linux/drivers/mmc/core/sdio_uart.c
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00

1184 lines
28 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* SDIO UART/GPS driver
*
* Based on drivers/serial/8250.c and drivers/serial/serial_core.c
* by Russell King.
*
* Author: Nicolas Pitre
* Created: June 15, 2007
* Copyright: MontaVista Software, Inc.
*/
/*
* Note: Although this driver assumes a 16550A-like UART implementation,
* it is not possible to leverage the common 8250/16550 driver, nor the
* core UART infrastructure, as they assumes direct access to the hardware
* registers, often under a spinlock. This is not possible in the SDIO
* context as SDIO access functions must be able to sleep.
*
* Because we need to lock the SDIO host to ensure an exclusive access to
* the card, we simply rely on that lock to also prevent and serialize
* concurrent access to the same port.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mutex.h>
#include <linux/seq_file.h>
#include <linux/serial_reg.h>
#include <linux/circ_buf.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/kfifo.h>
#include <linux/slab.h>
#include <linux/mmc/core.h>
#include <linux/mmc/card.h>
#include <linux/mmc/sdio_func.h>
#include <linux/mmc/sdio_ids.h>
#define UART_NR 8 /* Number of UARTs this driver can handle */
#define FIFO_SIZE PAGE_SIZE
#define WAKEUP_CHARS 256
struct uart_icount {
__u32 cts;
__u32 dsr;
__u32 rng;
__u32 dcd;
__u32 rx;
__u32 tx;
__u32 frame;
__u32 overrun;
__u32 parity;
__u32 brk;
};
struct sdio_uart_port {
struct tty_port port;
unsigned int index;
struct sdio_func *func;
struct mutex func_lock;
struct task_struct *in_sdio_uart_irq;
unsigned int regs_offset;
struct kfifo xmit_fifo;
spinlock_t write_lock;
struct uart_icount icount;
unsigned int uartclk;
unsigned int mctrl;
unsigned int rx_mctrl;
unsigned int read_status_mask;
unsigned int ignore_status_mask;
unsigned char x_char;
unsigned char ier;
unsigned char lcr;
};
static struct sdio_uart_port *sdio_uart_table[UART_NR];
static DEFINE_SPINLOCK(sdio_uart_table_lock);
static int sdio_uart_add_port(struct sdio_uart_port *port)
{
int index, ret = -EBUSY;
mutex_init(&port->func_lock);
spin_lock_init(&port->write_lock);
if (kfifo_alloc(&port->xmit_fifo, FIFO_SIZE, GFP_KERNEL))
return -ENOMEM;
spin_lock(&sdio_uart_table_lock);
for (index = 0; index < UART_NR; index++) {
if (!sdio_uart_table[index]) {
port->index = index;
sdio_uart_table[index] = port;
ret = 0;
break;
}
}
spin_unlock(&sdio_uart_table_lock);
return ret;
}
static struct sdio_uart_port *sdio_uart_port_get(unsigned index)
{
struct sdio_uart_port *port;
if (index >= UART_NR)
return NULL;
spin_lock(&sdio_uart_table_lock);
port = sdio_uart_table[index];
if (port)
tty_port_get(&port->port);
spin_unlock(&sdio_uart_table_lock);
return port;
}
static void sdio_uart_port_put(struct sdio_uart_port *port)
{
tty_port_put(&port->port);
}
static void sdio_uart_port_remove(struct sdio_uart_port *port)
{
struct sdio_func *func;
spin_lock(&sdio_uart_table_lock);
sdio_uart_table[port->index] = NULL;
spin_unlock(&sdio_uart_table_lock);
/*
* We're killing a port that potentially still is in use by
* the tty layer. Be careful to prevent any further access
* to the SDIO function and arrange for the tty layer to
* give up on that port ASAP.
* Beware: the lock ordering is critical.
