diff options
Diffstat (limited to 'drivers/tty/serial/sb1250-duart.c')
| -rw-r--r-- | drivers/tty/serial/sb1250-duart.c | 968 |
1 files changed, 968 insertions, 0 deletions
diff --git a/drivers/tty/serial/sb1250-duart.c b/drivers/tty/serial/sb1250-duart.c new file mode 100644 index 000000000..329aced26 --- /dev/null +++ b/drivers/tty/serial/sb1250-duart.c @@ -0,0 +1,968 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Support for the asynchronous serial interface (DUART) included + * in the BCM1250 and derived System-On-a-Chip (SOC) devices. + * + * Copyright (c) 2007 Maciej W. Rozycki + * + * Derived from drivers/char/sb1250_duart.c for which the following + * copyright applies: + * + * Copyright (c) 2000, 2001, 2002, 2003, 2004 Broadcom Corporation + * + * References: + * + * "BCM1250/BCM1125/BCM1125H User Manual", Broadcom Corporation + */ + +#if defined(CONFIG_SERIAL_SB1250_DUART_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) +#define SUPPORT_SYSRQ +#endif + +#include <linux/compiler.h> +#include <linux/console.h> +#include <linux/delay.h> +#include <linux/errno.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/ioport.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/major.h> +#include <linux/serial.h> +#include <linux/serial_core.h> +#include <linux/spinlock.h> +#include <linux/sysrq.h> +#include <linux/tty.h> +#include <linux/tty_flip.h> +#include <linux/types.h> + +#include <linux/refcount.h> +#include <asm/io.h> +#include <asm/war.h> + +#include <asm/sibyte/sb1250.h> +#include <asm/sibyte/sb1250_uart.h> +#include <asm/sibyte/swarm.h> + + +#if defined(CONFIG_SIBYTE_BCM1x55) || defined(CONFIG_SIBYTE_BCM1x80) +#include <asm/sibyte/bcm1480_regs.h> +#include <asm/sibyte/bcm1480_int.h> + +#define SBD_CHANREGS(line) A_BCM1480_DUART_CHANREG((line), 0) +#define SBD_CTRLREGS(line) A_BCM1480_DUART_CTRLREG((line), 0) +#define SBD_INT(line) (K_BCM1480_INT_UART_0 + (line)) + +#define DUART_CHANREG_SPACING BCM1480_DUART_CHANREG_SPACING + +#define R_DUART_IMRREG(line) R_BCM1480_DUART_IMRREG(line) +#define R_DUART_INCHREG(line) R_BCM1480_DUART_INCHREG(line) +#define R_DUART_ISRREG(line) R_BCM1480_DUART_ISRREG(line) + +#elif defined(CONFIG_SIBYTE_SB1250) || defined(CONFIG_SIBYTE_BCM112X) +#include <asm/sibyte/sb1250_regs.h> +#include <asm/sibyte/sb1250_int.h> + +#define SBD_CHANREGS(line) A_DUART_CHANREG((line), 0) +#define SBD_CTRLREGS(line) A_DUART_CTRLREG(0) +#define SBD_INT(line) (K_INT_UART_0 + (line)) + +#else +#error invalid SB1250 UART configuration + +#endif + + +MODULE_AUTHOR("Maciej W. Rozycki <macro@linux-mips.org>"); +MODULE_DESCRIPTION("BCM1xxx on-chip DUART serial driver"); +MODULE_LICENSE("GPL"); + + +#define DUART_MAX_CHIP 2 +#define DUART_MAX_SIDE 2 + +/* + * Per-port state. + */ +struct sbd_port { + struct sbd_duart *duart; + struct uart_port port; + unsigned char __iomem *memctrl; + int tx_stopped; + int initialised; +}; + +/* + * Per-DUART state for the shared register space. + */ +struct sbd_duart { + struct sbd_port sport[2]; + unsigned long mapctrl; + refcount_t map_guard; +}; + +#define to_sport(uport) container_of(uport, struct sbd_port, port) + +static struct sbd_duart sbd_duarts[DUART_MAX_CHIP]; + + +/* + * Reading