From patchwork Wed Oct 29 00:52:51 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Chang, Rebecca Swee Fun" X-Patchwork-Id: 5183041 Return-Path: X-Original-To: patchwork-ltsi-dev@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id E64819F318 for ; Wed, 29 Oct 2014 00:53:36 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id E2E1220172 for ; Wed, 29 Oct 2014 00:53:35 +0000 (UTC) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id CCBDF20165 for ; Wed, 29 Oct 2014 00:53:34 +0000 (UTC) Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id 12898A54; Wed, 29 Oct 2014 00:53:34 +0000 (UTC) X-Original-To: ltsi-dev@lists.linuxfoundation.org Delivered-To: ltsi-dev@mail.linuxfoundation.org Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 91B7926 for ; Wed, 29 Oct 2014 00:53:32 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by smtp1.linuxfoundation.org (Postfix) with ESMTP id B18D11FD46 for ; Wed, 29 Oct 2014 00:53:31 +0000 (UTC) Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga102.fm.intel.com with ESMTP; 28 Oct 2014 17:53:31 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.04,806,1406617200"; d="scan'208";a="622447161" Received: from rebeccas-ilbpg2.png.intel.com ([10.88.227.41]) by fmsmga002.fm.intel.com with ESMTP; 28 Oct 2014 17:53:30 -0700 From: Chang Rebecca Swee Fun To: LTSI Mailing List Date: Wed, 29 Oct 2014 08:52:51 +0800 Message-Id: <1414543978-24145-2-git-send-email-rebecca.swee.fun.chang@intel.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1414543978-24145-1-git-send-email-rebecca.swee.fun.chang@intel.com> References: <1414543978-24145-1-git-send-email-rebecca.swee.fun.chang@intel.com> X-Spam-Status: No, score=-4.8 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org Cc: Chang Rebecca Swee Fun Subject: [LTSI-dev] [PATCH 1/8] pwm: add support for Intel Low Power Subsystem PWM X-BeenThere: ltsi-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: "A list to discuss patches, development, and other things related to the LTSI project" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: ltsi-dev-bounces@lists.linuxfoundation.org Errors-To: ltsi-dev-bounces@lists.linuxfoundation.org X-Virus-Scanned: ClamAV using ClamSMTP From: Mika Westerberg Add support for Intel Low Power I/O subsystem PWM controllers found on Intel BayTrail SoC. Signed-off-by: Mika Westerberg Signed-off-by: Chew, Kean Ho Signed-off-by: Chang, Rebecca Swee Fun Signed-off-by: Chew, Chiau Ee Signed-off-by: Thierry Reding (cherry picked from commit d16a5aa9e821633a3095d7a88cd1d2cd108bf966) Signed-off-by: Chang Rebecca Swee Fun --- drivers/pwm/Kconfig | 10 +++ drivers/pwm/Makefile | 1 + drivers/pwm/pwm-lpss.c | 183 ++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 194 insertions(+) create mode 100644 drivers/pwm/pwm-lpss.c diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig index 22f2f28..36bf194 100644 --- a/drivers/pwm/Kconfig +++ b/drivers/pwm/Kconfig @@ -119,6 +119,16 @@ config PWM_LPC32XX To compile this driver as a module, choose M here: the module will be called pwm-lpc32xx. +config PWM_LPSS + tristate "Intel LPSS PWM support" + depends on ACPI + help + Generic PWM framework driver for Intel Low Power Subsystem PWM + controller. + + To compile this driver as a module, choose M here: the module + will be called pwm-lpss. + config PWM_MXS tristate "Freescale MXS PWM support" depends on ARCH_MXS && OF diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile index d8906ec..61bf073 100644 --- a/drivers/pwm/Makefile +++ b/drivers/pwm/Makefile @@ -9,6 +9,7 @@ obj-$(CONFIG_PWM_IMX) += pwm-imx.o obj-$(CONFIG_PWM_JZ4740) += pwm-jz4740.o obj-$(CONFIG_PWM_LP3943) += pwm-lp3943.o obj-$(CONFIG_PWM_LPC32XX) += pwm-lpc32xx.o +obj-$(CONFIG_PWM_LPSS) += pwm-lpss.o obj-$(CONFIG_PWM_MXS) += pwm-mxs.o obj-$(CONFIG_PWM_PCA9685) += pwm-pca9685.o obj-$(CONFIG_PWM_PUV3) += pwm-puv3.o diff --git a/drivers/pwm/pwm-lpss.c b/drivers/pwm/pwm-lpss.c new file mode 100644 index 0000000..449e372 --- /dev/null +++ b/drivers/pwm/pwm-lpss.c @@ -0,0 +1,183 @@ +/* + * Intel Low Power Subsystem PWM controller driver + * + * Copyright (C) 2014, Intel