/*
* Compatibility mode handshaking is a matter of writing data,
* strobing it, and waiting for the printer to stop being busy.
*/
static long write_compat(unsigned minor, const char *c, unsigned long cnt)
{
long rc;
unsigned short pins = get_pins(minor);
unsigned long remaining = cnt;
while (remaining > 0) {
unsigned char byte;
get_user_ret(byte, c, -EFAULT);
c += 1;
rc = wait_for(BPP_GP_nAck, BPP_GP_Busy, TIME_IDLE_LIMIT, minor);
if (rc == -1) return -ETIMEDOUT;
bpp_outb_p(byte, base_addrs[minor]);
remaining -= 1;
/* snooze(1, minor); */
pins &= ~BPP_PP_nStrobe;
set_pins(pins, minor);
rc = wait_for(BPP_GP_Busy, 0, TIME_PResponse, minor);
pins |= BPP_PP_nStrobe;
set_pins(pins, minor);
}
return cnt - remaining;
}
static unsigned i2csw_Read(int dev, bool last) {
unsigned char val = 0;
int i, databit;
// read data byte
for(i=0; i<8; i++)
{
set_pins(dev, 0, 1); delay_us(I2CSW_delay[dev]); // set SDA as input
set_pins(dev, 1, 1); delay_us(I2CSW_delay[dev]); // send a clock
databit = read_sda(dev);
val = (val << 1) | (unsigned char)databit;
}
set_pins(dev, 0, 1);
if (last == false)
{ // send ACK
set_pins(dev, 0, 0); delay_us(I2CSW_delay[dev]); // set SDA = 0
set_pins(dev, 1, 0); delay_us(I2CSW_delay[dev]); // send a clock
set_pins(dev, 0, 0);
}
else
{ // send NACK
set_pins(dev, 0, 1); delay_us(I2CSW_delay[dev]); // set SDA = 1
set_pins(dev, 1, 1); delay_us(I2CSW_delay[dev]); // send a clock
set_pins(dev, 0, 1);
}
return (unsigned)val;
}
static long read_nibble(unsigned minor, char __user *c, unsigned long cnt)
{
unsigned long remaining = cnt;
long rc;
while (remaining > 0) {
unsigned char byte = 0;
int pins;
/* Event 7: request nibble */
set_pins(BPP_PP_nSelectIn|BPP_PP_nStrobe, minor);
/* Wait for event 9: Peripher strobes first nibble */
pins = wait_for(0, BPP_GP_nAck, TIME_IDLE_LIMIT, minor);
if (pins == -1) return -ETIMEDOUT;
/* Event 10: I handshake nibble */
set_pins(BPP_PP_nSelectIn|BPP_PP_nStrobe|BPP_PP_nAutoFd, minor);
if (pins & BPP_GP_nFault) byte |= 0x01;
if (pins & BPP_GP_Select) byte |= 0x02;
if (pins & BPP_GP_PError) byte |= 0x04;
if (pins & BPP_GP_Busy) byte |= 0x08;
/* Wait for event 11: Peripheral handshakes nibble */
rc = wait_for(BPP_GP_nAck, 0, TIME_PResponse, minor);
/* Event 7: request nibble */
set_pins(BPP_PP_nSelectIn|BPP_PP_nStrobe, minor);
/* Wait for event 9: Peripher strobes first nibble */
pins = wait_for(0, BPP_GP_nAck, TIME_PResponse, minor);
if (rc == -1) return -ETIMEDOUT;
/* Event 10: I handshake nibble */
set_pins(BPP_PP_nSelectIn|BPP_PP_nStrobe|BPP_PP_nAutoFd, minor);
if (pins & BPP_GP_nFault) byte |= 0x10;
if (pins & BPP_GP_Select) byte |= 0x20;
if (pins & BPP_GP_PError) byte |= 0x40;
if (pins & BPP_GP_Busy) byte |= 0x80;
if (put_user(byte, c))
return -EFAULT;
c += 1;
remaining -= 1;
/* Wait for event 11: Peripheral handshakes nibble */
rc = wait_for(BPP_GP_nAck, 0, TIME_PResponse, minor);
if (rc == -1) return -EIO;
}
return cnt - remaining;
}
static int bpp_ioctl(struct inode *inode, struct file *f, unsigned int cmd,
unsigned long arg)
{
int errno = 0;
unsigned minor = MINOR(inode->i_rdev);
if (minor >= BPP_NO) return -ENODEV;
if (!instances[minor].present) return -ENODEV;
switch (cmd) {
case BPP_PUT_PINS:
set_pins(arg, minor);
break;
case BPP_GET_PINS:
errno = get_pins(minor);
break;
case BPP_PUT_DATA:
bpp_outb_p(arg, base_addrs[minor]);
break;
case BPP_GET_DATA:
errno = bpp_inb_p(base_addrs[minor]);
break;
case BPP_SET_INPUT:
if (arg)
if (instances[minor].enhanced) {
unsigned short bits = get_pins(minor);
instances[minor].direction = 0x20;
set_pins(bits, minor);
} else {
errno = -ENOTTY;
}
else {
unsigned short bits = get_pins(minor);
instances[minor].direction = 0x00;
set_pins(bits, minor);
}
break;
default:
errno = -EINVAL;
}
return errno;
}
/*
* Write data using ECP mode. Watch out that the port may be set up
* for reading. If so, turn the port around.
