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877 lines
22 KiB
877 lines
22 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Copyright 2007, Frank A Kingswood <[email protected]> |
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* Copyright 2007, Werner Cornelius <[email protected]> |
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* Copyright 2009, Boris Hajduk <[email protected]> |
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* |
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* ch341.c implements a serial port driver for the Winchiphead CH341. |
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* |
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* The CH341 device can be used to implement an RS232 asynchronous |
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* serial port, an IEEE-1284 parallel printer port or a memory-like |
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* interface. In all cases the CH341 supports an I2C interface as well. |
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* This driver only supports the asynchronous serial interface. |
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*/ |
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|
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#include <linux/kernel.h> |
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#include <linux/tty.h> |
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#include <linux/module.h> |
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#include <linux/slab.h> |
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#include <linux/usb.h> |
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#include <linux/usb/serial.h> |
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#include <linux/serial.h> |
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#include <asm/unaligned.h> |
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|
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#define DEFAULT_BAUD_RATE 9600 |
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#define DEFAULT_TIMEOUT 1000 |
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|
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/* flags for IO-Bits */ |
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#define CH341_BIT_RTS (1 << 6) |
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#define CH341_BIT_DTR (1 << 5) |
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|
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/******************************/ |
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/* interrupt pipe definitions */ |
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/******************************/ |
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/* always 4 interrupt bytes */ |
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/* first irq byte normally 0x08 */ |
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/* second irq byte base 0x7d + below */ |
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/* third irq byte base 0x94 + below */ |
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/* fourth irq byte normally 0xee */ |
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|
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/* second interrupt byte */ |
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#define CH341_MULT_STAT 0x04 /* multiple status since last interrupt event */ |
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|
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/* status returned in third interrupt answer byte, inverted in data |
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from irq */ |
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#define CH341_BIT_CTS 0x01 |
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#define CH341_BIT_DSR 0x02 |
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#define CH341_BIT_RI 0x04 |
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#define CH341_BIT_DCD 0x08 |
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#define CH341_BITS_MODEM_STAT 0x0f /* all bits */ |
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|
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/* Break support - the information used to implement this was gleaned from |
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* the Net/FreeBSD uchcom.c driver by Takanori Watanabe. Domo arigato. |
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*/ |
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|
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#define CH341_REQ_READ_VERSION 0x5F |
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#define CH341_REQ_WRITE_REG 0x9A |
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#define CH341_REQ_READ_REG 0x95 |
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#define CH341_REQ_SERIAL_INIT 0xA1 |
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#define CH341_REQ_MODEM_CTRL 0xA4 |
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|
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#define CH341_REG_BREAK 0x05 |
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#define CH341_REG_PRESCALER 0x12 |
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#define CH341_REG_DIVISOR 0x13 |
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#define CH341_REG_LCR 0x18 |
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#define CH341_REG_LCR2 0x25 |
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|
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#define CH341_NBREAK_BITS 0x01 |
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|
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#define CH341_LCR_ENABLE_RX 0x80 |
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#define CH341_LCR_ENABLE_TX 0x40 |
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#define CH341_LCR_MARK_SPACE 0x20 |
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#define CH341_LCR_PAR_EVEN 0x10 |
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#define CH341_LCR_ENABLE_PAR 0x08 |
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#define CH341_LCR_STOP_BITS_2 0x04 |
