/* * linux/drivers/char/serial_amba.c * * Driver for AMBA serial ports * * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o. * * Copyright 1999 ARM Limited * Copyright (C) 2000 Deep Blue Solutions Ltd. * * 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. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * * $Id: serial_amba.c,v 1.1.1.1 2003/06/23 22:18:34 jharrell Exp $ * * This is a generic driver for ARM AMBA-type serial ports. They * have a lot of 16550-like features, but are not register compatable. * Note that although they do have CTS, DCD and DSR inputs, they do * not have an RI input, nor do they have DTR or RTS outputs. If * required, these have to be supplied via some other means (eg, GPIO) * and hooked into this driver. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #if defined(CONFIG_SERIAL_AMBA_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) #define SUPPORT_SYSRQ #endif #include #include #define UART_NR 2 #define SERIAL_AMBA_MAJOR 204 #define SERIAL_AMBA_MINOR 16 #define SERIAL_AMBA_NR UART_NR #define CALLOUT_AMBA_NAME "cuaam" #define CALLOUT_AMBA_MAJOR 205 #define CALLOUT_AMBA_MINOR 16 #define CALLOUT_AMBA_NR UART_NR static struct tty_driver normal, callout; static struct tty_struct *amba_table[UART_NR]; static struct termios *amba_termios[UART_NR], *amba_termios_locked[UART_NR]; #ifdef SUPPORT_SYSRQ static struct console amba_console; #endif #define AMBA_ISR_PASS_LIMIT 256 /* * Access macros for the AMBA UARTs */ #define UART_GET_INT_STATUS(p) readb((p)->membase + AMBA_UARTIIR) #define UART_PUT_ICR(p, c) writel((c), (p)->membase + AMBA_UARTICR) #define UART_GET_FR(p) readb((p)->membase + AMBA_UARTFR) #define UART_GET_CHAR(p) readb((p)->membase + AMBA_UARTDR) #define UART_PUT_CHAR(p, c) writel((c), (p)->membase + AMBA_UARTDR) #define UART_GET_RSR(p) readb((p)->membase + AMBA_UARTRSR) #define UART_GET_CR(p) readb((p)->membase + AMBA_UARTCR) #define UART_PUT_CR(p,c) writel((c), (p)->membase + AMBA_UARTCR) #define UART_GET_LCRL(p) readb((p)->membase + AMBA_UARTLCR_L) #define UART_PUT_LCRL(p,c) writel((c), (p)->membase + AMBA_UARTLCR_L) #define UART_GET_LCRM(p) readb((p)->membase + AMBA_UARTLCR_M) #define UART_PUT_LCRM(p,c) writel((c), (p)->membase + AMBA_UARTLCR_M) #define UART_GET_LCRH(p) readb((p)->membase + AMBA_UARTLCR_H) #define UART_PUT_LCRH(p,c) writel((c), (p)->membase + AMBA_UARTLCR_H) #define UART_RX_DATA(s) (((s) & AMBA_UARTFR_RXFE) == 0) #define UART_TX_READY(s) (((s) & AMBA_UARTFR_TXFF) == 0) #define UART_TX_EMPTY(p) ((UART_GET_FR(p) & AMBA_UARTFR_TMSK) == 0) #define UART_DUMMY_RSR_RX 256 #define UART_PORT_SIZE 64 /* * On the Integrator platform, the port RTS and DTR are provided by * bits in the following SC_CTRLS register bits: * RTS DTR * UART0 7 6 * UART1 5 4 * * We encode this bit information into port->driver_priv using the * following macros. */ //#define PORT_CTRLS(dtrbit,rtsbit) ((1 << dtrbit) | (1 << (16 + rtsbit))) #define PORT_CTRLS_DTR(port) (1 << (port)->unused[1]) #define PORT_CTRLS_RTS(port) (1 << (port)->unused[0]) #define SC_CTRLC (IO_ADDRESS(INTEGRATOR_SC_BASE) + INTEGRATOR_SC_CTRLC_OFFSET) #define SC_CTRLS (IO_ADDRESS(INTEGRATOR_SC_BASE) + INTEGRATOR_SC_CTRLS_OFFSET) /* * Our private driver data mappings. */ #define drv_old_status driver_priv static void ambauart_stop_tx(struct uart_port *port, u_int from_tty) { unsigned int cr; cr = UART_GET_CR(port); cr &= ~AMBA_UARTCR_TIE; UART_PUT_CR(port, cr); } static void ambauart_start_tx(struct uart_port *port, u_int nonempty, u_int