--- /dev/null
+/*
+ * linux/drivers/mmc/card/sdio_uart.c - 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.
+ *
+ * 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.
+ */
+
+/*
+ * 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/mutex.h>
+#include <linux/serial_reg.h>
+#include <linux/circ_buf.h>
+#include <linux/gfp.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.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 UART_XMIT_SIZE PAGE_SIZE
+#define WAKEUP_CHARS 256
+
+#define circ_empty(circ) ((circ)->head == (circ)->tail)
+#define circ_clear(circ) ((circ)->head = (circ)->tail = 0)
+
+#define circ_chars_pending(circ) \
+ (CIRC_CNT((circ)->head, (circ)->tail, UART_XMIT_SIZE))
+
+#define circ_chars_free(circ) \
+ (CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE))
+
+
+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 kref kref;
+ struct tty_struct *tty;
+ unsigned int index;
+ unsigned int opened;
+ struct mutex open_lock;
+ struct sdio_func *func;
+ struct mutex func_lock;
+ unsigned int regs_offset;
+ struct circ_buf xmit;
+ spinlock_t write_lock;
+ struct uart_icount icount;
+ unsigned int uartclk;
+ unsigned int 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;
+
+ kref_init(&port->kref);
+ mutex_init(&port->open_lock);
+ mutex_init(&port->func_lock);
+ spin_lock_init(&port->write_lock);
+
+ 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)
+ kref_get(&port->kref);
+ spin_unlock(&sdio_uart_table_lock);
+
+ return port;
+}
+
+static void sdio_uart_port_destroy(struct kref *kref)
+{
+ struct sdio_uart_port *port =
+ container_of(kref, struct sdio_uart_port, kref);
+ kfree(port);
+}
+
+static void sdio_uart_port_put(struct sdio_uart_port *port)
+{
+ kref_put(&port->kref, sdio_uart_port_destroy);
+}
+
+static void sdio_uart_port_remove(struct sdio_uart_port *port)
+{
+ struct sdio_func *func;
+
+ BUG_ON(sdio_uart_table[port->index] != port);
+
+ 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->open_lock);
+ mutex_lock(&port->func_lock);
+ func = port->func;
+ sdio_claim_host(func);
+ port->func = NULL;
+ mutex_unlock(&port->func_lock);
+ if (port->opened)
+ tty_hangup(port->tty);
+ mutex_unlock(&port->open_lock);
+ 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;
+ }
+ sdio_claim_host(port->func);
+ mutex_unlock(&port->func_lock);
+ return 0;
+}
+
+static inline void sdio_uart_release_func(struct sdio_uart_port *port)
+{
+ 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;
+
+ 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, int *status)
+{
+ struct tty_struct *tty = port->tty;
+ 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(tty, 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(tty, 0, TTY_OVERRUN);
+
+ *status = sdio_in(port, UART_LSR);
+ } while ((*status & UART_LSR_DR) && (max_count-- > 0));
+ tty_flip_buffer_push(tty);
+}
+
+static void sdio_uart_transmit_chars(struct sdio_uart_port *port)
+{
+ struct circ_buf *xmit = &port->xmit;
+ int count;
+
+ if (port->x_char) {
+ sdio_out(port, UART_TX, port->x_char);
+ port->icount.tx++;
+ port->x_char = 0;
+ return;
+ }
