diff options
Diffstat (limited to 'drivers/serial')
| -rw-r--r-- | drivers/serial/Kconfig | 31 | ||||
| -rw-r--r-- | drivers/serial/Makefile | 1 | ||||
| -rw-r--r-- | drivers/serial/altera_uart.c | 570 |
3 files changed, 602 insertions, 0 deletions
diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig index f4050e678460..8b23165bc5dc 100644 --- a/drivers/serial/Kconfig +++ b/drivers/serial/Kconfig @@ -1544,4 +1544,35 @@ config SERIAL_ALTERA_JTAGUART_CONSOLE_BYPASS Bypass console output and keep going even if there is no JTAG terminal connection with the host. +config SERIAL_ALTERA_UART + tristate "Altera UART support" + select SERIAL_CORE + help + This driver supports the Altera softcore UART port. + +config SERIAL_ALTERA_UART_MAXPORTS + int "Maximum number of Altera UART ports" + depends on SERIAL_ALTERA_UART + default 4 + help + This setting lets you define the maximum number of the Altera + UART ports. The usual default varies from board to board, and + this setting is a way of catering for that. + +config SERIAL_ALTERA_UART_BAUDRATE + int "Default baudrate for Altera UART ports" + depends on SERIAL_ALTERA_UART + default 115200 + help + This setting lets you define what the default baudrate is for the + Altera UART ports. The usual default varies from board to board, + and this setting is a way of catering for that. + +config SERIAL_ALTERA_UART_CONSOLE + bool "Altera UART console support" + depends on SERIAL_ALTERA_UART=y + select SERIAL_CORE_CONSOLE + help + Enable a Altera UART port to be the system console. + endmenu diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile index 7f9d225d0430..208a85572c32 100644 --- a/drivers/serial/Makefile +++ b/drivers/serial/Makefile @@ -83,3 +83,4 @@ obj-$(CONFIG_SERIAL_QE) += ucc_uart.o obj-$(CONFIG_SERIAL_TIMBERDALE) += timbuart.o obj-$(CONFIG_SERIAL_GRLIB_GAISLER_APBUART) += apbuart.o obj-$(CONFIG_SERIAL_ALTERA_JTAGUART) += altera_jtaguart.o +obj-$(CONFIG_SERIAL_ALTERA_UART) += altera_uart.o diff --git a/drivers/serial/altera_uart.c b/drivers/serial/altera_uart.c new file mode 100644 index 000000000000..bcee156d2f2e --- /dev/null +++ b/drivers/serial/altera_uart.c @@ -0,0 +1,570 @@ +/* + * altera_uart.c -- Altera UART driver + * + * Based on mcf.c -- Freescale ColdFire UART driver + * + * (C) Copyright 2003-2007, Greg Ungerer <gerg@snapgear.com> + * (C) Copyright 2008, Thomas Chou <thomas@wytron.com.tw> + * (C) Copyright 2010, Tobias Klauser <tklauser@distanz.ch> + * + * 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. + */ + +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/module.h> +#include <linux/console.h> +#include <linux/tty.h> +#include <linux/tty_flip.h> +#include <linux/serial.h> +#include <linux/serial_core.h> +#include <linux/platform_device.h> +#include <linux/io.h> +#include <linux/altera_uart.h> + +#define DRV_NAME "altera_uart" + +/* + * Altera UART register definitions according to the Nios UART datasheet: + * http://www.altera.com/literature/ds/ds_nios_uart.pdf + */ + +#define ALTERA_UART_SIZE 32 + +#define ALTERA_UART_RXDATA_REG 0 +#define ALTERA_UART_TXDATA_REG 4 +#define ALTERA_UART_STATUS_REG 8 +#define ALTERA_UART_CONTROL_REG 12 +#define ALTERA_UART_DIVISOR_REG 16 +#define ALTERA_UART_EOP_REG 20 + +#define ALTERA_UART_STATUS_PE_MSK 0x0001 /* parity error */ +#define ALTERA_UART_STATUS_FE_MSK 0x0002 /* framing error */ +#define ALTERA_UART_STATUS_BRK_MSK 0x0004 /* break */ +#define ALTERA_UART_STATUS_ROE_MSK 0x0008 /* RX overrun error */ +#define ALTERA_UART_STATUS_TOE_MSK 0x0010 /* TX overrun error */ +#define ALTERA_UART_STATUS_TMT_MSK 0x0020 /* TX shift register