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#define CH341_LCR_CS8 0x03 |
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#define CH341_LCR_CS7 0x02 |
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#define CH341_LCR_CS6 0x01 |
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#define CH341_LCR_CS5 0x00 |
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|
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#define CH341_QUIRK_LIMITED_PRESCALER BIT(0) |
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#define CH341_QUIRK_SIMULATE_BREAK BIT(1) |
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|
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static const struct usb_device_id id_table[] = { |
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{ USB_DEVICE(0x1a86, 0x5512) }, |
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{ USB_DEVICE(0x1a86, 0x5523) }, |
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{ USB_DEVICE(0x1a86, 0x7522) }, |
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{ USB_DEVICE(0x1a86, 0x7523) }, |
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{ USB_DEVICE(0x4348, 0x5523) }, |
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{ USB_DEVICE(0x9986, 0x7523) }, |
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{ }, |
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}; |
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MODULE_DEVICE_TABLE(usb, id_table); |
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|
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struct ch341_private { |
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spinlock_t lock; /* access lock */ |
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unsigned baud_rate; /* set baud rate */ |
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u8 mcr; |
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u8 msr; |
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u8 lcr; |
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unsigned long quirks; |
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unsigned long break_end; |
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}; |
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static void ch341_set_termios(struct tty_struct *tty, |
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struct usb_serial_port *port, |
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struct ktermios *old_termios); |
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static int ch341_control_out(struct usb_device *dev, u8 request, |
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u16 value, u16 index) |
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{ |
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int r; |
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dev_dbg(&dev->dev, "%s - (%02x,%04x,%04x)\n", __func__, |
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request, value, index); |
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r = usb_control_msg(dev, usb_sndctrlpipe(dev, 0), request, |
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USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_OUT, |
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value, index, NULL, 0, DEFAULT_TIMEOUT); |
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if (r < 0) |
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dev_err(&dev->dev, "failed to send control message: %d\n", r); |
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return r; |
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} |
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static int ch341_control_in(struct usb_device *dev, |
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u8 request, u16 value, u16 index, |
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char *buf, unsigned bufsize) |
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{ |
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int r; |
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dev_dbg(&dev->dev, "%s - (%02x,%04x,%04x,%u)\n", __func__, |
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request, value, index, bufsize); |
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r = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), request, |
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USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN, |
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value, index, buf, bufsize, DEFAULT_TIMEOUT); |
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if (r < (int)bufsize) { |
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if (r >= 0) { |
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dev_err(&dev->dev, |
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"short control message received (%d < %u)\n", |
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r, bufsize); |
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r = -EIO; |
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} |
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dev_err(&dev->dev, "failed to receive control message: %d\n", |
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r); |
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return r; |
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} |
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return 0; |
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} |
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#define CH341_CLKRATE 48000000 |
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#define CH341_CLK_DIV(ps, fact) (1 << (12 - 3 * (ps) - (fact))) |
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#define CH341_MIN_RATE(ps) (CH341_CLKRATE / (CH341_CLK_DIV((ps), 1) * 512)) |
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static const speed_t ch341_min_rates[] = { |
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CH341_MIN_RATE(0), |
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CH341_MIN_RATE(1), |
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CH341_MIN_RATE(2), |
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CH341_MIN_RATE(3), |
