libsigrok/src/hardware/hung-chang-dso-2100/protocol.c

465 lines
14 KiB
C

/*
* This file is part of the libsigrok project.
*
* Copyright (C) 2015 Daniel Glöckner <daniel-gl@gmx.net>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <config.h>
#include <ieee1284.h>
#include "protocol.h"
/* The firmware can be in the following states:
* 0x00 Temporary state during initialization
* Automatically transitions to state 0x01
* 0x01 Idle, this state updates calibration caps
* Send 0x02 to go to state 0x21
* Send 0x03 to go to state 0x03
* Send 0x04 to go to state 0x14
* 0x21 Trigger is armed, caps are _not_ updated
* Send 0x99 to check if trigger event occured
* if triggered, goes to state 0x03
* else stays in state 0x21
* Send 0xFE to generate artificial trigger event
* returns to state 0x21
* but next 0x99 will succeed
* Send 0xFF to go to state 0x03 (abort capture)
* 0x03 Extracts two 500 sample subsets from the 5000
* sample capture buffer for readout
* When reading samples, the FPGA starts at the
* first of the 1000 samples and automatically
* advances to the next.
* Send 0x04 to go to state 0x0F
* 0x14 Scroll acquisition mode, update calib caps
* When reading samples, the FPGA provides the
* current value of the ADCs
* Send 0xFF to go to state 0x0F
* 0x0F Send channel number (1 or 2) to go to next state
* There are actually two 0x0F states in series
* which both expect the channel number.
* If the values don't match, they are discarded.
* The next state 0x05 is entered anyway
* 0x05 Same as state 0x0F but expects sample rate index.
* The next state is 0x08
* 0x08 Same as state 0x0F but expects step size + 1 for
* the second 500 sample subset
* The next state is 0x09
* 0x09 Same as state 0x0F but expects step size + 1 for
* the first 500 sample subset
* The next state is 0x06
* 0x06 Same as state 0x0F but expects vdiv and coupling
* configuration for the first channel and trigger
* source selection.
* (U46 in the schematics)
* The next state is 0x07
* 0x07 Same as state 0x0F but expects vdiv and coupling
* configuration for the first channel and trigger
* type (edge, TV hsync, TV vsync).
* (U47 in the schematics)
* The next state is 0x0A
* 0x0A Same as state 0x0F but expects a parameter X + 1
* that determines the offset of the second 500 sample
* subset
* Offset = 5 * X * step size for first subset
* The next state is 0x0B
* 0x0B Same as state 0x0F but expects the type of edge to
* trigger on (rising or falling)
* The next state is 0x0C
* 0x0C Same as state 0x0F but expects the calibration
* value for the first channel's position
* (POS1 in the schematics)
* The next state is 0x0D
* 0x0D Same as state 0x0F but expects the calibration
* value for the second channel's position
* (POS2 in the schematics)
* The next state is 0x0E
* 0x0E Same as state 0x0F but expects the trigger level
* (TRIGLEVEL in the schematics)
* Keep in mind that trigger sources are AC coupled
* The next state is 0x10
* 0x10 Same as state 0x0F but expects the calibration
* value for the first channel's offset
* (OFFSET1 in the schematics)
* The next state is 0x11
* 0x11 Same as state 0x0F but expects the calibration
* value for the first channel's gain
* (GAIN1 in the schematics)
* The next state is 0x12
* 0x12 Same as state 0x0F but expects the calibration
* value for the second channel's offset
* (OFFSET2 in the schematics)
* The next state is 0x13
* 0x13 Same as state 0x0F but expects the calibration
* value for the second channel's gain
* (GAIN2 in the schematics)
* The next state is 0x01
*
* The Mailbox appears to be half duplex.
* If one side writes a byte into the mailbox, it
* reads 0 until the other side has written a byte.
* So you can't transfer 0.
*
* As the status signals are unconnected, the device is not
* IEEE1284 compliant and can't make use of EPP or ECP transfers.
