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linux/drivers/char/scc.h

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/*
* atari_SCC.h: Definitions for the Am8530 Serial Communications Controller
*
* Copyright 1994 Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de>
*
* 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.
*
*/
#ifndef _SCC_H
#define _SCC_H
#include <linux/delay.h>
/* Special configuration ioctls for the Atari SCC5380 Serial
* Communications Controller
*/
/* ioctl command codes */
#define TIOCGATSCC 0x54c0 /* get SCC configuration */
#define TIOCSATSCC 0x54c1 /* set SCC configuration */
#define TIOCDATSCC 0x54c2 /* reset configuration to defaults */
/* Clock sources */
#define CLK_RTxC 0
#define CLK_TRxC 1
#define CLK_PCLK 2
/* baud_bases for the common clocks in the Atari. These are the real
* frequencies divided by 16.
*/
#define SCC_BAUD_BASE_TIMC 19200 /* 0.3072 MHz from TT-MFP, Timer C */
#define SCC_BAUD_BASE_BCLK 153600 /* 2.4576 MHz */
#define SCC_BAUD_BASE_PCLK4 229500 /* 3.6720 MHz */
#define SCC_BAUD_BASE_PCLK 503374 /* 8.0539763 MHz */
#define SCC_BAUD_BASE_NONE 0 /* for not connected or unused
* clock sources */
/* The SCC clock configuration structure */
struct scc_clock_config {
unsigned RTxC_base; /* base_baud of RTxC */
unsigned TRxC_base; /* base_baud of TRxC */
unsigned PCLK_base; /* base_baud of PCLK, both channels! */
struct {
unsigned clksrc; /* CLK_RTxC, CLK_TRxC or CLK_PCLK */
unsigned divisor; /* divisor for base baud, valid values:
* see below */
} baud_table[17]; /* For 50, 75, 110, 135, 150, 200, 300,
* 600, 1200, 1800, 2400, 4800, 9600,
* 19200, 38400, 57600 and 115200 bps.
* The last two could be replaced by
* other rates > 38400 if they're not
* possible.
*/
};
/* The following divisors are valid:
*
* - CLK_RTxC: 1 or even (1, 2 and 4 are the direct modes, > 4 use
* the BRG)
*
* - CLK_TRxC: 1, 2 or 4 (no BRG, only direct modes possible)
*
* - CLK_PCLK: >= 4 and even (no direct modes, only BRG)
*
*/
struct scc_port {
struct gs_port gs;
volatile unsigned char *ctrlp;
volatile unsigned char *datap;
int x_char; /* xon/xoff character */
int c_dcd;
int channel;
struct scc_port *port_a; /* Reference to port A and B */
struct scc_port *port_b; /* structs for reg access */
};
#define SCC_MAGIC 0x52696368
/***********************************************************************/
/* */
/* Register Names */
/* */
/***********************************************************************/
/* The SCC documentation gives no explicit names to the registers,
* they're just called WR0..15 and RR0..15. To make the source code
* better readable and make the transparent write reg read access (see
* below) possible, I christen them here with self-invented names.
* Note that (real) read registers are assigned numbers 16..31. WR7'
* has number 33.
