 c9a33054bf
			
		
	
	
		c9a33054bf
		
	
	
	
	
		
			
			git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5264 c046a42c-6fe2-441c-8c8c-71466251a162
		
			
				
	
	
		
			847 lines
		
	
	
		
			25 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			847 lines
		
	
	
		
			25 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * QEMU 16550A UART emulation
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|  *
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|  * Copyright (c) 2003-2004 Fabrice Bellard
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|  * Copyright (c) 2008 Citrix Systems, Inc.
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|  *
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|  * Permission is hereby granted, free of charge, to any person obtaining a copy
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|  * of this software and associated documentation files (the "Software"), to deal
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|  * in the Software without restriction, including without limitation the rights
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|  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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|  * copies of the Software, and to permit persons to whom the Software is
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|  * furnished to do so, subject to the following conditions:
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|  *
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|  * The above copyright notice and this permission notice shall be included in
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|  * all copies or substantial portions of the Software.
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|  *
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|  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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|  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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|  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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|  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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|  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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|  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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|  * THE SOFTWARE.
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|  */
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| #include "hw.h"
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| #include "qemu-char.h"
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| #include "isa.h"
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| #include "pc.h"
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| #include "qemu-timer.h"
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| 
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| //#define DEBUG_SERIAL
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| 
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| #define UART_LCR_DLAB	0x80	/* Divisor latch access bit */
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| 
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| #define UART_IER_MSI	0x08	/* Enable Modem status interrupt */
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| #define UART_IER_RLSI	0x04	/* Enable receiver line status interrupt */
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| #define UART_IER_THRI	0x02	/* Enable Transmitter holding register int. */
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| #define UART_IER_RDI	0x01	/* Enable receiver data interrupt */
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| 
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| #define UART_IIR_NO_INT	0x01	/* No interrupts pending */
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| #define UART_IIR_ID	0x06	/* Mask for the interrupt ID */
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| 
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| #define UART_IIR_MSI	0x00	/* Modem status interrupt */
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| #define UART_IIR_THRI	0x02	/* Transmitter holding register empty */
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| #define UART_IIR_RDI	0x04	/* Receiver data interrupt */
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| #define UART_IIR_RLSI	0x06	/* Receiver line status interrupt */
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| #define UART_IIR_CTI    0x0C    /* Character Timeout Indication */
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| 
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| #define UART_IIR_FENF   0x80    /* Fifo enabled, but not functionning */
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| #define UART_IIR_FE     0xC0    /* Fifo enabled */
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| 
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| /*
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|  * These are the definitions for the Modem Control Register
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|  */
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| #define UART_MCR_LOOP	0x10	/* Enable loopback test mode */
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| #define UART_MCR_OUT2	0x08	/* Out2 complement */
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| #define UART_MCR_OUT1	0x04	/* Out1 complement */
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| #define UART_MCR_RTS	0x02	/* RTS complement */
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| #define UART_MCR_DTR	0x01	/* DTR complement */
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| 
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| /*
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|  * These are the definitions for the Modem Status Register
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|  */
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| #define UART_MSR_DCD	0x80	/* Data Carrier Detect */
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| #define UART_MSR_RI	0x40	/* Ring Indicator */
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| #define UART_MSR_DSR	0x20	/* Data Set Ready */
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| #define UART_MSR_CTS	0x10	/* Clear to Send */
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| #define UART_MSR_DDCD	0x08	/* Delta DCD */
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| #define UART_MSR_TERI	0x04	/* Trailing edge ring indicator */
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| #define UART_MSR_DDSR	0x02	/* Delta DSR */
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| #define UART_MSR_DCTS	0x01	/* Delta CTS */
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| #define UART_MSR_ANY_DELTA 0x0F	/* Any of the delta bits! */
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| 
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| #define UART_LSR_TEMT	0x40	/* Transmitter empty */
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| #define UART_LSR_THRE	0x20	/* Transmit-hold-register empty */
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| #define UART_LSR_BI	0x10	/* Break interrupt indicator */
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| #define UART_LSR_FE	0x08	/* Frame error indicator */
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| #define UART_LSR_PE	0x04	/* Parity error indicator */
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| #define UART_LSR_OE	0x02	/* Overrun error indicator */
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| #define UART_LSR_DR	0x01	/* Receiver data ready */
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| #define UART_LSR_INT_ANY 0x1E	/* Any of the lsr-interrupt-triggering status bits */
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| 
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| /* Interrupt trigger levels. The byte-counts are for 16550A - in newer UARTs the byte-count for each ITL is higher. */
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| 
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| #define UART_FCR_ITL_1      0x00 /* 1 byte ITL */
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| #define UART_FCR_ITL_2      0x40 /* 4 bytes ITL */
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| #define UART_FCR_ITL_3      0x80 /* 8 bytes ITL */
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| #define UART_FCR_ITL_4      0xC0 /* 14 bytes ITL */
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| 
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| #define UART_FCR_DMS        0x08    /* DMA Mode Select */
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| #define UART_FCR_XFR        0x04    /* XMIT Fifo Reset */
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| #define UART_FCR_RFR        0x02    /* RCVR Fifo Reset */
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| #define UART_FCR_FE         0x01    /* FIFO Enable */
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| 
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| #define UART_FIFO_LENGTH    16      /* 16550A Fifo Length */
