linux-kernel - Re: [PATCH v2 2/9] spi: stm32: Add OSPI driver

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <ec35dbd3-5730-4cc8-8025-d349740d1ba5@sirena.org.uk>
Date: Tue, 28 Jan 2025 12:37:19 +0000
From: Mark Brown <broonie@...nel.org>
To: patrice.chotard@...s.st.com
Cc: Rob Herring <robh@...nel.org>, Krzysztof Kozlowski <krzk+dt@...nel.org>,
	Conor Dooley <conor+dt@...nel.org>,
	Alexandre Torgue <alexandre.torgue@...s.st.com>,
	Philipp Zabel <p.zabel@...gutronix.de>,
	Maxime Coquelin <mcoquelin.stm32@...il.com>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Arnd Bergmann <arnd@...db.de>,
	Catalin Marinas <catalin.marinas@....com>,
	Will Deacon <will@...nel.org>, linux-spi@...r.kernel.org,
	devicetree@...r.kernel.org,
	linux-stm32@...md-mailman.stormreply.com,
	linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
	christophe.kerello@...s.st.com
Subject: Re: [PATCH v2 2/9] spi: stm32: Add OSPI driver

On Tue, Jan 28, 2025 at 09:17:24AM +0100, patrice.chotard@...s.st.com wrote:

> +static int stm32_ospi_tx_poll(struct stm32_ospi *ospi, u8 *buf, u32 len, bool read)
> +{

> +	if (read)
> +		tx_fifo = stm32_ospi_read_fifo;
> +	else
> +		tx_fifo = stm32_ospi_write_fifo;

> +		tx_fifo(buf++, regs_base + OSPI_DR);

It feels like the _tx_poll and tx_fifo naming is a landmine waiting to
surprise people in the future.  The code sharing makes sense but the
naming is just looking to cause surprises, especially with it just being
a bool selecting read or write.

> +static int stm32_ospi_tx(struct stm32_ospi *ospi, const struct spi_mem_op *op)
> +{

> +       return stm32_ospi_tx_poll(ospi, buf, op->data.nbytes,
> +                                op->data.dir == SPI_MEM_DATA_IN);

Though the one caller is also using _tx only naming, it's a bit more
tied in with the op sending though.

> +	ctrl->mode_bits = SPI_RX_DUAL | SPI_RX_QUAD |
> +			  SPI_TX_DUAL | SPI_TX_QUAD |
> +			  SPI_TX_OCTAL | SPI_RX_OCTAL;
> +	ctrl->setup = stm32_ospi_setup;
> +	ctrl->bus_num = -1;
> +	ctrl->mem_ops = &stm32_ospi_mem_ops;
> +	ctrl->use_gpio_descriptors = true;
> +	ctrl->transfer_one_message = stm32_ospi_transfer_one_message;
> +	ctrl->num_chipselect = STM32_OSPI_MAX_NORCHIP;
> +	ctrl->dev.of_node = dev->of_node;

It looks like the controller only does half duplex as well so it should
set SPI_CONTROLLER_HALF_DUPLEX.

Download attachment "signature.asc" of type "application/pgp-signature" (489 bytes)