and writing SB1250 DUART registers. + * + * There are three register spaces: two per-channel ones and + * a shared one. We have to define accessors appropriately. + * All registers are 64-bit and all but the Baud Rate Clock + * registers only define 8 least significant bits. There is + * also a workaround to take into account. Raw accessors use + * the full register width, but cooked ones truncate it + * intentionally so that the rest of the driver does not care. + */ +static u64 __read_sbdchn(struct sbd_port *sport, int reg) +{ + void __iomem *csr = sport->port.membase + reg; + + return __raw_readq(csr); +} + +static u64 __read_sbdshr(struct sbd_port *sport, int reg) +{ + void __iomem *csr = sport->memctrl + reg; + + return __raw_readq(csr); +} + +static void __write_sbdchn(struct sbd_port *sport, int reg, u64 value) +{ + void __iomem *csr = sport->port.membase + reg; + + __raw_writeq(value, csr); +} + +static void __write_sbdshr(struct sbd_port *sport, int reg, u64 value) +{ + void __iomem *csr = sport->memctrl + reg; + + __raw_writeq(value, csr); +} + +/* + * In bug 1956, we get glitches that can mess up uart registers. This + * "read-mode-reg after any register access" is an accepted workaround. + */ +static void __war_sbd1956(struct sbd_port *sport) +{ + __read_sbdchn(sport, R_DUART_MODE_REG_1); + __read_sbdchn(sport, R_DUART_MODE_REG_2); +} + +static unsigned char read_sbdchn(struct sbd_port *sport, int reg) +{ + unsigned char retval; + + retval = __read_sbdchn(sport, reg); + if (SIBYTE_1956_WAR) + __war_sbd1956(sport); + return retval; +} + +static unsigned char read_sbdshr(struct sbd_port *sport, int reg) +{ + unsigned char retval; + + retval = __read_sbdshr(sport, reg); + if (SIBYTE_1956_WAR) + __war_sbd1956(sport); + return retval; +} + +static void write_sbdchn(struct sbd_port *sport, int reg, unsigned int value) +{ + __write_sbdchn(sport, reg, value); + if (SIBYTE_1956_WAR) + __war_sbd1956(sport); +} + +static void write_sbdshr(struct sbd_port *sport, int reg, unsigned int value) +{ + __write_sbdshr(sport, reg, value); + if (SIBYTE_1956_WAR) + __war_sbd1956(sport); +} + + +static int sbd_receive_ready(struct sbd_port *sport) +{ + return read_sbdchn(sport, R_DUART_STATUS) & M_DUART_RX_RDY; +} + +static int sbd_receive_drain(struct sbd_port *sport) +{ + int loops = 10000; + + while (sbd_receive_ready(sport) && --loops) + read_sbdchn(sport, R_DUART_RX_HOLD); + return loops; +} + +static int __maybe_unused sbd_transmit_ready(struct sbd_port *sport) +{ + return read_sbdchn(sport, R_DUART_STATUS) & M_DUART_TX_RDY; +} + +static int __maybe_unused sbd_transmit_drain(struct sbd_port *sport) +{ + int loops = 10000; + + while (!sbd_transmit_ready(sport) && --loops) + udelay(2); + return loops; +} + +static int sbd_transmit_empty(struct sbd_port *sport) +{ + return read_sbdchn(sport, R_DUART_STATUS) & M_DUART_TX_EMT; +} + +static int sbd_line_drain(struct sbd_port *sport) +{ + int loops = 10000; + + while (!sbd_transmit_empty(sport) && --loops) + udelay(2); + return loops; +} + + +static unsigned int sbd_tx_empty(struct uart_port *uport) +{ + struct sbd_port *sport = to_sport(uport); + + return sbd_transmit_empty(sport) ? TIOCSER_TEMT : 0; +} + +static unsigned int sbd_get_mctrl(struct uart_port *uport) +{ + struct sbd_port *sport = to_sport(uport); + unsigned int mctrl, status; + + status = read_sbdshr(sport, R_DUART_IN_PORT); + status >>= (uport->line) % 2; + mctrl = (!