/* * linux/drivers/char/amazon_asc.c * * Driver for AMAZONASC serial ports * * Copyright (C) 2004 Infineon IFAP DC COM CPE * Copyright (C) 2007 Felix Fietkau * Copyright (C) 2007 John Crispin * * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o. * Based on drivers/serial/serial_s3c2400.c * * 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: amazon_asc.c,v 1.2 2005/04/01 02:40:48 pliu Exp $ * * This is a generic driver for AMAZONASC-type serial ports. */ #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 #include #include #include #define PORT_AMAZONASC 111 #if defined(CONFIG_SERIAL_AMAZONASC_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) #define SUPPORT_SYSRQ #endif #include #define UART_NR 1 #define SERIAL_AMAZONASC_MAJOR TTY_MAJOR #define CALLOUT_AMAZONASC_MAJOR TTYAUX_MAJOR #define SERIAL_AMAZONASC_MINOR 64 #define SERIAL_AMAZONASC_NR UART_NR extern void prom_printf(const char * fmt, ...); static struct uart_port amazonasc_ports[UART_NR]; static struct uart_driver amazonasc_reg; #ifdef CONFIG_SERIAL_AMAZONASC_CONSOLE /*SUPPORT_SYSRQ*/ static struct console amazonasc_console; #endif static unsigned int uartclk = 0; #define SET_BIT(reg, mask) *reg |= (mask) #define CLEAR_BIT(reg, mask) *reg &= (~mask) #define CLEAR_BITS(reg, mask) CLEAR_BIT(reg, mask) #define SET_BITS(reg, mask) SET_BIT(reg, mask) #define SET_BITFIELD(reg, mask, off, val) \ {*reg &= (~mask); *reg |= (val << off);} static void amazonasc_tx_chars(struct uart_port *port); /* fake flag to indicate CREAD was not set -> throw away all bytes */ #define UART_DUMMY_UER_RX 1 /* macro to set the bit corresponding to an interrupt number */ #define BIT_NO(irq) (1 << (irq - 64)) #define SERIAL_DEBUG extern unsigned int amazon_get_fpi_hz(void); static int tx_enabled = 0; static void amazonasc_stop_tx(struct uart_port *port) { /* fifo underrun shuts up after firing once */ return; } static void amazonasc_start_tx(struct uart_port *port) { unsigned long flags; local_irq_save(flags); amazonasc_tx_chars(port); local_irq_restore(flags); return; } static void amazonasc_stop_rx(struct uart_port *port) { /* clear the RX enable bit */ *AMAZON_ASC_WHBCON = ASCWHBCON_CLRREN; } static void amazonasc_enable_ms(struct uart_port *port) { /* no modem signals */ return; } static void amazonasc_rx_chars(struct uart_port *port) { struct tty_struct *tty = port->info->tty; unsigned int ch = 0, rsr = 0, fifocnt; unsigned long flags; fifocnt = *AMAZON_ASC_FSTAT & ASCFSTAT_RXFFLMASK; while (fifocnt--) { u8 flag = TTY_NORMAL; ch = *AMAZON_ASC_RBUF; rsr = (*AMAZON_ASC_CON & ASCCON_ANY) | UART_DUMMY_UER_RX; tty_flip_buffer_push(tty); port->icount.rx++; /* * Note that the error handling code is * out of the main execution path */ if (rsr & ASCCON_ANY) { if (rsr & ASCCON_PE) { port->icount.parity++; SET_BIT(AMAZON_ASC_WHBCON, ASCWHBCON_CLRPE); } else if (rsr & ASCCON_FE) { port->icount.frame++; SET_BIT(AMAZON_ASC_WHBCON, ASCWHBCON_CLRFE); } if (rsr & ASCCON_OE) { port->icount.overrun++; SET_BIT(AMAZON_ASC_WHBCON, ASCWHBCON_CLROE); } rsr &= port->read_status_mask; if (rsr & ASCCON_PE) flag = TTY_PARITY; else if (rsr & ASCCON_FE) flag = TTY_FRAME; } if ((rsr & port->ignore_status_mask) == 0) tty_insert_flip_char(tty, ch, flag); if (rsr & ASCCON_OE) /* * Overrun is special, since it's reported * immediately, and doesn't affect the current * character */ tty_insert_flip_char(tty, 0, TTY_OVERRUN); } if (ch != 0) tty_flip_buffer_push(tty); return; } static void amazonasc_tx_chars(struct uart_port *port) { struct circ_buf *xmit = &port->info->xmit; if (uart_tx_stopped(port)) { amazonasc_stop_tx(port); return; } while (((*AMAZON_ASC_FSTAT & ASCFSTAT_TXFFLMASK) >> ASCFSTAT_TXFFLOFF) != AMAZONASC_TXFIFO_FULL) { if (port->x_char) { *AMAZON_ASC_TBUF = port->x_char; port->icount.tx++; port->x_char = 0; continue; } if (uart_circ_empty(xmit)) break; *AMAZON_ASC_TBUF = xmit->buf[xmit->tail]; xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); port->icount.tx++; } if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) uart_write_wakeup(port); } static irqreturn_t amazonasc_tx_int(int irq, void *port) { *(AMAZON_ASC_IRNCR1) = ASC_IRNCR_TIR; amazonasc_start_tx(port); /* clear any pending interrupts */ SET_BIT(AMAZON_ASC_WHBCON, ASCWHBCON_CLRPE); SET_BIT(AMAZON_ASC_WHBCON, ASCWHBCON_CLRFE); SET_BIT(AMAZON_ASC_WHBCON, ASCWHBCON_CLROE); return IRQ_HANDLED; } static irqreturn_t amazonasc_er_int(int irq, void *port) { /* clear any pending interrupts */ SET_BIT(AMAZON_ASC_WHBCON, ASCWHBCON_CLRPE); SET_BIT(AMAZON_ASC_WHBCON, ASCWHBCON_CLRFE); SET_BIT(AMAZON_ASC_WHBCON, ASCWHBCON_CLROE); return IRQ_HANDLED; } static irqreturn_t amazonasc_rx_int(int irq, void *port) { *(AMAZON_ASC_IRNCR1) = ASC_IRNCR_RIR; amazonasc_rx_chars((struct uart_port *) port); return IRQ_HANDLED; } static u_int amazonasc_tx_empty(struct uart_port *port) { int status; /* * FSTAT tells exactly how many bytes are in the FIFO. * The question is whether we really need to wait for all * 16 bytes to be transmitted before reporting that the * transmitter is empty. */ status = *AMAZON_ASC_FSTAT & ASCFSTAT_TXFFLMASK; return status ? 0 : TIOCSER_TEMT; } static u_int amazonasc_get_mctrl(struct uart_port *port) { /* no modem control signals - the readme says to pretend all are set */ return TIOCM_CTS|TIOCM_CAR|TIOCM_DSR; } static void amazonasc_set_mctrl(struct uart_port *port, u_int mctrl) { /* no modem control - just return */ return; } static void amazonasc_break_ctl(struct uart_port *port, int break_state) { /* no way to send a break */ return; } static int amazonasc_startup(struct uart_port *port) { unsigned int con = 0; unsigned long flags; int retval; /* this assumes: CON.BRS = CON.FDE = 0 */ if (uartclk == 0) uartclk = amazon_get_fpi_hz(); amazonasc_ports[0].uartclk = uartclk; /* block the IRQs */ local_irq_save(flags); /* this setup was probably already done in u-boot */ /* ASC and GPIO Port 1 bits 3 and 4 share the same pins * P1.3 (RX) in, Alternate 10 * P1.4 (TX) in, Alternate 10 */ SET_BITFIELD((AMAZON_GPIO_P1_DIR), 0x8, 4, 1); //P1.4 output, P1.3 input SET_BIT((AMAZON_GPIO_P1_ALTSEL0), 0x18); //ALTSETL0 11 CLEAR_BIT((AMAZON_GPIO_P1_ALTSEL1), 0x18); //ALTSETL1 00 SET_BITFIELD((AMAZON_GPIO_P1_OD), 0x8, 4, 1); /* set up the CLC */ CLEAR_BIT(AMAZON_ASC_CLC, AMAZON_ASC_CLC_DISS); SET_BITFIELD(AMAZON_ASC_CLC, ASCCLC_RMCMASK, ASCCLC_RMCOFFSET, 1); /* asynchronous mode */ con = ASCCON_M_8ASYNC; /* set error signals - framing and overrun */ con |= ASCCON_FEN; con |= ASCCON_OEN; con |= ASCCON_PEN; /* choose the line - there's only one */ *AMAZON_ASC_PISEL = 0; #if 1 *AMAZON_ASC_TXFCON = (((AMAZONASC_TXFIFO_FL<c_cflag; iflag = new->c_iflag; /* byte size and parity */ switch (cflag & CSIZE) { /* 7 bits are always with parity */ case CS7: con = ASCCON_M_7ASYNCPAR; break; /* the ASC only suports 7 and 8 bits */ case CS5: case CS6: default: if (cflag & PARENB) con = ASCCON_M_8ASYNCPAR; else con = ASCCON_M_8ASYNC; break; } if (cflag & CSTOPB) con |= ASCCON_STP; if (cflag & PARENB) { if (!