diff options
Diffstat (limited to 'drivers/tty/serial/sc16is7xx.c')
| -rw-r--r-- | drivers/tty/serial/sc16is7xx.c | 263 |
1 files changed, 231 insertions, 32 deletions
diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c index 3a6c68e19c80d2..e857fb61efbfc4 100644 --- a/drivers/tty/serial/sc16is7xx.c +++ b/drivers/tty/serial/sc16is7xx.c @@ -289,6 +289,14 @@ * XON1, XON2, XOFF1 and * XOFF2 */ +#define SC16IS7XX_EFR_FLOWCTRL_BITS (SC16IS7XX_EFR_AUTORTS_BIT | \ + SC16IS7XX_EFR_AUTOCTS_BIT | \ + SC16IS7XX_EFR_XOFF2_DETECT_BIT | \ + SC16IS7XX_EFR_SWFLOW3_BIT | \ + SC16IS7XX_EFR_SWFLOW2_BIT | \ + SC16IS7XX_EFR_SWFLOW1_BIT | \ + SC16IS7XX_EFR_SWFLOW0_BIT) + /* Misc definitions */ #define SC16IS7XX_FIFO_SIZE (64) @@ -298,6 +306,7 @@ struct sc16is7xx_devtype { char name[10]; int nr_gpio; int nr_uart; + int has_mctrl; }; #define SC16IS7XX_RECONF_MD (1 << 0) @@ -306,7 +315,8 @@ struct sc16is7xx_devtype { struct sc16is7xx_one_config { unsigned int flags; - u8 ier_clear; + u8 ier_mask; + u8 ier_val; }; struct sc16is7xx_one { @@ -314,8 +324,10 @@ struct sc16is7xx_one { u8 line; struct kthread_work tx_work; struct kthread_work reg_work; + struct kthread_delayed_work ms_work; struct sc16is7xx_one_config config; bool irda_mode; + unsigned int old_mctrl; }; struct sc16is7xx_port { @@ -340,6 +352,9 @@ static struct uart_driver sc16is7xx_uart = { .nr = SC16IS7XX_MAX_DEVS, }; +static void sc16is7xx_ier_set(struct uart_port *port, u8 bit); +static void sc16is7xx_stop_tx(struct uart_port *port); + #define to_sc16is7xx_port(p,e) ((container_of((p), struct sc16is7xx_port, e))) #define to_sc16is7xx_one(p,e) ((container_of((p), struct sc16is7xx_one, e))) @@ -432,30 +447,35 @@ static const struct sc16is7xx_devtype sc16is74x_devtype = { .name = "SC16IS74X", .nr_gpio = 0, .nr_uart = 1, + .has_mctrl = 0, }; static const struct sc16is7xx_devtype sc16is750_devtype = { .name = "SC16IS750", - .nr_gpio = 8, + .nr_gpio = 4, .nr_uart = 1, + .has_mctrl = 1, }; static const struct sc16is7xx_devtype sc16is752_devtype = { .name = "SC16IS752", - .nr_gpio = 8, + .nr_gpio = 0, .nr_uart = 2, + .has_mctrl = 1, }; static const struct sc16is7xx_devtype sc16is760_devtype = { .name = "SC16IS760", - .nr_gpio = 8, + .nr_gpio = 4, .nr_uart = 1, + .has_mctrl = 1, }; static const struct sc16is7xx_devtype sc16is762_devtype = { .name = "SC16IS762", - .nr_gpio = 8, + .nr_gpio = 0, .nr_uart = 2, + .has_mctrl = 1, }; static bool sc16is7xx_regmap_volatile(struct device *dev, unsigned int reg) @@ -523,8 +543,10 @@ static int sc16is7xx_set_baud(struct uart_port *port, int baud) /* Enable enhanced features */ regcache_cache_bypass(s->regmap, true); - sc16is7xx_port_write(port, SC16IS7XX_EFR_REG, - SC16IS7XX_EFR_ENABLE_BIT); + sc16is7xx_port_update(port, SC16IS7XX_EFR_REG, + SC16IS7XX_EFR_ENABLE_BIT, + SC16IS7XX_EFR_ENABLE_BIT); + regcache_cache_bypass(s->regmap, false); /* Put LCR back to the normal mode */ @@ -635,6 +657,7 @@ static void sc16is7xx_handle_tx(struct uart_port *port) struct sc16is7xx_port *s = dev_get_drvdata(port->dev); struct circ_buf *xmit = &port->state->xmit; unsigned int txlen, to_send, i; + unsigned long flags; if (unlikely(port->x_char)) { sc16is7xx_port_write(port, SC16IS7XX_THR_REG, port->x_char); @@ -643,8 +666,12 @@ static void