From 238b8721a554a33a451a3f13bdb5be8fe5cfc927 Mon Sep 17 00:00:00 2001 From: Peter Korsgaard Date: Wed, 6 Dec 2006 20:35:17 -0800 Subject: [PATCH] [PATCH] serial uartlite driver Add a driver for the Xilinx uartlite serial controller used in boards with the PPC405 core in the Xilinx V2P/V4 fpgas. The hardware is very simple (baudrate/start/stopbits fixed and no break support). See the datasheet for details: http://www.xilinx.com/bvdocs/ipcenter/data_sheet/opb_uartlite.pdf See http://thread.gmane.org/gmane.linux.serial/1237/ for the email thread. Signed-off-by: Peter Korsgaard Acked-by: Olof Johansson Cc: Russell King Cc: Alan Cox Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- MAINTAINERS | 6 + drivers/serial/Kconfig | 19 ++ drivers/serial/Makefile | 1 + drivers/serial/uartlite.c | 505 ++++++++++++++++++++++++++++++++++++ include/linux/serial_core.h | 2 + 5 files changed, 533 insertions(+) create mode 100644 drivers/serial/uartlite.c diff --git a/MAINTAINERS b/MAINTAINERS index 5dff26814a06..fa1bba8de1f8 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -3454,6 +3454,12 @@ W: http://oss.sgi.com/projects/xfs T: git git://oss.sgi.com:8090/xfs/xfs-2.6 S: Supported +XILINX UARTLITE SERIAL DRIVER +P: Peter Korsgaard +M: jacmet@sunsite.dk +L: linux-serial@vger.kernel.org +S: Maintained + X86 3-LEVEL PAGING (PAE) SUPPORT P: Ingo Molnar M: mingo@redhat.com diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig index 0b71e7d18903..e936c91640b4 100644 --- a/drivers/serial/Kconfig +++ b/drivers/serial/Kconfig @@ -511,6 +511,25 @@ config SERIAL_IMX_CONSOLE your boot loader (lilo or loadlin) about how to pass options to the kernel at boot time.) +config SERIAL_UARTLITE + tristate "Xilinx uartlite serial port support" + depends on PPC32 + select SERIAL_CORE + help + Say Y here if you want to use the Xilinx uartlite serial controller. + + To compile this driver as a module, choose M here: the + module will be called uartlite.ko. + +config SERIAL_UARTLITE_CONSOLE + bool "Support for console on Xilinx uartlite serial port" + depends on SERIAL_UARTLITE=y + select SERIAL_CORE_CONSOLE + help + Say Y here if you wish to use a Xilinx uartlite as the system + console (the system console is the device which receives all kernel + messages and warnings and which allows logins in single user mode). + config SERIAL_SUNCORE bool depends on SPARC diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile index b4d8a7c182e3..0dba0017a006 100644 --- a/drivers/serial/Makefile +++ b/drivers/serial/Makefile @@ -55,4 +55,5 @@ obj-$(CONFIG_SERIAL_VR41XX) += vr41xx_siu.o obj-$(CONFIG_SERIAL_SGI_IOC4) += ioc4_serial.o obj-$(CONFIG_SERIAL_SGI_IOC3) += ioc3_serial.o obj-$(CONFIG_SERIAL_ATMEL) += atmel_serial.o +obj-$(CONFIG_SERIAL_UARTLITE) += uartlite.o obj-$(CONFIG_SERIAL_NETX) += netx-serial.o diff --git a/drivers/serial/uartlite.c b/drivers/serial/uartlite.c new file mode 100644 index 000000000000..83690653b78b --- /dev/null +++ b/drivers/serial/uartlite.c @@ -0,0 +1,505 @@ +/* + * uartlite.c: Serial driver for Xilinx uartlite serial controller + * + * Peter Korsgaard + * + * This file is licensed under the terms of the GNU General Public License + * version 2. This program is licensed "as is" without any warranty of any + * kind, whether express or implied. