diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2011-01-20 16:39:23 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2011-01-20 16:39:23 -0800 |
commit | fc887b15d935ead2a00aef5779a18034e7c69ee1 (patch) | |
tree | 30daa1c9bafbf179047047c67d11ccd98e27d809 /drivers/tty/serial/sh-sci.c | |
parent | 466c19063b4b426d5c362572787cb249fbf4296b (diff) | |
parent | df6212529c646710502657b18d8f42927f3dda81 (diff) |
Merge branch 'tty-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6
* 'tty-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6:
tty: update MAINTAINERS file due to driver movement
tty: move drivers/serial/ to drivers/tty/serial/
tty: move hvc drivers to drivers/tty/hvc/
Diffstat (limited to 'drivers/tty/serial/sh-sci.c')
-rw-r--r-- | drivers/tty/serial/sh-sci.c | 2079 |
1 files changed, 2079 insertions, 0 deletions
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c new file mode 100644 index 000000000000..92c91c83edde --- /dev/null +++ b/drivers/tty/serial/sh-sci.c @@ -0,0 +1,2079 @@ +/* + * drivers/serial/sh-sci.c + * + * SuperH on-chip serial module support. (SCI with no FIFO / with FIFO) + * + * Copyright (C) 2002 - 2011 Paul Mundt + * Modified to support SH7720 SCIF. Markus Brunner, Mark Jonas (Jul 2007). + * + * based off of the old drivers/char/sh-sci.c by: + * + * Copyright (C) 1999, 2000 Niibe Yutaka + * Copyright (C) 2000 Sugioka Toshinobu + * Modified to support multiple serial ports. Stuart Menefy (May 2000). + * Modified to support SecureEdge. David McCullough (2002) + * Modified to support SH7300 SCIF. Takashi Kusuda (Jun 2003). + * Removed SH7300 support (Jul 2007). + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + */ +#if defined(CONFIG_SERIAL_SH_SCI_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) +#define SUPPORT_SYSRQ +#endif + +#undef DEBUG + +#include <linux/module.h> +#include <linux/errno.h> +#include <linux/timer.h> +#include <linux/interrupt.h> +#include <linux/tty.h> +#include <linux/tty_flip.h> +#include <linux/serial.h> +#include <linux/major.h> +#include <linux/string.h> +#include <linux/sysrq.h> +#include <linux/ioport.h> +#include <linux/mm.h> +#include <linux/init.h> +#include <linux/delay.h> +#include <linux/console.h> +#include <linux/platform_device.h> +#include <linux/serial_sci.h> +#include <linux/notifier.h> +#include <linux/cpufreq.h> +#include <linux/clk.h> +#include <linux/ctype.h> +#include <linux/err.h> +#include <linux/list.h> +#include <linux/dmaengine.h> +#include <linux/scatterlist.h> +#include <linux/slab.h> + +#ifdef CONFIG_SUPERH +#include <asm/sh_bios.h> +#endif + +#ifdef CONFIG_H8300 +#include <asm/gpio.h> +#endif + +#include "sh-sci.h" + +struct sci_port { + struct uart_port port; + + /* Port type */ + unsigned int type; + + /* Port IRQs: ERI, RXI, TXI, BRI (optional) */ + unsigned int irqs[SCIx_NR_IRQS]; + + /* Port enable callback */ + void (*enable)(struct uart_port *port); + + /* Port disable callback */ + void (*disable)(struct uart_port *port); + + /* Break timer */ + struct timer_list break_timer; + int break_flag; + + /* SCSCR initialization */ + unsigned int scscr; + + /* SCBRR calculation algo */ + unsigned int scbrr_algo_id; + + /* Interface clock */ + struct clk *iclk; + /* Function clock */ + struct clk *fclk; + + struct list_head node; + + struct dma_chan *chan_tx; + struct dma_chan *chan_rx; + +#ifdef CONFIG_SERIAL_SH_SCI_DMA + struct device *dma_dev; + unsigned int slave_tx; + unsigned int slave_rx; + struct dma_async_tx_descriptor *desc_tx; + struct dma_async_tx_descriptor *desc_rx[2]; + dma_cookie_t cookie_tx; + dma_cookie_t cookie_rx[2]; + dma_cookie_t active_rx; + struct scatterlist sg_tx; + unsigned int sg_len_tx; + struct scatterlist sg_rx[2]; + size_t buf_len_rx; + struct sh_dmae_slave param_tx; + struct sh_dmae_slave param_rx; + struct