* Re: [RFC 5/7] iio: inv_mpu6050: Add support for auxiliary I2C master
[not found] ` <4aeaced7c1c8e222996df4c1b4b71e505ab256f7.1461953982.git.leonard.crestez-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
@ 2016-05-01 17:27 ` Jonathan Cameron
2016-05-05 12:38 ` Crestez Dan Leonard
0 siblings, 1 reply; 5+ messages in thread
From: Jonathan Cameron @ 2016-05-01 17:27 UTC (permalink / raw)
To: Crestez Dan Leonard, linux-iio-u79uwXL29TY76Z2rM5mHXA
Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA, Hartmut Knaack,
Lars-Peter Clausen, Peter Meerwald-Stadler, Daniel Baluta, Ge Gao,
Peter Rosin, Linux I2C, Wolfram Sang,
devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Mark Rutland,
Rob Herring, Pawel Moll, Ian Campbell, Kumar Gala
On 29/04/16 20:02, Crestez Dan Leonard wrote:
> The MPU has an auxiliary I2C bus for connecting external
> sensors. This bus has two operating modes:
> * pass-through, which connects the primary and auxiliary busses
> together. This is already supported via an i2c mux.
> * I2C master mode, where the mpu60x0 acts as a master to any external
> connected sensors. This is implemented by this patch.
>
> This I2C master mode also works when the MPU itself is connected via
> SPI.
>
> I2C master supports up to 5 slaves. Slaves 0-3 have a common operating
> mode while slave 4 is different. This patch implements an i2c adapter
> using slave 4 because it has a cleaner interface and it has an
> interrupt that signals when data from slave to master arrived.
>
> Signed-off-by: Crestez Dan Leonard <leonard.crestez-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Quite a few missing cc's here. Device tree bindings => device tree list
and maintainers. Master i2c device => wolfram + linux-i2c.
All these people need to be included in this sort of discussion.
The quirk used to avoid unecessary writes to one of the registers bothers
me in that it's not obviously correct. Perhaps using a read / write pair
would be nicer?
> ---
> .../devicetree/bindings/iio/imu/inv_mpu6050.txt | 61 +++++-
> drivers/iio/imu/inv_mpu6050/inv_mpu_core.c | 239 ++++++++++++++++++++-
> drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h | 46 ++++
> drivers/iio/imu/inv_mpu6050/inv_mpu_trigger.c | 8 -
> 4 files changed, 341 insertions(+), 13 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/iio/imu/inv_mpu6050.txt b/Documentation/devicetree/bindings/iio/imu/inv_mpu6050.txt
> index a9fc11e..aaf12b4 100644
> --- a/Documentation/devicetree/bindings/iio/imu/inv_mpu6050.txt
> +++ b/Documentation/devicetree/bindings/iio/imu/inv_mpu6050.txt
> @@ -1,16 +1,27 @@
> InvenSense MPU-6050 Six-Axis (Gyro + Accelerometer) MEMS MotionTracking Device
>
> -http://www.invensense.com/mems/gyro/mpu6050.html
If this is invalid, please add an up to date link if possible.
> -
> Required properties:
> - - compatible : should be "invensense,mpu6050"
> - - reg : the I2C address of the sensor
> + - compatible : should be "invensense,mpuXXXX"
List them all explicitly here rather than wild cards.
> + - reg : the I2C or SPI address of the sensor
> - interrupt-parent : should be the phandle for the interrupt controller
> - interrupts : interrupt mapping for GPIO IRQ
>
> Optional properties:
> - mount-matrix: an optional 3x3 mounting rotation matrix
> + - inv,i2c-aux-master: operate aux i2c in "master mode" (default is mux).
> +
> +Valid compatible strings:
Vendor prefix? These will work for historical reasons, but now vendor
prefix should definitely be there as well.
> + - mpu6000
> + - mpu6050
> + - mpu6500
> + - mpu9150
> +
> +It is possible to attach auxiliary sensors to the MPU and have them be handled
> +by linux. Those auxiliary sensors are described as an i2c bus.
> +
> +Devices connected in "bypass" mode must be listed behind i2c@0 with the address 0
>
> +Devices connected in "master" mode must be listed behind i2c@1 with the address 1
>
> Example:
> mpu6050@68 {
> @@ -28,3 +39,45 @@ Example:
> "0", /* y2 */
> "0.984807753012208"; /* z2 */
> };
> +
> +Example describing mpu9150 (which includes an ak9875 on chip):
> + mpu9150@68 {
> + compatible = "invensense,mpu9150";
> + reg = <0x68>;
> + interrupt-parent = <&gpio1>;
> + interrupts = <18 1>;
> +
> + #address-cells = <1>;
> + #size-cells = <0>;
> + i2c@0 {
> + reg = <0>;
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + ak8975@0c {
> + compatible = "ak,ak8975";
> + reg = <0x0c>;
> + };
> + };
> + };
> +
> +Example describing a mpu6500 via SPI with an hmc5883l on auxiliary i2c:
> + mpu6500@0 {
> + compatible = "inv,mpu6500";
> + reg = <0x0>;
> + spi-max-frequency = <1000000>;
> + interrupt-parent = <&gpio1>;
> + interrupts = <31 1>;
> +
> + inv,i2c-aux-master