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| 
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| #define XMIT_FIFO           0
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| #define RECV_FIFO           1
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| #define MAX_XMIT_RETRY      4
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| 
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| struct SerialFIFO {
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|     uint8_t data[UART_FIFO_LENGTH];
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|     uint8_t count;
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|     uint8_t itl;                        /* Interrupt Trigger Level */
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|     uint8_t tail;
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|     uint8_t head;
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| } typedef SerialFIFO;
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| 
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| struct SerialState {
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|     uint16_t divider;
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|     uint8_t rbr; /* receive register */
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|     uint8_t thr; /* transmit holding register */
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|     uint8_t tsr; /* transmit shift register */
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|     uint8_t ier;
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|     uint8_t iir; /* read only */
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|     uint8_t lcr;
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|     uint8_t mcr;
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|     uint8_t lsr; /* read only */
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|     uint8_t msr; /* read only */
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|     uint8_t scr;
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|     uint8_t fcr;
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|     /* NOTE: this hidden state is necessary for tx irq generation as
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|        it can be reset while reading iir */
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|     int thr_ipending;
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|     qemu_irq irq;
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|     CharDriverState *chr;
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|     int last_break_enable;
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|     target_phys_addr_t base;
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|     int it_shift;
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|     int baudbase;
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|     int tsr_retry;
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| 
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|     uint64_t last_xmit_ts;              /* Time when the last byte was successfully sent out of the tsr */
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|     SerialFIFO recv_fifo;
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|     SerialFIFO xmit_fifo;
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| 
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|     struct QEMUTimer *fifo_timeout_timer;
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|     int timeout_ipending;                   /* timeout interrupt pending state */
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|     struct QEMUTimer *transmit_timer;
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| 
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| 
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|     uint64_t char_transmit_time;               /* time to transmit a char in ticks*/
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|     int poll_msl;
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| 
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|     struct QEMUTimer *modem_status_poll;
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| };
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| 
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| static void serial_receive1(void *opaque, const uint8_t *buf, int size);
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| 
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| static void fifo_clear(SerialState *s, int fifo)
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| {
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|     SerialFIFO *f = (fifo) ? &s->recv_fifo : &s->xmit_fifo;
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|     memset(f->data, 0, UART_FIFO_LENGTH);
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|     f->count = 0;
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|     f->head = 0;
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|     f->tail = 0;
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| }
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| 
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| static int fifo_put(SerialState *s, int fifo, uint8_t chr)
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| {
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|     SerialFIFO *f = (fifo) ? &s->recv_fifo : &s->xmit_fifo;
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| 
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|     f->data[f->head++] = chr;
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| 
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|     if (f->head == UART_FIFO_LENGTH)
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|         f->head = 0;
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|     f->count++;
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| 
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|     return 1;
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| }
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| 
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| static uint8_t fifo_get(SerialState *s, int fifo)
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| {
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|     SerialFIFO *f = (fifo) ? &s->recv_fifo : &s->xmit_fifo;
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|     uint8_t c;
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| 
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|     if(f->count == 0)
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|         return 0;
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| 
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|     c = f->data[f->tail++];
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|     if (f->tail == UART_FIFO_LENGTH)
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|         f->tail = 0;
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|     f->count--;
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| 
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|     return c;
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| }
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| 
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| static void serial_update_irq(SerialState *s)
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| {
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|     uint8_t tmp_iir = UART_IIR_NO_INT;
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| 
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|     if ((s->ier & UART_IER_RLSI) && (s->lsr & UART_LSR_INT_ANY)) {
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|         tmp_iir = UART_IIR_RLSI;
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|     } else if ((s->ier & UART_IER_RDI) && s->timeout_ipending) {
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|         /* Note that(s->ier & UART_IER_RDI) can mask this interrupt,
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|          * this is not in the specification but is observed on existing
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|          * hardware.  */
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|         tmp_iir = UART_IIR_CTI;
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|     } else if ((s->ier & UART_IER_RDI) && (s->lsr & UART_LSR_DR)) {
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|         if (!(s->fcr & UART_FCR_FE)) {
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|            tmp_iir = UART_IIR_RDI;
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|         } else if (s->recv_fifo.count >= s->recv_fifo.itl) {
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|            tmp_iir = UART_IIR_RDI;
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|         }
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|     } else if ((s->ier & UART_IER_THRI) && s->thr_ipending) {
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|         tmp_iir = UART_IIR_THRI;
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|     } else if ((s->ier & UART_IER_MSI) && (s->msr & UART_MSR_ANY_DELTA)) {
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|         tmp_iir = UART_IIR_MSI;
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|     }