* It drives the data lines when control is set to:
* 0 => Channel A data
* C1284_NAUTOFD => Channel B data
* C1284_NSELECTIN => Mailbox
* C1284_NSELECTIN | C1284_NAUTOFD => 0x55
*
* It takes about 200ns for the data lines to become stable after
* the control lines have been changed. This driver assumes that
* parallel port access is slow enough to not require additional
* delays.
*
* Channel values in state 0x14 and the mailbox can change their
* value while they are selected, the latter of course only from
* 0 to a valid state. Beware of intermediate values.
*
* SRAM N layout (N = 1 or 2):
* 0x0000-0x13ff samples captured from ADC N
* 0x4000-0x41f3 bytes extracted from 0x6000 with step1
* (both ADCs but only channel N)
* 0x41f4-0x43e7 bytes extracted from 0x6000+5*step1*shift
* with step2 (both ADCs but only channel N)
* 0x43e8-0x43ea {0x01, 0xfe, 0x80}
* 0x43eb-0x444e copy of bytes from 0x4320
* 0x6000-0x7387 interleaved SRAM 1 and SRAM 2 bytes from
* 0x0001 to 0x09c5 after channel N was captured
*
* On a trigger event the FPGA directs the ADC samples to the region
* at 0x0000. The microcontroller then copies 5000 samples from 0x0001
* to 0x6000. Each time state 0x03 is entered, the bytes from 0x4000
* to 0x444e are filled and the start address for readout is reset to
* 0x4000. Readout will wrap around back to 0x4000 after reaching 0x7fff.
*
* As you can see from the layout, it was probably intended to capture
* 5000 samples for both probes before they are read out. We don't do that
* to be able to read the full 10k samples captured by the FPGA. It would
* be useless anyway if you don't capture repetitive signals. We're also
* not reading the two samples at 0x0000 to save a few milliseconds.
*/
static const struct {
uint16_t num;
uint8_t step1;
uint8_t shift;
uint8_t interleave;
} readout_steps[] = {
{ 1000, 1, 100, 0 },
{ 500, 100, 2, 0 },
{ 500, 100, 3, 0 },
{ 500, 100, 4, 0 },
{ 500, 100, 5, 0 },
{ 500, 100, 6, 0 },
{ 500, 100, 7, 0 },
{ 500, 100, 8, 0 },
{ 500, 100, 9, 0 },
{ 499, 212, 41, 1 },
{ 500, 157, 56, 1 },
{ 500, 247, 36, 1 },
{ 500, 232, 180, 1 },
{ 500, 230, 182, 1 },
{ 120, 212, 43, 1 }
};
SR_PRIV void hung_chang_dso_2100_reset_port(struct parport *port)
{
ieee1284_write_control(port,
C1284_NSTROBE | C1284_NAUTOFD | C1284_NSELECTIN);
ieee1284_data_dir(port, 0);
}
SR_PRIV gboolean hung_chang_dso_2100_check_id(struct parport *port)
{
gboolean ret = FALSE;
if (ieee1284_data_dir(port, 1) != E1284_OK)
goto fail;
ieee1284_write_control(port, C1284_NSTROBE | C1284_NAUTOFD | C1284_NSELECTIN);
ieee1284_write_control(port, C1284_NAUTOFD | C1284_NSELECTIN);
if (ieee1284_read_data(port) != 0x55)
goto fail;
ret = TRUE;
fail:
hung_chang_dso_2100_reset_port(port);
return ret;
}
SR_PRIV void hung_chang_dso_2100_write_mbox(struct parport *port, uint8_t val)
{
sr_dbg("mbox <= %X", val);
ieee1284_write_control(port,
C1284_NSTROBE | C1284_NINIT | C1284_NSELECTIN);
ieee1284_data_dir(port, 0);
ieee1284_write_data(port, val);
ieee1284_write_control(port, C1284_NINIT | C1284_NSELECTIN);
ieee1284_write_control(port,
C1284_NSTROBE | C1284_NINIT | C1284_NSELECTIN);
ieee1284_data_dir(port, 1);
ieee1284_write_control(port,
C1284_NSTROBE | C1284_NAUTOFD | C1284_NINIT | C1284_NSELECTIN);
}
SR_PRIV uint8_t hung_chang_dso_2100_read_mbox(struct parport *port, float timeout)
{
GTimer *timer = NULL;
uint8_t val;
ieee1284_write_control(port, C1284_NSTROBE | C1284_NSELECTIN);
ieee1284_write_control(port, C1284_NSELECTIN);
for (;;) {
if (ieee1284_read_data(port)) {
/* Always read the value a second time.
