Re: [PATCH v5 8/8] v4l2: Add a V4L2 driver for SI476X MFD
From: Hans Verkuil
Date: Tue Feb 26 2013 - 03:26:49 EST
On Tue February 26 2013 07:38:54 Andrey Smirnov wrote:
> From: Andrey Smirnov <andreysm@charmander.(none)>
>
> This commit adds a driver that exposes all the radio related
> functionality of the Si476x series of chips via the V4L2 subsystem.
>
> Signed-off-by: Andrey Smirnov <andrew.smirnov@xxxxxxxxx>
> ---
> Documentation/video4linux/si476x.txt | 187 ++++
> drivers/media/radio/Kconfig | 17 +
> drivers/media/radio/Makefile | 1 +
> drivers/media/radio/radio-si476x.c | 1581 ++++++++++++++++++++++++++++++++++
> include/media/si476x.h | 426 +++++++++
> 5 files changed, 2212 insertions(+)
> create mode 100644 Documentation/video4linux/si476x.txt
> create mode 100644 drivers/media/radio/radio-si476x.c
> create mode 100644 include/media/si476x.h
>
<snip>
> diff --git a/drivers/media/radio/radio-si476x.c b/drivers/media/radio/radio-si476x.c
> new file mode 100644
> index 0000000..568cd82
> --- /dev/null
> +++ b/drivers/media/radio/radio-si476x.c
> @@ -0,0 +1,1581 @@
> +/*
> + * drivers/media/radio/radio-si476x.c -- V4L2 driver for SI476X chips
> + *
> + * Copyright (C) 2012 Innovative Converged Devices(ICD)
> + * Copyright (C) 2013 Andrey Smirnov
> + *
> + * Author: Andrey Smirnov <andrew.smirnov@xxxxxxxxx>
> + *
> + * 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; version 2 of the License.
> + *
> + * 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.
> + *
> + */
> +
> +#include <linux/module.h>
> +#include <linux/delay.h>
> +#include <linux/interrupt.h>
> +#include <linux/slab.h>
> +#include <linux/atomic.h>
> +#include <linux/videodev2.h>
> +#include <linux/mutex.h>
> +#include <linux/debugfs.h>
> +#include <media/v4l2-common.h>
> +#include <media/v4l2-ioctl.h>
> +#include <media/v4l2-ctrls.h>
> +#include <media/v4l2-event.h>
> +#include <media/v4l2-device.h>
> +
> +#include <media/si476x.h>
> +#include <linux/mfd/si476x-core.h>
> +
> +#define FM_FREQ_RANGE_LOW 64000000
> +#define FM_FREQ_RANGE_HIGH 108000000
> +
> +#define AM_FREQ_RANGE_LOW 520000
> +#define AM_FREQ_RANGE_HIGH 30000000
> +
> +#define PWRLINEFLTR (1 << 8)
> +
> +#define FREQ_MUL (10000000 / 625)
> +
> +#define SI476X_PHDIV_STATUS_LINK_LOCKED(status) (0b10000000 & (status))
> +
> +#define DRIVER_NAME "si476x-radio"
> +#define DRIVER_CARD "SI476x AM/FM Receiver"
> +
> +enum si476x_freq_bands {
> + SI476X_BAND_FM,
> + SI476X_BAND_AM,
> +};
> +
> +static const struct v4l2_frequency_band si476x_bands[] = {
> + [SI476X_BAND_FM] = {
> + .type = V4L2_TUNER_RADIO,
> + .index = SI476X_BAND_FM,
> + .capability = V4L2_TUNER_CAP_LOW
> + | V4L2_TUNER_CAP_STEREO
> + | V4L2_TUNER_CAP_RDS
> + | V4L2_TUNER_CAP_RDS_BLOCK_IO
> + | V4L2_TUNER_CAP_FREQ_BANDS,
> + .rangelow = 64 * FREQ_MUL,
> + .rangehigh = 108 * FREQ_MUL,
> + .modulation = V4L2_BAND_MODULATION_FM,
> + },
> + [SI476X_BAND_AM] = {
> + .type = V4L2_TUNER_RADIO,
> + .index = SI476X_BAND_AM,
> + .capability = V4L2_TUNER_CAP_LOW | V4L2_TUNER_CAP_FREQ_BANDS,
> + .rangelow = 0.52 * FREQ_MUL,
> + .rangehigh = 30 * FREQ_MUL,
> + .modulation = V4L2_BAND_MODULATION_AM,
> + },
> +};
> +
> +static inline bool si476x_radio_freq_is_inside_of_the_band(u32 freq, int band)
> +{
> + return freq >= si476x_bands[band].rangelow &&
> + freq <= si476x_bands[band].rangehigh;
> +}
> +
> +static inline bool si476x_radio_range_is_inside_of_the_band(u32 low, u32 high, int band)
> +{
> + return low >= si476x_bands[band].rangelow &&
> + high <= si476x_bands[band].rangehigh;
> +}
> +
> +
> +
> +static int si476x_radio_s_ctrl(struct v4l2_ctrl *ctrl);
> +static int si476x_radio_g_volatile_ctrl(struct v4l2_ctrl *ctrl);
> +
> +static const char * const deemphasis[] = {
> + "75 us",
> + "50 us",
> +};
Obsolete array, can be removed.
