| /* |
| * 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/sched.h> |
| #include <linux/mutex.h> |
| #include <linux/seq_file.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 tty_port port; |
| struct kref kref; |
| struct tty_struct *tty; |
| unsigned int index; |
| struct sdio_func *func; |
| struct mutex func_lock; |
| struct task_struct *in_sdio_uart_irq; |
| unsigned int regs_offset; |
| struct circ_buf xmit; |
| 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; |
| |
| kref_init(&port->kref); |
| 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; |
| struct tty_struct *tty; |
| |
| 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->port.mutex); |
| mutex_lock(&port->func_lock); |
| func = port->func; |
| sdio_claim_host(func); |
| port->func = NULL; |
| mutex_unlock(&port->func_lock); |
| tty = tty_port_tty_get(&port->port); |
| /* tty_hangup is async so is this safe as is ?? */ |
| if (tty) { |
| tty_hangup(tty); |
| tty_kref_put(tty); |
| } |
| 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) |
| { |
| struct tty_struct *tty = tty_port_tty_get(&port->port); |
| 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) |
| if (tty) |
| 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) |
| if (tty) |
| tty_insert_flip_char(tty, 0, TTY_OVERRUN); |
| |
| *status = sdio_in(port, UART_LSR); |
| } while ((*status & UART_LSR_DR) && (max_count-- > 0)); |
| if (tty) { |
| tty_flip_buffer_push(tty); |
| tty_kref_put(tty); |
| } |
| } |
| |
| static void sdio_uart_transmit_chars(struct sdio_uart_port *port) |
| { |
| struct circ_buf *xmit = &port->xmit; |
| int count; |
| struct tty_struct *tty; |
| |
| 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 || circ_empty(xmit) || |
| tty->stopped || tty->hw_stopped) { |
| sdio_uart_stop_tx(port); |
| tty_kref_put(tty); |
| 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(tty); |
| |
| if (circ_empty(xmit)) |
| 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 = tty_port_tty_get(&port->port); |
| if (tty) { |
| tty_hangup(tty); |
| tty_kref_put(tty); |
| } |
| } |
| } |
| if (status & UART_MSR_DCTS) { |
| port->icount.cts++; |
| tty = tty_port_tty_get(&port->port); |
| if (tty && (tty->termios->c_cflag & CRTSCTS)) { |
| 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); |
| 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, &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, tty->termios, NULL); |
| |
| if (tty->termios->c_cflag & CBAUD) |
| sdio_uart_set_mctrl(port, TIOCM_RTS | TIOCM_DTR); |
| |
| if (tty->termios->c_cflag & CRTSCTS) |
| 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; |
| |
| err3: |
| sdio_disable_func(port->func); |
| err2: |
| sdio_uart_release_func(port); |
| err1: |
| free_page((unsigned long)port->xmit.buf); |
| 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) |
| goto skip; |
| |
| 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); |
| |
| skip: |
| /* Free the transmit buffer page. */ |
| free_page((unsigned long)port->xmit.buf); |
| } |
| |
| /** |
| * 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_init_termios(tty); |
| |
| if (ret == 0) { |
| tty_driver_kref_get(driver); |
| tty->count++; |
| /* This is the ref sdio_uart_port get provided */ |
| tty->driver_data = port; |
| driver->ttys[idx] = tty; |
| } 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; |
| 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; |
| |
| 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 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 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 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 int sdio_uart_proc_open(struct inode *inode, struct file *file) |
| { |
| return single_open(file, sdio_uart_proc_show, NULL); |
| } |
| |
| static const struct file_operations sdio_uart_proc_fops = { |
| .owner = THIS_MODULE, |
| .open = sdio_uart_proc_open, |
| .read = seq_read, |
| .llseek = seq_lseek, |
| .release = single_release, |
| }; |
| |
| 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, |
| }; |
| |
| 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_fops = &sdio_uart_proc_fops, |
| }; |
| |
| 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); |
| 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_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_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"); |