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}; |
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/* Supported range is 46 to 3000000 bps. */ |
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#define CH341_MIN_BPS DIV_ROUND_UP(CH341_CLKRATE, CH341_CLK_DIV(0, 0) * 256) |
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#define CH341_MAX_BPS (CH341_CLKRATE / (CH341_CLK_DIV(3, 0) * 2)) |
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/* |
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* The device line speed is given by the following equation: |
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* |
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* baudrate = 48000000 / (2^(12 - 3 * ps - fact) * div), where |
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* |
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* 0 <= ps <= 3, |
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* 0 <= fact <= 1, |
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* 2 <= div <= 256 if fact = 0, or |
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* 9 <= div <= 256 if fact = 1 |
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*/ |
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static int ch341_get_divisor(struct ch341_private *priv, speed_t speed) |
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{ |
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unsigned int fact, div, clk_div; |
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bool force_fact0 = false; |
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int ps; |
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/* |
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* Clamp to supported range, this makes the (ps < 0) and (div < 2) |
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* sanity checks below redundant. |
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*/ |
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speed = clamp_val(speed, CH341_MIN_BPS, CH341_MAX_BPS); |
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/* |
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* Start with highest possible base clock (fact = 1) that will give a |
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* divisor strictly less than 512. |
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*/ |
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fact = 1; |
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for (ps = 3; ps >= 0; ps--) { |
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if (speed > ch341_min_rates[ps]) |
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break; |
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} |
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if (ps < 0) |
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return -EINVAL; |
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/* Determine corresponding divisor, rounding down. */ |
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clk_div = CH341_CLK_DIV(ps, fact); |
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div = CH341_CLKRATE / (clk_div * speed); |
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/* Some devices require a lower base clock if ps < 3. */ |
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if (ps < 3 && (priv->quirks & CH341_QUIRK_LIMITED_PRESCALER)) |
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force_fact0 = true; |
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/* Halve base clock (fact = 0) if required. */ |
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if (div < 9 || div > 255 || force_fact0) { |
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div /= 2; |
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clk_div *= 2; |
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fact = 0; |
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} |
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if (div < 2) |
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return -EINVAL; |
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/* |
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* Pick next divisor if resulting rate is closer to the requested one, |
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* scale up to avoid rounding errors on low rates. |
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*/ |
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if (16 * CH341_CLKRATE / (clk_div * div) - 16 * speed >= |
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16 * speed - 16 * CH341_CLKRATE / (clk_div * (div + 1))) |
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div++; |
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/* |
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* Prefer lower base clock (fact = 0) if even divisor. |
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* |
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* Note that this makes the receiver more tolerant to errors. |
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*/ |
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if (fact == 1 && div % 2 == 0) { |
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div /= 2; |
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fact = 0; |
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} |
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return (0x100 - div) << 8 | fact << 2 | ps; |
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} |
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static int ch341_set_baudrate_lcr(struct usb_device *dev, |
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struct ch341_private *priv, |
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speed_t baud_rate, u8 lcr) |
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{ |
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int val; |
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int r; |
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if (!baud_rate) |
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return -EINVAL; |
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val = ch341_get_divisor(priv, baud_rate); |
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if (val < 0) |
