linux/drivers/usb/serial/f81232.c
Ji-Ze Hong (Peter Hong) 7f6fc50242 USB: serial: f81232: implement break control
Implement Fintek F81232 break on/off with LCR register.
It's the same with 16550A LCR register layout.

Signed-off-by: Ji-Ze Hong (Peter Hong) <hpeter+linux_kernel@gmail.com>
[ johan: fix corrupt line settings on break due to missing shadow_lcr
  update in set_termios() ]
Signed-off-by: Johan Hovold <johan@kernel.org>
2019-05-03 09:19:55 +02:00

835 lines
19 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Fintek F81232 USB to serial adaptor driver
*
* Copyright (C) 2012 Greg Kroah-Hartman (gregkh@linuxfoundation.org)
* Copyright (C) 2012 Linux Foundation
*/
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/tty.h>
#include <linux/tty_driver.h>
#include <linux/tty_flip.h>
#include <linux/serial.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/mutex.h>
#include <linux/uaccess.h>
#include <linux/usb.h>
#include <linux/usb/serial.h>
#include <linux/serial_reg.h>
static const struct usb_device_id id_table[] = {
{ USB_DEVICE(0x1934, 0x0706) },
{ } /* Terminating entry */
};
MODULE_DEVICE_TABLE(usb, id_table);
/* Maximum baudrate for F81232 */
#define F81232_MAX_BAUDRATE 1500000
#define F81232_DEF_BAUDRATE 9600
/* USB Control EP parameter */
#define F81232_REGISTER_REQUEST 0xa0
#define F81232_GET_REGISTER 0xc0
#define F81232_SET_REGISTER 0x40
#define SERIAL_BASE_ADDRESS 0x0120
#define RECEIVE_BUFFER_REGISTER (0x00 + SERIAL_BASE_ADDRESS)
#define INTERRUPT_ENABLE_REGISTER (0x01 + SERIAL_BASE_ADDRESS)
#define FIFO_CONTROL_REGISTER (0x02 + SERIAL_BASE_ADDRESS)
#define LINE_CONTROL_REGISTER (0x03 + SERIAL_BASE_ADDRESS)
#define MODEM_CONTROL_REGISTER (0x04 + SERIAL_BASE_ADDRESS)
#define LINE_STATUS_REGISTER (0x05 + SERIAL_BASE_ADDRESS)
#define MODEM_STATUS_REGISTER (0x06 + SERIAL_BASE_ADDRESS)
/*
* F81232 Clock registers (106h)
*
* Bit1-0: Clock source selector
* 00: 1.846MHz.
* 01: 18.46MHz.
* 10: 24MHz.
* 11: 14.77MHz.
*/
#define F81232_CLK_REGISTER 0x106
#define F81232_CLK_1_846_MHZ 0
#define F81232_CLK_18_46_MHZ BIT(0)
#define F81232_CLK_24_MHZ BIT(1)
#define F81232_CLK_14_77_MHZ (BIT(1) | BIT(0))
#define F81232_CLK_MASK GENMASK(1, 0)
struct f81232_private {
struct mutex lock;
u8 modem_control;
u8 modem_status;
u8 shadow_lcr;
speed_t baud_base;
struct work_struct lsr_work;
struct work_struct interrupt_work;
struct usb_serial_port *port;
};
static u32 const baudrate_table[] = { 115200, 921600, 1152000, 1500000 };
static u8 const clock_table[] = { F81232_CLK_1_846_MHZ, F81232_CLK_14_77_MHZ,
F81232_CLK_18_46_MHZ, F81232_CLK_24_MHZ };
static int calc_baud_divisor(speed_t baudrate, speed_t clockrate)
{
if (!baudrate)
return 0;
return DIV_ROUND_CLOSEST(clockrate, baudrate);
}
static int f81232_get_register(struct usb_serial_port *port, u16 reg, u8 *val)
{
int status;
u8 *tmp;
struct usb_device *dev = port->serial->dev;
tmp = kmalloc(sizeof(*val), GFP_KERNEL);
if (!tmp)
return -ENOMEM;
status = usb_control_msg(dev,
usb_rcvctrlpipe(dev, 0),
F81232_REGISTER_REQUEST,
F81232_GET_REGISTER,
reg,
0,
tmp,
sizeof(*val),
USB_CTRL_GET_TIMEOUT);
if (status != sizeof(*val)) {
