From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752148AbcFNJNe (ORCPT ); Tue, 14 Jun 2016 05:13:34 -0400 Received: from down.free-electrons.com ([37.187.137.238]:59607 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752101AbcFNJNb (ORCPT ); Tue, 14 Jun 2016 05:13:31 -0400 From: Boris Brezillon To: Thierry Reding , linux-pwm@vger.kernel.org, Mark Brown , Liam Girdwood Cc: Heiko Stuebner , linux-rockchip@lists.infradead.org, Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Milo Kim , Doug Anderson , Caesar Wang , Stephen Barber , Brian Norris , Ajit Pal Singh , Srinivas Kandagatla , Maxime Coquelin , Patrice Chotard , kernel@stlinux.com, Laxman Dewangan , Boris Brezillon Subject: [PATCH v3 07/14] pwm: sti: Add support for hardware readout Date: Tue, 14 Jun 2016 11:13:15 +0200 Message-Id: <1465895602-31008-8-git-send-email-boris.brezillon@free-electrons.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1465895602-31008-1-git-send-email-boris.brezillon@free-electrons.com> References: <1465895602-31008-1-git-send-email-boris.brezillon@free-electrons.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Implement ->get_state() to provide support for initial state retrieval. Signed-off-by: Boris Brezillon --- drivers/pwm/pwm-sti.c | 38 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) diff --git a/drivers/pwm/pwm-sti.c b/drivers/pwm/pwm-sti.c index 92abbd5..6300d3e 100644 --- a/drivers/pwm/pwm-sti.c +++ b/drivers/pwm/pwm-sti.c @@ -238,6 +238,43 @@ static void sti_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) mutex_unlock(&pc->sti_pwm_lock); } +static void sti_pwm_get_state(struct pwm_chip *chip, + struct pwm_device *pwm, + struct pwm_state *state) +{ + struct sti_pwm_chip *pc = to_sti_pwmchip(chip); + unsigned int regval, prescaler; + int ret; + + /* The clock has to be enabled to access PWM registers */ + ret = clk_enable(pc->clk); + if (ret) { + dev_err(chip->dev, "Failed to enable PWM clk"); + return; + } + + regmap_field_read(pc->prescale_high, ®val); + prescaler = regval << 4; + regmap_field_read(pc->prescale_low, ®val); + prescaler |= regval; + state->period = DIV_ROUND_CLOSEST_ULL((u64)(prescaler + 1) * + NSEC_PER_SEC * + (pc->cdata->max_pwm_cnt + 1), + pc->clk_rate); + + regmap_read(pc->regmap, STI_DS_REG(pwm->hwpwm), ®val); + state->duty_cycle = DIV_ROUND_CLOSEST_ULL((u64)(regval + 1) * + state->period, + pc->cdata->max_pwm_cnt + 1); + + regmap_field_read(pc->pwm_en, ®val); + state->enabled = regval; + + state->polarity = PWM_POLARITY_NORMAL; + + clk_disable(pc->clk); +} + static void sti_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm) { struct sti_pwm_chip *pc = to_sti_pwmchip(chip); @@ -249,6 +286,7 @@ static const struct pwm_ops sti_pwm_ops = { .config = sti_pwm_config, .enable = sti_pwm_enable, .disable = sti_pwm_disable, + .get_state = sti_pwm_get_state, .free = sti_pwm_free, .owner = THIS_MODULE, }; -- 2.7.4