*/
static long write_ecp(unsigned minor, const char __user *c, unsigned long cnt)
{
unsigned short pins = get_pins(minor);
unsigned long remaining = cnt;
if (instances[minor].direction) {
int rc;
/* Event 47 Request bus be turned around */
pins |= BPP_PP_nInit;
set_pins(pins, minor);
/* Wait for Event 49: Peripheral relinquished bus */
rc = wait_for(BPP_GP_PError, 0, TIME_PResponse, minor);
pins |= BPP_PP_nAutoFd;
instances[minor].direction = 0;
set_pins(pins, minor);
}
while (remaining > 0) {
unsigned char byte;
int rc;
if (get_user(byte, c))
return -EFAULT;
rc = wait_for(0, BPP_GP_Busy, TIME_PResponse, minor);
if (rc == -1) return -ETIMEDOUT;
c += 1;
bpp_outb_p(byte, base_addrs[minor]);
pins &= ~BPP_PP_nStrobe;
set_pins(pins, minor);
pins |= BPP_PP_nStrobe;
rc = wait_for(BPP_GP_Busy, 0, TIME_PResponse, minor);
if (rc == -1) return -EIO;
set_pins(pins, minor);
}
return cnt - remaining;
}
static void probeLptPort(unsigned idx)
{
unsigned int testvalue;
const unsigned short lpAddr = base_addrs[idx];
instances[idx].present = 0;
instances[idx].enhanced = 0;
instances[idx].direction = 0;
instances[idx].mode = COMPATIBILITY;
instances[idx].wait_queue = 0;
instances[idx].run_length = 0;
instances[idx].run_flag = 0;
init_timer(&instances[idx].timer_list);
instances[idx].timer_list.function = bpp_wake_up;
if (check_region(lpAddr,3)) return;
/*
* First, make sure the instance exists. Do this by writing to
* the data latch and reading the value back. If the port *is*
* present, test to see if it supports extended-mode
* operation. This will be required for IEEE1284 reverse
* transfers.
*/
outb_p(BPP_PROBE_CODE, lpAddr);
for (testvalue=0; testvalue<BPP_DELAY; testvalue++)
;
testvalue = inb_p(lpAddr);
if (testvalue == BPP_PROBE_CODE) {
unsigned save;
instances[idx].present = 1;
request_region(lpAddr,3, dev_name);
save = inb_p(lpAddr+2);
for (testvalue=0; testvalue<BPP_DELAY; testvalue++)
;
outb_p(save|0x20, lpAddr+2);
for (testvalue=0; testvalue<BPP_DELAY; testvalue++)
;
outb_p(~BPP_PROBE_CODE, lpAddr);
for (testvalue=0; testvalue<BPP_DELAY; testvalue++)
;
testvalue = inb_p(lpAddr);
if ((testvalue&0xff) == (0xff&~BPP_PROBE_CODE))
instances[idx].enhanced = 0;
else
instances[idx].enhanced = 1;
outb_p(save, lpAddr+2);
}
/*
* Leave the port in compat idle mode.
