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path: root/drivers/usb/serial/cp210x.c
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-rw-r--r--drivers/usb/serial/cp210x.c217
1 files changed, 171 insertions, 46 deletions
diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c
index 7bec1e730b20..9e1c609792fb 100644
--- a/drivers/usb/serial/cp210x.c
+++ b/drivers/usb/serial/cp210x.c
@@ -3,6 +3,7 @@
* Silicon Laboratories CP210x USB to RS232 serial adaptor driver
*
* Copyright (C) 2005 Craig Shelley (craig@microtron.org.uk)
+ * Copyright (C) 2010-2021 Johan Hovold (johan@kernel.org)
*
* Support to set flow control line levels using TIOCMGET and TIOCMSET
* thanks to Karl Hiramoto karl@hiramoto.org. RTSCTS hardware flow
@@ -16,9 +17,7 @@
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/module.h>
-#include <linux/moduleparam.h>
#include <linux/usb.h>
-#include <linux/uaccess.h>
#include <linux/usb/serial.h>
#include <linux/gpio/driver.h>
#include <linux/bitops.h>
@@ -45,7 +44,7 @@ static int cp210x_attach(struct usb_serial *);
static void cp210x_disconnect(struct usb_serial *);
static void cp210x_release(struct usb_serial *);
static int cp210x_port_probe(struct usb_serial_port *);
-static int cp210x_port_remove(struct usb_serial_port *);
+static void cp210x_port_remove(struct usb_serial_port *);
static void cp210x_dtr_rts(struct usb_serial_port *port, int on);
static void cp210x_process_read_urb(struct urb *urb);
static void cp210x_enable_event_mode(struct usb_serial_port *port);
@@ -268,7 +267,12 @@ struct cp210x_port_private {
u8 bInterfaceNumber;
bool event_mode;
enum cp210x_event_state event_state;
- u8 lsr;
+ u8 lsr;
+
+ struct mutex mutex;
+ bool crtscts;
+ bool dtr;
+ bool rts;
};
static struct usb_serial_driver cp210x_device = {
@@ -379,6 +383,16 @@ static struct usb_serial_driver * const serial_drivers[] = {
#define CONTROL_WRITE_DTR 0x0100
#define CONTROL_WRITE_RTS 0x0200
+/* CP210X_(GET|SET)_CHARS */
+struct cp210x_special_chars {
+ u8 bEofChar;
+ u8 bErrorChar;
+ u8 bBreakChar;
+ u8 bEventChar;
+ u8 bXonChar;
+ u8 bXoffChar;
+};
+
/* CP210X_VENDOR_SPECIFIC values */
#define CP210X_READ_2NCONFIG 0x000E
#define CP210X_READ_LATCH 0x00C2
@@ -437,17 +451,14 @@ struct cp210x_flow_ctl {
/* cp210x_flow_ctl::ulControlHandshake */
#define CP210X_SERIAL_DTR_MASK GENMASK(1, 0)
-#define CP210X_SERIAL_DTR_SHIFT(_mode) (_mode)
+#define CP210X_SERIAL_DTR_INACTIVE (0 << 0)
+#define CP210X_SERIAL_DTR_ACTIVE (1 << 0)
+#define CP210X_SERIAL_DTR_FLOW_CTL (2 << 0)
#define CP210X_SERIAL_CTS_HANDSHAKE BIT(3)
#define CP210X_SERIAL_DSR_HANDSHAKE BIT(4)
#define CP210X_SERIAL_DCD_HANDSHAKE BIT(5)
#define CP210X_SERIAL_DSR_SENSITIVITY BIT(6)
-/* values for cp210x_flow_ctl::ulControlHandshake::CP210X_SERIAL_DTR_MASK */
-#define CP210X_SERIAL_DTR_INACTIVE 0
-#define CP210X_SERIAL_DTR_ACTIVE 1
-#define CP210X_SERIAL_DTR_FLOW_CTL 2
-
/* cp210x_flow_ctl::ulFlowReplace */
#define CP210X_SERIAL_AUTO_TRANSMIT BIT(0)
#define CP210X_SERIAL_AUTO_RECEIVE BIT(1)
@@ -455,14 +466,11 @@ struct cp210x_flow_ctl {
#define CP210X_SERIAL_NULL_STRIPPING BIT(3)
#define CP210X_SERIAL_BREAK_CHAR BIT(4)
#define CP210X_SERIAL_RTS_MASK GENMASK(7, 6)
-#define CP210X_SERIAL_RTS_SHIFT(_mode) (_mode << 6)