sc16is7xx_handle_tx(struct uart_port *port) return; } - if (uart_circ_empty(xmit) || uart_tx_stopped(port)) + if (uart_circ_empty(xmit) || uart_tx_stopped(port)) { + spin_lock_irqsave(&port->lock, flags); + sc16is7xx_stop_tx(port); + spin_unlock_irqrestore(&port->lock, flags); return; + } /* Get length of data pending in circular buffer */ to_send = uart_circ_chars_pending(xmit); @@ -671,8 +698,56 @@ static void sc16is7xx_handle_tx(struct uart_port *port) sc16is7xx_fifo_write(port, to_send); } + spin_lock_irqsave(&port->lock, flags); if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) uart_write_wakeup(port); + + if (uart_circ_empty(xmit)) + sc16is7xx_stop_tx(port); + spin_unlock_irqrestore(&port->lock, flags); +} + +static unsigned int sc16is7xx_get_hwmctrl(struct uart_port *port) +{ + u8 msr = sc16is7xx_port_read(port, SC16IS7XX_MSR_REG); + unsigned int mctrl = 0; + + mctrl |= (msr & SC16IS7XX_MSR_CTS_BIT) ? TIOCM_CTS : 0; + mctrl |= (msr & SC16IS7XX_MSR_DSR_BIT) ? TIOCM_DSR : 0; + mctrl |= (msr & SC16IS7XX_MSR_CD_BIT) ? TIOCM_CAR : 0; + mctrl |= (msr & SC16IS7XX_MSR_RI_BIT) ? TIOCM_RNG : 0; + return mctrl; +} + +static void sc16is7xx_update_mlines(struct sc16is7xx_one *one) +{ + struct uart_port *port = &one->port; + struct sc16is7xx_port *s = dev_get_drvdata(port->dev); + unsigned long flags; + unsigned int status, changed; + + lockdep_assert_held_once(&s->efr_lock); + + status = sc16is7xx_get_hwmctrl(port); + changed = status ^ one->old_mctrl; + + if (changed == 0) + return; + + one->old_mctrl = status; + + spin_lock_irqsave(&port->lock, flags); + if ((changed & TIOCM_RNG) && (status & TIOCM_RNG)) + port->icount.rng++; + if (changed & TIOCM_DSR) + port->icount.dsr++; + if (changed & TIOCM_CAR) + uart_handle_dcd_change(port, status & TIOCM_CAR); + if (changed & TIOCM_CTS) + uart_handle_cts_change(port, status & TIOCM_CTS); + + wake_up_interruptible(&port->state->port.delta_msr_wait); + spin_unlock_irqrestore(&port->lock, flags); } static bool sc16is7xx_port_irq(struct sc16is7xx_port *s, int portno) @@ -681,6 +756,7 @@ static bool sc16is7xx_port_irq(struct sc16is7xx_port *s, int portno) do { unsigned int iir, rxlen; + struct sc16is7xx_one *one = to_sc16is7xx_one(port, port); iir = sc16is7xx_port_read(port, SC16IS7XX_IIR_REG); if (iir & SC16IS7XX_IIR_NO_INT_BIT) @@ -697,6 +773,11 @@ static bool sc16is7xx_port_irq(struct sc16is7xx_port *s, int portno) if (rxlen) sc16is7xx_handle_rx(port, rxlen, iir); break; + /* CTSRTS interrupt comes only when CTS goes inactive */ + case SC16IS7XX_IIR_CTSRTS_SRC: + case SC16IS7XX_IIR_MSI_SRC: + sc16is7xx_update_mlines(one); + break; case SC16IS7XX_IIR_THRI_SRC: sc16is7xx_handle_tx(port); break; @@ -735,6 +816,7 @@ static void sc16is7xx_tx_proc(struct kthread_work *ws) { struct uart_port *port = &(to_sc16is7xx_one(ws, tx_work)->port); struct sc16is7xx_port *s = dev_get_drvdata(port->dev); + unsigned long flags; if ((port->rs485.flags & SER_RS485_ENABLED) && (port->rs485.delay_rts_before_send > 0)) @@ -743,6 +825,10 @@ static void sc16is7xx_tx_proc(struct kthread_work *ws) mutex_lock(&s->efr_lock); sc16is7xx_handle_tx(port); mutex_unlock(&s->efr_lock); + + spin_lock_irqsave(&port->lock, flags); + sc16is7xx_ier_set(port, SC16IS7XX_IER_THRI_BIT); + spin_unlock_irqrestore(&port->lock, flags); } static