Linux Kernel Mentees Archive on lore.kernel.org
 help / color / Atom feed
From: "Daniel W. S. Almeida" <dwlsalmeida@gmail.com>
To: mchehab+huawei@kernel.org, sean@mess.org,
	kstewart@linuxfoundation.org, allison@lohutok.net,
	tglx@linutronix.de
Cc: linux-kernel@vger.kernel.org,
	linux-kernel-mentees@lists.linuxfoundation.org,
	"Daniel W. S. Almeida" <dwlsalmeida@gmail.com>,
	linux-media@vger.kernel.org
Subject: [Linux-kernel-mentees] [RFC, WIP, v6 02/10] media: vidtv: implement a tuner driver
Date: Wed, 20 May 2020 04:03:26 -0300
Message-ID: <20200520070334.1778751-3-dwlsalmeida@gmail.com> (raw)
In-Reply-To: <20200520070334.1778751-1-dwlsalmeida@gmail.com>

From: "Daniel W. S. Almeida" <dwlsalmeida@gmail.com>

The virtual DVB test driver serves as a reference DVB driver and helps
validate the existing APIs in the media subsystem. It can also aid developers
working on userspace applications.

This dummy tuner should support common TV standards such as DVB-T/T2/S/S2,
ISDB-T and ATSC when completed.

Signed-off-by: Daniel W. S. Almeida <dwlsalmeida@gmail.com>
---
 drivers/media/test-drivers/vidtv/Makefile     |   3 +
 .../media/test-drivers/vidtv/vidtv_tuner.c    | 408 ++++++++++++++++++
 .../media/test-drivers/vidtv/vidtv_tuner.h    |  26 ++
 3 files changed, 437 insertions(+)
 create mode 100644 drivers/media/test-drivers/vidtv/vidtv_tuner.c
 create mode 100644 drivers/media/test-drivers/vidtv/vidtv_tuner.h

diff --git a/drivers/media/test-drivers/vidtv/Makefile b/drivers/media/test-drivers/vidtv/Makefile
index d1558d84eeaed..58e022c094e5e 100644
--- a/drivers/media/test-drivers/vidtv/Makefile
+++ b/drivers/media/test-drivers/vidtv/Makefile
@@ -1,2 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0
 
