/* * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o. * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 as published * by the Free Software Foundation. * * 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 * * Copyright (C) 2004 Infineon IFAP DC COM CPE * Copyright (C) 2007 Felix Fietkau <nbd@openwrt.org> * Copyright (C) 2007 John Crispin <blogic@openwrt.org> * Copyright (C) 2010 Thomas Langer, <thomas.langer@lantiq.com> */ #include <linux/slab.h> #include <linux/module.h> #include <linux/ioport.h> #include <linux/init.h> #include <linux/console.h> #include <linux/sysrq.h> #include <linux/device.h> #include <linux/tty.h> #include <linux/tty_flip.h> #include <linux/serial_core.h> #include <linux/serial.h> #include <linux/of_platform.h> #include <linux/of_address.h> #include <linux/of_irq.h> #include <linux/io.h> #include <linux/clk.h> #include <linux/gpio.h> #include <lantiq_soc.h> #define PORT_LTQ_ASC 111 #define MAXPORTS 2 #define UART_DUMMY_UER_RX 1 #define DRVNAME "lantiq,asc" #ifdef __BIG_ENDIAN #define LTQ_ASC_TBUF (0x0020 + 3) #define LTQ_ASC_RBUF (0x0024 + 3) #else #define LTQ_ASC_TBUF 0x0020 #define LTQ_ASC_RBUF 0x0024 #endif #define LTQ_ASC_FSTAT 0x0048 #define LTQ_ASC_WHBSTATE 0x0018 #define LTQ_ASC_STATE 0x0014 #define LTQ_ASC_IRNCR 0x00F8 #define LTQ_ASC_CLC 0x0000 #define LTQ_ASC_ID 0x0008 #define LTQ_ASC_PISEL 0x0004 #define LTQ_ASC_TXFCON 0x0044 #define LTQ_ASC_RXFCON 0x0040 #define LTQ_ASC_CON 0x0010 #define LTQ_ASC_BG 0x0050 #define LTQ_ASC_IRNREN 0x00F4 #define ASC_IRNREN_TX 0x1 #define ASC_IRNREN_RX 0x2 #define ASC_IRNREN_ERR 0x4 #define ASC_IRNREN_TX_BUF 0x8 #define ASC_IRNCR_TIR 0x1 #define ASC_IRNCR_RIR 0x2 #define ASC_IRNCR_EIR 0x4 #define ASCOPT_CSIZE 0x3 #define TXFIFO_FL 1 #define RXFIFO_FL 1 #define ASCCLC_DISS 0x2 #define ASCCLC_RMCMASK 0x0000FF00 #define ASCCLC_RMCOFFSET 8 #define ASCCON_M_8ASYNC 0x0 #define ASCCON_M_7ASYNC 0x2 #define ASCCON_ODD 0x00000020 #define ASCCON_STP 0x00000080 #define ASCCON_BRS 0x00000100 #define ASCCON_FDE 0x00000200 #define ASCCON_R 0x00008000 #define ASCCON_FEN 0x00020000 #define ASCCON_ROEN 0x00080000 #define ASCCON_TOEN 0x00100000 #define ASCSTATE_PE 0x00010000 #define ASCSTATE_FE 0x00020000 #define ASCSTATE_ROE 0x00080000 #define ASCSTATE_ANY (ASCSTATE_ROE|ASCSTATE_PE|ASCSTATE_FE) #define ASCWHBSTATE_CLRREN 0x00000001 #define ASCWHBSTATE_SETREN 0x00000002 #define ASCWHBSTATE_CLRPE 0x00000004 #define ASCWHBSTATE_CLRFE 0x00000008 #define ASCWHBSTATE_CLRROE 0x00000020 #define ASCTXFCON_TXFEN 0x0001 #define ASCTXFCON_TXFFLU 0x0002 #define ASCTXFCON_TXFITLMASK 0x3F00 #define ASCTXFCON_TXFITLOFF 8 #define ASCRXFCON_RXFEN 0x0001 #define ASCRXFCON_RXFFLU 0x0002 #define ASCRXFCON_RXFITLMASK 0x3F00 #define ASCRXFCON_RXFITLOFF 8 #define ASCFSTAT_RXFFLMASK 0x003F #define ASCFSTAT_TXFFLMASK 0x3F00 #define ASCFSTAT_TXFREEMASK 0x3F000000 #define ASCFSTAT_TXFREEOFF 24 static void lqasc_tx_chars(struct uart_port *port); static struct ltq_uart_port *lqasc_port[MAXPORTS]; static struct uart_driver lqasc_reg; static DEFINE_SPINLOCK(ltq_asc_lock); struct ltq_uart_port { struct uart_port port; /* clock used to derive divider */ struct clk *fpiclk; /* clock gating of the ASC core */ struct clk *clk; unsigned int tx_irq; unsigned int rx_irq; unsigned int err_irq; }; static inline struct ltq_uart_port *to_ltq_uart_port(struct uart_port *port) { return container_of(port, struct