From mboxrd@z Thu Jan 1 00:00:00 1970 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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,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 E2844C43441 for ; Thu, 15 Nov 2018 09:36:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B3B76223CB for ; Thu, 15 Nov 2018 09:36:56 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B3B76223CB Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=csie.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-bluetooth-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388173AbeKOTnN (ORCPT ); Thu, 15 Nov 2018 14:43:13 -0500 Received: from mirror2.csie.ntu.edu.tw ([140.112.30.76]:46470 "EHLO wens.csie.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388019AbeKOTnM (ORCPT ); Thu, 15 Nov 2018 14:43:12 -0500 Received: by wens.csie.org (Postfix, from userid 1000) id D58CA5FD95; Thu, 15 Nov 2018 17:36:04 +0800 (CST) From: Chen-Yu Tsai To: Marcel Holtmann , Johan Hedberg , Rob Herring , Mark Rutland , Maxime Ripard Cc: Chen-Yu Tsai , Loic Poulain , linux-bluetooth@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 08/15] Bluetooth: hci_bcm: Add support for LPO clock Date: Thu, 15 Nov 2018 17:35:56 +0800 Message-Id: <20181115093603.26729-9-wens@csie.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181115093603.26729-1-wens@csie.org> References: <20181115093603.26729-1-wens@csie.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-bluetooth-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-bluetooth@vger.kernel.org The Broadcom Bluetooth controllers support a secondary LPO clock at 32.768 kHz. This external clock provides low power timing, and also a way to detect the frequency of the main reference clock. On many designs without NVRAM and a non-default reference clock, this must be used or the controller will not function correctly. Signed-off-by: Chen-Yu Tsai --- drivers/bluetooth/hci_bcm.c | 41 ++++++++++++++++++++++++++++++++----- 1 file changed, 36 insertions(+), 5 deletions(-) diff --git a/drivers/bluetooth/hci_bcm.c b/drivers/bluetooth/hci_bcm.c index 1584c95c9c34..345d728a5434 100644 --- a/drivers/bluetooth/hci_bcm.c +++ b/drivers/bluetooth/hci_bcm.c @@ -72,7 +72,8 @@ * @btpu: Apple ACPI method to drive BT_REG_ON pin high ("Bluetooth Power Up") * @btpd: Apple ACPI method to drive BT_REG_ON pin low ("Bluetooth Power Down") * @txco_clk: external reference frequency clock used by Bluetooth device - * @clk_enabled: whether @txco_clk is prepared and enabled + * @lpo_clk: external LPO clock used by Bluetooth device + * @clk_enabled: whether clocks are prepared and enabled * @init_speed: default baudrate of Bluetooth device; * the host UART is initially set to this baudrate so that * it can configure the Bluetooth device for @oper_speed @@ -103,6 +104,7 @@ struct bcm_device { #endif struct clk *txco_clk; + struct clk *lpo_clk; bool clk_enabled; u32 init_speed; @@ -215,21 +217,34 @@ static int bcm_gpio_set_power(struct bcm_device *dev, bool powered) int err; if (powered && !dev->clk_enabled) { - err = clk_prepare_enable(dev->txco_clk); + /* LPO clock needs to be 32.768 kHz */ + err = clk_set_rate(dev->lpo_clk, 32768); + if (err) { + dev_err(dev->dev, "Could not set LPO clock rate\n"); + return err; + } + + err = clk_prepare_enable(dev->lpo_clk); if (err) return err; + + err = clk_prepare_enable(dev->txco_clk); + if (err) + goto err_lpo_clk_disable; } err = dev->set_shutdown(dev, powered); if (err) - goto err_clk_disable; + goto err_txco_clk_disable; err = dev->set_device_wakeup(dev, powered); if (err) goto err_revert_shutdown; - if (!powered && dev->clk_enabled) + if (!powered && dev->clk_enabled) { clk_disable_unprepare(dev->txco_clk); + clk_disable_unprepare(dev->lpo_clk); + } dev->clk_enabled = powered; @@ -237,9 +252,12 @@ static int bcm_gpio_set_power(struct bcm_device *dev, bool powered) err_revert_shutdown: dev->set_shutdown(dev, !powered); -err_clk_disable: +err_txco_clk_disable: if (powered && !dev->clk_enabled) clk_disable_unprepare(dev->txco_clk); +err_lpo_clk_disable: + if (powered && !dev->clk_enabled) + clk_disable_unprepare(dev->lpo_clk); return err; } @@ -934,6 +952,19 @@ static int bcm_get_resources(struct bcm_device *dev) if (IS_ERR(dev->txco_clk)) dev->txco_clk = NULL; + dev->lpo_clk = devm_clk_get(dev->dev, "lpo"); + if (dev->lpo_clk == ERR_PTR(-EPROBE_DEFER)) + return PTR_ERR(dev->lpo_clk); + + if (IS_ERR(dev->lpo_clk)) + dev->lpo_clk = NULL; + + /* Check if we accidentally fetched the lpo clock twice */ + if (dev->lpo_clk && clk_is_match(dev->lpo_clk, dev->txco_clk)) { + devm_clk_put(dev->dev, dev->txco_clk); + dev->txco_clk = NULL; + } + dev->device_wakeup = devm_gpiod_get_optional(dev->dev, "device-wakeup", GPIOD_OUT_LOW); if (IS_ERR(dev->device_wakeup)) -- 2.19.1