+dvb-vidtv-tuner-objs := vidtv_tuner.o
+
+obj-$(CONFIG_DVB_VIDTV)	+= dvb-vidtv-tuner.o
diff --git a/drivers/media/test-drivers/vidtv/vidtv_tuner.c b/drivers/media/test-drivers/vidtv/vidtv_tuner.c
new file mode 100644
index 0000000000000..3f2b4b9a6d568
--- /dev/null
+++ b/drivers/media/test-drivers/vidtv/vidtv_tuner.c
@@ -0,0 +1,408 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * The Virtual DVB test driver serves as a reference DVB driver and helps
+ * validate the existing APIs in the media subsystem. It can also aid
+ * developers working on userspace applications.
+ *
+ * The vidtv tuner should support common TV standards such as
+ * DVB-T/T2/S/S2, ISDB-T and ATSC when completed.
+ *
+ * Written by Daniel W. S. Almeida <dwlsalmeida@gmail.com>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ":%s, %d: " fmt, __func__, __LINE__
+
+#include <linux/errno.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <media/dvb_frontend.h>
+#include <linux/printk.h>
+#include <linux/ratelimit.h>
+
+#include "vidtv_tuner.h"
+
+MODULE_DESCRIPTION("Virtual DVB Tuner");
+MODULE_AUTHOR("Daniel W. S. Almeida");
+MODULE_LICENSE("GPL");
+
+struct vidtv_tuner_cnr_to_qual_s {
+	/* attempt to use the same values as libdvbv5 */
+	u32 modulation;
+	u32 fec;
+	u32 cnr_ok, cnr_good;
+};
+
+static const struct vidtv_tuner_cnr_to_qual_s vidtv_tuner_c_cnr_2_qual[] = {
+	/* from libdvbv5 source code, in milli db */
+	{ QAM_256, FEC_NONE,  34000, 38000},
+	{ QAM_64,  FEC_NONE,  30000, 34000},
+};
+
+static const struct vidtv_tuner_cnr_to_qual_s vidtv_tuner_s_cnr_2_qual[] = {
+	/* from libdvbv5 source code, in milli db */
+	{ QPSK, FEC_1_2,  7000, 10000},
+
+	{ QPSK, FEC_2_3,  9000, 12000},
+	{ QPSK, FEC_3_4, 10000, 13000},
+	{ QPSK, FEC_5_6, 11000, 14000},
+
+	{ QPSK, FEC_7_8, 12000, 15000},
+};
+
+static const struct vidtv_tuner_cnr_to_qual_s vidtv_tuner_s2_cnr_2_qual[] = {
+	/* from libdvbv5 source code, in milli db */
+	{ QPSK,  FEC_1_2,   9000,  12000},
+	{ QPSK,  FEC_2_3,  11000,  14000},
+	{ QPSK,  FEC_3_4,  12000,  15000},
+	{ QPSK,  FEC_5_6,  12000,  15000},
+	{ QPSK,  FEC_8_9,  13000,  16000},
+	{ QPSK,  FEC_9_10, 13500,  16500},
+	{ PSK_8, FEC_2_3,  14500,  17500},
+	{ PSK_8, FEC_3_4,  16000,  19000},
+	{ PSK_8, FEC_5_6,  17500,  20500},
+	{ PSK_8, FEC_8_9,  19000,  22000},
+};
+
+static const struct vidtv_tuner_cnr_to_qual_s vidtv_tuner_t_cnr_2_qual[] = {
+	/* from libdvbv5 source code, in milli db*/
+	{   QPSK, FEC_1_2,  4100,  5900},
+	{   QPSK, FEC_2_3,  6100,  9600},
+	{   QPSK, FEC_3_4,  7200, 12400},
+	{   QPSK, FEC_5_6,  8500, 15600},
+	{   QPSK, FEC_7_8,  9200, 17500},
+
+	{ QAM_16, FEC_1_2,  9800, 11800},
+	{ QAM_16, FEC_2_3, 12100, 15300},
+	{ QAM_16, FEC_3_4, 13400, 18100},
+	{ QAM_16, FEC_5_6, 14800, 21300},
+	{ QAM_16, FEC_7_8, 15700, 23600},
+
+	{ QAM_64, FEC_1_2, 14000, 16000},
+	{ QAM_64, FEC_2_3, 19900, 25400},
+	{ QAM_64, FEC_3_4, 24900, 27900},
+	{ QAM_64, FEC_5_6, 21300, 23300},
+	{ QAM_64, FEC_7_8, 22000, 24000},
+};
+
+struct vidtv_tuner_hardware_state {
+	bool asleep;
+	u32 lock_status;
+	u32 if_frequency;
+	u32 tuned_frequency;
