242 lines · c
1// SPDX-License-Identifier: GPL-2.02//3// QiHeng Electronics ch341a USB-to-SPI adapter driver4//5// Copyright (C) 2024 Johannes Thumshirn <jth@kernel.org>6//7// Based on ch341a_spi.c from the flashrom project.8 9#include <linux/module.h>10#include <linux/usb.h>11#include <linux/spi/spi.h>12 13#define CH341_PACKET_LENGTH 3214#define CH341_DEFAULT_TIMEOUT 100015 16#define CH341A_CMD_UIO_STREAM 0xab17 18#define CH341A_CMD_UIO_STM_END 0x2019#define CH341A_CMD_UIO_STM_DIR 0x4020#define CH341A_CMD_UIO_STM_OUT 0x8021 22#define CH341A_CMD_I2C_STREAM 0xaa23#define CH341A_CMD_I2C_STM_SET 0x6024#define CH341A_CMD_I2C_STM_END 0x0025 26#define CH341A_CMD_SPI_STREAM 0xa827 28#define CH341A_STM_I2C_100K 0x0129 30struct ch341_spi_dev {31 struct spi_controller *ctrl;32 struct usb_device *udev;33 unsigned int write_pipe;34 unsigned int read_pipe;35 int rx_len;36 void *rx_buf;37 u8 *tx_buf;38 struct urb *rx_urb;39 struct spi_device *spidev;40};41 42static void ch341_set_cs(struct spi_device *spi, bool is_high)43{44 struct ch341_spi_dev *ch341 =45 spi_controller_get_devdata(spi->controller);46 int err;47 48 memset(ch341->tx_buf, 0, CH341_PACKET_LENGTH);49 ch341->tx_buf[0] = CH341A_CMD_UIO_STREAM;50 ch341->tx_buf[1] = CH341A_CMD_UIO_STM_OUT | (is_high ? 0x36 : 0x37);51 52 if (is_high) {53 ch341->tx_buf[2] = CH341A_CMD_UIO_STM_DIR | 0x3f;54 ch341->tx_buf[3] = CH341A_CMD_UIO_STM_END;55 } else {56 ch341->tx_buf[2] = CH341A_CMD_UIO_STM_END;57 }58 59 err = usb_bulk_msg(ch341->udev, ch341->write_pipe, ch341->tx_buf,60 (is_high ? 4 : 3), NULL, CH341_DEFAULT_TIMEOUT);61 if (err)62 dev_err(&spi->dev,63 "error sending USB message for setting CS (%d)\n", err);64}65 66static int ch341_transfer_one(struct spi_controller *host,67 struct spi_device *spi,68 struct spi_transfer *trans)69{70 struct ch341_spi_dev *ch341 =71 spi_controller_get_devdata(spi->controller);72 int len;73 int ret;74 75 len = min(CH341_PACKET_LENGTH, trans->len + 1);76 77 memset(ch341->tx_buf, 0, CH341_PACKET_LENGTH);78 79 ch341->tx_buf[0] = CH341A_CMD_SPI_STREAM;80 81 memcpy(ch341->tx_buf + 1, trans->tx_buf, len);82 83 ret = usb_bulk_msg(ch341->udev, ch341->write_pipe, ch341->tx_buf, len,84 NULL, CH341_DEFAULT_TIMEOUT);85 if (ret)86 return ret;87 88 return usb_bulk_msg(ch341->udev, ch341->read_pipe, trans->rx_buf,89 len - 1, NULL, CH341_DEFAULT_TIMEOUT);90}91 92static void ch341_recv(struct urb *urb)93{94 struct ch341_spi_dev *ch341 = urb->context;95 struct usb_device *udev = ch341->udev;96 97 switch (urb->status) {98 case 0:99 /* success */100 break;101 case -ENOENT:102 case -ECONNRESET:103 case -EPIPE:104 case -ESHUTDOWN:105 dev_dbg(&udev->dev, "rx urb terminated with status: %d\n",106 urb->status);107 return;108 default:109 dev_dbg(&udev->dev, "rx urb error: %d\n", urb->status);110 break;111 }112}113 114static int ch341_config_stream(struct ch341_spi_dev *ch341)115{116 memset(ch341->tx_buf, 0, CH341_PACKET_LENGTH);117 ch341->tx_buf[0] = CH341A_CMD_I2C_STREAM;118 ch341->tx_buf[1] = CH341A_CMD_I2C_STM_SET | CH341A_STM_I2C_100K;119 ch341->tx_buf[2] = CH341A_CMD_I2C_STM_END;120 121 return usb_bulk_msg(ch341->udev, ch341->write_pipe, ch341->tx_buf, 3,122 NULL, CH341_DEFAULT_TIMEOUT);123}124 125static int ch341_enable_pins(struct ch341_spi_dev *ch341, bool enable)126{127 memset(ch341->tx_buf, 0, CH341_PACKET_LENGTH);128 ch341->tx_buf[0] = CH341A_CMD_UIO_STREAM;129 ch341->tx_buf[1] = CH341A_CMD_UIO_STM_OUT | 0x37;130 ch341->tx_buf[2] = CH341A_CMD_UIO_STM_DIR | (enable ? 