*/
set_pins(BPP_PP_nAutoFd|BPP_PP_nStrobe|BPP_PP_nInit, idx);
printk("bpp%d: Port at 0x%03x: Enhanced mode %s\n", idx, base_addrs[idx],
instances[idx].enhanced? "SUPPORTED" : "UNAVAILABLE");
}
static ssize_t bpp_read(struct file *f, char *c, size_t cnt, loff_t * ppos)
{
long rc;
const unsigned minor = MINOR(f->f_dentry->d_inode->i_rdev);
if (minor >= BPP_NO) return -ENODEV;
if (!instances[minor].present) return -ENODEV;
switch (instances[minor].mode) {
default:
if (instances[minor].mode != COMPATIBILITY)
terminate(minor);
if (instances[minor].enhanced) {
/* For now, do all reads with ECP-RLE mode */
unsigned short pins;
rc = negotiate(DEFAULT_ECP, minor);
if (rc < 0) break;
instances[minor].mode = ECP_RLE;
/* Event 30: set nAutoFd low to setup for ECP mode */
pins = get_pins(minor);
pins &= ~BPP_PP_nAutoFd;
set_pins(pins, minor);
/* Wait for Event 31: peripheral ready */
rc = wait_for(BPP_GP_PError, 0, TIME_PResponse, minor);
if (rc == -1) return -ETIMEDOUT;
rc = read_ecp(minor, c, cnt);
} else {
rc = negotiate(DEFAULT_NIBBLE, minor);
if (rc < 0) break;
instances[minor].mode = NIBBLE;
rc = read_nibble(minor, c, cnt);
}
break;
case NIBBLE:
rc = read_nibble(minor, c, cnt);
break;
case ECP:
case ECP_RLE:
rc = read_ecp(minor, c, cnt);
break;
}
return rc;
}
void system_init()
{
/* Stop the watchdog */
startup_watchdog_disable(); /* Do it right now, before it gets a chance to break in */
/* Note: Brown-Out detection must be powered to operate the ADC. adc_on() will power
* it back on if called after system_init() */
system_brown_out_detection_config(0);
system_set_default_power_state();
clock_config(SELECTED_FREQ);
set_pins(common_pins);
set_pins(adc_pins);
gpio_on();
status_led_config(&status_led_green, &status_led_red);
/* System tick timer MUST be configured and running in order to use the sleeping functions */
systick_timer_on(1); /* 1ms */
systick_start();
}
/*
* Return ZERO(0) If the negotiation succeeds, an errno otherwise. An
* errno means something broke, and I do not yet know how to fix it.
*/
static int negotiate(unsigned char mode, unsigned minor)
{
int rc;
unsigned short pins = get_pins(minor);
if (pins & BPP_PP_nSelectIn) return -EIO;
/* Event 0: Write the mode to the data lines */
bpp_outb_p(mode, base_addrs[minor]);
snooze(TIME_PSetup, minor);
/* Event 1: Strobe the mode code into the peripheral */
set_pins(BPP_PP_nSelectIn|BPP_PP_nStrobe|BPP_PP_nInit, minor);
/* Wait for Event 2: Peripheral responds as a 1284 device. */
rc = wait_for(BPP_GP_PError|BPP_GP_Select|BPP_GP_nFault,
BPP_GP_nAck,
TIME_PResponse,
minor);
if (rc == -1) return -ETIMEDOUT;
/* Event 3: latch extensibility request */
set_pins(BPP_PP_nSelectIn|BPP_PP_nInit, minor);
/* ... quick nap while peripheral ponders the byte i'm sending...*/
snooze(1, minor);
/* Event 4: restore strobe, to ACK peripheral's response. */
set_pins(BPP_PP_nSelectIn|BPP_PP_nAutoFd|BPP_PP_nStrobe|BPP_PP_nInit, minor);
/* Wait for Event 6: Peripheral latches response bits */
rc = wait_for(BPP_GP_nAck, 0, TIME_PSetup+TIME_PResponse, minor);
if (rc == -1) return -EIO;
/* A 1284 device cannot refuse nibble mode */
if (mode == DEFAULT_NIBBLE) return 0;
if (pins & BPP_GP_Select) return 0;
return -EPROTONOSUPPORT;
}
static void probeLptPort(unsigned idx)
{
void __iomem *rp = base_addrs[idx];
__u32 csr;
char *brand;
instances[idx].present = 0;
instances[idx].enhanced = 0;
instances[idx].direction = 0;
instances[idx].mode = COMPATIBILITY;
instances[idx].run_length = 0;
instances[idx].run_flag = 0;
if (!rp) return;
instances[idx].present = 1;
instances[idx].enhanced = 1; /* Sure */
csr = sbus_readl(rp + BPP_CSR);
if ((csr & P_DRAINING) != 0 && (csr & P_ERR_PEND) == 0) {
udelay(20);
csr = sbus_readl(rp + BPP_CSR);
if ((csr & P_DRAINING) != 0 && (csr & P_ERR_PEND) == 0) {
printk("bpp%d: DRAINING still active (0x%08x)\n", idx, csr);
}
}
printk("bpp%d: reset with 0x%08x ..", idx, csr);
sbus_writel((csr | P_RESET) & ~P_INT_EN, rp + BPP_CSR);
udelay(500);
sbus_writel(sbus_readl(rp + BPP_CSR) & ~P_RESET, rp + BPP_CSR);
csr = sbus_readl(rp + BPP_CSR);
printk(" done with csr=0x%08x ocr=0x%04x\n",
csr, sbus_readw(rp + BPP_OCR));
switch (csr & P_DEV_ID_MASK) {
case P_DEV_ID_ZEBRA:
brand = "Zebra";
break;
case P_DEV_ID_L64854:
brand = "DMA2";
break;
default:
brand = "Unknown";
}
printk("bpp%d: %s at %p\n", idx, brand, rp);
/*
* Leave the port in compat idle mode.