from_tty) { if (nonempty) { unsigned int cr; cr = UART_GET_CR(port); cr |= AMBA_UARTCR_TIE; UART_PUT_CR(port, cr); } } static void ambauart_stop_rx(struct uart_port *port) { unsigned int cr; cr = UART_GET_CR(port); cr &= ~(AMBA_UARTCR_RIE | AMBA_UARTCR_RTIE); UART_PUT_CR(port, cr); } static void ambauart_enable_ms(struct uart_port *port) { unsigned int cr; cr = UART_GET_CR(port); cr |= AMBA_UARTCR_MSIE; UART_PUT_CR(port, cr); } static void #ifdef SUPPORT_SYSRQ ambauart_rx_chars(struct uart_info *info, struct pt_regs *regs) #else ambauart_rx_chars(struct uart_info *info) #endif { struct tty_struct *tty = info->tty; unsigned int status, ch, rsr, max_count = 256; struct uart_port *port = info->port; status = UART_GET_FR(port); while (UART_RX_DATA(status) && max_count--) { if (tty->flip.count >= TTY_FLIPBUF_SIZE) { tty->flip.tqueue.routine((void *)tty); if (tty->flip.count >= TTY_FLIPBUF_SIZE) { printk(KERN_WARNING "TTY_DONT_FLIP set\n"); return; } } ch = UART_GET_CHAR(port); *tty->flip.char_buf_ptr = ch; *tty->flip.flag_buf_ptr = TTY_NORMAL; port->icount.rx++; /* * Note that the error handling code is * out of the main execution path */ rsr = UART_GET_RSR(port) | UART_DUMMY_RSR_RX; if (rsr & AMBA_UARTRSR_ANY) { if (rsr & AMBA_UARTRSR_BE) { rsr &= ~(AMBA_UARTRSR_FE | AMBA_UARTRSR_PE); port->icount.brk++; if (uart_handle_break(info, &amba_console)) goto ignore_char; } else if (rsr & AMBA_UARTRSR_PE) port->icount.parity++; else if (rsr & AMBA_UARTRSR_FE) port->icount.frame++; if (rsr & AMBA_UARTRSR_OE) port->icount.overrun++; rsr &= port->read_status_mask; if (rsr & AMBA_UARTRSR_BE) *tty->flip.flag_buf_ptr = TTY_BREAK; else if (rsr & AMBA_UARTRSR_PE) *tty->flip.flag_buf_ptr = TTY_PARITY; else if (rsr & AMBA_UARTRSR_FE) *tty->flip.flag_buf_ptr = TTY_FRAME; } if (uart_handle_sysrq_char(info, ch, regs)) goto ignore_char; if ((rsr & port->ignore_status_mask) == 0) { tty->flip.flag_buf_ptr++; tty->flip.char_buf_ptr++; tty->flip.count++; } if ((rsr & AMBA_UARTRSR_OE) && tty->flip.count < TTY_FLIPBUF_SIZE) { /* * Overrun is special, since it's reported * immediately, and doesn't affect the current * character */ *tty->flip.char_buf_ptr++ = 0; *tty->flip.flag_buf_ptr++ = TTY_OVERRUN; tty->flip.count++; } ignore_char: status = UART_GET_FR(port); } tty_flip_buffer_push(tty); return; } static void ambauart_tx_chars(struct uart_info *info) { struct uart_port *port = info->port; int count; if (port->x_char) { UART_PUT_CHAR(port, port->x_char); port->icount.tx++; port->x_char = 0; return; } if (info->xmit.head == info->xmit.tail || info->tty->stopped || info->tty->hw_stopped) { ambauart_stop_tx(port, 0); return; } count = port->fifosize >> 1; do { UART_PUT_CHAR(port, info->xmit.buf[info->xmit.tail]); info->xmit.tail = (info->xmit.tail + 1) & (UART_XMIT_SIZE - 1); port->icount.tx++; if (info->xmit.head == info->xmit.tail) break; } while (--count > 0); if (CIRC_CNT(info->xmit.head, info->xmit.tail, UART_XMIT_SIZE) < WAKEUP_CHARS) uart_event(info, EVT_WRITE_WAKEUP); if (info->xmit.head == info->xmit.tail) ambauart_stop_tx(info->port, 0); } static void ambauart_modem_status(struct uart_info *info) { struct uart_port *port = info->port; unsigned int status, delta; UART_PUT_ICR(port, 0); status = UART_GET_FR(port) & AMBA_UARTFR_MODEM_ANY; delta = status ^ info->drv_old_status; info->drv_old_status = status; if (!delta) return; if (delta & AMBA_UARTFR_DCD) uart_handle_dcd_change(info, status & AMBA_UARTFR_DCD); if (delta & AMBA_UARTFR_DSR) port->icount.dsr++; if (delta & AMBA_UARTFR_CTS) uart_handle_cts_change(info, status & AMBA_UARTFR_CTS); wake_up_interruptible(&info->delta_msr_wait); } static void ambauart_int(int irq, void *dev_id, struct pt_regs *regs) { struct uart_info *info = dev_id; unsigned int status, pass_counter = AMBA_ISR_PASS_LIMIT; status = UART_GET_INT_STATUS(info->port); do { if (status & (AMBA_UARTIIR_RTIS | AMBA_UARTIIR_RIS)) #ifdef SUPPORT_SYSRQ ambauart_rx_chars(info, regs); #else ambauart_rx_chars(info); #endif if (status & AMBA_UARTIIR_TIS) ambauart_tx_chars(info); if (status & AMBA_UARTIIR_MIS) ambauart_modem_status(info); if (pass_counter-- == 0) break; status = UART_GET_INT_STATUS(info->port); } while (status & (AMBA_UARTIIR_RTIS | AMBA_UARTIIR_RIS | AMBA_UARTIIR_TIS)); } static u_int ambauart_tx_empty(struct uart_port *port) { return UART_GET_FR(port) & AMBA_UARTFR_BUSY ? 0 : TIOCSER_TEMT; } static u_int ambauart_get_mctrl(struct uart_port *port) { unsigned int result = 0; unsigned int status; status = UART_GET_FR(port); if (status & AMBA_UARTFR_DCD) result |= TIOCM_CAR; if (status & AMBA_UARTFR_DSR) result |= TIOCM_DSR; if (status & AMBA_UARTFR_CTS) result |= TIOCM_CTS; return result; } static void ambauart_set_mctrl(struct uart_port *port, u_int mctrl) { u_int ctrls = 0, ctrlc = 0; if (mctrl & TIOCM_RTS) ctrlc |= PORT_CTRLS_RTS(port); else ctrls |= PORT_CTRLS_RTS(port); if (mctrl & TIOCM_DTR) ctrlc |= PORT_CTRLS_DTR(port); else ctrls |= PORT_CTRLS_DTR(port); __raw_writel(ctrls, SC_CTRLS); __raw_writel(ctrlc, SC_CTRLC); } static void ambauart_break_ctl(struct uart_port *port, int break_state) { unsigned int lcr_h; lcr_h = UART_GET_LCRH(port); if (break_state == -1) lcr_h |= AMBA_UARTLCR_H_BRK; else lcr_h &= ~AMBA_UARTLCR_H_BRK; UART_PUT_LCRH(port, lcr_h); } static int ambauart_startup(struct uart_port *port, struct uart_info *info) { int retval; /* * Allocate the IRQ */ retval = request_irq(port->irq, ambauart_int, 0, "amba", info); if (retval) return retval; /* * initialise the old status of the modem signals */ info->drv_old_status = UART_GET_FR(port) & AMBA_UARTFR_MODEM_ANY; /* * Finally, enable interrupts */ UART_PUT_CR(port, AMBA_UARTCR_UARTEN | AMBA_UARTCR_RIE | AMBA_UARTCR_RTIE); return 0; } static void ambauart_shutdown(struct uart_port *port, struct uart_info *info) { /* * Free the interrupt */ free_irq(port->irq, info); /* * disable all interrupts, disable the port */ UART_PUT_CR(port, 0); /* disable break condition and fifos */ UART_PUT_LCRH(port, UART_GET_LCRH(port) & ~(AMBA_UARTLCR_H_BRK | AMBA_UARTLCR_H_FEN)); } static void ambauart_change_speed(struct uart_port *port, u_int cflag, u_int iflag, u_int quot) { u_int lcr_h, old_cr; unsigned long flags; #if DEBUG printk("ambauart_set_cflag(0x%x) called\n", cflag); #endif /* byte size and parity */ switch (cflag & CSIZE) { case CS5: lcr_h = AMBA_UARTLCR_H_WLEN_5; break; case CS6: lcr_h = AMBA_UARTLCR_H_WLEN_6; break; case CS7: lcr_h = AMBA_UARTLCR_H_WLEN_7; break; default: lcr_h = AMBA_UARTLCR_H_WLEN_8; break; // CS8 } if (cflag & CSTOPB) lcr_h |= AMBA_UARTLCR_H_STP2; if (cflag & PARENB) { lcr_h |= AMBA_UARTLCR_H_PEN; if (!