+#define CP210X_SERIAL_RTS_INACTIVE (0 << 6)
+#define CP210X_SERIAL_RTS_ACTIVE (1 << 6)
+#define CP210X_SERIAL_RTS_FLOW_CTL (2 << 6)
#define CP210X_SERIAL_XOFF_CONTINUE BIT(31)
-/* values for cp210x_flow_ctl::ulFlowReplace::CP210X_SERIAL_RTS_MASK */
-#define CP210X_SERIAL_RTS_INACTIVE 0
-#define CP210X_SERIAL_RTS_ACTIVE 1
-#define CP210X_SERIAL_RTS_FLOW_CTL 2
-
/* CP210X_VENDOR_SPECIFIC, CP210X_GET_DEVICEMODE call reads these 0x2 bytes. */
struct cp210x_pin_mode {
u8 eci;
@@ -666,16 +674,13 @@ static int cp210x_write_reg_block(struct usb_serial_port *port, u8 req,
kfree(dmabuf);
- if (result == bufsize) {
- result = 0;
- } else {
+ if (result < 0) {
dev_err(&port->dev, "failed set req 0x%x size %d status: %d\n",
req, bufsize, result);
- if (result >= 0)
- result = -EIO;
+ return result;
}
- return result;
+ return 0;
}
/*
@@ -712,17 +717,14 @@ static int cp210x_write_vendor_block(struct usb_serial *serial, u8 type,
kfree(dmabuf);
- if (result == bufsize) {
- result = 0;
- } else {
+ if (result < 0) {
dev_err(&serial->interface->dev,
"failed to set vendor val 0x%04x size %d: %d\n", val,
bufsize, result);
- if (result >= 0)
- result = -EIO;
+ return result;
}
- return result;
+ return 0;
}
#endif
@@ -1076,30 +1078,80 @@ static void cp210x_disable_event_mode(struct usb_serial_port *port)
port_priv->event_mode = false;
}
+static int cp210x_set_chars(struct usb_serial_port *port,
+ struct cp210x_special_chars *chars)
+{
+ struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
+ struct usb_serial *serial = port->serial;
+ void *dmabuf;
+ int result;
+
+ dmabuf = kmemdup(chars, sizeof(*chars), GFP_KERNEL);
+ if (!dmabuf)
+ return -ENOMEM;
+
+ result = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
+ CP210X_SET_CHARS, REQTYPE_HOST_TO_INTERFACE, 0,
+ port_priv->bInterfaceNumber,
+ dmabuf, sizeof(*chars), USB_CTRL_SET_TIMEOUT);
+
+ kfree(dmabuf);
+
+ if (result < 0) {
+ dev_err(&port->dev, "failed to set special chars: %d\n", result);
+ return result;
+ }
+
+ return 0;
+}
+
static bool cp210x_termios_change(const struct ktermios *a, const struct ktermios *b)
{
- bool iflag_change;
+ bool iflag_change, cc_change;
- iflag_change = ((a->c_iflag ^ b->c_iflag) & INPCK);
+ iflag_change = ((a->c_iflag ^ b->c_iflag) & (INPCK | IXON | IXOFF));
+ cc_change = a->c_cc[VSTART] != b->c_cc[VSTART] ||
+ a->c_cc[VSTOP] != b->c_cc[VSTOP];
- return tty_termios_hw_change(a, b) || iflag_change;
+ return tty_termios_hw_change(a, b) || iflag_change || cc_change;
}
static void cp210x_set_flow_control(struct tty_struct *tty,
struct usb_serial_port *port, struct ktermios *old_termios)
{
+ struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
+ struct cp210x_special_chars chars;
struct cp210x_flow_ctl flow_ctl;
u32 flow_repl;
u32 ctl_hs;
int ret;
- if (old_termios && C_CRTSCTS(tty) == (old_termios->c_cflag & CRTSCTS))
+ if (old_termios &&
+ C_CRTSCTS(tty) == (old_termios->c_cflag & CRTSCTS) &&
+ I_IXON(tty) == (old_termios->c_iflag & IXON) &&
+ I_IXOFF(tty) == (old_termios->c_iflag & IXOFF) &&
+ START_CHAR(tty) == old_termios->c_cc[VSTART] &&
+ STOP_CHAR(tty) == old_termios->c_cc[VSTOP]) {
return;
+ }
+
+ if (I_IXON(tty) || I_IXOFF(tty)) {
