[media] vivid: add support for software defined radio

This adds support for an SDR capture device. It generates simple
sine/cosine waves. The code for that has been contributed by
Antti.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

2 files changed, 533 insertions, 0 deletions

diff --git a/drivers/media/platform/vivid/vivid-sdr-cap.c b/drivers/media/platform/vivid/vivid-sdr-cap.c
new file mode 100644
index 000000000000..8c5d661cfc49
--- /dev/null
+++ b/drivers/media/platform/vivid/vivid-sdr-cap.c
@@ -0,0 +1,499 @@
+/*
+ * vivid-sdr-cap.c - software defined radio support functions.
+ *
+ * Copyright 2014 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
+ *
+ * This program is free software; you may 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.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/kthread.h>
+#include <linux/freezer.h>
+#include <linux/videodev2.h>
+#include <linux/v4l2-dv-timings.h>
+#include <media/v4l2-common.h>
+#include <media/v4l2-event.h>
+#include <media/v4l2-dv-timings.h>
+
+#include "vivid-core.h"
+#include "vivid-ctrls.h"
+#include "vivid-sdr-cap.h"
+
+static const struct v4l2_frequency_band bands_adc[] = {
+        {
+                .tuner = 0,
+                .type = V4L2_TUNER_ADC,
+                .index = 0,
+                .capability = V4L2_TUNER_CAP_1HZ | V4L2_TUNER_CAP_FREQ_BANDS,
+                .rangelow   =  300000,
+                .rangehigh  =  300000,
+        },
+        {
+                .tuner = 0,
+                .type = V4L2_TUNER_ADC,
+                .index = 1,
+                .capability = V4L2_TUNER_CAP_1HZ | V4L2_TUNER_CAP_FREQ_BANDS,
+                .rangelow   =  900001,
+                .rangehigh  = 2800000,
+        },
+        {
+                .tuner = 0,
+                .type = V4L2_TUNER_ADC,
+                .index = 2,
+                .capability = V4L2_TUNER_CAP_1HZ | V4L2_TUNER_CAP_FREQ_BANDS,
+                .rangelow   = 3200000,
+                .rangehigh  = 3200000,
+        },
+};
+
+/* ADC band midpoints */
+#define BAND_ADC_0 ((bands_adc[0].rangehigh + bands_adc[1].rangelow) / 2)
+#define BAND_ADC_1 ((bands_adc[1].rangehigh + bands_adc[2].rangelow) / 2)
+
+static const struct v4l2_frequency_band bands_fm[] = {
+        {
+                .tuner = 1,
+                .type = V4L2_TUNER_RF,
+                .index = 0,
+                .capability = V4L2_TUNER_CAP_1HZ | V4L2_TUNER_CAP_FREQ_BANDS,
+                .rangelow   =    50000000,
+                .rangehigh  =  2000000000,
+        },
+};
+
+static void vivid_thread_sdr_cap_tick(struct vivid_dev *dev)
+{
+        struct vivid_buffer *sdr_cap_buf = NULL;
+
+        dprintk(dev, 1, "SDR Capture Thread Tick\n");
+
+        /* Drop a certain percentage of buffers. */
+        if (dev->perc_dropped_buffers &&
+            prandom_u32_max(100) < dev->perc_dropped_buffers)
+                return;
+
+        spin_lock(&dev->slock);
+        if (!list_empty(&dev->sdr_cap_active)) {
+                sdr_cap_buf = list_entry(dev->sdr_cap_active.next,
+                                         struct vivid_buffer, list);
+                list_del(&sdr_cap_buf->list);
+        }
+        spin_unlock(&dev->slock);
+
+        if (sdr_cap_buf) {
+                sdr_cap_buf->vb.v4l2_buf.sequence = dev->sdr_cap_seq_count;
+                vivid_sdr_cap_process(dev, sdr_cap_buf);
+                v4l2_get_timestamp(&sdr_cap_buf->vb.v4l2_buf.timestamp);
+                sdr_cap_buf->vb.v4l2_buf.timestamp.tv_sec += dev->time_wrap_offset;
+                vb2_buffer_done(&sdr_cap_buf->vb, dev->dqbuf_error ?
