From patchwork Mon Feb 18 14:03:18 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Patrick Havelange X-Patchwork-Id: 10818115 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 792771399 for ; Mon, 18 Feb 2019 14:24:38 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6695329FA1 for ; Mon, 18 Feb 2019 14:24:38 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 5A4032A06E; Mon, 18 Feb 2019 14:24:38 +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=-7.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A3F8C29FA1 for ; Mon, 18 Feb 2019 14:24:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731473AbfBROYg (ORCPT ); Mon, 18 Feb 2019 09:24:36 -0500 Received: from mail-ed1-f66.google.com ([209.85.208.66]:42414 "EHLO mail-ed1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389782AbfBRODz (ORCPT ); Mon, 18 Feb 2019 09:03:55 -0500 Received: by mail-ed1-f66.google.com with SMTP id j89so4517479edb.9 for ; Mon, 18 Feb 2019 06:03:53 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=essensium-com.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=y8ELJQgbv7DeZTb+dT/figIxEA2QKkZyGqslXLAy5pw=; b=1EEQllAKYnQmKGyF7FtBV8s+Yo0LgZ+xETEnQoTbs89uCfBgFIQ0qHbAaUYBZBPsKS fwFn/5j6UMtojlsPU7N8YLaHy18t/D6CuMvAXYNDRIUtQk/eCiX9LSKmj6GwJCC3WR8l mchRPF0/tfIt1ap/CB6BXikspkpVKxs3SSEdLUlDWBBPnYeez50q7QhiUYLNud3XA+Le LByS6/3fi9R3gdcpvfOaFHw0k5Ivdg7qqhSklk5ULNmLTmb/AgDfU2BqomRkWEATbXc/ M15uee4hiqq4EopIi4zU3U84DDY781Duvz2ek9XRndzF0Rj6m6jcRRQcLG84cdIaKg84 w1lw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=y8ELJQgbv7DeZTb+dT/figIxEA2QKkZyGqslXLAy5pw=; b=Odmu5XTmolmGppQI0CMoUzIDac61v/Gax2owHcywUg32649UFbPkNUTtyq8ycYZ1K7 GfmuDsaxIgldoWMOlpfDCg6GP+KGzL30mCK4fSpWJq5rTt1wBS8Hg7uq7DAMHpHQRN7T qm4T3gIMboT9i/X8Iy/X1xCfDeEMa5M1Q2UIuFZzNWpr27vEXUm9PV/V8qUAmQzV5CXx mr/J8qm+Ql/TnTbIkFHECGuHr/zrquCtI9rgv4PLZR5y1AIMircmv5wo0B8G5AFo2GbV ZrN1SsPKSf7AwFUBzxuhkXG3NK07eaWRRMf+yhjk9AxDRInsn3pIxY3uslTGUWFvECw5 2Pww== X-Gm-Message-State: AHQUAuZ1FcWxFSNqKIMTLCYHwg3uOzgEXvpwarxGqH4ZI4PGMTJD8gcy PxZ1IIMOn5fU26YJ50S1h8Ai+g== X-Google-Smtp-Source: AHgI3IYrC+euDCA6+19B7LQzEHnG2fbshumRDoikpwE8u2sTiM5Yfqae37ry7AmGJn2cYvKCWgnr7w== X-Received: by 2002:a50:94d6:: with SMTP id t22mr19337308eda.232.1550498632701; Mon, 18 Feb 2019 06:03:52 -0800 (PST) Received: from localhost.localdomain (ip-188-118-3-185.reverse.destiny.be. [188.118.3.185]) by smtp.gmail.com with ESMTPSA id w48sm1421606eda.88.2019.02.18.06.03.51 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 18 Feb 2019 06:03:52 -0800 (PST) From: Patrick Havelange To: Jonathan Cameron , Hartmut Knaack , Lars-Peter Clausen , Peter Meerwald-Stadler , Rob Herring , Mark Rutland , Shawn Guo , Li Yang , Daniel Lezcano , Thomas Gleixner , Thierry Reding , Esben Haabendal , William Breathitt Gray , Linus Walleij , linux-iio@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-pwm@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Cc: Patrick Havelange Subject: [PATCH 5/8] iio/counter: add FlexTimer Module Quadrature decoder counter driver Date: Mon, 18 Feb 2019 15:03:18 +0100 Message-Id: <20190218140321.19166-5-patrick.havelange@essensium.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190218140321.19166-1-patrick.havelange@essensium.com> References: <20190218140321.19166-1-patrick.havelange@essensium.com> Sender: linux-iio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This driver exposes the counter for the quadrature decoder of the FlexTimer Module, present in the LS1021A soc. Signed-off-by: Patrick Havelange Reviewed-by: Esben Haabendal --- drivers/iio/counter/Kconfig | 10 + drivers/iio/counter/Makefile | 1 + drivers/iio/counter/ftm-quaddec.c | 294 ++++++++++++++++++++++++++++++ 3 files changed, 305 insertions(+) create mode 100644 drivers/iio/counter/ftm-quaddec.c diff --git a/drivers/iio/counter/Kconfig b/drivers/iio/counter/Kconfig index bf1e559ad7cd..4641cb2e752a 100644 --- a/drivers/iio/counter/Kconfig +++ b/drivers/iio/counter/Kconfig @@ -31,4 +31,14 @@ config STM32_LPTIMER_CNT To compile this driver as a module, choose M here: the module will be called stm32-lptimer-cnt. + +config FTM_QUADDEC + tristate "Flex Timer Module Quadrature decoder driver" + help + Select this option to enable the Flex Timer Quadrature decoder + driver. + + To compile this driver as a module, choose M here: the + module will be called ftm-quaddec. + endmenu diff --git a/drivers/iio/counter/Makefile b/drivers/iio/counter/Makefile index 1b9a896eb488..757c1f4196af 100644 --- a/drivers/iio/counter/Makefile +++ b/drivers/iio/counter/Makefile @@ -6,3 +6,4 @@ obj-$(CONFIG_104_QUAD_8) += 104-quad-8.o obj-$(CONFIG_STM32_LPTIMER_CNT) += stm32-lptimer-cnt.o +obj-$(CONFIG_FTM_QUADDEC) += ftm-quaddec.o diff --git a/drivers/iio/counter/ftm-quaddec.c b/drivers/iio/counter/ftm-quaddec.c new file mode 100644 index 000000000000..ca7e55a9ab3f --- /dev/null +++ b/drivers/iio/counter/ftm-quaddec.c @@ -0,0 +1,294 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Flex Timer Module Quadrature decoder + * + * This module implements a driver for decoding the FTM quadrature + * of ex. a LS1021A + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +struct ftm_quaddec { + struct platform_device *pdev; + void __iomem *ftm_base; + bool big_endian; + struct mutex ftm_quaddec_mutex; +}; + +#define HASFLAGS(flag, bits) ((flag & bits) ? 1 : 0) + +#define DEFAULT_POLL_INTERVAL 100 /* in msec */ + +static void ftm_read(struct ftm_quaddec *ftm, uint32_t offset, uint32_t *data) +{ + if (ftm->big_endian) + *data = ioread32be(ftm->ftm_base + offset); + else + *data = ioread32(ftm->ftm_base + offset); +} + +static void ftm_write(struct ftm_quaddec *ftm, uint32_t offset, uint32_t data) +{ + if (ftm->big_endian) + iowrite32be(data, ftm->ftm_base + offset); + else + iowrite32(data, ftm->ftm_base + offset); +} + +/* take mutex + * call ftm_clear_write_protection + * update settings + * call ftm_set_write_protection + * release mutex + */ +static void ftm_clear_write_protection(struct ftm_quaddec *ftm) +{ + uint32_t flag; + + /* First see if it is enabled */ + ftm_read(ftm, FTM_FMS, &flag); + + if (flag & FTM_FMS_WPEN) { + ftm_read(ftm, FTM_MODE, &flag); + ftm_write(ftm, FTM_MODE, flag | FTM_MODE_WPDIS); + } +} + +static void ftm_set_write_protection(struct ftm_quaddec *ftm) +{ + ftm_write(ftm, FTM_FMS, FTM_FMS_WPEN); +} + +static void ftm_reset_counter(struct ftm_quaddec *ftm) +{ + /* Reset hardware counter to CNTIN */ + ftm_write(ftm, FTM_CNT, 0x0); +} + +static void ftm_quaddec_init(struct ftm_quaddec *ftm) +{ + ftm_clear_write_protection(ftm); + + /* Do not write in the region from the CNTIN register through the + * PWMLOAD register when FTMEN = 0. + */ + ftm_write(ftm, FTM_MODE, FTM_MODE_FTMEN); /* enable FTM */ + ftm_write(ftm, FTM_CNTIN, 0x0000); /* zero init value */ + ftm_write(ftm, FTM_MOD, 0xffff); /* max overflow value */ + ftm_write(ftm, FTM_CNT, 0x0); /* reset counter value */ + ftm_write(ftm, FTM_SC, FTM_SC_PS_1); /* prescale with x1 */ + /* Select quad mode */ + ftm_write(ftm, FTM_QDCTRL, FTM_QDCTRL_QUADEN); + + /* Unused features and reset to default section */ + ftm_write(ftm, FTM_POL, 0x0); /* polarity is active high */ + ftm_write(ftm, FTM_FLTCTRL, 0x0); /* all faults disabled */ + ftm_write(ftm, FTM_SYNCONF, 0x0); /* disable all sync */ + ftm_write(ftm, FTM_SYNC, 0xffff); + + /* Lock the FTM */ + ftm_set_write_protection(ftm); +} + +static int ftm_quaddec_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + struct ftm_quaddec *ftm = iio_priv(indio_dev); + uint32_t counter; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + ftm_read(ftm, FTM_CNT, &counter); + *val = counter; + return IIO_VAL_INT; + default: + return -EINVAL; + } +} + +static ssize_t ftm_write_reset(struct iio_dev *indio_dev, + uintptr_t private, + struct iio_chan_spec const *chan, + const char *buf, size_t