From patchwork Wed Dec 12 22:09:00 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paul Cercueil X-Patchwork-Id: 10727269 X-Patchwork-Delegate: paulburton@kernel.org 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 48F151759 for ; Wed, 12 Dec 2018 22:18:28 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3B5202B780 for ; Wed, 12 Dec 2018 22:18:28 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2FA422B78D; Wed, 12 Dec 2018 22:18:28 +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=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham 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 7569E2B780 for ; Wed, 12 Dec 2018 22:18:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728826AbeLLWSO (ORCPT ); Wed, 12 Dec 2018 17:18:14 -0500 Received: from outils.crapouillou.net ([89.234.176.41]:40740 "EHLO crapouillou.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728463AbeLLWQw (ORCPT ); Wed, 12 Dec 2018 17:16:52 -0500 From: Paul Cercueil To: Thierry Reding , Rob Herring , Mark Rutland , Daniel Lezcano , Thomas Gleixner , Ralf Baechle , Paul Burton , James Hogan , Jonathan Corbet Cc: Mathieu Malaterre , Ezequiel Garcia , PrasannaKumar Muralidharan , linux-pwm@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-watchdog@vger.kernel.org, linux-mips@vger.kernel.org, linux-doc@vger.kernel.org, linux-clk@vger.kernel.org, od@zcrc.me, Maarten ter Huurne , Paul Cercueil Subject: [PATCH v8 05/26] clocksource: Add driver for the Ingenic JZ47xx OST Date: Wed, 12 Dec 2018 23:09:00 +0100 Message-Id: <20181212220922.18759-6-paul@crapouillou.net> In-Reply-To: <20181212220922.18759-1-paul@crapouillou.net> References: <20181212220922.18759-1-paul@crapouillou.net> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=crapouillou.net; s=mail; t=1544652581; bh=evrNnQngZB+jBK+HkEva3OYxazvHfxLjk1zzo0QvVss=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References; b=X4tGzMl+dZlfRVVcLHpGaPk6LUEJcN/5xXFE4ufB3czrePayKVYvmY+EO5CA0Tc9qYdJCxO574IvcZn32fw5hjYaOD+I/JmFfaar20B2XQc+gsjjkvFUpvs5vq1mRJW0o/UMAXo0R0svPIkn0biTqkN7RefU1ESlaTtdorHdnRI= Sender: linux-mips-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Maarten ter Huurne OST is the OS Timer, a 64-bit timer/counter with buffered reading. SoCs before the JZ4770 had (if any) a 32-bit OST; the JZ4770 and JZ4780 have a 64-bit OST. This driver will register both a clocksource and a sched_clock to the system. Signed-off-by: Maarten ter Huurne Signed-off-by: Paul Cercueil --- Notes: v5: New patch v6: - Get rid of SoC IDs; pass pointer to ingenic_ost_soc_info as devicetree match data instead. - Use device_get_match_data() instead of the of_* variant - Handle error of dev_get_regmap() properly v7: Fix section mismatch by using builtin_platform_driver_probe() v8: builtin_platform_driver_probe() does not work anymore in 4.20-rc6? The probe function won't be called. Work around this for now by using late_initcall. drivers/clocksource/Kconfig | 8 ++ drivers/clocksource/Makefile | 1 + drivers/clocksource/ingenic-ost.c | 215 ++++++++++++++++++++++++++++++++++++++ 3 files changed, 224 insertions(+) create mode 100644 drivers/clocksource/ingenic-ost.c diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig index 4e69af15c3e7..e0646878b0de 100644 --- a/drivers/clocksource/Kconfig +++ b/drivers/clocksource/Kconfig @@ -648,4 +648,12 @@ config INGENIC_TIMER help Support for the timer/counter unit of the Ingenic JZ SoCs. +config INGENIC_OST + bool "Ingenic JZ47xx Operating System Timer" + depends on MIPS || COMPILE_TEST + depends on COMMON_CLK + select INGENIC_TIMER + help + Support for the OS Timer of the Ingenic JZ4770 or similar SoC. + endmenu diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile index 7c8f790dcf67..7faa8108574a 100644 --- a/drivers/clocksource/Makefile +++ b/drivers/clocksource/Makefile @@ -75,6 +75,7 @@ obj-$(CONFIG_ASM9260_TIMER) += asm9260_timer.o obj-$(CONFIG_H8300_TMR8) += h8300_timer8.o obj-$(CONFIG_H8300_TMR16) += h8300_timer16.o obj-$(CONFIG_H8300_TPU) += h8300_tpu.o +obj-$(CONFIG_INGENIC_OST) += ingenic-ost.o obj-$(CONFIG_INGENIC_TIMER) += ingenic-timer.o obj-$(CONFIG_CLKSRC_ST_LPC) += clksrc_st_lpc.o obj-$(CONFIG_X86_NUMACHIP) += numachip.o diff --git a/drivers/clocksource/ingenic-ost.c b/drivers/clocksource/ingenic-ost.c new file mode 100644 index 000000000000..cc0fee3efd29 --- /dev/null +++ b/drivers/clocksource/ingenic-ost.c @@ -0,0 +1,215 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * JZ47xx SoCs TCU Operating System Timer driver + * + * Copyright (C) 2016 Maarten ter Huurne + * Copyright (C) 2018 Paul Cercueil + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#include "ingenic-timer.h" + +#define TCU_OST_TCSR_MASK 0xc0 +#define TCU_OST_TCSR_CNT_MD BIT(15) + +#define TCU_OST_CHANNEL 15 + +struct ingenic_ost_soc_info { + bool is64bit; +}; + +struct ingenic_ost { + struct regmap *map; + struct clk *clk; + + struct clocksource cs; +}; + +static u64 notrace ingenic_ost_read_cntl(void) +{ + /* Bypass the regmap here as we must return as soon as possible */ + return readl(ingenic_tcu_base + TCU_REG_OST_CNTL); +} + +static u64 notrace ingenic_ost_read_cnth(void) +{ + /* Bypass the regmap here as we must return as soon as possible */ + return readl(ingenic_tcu_base + TCU_REG_OST_CNTH); +} + +static u64 notrace ingenic_ost_clocksource_read(struct clocksource *cs) +{ + u32 val1, val2; + u64 count, recount; + s64 diff; + + /* + * The buffering of the upper 32 bits of the timer prevents wrong + * results from the bottom 32 bits overflowing due to the timer ticking + * along. However, it does not prevent wrong results from simultaneous + * reads of the timer, which could reset the buffer mid-read. + * Since this kind of wrong read can happen only when the bottom bits + * overflow, there will be minutes between wrong reads, so if we read + * twice in succession, at least one of the reads will be correct. + */ + + /* Bypass the regmap here as we must return as soon as possible */ + val1 = readl(ingenic_tcu_base + TCU_REG_OST_CNTL); + val2 = readl(ingenic_tcu_base + TCU_REG_OST_CNTHBUF); + count = (u64)val1 | (u64)val2 << 32; + + val1 = readl(ingenic_tcu_base + TCU_REG_OST_CNTL); + val2 = readl(ingenic_tcu_base + TCU_REG_OST_CNTHBUF); + recount = (u64)val1 | (u64)val2 << 32; + + /* + * A wrong read will produce a result that is 1<<32 too high: the bottom + * part from before overflow and the upper part from after overflow. + * Therefore, the lower value of the two reads is the correct value. + */ + + diff = (s64)(recount - count); + if (unlikely(diff < 0)) + count = recount; + + return count; +} + +static int __init