On Fri, Jul 05, 2024 at 04:51:37PM +0200, Johannes Thumshirn wrote:
> --- a/drivers/spi/Kconfig
> +++ b/drivers/spi/Kconfig
> @@ -1198,6 +1198,12 @@ config SPI_AMD
> help
> Enables SPI controller driver for AMD SoC.
>
> +config SPI_CH341
> + tristate "CH341 USB2SPI adapter"
> + depends on SPI_MASTER && USB
> + help
> + Enables the SPI controller on the CH341a USB to serial chip
> +
> #
> # Add new SPI master controllers in alphabetical order above this line
> #
Like the comment says please keep these files sorted (I appreciate
there's some things been missed).
> +++ b/drivers/spi/spi-ch341.c
> @@ -0,0 +1,236 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * QiHeng Electronics ch341a USB-to-SPI adapter driver
> + *
> + * Copyright (C) 2024 Johannes Thumshirn <jth@xxxxxxxxxx>
Please make the entire comment block a C++ one so things look clearer.
> +static void ch341_set_cs(struct spi_device *spi, bool is_high)
> +{
> + struct ch341_spi_dev *ch341 =
> + spi_controller_get_devdata(spi->controller);
> +
> + memset(ch341->tx_buf, 0, CH341_PACKET_LENGTH);
> + ch341->tx_buf[0] = CH341A_CMD_UIO_STREAM;
> + ch341->tx_buf[1] = CH341A_CMD_UIO_STM_OUT | (is_high ? 0x36 : 0x37);
> +
> + if (is_high) {
> + ch341->tx_buf[2] = CH341A_CMD_UIO_STM_DIR | 0x3f;
> + ch341->tx_buf[3] = CH341A_CMD_UIO_STM_END;
> + } else {
> + ch341->tx_buf[2] = CH341A_CMD_UIO_STM_END;
> + }
> +
> + (void)usb_bulk_msg(ch341->udev, ch341->write_pipe, ch341->tx_buf,
> + (is_high ? 4 : 3), NULL, CH341_DEFAULT_TIMEOUT);
The cast to void here is very suspicious, what's it doing?
> +static int ch341_config_stream(struct ch341_spi_dev *ch341, int speed)
> +{
> + memset(ch341->tx_buf, 0, CH341_PACKET_LENGTH);
> + ch341->tx_buf[0] = CH341A_CMD_I2C_STREAM;
> + ch341->tx_buf[1] = CH341A_CMD_I2C_STM_SET | (speed & 0x7);
> + ch341->tx_buf[2] = CH341A_CMD_I2C_STM_END;
> +
> + return usb_bulk_msg(ch341->udev, ch341->write_pipe, ch341->tx_buf, 3,
> + NULL, CH341_DEFAULT_TIMEOUT);
No validation of speed?
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