work_struct work_tx; + struct work_struct work_rx; + struct timer_list rx_timer; + unsigned int rx_timeout; +#endif +}; + +struct sh_sci_priv { + spinlock_t lock; + struct list_head ports; + struct notifier_block clk_nb; +}; + +/* Function prototypes */ +static void sci_stop_tx(struct uart_port *port); + +#define SCI_NPORTS CONFIG_SERIAL_SH_SCI_NR_UARTS + +static struct sci_port sci_ports[SCI_NPORTS]; +static struct uart_driver sci_uart_driver; + +static inline struct sci_port * +to_sci_port(struct uart_port *uart) +{ + return container_of(uart, struct sci_port, port); +} + +#if defined(CONFIG_CONSOLE_POLL) || defined(CONFIG_SERIAL_SH_SCI_CONSOLE) + +#ifdef CONFIG_CONSOLE_POLL +static inline void handle_error(struct uart_port *port) +{ + /* Clear error flags */ + sci_out(port, SCxSR, SCxSR_ERROR_CLEAR(port)); +} + +static int sci_poll_get_char(struct uart_port *port) +{ + unsigned short status; + int c; + + do { + status = sci_in(port, SCxSR); + if (status & SCxSR_ERRORS(port)) { + handle_error(port); + continue; + } + break; + } while (1); + + if (!(status & SCxSR_RDxF(port))) + return NO_POLL_CHAR; + + c = sci_in(port, SCxRDR); + + /* Dummy read */ + sci_in(port, SCxSR); + sci_out(port, SCxSR, SCxSR_RDxF_CLEAR(port)); + + return c; +} +#endif + +static void sci_poll_put_char(struct uart_port *port, unsigned char c) +{ + unsigned short status; + + do { + status = sci_in(port, SCxSR); + } while (!(status & SCxSR_TDxE(port))); + + sci_out(port, SCxTDR, c); + sci_out(port, SCxSR, SCxSR_TDxE_CLEAR(port) & ~SCxSR_TEND(port)); +} +#endif /* CONFIG_CONSOLE_POLL || CONFIG_SERIAL_SH_SCI_CONSOLE */ + +#if defined(__H8300H__) || defined(__H8300S__) +static void sci_init_pins(struct uart_port *port, unsigned int cflag) +{ + int ch = (port->mapbase - SMR0) >> 3; + + /* set DDR regs */ + H8300_GPIO_DDR(h8300_sci_pins[ch].port, + h8300_sci_pins[ch].rx, + H8300_GPIO_INPUT); + H8300_GPIO_DDR(h8300_sci_pins[ch].port, + h8300_sci_pins[ch].tx, + H8300_GPIO_OUTPUT); + + /* tx mark output*/ + H8300_SCI_DR(ch) |= h8300_sci_pins[ch].tx; +} +#elif defined(CONFIG_CPU_SUBTYPE_SH7710) || defined(CONFIG_CPU_SUBTYPE_SH7712) +static inline void sci_init_pins(struct uart_port *port, unsigned int cflag) +{ + if (port->mapbase == 0xA4400000) { + __raw_writew(__raw_readw(PACR) & 0xffc0, PACR); + __raw_writew(__raw_readw(PBCR) & 0x0fff, PBCR); + } else if (port->mapbase == 0xA4410000) + __raw_writew(__raw_readw(PBCR) & 0xf003, PBCR); +} +#elif defined(CONFIG_CPU_SUBTYPE_SH7720) || defined(CONFIG_CPU_SUBTYPE_SH7721) +static inline void sci_init_pins(struct uart_port *port, unsigned int cflag) +{ + unsigned short data; + + if (cflag & CRTSCTS) { + /* enable RTS/CTS */ + if (port->mapbase == 0xa4430000) { /* SCIF0 */ + /* Clear PTCR bit 9-2; enable all scif pins but sck */ + data = __raw_readw(PORT_PTCR); + __raw_writew((data & 0xfc03), PORT_PTCR); + } else if (port->mapbase == 0xa4438000) { /* SCIF1 */ + /* Clear PVCR bit 9-2 */ + data = __raw_readw(PORT_PVCR); + __raw_writew((data & 0xfc03), PORT_PVCR); + } + } else { + if (port->mapbase == 0xa4430000) { /* SCIF0 */ + /* Clear PTCR bit 5-2; enable only tx and rx */ + data = __raw_readw(PORT_PTCR); + __raw_writew((data & 0xffc3), PORT_PTCR); + } else if (port->mapbase == 0xa4438000) { /* SCIF1 */ + /* Clear PVCR bit 5-2 */ + data = __raw_readw(PORT_PVCR); + __raw_writew((data & 0xffc3), PORT_PVCR); + } + } +} +#elif defined(CONFIG_CPU_SH3) +/* For SH7705, SH7706, SH7707, SH7709, SH7709A, SH7729 */ +static inline void sci_init_pins(struct uart_port *port, unsigned int cflag) +{ + unsigned short data; + + /* We need to set SCPCR to enable RTS/CTS */ + data = __raw_readw(SCPCR); + /* Clear out SCP7MD1,0, SCP6MD1,0, SCP4MD1,0*/ + __raw_writew(data & 0x0fcf, SCPCR); + + if (!