(cflag & PARODD)) lcr_h |= AMBA_UARTLCR_H_EPS; } if (port->fifosize > 1) lcr_h |= AMBA_UARTLCR_H_FEN; port->read_status_mask = AMBA_UARTRSR_OE; if (iflag & INPCK) port->read_status_mask |= AMBA_UARTRSR_FE | AMBA_UARTRSR_PE; if (iflag & (BRKINT | PARMRK)) port->read_status_mask |= AMBA_UARTRSR_BE; /* * Characters to ignore */ port->ignore_status_mask = 0; if (iflag & IGNPAR) port->ignore_status_mask |= AMBA_UARTRSR_FE | AMBA_UARTRSR_PE; if (iflag & IGNBRK) { port->ignore_status_mask |= AMBA_UARTRSR_BE; /* * If we're ignoring parity and break indicators, * ignore overruns too (for real raw support). */ if (iflag & IGNPAR) port->ignore_status_mask |= AMBA_UARTRSR_OE; } /* * Ignore all characters if CREAD is not set. */ if ((cflag & CREAD) == 0) port->ignore_status_mask |= UART_DUMMY_RSR_RX; /* first, disable everything */ save_flags(flags); cli(); old_cr = UART_GET_CR(port) & ~AMBA_UARTCR_MSIE; if ((port->flags & ASYNC_HARDPPS_CD) || (cflag & CRTSCTS) || !(cflag & CLOCAL)) old_cr |= AMBA_UARTCR_MSIE; UART_PUT_CR(port, 0); /* Set baud rate */ quot -= 1; UART_PUT_LCRM(port, ((quot & 0xf00) >> 8)); UART_PUT_LCRL(port, (quot & 0xff)); /* * ----------v----------v----------v----------v----- * NOTE: MUST BE WRITTEN AFTER UARTLCR_M & UARTLCR_L * ----------^----------^----------^----------^----- */ UART_PUT_LCRH(port, lcr_h); UART_PUT_CR(port, old_cr); restore_flags(flags); } static const char *ambauart_type(struct uart_port *port) { return port->type == PORT_AMBA ? "AMBA" : NULL; } /* * Release the memory region(s) being used by 'port' */ static void ambauart_release_port(struct uart_port *port) { release_mem_region(port->mapbase, UART_PORT_SIZE); } /* * Request the memory region(s) being used by 'port' */ static int ambauart_request_port(struct uart_port *port) { return request_mem_region(port->mapbase, UART_PORT_SIZE, "serial_amba") != NULL ? 0 : -EBUSY; } /* * Configure/autoconfigure the port. */ static void ambauart_config_port(struct uart_port *port, int flags) { if (flags & UART_CONFIG_TYPE) { port->type = PORT_AMBA; ambauart_request_port(port); } } /* * verify the new serial_struct (for TIOCSSERIAL). */ static int ambauart_verify_port(struct uart_port *port, struct serial_struct *ser) { int ret = 0; if (ser->type != PORT_UNKNOWN && ser->type != PORT_AMBA) ret = -EINVAL; if (ser->irq < 0 || ser->irq >= NR_IRQS) ret = -EINVAL; if (ser->baud_base < 9600) ret = -EINVAL; return ret; } static struct uart_ops amba_pops = { tx_empty: ambauart_tx_empty, set_mctrl: ambauart_set_mctrl, get_mctrl: ambauart_get_mctrl, stop_tx: ambauart_stop_tx, start_tx: ambauart_start_tx, stop_rx: ambauart_stop_rx, enable_ms: ambauart_enable_ms, break_ctl: ambauart_break_ctl, startup: ambauart_startup, shutdown: ambauart_shutdown, change_speed: ambauart_change_speed, type: ambauart_type, release_port: ambauart_release_port, request_port: ambauart_request_port, config_port: ambauart_config_port, verify_port: ambauart_verify_port, }; static struct uart_port amba_ports[UART_NR] = { { membase: (void *)IO_ADDRESS(INTEGRATOR_UART0_BASE), mapbase: INTEGRATOR_UART0_BASE, iotype: SERIAL_IO_MEM, irq: IRQ_UARTINT0, uartclk: 14745600, fifosize: 16, unused: { 4, 5 }, /*driver_priv: PORT_CTRLS(5, 4), */ ops: &amba_pops, flags: ASYNC_BOOT_AUTOCONF, }, { membase: (void *)IO_ADDRESS(INTEGRATOR_UART1_BASE), mapbase: INTEGRATOR_UART1_BASE, iotype: SERIAL_IO_MEM, irq: IRQ_UARTINT1, uartclk: 14745600, fifosize: 16, unused: { 6, 7 }, /*driver_priv: PORT_CTRLS(7, 6), */ ops: &amba_pops, flags: ASYNC_BOOT_AUTOCONF, } }; #ifdef CONFIG_SERIAL_AMBA_CONSOLE #ifdef used_and_not_const_char_pointer static int ambauart_console_read(struct uart_port *port, char *s, u_int count) { unsigned int status; int c; #if DEBUG printk("ambauart_console_read() called\n"); #endif c = 0; while (c < count) { status = UART_GET_FR(port); if (UART_RX_DATA(status)) { *s++ = UART_GET_CHAR(port); c++; } else { // nothing more to get, return return c; } } // return the count return c; } #endif static void ambauart_console_write(struct console *co, const char *s, u_int count) { struct uart_port *port = amba_ports + co->index; unsigned int status, old_cr; int i; /* * First save the CR then disable the interrupts */ old_cr = UART_GET_CR(port); UART_PUT_CR(port, AMBA_UARTCR_UARTEN); /* * Now, do each character */ for (i = 0; i < count; i++) { do { status = UART_GET_FR(port); } while (!UART_TX_READY(status)); UART_PUT_CHAR(port, s[i]); if (s[i] == '\n') { do { status = UART_GET_FR(port); } while (!UART_TX_READY(status)); UART_PUT_CHAR(port, '\r'); } } /* * Finally, wait for transmitter to become empty * and restore the TCR */ do { status = UART_GET_FR(port); } while (status & AMBA_UARTFR_BUSY); UART_PUT_CR(port, old_cr); } static kdev_t ambauart_console_device(struct console *co) { return MKDEV(SERIAL_AMBA_MAJOR, SERIAL_AMBA_MINOR + co->index); } static int ambauart_console_wait_key(struct console *co) { struct uart_port *port = amba_ports + co->index; unsigned int status; do { status = UART_GET_FR(port); } while (!UART_RX_DATA(status)); return UART_GET_CHAR(port); } static void __init ambauart_console_get_options(struct uart_port *port, int *baud, int *parity, int *bits) { if (UART_GET_CR(port) & AMBA_UARTCR_UARTEN) { u_int lcr_h, quot; lcr_h = UART_GET_LCRH(port); *parity = 'n'; if (lcr_h & AMBA_UARTLCR_H_PEN) { if (lcr_h & AMBA_UARTLCR_H_EPS) *parity = 'e'; else *parity = 'o'; } if ((lcr_h & 0x60) == AMBA_UARTLCR_H_WLEN_7) *bits = 7; else *bits = 8; quot = UART_GET_LCRL(port) | UART_GET_LCRM(port) << 8; *baud = port->uartclk / (16 * (quot + 1)); } } static int __init ambauart_console_setup(struct console *co, char *options) { struct uart_port *port; int baud = 38400; int bits = 8; int parity = 'n'; int flow = 'n'; /* * Check whether an invalid uart number has been specified, and * if so, search for the first available port that does have * console support. */ port = uart_get_console(amba_ports, UART_NR, co); if (options) uart_parse_options(options, &baud, &parity, &bits, &flow); else ambauart_console_get_options(port, &baud, &parity, &bits); return uart_set_options(port, co, baud, parity, bits, flow); } static struct console amba_console = { name: "ttyAM", write: ambauart_console_write, #ifdef used_and_not_const_char_pointer read: ambauart_console_read, #endif device: ambauart_console_device, wait_key: ambauart_console_wait_key, setup: ambauart_console_setup, flags: CON_PRINTBUFFER, index: -1, }; void __init ambauart_console_init(void) { register_console(&amba_console); } #define AMBA_CONSOLE &amba_console #else #define AMBA_CONSOLE NULL #endif static struct uart_driver amba_reg = { owner: THIS_MODULE, normal_major: SERIAL_AMBA_MAJOR, #ifdef CONFIG_DEVFS_FS normal_name: "ttyAM%d", callout_name: "cuaam%d", #else normal_name: "ttyAM", callout_name: "cuaam", #endif normal_driver: &normal, callout_major: CALLOUT_AMBA_MAJOR, callout_driver: &callout, table: amba_table, termios: amba_termios, termios_locked: amba_termios_locked, minor: SERIAL_AMBA_MINOR, nr: UART_NR, port: amba_ports, cons: AMBA_CONSOLE, }; static int __init ambauart_init(void) { return uart_register_driver(&amba_reg); } static void __exit ambauart_exit(void) { uart_unregister_driver(&amba_reg); } module_init(ambauart_init); module_exit(ambauart_exit); EXPORT_NO_SYMBOLS; MODULE_AUTHOR("ARM Ltd/Deep Blue Solutions Ltd"); MODULE_DESCRIPTION("ARM AMBA serial port driver"); MODULE_LICENSE("GPL");