From patchwork Thu Jan 26 02:07:07 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Brandt X-Patchwork-Id: 9538319 X-Patchwork-Delegate: geert@linux-m68k.org 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 10971604A7 for ; Thu, 26 Jan 2017 02:08:37 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D958D27C0C for ; Thu, 26 Jan 2017 02:08:36 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id CD1A427F07; Thu, 26 Jan 2017 02:08:36 +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=-6.9 required=2.0 tests=BAYES_00,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 1CC4527C0C for ; Thu, 26 Jan 2017 02:08:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752536AbdAZCIf (ORCPT ); Wed, 25 Jan 2017 21:08:35 -0500 Received: from relmlor1.renesas.com ([210.160.252.171]:60406 "EHLO relmlie4.idc.renesas.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752478AbdAZCIf (ORCPT ); Wed, 25 Jan 2017 21:08:35 -0500 Received: from unknown (HELO relmlir2.idc.renesas.com) ([10.200.68.152]) by relmlie4.idc.renesas.com with ESMTP; 26 Jan 2017 11:08:24 +0900 Received: from relmlac3.idc.renesas.com (relmlac3.idc.renesas.com [10.200.69.23]) by relmlir2.idc.renesas.com (Postfix) with ESMTP id F1B484CB43; Thu, 26 Jan 2017 11:08:24 +0900 (JST) Received: by relmlac3.idc.renesas.com (Postfix, from userid 0) id EF56018070; Thu, 26 Jan 2017 11:08:24 +0900 (JST) Received: from relmlac3.idc.renesas.com (localhost [127.0.0.1]) by relmlac3.idc.renesas.com (Postfix) with ESMTP id E2A431806F; Thu, 26 Jan 2017 11:08:24 +0900 (JST) Received: from relmlii1.idc.renesas.com [10.200.68.65] by relmlac3.idc.renesas.com with ESMTP id MAG20886; Thu, 26 Jan 2017 11:08:24 +0900 X-IronPort-AV: E=Sophos;i="5.33,287,1477926000"; d="scan'208";a="231867611" Received: from unknown (HELO rtamta01.rta.renesas.com) ([143.103.48.75]) by relmlii1.idc.renesas.com with ESMTP; 26 Jan 2017 11:08:23 +0900 Received: from localhost.localdomain (unknown [143.103.58.153]) by rtamta01.rta.renesas.com (Postfix) with ESMTP id ABDEF38F; Thu, 26 Jan 2017 02:08:16 +0000 (UTC) From: Chris Brandt To: Rob Herring , Mark Rutland , Simon Horman , Magnus Damm , Russell King , Daniel Lezcano , Thomas Gleixner , Geert Uytterhoeven Cc: devicetree@vger.kernel.org, linux-renesas-soc@vger.kernel.org, Chris Brandt Subject: [PATCH v4 2/2] clocksource: Add renesas-ostm timer driver Date: Wed, 25 Jan 2017 21:07:07 -0500 Message-Id: <20170126020707.4376-3-chris.brandt@renesas.com> X-Mailer: git-send-email 2.10.1 In-Reply-To: <20170126020707.4376-1-chris.brandt@renesas.com> References: <20170126020707.4376-1-chris.brandt@renesas.com> Sender: linux-renesas-soc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-renesas-soc@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This patch adds a OSTM driver for the Renesas architecture. The OS Timer (OSTM) has independent channels that can be used as a freerun or interval times. This driver uses the first probed device as a clocksource and then any additional devices as clock events. Signed-off-by: Chris Brandt --- v3: * Added more details to commit log * Kconfig: SYS_SUPPORTS_RENESAS_OSTM to just RENESAS_OSTM * removed all MODULE code (this driver is builtin only) * removed items from 'struct ostm_device' * changed ioread8 to readb * explain endless while loop * removed un-needed vars like 'ret' * removed WARN_ON(!clockevent_state_oneshot(ced)); * removed "failed to allocate memory" message * remove pm_runtime calls * remove "earlytimer" register (only for sh, not arm) * convert from platform driver to CLOCKSOURCE_OF_DECLARE * ostm_probe code is now in ostm_init v2: * changed implementation to be independent channel nodes --- arch/arm/mach-shmobile/Kconfig | 1 + drivers/clocksource/Kconfig | 7 + drivers/clocksource/Makefile | 1 + drivers/clocksource/renesas-ostm.c | 262 +++++++++++++++++++++++++++++++++++++ 4 files changed, 271 insertions(+) create mode 100644 drivers/clocksource/renesas-ostm.c diff --git a/arch/arm/mach-shmobile/Kconfig b/arch/arm/mach-shmobile/Kconfig index 2bb4b09..ad7d604 100644 --- a/arch/arm/mach-shmobile/Kconfig +++ b/arch/arm/mach-shmobile/Kconfig @@ -57,6 +57,7 @@ config ARCH_R7S72100 select PM select PM_GENERIC_DOMAINS select SYS_SUPPORTS_SH_MTU2 + select RENESAS_OSTM config ARCH_R8A73A4 bool "R-Mobile APE6 (R8A73A40)" diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig index 4866f7a..a0786a6 100644 --- a/drivers/clocksource/Kconfig +++ b/drivers/clocksource/Kconfig @@ -467,6 +467,13 @@ config SH_TIMER_MTU2 Timer Pulse Unit 2 (MTU2) hardware available on SoCs from Renesas. This hardware comes with 16 bit-timer registers. +config RENESAS_OSTM + bool "Renesas OSTM timer driver" if COMPILE_TEST + depends on GENERIC_CLOCKEVENTS + select CLKSRC_MMIO + help + Enables the support for the Renesas OSTM. + config SH_TIMER_TMU bool "Renesas TMU timer driver" if COMPILE_TEST depends on GENERIC_CLOCKEVENTS diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile index a14111e..bbd163b 100644 --- a/drivers/clocksource/Makefile +++ b/drivers/clocksource/Makefile @@ -8,6 +8,7 @@ obj-$(CONFIG_CS5535_CLOCK_EVENT_SRC) += cs5535-clockevt.o obj-$(CONFIG_CLKSRC_JCORE_PIT) += jcore-pit.o obj-$(CONFIG_SH_TIMER_CMT) += sh_cmt.o obj-$(CONFIG_SH_TIMER_MTU2) += sh_mtu2.o +obj-$(CONFIG_RENESAS_OSTM) += renesas-ostm.o obj-$(CONFIG_SH_TIMER_TMU) += sh_tmu.o obj-$(CONFIG_EM_TIMER_STI) += em_sti.o obj-$(CONFIG_CLKBLD_I8253) += i8253.o diff --git a/drivers/clocksource/renesas-ostm.c b/drivers/clocksource/renesas-ostm.c new file mode 100644 index 0000000..757bd71 --- /dev/null +++ b/drivers/clocksource/renesas-ostm.c @@ -0,0 +1,262 @@ +/* + * Renesas Timer Support - OSTM + * + * 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; either version 2 of the License + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; 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 + +/* + * The OSTM contains independent channels. + * The first OSTM channel probed will be set up as a free running + * clocksource. Additionally we will use this clocksource for the system + * schedule timer sched_clock(). + * + * The second (or more) channel probed will be set up as an interrupt + * driven clock event. + */ + +struct ostm_device { + void __iomem *base; + unsigned long ticks_per_jiffy; + struct clock_event_device ced; +}; + +static void __iomem *system_clock; /* For sched_clock() */ + +/* OSTM REGISTERS */ +#define OSTM_CMP 0x000 /* RW,32 */ +#define OSTM_CNT 0x004 /* R,32 */ +#define OSTM_TE 0x010 /* R,8 */ +#define OSTM_TS 0x014 /* W,8 */ +#define OSTM_TT 0x018 /* W,8 */ +#define OSTM_CTL 0x020 /* RW,8 */ + +#define TE 0x01 +#define TS 0x01 +#define TT 0x01 +#define CTL_PERIODIC 0x00 +#define CTL_ONESHOT 0x02 +#define CTL_FREERUN 0x02 + +static struct ostm_device *ced_to_ostm(struct clock_event_device *ced) +{ + return container_of(ced, struct ostm_device, ced); +} + +static void ostm_timer_stop(struct ostm_device *ostm) +{ + if (readb(ostm->base + OSTM_TE) & TE) { + iowrite8(TT, ostm->base + OSTM_TT); + + /* + * Read back the register simply to confirm the write operation + * has completed since I/O writes can sometimes get queued by + * the bus architecture. + */ + while (readb(ostm->base + OSTM_TE) & TE) + ; + } +} + +static int __init ostm_init_clksrc(struct ostm_device *ostm, unsigned long rate) +{ + /* + * irq not used (clock sources don't use interrupts) + */ + + ostm_timer_stop(ostm); + + iowrite32(0, ostm->base + OSTM_CMP); + iowrite8(CTL_FREERUN, ostm->base + OSTM_CTL); + iowrite8(TS, ostm->base + OSTM_TS); + + return clocksource_mmio_init(ostm->base + OSTM_CNT, + "ostm", rate, + 