From nobody Thu Dec 25 03:36:08 2025 Received: from mail-pf1-f169.google.com (mail-pf1-f169.google.com [209.85.210.169]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 481C9524A3 for ; Tue, 23 Jan 2024 06:18:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.169 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705990684; cv=none; b=mw15vGPs9kbbOjmFNCKjaMq/M6VU6GN/DXIyUFkg9f02INxHKYjnnpeFNndvhGCNyZf+cvHVzXhpkym1Jd1ZQb/vMWj6MBi6Oxz8P+LTIvbgW7wbb6rOk5szHL4wocYRQo54BSjNZdVHapZbJtAmSUq2yWtvqewvfpREv32zOr4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705990684; c=relaxed/simple; bh=d06KhWfzzNhEwLATG5EAKVuMF8lG+Vj1y10Kz7W9+ck=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=XJlgN/KV8W0VbFjyI574VBe8CviNmOYA60oEZYsiYhRsA42tJzvtnVc3GK1UMHft2U67dQIXSPFCqJZtxMca6ucFYtErQiHeO3/87N3A8Ib9nyVPb1jj+YixoBQTh7lmS9rd3Tlfcfar4Vw/OX1X85AJ+ASnEuNEsfo7nHYVKxI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=sifive.com; spf=pass smtp.mailfrom=sifive.com; dkim=pass (2048-bit key) header.d=sifive.com header.i=@sifive.com header.b=Jh0u21DP; arc=none smtp.client-ip=209.85.210.169 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=sifive.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sifive.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=sifive.com header.i=@sifive.com header.b="Jh0u21DP" Received: by mail-pf1-f169.google.com with SMTP id d2e1a72fcca58-6dbb26ec1deso4084243b3a.0 for ; Mon, 22 Jan 2024 22:18:03 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sifive.com; s=google; t=1705990682; x=1706595482; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=cvJrbymRDVqsWiIagFJrDLqKjAGvymGFfMj4nY9d7Jo=; b=Jh0u21DPLVeCt7bQ7t/gweGDNXqOIZ5NRYS6eqCkWL5cT7gUmUT+5y0UATXHigJZ5+ iFqRl/liZyKbF4+/xmK7B3n9yIxiYXXYmFFt2xytr+I59FUluy3OgfH8bfv0awAEVWnr ymMGgyF2MFzbvJA7/hXosVGu33yJmwz8hqV5mlQ03ZTrg17xSsI8zi2iSGZWyMH/IitL 9VRD5rdlus9AjhzZ3eKdA6k9QQUbblYltd+Q0zRB0oXx0wqRU35A8XKmBjloa3D58RAd pJ3u9eysWacsiIt3mYVXcr9gfCq5IR49Ig9ycFpZJn7dTYVZtqN6IIivlMu8zp3Ampby hrwg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1705990682; x=1706595482; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=cvJrbymRDVqsWiIagFJrDLqKjAGvymGFfMj4nY9d7Jo=; b=MD+syt3xuNDSWy8fzsdZ9f2/LveWf+cyAisZJMcyq4Yq71c7ZlpcU3g2Dl40ivHJ0h PWz4iPPGky9Xb5yCDdXVXARjKw5sGlhuTvA5ErMAkjWIa5jCze8eqK1cupfPca0YYBLW /9ltHWyOdeHGzpNr/sLFXtQgmSrxGJRzA0l9FKBlxYCtyiOFH08Z0fzskPwpLSfnU2RS zxbpPPzx9LOlNkRbJMpv0+5RrwUWOPdRjWfa4DP+MBTbZvc5OMCR9OB7bbCXh0yQB/J+ Tfwsbb8L+UEhYhBF13/BmkjfqfzuCw6oXDVe6GE3bAVg8ZQEqsw+wRWIk72sgx+LroKj 41ug== X-Gm-Message-State: AOJu0YwYkhZO00FCTISbT+zy/1zKIsaRP4vzNaqcA9bF0WmUrLQauDW8 YEa30ynvH5zN91TZUYxXaZTUy1z8qmr5aICeE1OEzjYN8O3JQf8tWndxlI0EtM13iWuCRI9jBF0 r X-Google-Smtp-Source: AGHT+IEOZE+FU/vU9PCxfaGkCTPgaFa/4ycXAtuyVM2ziXvmuqSrHD4wV/6kejsabMmCEqh/hFuYzQ== X-Received: by 2002:a05:6a20:3d96:b0:19a:da41:9da with SMTP id s22-20020a056a203d9600b0019ada4109damr6938288pzi.13.1705990682643; Mon, 22 Jan 2024 22:18:02 -0800 (PST) Received: from hsinchu15.internal.sifive.com (59-124-168-89.hinet-ip.hinet.net. [59.124.168.89]) by smtp.gmail.com with ESMTPSA id p7-20020a170902b08700b001d733c88646sm4425376plr.216.2024.01.22.22.17.