(cflag & CRTSCTS)) { + /* We need to set SCPCR to enable RTS/CTS */ + data = __raw_readw(SCPCR); + /* Clear out SCP7MD1,0, SCP4MD1,0, + Set SCP6MD1,0 = {01} (output) */ + __raw_writew((data & 0x0fcf) | 0x1000, SCPCR); + + data = __raw_readb(SCPDR); + /* Set /RTS2 (bit6) = 0 */ + __raw_writeb(data & 0xbf, SCPDR); + } +} +#elif defined(CONFIG_CPU_SUBTYPE_SH7722) +static inline void sci_init_pins(struct uart_port *port, unsigned int cflag) +{ + unsigned short data; + + if (port->mapbase == 0xffe00000) { + data = __raw_readw(PSCR); + data &= ~0x03cf; + if (!(cflag & CRTSCTS)) + data |= 0x0340; + + __raw_writew(data, PSCR); + } +} +#elif defined(CONFIG_CPU_SUBTYPE_SH7757) || \ + defined(CONFIG_CPU_SUBTYPE_SH7763) || \ + defined(CONFIG_CPU_SUBTYPE_SH7780) || \ + defined(CONFIG_CPU_SUBTYPE_SH7785) || \ + defined(CONFIG_CPU_SUBTYPE_SH7786) || \ + defined(CONFIG_CPU_SUBTYPE_SHX3) +static inline void sci_init_pins(struct uart_port *port, unsigned int cflag) +{ + if (!(cflag & CRTSCTS)) + __raw_writew(0x0080, SCSPTR0); /* Set RTS = 1 */ +} +#elif defined(CONFIG_CPU_SH4) && !defined(CONFIG_CPU_SH4A) +static inline void sci_init_pins(struct uart_port *port, unsigned int cflag) +{ + if (!(cflag & CRTSCTS)) + __raw_writew(0x0080, SCSPTR2); /* Set RTS = 1 */ +} +#else +static inline void sci_init_pins(struct uart_port *port, unsigned int cflag) +{ + /* Nothing to do */ +} +#endif + +#if defined(CONFIG_CPU_SUBTYPE_SH7760) || \ + defined(CONFIG_CPU_SUBTYPE_SH7780) || \ + defined(CONFIG_CPU_SUBTYPE_SH7785) || \ + defined(CONFIG_CPU_SUBTYPE_SH7786) +static int scif_txfill(struct uart_port *port) +{ + return sci_in(port, SCTFDR) & 0xff; +} + +static int scif_txroom(struct uart_port *port) +{ + return SCIF_TXROOM_MAX - scif_txfill(port); +} + +static int scif_rxfill(struct uart_port *port) +{ + return sci_in(port, SCRFDR) & 0xff; +} +#elif defined(CONFIG_CPU_SUBTYPE_SH7763) +static int scif_txfill(struct uart_port *port) +{ + if (port->mapbase == 0xffe00000 || + port->mapbase == 0xffe08000) + /* SCIF0/1*/ + return sci_in(port, SCTFDR) & 0xff; + else + /* SCIF2 */ + return sci_in(port, SCFDR) >> 8; +} + +static int scif_txroom(struct uart_port *port) +{ + if (port->mapbase == 0xffe00000 || + port->mapbase == 0xffe08000) + /* SCIF0/1*/ + return SCIF_TXROOM_MAX - scif_txfill(port); + else + /* SCIF2 */ + return SCIF2_TXROOM_MAX - scif_txfill(port); +} + +static int scif_rxfill(struct uart_port *port) +{ + if ((port->mapbase == 0xffe00000) || + (port->mapbase == 0xffe08000)) { + /* SCIF0/1*/ + return sci_in(port, SCRFDR) & 0xff; + } else { + /* SCIF2 */ + return sci_in(port, SCFDR) & SCIF2_RFDC_MASK; + } +} +#elif defined(CONFIG_ARCH_SH7372) +static int scif_txfill(struct uart_port *port) +{ + if (port->type == PORT_SCIFA) + return sci_in(port, SCFDR) >> 8; + else + return sci_in(port, SCTFDR); +} + +static int scif_txroom(struct uart_port *port) +{ + return port->fifosize - scif_txfill(port); +} + +static int scif_rxfill(struct uart_port *port) +{ + if (port->type == PORT_SCIFA) + return sci_in(port, SCFDR) & SCIF_RFDC_MASK; + else + return sci_in(port, SCRFDR); +} +#else +static int scif_txfill(struct uart_port *port) +{ + return sci_in(port, SCFDR) >> 8; +} + +static int scif_txroom(struct uart_port *port) +{ + return SCIF_TXROOM_MAX - scif_txfill(port); +} + +static int scif_rxfill(struct uart_port *port) +{ + return sci_in(port, SCFDR) & SCIF_RFDC_MASK; +} +#endif + +static int sci_txfill(struct uart_port *port) +{ + return !(sci_in(port, SCxSR) & SCI_TDRE); +} + +static int sci_txroom(struct uart_port *port) +{ + return !sci_txfill(port); +} + +static int sci_rxfill(struct uart_port *port) +{ + return (sci_in(port, SCxSR) & SCxSR_RDxF(port)) != 0; +} + +/* ********************************************************************** * + * the interrupt related routines * + * ********************************************************************** */ + +static void sci_transmit_chars(struct uart_port *port) +{ + struct circ_buf *xmit = &port->state->xmit; + unsigned int stopped = uart_tx_stopped(port); + unsigned short status; + unsigned short ctrl; + int count; + + status = sci_in(port, SCxSR); + if (!