dev_err(&port->dev, "%s failed status: %d\n", __func__, status);
if (status < 0)
status = usb_translate_errors(status);
else
status = -EIO;
} else {
status = 0;
*val = *tmp;
}
kfree(tmp);
return status;
}
static int f81232_set_register(struct usb_serial_port *port, u16 reg, u8 val)
{
int status;
u8 *tmp;
struct usb_device *dev = port->serial->dev;
tmp = kmalloc(sizeof(val), GFP_KERNEL);
if (!tmp)
return -ENOMEM;
*tmp = val;
status = usb_control_msg(dev,
usb_sndctrlpipe(dev, 0),
F81232_REGISTER_REQUEST,
F81232_SET_REGISTER,
reg,
0,
tmp,
sizeof(val),
USB_CTRL_SET_TIMEOUT);
if (status != sizeof(val)) {
dev_err(&port->dev, "%s failed status: %d\n", __func__, status);
if (status < 0)
status = usb_translate_errors(status);
else
status = -EIO;
} else {
status = 0;
}
kfree(tmp);
return status;
}
static int f81232_set_mask_register(struct usb_serial_port *port, u16 reg,
u8 mask, u8 val)
{
int status;
u8 tmp;
status = f81232_get_register(port, reg, &tmp);
if (status)
return status;
tmp = (tmp & ~mask) | (val & mask);
return f81232_set_register(port, reg, tmp);
}
static void f81232_read_msr(struct usb_serial_port *port)
{
int status;
u8 current_msr;
struct tty_struct *tty;
struct f81232_private *priv = usb_get_serial_port_data(port);
mutex_lock(&priv->lock);
status = f81232_get_register(port, MODEM_STATUS_REGISTER,
&current_msr);
if (status) {
dev_err(&port->dev, "%s fail, status: %d\n", __func__, status);
mutex_unlock(&priv->lock);
return;
}
if (!(current_msr & UART_MSR_ANY_DELTA)) {
mutex_unlock(&priv->lock);
return;
}
priv->modem_status = current_msr;
if (current_msr & UART_MSR_DCTS)
port->icount.cts++;
if (current_msr & UART_MSR_DDSR)
port->icount.dsr++;
if (current_msr & UART_MSR_TERI)
port->icount.rng++;
if (current_msr & UART_MSR_DDCD) {
port->icount.dcd++;
tty = tty_port_tty_get(&port->port);
if (tty) {
usb_serial_handle_dcd_change(port, tty,
current_msr & UART_MSR_DCD);
tty_kref_put(tty);
}
}
wake_up_interruptible(&port->port.delta_msr_wait);
mutex_unlock(&priv->lock);
}
static int f81232_set_mctrl(struct usb_serial_port *port,
unsigned int set, unsigned int clear)
{
u8 val;
int status;
struct f81232_private *priv = usb_get_serial_port_data(port);
if (((set | clear) & (TIOCM_DTR | TIOCM_RTS)) == 0)
return 0; /* no change */
/* 'set' takes precedence over 'clear' */
clear &= ~set;
/* force enable interrupt with OUT2 */
mutex_lock(&priv->lock);
val = UART_MCR_OUT2 | priv->modem_control;
if (clear & TIOCM_DTR)
val &= ~UART_MCR_DTR;
if (clear & TIOCM_RTS)
val &= ~UART_MCR_RTS;
if (set & TIOCM_DTR)
val |= UART_MCR_DTR;
if (set & TIOCM_RTS)
val |= UART_MCR_RTS;
dev_dbg(&port->dev, "%s new:%02x old:%02x\n", __func__,
val, priv->modem_control);
status = f81232_set_register(port, MODEM_CONTROL_REGISTER, val);
if (status) {
dev_err(&port->dev, "%s set MCR status < 0\n", __func__);
mutex_unlock(&priv->lock);
return status;
}
priv->modem_control = val;
mutex_unlock(&priv->lock);
return 0;
}
static void f81232_update_line_status(struct usb_serial_port *port,
unsigned char *data,
size_t actual_length)
{
struct f81232_private *priv = usb_get_serial_port_data(port);
if (!actual_length)
return;