> + i2c@1 {
> + reg = <1>;
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + hmc5883l@1e {
> + compatible = "honeywell,hmc5883l";
> + reg = <0x1e>;
> + };
> + };
> + };
> diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
> index 5918c23..064fc07 100644
> --- a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
> +++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
> @@ -25,6 +25,8 @@
> #include <linux/iio/iio.h>
> #include <linux/i2c-mux.h>
> #include <linux/acpi.h>
> +#include <linux/completion.h>
> +
> #include "inv_mpu_iio.h"
>
> /*
> @@ -57,6 +59,12 @@ static const struct inv_mpu6050_reg_map reg_set_6500 = {
> .int_pin_cfg = INV_MPU6050_REG_INT_PIN_CFG,
> .accl_offset = INV_MPU6500_REG_ACCEL_OFFSET,
> .gyro_offset = INV_MPU6050_REG_GYRO_OFFSET,
> + .slv4_addr = INV_MPU6050_REG_I2C_SLV4_ADDR,
> + .slv4_reg = INV_MPU6050_REG_I2C_SLV4_REG,
> + .slv4_do = INV_MPU6050_REG_I2C_SLV4_DO,
> + .slv4_ctrl = INV_MPU6050_REG_I2C_SLV4_CTRL,
> + .slv4_di = INV_MPU6050_REG_I2C_SLV4_DI,
> + .mst_status = INV_MPU6050_REG_I2C_MST_STATUS,
> };
>
> static const struct inv_mpu6050_reg_map reg_set_6050 = {
> @@ -77,6 +85,12 @@ static const struct inv_mpu6050_reg_map reg_set_6050 = {
> .int_pin_cfg = INV_MPU6050_REG_INT_PIN_CFG,
> .accl_offset = INV_MPU6050_REG_ACCEL_OFFSET,
> .gyro_offset = INV_MPU6050_REG_GYRO_OFFSET,
> + .slv4_addr = INV_MPU6050_REG_I2C_SLV4_ADDR,
> + .slv4_reg = INV_MPU6050_REG_I2C_SLV4_REG,
> + .slv4_do = INV_MPU6050_REG_I2C_SLV4_DO,
> + .slv4_ctrl = INV_MPU6050_REG_I2C_SLV4_CTRL,
> + .slv4_di = INV_MPU6050_REG_I2C_SLV4_DI,
> + .mst_status = INV_MPU6050_REG_I2C_MST_STATUS,
> };
>
> static const struct inv_mpu6050_chip_config chip_config_6050 = {
> @@ -130,6 +144,10 @@ static bool inv_mpu6050_volatile_reg(struct device *dev, unsigned int reg)
> case INV_MPU6050_REG_FIFO_COUNT_H:
> case INV_MPU6050_REG_FIFO_COUNT_H + 1:
> case INV_MPU6050_REG_FIFO_R_W:
> + case INV_MPU6050_REG_I2C_MST_STATUS:
> + case INV_MPU6050_REG_INT_STATUS:
> + case INV_MPU6050_REG_I2C_SLV4_CTRL:
> + case INV_MPU6050_REG_I2C_SLV4_DI:
> return true;
> default:
> return false;
> @@ -140,6 +158,8 @@ static bool inv_mpu6050_precious_reg(struct device *dev, unsigned int reg)
> {
> switch (reg) {
> case INV_MPU6050_REG_FIFO_R_W:
> + case INV_MPU6050_REG_I2C_MST_STATUS:
> + case INV_MPU6050_REG_INT_STATUS:
> return true;
> default:
> return false;
> @@ -852,6 +872,196 @@ static int inv_check_and_setup_chip(struct inv_mpu6050_state *st)
> return 0;
> }
>
> +static irqreturn_t inv_mpu_irq_handler(int irq, void *private)
> +{
> + struct inv_mpu6050_state *st = (struct inv_mpu6050_state *)private;
> +
> + iio_trigger_poll(st->trig);
> +
> + return IRQ_WAKE_THREAD;
> +}
> +
> +static irqreturn_t inv_mpu_irq_thread_handler(int irq, void *private)
> +{
> + struct inv_mpu6050_state *st = (struct inv_mpu6050_state *)private;
> + int ret, val;
> +
> + ret = regmap_read(st->map, st->reg->mst_status, &val);
> + if (ret < 0)
> + return ret;
> +
> +#ifdef CONFIG_I2C
> + if (val & INV_MPU6050_BIT_I2C_SLV4_DONE)
> + complete(&st->slv4_done);
> +#endif
> +
> + return IRQ_HANDLED;
> +}
> +
> +#ifdef CONFIG_I2C
> +static u32 inv_mpu_i2c_functionality(struct i2c_adapter *adap)
> +{
> + return I2C_FUNC_SMBUS_BYTE_DATA;
> +}
> +
> +static int
> +inv_mpu_i2c_smbus_xfer(struct i2c_adapter *adap, u16 addr,
> + unsigned short flags, char read_write, u8 command,
> + int size, union i2c_smbus_data *data)
> +{
> + struct inv_mpu6050_state *st = i2c_get_adapdata(adap);
> + struct iio_dev *indio_dev = iio_priv_to_dev(st);
> +
> + unsigned long time_left;
> + int result, val;
> + u8 ctrl;
> +
> + /*
> + * The i2c adapter we implement is extremely limited.
> + * Check for callers that don't check functionality bits.
> + *
> + * If we don't check we might succesfully return incorrect data.
> + */
> + if (size != I2C_SMBUS_BYTE_DATA) {
> + dev_err(&adap->dev, "unsupported xfer rw=%d size=%d\n",
> + read_write, size);
> + dump_stack();
> + return -EINVAL;
> + }
> +
> + mutex_lock(&indio_dev->mlock);
> + result = inv_mpu6050_set_power_itg(st, true);
> + mutex_unlock(&indio_dev->mlock);
> + if (result < 0)
> + return result;
> +
> + if (read_write == I2C_SMBUS_WRITE)
> + addr |= INV_MPU6050_BIT_I2C_SLV4_W;
> + else
> + addr |= INV_MPU6050_BIT_I2C_SLV4_R;
> +
> + /*
> + * Regmap will never ignore writes but it will ignore full-register
> + * updates to the same value.
Hmm. I'd missed this distinction. Feels decidely 'interesting'... and makes
my earlier suggestion invalid as I guess the fields stuff uses update bits
internally.
> + *
> + * This avoids having to touch slv4_addr when doing consecutive
> + * reads/writes with the same device.
