serial.c

linux-2.4.29操作系统的源码

	CONTROL_PINS_PORT_NOT_USED(3)
#endif		
	}
};
#else  /* CONFIG_ETRAX_SERX_DTR_RI_DSR_CD_MIXED */

/* All pins are on either PA or PB for each serial port */
#define CONTROL_PINS_PORT_NOT_USED(line) \
  &dummy_ser[line], &dummy_ser[line], \
  DUMMY_DTR_MASK, DUMMY_RI_MASK, DUMMY_DSR_MASK, DUMMY_CD_MASK
    

struct control_pins
{
	volatile unsigned char *port;
	unsigned char          *shadow;

	unsigned char dtr_mask;
	unsigned char ri_mask;
	unsigned char dsr_mask;
	unsigned char cd_mask;
};

#define dtr_port port
#define dtr_shadow shadow
#define ri_port port
#define ri_shadow shadow
#define dsr_port port
#define dsr_shadow shadow
#define cd_port port
#define cd_shadow shadow

static const struct control_pins e100_modem_pins[NR_PORTS] = 
{
	/* Ser 0 */
	{
#ifdef CONFIG_ETRAX_SERIAL_PORT0
	E100_STRUCT_PORT(0,DTR), E100_STRUCT_SHADOW(0,DTR),
	E100_STRUCT_MASK(0,DTR),
	E100_STRUCT_MASK(0,RI),
	E100_STRUCT_MASK(0,DSR),
	E100_STRUCT_MASK(0,CD)
#else
	CONTROL_PINS_PORT_NOT_USED(0)
#endif	
	},

	/* Ser 1 */
	{
#ifdef CONFIG_ETRAX_SERIAL_PORT1	  
	E100_STRUCT_PORT(1,DTR), E100_STRUCT_SHADOW(1,DTR),
	E100_STRUCT_MASK(1,DTR),
	E100_STRUCT_MASK(1,RI),
	E100_STRUCT_MASK(1,DSR),
	E100_STRUCT_MASK(1,CD)
#else
	CONTROL_PINS_PORT_NOT_USED(1)
#endif		
	},

	/* Ser 2 */
	{
#ifdef CONFIG_ETRAX_SERIAL_PORT2	  
	E100_STRUCT_PORT(2,DTR), E100_STRUCT_SHADOW(2,DTR),
	E100_STRUCT_MASK(2,DTR),
	E100_STRUCT_MASK(2,RI),
	E100_STRUCT_MASK(2,DSR),
	E100_STRUCT_MASK(2,CD)
#else
	CONTROL_PINS_PORT_NOT_USED(2)
#endif		
	},

	/* Ser 3 */
	{
#ifdef CONFIG_ETRAX_SERIAL_PORT3	  
	E100_STRUCT_PORT(3,DTR), E100_STRUCT_SHADOW(3,DTR),
	E100_STRUCT_MASK(3,DTR),
	E100_STRUCT_MASK(3,RI),
	E100_STRUCT_MASK(3,DSR),
	E100_STRUCT_MASK(3,CD)
#else
	CONTROL_PINS_PORT_NOT_USED(3)
#endif		
	}
};
#endif /* !CONFIG_ETRAX_SERX_DTR_RI_DSR_CD_MIXED */

#if defined(CONFIG_ETRAX_RS485) && defined(CONFIG_ETRAX_RS485_ON_PA)
unsigned char rs485_pa_port = CONFIG_ETRAX_RS485_ON_PA_BIT;
#endif


#define E100_RTS_MASK 0x20
#define E100_CTS_MASK 0x40

/* All serial port signals are active low:
 * active   = 0 -> 3.3V to RS-232 driver -> -12V on RS-232 level
 * inactive = 1 -> 0V   to RS-232 driver -> +12V on RS-232 level
 *
 * These macros returns the pin value: 0=0V, >=1 = 3.3V on ETRAX chip
 */

