From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from saturn.retrosnub.co.uk ([178.18.118.26]:60168 "EHLO saturn.retrosnub.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752732AbaCOPCH (ORCPT ); Sat, 15 Mar 2014 11:02:07 -0400 Message-ID: <53246BA9.3040903@kernel.org> Date: Sat, 15 Mar 2014 15:03:05 +0000 From: Jonathan Cameron MIME-Version: 1.0 To: Srinivas Pandruvada , Lars-Peter Clausen CC: linux-iio@vger.kernel.org Subject: Re: [PATCH 1/3] iio: ak8975 : Add AK8963 compatibility mode support References: <1394572557-8102-1-git-send-email-srinivas.pandruvada@linux.intel.com> <532031FC.6010401@metafoo.de> <5320A7AF.3010500@linux.intel.com> In-Reply-To: <5320A7AF.3010500@linux.intel.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Sender: linux-iio-owner@vger.kernel.org List-Id: linux-iio@vger.kernel.org On 12/03/14 18:30, Srinivas Pandruvada wrote: > On 03/12/2014 03:07 AM, Lars-Peter Clausen wrote: >> On 03/11/2014 10:15 PM, Srinivas Pandruvada wrote: >>> AK8963 and AK8975 use same register definitions, except the range >>> of X,Y,Z values. Added support of 8963 based on i2c_device_id. >>> Unfortunately there is no way to detect the type via registers, >>> both device registers return 0x48 as id of chipset. >>> >>> Signed-off-by: Srinivas Pandruvada >> >> Hi, >> >> a few small comments. >> > > Thanks. I will take care in the next version. > > -Srinivas Other than points Lars raised, this looks fine to me. Jonathan > >>> --- >>> drivers/iio/magnetometer/Kconfig | 3 ++- >>> drivers/iio/magnetometer/ak8975.c | 40 +++++++++++++++++++++++++++++++++++---- >>> 2 files changed, 38 insertions(+), 5 deletions(-) >>> >>> diff --git a/drivers/iio/magnetometer/Kconfig b/drivers/iio/magnetometer/Kconfig >>> index d86d226..05a364c54 100644 >>> --- a/drivers/iio/magnetometer/Kconfig >>> +++ b/drivers/iio/magnetometer/Kconfig >>> @@ -11,7 +11,8 @@ config AK8975 >>> depends on GPIOLIB >>> help >>> Say yes here to build support for Asahi Kasei AK8975 3-Axis >>> - Magnetometer. >>> + Magnetometer. This driver can also support AK8963, if i2c >>> + device name is identified as ak8963. >>> >>> To compile this driver as a module, choose M here: the module >>> will be called ak8975. >>> diff --git a/drivers/iio/magnetometer/ak8975.c b/drivers/iio/magnetometer/ak8975.c >>> index 0542354..a55c94f 100644 >>> --- a/drivers/iio/magnetometer/ak8975.c >>> +++ b/drivers/iio/magnetometer/ak8975.c >>> @@ -85,7 +85,15 @@ >>> #define AK8975_MAX_CONVERSION_TIMEOUT 500 >>> #define AK8975_CONVERSION_DONE_POLL_TIME 10 >>> #define AK8975_DATA_READY_TIMEOUT ((100*HZ)/1000) >>> -#define RAW_TO_GAUSS(asa) ((((asa) + 128) * 3000) / 256) >>> +#define RAW_TO_GAUSS_8975(asa) ((((asa) + 128) * 3000) / 256) >>> +#define RAW_TO_GAUSS_8963(asa) ((((asa) + 128) * 6000) / 256) >>> + >>> +/* Compatible Asahi Kasei Compass parts */ >>> +enum asahi_compass_chipset { >>> + AK8975, >>> + AK8963, >>> + AK_INVALID, >> >> Not sure if you need AK_INVALID, it is never used. >> >>> +}; >>> >>> /* >>> * Per-instance context data for the device. >>> @@ -101,6 +109,7 @@ struct ak8975_data { >>> int eoc_irq; >>> wait_queue_head_t data_ready_queue; >>> unsigned long flags; >>> + int chipset; >> >> enum asahi_compass_chipset ... >> >>> }; >>> >>> static const int ak8975_index_to_reg[] = { >>> @@ -272,9 +281,21 @@ static int ak8975_setup(struct i2c_client *client) >>> * Since ASA doesn't change, we cache the resultant scale factor into the >>> * device context in ak8975_setup(). >>> */ >>> - data->raw_to_gauss[0] = RAW_TO_GAUSS(data->asa[0]); >>> - data->raw_to_gauss[1] = RAW_TO_GAUSS(data->asa[1]); >>> - data->raw_to_gauss[2] = RAW_TO_GAUSS(data->asa[2]); >>> + if (data->chipset == AK8963) { >>> + /* >>> + * H range is +-8190 and magnetometer range is +-4912. >>> + * So HuT using the above explanation for 8975, >>> + * 4912/8190 = ~ 6/10. >>> + * So the Hadj should use 6/10 instead of 3/10. >>> + */ >>> + data->raw_to_gauss[0] = RAW_TO_GAUSS_8963(data->asa[0]); >>> + data->raw_to_gauss[1] = RAW_TO_GAUSS_8963(data->asa[1]); >>> + data->raw_to_gauss[2] = RAW_TO_GAUSS_8963(data->asa[2]); >>> + } else { >>> + data->raw_to_gauss[0] = RAW_TO_GAUSS_8975(data->asa[0]); >>> + data->raw_to_gauss[1] = RAW_TO_GAUSS_8975(data->asa[1]); >>> + data->raw_to_gauss[2] = RAW_TO_GAUSS_8975(data->asa[2]); >>> + } >>> >>> return 0; >>> } >>> @@ -499,6 +520,16 @@ static int ak8975_probe(struct i2c_client *client, >>> data->eoc_gpio = eoc_gpio; >>> data->eoc_irq = 0; >>> >>> + if (id) { >> >> id will never be NULL. >> >>> + data->chipset = (int)(id->driver_data); >>> + if (data->chipset == AK8963) >>> + dev_dbg(&client->dev, >>> + "AK8975 driver is running in AK8963 mode\n"); >>> + else >>> + dev_dbg(&client->dev, >>> + "AK8975 driver is running in normal mode\n"); >> >> How about printing just id->name, this way you do not have to add a new else branch when a new part is supported. >> >>> + } >>> + >>> /* Perform some basic start-of-day setup of the device. */ >>> err = ak8975_setup(client); >>> if (err < 0) { >>> @@ -552,6 +583,7 @@ static int ak8975_remove(struct i2c_client *client) >>> >>> static const struct i2c_device_id ak8975_id[] = { >>> {"ak8975", 0}, >> >> Should change the 0 to AK8975 >> >>> + {"ak8963", AK8963}, >>> {} >>> }; >>> >>> >> >> > > -- > To unsubscribe from this list: send the line "unsubscribe linux-iio" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html