+	u32 bandwidth;
+};
+
+struct vidtv_tuner_dev {
+	struct dvb_frontend *fe;
+	struct vidtv_tuner_hardware_state hw_state;
+	struct vidtv_tuner_config config;
+};
+
+static struct vidtv_tuner_dev*
+vidtv_tuner_get_dev(struct dvb_frontend *fe)
+{
+	struct i2c_client *client = fe->tuner_priv;
+
+	return i2c_get_clientdata(client);
+}
+
+static s32 vidtv_tuner_check_frequency_shift(struct dvb_frontend *fe)
+{
+	struct vidtv_tuner_dev *tuner_dev = vidtv_tuner_get_dev(fe);
+	struct dtv_frontend_properties *c = &fe->dtv_property_cache;
+	struct vidtv_tuner_config config  = tuner_dev->config;
+	u32    *valid_freqs               = NULL;
+	u32    array_sz                   = 0;
+	u32 i;
+	u32 shift;
+
+	switch (c->delivery_system) {
+	case SYS_DVBT:
+	case SYS_DVBT2:
+		valid_freqs = config.vidtv_valid_dvb_t_freqs;
+		array_sz    = ARRAY_SIZE(config.vidtv_valid_dvb_t_freqs);
+		break;
+	case SYS_DVBS:
+	case SYS_DVBS2:
+		valid_freqs = config.vidtv_valid_dvb_s_freqs;
+		array_sz    = ARRAY_SIZE(config.vidtv_valid_dvb_s_freqs);
+		break;
+	case SYS_DVBC_ANNEX_A:
+		valid_freqs = config.vidtv_valid_dvb_c_freqs;
+		array_sz    = ARRAY_SIZE(config.vidtv_valid_dvb_c_freqs);
+		break;
+
+	default:
+		pr_warn("%s: unsupported delivery system: %u\n",
+			__func__,
+			c->delivery_system);
+
+		return -EINVAL;
+	}
+
+	for (i = 0; i < array_sz; i++) {
+		shift = abs(c->frequency - valid_freqs[i]);
+
+		if (!shift)
+			return 0;
+
+		/*
+		 * This will provide a value from 0 to 100 that would
+		 * indicate how far is the tuned frequency from the
+		 * right one.
+		 */
+		if (shift < config.max_frequency_shift_hz)
+			return shift * 100 / config.max_frequency_shift_hz;
+	}
+
+	return -EINVAL;
+}
+
+static int
+vidtv_tuner_get_signal_strength(struct dvb_frontend *fe, u16 *strength)
+{
+	struct dtv_frontend_properties *c          = &fe->dtv_property_cache;
+	const struct vidtv_tuner_cnr_to_qual_s *cnr2qual = NULL;
+	u32    array_size                          = 0;
+	s32 shift;
+	u32 i;
+
+	shift = vidtv_tuner_check_frequency_shift(fe);
+
+	switch (c->delivery_system) {
+	case SYS_DVBT:
+	case SYS_DVBT2:
+		cnr2qual   = vidtv_tuner_t_cnr_2_qual;
+		array_size = ARRAY_SIZE(vidtv_tuner_t_cnr_2_qual);
+		break;
+
+	case SYS_DVBS:
+		cnr2qual   = vidtv_tuner_s_cnr_2_qual;
+		array_size = ARRAY_SIZE(vidtv_tuner_s_cnr_2_qual);
+		break;
+
+	case SYS_DVBS2:
+		cnr2qual   = vidtv_tuner_s2_cnr_2_qual;
+		array_size = ARRAY_SIZE(vidtv_tuner_s2_cnr_2_qual);
+		break;
+
+	case SYS_DVBC_ANNEX_A:
+		cnr2qual   = vidtv_tuner_c_cnr_2_qual;
+		array_size = ARRAY_SIZE(vidtv_tuner_c_cnr_2_qual);
+		break;
+
+	default:
+		pr_warn_ratelimited("%s: unsupported delivery system: %u\n",
+				    __func__,
+				    c->delivery_system);
+		return -EINVAL;
+	}
+
+	for (i = 0; i <= array_size; i++) {
+		if (cnr2qual[i].modulation != c->modulation ||
+		    cnr2qual[i].fec != c->fec_inner)
+			continue;
+
+		if (!shift) {
+			*strength = cnr2qual[i].cnr_good;
+			return 0;
+		}
+		if (shift < 0) {	/* Channel not tuned */
+			*strength = 0;
+			return 0;
+		}
+		/*
+		 * Channel tuned at wrong frequency. Simulate that the