/* Output */
#define E100_RTS_GET(info) ((info)->rx_ctrl & E100_RTS_MASK)
/* Input */
#define E100_CTS_GET(info) ((info)->port[REG_STATUS] & E100_CTS_MASK)

/* These are typically PA or PB and 0 means 0V, 1 means 3.3V */
/* Is an output */
#define E100_DTR_GET(info) ((*e100_modem_pins[(info)->line].dtr_shadow) & e100_modem_pins[(info)->line].dtr_mask)

/* Normally inputs */
#define E100_RI_GET(info) ((*e100_modem_pins[(info)->line].ri_port) & e100_modem_pins[(info)->line].ri_mask)
#define E100_CD_GET(info) ((*e100_modem_pins[(info)->line].cd_port) & e100_modem_pins[(info)->line].cd_mask)

/* Input */
#define E100_DSR_GET(info) ((*e100_modem_pins[(info)->line].dsr_port) & e100_modem_pins[(info)->line].dsr_mask)


/*
 * tmp_buf is used as a temporary buffer by serial_write.  We need to
 * lock it in case the memcpy_fromfs blocks while swapping in a page,
 * and some other program tries to do a serial write at the same time.
 * Since the lock will only come under contention when the system is
 * swapping and available memory is low, it makes sense to share one
 * buffer across all the serial ports, since it significantly saves
 * memory if large numbers of serial ports are open.
 */
static unsigned char *tmp_buf;
#ifdef DECLARE_MUTEX
static DECLARE_MUTEX(tmp_buf_sem);
#else
static struct semaphore tmp_buf_sem = MUTEX;
#endif

#ifdef CONFIG_ETRAX_SERIAL_FLUSH_DMA_FAST

/* clock select 10 for timer 1 gives 230400 Hz */
#define FASTTIMER_SELECT (10)
/* we use a source of 230400 Hz and a divider of 15 => 15360 Hz */
#define FASTTIMER_DIV (15)

/* fast flush timer stuff */
static int fast_timer_started = 0;
static unsigned long int fast_timer_ints = 0;

static void _INLINE_ start_flush_timer(void)
{
	if (fast_timer_started)
		return;

	*R_TIMER_CTRL = r_timer_ctrl_shadow = 
		(r_timer_ctrl_shadow &
		 ~IO_MASK(R_TIMER_CTRL, timerdiv1) &
		 ~IO_MASK(R_TIMER_CTRL, tm1) &
		 ~IO_MASK(R_TIMER_CTRL, clksel1)) | 
		IO_FIELD(R_TIMER_CTRL, timerdiv1, FASTTIMER_DIV) |
		IO_STATE(R_TIMER_CTRL, tm1, stop_ld) | 
		IO_FIELD(R_TIMER_CTRL, clksel1, FASTTIMER_SELECT);

	*R_TIMER_CTRL = r_timer_ctrl_shadow = 
		(r_timer_ctrl_shadow & ~IO_MASK(R_TIMER_CTRL, tm1)) |
		IO_STATE(R_TIMER_CTRL, tm1, run);

	/* enable timer1 irq */

	*R_IRQ_MASK0_SET = IO_STATE(R_IRQ_MASK0_SET, timer1, set);

	fast_timer_started = 1;
}
#endif /* CONFIG_ETRAX_SERIAL_FLUSH_DMA_FAST */

/* Calculate the chartime depending on baudrate, numbor of bits etc. */
static void update_char_time(struct e100_serial * info)
{
	tcflag_t cflags = info->tty->termios->c_cflag;
	int bits;

	/* calc. number of bits / data byte */
	/* databits + startbit and 1 stopbit */
	if ((cflags & CSIZE) == CS7)
		bits = 9;
	else
		bits = 10;  

	if (cflags & CSTOPB)     /* 2 stopbits ? */
		bits++;

	if (cflags & PARENB)     /* parity bit ? */
		bits++;

