diff options
Diffstat (limited to 'drivers/tty/serial/serial_ks8695.c')
| -rw-r--r-- | drivers/tty/serial/serial_ks8695.c | 698 |
1 files changed, 698 insertions, 0 deletions
diff --git a/drivers/tty/serial/serial_ks8695.c b/drivers/tty/serial/serial_ks8695.c new file mode 100644 index 000000000..b461d7911 --- /dev/null +++ b/drivers/tty/serial/serial_ks8695.c @@ -0,0 +1,698 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Driver for KS8695 serial ports + * + * Based on drivers/serial/serial_amba.c, by Kam Lee. + * + * Copyright 2002-2005 Micrel Inc. + */ +#include <linux/module.h> +#include <linux/tty.h> +#include <linux/tty_flip.h> +#include <linux/ioport.h> +#include <linux/init.h> +#include <linux/serial.h> +#include <linux/console.h> +#include <linux/sysrq.h> +#include <linux/device.h> + +#include <asm/io.h> +#include <asm/irq.h> +#include <asm/mach/irq.h> + +#include <mach/regs-uart.h> +#include <mach/regs-irq.h> + +#if defined(CONFIG_SERIAL_KS8695_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) +#define SUPPORT_SYSRQ +#endif + +#include <linux/serial_core.h> + + +#define SERIAL_KS8695_MAJOR 204 +#define SERIAL_KS8695_MINOR 16 +#define SERIAL_KS8695_DEVNAME "ttyAM" + +#define SERIAL_KS8695_NR 1 + +/* + * Access macros for the KS8695 UART + */ +#define UART_GET_CHAR(p) (__raw_readl((p)->membase + KS8695_URRB) & 0xFF) +#define UART_PUT_CHAR(p, c) __raw_writel((c), (p)->membase + KS8695_URTH) +#define UART_GET_FCR(p) __raw_readl((p)->membase + KS8695_URFC) +#define UART_PUT_FCR(p, c) __raw_writel((c), (p)->membase + KS8695_URFC) +#define UART_GET_MSR(p) __raw_readl((p)->membase + KS8695_URMS) +#define UART_GET_LSR(p) __raw_readl((p)->membase + KS8695_URLS) +#define UART_GET_LCR(p) __raw_readl((p)->membase + KS8695_URLC) +#define UART_PUT_LCR(p, c) __raw_writel((c), (p)->membase + KS8695_URLC) +#define UART_GET_MCR(p) __raw_readl((p)->membase + KS8695_URMC) +#define UART_PUT_MCR(p, c) __raw_writel((c), (p)->membase + KS8695_URMC) +#define UART_GET_BRDR(p) __raw_readl((p)->membase + KS8695_URBD) +#define UART_PUT_BRDR(p, c) __raw_writel((c), (p)->membase + KS8695_URBD) + +#define KS8695_CLR_TX_INT() __raw_writel(1 << KS8695_IRQ_UART_TX, KS8695_IRQ_VA + KS8695_INTST) + +#define UART_DUMMY_LSR_RX 0x100 +#define UART_PORT_SIZE (KS8695_USR - KS8695_URRB + 4) + +static inline int tx_enabled(struct uart_port *port) +{ + return port->unused[0] & 1; +} + +static inline int rx_enabled(struct uart_port *port) +{ + return port->unused[0] & 2; +} + +static inline int ms_enabled(struct uart_port *port) +{ + return port->unused[0] & 4; +} + +static inline void ms_enable(struct uart_port *port, int enabled) +{ + if(enabled) + port->unused[0] |= 4; + else + port->unused[0] &= ~4; +} + +static inline void rx_enable(struct uart_port *port, int enabled) +{ + if(enabled) + port->unused[0] |= 2; + else + port->unused[0] &= ~2; +} + +static inline void tx_enable(struct uart_port *port, int enabled) +{ + if(enabled) + port->unused[0] |= 1; + else + port->unused[0] &= ~1; +} + + +#ifdef SUPPORT_SYSRQ +static struct console ks8695_console; +#endif + +static void ks8695uart_stop_tx(struct uart_port *port) +{ + if (tx_enabled(port)) { + /* use disable_irq_nosync() and not disable_irq() to avoid self + * imposed deadlock by