From mboxrd@z Thu Jan 1 00:00:00 1970 From: Charles Keepax Subject: Re: [PATCH] mfd: wm8994: declare dc servo register for wm8958 as volatile Date: Wed, 13 Aug 2014 13:32:32 +0100 Message-ID: <20140813123231.GK15833@opensource.wolfsonmicro.com> References: <1407926786-8528-1-git-send-email-nikesh@opensource.wolfsonmicro.com> <20140813111338.GG15833@opensource.wolfsonmicro.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20140813111338.GG15833@opensource.wolfsonmicro.com> Sender: linux-kernel-owner@vger.kernel.org To: Nikesh Oswal Cc: alsa-devel@alsa-project.org, tiwai@suse.de, patches@opensource.wolfsonmicro.com, linux-kernel@vger.kernel.org, lgirdwood@gmail.com, broonie@kernel.org, perex@perex.cz List-Id: alsa-devel@alsa-project.org On Wed, Aug 13, 2014 at 12:13:38PM +0100, Charles Keepax wrote: > On Wed, Aug 13, 2014 at 11:46:25AM +0100, Nikesh Oswal wrote: > > DC Servo register 57h holds the DC offset value after the hardware has > > completed the DC Servo Correction, so declare this register as volatile > > because it is changed by the hardware. > > > > Signed-off-by: Nikesh Oswal > > --- > > drivers/mfd/wm8994-regmap.c | 1 + > > include/linux/mfd/wm8994/registers.h | 1 + > > 2 files changed, 2 insertions(+) > > > > diff --git a/drivers/mfd/wm8994-regmap.c b/drivers/mfd/wm8994-regmap.c > > index 2fbce9c..e775565 100644 > > --- a/drivers/mfd/wm8994-regmap.c > > +++ b/drivers/mfd/wm8994-regmap.c > > @@ -1169,6 +1169,7 @@ static bool wm8958_volatile_register(struct device *dev, unsigned int reg) > > case WM8958_FW_MINOR_0: > > case WM8958_FW_PATCH_1: > > case WM8958_FW_PATCH_0: > > + case WM8958_DC_SERVO: > > I think you can just use the WM8994_DC_SERVO_4 define the > register is called DC Servo (4) in the datasheet. > > Also would it be worth adding DC_SERVO_1 and DC_SERVO_READBACK as > they are being treated as volatile on 8994 and look identical in > the datasheet. Sorry missed the call to wm8994_volatile_register ignore this second comment here. Thanks, Charles