*/
#define COMMAND_REG 0 /* wo */
#define INT_AND_DMA_REG 1 /* wo */
#define INT_VECTOR_REG 2 /* rw, common to both channels */
#define RX_CTRL_REG 3 /* rw */
#define AUX1_CTRL_REG 4 /* rw */
#define TX_CTRL_REG 5 /* rw */
#define SYNC_ADR_REG 6 /* wo */
#define SYNC_CHAR_REG 7 /* wo */
#define SDLC_OPTION_REG 33 /* wo */
#define TX_DATA_REG 8 /* wo */
#define MASTER_INT_CTRL 9 /* wo, common to both channels */
#define AUX2_CTRL_REG 10 /* rw */
#define CLK_CTRL_REG 11 /* wo */
#define TIMER_LOW_REG 12 /* rw */
#define TIMER_HIGH_REG 13 /* rw */
#define DPLL_CTRL_REG 14 /* wo */
#define INT_CTRL_REG 15 /* rw */
#define STATUS_REG 16 /* ro */
#define SPCOND_STATUS_REG 17 /* wo */
/* RR2 is WR2 for Channel A, Channel B gives vector + current status: */
#define CURR_VECTOR_REG 18 /* Ch. B only, Ch. A for rw */
#define INT_PENDING_REG 19 /* Channel A only! */
/* RR4 is WR4, if b6(MR7') == 1 */
/* RR5 is WR5, if b6(MR7') == 1 */
#define FS_FIFO_LOW_REG 22 /* ro */
#define FS_FIFO_HIGH_REG 23 /* ro */
#define RX_DATA_REG 24 /* ro */
/* RR9 is WR3, if b6(MR7') == 1 */
#define DPLL_STATUS_REG 26 /* ro */
/* RR11 is WR10, if b6(MR7') == 1 */
/* RR12 is WR12 */
/* RR13 is WR13 */
/* RR14 not present */
/* RR15 is WR15 */
/***********************************************************************/
/* */
/* Register Values */
/* */
/***********************************************************************/
/* WR0: COMMAND_REG "CR" */
#define CR_RX_CRC_RESET 0x40
#define CR_TX_CRC_RESET 0x80
#define CR_TX_UNDERRUN_RESET 0xc0
#define CR_EXTSTAT_RESET 0x10
#define CR_SEND_ABORT 0x18
#define CR_ENAB_INT_NEXT_RX 0x20
#define CR_TX_PENDING_RESET 0x28
#define CR_ERROR_RESET 0x30
#define CR_HIGHEST_IUS_RESET 0x38
/* WR1: INT_AND_DMA_REG "IDR" */
#define IDR_EXTSTAT_INT_ENAB 0x01
#define IDR_TX_INT_ENAB 0x02
#define IDR_PARERR_AS_SPCOND 0x04
#define IDR_RX_INT_DISAB 0x00
#define IDR_RX_INT_FIRST 0x08
#define IDR_RX_INT_ALL 0x10
#define IDR_RX_INT_SPCOND 0x18
#define IDR_RX_INT_MASK 0x18
#define IDR_WAITREQ_RX 0x20
#define IDR_WAITREQ_IS_REQ 0x40
#define IDR_WAITREQ_ENAB 0x80
/* WR3: RX_CTRL_REG "RCR" */
#define RCR_RX_ENAB 0x01
#define RCR_DISCARD_SYNC_CHARS 0x02
#define RCR_ADDR_SEARCH 0x04
#define RCR_CRC_ENAB 0x08
#define RCR_SEARCH_MODE 0x10
#define RCR_AUTO_ENAB_MODE 0x20
#define RCR_CHSIZE_MASK 0xc0
#define RCR_CHSIZE_5 0x00
#define RCR_CHSIZE_6 0x40
#define RCR_CHSIZE_7 0x80
#define RCR_CHSIZE_8 0xc0
/* WR4: AUX1_CTRL_REG "A1CR" */
#define A1CR_PARITY_MASK 0x03
#define A1CR_PARITY_NONE 0x00
#define A1CR_PARITY_ODD 0x01
#define A1CR_PARITY_EVEN 0x03
#define A1CR_MODE_MASK 0x0c
#define A1CR_MODE_SYNCR 0x00
#define A1CR_MODE_ASYNC_1 0x04
#define A1CR_MODE_ASYNC_15 0x08
#define A1CR_MODE_ASYNC_2 0x0c
#define A1CR_SYNCR_MODE_MASK 0x30
#define A1CR_SYNCR_MONOSYNC 0x00
#define A1CR_SYNCR_BISYNC 0x10
#define A1CR_SYNCR_SDLC 0x20
#define A1CR_SYNCR_EXTCSYNC 0x30
#define A1CR_CLKMODE_MASK 0xc0
#define A1CR_CLKMODE_x1 0x00
#define A1CR_CLKMODE_x16 0x40
#define A1CR_CLKMODE_x32 0x80