	/* calc timeout */
	info->char_time_usec = ((bits * 1000000) / info->baud) + 1;
	info->flush_time_usec = 4*info->char_time_usec;
	if (info->flush_time_usec < MIN_FLUSH_TIME_USEC)
		info->flush_time_usec = MIN_FLUSH_TIME_USEC;
}

/*
 * This function maps from the Bxxxx defines in asm/termbits.h into real
 * baud rates.
 */

static int 
cflag_to_baud(unsigned int cflag)
{
	static int baud_table[] = {
		0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400,
		4800, 9600, 19200, 38400 };

	static int ext_baud_table[] = {
		0, 57600, 115200, 230400, 460800, 921600, 1843200, 6250000,
                0, 0, 0, 0, 0, 0, 0, 0 };

	if (cflag & CBAUDEX)
		return ext_baud_table[(cflag & CBAUD) & ~CBAUDEX];
	else 
		return baud_table[cflag & CBAUD];
}

/* and this maps to an etrax100 hardware baud constant */

static unsigned char 
cflag_to_etrax_baud(unsigned int cflag)
{
	char retval;

	static char baud_table[] = {
		-1, -1, -1, -1, -1, -1, -1, 0, 1, 2, -1, 3, 4, 5, 6, 7 };

	static char ext_baud_table[] = {
		-1, 8, 9, 10, 11, 12, 13, 14, -1, -1, -1, -1, -1, -1, -1, -1 };

	if (cflag & CBAUDEX)
		retval = ext_baud_table[(cflag & CBAUD) & ~CBAUDEX];
	else 
		retval = baud_table[cflag & CBAUD];

	if (retval < 0) {
		printk(KERN_WARNING "serdriver tried setting invalid baud rate, flags %x.\n", cflag);
		retval = 5; /* choose default 9600 instead */
	}

	return retval | (retval << 4); /* choose same for both TX and RX */
}


/* Various static support functions */

/* Functions to set or clear DTR/RTS on the requested line */
/* It is complicated by the fact that RTS is a serial port register, while
 * DTR might not be implemented in the HW at all, and if it is, it can be on
 * any general port.
 */


static inline void 
e100_dtr(struct e100_serial *info, int set)
{
#ifndef CONFIG_SVINTO_SIM
	unsigned char mask = e100_modem_pins[info->line].dtr_mask;

#ifdef SERIAL_DEBUG_IO  
	printk("ser%i dtr %i mask: 0x%02X\n", info->line, set, mask);
	printk("ser%i shadow before 0x%02X get: %i\n", 
	       info->line, *e100_modem_pins[info->line].dtr_shadow,
	       E100_DTR_GET(info));
#endif
	/* DTR is active low */
	{
		unsigned long flags;

		save_flags(flags);
		cli();
		*e100_modem_pins[info->line].dtr_shadow &= ~mask;
		*e100_modem_pins[info->line].dtr_shadow |= (set ? 0 : mask); 
		*e100_modem_pins[info->line].dtr_port = *e100_modem_pins[info->line].dtr_shadow;
		restore_flags(flags);
	}
	
#ifdef SERIAL_DEBUG_IO
	printk("ser%i shadow after 0x%02X get: %i\n", 
	       info->line, *e100_modem_pins[info->line].dtr_shadow, 
	       E100_DTR_GET(info));
#endif
#endif
}

/* set = 0 means 3.3V on the pin, bitvalue: 0=active, 1=inactive  
 *                                          0=0V    , 1=3.3V
 */
static inline void 
e100_rts(struct e100_serial *info, int set)
{
#ifndef CONFIG_SVINTO_SIM
	unsigned long flags;
	save_flags(flags);
	cli();
	info->rx_ctrl &= ~E100_RTS_MASK;
	info->rx_ctrl |= (set ? 0 : E100_RTS_MASK);  /* RTS is active low */
	info->port[REG_REC_CTRL] = info->rx_ctrl;
	restore_flags(flags);
#ifdef SERIAL_DEBUG_IO  
	printk("ser%i rts %i\n", info->line, set);
#endif
#endif
}