state */ +#define ALTERA_UART_STATUS_TRDY_MSK 0x0040 /* TX ready */ +#define ALTERA_UART_STATUS_RRDY_MSK 0x0080 /* RX ready */ +#define ALTERA_UART_STATUS_E_MSK 0x0100 /* exception condition */ +#define ALTERA_UART_STATUS_DCTS_MSK 0x0400 /* CTS logic-level change */ +#define ALTERA_UART_STATUS_CTS_MSK 0x0800 /* CTS logic state */ +#define ALTERA_UART_STATUS_EOP_MSK 0x1000 /* EOP written/read */ + + /* Enable interrupt on... */ +#define ALTERA_UART_CONTROL_PE_MSK 0x0001 /* ...parity error */ +#define ALTERA_UART_CONTROL_FE_MSK 0x0002 /* ...framing error */ +#define ALTERA_UART_CONTROL_BRK_MSK 0x0004 /* ...break */ +#define ALTERA_UART_CONTROL_ROE_MSK 0x0008 /* ...RX overrun */ +#define ALTERA_UART_CONTROL_TOE_MSK 0x0010 /* ...TX overrun */ +#define ALTERA_UART_CONTROL_TMT_MSK 0x0020 /* ...TX shift register empty */ +#define ALTERA_UART_CONTROL_TRDY_MSK 0x0040 /* ...TX ready */ +#define ALTERA_UART_CONTROL_RRDY_MSK 0x0080 /* ...RX ready */ +#define ALTERA_UART_CONTROL_E_MSK 0x0100 /* ...exception*/ + +#define ALTERA_UART_CONTROL_TRBK_MSK 0x0200 /* TX break */ +#define ALTERA_UART_CONTROL_DCTS_MSK 0x0400 /* Interrupt on CTS change */ +#define ALTERA_UART_CONTROL_RTS_MSK 0x0800 /* RTS signal */ +#define ALTERA_UART_CONTROL_EOP_MSK 0x1000 /* Interrupt on EOP */ + +/* + * Local per-uart structure. + */ +struct altera_uart { + struct uart_port port; + unsigned int sigs; /* Local copy of line sigs */ + unsigned short imr; /* Local IMR mirror */ +}; + +static unsigned int altera_uart_tx_empty(struct uart_port *port) +{ + return (readl(port->membase + ALTERA_UART_STATUS_REG) & + ALTERA_UART_STATUS_TMT_MSK) ? TIOCSER_TEMT : 0; +} + +static unsigned int altera_uart_get_mctrl(struct uart_port *port) +{ + struct altera_uart *pp = container_of(port, struct altera_uart, port); + unsigned long flags; + unsigned int sigs; + + spin_lock_irqsave(&port->lock, flags); + sigs = + (readl(port->membase + ALTERA_UART_STATUS_REG) & + ALTERA_UART_STATUS_CTS_MSK) ? TIOCM_CTS : 0; + sigs |= (pp->sigs & TIOCM_RTS); + spin_unlock_irqrestore(&port->lock, flags); + + return sigs; +} + +static void altera_uart_set_mctrl(struct uart_port *port, unsigned int sigs) +{ + struct altera_uart *pp = container_of(port, struct altera_uart, port); + unsigned long flags; + + spin_lock_irqsave(&port->lock, flags); + pp->sigs = sigs; + if (sigs & TIOCM_RTS) + pp->imr |= ALTERA_UART_CONTROL_RTS_MSK; + else + pp->imr &= ~ALTERA_UART_CONTROL_RTS_MSK; + writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG); + spin_unlock_irqrestore(&port->lock, flags); +} + +static void altera_uart_start_tx(struct uart_port *port) +{ + struct altera_uart *pp = container_of(port, struct altera_uart, port); + unsigned long flags; + + spin_lock_irqsave(&port->lock, flags); + pp->imr |= ALTERA_UART_CONTROL_TRDY_MSK; + writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG); + spin_unlock_irqrestore(&port->lock, flags); +} + +static void altera_uart_stop_tx(struct uart_port *port) +{ + struct altera_uart *pp = container_of(port, struct altera_uart, port); + unsigned long flags; + + spin_lock_irqsave(&port->lock, flags); + pp->imr &= ~ALTERA_UART_CONTROL_TRDY_MSK; + writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG); + spin_unlock_irqrestore(&port->lock, flags); +} + +static void altera_uart_stop_rx(struct uart_port *port) +{ + struct altera_uart *pp = container_of(port, struct altera_uart, port); + unsigned long flags; + + spin_lock_irqsave(&port->lock, flags); + pp->imr &= ~ALTERA_UART_CONTROL_RRDY_MSK; + writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG); + spin_unlock_irqrestore(&port->lock, flags); +} + +static