From patchwork Fri May 20 18:05:51 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yendapally Reddy Dhananjaya Reddy X-Patchwork-Id: 9129989 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 82D7A6048B for ; Fri, 20 May 2016 18:08:32 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 7623927CC9 for ; Fri, 20 May 2016 18:08:32 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 6AF0727D10; Fri, 20 May 2016 18:08:32 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.1 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_MED, T_DKIM_INVALID autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id C9FBA27CC9 for ; Fri, 20 May 2016 18:08:31 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1b3oov-0004XF-TK; Fri, 20 May 2016 18:06:45 +0000 Received: from mail-pa0-x22a.google.com ([2607:f8b0:400e:c03::22a]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1b3ooi-0004Qe-Dq for linux-arm-kernel@lists.infradead.org; Fri, 20 May 2016 18:06:34 +0000 Received: by mail-pa0-x22a.google.com with SMTP id tb2so24650350pac.2 for ; Fri, 20 May 2016 11:06:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=broadcom.com; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=4LNL63eYcy28a0qzls+F4PTBxmyvYpC4wyf1TuMPpzg=; b=hI+bqjj7JoZo+j/rTd67ctzOuu1kKrLujwFXt6Tzr+6x5eYA50FIrWBZ/Td4zx/kq2 ESiRAkyd+p6FJSl008KsEPfYvPkVAjJyFxREH62U9maTNuaDo0Y9HHIe7XLX8c26NG9B HFtBH8PeUEK/Jvkkkl452hIN0KYD+wqPj71SQ= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=4LNL63eYcy28a0qzls+F4PTBxmyvYpC4wyf1TuMPpzg=; b=llHWRtpDTACK/XEkxICzE8RL5NUJ8cSVMBK0TqqX2EribSuPFFU0vVpZzST2pWJ8oJ BMMBndhhdiqdseMlxq2cwZCOS8IjvOGawUjd3g6IifYh/42kW74oZL9SStwWnRvz0XIg mRKtv8lJja30ihW45S2ArhPKOyYrwht8DLVEsREINtxSbQnuPM44N9n49iBHMQnCjES6 I5C8of0OGfwe1eA2NwNtrAM6FpoGs8MA+PuYT53xK/grYAuZkFGpeNwJgeLNXqqjxjaO uZzxSHzOHyX8C8yLAGW3DQElTZbrNUl4oWEx1/zXE/HjdH+YCo939XEOm05sJAO5/Gsn Z8cg== X-Gm-Message-State: AOPr4FVWA1cJrCttaTLsC20JZXY9d3XLlfVkupsKfQ8ofpgwaNneGVqMxoSADF3K7pn1Dqxq X-Received: by 10.67.21.177 with SMTP id hl17mr6789222pad.39.1463767570735; Fri, 20 May 2016 11:06:10 -0700 (PDT) Received: from xl-rtp-02.rtp.broadcom.com ([216.31.219.19]) by smtp.gmail.com with ESMTPSA id zn7sm28768971pac.41.2016.05.20.11.06.08 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 20 May 2016 11:06:10 -0700 (PDT) From: Yendapally Reddy Dhananjaya Reddy To: Thierry Reding , Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , Ray Jui , Scott Branden , Jon Mason , Russell King Subject: [PATCH v2 2/3] pwm: iproc: Add support for Broadcom iproc pwm controller Date: Fri, 20 May 2016 14:05:51 -0400 Message-Id: <1463767552-30670-3-git-send-email-yendapally.reddy@broadcom.com> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1463767552-30670-1-git-send-email-yendapally.reddy@broadcom.com> References: <1463767552-30670-1-git-send-email-yendapally.reddy@broadcom.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160520_110632_653212_50B07785 X-CRM114-Status: GOOD ( 26.44 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-pwm@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Yendapally Reddy Dhananjaya Reddy , bcm-kernel-feedback-list@broadcom.com, linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP Add support for the PWM controller present in Broadcom's iProc family of SoCs. This driver is derived from the pwm-bcm-kona driver, with changes to the register offsets and bit