+                                VB2_BUF_STATE_ERROR : VB2_BUF_STATE_DONE);
+                dev->dqbuf_error = false;
+        }
+}
+
+static int vivid_thread_sdr_cap(void *data)
+{
+        struct vivid_dev *dev = data;
+        u64 samples_since_start;
+        u64 buffers_since_start;
+        u64 next_jiffies_since_start;
+        unsigned long jiffies_since_start;
+        unsigned long cur_jiffies;
+        unsigned wait_jiffies;
+
+        dprintk(dev, 1, "SDR Capture Thread Start\n");
+
+        set_freezable();
+
+        /* Resets frame counters */
+        dev->sdr_cap_seq_offset = 0;
+        if (dev->seq_wrap)
+                dev->sdr_cap_seq_offset = 0xffffff80U;
+        dev->jiffies_sdr_cap = jiffies;
+        dev->sdr_cap_seq_resync = false;
+
+        for (;;) {
+                try_to_freeze();
+                if (kthread_should_stop())
+                        break;
+
+                mutex_lock(&dev->mutex);
+                cur_jiffies = jiffies;
+                if (dev->sdr_cap_seq_resync) {
+                        dev->jiffies_sdr_cap = cur_jiffies;
+                        dev->sdr_cap_seq_offset = dev->sdr_cap_seq_count + 1;
+                        dev->sdr_cap_seq_count = 0;
+                        dev->sdr_cap_seq_resync = false;
+                }
+                /* Calculate the number of jiffies since we started streaming */
+                jiffies_since_start = cur_jiffies - dev->jiffies_sdr_cap;
+                /* Get the number of buffers streamed since the start */
+                buffers_since_start = (u64)jiffies_since_start * dev->sdr_adc_freq +
+                                      (HZ * SDR_CAP_SAMPLES_PER_BUF) / 2;
+                do_div(buffers_since_start, HZ * SDR_CAP_SAMPLES_PER_BUF);
+
+                /*
+                 * After more than 0xf0000000 (rounded down to a multiple of
+                 * 'jiffies-per-day' to ease jiffies_to_msecs calculation)
+                 * jiffies have passed since we started streaming reset the
+                 * counters and keep track of the sequence offset.
+                 */
+                if (jiffies_since_start > JIFFIES_RESYNC) {
+                        dev->jiffies_sdr_cap = cur_jiffies;
+                        dev->sdr_cap_seq_offset = buffers_since_start;
+                        buffers_since_start = 0;
+                }
+                dev->sdr_cap_seq_count = buffers_since_start + dev->sdr_cap_seq_offset;
+
+                vivid_thread_sdr_cap_tick(dev);
+                mutex_unlock(&dev->mutex);
+
+                /*
+                 * Calculate the number of samples streamed since we started,
+                 * not including the current buffer.
+                 */
+                samples_since_start = buffers_since_start * SDR_CAP_SAMPLES_PER_BUF;
+
+                /* And the number of jiffies since we started */
+                jiffies_since_start = jiffies - dev->jiffies_sdr_cap;
+
+                /* Increase by the number of samples in one buffer */
+                samples_since_start += SDR_CAP_SAMPLES_PER_BUF;
+                /*
+                 * Calculate when that next buffer is supposed to start
+                 * in jiffies since we started streaming.
+                 */
+                next_jiffies_since_start = samples_since_start * HZ +
+                                           dev->sdr_adc_freq / 2;
+                do_div(next_jiffies_since_start, dev->sdr_adc_freq);
+                /* If it is in the past, then just schedule asap */
+                if (next_jiffies_since_start < jiffies_since_start)
+                        next_jiffies_since_start = jiffies_since_start;
+
+                wait_jiffies = next_jiffies_since_start - jiffies_since_start;
+                schedule_timeout_interruptible(wait_jiffies ? wait_jiffies : 1);
+        }
+        dprintk(dev, 1, "SDR Capture Thread End\n");
+        return 0;
+}
+
+static int sdr_cap_queue_setup(struct vb2_queue *vq, const struct v4l2_format *fmt,
+                       unsigned *nbuffers, unsigned *nplanes,
+                       unsigned sizes[], void *alloc_ctxs[])
+{
+        /* 2 = max 16-bit sample returned */
+        sizes[0] = SDR_CAP_SAMPLES_PER_BUF * 2;
+        *nplanes = 1;
+        return 0;
+}
+
+static int sdr_cap_buf_prepare(struct vb2_buffer *vb)
+{
+        struct vivid_dev *dev = vb2_get_drv_priv(vb->vb2_queue);
+        unsigned size = SDR_CAP_SAMPLES_PER_BUF * 2;
+
+        dprintk(dev, 1, "%s\n", __func__);
+
+        if (dev->buf_prepare_error) {
+                /*
+                 * Error injection: test what happens if buf_prepare() returns
+                 * an error.