+		 * Carrier S/N ratio is not too good.
+		 */
+
+		*strength = cnr2qual[i].cnr_ok -
+			    (cnr2qual[i].cnr_good - cnr2qual[i].cnr_ok);
+		return 0;
+	}
+
+	/*
+	 * do a linear interpolation between 34dB and 10dB if we can't
+	 * match against the table
+	 */
+	*strength = 34 - 24 * shift / 100;
+	return 0;
+}
+
+static int vidtv_tuner_init(struct dvb_frontend *fe)
+{
+	struct vidtv_tuner_dev *tuner_dev = vidtv_tuner_get_dev(fe);
+	struct vidtv_tuner_config config  = tuner_dev->config;
+
+	msleep_interruptible(config.mock_power_up_delay_msec);
+
+	tuner_dev->hw_state.asleep       = false;
+	tuner_dev->hw_state.if_frequency = 5000;
+
+	return 0;
+}
+
+static int vidtv_tuner_sleep(struct dvb_frontend *fe)
+{
+	struct vidtv_tuner_dev *tuner_dev = vidtv_tuner_get_dev(fe);
+
+	tuner_dev->hw_state.asleep = true;
+	return 0;
+}
+
+static int vidtv_tuner_suspend(struct dvb_frontend *fe)
+{
+	struct vidtv_tuner_dev *tuner_dev = vidtv_tuner_get_dev(fe);
+
+	tuner_dev->hw_state.asleep = true;
+	return 0;
+}
+
+static int vidtv_tuner_resume(struct dvb_frontend *fe)
+{
+	struct vidtv_tuner_dev *tuner_dev = vidtv_tuner_get_dev(fe);
+
+	tuner_dev->hw_state.asleep = false;
+	return 0;
+}
+
+static int vidtv_tuner_set_params(struct dvb_frontend *fe)
+{
+	struct vidtv_tuner_dev *tuner_dev = vidtv_tuner_get_dev(fe);
+	struct vidtv_tuner_config config  = tuner_dev->config;
+	struct dtv_frontend_properties *c = &fe->dtv_property_cache;
+	u32    min_freq               = fe->ops.tuner_ops.info.frequency_min_hz;
+	u32    max_freq               = fe->ops.tuner_ops.info.frequency_max_hz;
+	u32    min_bw                 = fe->ops.tuner_ops.info.bandwidth_min;
+	u32    max_bw                 = fe->ops.tuner_ops.info.bandwidth_max;
+
+	if (c->frequency < min_freq  || c->frequency > max_freq  ||
+	    c->bandwidth_hz < min_bw || c->bandwidth_hz > max_bw) {
+		tuner_dev->hw_state.lock_status = 0;
+		return -EINVAL;
+	}
+
+	tuner_dev->hw_state.tuned_frequency = c->frequency;
+	tuner_dev->hw_state.bandwidth       = c->bandwidth_hz;
+	tuner_dev->hw_state.lock_status     = TUNER_STATUS_LOCKED;
+
+	msleep_interruptible(config.mock_tune_delay_msec);
+	return 0;
+}
+
+static int vidtv_tuner_set_config(struct dvb_frontend *fe,
+				  void *priv_cfg)
+{
+	struct vidtv_tuner_dev *tuner_dev = vidtv_tuner_get_dev(fe);
+
+	memcpy(&tuner_dev->config, priv_cfg, sizeof(tuner_dev->config));
+
+	return 0;
+}
+
+static int vidtv_tuner_get_frequency(struct dvb_frontend *fe,
+				     u32 *frequency)
+{
+	struct vidtv_tuner_dev *tuner_dev = vidtv_tuner_get_dev(fe);
+
+	*frequency = tuner_dev->hw_state.tuned_frequency;
+
+	return 0;
+}
+
+static int vidtv_tuner_get_bandwidth(struct dvb_frontend *fe,
+				     u32 *bandwidth)
+{
+	struct vidtv_tuner_dev *tuner_dev = vidtv_tuner_get_dev(fe);
+
+	*bandwidth = tuner_dev->hw_state.bandwidth;
+
+	return 0;
+}
+
+static int vidtv_tuner_get_if_frequency(struct dvb_frontend *fe,
+					u32 *frequency)
+{
+	struct vidtv_tuner_dev *tuner_dev = vidtv_tuner_get_dev(fe);
+
+	*frequency = tuner_dev->hw_state.if_frequency;
+
+	return 0;