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| 
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|     s->iir = tmp_iir | (s->iir & 0xF0);
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| 
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|     if (tmp_iir != UART_IIR_NO_INT) {
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|         qemu_irq_raise(s->irq);
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|     } else {
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|         qemu_irq_lower(s->irq);
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|     }
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| }
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| 
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| static void serial_update_parameters(SerialState *s)
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| {
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|     int speed, parity, data_bits, stop_bits, frame_size;
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|     QEMUSerialSetParams ssp;
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| 
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|     if (s->divider == 0)
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|         return;
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| 
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|     frame_size = 1;
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|     if (s->lcr & 0x08) {
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|         if (s->lcr & 0x10)
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|             parity = 'E';
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|         else
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|             parity = 'O';
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|     } else {
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|             parity = 'N';
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|             frame_size = 0;
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|     }
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|     if (s->lcr & 0x04)
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|         stop_bits = 2;
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|     else
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|         stop_bits = 1;
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| 
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|     data_bits = (s->lcr & 0x03) + 5;
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|     frame_size += data_bits + stop_bits;
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|     speed = s->baudbase / s->divider;
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|     ssp.speed = speed;
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|     ssp.parity = parity;
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|     ssp.data_bits = data_bits;
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|     ssp.stop_bits = stop_bits;
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|     s->char_transmit_time =  (ticks_per_sec / speed) * frame_size;
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|     qemu_chr_ioctl(s->chr, CHR_IOCTL_SERIAL_SET_PARAMS, &ssp);
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| #if 0
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|     printf("speed=%d parity=%c data=%d stop=%d\n",
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|            speed, parity, data_bits, stop_bits);
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| #endif
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| }
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| 
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| static void serial_update_msl(SerialState *s)
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| {
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|     uint8_t omsr;
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|     int flags;
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| 
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|     qemu_del_timer(s->modem_status_poll);
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| 
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|     if (qemu_chr_ioctl(s->chr,CHR_IOCTL_SERIAL_GET_TIOCM, &flags) == -ENOTSUP) {
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|         s->poll_msl = -1;
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|         return;
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|     }
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| 
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|     omsr = s->msr;
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| 
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|     s->msr = (flags & CHR_TIOCM_CTS) ? s->msr | UART_MSR_CTS : s->msr & ~UART_MSR_CTS;
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|     s->msr = (flags & CHR_TIOCM_DSR) ? s->msr | UART_MSR_DSR : s->msr & ~UART_MSR_DSR;
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|     s->msr = (flags & CHR_TIOCM_CAR) ? s->msr | UART_MSR_DCD : s->msr & ~UART_MSR_DCD;
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|     s->msr = (flags & CHR_TIOCM_RI) ? s->msr | UART_MSR_RI : s->msr & ~UART_MSR_RI;
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| 
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|     if (s->msr != omsr) {
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|          /* Set delta bits */
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|          s->msr = s->msr | ((s->msr >> 4) ^ (omsr >> 4));
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|          /* UART_MSR_TERI only if change was from 1 -> 0 */
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|          if ((s->msr & UART_MSR_TERI) && !(omsr & UART_MSR_RI))
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|              s->msr &= ~UART_MSR_TERI;
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|          serial_update_irq(s);
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|     }
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| 
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|     /* The real 16550A apparently has a 250ns response latency to line status changes.
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|        We'll be lazy and poll only every 10ms, and only poll it at all if MSI interrupts are turned on */
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| 
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|     if (s->poll_msl)
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|         qemu_mod_timer(s->modem_status_poll, qemu_get_clock(vm_clock) + ticks_per_sec / 100);
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| }
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| 
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| static void serial_xmit(void *opaque)
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| {
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|     SerialState *s = opaque;
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|     uint64_t new_xmit_ts = qemu_get_clock(vm_clock);
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| 
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|     if (s->tsr_retry <= 0) {
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|         if (s->fcr & UART_FCR_FE) {
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|             s->tsr = fifo_get(s,XMIT_FIFO);
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|             if (!s->xmit_fifo.count)
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|                 s->lsr |= UART_LSR_THRE;
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|         } else {
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|             s->tsr = s->thr;
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|             s->lsr |= UART_LSR_THRE;
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|         }
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|     }
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| 
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|     if (s->mcr & UART_MCR_LOOP) {
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|         /* in loopback mode, say that we just received a char */
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|         serial_receive1(s, &s->tsr, 1);
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|     } else if (qemu_chr_write(s->chr, &s->tsr, 1) != 1) {
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|         if ((s->tsr_retry > 0) && (s->tsr_retry <= MAX_XMIT_RETRY)) {
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|             s->tsr_retry++;
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|             qemu_mod_timer(s->transmit_timer,  new_xmit_ts + s->char_transmit_time);
 | |
|             return;
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|         } else if (s->poll_msl < 0) {
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|             /* If we exceed MAX_XMIT_RETRY and the backend is not a real serial port, then
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|             drop any further failed writes instantly, until we get one that goes through.