void altera_uart_break_ctl(struct uart_port *port, int break_state) +{ + struct altera_uart *pp = container_of(port, struct altera_uart, port); + unsigned long flags; + + spin_lock_irqsave(&port->lock, flags); + if (break_state == -1) + pp->imr |= ALTERA_UART_CONTROL_TRBK_MSK; + else + pp->imr &= ~ALTERA_UART_CONTROL_TRBK_MSK; + writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG); + spin_unlock_irqrestore(&port->lock, flags); +} + +static void altera_uart_enable_ms(struct uart_port *port) +{ +} + +static void altera_uart_set_termios(struct uart_port *port, + struct ktermios *termios, + struct ktermios *old) +{ + unsigned long flags; + unsigned int baud, baudclk; + + baud = uart_get_baud_rate(port, termios, old, 0, 4000000); + baudclk = port->uartclk / baud; + + if (old) + tty_termios_copy_hw(termios, old); + tty_termios_encode_baud_rate(termios, baud, baud); + + spin_lock_irqsave(&port->lock, flags); + writel(baudclk, port->membase + ALTERA_UART_DIVISOR_REG); + spin_unlock_irqrestore(&port->lock, flags); +} + +static void altera_uart_rx_chars(struct altera_uart *pp) +{ + struct uart_port *port = &pp->port; + unsigned char ch, flag; + unsigned short status; + + while ((status = readl(port->membase + ALTERA_UART_STATUS_REG)) & + ALTERA_UART_STATUS_RRDY_MSK) { + ch = readl(port->membase + ALTERA_UART_RXDATA_REG); + flag = TTY_NORMAL; + port->icount.rx++; + + if (status & ALTERA_UART_STATUS_E_MSK) { + writel(status, port->membase + ALTERA_UART_STATUS_REG); + + if (status & ALTERA_UART_STATUS_BRK_MSK) { + port->icount.brk++; + if (uart_handle_break(port)) + continue; + } else if (status & ALTERA_UART_STATUS_PE_MSK) { + port->icount.parity++; + } else if (status & ALTERA_UART_STATUS_ROE_MSK) { + port->icount.overrun++; + } else if (status & ALTERA_UART_STATUS_FE_MSK) { + port->icount.frame++; + } + + status &= port->read_status_mask; + + if (status & ALTERA_UART_STATUS_BRK_MSK) + flag = TTY_BREAK; + else if (status & ALTERA_UART_STATUS_PE_MSK) + flag = TTY_PARITY; + else if (status & ALTERA_UART_STATUS_FE_MSK) + flag = TTY_FRAME; + } + + if (uart_handle_sysrq_char(port, ch)) + continue; + uart_insert_char(port, status, ALTERA_UART_STATUS_ROE_MSK, ch, + flag); + } + + tty_flip_buffer_push(port->state->port.tty); +} + +static void altera_uart_tx_chars(struct altera_uart *pp) +{ + struct uart_port *port = &pp->port; + struct circ_buf *xmit = &port->state->xmit; + + if (port->x_char) { + /* Send special char - probably flow control */ + writel(port->x_char, port->membase + ALTERA_UART_TXDATA_REG); + port->x_char = 0; + port->icount.tx++; + return; + } + + while (readl(port->membase + ALTERA_UART_STATUS_REG) & + ALTERA_UART_STATUS_TRDY_MSK) { + if (xmit->head == xmit->tail) + break; + writel(xmit->buf[xmit->tail], + port->membase + ALTERA_UART_TXDATA_REG); + xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); + port->icount.tx++; + } + + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) + uart_write_wakeup(port); + + if (xmit->head == xmit->tail) { + pp->imr &= ~ALTERA_UART_CONTROL_TRDY_MSK; + writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG); + } +} + +static irqreturn_t altera_uart_interrupt(int irq, void *data) +{ + struct uart_port *port = data; + struct altera_uart *pp = container_of(port, struct altera_uart, port); + unsigned int isr; + + isr = readl(port->membase + ALTERA_UART_STATUS_REG) & pp->imr; + if (isr & ALTERA_UART_STATUS_RRDY_MSK) + altera_uart_rx_chars(pp); + if (isr & ALTERA_UART_STATUS_TRDY_MSK) + altera_uart_tx_chars(pp); + return IRQ_RETVAL(isr); +} + +static void altera_uart_config_port(struct