*/
set_pins(BPP_PP_nAutoFd|BPP_PP_nStrobe|BPP_PP_nInit, idx);
return;
}
static void probeLptPort(unsigned idx)
{
volatile struct bpp_regs *rp = base_addrs[idx];
__u32 csr;
char *brand;
instances[idx].present = 0;
instances[idx].enhanced = 0;
instances[idx].direction = 0;
instances[idx].mode = COMPATIBILITY;
instances[idx].wait_queue = 0;
instances[idx].run_length = 0;
instances[idx].run_flag = 0;
init_timer(&instances[idx].timer_list);
instances[idx].timer_list.function = bpp_wake_up;
if (rp == 0) return;
instances[idx].present = 1;
instances[idx].enhanced = 1; /* Sure */
if (((csr = rp->p_csr) & P_DRAINING) != 0 && (csr & P_ERR_PEND) == 0) {
udelay(20);
csr = rp->p_csr;
if ((csr & P_DRAINING) != 0 && (csr & P_ERR_PEND) == 0) {
printk("bpp%d: DRAINING still active (0x%08x)\n", idx, csr);
}
}
printk("bpp%d: reset with 0x%08x ..", idx, csr);
rp->p_csr = (csr | P_RESET) & ~P_INT_EN;
udelay(500);
rp->p_csr &= ~P_RESET;
printk(" done with csr=0x%08x ocr=0x%04x\n", rp->p_csr, rp->p_ocr);
switch (rp->p_csr & P_DEV_ID_MASK) {
case P_DEV_ID_ZEBRA:
brand = "Zebra";
break;
case P_DEV_ID_L64854:
brand = "DMA2";
break;
default:
brand = "Unknown";
}
printk("bpp%d: %s at 0x%p\n", idx, brand, rp);
/*
* Leave the port in compat idle mode.
*/
set_pins(BPP_PP_nAutoFd|BPP_PP_nStrobe|BPP_PP_nInit, idx);
return;
}
static bool i2csw_Write(int dev, unsigned char val) {
int i, databit;
// send data byte
for(i=0; i<8; i++)
{
databit = ((val & 0x80) == 0)? 0 : 1;
set_pins(dev, 0, databit); delay_us(I2CSW_delay[dev]); // set data bit
set_pins(dev, 1, databit); delay_us(I2CSW_delay[dev]); // send a clock
set_pins(dev, 0, databit);
val = val << 1;
}
// read ACK
set_pins(dev, 0, 1); delay_us(I2CSW_delay[dev]); // set SDA as input
set_pins(dev, 1, 1); delay_us(I2CSW_delay[dev]); // send a clock
if (read_sda(dev) == 1)
{
err_SetMsg(ERROR_I2CACKERR, "receive no ACK after transmitting");
return false;
}
set_pins(dev, 0, 1);
return true;
}
int main()
{
/*
* Set the thing at the adress of an int to 0.
