From patchwork Tue Dec 19 16:30:29 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Young X-Patchwork-Id: 13498497 Received: from gofer.mess.org (gofer.mess.org [88.97.38.141]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 48E3622331; Tue, 19 Dec 2023 16:31:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=mess.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=mess.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=mess.org header.i=@mess.org header.b="NYfu6jWK"; dkim=pass (2048-bit key) header.d=mess.org header.i=@mess.org header.b="blkhsLd0" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=mess.org; s=2020; t=1703003468; bh=hUUyx2Ra/j0PfiviV+OXUA5B+Rr5c5IfU2vtPHgn40o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NYfu6jWKFgj9mC3ee/nZq7ODltMtE9iQU5keKKmA+PGIHhF1oFMXX08UunGXfJU60 +YEdnVlG/tKBb7HpXA7iq68T83Hs17eygkJcyBeDOtMHvG9FAxQZzqgH7wlIv772PX oeTrxH6APT5WkRi71pL7t0eqcjInM1v+HoGN+YhZiVOwZSUPm+ooOUvyjS58j4quNt sTUXD6t/z29XaNqGRIzQW1Wb1Dr3VeUmucCSZGdtVj+qxPPGedGFsFiS2vGuAyWJga gaqpCKMyIxL+o2QVFsw0OzqmidSRhiEiCWff4TJ7DuiR0fnn/cGzdO+cQHjizKvyL5 csiqF/k8KFg+g== Received: by gofer.mess.org (Postfix, from userid 501) id C019010029E; Tue, 19 Dec 2023 16:31:08 +0000 (GMT) X-Spam-Level: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=mess.org; s=2020; t=1703003449; bh=hUUyx2Ra/j0PfiviV+OXUA5B+Rr5c5IfU2vtPHgn40o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=blkhsLd0GFn35E4dfO2DkD3V2fcGTIjuMIvfsWsX/UuDFkNgoaHlERe4GJE1v/b8r yT3XrpVFzaHEUhrmfzj9fBRmTBO4944oiniOix5V+6Y7vmYpZ5fyCKKS1PR+tD/rVL dDx+GS+JdhPR+9zcTFviaaUCOHnQZJoUqLtLxbKcm7iDE6ttXpxDyjanX5DGJWZ6J5 bjw6fvYW3wYn5O3szjShT6yul4oYeAYvrmEV1SxhjrxbP8RkysqwwN9A97bX5sQvSF cxzzLAPrVPcITAEJZmiFxivO+SFoHVX5yZYMYmJ4r6psC0nuc0ktR/YUNzkKJDU0ju mHX7oGDUUpP2A== Received: from localhost.localdomain (bigcore.local [IPv6:2a02:8011:d000:212:ca7f:54ff:fe51:14d6]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by gofer.mess.org (Postfix) with ESMTPSA id C18ED1009FF; Tue, 19 Dec 2023 16:30:49 +0000 (GMT) From: Sean Young To: linux-media@vger.kernel.org, linux-pwm@vger.kernel.org, Ivaylo Dimitrov , Thierry Reding , =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= , Sean Young , Mauro Carvalho Chehab Cc: linux-kernel@vger.kernel.org Subject: [PATCH v10 6/6] media: pwm-ir-tx: Trigger edges from hrtimer interrupt context Date: Tue, 19 Dec 2023 16:30:29 +0000 Message-ID: <1a5750d4eb3e4f777a123b094fdd66d3b16d2b9d.1703003288.git.sean@mess.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 This makes the generated IR much more precise. Before this change, the driver is unreliable and many users opted to use gpio-ir-tx instead. Signed-off-by: Sean Young --- drivers/media/rc/pwm-ir-tx.c | 83 +++++++++++++++++++++++++++++++++--- 1 file changed, 78 insertions(+), 5 deletions(-) diff --git a/drivers/media/rc/pwm-ir-tx.c b/drivers/media/rc/pwm-ir-tx.c index cf51e2760975..fe368aebbc13 100644 --- a/drivers/media/rc/pwm-ir-tx.c +++ b/drivers/media/rc/pwm-ir-tx.c @@ -10,6 +10,8 @@ #include #include #include +#include +#include #include #define DRIVER_NAME "pwm-ir-tx" @@ -17,8 +19,14 @@ struct pwm_ir { struct pwm_device *pwm; - unsigned int carrier; - unsigned int duty_cycle; + struct hrtimer timer; + struct completion tx_done; + struct pwm_state *state; + u32 carrier; + u32 duty_cycle; + const unsigned int *txbuf; + unsigned int txbuf_len; + unsigned int txbuf_index; }; static const struct of_device_id pwm_ir_of_match[] = { @@ -49,8 +57,8 @@ static int pwm_ir_set_carrier(struct rc_dev *dev, u32 carrier) return 0; } -static int pwm_ir_tx(struct rc_dev *dev, unsigned int *txbuf, - unsigned int count) +static int pwm_ir_tx_sleep(struct rc_dev *dev, unsigned int *txbuf, + unsigned int count) { struct pwm_ir *pwm_ir = dev->priv; struct pwm_device *pwm = pwm_ir->pwm; @@ -82,6 +90,62 @@ static int pwm_ir_tx(struct rc_dev *dev, unsigned int *txbuf, return count; } +static int pwm_ir_tx_atomic(struct rc_dev *dev, unsigned int *txbuf, + unsigned int count) +{ + struct pwm_ir *pwm_ir = dev->priv; + struct pwm_device *pwm = pwm_ir->pwm; + struct pwm_state state; + + pwm_init_state(pwm, &state); + + state.period = DIV_ROUND_CLOSEST(NSEC_PER_SEC, pwm_ir->carrier); + pwm_set_relative_duty_cycle(&state, pwm_ir->duty_cycle, 100); + + pwm_ir->txbuf = txbuf; + pwm_ir->txbuf_len = count; + pwm_ir->txbuf_index = 0; + pwm_ir->state = &state; + + hrtimer_start(&pwm_ir->timer, 0, HRTIMER_MODE_REL); + + wait_for_completion(&pwm_ir->tx_done); + + return count; +} + +static enum hrtimer_restart pwm_ir_timer(struct hrtimer *timer) +{ + struct pwm_ir *pwm_ir = container_of(timer, struct pwm_ir, timer); + ktime_t now; + + /* + * If we happen to hit an odd latency spike, loop through the + * pulses until we catch up. + */ + do { + u64 ns; + + pwm_ir->state->enabled = !(pwm_ir->txbuf_index % 2); + pwm_apply_atomic(pwm_ir->pwm, pwm_ir->state); + + if (pwm_ir->txbuf_index >= pwm_ir->txbuf_len) { + complete(&pwm_ir->tx_done); + + return HRTIMER_NORESTART; + } + + ns = US_TO_NS(pwm_ir->txbuf[pwm_ir->txbuf_index]); + hrtimer_add_expires_ns(timer, ns); + + pwm_ir->txbuf_index++; + + now = timer->base->get_time(); + } while (hrtimer_get_expires_tv64(timer) < now); + + return HRTIMER_RESTART; +} + static int pwm_ir_probe(struct platform_device *pdev) { struct pwm_ir *pwm_ir; @@ -103,10 +167,19 @@ static int pwm_ir_probe(struct platform_device *pdev) if (!rcdev) return -ENOMEM; + if (pwm_might_sleep(pwm_ir->pwm)) { + dev_info(&pdev->dev, "TX will not be accurate as PWM device might sleep\n"); + rcdev->tx_ir = pwm_ir_tx_sleep; + } else { + init_completion(&pwm_ir->tx_done); + hrtimer_init(&pwm_ir->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + pwm_ir->timer.function = pwm_ir_timer; + rcdev->tx_ir = pwm_ir_tx_atomic; + } + rcdev->priv = pwm_ir; rcdev->driver_name = DRIVER_NAME; rcdev->device_name = DEVICE_NAME; - rcdev->tx_ir = pwm_ir_tx; rcdev->s_tx_duty_cycle = pwm_ir_set_duty_cycle; rcdev->s_tx_carrier = pwm_ir_set_carrier;