diff options
Diffstat (limited to 'drivers/tty/serial/uartlite.c')
| -rw-r--r-- | drivers/tty/serial/uartlite.c | 709 |
1 files changed, 709 insertions, 0 deletions
diff --git a/drivers/tty/serial/uartlite.c b/drivers/tty/serial/uartlite.c new file mode 100644 index 000000000000..d2fce865b731 --- /dev/null +++ b/drivers/tty/serial/uartlite.c @@ -0,0 +1,709 @@ +/* + * uartlite.c: Serial driver for Xilinx uartlite serial controller + * + * Copyright (C) 2006 Peter Korsgaard <jacmet@sunsite.dk> + * Copyright (C) 2007 Secret Lab Technologies Ltd. + * + * 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 <linux/platform_device.h> +#include <linux/module.h> +#include <linux/console.h> +#include <linux/serial.h> +#include <linux/serial_core.h> +#include <linux/tty.h> +#include <linux/delay.h> +#include <linux/interrupt.h> +#include <linux/init.h> +#include <asm/io.h> +#if defined(CONFIG_OF) && (defined(CONFIG_PPC32) || defined(CONFIG_MICROBLAZE)) +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/of_device.h> +#include <linux/of_platform.h> + +/* Match table for of_platform binding */ +static struct of_device_id ulite_of_match[] __devinitdata = { + { .compatible = "xlnx,opb-uartlite-1.00.b", }, + { .compatible = "xlnx,xps-uartlite-1.00.a", }, + {} +}; +MODULE_DEVICE_TABLE(of, ulite_of_match); + +#endif + +#define ULITE_NAME "ttyUL" +#define ULITE_MAJOR 204 +#define ULITE_MINOR 187 +#define ULITE_NR_UARTS 4 + +/* --------------------------------------------------------------------- + * Register definitions + * + * For register details see datasheet: + * http://www.xilinx.com/support/documentation/ip_documentation/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 ulite_ports[ULITE_NR_UARTS]; + +/* --------------------------------------------------------------------- + * Core UART driver operations + */ + +static int ulite_receive(struct uart_port *port, int stat) +{ + struct tty_struct *tty = port->state->port.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 = ioread32be(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->state->xmit; + + if (stat & ULITE_STATUS_TXFULL) + return 0; + + if (port->x_char) { + iowrite32be(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; + + iowrite32be(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 = dev_id; + int busy, n = 0; + + do { + int stat = ioread32be(port->membase + ULITE_STATUS); + busy = ulite_receive(port, stat); + busy |= ulite_transmit(port, stat); + n++; + } while (busy); + + /* work done? */ + if (n > 1) { + tty_flip_buffer_push(port->state->port.tty); + return IRQ_HANDLED; + } else { + return IRQ_NONE; + } +} + +static unsigned int ulite_tx_empty(struct uart_port *port) +{ + unsigned long flags; + unsigned int ret; + + spin_lock_irqsave(&port->lock, flags); + ret = ioread32be(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, ioread32be(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_SHARED | IRQF_SAMPLE_RANDOM, "uartlite", port); + if (ret) + return ret; + + iowrite32be(ULITE_CONTROL_RST_RX | ULITE_CONTROL_RST_TX, + port->membase + ULITE_CONTROL); + iowrite32be(ULITE_CONTROL_IE, port->membase + ULITE_CONTROL); + + return 0; +} + +static void ulite_shutdown(struct uart_port *port) +{ + iowrite32be(0, port->membase + ULITE_CONTROL); + ioread32be(port->membase + ULITE_CONTROL); /* dummy */ + free_irq(port->irq, port); +} + +static void ulite_set_termios(struct uart_port *port, struct ktermios *termios, + struct ktermios *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 = NULL; +} + +static int ulite_request_port(struct uart_port *port) +{ + pr_debug("ulite console: port=%p; port->mapbase=%llx\n", + port, (unsigned long long) port->mapbase); + + 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) +{ + if (!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; +} + +#ifdef CONFIG_CONSOLE_POLL +static int ulite_get_poll_char(struct uart_port *port) +{ + if (!