> +
> +enum phase_diversity_modes_idx {
> + SI476X_IDX_PHDIV_DISABLED,
> + SI476X_IDX_PHDIV_PRIMARY_COMBINING,
> + SI476X_IDX_PHDIV_PRIMARY_ANTENNA,
> + SI476X_IDX_PHDIV_SECONDARY_ANTENNA,
> + SI476X_IDX_PHDIV_SECONDARY_COMBINING,
> +};
> +
> +static const char * const phase_diversity_modes[] = {
> + [SI476X_IDX_PHDIV_DISABLED] = "Disabled",
Question: what does it mean if this is disabled? That none of the antennas
are working? That would imply that you get no reception at all.
> + [SI476X_IDX_PHDIV_PRIMARY_COMBINING] = "Primary W/Secondary",
Just write in full: "Primary with Secondary"
> + [SI476X_IDX_PHDIV_PRIMARY_ANTENNA] = "Primary(Primary Antenna)",
This becomes: "Primary Antenna"
> + [SI476X_IDX_PHDIV_SECONDARY_ANTENNA] = "Primary(Seconadary Antenna)",
"Secondary Antenna"
> + [SI476X_IDX_PHDIV_SECONDARY_COMBINING] = "Secondary W/Primary",
"Secondary with Primary"
> +};
> +
> +static inline enum phase_diversity_modes_idx
> +si476x_phase_diversity_mode_to_idx(enum si476x_phase_diversity_mode mode)
> +{
> + switch (mode) {
> + default: /* FALLTHROUGH */
> + case SI476X_PHDIV_DISABLED:
> + return SI476X_IDX_PHDIV_DISABLED;
> + case SI476X_PHDIV_PRIMARY_COMBINING:
> + return SI476X_IDX_PHDIV_PRIMARY_COMBINING;
> + case SI476X_PHDIV_PRIMARY_ANTENNA:
> + return SI476X_IDX_PHDIV_PRIMARY_ANTENNA;
> + case SI476X_PHDIV_SECONDARY_ANTENNA:
> + return SI476X_IDX_PHDIV_SECONDARY_ANTENNA;
> + case SI476X_PHDIV_SECONDARY_COMBINING:
> + return SI476X_IDX_PHDIV_SECONDARY_COMBINING;
> + }
> +}
> +
> +static inline enum si476x_phase_diversity_mode
> +si476x_phase_diversity_idx_to_mode(enum phase_diversity_modes_idx idx)
> +{
> + static const int idx_to_value[] = {
> + [SI476X_IDX_PHDIV_DISABLED] = SI476X_PHDIV_DISABLED,
> + [SI476X_IDX_PHDIV_PRIMARY_COMBINING] = SI476X_PHDIV_PRIMARY_COMBINING,
> + [SI476X_IDX_PHDIV_PRIMARY_ANTENNA] = SI476X_PHDIV_PRIMARY_ANTENNA,
> + [SI476X_IDX_PHDIV_SECONDARY_ANTENNA] = SI476X_PHDIV_SECONDARY_ANTENNA,
> + [SI476X_IDX_PHDIV_SECONDARY_COMBINING] = SI476X_PHDIV_SECONDARY_COMBINING,
> + };
> +
> + return idx_to_value[idx];
> +}
> +
> +static const struct v4l2_ctrl_ops si476x_ctrl_ops = {
> + .g_volatile_ctrl = si476x_radio_g_volatile_ctrl,
> + .s_ctrl = si476x_radio_s_ctrl,
> +};
> +
> +
> +enum si476x_ctrl_idx {
> + SI476X_IDX_RSSI_THRESHOLD,
> + SI476X_IDX_SNR_THRESHOLD,
> + SI476X_IDX_MAX_TUNE_ERROR,
> + SI476X_IDX_HARMONICS_COUNT,
> + SI476X_IDX_DIVERSITY_MODE,
> + SI476X_IDX_INTERCHIP_LINK,
> +};
> +static struct v4l2_ctrl_config si476x_ctrls[] = {
> +
> + /**
> + * SI476X during its station seeking(or tuning) process uses several
> + * parameters to detrmine if "the station" is valid:
> + *
> + * - Signal's SNR(in dBuV) must be lower than
> + * #V4L2_CID_SI476X_SNR_THRESHOLD
> + * - Signal's RSSI(in dBuV) must be greater than
> + * #V4L2_CID_SI476X_RSSI_THRESHOLD
> + * - Signal's frequency deviation(in units of 2ppm) must not be
