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Message-ID: <0c0d1b2030960cdc2840d84645538fe3a9c8b9a6.camel@gmail.com>
Subject: Re: [PATCH v3 2/6] spi: bitbang: Implement support for MOSI idle
 state configuration
From: Nuno =?ISO-8859-1?Q?S=E1?= <noname.nuno@gmail.com>
To: Marcelo Schmitt <marcelo.schmitt@analog.com>, broonie@kernel.org, 
 lars@metafoo.de, Michael.Hennerich@analog.com, jic23@kernel.org, 
 robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org, conor+dt@kernel.org,
  nuno.sa@analog.com, dlechner@baylibre.com, marcelo.schmitt1@gmail.com
Cc: linux-iio@vger.kernel.org, devicetree@vger.kernel.org, 
	linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org
Date: Wed, 05 Jun 2024 11:30:35 +0200
In-Reply-To: <811a2771d93c16b48fb37286e648a03171c8d2bc.1717539384.git.marcelo.schmitt@analog.com>
References: <cover.1717539384.git.marcelo.schmitt@analog.com>
	 <811a2771d93c16b48fb37286e648a03171c8d2bc.1717539384.git.marcelo.schmitt@analog.com>
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On Tue, 2024-06-04 at 19:42 -0300, Marcelo Schmitt wrote:
> Some SPI peripherals may require strict MOSI line state when the controll=
er
> is not clocking out data.
> Implement support for MOSI idle state configuration (low or high) by
> setting the data output line level on controller setup and after transfer=
s.
> Bitbang operations now call controller specific set_mosi_idle() call back
> to set MOSI to its idle state.
> The MOSI line is kept at its idle state if no tx buffer is provided.
>=20
> Signed-off-by: Marcelo Schmitt <marcelo.schmitt@analog.com>
> ---

Some minor nit below in case a re-spin is needed. Anyways,

Acked-by: Nuno Sa <nuno.sa@analog.com>

> =C2=A0drivers/spi/spi-bitbang.c=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 | 24 =
++++++++++++++++++++++++
> =C2=A0include/linux/spi/spi_bitbang.h |=C2=A0 1 +
> =C2=A02 files changed, 25 insertions(+)
>=20
> diff --git a/drivers/spi/spi-bitbang.c b/drivers/spi/spi-bitbang.c
> index ca5cc67555c5..3dee085d3570 100644
> --- a/drivers/spi/spi-bitbang.c
> +++ b/drivers/spi/spi-bitbang.c
> @@ -63,21 +63,28 @@ static unsigned bitbang_txrx_8(
> =C2=A0	unsigned flags
> =C2=A0)
> =C2=A0{
> +	struct spi_bitbang	*bitbang;
> =C2=A0	unsigned		bits =3D t->bits_per_word;
> =C2=A0	unsigned		count =3D t->len;
> =C2=A0	const u8		*tx =3D t->tx_buf;
> =C2=A0	u8			*rx =3D t->rx_buf;
> =C2=A0
> +	bitbang =3D spi_controller_get_devdata(spi->controller);
> =C2=A0	while (likely(count > 0)) {
> =C2=A0		u8		word =3D 0;
> =C2=A0
> =C2=A0		if (tx)
> =C2=A0			word =3D *tx++;
> +		else
> +			word =3D (spi->mode & SPI_MOSI_IDLE_HIGH) ? 0xFF : 0;

no need for ()

> =C2=A0		word =3D txrx_word(spi, ns, word, bits, flags);
> =C2=A0		if (rx)
> =C2=A0			*rx++ =3D word;
> =C2=A0		count -=3D 1;
> =C2=A0	}
> +	if (bitbang->set_mosi_idle)
> +		bitbang->set_mosi_idle(spi);
> +
> =C2=A0	return t->len - count;
> =C2=A0}
> =C2=A0
> @@ -92,21 +99,28 @@ static unsigned bitbang_txrx_16(
> =C2=A0	unsigned flags
> =C2=A0)
> =C2=A0{
> +	struct spi_bitbang	*bitbang;
> =C2=A0	unsigned		bits =3D t->bits_per_word;
> =C2=A0	unsigned		count =3D t->len;
> =C2=A0	const u16		*tx =3D t->tx_buf;
> =C2=A0	u16			*rx =3D t->rx_buf;
> =C2=A0
> +	bitbang =3D spi_controller_get_devdata(spi->controller);
> =C2=A0	while (likely(count > 1)) {
> =C2=A0		u16		word =3D 0;
> =C2=A0
> =C2=A0		if (tx)
> =C2=A0			word =3D *tx++;
> +		else
> +			word =3D (spi->mode & SPI_MOSI_IDLE_HIGH) ? 0xFFFF : 0;

ditto (and for the txrx8 function)


- Nuno S=C3=A1