/* * Freescale STMP37XX/STMP378X Application UART driver * * Author: dmitry pervushin <dimka@embeddedalley.com> * * Copyright 2008-2010 Freescale Semiconductor, Inc. * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved. * * The code contained herein is licensed under the GNU General Public * License. You may obtain a copy of the GNU General Public License * Version 2 or later at the following locations: * * http://www.opensource.org/licenses/gpl-license.html * http://www.gnu.org/copyleft/gpl.html */ #include <linux/kernel.h> #include <linux/errno.h> #include <linux/init.h> #include <linux/console.h> #include <linux/interrupt.h> #include <linux/module.h> #include <linux/slab.h> #include <linux/wait.h> #include <linux/tty.h> #include <linux/tty_driver.h> #include <linux/tty_flip.h> #include <linux/serial.h> #include <linux/serial_core.h> #include <linux/platform_device.h> #include <linux/device.h> #include <linux/clk.h> #include <linux/delay.h> #include <linux/io.h> #include <asm/cacheflush.h> #define MXS_AUART_PORTS 5 #define AUART_CTRL0 0x00000000 #define AUART_CTRL0_SET 0x00000004 #define AUART_CTRL0_CLR 0x00000008 #define AUART_CTRL0_TOG 0x0000000c #define AUART_CTRL1 0x00000010 #define AUART_CTRL1_SET 0x00000014 #define AUART_CTRL1_CLR 0x00000018 #define AUART_CTRL1_TOG 0x0000001c #define AUART_CTRL2 0x00000020 #define AUART_CTRL2_SET 0x00000024 #define AUART_CTRL2_CLR 0x00000028 #define AUART_CTRL2_TOG 0x0000002c #define AUART_LINECTRL 0x00000030 #define AUART_LINECTRL_SET 0x00000034 #define AUART_LINECTRL_CLR 0x00000038 #define AUART_LINECTRL_TOG 0x0000003c #define AUART_LINECTRL2 0x00000040 #define AUART_LINECTRL2_SET 0x00000044 #define AUART_LINECTRL2_CLR 0x00000048 #define AUART_LINECTRL2_TOG 0x0000004c #define AUART_INTR 0x00000050 #define AUART_INTR_SET 0x00000054 #define AUART_INTR_CLR 0x00000058 #define AUART_INTR_TOG 0x0000005c #define AUART_DATA 0x00000060 #define AUART_STAT 0x00000070 #define AUART_DEBUG 0x00000080 #define AUART_VERSION 0x00000090 #define AUART_AUTOBAUD 0x000000a0 #define AUART_CTRL0_SFTRST (1 << 31) #define AUART_CTRL0_CLKGATE (1 << 30) #define AUART_CTRL2_CTSEN (1 << 15) #define AUART_CTRL2_RTS (1 << 11) #define AUART_CTRL2_RXE (1 << 9) #define AUART_CTRL2_TXE (1 << 8) #define AUART_CTRL2_UARTEN (1 << 0) #define AUART_LINECTRL_BAUD_DIVINT_SHIFT 16 #define AUART_LINECTRL_BAUD_DIVINT_MASK 0xffff0000 #define AUART_LINECTRL_BAUD_DIVINT(v) (((v) & 0xffff) << 16) #define AUART_LINECTRL_BAUD_DIVFRAC_SHIFT 8 #define AUART_LINECTRL_BAUD_DIVFRAC_MASK 0x00003f00 #define AUART_LINECTRL_BAUD_DIVFRAC(v) (((v) & 0x3f) << 8) #define AUART_LINECTRL_WLEN_MASK 0x00000060 #define AUART_LINECTRL_WLEN(v) (((v) & 0x3) << 5) #define AUART_LINECTRL_FEN (1 << 4) #define AUART_LINECTRL_STP2 (1 << 3) #define AUART_LINECTRL_EPS (1 << 2) #define AUART_LINECTRL_PEN (1 << 1) #define AUART_LINECTRL_BRK (1 << 0) #define AUART_INTR_RTIEN (1 << 22) #define AUART_INTR_TXIEN (1 << 