(status & SCxSR_TDxE(port))) { + ctrl = sci_in(port, SCSCR); + if (uart_circ_empty(xmit)) + ctrl &= ~SCSCR_TIE; + else + ctrl |= SCSCR_TIE; + sci_out(port, SCSCR, ctrl); + return; + } + + if (port->type == PORT_SCI) + count = sci_txroom(port); + else + count = scif_txroom(port); + + do { + unsigned char c; + + if (port->x_char) { + c = port->x_char; + port->x_char = 0; + } else if (!uart_circ_empty(xmit) && !stopped) { + c = xmit->buf[xmit->tail]; + xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); + } else { + break; + } + + sci_out(port, SCxTDR, c); + + port->icount.tx++; + } while (--count > 0); + + sci_out(port, SCxSR, SCxSR_TDxE_CLEAR(port)); + + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) + uart_write_wakeup(port); + if (uart_circ_empty(xmit)) { + sci_stop_tx(port); + } else { + ctrl = sci_in(port, SCSCR); + + if (port->type != PORT_SCI) { + sci_in(port, SCxSR); /* Dummy read */ + sci_out(port, SCxSR, SCxSR_TDxE_CLEAR(port)); + } + + ctrl |= SCSCR_TIE; + sci_out(port, SCSCR, ctrl); + } +} + +/* On SH3, SCIF may read end-of-break as a space->mark char */ +#define STEPFN(c) ({int __c = (c); (((__c-1)|(__c)) == -1); }) + +static inline void sci_receive_chars(struct uart_port *port) +{ + struct sci_port *sci_port = to_sci_port(port); + struct tty_struct *tty = port->state->port.tty; + int i, count, copied = 0; + unsigned short status; + unsigned char flag; + + status = sci_in(port, SCxSR); + if (!(status & SCxSR_RDxF(port))) + return; + + while (1) { + if (port->type == PORT_SCI) + count = sci_rxfill(port); + else + count = scif_rxfill(port); + + /* Don't copy more bytes than there is room for in the buffer */ + count = tty_buffer_request_room(tty, count); + + /* If for any reason we can't copy more data, we're done! */ + if (count == 0) + break; + + if (port->type == PORT_SCI) { + char c = sci_in(port, SCxRDR); + if (uart_handle_sysrq_char(port, c) || + sci_port->break_flag) + count = 0; + else + tty_insert_flip_char(tty, c, TTY_NORMAL); + } else { + for (i = 0; i < count; i++) { + char c = sci_in(port, SCxRDR); + status = sci_in(port, SCxSR); +#if defined(CONFIG_CPU_SH3) + /* Skip "chars" during break */ + if (sci_port->break_flag) { + if ((c == 0) && + (status & SCxSR_FER(port))) { + count--; i--; + continue; + } + + /* Nonzero => end-of-break */ + dev_dbg(port->dev, "debounce<%02x>\n", c); + sci_port->break_flag = 0; + + if (STEPFN(c)) { + count--; i--; + continue; + } + } +#endif /* CONFIG_CPU_SH3 */ + if (uart_handle_sysrq_char(port, c)) { + count--; i--; + continue; + } + + /* Store data and status */ + if (status & SCxSR_FER(port)) { + flag = TTY_FRAME; + dev_notice(port->dev, "frame error\n"); + } else if (status & SCxSR_PER(port)) { + flag = TTY_PARITY; + dev_notice(port->dev, "parity error\n"); + } else + flag = TTY_NORMAL; + + tty_insert_flip_char(tty, c, flag); + } + } + + sci_in(port, SCxSR); /* dummy read */ + sci_out(port, SCxSR, SCxSR_RDxF_CLEAR(port)); + + copied += count; + port->icount.rx += count; + } + + if (copied) { + /* Tell the rest of the system the news. New characters! */ + tty_flip_buffer_push(tty); + } else { + sci_in(port, SCxSR); /* dummy read */ + sci_out(port, SCxSR, SCxSR_RDxF_CLEAR(port)); + } +} + +#define SCI_BREAK_JIFFIES (HZ/20) +/* The sci generates interrupts during the break, + * 1 per millisecond or so during the break period, for 9600 baud. + * So dont bother disabling interrupts. + * But dont want more than 1 break event. + * Use a kernel timer to periodically poll the rx line until + * the break is finished. + */ +static void sci_schedule_break_timer(struct sci_port *port) +{ + port->break_timer.expires = jiffies + SCI_BREAK_JIFFIES; + add_timer(&port->break_timer); +} +/* Ensure that two consecutive samples find the break over. */ +static void sci_break_timer(unsigned long data) +{ + struct sci_port *port = (struct sci_port *)data; + + if (sci_rxd_in(&port->port) == 0) { + port->break_flag = 1; + sci_schedule_break_timer(port); + } else if (port->break_flag == 1) { + /* break is over. */ + port->break_flag = 2; + sci_schedule_break_timer(port); + } else + port->break_flag = 0; +} + +static inline int sci_handle_errors(struct uart_port *port) +{ + int copied = 0; + unsigned short status = sci_in(port, SCxSR); + struct tty_struct *tty = port->state->port.tty; + + if (status & SCxSR_ORER(port)) { + /* overrun error */ + if (tty_insert_flip_char(tty, 0, TTY_OVERRUN)) + copied++; + + dev_notice(port->dev, "overrun error"); + } + + if (status & SCxSR_FER(port)) { + if (sci_rxd_in(port) == 0) { + /* Notify of BREAK */ + struct sci_port *sci_port = to_sci_port(port); + + if (!sci_port->break_flag) { + sci_port->break_flag = 1; + sci_schedule_break_timer(sci_port); + + /* Do sysrq handling. */ + if (uart_handle_break(port)) + return 0; + + dev_dbg(port->dev, "BREAK detected\n"); + + if (tty_insert_flip_char(tty, 0, TTY_BREAK)) + copied++; + } + + } else { + /* frame error */ + if (tty_insert_flip_char(tty, 0, TTY_FRAME)) + copied++; + + dev_notice(port->dev, "frame error\n"); + } + } + + if (status & SCxSR_PER(port)) { + /* parity error */ + if (tty_insert_flip_char(tty, 0, TTY_PARITY)) + copied++; + + dev_notice(port->dev, "parity error"); + } + + if (copied) + tty_flip_buffer_push(tty); + + return copied; +} + +static inline int sci_handle_fifo_overrun(struct uart_port *port) +{ + struct tty_struct *tty = port->state->port.tty; + int copied = 0; + + if (port->type != PORT_SCIF) + return 0; + + if ((sci_in(port, SCLSR) & SCIF_ORER) != 0) { + sci_out(port, SCLSR, 0); + + tty_insert_flip_char(tty, 0, TTY_OVERRUN); + tty_flip_buffer_push(tty); + + dev_notice(port->dev, "overrun error\n"); + copied++; + } + + return copied; +} + +static inline int sci_handle_breaks(struct uart_port *port) +{ + int copied = 0; + unsigned short status = sci_in(port, SCxSR); + struct tty_struct *tty = port->state->port.tty; + struct sci_port *s = to_sci_port(port); + + if (uart_handle_break(port)) + return 0; + + if (!s->break_flag && status & SCxSR_BRK(port)) { +#if defined(CONFIG_CPU_SH3) + /* Debounce break */ + s->break_flag = 1; +#endif + /* Notify of BREAK */ + if (tty_insert_flip_char(tty, 0, TTY_BREAK)) + copied++; + + dev_dbg(port->dev, "BREAK detected\n"); + } + + if (copied) + tty_flip_buffer_push(tty); + + copied += sci_handle_fifo_overrun(port); + + return copied; +} + +static irqreturn_t sci_rx_interrupt(int irq, void *ptr) +{ +#ifdef CONFIG_SERIAL_SH_SCI_DMA + struct uart_port *port = ptr; + struct sci_port *s = to_sci_port(port); + + if (s->chan_rx) { + u16 scr = sci_in(port, SCSCR); + u16 ssr = sci_in(port, SCxSR); + + /* Disable future Rx interrupts */ + if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) { + disable_irq_nosync(irq); + scr |= 0x4000; + } else { + scr &= ~SCSCR_RIE; + } + sci_out(port, SCSCR, scr); + /* Clear current interrupt */ + sci_out(port, SCxSR, ssr & ~(1 | SCxSR_RDxF(port))); + dev_dbg(port->dev, "Rx IRQ %lu: setup t-out in %u jiffies\n", + jiffies, s->rx_timeout); + mod_timer(&s->rx_timer, jiffies + s->rx_timeout); + + return IRQ_HANDLED; + } +#endif + + /* I think sci_receive_chars has to be called irrespective + * of whether the I_IXOFF is set, otherwise, how is the interrupt + * to be disabled? + */ + sci_receive_chars(ptr); + + return IRQ_HANDLED; +} + +static irqreturn_t sci_tx_interrupt(int