From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 44ACDC3A5A9 for ; Sat, 2 May 2020 05:58:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0BF5321775 for ; Sat, 2 May 2020 05:58:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588399121; bh=8xGvidCo3dcoGJONF8kMUHfmgcdS7Cl0+4mR4KOeD4M=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=rJsXunsNJ88apzx+GsiYngLjq9Hr+u9eTn6YRs6gotMFzayKlI2xofQ39Df/oBZj7 kPERv4+69MC+myyKchgkhkrQeiNn7SCCUVlurji0mO+gcBEL1lotJpgD9RhmIP0l7w AaoAjugNdXMJQJ+z3vTJ9/y+10zn2faySXNJ8bv4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727853AbgEBF6k (ORCPT ); Sat, 2 May 2020 01:58:40 -0400 Received: from mail.kernel.org ([198.145.29.99]:46374 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726468AbgEBF6j (ORCPT ); Sat, 2 May 2020 01:58:39 -0400 Received: from coco.lan (ip5f5ad5c5.dynamic.kabel-deutschland.de [95.90.213.197]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A6FC7208DB; Sat, 2 May 2020 05:58:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588399118; bh=8xGvidCo3dcoGJONF8kMUHfmgcdS7Cl0+4mR4KOeD4M=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=WYYdOCAno474l0vsG5AFKzDeDKohFAH/GYaqX9IMom9mKCyj9QNxCTE/835asapIH L09+bDX2Tmo2rAFJS06nQptinX5vVuHVtIQVrSE+m8h6U3+tbJuH4cLfumuxxt/LRV GQ6d/19OQ+a2ylV78tsHlCSD84h/S4Maj4NIGwSM= Date: Sat, 2 May 2020 07:58:33 +0200 From: Mauro Carvalho Chehab To: "Daniel W. S. Almeida" Cc: sean@mess.org, kstewart@linuxfoundation.org, allison@lohutok.net, tglx@linutronix.de, linux-media@vger.kernel.org, skhan@linuxfoundation.org, linux-kernel-mentees@lists.linuxfoundation.org, linux-kernel@vger.kernel.org Subject: Re: [RFC, WIP, v4 03/11] media: vidtv: implement a demodulator driver Message-ID: <20200502075833.60e74029@coco.lan> In-Reply-To: <20200502032216.197977-4-dwlsalmeida@gmail.com> References: <20200502032216.197977-1-dwlsalmeida@gmail.com> <20200502032216.197977-4-dwlsalmeida@gmail.com> X-Mailer: Claws Mail 3.17.5 (GTK+ 2.24.32; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Sat, 2 May 2020 00:22:08 -0300 "Daniel W. S. Almeida" escreveu: > From: "Daniel W. S. Almeida" > > Implement a I2C demodulator driver, simulating support for DVB-T, DVB-C > and DVB-S. > > This demodulator will periodically check the signal quality against a table > and drop the TS lock if it drops below a threshold value, regaining it in > the event that the signal improves. > > Signed-off-by: Daniel W. S. Almeida > --- > drivers/media/test-drivers/vidtv/Makefile | 2 +- > .../media/test-drivers/vidtv/vidtv_demod.c | 493 ++++++++++++++++++ > .../media/test-drivers/vidtv/vidtv_demod.h | 43 ++ > 3 files changed, 537 insertions(+), 1 deletion(-) > create mode 100644 drivers/media/test-drivers/vidtv/vidtv_demod.c > create mode 100644 drivers/media/test-drivers/vidtv/vidtv_demod.h > > diff --git a/drivers/media/test-drivers/vidtv/Makefile b/drivers/media/test-drivers/vidtv/Makefile > index e625810a82603..36ba00ddc0d1e 100644 > --- a/drivers/media/test-drivers/vidtv/Makefile > +++ b/drivers/media/test-drivers/vidtv/Makefile > @@ -1,3 +1,3 @@ > # SPDX-License-Identifier: GPL-2.0 > > -obj-$(CONFIG_DVB_VIDTV) += vidtv_tuner.o > +obj-$(CONFIG_DVB_VIDTV) += vidtv_tuner.o vidtv_demod.o > diff --git