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|             This is to prevent guests that log to unconnected pipes or pty's from stalling. */
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|             s->tsr_retry = -1;
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|         }
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|     }
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|     else {
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|         s->tsr_retry = 0;
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|     }
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| 
 | |
|     s->last_xmit_ts = qemu_get_clock(vm_clock);
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|     if (!(s->lsr & UART_LSR_THRE))
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|         qemu_mod_timer(s->transmit_timer, s->last_xmit_ts + s->char_transmit_time);
 | |
| 
 | |
|     if (s->lsr & UART_LSR_THRE) {
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|         s->lsr |= UART_LSR_TEMT;
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|         s->thr_ipending = 1;
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|         serial_update_irq(s);
 | |
|     }
 | |
| }
 | |
| 
 | |
| 
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| static void serial_ioport_write(void *opaque, uint32_t addr, uint32_t val)
 | |
| {
 | |
|     SerialState *s = opaque;
 | |
| 
 | |
|     addr &= 7;
 | |
| #ifdef DEBUG_SERIAL
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|     printf("serial: write addr=0x%02x val=0x%02x\n", addr, val);
 | |
| #endif
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|     switch(addr) {
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|     default:
 | |
|     case 0:
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|         if (s->lcr & UART_LCR_DLAB) {
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|             s->divider = (s->divider & 0xff00) | val;
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|             serial_update_parameters(s);
 | |
|         } else {
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|             s->thr = (uint8_t) val;
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|             if(s->fcr & UART_FCR_FE) {
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|                   fifo_put(s, XMIT_FIFO, s->thr);
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|             s->thr_ipending = 0;
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|                   s->lsr &= ~UART_LSR_TEMT;
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|             s->lsr &= ~UART_LSR_THRE;
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|             serial_update_irq(s);
 | |
|             } else {
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|                   s->thr_ipending = 0;
 | |
|                   s->lsr &= ~UART_LSR_THRE;
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|                   serial_update_irq(s);
 | |
|             }
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|             serial_xmit(s);
 | |
|         }
 | |
|         break;
 | |
|     case 1:
 | |
|         if (s->lcr & UART_LCR_DLAB) {
 | |
|             s->divider = (s->divider & 0x00ff) | (val << 8);
 | |
|             serial_update_parameters(s);
 | |
|         } else {
 | |
|             s->ier = val & 0x0f;
 | |
|             /* If the backend device is a real serial port, turn polling of the modem
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|                status lines on physical port on or off depending on UART_IER_MSI state */
 | |
|             if (s->poll_msl >= 0) {
 | |
|                 if (s->ier & UART_IER_MSI) {
 | |
|                      s->poll_msl = 1;
 | |
|                      serial_update_msl(s);
 | |
|                 } else {
 | |
|                      qemu_del_timer(s->modem_status_poll);
 | |
|                      s->poll_msl = 0;