*/
mutex_lock(&port->port.mutex);
mutex_lock(&port->func_lock);
func = port->func;
sdio_claim_host(func);
port->func = NULL;
mutex_unlock(&port->func_lock);
/* tty_hangup is async so is this safe as is ?? */
tty_port_tty_hangup(&port->port, false);
mutex_unlock(&port->port.mutex);
sdio_release_irq(func);
sdio_disable_func(func);
sdio_release_host(func);
sdio_uart_port_put(port);
}
static int sdio_uart_claim_func(struct sdio_uart_port *port)
{
mutex_lock(&port->func_lock);
if (unlikely(!port->func)) {
mutex_unlock(&port->func_lock);
return -ENODEV;
}
if (likely(port->in_sdio_uart_irq != current))
sdio_claim_host(port->func);
mutex_unlock(&port->func_lock);
return 0;
}
static inline void sdio_uart_release_func(struct sdio_uart_port *port)
{
if (likely(port->in_sdio_uart_irq != current))
sdio_release_host(port->func);
}
static inline unsigned int sdio_in(struct sdio_uart_port *port, int offset)
{
unsigned char c;
c = sdio_readb(port->func, port->regs_offset + offset, NULL);
return c;
}
static inline void sdio_out(struct sdio_uart_port *port, int offset, int value)
{
sdio_writeb(port->func, value, port->regs_offset + offset, NULL);
}
static unsigned int sdio_uart_get_mctrl(struct sdio_uart_port *port)
{
unsigned char status;
unsigned int ret;
/* FIXME: What stops this losing the delta bits and breaking
sdio_uart_check_modem_status ? */
status = sdio_in(port, UART_MSR);
ret = 0;
if (status & UART_MSR_DCD)
ret |= TIOCM_CAR;
if (status & UART_MSR_RI)
ret |= TIOCM_RNG;
if (status & UART_MSR_DSR)
ret |= TIOCM_DSR;
if (status & UART_MSR_CTS)
ret |= TIOCM_CTS;
return ret;
}
static void sdio_uart_write_mctrl(struct sdio_uart_port *port,
unsigned int mctrl)
{
unsigned char mcr = 0;
if (mctrl & TIOCM_RTS)
mcr |= UART_MCR_RTS;
if (mctrl & TIOCM_DTR)
mcr |= UART_MCR_DTR;
if (mctrl & TIOCM_OUT1)
mcr |= UART_MCR_OUT1;
if (mctrl & TIOCM_OUT2)
mcr |= UART_MCR_OUT2;
if (mctrl & TIOCM_LOOP)
mcr |= UART_MCR_LOOP;
sdio_out(port, UART_MCR, mcr);
}
static inline void sdio_uart_update_mctrl(struct sdio_uart_port *port,
unsigned int set, unsigned int clear)
{
unsigned int old;
old = port->mctrl;
port->mctrl = (old & ~clear) | set;
if (old != port->mctrl)
sdio_uart_write_mctrl(port, port->mctrl);
}
#define sdio_uart_set_mctrl(port, x) sdio_uart_update_mctrl(port, x, 0)
#define sdio_uart_clear_mctrl(port, x) sdio_uart_update_mctrl(port, 0, x)
static void sdio_uart_change_speed(struct sdio_uart_port *port,
struct ktermios *termios,
struct ktermios *old)
{
unsigned char cval, fcr = 0;
unsigned int baud, quot;
switch (termios->c_cflag & CSIZE) {
case CS5:
cval = UART_LCR_WLEN5;
break;
case CS6:
cval = UART_LCR_WLEN6;
break;
case CS7:
cval = UART_LCR_WLEN7;
break;
default:
case CS8:
cval = UART_LCR_WLEN8;
break;
}
if (termios->c_cflag & CSTOPB)
cval |= UART_LCR_STOP;
if (termios->c_cflag & PARENB)
cval |= UART_LCR_PARITY;
if (!(termios->c_cflag & PARODD))
cval |= UART_LCR_EPAR;
for (;;) {
baud = tty_termios_baud_rate(termios);
if (baud == 0)
baud = 9600; /* Special case: B0 rate. */
if (baud <= port->uartclk)
break;
/*
* Oops, the quotient was zero. Try again with the old
* baud rate if possible, otherwise default to 9600.
*/
termios->c_cflag &= ~CBAUD;
if (old) {
termios->c_cflag |= old->c_cflag & CBAUD;
old = NULL;
} else
termios->c_cflag |= B9600;
}
quot = (2 * port->uartclk + baud) / (2 * baud);
if (baud < 2400)
fcr = UART_FCR_ENABLE_FIFO | UART_FCR_TRIGGER_1;
else
fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10;
port->read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
if (termios->c_iflag & INPCK)
port->read_status_mask |= UART_LSR_FE | UART_LSR_PE;
if (termios->c_iflag & (BRKINT | PARMRK))
port->read_status_mask |= UART_LSR_BI;
/*
* Characters to ignore
*/
port->ignore_status_mask = 0;
if (termios->c_iflag & IGNPAR)
port->ignore_status_mask |= UART_LSR_PE | UART_LSR_FE;
if (termios->c_iflag & IGNBRK) {
port->ignore_status_mask |= UART_LSR_BI;
/*
* If we're ignoring parity and break indicators,
* ignore overruns too (for real raw support).