> + */
> + result = regmap_update_bits(st->map, st->reg->slv4_addr, 0xff, addr);
> + if (result < 0)
> + return result;
> +
> + result = regmap_write(st->map, st->reg->slv4_reg, command);
> + if (result < 0)
> + return result;
> +
> + if (read_write == I2C_SMBUS_WRITE) {
> + result = regmap_write(st->map, st->reg->slv4_do, data->byte);
> + if (result < 0)
> + return result;
> + }
> +
> + ctrl = INV_MPU6050_BIT_SLV4_EN | INV_MPU6050_BIT_SLV4_INT_EN;
> + result = regmap_write(st->map, st->reg->slv4_ctrl, ctrl);
> + if (result < 0)
> + return result;
> +
> + /* Wait for completion for both reads and writes */
> + time_left = wait_for_completion_timeout(&st->slv4_done, HZ);
> + if (!time_left)
> + return -ETIMEDOUT;
> +
> + if (read_write == I2C_SMBUS_READ) {
> + result = regmap_read(st->map, st->reg->slv4_di, &val);
> + if (result < 0)
> + return result;
> + data->byte = val;
> + }
> +
> + mutex_lock(&indio_dev->mlock);
> + result = inv_mpu6050_set_power_itg(st, false);
> + mutex_unlock(&indio_dev->mlock);
> + if (result < 0)
> + return result;
> + return 0;
> +}
> +
> +static const struct i2c_algorithm inv_mpu_i2c_algo = {
> + .smbus_xfer = inv_mpu_i2c_smbus_xfer,
> + .functionality = inv_mpu_i2c_functionality,
> +};
> +
> +static struct device_node *inv_mpu_get_aux_i2c_ofnode(struct device_node *parent)
> +{
> + struct device_node *child;
> + int result;
> + u32 reg;
> +
> + if (!parent)
> + return NULL;
> + for_each_child_of_node(parent, child) {
> + result = of_property_read_u32(child, "reg", ®);
> + if (result)
> + continue;
> + if (reg == 1 && !strcmp(child->name, "i2c"))
> + return child;
> + }
> +
> + return NULL;
> +}
> +
> +static int inv_mpu_probe_aux_master(struct iio_dev* indio_dev)
> +{
> + struct inv_mpu6050_state *st = iio_priv(indio_dev);
> + struct device *dev = regmap_get_device(st->map);
> + int result;
> +
> + /* First check i2c-aux-master property */
> + st->i2c_aux_master_mode = of_property_read_bool(dev->of_node,
> + "inv,i2c-aux-master");
> + if (!st->i2c_aux_master_mode)
> + return 0;
> + dev_info(dev, "Configuring aux i2c in master mode\n");
> +
> + result = inv_mpu6050_set_power_itg(st, true);
> + if (result < 0)
> + return result;
> +
> + /* enable master */
> + st->chip_config.user_ctrl |= INV_MPU6050_BIT_I2C_MST_EN;
> + result = regmap_write(st->map, st->reg->user_ctrl, st->chip_config.user_ctrl);
> + if (result < 0)
> + return result;
> +
> + result = regmap_update_bits(st->map, st->reg->int_enable,
> + INV_MPU6050_BIT_MST_INT_EN,
> + INV_MPU6050_BIT_MST_INT_EN);
> + if (result < 0)
> + return result;
> +
> + result = inv_mpu6050_set_power_itg(st, false);
> + if (result < 0)
> + return result;
> +
> + init_completion(&st->slv4_done);
> + st->aux_master_adapter.owner = THIS_MODULE;
> + st->aux_master_adapter.algo = &inv_mpu_i2c_algo;
> + st->aux_master_adapter.dev.parent = dev;
> + snprintf(st->aux_master_adapter.name, sizeof(st->aux_master_adapter.name),
> + "aux-master-%s", indio_dev->name);
> + st->aux_master_adapter.dev.of_node = inv_mpu_get_aux_i2c_ofnode(dev->of_node);
> + i2c_set_adapdata(&st->aux_master_adapter, st);
> + /* This will also probe aux devices so transfers must work now */
> + result = i2c_add_adapter(&st->aux_master_adapter);
> + if (result < 0) {
> + dev_err(dev, "i2x aux master register fail %d\n", result);
> + return result;
> + }
> +
> + return 0;
> +}
> +#endif
> +
> int inv_mpu_core_probe(struct regmap *regmap, int irq, const char *name,
> int (*inv_mpu_bus_setup)(struct iio_dev *), int chip_type)
> {
> @@ -931,16 +1141,39 @@ int inv_mpu_core_probe(struct regmap *regmap, int irq, const char *name,
> goto out_unreg_ring;
> }
>
> + /* Request interrupt for trigger and i2c master adapter */
> + result = devm_request_threaded_irq(&indio_dev->dev, st->irq,
> + &inv_mpu_irq_handler,
> + &inv_mpu_irq_thread_handler,
> + IRQF_TRIGGER_RISING, "inv_mpu",
> + st);
> + if (result) {
> + dev_err(dev, "request irq fail %d\n", result);
> + goto out_remove_trigger;
> + }
> +
> +#ifdef CONFIG_I2C
> + result = inv_mpu_probe_aux_master(indio_dev);
> + if (result < 0) {
> + dev_err(dev, "i2c aux master probe fail %d\n", result);
> + goto out_remove_trigger;
> + }
> +#endif
> +
> INIT_KFIFO(st->timestamps);
> spin_lock_init(&st->time_stamp_lock);
> result = iio_device_register(indio_dev);
> if (result) {
> dev_err(dev, "IIO register fail %d\n", result);
> - goto out_remove_trigger;
> + goto out_del_adapter;
> }
>
> return 0;
>
> +out_del_adapter:
> +#ifdef CONFIG_I2C
> + i2c_del_adapter(&st->aux_master_adapter);
> +#endif
> out_remove_trigger:
> inv_mpu6050_remove_trigger(st);
> out_unreg_ring:
> @@ -952,10 +1185,14 @@ EXPORT_SYMBOL_GPL(inv_mpu_core_probe);
> int inv_mpu_core_remove(struct device *dev)
> {
> struct iio_dev *indio_dev = dev_get_drvdata(dev);
> + struct inv_mpu6050_state *st = iio_priv(indio_dev);
>
> iio_device_unregister(indio_dev);
> inv_mpu6050_remove_trigger(iio_priv(indio_dev));
> iio_triggered_buffer_cleanup(indio_dev);
> +#ifdef CONFIG_I2C
> + i2c_del_adapter(&st->aux_master_adapter);
> +#endif
>
> return 0;
> }
> diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h b/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
> index bd2c0fd..9d15633 100644
> --- a/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
> +++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
> @@ -42,6 +42,13 @@
> * @int_pin_cfg; Controls interrupt pin configuration.