 | |
|                 }
 | |
|             }
 | |
|             if (s->lsr & UART_LSR_THRE) {
 | |
|                 s->thr_ipending = 1;
 | |
|                 serial_update_irq(s);
 | |
|             }
 | |
|         }
 | |
|         break;
 | |
|     case 2:
 | |
|         val = val & 0xFF;
 | |
| 
 | |
|         if (s->fcr == val)
 | |
|             break;
 | |
| 
 | |
|         /* Did the enable/disable flag change? If so, make sure FIFOs get flushed */
 | |
|         if ((val ^ s->fcr) & UART_FCR_FE)
 | |
|             val |= UART_FCR_XFR | UART_FCR_RFR;
 | |
| 
 | |
|         /* FIFO clear */
 | |
| 
 | |
|         if (val & UART_FCR_RFR) {
 | |
|             qemu_del_timer(s->fifo_timeout_timer);
 | |
|             s->timeout_ipending=0;
 | |
|             fifo_clear(s,RECV_FIFO);
 | |
|         }
 | |
| 
 | |
|         if (val & UART_FCR_XFR) {
 | |
|             fifo_clear(s,XMIT_FIFO);
 | |
|         }
 | |
| 
 | |
|         if (val & UART_FCR_FE) {
 | |
|             s->iir |= UART_IIR_FE;
 | |
|             /* Set RECV_FIFO trigger Level */
 | |
|             switch (val & 0xC0) {
 | |
|             case UART_FCR_ITL_1:
 | |
|                 s->recv_fifo.itl = 1;
 | |
|                 break;
 | |
|             case UART_FCR_ITL_2:
 | |
|                 s->recv_fifo.itl = 4;
 | |
|                 break;
 | |
|             case UART_FCR_ITL_3:
 | |
|                 s->recv_fifo.itl = 8;
 | |
|                 break;
 | |
|             case UART_FCR_ITL_4:
 | |
|                 s->recv_fifo.itl = 14;
 | |
|                 break;
 | |
|             }
 | |
|         } else
 | |
|             s->iir &= ~UART_IIR_FE;
 | |
| 
 | |
|         /* Set fcr - or at least the bits in it that are supposed to "stick" */
 | |
|         s->fcr = val & 0xC9;
 | |
|         serial_update_irq(s);
 | |
|         break;
 | |
|     case 3:
 | |
|         {
 | |
|             int break_enable;
 | |
|             s->lcr = val;
 | |
|             serial_update_parameters(s);
 | |
|             break_enable = (val >> 6) & 1;
 | |
|             if (break_enable != s->last_break_enable) {
 | |
|                 s->last_break_enable = break_enable;
 | |
|                 qemu_chr_ioctl(s->chr, CHR_IOCTL_SERIAL_SET_BREAK,
 | |
|                                &break_enable);
 | |
|             }
 | |
|         }
 | |
|         break;
 | |
|     case 4:
 | |
|         {
 | |
|             int flags;
 | |
|             int old_mcr = s->mcr;
 | |
|             s->mcr = val & 0x1f;
 | |
|             if (val & UART_MCR_LOOP)
 | |
|                 break;
 | |
| 
 | |
|             if (s->poll_msl >= 0 && old_mcr != s->mcr) {
 | |
| 
 | |
|                 qemu_chr_ioctl(s->chr,CHR_IOCTL_SERIAL_GET_TIOCM, &flags);
 | |
| 
 | |
|                 flags &= ~(CHR_TIOCM_RTS | CHR_TIOCM_DTR);
 | |
| 
 | |
|                 if (val & UART_MCR_RTS)
 | |
|                     flags |= CHR_TIOCM_RTS;
 | |
|                 if (val & UART_MCR_DTR)
 | |
|                     flags |= CHR_TIOCM_DTR;
 | |
| 
 | |
|                 qemu_chr_ioctl(s->chr,CHR_IOCTL_SERIAL_SET_TIOCM, &flags);
 | |
|                 /* Update the modem status after a one-character-send wait-time, since there may be a response
 | |
|                    from the device/computer at the other end of the serial line */
 | |
|                 qemu_mod_timer(s->modem_status_poll, qemu_get_clock(vm_clock) + s->char_transmit_time);
 | |
|             }
 | |
|         }
 | |
|         break;
 | |
|     case 5:
 | |
|         break;
 | |
|     case 6:
 | |
|         break;
 | |
|     case 7:
 | |
|         s->scr = val;
 | |
|         break;
 | |
|     }
 | |
| }
 | |
| 
 | |
| static uint32_t serial_ioport_read(void *opaque, uint32_t addr)
 | |
| {
 | |
|     SerialState *s = opaque;
 | |
|     uint32_t ret;
 | |
| 
 | |
|     addr &= 7;
 | |
|     switch(addr) {
 | |
|     default:
 | |
|     case 0:
 | |
|         if (s->lcr & UART_LCR_DLAB) {
 | |