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return -EINVAL; |
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/* |
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* CH341A buffers data until a full endpoint-size packet (32 bytes) |
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* has been received unless bit 7 is set. |
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*/ |
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val |= BIT(7); |
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r = ch341_control_out(dev, CH341_REQ_WRITE_REG, |
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CH341_REG_DIVISOR << 8 | CH341_REG_PRESCALER, |
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val); |
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if (r) |
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return r; |
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/* |
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* Chip versions before version 0x30 as read using |
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* CH341_REQ_READ_VERSION used separate registers for line control |
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* (stop bits, parity and word length). Version 0x30 and above use |
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* CH341_REG_LCR only and CH341_REG_LCR2 is always set to zero. |
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*/ |
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r = ch341_control_out(dev, CH341_REQ_WRITE_REG, |
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CH341_REG_LCR2 << 8 | CH341_REG_LCR, lcr); |
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if (r) |
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return r; |
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return r; |
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} |
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static int ch341_set_handshake(struct usb_device *dev, u8 control) |
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{ |
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return ch341_control_out(dev, CH341_REQ_MODEM_CTRL, ~control, 0); |
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} |
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static int ch341_get_status(struct usb_device *dev, struct ch341_private *priv) |
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{ |
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const unsigned int size = 2; |
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char *buffer; |
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int r; |
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unsigned long flags; |
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buffer = kmalloc(size, GFP_KERNEL); |
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if (!buffer) |
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return -ENOMEM; |
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r = ch341_control_in(dev, CH341_REQ_READ_REG, 0x0706, 0, buffer, size); |
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if (r < 0) |
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goto out; |
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spin_lock_irqsave(&priv->lock, flags); |
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priv->msr = (~(*buffer)) & CH341_BITS_MODEM_STAT; |
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spin_unlock_irqrestore(&priv->lock, flags); |
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out: kfree(buffer); |
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return r; |
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} |
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/* -------------------------------------------------------------------------- */ |
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static int ch341_configure(struct usb_device *dev, struct ch341_private *priv) |
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{ |
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const unsigned int size = 2; |
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char *buffer; |
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int r; |
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buffer = kmalloc(size, GFP_KERNEL); |
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if (!buffer) |
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return -ENOMEM; |
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/* expect two bytes 0x27 0x00 */ |
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r = ch341_control_in(dev, CH341_REQ_READ_VERSION, 0, 0, buffer, size); |
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if (r < 0) |
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goto out; |
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dev_dbg(&dev->dev, "Chip version: 0x%02x\n", buffer[0]); |
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r = ch341_control_out(dev, CH341_REQ_SERIAL_INIT, 0, 0); |
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if (r < 0) |
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goto out; |
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r = ch341_set_baudrate_lcr(dev, priv, priv->baud_rate, priv->lcr); |
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if (r < 0) |
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goto out; |
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r = ch341_set_handshake(dev, priv->mcr); |
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out: kfree(buffer); |
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return r; |
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} |
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static int ch341_detect_quirks(struct usb_serial_port *port) |
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{ |
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struct ch341_private *priv = usb_get_serial_port_data(port); |
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struct usb_device *udev = port->serial->dev; |
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const unsigned int size = 2; |
