// SPDX-License-Identifier: GPL-2.0+ /* * High Speed Serial Ports on NXP LPC32xx SoC * * Authors: Kevin Wells * Roland Stigge * * Copyright (C) 2010 NXP Semiconductors * Copyright (C) 2012 Roland Stigge */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * High Speed UART register offsets */ #define LPC32XX_HSUART_FIFO(x) ((x) + 0x00) #define LPC32XX_HSUART_LEVEL(x) ((x) + 0x04) #define LPC32XX_HSUART_IIR(x) ((x) + 0x08) #define LPC32XX_HSUART_CTRL(x) ((x) + 0x0C) #define LPC32XX_HSUART_RATE(x) ((x) + 0x10) #define LPC32XX_HSU_BREAK_DATA (1 << 10) #define LPC32XX_HSU_ERROR_DATA (1 << 9) #define LPC32XX_HSU_RX_EMPTY (1 << 8) #define LPC32XX_HSU_TX_LEV(n) (((n) >> 8) & 0xFF) #define LPC32XX_HSU_RX_LEV(n) ((n) & 0xFF) #define LPC32XX_HSU_TX_INT_SET (1 << 6) #define LPC32XX_HSU_RX_OE_INT (1 << 5) #define LPC32XX_HSU_BRK_INT (1 << 4) #define LPC32XX_HSU_FE_INT (1 << 3) #define LPC32XX_HSU_RX_TIMEOUT_INT (1 << 2) #define LPC32XX_HSU_RX_TRIG_INT (1 << 1) #define LPC32XX_HSU_TX_INT (1 << 0) #define LPC32XX_HSU_HRTS_INV (1 << 21) #define LPC32XX_HSU_HRTS_TRIG_8B (0x0 << 19) #define LPC32XX_HSU_HRTS_TRIG_16B (0x1 << 19) #define LPC32XX_HSU_HRTS_TRIG_32B (0x2 << 19) #define LPC32XX_HSU_HRTS_TRIG_48B (0x3 << 19) #define LPC32XX_HSU_HRTS_EN (1 << 18) #define LPC32XX_HSU_TMO_DISABLED (0x0 << 16) #define LPC32XX_HSU_TMO_INACT_4B (0x1 << 16) #define LPC32XX_HSU_TMO_INACT_8B (0x2 << 16) #define LPC32XX_HSU_TMO_INACT_16B (0x3 << 16) #define LPC32XX_HSU_HCTS_INV (1 << 15) #define LPC32XX_HSU_HCTS_EN (1 << 14) #define LPC32XX_HSU_OFFSET(n) ((n) << 9) #define LPC32XX_HSU_BREAK (1 << 8) #define LPC32XX_HSU_ERR_INT_EN (1 << 7) #define LPC32XX_HSU_RX_INT_EN (1 << 6) #define LPC32XX_HSU_TX_INT_EN (1 << 5) #define LPC32XX_HSU_RX_TL1B (0x0 << 2) #define LPC32XX_HSU_RX_TL4B (0x1 << 2) #define LPC32XX_HSU_RX_TL8B (0x2 << 2) #define LPC32XX_HSU_RX_TL16B (0x3 << 2) #define LPC32XX_HSU_RX_TL32B (0x4 << 2) #define LPC32XX_HSU_RX_TL48B (0x5 << 2) #define LPC32XX_HSU_TX_TLEMPTY (0x0 << 0) #define LPC32XX_HSU_TX_TL0B (0x0 << 0) #define LPC32XX_HSU_TX_TL4B (0x1 << 0) #define LPC32XX_HSU_TX_TL8B (0x2 << 0) #define LPC32XX_HSU_TX_TL16B (0x3 << 0) #define LPC32XX_MAIN_OSC_FREQ 13000000 #define MODNAME "lpc32xx_hsuart" struct lpc32xx_hsuart_port { struct uart_port port; }; #define FIFO_READ_LIMIT 128 #define MAX_PORTS 3 #define LPC32XX_TTY_NAME "ttyTX" static struct lpc32xx_hsuart_port lpc32xx_hs_ports[MAX_PORTS]; #ifdef CONFIG_SERIAL_HS_LPC32XX_CONSOLE static void wait_for_xmit_empty(struct uart_port *port) { unsigned int timeout = 10000; do { if (LPC32XX_HSU_TX_LEV(readl(LPC32XX_HSUART_LEVEL( port->membase))) == 0) break; if (--timeout == 0) break; udelay(1); } while (1); } static void wait_for_xmit_ready(struct uart_port *port) { unsigned int timeout = 10000; while (1) { if (LPC32XX_HSU_TX_LEV(readl(LPC32XX_HSUART_LEVEL( port->membase))) < 32) break; if (--timeout == 