diff options
Diffstat (limited to 'tuner.c')
| -rw-r--r-- | tuner.c | 208 |
1 files changed, 208 insertions, 0 deletions
@@ -0,0 +1,208 @@ +/* + * fmrxd - a daemon to enable and multiplex access to the N950/N9 radio tuner + * Copyright (C) 2011 Javier S. Pedro <maemo@javispedro.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 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 Street, Fifth Floor, Boston, MA 02110-1301 USA. +*/ + +#include <stdbool.h> +#include <string.h> +#include <errno.h> +#include <unistd.h> +#include <fcntl.h> +#include <sys/ioctl.h> +#include <glib.h> +#include <linux/videodev2.h> + +#include "fmrxd.h" + +int tuner_fd = -1; + +static bool tuner_precise; +static unsigned long tuner_min, tuner_max; + +static unsigned long tuner_freq = 0; + +static inline unsigned long v4l_to_hz(unsigned f) +{ + if (tuner_precise) { + /* f * 62.5 */ + return (f * 125UL) / 2; + } else { + return f * 62500UL; + } +} + +static inline unsigned hz_to_v4l(unsigned long f) +{ + if (tuner_precise) { + /* f / 62.5 */ + return (f * 2UL) / 125; + } else { + return f / 62500; + } +} + +static inline unsigned long mhz_to_hz(double f) +{ + return f * 1000000.0; +} + +static inline double hz_to_mhz(unsigned long f) +{ + return f / 1000000.0; +} + +static bool tuner_tune(unsigned long hz) +{ + struct v4l2_frequency t_freq = { + .tuner = TUNER_DEVICE_ID, + .type = V4L2_TUNER_RADIO, + .frequency = hz_to_v4l(hz) + }; + + g_return_val_if_fail(tuner_fd != -1, false); + + if (ioctl(tuner_fd, VIDIOC_S_FREQUENCY, &t_freq) < 0) { + g_warning("Failed to tune: %s", strerror(errno)); + return false; + } + + return true; +} + +static unsigned long tuner_get_tuned_freq() +{ + struct v4l2_frequency t_freq = { + .tuner = TUNER_DEVICE_ID + }; + + g_return_val_if_fail(tuner_fd != -1, 0); + + if (ioctl(tuner_fd, VIDIOC_G_FREQUENCY, &t_freq) < 0) { + g_warning("Failed to get freq: %s", strerror(errno)); + return 0; + } + + return v4l_to_hz(t_freq.frequency); +} + +static uint16_t tuner_get_signal() +{ + struct v4l2_tuner t_tuner = { + .index = TUNER_DEVICE_ID + }; + + g_return_val_if_fail(tuner_fd != -1, 0); + + if (ioctl(tuner_fd, VIDIOC_G_TUNER, &t_tuner) < 0) { + g_warning("Failed to get signal level: %s", strerror(errno)); + return 0; + } + + return t_tuner.signal; +} + +bool configure_tuner(bool on) +{ + if (on) { + struct v4l2_tuner tuner = { 0 }; + int res; + + tuner_fd = open(TUNER_DEVICE, O_RDONLY); + if (tuner_fd == -1) { + g_critical("Couldn't open V4L2 tuner"); + return false; + } + + tuner.index = 0; + res = ioctl(tuner_fd, VIDIOC_G_TUNER, &tuner); + if (res < 0) { + g_critical("Couldn't get V4L2 tuner information"); + return false; + } + + if (tuner.type != V4L2_TUNER_RADIO) { + g_critical("Not a radio tuner\n"); + return false; + } + + tuner_precise = (tuner.capability & V4L2_TUNER_CAP_LOW) ? + TRUE : FALSE; + tuner_min = v4l_to_hz(tuner.rangelow); + tuner_max = v4l_to_hz(tuner.rangelow); + + if (tuner_freq >= tuner_min && tuner_freq <= tuner_max && + tuner_tune(tuner_freq)) { + // All is well, we are on air! + } else { + // Use whatever frequency the tuner is currently using + tuner_freq = tuner_get_tuned_freq(); + } + + server_notify_tuned(hz_to_mhz(tuner_freq)); + + return true; + } else { + if (tuner_fd != -1) { + close(tuner_fd); + tuner_fd = -1; + } + return true; + } +} + +bool tuner_set_frequency(double mhz) +{ + unsigned long hz = mhz_to_hz(mhz); + + if (tuner_tune(hz)) { + g_message("Tuned to %.1f Mhz", mhz); + server_notify_tuned(mhz); + tuner_freq = hz; + rds_reset(); + return true; + } + + return false; +} + +bool tuner_search(bool forward) +{ + struct v4l2_hw_freq_seek t_freq_seek = { + .tuner = TUNER_DEVICE_ID, + .type = V4L2_TUNER_RADIO, + .seek_upward = forward + }; + + g_return_val_if_fail(tuner_fd != -1, false); + + if (ioctl(tuner_fd, VIDIOC_S_HW_FREQ_SEEK, &t_freq_seek) < 0) { + g_warning("Failed to start seek: %s", strerror(errno)); + return false; + } + + // Search complete, get new frequency + unsigned long hz = tuner_get_tuned_freq(); + if (!hz) { + return false; + } + + // Got new frequency, fire signals. + tuner_freq = hz; + server_notify_tuned(hz_to_mhz(hz)); + rds_reset(); + return true; +} |