(status & M_DUART_IN_PIN0_VAL) ? TIOCM_CTS : 0) | + (!(status & M_DUART_IN_PIN4_VAL) ? TIOCM_CAR : 0) | + (!(status & M_DUART_RIN0_PIN) ? TIOCM_RNG : 0) | + (!(status & M_DUART_IN_PIN2_VAL) ? TIOCM_DSR : 0); + return mctrl; +} + +static void sbd_set_mctrl(struct uart_port *uport, unsigned int mctrl) +{ + struct sbd_port *sport = to_sport(uport); + unsigned int clr = 0, set = 0, mode2; + + if (mctrl & TIOCM_DTR) + set |= M_DUART_SET_OPR2; + else + clr |= M_DUART_CLR_OPR2; + if (mctrl & TIOCM_RTS) + set |= M_DUART_SET_OPR0; + else + clr |= M_DUART_CLR_OPR0; + clr <<= (uport->line) % 2; + set <<= (uport->line) % 2; + + mode2 = read_sbdchn(sport, R_DUART_MODE_REG_2); + mode2 &= ~M_DUART_CHAN_MODE; + if (mctrl & TIOCM_LOOP) + mode2 |= V_DUART_CHAN_MODE_LCL_LOOP; + else + mode2 |= V_DUART_CHAN_MODE_NORMAL; + + write_sbdshr(sport, R_DUART_CLEAR_OPR, clr); + write_sbdshr(sport, R_DUART_SET_OPR, set); + write_sbdchn(sport, R_DUART_MODE_REG_2, mode2); +} + +static void sbd_stop_tx(struct uart_port *uport) +{ + struct sbd_port *sport = to_sport(uport); + + write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_DIS); + sport->tx_stopped = 1; +}; + +static void sbd_start_tx(struct uart_port *uport) +{ + struct sbd_port *sport = to_sport(uport); + unsigned int mask; + + /* Enable tx interrupts. */ + mask = read_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2)); + mask |= M_DUART_IMR_TX; + write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2), mask); + + /* Go!, go!, go!... */ + write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_EN); + sport->tx_stopped = 0; +}; + +static void sbd_stop_rx(struct uart_port *uport) +{ + struct sbd_port *sport = to_sport(uport); + + write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2), 0); +}; + +static void sbd_enable_ms(struct uart_port *uport) +{ + struct sbd_port *sport = to_sport(uport); + + write_sbdchn(sport, R_DUART_AUXCTL_X, + M_DUART_CIN_CHNG_ENA | M_DUART_CTS_CHNG_ENA); +} + +static void sbd_break_ctl(struct uart_port *uport, int break_state) +{ + struct sbd_port *sport = to_sport(uport); + + if (break_state == -1) + write_sbdchn(sport, R_DUART_CMD, V_DUART_MISC_CMD_START_BREAK); + else + write_sbdchn(sport, R_DUART_CMD, V_DUART_MISC_CMD_STOP_BREAK); +} + + +static void sbd_receive_chars(struct sbd_port *sport) +{ + struct uart_port *uport = &sport->port; + struct uart_icount *icount; + unsigned int status, ch, flag; + int count; + + for (count = 16; count; count--) { + status = read_sbdchn(sport, R_DUART_STATUS); + if (!