+ memset(&chars, 0, sizeof(chars));
+
+ chars.bXonChar = START_CHAR(tty);
+ chars.bXoffChar = STOP_CHAR(tty);
+
+ ret = cp210x_set_chars(port, &chars);
+ if (ret)
+ return;
+ }
+
+ mutex_lock(&port_priv->mutex);
ret = cp210x_read_reg_block(port, CP210X_GET_FLOW, &flow_ctl,
sizeof(flow_ctl));
if (ret)
- return;
+ goto out_unlock;
ctl_hs = le32_to_cpu(flow_ctl.ulControlHandshake);
flow_repl = le32_to_cpu(flow_ctl.ulFlowReplace);
@@ -1108,26 +1160,51 @@ static void cp210x_set_flow_control(struct tty_struct *tty,
ctl_hs &= ~CP210X_SERIAL_DCD_HANDSHAKE;
ctl_hs &= ~CP210X_SERIAL_DSR_SENSITIVITY;
ctl_hs &= ~CP210X_SERIAL_DTR_MASK;
- ctl_hs |= CP210X_SERIAL_DTR_SHIFT(CP210X_SERIAL_DTR_ACTIVE);
+ if (port_priv->dtr)
+ ctl_hs |= CP210X_SERIAL_DTR_ACTIVE;
+ else
+ ctl_hs |= CP210X_SERIAL_DTR_INACTIVE;
+ flow_repl &= ~CP210X_SERIAL_RTS_MASK;
if (C_CRTSCTS(tty)) {
ctl_hs |= CP210X_SERIAL_CTS_HANDSHAKE;
- flow_repl &= ~CP210X_SERIAL_RTS_MASK;
- flow_repl |= CP210X_SERIAL_RTS_SHIFT(CP210X_SERIAL_RTS_FLOW_CTL);
+ if (port_priv->rts)
+ flow_repl |= CP210X_SERIAL_RTS_FLOW_CTL;
+ else
+ flow_repl |= CP210X_SERIAL_RTS_INACTIVE;
+ port_priv->crtscts = true;
} else {
ctl_hs &= ~CP210X_SERIAL_CTS_HANDSHAKE;
- flow_repl &= ~CP210X_SERIAL_RTS_MASK;
- flow_repl |= CP210X_SERIAL_RTS_SHIFT(CP210X_SERIAL_RTS_ACTIVE);
+ if (port_priv->rts)
+ flow_repl |= CP210X_SERIAL_RTS_ACTIVE;
+ else
+ flow_repl |= CP210X_SERIAL_RTS_INACTIVE;
+ port_priv->crtscts = false;
}
- dev_dbg(&port->dev, "%s - ulControlHandshake=0x%08x, ulFlowReplace=0x%08x\n",
- __func__, ctl_hs, flow_repl);
+ if (I_IXOFF(tty))
+ flow_repl |= CP210X_SERIAL_AUTO_RECEIVE;
+ else
+ flow_repl &= ~CP210X_SERIAL_AUTO_RECEIVE;
+
+ if (I_IXON(tty))
+ flow_repl |= CP210X_SERIAL_AUTO_TRANSMIT;
+ else
+ flow_repl &= ~CP210X_SERIAL_AUTO_TRANSMIT;
+
+ flow_ctl.ulXonLimit = cpu_to_le32(128);
+ flow_ctl.ulXoffLimit = cpu_to_le32(128);
+
+ dev_dbg(&port->dev, "%s - ctrl = 0x%02x, flow = 0x%02x\n", __func__,
+ ctl_hs, flow_repl);
flow_ctl.ulControlHandshake = cpu_to_le32(ctl_hs);
flow_ctl.ulFlowReplace = cpu_to_le32(flow_repl);
cp210x_write_reg_block(port, CP210X_SET_FLOW, &flow_ctl,
sizeof(flow_ctl));
+out_unlock:
+ mutex_unlock(&port_priv->mutex);
}
static void cp210x_set_termios(struct tty_struct *tty,
@@ -1212,28 +1289,77 @@ static int cp210x_tiocmset(struct tty_struct *tty,
static int cp210x_tiocmset_port(struct usb_serial_port *port,
unsigned int set, unsigned int clear)
{
+ struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
+ struct cp210x_flow_ctl flow_ctl;
+ u32 ctl_hs, flow_repl;
u16 control = 0;
+ int ret;
+
+ mutex_lock(&port_priv->mutex);
if (set & TIOCM_RTS) {
+ port_priv->rts = true;
control |= CONTROL_RTS;
control |= CONTROL_WRITE_RTS;
}
if (set & TIOCM_DTR) {
+ port_priv->dtr = true;
control |= CONTROL_DTR;
control |= CONTROL_WRITE_DTR;
}
if (clear & TIOCM_RTS) {
+ port_priv->rts = false;
control &= ~CONTROL_RTS;
control |= CONTROL_WRITE_RTS;
}
if (clear & TIOCM_DTR) {
+ port_priv->dtr = false;
control &= ~CONTROL_DTR;
control |= CONTROL_WRITE_DTR;
}
- dev_dbg(&port->dev, "%s - control = 0x%.4x\n", __func__, control);
+ /*
+ * Use SET_FLOW to set DTR and enable/disable auto-RTS when hardware
+ * flow control is enabled.