uart_port *port, int flags) +{ + port->type = PORT_ALTERA_UART; + + /* Clear mask, so no surprise interrupts. */ + writel(0, port->membase + ALTERA_UART_CONTROL_REG); + /* Clear status register */ + writel(0, port->membase + ALTERA_UART_STATUS_REG); +} + +static int altera_uart_startup(struct uart_port *port) +{ + struct altera_uart *pp = container_of(port, struct altera_uart, port); + unsigned long flags; + int ret; + + ret = request_irq(port->irq, altera_uart_interrupt, IRQF_DISABLED, + DRV_NAME, port); + if (ret) { + pr_err(DRV_NAME ": unable to attach Altera UART %d " + "interrupt vector=%d\n", port->line, port->irq); + return ret; + } + + spin_lock_irqsave(&port->lock, flags); + + /* Enable RX interrupts now */ + pp->imr = ALTERA_UART_CONTROL_RRDY_MSK; + writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG); + + spin_unlock_irqrestore(&port->lock, flags); + + return 0; +} + +static void altera_uart_shutdown(struct uart_port *port) +{ + struct altera_uart *pp = container_of(port, struct altera_uart, port); + unsigned long flags; + + spin_lock_irqsave(&port->lock, flags); + + /* Disable all interrupts now */ + pp->imr = 0; + writel(pp->imr, port->membase + ALTERA_UART_CONTROL_REG); + + spin_unlock_irqrestore(&port->lock, flags); + + free_irq(port->irq, port); +} + +static const char *altera_uart_type(struct uart_port *port) +{ + return (port->type == PORT_ALTERA_UART) ? "Altera UART" : NULL; +} + +static int altera_uart_request_port(struct uart_port *port) +{ + /* UARTs always present */ + return 0; +} + +static void altera_uart_release_port(struct uart_port *port) +{ + /* Nothing to release... */ +} + +static int altera_uart_verify_port(struct uart_port *port, + struct serial_struct *ser) +{ + if ((ser->type != PORT_UNKNOWN) && (ser->type != PORT_ALTERA_UART)) + return -EINVAL; + return 0; +} + +/* + * Define the basic serial functions we support. + */ +static struct uart_ops altera_uart_ops = { + .tx_empty = altera_uart_tx_empty, + .get_mctrl = altera_uart_get_mctrl, + .set_mctrl = altera_uart_set_mctrl, + .start_tx = altera_uart_start_tx, + .stop_tx = altera_uart_stop_tx, + .stop_rx = altera_uart_stop_rx, + .enable_ms = altera_uart_enable_ms, + .break_ctl = altera_uart_break_ctl, + .startup = altera_uart_startup, + .shutdown = altera_uart_shutdown, + .set_termios = altera_uart_set_termios, + .type = altera_uart_type, + .request_port = altera_uart_request_port, + .release_port = altera_uart_release_port, + .config_port = altera_uart_config_port, + .verify_port = altera_uart_verify_port, +}; + +static struct altera_uart altera_uart_ports[CONFIG_SERIAL_ALTERA_UART_MAXPORTS]; + +#if defined(CONFIG_SERIAL_ALTERA_UART_CONSOLE) + +int __init early_altera_uart_setup(struct altera_uart_platform_uart *platp) +{ + struct uart_port *port; + int i; + + for (i = 0; i < CONFIG_SERIAL_ALTERA_UART_MAXPORTS && platp[i].mapbase; i++) { + port = &altera_uart_ports[i].port; + + port->line = i; + port->type = PORT_ALTERA_UART; + port->mapbase = platp[i].mapbase; + port->membase = ioremap(port->mapbase, ALTERA_UART_SIZE); + port->iotype = SERIAL_IO_MEM; + port->irq = platp[i].irq; + port->uartclk = platp[i].uartclk; + port->flags = ASYNC_BOOT_AUTOCONF; + port->ops = &altera_uart_ops; + } + + return 0; +} + +static void altera_uart_console_putc(struct console *co, const char c) +{ + struct uart_port *port = &(altera_uart_ports + co->index)->port; + int i; + + for (i = 0; i < 0x10000; i++) { + if (readl(port->membase + ALTERA_UART_STATUS_REG) & + ALTERA_UART_STATUS_TRDY_MSK) + break; + } + writel(c, port->membase + ALTERA_UART_TXDATA_REG); + for (i = 