void sc16is7xx_reconf_rs485(struct uart_port *port) @@ -777,22 +863,27 @@ static void sc16is7xx_reg_proc(struct kthread_work *ws) spin_unlock_irqrestore(&one->port.lock, irqflags); if (config.flags & SC16IS7XX_RECONF_MD) { + u8 mcr = 0; + + /* Device ignores RTS setting when hardware flow is enabled */ + if (one->port.mctrl & TIOCM_RTS) + mcr |= SC16IS7XX_MCR_RTS_BIT; + + if (one->port.mctrl & TIOCM_DTR) + mcr |= SC16IS7XX_MCR_DTR_BIT; + + if (one->port.mctrl & TIOCM_LOOP) + mcr |= SC16IS7XX_MCR_LOOP_BIT; sc16is7xx_port_update(&one->port, SC16IS7XX_MCR_REG, + SC16IS7XX_MCR_RTS_BIT | + SC16IS7XX_MCR_DTR_BIT | SC16IS7XX_MCR_LOOP_BIT, - (one->port.mctrl & TIOCM_LOOP) ? - SC16IS7XX_MCR_LOOP_BIT : 0); - sc16is7xx_port_update(&one->port, SC16IS7XX_MCR_REG, - SC16IS7XX_MCR_RTS_BIT, - (one->port.mctrl & TIOCM_RTS) ? - SC16IS7XX_MCR_RTS_BIT : 0); - sc16is7xx_port_update(&one->port, SC16IS7XX_MCR_REG, - SC16IS7XX_MCR_DTR_BIT, - (one->port.mctrl & TIOCM_DTR) ? - SC16IS7XX_MCR_DTR_BIT : 0); + mcr); } + if (config.flags & SC16IS7XX_RECONF_IER) sc16is7xx_port_update(&one->port, SC16IS7XX_IER_REG, - config.ier_clear, 0); + config.ier_mask, config.ier_val); if (config.flags & SC16IS7XX_RECONF_RS485) sc16is7xx_reconf_rs485(&one->port); @@ -803,8 +894,24 @@ static void sc16is7xx_ier_clear(struct uart_port *port, u8 bit) struct sc16is7xx_port *s = dev_get_drvdata(port->dev); struct sc16is7xx_one *one = to_sc16is7xx_one(port, port); + lockdep_assert_held_once(&port->lock); + + one->config.flags |= SC16IS7XX_RECONF_IER; + one->config.ier_mask |= bit; + one->config.ier_val &= ~bit; + kthread_queue_work(&s->kworker, &one->reg_work); +} + +static void sc16is7xx_ier_set(struct uart_port *port, u8 bit) +{ + struct sc16is7xx_port *s = dev_get_drvdata(port->dev); + struct sc16is7xx_one *one = to_sc16is7xx_one(port, port); + + lockdep_assert_held_once(&port->lock); + one->config.flags |= SC16IS7XX_RECONF_IER; - one->config.ier_clear |= bit; + one->config.ier_mask |= bit; + one->config.ier_val |= bit; kthread_queue_work(&s->kworker, &one->reg_work); } @@ -818,6 +925,30 @@ static void sc16is7xx_stop_rx(struct uart_port *port) sc16is7xx_ier_clear(port, SC16IS7XX_IER_RDI_BIT); } +static void sc16is7xx_ms_proc(struct kthread_work *ws) +{ + struct sc16is7xx_one *one = to_sc16is7xx_one(ws, ms_work.work); + struct sc16is7xx_port *s = dev_get_drvdata(one->port.dev); + + if (one->port.state) { + mutex_lock(&s->efr_lock); + sc16is7xx_update_mlines(one); + mutex_unlock(&s->efr_lock); + + kthread_queue_delayed_work(&s->kworker, &one->ms_work, HZ); + } +} + +static void sc16is7xx_enable_ms(struct uart_port *port) +{ + struct sc16is7xx_one *one = to_sc16is7xx_one(port, port); + struct sc16is7xx_port *s = dev_get_drvdata(port->dev); + + lockdep_assert_held_once(&port->lock); + + kthread_queue_delayed_work(&s->kworker, &one->ms_work, 0); +} + static void sc16is7xx_start_tx(struct uart_port *port) { struct sc16is7xx_port *s = dev_get_drvdata(port->dev); @@ -826,6 +957,29 @@ static void sc16is7xx_start_tx(struct uart_port *port) kthread_queue_work(&s->kworker, &one->tx_work); } +static void sc16is7xx_throttle(struct uart_port *port) +{ + unsigned long flags; + + /* + * Hardware flow control is enabled