ingenic_ost_probe(struct platform_device *pdev) +{ + const struct ingenic_ost_soc_info *soc_info; + struct device *dev = &pdev->dev; + struct ingenic_ost *ost; + struct clocksource *cs; + unsigned long rate, flags; + int err; + + soc_info = device_get_match_data(dev); + if (!soc_info) + return -EINVAL; + + ost = devm_kzalloc(dev, sizeof(*ost), GFP_KERNEL); + if (!ost) + return -ENOMEM; + + ost->map = dev_get_regmap(dev->parent, NULL); + if (!ost->map) { + dev_err(dev, "regmap not found\n"); + return -EINVAL; + } + + ost->clk = devm_clk_get(dev, "ost"); + if (IS_ERR(ost->clk)) + return PTR_ERR(ost->clk); + + err = clk_prepare_enable(ost->clk); + if (err) + return err; + + /* Clear counter high/low registers */ + if (soc_info->is64bit) + regmap_write(ost->map, TCU_REG_OST_CNTL, 0); + regmap_write(ost->map, TCU_REG_OST_CNTH, 0); + + /* Don't reset counter at compare value. */ + regmap_update_bits(ost->map, TCU_REG_OST_TCSR, + TCU_OST_TCSR_MASK, TCU_OST_TCSR_CNT_MD); + + rate = clk_get_rate(ost->clk); + + /* Enable OST TCU channel */ + regmap_write(ost->map, TCU_REG_TESR, BIT(TCU_OST_CHANNEL)); + + cs = &ost->cs; + cs->name = "ingenic-ost"; + cs->rating = 320; + cs->flags = CLOCK_SOURCE_IS_CONTINUOUS; + + if (soc_info->is64bit) { + cs->mask = CLOCKSOURCE_MASK(64); + cs->read = ingenic_ost_clocksource_read; + } else { + cs->mask = CLOCKSOURCE_MASK(32); + cs->read = (u64 (*)(struct clocksource *))ingenic_ost_read_cnth; + } + + err = clocksource_register_hz(cs, rate); + if (err) { + dev_err(dev, "clocksource registration failed: %d\n", err); + clk_disable_unprepare(ost->clk); + return err; + } + + /* Cannot register a sched_clock with interrupts on */ + local_irq_save(flags); + if (soc_info->is64bit) + sched_clock_register(ingenic_ost_read_cntl, 32, rate); + else + sched_clock_register(ingenic_ost_read_cnth, 32, rate); + local_irq_restore(flags); + + return 0; +} + +#ifdef CONFIG_PM_SLEEP +static int ingenic_ost_suspend(struct device *dev) +{ + struct ingenic_ost *ost = dev_get_drvdata(dev); + + clk_disable(ost->clk); + return 0; +} + +static int ingenic_ost_resume(struct device *dev) +{ + struct ingenic_ost *ost = dev_get_drvdata(dev); + + return clk_enable(ost->clk); +} + +static SIMPLE_DEV_PM_OPS(ingenic_ost_pm_ops, ingenic_ost_suspend, + ingenic_ost_resume); +#define INGENIC_OST_PM_OPS (&ingenic_ost_pm_ops) +#else +#define INGENIC_OST_PM_OPS NULL +#endif /* CONFIG_PM_SUSPEND */ + +static const struct ingenic_ost_soc_info jz4725b_ost_soc_info = { + .is64bit = false, +}; + +static const struct ingenic_ost_soc_info jz4770_ost_soc_info = { + .is64bit = true, +}; + +static const struct of_device_id ingenic_ost_of_match[] = { + { .compatible = "ingenic,jz4725b-ost", .data = &jz4725b_ost_soc_info, }, + { .compatible = "ingenic,jz4770-ost", .data = &jz4770_ost_soc_info, }, + { } +}; + +static struct platform_driver ingenic_ost_driver = { + .driver = { + .name = "ingenic-ost", + .pm = INGENIC_OST_PM_OPS, + .of_match_table = ingenic_ost_of_match, + }, +}; + +/* FIXME: Using device_initcall (or buildin_platform_driver_probe) results + * in the driver not being probed at all. It worked in 4.18... + */ +static int __init ingenic_ost_drv_register(void) +{ + return platform_driver_probe(&ingenic_ost_driver, + ingenic_ost_probe); +} +late_initcall(ingenic_ost_drv_register);