#define A1CR_CLKMODE_x64 0xc0
/* WR5: TX_CTRL_REG "TCR" */
#define TCR_TX_CRC_ENAB 0x01
#define TCR_RTS 0x02
#define TCR_USE_CRC_CCITT 0x00
#define TCR_USE_CRC_16 0x04
#define TCR_TX_ENAB 0x08
#define TCR_SEND_BREAK 0x10
#define TCR_CHSIZE_MASK 0x60
#define TCR_CHSIZE_5 0x00
#define TCR_CHSIZE_6 0x20
#define TCR_CHSIZE_7 0x40
#define TCR_CHSIZE_8 0x60
#define TCR_DTR 0x80
/* WR7': SLDC_OPTION_REG "SOR" */
#define SOR_AUTO_TX_ENAB 0x01
#define SOR_AUTO_EOM_RESET 0x02
#define SOR_AUTO_RTS_MODE 0x04
#define SOR_NRZI_DISAB_HIGH 0x08
#define SOR_ALT_DTRREQ_TIMING 0x10
#define SOR_READ_CRC_CHARS 0x20
#define SOR_EXTENDED_REG_ACCESS 0x40
/* WR9: MASTER_INT_CTRL "MIC" */
#define MIC_VEC_INCL_STAT 0x01
#define MIC_NO_VECTOR 0x02
#define MIC_DISAB_LOWER_CHAIN 0x04
#define MIC_MASTER_INT_ENAB 0x08
#define MIC_STATUS_HIGH 0x10
#define MIC_IGN_INTACK 0x20
#define MIC_NO_RESET 0x00
#define MIC_CH_A_RESET 0x40
#define MIC_CH_B_RESET 0x80
#define MIC_HARD_RESET 0xc0
/* WR10: AUX2_CTRL_REG "A2CR" */
#define A2CR_SYNC_6 0x01
#define A2CR_LOOP_MODE 0x02
#define A2CR_ABORT_ON_UNDERRUN 0x04
#define A2CR_MARK_IDLE 0x08
#define A2CR_GO_ACTIVE_ON_POLL 0x10
#define A2CR_CODING_MASK 0x60
#define A2CR_CODING_NRZ 0x00
#define A2CR_CODING_NRZI 0x20
#define A2CR_CODING_FM1 0x40
#define A2CR_CODING_FM0 0x60
#define A2CR_PRESET_CRC_1 0x80
/* WR11: CLK_CTRL_REG "CCR" */
#define CCR_TRxCOUT_MASK 0x03
#define CCR_TRxCOUT_XTAL 0x00
#define CCR_TRxCOUT_TXCLK 0x01
#define CCR_TRxCOUT_BRG 0x02
#define CCR_TRxCOUT_DPLL 0x03
#define CCR_TRxC_OUTPUT 0x04
#define CCR_TXCLK_MASK 0x18
#define CCR_TXCLK_RTxC 0x00
#define CCR_TXCLK_TRxC 0x08
#define CCR_TXCLK_BRG 0x10
#define CCR_TXCLK_DPLL 0x18
#define CCR_RXCLK_MASK 0x60
#define CCR_RXCLK_RTxC 0x00
#define CCR_RXCLK_TRxC 0x20
#define CCR_RXCLK_BRG 0x40
#define CCR_RXCLK_DPLL 0x60
#define CCR_RTxC_XTAL 0x80
/* WR14: DPLL_CTRL_REG "DCR" */
#define DCR_BRG_ENAB 0x01
#define DCR_BRG_USE_PCLK 0x02
#define DCR_DTRREQ_IS_REQ 0x04
#define DCR_AUTO_ECHO 0x08
#define DCR_LOCAL_LOOPBACK 0x10
#define DCR_DPLL_EDGE_SEARCH 0x20
#define DCR_DPLL_ERR_RESET 0x40
#define DCR_DPLL_DISAB 0x60
#define DCR_DPLL_CLK_BRG 0x80
#define DCR_DPLL_CLK_RTxC 0xa0
#define DCR_DPLL_FM 0xc0
#define DCR_DPLL_NRZI 0xe0
/* WR15: INT_CTRL_REG "ICR" */
#define ICR_OPTIONREG_SELECT 0x01
#define ICR_ENAB_BRG_ZERO_INT 0x02
#define ICR_USE_FS_FIFO 0x04
#define ICR_ENAB_DCD_INT 0x08
#define ICR_ENAB_SYNC_INT 0x10
#define ICR_ENAB_CTS_INT 0x20
#define ICR_ENAB_UNDERRUN_INT 0x40
#define ICR_ENAB_BREAK_INT 0x80
/* RR0: STATUS_REG "SR" */
#define SR_CHAR_AVAIL 0x01
#define SR_BRG_ZERO 0x02
#define SR_TX_BUF_EMPTY 0x04
#define SR_DCD 0x08
#define SR_SYNC_ABORT 0x10
#define SR_CTS 0x20
#define SR_TX_UNDERRUN 0x40
#define SR_BREAK 0x80
/* RR1: SPCOND_STATUS_REG "SCSR" */
#define SCSR_ALL_SENT 0x01
#define SCSR_RESIDUAL_MASK 0x0e
#define SCSR_PARITY_ERR 0x10
#define SCSR_RX_OVERRUN 0x20
#define SCSR_CRC_FRAME_ERR 0x40
#define SCSR_END_OF_FRAME 0x80
/* RR3: INT_PENDING_REG "IPR" */
