From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rasmus Villemoes Subject: [PATCH 3/4] pwm: mxs: add support for inverse polarity Date: Mon, 23 Sep 2019 10:13:47 +0200 Message-ID: <20190923081348.6843-4-linux@rasmusvillemoes.dk> References: <20190923081348.6843-1-linux@rasmusvillemoes.dk> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20190923081348.6843-1-linux@rasmusvillemoes.dk> Sender: linux-kernel-owner@vger.kernel.org To: Thierry Reding , Shawn Guo , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam , NXP Linux Team Cc: devicetree@vger.kernel.org, Rob Herring , Rasmus Villemoes , linux-pwm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org List-Id: linux-pwm@vger.kernel.org If I'm reading of_pwm_xlate_with_flags() right, existing device trees that set #pwm-cells = 2 will continue to work. Signed-off-by: Rasmus Villemoes --- drivers/pwm/pwm-mxs.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/drivers/pwm/pwm-mxs.c b/drivers/pwm/pwm-mxs.c index 284107784dad..c46697acaf11 100644 --- a/drivers/pwm/pwm-mxs.c +++ b/drivers/pwm/pwm-mxs.c @@ -25,8 +25,11 @@ #define PERIOD_PERIOD(p) ((p) & 0xffff) #define PERIOD_PERIOD_MAX 0x10000 #define PERIOD_ACTIVE_HIGH (3 << 16) +#define PERIOD_ACTIVE_LOW (2 << 16) +#define PERIOD_INACTIVE_HIGH (3 << 18) #define PERIOD_INACTIVE_LOW (2 << 18) #define PERIOD_POLARITY_NORMAL (PERIOD_ACTIVE_HIGH | PERIOD_INACTIVE_LOW) +#define PERIOD_POLARITY_INVERSE (PERIOD_ACTIVE_LOW | PERIOD_INACTIVE_HIGH) #define PERIOD_CDIV(div) (((div) & 0x7) << 20) #define PERIOD_CDIV_MAX 8 @@ -50,9 +53,7 @@ static int mxs_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, unsigned int period_cycles, duty_cycles; unsigned long rate; unsigned long long c; - - if (state->polarity != PWM_POLARITY_NORMAL) - return -ENOTSUPP; + unsigned int pol_bits; rate = clk_get_rate(mxs->clk); while (1) { @@ -81,9 +82,12 @@ static int mxs_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, return ret; } + pol_bits = state->polarity == PWM_POLARITY_NORMAL ? + PERIOD_POLARITY_NORMAL : PERIOD_POLARITY_INVERSE; + writel(duty_cycles << 16, mxs->base + PWM_ACTIVE0 + pwm->hwpwm * 0x20); - writel(PERIOD_PERIOD(period_cycles) | PERIOD_POLARITY_NORMAL | PERIOD_CDIV(div), + writel(PERIOD_PERIOD(period_cycles) | pol_bits | PERIOD_CDIV(div), mxs->base + PWM_PERIOD0 + pwm->hwpwm * 0x20); if (state->enabled) { @@ -129,6 +133,8 @@ static int mxs_pwm_probe(struct platform_device *pdev) mxs->chip.dev = &pdev->dev; mxs->chip.ops = &mxs_pwm_ops; + mxs->chip.of_xlate = of_pwm_xlate_with_flags; + mxs->chip.of_pwm_n_cells = 3; mxs->chip.base = -1; ret = of_property_read_u32(np, "fsl,pwm-number", &mxs->chip.npwm); -- 2.20.1