|             ret = s->divider & 0xff;
 | |
|         } else {
 | |
|             if(s->fcr & UART_FCR_FE) {
 | |
|                 ret = fifo_get(s,RECV_FIFO);
 | |
|                 if (s->recv_fifo.count == 0)
 | |
|                     s->lsr &= ~(UART_LSR_DR | UART_LSR_BI);
 | |
|                 else
 | |
|                     qemu_mod_timer(s->fifo_timeout_timer, qemu_get_clock (vm_clock) + s->char_transmit_time * 4);
 | |
|                 s->timeout_ipending = 0;
 | |
|             } else {
 | |
|                 ret = s->rbr;
 | |
|                 s->lsr &= ~(UART_LSR_DR | UART_LSR_BI);
 | |
|             }
 | |
|             serial_update_irq(s);
 | |
|             if (!(s->mcr & UART_MCR_LOOP)) {
 | |
|                 /* in loopback mode, don't receive any data */
 | |
|                 qemu_chr_accept_input(s->chr);
 | |
|             }
 | |
|         }
 | |
|         break;
 | |
|     case 1:
 | |
|         if (s->lcr & UART_LCR_DLAB) {
 | |
|             ret = (s->divider >> 8) & 0xff;
 | |
|         } else {
 | |
|             ret = s->ier;
 | |
|         }
 | |
|         break;
 | |
|     case 2:
 | |
|         ret = s->iir;
 | |
|             s->thr_ipending = 0;
 | |
|         serial_update_irq(s);
 | |
|         break;
 | |
|     case 3:
 | |
|         ret = s->lcr;
 | |
|         break;
 | |
|     case 4:
 | |
|         ret = s->mcr;
 | |
|         break;
 | |
|     case 5:
 | |
|         ret = s->lsr;
 | |
|         /* Clear break interrupt */
 | |
|         if (s->lsr & UART_LSR_BI) {
 | |
|             s->lsr &= ~UART_LSR_BI;
 | |
|             serial_update_irq(s);
 | |
|         }
 | |
|         break;
 | |
|     case 6:
 | |
|         if (s->mcr & UART_MCR_LOOP) {
 | |
|             /* in loopback, the modem output pins are connected to the
 | |
|                inputs */
 | |
|             ret = (s->mcr & 0x0c) << 4;
 | |
|             ret |= (s->mcr & 0x02) << 3;
 | |
|             ret |= (s->mcr & 0x01) << 5;
 | |
|         } else {
 | |
|             if (s->poll_msl >= 0)
 | |
|                 serial_update_msl(s);
 | |
|             ret = s->msr;
 | |
|             /* Clear delta bits & msr int after read, if they were set */
 | |
|             if (s->msr & UART_MSR_ANY_DELTA) {
 | |
|                 s->msr &= 0xF0;
 | |
|                 serial_update_irq(s);
 | |
|             }
 | |
|         }
 | |
|         break;
 | |
|     case 7:
 | |
|         ret = s->scr;
 | |
|         break;
 | |
|     }
 | |
| #ifdef DEBUG_SERIAL
 | |
|     printf("serial: read addr=0x%02x val=0x%02x\n", addr, ret);
 | |
| #endif
 | |
|     return ret;
 | |
| }
 | |
| 
 | |
| static int serial_can_receive(SerialState *s)
 | |
| {
 | |
|     if(s->fcr & UART_FCR_FE) {
 | |
|         if(s->recv_fifo.count < UART_FIFO_LENGTH)
 | |
|         /* Advertise (fifo.itl - fifo.count) bytes when count < ITL, and 1 if above. If UART_FIFO_LENGTH - fifo.count is
 | |
|         advertised the effect will be to almost always fill the fifo completely before the guest has a chance to respond,
 | |
|         effectively overriding the ITL that the guest has set. */
 | |
|              return (s->recv_fifo.count <= s->recv_fifo.itl) ? s->recv_fifo.itl - s->recv_fifo.count : 1;
 | |
|         else
 | |
|              return 0;
 | |
|     } else {
 | |
|     return !(s->lsr & UART_LSR_DR);
 | |
|     }
 | |
| }
 | |
| 
 | |
| static void serial_receive_break(SerialState *s)
 | |
| {
 | |
|     s->rbr = 0;
 | |
|     s->lsr |= UART_LSR_BI | UART_LSR_DR;
 | |
|     serial_update_irq(s);
 | |
| }
 | |
| 
 | |
| /* There's data in recv_fifo and s->rbr has not been read for 4 char transmit times */
 | |
| static void fifo_timeout_int (void *opaque) {
 | |
|     SerialState *s = opaque;
 | |
|     if (s->recv_fifo.count) {
 | |
|         s->timeout_ipending = 1;
 | |
|         serial_update_irq(s);
 | |
|     }
 | |
| }
 | |
| 
 | |
| static int serial_can_receive1(void *opaque)
 | |
| {
 | |
|     SerialState *s = opaque;
 | |