switch (data[0] & 0x07) {
case 0x00: /* msr change */
dev_dbg(&port->dev, "IIR: MSR Change: %02x\n", data[0]);
schedule_work(&priv->interrupt_work);
break;
case 0x02: /* tx-empty */
break;
case 0x04: /* rx data available */
break;
case 0x06: /* lsr change */
/* we can forget it. the LSR will read from bulk-in */
dev_dbg(&port->dev, "IIR: LSR Change: %02x\n", data[0]);
break;
}
}
static void f81232_read_int_callback(struct urb *urb)
{
struct usb_serial_port *port = urb->context;
unsigned char *data = urb->transfer_buffer;
unsigned int actual_length = urb->actual_length;
int status = urb->status;
int retval;
switch (status) {
case 0:
/* success */
break;
case -ECONNRESET:
case -ENOENT:
case -ESHUTDOWN:
/* this urb is terminated, clean up */
dev_dbg(&port->dev, "%s - urb shutting down with status: %d\n",
__func__, status);
return;
default:
dev_dbg(&port->dev, "%s - nonzero urb status received: %d\n",
__func__, status);
goto exit;
}
usb_serial_debug_data(&port->dev, __func__,
urb->actual_length, urb->transfer_buffer);
f81232_update_line_status(port, data, actual_length);
exit:
retval = usb_submit_urb(urb, GFP_ATOMIC);
if (retval)
dev_err(&urb->dev->dev,
"%s - usb_submit_urb failed with result %d\n",
__func__, retval);
}
static void f81232_process_read_urb(struct urb *urb)
{
struct usb_serial_port *port = urb->context;
struct f81232_private *priv = usb_get_serial_port_data(port);
unsigned char *data = urb->transfer_buffer;
char tty_flag;
unsigned int i;
u8 lsr;
/*
* When opening the port we get a 1-byte packet with the current LSR,
* which we discard.
*/
if ((urb->actual_length < 2) || (urb->actual_length % 2))
return;
/* bulk-in data: [LSR(1Byte)+DATA(1Byte)][LSR(1Byte)+DATA(1Byte)]... */
for (i = 0; i < urb->actual_length; i += 2) {
tty_flag = TTY_NORMAL;
lsr = data[i];
if (lsr & UART_LSR_BRK_ERROR_BITS) {
if (lsr & UART_LSR_BI) {
tty_flag = TTY_BREAK;
port->icount.brk++;
usb_serial_handle_break(port);
} else if (lsr & UART_LSR_PE) {
tty_flag = TTY_PARITY;
port->icount.parity++;
} else if (lsr & UART_LSR_FE) {
tty_flag = TTY_FRAME;
port->icount.frame++;
}
if (lsr & UART_LSR_OE) {
port->icount.overrun++;
schedule_work(&priv->lsr_work);
tty_insert_flip_char(&port->port, 0,
TTY_OVERRUN);
}
}
if (port->port.console && port->sysrq) {
if (usb_serial_handle_sysrq_char(port, data[i + 1]))
continue;
}
tty_insert_flip_char(&port->port, data[i + 1], tty_flag);
}
tty_flip_buffer_push(&port->port);
}
static void f81232_break_ctl(struct tty_struct *tty, int break_state)
{
struct usb_serial_port *port = tty->driver_data;
struct f81232_private *priv = usb_get_serial_port_data(port);
int status;
mutex_lock(&priv->lock);
if (break_state)
priv->shadow_lcr |= UART_LCR_SBC;
else
priv->shadow_lcr &= ~UART_LCR_SBC;
status = f81232_set_register(port, LINE_CONTROL_REGISTER,
priv->shadow_lcr);
if (status)
dev_err(&port->dev, "set break failed: %d\n", status);
mutex_unlock(&priv->lock);
}
static int f81232_find_clk(speed_t baudrate)
{
int idx;
for (idx = 0; idx < ARRAY_SIZE(baudrate_table); ++idx) {
if (baudrate <= baudrate_table[idx] &&
baudrate_table[idx] % baudrate == 0)
return idx;
}
return -EINVAL;
}
