Hi,
did you pursue your work on the mpu6050 ?
I have a hard time figuring how to use the invensense driver. Is it worth 
it ?

thanks

Le mardi 13 mai 2014 22:46:55 UTC+2, [email protected] a écrit :
>
> Hi, 
> I have got a small project at home running the inv_mpu6050 driver on a 
> 3.8.13 kernel. To get it working I had to modify the driver, so that it 
> accepts device tree parameters, then I wrote a cape configuration for the 
> i2c and the mpu6050 device and voila it worked. I added the driver to the 
> kernel and then add the cape to the device tree by echoing the cape name to 
> /sys/devices/bone_capemgr.8/slots. So then I had: 
>
> cat /sys/devices/bone_capemgr.8/slots
>  0: 54:PF--- 
>  1: 55:PF--- 
>  2: 56:PF--- 
>  3: 57:PF--- 
>  4: ff:P-O-L Override Board Name,00A0,Override Manuf,BB-BONE-MPU6050
>
> lsmod
> Module                  Size  Used by
> inv_mpu6050             7868  0 
> g_multi                47670  0 
> libcomposite           14299  1 g_multi
> mt7601Usta            601404  0 
>
> ls /sys/bus/iio/devices/iio:device0/
> buffer         in_accel_scale  in_accel_z_raw    in_anglvel_y_raw  
> in_temp_offset  name         sampling_frequency_available  trigger
> dev         in_accel_x_raw  in_anglvel_scale  in_anglvel_z_raw  
> in_temp_raw     power         scan_elements               uevent
> in_accel_matrix  in_accel_y_raw  in_anglvel_x_raw  in_gyro_matrix    
> in_temp_scale   sampling_frequency  subsystem
>
> cat /sys/bus/iio/devices/iio:device0/*raw
> -8202
> -458
> 11288
> 10
> 51
> 109
> -4967
>
> But now to the downside of it all. If I try to access the values, e.g. 
> /sys/bus/iio/devices/iio:device0/in_accel_x_raw it takes more than 100ms?
> Well I am still working on some improvements in the driver's device tree 
> (the parameters can be negative, but the dtc version I have got can not 
> handle unary parameters yet), but when I am finished I will commit the 
> driver back to the community. 
>
> My work so far: 
> -) The Cape File: 
> /*
>  * Copyright (C) 2014 Thomas Grazadei
>  *
>  * Make use of the Invensense MPU6050                    
>  *
>  * This program is free software; you can redistribute it and/or modify
>  * it under the terms of the GNU General Public License version 2 as
>  * published by the Free Software Foundation.
>  */
> /dts-v1/;
> /plugin/;
>
> / {
>         compatible = "ti,beaglebone", "ti,beaglebone-black";
>
>         /* identification */
>         part-number = "BB-MPU6050";
>         version = "00A0";
>
>         /* state the resources this cape uses */
>         exclusive-use =
>                 /* the pin header uses */
>                 "P9.18",        /* i2c1_sda */
>                 "P9.17",        /* i2c1_scl */
>                 /* the hardware ip uses */
>                 "i2c1";
>
>         fragment@0 {
>                 target = <&am33xx_pinmux>;
>                 __overlay__ {
>                         bb_i2c1_pins: pinmux_bb_i2c1_pins {
>                                 pinctrl-single,pins = <
>                                         0x158 0x72      /* 
> spi0_d1.i2c1_sda, SLEWCTRL_SLOW | INPUT_PULLUP | MODE2 */
>                                         0x15c 0x72      /* 
> spi0_cs0.i2c1_scl, SLEWCTRL_SLOW | INPUT_PULLUP | MODE2 */
>                                 >;
>                         };
>                 };
>         };
>
>         fragment@1 {
>                 target = <&i2c1>;       /* i2c1 is numbered correctly */
>                 __overlay__ {
>                         status = "okay";
>                         pinctrl-names = "default";
>                         pinctrl-0 = <&bb_i2c1_pins>;
>
>                         /* this is the configuration part */
>                         clock-frequency = <400000>;
>
>                         #address-cells = <1>;
>                         #size-cells = <0>;
>