*/
if (termios->c_iflag & IGNPAR)
port->ignore_status_mask |= UART_LSR_OE;
}
/*
* ignore all characters if CREAD is not set
*/
if ((termios->c_cflag & CREAD) == 0)
port->ignore_status_mask |= UART_LSR_DR;
/*
* CTS flow control flag and modem status interrupts
*/
port->ier &= ~UART_IER_MSI;
if ((termios->c_cflag & CRTSCTS) || !(termios->c_cflag & CLOCAL))
port->ier |= UART_IER_MSI;
port->lcr = cval;
sdio_out(port, UART_IER, port->ier);
sdio_out(port, UART_LCR, cval | UART_LCR_DLAB);
sdio_out(port, UART_DLL, quot & 0xff);
sdio_out(port, UART_DLM, quot >> 8);
sdio_out(port, UART_LCR, cval);
sdio_out(port, UART_FCR, fcr);
sdio_uart_write_mctrl(port, port->mctrl);
}
static void sdio_uart_start_tx(struct sdio_uart_port *port)
{
if (!(port->ier & UART_IER_THRI)) {
port->ier |= UART_IER_THRI;
sdio_out(port, UART_IER, port->ier);
}
}
static void sdio_uart_stop_tx(struct sdio_uart_port *port)
{
if (port->ier & UART_IER_THRI) {
port->ier &= ~UART_IER_THRI;
sdio_out(port, UART_IER, port->ier);
}
}
static void sdio_uart_stop_rx(struct sdio_uart_port *port)
{
port->ier &= ~UART_IER_RLSI;
port->read_status_mask &= ~UART_LSR_DR;
sdio_out(port, UART_IER, port->ier);
}
static void sdio_uart_receive_chars(struct sdio_uart_port *port,
unsigned int *status)
{
unsigned int ch, flag;
int max_count = 256;
do {
ch = sdio_in(port, UART_RX);
flag = TTY_NORMAL;
port->icount.rx++;
if (unlikely(*status & (UART_LSR_BI | UART_LSR_PE |
UART_LSR_FE | UART_LSR_OE))) {
/*
* For statistics only
*/
if (*status & UART_LSR_BI) {
*status &= ~(UART_LSR_FE | UART_LSR_PE);
port->icount.brk++;
} else if (*status & UART_LSR_PE)
port->icount.parity++;
else if (*status & UART_LSR_FE)
port->icount.frame++;
if (*status & UART_LSR_OE)
port->icount.overrun++;
/*
* Mask off conditions which should be ignored.
*/
*status &= port->read_status_mask;
if (*status & UART_LSR_BI)
flag = TTY_BREAK;
else if (*status & UART_LSR_PE)
flag = TTY_PARITY;
else if (*status & UART_LSR_FE)
flag = TTY_FRAME;
}
if ((*status & port->ignore_status_mask & ~UART_LSR_OE) == 0)
tty_insert_flip_char(&port->port, ch, flag);
/*
* Overrun is special. Since it's reported immediately,
* it doesn't affect the current character.