> * @accl_offset: Controls the accelerometer calibration offset.
> * @gyro_offset: Controls the gyroscope calibration offset.
> + * @mst_status: secondary I2C master interrupt source status
> + * @slv4_addr: I2C slave address for slave 4 transaction
> + * @slv4_reg: I2C register used with slave 4 transaction
> + * @slv4_di: I2C data in register for slave 4 transaction
> + * @slv4_ctrl: I2C slave 4 control register
> + * @slv4_do: I2C data out register for slave 4 transaction
> +
> */
> struct inv_mpu6050_reg_map {
> u8 sample_rate_div;
> @@ -61,6 +68,15 @@ struct inv_mpu6050_reg_map {
> u8 int_pin_cfg;
> u8 accl_offset;
> u8 gyro_offset;
> + u8 mst_status;
> +
> + /* slave 4 registers */
> + u8 slv4_addr;
> + u8 slv4_reg;
> + u8 slv4_di; /* data in */
> + u8 slv4_ctrl;
> + u8 slv4_do; /* data out */
> +
> };
>
> /*device enum */
> @@ -139,6 +155,15 @@ struct inv_mpu6050_state {
> DECLARE_KFIFO(timestamps, long long, TIMESTAMP_FIFO_SIZE);
> struct regmap *map;
> int irq;
> +
> + /* if the MPU connects to aux devices as a master */
> + bool i2c_aux_master_mode;
> +
> +#ifdef CONFIG_I2C
> + /* I2C adapter for talking to aux sensors in "master" mode */
> + struct i2c_adapter aux_master_adapter;
> + struct completion slv4_done;
> +#endif
> };
>
> /*register and associated bit definition*/
> @@ -154,9 +179,30 @@ struct inv_mpu6050_state {
> #define INV_MPU6050_BIT_ACCEL_OUT 0x08
> #define INV_MPU6050_BITS_GYRO_OUT 0x70
>
> +#define INV_MPU6050_REG_I2C_SLV4_ADDR 0x31
> +#define INV_MPU6050_BIT_I2C_SLV4_R 0x80
> +#define INV_MPU6050_BIT_I2C_SLV4_W 0x00
> +
> +#define INV_MPU6050_REG_I2C_SLV4_REG 0x32
> +#define INV_MPU6050_REG_I2C_SLV4_DO 0x33
> +#define INV_MPU6050_REG_I2C_SLV4_CTRL 0x34
> +
> +#define INV_MPU6050_BIT_SLV4_EN 0x80
> +#define INV_MPU6050_BIT_SLV4_INT_EN 0x40
> +#define INV_MPU6050_BIT_SLV4_DIS 0x20
> +
> +#define INV_MPU6050_REG_I2C_SLV4_DI 0x35
> +
> +#define INV_MPU6050_REG_I2C_MST_STATUS 0x36
> +#define INV_MPU6050_BIT_I2C_SLV4_DONE 0x40
> +
> #define INV_MPU6050_REG_INT_ENABLE 0x38
> #define INV_MPU6050_BIT_DATA_RDY_EN 0x01
> #define INV_MPU6050_BIT_DMP_INT_EN 0x02
> +#define INV_MPU6050_BIT_MST_INT_EN 0x08
> +
> +#define INV_MPU6050_REG_INT_STATUS 0x3A
> +#define INV_MPU6050_BIT_MST_INT 0x08
>
> #define INV_MPU6050_REG_RAW_ACCEL 0x3B
> #define INV_MPU6050_REG_TEMPERATURE 0x41
> diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_trigger.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_trigger.c
> index fc55923..a334ed9 100644
> --- a/drivers/iio/imu/inv_mpu6050/inv_mpu_trigger.c
> +++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_trigger.c
> @@ -126,14 +126,6 @@ int inv_mpu6050_probe_trigger(struct iio_dev *indio_dev)
> if (!st->trig)
> return -ENOMEM;
>
> - ret = devm_request_irq(&indio_dev->dev, st->irq,
> - &iio_trigger_generic_data_rdy_poll,
> - IRQF_TRIGGER_RISING,
> - "inv_mpu",
> - st->trig);
> - if (ret)
> - return ret;
> -
> st->trig->dev.parent = regmap_get_device(st->map);
> st->trig->ops = &inv_mpu_trigger_ops;
> iio_trigger_set_drvdata(st->trig, indio_dev);
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [RFC 7/7] iio: inv_mpu6050: Add support for external sensors
[not found] ` <c2631025b2405ad01c92964ed185d73647593f17.1461953982.git.leonard.crestez@intel.com>
@ 2016-05-01 17:54 ` Jonathan Cameron
2016-05-02 12:15 ` Rob Herring
0 siblings, 1 reply; 5+ messages in thread
From: Jonathan Cameron @ 2016-05-01 17:54 UTC (permalink / raw)
To: Crestez Dan Leonard, linux-iio@vger.kernel.org
Cc: linux-kernel, Hartmut Knaack, Lars-Peter Clausen,
Peter Meerwald-Stadler, Daniel Baluta, Ge Gao,
devicetree@vger.kernel.org, Mark Rutland, Rob Herring, Pawel Moll,
Ian Campbell, Kumar Gala, Linux I2C, Wolfram Sang, Peter Rosin
On 29/04/16 20:02, Crestez Dan Leonard wrote:
> This works by copying their channels at probe time.