ltq_uart_port, port); } static void lqasc_stop_tx(struct uart_port *port) { return; } static void lqasc_start_tx(struct uart_port *port) { unsigned long flags; spin_lock_irqsave(<q_asc_lock, flags); lqasc_tx_chars(port); spin_unlock_irqrestore(<q_asc_lock, flags); return; } static void lqasc_stop_rx(struct uart_port *port) { ltq_w32(ASCWHBSTATE_CLRREN, port->membase + LTQ_ASC_WHBSTATE); } static void lqasc_enable_ms(struct uart_port *port) { } static int lqasc_rx_chars(struct uart_port *port) { struct tty_port *tport = &port->state->port; unsigned int ch = 0, rsr = 0, fifocnt; fifocnt = ltq_r32(port->membase + LTQ_ASC_FSTAT) & ASCFSTAT_RXFFLMASK; while (fifocnt--) { u8 flag = TTY_NORMAL; ch = ltq_r8(port->membase + LTQ_ASC_RBUF); rsr = (ltq_r32(port->membase + LTQ_ASC_STATE) & ASCSTATE_ANY) | UART_DUMMY_UER_RX; tty_flip_buffer_push(tport); port->icount.rx++; /* * Note that the error handling code is * out of the main execution path */ if (rsr & ASCSTATE_ANY) { if (rsr & ASCSTATE_PE) { port->icount.parity++; ltq_w32_mask(0, ASCWHBSTATE_CLRPE, port->membase + LTQ_ASC_WHBSTATE); } else if (rsr & ASCSTATE_FE) { port->icount.frame++; ltq_w32_mask(0, ASCWHBSTATE_CLRFE, port->membase + LTQ_ASC_WHBSTATE); } if (rsr & ASCSTATE_ROE) { port->icount.overrun++; ltq_w32_mask(0, ASCWHBSTATE_CLRROE, port->membase + LTQ_ASC_WHBSTATE); } rsr &= port->read_status_mask; if (rsr & ASCSTATE_PE) flag = TTY_PARITY; else if (rsr & ASCSTATE_FE) flag = TTY_FRAME; } if ((rsr & port->ignore_status_mask) == 0) tty_insert_flip_char(tport, ch, flag); if (rsr & ASCSTATE_ROE) /* * Overrun is special, since it's reported * immediately, and doesn't affect the current * character */ tty_insert_flip_char(tport, 0, TTY_OVERRUN); } if (ch != 0) tty_flip_buffer_push(tport); return 0; } static void lqasc_tx_chars(struct uart_port *port) { struct circ_buf *xmit = &port->state->xmit; if (uart_tx_stopped(port)) { lqasc_stop_tx(port); return; } while (((ltq_r32(port->membase + LTQ_ASC_FSTAT) & ASCFSTAT_TXFREEMASK) >> ASCFSTAT_TXFREEOFF) != 0) { if (port->x_char) { ltq_w8(port->x_char, port->membase + LTQ_ASC_TBUF); port->icount.tx++; port->x_char = 0; continue; } if (uart_circ_empty(xmit)) break; ltq_w8(port->state->xmit.buf[port->state->xmit.tail], port->membase + LTQ_ASC_TBUF); 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 lqasc_tx_int(int irq, void *_port) { unsigned long flags; struct uart_port *port = (struct uart_port *)_port; spin_lock_irqsave(<q_asc_lock, flags); ltq_w32(ASC_IRNCR_TIR, port->membase + LTQ_ASC_IRNCR); spin_unlock_irqrestore(<q_asc_lock, flags); lqasc_start_tx(port); return IRQ_HANDLED; } static irqreturn_t lqasc_err_int(int irq, void *_port) { unsigned long flags; struct uart_port *port = (struct uart_port *)_port; spin_lock_irqsave(<q_asc_lock, flags); /* clear any pending interrupts */ ltq_w32_mask(0, ASCWHBSTATE_CLRPE | ASCWHBSTATE_CLRFE | ASCWHBSTATE_CLRROE, port->membase + LTQ_ASC_WHBSTATE); spin_unlock_irqrestore(<q_asc_lock, flags); return IRQ_HANDLED; } static irqreturn_t lqasc_rx_int(int irq, void *_port) { unsigned long flags; struct uart_port *port = (struct uart_port *)_port; spin_lock_irqsave(<q_asc_lock, flags); ltq_w32(ASC_IRNCR_RIR, port->membase + LTQ_ASC_IRNCR); lqasc_rx_chars(port); spin_unlock_irqrestore(<q_asc_lock, flags); return IRQ_HANDLED; } static unsigned int lqasc_tx_empty(struct uart_port *port) { int status; status = ltq_r32(port->membase + LTQ_ASC_FSTAT) & ASCFSTAT_TXFFLMASK; return status ? 