diff options
Diffstat (limited to 'drivers/mmc/core/sdio_uart.c')
| -rw-r--r-- | drivers/mmc/core/sdio_uart.c | 1200 |
1 files changed, 1200 insertions, 0 deletions
diff --git a/drivers/mmc/core/sdio_uart.c b/drivers/mmc/core/sdio_uart.c new file mode 100644 index 000000000000..d3c91f412b69 --- /dev/null +++ b/drivers/mmc/core/sdio_uart.c @@ -0,0 +1,1200 @@ +/* + * 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/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 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, + .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_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) { + 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"); |