and thus the device ignores RTS + * value set in MCR register. Stop reading data from RX FIFO so the + * AutoRTS feature will de-activate RTS output. + */ + spin_lock_irqsave(&port->lock, flags); + sc16is7xx_ier_clear(port, SC16IS7XX_IER_RDI_BIT); + spin_unlock_irqrestore(&port->lock, flags); +} + +static void sc16is7xx_unthrottle(struct uart_port *port) +{ + unsigned long flags; + + spin_lock_irqsave(&port->lock, flags); + sc16is7xx_ier_set(port, SC16IS7XX_IER_RDI_BIT); + spin_unlock_irqrestore(&port->lock, flags); +} + static unsigned int sc16is7xx_tx_empty(struct uart_port *port) { unsigned int lsr; @@ -837,10 +991,10 @@ static unsigned int sc16is7xx_tx_empty(struct uart_port *port) static unsigned int sc16is7xx_get_mctrl(struct uart_port *port) { - /* DCD and DSR are not wired and CTS/RTS is handled automatically - * so just indicate DSR and CAR asserted - */ - return TIOCM_DSR | TIOCM_CAR; + struct sc16is7xx_one *one = to_sc16is7xx_one(port, port); + + /* Called with port lock taken so we can only return cached value */ + return one->old_mctrl; } static void sc16is7xx_set_mctrl(struct uart_port *port, unsigned int mctrl) @@ -864,8 +1018,12 @@ static void sc16is7xx_set_termios(struct uart_port *port, struct ktermios *old) { struct sc16is7xx_port *s = dev_get_drvdata(port->dev); + struct sc16is7xx_one *one = to_sc16is7xx_one(port, port); unsigned int lcr, flow = 0; int baud; + unsigned long flags; + + kthread_cancel_delayed_work_sync(&one->ms_work); /* Mask termios capabilities we don't support */ termios->c_cflag &= ~CMSPAR; @@ -927,15 +1085,22 @@ static void sc16is7xx_set_termios(struct uart_port *port, regcache_cache_bypass(s->regmap, true); sc16is7xx_port_write(port, SC16IS7XX_XON1_REG, termios->c_cc[VSTART]); sc16is7xx_port_write(port, SC16IS7XX_XOFF1_REG, termios->c_cc[VSTOP]); - if (termios->c_cflag & CRTSCTS) + + port->status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS); + if (termios->c_cflag & CRTSCTS) { flow |= SC16IS7XX_EFR_AUTOCTS_BIT | SC16IS7XX_EFR_AUTORTS_BIT; + port->status |= UPSTAT_AUTOCTS | UPSTAT_AUTORTS; + } if (termios->c_iflag & IXON) flow |= SC16IS7XX_EFR_SWFLOW3_BIT; if (termios->c_iflag & IXOFF) flow |= SC16IS7XX_EFR_SWFLOW1_BIT; - sc16is7xx_port_write(port, SC16IS7XX_EFR_REG, flow); + sc16is7xx_port_update(port, + SC16IS7XX_EFR_REG, + SC16IS7XX_EFR_FLOWCTRL_BITS, + flow); regcache_cache_bypass(s->regmap, false); /* Update LCR register */ @@ -951,8 +1116,15 @@ static void sc16is7xx_set_termios(struct uart_port *port, /* Setup baudrate generator */ baud = sc16is7xx_set_baud(port, baud); + spin_lock_irqsave(&port->lock, flags); + /* Update timeout according to new baud rate */ uart_update_timeout(port, termios->c_cflag, baud); + + if (UART_ENABLE_MS(port, termios->c_cflag)) + sc16is7xx_enable_ms(port); + + spin_unlock_irqrestore(&port->lock, flags); } static int sc16is7xx_config_rs485(struct uart_port *port, @@ -993,6 +1165,7 @@ static int sc16is7xx_startup(struct uart_port *port) struct sc16is7xx_one *one = to_sc16is7xx_one(port, port); struct sc16is7xx_port *s = dev_get_drvdata(port->dev); unsigned int val; + unsigned long flags; sc16is7xx_power(port, 1); @@ -1010,8 +1183,9 @@ static int sc16is7xx_startup(struct uart_port *port) regcache_cache_bypass(s->regmap, true); /* Enable