[libsigrok.git] / src / hardware / raspberrypi-pico / api.c

/*
 * This file is part of the libsigrok project.
 *
 * Copyright (C) 2022 Shawn Walker <ac0bi00@gmail.com>
 *
 * 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/>.
 */
//debug print levels are err/warn/info/dbg/spew
#include <config.h>
#include <fcntl.h>
#include <glib.h>
#include <math.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include <unistd.h>
#include <libsigrok/libsigrok.h>
#include "libsigrok-internal.h"
#include "protocol.h"

//Baud rate is really a don't care because we run USB CDC, dtr must be 1.
//flow should be zero since we don't
//use xon/xoff
#define SERIALCOMM "115200/8n1/dtr=1/rts=0/flow=0"

static const uint32_t scanopts[] = {
        SR_CONF_CONN,           //Required OS name for the port, i.e. /dev/ttyACM0
        SR_CONF_SERIALCOMM,     //Optional config of the port, i.e. 115200/8n1
};
//Sample rate can either provide a std_gvar_samplerates_steps or a std_gvar_samplerates.
//The latter is just a long list of every supported rate.
//For the steps, pulseview/pv/toolbars/mainbar.cpp will do a min,max,step.  If step is 
//1 then it provides a 1,2,5,10 select otherwise it allows a spin box.
//Going with the full list because while the spin box is more flexible, it is harder to read
static const uint64_t samplerates[] = {
        SR_KHZ(5),
        SR_KHZ(6),
        SR_KHZ(8),
        SR_KHZ(10),
        SR_KHZ(20),
        SR_KHZ(30),
        SR_KHZ(40),
        SR_KHZ(50),
        SR_KHZ(60),
        SR_KHZ(80),
        SR_KHZ(100),
        SR_KHZ(125),
        SR_KHZ(150),
        SR_KHZ(160),//max rate of 3 ADC channels that has integer divisor/dividend
        SR_KHZ(200),
        SR_KHZ(250), //max rate of 2 ADC channels
        SR_KHZ(300),
        SR_KHZ(400),
        SR_KHZ(500),
        SR_KHZ(600),
        SR_KHZ(800),
        //Give finer granularity near the thresholds of RLE effectiveness ~1-4Msps
        //Also use 1.2 and 2.4 as likely max values for ADC overclocking
        SR_MHZ(1),
        SR_MHZ(1.2),
        SR_MHZ(1.5),
        SR_MHZ(2),
        SR_MHZ(2.4),
        SR_MHZ(3),
        SR_MHZ(4),
        SR_MHZ(5),
        SR_MHZ(6),
        SR_MHZ(8),
        SR_MHZ(10),
        SR_MHZ(15),
        SR_MHZ(20),
        SR_MHZ(30),
        SR_MHZ(40),
        SR_MHZ(60),
        //The baseline 120Mhz PICO clock won't support an 80 or 100
        //with non fractional divisor, but an overclocked version or one
        //that modified sysclk could
        SR_MHZ(80),
        SR_MHZ(100),
        SR_MHZ(120),
        //These may not be practically useful, but someone might want to
        //try to make it work with overclocking
        SR_MHZ(150),
        SR_MHZ(200),
        SR_MHZ(240)     
};

static const uint32_t drvopts[] = {
        SR_CONF_OSCILLOSCOPE,
        SR_CONF_LOGIC_ANALYZER,
};

//SW trigger requires this
static const int32_t trigger_matches[] = {
        SR_TRIGGER_ZERO,
        SR_TRIGGER_ONE,
        SR_TRIGGER_RISING,
        SR_TRIGGER_FALLING,
        SR_TRIGGER_EDGE,
};


static const uint32_t devopts[] = {
//CLI prefers LIMIT_SAMPLES to be a list of high,low
        SR_CONF_LIMIT_SAMPLES | SR_CONF_GET | SR_CONF_SET | SR_CONF_LIST,
        SR_CONF_TRIGGER_MATCH | SR_CONF_LIST,
        SR_CONF_CAPTURE_RATIO | SR_CONF_GET | SR_CONF_SET,
//pulseview needs a list return to allow sample rate setting
        SR_CONF_SAMPLERATE | SR_CONF_GET | SR_CONF_SET | SR_CONF_LIST,
};

