From patchwork Mon Dec 11 08:24:55 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Young X-Patchwork-Id: 13486810 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=mess.org header.i=@mess.org header.b="miR0ziVm"; dkim=pass (2048-bit key) header.d=mess.org header.i=@mess.org header.b="cVjm5ncx" Received: from gofer.mess.org (gofer.mess.org [88.97.38.141]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2F800F4; Mon, 11 Dec 2023 00:25:28 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=mess.org; s=2020; t=1702283126; bh=1Pzpw4wRIhFn8KXi9YpPX721/2iY1wS7k0zbhkrn6/o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=miR0ziVmQdQxua5yuI60yddc5/3DbsRZRTogApaK3iOraqn8/RbS5i7h9FGK4FNhr waBAi79OwzrNkhGf9MiGm+OoQh5sXDVVlIFY687fD4UMXCxSRtKb3OR40piDsknnWE AI8qw7NEfTRfs5zEsVcjTmnd1S2I1VPDwqsEn8sSv0jO4UqqDFzhpTEOoz2wq/TzaQ 2Xy0Xf9917/xZLo7k2BySPJcG6XlFMUk3Kxd+ke0ef7GvVsXcq9YCGN/KUBd+KzsAG YPXGTaUs/TTJ8hkYqAE7y0/7yJz6KtfrwmjUq5rkvyQw/JWjttPLi8DrD5yI1aMl9o /9xcStdiP7B8A== Received: by gofer.mess.org (Postfix, from userid 501) id B0F5910029E; Mon, 11 Dec 2023 08:25:26 +0000 (GMT) X-Spam-Level: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=mess.org; s=2020; t=1702283109; bh=1Pzpw4wRIhFn8KXi9YpPX721/2iY1wS7k0zbhkrn6/o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cVjm5ncxP6j5WD7HjGh5E3TU8KMdqxRKvE9dnmMCQj0quqVeS5cjJYVOLnQb+/KrN sJmvj6OeJWvUUKNl/06kCCDfKf5G02Rr51gfovZKva78ajViTxvCTxeWDQaFpdy8qk 4kdni75Sao1C14adcIO9xjhwXbpN8tBBLDsX8A8NnvqG+DvD93fwHNhZZlCqo96bb7 ewo9Me6prAawKQNb/z3tNffcOxYTyKb/wmEasXGxv7DFfb4nGcnssXU5GFZg5CptEU Ze0HxVO2Ok/xrlGIU80x+FKBh91MCG76k4pzxjzE2loF7R1ITo7k8xYNNCwBIqdM+T qlymitpnM3+TA== 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 B6D9D1009FC; Mon, 11 Dec 2023 08:25:09 +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 v7 4/4] media: pwm-ir-tx: Trigger edges from hrtimer interrupt context Date: Mon, 11 Dec 2023 08:24:55 +0000 Message-ID: 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 | 79 ++++++++++++++++++++++++++++++++++-- 1 file changed, 76 insertions(+), 3 deletions(-) diff --git a/drivers/media/rc/pwm-ir-tx.c b/drivers/media/rc/pwm-ir-tx.c index cf51e27609759..168f0b3539fa0 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[] = { @@ -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; + } 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;