Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755676Ab3GYMS3 (ORCPT ); Thu, 25 Jul 2013 08:18:29 -0400 Received: from hqemgate16.nvidia.com ([216.228.121.65]:18168 "EHLO hqemgate16.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751639Ab3GYMS0 (ORCPT ); Thu, 25 Jul 2013 08:18:26 -0400 X-PGP-Universal: processed; by hqnvupgp08.nvidia.com on Thu, 25 Jul 2013 05:17:14 -0700 From: Laxman Dewangan To: CC: , , , , , , , , , , Laxman Dewangan Subject: [PATCH] drivers/rtc/rtc-palmas.c: support for backup battery charging Date: Thu, 25 Jul 2013 17:59:03 +0530 Message-ID: <1374755343-32573-1-git-send-email-ldewangan@nvidia.com> X-Mailer: git-send-email 1.7.1.1 MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4010 Lines: 116 Palmas series device like TPS65913, TPS80036 supports the backup battery for powering the RTC when no other energy source is available. The backup battery is optional, connected to the VBACKUP pin, and can be nonrechargeable or rechargeable. The rechargeable battery can be charged from the system supply using the backup battery charger. Add support for enabling charging of this backup battery. Also add the DT binding document and the new properties to have this support. Signed-off-by: Laxman Dewangan --- .../devicetree/bindings/rtc/rtc-palmas.txt | 28 ++++++++++++++ drivers/rtc/rtc-palmas.c | 39 ++++++++++++++++++++ 2 files changed, 67 insertions(+), 0 deletions(-) create mode 100644 Documentation/devicetree/bindings/rtc/rtc-palmas.txt diff --git a/Documentation/devicetree/bindings/rtc/rtc-palmas.txt b/Documentation/devicetree/bindings/rtc/rtc-palmas.txt new file mode 100644 index 0000000..e4b6910 --- /dev/null +++ b/Documentation/devicetree/bindings/rtc/rtc-palmas.txt @@ -0,0 +1,28 @@ +Palmas RTC controller bindings + +Required properties: +- compatible: + - "ti,palams-rtc" for palma series of the RTC controller +- interrupt-parent: Parent interrupt device, must be handle of palams node. +- interrupts: Interrupt number of RTC submodule on device. + +Optional properties: +- ti,back-bat-chg-enable: The palmas series device like TPS65913 or TPS80036 + supports the battery backup for powering the RTC when main battery is + removed or in very low power state. This flag will enable the backup + battery charging. +- ti,back-bat-chg-current: Configure charging current. Device supports the + charging current as < 100mA or >100mA. + +Example: + palmas: tps65913@58 { + ::::::::::: + palmas_rtc: rtc { + compatible = "ti,palmas-rtc"; + interrupt-parent = <&palmas>; + interrupts = <8 0>; + ti,back-bat-chg-enable; + ti,back-bat-chg-current = <100>; + }; + ::::::::::: + }; diff --git a/drivers/rtc/rtc-palmas.c b/drivers/rtc/rtc-palmas.c index a1fecc8..1a7c44a 100644 --- a/drivers/rtc/rtc-palmas.c +++ b/drivers/rtc/rtc-palmas.c @@ -238,6 +238,19 @@ static int palmas_rtc_probe(struct platform_device *pdev) struct palmas *palmas = dev_get_drvdata(pdev->dev.parent); struct palmas_rtc *palmas_rtc = NULL; int ret; + bool enable_bb_charging = false; + u32 bb_charging_current = 100; + + if (pdev->dev.of_node) { + u32 pval; + + enable_bb_charging = of_property_read_bool(pdev->dev.of_node, + "ti,back-bat-chg-enable"); + ret = of_property_read_u32(pdev->dev.of_node, + "ti,back-bat-chg-current", &pval); + if (!ret) + bb_charging_current = pval; + } palmas_rtc = devm_kzalloc(&pdev->dev, sizeof(struct palmas_rtc), GFP_KERNEL); @@ -254,6 +267,32 @@ static int palmas_rtc_probe(struct platform_device *pdev) palmas_rtc->dev = &pdev->dev; platform_set_drvdata(pdev, palmas_rtc); + if (enable_bb_charging) { + unsigned reg = 0; + + if (bb_charging_current < 100) + reg |= PALMAS_BACKUP_BATTERY_CTRL_BBS_BBC_LOW_ICHRG; + + ret = palmas_update_bits(palmas, PALMAS_PMU_CONTROL_BASE, + PALMAS_BACKUP_BATTERY_CTRL, + PALMAS_BACKUP_BATTERY_CTRL_BBS_BBC_LOW_ICHRG, reg); + if (ret < 0) { + dev_err(&pdev->dev, + "BACKUP_BATTERY_CTRL update failed, %d\n", ret); + return ret; + } + + ret = palmas_update_bits(palmas, PALMAS_PMU_CONTROL_BASE, + PALMAS_BACKUP_BATTERY_CTRL, + PALMAS_BACKUP_BATTERY_CTRL_BB_CHG_EN, + PALMAS_BACKUP_BATTERY_CTRL_BB_CHG_EN); + if (ret < 0) { + dev_err(&pdev->dev, + "BACKUP_BATTERY_CTRL update failed, %d\n", ret); + return ret; + } + } + /* Start RTC */ ret = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG, PALMAS_RTC_CTRL_REG_STOP_RTC, -- 1.7.1.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/