a/drivers/media/test-drivers/vidtv/vidtv_demod.c b/drivers/media/test-drivers/vidtv/vidtv_demod.c > new file mode 100644 > index 0000000000000..e5f157e4bbe48 > --- /dev/null > +++ b/drivers/media/test-drivers/vidtv/vidtv_demod.c > @@ -0,0 +1,493 @@ > +// SPDX-License-Identifier: GPL-2.0-or-later > +/* > + * 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. > + * > + * Written by Daniel W. S. Almeida > + * Based on the example driver written by Emard > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include "vidtv_demod.h" > + > +MODULE_DESCRIPTION("Virtual DVB Demodulator Driver"); > +MODULE_AUTHOR("Daniel W. S. Almeida"); > +MODULE_LICENSE("GPL"); > + > +struct vidtv_demod_cnr_to_qual_s vidtv_demod_c_cnr_2_qual[] = { > + /* from libdvbv5 source code, in milli db */ > + { QAM_256, FEC_NONE, 34000, 38000}, > + { QAM_64, FEC_NONE, 30000, 34000}, > +}; > + > +struct vidtv_demod_cnr_to_qual_s vidtv_demod_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}, > +}; > + > +struct vidtv_demod_cnr_to_qual_s vidtv_demod_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 struct vidtv_demod_cnr_to_qual_s vidtv_demod_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}, > +}; > + > +static struct vidtv_demod_cnr_to_qual_s > +*vidtv_match_cnr_s(struct dvb_frontend *fe) > +{ > + struct dtv_frontend_properties *c; > + struct vidtv_demod_cnr_to_qual_s *cnr2qual = NULL; > + u32 array_size = 0; > + u32 i; > + > + c = &fe->dtv_property_cache; > + > + switch (c->delivery_system) { > + case SYS_DVBT: > + case SYS_DVBT2: > + cnr2qual = vidtv_demod_t_cnr_2_qual; > + array_size = ARRAY_SIZE(vidtv_demod_t_cnr_2_qual); > + break; > + > + case SYS_DVBS: > + cnr2qual = vidtv_demod_s_cnr_2_qual; > + array_size = ARRAY_SIZE(vidtv_demod_s_cnr_2_qual); > + break; > + > + case SYS_DVBS2: > + cnr2qual = vidtv_demod_s2_cnr_2_qual; > + array_size = ARRAY_SIZE(vidtv_demod_s2_cnr_2_qual); > + break; > + > + case SYS_DVBC_ANNEX_A: > + cnr2qual = vidtv_demod_c_cnr_2_qual; > + array_size = ARRAY_SIZE(vidtv_demod_c_cnr_2_qual); > + break; > + > + default: > + pr_warn("%s: unsupported delivery system: %u\n", > + __func__, > + c->delivery_system); > + break; > + } > + > + for (i = 0; i <= array_size; i++) > + if (cnr2qual[i].modulation == c->modulation && > + cnr2qual[i].fec == c->fec_inner) > + return &cnr2qual[i]; > + > + return NULL; /* not found */ > +} > + > +static void vidtv_demod_poll_snr_handler(struct work_struct *work) > +{ > + /* > + * periodically check the signal quality and eventually > + * lose the TS lock if it dips too low > + */ > + struct vidtv_demod_state *state; > + struct dtv_frontend_properties *c; > + struct vidtv_demod_cnr_to_qual_s *cnr2qual = NULL; > + struct vidtv_demod_config *config; > + u16 snr = 0; > + > + state = container_of(work, struct vidtv_demod_state, poll_snr.work); > + c = &state->frontend.dtv_property_cache; > + config = &state->config; > + > + if (!state->frontend.ops.tuner_ops.get_rf_strength) > + return; > + > + state->frontend.ops.tuner_ops.get_rf_strength(&state->frontend, &snr); > + > + cnr2qual = vidtv_match_cnr_s(&state->frontend); > + if (!cnr2qual) > + return; > + > + if (snr < cnr2qual->cnr_ok) { > + /* eventually lose the TS lock */ > + if (prandom_u32_max(100) < config->drop_tslock_prob_on_low_snr) > + state->status = 0; > + } else { > + /* recover if the signal improves */ > + if (prandom_u32_max(100) < > + config->recover_tslock_prob_on_good_snr) > + state->status = FE_HAS_SIGNAL | > + FE_HAS_CARRIER | > + FE_HAS_VITERBI | > + FE_HAS_SYNC | > + FE_HAS_LOCK; > + } > + > + schedule_delayed_work(&state->poll_snr, msecs_to_jiffies(2000)); I would place the time (2000) on a #define at the top. > +} > + > +static int vidtv_demod_read_status(struct dvb_frontend *fe, > + enum fe_status *status) > +{ > + struct vidtv_demod_state *state = fe->demodulator_priv; > + > + *status = state->status; > + > + return 0; > +} > +static int vidtv_demod_read_ber(struct dvb_frontend *fe, u32 *ber) > +{ > + *ber = 0; > + return 0; > +} > + > +static int vidtv_demod_read_signal_strength(struct dvb_frontend *fe, > + u16 *strength) > +{ > + *strength = 0; > + return 0; > +} > + > +static int vidtv_demod_read_snr(struct dvb_frontend *fe, u16 *snr) > +{ > + *snr = 0; > + return 0; > +} > + > +static int vidtv_demod_read_ucblocks(struct dvb_frontend *fe, u32 *ucblocks) > +{ > + *ucblocks = 0; > + return 0; > +} Hmm... I'm actually in doubt about the above legacy DVB-3 ops. Let's keep it for now, but I may submit a patch to dvb-core for it to use the data from the cache, if someone use those legacy ioctls and the corresponding fe->ops is not defined by a demod. > + > +/* > + * Should only be implemented if it actually reads something from the hardware. > + * Also, it should check for the locks, in order to avoid report wrong data > + * to userspace. > + */ I would rewrite it as: /* * NOTE: * This is implemented here just to be used as an example for real * demod drivers. * * Should only be implemented if it actually reads something from the hardware. * Also, it should check for the locks, in order to avoid report wrong data * to userspace. */ > +static int vidtv_demod_get_frontend(struct dvb_frontend *fe, > + struct dtv_frontend_properties *p) > +{ > + return 0; > +} > + > +static int vidtv_demod_set_frontend(struct dvb_frontend *fe) > +{ > + struct vidtv_demod_state *state = fe->demodulator_priv; > + struct vidtv_demod_cnr_to_qual_s *cnr2qual = NULL; > + u32 tuner_status = 0; > + > + if (fe->ops.tuner_ops.set_params) { > + fe->ops.tuner_ops.set_params(fe); > + > + /* store the CNR returned by the tuner */ > + fe->ops.tuner_ops.get_rf_strength(fe, &state->tuner_cnr); > + > + fe->ops.tuner_ops.get_status(fe, &tuner_status); > + state->status = (state->tuner_cnr > 0) ? FE_HAS_SIGNAL | > + FE_HAS_CARRIER | > + FE_HAS_VITERBI | > + FE_HAS_SYNC | > + FE_HAS_LOCK : > + 0; > + cnr2qual = vidtv_match_cnr_s(fe); > + > + /* signal isn't good: might lose the lock eventually */ > + if (tuner_status == TUNER_STATUS_LOCKED && > + state->tuner_cnr < cnr2qual->cnr_good) { > + schedule_delayed_work(&state->poll_snr, > + msecs_to_jiffies(2000)); Use the same define as above mentioned for the msecs time. > + > + state->poll_snr_thread_running = true; > + } > + > + if (fe->ops.i2c_gate_ctrl) > + fe->ops.i2c_gate_ctrl(fe, 0); > + } > + > + return 0; > +} > + > +static int vidtv_demod_sleep(struct dvb_frontend *fe) > +{ > + struct vidtv_demod_state *state = fe->demodulator_priv; > + > + if (state->poll_snr_thread_running) { > + cancel_delayed_work_sync(&state->poll_snr); > + state->poll_snr_thread_running = false; > + state->poll_snr_thread_restart = true; > + } > + return 0; > +} > + > +static int vidtv_demod_init(struct dvb_frontend *fe) > +{ > + struct vidtv_demod_state *state = fe->demodulator_priv; > + u32 tuner_status = 0; > + > + if (state->cold_start) > + INIT_DELAYED_WORK(&state->poll_snr, > + &vidtv_demod_poll_snr_handler); > + > + /* > + * At resume, start the snr poll thread only if it was suspended with > + * the thread running. Extra care should be taken here, as some tuner > + * status change might happen at resume time (for example, due to a > + * ioctl syscall to set_frontend, or due to a release syscall). typo: "a ioctl" -> "an ioctl" > + */ > + fe->ops.tuner_ops.get_status(fe, &tuner_status); > + > + if (tuner_status == TUNER_STATUS_LOCKED && > + state->poll_snr_thread_restart) { > + schedule_delayed_work(&state->poll_snr, > + msecs_to_jiffies(2000)); Same note about the timing constant. Keep all those "2000" inside something like: $define POLL_THREAD_TIME 2000 /* msecs */ > + > + state->poll_snr_thread_restart = false; > + } > + > + state->cold_start = false; > + return 0; > +} > + > +static int vidtv_demod_set_tone(struct dvb_frontend *fe, > + enum fe_sec_tone_mode tone) > +{ > + return 0; > +} > + > +static int vidtv_demod_set_voltage(struct dvb_frontend *fe, > + enum fe_sec_voltage voltage) > +{ > + return 0; > +} It would be worth adding a note for each of the above stating that they should be implemented only if if the demod has support for DVB/S and/or DVB/S2 > +static void vidtv_demod_release(struct dvb_frontend *fe) > +{ > + struct vidtv_demod_state *state = fe->demodulator_priv; > + > + if (state->poll_snr_thread_running) > + cancel_delayed_work_sync(&state->poll_snr); > + > + kfree(state); > +} > + > +static const struct dvb_frontend_ops vidtv_demod_ofdm_ops = { > + .delsys = { SYS_DVBT }, > + .info = { > + .name = "Dummy DVB-T", > + .frequency_min_hz = 0, > + .frequency_max_hz = 863250 * kHz, > + .frequency_stepsize_hz = 62500, > + .caps = FE_CAN_FEC_1_2 | > + FE_CAN_FEC_2_3 | > + FE_CAN_FEC_3_4 | > + FE_CAN_FEC_4_5 | > + FE_CAN_FEC_5_6 | > + FE_CAN_FEC_6_7 | > + FE_CAN_FEC_7_8 | > + FE_CAN_FEC_8_9 | > + FE_CAN_FEC_AUTO | > + FE_CAN_QAM_16 | > + FE_CAN_QAM_64 | > + FE_CAN_QAM_AUTO | > + FE_CAN_TRANSMISSION_MODE_AUTO | > + FE_CAN_GUARD_INTERVAL_AUTO | > + FE_CAN_HIERARCHY_AUTO, > + }, > + > + .release = vidtv_demod_release, > + > + .init = vidtv_demod_init, > + .sleep = vidtv_demod_sleep, > + > + .set_frontend = vidtv_demod_set_frontend, > + .get_frontend = vidtv_demod_get_frontend, > + > + .read_status = vidtv_demod_read_status, > + .read_ber = vidtv_demod_read_ber, > + .read_signal_strength = vidtv_demod_read_signal_strength, > + .read_snr = vidtv_demod_read_snr, > + .read_ucblocks = vidtv_demod_read_ucblocks, > +}; > + > +static const struct dvb_frontend_ops vidtv_demod_qam_ops = { > + .delsys = { SYS_DVBC_ANNEX_A }, > + .info = { > + .name = "Dummy DVB-C", > + .frequency_min_hz = 51 * MHz, > + .frequency_max_hz = 858 * MHz, > + .frequency_stepsize_hz = 62500, > + /* symbol_rate_min: SACLK/64 == (XIN/2)/64 */ > + .symbol_rate_min = (57840000 / 2) / 64, > + .symbol_rate_max = (57840000 / 2) / 4, /* SACLK/4 */ > + .caps = FE_CAN_QAM_16 | > + FE_CAN_QAM_32 | > + FE_CAN_QAM_64 | > + FE_CAN_QAM_128 | > + FE_CAN_QAM_256 | > + FE_CAN_FEC_AUTO | > + FE_CAN_INVERSION_AUTO > + }, > + > + .release = vidtv_demod_release, > + > + .init = vidtv_demod_init, > + .sleep = vidtv_demod_sleep, > + > + .set_frontend = vidtv_demod_set_frontend, > + .get_frontend = vidtv_demod_get_frontend, > + > + .read_status = vidtv_demod_read_status, > + .read_ber = vidtv_demod_read_ber, > + .read_signal_strength = vidtv_demod_read_signal_strength, > + .read_snr = vidtv_demod_read_snr, > + .read_ucblocks = vidtv_demod_read_ucblocks, > +}; > + > +static const struct dvb_frontend_ops vidtv_demod_qpsk_ops = { > + .delsys = { SYS_DVBS }, > + .info = { > + .name = "Dummy DVB-S", > + .frequency_min_hz = 950 * MHz, > + .frequency_max_hz = 2150 * MHz, > + .frequency_stepsize_hz = 250 * kHz, > + .frequency_tolerance_hz = 29500 * kHz, > + .symbol_rate_min = 1000000, > + .symbol_rate_max = 45000000, > + .caps = FE_CAN_INVERSION_AUTO | > + FE_CAN_FEC_1_2 | > + FE_CAN_FEC_2_3 | > + FE_CAN_FEC_3_4 | > + FE_CAN_FEC_5_6 | > + FE_CAN_FEC_7_8 | > + FE_CAN_FEC_AUTO | > + FE_CAN_QPSK > + }, > + > + .release = vidtv_demod_release, > + > + .init = vidtv_demod_init, > + .sleep = vidtv_demod_sleep, > + > + .set_frontend = vidtv_demod_set_frontend, > + .get_frontend = vidtv_demod_get_frontend, > + > + .read_status = vidtv_demod_read_status, > + .read_ber = vidtv_demod_read_ber, > + .read_signal_strength = vidtv_demod_read_signal_strength, > + .read_snr = vidtv_demod_read_snr, > + .read_ucblocks = vidtv_demod_read_ucblocks, > + > + .set_voltage = vidtv_demod_set_voltage, > + .set_tone = vidtv_demod_set_tone, > +}; The recommended way is to place everything on a single entry: static const struct dvb_frontend_ops vidtv_demod_ops = { .delsys = { SYS_DVBT, SYS_DVBT2, SYS_DVBC_ANNEX_A, SYS_DVBS, SYS_DVBS2, }, .info = { .name = "Dummy demod for DVB-T/T2/C/S/S2", .frequency_min_hz = 51 * MHz, .frequency_max_hz = 2150 * MHz, .frequency_stepsize_hz = 62500, .frequency_tolerance_hz = 29500 * kHz, .symbol_rate_min = 1000000, .symbol_rate_max = 45000000, .caps = FE_CAN_FEC_1_2 | FE_CAN_FEC_2_3 | FE_CAN_FEC_3_4 | FE_CAN_FEC_4_5 | FE_CAN_FEC_5_6 | FE_CAN_FEC_6_7 | FE_CAN_FEC_7_8 | FE_CAN_FEC_8_9 | FE_CAN_FEC_AUTO | FE_CAN_QAM_16 | FE_CAN_QAM_64 | FE_CAN_QAM_32 | FE_CAN_QAM_128 | FE_CAN_QAM_256 | FE_CAN_QAM_AUTO | FE_CAN_QPSK | FE_CAN_FEC_AUTO | FE_CAN_INVERSION_AUTO | FE_CAN_TRANSMISSION_MODE_AUTO | FE_CAN_GUARD_INTERVAL_AUTO | FE_CAN_HIERARCHY_AUTO, }, .release = vidtv_demod_release, .init = vidtv_demod_init, .sleep = vidtv_demod_sleep, .set_frontend = vidtv_demod_set_frontend, .get_frontend = vidtv_demod_get_frontend, .read_status = vidtv_demod_read_status, .read_ber = vidtv_demod_read_ber, .read_signal_strength = vidtv_demod_read_signal_strength, .read_snr = vidtv_demod_read_snr, .read_ucblocks = vidtv_demod_read_ucblocks, /* For DVB-S/S2 */ .set_voltage = vidtv_demod_set_voltage, .set_tone = vidtv_demod_set_tone, }; > + > +static const struct i2c_device_id vidtv_demod_i2c_id_table[] = { > + {"vidtv_demod", 0}, > + {} > +}; > +MODULE_DEVICE_TABLE(i2c, vidtv_demod_i2c_id_table); > + > +static