static void f81232_set_baudrate(struct tty_struct *tty,
struct usb_serial_port *port, speed_t baudrate,
speed_t old_baudrate)
{
struct f81232_private *priv = usb_get_serial_port_data(port);
u8 lcr;
int divisor;
int status = 0;
int i;
int idx;
speed_t baud_list[] = { baudrate, old_baudrate, F81232_DEF_BAUDRATE };
for (i = 0; i < ARRAY_SIZE(baud_list); ++i) {
idx = f81232_find_clk(baud_list[i]);
if (idx >= 0) {
baudrate = baud_list[i];
tty_encode_baud_rate(tty, baudrate, baudrate);
break;
}
}
if (idx < 0)
return;
priv->baud_base = baudrate_table[idx];
divisor = calc_baud_divisor(baudrate, priv->baud_base);
status = f81232_set_mask_register(port, F81232_CLK_REGISTER,
F81232_CLK_MASK, clock_table[idx]);
if (status) {
dev_err(&port->dev, "%s failed to set CLK_REG: %d\n",
__func__, status);
return;
}
status = f81232_get_register(port, LINE_CONTROL_REGISTER,
&lcr); /* get LCR */
if (status) {
dev_err(&port->dev, "%s failed to get LCR: %d\n",
__func__, status);
return;
}
status = f81232_set_register(port, LINE_CONTROL_REGISTER,
lcr | UART_LCR_DLAB); /* Enable DLAB */
if (status) {
dev_err(&port->dev, "%s failed to set DLAB: %d\n",
__func__, status);
return;
}
status = f81232_set_register(port, RECEIVE_BUFFER_REGISTER,
divisor & 0x00ff); /* low */
if (status) {
dev_err(&port->dev, "%s failed to set baudrate MSB: %d\n",
__func__, status);
goto reapply_lcr;
}
status = f81232_set_register(port, INTERRUPT_ENABLE_REGISTER,
(divisor & 0xff00) >> 8); /* high */
if (status) {
dev_err(&port->dev, "%s failed to set baudrate LSB: %d\n",
__func__, status);
}
reapply_lcr:
status = f81232_set_register(port, LINE_CONTROL_REGISTER,
lcr & ~UART_LCR_DLAB);
if (status) {
dev_err(&port->dev, "%s failed to set DLAB: %d\n",
__func__, status);
}
}
static int f81232_port_enable(struct usb_serial_port *port)
{
u8 val;
int status;
/* fifo on, trigger8, clear TX/RX*/
val = UART_FCR_TRIGGER_8 | UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR |
UART_FCR_CLEAR_XMIT;
status = f81232_set_register(port, FIFO_CONTROL_REGISTER, val);
if (status) {
dev_err(&port->dev, "%s failed to set FCR: %d\n",
__func__, status);
return status;
}
/* MSR Interrupt only, LSR will read from Bulk-in odd byte */
status = f81232_set_register(port, INTERRUPT_ENABLE_REGISTER,
UART_IER_MSI);
if (status) {
dev_err(&port->dev, "%s failed to set IER: %d\n",
__func__, status);
return status;
}
return 0;
}
static int f81232_port_disable(struct usb_serial_port *port)
{
int status;
status = f81232_set_register(port, INTERRUPT_ENABLE_REGISTER, 0);
if (status) {
dev_err(&port->dev, "%s failed to set IER: %d\n",
__func__, status);
return status;
}
return 0;
}
static void f81232_set_termios(struct tty_struct *tty,
struct usb_serial_port *port, struct ktermios *old_termios)
{
struct f81232_private *priv = usb_get_serial_port_data(port);
u8 new_lcr = 0;
int status = 0;
speed_t baudrate;
speed_t old_baud;
/* Don't change anything if nothing has changed */
if (old_termios && !tty_termios_hw_change(&tty->termios, old_termios))
return;
if (C_BAUD(tty) == B0)
f81232_set_mctrl(port, 0, TIOCM_DTR | TIOCM_RTS);
else if (old_termios && (old_termios->c_cflag & CBAUD) == B0)
