Annotation of funnyos/arch/sam7s64/dev/p64lcd.c, Revision 1.1
1.1 ! nbrk 1: /*
! 2: * $Id$
! 3: */
! 4: #include <sys/types.h>
! 5: #include <sys/device.h>
! 6: #include <sys/gpio.h>
! 7: #include <dev/lcd/44780var.h>
! 8:
! 9: #include <arch/sam7s64/dev/at91sam7.h>
! 10:
! 11: /*
! 12: * 44780-based LCD connected to my p64 board.
! 13: * Wiring for chip logic:
! 14: * RS -> PA10
! 15: * R/W -> PA9
! 16: * E -> PA8
! 17: * D{0..7} -> PA{7,6,5,4,3,2,1,0}
! 18: *
! 19: * We will fake-up as a 10-bit bus for our child (real 44780 driver).
! 20: * This 10-bit bus is: MSB <RS><R/W><D7>..<D0> LSB
! 21: * Please note that p64lcd_read() returns 8-bit D0..D7.
! 22: */
! 23: int p64lcd_attach(struct device *self, uint32_t loc, uint8_t flags);
! 24: void p64lcd_write(void *pldd, uint16_t data);
! 25: uint8_t p64lcd_read(void *pldd);
! 26: uint8_t p64lcd_readbf(void *pldd);
! 27: void p64lcd_strobe(void *pldd);
! 28:
! 29: /* our devdata */
! 30: struct p64lcd_dd {
! 31: struct gpio_controller *pl_gcp;
! 32:
! 33: struct h44780_busops pl_bus; /* our 10-bit control bus for driver */
! 34: };
! 35:
! 36: struct driver p64lcd_dr = {
! 37: sizeof(struct p64lcd_dd),
! 38: p64lcd_attach,
! 39: NULL,
! 40: NULL
! 41: };
! 42:
! 43:
! 44: int
! 45: p64lcd_attach(struct device *self, uint32_t loc, uint8_t flags)
! 46: {
! 47: struct p64lcd_dd *ddp = self->dv_devdata;
! 48: struct gpio_pin pin;
! 49: uint8_t i;
! 50: int j;
! 51:
! 52: /* grab parent's gpio_controller */
! 53: ddp->pl_gcp = self->dv_parent->dv_aux;
! 54:
! 55: /* configure pins */
! 56: pin.gp_pio = 1;
! 57: pin.gp_flags = GPIO_PIN_OUTPUT; /* XXX what about read? */
! 58: pin.gp_value = 0;
! 59: for(i = 0; i < 11; i++) {
! 60: pin.gp_pinno = i;
! 61: ddp->pl_gcp->gc_pinset(ddp->pl_gcp->gc_selfdd, pin);
! 62: }
! 63:
! 64: /* XXX enable synchronous data output on our data lines */
! 65: *AT91C_PIOA_OWER = 0xff;
! 66: // *AT91C_PIOA_ODSR = 0xaa;
! 67: // *AT91C_PIOA_ODSR = ~0xaa;
! 68:
! 69: printf("p64 10-bit bus for LCD, dedicated E strobe\n");
! 70:
! 71: /* link 44780_ops */
! 72: ddp->pl_bus.write = p64lcd_write;
! 73: ddp->pl_bus.read = p64lcd_read;
! 74: ddp->pl_bus.readbf = p64lcd_readbf;
! 75: ddp->pl_bus.strobe = p64lcd_strobe;
! 76: ddp->pl_bus.selfdd = ddp;
! 77:
! 78: /* export */
! 79: self->dv_aux = &ddp->pl_bus;
! 80:
! 81: return(0);
! 82: }
! 83:
! 84: void
! 85: p64lcd_write(void *pldd, uint16_t data)
! 86: {
! 87: uint32_t setmask = 0;
! 88: uint8_t i, rs, rw = rs = 0;
! 89: /*
! 90: * Decode and place given 10-bit data on the wires.
! 91: * We will use raw PIOA registers instead of gpio_controller abstraction
! 92: * so we can hit all pins in one shoot.
! 93: */
! 94: /*
! 95: * Caller gives us: <RS><RW><D7><D6><D5><D4><D3><D2><D1><D0> (LSB)
! 96: */
! 97: /* strip unneeded bits */
! 98: data = data & 0x3ff;
! 99:
! 100: /* XXX bring all our lines to high */
! 101: //*AT91C_PIOA_CODR = 0x3ff;
! 102:
! 103: /* check if caller requested to assert RS */
! 104: if (data & 0x200)
! 105: rs = 1;
! 106: // setmask |= 1 << 10; /* 'RS' is PA10 */
! 107: // *AT91C_PIOA_CODR = 1 << 10;
! 108: // else *AT91C_PIOA_SODR = 1 << 10;
! 109:
! 110: /* check if caller requested to assert R/W */
! 111: if (data & 0x100)
! 112: rw = 1;
! 113: // setmask |= 1 << 9; /* 'RW' is PA9 */
! 114: // *AT91C_PIOA_CODR = 1 << 9;
! 115: // else *AT91C_PIOA_SODR = 1 << 9;
! 116:
! 117: /*
! 118: * Deal with LSB of data which contains D0..D7 value.
! 119: * Since D0..D7 is wired to PA7..PA0 we need to reverse bits.
! 120: */
! 121:
! 122: for(i = 0; i < 7; i++)
! 123: if (data & (1 << i))
! 124: setmask |= 1 << (7 - i);
! 125: // setmask = data & 0xff;
! 126:
! 127: printf("p64lcd_write: rs=%d rw=%d setmask=0x%x\n", rs, rw, setmask);
! 128:
! 129: // *AT91C_PIOA_SODR = setmask;
! 130: // *AT91C_PIOA_CODR = (uint8_t)(~setmask);
! 131: if (rs)
! 132: *AT91C_PIOA_SODR = 1 << 10;
! 133: else
! 134: *AT91C_PIOA_CODR = 1 << 10;
! 135:
! 136: if (rw)
! 137: *AT91C_PIOA_SODR = 1 << 9;
! 138: else
! 139: *AT91C_PIOA_CODR = 1 << 9;
! 140:
! 141: /* E high */
! 142: *AT91C_PIOA_SODR = 1 << 8;
! 143:
! 144: *AT91C_PIOA_ODSR = setmask;
! 145:
! 146: /* E low */
! 147: *AT91C_PIOA_CODR = 1 << 8;
! 148:
! 149: //*AT91C_PIOA_ODSR = ~setmask;
! 150: }
! 151:
! 152:
! 153: uint8_t
! 154: p64lcd_read(void *pldd)
! 155: {
! 156: /* TODO */
! 157:
! 158:
! 159: return(1);
! 160: }
! 161:
! 162:
! 163: uint8_t
! 164: p64lcd_readbf(void *pldd)
! 165: {
! 166: /* TODO */
! 167:
! 168: return(1);
! 169: }
! 170:
! 171:
! 172: void
! 173: p64lcd_strobe(void *pldd)
! 174: {
! 175: volatile int i;
! 176: *AT91C_PIOA_SODR = 1 << 8;
! 177: /* XXX delay? */
! 178: for(i = 0; i < 10; i++)
! 179: ;
! 180: *AT91C_PIOA_CODR = 1 << 8;
! 181: }
! 182:
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