static struct sr_dev_driver raspberrypi_pico_driver_info;


static GSList *scan(struct sr_dev_driver *di, GSList * options)
{
        struct sr_config *src;
        struct sr_dev_inst *sdi;
        struct sr_serial_dev_inst *serial;
        struct dev_context *devc;
        struct sr_channel *ch;
        GSList *l;
        int num_read;
        unsigned int i;
        const char *conn, *serialcomm;
        char buf[32];
        int len;
        uint8_t num_a, num_d, a_size;
        gchar *channel_name;

        conn = serialcomm = NULL;
        for (l = options; l; l = l->next) {
                src = l->data;
                switch (src->key) {
                case SR_CONF_CONN:
                        conn = g_variant_get_string(src->data, NULL);
                        break;
                case SR_CONF_SERIALCOMM:
                        serialcomm = g_variant_get_string(src->data, NULL);
                        break;
                }
        }
        if (!conn)
                return NULL;

        if (!serialcomm)
                serialcomm = SERIALCOMM;

        serial = sr_serial_dev_inst_new(conn, serialcomm);
        sr_info("Opening %s.", conn);
        if (serial_open(serial, SERIAL_RDWR) != SR_OK) {
                sr_err("1st serial open fail");
                return NULL;
        }

        sr_info("Resetting device with *s at %s.", conn);
        send_serial_char(serial, '*');
        g_usleep(10000);
        //drain any inflight data
        do {
                sr_warn("Drain reads");
                len = serial_read_blocking(serial, buf, 32, 100);
                sr_warn("Drain reads done");
                if (len)
                        sr_dbg("Dropping in flight serial data");
        } while (len > 0);


        //Send identify 
        num_read = send_serial_w_resp(serial, "i\n", buf, 17);
        if (num_read < 16) {
                sr_err("1st identify failed");
                serial_close(serial);
                g_usleep(100000);
                if (serial_open(serial, SERIAL_RDWR) != SR_OK) {
                        sr_err("2nd serial open fail");
                        return NULL;
                }
                g_usleep(100000);
                sr_err("Send second *");
                send_serial_char(serial, '*');
                g_usleep(100000);
                num_read = send_serial_w_resp(serial, "i\n", buf, 17);
                if (num_read < 10) {
                        sr_err("Second attempt failed");
                        return NULL;
                }
        }
        //Expected ID response is SRPICO,AxxyDzz,VV 
        //where xx are number of analog channels, y is bytes per analog sample
        //and zz is number of digital channels, and VV is two digit version# which must be 02
        if ((num_read < 16)
            || (strncmp(buf, "SRPICO,A", 8))
            || (buf[11] != 'D')
            || (buf[15] != '0')
            || (buf[16] != '2')) {
                sr_err("ERROR:Bad response string %s %d", buf, num_read);
                return NULL;
        }
        a_size = buf[10] - '0';
        buf[10] = '\0';         //Null to end the str for atois
        buf[14] = '\0';         //Null to end the str for atois
        num_a = atoi(&buf[8]);
        num_d = atoi(&buf[12]);