f81232_set_mctrl(port, TIOCM_DTR | TIOCM_RTS, 0);
baudrate = tty_get_baud_rate(tty);
if (baudrate > 0) {
if (old_termios)
old_baud = tty_termios_baud_rate(old_termios);
else
old_baud = F81232_DEF_BAUDRATE;
f81232_set_baudrate(tty, port, baudrate, old_baud);
}
if (C_PARENB(tty)) {
new_lcr |= UART_LCR_PARITY;
if (!C_PARODD(tty))
new_lcr |= UART_LCR_EPAR;
if (C_CMSPAR(tty))
new_lcr |= UART_LCR_SPAR;
}
if (C_CSTOPB(tty))
new_lcr |= UART_LCR_STOP;
switch (C_CSIZE(tty)) {
case CS5:
new_lcr |= UART_LCR_WLEN5;
break;
case CS6:
new_lcr |= UART_LCR_WLEN6;
break;
case CS7:
new_lcr |= UART_LCR_WLEN7;
break;
default:
case CS8:
new_lcr |= UART_LCR_WLEN8;
break;
}
mutex_lock(&priv->lock);
new_lcr |= (priv->shadow_lcr & UART_LCR_SBC);
status = f81232_set_register(port, LINE_CONTROL_REGISTER, new_lcr);
if (status) {
dev_err(&port->dev, "%s failed to set LCR: %d\n",
__func__, status);
}
priv->shadow_lcr = new_lcr;
mutex_unlock(&priv->lock);
}
static int f81232_tiocmget(struct tty_struct *tty)
{
int r;
struct usb_serial_port *port = tty->driver_data;
struct f81232_private *port_priv = usb_get_serial_port_data(port);
u8 mcr, msr;
/* force get current MSR changed state */
f81232_read_msr(port);
mutex_lock(&port_priv->lock);
mcr = port_priv->modem_control;
msr = port_priv->modem_status;
mutex_unlock(&port_priv->lock);
r = (mcr & UART_MCR_DTR ? TIOCM_DTR : 0) |
(mcr & UART_MCR_RTS ? TIOCM_RTS : 0) |
(msr & UART_MSR_CTS ? TIOCM_CTS : 0) |
(msr & UART_MSR_DCD ? TIOCM_CAR : 0) |
(msr & UART_MSR_RI ? TIOCM_RI : 0) |
(msr & UART_MSR_DSR ? TIOCM_DSR : 0);
return r;
}
static int f81232_tiocmset(struct tty_struct *tty,
unsigned int set, unsigned int clear)
{
struct usb_serial_port *port = tty->driver_data;
return f81232_set_mctrl(port, set, clear);
}
static int f81232_open(struct tty_struct *tty, struct usb_serial_port *port)
{
int result;
result = f81232_port_enable(port);
if (result)
return result;
/* Setup termios */
if (tty)
f81232_set_termios(tty, port, NULL);
result = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
if (result) {
dev_err(&port->dev, "%s - failed submitting interrupt urb,"
" error %d\n", __func__, result);
return result;
}
result = usb_serial_generic_open(tty, port);
if (result) {
usb_kill_urb(port->interrupt_in_urb);
return result;
}
return 0;
}
static void f81232_close(struct usb_serial_port *port)
{
struct f81232_private *port_priv = usb_get_serial_port_data(port);
f81232_port_disable(port);
usb_serial_generic_close(port);
usb_kill_urb(port->interrupt_in_urb);
flush_work(&port_priv->interrupt_work);
flush_work(&port_priv->lsr_work);
}
static void f81232_dtr_rts(struct usb_serial_port *port, int on)
{
if (on)
f81232_set_mctrl(port, TIOCM_DTR | TIOCM_RTS, 0);
else
f81232_set_mctrl(port, 0, TIOCM_DTR | TIOCM_RTS);
}
static int f81232_carrier_raised(struct usb_serial_port *port)
{
u8 msr;
struct f81232_private *priv = usb_get_serial_port_data(port);
mutex_lock(&priv->lock);
msr = priv->modem_status;
mutex_unlock(&priv->lock);
if (msr & UART_MSR_DCD)
return 1;
return 0;
}
static int f81232_get_serial_info(struct tty_struct *tty,
struct serial_struct *ss)
{
struct usb_serial_port *port = tty->driver_data;