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unsigned long quirks = 0; |
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char *buffer; |
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int r; |
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|
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buffer = kmalloc(size, GFP_KERNEL); |
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if (!buffer) |
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return -ENOMEM; |
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/* |
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* A subset of CH34x devices does not support all features. The |
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* prescaler is limited and there is no support for sending a RS232 |
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* break condition. A read failure when trying to set up the latter is |
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* used to detect these devices. |
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*/ |
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r = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0), CH341_REQ_READ_REG, |
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USB_TYPE_VENDOR | USB_RECIP_DEVICE | USB_DIR_IN, |
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CH341_REG_BREAK, 0, buffer, size, DEFAULT_TIMEOUT); |
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if (r == -EPIPE) { |
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dev_info(&port->dev, "break control not supported, using simulated break\n"); |
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quirks = CH341_QUIRK_LIMITED_PRESCALER | CH341_QUIRK_SIMULATE_BREAK; |
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r = 0; |
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goto out; |
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} |
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if (r != size) { |
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if (r >= 0) |
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r = -EIO; |
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dev_err(&port->dev, "failed to read break control: %d\n", r); |
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goto out; |
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} |
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|
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r = 0; |
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out: |
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kfree(buffer); |
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if (quirks) { |
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dev_dbg(&port->dev, "enabling quirk flags: 0x%02lx\n", quirks); |
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priv->quirks |= quirks; |
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} |
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return r; |
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} |
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static int ch341_port_probe(struct usb_serial_port *port) |
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{ |
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struct ch341_private *priv; |
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int r; |
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priv = kzalloc(sizeof(struct ch341_private), GFP_KERNEL); |
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if (!priv) |
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return -ENOMEM; |
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spin_lock_init(&priv->lock); |
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priv->baud_rate = DEFAULT_BAUD_RATE; |
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/* |
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* Some CH340 devices appear unable to change the initial LCR |
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* settings, so set a sane 8N1 default. |
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*/ |
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priv->lcr = CH341_LCR_ENABLE_RX | CH341_LCR_ENABLE_TX | CH341_LCR_CS8; |
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r = ch341_configure(port->serial->dev, priv); |
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if (r < 0) |
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goto error; |
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usb_set_serial_port_data(port, priv); |
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r = ch341_detect_quirks(port); |
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if (r < 0) |
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goto error; |
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return 0; |
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error: kfree(priv); |
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return r; |
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} |
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static void ch341_port_remove(struct usb_serial_port *port) |
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{ |
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struct ch341_private *priv; |
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priv = usb_get_serial_port_data(port); |
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kfree(priv); |
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} |
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static int ch341_carrier_raised(struct usb_serial_port *port) |
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{ |
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struct ch341_private *priv = usb_get_serial_port_data(port); |
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if (priv->msr & CH341_BIT_DCD) |
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return 1; |
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return 0; |
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} |
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static void ch341_dtr_rts(struct usb_serial_port *port, int on) |