0) break; udelay(1); } } static void lpc32xx_hsuart_console_putchar(struct uart_port *port, unsigned char ch) { wait_for_xmit_ready(port); writel((u32)ch, LPC32XX_HSUART_FIFO(port->membase)); } static void lpc32xx_hsuart_console_write(struct console *co, const char *s, unsigned int count) { struct lpc32xx_hsuart_port *up = &lpc32xx_hs_ports[co->index]; unsigned long flags; int locked = 1; touch_nmi_watchdog(); if (oops_in_progress) locked = uart_port_trylock_irqsave(&up->port, &flags); else uart_port_lock_irqsave(&up->port, &flags); uart_console_write(&up->port, s, count, lpc32xx_hsuart_console_putchar); wait_for_xmit_empty(&up->port); if (locked) uart_port_unlock_irqrestore(&up->port, flags); } static int __init lpc32xx_hsuart_console_setup(struct console *co, char *options) { struct uart_port *port; int baud = 115200; int bits = 8; int parity = 'n'; int flow = 'n'; if (co->index >= MAX_PORTS) co->index = 0; port = &lpc32xx_hs_ports[co->index].port; if (!port->membase) return -ENODEV; if (options) uart_parse_options(options, &baud, &parity, &bits, &flow); lpc32xx_loopback_set(port->mapbase, 0); /* get out of loopback mode */ return uart_set_options(port, co, baud, parity, bits, flow); } static struct uart_driver lpc32xx_hsuart_reg; static struct console lpc32xx_hsuart_console = { .name = LPC32XX_TTY_NAME, .write = lpc32xx_hsuart_console_write, .device = uart_console_device, .setup = lpc32xx_hsuart_console_setup, .flags = CON_PRINTBUFFER, .index = -1, .data = &lpc32xx_hsuart_reg, }; static int __init lpc32xx_hsuart_console_init(void) { register_console(&lpc32xx_hsuart_console); return 0; } console_initcall(lpc32xx_hsuart_console_init); #define LPC32XX_HSUART_CONSOLE (&lpc32xx_hsuart_console) #else #define LPC32XX_HSUART_CONSOLE NULL #endif static struct uart_driver lpc32xx_hs_reg = { .owner = THIS_MODULE, .driver_name = MODNAME, .dev_name = LPC32XX_TTY_NAME, .nr = MAX_PORTS, .cons = LPC32XX_HSUART_CONSOLE, }; static int uarts_registered; static unsigned int __serial_get_clock_div(unsigned long uartclk, unsigned long rate) { u32 div, goodrate, hsu_rate, l_hsu_rate, comprate; u32 rate_diff; /* Find the closest divider to get the desired clock rate */ div = uartclk / rate; goodrate = hsu_rate = (div / 14) - 1; if (hsu_rate != 0) hsu_rate--; /* Tweak divider */ l_hsu_rate = hsu_rate + 3; rate_diff = 0xFFFFFFFF; while (hsu_rate < l_hsu_rate) { comprate = uartclk / ((hsu_rate + 1) * 14); if (abs(comprate - rate) < rate_diff) { goodrate = hsu_rate; rate_diff = abs(comprate - rate); } hsu_rate++; } return goodrate; } static void __serial_uart_flush(struct uart_port *port) { int cnt = 0; while ((readl(LPC32XX_HSUART_LEVEL(port->membase)) > 0) && (cnt++ < FIFO_READ_LIMIT)) readl(LPC32XX_HSUART_FIFO(port->membase)); } static void __serial_lpc32xx_rx(struct uart_port *port) { struct tty_port *tport = &port->state->port; unsigned int tmp, flag; /* Read data from FIFO and push into terminal */ tmp = readl(LPC32XX_HSUART_FIFO(port->membase)); while (!