300, 32, clocksource_mmio_readl_up); +} + +static u64 notrace ostm_read_sched_clock(void) +{ + return readl(system_clock); +} + +static void __init ostm_init_sched_clock(struct ostm_device *ostm, + unsigned long rate) +{ + system_clock = ostm->base + OSTM_CNT; + sched_clock_register(ostm_read_sched_clock, 32, rate); +} + +static int ostm_clock_event_next(unsigned long delta, + struct clock_event_device *ced) +{ + struct ostm_device *ostm = ced_to_ostm(ced); + + ostm_timer_stop(ostm); + + iowrite32(delta, ostm->base + OSTM_CMP); + iowrite8(CTL_ONESHOT, ostm->base + OSTM_CTL); + iowrite8(TS, ostm->base + OSTM_TS); + + return 0; +} + +static int ostm_shutdown(struct clock_event_device *ced) +{ + struct ostm_device *ostm = ced_to_ostm(ced); + + ostm_timer_stop(ostm); + + return 0; +} +static int ostm_set_periodic(struct clock_event_device *ced) +{ + struct ostm_device *ostm = ced_to_ostm(ced); + + if (clockevent_state_oneshot(ced) || clockevent_state_periodic(ced)) + ostm_timer_stop(ostm); + + iowrite32(ostm->ticks_per_jiffy - 1, ostm->base + OSTM_CMP); + iowrite8(CTL_PERIODIC, ostm->base + OSTM_CTL); + iowrite8(TS, ostm->base + OSTM_TS); + + return 0; +} + +static int ostm_set_oneshot(struct clock_event_device *ced) +{ + struct ostm_device *ostm = ced_to_ostm(ced); + + ostm_timer_stop(ostm); + + return 0; +} + +static irqreturn_t ostm_timer_interrupt(int irq, void *dev_id) +{ + struct ostm_device *ostm = dev_id; + + if (clockevent_state_oneshot(&ostm->ced)) + ostm_timer_stop(ostm); + + /* notify clockevent layer */ + if (ostm->ced.event_handler) + ostm->ced.event_handler(&ostm->ced); + + return IRQ_HANDLED; +} + +static int __init ostm_init_clkevt(struct ostm_device *ostm, int irq, + unsigned long rate) +{ + struct clock_event_device *ced = &ostm->ced; + int ret = -ENXIO; + + ret = request_irq(irq, ostm_timer_interrupt, + IRQF_TIMER | IRQF_IRQPOLL, + "ostm", ostm); + if (ret) { + pr_err("ostm: failed to request irq\n"); + return ret; + } + + ced->name = "ostm"; + ced->features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC; + ced->set_state_shutdown = ostm_shutdown; + ced->set_state_periodic = ostm_set_periodic; + ced->set_state_oneshot = ostm_set_oneshot; + ced->set_next_event = ostm_clock_event_next; + ced->shift = 32; + ced->rating = 300; + ced->cpumask = cpumask_of(0); + clockevents_config_and_register(ced, rate, 0xf, 0xffffffff); + + return 0; +} + +static int __init ostm_init(struct device_node *np) +{ + struct ostm_device *ostm; + int ret = -EFAULT; + struct clk *ostm_clk; + int irq; + unsigned long rate; + + ostm = kzalloc(sizeof(*ostm), GFP_KERNEL); + if (!ostm) + return -ENOMEM; + + ostm->base = of_iomap(np, 0); + if (!ostm->base) { + pr_err("ostm: failed to remap I/O memory\n"); + goto err; + } + + irq = irq_of_parse_and_map(np, 0); + if (irq < 0) { + pr_err("ostm: Failed to get irq\n"); + goto err; + } + + ostm_clk = of_clk_get(np, 0); + if (IS_ERR(ostm_clk)) { + pr_err("ostm: Failed to get clock\n"); + ostm_clk = NULL; + goto err; + } + + ret = clk_prepare_enable(ostm_clk); + if (ret) { + pr_err("ostm: Failed to enable clock\n"); + goto err; + } + + rate = clk_get_rate(ostm_clk); + ostm->ticks_per_jiffy = (rate + HZ / 2) / HZ; + + /* + * First probed device will be used as system clocksource. Any + * additional devices will be used as clock events. + */ + if (!system_clock) { + ret = ostm_init_clksrc(ostm, rate); + + if (!ret) { + ostm_init_sched_clock(ostm, rate); + pr_info("ostm: used for clocksource\n"); + } + + } else { + ret = ostm_init_clkevt(ostm, irq, rate); + + if (!ret) + pr_info("ostm: used for clock events\n"); + } + +err: + if (ret) { + clk_disable_unprepare(ostm_clk); + iounmap(ostm->base); + kfree(ostm); + return ret; + } + + return 0; +} + +CLOCKSOURCE_OF_DECLARE(ostm, "renesas,ostm", ostm_init);