circuitpython/ports/nrf/common-hal/bleio/Characteristic.c

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/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) Dan Halbert for Adafruit Industries
* Copyright (c) 2018 Artur Pacholec
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "py/runtime.h"
#include "shared-bindings/bleio/__init__.h"
#include "shared-bindings/bleio/Characteristic.h"
#include "shared-bindings/bleio/Descriptor.h"
#include "shared-bindings/bleio/Service.h"
static volatile bleio_characteristic_obj_t *m_read_characteristic;
STATIC uint16_t characteristic_get_cccd(uint16_t cccd_handle, uint16_t conn_handle) {
uint16_t cccd;
ble_gatts_value_t value = {
.p_value = (uint8_t*) &cccd,
.len = 2,
};
const uint32_t err_code = sd_ble_gatts_value_get(conn_handle, cccd_handle, &value);
if (err_code == BLE_ERROR_GATTS_SYS_ATTR_MISSING) {
// CCCD is not set, so say that neither Notify nor Indicate is enabled.
cccd = 0;
} else if (err_code != NRF_SUCCESS) {
mp_raise_OSError_msg_varg(translate("Failed to read CCCD value, err 0x%04x"), err_code);
}
return cccd;
}
STATIC void characteristic_on_gattc_read_rsp_evt(ble_evt_t *ble_evt, void *param) {
switch (ble_evt->header.evt_id) {
// More events may be handled later, so keep this as a switch.
case BLE_GATTC_EVT_READ_RSP: {
ble_gattc_evt_read_rsp_t *response = &ble_evt->evt.gattc_evt.params.read_rsp;
if (m_read_characteristic) {
m_read_characteristic->value = mp_obj_new_bytearray(response->len, response->data);
}
// Indicate to busy-wait loop that we've read the attribute value.
m_read_characteristic = NULL;
break;
}
default:
// For debugging.
// mp_printf(&mp_plat_print, "Unhandled characteristic event: 0x%04x\n", ble_evt->header.evt_id);
break;
}
}
STATIC void characteristic_gatts_notify_indicate(uint16_t handle, uint16_t conn_handle, mp_buffer_info_t *bufinfo, uint16_t hvx_type) {
uint16_t hvx_len = bufinfo->len;
ble_gatts_hvx_params_t hvx_params = {
.handle = handle,
.type = hvx_type,
.offset = 0,
.p_len = &hvx_len,
.p_data = bufinfo->buf,
};
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while (1) {
const uint32_t err_code = sd_ble_gatts_hvx(conn_handle, &hvx_params);
if (err_code == NRF_SUCCESS) {
break;
}
// TX buffer is full
// We could wait for an event indicating the write is complete, but just retrying is easier.
if (err_code == NRF_ERROR_RESOURCES) {
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RUN_BACKGROUND_TASKS;
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continue;
}
// Some real error has occurred.
mp_raise_OSError_msg_varg(translate("Failed to notify or indicate attribute value, err 0x%04x"), err_code);
}
}
STATIC void characteristic_gattc_read(bleio_characteristic_obj_t *characteristic) {
const uint16_t conn_handle = common_hal_bleio_device_get_conn_handle(characteristic->service->device);
common_hal_bleio_check_connected(conn_handle);
// Set to NULL in event loop after event.
m_read_characteristic = characteristic;
ble_drv_add_event_handler(characteristic_on_gattc_read_rsp_evt, characteristic);
const uint32_t err_code = sd_ble_gattc_read(conn_handle, characteristic->handle, 0);
if (err_code != NRF_SUCCESS) {
mp_raise_OSError_msg_varg(translate("Failed to read attribute value, err 0x%04x"), err_code);
}
while (m_read_characteristic != NULL) {
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RUN_BACKGROUND_TASKS;
}
ble_drv_remove_event_handler(characteristic_on_gattc_read_rsp_evt, characteristic);
}
void common_hal_bleio_characteristic_construct(bleio_characteristic_obj_t *self, bleio_service_obj_t *service, bleio_uuid_obj_t *uuid, bleio_characteristic_properties_t props, bleio_attribute_security_mode_t read_perm, bleio_attribute_security_mode_t write_perm, mp_int_t max_length, bool fixed_length, mp_buffer_info_t *initial_value_bufinfo) {
self->service = service;
self->uuid = uuid;
self->handle = BLE_GATT_HANDLE_INVALID;
self->props = props;
self->read_perm = read_perm;
self->write_perm = write_perm;
self->descriptor_list = mp_obj_new_list(0, NULL);
const mp_int_t max_length_max = fixed_length ? BLE_GATTS_FIX_ATTR_LEN_MAX : BLE_GATTS_VAR_ATTR_LEN_MAX;
if (max_length < 0 || max_length > max_length_max) {
mp_raise_ValueError_varg(translate("mnax_length must be 0-%d when fixed_length is %s"),
max_length_max, fixed_length ? "True" : "False");
}
self->max_length = max_length;
self->fixed_length = fixed_length;
common_hal_bleio_characteristic_set_value(self, initial_value_bufinfo);
}
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mp_obj_list_t *common_hal_bleio_characteristic_get_descriptor_list(bleio_characteristic_obj_t *self) {
return self->descriptor_list;
}
bleio_service_obj_t *common_hal_bleio_characteristic_get_service(bleio_characteristic_obj_t *self) {
return self->service;
}
mp_obj_t common_hal_bleio_characteristic_get_value(bleio_characteristic_obj_t *self) {
// Do GATT operations only if this characteristic has been added to a registered service.
if (self->handle != BLE_GATT_HANDLE_INVALID) {
uint16_t conn_handle = common_hal_bleio_device_get_conn_handle(self->service->device);
if (common_hal_bleio_service_get_is_remote(self->service)) {
// self->value is set by evt handler.