(status & M_DUART_RX_RDY)) + break; + + ch = read_sbdchn(sport, R_DUART_RX_HOLD); + + flag = TTY_NORMAL; + + icount = &uport->icount; + icount->rx++; + + if (unlikely(status & + (M_DUART_RCVD_BRK | M_DUART_FRM_ERR | + M_DUART_PARITY_ERR | M_DUART_OVRUN_ERR))) { + if (status & M_DUART_RCVD_BRK) { + icount->brk++; + if (uart_handle_break(uport)) + continue; + } else if (status & M_DUART_FRM_ERR) + icount->frame++; + else if (status & M_DUART_PARITY_ERR) + icount->parity++; + if (status & M_DUART_OVRUN_ERR) + icount->overrun++; + + status &= uport->read_status_mask; + if (status & M_DUART_RCVD_BRK) + flag = TTY_BREAK; + else if (status & M_DUART_FRM_ERR) + flag = TTY_FRAME; + else if (status & M_DUART_PARITY_ERR) + flag = TTY_PARITY; + } + + if (uart_handle_sysrq_char(uport, ch)) + continue; + + uart_insert_char(uport, status, M_DUART_OVRUN_ERR, ch, flag); + } + + tty_flip_buffer_push(&uport->state->port); +} + +static void sbd_transmit_chars(struct sbd_port *sport) +{ + struct uart_port *uport = &sport->port; + struct circ_buf *xmit = &sport->port.state->xmit; + unsigned int mask; + int stop_tx; + + /* XON/XOFF chars. */ + if (sport->port.x_char) { + write_sbdchn(sport, R_DUART_TX_HOLD, sport->port.x_char); + sport->port.icount.tx++; + sport->port.x_char = 0; + return; + } + + /* If nothing to do or stopped or hardware stopped. */ + stop_tx = (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port)); + + /* Send char. */ + if (!stop_tx) { + write_sbdchn(sport, R_DUART_TX_HOLD, xmit->buf[xmit->tail]); + xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); + sport->port.icount.tx++; + + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) + uart_write_wakeup(&sport->port); + } + + /* Are we are done? */ + if (stop_tx || uart_circ_empty(xmit)) { + /* Disable tx interrupts. */ + mask = read_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2)); + mask &= ~M_DUART_IMR_TX; + write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2), mask); + } +} + +static void sbd_status_handle(struct sbd_port *sport) +{ + struct uart_port *uport = &sport->port; + unsigned int delta; + + delta = read_sbdshr(sport, R_DUART_INCHREG((uport->line) % 2)); + delta >>= (uport->line) % 2; + + if (delta & (M_DUART_IN_PIN0_VAL << S_DUART_IN_PIN_CHNG)) + uart_handle_cts_change(uport, !(delta & M_DUART_IN_PIN0_VAL)); + + if (delta & (M_DUART_IN_PIN2_VAL << S_DUART_IN_PIN_CHNG)) + uport->icount.dsr++; + + if (delta & ((M_DUART_IN_PIN2_VAL | M_DUART_IN_PIN0_VAL) << + S_DUART_IN_PIN_CHNG)) + wake_up_interruptible(&uport->state->port.delta_msr_wait); +} + +static irqreturn_t sbd_interrupt(int irq, void *dev_id) +{ + struct sbd_port *sport = dev_id; + struct uart_port *uport = &sport->port; + irqreturn_t status = IRQ_NONE; + unsigned int intstat; + int count; + + for (count = 16; count; count--) { + intstat = read_sbdshr(sport, + R_DUART_ISRREG((uport->line) % 2)); + intstat &= read_sbdshr(sport, + R_DUART_IMRREG((uport->line) % 2)); + intstat &= M_DUART_ISR_ALL; + if (!intstat) + break; + + if (intstat & M_DUART_ISR_RX) + sbd_receive_chars(sport); + if (intstat & M_DUART_ISR_IN) + sbd_status_handle(sport); + if (intstat & M_DUART_ISR_TX) + sbd_transmit_chars(sport); + + status = IRQ_HANDLED; + } + + return status; +} + + +static int sbd_startup(struct uart_port *uport) +{ + struct sbd_port *sport = to_sport(uport); + unsigned int mode1; + int ret; + + ret = request_irq(sport->port.irq, sbd_interrupt, + IRQF_SHARED, "sb1250-duart", sport); + if (ret) + return ret; + + /* Clear the receive FIFO. */ + sbd_receive_drain(sport); + + /* Clear the