/* If this behaves as a modem, RI and CD is an output */
static inline void 
e100_ri_out(struct e100_serial *info, int set)
{
#ifndef CONFIG_SVINTO_SIM
	/* RI is active low */
	{
		unsigned char mask = e100_modem_pins[info->line].ri_mask;
		unsigned long flags;

		save_flags(flags);
		cli();
		*e100_modem_pins[info->line].ri_shadow &= ~mask;
		*e100_modem_pins[info->line].ri_shadow |= (set ? 0 : mask); 
		*e100_modem_pins[info->line].ri_port = *e100_modem_pins[info->line].ri_shadow;
		restore_flags(flags);
	}
#endif
}
static inline void 
e100_cd_out(struct e100_serial *info, int set)
{
#ifndef CONFIG_SVINTO_SIM
	/* CD is active low */
	{
		unsigned char mask = e100_modem_pins[info->line].cd_mask;
		unsigned long flags;

		save_flags(flags);
		cli();
		*e100_modem_pins[info->line].cd_shadow &= ~mask;
		*e100_modem_pins[info->line].cd_shadow |= (set ? 0 : mask); 
		*e100_modem_pins[info->line].cd_port = *e100_modem_pins[info->line].cd_shadow;
		restore_flags(flags);
	}
#endif
}

static inline void
e100_disable_rx(struct e100_serial *info)
{
#ifndef CONFIG_SVINTO_SIM
	/* disable the receiver */
	info->port[REG_REC_CTRL] =
		(info->rx_ctrl &= ~IO_MASK(R_SERIAL0_REC_CTRL, rec_enable));
#endif
}

static inline void 
e100_enable_rx(struct e100_serial *info)
{
#ifndef CONFIG_SVINTO_SIM
	/* enable the receiver */
	info->port[REG_REC_CTRL] =
		(info->rx_ctrl |= IO_MASK(R_SERIAL0_REC_CTRL, rec_enable));
#endif
}

/* the rx DMA uses both the dma_descr and the dma_eop interrupts */

static inline void
e100_disable_rxdma_irq(struct e100_serial *info) 
{
#ifdef SERIAL_DEBUG_INTR
	printk("rxdma_irq(%d): 0\n",info->line);
#endif
	DINTR1(DEBUG_LOG(info->line,"IRQ disable_rxdma_irq %i\n", info->line));
	*R_IRQ_MASK2_CLR = (info->irq << 2) | (info->irq << 3);
}

static inline void
e100_enable_rxdma_irq(struct e100_serial *info) 
{
#ifdef SERIAL_DEBUG_INTR
	printk("rxdma_irq(%d): 1\n",info->line);
#endif
	DINTR1(DEBUG_LOG(info->line,"IRQ enable_rxdma_irq %i\n", info->line));
	*R_IRQ_MASK2_SET = (info->irq << 2) | (info->irq << 3);
}

/* the tx DMA uses only dma_descr interrupt */

static inline void
e100_disable_txdma_irq(struct e100_serial *info) 
{
#ifdef SERIAL_DEBUG_INTR
	printk("txdma_irq(%d): 0\n",info->line);
#endif
	DINTR1(DEBUG_LOG(info->line,"IRQ disable_txdma_irq %i\n", info->line));
	*R_IRQ_MASK2_CLR = info->irq;
}

static inline void
e100_enable_txdma_irq(struct e100_serial *info) 
{
#ifdef SERIAL_DEBUG_INTR
	printk("txdma_irq(%d): 1\n",info->line);
#endif
	DINTR1(DEBUG_LOG(info->line,"IRQ enable_txdma_irq %i\n", info->line));
	*R_IRQ_MASK2_SET = info->irq;
}

static _INLINE_ void