+ */
+ if (port_priv->crtscts && control & CONTROL_WRITE_RTS) {
+ ret = cp210x_read_reg_block(port, CP210X_GET_FLOW, &flow_ctl,
+ sizeof(flow_ctl));
+ if (ret)
+ goto out_unlock;
+
+ ctl_hs = le32_to_cpu(flow_ctl.ulControlHandshake);
+ flow_repl = le32_to_cpu(flow_ctl.ulFlowReplace);
+
+ ctl_hs &= ~CP210X_SERIAL_DTR_MASK;
+ if (port_priv->dtr)
+ ctl_hs |= CP210X_SERIAL_DTR_ACTIVE;
+ else
+ ctl_hs |= CP210X_SERIAL_DTR_INACTIVE;
- return cp210x_write_u16_reg(port, CP210X_SET_MHS, control);
+ flow_repl &= ~CP210X_SERIAL_RTS_MASK;
+ if (port_priv->rts)
+ flow_repl |= CP210X_SERIAL_RTS_FLOW_CTL;
+ else
+ flow_repl |= CP210X_SERIAL_RTS_INACTIVE;
+
+ flow_ctl.ulControlHandshake = cpu_to_le32(ctl_hs);
+ flow_ctl.ulFlowReplace = cpu_to_le32(flow_repl);
+
+ dev_dbg(&port->dev, "%s - ctrl = 0x%02x, flow = 0x%02x\n",
+ __func__, ctl_hs, flow_repl);
+
+ ret = cp210x_write_reg_block(port, CP210X_SET_FLOW, &flow_ctl,
+ sizeof(flow_ctl));
+ } else {
+ dev_dbg(&port->dev, "%s - control = 0x%04x\n", __func__, control);
+
+ ret = cp210x_write_u16_reg(port, CP210X_SET_MHS, control);
+ }
+out_unlock:
+ mutex_unlock(&port_priv->mutex);
+
+ return ret;
}
static void cp210x_dtr_rts(struct usb_serial_port *port, int on)
@@ -1261,7 +1387,7 @@ static int cp210x_tiocmget(struct tty_struct *tty)
|((control & CONTROL_RING)? TIOCM_RI : 0)
|((control & CONTROL_DCD) ? TIOCM_CD : 0);
- dev_dbg(&port->dev, "%s - control = 0x%.2x\n", __func__, control);
+ dev_dbg(&port->dev, "%s - control = 0x%02x\n", __func__, control);
return result;
}
@@ -1710,20 +1836,19 @@ static int cp210x_port_probe(struct usb_serial_port *port)
return -ENOMEM;
port_priv->bInterfaceNumber = cp210x_interface_num(serial);
+ mutex_init(&port_priv->mutex);
usb_set_serial_port_data(port, port_priv);
return 0;
}
-static int cp210x_port_remove(struct usb_serial_port *port)
+static void cp210x_port_remove(struct usb_serial_port *port)
{
struct cp210x_port_private *port_priv;
port_priv = usb_get_serial_port_data(port);
kfree(port_priv);
-
- return 0;
}
static void cp210x_init_max_speed(struct usb_serial *serial)
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.