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Diffstat (limited to 'drivers/spi/spi-ch341.c')
-rw-r--r--drivers/spi/spi-ch341.c241
1 files changed, 241 insertions, 0 deletions
diff --git a/drivers/spi/spi-ch341.c b/drivers/spi/spi-ch341.c
new file mode 100644
index 000000000000..d2351812d310
--- /dev/null
+++ b/drivers/spi/spi-ch341.c
@@ -0,0 +1,241 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// QiHeng Electronics ch341a USB-to-SPI adapter driver
+//
+// Copyright (C) 2024 Johannes Thumshirn <jth@kernel.org>
+//
+// Based on ch341a_spi.c from the flashrom project.
+
+#include <linux/module.h>
+#include <linux/usb.h>
+#include <linux/spi/spi.h>
+
+#define CH341_PACKET_LENGTH 32
+#define CH341_DEFAULT_TIMEOUT 1000
+
+#define CH341A_CMD_UIO_STREAM 0xab
+
+#define CH341A_CMD_UIO_STM_END 0x20
+#define CH341A_CMD_UIO_STM_DIR 0x40
+#define CH341A_CMD_UIO_STM_OUT 0x80
+
+#define CH341A_CMD_I2C_STREAM 0xaa
+#define CH341A_CMD_I2C_STM_SET 0x60
+#define CH341A_CMD_I2C_STM_END 0x00
+
+#define CH341A_CMD_SPI_STREAM 0xa8
+
+#define CH341A_STM_I2C_100K 0x01
+
+struct ch341_spi_dev {
+ struct spi_controller *ctrl;
+ struct usb_device *udev;
+ unsigned int write_pipe;
+ unsigned int read_pipe;
+ int rx_len;
+ void *rx_buf;
+ u8 *tx_buf;
+ struct urb *rx_urb;
+ struct spi_device *spidev;
+};
+
+static void ch341_set_cs(struct spi_device *spi, bool is_high)
+{
+ struct ch341_spi_dev *ch341 =
+ spi_controller_get_devdata(spi->controller);
+ int err;
+
+ 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;
+ }
+
+ err = usb_bulk_msg(ch341->udev, ch341->write_pipe, ch341->tx_buf,
+ (is_high ? 4 : 3), NULL, CH341_DEFAULT_TIMEOUT);
+ if (err)
+ dev_err(&spi->dev,
+ "error sending USB message for setting CS (%d)\n", err);
+}
+
+static int ch341_transfer_one(struct spi_controller *host,
+ struct spi_device *spi,
+ struct spi_transfer *trans)
+{
+ struct ch341_spi_dev *ch341 =
+ spi_controller_get_devdata(spi->controller);
+ int len;
+ int ret;
+
+ len = min(CH341_PACKET_LENGTH, trans->len + 1);
+
+ memset(ch341->tx_buf, 0, CH341_PACKET_LENGTH);
+
+ ch341->tx_buf[0] = CH341A_CMD_SPI_STREAM;
+
+ memcpy(ch341->tx_buf + 1, trans->tx_buf, len);
+
+ ret = usb_bulk_msg(ch341->udev, ch341->write_pipe, ch341->tx_buf, len,
+ NULL, CH341_DEFAULT_TIMEOUT);
+ if (ret)
+ return ret;
+
+ return usb_bulk_msg(ch341->udev, ch341->read_pipe, trans->rx_buf,
+ len - 1, NULL, CH341_DEFAULT_TIMEOUT);
+}
+
+static void ch341_recv(struct urb *urb)
+{
+ struct ch341_spi_dev *ch341 = urb->context;
+ struct usb_device *udev = ch341->udev;
+
+ switch (urb->status) {
+ case 0:
+ /* success */
+ break;
+ case -ENOENT:
+ case -ECONNRESET:
+ case -EPIPE:
+ case -ESHUTDOWN:
+ dev_dbg(&udev->dev, "rx urb terminated with status: %d\n",
+ urb->status);
+ return;
+ default:
+ dev_dbg(&udev->dev, "rx urb error: %d\n", urb->status);
+ break;
+ }
+}
+
+static int ch341_config_stream(struct ch341_spi_dev *ch341)
+{
+ 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 | CH341A_STM_I2C_100K;
+ 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);
+}
+