0x3f : 0x00);131 ch341->tx_buf[3] = CH341A_CMD_UIO_STM_END;132 133 return usb_bulk_msg(ch341->udev, ch341->write_pipe, ch341->tx_buf, 4,134 NULL, CH341_DEFAULT_TIMEOUT);135}136 137static struct spi_board_info chip = {138 .modalias = "spi-ch341a",139};140 141static int ch341_probe(struct usb_interface *intf,142 const struct usb_device_id *id)143{144 struct usb_device *udev = interface_to_usbdev(intf);145 struct usb_endpoint_descriptor *in, *out;146 struct ch341_spi_dev *ch341;147 struct spi_controller *ctrl;148 int ret;149 150 ret = usb_find_common_endpoints(intf->cur_altsetting, &in, &out, NULL,151 NULL);152 if (ret)153 return ret;154 155 ctrl = devm_spi_alloc_master(&udev->dev, sizeof(struct ch341_spi_dev));156 if (!ctrl)157 return -ENOMEM;158 159 ch341 = spi_controller_get_devdata(ctrl);160 ch341->ctrl = ctrl;161 ch341->udev = udev;162 ch341->write_pipe = usb_sndbulkpipe(udev, usb_endpoint_num(out));163 ch341->read_pipe = usb_rcvbulkpipe(udev, usb_endpoint_num(in));164 165 ch341->rx_len = usb_endpoint_maxp(in);166 ch341->rx_buf = devm_kzalloc(&udev->dev, ch341->rx_len, GFP_KERNEL);167 if (!ch341->rx_buf)168 return -ENOMEM;169 170 ch341->rx_urb = usb_alloc_urb(0, GFP_KERNEL);171 if (!ch341->rx_urb)172 return -ENOMEM;173 174 ch341->tx_buf =175 devm_kzalloc(&udev->dev, CH341_PACKET_LENGTH, GFP_KERNEL);176 if (!ch341->tx_buf)177 return -ENOMEM;178 179 usb_fill_bulk_urb(ch341->rx_urb, udev, ch341->read_pipe, ch341->rx_buf,180 ch341->rx_len, ch341_recv, ch341);181 182 ret = usb_submit_urb(ch341->rx_urb, GFP_KERNEL);183 if (ret) {184 usb_free_urb(ch341->rx_urb);185 return -ENOMEM;186 }187 188 ctrl->bus_num = -1;189 ctrl->mode_bits = SPI_CPHA;190 ctrl->transfer_one = ch341_transfer_one;191 ctrl->set_cs = ch341_set_cs;192 ctrl->auto_runtime_pm = false;193 194 usb_set_intfdata(intf, ch341);195 196 ret = ch341_config_stream(ch341);197 if (ret)198 return ret;199 200 ret = ch341_enable_pins(ch341, true);201 if (ret)202 return ret;203 204 ret = spi_register_controller(ctrl);205 if (ret)206 return ret;207 208 ch341->spidev = spi_new_device(ctrl, &chip);209 if (!ch341->spidev)210 return -ENOMEM;211 212 return 0;213}214 215static void ch341_disconnect(struct usb_interface *intf)216{217 struct ch341_spi_dev *ch341 = usb_get_intfdata(intf);218 219 spi_unregister_device(ch341->spidev);220 spi_unregister_controller(ch341->ctrl);221 ch341_enable_pins(ch341, false);222 usb_free_urb(ch341->rx_urb);223}224 225static const struct usb_device_id ch341_id_table[] = {226 { USB_DEVICE(0x1a86, 0x5512) },227 { }228};229MODULE_DEVICE_TABLE(usb, ch341_id_table);230 231static struct usb_driver ch341a_usb_driver = {232 .name = "spi-ch341",233 .probe = ch341_probe,234 .disconnect = ch341_disconnect,235 .id_table = ch341_id_table,236};237module_usb_driver(ch341a_usb_driver);238 239MODULE_AUTHOR("Johannes Thumshirn <jth@kernel.org>");240MODULE_DESCRIPTION("QiHeng Electronics ch341 USB2SPI");241MODULE_LICENSE("GPL v2");242