+ if (circ_empty(xmit) || port->tty->stopped || port->tty->hw_stopped) {
+ sdio_uart_stop_tx(port);
+ return;
+ }
+
+ count = 16;
+ do {
+ sdio_out(port, UART_TX, xmit->buf[xmit->tail]);
+ xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+ port->icount.tx++;
+ if (circ_empty(xmit))
+ break;
+ } while (--count > 0);
+
+ if (circ_chars_pending(xmit) < WAKEUP_CHARS)
+ tty_wakeup(port->tty);
+
+ if (circ_empty(xmit))
+ sdio_uart_stop_tx(port);
+}
+
+static void sdio_uart_check_modem_status(struct sdio_uart_port *port)
+{
+ int status;
+
+ 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++;
+ if (status & UART_MSR_DCTS) {
+ port->icount.cts++;
+ if (port->tty->termios->c_cflag & CRTSCTS) {
+ int cts = (status & UART_MSR_CTS);
+ if (port->tty->hw_stopped) {
+ if (cts) {
+ port->tty->hw_stopped = 0;
+ sdio_uart_start_tx(port);
+ tty_wakeup(port->tty);
+ }
+ } else {
+ if (!cts) {
+ port->tty->hw_stopped = 1;
+ sdio_uart_stop_tx(port);
+ }
+ }
+ }
+ }
+}
+
+/*
+ * 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;
+
+ iir = sdio_in(port, UART_IIR);
+ if (iir & UART_IIR_NO_INT)
+ return;
+ 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);
+}
+
+static int sdio_uart_startup(struct sdio_uart_port *port)
+{
+ unsigned long page;
+ 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, &port->tty->flags);
+
+ /* Initialise and allocate the transmit buffer. */
+ page = __get_free_page(GFP_KERNEL);
+ if (!page)
+ return -ENOMEM;
+ port->xmit.buf = (unsigned char *)page;
+ circ_clear(&port->xmit);
+
+ ret = sdio_uart_claim_func(port);
+ if (ret)
+ goto err1;
+ ret = sdio_enable_func(port->func);
+ if (ret)
+ goto err2;
+ ret = sdio_claim_irq(port->func, sdio_uart_irq);
+ if (ret)
+ goto err3;
+
+ /*
+ * 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, port->tty->termios, NULL);
+
+ if (port->tty->termios->c_cflag & CBAUD)
+ sdio_uart_set_mctrl(port, TIOCM_RTS | TIOCM_DTR);
+
+ if (port->tty->termios->c_cflag & CRTSCTS)
+ if (!(sdio_uart_get_mctrl(port) & TIOCM_CTS))
+ port->tty->hw_stopped = 1;
+
+ clear_bit(TTY_IO_ERROR, &port->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;
+
+err3:
+ sdio_disable_func(port->func);
+err2:
+ sdio_uart_release_func(port);
+err1:
+ free_page((unsigned long)port->xmit.buf);
+ return ret;
+}
+
+static void sdio_uart_shutdown(struct sdio_uart_port *port)
+{
+ int ret;
+
+ ret = sdio_uart_claim_func(port);
+ if (ret)
+ goto skip;
+
+ sdio_uart_stop_rx(port);
+
+ /* TODO: wait here for TX FIFO to drain */
+
+ /* Turn off DTR and RTS early. */
+ if (port->tty->termios->c_cflag & HUPCL)
+ sdio_uart_clear_mctrl(port, TIOCM_DTR | TIOCM_RTS);
+
+ /* 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);
+
+skip:
+ /* Free the transmit buffer page. */
+ free_page((unsigned long)port->xmit.buf);
+}
+
+static int sdio_uart_open (struct tty_struct *tty, struct file * filp)
+{
+ struct sdio_uart_port *port;
+ int ret;
+
+ port = sdio_uart_port_get(tty->index);
+ if (!port)
+ return -ENODEV;
+
+ mutex_lock(&port->open_lock);
+
+ /*
+ * Make sure not to mess up with a dead port
+ * which has not been closed yet.