>
> Signed-off-by: Crestez Dan Leonard <leonard.crestez@intel.com>
This is some mixture of deeply nefarious and rather cool.
Great bit of work all in all.
Cc'd device tree list and maintainers - to them - this is downright mad
hardware - basically a partial i2c offload engine sitting on either i2c or
spi buses with lots of iritating restrictions but useful stuff like a fifo
between it and the rest of the world - upshot it's much much faster than
actually addressing these devices directly...
First time I read the datasheet for this part - I thought no one would ever
figure out / go to the effort of supporting this functionality. Turns
out I was wrong!
It is the only part I know of allowing this level of flexibility as a sensor
hub. Most sensor hubs hide entirely what is going on behind them whereas this
one exposes what is going on...
Also cc'd the i2c list / Peter, Wolfram and Mark (just because they might be
interested!)
Jonathan
> ---
> .../devicetree/bindings/iio/imu/inv_mpu6050.txt | 37 +-
> drivers/iio/imu/inv_mpu6050/inv_mpu_core.c | 420 ++++++++++++++++++++-
> drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h | 63 +++-
> drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c | 48 ++-
> 4 files changed, 555 insertions(+), 13 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/iio/imu/inv_mpu6050.txt b/Documentation/devicetree/bindings/iio/imu/inv_mpu6050.txt
> index aaf12b4..79b8326 100644
> --- a/Documentation/devicetree/bindings/iio/imu/inv_mpu6050.txt
> +++ b/Documentation/devicetree/bindings/iio/imu/inv_mpu6050.txt
> @@ -23,6 +23,28 @@ Devices connected in "bypass" mode must be listed behind i2c@0 with the address
>
> Devices connected in "master" mode must be listed behind i2c@1 with the address 1
>
> +It is possible to configure the MPU to automatically fetch reading for
> +devices connected on the auxiliary i2c bus without CPU intervention. When this
> +is done the driver will present the channels of the slaved devices as if they
> +belong to the MPU device itself.
> +
> +Reads and write to config values (like scaling factors) are forwarded to the
> +other driver while data reads are handled from MPU registers. The channels are
> +also available through the MPU's iio triggered buffer mechanism. This feature
> +can allow sampling up to 24 bytes from 4 slaves at a much higher rate.
> +
> +This is be specified in device tree as an "inv,external-sensors" node which
> +have children indexed by slave ids 0 to 3. The child node identifying each
> +external sensor reading has the following properties:
> + - reg: 0 to 3 slave index
> + - inv,addr : the I2C address to read from
> + - inv,reg : the I2C register to read from
> + - inv,len : read length from the device
> + - inv,external-channels : list of slaved channels specified by config index.
I wonder if we want to try and make these generic - probably not until we have
at least one more device doing something similar...
> +
> +The sum of storagebits for external channels must equal the read length. Only
> +16bit channels are currently supported.
> +
> Example:
> mpu6050@68 {
> compatible = "invensense,mpu6050";
> @@ -61,7 +83,8 @@ Example describing mpu9150 (which includes an ak9875 on chip):
> };
> };
>
> -Example describing a mpu6500 via SPI with an hmc5883l on auxiliary i2c:
> +Example describing a mpu6500 via SPI with an hmc5883l on aux i2c configured for
> +automatic external readings as slave 0:
> mpu6500@0 {
> compatible = "inv,mpu6500";
> reg = <0x0>;
> @@ -80,4 +103,16 @@ Example describing a mpu6500 via SPI with an hmc5883l on auxiliary i2c:
> reg = <0x1e>;
> };
> };
> +
> + inv,external-sensors {
> + #address-cells = <1>;
> + #size-cells = <0>;
> + hmc5833l@0 {
> + reg = <0>;
> + inv,addr = <0x1e>;
> + inv,reg = <3>;
> + inv,len = <6>;
> + inv,external-channels = <0 1 2>;
> + };
> + };
> };
> diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
> index 712e901..224be3c 100644
> --- a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
> +++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
> @@ -41,6 +41,8 @@ static const int gyro_scale_6050[] = {133090, 266181, 532362, 1064724};
> */
> static const int accel_scale[] = {598, 1196, 2392, 4785};
>
> +#define INV_MPU6050_NUM_INT_CHAN 8
> +
> static const struct inv_mpu6050_reg_map reg_set_6500 = {
> .sample_rate_div = INV_MPU6050_REG_SAMPLE_RATE_DIV,
> .lpf = INV_MPU6050_REG_CONFIG,
> @@ -136,6 +138,9 @@ static bool inv_mpu6050_volatile_reg(struct device *dev, unsigned int reg)
> return true;
> if (reg >= INV_MPU6050_REG_RAW_GYRO && reg < INV_MPU6050_REG_RAW_GYRO + 6)
> return true;
> + if (reg < INV_MPU6050_REG_EXT_SENS_DATA_00 + INV_MPU6050_CNT_EXT_SENS_DATA &&
> + reg >= INV_MPU6050_REG_EXT_SENS_DATA_00)
> + return true;
> switch (reg) {
> case INV_MPU6050_REG_TEMPERATURE:
> case INV_MPU6050_REG_TEMPERATURE + 1:
> @@ -340,13 +345,115 @@ static int inv_mpu6050_sensor_show(struct inv_mpu6050_state *st, int reg,
> return IIO_VAL_INT;
> }
>
> +static bool iio_chan_needs_swab(const struct iio_chan_spec *chan)
> +{
> +#if defined(__LITTLE_ENDIAN)
> + return chan->scan_type.endianness == IIO_BE;
> +#elif defined(__BIG_ENDIAN)
> + return chan->scan_type.endianness == IIO_LE;
> +#else
> + #error undefined endianness
> +#endif
> +}
> +
> +/* Convert iio buffer format to IIO_CHAN_INFO_RAW value */
> +static int iio_bufval_to_rawval(const struct iio_chan_spec *chan, void *buf, int *val)
> +{
> + switch (chan->scan_type.storagebits) {
> + case 8: *val = *((u8*)buf); break;
> + case 16: *val = *(u16*)buf; break;
> + case 32: *val = *(u32*)buf; break;
> + default: return -EINVAL;
> + }
> +
> + *val >>= chan->scan_type.shift;
> + *val &= (1 << chan->scan_type.realbits) - 1;
> + if (iio_chan_needs_swab(chan)) {
> + if (chan->scan_type.storagebits == 16)
> + *val = swab16(*val);
> + else if (chan->scan_type.storagebits == 32)
> + *val = swab32(*val);
This needs some explanatory comments!