> + * more than #V4L2_CID_SI476X_MAX_TUNE_ERROR
> + */
> + [SI476X_IDX_RSSI_THRESHOLD] = {
> + .ops = &si476x_ctrl_ops,
> + .id = V4L2_CID_SI476X_RSSI_THRESHOLD,
> + .name = "Valid RSSI Threshold",
> + .type = V4L2_CTRL_TYPE_INTEGER,
> + .min = -128,
> + .max = 127,
> + .step = 1,
> + },
> + [SI476X_IDX_SNR_THRESHOLD] = {
> + .ops = &si476x_ctrl_ops,
> + .id = V4L2_CID_SI476X_SNR_THRESHOLD,
> + .type = V4L2_CTRL_TYPE_INTEGER,
> + .name = "Valid SNR Threshold",
> + .min = -128,
> + .max = 127,
> + .step = 1,
> + },
> + [SI476X_IDX_MAX_TUNE_ERROR] = {
> + .ops = &si476x_ctrl_ops,
> + .id = V4L2_CID_SI476X_MAX_TUNE_ERROR,
> + .type = V4L2_CTRL_TYPE_INTEGER,
> + .name = "Max Tune Errors",
> + .min = 0,
> + .max = 126 * 2,
> + .step = 2,
> + },
> +
> + /**
> + * #V4L2_CID_SI476X_HARMONICS_COUNT -- number of harmonics
> + * built-in power-line noise supression filter is to reject
> + * during AM-mode operation.
> + */
> + [SI476X_IDX_HARMONICS_COUNT] = {
> + .ops = &si476x_ctrl_ops,
> + .id = V4L2_CID_SI476X_HARMONICS_COUNT,
> + .type = V4L2_CTRL_TYPE_INTEGER,
> +
> + .name = "Count Of Harmonics To Reject",
Use lower case "of" and "to". Don't blame me, blame the style guides
w.r.t. titles :-)
> + .min = 0,
> + .max = 20,
> + .step = 1,
> + },
> +
> + /**
> + * #V4L2_CID_SI476X_DIVERSITY_MODE -- configuration which
> + * two tuners working in diversity mode are to work in.
> + *
> + * - #SI476X_IDX_PHDIV_DISABLED diversity mode disabled
> + * - #SI476X_IDX_PHDIV_PRIMARY_COMBINING diversity mode is
> + * on, primary tuner's antenna is the main one.
> + * - #SI476X_IDX_PHDIV_PRIMARY_ANTENNA diversity mode is
> + * off, primary tuner's antenna is the main one.
> + * - #SI476X_IDX_PHDIV_SECONDARY_ANTENNA diversity mode is
> + * off, secondary tuner's antenna is the main one.
> + * - #SI476X_IDX_PHDIV_SECONDARY_COMBINING diversity mode is
> + * on, secondary tuner's antenna is the main one.
> + */
> + [SI476X_IDX_DIVERSITY_MODE] = {
> + .ops = &si476x_ctrl_ops,
> + .id = V4L2_CID_SI476X_DIVERSITY_MODE,
> + .type = V4L2_CTRL_TYPE_MENU,
> + .name = "Phase Diversity Mode",
> + .qmenu = phase_diversity_modes,
> + .min = 0,
> + .max = ARRAY_SIZE(phase_diversity_modes) - 1,
> + },
> +
> + /**
> + * #V4L2_CID_SI476X_INTERCHIP_LINK -- inter-chip link in
> + * diversity mode indicator. Allows user to detrmine if two
Typo: 'determine'
> + * chips working in diversity mode have established a link
> + * between each other and if the system as awhole uses
"a whole"
> + * signals from both antennas to receive FM radio.
> + */
> + [SI476X_IDX_INTERCHIP_LINK] = {
> + .ops = &si476x_ctrl_ops,
> + .id = V4L2_CID_SI476X_INTERCHIP_LINK,
> + .type = V4L2_CTRL_TYPE_BOOLEAN,
> + .flags = V4L2_CTRL_FLAG_READ_ONLY | V4L2_CTRL_FLAG_VOLATILE,
> + .name = "Inter-Chip Link",
> + .min = 0,
> + .max = 1,
> + .step = 1,
> + },
> +};
<snip>
Regards,
Hans
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