#define IPR_B_EXTSTAT 0x01
#define IPR_B_TX 0x02
#define IPR_B_RX 0x04
#define IPR_A_EXTSTAT 0x08
#define IPR_A_TX 0x10
#define IPR_A_RX 0x20
/* RR7: FS_FIFO_HIGH_REG "FFHR" */
#define FFHR_CNT_MASK 0x3f
#define FFHR_IS_FROM_FIFO 0x40
#define FFHR_FIFO_OVERRUN 0x80
/* RR10: DPLL_STATUS_REG "DSR" */
#define DSR_ON_LOOP 0x02
#define DSR_ON_LOOP_SENDING 0x10
#define DSR_TWO_CLK_MISSING 0x40
#define DSR_ONE_CLK_MISSING 0x80
/***********************************************************************/
/* */
/* Register Access */
/* */
/***********************************************************************/
/* The SCC needs 3.5 PCLK cycles recovery time between to register
* accesses. PCLK runs with 8 MHz on an Atari, so this delay is 3.5 *
* 125 ns = 437.5 ns. This is too short for udelay().
* 10/16/95: A tstb mfp.par_dt_reg takes 600ns (sure?) and thus should be
* quite right
*/
#define scc_reg_delay() \
do { \
if (MACH_IS_MVME16x || MACH_IS_BVME6000 || MACH_IS_MVME147) \
__asm__ __volatile__ ( " nop; nop"); \
else if (MACH_IS_ATARI) \
__asm__ __volatile__ ( "tstb %0" : : "g" (*_scc_del) : "cc" );\
} while (0)
static unsigned char scc_shadow[2][16];
/* The following functions should relax the somehow complicated
* register access of the SCC. _SCCwrite() stores all written values
* (except for WR0 and WR8) in shadow registers for later recall. This
* removes the burden of remembering written values as needed. The
* extra work of storing the value doesn't count, since a delay is
* needed after a SCC access anyway. Additionally, _SCCwrite() manages
* writes to WR0 and WR8 differently, because these can be accessed
* directly with less overhead. Another special case are WR7 and WR7'.
* _SCCwrite automatically checks what of this registers is selected
* and changes b0 of WR15 if needed.
*
* _SCCread() for standard read registers is straightforward, except
* for RR2 (split into two "virtual" registers: one for the value
* written to WR2 (from the shadow) and one for the vector including
* status from RR2, Ch. B) and RR3. The latter must be read from
* Channel A, because it reads as all zeros on Ch. B. RR0 and RR8 can
* be accessed directly as before.
*
* The two inline function contain complicated switch statements. But
* I rely on regno and final_delay being constants, so gcc can reduce
* the whole stuff to just some assembler statements.
*
* _SCCwrite and _SCCread aren't intended to be used directly under
* normal circumstances. The macros SCCread[_ND] and SCCwrite[_ND] are
* for that purpose. They assume that a local variable 'port' is
* declared and pointing to the port's scc_struct entry. The
* variants with "_NB" appended should be used if no other SCC
* accesses follow immediately (within 0.5 usecs). They just skip the
* final delay nops.
*
* Please note that accesses to SCC registers should only take place
* when interrupts are turned off (at least if SCC interrupts are
* enabled). Otherwise, an interrupt could interfere with the
* two-stage accessing process.