interrupt registers. */ + write_sbdchn(sport, R_DUART_CMD, V_DUART_MISC_CMD_RESET_BREAK_INT); + read_sbdshr(sport, R_DUART_INCHREG((uport->line) % 2)); + + /* Set rx/tx interrupt to FIFO available. */ + mode1 = read_sbdchn(sport, R_DUART_MODE_REG_1); + mode1 &= ~(M_DUART_RX_IRQ_SEL_RXFULL | M_DUART_TX_IRQ_SEL_TXEMPT); + write_sbdchn(sport, R_DUART_MODE_REG_1, mode1); + + /* Disable tx, enable rx. */ + write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_DIS | M_DUART_RX_EN); + sport->tx_stopped = 1; + + /* Enable interrupts. */ + write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2), + M_DUART_IMR_IN | M_DUART_IMR_RX); + + return 0; +} + +static void sbd_shutdown(struct uart_port *uport) +{ + struct sbd_port *sport = to_sport(uport); + + write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_DIS | M_DUART_RX_DIS); + sport->tx_stopped = 1; + free_irq(sport->port.irq, sport); +} + + +static void sbd_init_port(struct sbd_port *sport) +{ + struct uart_port *uport = &sport->port; + + if (sport->initialised) + return; + + /* There is no DUART reset feature, so just set some sane defaults. */ + write_sbdchn(sport, R_DUART_CMD, V_DUART_MISC_CMD_RESET_TX); + write_sbdchn(sport, R_DUART_CMD, V_DUART_MISC_CMD_RESET_RX); + write_sbdchn(sport, R_DUART_MODE_REG_1, V_DUART_BITS_PER_CHAR_8); + write_sbdchn(sport, R_DUART_MODE_REG_2, 0); + write_sbdchn(sport, R_DUART_FULL_CTL, + V_DUART_INT_TIME(0) | V_DUART_SIG_FULL(15)); + write_sbdchn(sport, R_DUART_OPCR_X, 0); + write_sbdchn(sport, R_DUART_AUXCTL_X, 0); + write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2), 0); + + sport->initialised = 1; +} + +static void sbd_set_termios(struct uart_port *uport, struct ktermios *termios, + struct ktermios *old_termios) +{ + struct sbd_port *sport = to_sport(uport); + unsigned int mode1 = 0, mode2 = 0, aux = 0; + unsigned int mode1mask = 0, mode2mask = 0, auxmask = 0; + unsigned int oldmode1, oldmode2, oldaux; + unsigned int baud, brg; + unsigned int command; + + mode1mask |= ~(M_DUART_PARITY_MODE | M_DUART_PARITY_TYPE_ODD | + M_DUART_BITS_PER_CHAR); + mode2mask |= ~M_DUART_STOP_BIT_LEN_2; + auxmask |= ~M_DUART_CTS_CHNG_ENA; + + /* Byte size. */ + switch (termios->c_cflag & CSIZE) { + case CS5: + case CS6: + /* Unsupported, leave unchanged. */ + mode1mask |= M_DUART_PARITY_MODE; + break; + case CS7: + mode1 |= V_DUART_BITS_PER_CHAR_7; + break; + case CS8: + default: + mode1 |= V_DUART_BITS_PER_CHAR_8; + break; + } + + /* Parity and stop bits. */ + if (termios->c_cflag & CSTOPB) + mode2 |= M_DUART_STOP_BIT_LEN_2; + else + mode2 |= M_DUART_STOP_BIT_LEN_1; + if (termios->c_cflag & PARENB) + mode1 |= V_DUART_PARITY_MODE_ADD; + else + mode1 |= V_DUART_PARITY_MODE_NONE; + if (termios->c_cflag & PARODD) + mode1 |= M_DUART_PARITY_TYPE_ODD; + else + mode1 |= M_DUART_PARITY_TYPE_EVEN; + + baud = uart_get_baud_rate(uport, termios, old_termios, 1200, 5000000); + brg = V_DUART_BAUD_RATE(baud); + /* The actual lower bound is 1221bps, so compensate. */ + if (brg > M_DUART_CLK_COUNTER) + brg = M_DUART_CLK_COUNTER; + + uart_update_timeout(uport, termios->c_cflag, baud); + + uport->read_status_mask = M_DUART_OVRUN_ERR; + if (termios->c_iflag & INPCK) + uport->read_status_mask |= M_DUART_FRM_ERR | + M_DUART_PARITY_ERR; + if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK)) + uport->read_status_mask |= M_DUART_RCVD_BRK; + + uport->ignore_status_mask = 0; + if (termios->c_iflag & IGNPAR) + uport->ignore_status_mask |= M_DUART_FRM_ERR | + M_DUART_PARITY_ERR; + if (termios->c_iflag & IGNBRK) { + uport->ignore_status_mask |= M_DUART_RCVD_BRK; + if (termios->c_iflag & IGNPAR) + uport->ignore_status_mask |= M_DUART_OVRUN_ERR; + } + + if (termios->c_cflag & CREAD) + command = M_DUART_RX_EN; + else + command = M_DUART_RX_DIS; + + if (termios->c_cflag & CRTSCTS) + aux |= M_DUART_CTS_CHNG_ENA; + else + aux &= ~M_DUART_CTS_CHNG_ENA; + + spin_lock(&uport->lock); + + if (sport->tx_stopped) + command |= M_DUART_TX_DIS; + else + command |= M_DUART_TX_EN; + + oldmode1 = read_sbdchn(sport, R_DUART_MODE_REG_1) & mode1mask; + oldmode2 = read_sbdchn(sport, R_DUART_MODE_REG_2) & mode2mask; + oldaux = read_sbdchn(sport, R_DUART_AUXCTL_X) & auxmask; + + if (!sport->tx_stopped) + sbd_line_drain(sport); + write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_DIS | M_DUART_RX_DIS); + + write_sbdchn(sport, R_DUART_MODE_REG_1, mode1 | oldmode1); + write_sbdchn(sport, R_DUART_MODE_REG_2, mode2 | oldmode2); + write_sbdchn(sport, R_DUART_CLK_SEL, brg); + write_sbdchn(sport, R_DUART_AUXCTL_X, aux | oldaux); + + write_sbdchn(sport, R_DUART_CMD, command); + + spin_unlock(&uport->lock); +} + + +static const char *sbd_type(struct uart_port *uport) +{ + return "SB1250 DUART"; +} + +static void sbd_release_port(struct uart_port *uport) +{ + struct sbd_port *sport = to_sport(uport); + struct sbd_duart *duart = sport->duart; + + iounmap(sport->memctrl); + sport->memctrl = NULL; + iounmap(uport->membase); + uport->membase = NULL; + + if(refcount_dec_and_test(&duart->map_guard)) + release_mem_region(duart->mapctrl, DUART_CHANREG_SPACING); + release_mem_region(uport->mapbase, DUART_CHANREG_SPACING); +} + +static int sbd_map_port(struct uart_port *uport) +{ + const char *err = KERN_ERR "sbd: Cannot map MMIO\n"; + struct sbd_port *sport = to_sport(uport); + struct sbd_duart *duart = sport->duart; + + if (!uport->membase) + uport->membase = ioremap_nocache(uport->mapbase, + DUART_CHANREG_SPACING); + if (!uport->membase) { + printk(err); + return -ENOMEM; + } + + if (!sport->memctrl) + sport->memctrl = ioremap_nocache(duart->mapctrl, + DUART_CHANREG_SPACING); + if (!sport->memctrl) { + printk(err); + iounmap(uport->membase); + uport->membase = NULL; + return -ENOMEM; + } + + return 0; +} + +static int sbd_request_port(struct uart_port *uport) +{ + const char *err = KERN_ERR "sbd: Unable to reserve MMIO resource\n"; + struct sbd_duart *duart = to_sport(uport)->duart; + int ret = 0; + + if (!request_mem_region(uport->mapbase, DUART_CHANREG_SPACING, + "sb1250-duart")) { + printk(err); + return -EBUSY; + } + refcount_inc(&duart->map_guard); + if (refcount_read(&duart->map_guard) == 1) { + if (!request_mem_region(duart->mapctrl, DUART_CHANREG_SPACING, + "sb1250-duart")) { + refcount_dec(&duart->map_guard); + printk(err); + ret = -EBUSY; + } + } + if (!ret) { + ret = sbd_map_port(uport); + if (ret) { + if (refcount_dec_and_test(&duart->map_guard)) + release_mem_region(duart->mapctrl, + DUART_CHANREG_SPACING); + } + } + if (ret) { + release_mem_region(uport->mapbase, DUART_CHANREG_SPACING); + return ret; + } + return 0; +} + +static void sbd_config_port(struct uart_port *uport, int flags) +{ + struct sbd_port *sport = to_sport(uport); + + if (flags & UART_CONFIG_TYPE) { + if (sbd_request_port(uport)) + return; + + uport->type = PORT_SB1250_DUART; + + sbd_init_port(sport); + } +} + +static int sbd_verify_port(struct uart_port *uport, struct serial_struct *ser) +{ + int ret = 0; + + if (ser->type != PORT_UNKNOWN && ser->type != PORT_SB1250_DUART) + ret = -EINVAL; + if (ser->irq != uport->irq) + ret = -EINVAL; + if (ser->baud_base != uport->uartclk / 16) + ret = -EINVAL; + return ret; +} + + +static const struct uart_ops sbd_ops = { + .tx_empty = sbd_tx_empty, + .set_mctrl = sbd_set_mctrl, + .get_mctrl = sbd_get_mctrl, + .stop_tx = sbd_stop_tx, + .start_tx = sbd_start_tx, + .stop_rx = sbd_stop_rx, + .enable_ms = sbd_enable_ms, + .break_ctl = sbd_break_ctl, + .startup = sbd_startup, + .shutdown = sbd_shutdown, + .set_termios = sbd_set_termios, + .type = sbd_type, + .release_port = sbd_release_port, + .request_port = sbd_request_port, + .config_port = sbd_config_port, + .verify_port = sbd_verify_port, +}; + +/* Initialize SB1250 DUART port structures. */ +static void __init sbd_probe_duarts(void) +{ + static int probed; + int chip, side; + int max_lines, line; + + if (probed) + return; + + /* Set the number of available units based on the SOC type. */ + switch (soc_type) { + case K_SYS_SOC_TYPE_BCM1x55: + case K_SYS_SOC_TYPE_BCM1x80: + max_lines = 4; + break; + default: + /* Assume at least two serial ports at the normal address. */ + max_lines = 2; + break; + } + + probed = 1; + + for (chip = 0, line = 0; chip < DUART_MAX_CHIP && line < max_lines; + chip++) { + sbd_duarts[chip].mapctrl = SBD_CTRLREGS(line); + + for (side = 0; side < DUART_MAX_SIDE && line < max_lines; + side++, line++) { + struct sbd_port *sport = &sbd_duarts[chip].sport[side]; + struct uart_port *uport = &sport->port; + + sport->duart = &sbd_duarts[chip]; + + uport->irq = SBD_INT(line); + uport->uartclk = 100000000 / 20 * 16; + uport->fifosize = 16; + uport->iotype = UPIO_MEM; + uport->flags = UPF_BOOT_AUTOCONF; + uport->ops = &sbd_ops; + uport->line = line; + uport->mapbase = SBD_CHANREGS(line); + } + } +} + + +#ifdef CONFIG_SERIAL_SB1250_DUART_CONSOLE +/* + * Serial console stuff. Very basic, polling driver for doing serial + * console output. The console_lock is held by the caller, so we + * shouldn't be interrupted for more console activity. + */ +static void sbd_console_putchar(struct uart_port *uport, int ch) +{ + struct sbd_port *sport = to_sport(uport); + + sbd_transmit_drain(sport); + write_sbdchn(sport, R_DUART_TX_HOLD, ch); +} + +static void sbd_console_write(struct console *co, const char *s, + unsigned int count) +{ + int chip = co->index / DUART_MAX_SIDE; + int side = co->index % DUART_MAX_SIDE; + struct sbd_port *sport = &sbd_duarts[chip].sport[side]; + struct uart_port *uport = &sport->port; + unsigned long flags; + unsigned int mask; + + /* Disable transmit interrupts and