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{ |
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struct ch341_private *priv = usb_get_serial_port_data(port); |
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unsigned long flags; |
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/* drop DTR and RTS */ |
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spin_lock_irqsave(&priv->lock, flags); |
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if (on) |
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priv->mcr |= CH341_BIT_RTS | CH341_BIT_DTR; |
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else |
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priv->mcr &= ~(CH341_BIT_RTS | CH341_BIT_DTR); |
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spin_unlock_irqrestore(&priv->lock, flags); |
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ch341_set_handshake(port->serial->dev, priv->mcr); |
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} |
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static void ch341_close(struct usb_serial_port *port) |
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{ |
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usb_serial_generic_close(port); |
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usb_kill_urb(port->interrupt_in_urb); |
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} |
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/* open this device, set default parameters */ |
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static int ch341_open(struct tty_struct *tty, struct usb_serial_port *port) |
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{ |
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struct ch341_private *priv = usb_get_serial_port_data(port); |
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int r; |
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|
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if (tty) |
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ch341_set_termios(tty, port, NULL); |
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dev_dbg(&port->dev, "%s - submitting interrupt urb\n", __func__); |
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r = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL); |
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if (r) { |
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dev_err(&port->dev, "%s - failed to submit interrupt urb: %d\n", |
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__func__, r); |
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return r; |
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} |
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r = ch341_get_status(port->serial->dev, priv); |
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if (r < 0) { |
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dev_err(&port->dev, "failed to read modem status: %d\n", r); |
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goto err_kill_interrupt_urb; |
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} |
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r = usb_serial_generic_open(tty, port); |
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if (r) |
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goto err_kill_interrupt_urb; |
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return 0; |
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err_kill_interrupt_urb: |
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usb_kill_urb(port->interrupt_in_urb); |
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|
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return r; |
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} |
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|
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/* Old_termios contains the original termios settings and |
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* tty->termios contains the new setting to be used. |
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*/ |
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static void ch341_set_termios(struct tty_struct *tty, |
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struct usb_serial_port *port, struct ktermios *old_termios) |
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{ |
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struct ch341_private *priv = usb_get_serial_port_data(port); |
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unsigned baud_rate; |
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unsigned long flags; |
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u8 lcr; |
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int r; |
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|
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/* redundant changes may cause the chip to lose bytes */ |
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if (old_termios && !tty_termios_hw_change(&tty->termios, old_termios)) |
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return; |
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|
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baud_rate = tty_get_baud_rate(tty); |
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|
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lcr = CH341_LCR_ENABLE_RX | CH341_LCR_ENABLE_TX; |
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|
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switch (C_CSIZE(tty)) { |
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case CS5: |
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lcr |= CH341_LCR_CS5; |
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break; |
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case CS6: |
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lcr |= CH341_LCR_CS6; |
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break; |
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case CS7: |
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lcr |= CH341_LCR_CS7; |
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break; |