*/
PORTA = 0;
PORTB = 0;
/*
* To the function set_pins, we are passing &PORTX which is
* the adress of (the thing at the address of an int)
*/
set_pins(&PORTA, (1 << PORTA2)|(1 << PORTA1)|(1 << PORTA0));
set_pins(&PORTB, (1 << PORTA7)|(1 << PORTA6)|(1 << PORTA5));
/*
* Print the thing at the address of an int
*/
printf("new value of PORTA : %d\n", PORTA);
printf("new value of PORTB : %d\n", PORTB);
return 0;
}
static int terminate(unsigned minor)
{
int rc;
/* Event 22: Request termination of 1284 mode */
set_pins(BPP_PP_nAutoFd|BPP_PP_nStrobe|BPP_PP_nInit, minor);
/* Wait for Events 23 and 24: ACK termination request. */
rc = wait_for(BPP_GP_Busy|BPP_GP_nFault,
BPP_GP_nAck,
TIME_PSetup+TIME_PResponse,
minor);
instances[minor].direction = 0;
instances[minor].mode = COMPATIBILITY;
if (rc == -1) {
return -EIO;
}
/* Event 25: Handshake by lowering nAutoFd */
set_pins(BPP_PP_nStrobe|BPP_PP_nInit, minor);
/* Event 26: Peripheral wiggles lines... */
/* Event 27: Peripheral sets nAck HIGH to ack handshake */
rc = wait_for(BPP_GP_nAck, 0, TIME_PResponse, minor);
if (rc == -1) {
set_pins(BPP_PP_nAutoFd|BPP_PP_nStrobe|BPP_PP_nInit, minor);
return -EIO;
}
/* Event 28: Finish phase by raising nAutoFd */
set_pins(BPP_PP_nAutoFd|BPP_PP_nStrobe|BPP_PP_nInit, minor);
return 0;
}
//draws the linebuffer to the lcd, some loop unrolling
void draw_linebuffer()
{
set_pins();
for (int32_t i = 0; i < SCREENX; i+=20)
{
set_data(line_buffer[i]);
pulse_pins();
set_data(line_buffer[i+1]);
pulse_pins();
set_data(line_buffer[i+2]);
pulse_pins();
set_data(line_buffer[i+3]);
pulse_pins();
set_data(line_buffer[i+4]);
pulse_pins();
set_data(line_buffer[i+5]);
pulse_pins();
set_data(line_buffer[i+6]);
pulse_pins();
set_data(line_buffer[i+7]);
pulse_pins();
set_data(line_buffer[i+8]);
pulse_pins();
set_data(line_buffer[i+9]);
pulse_pins();
set_data(line_buffer[i+10]);
pulse_pins();
set_data(line_buffer[i+11]);
pulse_pins();
set_data(line_buffer[i+12]);
pulse_pins();
set_data(line_buffer[i+13]);
pulse_pins();
set_data(line_buffer[i+14]);
pulse_pins();
set_data(line_buffer[i+15]);
pulse_pins();
set_data(line_buffer[i+16]);
pulse_pins();
set_data(line_buffer[i+17]);
pulse_pins();
set_data(line_buffer[i+18]);
pulse_pins();
set_data(line_buffer[i+19]);
pulse_pins();
}
unset_pins();
}
RBAPI(bool) i2c_Initialize2(unsigned devs, int i2c0irq, int i2c1irq) {
int i;
if (I2C_ioSection != -1)
{
err_SetMsg(ERROR_I2C_INUSE, "I2C lib was already opened");
return false;
}
if ((I2C_ioSection = io_Init()) == -1) return false;
if (i2c_SetDefaultBaseAddress() == 0x0000) i2c_SetBaseAddress(0xfb00);
i2c_SetIRQ(i2c0irq, i2c1irq);
I2C_action[0] = I2C_action[1] = I2CACT_DISABLE;
for (i=0; i<2; i++)
{
if ((i == 0) && ((devs & I2C_USEMODULE0) == 0)) continue;
if ((i == 1) && ((devs & I2C_USEMODULE1) == 0)) continue;
I2C_action[i] = I2CACT_IDLE;
//switch GPIO/I2C pins into GPIO pins
OLD_I2CGPIO3FLAG[i] = read_sb_reg(SB_IPFCTRL3_REG) & OLD_I2CGPIO3MASK[i]; //backup GPIO/I2C switch flag
write_sb_reg(SB_IPFCTRL3_REG, read_sb_reg(SB_IPFCTRL3_REG) & (~OLD_I2CGPIO3MASK[i]));