characteristic_gattc_read(self);
} else {
self->value = common_hal_bleio_gatts_read(self->handle, conn_handle);
}
}
return self->value;
}
void common_hal_bleio_characteristic_set_value(bleio_characteristic_obj_t *self, mp_buffer_info_t *bufinfo) {
if (self->fixed_length && bufinfo->len != self->max_length) {
mp_raise_ValueError(translate("Value length != required fixed length"));
}
if (bufinfo->len > self->max_length) {
mp_raise_ValueError(translate("Value length > max_length"));
}
self->value = mp_obj_new_bytes(bufinfo->buf, bufinfo->len);
// Do GATT operations only if this characteristic has been added to a registered service.
if (self->handle != BLE_GATT_HANDLE_INVALID) {
uint16_t conn_handle = common_hal_bleio_device_get_conn_handle(self->service->device);
if (common_hal_bleio_service_get_is_remote(self->service)) {
// Last argument is true if write-no-reponse desired.
common_hal_bleio_gattc_write(self->handle, conn_handle, bufinfo,
(self->props & CHAR_PROP_WRITE_NO_RESPONSE));
} else {
bool sent = false;
uint16_t cccd = 0;
const bool notify = self->props & CHAR_PROP_NOTIFY;
const bool indicate = self->props & CHAR_PROP_INDICATE;
if (notify | indicate) {
cccd = characteristic_get_cccd(self->cccd_handle, conn_handle);
}
// It's possible that both notify and indicate are set.
if (notify && (cccd & BLE_GATT_HVX_NOTIFICATION)) {
characteristic_gatts_notify_indicate(self->handle, conn_handle, bufinfo, BLE_GATT_HVX_NOTIFICATION);
sent = true;
}
if (indicate && (cccd & BLE_GATT_HVX_INDICATION)) {
characteristic_gatts_notify_indicate(self->handle, conn_handle, bufinfo, BLE_GATT_HVX_INDICATION);
sent = true;
}
if (!sent) {
common_hal_bleio_gatts_write(self->handle, conn_handle, bufinfo);
}
}
}
}
bleio_uuid_obj_t *common_hal_bleio_characteristic_get_uuid(bleio_characteristic_obj_t *self) {
return self->uuid;
}
bleio_characteristic_properties_t common_hal_bleio_characteristic_get_properties(bleio_characteristic_obj_t *self) {
return self->props;
}
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void common_hal_bleio_characteristic_add_descriptor(bleio_characteristic_obj_t *self, bleio_descriptor_obj_t *descriptor) {
ble_uuid_t desc_uuid;
bleio_uuid_convert_to_nrf_ble_uuid(descriptor->uuid, &desc_uuid);
ble_gatts_attr_md_t desc_attr_md = {
// Data passed is not in a permanent location and should be copied.
.vloc = BLE_GATTS_VLOC_STACK,
.vlen = !descriptor->fixed_length,
};
bleio_attribute_gatts_set_security_mode(&desc_attr_md.read_perm, descriptor->read_perm);
bleio_attribute_gatts_set_security_mode(&desc_attr_md.write_perm, descriptor->write_perm);
mp_buffer_info_t desc_value_bufinfo;
mp_get_buffer_raise(descriptor->value, &desc_value_bufinfo, MP_BUFFER_READ);
ble_gatts_attr_t desc_attr = {
.p_uuid = &desc_uuid,
.p_attr_md = &desc_attr_md,
.init_len = desc_value_bufinfo.len,
.p_value = desc_value_bufinfo.buf,
.init_offs = 0,
.max_len = descriptor->max_length,
};
uint32_t err_code = sd_ble_gatts_descriptor_add(self->handle, &desc_attr, &descriptor->handle);
if (err_code != NRF_SUCCESS) {
mp_raise_OSError_msg_varg(translate("Failed to add characteristic, err 0x%04x"), err_code);
}
mp_obj_list_append(self->descriptor_list, MP_OBJ_FROM_PTR(descriptor));
}
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void common_hal_bleio_characteristic_set_cccd(bleio_characteristic_obj_t *self, bool notify, bool indicate) {
if (self->cccd_handle == BLE_GATT_HANDLE_INVALID) {
mp_raise_ValueError(translate("No CCCD for this Characteristic"));
}
if (!common_hal_bleio_service_get_is_remote(self->service)) {
mp_raise_ValueError(translate("Can't set CCCD on local Characteristic"));
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}
const uint16_t conn_handle = common_hal_bleio_device_get_conn_handle(self->service->device);
common_hal_bleio_check_connected(conn_handle);
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uint16_t cccd_value =
(notify ? BLE_GATT_HVX_NOTIFICATION : 0) |
(indicate ? BLE_GATT_HVX_INDICATION : 0);
ble_gattc_write_params_t write_params = {
.write_op = BLE_GATT_OP_WRITE_REQ,
.handle = self->cccd_handle,
.p_value = (uint8_t *) &cccd_value,
.len = 2,
};
while (1) {
uint32_t err_code = sd_ble_gattc_write(conn_handle, &write_params);
if (err_code == NRF_SUCCESS) {
break;
}
// Write with response will return NRF_ERROR_BUSY if the response has not been received.
// Write without reponse will return NRF_ERROR_RESOURCES if too many writes are pending.
if (err_code == NRF_ERROR_BUSY || err_code == NRF_ERROR_RESOURCES) {
// We could wait for an event indicating the write is complete, but just retrying is easier.
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RUN_BACKGROUND_TASKS;
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continue;
}
// Some real error occurred.
mp_raise_OSError_msg_varg(translate("Failed to write CCCD, err 0x%04x"), err_code);
}
}