>                         /* add any i2c devices on the bus here */
>
>                         mpu6050@68 {
>                                 compatible = "inv,mpu6050";
>                                 reg = <0x68>;
>                                 orientation = <0xff 0 0 0 1 0 0 0 0xff>;
>                         };
>                 };
>         };
> };
>
> -) and the changes in the driver: 
> diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c 
> b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
> index 37ca05b..d101a0c 100644
> --- a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
> +++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
> @@ -648,6 +648,31 @@ static int inv_check_and_setup_chip(struct 
> inv_mpu6050_state *st,
>      return 0;
>  }
>  
> +static struct inv_mpu6050_platform_data*
> +    mpu6050_parse_dt(struct device* dev)
> +{
> +    struct device_node *np = dev->of_node;
> +    struct inv_mpu6050_platform_data *pdata;
> +
> +    if (!np) {
> +        dev_err(dev, "no device tree or platform data\n");
> +        return ERR_PTR(-EINVAL);
> +    }
> +
> +    pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
> +    if (!pdata)
> +        return ERR_PTR(-ENOMEM);
> +
> +
> +    if (of_property_read_u8_array(np, "orientation",
> +        pdata->orientation, sizeof(pdata->orientation)) != 0) {
> +        dev_err(dev, "no valid orientation property found\n");
> +        return ERR_PTR(-EINVAL);
> +    }
> +
> +    return pdata;
> +}
> +
>  /**
>   *  inv_mpu_probe() - probe function.
>   *  @client:          i2c client.
> @@ -660,6 +685,7 @@ static int inv_mpu_probe(struct i2c_client *client,
>  {
>      struct inv_mpu6050_state *st;
>      struct iio_dev *indio_dev;
> +    struct inv_mpu6050_platform_data* pdata;
>      int result;
>  
>      if (!i2c_check_functionality(client->adapter,
> @@ -675,8 +701,21 @@ static int inv_mpu_probe(struct i2c_client *client,
>      }
>      st = iio_priv(indio_dev);
>      st->client = client;
> -    st->plat_data = *(struct inv_mpu6050_platform_data
> -                *)dev_get_platdata(&client->dev);
> +    pdata = (struct inv_mpu6050_platform_data*)
> +        dev_get_platdata(&client->dev);
> +
> +    if (pdata == NULL) {
> +        /* check of devicetree */
> +        // printk(KERN_ERR "checking device tree for parameter infos");
> +        pdata = mpu6050_parse_dt(&client->dev);
> +    }
> +
> +    if (IS_ERR(pdata)) {
> +        return PTR_ERR(pdata);
> +    }
> +
> +    st->plat_data = *pdata;
> +
>      /* power is turned on inside check chip type*/
>      result = inv_check_and_setup_chip(st, id);
>      if (result)
> @@ -777,14 +816,22 @@ static const struct i2c_device_id inv_mpu_id[] = {
>  
>  MODULE_DEVICE_TABLE(i2c, inv_mpu_id);
>  
> +static struct of_device_id inv_mpu6050_i2c_of_match[] = {
> +    { .compatible = "inv,mpu6050", },
> +    { }
> +};
> +
> +MODULE_DEVICE_TABLE(of, inv_mpu6050_i2c_of_match);
> +
>  static struct i2c_driver inv_mpu_driver = {
>      .probe        =    inv_mpu_probe,
>      .remove        =    inv_mpu_remove,
>      .id_table    =    inv_mpu_id,
>      .driver = {
> -        .owner    =    THIS_MODULE,
> -        .name    =    "inv-mpu6050",
> -        .pm     =       INV_MPU6050_PMOPS,
> +        .owner        =     THIS_MODULE,
> +        .name        =     "inv-mpu6050",
> +        .pm         =     INV_MPU6050_PMOPS,
> +        .of_match_table =     inv_mpu6050_i2c_of_match,
>      },
>  };
>  
> cheers, 
> gardi
>
>
> Am Mittwoch, 7. Mai 2014 02:16:57 UTC+2 schrieb [email protected]:
>>
>> No we never got this (the Invensense driver) working.  We just stuck it 
>> out with reading /dev/i2c.  This is costing us a 20% time penalty which 
>> really really hurts.  We couldn't get anyone to take on fixing the 
>> unbelievably long read times (~1msec) on /dev/i2c either.