int vidtv_demod_i2c_probe(struct i2c_client *client, > + const struct i2c_device_id *id) > +{ > + struct vidtv_demod_config *config = client->dev.platform_data; > + struct vidtv_demod_state *state; > + const struct dvb_frontend_ops *ops; > + > + /* allocate memory for the internal state */ > + state = kzalloc(sizeof(*state), GFP_KERNEL); > + if (!state) > + return -ENOMEM; > + > + switch (config->chosen_delsys) { > + case SYS_DVBT: > + ops = &vidtv_demod_ofdm_ops; > + break; > + case SYS_DVBC_ANNEX_A: > + ops = &vidtv_demod_qam_ops; > + break; > + case SYS_DVBS: > + ops = &vidtv_demod_qpsk_ops; > + break; > + default: > + pr_err("%s: Unsupported delivery system. Falling back to DVB-T", > + __func__); > + ops = &vidtv_demod_ofdm_ops; > + break; > + } By placing everything into a single entry, you can get rid of the above. Nowadays, most demods are multi-standard. So, let's teach people to write just a single entry for it, instead of the legacy way of one entry per each delivery system. > + > + /* create dvb_frontend */ > + memcpy(&state->frontend.ops, > + ops, > + sizeof(struct dvb_frontend_ops)); > + > + state->frontend.demodulator_priv = state; > + /* return the pointer to the bridge driver */ > + config->frontend = &state->frontend; > + i2c_set_clientdata(client, state); > + > + return 0; > +} > + > +static int vidtv_demod_i2c_remove(struct i2c_client *client) > +{ > + struct vidtv_demod_state *state = i2c_get_clientdata(client); > + > + memset(&state->frontend.ops, 0, sizeof(struct dvb_frontend_ops)); > + state->frontend.demodulator_priv = NULL; > + kfree(state); > + > + return 0; > +} > + > +static struct i2c_driver vidtv_demod_i2c_driver = { > + .driver = { > + .name = "vidtv_demod", > + .suppress_bind_attrs = true, > + }, > + .probe = vidtv_demod_i2c_probe, > + .remove = vidtv_demod_i2c_remove, > + .id_table = vidtv_demod_i2c_id_table, > +}; > + > +module_i2c_driver(vidtv_demod_i2c_driver); > diff --git a/drivers/media/test-drivers/vidtv/vidtv_demod.h b/drivers/media/test-drivers/vidtv/vidtv_demod.h > new file mode 100644 > index 0000000000000..49c2a43f71661 > --- /dev/null > +++ b/drivers/media/test-drivers/vidtv/vidtv_demod.h > @@ -0,0 +1,43 @@ > +/* SPDX-License-Identifier: GPL-2.0-or-later */ > +/* > + * 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 > + * Based on the example driver written by Emard > + */ > + > +#ifndef VIDTV_DEMOD_H > +#define VIDTV_DEMOD_H > + > +#include > +#include > + > +struct vidtv_demod_cnr_to_qual_s { > + /* attempt to use the same values as libdvbv5 */ > + u32 modulation; > + u32 fec; > + u32 cnr_ok, cnr_good; > +}; > + > +struct vidtv_demod_config { > + struct dvb_frontend *frontend; > + /* probability of losing the lock due to low snr */ > + u8 drop_tslock_prob_on_low_snr; > + /* probability of recovering when the signal improves */ > + u8 recover_tslock_prob_on_good_snr; > + u8 chosen_delsys; > +}; > + > +struct vidtv_demod_state { > + struct dvb_frontend frontend; > + struct vidtv_demod_config config; > + struct delayed_work poll_snr; > + enum fe_status status; > + u16 tuner_cnr; > + bool cold_start; > + bool poll_snr_thread_running; > + bool poll_snr_thread_restart; > +}; > +#endif // VIDTV_DEMOD_H Thanks, Mauro