Create project

1 files changed, 163 insertions, 0 deletions

diff --git a/c_sources/osmo-fl2k.h b/c_sources/osmo-fl2k.h
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+/*
+ * osmo-fl2k, turns FL2000-based USB 3.0 to VGA adapters into
+ * low cost DACs
+ *
+ * Copyright (C) 2016-2018 by Steve Markgraf <steve@steve-m.de>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __FL2K_H
+#define __FL2K_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdint.h>
+#include "osmo-fl2k_export.h"
+
+enum fl2k_error {
+	FL2K_SUCCESS = 0,
+	FL2K_TRUE = 1,
+	FL2K_ERROR_INVALID_PARAM = -1,
+	FL2K_ERROR_NO_DEVICE = -2,
+	FL2K_ERROR_NOT_FOUND = -5,
+	FL2K_ERROR_BUSY = -6,
+	FL2K_ERROR_TIMEOUT = -7,
+	FL2K_ERROR_NO_MEM = -11,
+};
+
+typedef struct fl2k_data_info {
+	/* information provided by library */
+	void *ctx;
+	uint32_t underflow_cnt;		/* underflows since last callback */
+	uint32_t len;			/* buffer length */
+	int using_zerocopy;		/* using zerocopy kernel buffers */
+	int device_error;		/* device error happened, terminate application */
+
+	/* filled in by application */
+	int sampletype_signed;		/* are samples signed or unsigned? */
+	char *r_buf;			/* pointer to red buffer */
+	char *g_buf;			/* pointer to green buffer */
+	char *b_buf;			/* pointer to blue buffer */
+} fl2k_data_info_t;
+
+typedef struct fl2k_dev fl2k_dev_t;
+
+/** The transfer length was chosen by the following criteria:
+ * - Must be a supported resolution of the FL2000DX
+ * - Must be a multiple of 61440 bytes (URB payload length),
+ *   which is important for using the DAC without HSYNC/VSYNC blanking,
+ *   otherwise a couple of samples are missing between every buffer
+ * - Should be smaller than 4MB in order to be allocatable by kmalloc()
+ *   for zerocopy transfers
+ **/
+#define FL2K_BUF_LEN		(1280 * 1024)
+#define FL2K_XFER_LEN		(FL2K_BUF_LEN * 3)
+
+FL2K_API uint32_t fl2k_get_device_count(void);
+
+FL2K_API const char* fl2k_get_device_name(uint32_t index);
+
+FL2K_API int fl2k_open(fl2k_dev_t **dev, uint32_t index);
+
+FL2K_API int fl2k_close(fl2k_dev_t *dev);
+
+/* configuration functions */
+
+/*!
+ * Set the sample rate (pixel clock) for the device
+ *
+ * \param dev the device handle given by fl2k_open()
+ * \param samp_rate the sample rate to be set, maximum value depends
+ * 	  on host and USB controller
+ * \return 0 on success, -EINVAL on invalid rate
+ */
+FL2K_API int fl2k_set_sample_rate(fl2k_dev_t *dev, uint32_t target_freq);
+
+/*!
+ * Get actual sample rate the device is configured to.
+ *
+ * \param dev the device handle given by fl2k_open()
+ * \return 0 on error, sample rate in Hz otherwise
+ */
+FL2K_API uint32_t fl2k_get_sample_rate(fl2k_dev_t *dev);
+
+/* streaming functions */
+
+typedef void(*fl2k_tx_cb_t)(fl2k_data_info_t *data_info);
+
+/*!
+ * Starts the tx thread. This function will block until
+ * it is being canceled using fl2k_stop_tx()
+ *
+ * \param dev the device handle given by fl2k_open()
+ * \param ctx user specific context to pass via the callback function
+ * \param buf_num optional buffer count, buf_num * FL2K_BUF_LEN = overall buffer size
+ *		  set to 0 for default buffer count (4)
+ * \return 0 on success
+ */
+FL2K_API int fl2k_start_tx(fl2k_dev_t *dev, fl2k_tx_cb_t cb,
+		     void *ctx, uint32_t buf_num);
+
+/*!
+ * Cancel all pending asynchronous operations on the device.
+ *
+ * \param dev the device handle given by fl2k_open()
+ * \return 0 on success
+ */
+FL2K_API int fl2k_stop_tx(fl2k_dev_t *dev);
+
+/*!
+ * Read 4 bytes via the FL2K I2C bus
+ *
+ * \param dev the device handle given by fl2k_open()
+ * \param i2c_addr address of the I2C device
+ * \param reg_addr start address of the 4 bytes to be read
+ * \param data pointer to byte array of size 4
+ * \return 0 on success
+ * \note A read operation will look like this on the bus:
+ *       START, I2C_ADDR(W), REG_ADDR,   REP_START, I2C_ADDR(R), DATA[0], STOP
+ *       START, I2C_ADDR(W), REG_ADDR+1, REP_START, I2C_ADDR(R), DATA[1], STOP
+ *       START, I2C_ADDR(W), REG_ADDR+2, REP_START, I2C_ADDR(R), DATA[2], STOP
+ *       START, I2C_ADDR(W), REG_ADDR+3, REP_START, I2C_ADDR(R), DATA[3], STOP
+ */
+FL2K_API int fl2k_i2c_read(fl2k_dev_t *dev, uint8_t i2c_addr,
+		           uint8_t reg_addr, uint8_t *data);
+
+/*!
+ * Write 4 bytes via the FL2K I2C bus
+ *
+ * \param dev the device handle given by fl2k_open()
+ * \param i2c_addr address of the I2C device
+ * \param reg_addr start address of the 4 bytes to be written
+ * \param data pointer to byte array of size 4
+ * \return 0 on success
+ * \note A write operation will look like this on the bus:
+ *       START, I2C_ADDR(W), REG_ADDR,   DATA[0], STOP
+ *       START, I2C_ADDR(W), REG_ADDR+1, DATA[1], STOP
+ *       START, I2C_ADDR(W), REG_ADDR+2, DATA[2], STOP
+ *       START, I2C_ADDR(W), REG_ADDR+3, DATA[3], STOP
+ */
+FL2K_API int fl2k_i2c_write(fl2k_dev_t *dev, uint8_t i2c_addr,
+			    uint8_t reg_addr, uint8_t *data);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* __FL2K_H */