>> Some of us are hoping the up coming move to Debian from Angstrom will 
>> bring us an Invensense  driver in the distro that will somehow work.
>> On Tuesday, May 6, 2014 10:42:41 AM UTC-7, [email protected] wrote:
>>>
>>> Knowing this discussion is old, i have to ask did you get it working? 
>>> And my experience is with the bbw, not the bbb. but the i2c buss on my 
>>> device is 100khz. maximum is 400khz. I was able to get the accelerometer 
>>> and gyro values at a rate of 200hz without issue, which isn't the max the 
>>> chip can provide, but it's more than suitable for most applications. All 
>>> through accessing /dev/i2c-#. If you havent got the driver to work yet, I 
>>> can send you my tiny little C program that prints the data to the shell. 
>>>
>>> On Tuesday, October 15, 2013 5:02:59 PM UTC-5, [email protected] 
>>> wrote:
>>>>
>>>> We are using the Invensense MPU6050 IMU on I2C with Beaglebone Black 
>>>> (Angstrom 3.8.13). We can use I2C-tools and file I/O thru /dev/i2c but the 
>>>> read speed is disappointingly slow.  We only read the 3x gyros and 3x 
>>>> accels (each one byte at a time plus the 2 byte temperature reading) and 
>>>> it 
>>>> takes ~2msecs.  My estimate of the I2C bus cycles for a block read 
>>>> suggests this should take ~160 bus cycles or .38msec on a 400kHz I2C bus. 
>>>>
>>>> The distribution includes the Invensense driver inv-mpu6050.ko but 
>>>> there is no indication that reading through /dev/i2c invokes it.  This 
>>>> is a very popular IMU and Invensense widely distributes the driver over 
>>>> many Linux platforms.  The driver source includes “successful 
>>>> installation will create two directories under /sys/bus/iio/devices” and 
>>>> lists the files there (aka functions). I can never get these to show up.
>>>>
>>>> I can “insmod 
>>>> /lib/modules/3.8.13/kernel/drivers/iio/imu/inv_mpu6050/inv-mpu6050.ko” and 
>>>> “echo inv-mpu6050 0x68 > /sys/class/i2c-adapter/i2c-1/new_device”. This 
>>>> causes a new directory named 1-0068 to show in 
>>>> /sys/class/i2c-adapter/i2c-1with entries like name and modalias but no 
>>>> functions.  It never shows in /sys/bus/iio/devices.
>>>>
>>>> What constitutes “successful installation”?  
>>>>
>>>> What else is needed to get the inv-mpu6050 to expose functions in 
>>>> /sys/bus/iio/devices like the driver sources says?
>>>>
>>>> Beaglebone Black uses bone_capemgr for exposing driver functions for 
>>>> many devices.  “echo inv-mpu6050 0x68 > 
>>>> /sys/devices/bone_capmgr.9/slots” raises the gripe “write error: no such 
>>>> file or directory”.  (I can successfully load the am33xx_pwm driver 
>>>> this way.) Is this because there is no matching DT fragment in 
>>>> /lib/firmware? Is the inv-mpu6050 driver supposed to be invoked thru cape 
>>>> manager?
>>>> Then, most importantly, if I did read and write through the /sys tree 
>>>> using the Invensense driver would it be faster than /dev/i2c?
>>>> Help on sorting this out would be much appreciated.
>>>>
>>>

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