+                 */
+                dev->buf_prepare_error = false;
+                return -EINVAL;
+        }
+        if (vb2_plane_size(vb, 0) < size) {
+                dprintk(dev, 1, "%s data will not fit into plane (%lu < %u)\n",
+                                __func__, vb2_plane_size(vb, 0), size);
+                return -EINVAL;
+        }
+        vb2_set_plane_payload(vb, 0, size);
+
+        return 0;
+}
+
+static void sdr_cap_buf_queue(struct vb2_buffer *vb)
+{
+        struct vivid_dev *dev = vb2_get_drv_priv(vb->vb2_queue);
+        struct vivid_buffer *buf = container_of(vb, struct vivid_buffer, vb);
+
+        dprintk(dev, 1, "%s\n", __func__);
+
+        spin_lock(&dev->slock);
+        list_add_tail(&buf->list, &dev->sdr_cap_active);
+        spin_unlock(&dev->slock);
+}
+
+static int sdr_cap_start_streaming(struct vb2_queue *vq, unsigned count)
+{
+        struct vivid_dev *dev = vb2_get_drv_priv(vq);
+        int err = 0;
+
+        dprintk(dev, 1, "%s\n", __func__);
+        dev->sdr_cap_seq_count = 0;
+        if (dev->start_streaming_error) {
+                dev->start_streaming_error = false;
+                err = -EINVAL;
+        } else if (dev->kthread_sdr_cap == NULL) {
+                dev->kthread_sdr_cap = kthread_run(vivid_thread_sdr_cap, dev,
+                                "%s-sdr-cap", dev->v4l2_dev.name);
+
+                if (IS_ERR(dev->kthread_sdr_cap)) {
+                        v4l2_err(&dev->v4l2_dev, "kernel_thread() failed\n");
+                        err = PTR_ERR(dev->kthread_sdr_cap);
+                        dev->kthread_sdr_cap = NULL;
+                }
+        }
+        if (err) {
+                struct vivid_buffer *buf, *tmp;
+
+                list_for_each_entry_safe(buf, tmp, &dev->sdr_cap_active, list) {
+                        list_del(&buf->list);
+                        vb2_buffer_done(&buf->vb, VB2_BUF_STATE_QUEUED);
+                }
+        }
+        return err;
+}
+
+/* abort streaming and wait for last buffer */
+static void sdr_cap_stop_streaming(struct vb2_queue *vq)
+{
+        struct vivid_dev *dev = vb2_get_drv_priv(vq);
+
+        if (dev->kthread_sdr_cap == NULL)
+                return;
+
+        while (!list_empty(&dev->sdr_cap_active)) {
+                struct vivid_buffer *buf;
+
+                buf = list_entry(dev->sdr_cap_active.next, struct vivid_buffer, list);
+                list_del(&buf->list);
+                vb2_buffer_done(&buf->vb, VB2_BUF_STATE_ERROR);
+        }
+
+        /* shutdown control thread */
+        mutex_unlock(&dev->mutex);
+        kthread_stop(dev->kthread_sdr_cap);
+        dev->kthread_sdr_cap = NULL;
+        mutex_lock(&dev->mutex);
+}
+
+const struct vb2_ops vivid_sdr_cap_qops = {
+        .queue_setup            = sdr_cap_queue_setup,
+        .buf_prepare            = sdr_cap_buf_prepare,
+        .buf_queue              = sdr_cap_buf_queue,
+        .start_streaming        = sdr_cap_start_streaming,
+        .stop_streaming         = sdr_cap_stop_streaming,
+        .wait_prepare           = vivid_unlock,
+        .wait_finish            = vivid_lock,
+};
+
+int vivid_sdr_enum_freq_bands(struct file *file, void *fh, struct v4l2_frequency_band *band)
+{
+        switch (band->tuner) {
+        case 0:
+                if (band->index >= ARRAY_SIZE(bands_adc))
+                        return -EINVAL;
+                *band = bands_adc[band->index];
+                return 0;
+        case 1:
+                if (band->index >= ARRAY_SIZE(bands_fm))
+                        return -EINVAL;
+                *band = bands_fm[band->index];
+                return 0;
+        default:
+                return -EINVAL;
+        }
+}
+
+int vivid_sdr_g_frequency(struct file *file, void *fh, struct v4l2_frequency *vf)
+{
+        struct vivid_dev *dev = video_drvdata(file);