positions. It has been tested on the Northstar+ bcm958625HR board. Signed-off-by: Yendapally Reddy Dhananjaya Reddy --- drivers/pwm/Kconfig | 10 ++ drivers/pwm/Makefile | 1 + drivers/pwm/pwm-bcm-iproc.c | 320 ++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 331 insertions(+) create mode 100644 drivers/pwm/pwm-bcm-iproc.c diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig index c182efc..d298ebd 100644 --- a/drivers/pwm/Kconfig +++ b/drivers/pwm/Kconfig @@ -74,6 +74,16 @@ config PWM_ATMEL_TCB To compile this driver as a module, choose M here: the module will be called pwm-atmel-tcb. +config PWM_BCM_IPROC + tristate "iProc PWM support" + depends on ARCH_BCM_IPROC + help + Generic PWM framework driver for Broadcom iProc PWM block. This + block is used in Broadcom iProc SoC's. + + To compile this driver as a module, choose M here: the module + will be called pwm-bcm-iproc. + config PWM_BCM_KONA tristate "Kona PWM support" depends on ARCH_BCM_MOBILE diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile index dd35bc1..a196d79 100644 --- a/drivers/pwm/Makefile +++ b/drivers/pwm/Makefile @@ -4,6 +4,7 @@ obj-$(CONFIG_PWM_AB8500) += pwm-ab8500.o obj-$(CONFIG_PWM_ATMEL) += pwm-atmel.o obj-$(CONFIG_PWM_ATMEL_HLCDC_PWM) += pwm-atmel-hlcdc.o obj-$(CONFIG_PWM_ATMEL_TCB) += pwm-atmel-tcb.o +obj-$(CONFIG_PWM_BCM_IPROC) += pwm-bcm-iproc.o obj-$(CONFIG_PWM_BCM_KONA) += pwm-bcm-kona.o obj-$(CONFIG_PWM_BCM2835) += pwm-bcm2835.o obj-$(CONFIG_PWM_BERLIN) += pwm-berlin.o diff --git a/drivers/pwm/pwm-bcm-iproc.c b/drivers/pwm/pwm-bcm-iproc.c new file mode 100644 index 0000000..3ba3ca5 --- /dev/null +++ b/drivers/pwm/pwm-bcm-iproc.c @@ -0,0 +1,320 @@ +/* + * Copyright (C) 2016 Broadcom + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation version 2. + * + * This program is distributed "as is" WITHOUT ANY WARRANTY of any + * kind, whether express or implied; without even the implied warranty + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define IPROC_PWM_CTRL_OFFSET (0x00) +#define IPROC_PWM_CTRL_TYPE_SHIFT(chan) (15 + (chan)) +#define IPROC_PWM_CTRL_POLARITY_SHIFT(chan) (8 + (chan)) +#define IPROC_PWM_CTRL_EN_SHIFT(chan) (chan) + +#define IPROC_PWM_PERIOD_OFFSET(chan) (0x04 + ((chan) << 3)) +#define IPROC_PWM_PERIOD_MIN (0x02) +#define IPROC_PWM_PERIOD_MAX (0xffff) + +#define IPROC_PWM_DUTY_CYCLE_OFFSET(chan) (0x08 + ((chan) << 3)) +#define IPROC_PWM_DUTY_CYCLE_MIN (0x00) +#define IPROC_PWM_DUTY_CYCLE_MAX (0xffff) + +#define IPROC_PWM_PRESCALE_OFFSET (0x24) +#define IPROC_PWM_PRESCALE_BITS (0x06) +#define IPROC_PWM_PRESCALE_SHIFT(chan) ((3 - (chan)) * \ + IPROC_PWM_PRESCALE_BITS) +#define IPROC_PWM_PRESCALE_MASK(chan) (IPROC_PWM_PRESCALE_MAX << \ + IPROC_PWM_PRESCALE_SHIFT(chan)) +#define IPROC_PWM_PRESCALE_MIN (0x00) +#define IPROC_PWM_PRESCALE_MAX (0x3f) + +#define IPROC_PWM_CHANNEL_COUNT (0x04) + +struct iproc_pwmc { + struct pwm_chip chip; + void __iomem *base; + struct clk *clk; +}; + +static inline struct iproc_pwmc *to_iproc_pwmc(struct pwm_chip *_chip) +{ + return container_of(_chip, struct iproc_pwmc, chip); +} + +static void iproc_pwmc_unset_enable_bit(struct iproc_pwmc *ip, u32 chan) +{ + unsigned int value = readl(ip->base + IPROC_PWM_CTRL_OFFSET); + + value &= ~(1 << IPROC_PWM_CTRL_EN_SHIFT(chan)); + writel(value, ip->base + IPROC_PWM_CTRL_OFFSET); + + /* + * There must be a min 400ns delay between clearing trigger and