//send START & STOP signal to reset I2C devices
OLD_I2CGPIO3DIR[i] = io_inpb(0x9b) & (0x03 << (i*2+4)); //backup GPIO3 DIR
OLD_I2CGPIO3VAL[i] = io_inpb(0x7b) & (0x03 << (i*2+4)); //backup GPIO3 VAL
//set_pins(i, 1, 1); delay_ms(1); //SCL = 1, SDA = 1; START
//set_pins(i, 1, 0); delay_ms(1); //SCL = 1, SDA = 0
//set_pins(i, 0, 0); delay_ms(1); //SCL = 0, SDA = 0
//Note: if we send the above START, some I2C sensors, such as ADI ADXL345, may fail to respond
//set_pins(i, 0, 0); delay_ms(1); //SCL = 0, SDA = 0; STOP
//Note: if we perform the line above, some I2C sensors, such as MEMSIC MXC6202, may fail to respond
set_pins(i, 1, 0); delay_ms(1); //SCL = 1, SDA = 0
set_pins(i, 1, 1); delay_ms(1); //SCL = 1, SDA = 1
if (i2c_Reset(i) == false)
{
i2c_Close();
err_SetMsg(ERROR_I2C_INITFAIL, "can't reset the I2C modules");
return false;
}
i2c_DisableINT(i, I2CINT_ALL);
i2c_ClearSTAT(i, I2CSTAT_ALL);
//Remarks: for DX ver.2, we must disable the noise filter to ensure that 3.3Mbps works in high-speed mode
i2c_DisableNoiseFilter(i);
//i2c_EnableNoiseFilter(i);
i2c_DisableStandardHSM(i); //SCL open-drain in high-speed mode
//i2c_EnableStandardHSM(i);
i2c_SetSpeed(i, I2CMODE_AUTO, 100000L); //default 100Kbps
i2cslave_SetAddr(i, 0x7f); //set slave address 0x7F by default (change this if it collide with external I2C devices)
i2cslave_EnableACK(i);
//switch GPIO pins into I2C SCL,SDA pins
//Remarks: Vortex86DX's H/W I2C has an issue here; if you call i2c_Reset() in case GPIO/SCL pin = GPIO out 0,
// then, whenever you switch GPIO/SCL pin to SCL pin, the SCL pin always first send the 10 reset dummy clocks
write_sb_reg(SB_IPFCTRL3_REG, read_sb_reg(SB_IPFCTRL3_REG) | OLD_I2CGPIO3MASK[i]);
}
return true;
}
static void i2csw_Stop(int dev) {
set_pins(dev, 0, 0); timer_DelayMicroseconds(I2CSW_delay[dev]); // SCL = 0, SDA = 0
set_pins(dev, 1, 0); timer_DelayMicroseconds(I2CSW_delay[dev]); // SCL = 1, SDA = 0
set_pins(dev, 1, 1); // SCL = 1, SDA = 1
}
static long read_ecp(unsigned minor, char *c, unsigned long cnt)
{
unsigned long remaining;
long rc;
/* Turn ECP mode from forward to reverse if needed. */
if (! instances[minor].direction) {
unsigned short pins = get_pins(minor);
/* Event 38: Turn the bus around */
instances[minor].direction = 0x20;
pins &= ~BPP_PP_nAutoFd;
set_pins(pins, minor);
/* Event 39: Set pins for reverse mode. */
snooze(TIME_PSetup, minor);
set_pins(BPP_PP_nStrobe|BPP_PP_nSelectIn, minor);
/* Wait for event 40: Peripheral ready to be strobed */
rc = wait_for(0, BPP_GP_PError, TIME_PResponse, minor);
if (rc == -1) return -ETIMEDOUT;
}
remaining = cnt;
while (remaining > 0) {
/* If there is a run length for a repeated byte, repeat */
/* that byte a few times. */
if (instances[minor].run_length && !instances[minor].run_flag) {
char buffer[128];
unsigned idx;
unsigned repeat = remaining < instances[minor].run_length
? remaining
: instances[minor].run_length;
for (idx = 0 ; idx < repeat ; idx += 1)
buffer[idx] = instances[minor].repeat_byte;
copy_to_user_ret(c, buffer, repeat, -EFAULT);
remaining -= repeat;
c += repeat;
