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)
- extern 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 immediatly (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%dn", 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%dn", (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 */