setting + * it. Failing to do this may result in no PWM signal. + */ + ndelay(400); +} + +static void iproc_pwmc_set_enable_bit(struct iproc_pwmc *ip, unsigned int chan) +{ + unsigned int value = readl(ip->base + IPROC_PWM_CTRL_OFFSET); + + /* Set trigger bit to apply new settings */ + value |= 1 << IPROC_PWM_CTRL_EN_SHIFT(chan); + writel(value, ip->base + IPROC_PWM_CTRL_OFFSET); + + /* Trigger bit must be held high for at least 400 ns. */ + ndelay(400); +} + +static int iproc_pwmc_config(struct pwm_chip *chip, struct pwm_device *pwm, + int duty_ns, int period_ns) +{ + unsigned long prescale = IPROC_PWM_PRESCALE_MIN; + struct iproc_pwmc *ip = to_iproc_pwmc(chip); + unsigned int value, chan = pwm->hwpwm; + unsigned long period_cnt, duty_cnt; + u64 val, div, rate; + + rate = clk_get_rate(ip->clk); + if (!rate) { + dev_err(pwm->chip->dev, "pwm clock has no frequency\n"); + return -EINVAL; + } + + /* + * Find period count, duty count and prescale to suit duty_ns and + * period_ns. This is done according to formulas described below: + * + * period_ns = 10^9 * (PRESCALE + 1) * PC / PWM_CLK_RATE + * duty_ns = 10^9 * (PRESCALE + 1) * DC / PWM_CLK_RATE + * + * PC = (PWM_CLK_RATE * period_ns) / (10^9 * (PRESCALE + 1)) + * DC = (PWM_CLK_RATE * duty_ns) / (10^9 * (PRESCALE + 1)) + */ + while (1) { + div = 1000000000; + div *= 1 + prescale; + val = rate * period_ns; + period_cnt = div64_u64(val, div); + val = rate * duty_ns; + duty_cnt = div64_u64(val, div); + + if (period_cnt < IPROC_PWM_PERIOD_MIN || + duty_cnt < IPROC_PWM_DUTY_CYCLE_MIN) + return -EINVAL; + + if (period_cnt <= IPROC_PWM_PERIOD_MAX && + duty_cnt <= IPROC_PWM_DUTY_CYCLE_MAX) + break; + + /* Otherwise, increase prescale and recalculate counts */ + if (++prescale > IPROC_PWM_PRESCALE_MAX) + return -EINVAL; + } + + /* + * Don't apply settings if disabled. The period and duty cycle are + * always calculated above to ensure the new values are + * validated immediately instead of on enable. + */ + if (pwm_is_enabled(pwm)) { + iproc_pwmc_unset_enable_bit(ip, chan); + + value = readl(ip->base + IPROC_PWM_PRESCALE_OFFSET); + value &= ~IPROC_PWM_PRESCALE_MASK(chan); + value |= prescale << IPROC_PWM_PRESCALE_SHIFT(chan); + + writel(value, ip->base + IPROC_PWM_PRESCALE_OFFSET); + writel(period_cnt, ip->base + IPROC_PWM_PERIOD_OFFSET(chan)); + writel(duty_cnt, ip->base + IPROC_PWM_DUTY_CYCLE_OFFSET(chan)); + + iproc_pwmc_set_enable_bit(ip, chan); + } + + return 0; +} + +static int iproc_pwmc_set_polarity(struct pwm_chip *chip, + struct pwm_device *pwm, + enum pwm_polarity polarity) +{ + struct iproc_pwmc *ip = to_iproc_pwmc(chip); + unsigned int chan = pwm->hwpwm; + unsigned int value; + int ret; + + ret = clk_prepare_enable(ip->clk); + if (ret < 0) { + dev_err(chip->dev, "failed to enable clock: %d\n", ret); + return ret; + } + + iproc_pwmc_unset_enable_bit(ip, chan); + + value = readl(ip->base + IPROC_PWM_CTRL_OFFSET); + if (polarity == PWM_POLARITY_NORMAL) + value |= 1 << IPROC_PWM_CTRL_POLARITY_SHIFT(chan); + else + value &= ~(1 << IPROC_PWM_CTRL_POLARITY_SHIFT(chan)); + writel(value, ip->base + IPROC_PWM_CTRL_OFFSET); + + iproc_pwmc_set_enable_bit(ip, chan); + + clk_disable_unprepare(ip->clk); + + return 0; +} + +static int iproc_pwmc_enable(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct iproc_pwmc *ip = to_iproc_pwmc(chip); + int ret; + + ret = clk_prepare_enable(ip->clk); + if (ret < 0) { + dev_err(chip->dev, "failed to enable clock: %d\n", ret); + return ret; + } + + ret = iproc_pwmc_config(chip, pwm, pwm_get_duty_cycle(pwm), + pwm_get_period(pwm)); + if (ret < 0) { + clk_disable_unprepare(ip->clk); + return ret; + } + + return 0; +} + +static void iproc_pwmc_disable(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct iproc_pwmc *ip = to_iproc_pwmc(chip); + unsigned int chan = pwm->hwpwm; + unsigned int value; + + iproc_pwmc_unset_enable_bit(ip, chan); + + writel(0, ip->base + IPROC_PWM_DUTY_CYCLE_OFFSET(chan)); + writel(0, ip->base + IPROC_PWM_PERIOD_OFFSET(chan)); + + /* Set prescale to 0 for this channel */ + value = readl(ip->base + IPROC_PWM_PRESCALE_OFFSET); + value &= ~IPROC_PWM_PRESCALE_MASK(chan); + writel(value, ip->base + IPROC_PWM_PRESCALE_OFFSET); + + iproc_pwmc_set_enable_bit(ip, chan); + + clk_disable_unprepare(ip->clk); +} + +static const struct pwm_ops iproc_pwm_ops = { + .config = iproc_pwmc_config, + .set_polarity = iproc_pwmc_set_polarity, + .enable = iproc_pwmc_enable, + .disable = iproc_pwmc_disable, + .owner = THIS_MODULE, +}; + +static int iproc_pwmc_probe(struct platform_device *pdev) +{ + struct iproc_pwmc *ip; + struct resource *res; + unsigned int value; + unsigned int chan; + int ret; + + ip = devm_kzalloc(&pdev->dev, sizeof(*ip), GFP_KERNEL); + if (ip == NULL) + return -ENOMEM; + + platform_set_drvdata(pdev, ip); + + ip->chip.dev = &pdev->dev; + ip->chip.ops = &iproc_pwm_ops; + ip->chip.base = -1; + ip->chip.npwm = IPROC_PWM_CHANNEL_COUNT; + ip->chip.of_xlate = of_pwm_xlate_with_flags; + ip->chip.of_pwm_n_cells = 3; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + ip->base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(ip->base)) + return PTR_ERR(ip->base); + + ip->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(ip->clk)) { + dev_err(&pdev->dev, "failed to get clock: %ld\n", + PTR_ERR(ip->clk)); + return PTR_ERR(ip->clk); + } + + ret = clk_prepare_enable(ip->clk); + if (ret < 0) { + dev_err(&pdev->dev, "failed to enable clock: %d\n", ret); + return ret; + } + + /* Set full drive and normal polarity for all channels */ + value = readl(ip->base + IPROC_PWM_CTRL_OFFSET); + for (chan = 0; chan < ip->chip.npwm; chan++) { + value &= ~(1 << IPROC_PWM_CTRL_TYPE_SHIFT(chan)); + value |= 1 << IPROC_PWM_CTRL_POLARITY_SHIFT(chan); + } + writel(value, ip->base + IPROC_PWM_CTRL_OFFSET); + + clk_disable_unprepare(ip->clk); + + ret = pwmchip_add(&ip->chip); + if (ret < 0) + dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret); + + return ret; +} + +static int iproc_pwmc_remove(struct platform_device *pdev) +{ + struct iproc_pwmc *ip = platform_get_drvdata(pdev); + unsigned int chan; + + for (chan = 0; chan < ip->chip.npwm; chan++) + if (pwm_is_enabled(&ip->chip.pwms[chan])) + clk_disable_unprepare(ip->clk); + + return pwmchip_remove(&ip->chip); +} + +static const struct of_device_id bcm_iproc_pwmc_dt[] = { + { .compatible = "brcm,iproc-pwm" }, + { }, +}; +MODULE_DEVICE_TABLE(of, bcm_iproc_pwmc_dt); + +static struct platform_driver iproc_pwmc_driver = { + .driver = { + .name = "bcm-iproc-pwm", + .of_match_table = bcm_iproc_pwmc_dt, + }, + .probe = iproc_pwmc_probe, + .remove = iproc_pwmc_remove, +}; +module_platform_driver(iproc_pwmc_driver); + +MODULE_AUTHOR("Broadcom Corporation"); +MODULE_DESCRIPTION("Broadcom iProc PWM driver"); +MODULE_LICENSE("GPL v2");