struct f81232_private *priv = usb_get_serial_port_data(port);
ss->type = PORT_16550A;
ss->line = port->minor;
ss->port = port->port_number;
ss->baud_base = priv->baud_base;
return 0;
}
static void f81232_interrupt_work(struct work_struct *work)
{
struct f81232_private *priv =
container_of(work, struct f81232_private, interrupt_work);
f81232_read_msr(priv->port);
}
static void f81232_lsr_worker(struct work_struct *work)
{
struct f81232_private *priv;
struct usb_serial_port *port;
int status;
u8 tmp;
priv = container_of(work, struct f81232_private, lsr_work);
port = priv->port;
status = f81232_get_register(port, LINE_STATUS_REGISTER, &tmp);
if (status)
dev_warn(&port->dev, "read LSR failed: %d\n", status);
}
static int f81232_port_probe(struct usb_serial_port *port)
{
struct f81232_private *priv;
priv = kzalloc(sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
mutex_init(&priv->lock);
INIT_WORK(&priv->interrupt_work, f81232_interrupt_work);
INIT_WORK(&priv->lsr_work, f81232_lsr_worker);
usb_set_serial_port_data(port, priv);
port->port.drain_delay = 256;
priv->port = port;
return 0;
}
static int f81232_port_remove(struct usb_serial_port *port)
{
struct f81232_private *priv;
priv = usb_get_serial_port_data(port);
kfree(priv);
return 0;
}
static int f81232_suspend(struct usb_serial *serial, pm_message_t message)
{
struct usb_serial_port *port = serial->port[0];
struct f81232_private *port_priv = usb_get_serial_port_data(port);
int i;
for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i)
usb_kill_urb(port->read_urbs[i]);
usb_kill_urb(port->interrupt_in_urb);
if (port_priv) {
flush_work(&port_priv->interrupt_work);
flush_work(&port_priv->lsr_work);
}
return 0;
}
static int f81232_resume(struct usb_serial *serial)
{
struct usb_serial_port *port = serial->port[0];
int result;
if (tty_port_initialized(&port->port)) {
result = usb_submit_urb(port->interrupt_in_urb, GFP_NOIO);
if (result) {
dev_err(&port->dev, "submit interrupt urb failed: %d\n",
result);
return result;
}
}
return usb_serial_generic_resume(serial);
}
static struct usb_serial_driver f81232_device = {
.driver = {
.owner = THIS_MODULE,
.name = "f81232",
},
.id_table = id_table,
.num_ports = 1,
.bulk_in_size = 256,
.bulk_out_size = 256,
.open = f81232_open,
.close = f81232_close,
.dtr_rts = f81232_dtr_rts,
.carrier_raised = f81232_carrier_raised,
.get_serial = f81232_get_serial_info,
.break_ctl = f81232_break_ctl,
.set_termios = f81232_set_termios,
.tiocmget = f81232_tiocmget,
.tiocmset = f81232_tiocmset,
.tiocmiwait = usb_serial_generic_tiocmiwait,
.process_read_urb = f81232_process_read_urb,
.read_int_callback = f81232_read_int_callback,
.port_probe = f81232_port_probe,
.port_remove = f81232_port_remove,
.suspend = f81232_suspend,
.resume = f81232_resume,
};
static struct usb_serial_driver * const serial_drivers[] = {
&f81232_device,
NULL,
};
module_usb_serial_driver(serial_drivers, id_table);
MODULE_DESCRIPTION("Fintek F81232 USB to serial adaptor driver");
MODULE_AUTHOR("Greg Kroah-Hartman <gregkh@linuxfoundation.org>");
MODULE_AUTHOR("Peter Hong <peter_hong@fintek.com.tw>");
MODULE_LICENSE("GPL v2");