len) +{ + struct ftm_quaddec *ftm = iio_priv(indio_dev); + + /* Only "counter reset" is supported for now */ + if (!sysfs_streq(buf, "0")) { + dev_warn(&ftm->pdev->dev, "Reset only accepts '0'\n"); + return -EINVAL; + } + + ftm_reset_counter(ftm); + + return len; +} + +static int ftm_quaddec_get_prescaler(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan) +{ + struct ftm_quaddec *ftm = iio_priv(indio_dev); + uint32_t scflags; + + ftm_read(ftm, FTM_SC, &scflags); + + return scflags & FTM_SC_PS_MASK; +} + +static int ftm_quaddec_set_prescaler(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, + unsigned int type) +{ + struct ftm_quaddec *ftm = iio_priv(indio_dev); + + uint32_t scflags; + + mutex_lock(&ftm->ftm_quaddec_mutex); + + ftm_read(ftm, FTM_SC, &scflags); + + scflags &= ~FTM_SC_PS_MASK; + type &= FTM_SC_PS_MASK; /*just to be 100% sure*/ + + scflags |= type; + + /* Write */ + ftm_clear_write_protection(ftm); + ftm_write(ftm, FTM_SC, scflags); + ftm_set_write_protection(ftm); + + /* Also resets the counter as it is undefined anyway now */ + ftm_reset_counter(ftm); + + mutex_unlock(&ftm->ftm_quaddec_mutex); + return 0; +} + +static const char * const ftm_quaddec_prescaler[] = { + "1", "2", "4", "8", "16", "32", "64", "128" +}; + +static const struct iio_enum ftm_quaddec_prescaler_en = { + .items = ftm_quaddec_prescaler, + .num_items = ARRAY_SIZE(ftm_quaddec_prescaler), + .get = ftm_quaddec_get_prescaler, + .set = ftm_quaddec_set_prescaler, +}; + +static const struct iio_chan_spec_ext_info ftm_quaddec_ext_info[] = { + { + .name = "reset", + .shared = IIO_SEPARATE, + .write = ftm_write_reset, + }, + IIO_ENUM("prescaler", IIO_SEPARATE, &ftm_quaddec_prescaler_en), + IIO_ENUM_AVAILABLE("prescaler", &ftm_quaddec_prescaler_en), + {} +}; + +static const struct iio_chan_spec ftm_quaddec_channels = { + .type = IIO_COUNT, + .channel = 0, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), + .ext_info = ftm_quaddec_ext_info, + .indexed = 1, +}; + +static const struct iio_info ftm_quaddec_iio_info = { + .read_raw = ftm_quaddec_read_raw, +}; + +static int ftm_quaddec_probe(struct platform_device *pdev) +{ + struct iio_dev *indio_dev; + struct ftm_quaddec *ftm; + int ret; + + struct device_node *node = pdev->dev.of_node; + + indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*ftm)); + if (!indio_dev) + return -ENOMEM; + + ftm = iio_priv(indio_dev); + + platform_set_drvdata(pdev, ftm); + + ftm->pdev = pdev; + ftm->big_endian = of_property_read_bool(node, "big-endian"); + ftm->ftm_base = of_iomap(node, 0); + if (!ftm->ftm_base) + return -EINVAL; + + indio_dev->name = dev_name(&pdev->dev); + indio_dev->dev.parent = &pdev->dev; + indio_dev->info = &ftm_quaddec_iio_info; + indio_dev->num_channels = 1; + indio_dev->channels = &ftm_quaddec_channels; + + ftm_quaddec_init(ftm); + + mutex_init(&ftm->ftm_quaddec_mutex); + + ret = devm_iio_device_register(&pdev->dev, indio_dev); + if (ret) { + mutex_destroy(&ftm->ftm_quaddec_mutex); + iounmap(ftm->ftm_base); + } + return ret; +} + +static int ftm_quaddec_remove(struct platform_device *pdev) +{ + struct ftm_quaddec *ftm; + struct iio_dev *indio_dev; + + ftm = (struct ftm_quaddec *)platform_get_drvdata(pdev); + indio_dev = iio_priv_to_dev(ftm); + /* This is needed to remove sysfs entries */ + devm_iio_device_unregister(&pdev->dev, indio_dev); + + ftm_write(ftm, FTM_MODE, 0); + + iounmap(ftm->ftm_base); + mutex_destroy(&ftm->ftm_quaddec_mutex); + + return 0; +} + +static const struct of_device_id ftm_quaddec_match[] = { + { .compatible = "fsl,ftm-quaddec" }, + {}, +}; + +static struct platform_driver ftm_quaddec_driver = { + .driver = { + .name = "ftm-quaddec", + .owner = THIS_MODULE, + .of_match_table = ftm_quaddec_match, + }, + .probe = ftm_quaddec_probe, + .remove = ftm_quaddec_remove, +}; + +module_platform_driver(ftm_quaddec_driver); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Kjeld Flarup