(tmp & LPC32XX_HSU_RX_EMPTY)) { flag = TTY_NORMAL; port->icount.rx++; if (tmp & LPC32XX_HSU_ERROR_DATA) { /* Framing error */ writel(LPC32XX_HSU_FE_INT, LPC32XX_HSUART_IIR(port->membase)); port->icount.frame++; flag = TTY_FRAME; tty_insert_flip_char(tport, 0, TTY_FRAME); } if (!uart_prepare_sysrq_char(port, tmp & 0xff)) tty_insert_flip_char(tport, (tmp & 0xFF), flag); tmp = readl(LPC32XX_HSUART_FIFO(port->membase)); } tty_flip_buffer_push(tport); } static bool serial_lpc32xx_tx_ready(struct uart_port *port) { u32 level = readl(LPC32XX_HSUART_LEVEL(port->membase)); return LPC32XX_HSU_TX_LEV(level) < 64; } static void __serial_lpc32xx_tx(struct uart_port *port) { u8 ch; uart_port_tx(port, ch, serial_lpc32xx_tx_ready(port), writel(ch, LPC32XX_HSUART_FIFO(port->membase))); } static irqreturn_t serial_lpc32xx_interrupt(int irq, void *dev_id) { struct uart_port *port = dev_id; struct tty_port *tport = &port->state->port; u32 status; uart_port_lock(port); /* Read UART status and clear latched interrupts */ status = readl(LPC32XX_HSUART_IIR(port->membase)); if (status & LPC32XX_HSU_BRK_INT) { /* Break received */ writel(LPC32XX_HSU_BRK_INT, LPC32XX_HSUART_IIR(port->membase)); port->icount.brk++; uart_handle_break(port); } /* Framing error */ if (status & LPC32XX_HSU_FE_INT) writel(LPC32XX_HSU_FE_INT, LPC32XX_HSUART_IIR(port->membase)); if (status & LPC32XX_HSU_RX_OE_INT) { /* Receive FIFO overrun */ writel(LPC32XX_HSU_RX_OE_INT, LPC32XX_HSUART_IIR(port->membase)); port->icount.overrun++; tty_insert_flip_char(tport, 0, TTY_OVERRUN); tty_flip_buffer_push(tport); } /* Data received? */ if (status & (LPC32XX_HSU_RX_TIMEOUT_INT | LPC32XX_HSU_RX_TRIG_INT)) __serial_lpc32xx_rx(port); /* Transmit data request? */ if ((status & LPC32XX_HSU_TX_INT) && (!uart_tx_stopped(port))) { writel(LPC32XX_HSU_TX_INT, LPC32XX_HSUART_IIR(port->membase)); __serial_lpc32xx_tx(port); } uart_unlock_and_check_sysrq(port); return IRQ_HANDLED; } /* port->lock is not held. */ static unsigned int serial_lpc32xx_tx_empty(struct uart_port *port) { unsigned int ret = 0; if (LPC32XX_HSU_TX_LEV(readl(LPC32XX_HSUART_LEVEL(port->membase))) == 0) ret = TIOCSER_TEMT; return ret; } /* port->lock held by caller. */ static void serial_lpc32xx_set_mctrl(struct uart_port *port, unsigned int mctrl) { /* No signals are supported on HS UARTs */ } /* port->lock is held by caller and interrupts are disabled. */ static unsigned int serial_lpc32xx_get_mctrl(struct uart_port *port) { /* No signals are supported on HS UARTs */ return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS; } /* port->lock held by caller. */ static void serial_lpc32xx_stop_tx(struct uart_port *port) { u32 tmp; tmp = readl(LPC32XX_HSUART_CTRL(port->membase)); tmp &= ~LPC32XX_HSU_TX_INT_EN; writel(tmp, LPC32XX_HSUART_CTRL(port->membase)); } /* port->lock