Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757688AbcJXPZc (ORCPT ); Mon, 24 Oct 2016 11:25:32 -0400 Received: from up.free-electrons.com ([163.172.77.33]:46872 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752360AbcJXPZ3 (ORCPT ); Mon, 24 Oct 2016 11:25:29 -0400 Date: Mon, 24 Oct 2016 17:25:26 +0200 From: Boris Brezillon To: Lukasz Majewski Cc: Thierry Reding , Stefan Agner , linux-pwm@vger.kernel.org, linux-kernel@vger.kernel.org, Fabio Estevam , Fabio Estevam , Lothar Wassmann , Bhuvanchandra DV , kernel@pengutronix.de Subject: Re: [PATCH 4/6] pwm: imx: Provide atomic PWM support for IMXv2 PWM Message-ID: <20161024172526.798de5ce@bbrezillon> In-Reply-To: <1477259146-19167-5-git-send-email-l.majewski@majess.pl> References: <1477259146-19167-1-git-send-email-l.majewski@majess.pl> <1477259146-19167-5-git-send-email-l.majewski@majess.pl> X-Mailer: Claws Mail 3.13.2 (GTK+ 2.24.30; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3198 Lines: 112 On Sun, 23 Oct 2016 23:45:44 +0200 Lukasz Majewski wrote: > This commit provides apply() callback implementation for IMX's PWMv2. > > Suggested-by: Stefan Agner > Suggested-by: Boris Brezillon > Signed-off-by: Lukasz Majewski Reviewed-by: Boris Brezillon > --- > drivers/pwm/pwm-imx.c | 79 +++++++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 79 insertions(+) > > diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c > index f3577c5..df25379 100644 > --- a/drivers/pwm/pwm-imx.c > +++ b/drivers/pwm/pwm-imx.c > @@ -171,6 +171,84 @@ static void imx_pwm_wait_fifo_slot(struct pwm_chip *chip, > } > } > > +static int imx_pwm_apply_v2(struct pwm_chip *chip, struct pwm_device *pwm, > + struct pwm_state *state) > +{ > + unsigned long period_cycles, duty_cycles, prescale; > + struct imx_chip *imx = to_imx_chip(chip); > + struct pwm_state cstate; > + unsigned long long c; > + u32 cr = 0; > + int ret; > + > + ret = clk_prepare_enable(imx->clk_ipg); > + if (ret) > + return ret; > + > + pwm_get_state(pwm, &cstate); > + > + c = clk_get_rate(imx->clk_per); > + c *= state->period; > + > + do_div(c, 1000000000); > + period_cycles = c; > + > + prescale = period_cycles / 0x10000 + 1; > + > + period_cycles /= prescale; > + c = (unsigned long long)period_cycles * state->duty_cycle; > + do_div(c, state->period); > + duty_cycles = c; > + > + /* > + * according to imx pwm RM, the real period value should be > + * PERIOD value in PWMPR plus 2. > + */ > + if (period_cycles > 2) > + period_cycles -= 2; > + else > + period_cycles = 0; > + > + /* Enable the clock if the PWM is being enabled. */ > + if (state->enabled && !cstate.enabled) { > + ret = clk_prepare_enable(imx->clk_per); > + if (ret) > + return ret; > + } > + > + /* > + * Wait for a free FIFO slot if the PWM is already enabled, and flush > + * the FIFO if the PWM was disabled and is about to be enabled. > + */ > + if (cstate.enabled) > + imx_pwm_wait_fifo_slot(chip, pwm); > + else if (state->enabled) > + imx_pwm_sw_reset(chip); > + > + writel(duty_cycles, imx->mmio_base + MX3_PWMSAR); > + writel(period_cycles, imx->mmio_base + MX3_PWMPR); > + > + cr |= MX3_PWMCR_PRESCALER(prescale) | > + MX3_PWMCR_DOZEEN | MX3_PWMCR_WAITEN | > + MX3_PWMCR_DBGEN | MX3_PWMCR_CLKSRC_IPG_HIGH; > + > + if (state->enabled) > + cr |= MX3_PWMCR_EN; > + > + if (state->polarity == PWM_POLARITY_INVERSED) > + cr |= MX3_PWMCR_POUTC; > + > + writel(cr, imx->mmio_base + MX3_PWMCR); > + > + /* Disable the clock if the PWM is being disabled. */ > + if (!state->enabled && cstate.enabled) > + clk_disable_unprepare(imx->clk_per); > + > + clk_disable_unprepare(imx->clk_ipg); > + > + return 0; > +} > + > static int imx_pwm_config_v2(struct pwm_chip *chip, > struct pwm_device *pwm, int duty_ns, int period_ns) > { > @@ -322,6 +400,7 @@ static struct pwm_ops imx_pwm_ops_v2 = { > .disable = imx_pwm_disable, > .set_polarity = imx_pwm_set_polarity, > .config = imx_pwm_config, > + .apply = imx_pwm_apply_v2, > .owner = THIS_MODULE, > }; >