|     return serial_can_receive(s);
 | |
| }
 | |
| 
 | |
| static void serial_receive1(void *opaque, const uint8_t *buf, int size)
 | |
| {
 | |
|     SerialState *s = opaque;
 | |
|     if(s->fcr & UART_FCR_FE) {
 | |
|         int i;
 | |
|         for (i = 0; i < size; i++) {
 | |
|             fifo_put(s, RECV_FIFO, buf[i]);
 | |
|         }
 | |
|         s->lsr |= UART_LSR_DR;
 | |
|         /* call the timeout receive callback in 4 char transmit time */
 | |
|         qemu_mod_timer(s->fifo_timeout_timer, qemu_get_clock (vm_clock) + s->char_transmit_time * 4);
 | |
|     } else {
 | |
|         s->rbr = buf[0];
 | |
|         s->lsr |= UART_LSR_DR;
 | |
|     }
 | |
|     serial_update_irq(s);
 | |
| }
 | |
| 
 | |
| static void serial_event(void *opaque, int event)
 | |
| {
 | |
|     SerialState *s = opaque;
 | |
| #ifdef DEBUG_SERIAL
 | |
|     printf("serial: event %x\n", event);
 | |
| #endif
 | |
|     if (event == CHR_EVENT_BREAK)
 | |
|         serial_receive_break(s);
 | |
| }
 | |
| 
 | |
| static void serial_save(QEMUFile *f, void *opaque)
 | |
| {
 | |
|     SerialState *s = opaque;
 | |
| 
 | |
|     qemu_put_be16s(f,&s->divider);
 | |
|     qemu_put_8s(f,&s->rbr);
 | |
|     qemu_put_8s(f,&s->ier);
 | |
|     qemu_put_8s(f,&s->iir);
 | |
|     qemu_put_8s(f,&s->lcr);
 | |
|     qemu_put_8s(f,&s->mcr);
 | |
|     qemu_put_8s(f,&s->lsr);
 | |
|     qemu_put_8s(f,&s->msr);
 | |
|     qemu_put_8s(f,&s->scr);
 | |
|     qemu_put_8s(f,&s->fcr);
 | |
| }
 | |
| 
 | |
| static int serial_load(QEMUFile *f, void *opaque, int version_id)
 | |
| {
 | |
|     SerialState *s = opaque;
 | |
|     uint8_t fcr = 0;
 | |
| 
 | |
|     if(version_id > 3)
 | |
|         return -EINVAL;
 | |
| 
 | |
|     if (version_id >= 2)
 | |
|         qemu_get_be16s(f, &s->divider);
 | |
|     else
 | |
|         s->divider = qemu_get_byte(f);
 | |
|     qemu_get_8s(f,&s->rbr);
 | |
|     qemu_get_8s(f,&s->ier);
 | |
|     qemu_get_8s(f,&s->iir);
 | |
|     qemu_get_8s(f,&s->lcr);
 | |
|     qemu_get_8s(f,&s->mcr);
 | |
|     qemu_get_8s(f,&s->lsr);
 | |
|     qemu_get_8s(f,&s->msr);
 | |
|     qemu_get_8s(f,&s->scr);
 | |
| 
 | |
|     if (version_id >= 3)
 | |
|         qemu_get_8s(f,&fcr);
 | |
| 
 | |
|     /* Initialize fcr via setter to perform essential side-effects */
 | |
|     serial_ioport_write(s, 0x02, fcr);
 | |
|     return 0;
 | |
| }
 | |
| 
 | |
| static void serial_reset(void *opaque)
 | |
| {
 | |
|     SerialState *s = opaque;
 | |
| 
 | |
|     s->rbr = 0;
 | |
|     s->ier = 0;
 | |
|     s->iir = UART_IIR_NO_INT;
 | |
|     s->lcr = 0;
 | |
|     s->lsr = UART_LSR_TEMT | UART_LSR_THRE;
 | |
|     s->msr = UART_MSR_DCD | UART_MSR_DSR | UART_MSR_CTS;
 | |
|     /* Default to 9600 baud, no parity, one stop bit */
 | |
|     s->divider = 0x0C;
 | |
|     s->mcr = UART_MCR_OUT2;
 | |
|     s->scr = 0;
 | |
|     s->tsr_retry = 0;
 | |
|     s->char_transmit_time = (ticks_per_sec / 9600) * 9;
 | |
|     s->poll_msl = 0;
 | |
| 
 | |
|     fifo_clear(s,RECV_FIFO);
 | |
|     fifo_clear(s,XMIT_FIFO);
 | |
| 
 | |
|     s->last_xmit_ts = qemu_get_clock(vm_clock);
 | |
| 
 | |
|     s->thr_ipending = 0;
 | |
|     s->last_break_enable = 0;
 | |
|     qemu_irq_lower(s->irq);
 | |
| }
 | |
| 
 | |
| static void serial_init_core(SerialState *s, qemu_irq irq, int baudbase,
 | |
| 			     CharDriverState *chr)
 | |
| {
 | |
|     s->irq = irq;
 | |
|     s->baudbase = baudbase;
 | |
|     s->chr = chr;
 | |
| 
 | |
|     s->modem_status_poll = qemu_new_timer(vm_clock, (QEMUTimerCB *) serial_update_msl, s);
 | |
| 
 | |
|     s->fifo_timeout_timer = qemu_new_timer(vm_clock, (QEMUTimerCB *) fifo_timeout_int, s);
 | |
|     s->transmit_timer = qemu_new_timer(vm_clock, (QEMUTimerCB *) serial_xmit, s);
 | |
| 
 | |
|     qemu_register_reset(serial_reset, s);
 | |
|     serial_reset(s);
 | |
| 
 | |
| }
 | |
| 
 | |
| /* If fd is zero, it means that the serial device uses the console */
 | |