instances[minor].run_length -= repeat;
}
if (remaining == 0) break;
/* Wait for Event 43: Data active on the bus. */
rc = wait_for(0, BPP_GP_nAck, TIME_IDLE_LIMIT, minor);
if (rc == -1) break;
if (rc & BPP_GP_Busy) {
/* OK, this is data. read it in. */
unsigned char byte = bpp_inb(base_addrs[minor]);
put_user_ret(byte, c, -EFAULT);
c += 1;
remaining -= 1;
if (instances[minor].run_flag) {
instances[minor].repeat_byte = byte;
instances[minor].run_flag = 0;
}
} else {
unsigned char byte = bpp_inb(base_addrs[minor]);
if (byte & 0x80) {
printk("bpp%d: "
"Ignoring ECP channel %u from device.\n",
minor, byte & 0x7f);
} else {
instances[minor].run_length = byte;
instances[minor].run_flag = 1;
}
}
/* Event 44: I got it. */
set_pins(BPP_PP_nStrobe|BPP_PP_nAutoFd|BPP_PP_nSelectIn, minor);
/* Wait for event 45: peripheral handshake */
rc = wait_for(BPP_GP_nAck, 0, TIME_PResponse, minor);
if (rc == -1) return -ETIMEDOUT;
/* Event 46: Finish handshake */
set_pins(BPP_PP_nStrobe|BPP_PP_nSelectIn, minor);
}
return cnt - remaining;
}
static bool i2csw_Start(int dev, unsigned char addr, unsigned char rwbit, bool restart) {
int i, databit;
if (restart == false)
{ // send START signal
set_pins(dev, 1, 1); delay_us(I2CSW_delay[dev]); // SCL = 1, SDA = 1
set_pins(dev, 1, 0); delay_us(I2CSW_delay[dev]); // SCL = 1, SDA = 0
set_pins(dev, 0, 0); // SCL = 0, SDA = 0
}
else
if (I2C_swMode[dev] == I2CSW_LEGO)
{ // send LEGO NXT's I2C RESTART signal
set_pins(dev, 0, 0); delay_us(I2CSW_delay[dev]); // SCL = 0, SDA = 0
set_pins(dev, 1, 0); delay_us(I2CSW_delay[dev]); // SCL = 1, SDA = 0
set_pins(dev, 1, 1); delay_us(I2CSW_delay[dev]); // SCL = 1, SDA = 1
set_pins(dev, 0, 1); delay_us(I2CSW_delay[dev]); // LEGO NXT special: SCL = 0, SDA = 1
set_pins(dev, 1, 1); delay_us(I2CSW_delay[dev]); // SCL = 1, SDA = 1
set_pins(dev, 1, 0); delay_us(I2CSW_delay[dev]); // SCL = 1, SDA = 0
set_pins(dev, 0, 0); // SCL = 0, SDA = 0
}
else
{ // send normal I2C RESTART signal
set_pins(dev, 0, 0); delay_us(I2CSW_delay[dev]); // SCL = 0, SDA = 0
set_pins(dev, 0, 1); delay_us(I2CSW_delay[dev]); // SCL = 0, SDA = 1
set_pins(dev, 1, 1); delay_us(I2CSW_delay[dev]); // SCL = 1, SDA = 1
set_pins(dev, 1, 0); delay_us(I2CSW_delay[dev]); // SCL = 1, SDA = 0
set_pins(dev, 0, 0); // SCL = 0, SDA = 0
}
// send data byte
addr = (addr << 1) | rwbit;
for(i=0; i<8; i++)
{
databit = ((addr & 0x80) == 0)? 0 : 1;
set_pins(dev, 0, databit); delay_us(I2CSW_delay[dev]); // set data bit
set_pins(dev, 1, databit); delay_us(I2CSW_delay[dev]); // send a clock
set_pins(dev, 0, databit);
addr = addr << 1;
}
// read ACK
set_pins(dev, 0, 1); delay_us(I2CSW_delay[dev]); // set SDA as input
set_pins(dev, 1, 1); delay_us(I2CSW_delay[dev]); // send a clock
if (read_sda(dev) == 1)
{
err_SetMsg(ERROR_I2CACKERR, "receive no ACK after transmitting");
return false;
}
set_pins(dev, 0, 1);
return true;
}
static void i2csw_Stop(int dev) {
set_pins(dev, 0, 0); delay_us(I2CSW_delay[dev]); // SCL = 0, SDA = 0
set_pins(dev, 1, 0); delay_us(I2CSW_delay[dev]); // SCL = 1, SDA = 0
set_pins(dev, 1, 1); // SCL = 1, SDA = 1
}