0; i < 0x10000; i++) { + if (readl(port->membase + ALTERA_UART_STATUS_REG) & + ALTERA_UART_STATUS_TRDY_MSK) + break; + } +} + +static void altera_uart_console_write(struct console *co, const char *s, + unsigned int count) +{ + for (; count; count--, s++) { + altera_uart_console_putc(co, *s); + if (*s == '\n') + altera_uart_console_putc(co, '\r'); + } +} + +static int __init altera_uart_console_setup(struct console *co, char *options) +{ + struct uart_port *port; + int baud = CONFIG_SERIAL_ALTERA_UART_BAUDRATE; + int bits = 8; + int parity = 'n'; + int flow = 'n'; + + if (co->index < 0 || co->index >= CONFIG_SERIAL_ALTERA_UART_MAXPORTS) + return -EINVAL; + port = &altera_uart_ports[co->index].port; + if (port->membase == 0) + return -ENODEV; + + if (options) + uart_parse_options(options, &baud, &parity, &bits, &flow); + + return uart_set_options(port, co, baud, parity, bits, flow); +} + +static struct uart_driver altera_uart_driver; + +static struct console altera_uart_console = { + .name = "ttyS", + .write = altera_uart_console_write, + .device = uart_console_device, + .setup = altera_uart_console_setup, + .flags = CON_PRINTBUFFER, + .index = -1, + .data = &altera_uart_driver, +}; + +static int __init altera_uart_console_init(void) +{ + register_console(&altera_uart_console); + return 0; +} + +console_initcall(altera_uart_console_init); + +#define ALTERA_UART_CONSOLE (&altera_uart_console) + +#else + +#define ALTERA_UART_CONSOLE NULL + +#endif /* CONFIG_ALTERA_UART_CONSOLE */ + +/* + * Define the altera_uart UART driver structure. + */ +static struct uart_driver altera_uart_driver = { + .owner = THIS_MODULE, + .driver_name = DRV_NAME, + .dev_name = "ttyS", + .major = TTY_MAJOR, + .minor = 64, + .nr = CONFIG_SERIAL_ALTERA_UART_MAXPORTS, + .cons = ALTERA_UART_CONSOLE, +}; + +static int __devinit altera_uart_probe(struct platform_device *pdev) +{ + struct altera_uart_platform_uart *platp = pdev->dev.platform_data; + struct uart_port *port; + int i; + + for (i = 0; i < CONFIG_SERIAL_ALTERA_UART_MAXPORTS && platp[i].mapbase; i++) { + port = &altera_uart_ports[i].port; + + port->line = i; + port->type = PORT_ALTERA_UART; + port->mapbase = platp[i].mapbase; + port->membase = ioremap(port->mapbase, ALTERA_UART_SIZE); + port->iotype = SERIAL_IO_MEM; + port->irq = platp[i].irq; + port->uartclk = platp[i].uartclk; + port->ops = &altera_uart_ops; + port->flags = ASYNC_BOOT_AUTOCONF; + + uart_add_one_port(&altera_uart_driver, port); + } + + return 0; +} + +static int altera_uart_remove(struct platform_device *pdev) +{ + struct uart_port *port; + int i; + + for (i = 0; i < CONFIG_SERIAL_ALTERA_UART_MAXPORTS; i++) { + port = &altera_uart_ports[i].port; + if (port) + uart_remove_one_port(&altera_uart_driver, port); + } + + return 0; +} + +static struct platform_driver altera_uart_platform_driver = { + .probe = altera_uart_probe, + .remove = __devexit_p(altera_uart_remove), + .driver = { + .name = DRV_NAME, + .owner = THIS_MODULE, + .pm = NULL, + }, +}; + +static int __init altera_uart_init(void) +{ + int rc; + + rc = uart_register_driver(&altera_uart_driver); + if (rc) + return rc; + rc = platform_driver_register(&altera_uart_platform_driver); + if (rc) { + uart_unregister_driver(&altera_uart_driver); + return rc; + } + return 0; +} + +static void __exit altera_uart_exit(void) +{ + platform_driver_unregister(&altera_uart_platform_driver); + uart_unregister_driver(&altera_uart_driver); +} + +module_init(altera_uart_init); +module_exit(altera_uart_exit); + +MODULE_DESCRIPTION("Altera UART driver"); +MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:" DRV_NAME); |