From patchwork Wed Sep 30 16:22:01 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nicolas Ferre X-Patchwork-Id: 7300391 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 812409F731 for ; Wed, 30 Sep 2015 16:28:14 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 37B1120650 for ; Wed, 30 Sep 2015 16:28:13 +0000 (UTC) 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.kernel.org (Postfix) with ESMTPS id E451920643 for ; Wed, 30 Sep 2015 16:28:10 +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 1ZhKDC-0006hk-W1; Wed, 30 Sep 2015 16:26:35 +0000 Received: from eusmtp01.atmel.com ([212.144.249.242]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1ZhK9r-0004VA-0m for linux-arm-kernel@lists.infradead.org; Wed, 30 Sep 2015 16:23:41 +0000 Received: from tenerife.corp.atmel.com (10.161.101.13) by eusmtp01.atmel.com (10.161.101.30) with Microsoft SMTP Server id 14.3.235.1; Wed, 30 Sep 2015 18:22:23 +0200 From: Nicolas Ferre To: , , Alexandre Belloni , Subject: [PATCH v3 2/2] power: reset: at91-shdwc: add new shutdown controller driver Date: Wed, 30 Sep 2015 18:22:01 +0200 Message-ID: <1443630121-13912-3-git-send-email-nicolas.ferre@atmel.com> X-Mailer: git-send-email 2.1.3 In-Reply-To: <1443630121-13912-1-git-send-email-nicolas.ferre@atmel.com> References: <1443630121-13912-1-git-send-email-nicolas.ferre@atmel.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20150930_092308_104242_EF063712 X-CRM114-Status: GOOD ( 26.36 ) X-Spam-Score: -4.2 (----) 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: mark.rutland@arm.com, ijc+devicetree@hellion.org.uk, Nicolas Ferre , linux-kernel@vger.kernel.org, Maxime Ripard , Jean-Christophe PLAGNIOL-VILLARD , linux@roeck-us.net Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Sama5d2 SoC has a completely new shutdown controller with new features and register layout. It thus makes sense to add a new driver for this new peripheral. This driver is Device Tree only and handles events from the wake-up pin and the RTC. As the register layout may change in the future, so some values are encoded in a configuration structure. Signed-off-by: Nicolas Ferre --- Changes in v3: - add the slow clock handle as the IP uses it - remove useless protection at the beginning of pm_power_off handler - allow to compile it as a module - add COMPILE_TEST directive in Kconfig - update description in file header Changes in v2: - add MODULE_DEVICE_TABLE as advised by Sebastian Reichel - review indentation and braces to correct errors pointed out by checkpatch drivers/power/reset/Kconfig | 8 ++ drivers/power/reset/Makefile | 1 + drivers/power/reset/at91-shdwc.c | 288 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 297 insertions(+) create mode 100644 drivers/power/reset/at91-shdwc.c diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig index 1131cf75acc6..c989ffae7143 100644 --- a/drivers/power/reset/Kconfig +++ b/drivers/power/reset/Kconfig @@ -30,6 +30,14 @@ config POWER_RESET_AT91_RESET This driver supports restart for Atmel AT91SAM9 and SAMA5 SoCs +config POWER_RESET_AT91_SHDWC + tristate "Atmel AT91 shutdown controller driver" + depends on ARCH_AT91 || COMPILE_TEST + default SOC_SAMA5 + help + This driver supports the alternate shutdown controller for some Atmel + SAMA5 SoCs. It is present for example on SAMA5D2 SoC. + config POWER_RESET_AXXIA bool "LSI Axxia reset driver" depends on ARCH_AXXIA diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile index 096fa67047f6..6b9020ed3fb7 100644 --- a/drivers/power/reset/Makefile +++ b/drivers/power/reset/Makefile @@ -1,6 +1,7 @@ obj-$(CONFIG_POWER_RESET_AS3722) += as3722-poweroff.o obj-$(CONFIG_POWER_RESET_AT91_POWEROFF) += at91-poweroff.o obj-$(CONFIG_POWER_RESET_AT91_RESET) += at91-reset.o +obj-$(CONFIG_POWER_RESET_AT91_SHDWC) += at91-shdwc.o obj-$(CONFIG_POWER_RESET_AXXIA) += axxia-reset.o