*/
if (*status & ~port->ignore_status_mask & UART_LSR_OE)
tty_insert_flip_char(&port->port, 0, TTY_OVERRUN);
*status = sdio_in(port, UART_LSR);
} while ((*status & UART_LSR_DR) && (max_count-- > 0));
tty_flip_buffer_push(&port->port);
}
static void sdio_uart_transmit_chars(struct sdio_uart_port *port)
{
struct kfifo *xmit = &port->xmit_fifo;
int count;
struct tty_struct *tty;
u8 iobuf[16];
int len;
if (port->x_char) {
sdio_out(port, UART_TX, port->x_char);
port->icount.tx++;
port->x_char = 0;
return;
}
tty = tty_port_tty_get(&port->port);
if (tty == NULL || !kfifo_len(xmit) ||
tty->stopped || tty->hw_stopped) {
sdio_uart_stop_tx(port);
tty_kref_put(tty);
return;
}
len = kfifo_out_locked(xmit, iobuf, 16, &port->write_lock);
for (count = 0; count < len; count++) {
sdio_out(port, UART_TX, iobuf[count]);
port->icount.tx++;
}
len = kfifo_len(xmit);
if (len < WAKEUP_CHARS) {
tty_wakeup(tty);
if (len == 0)
sdio_uart_stop_tx(port);
}
tty_kref_put(tty);
}
static void sdio_uart_check_modem_status(struct sdio_uart_port *port)
{
int status;
struct tty_struct *tty;
status = sdio_in(port, UART_MSR);
if ((status & UART_MSR_ANY_DELTA) == 0)
return;
if (status & UART_MSR_TERI)
port->icount.rng++;
if (status & UART_MSR_DDSR)
port->icount.dsr++;
if (status & UART_MSR_DDCD) {
port->icount.dcd++;
/* DCD raise - wake for open */
if (status & UART_MSR_DCD)
wake_up_interruptible(&port->port.open_wait);
else {
/* DCD drop - hang up if tty attached */
tty_port_tty_hangup(&port->port, false);
}
}
if (status & UART_MSR_DCTS) {
port->icount.cts++;
tty = tty_port_tty_get(&port->port);
if (tty && C_CRTSCTS(tty)) {
int cts = (status & UART_MSR_CTS);
if (tty->hw_stopped) {
if (cts) {
tty->hw_stopped = 0;
sdio_uart_start_tx(port);
tty_wakeup(tty);
}
} else {
if (!cts) {
tty->hw_stopped = 1;
sdio_uart_stop_tx(port);
}
}
}
tty_kref_put(tty);
}
}
/*
* This handles the interrupt from one port.
*/
static void sdio_uart_irq(struct sdio_func *func)
{
struct sdio_uart_port *port = sdio_get_drvdata(func);
unsigned int iir, lsr;
/*
* In a few places sdio_uart_irq() is called directly instead of
* waiting for the actual interrupt to be raised and the SDIO IRQ
* thread scheduled in order to reduce latency. However, some
* interaction with the tty core may end up calling us back
* (serial echo, flow control, etc.) through those same places
* causing undesirable effects. Let's stop the recursion here.
*/
if (unlikely(port->in_sdio_uart_irq == current))
return;
iir = sdio_in(port, UART_IIR);
if (iir & UART_IIR_NO_INT)
return;
port->in_sdio_uart_irq = current;
lsr = sdio_in(port, UART_LSR);
if (lsr & UART_LSR_DR)
sdio_uart_receive_chars(port, &lsr);
sdio_uart_check_modem_status(port);
if (lsr & UART_LSR_THRE)
sdio_uart_transmit_chars(port);
port->in_sdio_uart_irq = NULL;
}
static int uart_carrier_raised(struct tty_port *tport)
{
struct sdio_uart_port *port =
container_of(tport, struct sdio_uart_port, port);
unsigned int ret = sdio_uart_claim_func(port);
if (ret) /* Missing hardware shouldn't block for carrier */
return 1;
ret = sdio_uart_get_mctrl(port);
sdio_uart_release_func(port);
if (ret & TIOCM_CAR)
return 1;
return 0;
}
/**
* uart_dtr_rts - port helper to set uart signals
* @tport: tty port to be updated
* @onoff: set to turn on DTR/RTS
*
* Called by the tty port helpers when the modem signals need to be
* adjusted during an open, close and hangup.
*/
static void uart_dtr_rts(struct tty_port *tport, int onoff)
{
struct sdio_uart_port *port =
container_of(tport, struct sdio_uart_port, port);
int ret = sdio_uart_claim_func(port);
if (ret)
return;
if (onoff == 0)
sdio_uart_clear_mctrl(port, TIOCM_DTR | TIOCM_RTS);
else
sdio_uart_set_mctrl(port, TIOCM_DTR | TIOCM_RTS);
sdio_uart_release_func(port);
}
/**
* sdio_uart_activate - start up hardware
* @tport: tty port to activate
* @tty: tty bound to this port
*
* Activate a tty port. The port locking guarantees us this will be
* run exactly once per set of opens, and if successful will see the
* shutdown method run exactly once to match. Start up and shutdown are
* protected from each other by the internal locking and will not run
* at the same time even during a hangup event.
*
* If we successfully start up the port we take an extra kref as we
* will keep it around until shutdown when the kref is dropped.