21) #define AUART_INTR_RXIEN (1 << 20) #define AUART_INTR_CTSMIEN (1 << 17) #define AUART_INTR_RTIS (1 << 6) #define AUART_INTR_TXIS (1 << 5) #define AUART_INTR_RXIS (1 << 4) #define AUART_INTR_CTSMIS (1 << 1) #define AUART_STAT_BUSY (1 << 29) #define AUART_STAT_CTS (1 << 28) #define AUART_STAT_TXFE (1 << 27) #define AUART_STAT_TXFF (1 << 25) #define AUART_STAT_RXFE (1 << 24) #define AUART_STAT_OERR (1 << 19) #define AUART_STAT_BERR (1 << 18) #define AUART_STAT_PERR (1 << 17) #define AUART_STAT_FERR (1 << 16) static struct uart_driver auart_driver; struct mxs_auart_port { struct uart_port port; unsigned int flags; unsigned int ctrl; unsigned int irq; struct clk *clk; struct device *dev; }; static void mxs_auart_stop_tx(struct uart_port *u); #define to_auart_port(u) container_of(u, struct mxs_auart_port, port) static inline void mxs_auart_tx_chars(struct mxs_auart_port *s) { struct circ_buf *xmit = &s->port.state->xmit; while (!(readl(s->port.membase + AUART_STAT) & AUART_STAT_TXFF)) { if (s->port.x_char) { s->port.icount.tx++; writel(s->port.x_char, s->port.membase + AUART_DATA); s->port.x_char = 0; continue; } if (!uart_circ_empty(xmit) && !uart_tx_stopped(&s->port)) { s->port.icount.tx++; writel(xmit->buf[xmit->tail], s->port.membase + AUART_DATA); xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) uart_write_wakeup(&s->port); } else break; } if (uart_circ_empty(&(s->port.state->xmit))) writel(AUART_INTR_TXIEN, s->port.membase + AUART_INTR_CLR); else writel(AUART_INTR_TXIEN, s->port.membase + AUART_INTR_SET); if (uart_tx_stopped(&s->port)) mxs_auart_stop_tx(&s->port); } static void mxs_auart_rx_char(struct mxs_auart_port *s) { int flag; u32 stat; u8 c; c = readl(s->port.membase + AUART_DATA); stat = readl(s->port.membase + AUART_STAT); flag = TTY_NORMAL; s->port.icount.rx++; if (stat & AUART_STAT_BERR) { s->port.icount.brk++; if (uart_handle_break(&s->port)) goto out; } else if (stat & AUART_STAT_PERR) { s->port.icount.parity++; } else if (stat & AUART_STAT_FERR) { s->port.icount.frame++; } /* * Mask off conditions which should be ingored. */ stat &= s->port.read_status_mask; if (stat & AUART_STAT_BERR) { flag = TTY_BREAK; } else if (stat & AUART_STAT_PERR) flag = TTY_PARITY; else if (stat & AUART_STAT_FERR) flag = TTY_FRAME; if (stat & AUART_STAT_OERR) s->port.icount.overrun++; if (uart_handle_sysrq_char(&s->port, c)) goto out; uart_insert_char(&s->port, stat, AUART_STAT_OERR, c, flag); out: writel(stat, s->port.membase + AUART_STAT); } static void mxs_auart_rx_chars(struct mxs_auart_port *s) { struct tty_struct *tty = s->port.state->port.tty; u32 stat = 0; for (;;) { stat = readl(s->port.membase + AUART_STAT); if (stat & AUART_STAT_RXFE) break; mxs_auart_rx_char(s); } writel(stat, s->port.membase + AUART_STAT); tty_flip_buffer_push(tty); } static int mxs_auart_request_port(struct uart_port *u) { return 0; } static int mxs_auart_verify_port(struct uart_port *u, struct serial_struct *ser) { if (u->type != PORT_UNKNOWN && u->type != PORT_IMX) return -EINVAL; return 0; } static void mxs_auart_config_port(struct uart_port *u, int flags) { } static const char *mxs_auart_type(struct uart_port *u) { struct mxs_auart_port *s = to_auart_port(u); return dev_name(s->dev); } static void mxs_auart_release_port(struct uart_port *u) { } static void mxs_auart_set_mctrl(struct uart_port *u, unsigned mctrl) { struct mxs_auart_port *s = to_auart_port(u); u32 ctrl = readl(u->membase + AUART_CTRL2); ctrl &= ~AUART_CTRL2_RTS; if (mctrl & TIOCM_RTS) ctrl |= AUART_CTRL2_RTS; s->ctrl = mctrl; writel(ctrl, u->membase + AUART_CTRL2); } static u32 mxs_auart_get_mctrl(struct uart_port *u) { struct mxs_auart_port *s = to_auart_port(u); u32 stat = readl(u->membase + AUART_STAT); int ctrl2 = readl(u->membase + AUART_CTRL2); u32 mctrl = s->ctrl; mctrl &= ~TIOCM_CTS; if (stat & AUART_STAT_CTS) mctrl |= TIOCM_CTS; if (ctrl2 & AUART_CTRL2_RTS) mctrl |= TIOCM_RTS; return mctrl; } static void mxs_auart_settermios(struct uart_port *u, struct ktermios *termios, struct ktermios *old) { u32 bm, ctrl, ctrl2, div; unsigned int cflag, baud; cflag = termios->c_cflag; ctrl = AUART_LINECTRL_FEN; ctrl2 = readl(u->membase + AUART_CTRL2); /* byte size */ switch (cflag & CSIZE) { case CS5: bm = 0; break; case CS6: bm = 1; break; case CS7: bm = 2; break; case CS8: bm = 3; break; default: return; } ctrl |= AUART_LINECTRL_WLEN(bm); /* parity */ if (cflag & PARENB) { ctrl |= AUART_LINECTRL_PEN; if ((cflag & PARODD) == 0) ctrl |= AUART_LINECTRL_EPS; } u->read_status_mask = 0; if (termios->c_iflag & INPCK) u->read_status_mask |= AUART_STAT_PERR; if (termios->c_iflag & (BRKINT | PARMRK)) u->read_status_mask |= AUART_STAT_BERR; /* * Characters to ignore */ u->ignore_status_mask = 0; if (termios->c_iflag & IGNPAR) u->ignore_status_mask |= AUART_STAT_PERR; if (termios->c_iflag & IGNBRK) { u->ignore_status_mask |= AUART_STAT_BERR; /* * If we're ignoring parity and break indicators, * ignore overruns too (for real raw support). */ if (termios->c_iflag & IGNPAR) u->ignore_status_mask |= AUART_STAT_OERR; } /* * ignore all characters if CREAD is not set */ if (cflag & CREAD) ctrl2 |= AUART_CTRL2_RXE; else ctrl2 &= ~AUART_CTRL2_RXE; /* figure out the stop bits requested */ if (cflag & CSTOPB) ctrl |= AUART_LINECTRL_STP2; /* figure out the hardware flow control settings */ if (cflag & CRTSCTS) ctrl2 |= AUART_CTRL2_CTSEN; else ctrl2 &= ~AUART_CTRL2_CTSEN; /* set baud rate */ baud = uart_get_baud_rate(u, termios, old, 0, u->uartclk); div = u->uartclk * 32 / baud; ctrl |= AUART_LINECTRL_BAUD_DIVFRAC(div & 0x3F); ctrl |= AUART_LINECTRL_BAUD_DIVINT(div >> 6); writel(ctrl, u->membase + AUART_LINECTRL); writel(ctrl2, u->membase + AUART_CTRL2); } static irqreturn_t mxs_auart_irq_handle(int irq, void *context) { u32 istatus, istat; struct mxs_auart_port *s = context; u32 stat = readl(s->port.membase + AUART_STAT); istatus = istat = readl(s->port.membase + AUART_INTR); if (istat & AUART_INTR_CTSMIS) { uart_handle_cts_change(&s->port, stat & AUART_STAT_CTS); writel(AUART_INTR_CTSMIS, s->port.membase + AUART_INTR_CLR); istat &= ~AUART_INTR_CTSMIS; } if (istat & (AUART_INTR_RTIS | AUART_INTR_RXIS)) { mxs_auart_rx_chars(s); istat &= ~(AUART_INTR_RTIS | AUART_INTR_RXIS); } if (istat & AUART_INTR_TXIS) { mxs_auart_tx_chars(s); istat &= ~AUART_INTR_TXIS; } writel(istatus & (AUART_INTR_RTIS | AUART_INTR_TXIS | AUART_INTR_RXIS | AUART_INTR_CTSMIS), s->port.membase + AUART_INTR_CLR); return IRQ_HANDLED; } static void mxs_auart_reset(struct uart_port *u) { int i; unsigned int reg; writel(AUART_CTRL0_SFTRST, u->membase + AUART_CTRL0_CLR); for (i = 0; i < 10000; i++) { reg = readl(u->membase + AUART_CTRL0); if (!(reg & AUART_CTRL0_SFTRST)) break; udelay(3); } writel(AUART_CTRL0_CLKGATE, u->membase + AUART_CTRL0_CLR); } static int mxs_auart_startup(struct uart_port *u) { struct mxs_auart_port *s = to_auart_port(u); clk_enable(s->clk); writel(AUART_CTRL0_CLKGATE, u->membase + AUART_CTRL0_CLR); writel(AUART_CTRL2_UARTEN, u->membase + AUART_CTRL2_SET); writel(AUART_INTR_RXIEN | AUART_INTR_RTIEN | AUART_INTR_CTSMIEN, u->membase + AUART_INTR); /* * Enable fifo so all four bytes of a DMA word are written to * output (otherwise, only the LSB is written, ie. 1 in 4 bytes) */ writel(AUART_LINECTRL_FEN, u->membase + AUART_LINECTRL_SET); return 0; } static void mxs_auart_shutdown(struct uart_port *u) { struct mxs_auart_port *s = to_auart_port(u); writel(AUART_CTRL2_UARTEN, u->membase + AUART_CTRL2_CLR); writel(AUART_CTRL0_CLKGATE, u->membase + AUART_CTRL0_SET); writel(AUART_INTR_RXIEN | AUART_INTR_RTIEN | AUART_INTR_CTSMIEN, u->membase + AUART_INTR_CLR); clk_disable(s->clk); } static unsigned int mxs_auart_tx_empty(struct uart_port *u) { if (readl(u->membase + AUART_STAT) & AUART_STAT_TXFE) return TIOCSER_TEMT; else return 0; } static void mxs_auart_start_tx(struct uart_port *u) { struct mxs_auart_port *s = to_auart_port(u); /* enable transmitter */ writel(AUART_CTRL2_TXE, u->membase + AUART_CTRL2_SET); mxs_auart_tx_chars(s); } static void mxs_auart_stop_tx(struct uart_port *u) { writel(AUART_CTRL2_TXE, u->membase + AUART_CTRL2_CLR); } static void mxs_auart_stop_rx(struct uart_port *u) { writel(AUART_CTRL2_RXE, u->membase + AUART_CTRL2_CLR); } static void mxs_auart_break_ctl(struct uart_port *u, int ctl) { if (ctl) writel(AUART_LINECTRL_BRK, u->membase + AUART_LINECTRL_SET); else writel(AUART_LINECTRL_BRK, u->membase + AUART_LINECTRL_CLR); } static void mxs_auart_enable_ms(struct uart_port *port) { /* just empty */ } static struct uart_ops mxs_auart_ops = { .tx_empty = mxs_auart_tx_empty, .start_tx = mxs_auart_start_tx, .stop_tx = mxs_auart_stop_tx, .stop_rx = mxs_auart_stop_rx, .enable_ms = mxs_auart_enable_ms, .break_ctl = mxs_auart_break_ctl, .set_mctrl = mxs_auart_set_mctrl, .get_mctrl = mxs_auart_get_mctrl, .startup = mxs_auart_startup, .shutdown = mxs_auart_shutdown, .set_termios = mxs_auart_settermios, .type = mxs_auart_type, .release_port = mxs_auart_release_port, .request_port = mxs_auart_request_port, .config_port = mxs_auart_config_port, .verify_port = mxs_auart_verify_port, }; static struct mxs_auart_port *auart_port[MXS_AUART_PORTS]; #ifdef CONFIG_SERIAL_MXS_AUART_CONSOLE static void mxs_auart_console_putchar(struct uart_port *port, int ch) { unsigned int to = 1000; while (readl(port->membase + AUART_STAT) & AUART_STAT_TXFF) { if (!to--) break; udelay(1); } writel(ch, port->membase + AUART_DATA); } static void auart_console_write(struct console *co, const char *str, unsigned int count) { struct mxs_auart_port *s; struct uart_port *port; unsigned int old_ctrl0, old_ctrl2; unsigned int to = 1000; if (co->index > MXS_AUART_PORTS || co->index < 0) return; s = auart_port[co->index]; port = &s->port; clk_enable(s->clk); /* First save the CR then disable the interrupts */ old_ctrl2 = readl(port->membase + AUART_CTRL2); old_ctrl0 = readl(port->membase + AUART_CTRL0); writel(AUART_CTRL0_CLKGATE, port->membase + AUART_CTRL0_CLR); writel(AUART_CTRL2_UARTEN | AUART_CTRL2_TXE, port->membase + AUART_CTRL2_SET); uart_console_write(port, str, count, mxs_auart_console_putchar); /* * Finally, wait for transmitter to become empty * and restore the TCR */ while (readl(port->membase + AUART_STAT) & AUART_STAT_BUSY) { if (!to--) break; udelay(1); } writel(old_ctrl0, port->membase + AUART_CTRL0); writel(old_ctrl2, port->membase + AUART_CTRL2); clk_disable(s->clk); } static void __init auart_console_get_options(struct uart_port *port, int *baud, int *parity, int *bits) { unsigned int lcr_h, quot; if (!(readl(port->membase + AUART_CTRL2) & AUART_CTRL2_UARTEN)) return; lcr_h = readl(port->membase + AUART_LINECTRL); *parity = 'n'; if (lcr_h & AUART_LINECTRL_PEN) { if (lcr_h & AUART_LINECTRL_EPS) *parity = 'e'; else *parity = 'o'; } if ((lcr_h & AUART_LINECTRL_WLEN_MASK) == AUART_LINECTRL_WLEN(2)) *bits = 7; else *bits = 8; quot = ((readl(port->membase + AUART_LINECTRL) & AUART_LINECTRL_BAUD_DIVINT_MASK)) >> (AUART_LINECTRL_BAUD_DIVINT_SHIFT - 6); quot |= ((readl(port->membase + AUART_LINECTRL) & AUART_LINECTRL_BAUD_DIVFRAC_MASK)) >> AUART_LINECTRL_BAUD_DIVFRAC_SHIFT; if (quot == 0) quot = 1; *baud = (port->uartclk << 2) / quot; } static int __init auart_console_setup(struct console *co, char *options) { struct mxs_auart_port *s; int baud = 9600; int bits = 8; int parity = 'n'; int flow = 'n'; int ret; /* * Check whether an invalid uart number has been specified, and * if so, search for the first available port that does have * console support. */ if (co->index == -1 || co->index >= ARRAY_SIZE(auart_port)) co->index = 0; s = auart_port[co->index]; if (!s) return -ENODEV; clk_enable(s->clk); if (options) uart_parse_options(options, &baud, &parity, &bits, &flow); else auart_console_get_options(&s->port, &baud, &parity, &bits); ret = uart_set_options(&s->port, co, baud, parity, bits, flow); clk_disable(s->clk); return ret; } static struct console auart_console = { .name = "ttyAPP", .write = auart_console_write, .device = uart_console_device, .setup = auart_console_setup, .flags = CON_PRINTBUFFER, .index = -1, .data = &auart_driver, }; #endif static struct uart_driver auart_driver = { .owner = THIS_MODULE, .driver_name = "ttyAPP", .dev_name = "ttyAPP", .major = 0, .minor = 0, .nr = MXS_AUART_PORTS, #ifdef CONFIG_SERIAL_MXS_AUART_CONSOLE .cons = &auart_console, #endif }; static int __devinit mxs_auart_probe(struct platform_device *pdev) { struct mxs_auart_port *s; u32 version; int ret = 0; struct resource *r; s = kzalloc(sizeof(struct mxs_auart_port), GFP_KERNEL); if (!s) { ret = -ENOMEM; goto out; } s->clk = clk_get(&pdev->dev, NULL); if (IS_ERR(s->clk)) { ret = PTR_ERR(s->clk); goto out_free; } r = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!r) { ret = -ENXIO; goto out_free_clk; } s->port.mapbase = r->start; s->port.membase = ioremap(r->start, resource_size(r)); s->port.ops = &mxs_auart_ops; s->port.iotype = UPIO_MEM; s->port.line = pdev->id < 0 ? 0 : pdev->id; s->port.fifosize = 16; s->port.uartclk = clk_get_rate(s->clk); s->port.type = PORT_IMX; s->port.dev = s->dev = get_device(&pdev->dev); s->flags = 0; s->ctrl = 0; s->irq = platform_get_irq(pdev, 0); s->port.irq = s->irq; ret = request_irq(s->irq, mxs_auart_irq_handle, 0, dev_name(&pdev->dev), s); if (ret) goto out_free_clk; platform_set_drvdata(pdev, s); auart_port[pdev->id] = s; mxs_auart_reset(&s->port); ret = uart_add_one_port(&auart_driver, &s->port); if (ret) goto out_free_irq; version = readl(s->port.membase + AUART_VERSION); dev_info(&pdev->dev, "Found APPUART %d.%d.%d\n", (version >> 24) & 0xff, (version >> 16) & 0xff, version & 0xffff); return 0; out_free_irq: auart_port[pdev->id] = NULL; free_irq(s->irq, s); out_free_clk: clk_put(s->clk); out_free: kfree(s); out: return ret; } static int __devexit mxs_auart_remove(struct platform_device *pdev) { struct mxs_auart_port *s = platform_get_drvdata(pdev); uart_remove_one_port(&auart_driver, &s->port); auart_port[pdev->id] = NULL; clk_put(s->clk); free_irq(s->irq, s); kfree(s); return 0; } static struct platform_driver mxs_auart_driver = { .probe = mxs_auart_probe, .remove = __devexit_p(mxs_auart_remove), .driver = { .name = "mxs-auart", .owner = THIS_MODULE, }, }; static int __init mxs_auart_init(void) { int r; r = uart_register_driver(&auart_driver); if (r) goto out; r = platform_driver_register(&mxs_auart_driver); if (r) goto out_err; return 0; out_err: uart_unregister_driver(&auart_driver); out: return r; } static void __exit mxs_auart_exit(void) { platform_driver_unregister(&mxs_auart_driver); uart_unregister_driver(&auart_driver); } module_init(mxs_auart_init); module_exit(mxs_auart_exit); MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("Freescale MXS application uart driver");