held by caller. */ static void serial_lpc32xx_start_tx(struct uart_port *port) { u32 tmp; __serial_lpc32xx_tx(port); tmp = readl(LPC32XX_HSUART_CTRL(port->membase)); tmp |= LPC32XX_HSU_TX_INT_EN; writel(tmp, LPC32XX_HSUART_CTRL(port->membase)); } /* port->lock held by caller. */ static void serial_lpc32xx_stop_rx(struct uart_port *port) { u32 tmp; tmp = readl(LPC32XX_HSUART_CTRL(port->membase)); tmp &= ~(LPC32XX_HSU_RX_INT_EN | LPC32XX_HSU_ERR_INT_EN); writel(tmp, LPC32XX_HSUART_CTRL(port->membase)); writel((LPC32XX_HSU_BRK_INT | LPC32XX_HSU_RX_OE_INT | LPC32XX_HSU_FE_INT), LPC32XX_HSUART_IIR(port->membase)); } /* port->lock is not held. */ static void serial_lpc32xx_break_ctl(struct uart_port *port, int break_state) { unsigned long flags; u32 tmp; uart_port_lock_irqsave(port, &flags); tmp = readl(LPC32XX_HSUART_CTRL(port->membase)); if (break_state != 0) tmp |= LPC32XX_HSU_BREAK; else tmp &= ~LPC32XX_HSU_BREAK; writel(tmp, LPC32XX_HSUART_CTRL(port->membase)); uart_port_unlock_irqrestore(port, flags); } /* port->lock is not held. */ static int serial_lpc32xx_startup(struct uart_port *port) { int retval; unsigned long flags; u32 tmp; uart_port_lock_irqsave(port, &flags); __serial_uart_flush(port); writel((LPC32XX_HSU_TX_INT | LPC32XX_HSU_FE_INT | LPC32XX_HSU_BRK_INT | LPC32XX_HSU_RX_OE_INT), LPC32XX_HSUART_IIR(port->membase)); writel(0xFF, LPC32XX_HSUART_RATE(port->membase)); /* * Set receiver timeout, HSU offset of 20, no break, no interrupts, * and default FIFO trigger levels */ tmp = LPC32XX_HSU_TX_TL8B | LPC32XX_HSU_RX_TL32B | LPC32XX_HSU_OFFSET(20) | LPC32XX_HSU_TMO_INACT_4B; writel(tmp, LPC32XX_HSUART_CTRL(port->membase)); lpc32xx_loopback_set(port->mapbase, 0); /* get out of loopback mode */ uart_port_unlock_irqrestore(port, flags); retval = request_irq(port->irq, serial_lpc32xx_interrupt, 0, MODNAME, port); if (!retval) writel((tmp | LPC32XX_HSU_RX_INT_EN | LPC32XX_HSU_ERR_INT_EN), LPC32XX_HSUART_CTRL(port->membase)); return retval; } /* port->lock is not held. */ static void serial_lpc32xx_shutdown(struct uart_port *port) { u32 tmp; unsigned long flags; uart_port_lock_irqsave(port, &flags); tmp = LPC32XX_HSU_TX_TL8B | LPC32XX_HSU_RX_TL32B | LPC32XX_HSU_OFFSET(20) | LPC32XX_HSU_TMO_INACT_4B; writel(tmp, LPC32XX_HSUART_CTRL(port->membase)); lpc32xx_loopback_set(port->mapbase, 1); /* go to loopback mode */ uart_port_unlock_irqrestore(port, flags); free_irq(port->irq, port); } /* port->lock is not held. */ static void serial_lpc32xx_set_termios(struct uart_port *port, struct ktermios *termios, const struct ktermios *old) { unsigned long flags; unsigned int baud, quot; u32 tmp; /* Always 8-bit, no parity, 1 stop bit */ termios->c_cflag &= ~(CSIZE | CSTOPB | PARENB | PARODD); termios->c_cflag |= CS8; termios->c_cflag &= ~(HUPCL | CMSPAR | CLOCAL | CRTSCTS); baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 14); quot = __serial_get_clock_div(port->uartclk, baud); uart_port_lock_irqsave(port, &flags); /* Ignore characters? */ tmp = readl(LPC32XX_HSUART_CTRL(port->membase)); if ((termios->c_cflag & CREAD) == 0) tmp &= ~(LPC32XX_HSU_RX_INT_EN | LPC32XX_HSU_ERR_INT_EN); else tmp |= LPC32XX_HSU_RX_INT_EN | LPC32XX_HSU_ERR_INT_EN; writel(tmp, LPC32XX_HSUART_CTRL(port->membase)); writel(quot, LPC32XX_HSUART_RATE(port->membase)); uart_update_timeout(port, termios->c_cflag, baud); uart_port_unlock_irqrestore(port, flags); /* Don't rewrite B0 */ if (tty_termios_baud_rate(termios)) tty_termios_encode_baud_rate(termios, baud, baud); } static const char *serial_lpc32xx_type(struct uart_port *port) { return MODNAME; } static void serial_lpc32xx_release_port(struct uart_port *port) { if ((port->iotype == UPIO_MEM32) && (port->mapbase)) { if (port->flags & UPF_IOREMAP) { iounmap(port->membase); port->membase = NULL; } release_mem_region(port->mapbase, SZ_4K); } } static int serial_lpc32xx_request_port(struct uart_port *port) { int ret = -ENODEV; if ((port->iotype == UPIO_MEM32) && (port->mapbase)) { ret = 0; if (!request_mem_region(port->mapbase, SZ_4K, MODNAME)) ret = -EBUSY; else if (port->flags & UPF_IOREMAP) { port->membase = ioremap(port->mapbase, SZ_4K); if (!port->membase) { release_mem_region(port->mapbase, SZ_4K); ret = -ENOMEM; } } } return ret; } static void serial_lpc32xx_config_port(struct uart_port *port, int uflags) { int ret; ret = serial_lpc32xx_request_port(port); if (ret < 0) return; port->type = PORT_UART00; port->fifosize = 64; __serial_uart_flush(port); writel((LPC32XX_HSU_TX_INT | LPC32XX_HSU_FE_INT | LPC32XX_HSU_BRK_INT | LPC32XX_HSU_RX_OE_INT), LPC32XX_HSUART_IIR(port->membase)); writel(0xFF, LPC32XX_HSUART_RATE(port->membase)); /* Set receiver timeout, HSU offset of 20, no break, no interrupts, and default FIFO trigger levels */ writel(LPC32XX_HSU_TX_TL8B | LPC32XX_HSU_RX_TL32B | LPC32XX_HSU_OFFSET(20) | LPC32XX_HSU_TMO_INACT_4B, LPC32XX_HSUART_CTRL(port->membase)); } static int serial_lpc32xx_verify_port(struct uart_port *port, struct serial_struct *ser) { int ret = 0; if (ser->type != PORT_UART00) ret = -EINVAL; return ret; } static const struct uart_ops serial_lpc32xx_pops = { .tx_empty = serial_lpc32xx_tx_empty, .set_mctrl = serial_lpc32xx_set_mctrl, .get_mctrl = serial_lpc32xx_get_mctrl, .stop_tx = serial_lpc32xx_stop_tx, .start_tx = serial_lpc32xx_start_tx, .stop_rx = serial_lpc32xx_stop_rx, .break_ctl = serial_lpc32xx_break_ctl, .startup = serial_lpc32xx_startup, .shutdown = serial_lpc32xx_shutdown, .set_termios = serial_lpc32xx_set_termios, .type = serial_lpc32xx_type, .release_port = serial_lpc32xx_release_port, .request_port = serial_lpc32xx_request_port, .config_port = serial_lpc32xx_config_port, .verify_port = serial_lpc32xx_verify_port, }; /* * Register a set of serial devices attached to a platform device */ static int serial_hs_lpc32xx_probe(struct platform_device *pdev) { struct lpc32xx_hsuart_port *p = &lpc32xx_hs_ports[uarts_registered]; int ret = 0; struct resource *res; if (uarts_registered >= MAX_PORTS) { dev_err(&pdev->dev, "Error: Number of possible ports exceeded (%d)!