irq, void *ptr) +{ + struct uart_port *port = ptr; + unsigned long flags; + + spin_lock_irqsave(&port->lock, flags); + sci_transmit_chars(port); + spin_unlock_irqrestore(&port->lock, flags); + + return IRQ_HANDLED; +} + +static irqreturn_t sci_er_interrupt(int irq, void *ptr) +{ + struct uart_port *port = ptr; + + /* Handle errors */ + if (port->type == PORT_SCI) { + if (sci_handle_errors(port)) { + /* discard character in rx buffer */ + sci_in(port, SCxSR); + sci_out(port, SCxSR, SCxSR_RDxF_CLEAR(port)); + } + } else { + sci_handle_fifo_overrun(port); + sci_rx_interrupt(irq, ptr); + } + + sci_out(port, SCxSR, SCxSR_ERROR_CLEAR(port)); + + /* Kick the transmission */ + sci_tx_interrupt(irq, ptr); + + return IRQ_HANDLED; +} + +static irqreturn_t sci_br_interrupt(int irq, void *ptr) +{ + struct uart_port *port = ptr; + + /* Handle BREAKs */ + sci_handle_breaks(port); + sci_out(port, SCxSR, SCxSR_BREAK_CLEAR(port)); + + return IRQ_HANDLED; +} + +static inline unsigned long port_rx_irq_mask(struct uart_port *port) +{ + /* + * Not all ports (such as SCIFA) will support REIE. Rather than + * special-casing the port type, we check the port initialization + * IRQ enable mask to see whether the IRQ is desired at all. If + * it's unset, it's logically inferred that there's no point in + * testing for it. + */ + return SCSCR_RIE | (to_sci_port(port)->scscr & SCSCR_REIE); +} + +static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr) +{ + unsigned short ssr_status, scr_status, err_enabled; + struct uart_port *port = ptr; + struct sci_port *s = to_sci_port(port); + irqreturn_t ret = IRQ_NONE; + + ssr_status = sci_in(port, SCxSR); + scr_status = sci_in(port, SCSCR); + err_enabled = scr_status & port_rx_irq_mask(port); + + /* Tx Interrupt */ + if ((ssr_status & SCxSR_TDxE(port)) && (scr_status & SCSCR_TIE) && + !s->chan_tx) + ret = sci_tx_interrupt(irq, ptr); + + /* + * Rx Interrupt: if we're using DMA, the DMA controller clears RDF / + * DR flags + */ + if (((ssr_status & SCxSR_RDxF(port)) || s->chan_rx) && + (scr_status & SCSCR_RIE)) + ret = sci_rx_interrupt(irq, ptr); + + /* Error Interrupt */ + if ((ssr_status & SCxSR_ERRORS(port)) && err_enabled) + ret = sci_er_interrupt(irq, ptr); + + /* Break Interrupt */ + if ((ssr_status & SCxSR_BRK(port)) && err_enabled) + ret = sci_br_interrupt(irq, ptr); + + return ret; +} + +/* + * Here we define a transistion notifier so that we can update all of our + * ports' baud rate when the peripheral clock changes. + */ +static int sci_notifier(struct notifier_block *self, + unsigned long phase, void *p) +{ + struct sh_sci_priv *priv = container_of(self, + struct sh_sci_priv, clk_nb); + struct sci_port *sci_port; + unsigned long flags; + + if ((phase == CPUFREQ_POSTCHANGE) || + (phase == CPUFREQ_RESUMECHANGE)) { + spin_lock_irqsave(&priv->lock, flags); + list_for_each_entry(sci_port, &priv->ports, node) + sci_port->port.uartclk = clk_get_rate(sci_port->iclk); + spin_unlock_irqrestore(&priv->lock, flags); + } + + return NOTIFY_OK; +} + +static void sci_clk_enable(struct uart_port *port) +{ + struct sci_port *sci_port = to_sci_port(port); + + clk_enable(sci_port->iclk); + sci_port->port.uartclk = clk_get_rate(sci_port->iclk); + clk_enable(sci_port->fclk); +} + +static void sci_clk_disable(struct uart_port *port) +{ + struct sci_port *sci_port = to_sci_port(port); + + clk_disable(sci_port->fclk); + clk_disable(sci_port->iclk); +} + +static int sci_request_irq(struct sci_port *port) +{ + int i; + irqreturn_t (*handlers[4])(int irq, void *ptr) = { + sci_er_interrupt, sci_rx_interrupt, sci_tx_interrupt, + sci_br_interrupt, + }; + const char *desc[] = { "SCI Receive Error", "SCI Receive Data Full", + "SCI Transmit Data Empty", "SCI Break" }; + + if (port->irqs[0] == port->irqs[1]) { + if (unlikely(!port->irqs[0])) + return -ENODEV; + + if (request_irq(port->irqs[0], sci_mpxed_interrupt, + IRQF_DISABLED, "sci", port)) { + dev_err(port->port.dev, "Can't allocate IRQ\n"); + return -ENODEV; + } + } else { + for (i = 0; i < ARRAY_SIZE(handlers); i++) { + if (unlikely(!port->irqs[i])) + continue; + + if (request_irq(port->irqs[i], handlers[i], + IRQF_DISABLED, desc[i], port)) { + dev_err(port->port.dev, "Can't allocate IRQ\n"); + return -ENODEV; + } + } + } + + return 0; +} + +static void sci_free_irq(struct sci_port *port) +{ + int i; + + if (port->irqs[0] == port->irqs[1]) + free_irq(port->irqs[0], port); + else { + for (i = 0; i < ARRAY_SIZE(port->irqs); i++) { + if (!port->irqs[i]) + continue; + + free_irq(port->irqs[i], port); + } + } +} + +static unsigned int sci_tx_empty(struct uart_port *port) +{ + unsigned short status = sci_in(port, SCxSR); + unsigned short in_tx_fifo = scif_txfill(port); + + return (status & SCxSR_TEND(port)) && !in_tx_fifo ? TIOCSER_TEMT : 0; +} + +static void sci_set_mctrl(struct uart_port *port, unsigned int mctrl) +{ + /* This routine is used for seting signals of: DTR, DCD, CTS/RTS */ + /* We use SCIF's hardware for CTS/RTS, so don't need any for that. */ + /* If you have signals for DTR and DCD, please implement here. */ +} + +static unsigned int sci_get_mctrl(struct uart_port *port) +{ + /* This routine is used for getting signals of: DTR, DCD, DSR, RI, + and CTS/RTS */ + + return TIOCM_DTR | TIOCM_RTS | TIOCM_DSR; +} + +#ifdef CONFIG_SERIAL_SH_SCI_DMA +static void sci_dma_tx_complete(void *arg) +{ + struct sci_port *s = arg; + struct uart_port *port = &s->port; + struct circ_buf *xmit = &port->state->xmit; + unsigned long flags; + + dev_dbg(port->dev, "%s(%d)\n", __func__, port->line); + + spin_lock_irqsave(&port->lock, flags); + + xmit->tail += sg_dma_len(&s->sg_tx); + xmit->tail &= UART_XMIT_SIZE - 1; + + port->icount.tx += sg_dma_len(&s->sg_tx); + + async_tx_ack(s->desc_tx); + s->cookie_tx = -EINVAL; + s->desc_tx = NULL; + + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) + uart_write_wakeup(port); + + if (!uart_circ_empty(xmit)) { + schedule_work(&s->work_tx); + } else if (port->type == PORT_SCIFA || port->type == PORT_SCIFB) { + u16 ctrl = sci_in(port, SCSCR); + sci_out(port, SCSCR, ctrl & ~SCSCR_TIE); + } + + spin_unlock_irqrestore(&port->lock, flags); +} + +/* Locking: called with port lock held */ +static int sci_dma_rx_push(struct sci_port *s, struct tty_struct *tty, + size_t count) +{ + struct uart_port *port = &s->port; + int i, active, room; + + room = tty_buffer_request_room(tty, count); + + if (s->active_rx == s->cookie_rx[0]) { + active = 0; + } else if (s->active_rx == s->cookie_rx[1]) { + active = 1; + } else { + dev_err(port->dev, "cookie %d not found!\n", s->active_rx); + return 0; + } + + if (room < count) + dev_warn(port->dev, "Rx overrun: dropping %u bytes\n", + count - room); + if (!room) + return room; + + for (i = 0; i < room; i++) + tty_insert_flip_char(tty, ((u8 *)sg_virt(&s->sg_rx[active]))[i], + TTY_NORMAL); + + port->icount.rx += room; + + return room; +} + +static void sci_dma_rx_complete(void *arg) +{ + struct sci_port *s = arg; + struct uart_port *port = &s->port; + struct tty_struct *tty = port->state->port.tty; + unsigned long flags; + int count; + + dev_dbg(port->dev, "%s(%d) active #%d\n", __func__, port->line, s->active_rx); + + spin_lock_irqsave(&port->lock, flags); + + count = sci_dma_rx_push(s, tty, s->buf_len_rx); + + mod_timer(&s->rx_timer, jiffies + s->rx_timeout); + + spin_unlock_irqrestore(&port->lock, flags); + + if (count) + tty_flip_buffer_push(tty); + + schedule_work(&s->work_rx); +} + +static void sci_start_rx(struct uart_port *port); +static void sci_start_tx(struct uart_port *port); + +static void sci_rx_dma_release(struct sci_port *s, bool enable_pio) +{ + struct