text: /*
   * This file is part of the libsigrok project.
   *
   * Copyright (C) 2013 Uwe Hermann <uwe@hermann-uwe.de>
   *
   * 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 2 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, write to the Free Software
   * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
   */
  
  #include <glib.h>
  #include "libsigrok.h"
  #include "libsigrok-internal.h"
  
  /**
   * Standard sr_driver_init() API helper.
   *
   * This function can be used to simplify most driver's init() API callback.
   *
   * It creates a new 'struct drv_context' (drvc), assigns sr_ctx to it, and
   * then 'drvc' is assigned to the 'struct sr_dev_driver' (di) that is passed.
   *
   * @param sr_ctx The libsigrok context to assign.
   * @param di The driver instance to use.
   * @param prefix A driver-specific prefix string used for log messages.
   *
   * @return SR_OK upon success, SR_ERR_ARG upon invalid arguments, or
   *         SR_ERR_MALLOC upon memory allocation errors.
   */
  SR_PRIV int std_init(struct sr_context *sr_ctx, struct sr_dev_driver *di,
  		     const char *prefix)
  {
  	struct drv_context *drvc;
  
  	if (!di) {
  		sr_err("%sInvalid driver, cannot initialize.", prefix);
  		return SR_ERR_ARG;
  	}
  
  	if (!(drvc = g_try_malloc(sizeof(struct drv_context)))) {
  		sr_err("%sDriver context malloc failed.", prefix);
  		return SR_ERR_MALLOC;
  	}
  
  	drvc->sr_ctx = sr_ctx;
  	drvc->instances = NULL;
  	di->priv = drvc;
  
  	return SR_OK;
  }
  
  /**
   * Standard API helper for sending an SR_DF_HEADER packet.
   *
   * This function can be used to simplify most driver's
   * dev_acquisition_start() API callback.
   *
   * @param sdi The device instance to use.
   * @param prefix A driver-specific prefix string used for log messages.
   * 		 Must not be NULL. An empty string is allowed.
   *
   * @return SR_OK upon success, SR_ERR_ARG upon invalid arguments, or
   *         SR_ERR upon other errors.
   */
  SR_PRIV int std_session_send_df_header(const struct sr_dev_inst *sdi,
  				       const char *prefix)
  {
  	int ret;
  	struct sr_datafeed_packet packet;
  	struct sr_datafeed_header header;
  
  	if (!prefix) {
  		sr_err("Invalid prefix.");
  		return SR_ERR_ARG;
  	}
  
  	sr_dbg("%sStarting acquisition.", prefix);
  
  	/* Send header packet to the session bus. */
  	sr_dbg("%sSending SR_DF_HEADER packet.", prefix);
  	packet.type = SR_DF_HEADER;
  	packet.payload = (uint8_t *)&header;
  	header.feed_version = 1;
  	gettimeofday(&header.starttime, NULL);
  
  	if ((ret = sr_session_send(sdi, &packet)) < 0) {
  		sr_err("%sFailed to send header packet: %d.", prefix, ret);
  		return ret;
  	}
  
  	return SR_OK;
  }
  
  #ifdef HAVE_LIBSERIALPORT
  
  /*
   * Standard sr_session_stop() API helper.
   *
   * This function can be used to simplify most (serial port based) driver's
   * dev_acquisition_stop() API callback.
   *
   * @param sdi The device instance for which acquisition should stop.
   *            Must not be NULL.
   * @param cb_data Opaque 'cb_data' pointer. Must not be NULL.
   * @param dev_close_fn Function pointer to the driver's dev_close().
   *               	  Must not be NULL.
   * @param serial The serial device instance (struct serial_dev_inst *).
   *               Must not be NULL.
   * @param prefix A driver-specific prefix string used for log messages.
   *               Must not be NULL. An empty string is allowed.
   *
   * @retval SR_OK Success.
   * @retval SR_ERR_ARG Invalid arguments.
   * @retval SR_ERR_DEV_CLOSED Device is closed.
   * @retval SR_ERR Other errors.
   */
  SR_PRIV int std_dev_acquisition_stop_serial(struct sr_dev_inst *sdi,
  			void *cb_data, dev_close_t dev_close_fn,
  			struct sr_serial_dev_inst *serial, const char *prefix)
  {
  	int ret;
  	struct sr_datafeed_packet packet;
  
  	if (!prefix) {
  		sr_err("Invalid prefix.");
  		return SR_ERR_ARG;
  	}
  
  	if (sdi->status != SR_ST_ACTIVE) {
  		sr_err("%sDevice inactive, can't stop acquisition.", prefix);
  		return SR_ERR_DEV_CLOSED;
  	}
  
  	sr_dbg("%sStopping acquisition.", prefix);
  
  	if ((ret = sr_source_remove(serial->fd)) < 0) {
  		sr_err("%sFailed to remove source: %d.", prefix, ret);
  		return ret;
  	}
  
  	if ((ret = dev_close_fn(sdi)) < 0) {
  		sr_err("%sFailed to close device: %d.", prefix, ret);
  		return ret;
  	}
  
  	/* Send SR_DF_END packet to the session bus. */
  	sr_dbg("%sSending SR_DF_END packet.", prefix);
  	packet.type = SR_DF_END;
  	packet.payload = NULL;
  	if ((ret = sr_session_send(cb_data, &packet)) < 0) {
  		sr_err("%sFailed to send SR_DF_END packet: %d.", prefix, ret);
  		return ret;
  	}
  
  	return SR_OK;
  }
  
  #endif
  
  /*
   * Standard driver dev_clear() helper.
   *
   * This function can be used to implement the dev_clear() driver API
   * callback. dev_close() is called before every sr_dev_inst is cleared.
   *
   * The only limitation is driver-specific device contexts (sdi->priv).
   * These are freed, but any dynamic allocation within structs stored
   * there cannot be freed.
   *
   * @param driver The driver which will have its instances released.
   * @param clear_private If not NULL, this points to a function called
   * with sdi->priv as argument. The function can then clear any device
   * instance-specific resources kept there. It must also clear the struct
   * pointed to by sdi->priv.
   *
   * @return SR_OK on success.
   */
  SR_PRIV int std_dev_clear(const struct sr_dev_driver *driver,
  		std_dev_clear_t clear_private)
  {
  	struct drv_context *drvc;
  	struct sr_dev_inst *sdi;
  	GSList *l;
  	int ret;
  
  	if (!(drvc = driver->priv))
  		/* Driver was never initialized, nothing to do. */
  		return SR_OK;
  
  	ret = SR_OK;
  	for (l = drvc->instances; l; l = l->next) {
  		if (!(sdi = l->data)) {
  			ret = SR_ERR_BUG;
  			continue;
  		}
  		if (driver->dev_close)
  			driver->dev_close(sdi);
  
  		if (sdi->conn) {
  #if HAVE_LIBSERIALPORT
  			if (sdi->inst_type == SR_INST_SERIAL)
  				sr_serial_dev_inst_free(sdi->conn);
  #endif
  #if HAVE_LIBUSB_1_0
  			if (sdi->inst_type == SR_INST_USB)
  				sr_usb_dev_inst_free(sdi->conn);
  #endif
  			if (sdi->inst_type == SR_INST_USBTMC)
  				sr_usbtmc_dev_inst_free(sdi->conn);
  		}
  		if (clear_private)
  			clear_private(sdi->priv);
  		else
  			g_free(sdi->priv);
  		sr_dev_inst_free(sdi);
  	}
  
  	g_slist_free(drvc->instances);
  	drvc->instances = NULL;
  
  	return ret;
  }
  