO;
> -- 
> 2.30.2
>