* The first one may be unstable. */
val = ieee1284_read_data(port);
break;
}
if (!timer) {
timer = g_timer_new();
} else if (g_timer_elapsed(timer, NULL) > timeout) {
val = 0;
break;
}
}
ieee1284_write_control(port, C1284_NSTROBE | C1284_NSELECTIN);
ieee1284_write_control(port,
C1284_NSTROBE | C1284_NAUTOFD | C1284_NINIT | C1284_NSELECTIN);
if (timer)
g_timer_destroy(timer);
sr_dbg("mbox == %X", val);
return val;
}
SR_PRIV int hung_chang_dso_2100_move_to(const struct sr_dev_inst *sdi, uint8_t target)
{
struct dev_context *devc = sdi->priv;
int timeout = 40;
uint8_t c;
while (timeout--) {
c = hung_chang_dso_2100_read_mbox(sdi->conn, 0.1);
if (c == target)
return SR_OK;
switch (c) {
case 0x00:
/* Can happen if someone wrote something into
* the mbox that was not expected by the uC.
* Alternating between 0xff and 4 helps in
* all states. */
c = (timeout & 1) ? 0xFF : 0x04;
break;
case 0x01:
switch (target) {
case 0x21: c = 2; break;
case 0x03: c = 3; break;
default: c = 4;
}
break;
case 0x03: c = 4; break;
case 0x05: c = devc->rate + 1; break;
case 0x06: c = devc->cctl[0]; break;
case 0x07: c = devc->cctl[1]; break;
case 0x08: c = 1 /* step 2 */ + 1 ; break;
case 0x09: c = readout_steps[devc->step].step1 + 1; break;
case 0x0A: c = readout_steps[devc->step].shift + 1; break;
case 0x0B: c = devc->edge + 1; break;
case 0x0C: c = devc->pos[0]; break;
case 0x0D: c = devc->pos[1]; break;
case 0x0E: c = devc->tlevel; break;
case 0x0F:
if (!devc->channel)
c = 1;
else if (readout_steps[devc->step].interleave)
c = devc->adc2 ? 2 : 1;
else
c = devc->channel;
break;
case 0x10: c = devc->offset[0]; break;
case 0x11: c = devc->gain[0]; break;
case 0x12: c = devc->offset[1]; break;
case 0x13: c = devc->gain[1]; break;
case 0x14:
case 0x21: c = 0xFF; break;
default:
return SR_ERR_DATA;
}
hung_chang_dso_2100_write_mbox(sdi->conn, c);
}
return SR_ERR_TIMEOUT;
}
static void skip_samples(struct parport *port, uint8_t ctrl, size_t num)
{
while (num--) {
ieee1284_write_control(port, ctrl & ~C1284_NSTROBE);
ieee1284_write_control(port, ctrl);
}
}
static void read_samples(struct parport *port, uint8_t ctrl, uint8_t *buf, size_t num, size_t stride)
{
while (num--) {
ieee1284_write_control(port, ctrl & ~C1284_NSTROBE);
*buf = ieee1284_read_data(port);
buf += stride;
ieee1284_write_control(port, ctrl);
}
}
static void push_samples(const struct sr_dev_inst *sdi, uint8_t *buf, size_t num)
{
struct dev_context *devc = sdi->priv;
float *data = devc->samples;
struct sr_datafeed_analog_old analog = {
.channels = devc->enabled_channel,
.num_samples = num,
.mq = SR_MQ_VOLTAGE,
.unit = SR_UNIT_VOLT,
.mqflags = 0,
.data = data,
};
struct sr_datafeed_packet packet = {