*/
static int sdio_uart_activate(struct tty_port *tport, struct tty_struct *tty)
{
struct sdio_uart_port *port =
container_of(tport, struct sdio_uart_port, port);
int ret;
/*
* Set the TTY IO error marker - we will only clear this
* once we have successfully opened the port.
*/
set_bit(TTY_IO_ERROR, &tty->flags);
kfifo_reset(&port->xmit_fifo);
ret = sdio_uart_claim_func(port);
if (ret)
return ret;
ret = sdio_enable_func(port->func);
if (ret)
goto err1;
ret = sdio_claim_irq(port->func, sdio_uart_irq);
if (ret)
goto err2;
/*
* Clear the FIFO buffers and disable them.
* (they will be reenabled in sdio_change_speed())
*/
sdio_out(port, UART_FCR, UART_FCR_ENABLE_FIFO);
sdio_out(port, UART_FCR, UART_FCR_ENABLE_FIFO |
UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
sdio_out(port, UART_FCR, 0);
/*
* Clear the interrupt registers.
*/
(void) sdio_in(port, UART_LSR);
(void) sdio_in(port, UART_RX);
(void) sdio_in(port, UART_IIR);
(void) sdio_in(port, UART_MSR);
/*
* Now, initialize the UART
*/
sdio_out(port, UART_LCR, UART_LCR_WLEN8);
port->ier = UART_IER_RLSI|UART_IER_RDI|UART_IER_RTOIE|UART_IER_UUE;
port->mctrl = TIOCM_OUT2;
sdio_uart_change_speed(port, &tty->termios, NULL);
if (C_BAUD(tty))
sdio_uart_set_mctrl(port, TIOCM_RTS | TIOCM_DTR);
if (C_CRTSCTS(tty))
if (!(sdio_uart_get_mctrl(port) & TIOCM_CTS))
tty->hw_stopped = 1;
clear_bit(TTY_IO_ERROR, &tty->flags);
/* Kick the IRQ handler once while we're still holding the host lock */
sdio_uart_irq(port->func);
sdio_uart_release_func(port);
return 0;
err2:
sdio_disable_func(port->func);
err1:
sdio_uart_release_func(port);
return ret;
}
/**
* sdio_uart_shutdown - stop hardware
* @tport: tty port to shut down
*
* Deactivate a tty port. The port locking guarantees us this will be
* run only if a successful matching activate already ran. The two are
* protected from each other by the internal locking and will not run
* at the same time even during a hangup event.
*/
static void sdio_uart_shutdown(struct tty_port *tport)
{
struct sdio_uart_port *port =
container_of(tport, struct sdio_uart_port, port);
int ret;
ret = sdio_uart_claim_func(port);
if (ret)
return;
sdio_uart_stop_rx(port);
/* Disable interrupts from this port */
sdio_release_irq(port->func);
port->ier = 0;
sdio_out(port, UART_IER, 0);
sdio_uart_clear_mctrl(port, TIOCM_OUT2);
/* Disable break condition and FIFOs. */
port->lcr &= ~UART_LCR_SBC;
sdio_out(port, UART_LCR, port->lcr);
sdio_out(port, UART_FCR, UART_FCR_ENABLE_FIFO |
UART_FCR_CLEAR_RCVR |
UART_FCR_CLEAR_XMIT);
sdio_out(port, UART_FCR, 0);
sdio_disable_func(port->func);
sdio_uart_release_func(port);
}
static void sdio_uart_port_destroy(struct tty_port *tport)
{
struct sdio_uart_port *port =
container_of(tport, struct sdio_uart_port, port);
kfifo_free(&port->xmit_fifo);
kfree(port);
}
/**
* sdio_uart_install - install method
* @driver: the driver in use (sdio_uart in our case)
* @tty: the tty being bound
*
* Look up and bind the tty and the driver together. Initialize
* any needed private data (in our case the termios)
*/
static int sdio_uart_install(struct tty_driver *driver, struct tty_struct *tty)
{
int idx = tty->index;
struct sdio_uart_port *port = sdio_uart_port_get(idx);
int ret = tty_standard_install(driver, tty);
if (ret == 0)
/* This is the ref sdio_uart_port get provided */
tty->driver_data = port;
else
sdio_uart_port_put(port);
return ret;
}
/**
* sdio_uart_cleanup - called on the last tty kref drop
* @tty: the tty being destroyed
*
* Called asynchronously when the last reference to the tty is dropped.
