From patchwork Fri Dec 7 08:29:33 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yoshihiro Shimoda X-Patchwork-Id: 10717625 X-Patchwork-Delegate: geert@linux-m68k.org Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 3549A13BB for ; Fri, 7 Dec 2018 08:32:04 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 232792E838 for ; Fri, 7 Dec 2018 08:32:04 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 13FEC2E846; Fri, 7 Dec 2018 08:32:04 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A23D42E84E for ; Fri, 7 Dec 2018 08:32:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725985AbeLGIcD (ORCPT ); Fri, 7 Dec 2018 03:32:03 -0500 Received: from relmlor1.renesas.com ([210.160.252.171]:12374 "EHLO relmlie5.idc.renesas.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725967AbeLGIcD (ORCPT ); Fri, 7 Dec 2018 03:32:03 -0500 X-IronPort-AV: E=Sophos;i="5.56,324,1539615600"; d="scan'208";a="2219281" Received: from unknown (HELO relmlir6.idc.renesas.com) ([10.200.68.152]) by relmlie5.idc.renesas.com with ESMTP; 07 Dec 2018 17:32:00 +0900 Received: from localhost.localdomain (unknown [10.166.17.210]) by relmlir6.idc.renesas.com (Postfix) with ESMTP id 6D13F4A77D2F; Fri, 7 Dec 2018 17:32:00 +0900 (JST) From: Yoshihiro Shimoda To: thierry.reding@gmail.com Cc: linux-pwm@vger.kernel.org, linux-renesas-soc@vger.kernel.org, Yoshihiro Shimoda Subject: [PATCH 5/5] pwm: rcar: add workaround to output "pseudo" low level Date: Fri, 7 Dec 2018 17:29:33 +0900 Message-Id: <1544171373-29618-6-git-send-email-yoshihiro.shimoda.uh@renesas.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1544171373-29618-1-git-send-email-yoshihiro.shimoda.uh@renesas.com> References: <1544171373-29618-1-git-send-email-yoshihiro.shimoda.uh@renesas.com> Sender: linux-renesas-soc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-renesas-soc@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This PWM Timer cannot output low because setting 0x000 is prohibited on PWMCNT.PH0 (High-Level Period) bitfields. So, avoiding the prohibited, this patch adds a workaround function to change the value from 0 to 1 as pseudo low level. Signed-off-by: Yoshihiro Shimoda --- drivers/pwm/pwm-rcar.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/drivers/pwm/pwm-rcar.c b/drivers/pwm/pwm-rcar.c index e479b6a..888cb37 100644 --- a/drivers/pwm/pwm-rcar.c +++ b/drivers/pwm/pwm-rcar.c @@ -166,6 +166,20 @@ static void rcar_pwm_disable(struct rcar_pwm_chip *rp) rcar_pwm_update(rp, RCAR_PWMCR_EN0, 0, RCAR_PWMCR); } +static void rcar_pwm_workaround_output_low(struct rcar_pwm_chip *rp) +{ + /* + * This PWM Timer cannot output low because setting 0x000 is + * prohibited on PWMCNT.PH0 (High-Level Period) bitfields. So, avoiding + * the prohibited, this function changes the value from 0 to 1 as + * pseudo low level. + * + * TODO: Add GPIO handling to output low level. + */ + if ((rp->pwmcnt & RCAR_PWMCNT_PH0_MASK) == 0) + rp->pwmcnt |= 1; +} + static int rcar_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, struct pwm_state *state) { @@ -179,6 +193,7 @@ static int rcar_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, rcar_pwm_update(rp, RCAR_PWMCR_SYNC, RCAR_PWMCR_SYNC, RCAR_PWMCR); rcar_pwm_calc_counter(rp, div, state->duty_cycle, state->period); + rcar_pwm_workaround_output_low(rp); ret = rcar_pwm_set_counter(rp); if (!ret) rcar_pwm_set_clock_control(rp, div);