diff options
| -rw-r--r-- | drivers/tty/serial/Kconfig | 9 | ||||
| -rw-r--r-- | drivers/tty/serial/pch_uart.c | 160 |
2 files changed, 168 insertions, 1 deletions
diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig index 5f479dada6f..956f2f02947 100644 --- a/drivers/tty/serial/Kconfig +++ b/drivers/tty/serial/Kconfig @@ -1575,6 +1575,15 @@ config SERIAL_PCH_UART ML7213/ML7223 is companion chip for Intel Atom E6xx series. ML7213/ML7223 is completely compatible for Intel EG20T PCH. +config SERIAL_PCH_UART_CONSOLE + bool "Support for console on Intel EG20T PCH UART/OKI SEMICONDUCTOR ML7213 IOH" + depends on SERIAL_PCH_UART=y + select SERIAL_CORE_CONSOLE + help + Say Y here if you wish to use the PCH UART 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_MSM_SMD bool "Enable tty device interface for some SMD ports" default n diff --git a/drivers/tty/serial/pch_uart.c b/drivers/tty/serial/pch_uart.c index 21febef926a..b950d059a78 100644 --- a/drivers/tty/serial/pch_uart.c +++ b/drivers/tty/serial/pch_uart.c @@ -25,6 +25,9 @@ #include <linux/interrupt.h> #include <linux/io.h> #include <linux/dmi.h> +#include <linux/console.h> +#include <linux/nmi.h> +#include <linux/delay.h> #include <linux/dmaengine.h> #include <linux/pch_dma.h> @@ -198,6 +201,10 @@ enum { #define PCI_VENDOR_ID_ROHM 0x10DB +#define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE) + +#define DEFAULT_BAUD_RATE 1843200 /* 1.8432MHz */ + struct pch_uart_buffer { unsigned char *buf; int size; @@ -272,6 +279,9 @@ static struct pch_uart_driver_data drv_dat[] = { [pch_ml7223_uart1] = {PCH_UART_2LINE, 1}, }; +#ifdef CONFIG_SERIAL_PCH_UART_CONSOLE +static struct eg20t_port *pch_uart_ports[PCH_UART_NR]; +#endif static unsigned int default_baud = 9600; static const int trigger_level_256[4] = { 1, 64, 128, 224 }; static const int trigger_level_64[4] = { 1, 16, 32, 56 }; @@ -1380,6 +1390,143 @@ static struct uart_ops pch_uart_ops = { .verify_port = pch_uart_verify_port }; +#ifdef CONFIG_SERIAL_PCH_UART_CONSOLE + +/* + * Wait for transmitter & holding register to empty + */ +static void wait_for_xmitr(struct eg20t_port *up, int bits) +{ + unsigned int status, tmout = 10000; + + /* Wait up to 10ms for the character(s) to be sent. */ + for (;;) { + status = ioread8(up->membase + UART_LSR); + + if ((status & bits) == bits) + break; + if (--tmout == 0) + break; + udelay(1); + } + + /* Wait up to 1s for flow control if necessary */ + if (up->port.flags & UPF_CONS_FLOW) { + unsigned int tmout; + for (tmout = 1000000; tmout; tmout--) { + unsigned int msr = ioread8(up->membase + UART_MSR); + if (msr & UART_MSR_CTS) + break; + udelay(1); + touch_nmi_watchdog(); + } + } +} + +static void pch_console_putchar(struct uart_port *port, int ch) +{ + struct eg20t_port *priv = + container_of(port, struct eg20t_port, port); + + wait_for_xmitr(priv, UART_LSR_THRE); + iowrite8(ch, priv->membase + PCH_UART_THR); +} + +/* + * Print a string to the serial port trying not to disturb + * any possible real use of the port... + * + * The console_lock must be held when we get here. + */ +static void +pch_console_write(struct console *co, const char *s, unsigned int count) +{ + struct eg20t_port *priv; + + unsigned long flags; + u8 ier; + int locked = 1; + + priv = pch_uart_ports[co->index]; + + touch_nmi_watchdog(); + + local_irq_save(flags); + if (priv->port.sysrq) { + /* serial8250_handle_port() already took the lock */ + locked = 0; + } else if (oops_in_progress) { + locked = spin_trylock(&priv->port.lock); + } else + spin_lock(&priv->port.lock); + + /* + * First save the IER then disable the interrupts + */ + ier = ioread8(priv->membase + UART_IER); + + pch_uart_hal_disable_interrupt(priv, PCH_UART_HAL_ALL_INT); + + uart_console_write(&priv->port, s, count, pch_console_putchar); + + /* + * Finally, wait for transmitter to become empty + * and restore the IER + */ + wait_for_xmitr(priv, BOTH_EMPTY); + iowrite8(ier, priv->membase + UART_IER); + + if (locked) + spin_unlock(&priv->port.lock); + local_irq_restore(flags); +} + +static int __init pch_console_setup(struct console *co, char *options) +{ + struct uart_port *port; + int baud = 9600; + int bits = 8; + int parity = 'n'; + int flow = 'n'; + + /* + * 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 >= PCH_UART_NR) + co->index = 0; + port = &pch_uart_ports[co->index]->port; + + if (!port || (!port->iobase && !port->membase)) + return -ENODEV; + + /* setup uartclock */ + port->uartclk = DEFAULT_BAUD_RATE; + + if (options) + uart_parse_options(options, &baud, &parity, &bits, &flow); + + return uart_set_options(port, co, baud, parity, bits, flow); +} + +static struct uart_driver pch_uart_driver; + +static struct console pch_console = { + .name = PCH_UART_DRIVER_DEVICE, + .write = pch_console_write, + .device = uart_console_device, + .setup = pch_console_setup, + .flags = CON_PRINTBUFFER | CON_ANYTIME, + .index = -1, + .data = &pch_uart_driver, +}; + +#define PCH_CONSOLE (&pch_console) +#else +#define PCH_CONSOLE NULL +#endif + static struct uart_driver pch_uart_driver = { .owner = THIS_MODULE, .driver_name = KBUILD_MODNAME, @@ -1387,6 +1534,7 @@ static struct uart_driver pch_uart_driver = { .major = 0, .minor = 0, .nr = PCH_UART_NR, + .cons = PCH_CONSOLE, }; static struct eg20t_port *pch_uart_init_port(struct pci_dev *pdev, @@ -1413,7 +1561,7 @@ static struct eg20t_port *pch_uart_init_port(struct pci_dev *pdev, if (!rxbuf) goto init_port_free_txbuf; - base_baud = 1843200; /* 1.8432MHz */ + base_baud = DEFAULT_BAUD_RATE; /* quirk for CM-iTC board */ board_name = dmi_get_system_info(DMI_BOARD_NAME); @@ -1463,6 +1611,9 @@ static struct eg20t_port *pch_uart_init_port(struct pci_dev *pdev, pci_set_drvdata(pdev, priv); pch_uart_hal_request(pdev, fifosize, base_baud); +#ifdef CONFIG_SERIAL_PCH_UART_CONSOLE + pch_uart_ports[board->line_no] = priv; +#endif ret = uart_add_one_port(&pch_uart_driver, &priv->port); if (ret < 0) goto init_port_hal_free; @@ -1470,6 +1621,9 @@ static struct eg20t_port *pch_uart_init_port(struct pci_dev *pdev, return priv; init_port_hal_free: +#ifdef CONFIG_SERIAL_PCH_UART_CONSOLE + pch_uart_ports[board->line_no] = NULL; +#endif free_page((unsigned long)rxbuf); init_port_free_txbuf: kfree(priv); @@ -1492,6 +1646,10 @@ static void pch_uart_pci_remove(struct pci_dev *pdev) priv = (struct eg20t_port *)pci_get_drvdata(pdev); pci_disable_msi(pdev); + +#ifdef CONFIG_SERIAL_PCH_UART_CONSOLE + pch_uart_ports[priv->port.line] = NULL; +#endif pch_uart_exit_port(priv); pci_disable_device(pdev); kfree(priv); |