        sdi = g_malloc0(sizeof(struct sr_dev_inst));
        sdi->status = SR_ST_INACTIVE;
        sdi->vendor = g_strdup("Raspberry Pi");
        sdi->model = g_strdup("PICO");
        sdi->version = g_strdup("00");
        sdi->conn = serial;
        sdi->driver = &raspberrypi_pico_driver_info;
        sdi->inst_type = SR_INST_SERIAL;
        sdi->serial_num = g_strdup("N/A");
        if (((num_a == 0) && (num_d == 0))
            || (num_a > MAX_ANALOG_CHANNELS)
            || (num_d > MAX_DIGITAL_CHANNELS)
            || (a_size < 1)
            || (a_size > 4)) {
                sr_err("ERROR: invalid channel config a %d d %d asz %d",
                       num_a, num_d, a_size);
                return NULL;
        }
        devc = g_malloc0(sizeof(struct dev_context));
        devc->a_size = a_size;
        //multiple bytes per analog sample not supported
        if ((num_a > 0) && (devc->a_size != 1)) {
                sr_err("Only Analog Size of 1 supported\n\r");
                return NULL;
        }
        devc->num_a_channels = num_a;
        devc->num_d_channels = num_d;
        devc->a_chan_mask = ((1 << num_a) - 1);
        devc->d_chan_mask = ((1 << num_d) - 1);
//The number of bytes that each digital sample in the buffers sent to the session. 
//All logical channels are packed together, where a slice of N channels takes roundup(N/8) bytes
//This never changes even if channels are disabled because PV expects disabled channels to still 
//be accounted for in the packing
        devc->dig_sample_bytes = ((devc->num_d_channels + 7) / 8);
        //These are the slice sizes of the data on the wire
        //1 7 bit field per byte
        devc->bytes_per_slice = (devc->num_a_channels * devc->a_size);
        if (devc->num_d_channels > 0) {
                // logic sent in groups of 7
                devc->bytes_per_slice += (devc->num_d_channels + 6) / 7;
        }
        sr_dbg("num channels a %d d %d bps %d dsb %d", num_a, num_d,
               devc->bytes_per_slice, devc->dig_sample_bytes);
//Each analog channel is it's own group
//Digital are just channels
//Grouping of channels is rather arbitrary as parameters like sample rate and number of samples
//apply to all changes.  Analog channels do have a scale and offset, but that is applied
//without involvement of the session.
        devc->analog_groups = g_malloc0(sizeof(struct sr_channel_group *) *
                                        devc->num_a_channels);
        for (i = 0; i < devc->num_a_channels; i++) {
                channel_name = g_strdup_printf("A%d", i);
                //sdi, index, type, enabled,name
                ch = sr_channel_new(sdi, i, SR_CHANNEL_ANALOG, TRUE,
                                    channel_name);
                devc->analog_groups[i] =
                    g_malloc0(sizeof(struct sr_channel_group));
                devc->analog_groups[i]->name = channel_name;
                devc->analog_groups[i]->channels =
                    g_slist_append(NULL, ch);
                sdi->channel_groups =
                    g_slist_append(sdi->channel_groups,
                                   devc->analog_groups[i]);
        }

        if (devc->num_d_channels > 0) {
                for (i = 0; i < devc->num_d_channels; i++) {
                        //Name digital channels starting at D2 to match pico board pin names
                        channel_name = g_strdup_printf("D%d", i + 2);
                        sr_channel_new(sdi, i, SR_CHANNEL_LOGIC, TRUE,
                                       channel_name);
                        g_free(channel_name);
                }

        }
        //In large sample usages we get the call to receive with large transfers.
        //Since the CDC serial implemenation can silenty lose data as it gets close to full, allocate
        //storage for a half buffer which in a worst case scenario has 2x ratio of transmitted bytes
        // to storage bytes. 
        //Note: The intent of making this buffer large is to prevent CDC serial buffer overflows.
        //However, it is likely that if the host is running slow (i.e. it's a raspberry pi model 3) that it becomes
        //compute bound and doesn't service CDC serial responses in time to not overflow the internal CDC buffers.
        //And thus no serial buffer is large enough.  But, it's only 32K....
        devc->serial_buffer_size = 32000;
        devc->buffer = NULL;
        sr_dbg("Setting serial buffer size: %i.",
               devc->serial_buffer_size);
        devc->cbuf_wrptr = 0;
        //While slices are sent as a group of one sample across all channels, sigrok wants analog 
        //channel data sent as separate packets.  
        //Logical trace values are packed together.
        //An RLE byte in normal mode can represent up to 1640 samples.
        //In D4 an RLE byte can represents up to 640 samples.
        //Rather than making the sample_buf_size 1640x the size of serial buff, we require that the process loops
        //push samples to the session as we get anywhere close to full.