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case CS8: |
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lcr |= CH341_LCR_CS8; |
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break; |
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} |
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|
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if (C_PARENB(tty)) { |
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lcr |= CH341_LCR_ENABLE_PAR; |
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if (C_PARODD(tty) == 0) |
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lcr |= CH341_LCR_PAR_EVEN; |
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if (C_CMSPAR(tty)) |
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lcr |= CH341_LCR_MARK_SPACE; |
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} |
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|
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if (C_CSTOPB(tty)) |
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lcr |= CH341_LCR_STOP_BITS_2; |
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|
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if (baud_rate) { |
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priv->baud_rate = baud_rate; |
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|
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r = ch341_set_baudrate_lcr(port->serial->dev, priv, |
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priv->baud_rate, lcr); |
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if (r < 0 && old_termios) { |
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priv->baud_rate = tty_termios_baud_rate(old_termios); |
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tty_termios_copy_hw(&tty->termios, old_termios); |
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} else if (r == 0) { |
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priv->lcr = lcr; |
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} |
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} |
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|
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spin_lock_irqsave(&priv->lock, flags); |
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if (C_BAUD(tty) == B0) |
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priv->mcr &= ~(CH341_BIT_DTR | CH341_BIT_RTS); |
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else if (old_termios && (old_termios->c_cflag & CBAUD) == B0) |
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priv->mcr |= (CH341_BIT_DTR | CH341_BIT_RTS); |
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spin_unlock_irqrestore(&priv->lock, flags); |
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|
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ch341_set_handshake(port->serial->dev, priv->mcr); |
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} |
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|
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/* |
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* A subset of all CH34x devices don't support a real break condition and |
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* reading CH341_REG_BREAK fails (see also ch341_detect_quirks). This function |
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* simulates a break condition by lowering the baud rate to the minimum |
|
* supported by the hardware upon enabling the break condition and sending |
|
* a NUL byte. |
|
* |
|
* Incoming data is corrupted while the break condition is being simulated. |
|
* |
|
* Normally the duration of the break condition can be controlled individually |
|
* by userspace using TIOCSBRK and TIOCCBRK or by passing an argument to |
|
* TCSBRKP. Due to how the simulation is implemented the duration can't be |
|
* controlled. The duration is always about (1s / 46bd * 9bit) = 196ms. |
|
*/ |
|
static void ch341_simulate_break(struct tty_struct *tty, int break_state) |
|
{ |
|
struct usb_serial_port *port = tty->driver_data; |
|
struct ch341_private *priv = usb_get_serial_port_data(port); |
|
unsigned long now, delay; |
|
int r; |
|
|
|
if (break_state != 0) { |
|
dev_dbg(&port->dev, "enter break state requested\n"); |
|
|
|
r = ch341_set_baudrate_lcr(port->serial->dev, priv, |
|
CH341_MIN_BPS, |
|
CH341_LCR_ENABLE_RX | CH341_LCR_ENABLE_TX | CH341_LCR_CS8); |
|
if (r < 0) { |
|
dev_err(&port->dev, |
|
"failed to change baud rate to %u: %d\n", |
|
CH341_MIN_BPS, r); |
|
goto restore; |
|
} |
|
|
|
r = tty_put_char(tty, '\0'); |
|
if (r < 0) { |
|
dev_err(&port->dev, |
|
"failed to write NUL byte for simulated break condition: %d\n", |
|
r); |
|
goto restore; |
|
} |
|
|
|
/* |
|
* Compute expected transmission duration including safety |
|
* margin. The original baud rate is only restored after the |
|
* computed point in time. |
|
* |
|
* 11 bits = 1 start, 8 data, 1 stop, 1 margin |
|
*/ |
|
priv->break_end = jiffies + (11 * HZ / CH341_MIN_BPS); |
|
|
|
return; |
|
} |
|
|
|
dev_dbg(&port->dev, "leave break state requested\n"); |
|
|
|
now = jiffies; |
|
|
|
if (time_before(now, priv->break_end)) { |
|
/* Wait until NUL byte is written */ |
|
delay = priv->break_end - now; |
|
dev_dbg(&port->dev, |
|
"wait %d ms while transmitting NUL byte at %u baud\n", |
|
jiffies_to_msecs(delay), CH341_MIN_BPS); |
|
schedule_timeout_interruptible(delay); |
|
} |
|
|
|
restore: |
|
/* Restore original baud rate */ |
|
r = ch341_set_baudrate_lcr(port->serial->dev, priv, priv->baud_rate, |
|
priv->lcr); |
|
if (r < 0) |
|
dev_err(&port->dev, |
|
"restoring original baud rate of %u failed: %d\n", |
|
priv->baud_rate, r); |
|
} |
|
|
|
static void ch341_break_ctl(struct tty_struct *tty, int break_state) |
|
{ |
|
const uint16_t ch341_break_reg = |
|
((uint16_t) CH341_REG_LCR << 8) | CH341_REG_BREAK; |
|
struct usb_serial_port *port = tty->driver_data; |
|
struct ch341_private *priv = usb_get_serial_port_data(port); |
|
int r; |
|
uint16_t reg_contents; |
|
uint8_t *break_reg; |
|
|
|
if (priv->quirks & CH341_QUIRK_SIMULATE_BREAK) { |
|
ch341_simulate_break(tty, break_state); |
|
return; |
|
} |
|
|
|
break_reg = kmalloc(2, GFP_KERNEL); |
|
if (!break_reg) |
|
return; |
|
|
|
