On 05/07/2024 19:41, Mark Brown wrote:
+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).
Oops. Fixed, sorry.
+++ 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.
I've never seen that in kernel code, but sure changed it.
+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?
Explicitly ignoring errors from usb_bulk_msg() as ->set_cs() can't really handle error returns.
I've changed it to an error print.
+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?
TBH I haven't found a command that reads the current settings of the device.
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