        devc->sample_buf_size = devc->serial_buffer_size;
        for (i = 0; i < devc->num_a_channels; i++) {
                devc->a_data_bufs[i] = NULL;
                devc->a_pretrig_bufs[i] = NULL;
        }
        devc->d_data_buf = NULL;
        devc->sample_rate = 5000;
        devc->capture_ratio = 10;
        devc->rxstate = RX_IDLE;
        sdi->priv = devc;
        //Set an initial value as various code relies on an inital value.
        devc->limit_samples = 1000;

        if (raspberrypi_pico_get_dev_cfg(sdi) != SR_OK) {
                return NULL;
        };

        sr_err("sr_err level logging enabled");
        sr_warn("sr_warn level logging enabled");
        sr_info("sr_info level logging enabled");
        sr_dbg("sr_dbg level logging enabled");
        sr_spew("sr_spew level logging enabled");
        serial_close(serial);
        return std_scan_complete(di, g_slist_append(NULL, sdi));

}



//Note that on the initial driver load we pull all values into local storage.
//Thus gets can return local data, but sets have to issue commands to device.
static int config_set(uint32_t key, GVariant * data,
                      const struct sr_dev_inst *sdi,
                      const struct sr_channel_group *cg)
{
        struct dev_context *devc;
        int ret;
        (void) cg;
        if (!sdi)
                return SR_ERR_ARG;
        devc = sdi->priv;
        ret = SR_OK;
        sr_dbg("Got config_set key %d \n", key);
        switch (key) {
        case SR_CONF_SAMPLERATE:
                devc->sample_rate = g_variant_get_uint64(data);
                sr_dbg("config_set sr %llu\n", devc->sample_rate);
                break;
        case SR_CONF_LIMIT_SAMPLES:
                devc->limit_samples = g_variant_get_uint64(data);
                sr_dbg("config_set slimit %" PRIu64 "\n", devc->limit_samples);
                break;
        case SR_CONF_CAPTURE_RATIO:
                devc->capture_ratio = g_variant_get_uint64(data);
                break;

        default:
                sr_err("ERROR:config_set undefine %d\n", key);
                ret = SR_ERR_NA;
        }

        return ret;
}

static int config_get(uint32_t key, GVariant ** data,
                      const struct sr_dev_inst *sdi,
                      const struct sr_channel_group *cg)
{
        struct dev_context *devc;
        sr_dbg("at config_get key %d", key);
        (void) cg;
        if (!sdi)
                return SR_ERR_ARG;

        devc = sdi->priv;
        switch (key) {
        case SR_CONF_SAMPLERATE:
                *data = g_variant_new_uint64(devc->sample_rate);
                sr_spew("sample rate get of %" PRIu64 "", devc->sample_rate);
                break;
        case SR_CONF_CAPTURE_RATIO:
                if (!sdi)
                        return SR_ERR;
                devc = sdi->priv;
                *data = g_variant_new_uint64(devc->capture_ratio);
                break;
        case SR_CONF_LIMIT_SAMPLES:
                sr_spew("config_get limit_samples of %llu",
                        devc->limit_samples);
                *data = g_variant_new_uint64(devc->limit_samples);
                break;
        default:
                sr_spew("unsupported cfg_get key %d", key);
                return SR_ERR_NA;
        }
        return SR_OK;
}

static int config_list(uint32_t key, GVariant ** data,
                       const struct sr_dev_inst *sdi,
                       const struct sr_channel_group *cg)
{
        (void) cg;
        //scan or device options are the only ones that can be called without a defined instance
        if ((key == SR_CONF_SCAN_OPTIONS)
            || (key == SR_CONF_DEVICE_OPTIONS)) {
                return STD_CONFIG_LIST(key, data, sdi, cg, scanopts,
                                       drvopts, devopts);
        }
        if (!sdi) {
                sr_err
                    ("ERROR:\n\r\n\r\n\r Call to config list with null sdi\n\r\n\r");
                return SR_ERR_ARG;
        }
        sr_dbg("start config_list with key %X\n", key);
        switch (key) {
        case SR_CONF_SAMPLERATE:
                sr_dbg("Return sample rate list");
                *data =
                    std_gvar_samplerates(ARRAY_AND_SIZE
                                               (samplerates));
                break;
//This must be set to get SW trigger support
        case SR_CONF_TRIGGER_MATCH:
                *data =
                    std_gvar_array_i32(ARRAY_AND_SIZE(trigger_matches));
                break;
        case SR_CONF_LIMIT_SAMPLES:
                //Really this limit is up to the memory capacity of the host,
                //and users that pick huge values deserve what they get.
                //But setting this limit to prevent really crazy things.
                *data = std_gvar_tuple_u64(1LL, 1000000000LL);
                sr_dbg("sr_config_list limit samples ");
                break;
        default:
                sr_dbg("reached default statement of config_list");