r = ch341_control_in(port->serial->dev, CH341_REQ_READ_REG, |
|
ch341_break_reg, 0, break_reg, 2); |
|
if (r < 0) { |
|
dev_err(&port->dev, "%s - USB control read error (%d)\n", |
|
__func__, r); |
|
goto out; |
|
} |
|
dev_dbg(&port->dev, "%s - initial ch341 break register contents - reg1: %x, reg2: %x\n", |
|
__func__, break_reg[0], break_reg[1]); |
|
if (break_state != 0) { |
|
dev_dbg(&port->dev, "%s - Enter break state requested\n", __func__); |
|
break_reg[0] &= ~CH341_NBREAK_BITS; |
|
break_reg[1] &= ~CH341_LCR_ENABLE_TX; |
|
} else { |
|
dev_dbg(&port->dev, "%s - Leave break state requested\n", __func__); |
|
break_reg[0] |= CH341_NBREAK_BITS; |
|
break_reg[1] |= CH341_LCR_ENABLE_TX; |
|
} |
|
dev_dbg(&port->dev, "%s - New ch341 break register contents - reg1: %x, reg2: %x\n", |
|
__func__, break_reg[0], break_reg[1]); |
|
reg_contents = get_unaligned_le16(break_reg); |
|
r = ch341_control_out(port->serial->dev, CH341_REQ_WRITE_REG, |
|
ch341_break_reg, reg_contents); |
|
if (r < 0) |
|
dev_err(&port->dev, "%s - USB control write error (%d)\n", |
|
__func__, r); |
|
out: |
|
kfree(break_reg); |
|
} |
|
|
|
static int ch341_tiocmset(struct tty_struct *tty, |
|
unsigned int set, unsigned int clear) |
|
{ |
|
struct usb_serial_port *port = tty->driver_data; |
|
struct ch341_private *priv = usb_get_serial_port_data(port); |
|
unsigned long flags; |
|
u8 control; |
|
|
|
spin_lock_irqsave(&priv->lock, flags); |
|
if (set & TIOCM_RTS) |
|
priv->mcr |= CH341_BIT_RTS; |
|
if (set & TIOCM_DTR) |
|
priv->mcr |= CH341_BIT_DTR; |
|
if (clear & TIOCM_RTS) |
|
priv->mcr &= ~CH341_BIT_RTS; |
|
if (clear & TIOCM_DTR) |
|
priv->mcr &= ~CH341_BIT_DTR; |
|
control = priv->mcr; |
|
spin_unlock_irqrestore(&priv->lock, flags); |
|
|
|
return ch341_set_handshake(port->serial->dev, control); |
|
} |
|
|
|
static void ch341_update_status(struct usb_serial_port *port, |
|
unsigned char *data, size_t len) |
|
{ |
|
struct ch341_private *priv = usb_get_serial_port_data(port); |
|
struct tty_struct *tty; |
|
unsigned long flags; |
|
u8 status; |
|
u8 delta; |
|
|
|
if (len < 4) |
|
return; |
|
|
|
status = ~data[2] & CH341_BITS_MODEM_STAT; |
|
|
|
spin_lock_irqsave(&priv->lock, flags); |
|
delta = status ^ priv->msr; |
|
priv->msr = status; |
|
spin_unlock_irqrestore(&priv->lock, flags); |
|
|
|
if (data[1] & CH341_MULT_STAT) |
|
dev_dbg(&port->dev, "%s - multiple status change\n", __func__); |
|
|
|
if (!delta) |
|
return; |
|
|
|
if (delta & CH341_BIT_CTS) |
|
port->icount.cts++; |
|
if (delta & CH341_BIT_DSR) |
|
port->icount.dsr++; |
|
if (delta & CH341_BIT_RI) |
|
port->icount.rng++; |
|
if (delta & CH341_BIT_DCD) { |
|
port->icount.dcd++; |
|
tty = tty_port_tty_get(&port->port); |
|
if (tty) { |
|
usb_serial_handle_dcd_change(port, tty, |
|
status & CH341_BIT_DCD); |
|
tty_kref_put(tty); |
|
} |
|
} |
|
|
|
wake_up_interruptible(&port->port.delta_msr_wait); |
|
} |
|
|
|
static void ch341_read_int_callback(struct urb *urb) |
|
{ |
|
struct usb_serial_port *port = urb->context; |
|
unsigned char *data = urb->transfer_buffer; |
|
unsigned int len = urb->actual_length; |
|
int status; |
|
|
|
switch (urb->status) { |
|
case 0: |
|
/* success */ |
|
break; |
|
case -ECONNRESET: |
|
case -ENOENT: |
|
case -ESHUTDOWN: |
|
/* this urb is terminated, clean up */ |
|
dev_dbg(&urb->dev->dev, "%s - urb shutting down: %d\n", |
|
__func__, urb->status); |
|
return; |
|
default: |
|
dev_dbg(&urb->dev->dev, "%s - nonzero urb status: %d\n", |
|
__func__, urb->status); |
|
goto exit; |
|
} |
|
|
|
usb_serial_debug_data(&port->dev, __func__, len, data); |
|
ch341_update_status(port, data, len); |
|
exit: |
|
status = usb_submit_urb(urb, GFP_ATOMIC); |
|
if (status) { |
|
dev_err(&urb->dev->dev, "%s - usb_submit_urb failed: %d\n", |
|
__func__, status); |
|
} |
|
} |
|
|
|
static int ch341_tiocmget(struct tty_struct *tty) |
|
{ |
|
struct usb_serial_port *port = tty->driver_data; |
|
struct ch341_private *priv = usb_get_serial_port_data(port); |
|
unsigned long flags; |
|
u8 mcr; |
|
u8 status; |
|
unsigned int result; |
|
|
|
spin_lock_irqsave(&priv->lock, flags); |
|
mcr = priv->mcr; |
|
status = priv->msr; |
|
spin_unlock_irqrestore(&priv->lock, flags); |
|
|
|
result = ((mcr & CH341_BIT_DTR) ? TIOCM_DTR : 0) |
|
| ((mcr & CH341_BIT_RTS) ? TIOCM_RTS : 0) |
|
| ((status & CH341_BIT_CTS) ? TIOCM_CTS : 0) |
|
| ((status & CH341_BIT_DSR) ? TIOCM_DSR : 0) |
|
| ((status & CH341_BIT_RI) ? TIOCM_RI : 0) |
|
| ((status & CH341_BIT_DCD) ? TIOCM_CD : 0); |
|
|
|
dev_dbg(&port->dev, "%s - result = %x\n", __func__, result); |
|
|
|
return result; |
|
} |
|
|
|
static int ch341_reset_resume(struct usb_serial *serial) |
|
{ |
|
struct usb_serial_port *port = serial->port[0]; |
|
struct ch341_private *priv; |
|
int ret; |
|
|
|
priv = usb_get_serial_port_data(port); |
|
if (!priv) |
|
return 0; |
|
|
|
/* reconfigure ch341 serial port after bus-reset */ |
|
ch341_configure(serial->dev, priv); |
|
|
|
if (tty_port_initialized(&port->port)) { |
|
ret = usb_submit_urb(port->interrupt_in_urb, GFP_NOIO); |
|
if (ret) { |
|
dev_err(&port->dev, "failed to submit interrupt urb: %d\n", |
|
ret); |
|
return ret; |
|
} |
|
|
|
ret = ch341_get_status(port->serial->dev, priv); |
|
if (ret < 0) { |
|
dev_err(&port->dev, "failed to read modem status: %d\n", |
|
ret); |
|
} |
|
} |
|
|
|
return usb_serial_generic_resume(serial); |
|
} |
|
|
|
static struct usb_serial_driver ch341_device = { |
|
.driver = { |
|
.owner = THIS_MODULE, |
|
.name = "ch341-uart", |
|
}, |
|
.id_table = id_table, |
|
.num_ports = 1, |
|
.open = ch341_open, |
|
.dtr_rts = ch341_dtr_rts, |
|
.carrier_raised = ch341_carrier_raised, |
|
.close = ch341_close, |
|
.set_termios = ch341_set_termios, |
|
.break_ctl = ch341_break_ctl, |
|
.tiocmget = ch341_tiocmget, |
|
.tiocmset = ch341_tiocmset, |
|
.tiocmiwait = usb_serial_generic_tiocmiwait, |
|
.read_int_callback = ch341_read_int_callback, |
|
.port_probe = ch341_port_probe, |
|
.port_remove = ch341_port_remove, |
|
.reset_resume = ch341_reset_resume, |
|
}; |
|
|
|
static struct usb_serial_driver * const serial_drivers[] = { |
|
&ch341_device, NULL |
|
}; |
|
|
|
module_usb_serial_driver(serial_drivers, id_table); |
|
|
|
MODULE_LICENSE("GPL v2");
|
|
|