+ */
+ if (tty->driver_data && tty->driver_data != port) {
+ mutex_unlock(&port->open_lock);
+ sdio_uart_port_put(port);
+ return -EBUSY;
+ }
+
+ if (!port->opened) {
+ tty->driver_data = port;
+ port->tty = tty;
+ ret = sdio_uart_startup(port);
+ if (ret) {
+ tty->driver_data = NULL;
+ port->tty = NULL;
+ mutex_unlock(&port->open_lock);
+ sdio_uart_port_put(port);
+ return ret;
+ }
+ }
+ port->opened++;
+ mutex_unlock(&port->open_lock);
+ return 0;
+}
+
+static void sdio_uart_close(struct tty_struct *tty, struct file * filp)
+{
+ struct sdio_uart_port *port = tty->driver_data;
+
+ if (!port)
+ return;
+
+ mutex_lock(&port->open_lock);
+ BUG_ON(!port->opened);
+
+ /*
+ * This is messy. The tty layer calls us even when open()
+ * returned an error. Ignore this close request if tty->count
+ * is larger than port->count.
+ */
+ if (tty->count > port->opened) {
+ mutex_unlock(&port->open_lock);
+ return;
+ }
+
+ if (--port->opened == 0) {
+ tty->closing = 1;
+ sdio_uart_shutdown(port);
+ tty_ldisc_flush(tty);
+ port->tty = NULL;
+ tty->driver_data = NULL;
+ tty->closing = 0;
+ }
+ mutex_unlock(&port->open_lock);
+ sdio_uart_port_put(port);
+}
+
+static int sdio_uart_write(struct tty_struct * tty, const unsigned char *buf,
+ int count)
+{
+ struct sdio_uart_port *port = tty->driver_data;
+ struct circ_buf *circ = &port->xmit;
+ int c, ret = 0;
+
+ if (!port->func)
+ return -ENODEV;
+
+ spin_lock(&port->write_lock);
+ while (1) {
+ c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE);
+ if (count < c)
+ c = count;
+ if (c <= 0)
+ break;
+ memcpy(circ->buf + circ->head, buf, c);
+ circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1);
+ buf += c;
+ count -= c;
+ ret += c;
+ }
+ spin_unlock(&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 port ? circ_chars_free(&port->xmit) : 0;
+}
+
+static int sdio_uart_chars_in_buffer(struct tty_struct *tty)
+{
+ struct sdio_uart_port *port = tty->driver_data;
+ return port ? circ_chars_pending(&port->xmit) : 0;
+}
+
+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) && !(tty->termios->c_cflag & CRTSCTS))
+ 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 (tty->termios->c_cflag & CRTSCTS)
+ 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) && !(tty->termios->c_cflag & CRTSCTS))
+ 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 (tty->termios->c_cflag & CRTSCTS)
+ 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;
+
+#define RELEVANT_IFLAG(iflag) ((iflag) & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
+
+ if ((cflag ^ old_termios->c_cflag) == 0 &&
+ RELEVANT_IFLAG(tty->termios->c_iflag ^ old_termios->c_iflag) == 0)
+ return;
+
+ 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) || !test_bit(TTY_THROTTLED, &tty->flags))
+ 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 void sdio_uart_break_ctl(struct tty_struct *tty, int break_state)
+{
+ struct sdio_uart_port *port = tty->driver_data;
+
+ if (sdio_uart_claim_func(port) != 0)
+ return;
+
+ 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);
+}
+
+static int sdio_uart_tiocmget(struct tty_struct *tty, struct file *file)
+{
+ 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, struct file *file,
+ 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 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,
+ .break_ctl = sdio_uart_break_ctl,
+ .tiocmget = sdio_uart_tiocmget,
+ .tiocmset = sdio_uart_tiocmset,
+};
+
+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) {
+ printk(KERN_WARNING "%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) {
+ printk(KERN_WARNING
+ "%s: can't find tuple 0x91 subtuple 0 (SUBTPL_SIOREG) for GPS class\n",
+ sdio_func_id(func));
+ kfree(port);
+ return -EINVAL;
+ }
+ printk(KERN_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);
+ printk(KERN_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;
+ printk(KERN_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);
+
+ ret = sdio_uart_add_port(port);
+ if (ret) {
+ kfree(port);
+ } else {
+ struct device *dev;
+ dev = tty_register_device(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->owner = THIS_MODULE;
+ 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_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");
projects / linux-2.6 / commitdiff