                return SR_ERR_NA;
        }

        return SR_OK;
}

static int dev_acquisition_start(const struct sr_dev_inst *sdi)
{
        struct sr_serial_dev_inst *serial;
        struct dev_context *devc;
        struct sr_channel *ch;
        struct sr_trigger *trigger;
        char tmpstr[20];
        char buf[32];
        GSList *l;
        int a_enabled = 0, d_enabled = 0, len;
        serial = sdi->conn;
        int i,num_read;
        devc = sdi->priv;
        sr_dbg("Enter acq start");
        sr_dbg("dsbstart %d", devc->dig_sample_bytes);
        devc->buffer = g_malloc(devc->serial_buffer_size);
        if (!(devc->buffer)) {
                sr_err("ERROR:serial buffer malloc fail");
                return SR_ERR_MALLOC;
        }
        //Get device in idle state
        if (serial_drain(serial) != SR_OK) {
                sr_err("Initial Drain Failed\n\r");
                return SR_ERR;
        }
        send_serial_char(serial, '*');
        if (serial_drain(serial) != SR_OK) {
                sr_err("Second Drain Failed\n\r");
                return SR_ERR;
        }

        for (l = sdi->channels; l; l = l->next) {
                ch = l->data;
                sr_dbg("c %d enabled %d name %s\n", ch->index, ch->enabled,
                       ch->name);

                if (ch->name[0] == 'A') {
                        devc->a_chan_mask &= ~(1 << ch->index);
                        if (ch->enabled) {
                                devc->a_chan_mask |=
                                    (ch->enabled << ch->index);
                                a_enabled++;
                        }
                }
                if (ch->name[0] == 'D') {
                        devc->d_chan_mask &= ~(1 << ch->index);
                        if (ch->enabled) {
                                devc->d_chan_mask |=
                                    (ch->enabled << ch->index);
                                d_enabled++;
                        }
                }
                sr_info("Channel enable masks D 0x%X A 0x%X",
                        devc->d_chan_mask, devc->a_chan_mask);
                sprintf(tmpstr, "%c%d%d\n", ch->name[0], ch->enabled,
                        ch->index);
                if (send_serial_w_ack(serial, tmpstr) != SR_OK) {
                        sr_err("ERROR:Channel enable fail");
                        return SR_ERR;
                } else {

                }
        }//for all channels
        //ensure data channels are continuous
        int invalid = 0;
        for (i = 0; i < 32; i++) {
                if ((devc->d_chan_mask >> i) & 1) {
                        if (invalid) {
                                sr_err
                                    ("Digital channel mask 0x%X not continous\n\r",
                                     devc->d_chan_mask);
                                return SR_ERR;
                        }
                } else {
                        invalid = 1;
                }
        }
        //recalculate bytes_per_slice based on which analog channels are enabled 
        devc->bytes_per_slice = (a_enabled * devc->a_size);

        for (i = 0; i < devc->num_d_channels; i += 7) {
                if (((devc->d_chan_mask) >> i) & (0x7F)) {
                        (devc->bytes_per_slice)++;
                }
        }
        if ((a_enabled == 0) && (d_enabled == 0)) {
                sr_err("ERROR:No channels enabled");
                return SR_ERR;
        }
        sr_dbg("bps %d\n", devc->bytes_per_slice);

