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linux-zen-desktop/drivers/mmc/core/sdio_uart.c

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// 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.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,
const struct ktermios *old)
{
unsigned char cval, fcr = 0;
unsigned int baud, quot;
cval = UART_LCR_WLEN(tty_get_char_size(termios->c_cflag));
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->flow.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 = false;
sdio_uart_start_tx(port);
tty_wakeup(tty);
}
} else {
if (!cts) {
tty->hw_stopped = true;
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 bool 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);
return ret & TIOCM_CAR;
}
/**
* uart_dtr_rts - port helper to set uart signals
* @tport: tty port to be updated
* @active: 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, bool active)
{
struct sdio_uart_port *port =
container_of(tport, struct sdio_uart_port, port);
int ret = sdio_uart_claim_func(port);
if (ret)
return;
if (!active)
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 = true;
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 unsigned 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 unsigned 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,
const 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 = false;
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 = true;
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 = tty_alloc_driver(UART_NR,
TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV);
if (IS_ERR(tty_drv))
return PTR_ERR(tty_drv);
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->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:
tty_driver_kref_put(tty_drv);
return ret;
}
static void __exit sdio_uart_exit(void)
{
sdio_unregister_driver(&sdio_uart_driver);
tty_unregister_driver(sdio_uart_tty_driver);
tty_driver_kref_put(sdio_uart_tty_driver);
}
module_init(sdio_uart_init);
module_exit(sdio_uart_exit);
MODULE_AUTHOR("Nicolas Pitre");
MODULE_LICENSE("GPL");
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