* We cannot destroy the tty->driver_data port kref until this point
*/
static void sdio_uart_cleanup(struct tty_struct *tty)
{
struct sdio_uart_port *port = tty->driver_data;
tty->driver_data = NULL; /* Bug trap */
sdio_uart_port_put(port);
}
/*
* Open/close/hangup is now entirely boilerplate
*/
static int sdio_uart_open(struct tty_struct *tty, struct file *filp)
{
struct sdio_uart_port *port = tty->driver_data;
return tty_port_open(&port->port, tty, filp);
}
static void sdio_uart_close(struct tty_struct *tty, struct file * filp)
{
struct sdio_uart_port *port = tty->driver_data;
tty_port_close(&port->port, tty, filp);
}
static void sdio_uart_hangup(struct tty_struct *tty)
{
struct sdio_uart_port *port = tty->driver_data;
tty_port_hangup(&port->port);
}
static int sdio_uart_write(struct tty_struct *tty, const unsigned char *buf,
int count)
{
struct sdio_uart_port *port = tty->driver_data;
int ret;
if (!port->func)
return -ENODEV;
ret = kfifo_in_locked(&port->xmit_fifo, buf, count, &port->write_lock);
if (!(port->ier & UART_IER_THRI)) {
int err = sdio_uart_claim_func(port);
if (!err) {
sdio_uart_start_tx(port);
sdio_uart_irq(port->func);
sdio_uart_release_func(port);
} else
ret = err;
}
return ret;
}
static int sdio_uart_write_room(struct tty_struct *tty)
{
struct sdio_uart_port *port = tty->driver_data;
return FIFO_SIZE - kfifo_len(&port->xmit_fifo);
}
static int sdio_uart_chars_in_buffer(struct tty_struct *tty)
{
struct sdio_uart_port *port = tty->driver_data;
return kfifo_len(&port->xmit_fifo);
}
static void sdio_uart_send_xchar(struct tty_struct *tty, char ch)
{
struct sdio_uart_port *port = tty->driver_data;
port->x_char = ch;
if (ch && !(port->ier & UART_IER_THRI)) {
if (sdio_uart_claim_func(port) != 0)
return;
sdio_uart_start_tx(port);
sdio_uart_irq(port->func);
sdio_uart_release_func(port);
}
}
static void sdio_uart_throttle(struct tty_struct *tty)
{
struct sdio_uart_port *port = tty->driver_data;
if (!I_IXOFF(tty) && !C_CRTSCTS(tty))
return;
if (sdio_uart_claim_func(port) != 0)
return;
if (I_IXOFF(tty)) {
port->x_char = STOP_CHAR(tty);
sdio_uart_start_tx(port);
}
if (C_CRTSCTS(tty))
sdio_uart_clear_mctrl(port, TIOCM_RTS);
sdio_uart_irq(port->func);
sdio_uart_release_func(port);
}
static void sdio_uart_unthrottle(struct tty_struct *tty)
{
struct sdio_uart_port *port = tty->driver_data;
if (!I_IXOFF(tty) && !C_CRTSCTS(tty))
return;
if (sdio_uart_claim_func(port) != 0)
return;
if (I_IXOFF(tty)) {
if (port->x_char) {
port->x_char = 0;
} else {
port->x_char = START_CHAR(tty);
sdio_uart_start_tx(port);
}
}
if (C_CRTSCTS(tty))
sdio_uart_set_mctrl(port, TIOCM_RTS);
sdio_uart_irq(port->func);
sdio_uart_release_func(port);
}
static void sdio_uart_set_termios(struct tty_struct *tty,
struct ktermios *old_termios)
{
struct sdio_uart_port *port = tty->driver_data;
unsigned int cflag = tty->termios.c_cflag;
if (sdio_uart_claim_func(port) != 0)
return;
sdio_uart_change_speed(port, &tty->termios, old_termios);
/* Handle transition to B0 status */
if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
sdio_uart_clear_mctrl(port, TIOCM_RTS | TIOCM_DTR);
/* Handle transition away from B0 status */
if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
unsigned int mask = TIOCM_DTR;
if (!(cflag & CRTSCTS) || !tty_throttled(tty))
mask |= TIOCM_RTS;
sdio_uart_set_mctrl(port, mask);
}
/* Handle turning off CRTSCTS */
if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) {
tty->hw_stopped = 0;
sdio_uart_start_tx(port);