> + }
> + if (chan->scan_type.sign == 's')
> + *val = sign_extend32(*val, chan->scan_type.storagebits - 1);
> +
> + return 0;
> +}
> +
> +static int
> +inv_mpu6050_read_raw_external(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan,
> + int *val, int *val2, long mask)
> +{
> + int result;
> + struct inv_mpu6050_state *st = iio_priv(indio_dev);
> + int chan_index = chan - indio_dev->channels;
> + struct inv_mpu6050_ext_chan_state *ext_chan_state =
> + &st->ext_chan[chan_index - INV_MPU6050_NUM_INT_CHAN];
> + struct inv_mpu6050_ext_sens_state *ext_sens_state =
> + &st->ext_sens[ext_chan_state->ext_sens_index];
> + struct iio_dev *orig_dev = ext_sens_state->orig_dev;
> + const struct iio_chan_spec *orig_chan = &orig_dev->channels[ext_chan_state->orig_chan_index];
> + int data_offset;
> + int data_length;
> + u8 buf[4];
> +
> + /* Everything but raw data reads is forwarded. */
> + if (mask != IIO_CHAN_INFO_RAW)
> + return orig_dev->info->read_raw(orig_dev, orig_chan, val, val2, mask);
Obviously this is useful for testing, but on a polled interface do we actually
care that it is quicker to go directly? I'd be tempted to not bother except
for the buffered mode.
> +
> + /* Raw reads are handled directly. */
> + data_offset = INV_MPU6050_REG_EXT_SENS_DATA_00 + ext_chan_state->data_offset;
> + data_length = chan->scan_type.storagebits / 8;
> + if (data_length > sizeof(buf)) {
> + return -EINVAL;
> + }
> +
> + mutex_lock(&indio_dev->mlock);
> + if (!st->chip_config.enable) {
> + result = inv_mpu6050_set_power_itg(st, true);
> + if (result)
> + goto error_unlock;
> + }
> + result = regmap_bulk_read(st->map, data_offset, buf, data_length);
> + if (result)
> + goto error_unpower;
> + if (!st->chip_config.enable) {
> + result = inv_mpu6050_set_power_itg(st, false);
> + if (result)
> + goto error_unlock;
> + }
> + mutex_unlock(&indio_dev->mlock);
> +
> + /* Convert buf to val and return success */
> + result = iio_bufval_to_rawval(chan, buf, val);
> + if (result)
> + return result;
> + return IIO_VAL_INT;
> +
> +error_unpower:
> + if (!st->chip_config.enable)
> + inv_mpu6050_set_power_itg(st, false);
> +error_unlock:
> + mutex_unlock(&indio_dev->mlock);
> + return result;
> +}
> +
> static int
> inv_mpu6050_read_raw(struct iio_dev *indio_dev,
> struct iio_chan_spec const *chan,
> int *val, int *val2, long mask)
> {
> - struct inv_mpu6050_state *st = iio_priv(indio_dev);
> + struct inv_mpu6050_state *st = iio_priv(indio_dev);
> int ret = 0;
> + int chan_index;
> +
> + if (chan < indio_dev->channels || chan > indio_dev->channels + indio_dev->num_channels) {
> + return -EINVAL;
> + }
> + chan_index = chan - indio_dev->channels;
> + if (chan_index >= INV_MPU6050_NUM_INT_CHAN)
> + return inv_mpu6050_read_raw_external(indio_dev, chan, val, val2, mask);
>
> switch (mask) {
> case IIO_CHAN_INFO_RAW:
> @@ -819,6 +926,309 @@ static const struct iio_info mpu_info = {
> .validate_trigger = inv_mpu6050_validate_trigger,
> };
>
> +extern struct device_type iio_device_type;
> +
> +static int iio_device_from_i2c_client_match(struct device *dev, void *data)
> +{
> + return dev->type == &iio_device_type;
> +}
> +
> +static struct iio_dev* iio_device_from_i2c_client(struct i2c_client* i2c)
> +{
> + struct device *child;
> +
> + child = device_find_child(&i2c->dev, NULL, iio_device_from_i2c_client_match);
> +
> + return (child ? dev_to_iio_dev(child) : NULL);
> +}
> +
> +static int inv_mpu_set_external_reads_enabled(struct inv_mpu6050_state *st, bool en)
> +{
> + int i, result, error = 0;
> +
> + /* Even if there are errors try to disable all slaves. */
> + for (i = 0; i < INV_MPU6050_MAX_EXT_SENSORS; ++i) {
> + result = regmap_update_bits(st->map, INV_MPU6050_REG_I2C_SLV_CTRL(i),
> + INV_MPU6050_BIT_I2C_SLV_EN,
> + en ? INV_MPU6050_BIT_I2C_SLV_EN : 0);
> + if (result) {
> + error = result;
> + }
> + }
> +
> + return error;
> +}
> +
> +static int inv_mpu_parse_one_ext_sens(struct device *dev,
> + struct device_node *np,
> + struct inv_mpu6050_ext_sens_spec *spec)
> +{
> + int result;
> + u32 addr, reg, len;
> +
> + result = of_property_read_u32(np, "inv,addr", &addr);
> + if (result)
> + return result;
> + result = of_property_read_u32(np, "inv,reg", ®);
> + if (result)
> + return result;
> + result = of_property_read_u32(np, "inv,len", &len);
> + if (result)
> + return result;
> +
> + spec->addr = addr;
> + spec->reg = reg;
> + spec->len = len;
> +
> + result = of_property_count_u32_elems(np, "inv,external-channels");
> + if (result < 0)
> + return result;
> + spec->num_ext_channels = result;
> + spec->ext_channels = devm_kmalloc(dev, spec->num_ext_channels * sizeof(*spec->ext_channels), GFP_KERNEL);
> + if (!spec->ext_channels)
