116 lines
3.0 KiB
C
116 lines
3.0 KiB
C
//---
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// gint:keysc:iokbd - I/O-based keyboard input
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//---
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#include <gint/defs/types.h>
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#include <gint/mpu/pfc.h>
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/* This file is SH7705-only. */
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#ifdef FX9860G
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#define PFC SH7705_PFC
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/* iokbd_delay() - wait a bit so that I/O can keep up
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May use the watchdog timer, but the keyboard driver will need to save it. */
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static void iokbd_delay(void)
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{
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__asm__(
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"nop\n\t"
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"nop\n\t"
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"nop\n\t"
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"nop\n\t"
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);
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#if 0
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/* Watchdog delay version */
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const int delay = 0xf4;
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/* Disable the watchdog timer interrupt and reset configuration */
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INTC.IPRB.BIT._WDT = 0;
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WDT.WTCSR.WRITE = 0xa500;
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/* Set the delay, input on Pphi / 256 and start counting */
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WDT.WTCNT.WRITE = 0x5a00 | (delay & 0xff);
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WDT.WTCSR.WRITE = 0xa505;
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WDT.WTCSR.WRITE = 0xa585;
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/* Actively wait for overflow, then clear the interrupt flag */
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while((WDT.WTCSR.READ.BYTE & 0x08) == 0);
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WDT.WTCSR.WRITE = 0xa500 | (WDT.WTCSR.READ.BYTE & 0xf7);
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/* Reset configuration, counter, and re-enabled interrupt */
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WDT.WTCSR.WRITE = 0xa500;
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WDT.WTCSR.WRITE = 0x5a00;
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INTC.IPRB.BIT._WDT = GINT_INTP_WDT;
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#endif
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}
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/* iokbd_row() - acquire hit status of a single row from the I/O ports
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@row Requested row number, 0..9
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Returns 8 bits of key state. */
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uint8_t iokbd_row(int row)
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{
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if((unsigned)row > 9) return 0x00;
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row ^= 1;
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/* This will enable output (01) on @row, input (10) everywhere else */
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uint16_t ctrl_mask = 0x0003 << ((row & 7) * 2);
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/* Enable output (0) on @row, input (1) everywhere else */
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uint8_t data_mask = ~(1 << (row & 7));
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/* When row < 8, the associated bits are in port B */
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if(row < 8)
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{
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/* Set @row as output in port B; port M is unused */
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PFC.PBCR = 0xaaaa ^ ctrl_mask;
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PFC.PMCR = (PFC.PMCR & 0xff00) | 0x00aa;
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iokbd_delay();
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/* Set @row to 0, everything else to 1 */
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PFC.PBDR = data_mask;
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PFC.PMDR = (PFC.PMDR & 0xf0) | 0x0f;
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iokbd_delay();
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}
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/* When row >= 8, the associated bits are in port M */
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else
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{
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/* Set @row as output in port M; port B is unused */
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PFC.PBCR = 0xaaaa;
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PFC.PMCR = (PFC.PMCR & 0xff00) | (0x00aa ^ ctrl_mask);
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iokbd_delay();
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/* Set @row to 0, everything else to 1 */
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PFC.PBDR = 0xff;
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PFC.PMDR = PFC.PMDR & data_mask;
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}
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/* Now read the input data from the keyboard! */
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uint8_t input = ~PFC.PADR;
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iokbd_delay();
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/* Reset the port configuration. I don't know why the intermediate step
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is necessary; refer to SimLo's documentation. */
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PFC.PBCR = 0xaaaa;
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PFC.PMCR = (PFC.PMCR & 0xff00) | 0x00aa;
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iokbd_delay();
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PFC.PBCR = 0x5555;
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PFC.PMCR = (PFC.PMCR & 0xff00) | 0x0055;
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iokbd_delay();
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/* Now also reset the data registers. This was forgotten from SimLo's
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CheckKeyRow() and blows up everything. */
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PFC.PBDR = 0x00;
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PFC.PMDR = PFC.PMDR & 0xf0;
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return input;
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}
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/* iokbd_scan() - scan ports A/B/M to generate 12 rows of key data */
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void iokbd_scan(uint8_t *scan)
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{
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/* Scan each row independently; the gain from scanning them altogether
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is probably not worth it */
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for(int i = 0; i < 12; i++) scan[i] = iokbd_row(i);
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}
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#endif /* FX9860G */
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