}
/* Handle turning on CRTSCTS */
if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) {
if (!(sdio_uart_get_mctrl(port) & TIOCM_CTS)) {
tty->hw_stopped = 1;
sdio_uart_stop_tx(port);
}
}
sdio_uart_release_func(port);
}
static int sdio_uart_break_ctl(struct tty_struct *tty, int break_state)
{
struct sdio_uart_port *port = tty->driver_data;
int result;
result = sdio_uart_claim_func(port);
if (result != 0)
return result;
if (break_state == -1)
port->lcr |= UART_LCR_SBC;
else
port->lcr &= ~UART_LCR_SBC;
sdio_out(port, UART_LCR, port->lcr);
sdio_uart_release_func(port);
return 0;
}
static int sdio_uart_tiocmget(struct tty_struct *tty)
{
struct sdio_uart_port *port = tty->driver_data;
int result;
result = sdio_uart_claim_func(port);
if (!result) {
result = port->mctrl | sdio_uart_get_mctrl(port);
sdio_uart_release_func(port);
}
return result;
}
static int sdio_uart_tiocmset(struct tty_struct *tty,
unsigned int set, unsigned int clear)
{
struct sdio_uart_port *port = tty->driver_data;
int result;
result = sdio_uart_claim_func(port);
if (!result) {
sdio_uart_update_mctrl(port, set, clear);
sdio_uart_release_func(port);
}
return result;
}
static int sdio_uart_proc_show(struct seq_file *m, void *v)
{
int i;
seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n",
"", "", "");
for (i = 0; i < UART_NR; i++) {
struct sdio_uart_port *port = sdio_uart_port_get(i);
if (port) {
seq_printf(m, "%d: uart:SDIO", i);
if (capable(CAP_SYS_ADMIN)) {
seq_printf(m, " tx:%d rx:%d",
port->icount.tx, port->icount.rx);
if (port->icount.frame)
seq_printf(m, " fe:%d",
port->icount.frame);
if (port->icount.parity)
seq_printf(m, " pe:%d",
port->icount.parity);
if (port->icount.brk)
seq_printf(m, " brk:%d",
port->icount.brk);
if (port->icount.overrun)
seq_printf(m, " oe:%d",
port->icount.overrun);
if (port->icount.cts)
seq_printf(m, " cts:%d",
port->icount.cts);
if (port->icount.dsr)
seq_printf(m, " dsr:%d",
port->icount.dsr);
if (port->icount.rng)
seq_printf(m, " rng:%d",
port->icount.rng);
if (port->icount.dcd)
seq_printf(m, " dcd:%d",
port->icount.dcd);
}
sdio_uart_port_put(port);
seq_putc(m, '\n');
}
}
return 0;
}
static const struct tty_port_operations sdio_uart_port_ops = {
.dtr_rts = uart_dtr_rts,
.carrier_raised = uart_carrier_raised,
.shutdown = sdio_uart_shutdown,
.activate = sdio_uart_activate,
.destruct = sdio_uart_port_destroy,
};
static const struct tty_operations sdio_uart_ops = {
.open = sdio_uart_open,
.close = sdio_uart_close,
.write = sdio_uart_write,
.write_room = sdio_uart_write_room,
.chars_in_buffer = sdio_uart_chars_in_buffer,
.send_xchar = sdio_uart_send_xchar,
.throttle = sdio_uart_throttle,
.unthrottle = sdio_uart_unthrottle,
.set_termios = sdio_uart_set_termios,
.hangup = sdio_uart_hangup,
.break_ctl = sdio_uart_break_ctl,
.tiocmget = sdio_uart_tiocmget,
.tiocmset = sdio_uart_tiocmset,
.install = sdio_uart_install,
.cleanup = sdio_uart_cleanup,
.proc_show = sdio_uart_proc_show,
};
static struct tty_driver *sdio_uart_tty_driver;
static int sdio_uart_probe(struct sdio_func *func,
const struct sdio_device_id *id)
{
struct sdio_uart_port *port;
int ret;
port = kzalloc(sizeof(struct sdio_uart_port), GFP_KERNEL);
if (!port)
return -ENOMEM;
if (func->class == SDIO_CLASS_UART) {
pr_warn("%s: need info on UART class basic setup\n",
sdio_func_id(func));
kfree(port);
return -ENOSYS;
} else if (func->class == SDIO_CLASS_GPS) {
/*
* We need tuple 0x91. It contains SUBTPL_SIOREG
* and SUBTPL_RCVCAPS.