.type = SR_DF_ANALOG_OLD,
.payload = &analog,
};
float factor = devc->factor;
while (num--)
data[num] = (buf[num] - 0x80) * factor;
sr_session_send(devc->cb_data, &packet);
}
static int read_subframe(const struct sr_dev_inst *sdi, uint8_t *buf)
{
struct dev_context *devc = sdi->priv;
uint8_t sig[3], ctrl;
unsigned int num;
gboolean interleave;
interleave = readout_steps[devc->step].interleave;
ctrl = C1284_NSTROBE;
if ((interleave && devc->adc2) || (!interleave && devc->channel == 2))
ctrl |= C1284_NAUTOFD;
ieee1284_write_control(sdi->conn, ctrl);
num = readout_steps[devc->step].num;
if (num < 1000)
skip_samples(sdi->conn, ctrl, 1000 - num);
read_samples(sdi->conn, ctrl, buf + (devc->adc2 ? 1 : 0), num,
interleave ? 2 : 1);
read_samples(sdi->conn, ctrl, sig, 3, 1);
if (sig[0] != 0x01 || sig[1] != 0xfe || sig[2] != 0x80) {
if (--devc->retries) {
sr_dbg("Missing signature at end of buffer, %i tries remaining",
devc->retries);
return TRUE;
} else {
sr_err("Failed to read frame without transfer errors");
devc->step = 0;
}
} else {
if (interleave && !devc->adc2) {
devc->adc2 = TRUE;
devc->retries = MAX_RETRIES;
return TRUE;
} else {
if (interleave)
num *= 2;
if (!devc->step) {
struct sr_datafeed_packet packet = {
.type = SR_DF_TRIGGER
};
push_samples(sdi, buf, 6);
sr_session_send(devc->cb_data, &packet);
buf += 6;
num -= 6;
}
push_samples(sdi, buf, num);
if (++devc->step > devc->last_step)
devc->step = 0;
}
}
devc->adc2 = FALSE;
devc->retries = MAX_RETRIES;
return devc->step > 0;
}
SR_PRIV int hung_chang_dso_2100_poll(int fd, int revents, void *cb_data)
{
struct sr_datafeed_packet packet = { .type = SR_DF_FRAME_BEGIN };
const struct sr_dev_inst *sdi;
struct dev_context *devc;
uint8_t state, buf[1000];
(void)fd;
(void)revents;
if (!(sdi = cb_data))
return TRUE;
if (!(devc = sdi->priv))
return TRUE;
if (devc->state_known)
hung_chang_dso_2100_write_mbox(sdi->conn, 0x99);
state = hung_chang_dso_2100_read_mbox(sdi->conn, 0.00025);
devc->state_known = (state != 0x00);
if (!devc->state_known || state == 0x21)
return TRUE;
if (state != 0x03) {
sr_err("Unexpected state 0x%X while checking for trigger", state);
return FALSE;
}
sr_session_send(devc->cb_data, &packet);
if (devc->channel) {
while (read_subframe(sdi, buf)) {
if (hung_chang_dso_2100_move_to(sdi, 1) != SR_OK)
break;
hung_chang_dso_2100_write_mbox(sdi->conn, 3);
g_usleep(1700);
if (hung_chang_dso_2100_read_mbox(sdi->conn, 0.02) != 0x03)
break;
}
}
packet.type = SR_DF_FRAME_END;
sr_session_send(devc->cb_data, &packet);
if (++devc->frame >= devc->frame_limit)
hung_chang_dso_2100_dev_acquisition_stop(sdi, devc->cb_data);
else
hung_chang_dso_2100_move_to(sdi, 0x21);
return TRUE;
}