| SerialState *serial_init(int base, qemu_irq irq, int baudbase,
 | |
|                          CharDriverState *chr)
 | |
| {
 | |
|     SerialState *s;
 | |
| 
 | |
|     s = qemu_mallocz(sizeof(SerialState));
 | |
|     if (!s)
 | |
|         return NULL;
 | |
| 
 | |
|     serial_init_core(s, irq, baudbase, chr);
 | |
| 
 | |
|     register_savevm("serial", base, 3, serial_save, serial_load, s);
 | |
| 
 | |
|     register_ioport_write(base, 8, 1, serial_ioport_write, s);
 | |
|     register_ioport_read(base, 8, 1, serial_ioport_read, s);
 | |
|     qemu_chr_add_handlers(chr, serial_can_receive1, serial_receive1,
 | |
|                           serial_event, s);
 | |
|     return s;
 | |
| }
 | |
| 
 | |
| /* Memory mapped interface */
 | |
| uint32_t serial_mm_readb (void *opaque, target_phys_addr_t addr)
 | |
| {
 | |
|     SerialState *s = opaque;
 | |
| 
 | |
|     return serial_ioport_read(s, (addr - s->base) >> s->it_shift) & 0xFF;
 | |
| }
 | |
| 
 | |
| void serial_mm_writeb (void *opaque,
 | |
|                        target_phys_addr_t addr, uint32_t value)
 | |
| {
 | |
|     SerialState *s = opaque;
 | |
| 
 | |
|     serial_ioport_write(s, (addr - s->base) >> s->it_shift, value & 0xFF);
 | |
| }
 | |
| 
 | |
| uint32_t serial_mm_readw (void *opaque, target_phys_addr_t addr)
 | |
| {
 | |
|     SerialState *s = opaque;
 | |
|     uint32_t val;
 | |
| 
 | |
|     val = serial_ioport_read(s, (addr - s->base) >> s->it_shift) & 0xFFFF;
 | |
| #ifdef TARGET_WORDS_BIGENDIAN
 | |
|     val = bswap16(val);
 | |
| #endif
 | |
|     return val;
 | |
| }
 | |
| 
 | |
| void serial_mm_writew (void *opaque,
 | |
|                        target_phys_addr_t addr, uint32_t value)
 | |
| {
 | |
|     SerialState *s = opaque;
 | |
| #ifdef TARGET_WORDS_BIGENDIAN
 | |
|     value = bswap16(value);
 | |
| #endif
 | |
|     serial_ioport_write(s, (addr - s->base) >> s->it_shift, value & 0xFFFF);
 | |
| }
 | |
| 
 | |
| uint32_t serial_mm_readl (void *opaque, target_phys_addr_t addr)
 | |
| {
 | |
|     SerialState *s = opaque;
 | |
|     uint32_t val;
 | |
| 
 | |
|     val = serial_ioport_read(s, (addr - s->base) >> s->it_shift);
 | |
| #ifdef TARGET_WORDS_BIGENDIAN
 | |
|     val = bswap32(val);
 | |
| #endif
 | |
|     return val;
 | |
| }
 | |
| 
 | |
| void serial_mm_writel (void *opaque,
 | |
|                        target_phys_addr_t addr, uint32_t value)
 | |
| {
 | |
|     SerialState *s = opaque;
 | |
| #ifdef TARGET_WORDS_BIGENDIAN
 | |
|     value = bswap32(value);
 | |
| #endif
 | |
|     serial_ioport_write(s, (addr - s->base) >> s->it_shift, value);
 | |
| }
 | |
| 
 | |
| static CPUReadMemoryFunc *serial_mm_read[] = {
 | |
|     &serial_mm_readb,
 | |
|     &serial_mm_readw,
 | |
|     &serial_mm_readl,
 | |
| };
 | |
| 
 | |
| static CPUWriteMemoryFunc *serial_mm_write[] = {
 | |
|     &serial_mm_writeb,
 | |
|     &serial_mm_writew,
 | |
|     &serial_mm_writel,
 | |
| };
 | |
| 
 | |
| SerialState *serial_mm_init (target_phys_addr_t base, int it_shift,
 | |
|                              qemu_irq irq, int baudbase,
 | |
|                              CharDriverState *chr, int ioregister)
 | |
| {
 | |
|     SerialState *s;
 | |
|     int s_io_memory;
 | |
| 
 | |
|     s = qemu_mallocz(sizeof(SerialState));
 | |
|     if (!s)
 | |
|         return NULL;
 | |
| 
 | |
|     s->base = base;
 | |
|     s->it_shift = it_shift;
 | |
| 
 | |
|     serial_init_core(s, irq, baudbase, chr);
 | |
|     register_savevm("serial", base, 3, serial_save, serial_load, s);
 | |
| 
 | |
|     if (ioregister) {
 | |
|         s_io_memory = cpu_register_io_memory(0, serial_mm_read,
 | |
|                                              serial_mm_write, s);
 | |
|         cpu_register_physical_memory(base, 8 << it_shift, s_io_memory);
 | |
|     }
 | |
|     qemu_chr_add_handlers(chr, serial_can_receive1, serial_receive1,
 | |
|                           serial_event, s);
 | |
|     serial_update_msl(s);
 | |
|     return s;
 | |
| }
 |