> + return -ENOMEM;
> + result = of_property_read_u32_array(np, "inv,external-channels",
> + spec->ext_channels,
> + spec->num_ext_channels);
> + if (result)
> + return result;
> +
> + return 0;
> +}
> +
> +static int inv_mpu_parse_ext_sens(struct device *dev,
> + struct device_node *node,
> + struct inv_mpu6050_ext_sens_spec *specs)
> +{
> + struct device_node *child;
> + int result;
> + u32 reg;
> +
> + for_each_available_child_of_node(node, child) {
> + result = of_property_read_u32(child, "reg", ®);
> + if (result)
> + return result;
> + if (reg > INV_MPU6050_MAX_EXT_SENSORS) {
> + dev_err(dev, "External sensor index %u out of range, max %d\n",
> + reg, INV_MPU6050_MAX_EXT_SENSORS);
> + return -EINVAL;
> + }
> + result = inv_mpu_parse_one_ext_sens(dev, child, &specs[reg]);
> + if (result)
> + return result;
> + }
> +
> + return 0;
> +}
> +
> +static int inv_mpu_get_ext_sens_spec(struct iio_dev *indio_dev)
> +{
> + struct inv_mpu6050_state *st = iio_priv(indio_dev);
> + struct device *dev = regmap_get_device(st->map);
> + struct device_node *node;
> + int result;
> +
> + node = of_get_child_by_name(dev->of_node, "inv,external-sensors");
> + if (node) {
> + result = inv_mpu_parse_ext_sens(dev, node, st->ext_sens_spec);
> + if (result)
> + dev_err(dev, "Failed to parsing external-sensors devicetree data\n");
> + return result;
> + }
> +
> + /* Maybe some other way to deal with this? */
Probably not ;)
> +
> + return 0;
> +}
> +
> +/* Struct used while enumerating devices and matching them */
> +struct inv_mpu_handle_ext_sensor_fnarg
> +{
> + struct iio_dev *indio_dev;
> +
> + /* Next scan index */
> + int scan_index;
> + /* Index among external channels */
> + int chan_index;
> + /* Offset in EXTDATA */
> + int data_offset;
> + struct iio_chan_spec *channels;
> +};
> +
> +static int inv_mpu_config_external_read(struct inv_mpu6050_state *st, int index,
> + const struct inv_mpu6050_ext_sens_spec *spec)
> +{
> + int result;
> +
> + result = regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_ADDR(index),
> + INV_MPU6050_BIT_I2C_SLV_RW | spec->addr);
> + if (result)
> + return result;
> + result = regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_REG(index), spec->reg);
> + if (result)
> + return result;
> + result = regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_CTRL(index),
> + INV_MPU6050_BIT_I2C_SLV_EN | spec->len);
> +
> + return result;
> +}
> +
> +static int inv_mpu_handle_ext_sensor_fn(struct device *dev, void *data)
> +{
> + struct inv_mpu_handle_ext_sensor_fnarg *fnarg = data;
> + struct iio_dev *indio_dev = fnarg->indio_dev;
> + struct inv_mpu6050_state *st = iio_priv(indio_dev);
> + struct device *mydev = regmap_get_device(st->map);
> + struct i2c_client *client;
> + struct iio_dev *orig_dev;
> + int i, j;
> +
> + client = i2c_verify_client(dev);
> + if (!client)
> + return 0;
> + orig_dev = iio_device_from_i2c_client(client);
> + if (!orig_dev)
> + return 0;
> + for (i = 0; i < INV_MPU6050_MAX_EXT_SENSORS; ++i) {
> + int start_data_offset;
> + struct inv_mpu6050_ext_sens_spec *ext_sens_spec = &st->ext_sens_spec[i];
> + struct inv_mpu6050_ext_sens_state *ext_sens_state = &st->ext_sens[i];
> +
> + if (ext_sens_spec->addr != client->addr)
> + continue;
> + if (ext_sens_state->orig_dev) {
> + dev_warn(&indio_dev->dev, "already found slave with at addr %d\n", client->addr);
> + continue;
> + }
> + dev_info(mydev, "external sensor %d is device %s\n",
> + i, orig_dev->name ?: dev_name(&orig_dev->dev));
> + ext_sens_state->orig_dev = orig_dev;
> + ext_sens_state->scan_mask = 0;
> + ext_sens_state->data_len = ext_sens_spec->len;
> + start_data_offset = fnarg->data_offset;
> +
> + /* Matched the device (by address). Now process channels: */
> + for (j = 0; j < ext_sens_spec->num_ext_channels; ++j) {
> + int orig_chan_index;
> + const struct iio_chan_spec *orig_chan_spec;
> + struct iio_chan_spec *chan_spec;
> + struct inv_mpu6050_ext_chan_state *chan_state;
> +
> + orig_chan_index = ext_sens_spec->ext_channels[j];
> + orig_chan_spec = &orig_dev->channels[orig_chan_index];
> + chan_spec = &fnarg->channels[INV_MPU6050_NUM_INT_CHAN + fnarg->chan_index];
> + chan_state = &st->ext_chan[fnarg->chan_index];
> +
> + chan_state->ext_sens_index = i;
> + chan_state->orig_chan_index = orig_chan_index;
> + chan_state->data_offset = fnarg->data_offset;
> + memcpy(chan_spec, orig_chan_spec, sizeof(struct iio_chan_spec));
> + chan_spec->scan_index = fnarg->scan_index;
> + ext_sens_state->scan_mask |= (1 << chan_spec->scan_index);
> + if (orig_chan_spec->scan_type.storagebits != 16) {
> + /*
> + * Supporting other channels sizes would require data read from the
> + * hardware fifo to comply with iio alignment.