        //Apply sample rate limits
        //While earlier versions forced a lower sample rate, the PICO seems to allow
        //ADC overclocking, and by not enforcing these limits it may support other devices.
        //Thus call sr_err to get something into the device logs, but allowing it to progress.
        if ((a_enabled == 3) && (devc->sample_rate > 160000)) {
                sr_err
                    ("WARN:3 channel ADC sample rate above 160khz");
        }
        if ((a_enabled == 2) && (devc->sample_rate > 250000)) {
                sr_err
                    ("WARN:2 channel ADC sample rate above 250khz");
        }
        if ((a_enabled == 1) && (devc->sample_rate > 500000)) {
                sr_err
                    ("WARN:1 channel ADC sample rate above 500khz");
        }
        //Depending on channel configs, rates below 5ksps are possible
        //but such a low rate can easily stream and this eliminates a lot
        //of special cases.
        if (devc->sample_rate < 5000) {
                sr_err("Sample rate override to min of 5ksps");
                devc->sample_rate = 5000;
        }
        //While PICO specs a max clock ~120-125Mhz, it does overclock in many cases
        //so leaving is a warning.
        if (devc->sample_rate > 120000000) {
                sr_err("WARN: Sample rate above 120Msps");
        }
        //It may take a very large number of samples to notice, but if digital and analog are enabled
        //and either PIO or ADC are fractional the samples will skew over time.
        //24Mhz is the max common divisor to the 120Mhz and 48Mhz ADC clock
        //so force an integer divisor to 24Mhz.
        if ((a_enabled > 0) && (d_enabled > 0)) {
                if (24000000ULL % (devc->sample_rate)) {
                        uint32_t commondivint =
                            24000000ULL / (devc->sample_rate);
                        //Always increment the divisor so that we go down in frequency to avoid max sample rate issues
                        commondivint++;
                        devc->sample_rate = 24000000ULL / commondivint;
                        //Make sure the divisor increement didn't make use go too low.
                        if (devc->sample_rate < 5000) {
                                devc->sample_rate = 50000;
                        }
                        sr_err
                            ("WARN: Forcing common integer divisor sample rate of %llu div %u\n\r",
                             devc->sample_rate, commondivint);
                }

        }
        //If we are only digital or only analog print a warning that the 
        //fractional divisors aren't a true PLL fractional feedback loop and thus
        //could have sample to sample variation.
        //These warnings of course assume that the device is programmed with the expected ratios
        //but non PICO implementations, or PICO implementations that use different divisors could avoid.
        //This generally won't be a problem because most of the sampe_rate pulldown values are integer divisors.
        if (a_enabled > 0) {
                if (48000000ULL % (devc->sample_rate * a_enabled)) {
                        sr_warn
                            ("WARN: Non integer ADC divisor of 48Mhz clock for sample rate %llu may cause sample to sample variability.",
                             devc->sample_rate);
                }
        }
        if (d_enabled > 0) {
                if (120000000ULL % (devc->sample_rate)) {
                        sr_warn
                            ("WARN: Non integer PIO divisor of 120Mhz for sample rate %llu may cause sample to sample variability.",
                             devc->sample_rate);
                }
        }

        
        sprintf(tmpstr, "L%" PRIu64 "\n", devc->limit_samples);
        if (send_serial_w_ack(serial, tmpstr) != SR_OK) {
                sr_err("Sample limit to device failed");
                return SR_ERR;
        }
        //To support future devices that may allow the analog scale/offset to change, call get_dev_cfg again to get new values
        if(raspberrypi_pico_get_dev_cfg(sdi) != SR_OK){
          sr_err("get_dev_cfg failure on start");
          return SR_ERR;
        }

        //With all other params set, we use the final sample rate setting as an opportunity for the device
        //to communicate any errors in configuration.
        //A single  "*" indicates success.
        //A "*" with subsequent data is success, but allows for the device to print something
        //to the error console without aborting.
        //A non "*" in the first character blocks the start
        sprintf(tmpstr, "R%llu\n", devc->sample_rate);
        num_read = send_serial_w_resp(serial, tmpstr, buf, 30);
        buf[num_read]=0;
        if((num_read>1)&&(buf[0]=='*')){
                sr_err("Sample rate to device success with resp %s",buf);
        }
        else if(!((num_read==1)&&(buf[0]=='*'))){
                sr_err("Sample rate to device failed");
                if(num_read>0){
                  buf[num_read]=0;
                  sr_err("sample_rate error string %s",buf);
                }
                return SR_ERR;
        }
        devc->sent_samples = 0;
        devc->byte_cnt = 0;
        devc->bytes_avail = 0;
        devc->wrptr = 0;
        devc->cbuf_wrptr = 0;
        len =
            serial_read_blocking(serial, devc->buffer,
                                 devc->serial_buffer_size,
                                 serial_timeout(serial, 4));
        if (len > 0) {
                sr_info("Pre-ARM drain had %d characters:", len);
                devc->buffer[len] = 0;
                sr_info("%s", devc->buffer);
        }