+static int ch341_enable_pins(struct ch341_spi_dev *ch341, bool enable)
+{
+ 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 | 0x37;
+ ch341->tx_buf[2] = CH341A_CMD_UIO_STM_DIR | (enable ? 0x3f : 0x00);
+ ch341->tx_buf[3] = CH341A_CMD_UIO_STM_END;
+
+ return usb_bulk_msg(ch341->udev, ch341->write_pipe, ch341->tx_buf, 4,
+ NULL, CH341_DEFAULT_TIMEOUT);
+}
+
+static struct spi_board_info chip = {
+ .modalias = "spi-ch341a",
+};
+
+static int ch341_probe(struct usb_interface *intf,
+ const struct usb_device_id *id)
+{
+ struct usb_device *udev = interface_to_usbdev(intf);
+ struct usb_endpoint_descriptor *in, *out;
+ struct ch341_spi_dev *ch341;
+ struct spi_controller *ctrl;
+ int ret;
+
+ ret = usb_find_common_endpoints(intf->cur_altsetting, &in, &out, NULL,
+ NULL);
+ if (ret)
+ return ret;
+
+ ctrl = devm_spi_alloc_master(&udev->dev, sizeof(struct ch341_spi_dev));
+ if (!ctrl)
+ return -ENOMEM;
+
+ ch341 = spi_controller_get_devdata(ctrl);
+ ch341->ctrl = ctrl;
+ ch341->udev = udev;
+ ch341->write_pipe = usb_sndbulkpipe(udev, usb_endpoint_num(out));
+ ch341->read_pipe = usb_rcvbulkpipe(udev, usb_endpoint_num(in));
+
+ ch341->rx_len = usb_endpoint_maxp(in);
+ ch341->rx_buf = devm_kzalloc(&udev->dev, ch341->rx_len, GFP_KERNEL);
+ if (!ch341->rx_buf)
+ return -ENOMEM;
+
+ ch341->rx_urb = usb_alloc_urb(0, GFP_KERNEL);
+ if (!ch341->rx_urb)
+ return -ENOMEM;
+
+ ch341->tx_buf =
+ devm_kzalloc(&udev->dev, CH341_PACKET_LENGTH, GFP_KERNEL);
+ if (!ch341->tx_buf)
+ return -ENOMEM;
+
+ usb_fill_bulk_urb(ch341->rx_urb, udev, ch341->read_pipe, ch341->rx_buf,
+ ch341->rx_len, ch341_recv, ch341);
+
+ ret = usb_submit_urb(ch341->rx_urb, GFP_KERNEL);
+ if (ret) {
+ usb_free_urb(ch341->rx_urb);
+ return -ENOMEM;
+ }
+
+ ctrl->bus_num = -1;
+ ctrl->mode_bits = SPI_CPHA;
+ ctrl->transfer_one = ch341_transfer_one;
+ ctrl->set_cs = ch341_set_cs;
+ ctrl->auto_runtime_pm = false;
+
+ usb_set_intfdata(intf, ch341);
+
+ ret = ch341_config_stream(ch341);
+ if (ret)
+ return ret;
+
+ ret = ch341_enable_pins(ch341, true);
+ if (ret)
+ return ret;
+
+ ret = spi_register_controller(ctrl);
+ if (ret)
+ return ret;
+
+ ch341->spidev = spi_new_device(ctrl, &chip);
+ if (!ch341->spidev)
+ return -ENOMEM;
+
+ return 0;
+}
+
+static void ch341_disconnect(struct usb_interface *intf)
+{
+ struct ch341_spi_dev *ch341 = usb_get_intfdata(intf);
+
+ spi_unregister_device(ch341->spidev);
+ spi_unregister_controller(ch341->ctrl);
+ ch341_enable_pins(ch341, false);
+ usb_free_urb(ch341->rx_urb);
+}
+
+static const struct usb_device_id ch341_id_table[] = {
+ { USB_DEVICE(0x1a86, 0x5512) },
+ { }
+};
+MODULE_DEVICE_TABLE(usb, ch341_id_table);
+
+static struct usb_driver ch341a_usb_driver = {
+ .name = "spi-ch341",
+ .probe = ch341_probe,
+ .disconnect = ch341_disconnect,
+ .id_table = ch341_id_table,
+};
+module_usb_driver(ch341a_usb_driver);
+
+MODULE_AUTHOR("Johannes Thumshirn <jth@kernel.org>");
+MODULE_DESCRIPTION("QiHeng Electronics ch341 USB2SPI");
+MODULE_LICENSE("GPL v2");
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-22 09:11:58 +0000