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define ULITE_MAJOR 204 +#define ULITE_MINOR 187 +#define ULITE_NR_UARTS 4 + +/* For register details see datasheet: + http://www.xilinx.com/bvdocs/ipcenter/data_sheet/opb_uartlite.pdf +*/ +#define ULITE_RX 0x00 +#define ULITE_TX 0x04 +#define ULITE_STATUS 0x08 +#define ULITE_CONTROL 0x0c + +#define ULITE_REGION 16 + +#define ULITE_STATUS_RXVALID 0x01 +#define ULITE_STATUS_RXFULL 0x02 +#define ULITE_STATUS_TXEMPTY 0x04 +#define ULITE_STATUS_TXFULL 0x08 +#define ULITE_STATUS_IE 0x10 +#define ULITE_STATUS_OVERRUN 0x20 +#define ULITE_STATUS_FRAME 0x40 +#define ULITE_STATUS_PARITY 0x80 + +#define ULITE_CONTROL_RST_TX 0x01 +#define ULITE_CONTROL_RST_RX 0x02 +#define ULITE_CONTROL_IE 0x10 + + +static struct uart_port ports[ULITE_NR_UARTS]; + +static int ulite_receive(struct uart_port *port, int stat) +{ + struct tty_struct *tty = port->info->tty; + unsigned char ch = 0; + char flag = TTY_NORMAL; + + if ((stat & (ULITE_STATUS_RXVALID | ULITE_STATUS_OVERRUN + | ULITE_STATUS_FRAME)) == 0) + return 0; + + /* stats */ + if (stat & ULITE_STATUS_RXVALID) { + port->icount.rx++; + ch = readb(port->membase + ULITE_RX); + + if (stat & ULITE_STATUS_PARITY) + port->icount.parity++; + } + + if (stat & ULITE_STATUS_OVERRUN) + port->icount.overrun++; + + if (stat & ULITE_STATUS_FRAME) + port->icount.frame++; + + + /* drop byte with parity error if IGNPAR specificed */ + if (stat & port->ignore_status_mask & ULITE_STATUS_PARITY) + stat &= ~ULITE_STATUS_RXVALID; + + stat &= port->read_status_mask; + + if (stat & ULITE_STATUS_PARITY) + flag = TTY_PARITY; + + + stat &= ~port->ignore_status_mask; + + if (stat & ULITE_STATUS_RXVALID) + tty_insert_flip_char(tty, ch, flag); + + if (stat & ULITE_STATUS_FRAME) + tty_insert_flip_char(tty, 0, TTY_FRAME); + + if (stat & ULITE_STATUS_OVERRUN) + tty_insert_flip_char(tty, 0, TTY_OVERRUN); + + return 1; +} + +static int ulite_transmit(struct uart_port *port, int stat) +{ + struct circ_buf *xmit = &port->info->xmit; + + if (stat & ULITE_STATUS_TXFULL) + return 0; + + if (port->x_char) { + writeb(port->x_char, port->membase + ULITE_TX); + port->x_char = 0; + port->icount.tx++; + return 1; + } + + if (uart_circ_empty(xmit) || uart_tx_stopped(port)) + return 0; + + writeb(xmit->buf[xmit->tail], port->membase + ULITE_TX); + xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE-1); + port->icount.tx++; + + /* wake up */ + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) + uart_write_wakeup(port); + + return 1; +} + +static irqreturn_t ulite_isr(int irq, void *dev_id) +{ + struct uart_port *port = (struct uart_port *)dev_id; + int busy; + + do { + int stat = readb(port->membase + ULITE_STATUS); + busy = ulite_receive(port, stat); + busy |= ulite_transmit(port, stat); + } while (busy); + + tty_flip_buffer_push(port->info->tty); + + return IRQ_HANDLED; +} + +static unsigned int ulite_tx_empty(struct uart_port *port) +{ + unsigned long flags; + unsigned int ret; + + spin_lock_irqsave(&port->lock, flags); + ret = readb(port->membase + ULITE_STATUS); + spin_unlock_irqrestore(&port->lock, flags); + + return ret & ULITE_STATUS_TXEMPTY ? TIOCSER_TEMT : 0; +} + +static unsigned int ulite_get_mctrl(struct uart_port *port) +{ + return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR; +} + +static void ulite_set_mctrl(struct uart_port *port, unsigned int mctrl) +{ + /* N/A */ +} + +static void ulite_stop_tx(struct uart_port *port) +{ + /* N/A */ +} + +static void ulite_start_tx(struct uart_port *port) +{ + ulite_transmit(port, readb(port->membase + ULITE_STATUS)); +} + +static void ulite_stop_rx(struct uart_port *port) +{ + /* don't forward any more data (like !CREAD) */ + port->ignore_status_mask = ULITE_STATUS_RXVALID | ULITE_STATUS_PARITY + | ULITE_STATUS_FRAME | ULITE_STATUS_OVERRUN; +} + +static void ulite_enable_ms(struct uart_port *port) +{ + /* N/A */ +} + +static void ulite_break_ctl(struct uart_port *port, int ctl) +{ + /* N/A */ +} + +static int ulite_startup(struct uart_port *port) +{ + int ret; + + ret = request_irq(port->irq, ulite_isr, + IRQF_DISABLED | IRQF_SAMPLE_RANDOM, "uartlite", port); + if (ret) + return ret; + + writeb(ULITE_CONTROL_RST_RX | ULITE_CONTROL_RST_TX, + port->membase + ULITE_CONTROL); + writeb(ULITE_CONTROL_IE, port->membase + ULITE_CONTROL); + + return 0; +} + +static void ulite_shutdown(struct uart_port *port) +{ + writeb(0, port->membase + ULITE_CONTROL); + readb(port->membase + ULITE_CONTROL); /* dummy */ + free_irq(port->irq, port); +} + +static void ulite_set_termios(struct uart_port *port, struct termios *termios, + struct termios *old) +{ + unsigned long flags; + unsigned int baud; + + spin_lock_irqsave(&port->lock, flags); + + port->read_status_mask = ULITE_STATUS_RXVALID | ULITE_STATUS_OVERRUN + | ULITE_STATUS_TXFULL; + + if (termios->c_iflag & INPCK) + port->read_status_mask |= + ULITE_STATUS_PARITY | ULITE_STATUS_FRAME; + + port->ignore_status_mask = 0; + if (termios->c_iflag & IGNPAR) + port->ignore_status_mask |= ULITE_STATUS_PARITY + | ULITE_STATUS_FRAME | ULITE_STATUS_OVERRUN; + + /* ignore all characters if CREAD is not set */ + if ((termios->c_cflag & CREAD) == 0) + port->ignore_status_mask |= + ULITE_STATUS_RXVALID | ULITE_STATUS_PARITY + | ULITE_STATUS_FRAME | ULITE_STATUS_OVERRUN; + + /* update timeout */ + baud = uart_get_baud_rate(port, termios, old, 0, 460800); + uart_update_timeout(port, termios->c_cflag, baud); + + spin_unlock_irqrestore(&port->lock, flags); +} + +static const char *ulite_type(struct uart_port *port) +{ + return port->type == PORT_UARTLITE ? "uartlite" : NULL; +} + +static void ulite_release_port(struct uart_port *port) +{ + release_mem_region(port->mapbase, ULITE_REGION); + iounmap(port->membase); + port->membase = 0; +} + +static int ulite_request_port(struct uart_port *port) +{ + if (!request_mem_region(port->mapbase, ULITE_REGION, "uartlite")) { + dev_err(port->dev, "Memory region busy\n"); + return -EBUSY; + } + + port->membase = ioremap(port->mapbase, ULITE_REGION); + if (!port->membase) { + dev_err(port->dev, "Unable to map registers\n"); + release_mem_region(port->mapbase, ULITE_REGION); + return -EBUSY; + } + + return 0; +} + +static void ulite_config_port(struct uart_port *port, int flags) +{ + ulite_request_port(port); + port->type = PORT_UARTLITE; +} + +static int ulite_verify_port(struct uart_port *port, struct serial_struct *ser) +{ + /* we don't want the core code to modify any port params */ + return -EINVAL; +} + +static struct uart_ops ulite_ops = { + .tx_empty = ulite_tx_empty, + .set_mctrl = ulite_set_mctrl, + .get_mctrl = ulite_get_mctrl, + .stop_tx = ulite_stop_tx, + .start_tx = ulite_start_tx, + .stop_rx = ulite_stop_rx, + .enable_ms = ulite_enable_ms, + .break_ctl = ulite_break_ctl, + .startup = ulite_startup, + .shutdown = ulite_shutdown, + .set_termios = ulite_set_termios, + .type = ulite_type, + .release_port = ulite_release_port, + .request_port = ulite_request_port, + .config_port = ulite_config_port, + .verify_port = ulite_verify_port +}; + +#ifdef CONFIG_SERIAL_UARTLITE_CONSOLE +static void ulite_console_wait_tx(struct uart_port *port) +{ + int i; + + /* wait up to 10ms for the character(s) to be sent */ + for (i = 0; i < 10000; i++) { + if (readb(port->membase + ULITE_STATUS) & ULITE_STATUS_TXEMPTY) + break; + udelay(1); + } +} + +static void ulite_console_putchar(struct uart_port *port, int ch) +{ + ulite_console_wait_tx(port); + writeb(ch, port->membase + ULITE_TX); +} + +static void ulite_console_write(struct console *co, const char *s, + unsigned int count) +{ + struct uart_port *port = &ports[co->index]; + unsigned long flags; + unsigned int ier; + int locked = 1; + + if (oops_in_progress) { + locked = spin_trylock_irqsave(&port->lock, flags); + } else + spin_lock_irqsave(&port->lock, flags); + + /* save and disable interrupt */ + ier = readb(port->membase + ULITE_STATUS) & ULITE_STATUS_IE; + writeb(0, port->membase + ULITE_CONTROL); + + uart_console_write(port, s, count, ulite_console_putchar); + + ulite_console_wait_tx(port); + + /* restore interrupt state */ + if (ier) + writeb(ULITE_CONTROL_IE, port->membase + ULITE_CONTROL); + + if (locked) + spin_unlock_irqrestore(&port->lock, flags); +} + +static int __init ulite_console_setup(struct console *co, char *options) +{ + struct uart_port *port; + int baud = 9600; + int bits = 8; + int parity = 'n'; + int flow = 'n'; + + if (co->index < 0 || co->index >= ULITE_NR_UARTS) + return -EINVAL; + + port = &ports[co->index]; + + /* not initialized yet? */ + if (!port->membase) + 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 ulite_uart_driver; + +static struct console ulite_console = { + .name = "ttyUL", + .write = ulite_console_write, + .device = uart_console_device, + .setup = ulite_console_setup, + .flags = CON_PRINTBUFFER, + .index = -1, /* Specified on the cmdline (e.g. console=ttyUL0 ) */ + .data = &ulite_uart_driver, +}; + +static int __init ulite_console_init(void) +{ + register_console(&ulite_console); + return 0; +} + +console_initcall(ulite_console_init); + +#endif /* CONFIG_SERIAL_UARTLITE_CONSOLE */ + +static struct uart_driver ulite_uart_driver = { + .owner = THIS_MODULE, + .driver_name = "uartlite", + .dev_name = "ttyUL", + .major = ULITE_MAJOR, + .minor = ULITE_MINOR, + .nr = ULITE_NR_UARTS, +#ifdef CONFIG_SERIAL_UARTLITE_CONSOLE + .cons = &ulite_console, +#endif +}; + +static int __devinit ulite_probe(struct platform_device *pdev) +{ + struct resource *res, *res2; + struct uart_port *port; + + if (pdev->id < 0 || pdev->id >= ULITE_NR_UARTS) + return -EINVAL; + + if (ports[pdev->id].membase) + return -EBUSY; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) + return -ENODEV; + + res2 = platform_get_resource(pdev, IORESOURCE_IRQ, 0); + if (!res2) + return -ENODEV; + + port = &ports[pdev->id]; + + port->fifosize = 16; + port->regshift = 2; + port->iotype = UPIO_MEM; + port->iobase = 1; /* mark port in use */ + port->mapbase = res->start; + port->membase = 0; + port->ops = &ulite_ops; + port->irq = res2->start; + port->flags = UPF_BOOT_AUTOCONF; + port->dev = &pdev->dev; + port->type = PORT_UNKNOWN; + port->line = pdev->id; + + uart_add_one_port(&ulite_uart_driver, port); + platform_set_drvdata(pdev, port); + + return 0; +} + +static int ulite_remove(struct platform_device *pdev) +{ + struct uart_port *port = platform_get_drvdata(pdev); + + platform_set_drvdata(pdev, NULL); + + if (port) + uart_remove_one_port(&ulite_uart_driver, port); + + /* mark port as free */ + port->membase = 0; + + return 0; +} + +static struct platform_driver ulite_platform_driver = { + .probe = ulite_probe, + .remove = ulite_remove, + .driver = { + .owner = THIS_MODULE, + .name = "uartlite", + }, +}; + +int __init ulite_init(void) +{ + int ret; + + ret = uart_register_driver(&ulite_uart_driver); + if (ret) + return ret; + + ret = platform_driver_register(&ulite_platform_driver); + if (ret) + uart_unregister_driver(&ulite_uart_driver); + + return ret; +} + +void __exit ulite_exit(void) +{ + platform_driver_unregister(&ulite_platform_driver); + uart_unregister_driver(&ulite_uart_driver); +} + +module_init(ulite_init); +module_exit(ulite_exit); + +MODULE_AUTHOR("Peter Korsgaard "); +MODULE_DESCRIPTION("Xilinx uartlite serial driver"); +MODULE_LICENSE("GPL"); diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h index 463ab953b092..827672136646 100644 --- a/include/linux/serial_core.h +++ b/include/linux/serial_core.h @@ -132,6 +132,8 @@ #define PORT_S3C2412 73 +/* Xilinx uartlite */ +#define PORT_UARTLITE 74 #ifdef __KERNEL__ -- 2.20.1