        for (i = 0; i < devc->num_a_channels; i++) {
                devc->a_data_bufs[i] =
                    g_malloc(devc->sample_buf_size * sizeof(float));
                if (!(devc->a_data_bufs[i])) {
                        sr_err("ERROR:analog buffer malloc fail");
                        return SR_ERR_MALLOC;
                }
        }
        if (devc->num_d_channels > 0) {
                devc->d_data_buf =
                    g_malloc(devc->sample_buf_size *
                             devc->dig_sample_bytes);
                if (!(devc->d_data_buf)) {
                        sr_err("ERROR:logic buffer malloc fail");
                        return SR_ERR_MALLOC;
                }
        }
        devc->pretrig_entries =
            (devc->capture_ratio * devc->limit_samples) / 100;
        //While the driver supports the passing of trigger info to the device
        //it has been found that the sw overhead of supporting triggering and 
        //pretrigger buffer entries etc.. ends up slowing the cores down enough
        //that the effective continous sample rate isn't much higher than that of sending
        //untriggered samples across USB.  Thus this code will remain but likely may 
        //not be used by the device, unless HW based triggers are implemented
        if ((trigger = sr_session_trigger_get(sdi->session))) {
                if (g_slist_length(trigger->stages) > 1)
                        return SR_ERR_NA;

                struct sr_trigger_stage *stage;
                struct sr_trigger_match *match;
                GSList *l;
                stage = g_slist_nth_data(trigger->stages, 0);
                if (!stage)
                        return SR_ERR_ARG;
                for (l = stage->matches; l; l = l->next) {
                        match = l->data;
                        if (!match->match)
                                continue;
                        if (!match->channel->enabled)
                                continue;
                        int idx = match->channel->index;
                        int8_t val;
                        switch(match->match){
                            case SR_TRIGGER_ZERO:
                              val=0; break;
                            case SR_TRIGGER_ONE:
                              val=1; break;
                            case SR_TRIGGER_RISING:
                              val=2; break;
                            case SR_TRIGGER_FALLING:
                              val=3; break;
                            case SR_TRIGGER_EDGE:
                              val=4; break;
                            default:
                              val=-1;
                        }
                        sr_info("Trigger value idx %d match %d",idx,match->match);
                        //Only set trigger on enabled channels
                        if((val>=0) && ((devc->d_chan_mask>>idx)&1)){
                          sprintf(&tmpstr[0], "t%d%02d\n", val,idx+2);
                          if (send_serial_w_ack(serial, tmpstr) != SR_OK) {
                            sr_err("Trigger cfg to device failed");
                            return SR_ERR;
                          }   

                        }
                }
                sprintf(&tmpstr[0], "p%d\n", devc->pretrig_entries);
                if (send_serial_w_ack(serial, tmpstr) != SR_OK) {
                    sr_err("Pretrig to device failed");
                            return SR_ERR; 
                }              
                devc->stl =
                    soft_trigger_logic_new(sdi, trigger,
                                           devc->pretrig_entries);
                if (!devc->stl)
                        return SR_ERR_MALLOC;
                devc->trigger_fired = FALSE;
                if (devc->pretrig_entries > 0) {
                        sr_dbg("Allocating pretrig buffers size %d",
                               devc->pretrig_entries);
                        for (i = 0; i < devc->num_a_channels; i++) {
                                if ((devc->a_chan_mask >> i) & 1) {
                                        devc->a_pretrig_bufs[i] =
                                            g_malloc0(sizeof(float) *
                                                      devc->
                                                      pretrig_entries);
                                        if (!devc->a_pretrig_bufs[i]) {
                                                sr_err
                                                    ("ERROR:Analog pretrigger buffer malloc failure, disabling");
                                                devc->trigger_fired = TRUE;
                                        }
                                }       //if chan_mask
                        }       //for num_a_channels
                }               //if pre_trigger
                sr_info("Entering sw triggered mode");
                //post the receive before starting the device to ensure we are ready to receive data ASAP
                serial_source_add(sdi->session, serial, G_IO_IN, 200,
                                  raspberrypi_pico_receive, (void *) sdi);
                sprintf(tmpstr, "C\n");
                if (send_serial_str(serial, tmpstr) != SR_OK)
                        return SR_ERR;