\n", uarts_registered + 1); return -ENXIO; } memset(p, 0, sizeof(*p)); res = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!res) { dev_err(&pdev->dev, "Error getting mem resource for HS UART port %d\n", uarts_registered); return -ENXIO; } p->port.mapbase = res->start; p->port.membase = NULL; ret = platform_get_irq(pdev, 0); if (ret < 0) return ret; p->port.irq = ret; p->port.iotype = UPIO_MEM32; p->port.uartclk = LPC32XX_MAIN_OSC_FREQ; p->port.regshift = 2; p->port.flags = UPF_BOOT_AUTOCONF | UPF_FIXED_PORT | UPF_IOREMAP; p->port.dev = &pdev->dev; p->port.ops = &serial_lpc32xx_pops; p->port.line = uarts_registered++; spin_lock_init(&p->port.lock); /* send port to loopback mode by default */ lpc32xx_loopback_set(p->port.mapbase, 1); ret = uart_add_one_port(&lpc32xx_hs_reg, &p->port); platform_set_drvdata(pdev, p); return ret; } /* * Remove serial ports registered against a platform device. */ static void serial_hs_lpc32xx_remove(struct platform_device *pdev) { struct lpc32xx_hsuart_port *p = platform_get_drvdata(pdev); uart_remove_one_port(&lpc32xx_hs_reg, &p->port); } #ifdef CONFIG_PM static int serial_hs_lpc32xx_suspend(struct platform_device *pdev, pm_message_t state) { struct lpc32xx_hsuart_port *p = platform_get_drvdata(pdev); uart_suspend_port(&lpc32xx_hs_reg, &p->port); return 0; } static int serial_hs_lpc32xx_resume(struct platform_device *pdev) { struct lpc32xx_hsuart_port *p = platform_get_drvdata(pdev); uart_resume_port(&lpc32xx_hs_reg, &p->port); return 0; } #else #define serial_hs_lpc32xx_suspend NULL #define serial_hs_lpc32xx_resume NULL #endif static const struct of_device_id serial_hs_lpc32xx_dt_ids[] = { { .compatible = "nxp,lpc3220-hsuart" }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, serial_hs_lpc32xx_dt_ids); static struct platform_driver serial_hs_lpc32xx_driver = { .probe = serial_hs_lpc32xx_probe, .remove = serial_hs_lpc32xx_remove, .suspend = serial_hs_lpc32xx_suspend, .resume = serial_hs_lpc32xx_resume, .driver = { .name = MODNAME, .of_match_table = serial_hs_lpc32xx_dt_ids, }, }; static int __init lpc32xx_hsuart_init(void) { int ret; ret = uart_register_driver(&lpc32xx_hs_reg); if (ret) return ret; ret = platform_driver_register(&serial_hs_lpc32xx_driver); if (ret) uart_unregister_driver(&lpc32xx_hs_reg); return ret; } static void __exit lpc32xx_hsuart_exit(void) { platform_driver_unregister(&serial_hs_lpc32xx_driver); uart_unregister_driver(&lpc32xx_hs_reg); } module_init(lpc32xx_hsuart_init); module_exit(lpc32xx_hsuart_exit); MODULE_AUTHOR("Kevin Wells "); MODULE_AUTHOR("Roland Stigge "); MODULE_DESCRIPTION("NXP LPC32XX High Speed UART driver"); MODULE_LICENSE("GPL");