From patchwork Thu Jan 16 08:06:25 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Lothar_Wa=C3=9Fmann?= X-Patchwork-Id: 311618 Return-Path: X-Original-To: incoming-dt@patchwork.ozlabs.org Delivered-To: patchwork-incoming-dt@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id EF4B42C0082 for ; Thu, 16 Jan 2014 19:08:57 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750976AbaAPII4 (ORCPT ); Thu, 16 Jan 2014 03:08:56 -0500 Received: from mail.karo-electronics.de ([81.173.242.67]:57306 "EHLO mail.karo-electronics.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750836AbaAPIIz (ORCPT ); Thu, 16 Jan 2014 03:08:55 -0500 From: =?UTF-8?q?Lothar=20Wa=C3=9Fmann?= To: linux-arm-kernel@lists.infradead.org, Shawn Guo , Sascha Hauer , Thierry Reding , Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , Rob Landley , linux-pwm@vger.kernel.org, devicetree@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Cc: =?UTF-8?q?Lothar=20Wa=C3=9Fmann?= Subject: [PATCHv2 2/2] pwm: imx: support polarity inversion Date: Thu, 16 Jan 2014 09:06:25 +0100 Message-Id: <1389859585-14006-3-git-send-email-LW@KARO-electronics.de> X-Mailer: git-send-email 1.7.2.5 In-Reply-To: <1389859585-14006-1-git-send-email-LW@KARO-electronics.de> References: <1389859585-14006-1-git-send-email-LW@KARO-electronics.de> MIME-Version: 1.0 Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org The i.MX PWM controller supports inverting the polarity of the PWM output. Make this feature available in the pxm-imx driver. Signed-off-by: Lothar Waßmann --- Documentation/devicetree/bindings/pwm/imx-pwm.txt | 5 +- drivers/pwm/pwm-imx.c | 42 +++++++++++++++++++++ 2 files changed, 45 insertions(+), 2 deletions(-) diff --git a/Documentation/devicetree/bindings/pwm/imx-pwm.txt b/Documentation/devicetree/bindings/pwm/imx-pwm.txt index b50d7a6d..d0b04b5 100644 --- a/Documentation/devicetree/bindings/pwm/imx-pwm.txt +++ b/Documentation/devicetree/bindings/pwm/imx-pwm.txt @@ -3,8 +3,9 @@ Freescale i.MX PWM controller Required properties: - compatible: should be "fsl,-pwm" - reg: physical base address and length of the controller's registers -- #pwm-cells: should be 2. See pwm.txt in this directory for a description of - the cells format. +- #pwm-cells: may be 2 for backwards compatibility or 3 to support + switching the output polarity. See pwm.txt in this directory for a + description of the cells format. - interrupts: The interrupt for the pwm controller Example: diff --git a/drivers/pwm/pwm-imx.c b/drivers/pwm/pwm-imx.c index 3b00a82..05461bb 100644 --- a/drivers/pwm/pwm-imx.c +++ b/drivers/pwm/pwm-imx.c @@ -36,6 +36,7 @@ #define MX3_PWMCR_DOZEEN (1 << 24) #define MX3_PWMCR_WAITEN (1 << 23) #define MX3_PWMCR_DBGEN (1 << 22) +#define MX3_PWMCR_POUTC (1 << 18) #define MX3_PWMCR_CLKSRC_IPG_HIGH (2 << 16) #define MX3_PWMCR_CLKSRC_IPG (1 << 16) #define MX3_PWMCR_EN (1 << 0) @@ -138,6 +139,9 @@ static int imx_pwm_config_v2(struct pwm_chip *chip, if (test_bit(PWMF_ENABLED, &pwm->flags)) cr |= MX3_PWMCR_EN; + if (pwm->polarity == PWM_POLARITY_INVERSED) + cr |= MX3_PWMCR_POUTC; + writel(cr, imx->mmio_base + MX3_PWMCR); return 0; @@ -155,6 +159,11 @@ static void imx_pwm_set_enable_v2(struct pwm_chip *chip, bool enable) else val &= ~MX3_PWMCR_EN; + if (chip->pwms[0].polarity == PWM_POLARITY_INVERSED) + val |= MX3_PWMCR_POUTC; + else + val &= ~MX3_PWMCR_POUTC; + writel(val, imx->mmio_base + MX3_PWMCR); } @@ -198,6 +207,17 @@ static void imx_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) clk_disable_unprepare(imx->clk_per); } +static int imx_pwm_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm, + enum pwm_polarity polarity) +{ + struct imx_chip *imx = to_imx_chip(chip); + + dev_dbg(imx->chip.dev, "%s: polarity set to %s\n", __func__, + polarity == PWM_POLARITY_INVERSED ? "inverted" : "normal"); + + return 0; +} + static struct pwm_ops imx_pwm_ops = { .enable = imx_pwm_enable, .disable = imx_pwm_disable, @@ -209,6 +229,7 @@ struct imx_pwm_data { int (*config)(struct pwm_chip *chip, struct pwm_device *pwm, int duty_ns, int period_ns); void (*set_enable)(struct pwm_chip *chip, bool enable); + unsigned output_polarity:1; }; static struct imx_pwm_data imx_pwm_data_v1 = { @@ -219,6 +240,7 @@ static struct imx_pwm_data imx_pwm_data_v1 = { static struct imx_pwm_data imx_pwm_data_v2 = { .config = imx_pwm_config_v2, .set_enable = imx_pwm_set_enable_v2, + .output_polarity = 1, }; static const struct of_device_id imx_pwm_dt_ids[] = { @@ -271,6 +293,26 @@ static int imx_pwm_probe(struct platform_device *pdev) return PTR_ERR(imx->mmio_base); data = of_id->data; + if (data->output_polarity) { + const struct device_node *np = pdev->dev.of_node; + u32 num_cells; + + dev_dbg(&pdev->dev, "PWM supports output inversion\n"); + ret = of_property_read_u32(np, "#pwm-cells", &num_cells); + if (ret < 0) { + dev_err(&pdev->dev, "missing property '#pwm-cells'\n"); + return ret; + } + if (num_cells == 3) { + imx_pwm_ops.set_polarity = imx_pwm_set_polarity; + imx->chip.of_xlate = of_pwm_xlate_with_flags; + } else if (num_cells != 2) { + dev_err(&pdev->dev, "'#pwm-cells' must be <2> or <3>\n"); + return -EINVAL; + } + imx->chip.of_pwm_n_cells = num_cells; + } + imx->config = data->config; imx->set_enable = data->set_enable;