+}
+
+static int vidtv_tuner_get_status(struct dvb_frontend *fe, u32 *status)
+{
+	struct vidtv_tuner_dev *tuner_dev = vidtv_tuner_get_dev(fe);
+
+	*status = tuner_dev->hw_state.lock_status;
+
+	return 0;
+}
+
+static const struct dvb_tuner_ops vidtv_tuner_ops = {
+	.init             = vidtv_tuner_init,
+	.sleep            = vidtv_tuner_sleep,
+	.suspend          = vidtv_tuner_suspend,
+	.resume           = vidtv_tuner_resume,
+	.set_params       = vidtv_tuner_set_params,
+	.set_config       = vidtv_tuner_set_config,
+	.get_bandwidth    = vidtv_tuner_get_bandwidth,
+	.get_frequency    = vidtv_tuner_get_frequency,
+	.get_if_frequency = vidtv_tuner_get_if_frequency,
+	.get_status       = vidtv_tuner_get_status,
+	.get_rf_strength  = vidtv_tuner_get_signal_strength
+};
+
+static const struct i2c_device_id vidtv_tuner_i2c_id_table[] = {
+	{"vidtv_tuner", 0},
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, vidtv_tuner_i2c_id_table);
+
+static int vidtv_tuner_i2c_probe(struct i2c_client *client,
+				 const struct i2c_device_id *id)
+{
+	struct vidtv_tuner_config *config = client->dev.platform_data;
+	struct dvb_frontend *fe           = config->fe;
+	struct vidtv_tuner_dev *tuner_dev = NULL;
+
+	tuner_dev = kzalloc(sizeof(*tuner_dev), GFP_KERNEL);
+	if (!tuner_dev)
+		return -ENOMEM;
+
+	tuner_dev->fe = config->fe;
+	i2c_set_clientdata(client, tuner_dev);
+
+	memcpy(&fe->ops.tuner_ops,
+	       &vidtv_tuner_ops,
+	       sizeof(struct dvb_tuner_ops));
+
+	fe->tuner_priv = client;
+
+	return 0;
+}
+
+static int vidtv_tuner_i2c_remove(struct i2c_client *client)
+{
+	struct vidtv_tuner_dev *tuner_dev = i2c_get_clientdata(client);
+	struct dvb_frontend *fe           = tuner_dev->fe;
+
+	memset(&fe->ops.tuner_ops, 0, sizeof(struct dvb_tuner_ops));
+	fe->tuner_priv = NULL;
+	kfree(tuner_dev);
+
+	return 0;
+}
+
+static struct i2c_driver vidtv_tuner_i2c_driver = {
+	.driver = {
+		.name                = "vidtv_tuner",
+		.suppress_bind_attrs = true,
+	},
+	.probe    = vidtv_tuner_i2c_probe,
+	.remove   = vidtv_tuner_i2c_remove,
+	.id_table = vidtv_tuner_i2c_id_table,
+};
+module_i2c_driver(vidtv_tuner_i2c_driver);
diff --git a/drivers/media/test-drivers/vidtv/vidtv_tuner.h b/drivers/media/test-drivers/vidtv/vidtv_tuner.h
new file mode 100644
index 0000000000000..46407739f5d44
--- /dev/null
+++ b/drivers/media/test-drivers/vidtv/vidtv_tuner.h
@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * The Virtual DTV test driver serves as a reference DVB driver and helps
+ * validate the existing APIs in the media subsystem. It can also aid
+ * developers working on userspace applications.
+ *
+ * Written by Daniel W. S. Almeida <dwlsalmeida@gmail.com>
+ */
+
+#ifndef VIDTV_TUNER_H
+#define VIDTV_TUNER_H
+
+#include <linux/types.h>
+#include <media/dvb_frontend.h>
+
+struct vidtv_tuner_config {
+	struct dvb_frontend *fe;
+	u32 mock_power_up_delay_msec;
+	u32 mock_tune_delay_msec;
+	u32 vidtv_valid_dvb_t_freqs[8];
+	u32 vidtv_valid_dvb_c_freqs[8];
+	u32 vidtv_valid_dvb_s_freqs[8];
+	u8  max_frequency_shift_hz;
+};
+
+#endif //VIDTV_TUNER_H
-- 
2.26.2