*/
struct sdio_func_tuple *tpl;
for (tpl = func->tuples; tpl; tpl = tpl->next) {
if (tpl->code != 0x91)
continue;
if (tpl->size < 10)
continue;
if (tpl->data[1] == 0) /* SUBTPL_SIOREG */
break;
}
if (!tpl) {
pr_warn("%s: can't find tuple 0x91 subtuple 0 (SUBTPL_SIOREG) for GPS class\n",
sdio_func_id(func));
kfree(port);
return -EINVAL;
}
pr_debug("%s: Register ID = 0x%02x, Exp ID = 0x%02x\n",
sdio_func_id(func), tpl->data[2], tpl->data[3]);
port->regs_offset = (tpl->data[4] << 0) |
(tpl->data[5] << 8) |
(tpl->data[6] << 16);
pr_debug("%s: regs offset = 0x%x\n",
sdio_func_id(func), port->regs_offset);
port->uartclk = tpl->data[7] * 115200;
if (port->uartclk == 0)
port->uartclk = 115200;
pr_debug("%s: clk %d baudcode %u 4800-div %u\n",
sdio_func_id(func), port->uartclk,
tpl->data[7], tpl->data[8] | (tpl->data[9] << 8));
} else {
kfree(port);
return -EINVAL;
}
port->func = func;
sdio_set_drvdata(func, port);
tty_port_init(&port->port);
port->port.ops = &sdio_uart_port_ops;
ret = sdio_uart_add_port(port);
if (ret) {
kfree(port);
} else {
struct device *dev;
dev = tty_port_register_device(&port->port,
sdio_uart_tty_driver, port->index, &func->dev);
if (IS_ERR(dev)) {
sdio_uart_port_remove(port);
ret = PTR_ERR(dev);
}
}
return ret;
}
static void sdio_uart_remove(struct sdio_func *func)
{
struct sdio_uart_port *port = sdio_get_drvdata(func);
tty_unregister_device(sdio_uart_tty_driver, port->index);
sdio_uart_port_remove(port);
}
static const struct sdio_device_id sdio_uart_ids[] = {
{ SDIO_DEVICE_CLASS(SDIO_CLASS_UART) },
{ SDIO_DEVICE_CLASS(SDIO_CLASS_GPS) },
{ /* end: all zeroes */ },
};
MODULE_DEVICE_TABLE(sdio, sdio_uart_ids);
static struct sdio_driver sdio_uart_driver = {
.probe = sdio_uart_probe,
.remove = sdio_uart_remove,
.name = "sdio_uart",
.id_table = sdio_uart_ids,
};
static int __init sdio_uart_init(void)
{
int ret;
struct tty_driver *tty_drv;
sdio_uart_tty_driver = tty_drv = alloc_tty_driver(UART_NR);
if (!tty_drv)
return -ENOMEM;
tty_drv->driver_name = "sdio_uart";
tty_drv->name = "ttySDIO";
tty_drv->major = 0; /* dynamically allocated */
tty_drv->minor_start = 0;
tty_drv->type = TTY_DRIVER_TYPE_SERIAL;
tty_drv->subtype = SERIAL_TYPE_NORMAL;
tty_drv->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV;
tty_drv->init_termios = tty_std_termios;
tty_drv->init_termios.c_cflag = B4800 | CS8 | CREAD | HUPCL | CLOCAL;
tty_drv->init_termios.c_ispeed = 4800;
tty_drv->init_termios.c_ospeed = 4800;
tty_set_operations(tty_drv, &sdio_uart_ops);
ret = tty_register_driver(tty_drv);
if (ret)
goto err1;
ret = sdio_register_driver(&sdio_uart_driver);
if (ret)
goto err2;
return 0;
err2:
tty_unregister_driver(tty_drv);
err1:
put_tty_driver(tty_drv);
return ret;
}
static void __exit sdio_uart_exit(void)
{
sdio_unregister_driver(&sdio_uart_driver);
tty_unregister_driver(sdio_uart_tty_driver);
put_tty_driver(sdio_uart_tty_driver);
}
module_init(sdio_uart_init);
module_exit(sdio_uart_exit);
MODULE_AUTHOR("Nicolas Pitre");
MODULE_LICENSE("GPL");