(ioread32be(port->membase + ULITE_STATUS) + & ULITE_STATUS_RXVALID)) + return NO_POLL_CHAR; + + return ioread32be(port->membase + ULITE_RX); +} + +static void ulite_put_poll_char(struct uart_port *port, unsigned char ch) +{ + while (ioread32be(port->membase + ULITE_STATUS) & ULITE_STATUS_TXFULL) + cpu_relax(); + + /* write char to device */ + iowrite32be(ch, port->membase + ULITE_TX); +} +#endif + +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_CONSOLE_POLL + .poll_get_char = ulite_get_poll_char, + .poll_put_char = ulite_put_poll_char, +#endif +}; + +/* --------------------------------------------------------------------- + * Console driver operations + */ + +#ifdef CONFIG_SERIAL_UARTLITE_CONSOLE +static void ulite_console_wait_tx(struct uart_port *port) +{ + int i; + u8 val; + + /* Spin waiting for TX fifo to have space available */ + for (i = 0; i < 100000; i++) { + val = ioread32be(port->membase + ULITE_STATUS); + if ((val & ULITE_STATUS_TXFULL) == 0) + break; + cpu_relax(); + } +} + +static void ulite_console_putchar(struct uart_port *port, int ch) +{ + ulite_console_wait_tx(port); + iowrite32be(ch, port->membase + ULITE_TX); +} + +static void ulite_console_write(struct console *co, const char *s, + unsigned int count) +{ + struct uart_port *port = &ulite_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 = ioread32be(port->membase + ULITE_STATUS) & ULITE_STATUS_IE; + iowrite32be(0, port->membase + ULITE_CONTROL); + + uart_console_write(port, s, count, ulite_console_putchar); + + ulite_console_wait_tx(port); + + /* restore interrupt state */ + if (ier) + iowrite32be(ULITE_CONTROL_IE, port->membase + ULITE_CONTROL); + + if (locked) + spin_unlock_irqrestore(&port->lock, flags); +} + +static int __devinit 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 = &ulite_ports[co->index]; + + /* Has the device been initialized yet? */ + if (!port->mapbase) { + pr_debug("console on ttyUL%i not present\n", co->index); + return -ENODEV; + } + + /* not initialized yet? */ + if (!port->membase) { + if (ulite_request_port(port)) + 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 = ULITE_NAME, + .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 = ULITE_NAME, + .major = ULITE_MAJOR, + .minor = ULITE_MINOR, + .nr = ULITE_NR_UARTS, +#ifdef CONFIG_SERIAL_UARTLITE_CONSOLE + .cons = &ulite_console, +#endif +}; + +/* --------------------------------------------------------------------- + * Port assignment functions (mapping devices to uart_port structures) + */ + +/** ulite_assign: register a uartlite device with the driver + * + * @dev: pointer to device structure + * @id: requested id number. Pass -1 for automatic port assignment + * @base: base address of uartlite registers + * @irq: irq number for uartlite + * + * Returns: 0 on success, <0 otherwise + */ +static int __devinit ulite_assign(struct device *dev, int id, u32 base, int irq) +{ + struct uart_port *port; + int rc; + + /* if id = -1; then scan for a free id and use that */ + if (id < 0) { + for (id = 0; id < ULITE_NR_UARTS; id++) + if (ulite_ports[id].mapbase == 0) + break; + } + if (id < 0 || id >= ULITE_NR_UARTS) { + dev_err(dev, "%s%i too large\n", ULITE_NAME, id); + return -EINVAL; + } + + if ((ulite_ports[id].mapbase) && (ulite_ports[id].mapbase != base)) { + dev_err(dev, "cannot assign to %s%i; it is already in use\n", + ULITE_NAME, id); + return -EBUSY; + } + + port = &ulite_ports[id]; + + spin_lock_init(&port->lock); + port->fifosize = 16; + port->regshift = 2; + port->iotype = UPIO_MEM; + port->iobase = 1; /* mark port in use */ + port->mapbase = base; + port->membase = NULL; + port->ops = &ulite_ops; + port->irq = irq; + port->flags = UPF_BOOT_AUTOCONF; + port->dev = dev; + port->type = PORT_UNKNOWN; + port->line = id; + + dev_set_drvdata(dev, port); + + /* Register the port */ + rc = uart_add_one_port(&ulite_uart_driver, port); + if (rc) { + dev_err(dev, "uart_add_one_port() failed; err=%i\n", rc); + port->mapbase = 0; + dev_set_drvdata(dev, NULL); + return rc; + } + + return 