From patchwork Fri Apr 9 09:07:09 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nobuhiro Iwamatsu X-Patchwork-Id: 419013 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 18766C43470 for ; Fri, 9 Apr 2021 09:07:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EC21961026 for ; Fri, 9 Apr 2021 09:07:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232865AbhDIJIA (ORCPT ); Fri, 9 Apr 2021 05:08:00 -0400 Received: from mo-csw1115.securemx.jp ([210.130.202.157]:52938 "EHLO mo-csw.securemx.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232911AbhDIJHy (ORCPT ); Fri, 9 Apr 2021 05:07:54 -0400 Received: by mo-csw.securemx.jp (mx-mo-csw1115) id 13997FLj009886; Fri, 9 Apr 2021 18:07:15 +0900 X-Iguazu-Qid: 2wHHQAoCJpBnoHL9nN X-Iguazu-QSIG: v=2; s=0; t=1617959235; q=2wHHQAoCJpBnoHL9nN; m=5uiJLV5o/+PKDCDn+xJ53joDVx82iVTYThx2yWXsBYc= Received: from imx2-a.toshiba.co.jp (imx2-a.toshiba.co.jp [106.186.93.35]) by relay.securemx.jp (mx-mr1112) id 13997EU8033245 (version=TLSv1.2 cipher=AES128-GCM-SHA256 bits=128 verify=NOT); Fri, 9 Apr 2021 18:07:14 +0900 Received: from enc01.toshiba.co.jp (enc01.toshiba.co.jp [106.186.93.100]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by imx2-a.toshiba.co.jp (Postfix) with ESMTPS id 2186C1000B4; Fri, 9 Apr 2021 18:07:14 +0900 (JST) Received: from hop001.toshiba.co.jp ([133.199.164.63]) by enc01.toshiba.co.jp with ESMTP id 13997Dx8025027; Fri, 9 Apr 2021 18:07:13 +0900 From: Nobuhiro Iwamatsu To: Rob Herring , Thierry Reding , =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= , Lee Jones Cc: devicetree@vger.kernel.org, linux-pwm@vger.kernel.org, punit1.agrawal@toshiba.co.jp, yuji2.ishikawa@toshiba.co.jp, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Nobuhiro Iwamatsu Subject: [PATCH v3 2/2] pwm: visconti: Add Toshiba Visconti SoC PWM support Date: Fri, 9 Apr 2021 18:07:09 +0900 X-TSB-HOP: ON Message-Id: <20210409090709.1918021-3-nobuhiro1.iwamatsu@toshiba.co.jp> X-Mailer: git-send-email 2.30.0.rc2 In-Reply-To: <20210409090709.1918021-1-nobuhiro1.iwamatsu@toshiba.co.jp> References: <20210409090709.1918021-1-nobuhiro1.iwamatsu@toshiba.co.jp> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org Add driver for the PWM controller on Toshiba Visconti ARM SoC. Signed-off-by: Nobuhiro Iwamatsu --- drivers/pwm/Kconfig | 9 ++ drivers/pwm/Makefile | 1 + drivers/pwm/pwm-visconti.c | 193 +++++++++++++++++++++++++++++++++++++ 3 files changed, 203 insertions(+) create mode 100644 drivers/pwm/pwm-visconti.c diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig index 9a4f66ae8070..8ae68d6203fb 100644 --- a/drivers/pwm/Kconfig +++ b/drivers/pwm/Kconfig @@ -601,6 +601,15 @@ config PWM_TWL_LED To compile this driver as a module, choose M here: the module will be called pwm-twl-led. +config PWM_VISCONTI + tristate "Toshiba Visconti PWM support" + depends on ARCH_VISCONTI || COMPILE_TEST + help + PWM Subsystem driver support for Toshiba Visconti SoCs. + + To compile this driver as a module, choose M here: the module + will be called pwm-visconti. + config PWM_VT8500 tristate "vt8500 PWM support" depends on ARCH_VT8500 || COMPILE_TEST diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile index 6374d3b1d6f3..d43b1e17e8e1 100644 --- a/drivers/pwm/Makefile +++ b/drivers/pwm/Makefile @@ -56,4 +56,5 @@ obj-$(CONFIG_PWM_TIECAP) += pwm-tiecap.o obj-$(CONFIG_PWM_TIEHRPWM) += pwm-tiehrpwm.o obj-$(CONFIG_PWM_TWL) += pwm-twl.o obj-$(CONFIG_PWM_TWL_LED) += pwm-twl-led.o +obj-$(CONFIG_PWM_VISCONTI) += pwm-visconti.o obj-$(CONFIG_PWM_VT8500) += pwm-vt8500.o diff --git a/drivers/pwm/pwm-visconti.c b/drivers/pwm/pwm-visconti.c new file mode 100644 index 000000000000..ff4a5f5b0009 --- /dev/null +++ b/drivers/pwm/pwm-visconti.c @@ -0,0 +1,193 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Toshiba Visconti pulse-width-modulation controller driver + * + * Copyright (c) 2020 TOSHIBA CORPORATION + * Copyright (c) 2020 Toshiba Electronic Devices & Storage Corporation + * + * Authors: Nobuhiro Iwamatsu + * + */ + +#include +#include +#include +#include +#include +#include + +#define PIPGM_PCSR(ch) (0x400 + 4 * (ch)) +#define PIPGM_PDUT(ch) (0x420 + 4 * (ch)) +#define PIPGM_PWMC(ch) (0x440 + 4 * (ch)) + +#define PIPGM_PWMC_PWMACT BIT(5) +#define PIPGM_PWMC_CLK_MASK GENMASK(1, 0) +#define PIPGM_PWMC_POLARITY_MASK GENMASK(5, 5) + +struct visconti_pwm_chip { + struct pwm_chip chip; + void __iomem *base; +}; + +#define