0 : TIOCSER_TEMT; } static unsigned int lqasc_get_mctrl(struct uart_port *port) { return TIOCM_CTS | TIOCM_CAR | TIOCM_DSR; } static void lqasc_set_mctrl(struct uart_port *port, u_int mctrl) { } static void lqasc_break_ctl(struct uart_port *port, int break_state) { } static int lqasc_startup(struct uart_port *port) { struct ltq_uart_port *ltq_port = to_ltq_uart_port(port); int retval; if (!IS_ERR(ltq_port->clk)) clk_enable(ltq_port->clk); port->uartclk = clk_get_rate(ltq_port->fpiclk); ltq_w32_mask(ASCCLC_DISS | ASCCLC_RMCMASK, (1 << ASCCLC_RMCOFFSET), port->membase + LTQ_ASC_CLC); ltq_w32(0, port->membase + LTQ_ASC_PISEL); ltq_w32( ((TXFIFO_FL << ASCTXFCON_TXFITLOFF) & ASCTXFCON_TXFITLMASK) | ASCTXFCON_TXFEN | ASCTXFCON_TXFFLU, port->membase + LTQ_ASC_TXFCON); ltq_w32( ((RXFIFO_FL << ASCRXFCON_RXFITLOFF) & ASCRXFCON_RXFITLMASK) | ASCRXFCON_RXFEN | ASCRXFCON_RXFFLU, port->membase + LTQ_ASC_RXFCON); /* make sure other settings are written to hardware before * setting enable bits */ wmb(); ltq_w32_mask(0, ASCCON_M_8ASYNC | ASCCON_FEN | ASCCON_TOEN | ASCCON_ROEN, port->membase + LTQ_ASC_CON); retval = request_irq(ltq_port->tx_irq, lqasc_tx_int, 0, "asc_tx", port); if (retval) { pr_err("failed to request lqasc_tx_int\n"); return retval; } retval = request_irq(ltq_port->rx_irq, lqasc_rx_int, 0, "asc_rx", port); if (retval) { pr_err("failed to request lqasc_rx_int\n"); goto err1; } retval = request_irq(ltq_port->err_irq, lqasc_err_int, 0, "asc_err", port); if (retval) { pr_err("failed to request lqasc_err_int\n"); goto err2; } ltq_w32(ASC_IRNREN_RX | ASC_IRNREN_ERR | ASC_IRNREN_TX, port->membase + LTQ_ASC_IRNREN); return 0; err2: free_irq(ltq_port->rx_irq, port); err1: free_irq(ltq_port->tx_irq, port); return retval; } static void lqasc_shutdown(struct uart_port *port) { struct ltq_uart_port *ltq_port = to_ltq_uart_port(port); free_irq(ltq_port->tx_irq, port); free_irq(ltq_port->rx_irq, port); free_irq(ltq_port->err_irq, port); ltq_w32(0, port->membase + LTQ_ASC_CON); ltq_w32_mask(ASCRXFCON_RXFEN, ASCRXFCON_RXFFLU, port->membase + LTQ_ASC_RXFCON); ltq_w32_mask(ASCTXFCON_TXFEN, ASCTXFCON_TXFFLU, port->membase + LTQ_ASC_TXFCON); if (!IS_ERR(ltq_port->clk)) clk_disable(ltq_port->clk); } static void lqasc_set_termios(struct uart_port *port, struct ktermios *new, struct ktermios *old) { unsigned int cflag; unsigned int iflag; unsigned int divisor; unsigned int baud; unsigned int con = 0; unsigned long flags; cflag = new->c_cflag; iflag = new->c_iflag; switch (cflag & CSIZE) { case CS7: con = ASCCON_M_7ASYNC; break; case CS5: case CS6: default: new->c_cflag &= ~ CSIZE; new->c_cflag |= CS8; con = ASCCON_M_8ASYNC; break; } cflag &= ~CMSPAR; /* Mark/Space parity is not supported */ if (cflag & CSTOPB) con |= ASCCON_STP; if (cflag & PARENB) { if (!(cflag & PARODD)) con &= ~ASCCON_ODD; else con |= ASCCON_ODD; } port->read_status_mask = ASCSTATE_ROE; if (iflag & INPCK) port->read_status_mask |= ASCSTATE_FE | ASCSTATE_PE; port->ignore_status_mask = 0; if (iflag & IGNPAR) port->ignore_status_mask |= ASCSTATE_FE | ASCSTATE_PE; if (iflag & IGNBRK) { /* * If we're ignoring parity and break indicators, * ignore overruns too (for real raw support). */ if (iflag & IGNPAR) port->ignore_status_mask |= ASCSTATE_ROE; } if ((cflag & CREAD) == 0) port->ignore_status_mask |= UART_DUMMY_UER_RX; /* set error signals - framing, parity and overrun, enable receiver */ con |= ASCCON_FEN | ASCCON_TOEN | ASCCON_ROEN; spin_lock_irqsave(<q_asc_lock, flags); /* set up CON */ ltq_w32_mask(0, con, port->membase + LTQ_ASC_CON); /* Set baud rate - take a divider of 2 into account */ baud = uart_get_baud_rate(port, new, old, 0, port->uartclk / 16); divisor = uart_get_divisor(port, baud); divisor = divisor / 2 - 1; /* disable the baudrate generator */ ltq_w32_mask(ASCCON_R, 0, port->membase + LTQ_ASC_CON); /* make sure the fractional divider is off */ ltq_w32_mask(ASCCON_FDE, 0, port->membase + LTQ_ASC_CON); /* set up to use divisor of 2 */ ltq_w32_mask(ASCCON_BRS, 0, port->membase + LTQ_ASC_CON); /* now we can write the new baudrate into the register */ ltq_w32(divisor, port->membase + LTQ_ASC_BG); /* turn the baudrate generator back on */ ltq_w32_mask(0, ASCCON_R, port->membase + LTQ_ASC_CON); /* enable rx */ ltq_w32(ASCWHBSTATE_SETREN, port->membase + LTQ_ASC_WHBSTATE); spin_unlock_irqrestore(<q_asc_lock, flags); /* Don't rewrite B0 */ if (tty_termios_baud_rate(new)) tty_termios_encode_baud_rate(new, baud, baud); uart_update_timeout(port, cflag, baud); } static const char* lqasc_type(struct uart_port *port) { if (port->type == PORT_LTQ_ASC) return DRVNAME; else return NULL; } static void lqasc_release_port(struct uart_port *port) { if (port->flags & UPF_IOREMAP) { iounmap(port->membase); port->membase = NULL; } } static int lqasc_request_port(struct uart_port *port) { struct platform_device *pdev = to_platform_device(port->dev); struct resource *res; int size; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!res) { dev_err(&pdev->dev, "cannot obtain I/O memory region"); return -ENODEV; } size = resource_size(res); res = devm_request_mem_region(&pdev->dev, res->start, size, dev_name(&pdev->dev)); if (!res) { dev_err(&pdev->dev, "cannot request I/O memory region"); return -EBUSY; } if (port->flags & UPF_IOREMAP) { port->membase = devm_ioremap_nocache(&pdev->dev, port->mapbase, size); if (port->membase == NULL) return -ENOMEM; } return 0; } static void lqasc_config_port(struct uart_port *port, int flags) { if (flags & UART_CONFIG_TYPE) { port->type = PORT_LTQ_ASC; lqasc_request_port(port); } } static int lqasc_verify_port(struct uart_port *port, struct serial_struct *ser) { int ret = 0; if (ser->type != PORT_UNKNOWN && ser->type != PORT_LTQ_ASC) 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 lqasc_pops = { .tx_empty = lqasc_tx_empty, .set_mctrl = lqasc_set_mctrl, .get_mctrl = lqasc_get_mctrl, .stop_tx = lqasc_stop_tx, .start_tx = lqasc_start_tx, .stop_rx = lqasc_stop_rx, .enable_ms = lqasc_enable_ms, .break_ctl = lqasc_break_ctl, .startup = lqasc_startup, .shutdown = lqasc_shutdown, .set_termios = lqasc_set_termios, .type = lqasc_type, .release_port = lqasc_release_port, .request_port = lqasc_request_port, .config_port = lqasc_config_port, .verify_port = lqasc_verify_port, }; static void lqasc_console_putchar(struct uart_port *port, int ch) { int fifofree; if (!port->membase) return; do { fifofree = (ltq_r32(port->membase + LTQ_ASC_FSTAT) & ASCFSTAT_TXFREEMASK) >> ASCFSTAT_TXFREEOFF; } while (fifofree == 0); ltq_w8(ch, port->membase + LTQ_ASC_TBUF); } static void lqasc_console_write(struct console *co, const char *s, u_int count) { struct ltq_uart_port *ltq_port; struct uart_port *port; unsigned long flags; if (co->index >= MAXPORTS) return; ltq_port = lqasc_port[co->index]; if (!ltq_port) return; port = <q_port->port; spin_lock_irqsave(<q_asc_lock, flags); uart_console_write(port, s, count, lqasc_console_putchar); spin_unlock_irqrestore(<q_asc_lock, flags); } static int __init lqasc_console_setup(struct console *co, char *options) { struct ltq_uart_port *ltq_port; struct uart_port *port; int baud = 115200; int bits = 8; int parity = 'n'; int flow = 'n'; if (co->index >= MAXPORTS) return -ENODEV; ltq_port = lqasc_port[co->index]; if (!ltq_port) return -ENODEV; port = <q_port->port; if (!IS_ERR(ltq_port->clk)) clk_enable(ltq_port->clk); port->uartclk = clk_get_rate(ltq_port->fpiclk); if (options) uart_parse_options(options, &baud, &parity, &bits, &flow); return uart_set_options(port, co, baud, parity, bits, flow); } static struct console lqasc_console = { .name = "ttyLTQ", .write = lqasc_console_write, .device = uart_console_device, .setup = lqasc_console_setup, .flags = CON_PRINTBUFFER, .index = -1, .data = &lqasc_reg, }; static int __init lqasc_console_init(void) { register_console(&lqasc_console); return 0; } console_initcall(lqasc_console_init); static struct uart_driver lqasc_reg = { .owner = THIS_MODULE, .driver_name = DRVNAME, .dev_name = "ttyLTQ", .major = 0, .minor = 0, .nr = MAXPORTS, .cons = &lqasc_console, }; static int __init lqasc_probe(struct platform_device *pdev) { struct device_node *node = pdev->dev.of_node; struct ltq_uart_port *ltq_port; struct uart_port *port; struct resource *mmres, irqres[3]; int line = 0; int ret; mmres = platform_get_resource(pdev, IORESOURCE_MEM, 0); ret = of_irq_to_resource_table(node, irqres, 3); if (!mmres || (ret != 3)) { dev_err(&pdev->dev, "failed to get memory/irq for serial port\n"); return -ENODEV; } /* check if this is the console port */ if (mmres->start != CPHYSADDR(LTQ_EARLY_ASC)) line = 1; if (lqasc_port[line]) { dev_err(&pdev->dev, "port %d already allocated\n", line); return -EBUSY; } ltq_port = devm_kzalloc(&pdev->dev, sizeof(struct ltq_uart_port), GFP_KERNEL); if (!ltq_port) return -ENOMEM; port = <q_port->port; port->iotype = SERIAL_IO_MEM; port->flags = ASYNC_BOOT_AUTOCONF | UPF_IOREMAP; port->ops = &lqasc_pops; port->fifosize = 16; port->type = PORT_LTQ_ASC, port->line = line; port->dev = &pdev->dev; /* unused, just to be backward-compatible */ port->irq = irqres[0].start; port->mapbase = mmres->start; ltq_port->fpiclk = clk_get_fpi(); if (IS_ERR(ltq_port->fpiclk)) { pr_err("failed to get fpi clk\n"); return -ENOENT; } /* not all asc ports have clock gates, lets ignore the return code */ ltq_port->clk = clk_get(&pdev->dev, NULL); ltq_port->tx_irq = irqres[0].start; ltq_port->rx_irq = irqres[1].start; ltq_port->err_irq = irqres[2].start; lqasc_port[line] = ltq_port; platform_set_drvdata(pdev, ltq_port); ret = uart_add_one_port(&lqasc_reg, port); return ret; } static const struct of_device_id ltq_asc_match[] = { { .compatible = DRVNAME }, {}, }; MODULE_DEVICE_TABLE(of, ltq_asc_match); static struct platform_driver lqasc_driver = { .driver = { .name = DRVNAME, .owner = THIS_MODULE, .of_match_table = ltq_asc_match, }, }; int __init init_lqasc(void) { int ret; ret = uart_register_driver(&lqasc_reg); if (ret != 0) return ret; ret = platform_driver_probe(&lqasc_driver, lqasc_probe); if (ret != 0) uart_unregister_driver(&lqasc_reg); return ret; } module_init(init_lqasc); MODULE_DESCRIPTION("Lantiq serial port driver"); MODULE_LICENSE("GPL");