Corporation + * Author: Mika Westerberg + * Author: Chew Kean Ho + * Author: Chang Rebecca Swee Fun + * Author: Chew Chiau Ee + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include +#include +#include +#include +#include +#include +#include + +#define PWM 0x00000000 +#define PWM_ENABLE BIT(31) +#define PWM_SW_UPDATE BIT(30) +#define PWM_BASE_UNIT_SHIFT 8 +#define PWM_BASE_UNIT_MASK 0x00ffff00 +#define PWM_ON_TIME_DIV_MASK 0x000000ff +#define PWM_DIVISION_CORRECTION 0x2 +#define PWM_LIMIT (0x8000 + PWM_DIVISION_CORRECTION) +#define NSECS_PER_SEC 1000000000UL + +struct pwm_lpss_chip { + struct pwm_chip chip; + void __iomem *regs; + struct clk *clk; +}; + +static inline struct pwm_lpss_chip *to_lpwm(struct pwm_chip *chip) +{ + return container_of(chip, struct pwm_lpss_chip, chip); +} + +static int pwm_lpss_config(struct pwm_chip *chip, struct pwm_device *pwm, + int duty_ns, int period_ns) +{ + struct pwm_lpss_chip *lpwm = to_lpwm(chip); + u8 on_time_div; + unsigned long c; + unsigned long long base_unit, freq = NSECS_PER_SEC; + u32 ctrl; + + do_div(freq, period_ns); + + /* The equation is: base_unit = ((freq / c) * 65536) + correction */ + base_unit = freq * 65536; + + c = clk_get_rate(lpwm->clk); + if (!c) + return -EINVAL; + + do_div(base_unit, c); + base_unit += PWM_DIVISION_CORRECTION; + if (base_unit > PWM_LIMIT) + return -EINVAL; + + if (duty_ns <= 0) + duty_ns = 1; + on_time_div = 255 - (255 * duty_ns / period_ns); + + ctrl = readl(lpwm->regs + PWM); + ctrl &= ~(PWM_BASE_UNIT_MASK | PWM_ON_TIME_DIV_MASK); + ctrl |= (u16) base_unit << PWM_BASE_UNIT_SHIFT; + ctrl |= on_time_div; + /* request PWM to update on next cycle */ + ctrl |= PWM_SW_UPDATE; + writel(ctrl, lpwm->regs + PWM); + + return 0; +} + +static int pwm_lpss_enable(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct pwm_lpss_chip *lpwm = to_lpwm(chip); + u32 ctrl; + int ret; + + ret = clk_prepare_enable(lpwm->clk); + if (ret) + return ret; + + ctrl = readl(lpwm->regs + PWM); + writel(ctrl | PWM_ENABLE, lpwm->regs + PWM); + + return 0; +} + +static void pwm_lpss_disable(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct pwm_lpss_chip *lpwm = to_lpwm(chip); + u32 ctrl; + + ctrl = readl(lpwm->regs + PWM); + writel(ctrl & ~PWM_ENABLE, lpwm->regs + PWM); + + clk_disable_unprepare(lpwm->clk); +} + +static const struct pwm_ops pwm_lpss_ops = { + .config = pwm_lpss_config, + .enable = pwm_lpss_enable, + .disable = pwm_lpss_disable, + .owner = THIS_MODULE, +}; + +static const struct acpi_device_id pwm_lpss_acpi_match[] = { + { "80860F09", 0 }, + { }, +}; +MODULE_DEVICE_TABLE(acpi, pwm_lpss_acpi_match); + +static int pwm_lpss_probe(struct platform_device *pdev) +{ + struct pwm_lpss_chip *lpwm; + struct resource *r; + int ret; + + lpwm = devm_kzalloc(&pdev->dev, sizeof(*lpwm), GFP_KERNEL); + if (!lpwm) + return -ENOMEM; + + r = platform_get_resource(pdev, IORESOURCE_MEM, 0); + + lpwm->regs = devm_ioremap_resource(&pdev->dev, r); + if (IS_ERR(lpwm->regs)) + return PTR_ERR(lpwm->regs); + + lpwm->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(lpwm->clk)) { + dev_err(&pdev->dev, "failed to get PWM clock\n"); + return PTR_ERR(lpwm->clk); + } + + lpwm->chip.dev = &pdev->dev; + lpwm->chip.ops = &pwm_lpss_ops; + lpwm->chip.base = -1; + lpwm->chip.npwm = 1; + + ret = pwmchip_add(&lpwm->chip); + if (ret) { + dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret); + return ret; + } + + platform_set_drvdata(pdev, lpwm); + return 0; +} + +static int pwm_lpss_remove(struct platform_device *pdev) +{ + struct pwm_lpss_chip *lpwm = platform_get_drvdata(pdev); + u32 ctrl; + + ctrl = readl(lpwm->regs + PWM); + writel(ctrl & ~PWM_ENABLE, lpwm->regs + PWM); + + return pwmchip_remove(&lpwm->chip); +} + +static struct platform_driver pwm_lpss_driver = { + .driver = { + .name = "pwm-lpss", + .acpi_match_table = pwm_lpss_acpi_match, + }, + .probe = pwm_lpss_probe, + .remove = pwm_lpss_remove, +}; +module_platform_driver(pwm_lpss_driver); + +MODULE_DESCRIPTION("PWM driver for Intel LPSS"); +MODULE_AUTHOR("Mika Westerberg "); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:pwm-lpss");