to_visconti_chip(chip) \ + container_of(chip, struct visconti_pwm_chip, chip) + +static int visconti_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, + const struct pwm_state *state) +{ + struct visconti_pwm_chip *priv = to_visconti_chip(chip); + u32 period, duty_cycle, pwmc0; + + dev_dbg(chip->dev, "%s: ch = %d en = %d p = 0x%llx d = 0x%llx\n", __func__, + pwm->hwpwm, state->enabled, state->period, state->duty_cycle); + + /* + * pwmc is a 2-bit divider for the input clock running at 1 MHz. + * When the settings of the PWM are modified, the new values are shadowed in hardware until + * the period register (PCSR) is written and the currently running period is completed. This + * way the hardware switches atomically from the old setting to the new. + * Also, disabling the hardware completes the currently running period and keeps the output + * at low level at all times. + */ + if (!state->enabled) { + writel(0, priv->base + PIPGM_PCSR(pwm->hwpwm)); + return 0; + } + + /* + * The biggest period the hardware can provide is + * (0xffff << 3) * 1000 ns + * This value fits easily in an u32, so simplify the maths by + * capping the values to 32 bit integers. + */ + if (state->period > (0xffff << 3) * 1000) + period = (0xffff << 3) * 1000; + else + period = state->period; + + if (state->duty_cycle > period) + duty_cycle = period; + else + duty_cycle = state->duty_cycle; + + /* + * The input clock runs fixed at 1 MHz, so we have only + * microsecond resolution and so can divide by + * NSEC_PER_SEC / CLKFREQ = 1000 without loosing precision. + */ + period /= 1000; + duty_cycle /= 1000; + + if (!period) + /* period too small */ + return -ERANGE; + + /* + * PWMC controls a divider that divides the input clk by a + * power of two between 1 and 8. As a smaller divider yields + * higher precision, pick the smallest possible one. + */ + if (period > 0xffff) { + pwmc0 = ilog2(period >> 16); + BUG_ON(pwmc0 > 3); + } else + pwmc0 = 0; + + period >>= pwmc0; + duty_cycle >>= pwmc0; + + if (state->polarity == PWM_POLARITY_INVERSED) + pwmc0 |= PIPGM_PWMC_PWMACT; + writel(pwmc0, priv->base + PIPGM_PWMC(pwm->hwpwm)); + writel(duty_cycle, priv->base + PIPGM_PDUT(pwm->hwpwm)); + writel(period, priv->base + PIPGM_PCSR(pwm->hwpwm)); + + return 0; +} + +static void visconti_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm, + struct pwm_state *state) +{ + struct visconti_pwm_chip *priv = to_visconti_chip(chip); + u32 period, duty, pwmc0, pwmc0_clk; + + period = readl(priv->base + PIPGM_PCSR(pwm->hwpwm)); + if (period) + state->enabled = true; + else + state->enabled = false; + + duty = readl(priv->base + PIPGM_PDUT(pwm->hwpwm)); + pwmc0 = readl(priv->base + PIPGM_PWMC(pwm->hwpwm)); + pwmc0_clk = pwmc0 & PIPGM_PWMC_CLK_MASK; + + state->period = (period << pwmc0_clk) * NSEC_PER_USEC; + state->duty_cycle = (duty << pwmc0_clk) * NSEC_PER_USEC; + if (pwmc0 & PIPGM_PWMC_POLARITY_MASK) + state->polarity = PWM_POLARITY_INVERSED; + else + state->polarity = PWM_POLARITY_NORMAL; +} + +static const struct pwm_ops visconti_pwm_ops = { + .apply = visconti_pwm_apply, + .get_state = visconti_pwm_get_state, + .owner = THIS_MODULE, +}; + +static int visconti_pwm_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct visconti_pwm_chip *priv; + int ret; + + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(priv->base)) + return PTR_ERR(priv->base); + + platform_set_drvdata(pdev, priv); + + priv->chip.dev = dev; + priv->chip.ops = &visconti_pwm_ops; + priv->chip.base = -1; + priv->chip.npwm = 4; + + ret = pwmchip_add(&priv->chip); + if (ret < 0) + return dev_err_probe(&pdev->dev, ret, "Cannot register visconti PWM\n"); + + dev_dbg(&pdev->dev, "visconti PWM registered\n"); + + return 0; +} + +static int visconti_pwm_remove(struct platform_device *pdev) +{ + struct visconti_pwm_chip *priv = platform_get_drvdata(pdev); + + return pwmchip_remove(&priv->chip); +} + +static const struct of_device_id visconti_pwm_of_match[] = { + { .compatible = "toshiba,visconti-pwm", }, + { } +}; +MODULE_DEVICE_TABLE(of, visconti_pwm_of_match); + +static struct platform_driver visconti_pwm_driver = { + .driver = { + .name = "pwm-visconti", + .of_match_table = visconti_pwm_of_match, + }, + .probe = visconti_pwm_probe, + .remove = visconti_pwm_remove, +}; +module_platform_driver(visconti_pwm_driver); + +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Nobuhiro Iwamatsu "); +MODULE_ALIAS("platform:pwm-visconti");