From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:53486 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965569AbcKXO64 (ORCPT ); Thu, 24 Nov 2016 09:58:56 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Keerthy , Lokesh Vutla , Dave Gerlach , Alexandre Belloni Subject: [PATCH 4.4 18/31] rtc: omap: Fix selecting external osc Date: Thu, 24 Nov 2016 15:55:39 +0100 Message-Id: <20161124145447.925966063@linuxfoundation.org> In-Reply-To: <20161124145446.993225208@linuxfoundation.org> References: <20161124145446.993225208@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Lokesh Vutla commit 3984903a2e3906d3def220e688040ce93368200a upstream. RTC can be clocked from an external 32KHz oscillator, or from the Peripheral PLL. The RTC has an internal oscillator buffer to support direct operation with a crystal. ---------------------------------------- | Device --------- | | | | | | | RTCSS | | | --------- | | | OSC |<------| RTC | | | | |------>| OSC |--- | | | | -------- | | | | | ----|clk | | | -------- | | | | | | PRCM |--- | | | | -------- -------- | ---------------------------------------- The RTC functional clock is sourced by default from the clock derived from the Peripheral PLL. In order to select source as external osc clk the following changes needs to be done: - Enable the RTC OSC (RTC_OSC_REG[4]OSC32K_GZ = 0) - Enable the clock mux(RTC_OSC_REG[6]K32CLK_EN = 1) - Select the external clock source (RTC_OSC_REG[3]32KCLK_SEL = 1) Fixes: 399cf0f63f6f2 ("rtc: omap: Add external clock enabling support") Signed-off-by: Keerthy Signed-off-by: Lokesh Vutla Signed-off-by: Dave Gerlach Signed-off-by: Alexandre Belloni Signed-off-by: Greg Kroah-Hartman --- drivers/rtc/rtc-omap.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/drivers/rtc/rtc-omap.c +++ b/drivers/rtc/rtc-omap.c @@ -109,6 +109,7 @@ /* OMAP_RTC_OSC_REG bit fields: */ #define OMAP_RTC_OSC_32KCLK_EN BIT(6) #define OMAP_RTC_OSC_SEL_32KCLK_SRC BIT(3) +#define OMAP_RTC_OSC_OSC32K_GZ_DISABLE BIT(4) /* OMAP_RTC_IRQWAKEEN bit fields: */ #define OMAP_RTC_IRQWAKEEN_ALARM_WAKEEN BIT(1) @@ -646,8 +647,9 @@ static int omap_rtc_probe(struct platfor */ if (rtc->has_ext_clk) { reg = rtc_read(rtc, OMAP_RTC_OSC_REG); - rtc_write(rtc, OMAP_RTC_OSC_REG, - reg | OMAP_RTC_OSC_SEL_32KCLK_SRC); + reg &= ~OMAP_RTC_OSC_OSC32K_GZ_DISABLE; + reg |= OMAP_RTC_OSC_32KCLK_EN | OMAP_RTC_OSC_SEL_32KCLK_SRC; + rtc_writel(rtc, OMAP_RTC_OSC_REG, reg); } rtc->type->lock(rtc);