_______________________________________________
Linux-kernel-mentees mailing list
Linux-kernel-mentees@lists.linuxfoundation.org
https://lists.linuxfoundation.org/mailman/listinfo/linux-kernel-mentees

  parent reply index

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-20  7:03 [Linux-kernel-mentees] [RFC, WIP, v6 00/10] media: vidtv: implement a virtual DVB driver Daniel W. S. Almeida
2020-05-20  7:03 ` [Linux-kernel-mentees] [RFC, WIP, v6 01/10] media: vidtv: add Kconfig entry Daniel W. S. Almeida
2020-05-28 22:50   ` Shuah Khan
2020-05-20  7:03 ` Daniel W. S. Almeida [this message]
2020-05-28 23:26   ` [Linux-kernel-mentees] [RFC, WIP, v6 02/10] media: vidtv: implement a tuner driver Shuah Khan
2020-05-20  7:03 ` [Linux-kernel-mentees] [RFC, WIP, v6 03/10] media: vidtv: implement a demodulator driver Daniel W. S. Almeida
2020-05-28 23:39   ` Shuah Khan
2020-05-20  7:03 ` [Linux-kernel-mentees] [RFC, WIP, v6 04/10] media: vidtv: add a bridge driver Daniel W. S. Almeida
2020-05-20  7:03 ` [Linux-kernel-mentees] [RFC, WIP, v6 05/10] media: vidtv: add wrappers for memcpy and memset Daniel W. S. Almeida
2020-05-20  7:03 ` [Linux-kernel-mentees] [RFC, WIP, v6 06/10] media: vidtv: add MPEG TS common code Daniel W. S. Almeida
2020-05-20  7:03 ` [Linux-kernel-mentees] [RFC, WIP, v6 07/10] media: vidtv: implement a PSI generator Daniel W. S. Almeida
2020-05-20  7:03 ` [Linux-kernel-mentees] [RFC, WIP, v6 08/10] media: vidtv: implement a PES packetizer Daniel W. S. Almeida
2020-05-20  7:03 ` [Linux-kernel-mentees] [RFC, WIP, v6 09/10] media: vidtv: Implement a SMPTE 302M encoder Daniel W. S. Almeida
2020-05-20  7:03 ` [Linux-kernel-mentees] [RFC, WIP, v6 10/10] media: vidtv: Add a MPEG Transport Stream Multiplexer Daniel W. S. Almeida
2020-05-28 21:39 ` [Linux-kernel-mentees] [RFC, WIP, v6 00/10] media: vidtv: implement a virtual DVB driver Shuah Khan
2020-05-28 23:57 ` Shuah Khan

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200520070334.1778751-3-dwlsalmeida@gmail.com \
    --to=dwlsalmeida@gmail.com \
    --cc=allison@lohutok.net \
    --cc=kstewart@linuxfoundation.org \
    --cc=linux-kernel-mentees@lists.linuxfoundation.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-media@vger.kernel.org \
    --cc=mchehab+huawei@kernel.org \
    --cc=sean@mess.org \
    --cc=tglx@linutronix.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux Kernel Mentees Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-kernel-mentees/0 linux-kernel-mentees/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-kernel-mentees linux-kernel-mentees/ https://lore.kernel.org/linux-kernel-mentees \
		linux-kernel-mentees@lists.linuxfoundation.org
	public-inbox-index linux-kernel-mentees

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.linuxfoundation.lists.linux-kernel-mentees


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git