obj-$(CONFIG_POWER_RESET_BRCMSTB) += brcmstb-reboot.o obj-$(CONFIG_POWER_RESET_GPIO) += gpio-poweroff.o diff --git a/drivers/power/reset/at91-shdwc.c b/drivers/power/reset/at91-shdwc.c new file mode 100644 index 000000000000..9163ebde9f14 --- /dev/null +++ b/drivers/power/reset/at91-shdwc.c @@ -0,0 +1,288 @@ +/* + * Atmel alternative Shutdown Controller (SHDWC) driver. + * Found on some SoCs as the sama5d2 for instance. + * + * Copyright (C) 2015 Atmel Corporation, + * Nicolas Ferre + * + * Evolved from driver at91-poweroff.c. + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + * + * TODO: + * - addition to status of other wake-up inputs [1 - 15] + * - Analog Comparator wake-up alarm + * - Serial RX wake-up alarm + * - low power debouncer + */ + +#include +#include +#include +#include +#include +#include + +#define SLOW_CLOCK_FREQ 32768 + +#define AT91_SHDW_CR 0x00 /* Shut Down Control Register */ +#define AT91_SHDW_SHDW BIT(0) /* Shut Down command */ +#define AT91_SHDW_KEY (0xa5 << 24) /* KEY Password */ + +#define AT91_SHDW_MR 0x04 /* Shut Down Mode Register */ +#define AT91_SHDW_WKUPDBC_SHIFT 24 +#define AT91_SHDW_WKUPDBC_MASK GENMASK(31, 16) +#define AT91_SHDW_WKUPDBC(x) (((x) << AT91_SHDW_WKUPDBC_SHIFT) \ + & AT91_SHDW_WKUPDBC_MASK) + +#define AT91_SHDW_SR 0x08 /* Shut Down Status Register */ +#define AT91_SHDW_WKUPIS_SHIFT 16 +#define AT91_SHDW_WKUPIS_MASK GENMASK(31, 16) +#define AT91_SHDW_WKUPIS(x) ((1 << (x)) << AT91_SHDW_WKUPIS_SHIFT \ + & AT91_SHDW_WKUPIS_MASK) + +#define AT91_SHDW_WUIR 0x0c /* Shutdown Wake-up Inputs Register */ +#define AT91_SHDW_WKUPEN_MASK GENMASK(15, 0) +#define AT91_SHDW_WKUPEN(x) ((1 << (x)) & AT91_SHDW_WKUPEN_MASK) +#define AT91_SHDW_WKUPT_SHIFT 16 +#define AT91_SHDW_WKUPT_MASK GENMASK(31, 16) +#define AT91_SHDW_WKUPT(x) ((1 << (x)) << AT91_SHDW_WKUPT_SHIFT \ + & AT91_SHDW_WKUPT_MASK) + +#define SHDW_WK_PIN(reg, cfg) ((reg) & AT91_SHDW_WKUPIS((cfg)->wkup_pin_input)) +#define SHDW_RTCWK(reg, cfg) (((reg) >> ((cfg)->sr_rtcwk_shift)) & 0x1) +#define SHDW_RTCWKEN(cfg) (1 << ((cfg)->mr_rtcwk_shift)) + +#define DBC_PERIOD_US(x) DIV_ROUND_UP_ULL((1000000 * (x)), \ + SLOW_CLOCK_FREQ) + +struct shdwc_config { + u8 wkup_pin_input; + u8 mr_rtcwk_shift; + u8 sr_rtcwk_shift; +}; + +struct shdwc { + struct shdwc_config *cfg; + void __iomem *at91_shdwc_base; +}; + +/* + * Hold configuration here, cannot be more than one instance of the driver + * since pm_power_off itself is global. + */ +static struct shdwc *at91_shdwc; +static struct clk *sclk; + +static const unsigned long long sdwc_dbc_period[] = { + 0, 3, 32, 512, 4096, 32768, +}; + +static void __init at91_wakeup_status(struct platform_device *pdev) +{ + struct shdwc *shdw = platform_get_drvdata(pdev); + u32 reg; + char *reason = "unknown"; + + reg = readl(shdw->at91_shdwc_base + AT91_SHDW_SR); + + dev_dbg(&pdev->dev, "%s: status = %#x\n", __func__, reg); + + /* Simple power-on, just bail out */ + if (!reg) + return; + + if (SHDW_WK_PIN(reg, shdw->cfg)) + reason = "WKUP pin"; + else if (SHDW_RTCWK(reg, shdw->cfg)) + reason = "RTC"; + + pr_info("AT91: Wake-Up source: %s\n", reason); +} + +static void at91_poweroff(void) +{ + writel(AT91_SHDW_KEY | AT91_SHDW_SHDW, + at91_shdwc->at91_shdwc_base + AT91_SHDW_CR); +} + +static u32 at91_shdwc_debouncer_value(struct platform_device *pdev, + u32 in_period_us) +{ + int i; + int max_idx = ARRAY_SIZE(sdwc_dbc_period) - 1; + unsigned long long period_us; + unsigned long long max_period_us = DBC_PERIOD_US(sdwc_dbc_period[max_idx]); + + if (in_period_us > max_period_us) { + dev_warn(&pdev->dev, + "debouncer period %u too big, reduced to %llu us\n", + in_period_us, max_period_us); + return max_idx; + } + + for (i = max_idx - 1; i > 0; i--) { + period_us = DBC_PERIOD_US(sdwc_dbc_period[i]); + dev_dbg(&pdev->dev, "%s: ref[%d] = %llu\n", + __func__, i, period_us); + if (in_period_us > period_us) + break; + } + + return i + 1; +} + +static u32 at91_shdwc_get_wakeup_input(struct platform_device *pdev, + struct device_node *np) +{ + struct device_node *cnp; + const char *pm; + u32 wk_input_mask; + u32 wuir = 0; + u32 wk_input; + + for_each_child_of_node(np, cnp) { + if (of_property_read_u32(cnp, "reg", &wk_input)) { + dev_warn(&pdev->dev, "reg property is missing for %s\n", + cnp->full_name); + continue; + } + + wk_input_mask = 1 << wk_input; + if (!