dma_chan *chan = s->chan_rx; + struct uart_port *port = &s->port; + + s->chan_rx = NULL; + s->cookie_rx[0] = s->cookie_rx[1] = -EINVAL; + dma_release_channel(chan); + if (sg_dma_address(&s->sg_rx[0])) + dma_free_coherent(port->dev, s->buf_len_rx * 2, + sg_virt(&s->sg_rx[0]), sg_dma_address(&s->sg_rx[0])); + if (enable_pio) + sci_start_rx(port); +} + +static void sci_tx_dma_release(struct sci_port *s, bool enable_pio) +{ + struct dma_chan *chan = s->chan_tx; + struct uart_port *port = &s->port; + + s->chan_tx = NULL; + s->cookie_tx = -EINVAL; + dma_release_channel(chan); + if (enable_pio) + sci_start_tx(port); +} + +static void sci_submit_rx(struct sci_port *s) +{ + struct dma_chan *chan = s->chan_rx; + int i; + + for (i = 0; i < 2; i++) { + struct scatterlist *sg = &s->sg_rx[i]; + struct dma_async_tx_descriptor *desc; + + desc = chan->device->device_prep_slave_sg(chan, + sg, 1, DMA_FROM_DEVICE, DMA_PREP_INTERRUPT); + + if (desc) { + s->desc_rx[i] = desc; + desc->callback = sci_dma_rx_complete; + desc->callback_param = s; + s->cookie_rx[i] = desc->tx_submit(desc); + } + + if (!desc || s->cookie_rx[i] < 0) { + if (i) { + async_tx_ack(s->desc_rx[0]); + s->cookie_rx[0] = -EINVAL; + } + if (desc) { + async_tx_ack(desc); + s->cookie_rx[i] = -EINVAL; + } + dev_warn(s->port.dev, + "failed to re-start DMA, using PIO\n"); + sci_rx_dma_release(s, true); + return; + } + dev_dbg(s->port.dev, "%s(): cookie %d to #%d\n", __func__, + s->cookie_rx[i], i); + } + + s->active_rx = s->cookie_rx[0]; + + dma_async_issue_pending(chan); +} + +static void work_fn_rx(struct work_struct *work) +{ + struct sci_port *s = container_of(work, struct sci_port, work_rx); + struct uart_port *port = &s->port; + struct dma_async_tx_descriptor *desc; + int new; + + if (s->active_rx == s->cookie_rx[0]) { + new = 0; + } else if (s->active_rx == s->cookie_rx[1]) { + new = 1; + } else { + dev_err(port->dev, "cookie %d not found!\n", s->active_rx); + return; + } + desc = s->desc_rx[new]; + + if (dma_async_is_tx_complete(s->chan_rx, s->active_rx, NULL, NULL) != + DMA_SUCCESS) { + /* Handle incomplete DMA receive */ + struct tty_struct *tty = port->state->port.tty; + struct dma_chan *chan = s->chan_rx; + struct sh_desc *sh_desc = container_of(desc, struct sh_desc, + async_tx); + unsigned long flags; + int count; + + chan->device->device_control(chan, DMA_TERMINATE_ALL, 0); + dev_dbg(port->dev, "Read %u bytes with cookie %d\n", + sh_desc->partial, sh_desc->cookie); + + spin_lock_irqsave(&port->lock, flags); + count = sci_dma_rx_push(s, tty, sh_desc->partial); + spin_unlock_irqrestore(&port->lock, flags); + + if (count) + tty_flip_buffer_push(tty); + + sci_submit_rx(s); + + return; + } + + s->cookie_rx[new] = desc->tx_submit(desc); + if (s->cookie_rx[new] < 0) { + dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n"); + sci_rx_dma_release(s, true); + return; + } + + s->active_rx = s->cookie_rx[!new]; + + dev_dbg(port->dev, "%s: cookie %d #%d, new active #%d\n", __func__, + s->cookie_rx[new], new, s->active_rx); +} + +static void work_fn_tx(struct work_struct *work) +{ + struct sci_port *s = container_of(work, struct sci_port, work_tx); + struct dma_async_tx_descriptor *desc; + struct dma_chan *chan = s->chan_tx; + struct uart_port *port = &s->port; + struct circ_buf *xmit = &port->state->xmit; + struct scatterlist *sg = &s->sg_tx; + + /* + * DMA is idle now. + * Port xmit buffer is already mapped, and it is one page... Just adjust + * offsets and lengths. Since it is a circular buffer, we have to + * transmit till the end, and then the rest. Take the port lock to get a + * consistent xmit buffer state. + */ + spin_lock_irq(&port->lock); + sg->offset = xmit->tail & (UART_XMIT_SIZE - 1); + sg_dma_address(sg) = (sg_dma_address(sg) & ~(UART_XMIT_SIZE - 1)) + + sg->offset; + sg_dma_len(s |