*
*/
static __inline__ void _SCCwrite(
struct scc_port *port,
unsigned char *shadow,
volatile unsigned char *_scc_del,
int regno,
unsigned char val, int final_delay )
{
switch( regno ) {
case COMMAND_REG:
/* WR0 can be written directly without pointing */
*port->ctrlp = val;
break;
case SYNC_CHAR_REG:
/* For WR7, first set b0 of WR15 to 0, if needed */
if (shadow[INT_CTRL_REG] & ICR_OPTIONREG_SELECT) {
*port->ctrlp = 15;
shadow[INT_CTRL_REG] &= ~ICR_OPTIONREG_SELECT;
scc_reg_delay();
*port->ctrlp = shadow[INT_CTRL_REG];
scc_reg_delay();
}
goto normal_case;
case SDLC_OPTION_REG:
/* For WR7', first set b0 of WR15 to 1, if needed */
if (!(shadow[INT_CTRL_REG] & ICR_OPTIONREG_SELECT)) {
*port->ctrlp = 15;
shadow[INT_CTRL_REG] |= ICR_OPTIONREG_SELECT;
scc_reg_delay();
*port->ctrlp = shadow[INT_CTRL_REG];
scc_reg_delay();
}
*port->ctrlp = 7;
shadow[8] = val; /* WR7' shadowed at WR8 */
scc_reg_delay();
*port->ctrlp = val;
break;
case TX_DATA_REG: /* WR8 */
/* TX_DATA_REG can be accessed directly on some h/w */
if (MACH_IS_MVME16x || MACH_IS_BVME6000 || MACH_IS_MVME147)
{
*port->ctrlp = regno;
scc_reg_delay();
*port->ctrlp = val;
}
else
*port->datap = val;
break;
case MASTER_INT_CTRL:
*port->ctrlp = regno;
val &= 0x3f; /* bits 6..7 are the reset commands */
scc_shadow[0][regno] = val;
scc_reg_delay();
*port->ctrlp = val;
break;
case DPLL_CTRL_REG:
*port->ctrlp = regno;
val &= 0x1f; /* bits 5..7 are the DPLL commands */
shadow[regno] = val;
scc_reg_delay();
*port->ctrlp = val;
break;
case 1 ... 6:
case 10 ... 13:
case 15:
normal_case:
*port->ctrlp = regno;
shadow[regno] = val;
scc_reg_delay();
*port->ctrlp = val;
break;
default:
printk( "Bad SCC write access to WR%d\n", regno );
break;
}
if (final_delay)
scc_reg_delay();
}
static __inline__ unsigned char _SCCread(
struct scc_port *port,
unsigned char *shadow,
volatile unsigned char *_scc_del,
int regno, int final_delay )
{
unsigned char rv;
switch( regno ) {
/* --- real read registers --- */
case STATUS_REG:
rv = *port->ctrlp;
break;
case INT_PENDING_REG:
/* RR3: read only from Channel A! */
port = port->port_a;
goto normal_case;
case RX_DATA_REG:
/* RR8 can be accessed directly on some h/w */
if (MACH_IS_MVME16x || MACH_IS_BVME6000 || MACH_IS_MVME147)
{
*port->ctrlp = 8;
scc_reg_delay();
rv = *port->ctrlp;
}
else
rv = *port->datap;
break;
case CURR_VECTOR_REG:
/* RR2 (vector including status) from Ch. B */
port = port->port_b;
goto normal_case;
/* --- reading write registers: access the shadow --- */
case 1 ... 7:
case 10 ... 15:
return shadow[regno]; /* no final delay! */
/* WR7' is special, because it is shadowed at the place of WR8 */
case SDLC_OPTION_REG:
return shadow[8]; /* no final delay! */
/* WR9 is special too, because it is common for both channels */
case MASTER_INT_CTRL:
return scc_shadow[0][9]; /* no final delay! */
default:
printk( "Bad SCC read access to %cR%d\n", (regno & 16) ? 'R' : 'W',
regno & ~16 );
break;
case SPCOND_STATUS_REG:
case FS_FIFO_LOW_REG:
case FS_FIFO_HIGH_REG:
case DPLL_STATUS_REG:
normal_case:
*port->ctrlp = regno & 0x0f;
scc_reg_delay();
rv = *port->ctrlp;
break;
}
if (final_delay)
scc_reg_delay();
return rv;
}
#define SCC_ACCESS_INIT(port) \
unsigned char *_scc_shadow = &scc_shadow[port->channel][0]
#define SCCwrite(reg,val) _SCCwrite(port,_scc_shadow,scc_del,(reg),(val),1)
#define SCCwrite_NB(reg,val) _SCCwrite(port,_scc_shadow,scc_del,(reg),(val),0)
#define SCCread(reg) _SCCread(port,_scc_shadow,scc_del,(reg),1)
#define SCCread_NB(reg) _SCCread(port,_scc_shadow,scc_del,(reg),0)
#define SCCmod(reg,and,or) SCCwrite((reg),(SCCread(reg)&(and))|(or))
#endif /* _SCC_H */
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