+
+        switch (vf->tuner) {
+        case 0:
+                vf->frequency = dev->sdr_adc_freq;
+                vf->type = V4L2_TUNER_ADC;
+                return 0;
+        case 1:
+                vf->frequency = dev->sdr_fm_freq;
+                vf->type = V4L2_TUNER_RF;
+                return 0;
+        default:
+                return -EINVAL;
+        }
+}
+
+int vivid_sdr_s_frequency(struct file *file, void *fh, const struct v4l2_frequency *vf)
+{
+        struct vivid_dev *dev = video_drvdata(file);
+        unsigned freq = vf->frequency;
+        unsigned band;
+
+        switch (vf->tuner) {
+        case 0:
+                if (vf->type != V4L2_TUNER_ADC)
+                        return -EINVAL;
+                if (freq < BAND_ADC_0)
+                        band = 0;
+                else if (freq < BAND_ADC_1)
+                        band = 1;
+                else
+                        band = 2;
+
+                freq = clamp_t(unsigned, freq,
+                                bands_adc[band].rangelow,
+                                bands_adc[band].rangehigh);
+
+                if (vb2_is_streaming(&dev->vb_sdr_cap_q) &&
+                    freq != dev->sdr_adc_freq) {
+                        /* resync the thread's timings */
+                        dev->sdr_cap_seq_resync = true;
+                }
+                dev->sdr_adc_freq = freq;
+                return 0;
+        case 1:
+                if (vf->type != V4L2_TUNER_RF)
+                        return -EINVAL;
+                dev->sdr_fm_freq = clamp_t(unsigned, freq,
+                                bands_fm[0].rangelow,
+                                bands_fm[0].rangehigh);
+                return 0;
+        default:
+                return -EINVAL;
+        }
+}
+
+int vivid_sdr_g_tuner(struct file *file, void *fh, struct v4l2_tuner *vt)
+{
+        switch (vt->index) {
+        case 0:
+                strlcpy(vt->name, "ADC", sizeof(vt->name));
+                vt->type = V4L2_TUNER_ADC;
+                vt->capability = V4L2_TUNER_CAP_1HZ | V4L2_TUNER_CAP_FREQ_BANDS;
+                vt->rangelow = bands_adc[0].rangelow;
+                vt->rangehigh = bands_adc[2].rangehigh;
+                return 0;
+        case 1:
+                strlcpy(vt->name, "RF", sizeof(vt->name));
+                vt->type = V4L2_TUNER_RF;
+                vt->capability = V4L2_TUNER_CAP_1HZ | V4L2_TUNER_CAP_FREQ_BANDS;
+                vt->rangelow = bands_fm[0].rangelow;
+                vt->rangehigh = bands_fm[0].rangehigh;
+                return 0;
+        default:
+                return -EINVAL;
+        }
+}
+
+int vivid_sdr_s_tuner(struct file *file, void *fh, const struct v4l2_tuner *vt)
+{
+        if (vt->index > 1)
+                return -EINVAL;
+        return 0;
+}
+
+int vidioc_enum_fmt_sdr_cap(struct file *file, void *fh, struct v4l2_fmtdesc *f)
+{
+        if (f->index)
+                return -EINVAL;
+        f->pixelformat = V4L2_SDR_FMT_CU8;
+        strlcpy(f->description, "IQ U8", sizeof(f->description));
+        return 0;
+}
+
+int vidioc_g_fmt_sdr_cap(struct file *file, void *fh, struct v4l2_format *f)
+{
+        f->fmt.sdr.pixelformat = V4L2_SDR_FMT_CU8;
+        f->fmt.sdr.buffersize = SDR_CAP_SAMPLES_PER_BUF * 2;
+        memset(f->fmt.sdr.reserved, 0, sizeof(f->fmt.sdr.reserved));
+        return 0;
+}
+
+#define FIXP_FRAC    (1 << 15)
+#define FIXP_PI      ((int)(FIXP_FRAC * 3.141592653589))
+
+/* cos() from cx88 driver: cx88-dsp.c */
+static s32 fixp_cos(unsigned int x)
+{
+        u32 t2, t4, t6, t8;
+        u16 period = x / FIXP_PI;
+
+        if (period % 2)
+                return -fixp_cos(x - FIXP_PI);
+        x = x % FIXP_PI;
+        if (x > FIXP_PI/2)
+                return -fixp_cos(FIXP_PI/2 - (x % (FIXP_PI/2)));
+        /* Now x is between 0 and FIXP_PI/2.