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 22 Jan 2024 22:18:02 -0800 (PST) From: Nylon Chen To: linux-riscv@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pwm@vger.kernel.org, conor@kernel.org, robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org, palmer@dabbelt.com, paul.walmsley@sifive.com, aou@eecs.berkeley.edu, thierry.reding@gmail.com, u.kleine-koenig@pengutronix.de Cc: vincent.chen@sifive.com, zong.li@sifve.com, nylon.chen@sifive.com, nylon7717@gmail.com Subject: [PATCH v7 2/3] pwm: sifive: change the PWM controlled LED algorithm Date: Tue, 23 Jan 2024 14:17:47 +0800 Message-ID: <20240123061748.8844-3-nylon.chen@sifive.com> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20240123061748.8844-1-nylon.chen@sifive.com> References: <20240123061748.8844-1-nylon.chen@sifive.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" The `frac` variable represents the pulse inactive time, and the result of this algorithm is the pulse active time. Therefore, we must reverse the = result. The reference is SiFive FU740-C000 Manual[0] Link: https://sifive.cdn.prismic.io/sifive/1a82e600-1f93-4f41-b2d8-86ed8b16= acba_fu740-c000-manual-v1p6.pdf [0] Co-developed-by: Zong Li Signed-off-by: Zong Li Co-developed-by: Vincent Chen Signed-off-by: Vincent Chen Signed-off-by: Nylon Chen --- drivers/pwm/pwm-sifive.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/pwm/pwm-sifive.c b/drivers/pwm/pwm-sifive.c index eabddb7c7820..b07c8598bb21 100644 --- a/drivers/pwm/pwm-sifive.c +++ b/drivers/pwm/pwm-sifive.c @@ -113,6 +113,7 @@ static int pwm_sifive_get_state(struct pwm_chip *chip, = struct pwm_device *pwm, u32 duty, val; =20 duty =3D readl(ddata->regs + PWM_SIFIVE_PWMCMP(pwm->hwpwm)); + duty =3D (1U << PWM_SIFIVE_CMPWIDTH) - 1 - duty; =20 state->enabled =3D duty > 0; =20 @@ -123,11 +124,10 @@ static int pwm_sifive_get_state(struct pwm_chip *chip= , struct pwm_device *pwm, state->period =3D ddata->real_period; state->duty_cycle =3D (u64)duty * ddata->real_period >> PWM_SIFIVE_CMPWIDTH; - state->polarity =3D PWM_POLARITY_INVERSED; + state->polarity =3D PWM_POLARITY_NORMAL; =20 return 0; } - static int pwm_sifive_apply(struct pwm_chip *chip, struct pwm_device *pwm, const struct pwm_state *state) { @@ -139,7 +139,7 @@ static int pwm_sifive_apply(struct pwm_chip *chip, stru= ct pwm_device *pwm, int ret =3D 0; u32 frac; =20 - if (state->polarity !=3D PWM_POLARITY_INVERSED) + if (state->polarity !=3D PWM_POLARITY_NORMAL) return -EINVAL; =20 cur_state =3D pwm->state; @@ -159,6 +159,7 @@ static int pwm_sifive_apply(struct pwm_chip *chip, stru= ct pwm_device *pwm, frac =3D DIV64_U64_ROUND_CLOSEST(num, state->period); /* The hardware cannot generate a 100% duty cycle */ frac =3D min(frac, (1U << PWM_SIFIVE_CMPWIDTH) - 1); + frac =3D (1U << PWM_SIFIVE_CMPWIDTH) - 1 - frac; =20 mutex_lock(&ddata->lock); if (state->period !=3D ddata->approx_period) { --=20 2.42.0