(wk_input_mask & AT91_SHDW_WKUPEN_MASK)) { + dev_warn(&pdev->dev, + "wake-up input %d out of bounds ignore\n", + wk_input); + continue; + } + wuir |= wk_input_mask; + + if (!of_property_read_string(cnp, "atmel,wakeup-type", &pm)) { + if (!strcasecmp(pm, "high")) + /* + * only add a type if "high" is specified. Low + * is the default. + */ + wuir |= AT91_SHDW_WKUPT(wk_input); + } + dev_dbg(&pdev->dev, "%s: (child %d) wuir = %#x\n", + __func__, wk_input, wuir); + } + + return wuir; +} + +static void at91_shdwc_dt_configure(struct platform_device *pdev) +{ + struct shdwc *shdw = platform_get_drvdata(pdev); + struct device_node *np = pdev->dev.of_node; + u32 mode = 0, tmp, input; + + if (!np) { + dev_err(&pdev->dev, "device node not found\n"); + return; + } + + if (!of_property_read_u32(np, "atmel,shdwc-debouncer", &tmp)) + mode |= AT91_SHDW_WKUPDBC(at91_shdwc_debouncer_value(pdev, tmp)); + + if (of_property_read_bool(np, "atmel,wakeup-rtc-timer")) + mode |= SHDW_RTCWKEN(shdw->cfg); + + dev_dbg(&pdev->dev, "%s: mode = %#x\n", __func__, mode); + writel(mode, shdw->at91_shdwc_base + AT91_SHDW_MR); + + input = at91_shdwc_get_wakeup_input(pdev, np); + writel(input, shdw->at91_shdwc_base + AT91_SHDW_WUIR); +} + +static const struct shdwc_config sama5d2_shdwc_config = { + .wkup_pin_input = 0, + .mr_rtcwk_shift = 17, + .sr_rtcwk_shift = 5, +}; + +static const struct of_device_id at91_shdwc_of_match[] = { + { + .compatible = "atmel,sama5d2-shdwc", + .data = &sama5d2_shdwc_config, + }, { + /*sentinel*/ + } +}; +MODULE_DEVICE_TABLE(of, at91_shdwc_of_match); + +static int __init at91_shdwc_probe(struct platform_device *pdev) +{ + struct resource *res; + const struct of_device_id *match; + int ret; + + if (!pdev->dev.of_node) + return -ENODEV; + + at91_shdwc = devm_kzalloc(&pdev->dev, sizeof(*at91_shdwc), GFP_KERNEL); + if (!at91_shdwc) + return -ENOMEM; + + platform_set_drvdata(pdev, at91_shdwc); + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + at91_shdwc->at91_shdwc_base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(at91_shdwc->at91_shdwc_base)) { + dev_err(&pdev->dev, "Could not map reset controller address\n"); + return PTR_ERR(at91_shdwc->at91_shdwc_base); + } + + match = of_match_node(at91_shdwc_of_match, pdev->dev.of_node); + at91_shdwc->cfg = (struct shdwc_config *)(match->data); + + sclk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(sclk)) + return PTR_ERR(sclk); + + ret = clk_prepare_enable(sclk); + if (ret) { + dev_err(&pdev->dev, "Could not enable slow clock\n"); + return ret; + } + + at91_wakeup_status(pdev); + + at91_shdwc_dt_configure(pdev); + + pm_power_off = at91_poweroff; + + return 0; +} + +static int __exit at91_shdwc_remove(struct platform_device *pdev) +{ + struct shdwc *shdw = platform_get_drvdata(pdev); + + if (pm_power_off == at91_poweroff) + pm_power_off = NULL; + + /* Reset values to disable wake-up features */ + writel(0, shdw->at91_shdwc_base + AT91_SHDW_MR); + writel(0, shdw->at91_shdwc_base + AT91_SHDW_WUIR); + + clk_disable_unprepare(sclk); + + return 0; +} + +static struct platform_driver at91_shdwc_driver = { + .remove = __exit_p(at91_shdwc_remove), + .driver = { + .name = "at91-shdwc", + .of_match_table = at91_shdwc_of_match, + }, +}; +module_platform_driver_probe(at91_shdwc_driver, at91_shdwc_probe); + +MODULE_AUTHOR("Nicolas Ferre "); +MODULE_DESCRIPTION("Atmel shutdown controller driver"); +MODULE_LICENSE("GPL v2");