+         * To calculate cos(x) we use it's Taylor polinom. */
+        t2 = x*x/FIXP_FRAC/2;
+        t4 = t2*x/FIXP_FRAC*x/FIXP_FRAC/3/4;
+        t6 = t4*x/FIXP_FRAC*x/FIXP_FRAC/5/6;
+        t8 = t6*x/FIXP_FRAC*x/FIXP_FRAC/7/8;
+        return FIXP_FRAC-t2+t4-t6+t8;
+}
+
+static inline s32 fixp_sin(unsigned int x)
+{
+        return -fixp_cos(x + (FIXP_PI / 2));
+}
+
+void vivid_sdr_cap_process(struct vivid_dev *dev, struct vivid_buffer *buf)
+{
+        u8 *vbuf = vb2_plane_vaddr(&buf->vb, 0);
+        unsigned long i;
+        unsigned long plane_size = vb2_plane_size(&buf->vb, 0);
+        int fixp_src_phase_step, fixp_i, fixp_q;
+
+        /*
+         * TODO: Generated beep tone goes very crackly when sample rate is
+         * increased to ~1Msps or more. That is because of huge rounding error
+         * of phase angle caused by used cosine implementation.
+         */
+
+        /* calculate phase step */
+        #define BEEP_FREQ 1000 /* 1kHz beep */
+        fixp_src_phase_step = DIV_ROUND_CLOSEST(2 * FIXP_PI * BEEP_FREQ,
+                        dev->sdr_adc_freq);
+
+        for (i = 0; i < plane_size; i += 2) {
+                dev->sdr_fixp_mod_phase += fixp_cos(dev->sdr_fixp_src_phase);
+                dev->sdr_fixp_src_phase += fixp_src_phase_step;
+
+                /*
+                 * Transfer phases to [0 / 2xPI] in order to avoid variable
+                 * overflow and make it suitable for cosine implementation
+                 * used, which does not support negative angles.
+                 */
+                while (dev->sdr_fixp_mod_phase < (0 * FIXP_PI))
+                        dev->sdr_fixp_mod_phase += (2 * FIXP_PI);
+                while (dev->sdr_fixp_mod_phase > (2 * FIXP_PI))
+                        dev->sdr_fixp_mod_phase -= (2 * FIXP_PI);
+
+                while (dev->sdr_fixp_src_phase > (2 * FIXP_PI))
+                        dev->sdr_fixp_src_phase -= (2 * FIXP_PI);
+
+                fixp_i = fixp_cos(dev->sdr_fixp_mod_phase);
+                fixp_q = fixp_sin(dev->sdr_fixp_mod_phase);
+
+                /* convert 'fixp float' to u8 */
+                /* u8 = X * 127.5f + 127.5f; where X is float [-1.0 / +1.0] */
+                fixp_i = fixp_i * 1275 + FIXP_FRAC * 1275;
+                fixp_q = fixp_q * 1275 + FIXP_FRAC * 1275;
+                *vbuf++ = DIV_ROUND_CLOSEST(fixp_i, FIXP_FRAC * 10);
+                *vbuf++ = DIV_ROUND_CLOSEST(fixp_q, FIXP_FRAC * 10);
+        }
+}
diff --git a/drivers/media/platform/vivid/vivid-sdr-cap.h b/drivers/media/platform/vivid/vivid-sdr-cap.h
new file mode 100644
index 000000000000..79c1890de972
--- /dev/null
+++ b/drivers/media/platform/vivid/vivid-sdr-cap.h
@@ -0,0 +1,34 @@
+/*
+ * vivid-sdr-cap.h - software defined radio support functions.
+ *
+ * Copyright 2014 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
+ *
+ * This program is free software; you may 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.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#ifndef _VIVID_SDR_CAP_H_
+#define _VIVID_SDR_CAP_H_
+
+int vivid_sdr_enum_freq_bands(struct file *file, void *fh, struct v4l2_frequency_band *band);
+int vivid_sdr_g_frequency(struct file *file, void *fh, struct v4l2_frequency *vf);
+int vivid_sdr_s_frequency(struct file *file, void *fh, const struct v4l2_frequency *vf);
+int vivid_sdr_g_tuner(struct file *file, void *fh, struct v4l2_tuner *vt);
+int vivid_sdr_s_tuner(struct file *file, void *fh, const struct v4l2_tuner *vt);
+int vidioc_enum_fmt_sdr_cap(struct file *file, void *fh, struct v4l2_fmtdesc *f);
+int vidioc_g_fmt_sdr_cap(struct file *file, void *fh, struct v4l2_format *f);
+void vivid_sdr_cap_process(struct vivid_dev *dev, struct vivid_buffer *buf);
+
+extern const struct vb2_ops vivid_sdr_cap_qops;
+
+#endif