not waiting for irq handler to end, + * since this ks8695uart_stop_tx() is called from interrupt context. + */ + disable_irq_nosync(KS8695_IRQ_UART_TX); + tx_enable(port, 0); + } +} + +static void ks8695uart_start_tx(struct uart_port *port) +{ + if (!tx_enabled(port)) { + enable_irq(KS8695_IRQ_UART_TX); + tx_enable(port, 1); + } +} + +static void ks8695uart_stop_rx(struct uart_port *port) +{ + if (rx_enabled(port)) { + disable_irq(KS8695_IRQ_UART_RX); + rx_enable(port, 0); + } +} + +static void ks8695uart_enable_ms(struct uart_port *port) +{ + if (!ms_enabled(port)) { + enable_irq(KS8695_IRQ_UART_MODEM_STATUS); + ms_enable(port,1); + } +} + +static void ks8695uart_disable_ms(struct uart_port *port) +{ + if (ms_enabled(port)) { + disable_irq(KS8695_IRQ_UART_MODEM_STATUS); + ms_enable(port,0); + } +} + +static irqreturn_t ks8695uart_rx_chars(int irq, void *dev_id) +{ + struct uart_port *port = dev_id; + unsigned int status, ch, lsr, flg, max_count = 256; + + status = UART_GET_LSR(port); /* clears pending LSR interrupts */ + while ((status & URLS_URDR) && max_count--) { + ch = UART_GET_CHAR(port); + flg = TTY_NORMAL; + + port->icount.rx++; + + /* + * Note that the error handling code is + * out of the main execution path + */ + lsr = UART_GET_LSR(port) | UART_DUMMY_LSR_RX; + if (unlikely(lsr & (URLS_URBI | URLS_URPE | URLS_URFE | URLS_URROE))) { + if (lsr & URLS_URBI) { + lsr &= ~(URLS_URFE | URLS_URPE); + port->icount.brk++; + if (uart_handle_break(port)) + goto ignore_char; + } + if (lsr & URLS_URPE) + port->icount.parity++; + if (lsr & URLS_URFE) + port->icount.frame++; + if (lsr & URLS_URROE) + port->icount.overrun++; + + lsr &= port->read_status_mask; + + if (lsr & URLS_URBI) + flg = TTY_BREAK; + else if (lsr & URLS_URPE) + flg = TTY_PARITY; + else if (lsr & URLS_URFE) + flg = TTY_FRAME; + } + + if (uart_handle_sysrq_char(port, ch)) + goto ignore_char; + + uart_insert_char(port, lsr, URLS_URROE, ch, flg); + +ignore_char: + status = UART_GET_LSR(port); + } + tty_flip_buffer_push(&port->state->port); + + return IRQ_HANDLED; +} + + +static irqreturn_t ks8695uart_tx_chars(int irq, void *dev_id) +{ + struct uart_port *port = dev_id; + struct circ_buf *xmit = &port->state->xmit; + unsigned int count; + + if (port->x_char) { + KS8695_CLR_TX_INT(); + UART_PUT_CHAR(port, port->x_char); + port->icount.tx++; + port->x_char = 0; + return IRQ_HANDLED; + } + + if (uart_tx_stopped(port) || uart_circ_empty(xmit)) { + ks8695uart_stop_tx(port); + return IRQ_HANDLED; + } + + count = 16; /* fifo size */ + while (!uart_circ_empty(xmit) && (count-- > 0)) { + KS8695_CLR_TX_INT(); + UART_PUT_CHAR(port, xmit->buf[xmit->tail]); + + 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 (uart_circ_empty(xmit)) + ks8695uart_stop_tx(port); + + return IRQ_HANDLED; +} + +static irqreturn_t ks8695uart_modem_status(int irq, void *dev_id) +{ + struct uart_port *port = dev_id; + unsigned int status; + + /* + * clear modem interrupt by reading MSR + */ + status = UART_GET_MSR(port); + + if (status & URMS_URDDCD) + uart_handle_dcd_change(port, status & URMS_URDDCD); + + if (status & URMS_URDDST) + port->icount.dsr++; + + if (status & URMS_URDCTS) + uart_handle_cts_change(port, status & URMS_URDCTS); + + if (status & URMS_URTERI) + port->icount.rng++; + + wake_up_interruptible(&port->state->port.delta_msr_wait); + + return IRQ_HANDLED; +} + +static unsigned int ks8695uart_tx_empty(struct uart_port *port) +{ + return (UART_GET_LSR(port) & URLS_URTE) ? TIOCSER_TEMT : 0; +} + +static unsigned int ks8695uart_get_mctrl(struct uart_port *port) +{ + unsigned int result = 0; + unsigned int status; + + status = UART_GET_MSR(port); + if (status & URMS_URDCD) + result |= TIOCM_CAR; + if (status & URMS_URDSR) + result |= TIOCM_DSR; + if (status & URMS_URCTS) + result |= TIOCM_CTS; + if (status & URMS_URRI) + result |= TIOCM_RI; + + return result; +} + +static void ks8695uart_set_mctrl(struct uart_port *port, u_int mctrl) +{ + unsigned int mcr; + + mcr = UART_GET_MCR(port); + if (mctrl & TIOCM_RTS) + mcr |= URMC_URRTS; + else + mcr &= ~URMC_URRTS; + + if (mctrl & TIOCM_DTR) + mcr |= URMC_URDTR; + else + mcr &= ~URMC_URDTR; + + UART_PUT_MCR(port, mcr); +} + +static void ks8695uart_break_ctl(struct uart_port *port, int break_state) +{ + unsigned int lcr; + + lcr = UART_GET_LCR(port); + + if (break_state == -1) + lcr |= URLC_URSBC; + else + lcr &= ~URLC_URSBC; + + UART_PUT_LCR(port, lcr); +} + +static int ks8695uart_startup(struct uart_port *port) +{ + int retval; + + irq_modify_status(KS8695_IRQ_UART_TX, IRQ_NOREQUEST, IRQ_NOAUTOEN); + tx_enable(port, 0); + rx_enable(port, 1); + ms_enable(port, 1); + + /* + * Allocate the IRQ + */ + retval = request_irq(KS8695_IRQ_UART_TX, ks8695uart_tx_chars, 0, "UART TX", port); + if (retval) + goto err_tx; + + retval = request_irq(KS8695_IRQ_UART_RX, ks8695uart_rx_chars, 0, "UART RX", port); + if (retval) + goto err_rx; + + retval = request_irq(KS8695_IRQ_UART_LINE_STATUS, ks8695uart_rx_chars, 0, "UART LineStatus", port); + if (retval) + goto err_ls; + + retval = request_irq(KS8695_IRQ_UART_MODEM_STATUS, ks8695uart_modem_status, 0, "UART ModemStatus", port); + if (retval) + goto err_ms; + + return 0; + +err_ms: + free_irq(KS8695_IRQ_UART_LINE_STATUS, port); +err_ls: + free_irq(KS8695_IRQ_UART_RX, port); +err_rx: + free_irq(KS8695_IRQ_UART_TX, port); +err_tx: + return retval; +} + +static void ks8695uart_shutdown(struct uart_port *port) +{ + /* + * Free the interrupt + */ + free_irq(KS8695_IRQ_UART_RX, port); + free_irq(KS8695_IRQ_UART_TX, port); + free_irq(KS8695_IRQ_UART_MODEM_STATUS, port); + free_irq(KS8695_IRQ_UART_LINE_STATUS, port); + + /* disable break condition and fifos */ + UART_PUT_LCR(port, UART_GET_LCR(port) & ~URLC_URSBC); + UART_PUT_FCR(port, UART_GET_FCR(port) & ~URFC_URFE); +} + +static void ks8695uart_set_termios(struct uart_port *port, struct ktermios *termios, struct ktermios *old) +{ + unsigned int lcr, fcr = 0; + unsigned long flags; + unsigned int baud, quot; + + /* + * Ask the core to calculate the divisor for us. + */ + baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16); + quot = uart_get_divisor(port, baud); + + switch (termios->c_cflag & CSIZE) { + case CS5: + lcr = URCL_5; + break; + case CS6: + lcr = URCL_6; + break; + case CS7: + lcr = URCL_7; + break; + default: + lcr = URCL_8; + break; + } + + /* stop bits */ + if (termios->c_cflag & CSTOPB) + lcr |= URLC_URSB; + + /* parity */ + if (termios->c_cflag & PARENB) { + if (termios->c_cflag & CMSPAR) { /* Mark or Space parity */ + if (termios->c_cflag & PARODD) + lcr |= URPE_MARK; + else + lcr |= URPE_SPACE; + } + else if (termios->c_cflag & PARODD) + lcr |= URPE_ODD; + else + lcr |= URPE_EVEN; + } + + if (port->fifosize > 1) + fcr = URFC_URFRT_8 | URFC_URTFR | URFC_URRFR | URFC_URFE; + + spin_lock_irqsave(&port->lock, flags); + + /* + * Update the per-port timeout. + */ + uart_update_timeout(port, termios->c_cflag, baud); + + port->read_status_mask = URLS_URROE; + if (termios->c_iflag & INPCK) + port->read_status_mask |= (URLS_URFE | URLS_URPE); + if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK)) + port->read_status_mask |= URLS_URBI; + + /* + * Characters to ignore + */ + port->ignore_status_mask = 0; + if (termios->c_iflag & IGNPAR) + port->ignore_status_mask |= (URLS_URFE | URLS_URPE); + if (termios->c_iflag & IGNBRK) { + port->ignore_status_mask |= URLS_URBI; + /* + * If we're ignoring parity and break indicators, + * ignore overruns too (for real raw support). + */ + if (termios->c_iflag & IGNPAR) + port->ignore_status_mask |= URLS_URROE; + } + + /* + * Ignore all characters if CREAD is not set. + */ + if ((termios->c_cflag & CREAD) == 0) + port->ignore_status_mask |= UART_DUMMY_LSR_RX; + + /* first, disable everything */ + if (UART_ENABLE_MS(port, termios->c_cflag)) + ks8695uart_enable_ms(port); + else + ks8695uart_disable_ms(port); + + /* Set baud rate */ + UART_PUT_BRDR(port, quot); + + UART_PUT_LCR(port, lcr); + UART_PUT_FCR(port, fcr); + + spin_unlock_irqrestore(&port->lock, flags); +} + +static const char *ks8695uart_type(struct uart_port *port) +{ + return port->type == PORT_KS8695 ? "KS8695" : NULL; +} + +/* + * Release the memory region(s) being used by 'port' + */ +static void ks8695uart_release_port(struct uart_port *port) +{ + release_mem_region(port->mapbase, UART_PORT_SIZE); +} + +/* + * Request the memory region(s) being used by 'port' + */ +static int ks8695uart_request_port(struct uart_port *port) +{ + return request_mem_region(port->mapbase, UART_PORT_SIZE, + "serial_ks8695") != NULL ? 0 : -EBUSY; +} + +/* + * Configure/autoconfigure the port. + */ +static void ks8695uart_config_port(struct uart_port *port, int flags) +{ + if (flags & UART_CONFIG_TYPE) { + port->type = PORT_KS8695; + ks8695uart_request_port(port); + } +} + +/* + * verify the new serial_struct (for TIOCSSERIAL). + */ +static int ks8695uart_verify_port(struct uart_port *port, struct serial_struct *ser) +{ + int ret = 0; + + if (ser->type != PORT_UNKNOWN && ser->type != PORT_KS8695) + ret = -EINVAL; + if (ser->irq != port->irq) + ret = -EINVAL; + if (ser->baud_base < 9600) + ret = -EINVAL; + return ret; +} + +static struct uart_ops ks8695uart_pops = { + .tx_empty = ks8695uart_tx_empty, + .set_mctrl = ks8695uart_set_mctrl, + .get_mctrl = ks8695uart_get_mctrl, + .stop_tx = ks8695uart_stop_tx, + .start_tx = ks8695uart_start_tx, + .stop_rx = ks8695uart_stop_rx, + .enable_ms = ks8695uart_enable_ms, + .break_ctl = ks8695uart_break_ctl, + .startup = ks8695uart_startup, + .shutdown = ks8695uart_shutdown, + .set_termios = ks8695uart_set_termios, + .type = ks8695uart_type, + .release_port = ks8695uart_release_port, + .request_port = ks8695uart_request_port, + .config_port = ks8695uart_config_port, + .verify_port = ks8695uart_verify_port, +}; + +static struct uart_port ks8695uart_ports[SERIAL_KS8695_NR] = { + { + .membase = KS8695_UART_VA, + .mapbase = KS8695_UART_PA, + .iotype = SERIAL_IO_MEM, + .irq = KS8695_IRQ_UART_TX, + .uartclk = KS8695_CLOCK_RATE * 16, + .fifosize = 16, + .ops = &ks8695uart_pops, + .flags = UPF_BOOT_AUTOCONF, + .line = 0, + } +}; + +#ifdef CONFIG_SERIAL_KS8695_CONSOLE +static void ks8695_console_putchar(struct uart_port *port, int ch) +{ + while (!