enable the transmitter. */ + spin_lock_irqsave(&uport->lock, flags); + mask = read_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2)); + write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2), + mask & ~M_DUART_IMR_TX); + write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_EN); + spin_unlock_irqrestore(&uport->lock, flags); + + uart_console_write(&sport->port, s, count, sbd_console_putchar); + + /* Restore transmit interrupts and the transmitter enable. */ + spin_lock_irqsave(&uport->lock, flags); + sbd_line_drain(sport); + if (sport->tx_stopped) + write_sbdchn(sport, R_DUART_CMD, M_DUART_TX_DIS); + write_sbdshr(sport, R_DUART_IMRREG((uport->line) % 2), mask); + spin_unlock_irqrestore(&uport->lock, flags); +} + +static int __init sbd_console_setup(struct console *co, char *options) +{ + int chip = co->index / DUART_MAX_SIDE; + int side = co->index % DUART_MAX_SIDE; + struct sbd_port *sport = &sbd_duarts[chip].sport[side]; + struct uart_port *uport = &sport->port; + int baud = 115200; + int bits = 8; + int parity = 'n'; + int flow = 'n'; + int ret; + + if (!sport->duart) + return -ENXIO; + + ret = sbd_map_port(uport); + if (ret) + return ret; + + sbd_init_port(sport); + + if (options) + uart_parse_options(options, &baud, &parity, &bits, &flow); + return uart_set_options(uport, co, baud, parity, bits, flow); +} + +static struct uart_driver sbd_reg; +static struct console sbd_console = { + .name = "duart", + .write = sbd_console_write, + .device = uart_console_device, + .setup = sbd_console_setup, + .flags = CON_PRINTBUFFER, + .index = -1, + .data = &sbd_reg +}; + +static int __init sbd_serial_console_init(void) +{ + sbd_probe_duarts(); + register_console(&sbd_console); + + return 0; +} + +console_initcall(sbd_serial_console_init); + +#define SERIAL_SB1250_DUART_CONSOLE &sbd_console +#else +#define SERIAL_SB1250_DUART_CONSOLE NULL +#endif /* CONFIG_SERIAL_SB1250_DUART_CONSOLE */ + + +static struct uart_driver sbd_reg = { + .owner = THIS_MODULE, + .driver_name = "sb1250_duart", + .dev_name = "duart", + .major = TTY_MAJOR, + .minor = SB1250_DUART_MINOR_BASE, + .nr = DUART_MAX_CHIP * DUART_MAX_SIDE, + .cons = SERIAL_SB1250_DUART_CONSOLE, +}; + +/* Set up the driver and register it. */ +static int __init sbd_init(void) +{ + int i, ret; + + sbd_probe_duarts(); + + ret = uart_register_driver(&sbd_reg); + if (ret) + return ret; + + for (i = 0; i < DUART_MAX_CHIP * DUART_MAX_SIDE; i++) { + struct sbd_duart *duart = &sbd_duarts[i / DUART_MAX_SIDE]; + struct sbd_port *sport = &duart->sport[i % DUART_MAX_SIDE]; + struct uart_port *uport = &sport->port; + + if (sport->duart) + uart_add_one_port(&sbd_reg, uport); + } + + return 0; +} + +/* Unload the driver. Unregister stuff, get ready to go away. */ +static void __exit sbd_exit(void) +{ + int i; + + for (i = DUART_MAX_CHIP * DUART_MAX_SIDE - 1; i >= 0; i--) { + struct sbd_duart *duart = &sbd_duarts[i / DUART_MAX_SIDE]; + struct sbd_port *sport = &duart->sport[i % DUART_MAX_SIDE]; + struct uart_port *uport = &sport->port; + + if (sport->duart) + uart_remove_one_port(&sbd_reg, uport); + } + + uart_unregister_driver(&sbd_reg); +} + +module_init(sbd_init); +module_exit(sbd_exit); |