        } else {
                devc->trigger_fired = TRUE;
                devc->pretrig_entries = 0;
                sr_info("Entering fixed sample mode");
                serial_source_add(sdi->session, serial, G_IO_IN, 200,
                                  raspberrypi_pico_receive, (void *) sdi);
                sprintf(tmpstr, "F\n");
                if (send_serial_str(serial, tmpstr) != SR_OK)
                        return SR_ERR;
        }
        std_session_send_df_header(sdi);

        sr_dbg("dsbstartend %d", devc->dig_sample_bytes);

        if (devc->trigger_fired)
                std_session_send_df_trigger(sdi);
        //Keep this at the end as we don't want to be RX_ACTIVE unless everything is ok
        devc->rxstate = RX_ACTIVE;

        return SR_OK;
}

//This function is called either by the protocol code if we reached all of the samples 
//or an error condition, and also by the user clicking stop in pulseview.
//It must always be called for any acquistion that was started to free memory.
static int dev_acquisition_stop(struct sr_dev_inst *sdi)
{
        struct dev_context *devc;
        struct sr_serial_dev_inst *serial;
        sr_dbg("****at dev_acquisition_stop");
        int len;
        devc = sdi->priv;
        serial = sdi->conn;

        std_session_send_df_end(sdi);
        //If we reached this while still active it is likely because the stop button was pushed 
        //in pulseview.
        //That is generally some kind of error condition, so we don't try to check the bytenct
        if (devc->rxstate == RX_ACTIVE) {
                sr_err("Reached dev_acquisition_stop in RX_ACTIVE");
        }
        if (devc->rxstate != RX_IDLE) {
                sr_err("Sending plus to stop device stream\n\r");
                send_serial_char(serial, '+');
        }
        //In case we get calls to receive force it to exit
        devc->rxstate = RX_IDLE;
        //drain data from device so that it doesn't confuse subsequent commands
        do {
                len =
                    serial_read_blocking(serial, devc->buffer,
                                         devc->serial_buffer_size, 100);
                if (len)
                        sr_err("Dropping %d device bytes\n\r", len);
        } while (len > 0);
        if (devc->buffer) {
                g_free(devc->buffer);
                devc->buffer = NULL;
        }
        for (int i = 0; i < devc->num_a_channels; i++) {
                if (devc->a_data_bufs[i]) {
                        g_free(devc->a_data_bufs[i]);
                        devc->a_data_bufs[i] = NULL;
                }
        }
        if (devc->d_data_buf) {
                g_free(devc->d_data_buf);
                devc->d_data_buf = NULL;
        }
        for (int i = 0; i < devc->num_a_channels; i++) {
                if (devc->a_pretrig_bufs[i])
                        g_free(devc->a_pretrig_bufs[i]);
                devc->a_pretrig_bufs[i] = NULL;
        }
        serial = sdi->conn;
        serial_source_remove(sdi->session, serial);
        return SR_OK;
}

static struct sr_dev_driver raspberrypi_pico_driver_info = {
        .name = "raspberrypi-pico",
        .longname = "RaspberryPI PICO",
        .api_version = 1,
        .init = std_init,
        .cleanup = std_cleanup,
        .scan = scan,
        .dev_list = std_dev_list,
        .dev_clear = std_dev_clear,
        .config_get = config_get,
        .config_set = config_set,
        .config_list = config_list,
        .dev_open = std_serial_dev_open,
        .dev_close = std_serial_dev_close,
        .dev_acquisition_start = dev_acquisition_start,
        .dev_acquisition_stop = dev_acquisition_stop,
        .context = NULL,
};

SR_REGISTER_DEV_DRIVER(raspberrypi_pico_driver_info);