0; +} + +/** ulite_release: register a uartlite device with the driver + * + * @dev: pointer to device structure + */ +static int __devexit ulite_release(struct device *dev) +{ + struct uart_port *port = dev_get_drvdata(dev); + int rc = 0; + + if (port) { + rc = uart_remove_one_port(&ulite_uart_driver, port); + dev_set_drvdata(dev, NULL); + port->mapbase = 0; + } + + return rc; +} + +/* --------------------------------------------------------------------- + * Platform bus binding + */ + +static int __devinit ulite_probe(struct platform_device *pdev) +{ + struct resource *res, *res2; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) + return -ENODEV; + + res2 = platform_get_resource(pdev, IORESOURCE_IRQ, 0); + if (!res2) + return -ENODEV; + + return ulite_assign(&pdev->dev, pdev->id, res->start, res2->start); +} + +static int __devexit ulite_remove(struct platform_device *pdev) +{ + return ulite_release(&pdev->dev); +} + +/* work with hotplug and coldplug */ +MODULE_ALIAS("platform:uartlite"); + +static struct platform_driver ulite_platform_driver = { + .probe = ulite_probe, + .remove = __devexit_p(ulite_remove), + .driver = { + .owner = THIS_MODULE, + .name = "uartlite", + }, +}; + +/* --------------------------------------------------------------------- + * OF bus bindings + */ +#if defined(CONFIG_OF) && (defined(CONFIG_PPC32) || defined(CONFIG_MICROBLAZE)) +static int __devinit +ulite_of_probe(struct platform_device *op, const struct of_device_id *match) +{ + struct resource res; + const unsigned int *id; + int irq, rc; + + dev_dbg(&op->dev, "%s(%p, %p)\n", __func__, op, match); + + rc = of_address_to_resource(op->dev.of_node, 0, &res); + if (rc) { + dev_err(&op->dev, "invalid address\n"); + return rc; + } + + irq = irq_of_parse_and_map(op->dev.of_node, 0); + + id = of_get_property(op->dev.of_node, "port-number", NULL); + + return ulite_assign(&op->dev, id ? *id : -1, res.start, irq); +} + +static int __devexit ulite_of_remove(struct platform_device *op) +{ + return ulite_release(&op->dev); +} + +static struct of_platform_driver ulite_of_driver = { + .probe = ulite_of_probe, + .remove = __devexit_p(ulite_of_remove), + .driver = { + .name = "uartlite", + .owner = THIS_MODULE, + .of_match_table = ulite_of_match, + }, +}; + +/* Registration helpers to keep the number of #ifdefs to a minimum */ +static inline int __init ulite_of_register(void) +{ + pr_debug("uartlite: calling of_register_platform_driver()\n"); + return of_register_platform_driver(&ulite_of_driver); +} + +static inline void __exit ulite_of_unregister(void) +{ + of_unregister_platform_driver(&ulite_of_driver); +} +#else /* CONFIG_OF && (CONFIG_PPC32 || CONFIG_MICROBLAZE) */ +/* Appropriate config not enabled; do nothing helpers */ +static inline int __init ulite_of_register(void) { return 0; } +static inline void __exit ulite_of_unregister(void) { } +#endif /* CONFIG_OF && (CONFIG_PPC32 || CONFIG_MICROBLAZE) */ + +/* --------------------------------------------------------------------- + * Module setup/teardown + */ + +int __init ulite_init(void) +{ + int ret; + + pr_debug("uartlite: calling uart_register_driver()\n"); + ret = uart_register_driver(&ulite_uart_driver); + if (ret) + goto err_uart; + + ret = ulite_of_register(); + if (ret) + goto err_of; + + pr_debug("uartlite: calling platform_driver_register()\n"); + ret = platform_driver_register(&ulite_platform_driver); + if (ret) + goto err_plat; + + return 0; + +err_plat: + ulite_of_unregister(); +err_of: + uart_unregister_driver(&ulite_uart_driver); +err_uart: + printk(KERN_ERR "registering uartlite driver failed: err=%i", ret); + return ret; +} + +void __exit ulite_exit(void) +{ + platform_driver_unregister(&ulite_platform_driver); + ulite_of_unregister(); + uart_unregister_driver(&ulite_uart_driver); +} + +module_init(ulite_init); +module_exit(ulite_exit); + +MODULE_AUTHOR("Peter Korsgaard <jacmet@sunsite.dk>"); +MODULE_DESCRIPTION("Xilinx uartlite serial driver"); +MODULE_LICENSE("GPL"); |