write access to enhanced features and internal clock div */ - sc16is7xx_port_write(port, SC16IS7XX_EFR_REG, - SC16IS7XX_EFR_ENABLE_BIT); + sc16is7xx_port_update(port, SC16IS7XX_EFR_REG, + SC16IS7XX_EFR_ENABLE_BIT, + SC16IS7XX_EFR_ENABLE_BIT); /* Enable TCR/TLR */ sc16is7xx_port_update(port, SC16IS7XX_MCR_REG, @@ -1042,23 +1216,34 @@ static int sc16is7xx_startup(struct uart_port *port) SC16IS7XX_EFCR_TXDISABLE_BIT, 0); - /* Enable RX, TX interrupts */ - val = SC16IS7XX_IER_RDI_BIT | SC16IS7XX_IER_THRI_BIT; + /* Enable RX, CTS change and modem lines interrupts */ + val = SC16IS7XX_IER_RDI_BIT | SC16IS7XX_IER_CTSI_BIT | + SC16IS7XX_IER_MSI_BIT; sc16is7xx_port_write(port, SC16IS7XX_IER_REG, val); + /* Enable modem status polling */ + spin_lock_irqsave(&port->lock, flags); + sc16is7xx_enable_ms(port); + spin_unlock_irqrestore(&port->lock, flags); + return 0; } static void sc16is7xx_shutdown(struct uart_port *port) { struct sc16is7xx_port *s = dev_get_drvdata(port->dev); + struct sc16is7xx_one *one = to_sc16is7xx_one(port, port); + + kthread_cancel_delayed_work_sync(&one->ms_work); /* Disable all interrupts */ sc16is7xx_port_write(port, SC16IS7XX_IER_REG, 0); - /* Disable TX/RX */ + /* Disable TX/RX, clear auto RS485 and RTS invert */ sc16is7xx_port_update(port, SC16IS7XX_EFCR_REG, SC16IS7XX_EFCR_RXDISABLE_BIT | - SC16IS7XX_EFCR_TXDISABLE_BIT, + SC16IS7XX_EFCR_TXDISABLE_BIT | + SC16IS7XX_EFCR_AUTO_RS485_BIT | + SC16IS7XX_EFCR_RTS_INVERT_BIT, SC16IS7XX_EFCR_RXDISABLE_BIT | SC16IS7XX_EFCR_TXDISABLE_BIT); @@ -1114,7 +1299,10 @@ static const struct uart_ops sc16is7xx_ops = { .get_mctrl = sc16is7xx_get_mctrl, .stop_tx = sc16is7xx_stop_tx, .start_tx = sc16is7xx_start_tx, + .throttle = sc16is7xx_throttle, + .unthrottle = sc16is7xx_unthrottle, .stop_rx = sc16is7xx_stop_rx, + .enable_ms = sc16is7xx_enable_ms, .break_ctl = sc16is7xx_break_ctl, .startup = sc16is7xx_startup, .shutdown = sc16is7xx_shutdown, @@ -1281,7 +1469,9 @@ static int sc16is7xx_probe(struct device *dev, s->p[i].port.uartclk = freq; s->p[i].port.rs485_config = sc16is7xx_config_rs485; s->p[i].port.ops = &sc16is7xx_ops; + s->p[i].old_mctrl = 0; s->p[i].port.line = sc16is7xx_alloc_line(); + if (s->p[i].port.line >= SC16IS7XX_MAX_DEVS) { ret = -ENOMEM; goto out_ports; @@ -1293,9 +1483,17 @@ static int sc16is7xx_probe(struct device *dev, sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_EFCR_REG, SC16IS7XX_EFCR_RXDISABLE_BIT | SC16IS7XX_EFCR_TXDISABLE_BIT); + + /* Use GPIO lines as modem status registers */ + if (devtype->has_mctrl) + sc16is7xx_port_write(&s->p[i].port, + SC16IS7XX_IOCONTROL_REG, + SC16IS7XX_IOCONTROL_MODEM_BIT); + /* Initialize kthread work structs */ kthread_init_work(&s->p[i].tx_work, sc16is7xx_tx_proc); kthread_init_work(&s->p[i].reg_work, sc16is7xx_reg_proc); + kthread_init_delayed_work(&s->p[i].ms_work, sc16is7xx_ms_proc); /* Register port */ uart_add_one_port(&sc16is7xx_uart, &s->p[i].port); @@ -1379,6 +1577,7 @@ static void sc16is7xx_remove(struct device *dev) #endif for (i = 0; i < s->devtype->nr_uart; i++) { + kthread_cancel_delayed_work_sync(&s->p[i].ms_work); uart_remove_one_port(&sc16is7xx_uart, &s->p[i].port); clear_bit(s->p[i].port.line, &sc16is7xx_lines); sc16is7xx_power(&s->p[i].port, 0); |