(cflag & PARODD)) con &= ~ASCCON_ODD; else con |= ASCCON_ODD; } port->read_status_mask = ASCCON_OE; if (iflag & INPCK) port->read_status_mask |= ASCCON_FE | ASCCON_PE; /* the ASC can't really detect or generate a BREAK */ #if 0 if (iflag & (BRKINT | PARMRK)) port->read_status_mask |= UERSTAT_BREAK; #endif /* * Characters to ignore */ port->ignore_status_mask = 0; if (iflag & IGNPAR) port->ignore_status_mask |= ASCCON_FE | ASCCON_PE; #if 0 /* always ignore breaks - the ASC can't handle them XXXX */ port->ignore_status_mask |= UERSTAT_BREAK; #endif if (iflag & IGNBRK) { /*port->ignore_status_mask |= UERSTAT_BREAK;*/ /* * If we're ignoring parity and break indicators, * ignore overruns too (for real raw support). */ if (iflag & IGNPAR) port->ignore_status_mask |= ASCCON_OE; } /* * Ignore all characters if CREAD is not set. */ if ((cflag & CREAD) == 0) port->ignore_status_mask |= UART_DUMMY_UER_RX; /* set error signals - framing, parity and overrun */ con |= ASCCON_FEN; con |= ASCCON_OEN; con |= ASCCON_PEN; /* enable the receiver */ con |= ASCCON_REN; /* block the IRQs */ local_irq_save(flags); /* set up CON */ *AMAZON_ASC_CON = con; /* Set baud rate - take a divider of 2 into account */ baud = uart_get_baud_rate(port, new, old, 0, port->uartclk/16); quot = uart_get_divisor(port, baud); quot = quot/2 - 1; /* the next 3 probably already happened when we set CON above */ /* disable the baudrate generator */ CLEAR_BIT(AMAZON_ASC_CON, ASCCON_R); /* make sure the fractional divider is off */ CLEAR_BIT(AMAZON_ASC_CON, ASCCON_FDE); /* set up to use divisor of 2 */ CLEAR_BIT(AMAZON_ASC_CON, ASCCON_BRS); /* now we can write the new baudrate into the register */ *AMAZON_ASC_BTR = quot; /* turn the baudrate generator back on */ SET_BIT(AMAZON_ASC_CON, ASCCON_R); /* unblock the IRQs */ local_irq_restore(flags); } static const char *amazonasc_type(struct uart_port *port) { return port->type == PORT_AMAZONASC ? "AMAZONASC" : NULL; } /* * Release the memory region(s) being used by 'port' */ static void amazonasc_release_port(struct uart_port *port) { return; } /* * Request the memory region(s) being used by 'port' */ static int amazonasc_request_port(struct uart_port *port) { return 0; } /* * Configure/autoconfigure the port. */ static void amazonasc_config_port(struct uart_port *port, int flags) { if (flags & UART_CONFIG_TYPE) { port->type = PORT_AMAZONASC; amazonasc_request_port(port); } } /* * verify the new serial_struct (for TIOCSSERIAL). */ static int amazonasc_verify_port(struct uart_port *port, struct serial_struct *ser) { int ret = 0; if (ser->type != PORT_UNKNOWN && ser->type != PORT_AMAZONASC) 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 amazonasc_pops = { .tx_empty = amazonasc_tx_empty, .set_mctrl = amazonasc_set_mctrl, .get_mctrl = amazonasc_get_mctrl, .stop_tx = amazonasc_stop_tx, .start_tx = amazonasc_start_tx, .stop_rx = amazonasc_stop_rx, .enable_ms = amazonasc_enable_ms, .break_ctl = amazonasc_break_ctl, .startup = amazonasc_startup, .shutdown = amazonasc_shutdown, .set_termios = amazonasc_set_termios, .type = amazonasc_type, .release_port = amazonasc_release_port, .request_port = amazonasc_request_port, .config_port = amazonasc_config_port, .verify_port = amazonasc_verify_port, }; static struct uart_port amazonasc_ports[UART_NR] = { { membase: (void *)AMAZON_ASC, mapbase: AMAZON_ASC, iotype: SERIAL_IO_MEM, irq: AMAZONASC_RIR, /* RIR */ uartclk: 0, /* filled in dynamically */ fifosize: 16, unused: { AMAZONASC_TIR, AMAZONASC_EIR}, /* xmit/error/xmit-buffer-empty IRQ */ type: PORT_AMAZONASC, ops: &amazonasc_pops, flags: ASYNC_BOOT_AUTOCONF, }, }; static void amazonasc_console_write(struct console *co, const char *s, u_int count) { int i, fifocnt; unsigned long flags; /* block the IRQ */ local_irq_save(flags); /* * Now, do each character */ for (i = 0; i < count;) { /* wait until the FIFO is not full */ do { fifocnt = (*AMAZON_ASC_FSTAT & ASCFSTAT_TXFFLMASK) >> ASCFSTAT_TXFFLOFF; } while (fifocnt == AMAZONASC_TXFIFO_FULL); #if 1 if (s[i] == '\0') { break; } #endif if (s[i] == '\n') { *AMAZON_ASC_TBUF = '\r'; do { fifocnt = (*AMAZON_ASC_FSTAT & ASCFSTAT_TXFFLMASK) >> ASCFSTAT_TXFFLOFF; } while (fifocnt == AMAZONASC_TXFIFO_FULL); } *AMAZON_ASC_TBUF = s[i]; i++; } /* for */ /* restore the IRQ */ local_irq_restore(flags); } static void __init amazonasc_console_get_options(struct uart_port *port, int *baud, int *parity, int *bits) { u_int lcr_h; lcr_h = *AMAZON_ASC_CON; /* do this only if the ASC is turned on */ if (lcr_h & ASCCON_R) { u_int quot, div, fdiv, frac; *parity = 'n'; if ((lcr_h & ASCCON_MODEMASK) == ASCCON_M_7ASYNCPAR || (lcr_h & ASCCON_MODEMASK) == ASCCON_M_8ASYNCPAR) { if (lcr_h & ASCCON_ODD) *parity = 'o'; else *parity = 'e'; } if ((lcr_h & ASCCON_MODEMASK) == ASCCON_M_7ASYNCPAR) *bits = 7; else *bits = 8; quot = *AMAZON_ASC_BTR + 1; /* this gets hairy if the fractional divider is used */ if (lcr_h & ASCCON_FDE) { div = 1; fdiv = *AMAZON_ASC_FDV; if (fdiv == 0) fdiv = 512; frac = 512; } else { div = lcr_h & ASCCON_BRS ? 3 : 2; fdiv = frac = 1; } /* * This doesn't work exactly because we use integer * math to calculate baud which results in rounding * errors when we try to go from quot -> baud !! * Try to make this work for both the fractional divider * and the simple divider. Also try to avoid rounding * errors using integer math. */ *baud = frac * (port->uartclk / (div * 512 * 16 * quot)); if (*baud > 1100 && *baud < 2400) *baud = 1200; if (*baud > 2300 && *baud < 4800) *baud = 2400; if (*baud > 4700 && *baud < 9600) *baud = 4800; if (*baud > 9500 && *baud < 19200) *baud = 9600; if (*baud > 19000 && *baud < 38400) *baud = 19200; if (*baud > 38400 && *baud < 57600) *baud = 38400; if (*baud > 57600 && *baud < 115200) *baud = 57600; if (*baud > 115200 && *baud < 230400) *baud = 115200; } } static int __init amazonasc_console_setup(struct console *co, char *options) { struct uart_port *port; int baud = 115200; int bits = 8; int parity = 'n'; int flow = 'n'; /* this assumes: CON.BRS = CON.FDE = 0 */ if (uartclk == 0) uartclk = amazon_get_fpi_hz(); co->index = 0; port = &amazonasc_ports[0]; amazonasc_ports[0].uartclk = uartclk; amazonasc_ports[0].type = PORT_AMAZONASC; if (options){ uart_parse_options(options, &baud, &parity, &bits, &flow); } return uart_set_options(port, co, baud, parity, bits, flow); } static struct uart_driver amazonasc_reg; static struct console amazonasc_console = { name: "ttyS", write: amazonasc_console_write, device: uart_console_device, setup: amazonasc_console_setup, flags: CON_PRINTBUFFER, index: -1, data: &amazonasc_reg, }; static int __init amazonasc_console_init(void) { register_console(&amazonasc_console); return 0; } console_initcall(amazonasc_console_init); static struct uart_driver amazonasc_reg = { .owner = THIS_MODULE, .driver_name = "serial", .dev_name = "ttyS", .major = TTY_MAJOR, .minor = 64, .nr = UART_NR, .cons = &amazonasc_console, }; static int __init amazonasc_init(void) { unsigned char res; uart_register_driver(&amazonasc_reg); res = uart_add_one_port(&amazonasc_reg, &amazonasc_ports[0]); return res; } static void __exit amazonasc_exit(void) { uart_unregister_driver(&amazonasc_reg); } module_init(amazonasc_init); module_exit(amazonasc_exit); MODULE_AUTHOR("Gary Jennejohn, Felix Fietkau, John Crispin"); MODULE_DESCRIPTION("MIPS AMAZONASC serial port driver"); MODULE_LICENSE("GPL");