Re: [PATCH v5 8/8] v4l2: Add a V4L2 driver for SI476X MFD
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.smir...@gmail.com
---
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 000..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.smir...@gmail.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; 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 6400
+#define FM_FREQ_RANGE_HIGH 10800
+
+#define AM_FREQ_RANGE_LOW52
+#define AM_FREQ_RANGE_HIGH 3000
+
+#define PWRLINEFLTR (1 8)
+
+#define FREQ_MUL (1000 / 625)
+
+#define SI476X_PHDIV_STATUS_LINK_LOCKED(status) (0b1000 (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
+
Re: [PATCH v5 8/8] v4l2: Add a V4L2 driver for SI476X MFD
snip
+
+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.
I am not an expert on these chips and, unfortunately, never had anyone
from SiLabs to talk to all the time I worked on this driver. But from
my understanding from working with the chip/reading of the datasheet,
when working in diversity mode two chips are connected to two
different antennas and interconnected between each other so that
secondary tuner can pass semi-processed signal to the primary one. So
to the best of my understanding those sttings cause the following mode
of operation:
* Disabled -- no link is established, tuner acts no differently than
if other tuner didn't exist.
* Primary combinig -- link is established, tuner is configured to be a
primary tuner using signal from both itself and a secondary one
* Primary antenna -- link is established, tuner is configured to be a
primary tuner using signal from its own antenna
* Secondary antenna -- link is established, tuner is configured to be
a primary tuner using signal from secondary tuner's antenna
* Secondary -- link is established, tuner is configured to be a
secondary tuner feeding the signal from its antenna to the primary one
It seems that Disabled setting is the setting one would want to use
if the chip is used in a non diversity-mode enabled system.
+ [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 =