(UART_GET_LSR(port) & URLS_URTHRE)) + barrier(); + + UART_PUT_CHAR(port, ch); +} + +static void ks8695_console_write(struct console *co, const char *s, u_int count) +{ + struct uart_port *port = ks8695uart_ports + co->index; + + uart_console_write(port, s, count, ks8695_console_putchar); +} + +static void __init ks8695_console_get_options(struct uart_port *port, int *baud, int *parity, int *bits) +{ + unsigned int lcr; + + lcr = UART_GET_LCR(port); + + switch (lcr & URLC_PARITY) { + case URPE_ODD: + *parity = 'o'; + break; + case URPE_EVEN: + *parity = 'e'; + break; + default: + *parity = 'n'; + } + + switch (lcr & URLC_URCL) { + case URCL_5: + *bits = 5; + break; + case URCL_6: + *bits = 6; + break; + case URCL_7: + *bits = 7; + break; + default: + *bits = 8; + } + + *baud = port->uartclk / (UART_GET_BRDR(port) & 0x0FFF); + *baud /= 16; + *baud &= 0xFFFFFFF0; +} + +static int __init ks8695_console_setup(struct console *co, char *options) +{ + struct uart_port *port; + int baud = 115200; + 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. + */ + port = uart_get_console(ks8695uart_ports, SERIAL_KS8695_NR, co); + + if (options) + uart_parse_options(options, &baud, &parity, &bits, &flow); + else + ks8695_console_get_options(port, &baud, &parity, &bits); + + return uart_set_options(port, co, baud, parity, bits, flow); +} + +static struct uart_driver ks8695_reg; + +static struct console ks8695_console = { + .name = SERIAL_KS8695_DEVNAME, + .write = ks8695_console_write, + .device = uart_console_device, + .setup = ks8695_console_setup, + .flags = CON_PRINTBUFFER, + .index = -1, + .data = &ks8695_reg, +}; + +static int __init ks8695_console_init(void) +{ + add_preferred_console(SERIAL_KS8695_DEVNAME, 0, NULL); + register_console(&ks8695_console); + return 0; +} + +console_initcall(ks8695_console_init); + +#define KS8695_CONSOLE &ks8695_console +#else +#define KS8695_CONSOLE NULL +#endif + +static struct uart_driver ks8695_reg = { + .owner = THIS_MODULE, + .driver_name = "serial_ks8695", + .dev_name = SERIAL_KS8695_DEVNAME, + .major = SERIAL_KS8695_MAJOR, + .minor = SERIAL_KS8695_MINOR, + .nr = SERIAL_KS8695_NR, + .cons = KS8695_CONSOLE, +}; + +static int __init ks8695uart_init(void) +{ + int i, ret; + + printk(KERN_INFO "Serial: Micrel KS8695 UART driver\n"); + + ret = uart_register_driver(&ks8695_reg); + if (ret) + return ret; + + for (i = 0; i < SERIAL_KS8695_NR; i++) + uart_add_one_port(&ks8695_reg, &ks8695uart_ports[0]); + + return 0; +} + +static void __exit ks8695uart_exit(void) +{ + int i; + + for (i = 0; i < SERIAL_KS8695_NR; i++) + uart_remove_one_port(&ks8695_reg, &ks8695uart_ports[0]); + uart_unregister_driver(&ks8695_reg); +} + +module_init(ks8695uart_init); +module_exit(ks8695uart_exit); + +MODULE_DESCRIPTION("KS8695 serial port driver"); +MODULE_AUTHOR("Micrel Inc."); +MODULE_LICENSE("GPL"); |