> + */
Or a demux/mux before iio_push_to_buffers.
> + dev_err(&indio_dev->dev, "All external channels must have 16 storage bits\n");
> + return -EINVAL;
> + }
> +
> + fnarg->scan_index++;
> + fnarg->chan_index++;
> + fnarg->data_offset += chan_spec->scan_type.storagebits / 8;
> + dev_info(mydev, "Reading external channel #%d scan_index %d data_offset %d"
> + " from original device %s chan #%d scan_index %d\n",
> + fnarg->chan_index, chan_spec->scan_index, chan_state->data_offset,
> + orig_dev->name ?: dev_name(&orig_dev->dev), orig_chan_index, orig_chan_spec->scan_index);
> + }
> + if (start_data_offset + ext_sens_spec->len != fnarg->data_offset) {
> + dev_warn(mydev, "length mismatch between i2c slave read length and slave channel spec\n");
> + return -EINVAL;
> + }
> +
> + return inv_mpu_config_external_read(st, i, ext_sens_spec);
> + }
> + return 0;
> +}
> +
> +static int inv_mpu6050_handle_ext_sensors(struct iio_dev *indio_dev)
> +{
> + struct inv_mpu6050_state *st = iio_priv(indio_dev);
> + struct device *dev = regmap_get_device(st->map);
> + struct inv_mpu_handle_ext_sensor_fnarg fnarg = {
> + .indio_dev = indio_dev,
> + .chan_index = 0,
> + .data_offset = 0,
> + .scan_index = INV_MPU6050_SCAN_TIMESTAMP,
> + };
> + int i, result;
> + int num_ext_chan = 0, sum_data_len = 0;
> +
> + inv_mpu_get_ext_sens_spec(indio_dev);
> + for (i = 0; i < INV_MPU6050_MAX_EXT_SENSORS; ++i) {
> + num_ext_chan += st->ext_sens_spec[i].num_ext_channels;
> + sum_data_len += st->ext_sens_spec[i].len;
> + }
> + if (sum_data_len > INV_MPU6050_CNT_EXT_SENS_DATA) {
> + dev_err(dev, "Too many bytes from external sensors:"
> + " requested=%d max=%d\n",
> + sum_data_len, INV_MPU6050_CNT_EXT_SENS_DATA);
> + return -EINVAL;
> + }
> +
> + /* Zero length means nothing to do */
> + if (!sum_data_len) {
> + indio_dev->channels = inv_mpu_channels;
> + indio_dev->num_channels = INV_MPU6050_NUM_INT_CHAN;
> + BUILD_BUG_ON(ARRAY_SIZE(inv_mpu_channels) != INV_MPU6050_NUM_INT_CHAN);
> + return 0;
> + }
> +
> + fnarg.channels = devm_kmalloc(indio_dev->dev.parent,
> + (num_ext_chan + INV_MPU6050_NUM_INT_CHAN) *
> + sizeof(struct iio_chan_spec),
> + GFP_KERNEL);
> + if (!fnarg.channels)
> + return -ENOMEM;
> + memcpy(fnarg.channels, inv_mpu_channels, sizeof(inv_mpu_channels));
> + memset(fnarg.channels + INV_MPU6050_NUM_INT_CHAN, 0,
> + num_ext_chan * sizeof(struct iio_chan_spec));
> +
> + st->ext_chan = devm_kzalloc(indio_dev->dev.parent,
> + (num_ext_chan) * sizeof(*st->ext_chan),
> + GFP_KERNEL);
> + if (!st->ext_chan)
> + return -ENOMEM;
> +
> + result = inv_mpu6050_set_power_itg(st, true);
> + if (result < 0)
> + return result;
> +
> + result = device_for_each_child(&st->aux_master_adapter.dev, &fnarg,
> + inv_mpu_handle_ext_sensor_fn);
> + if (result)
> + goto out_disable;
> + /* Timestamp channel has index 0 and last scan_index */
> + fnarg.channels[0].scan_index = fnarg.scan_index;
> +
> + if (fnarg.chan_index != num_ext_chan) {
> + dev_err(&indio_dev->dev, "Failed to match all external channels!\n");
> + result = -EINVAL;
> + goto out_disable;
> + }
> +
> + result = inv_mpu6050_set_power_itg(st, false);
> + indio_dev->channels = fnarg.channels;
> + indio_dev->num_channels = INV_MPU6050_NUM_INT_CHAN + num_ext_chan;
> + return result;
> +
> +out_disable:
> + inv_mpu6050_set_power_itg(st, false);
> + inv_mpu_set_external_reads_enabled(st, false);
> + return result;
> +}
> +
> /**
> * inv_check_and_setup_chip() - check and setup chip.
> */
> @@ -1121,8 +1531,6 @@ int inv_mpu_core_probe(struct regmap *regmap, int irq, const char *name,
> indio_dev->name = name;
> else
> indio_dev->name = dev_name(dev);
> - indio_dev->channels = inv_mpu_channels;
> - indio_dev->num_channels = ARRAY_SIZE(inv_mpu_channels);
>
> indio_dev->info = &mpu_info;
> indio_dev->modes = INDIO_BUFFER_TRIGGERED;
> @@ -1160,6 +1568,12 @@ int inv_mpu_core_probe(struct regmap *regmap, int irq, const char *name,
> }
> #endif
>
> + result = inv_mpu6050_handle_ext_sensors(indio_dev);
> + if (result < 0) {
> + dev_err(dev, "failed to configure channels %d\n", result);
> + goto out_remove_trigger;
> + }
> +
> INIT_KFIFO(st->timestamps);
> spin_lock_init(&st->time_stamp_lock);
> result = iio_device_register(indio_dev);
> diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h b/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
> index 9d406df..007fe75 100644
> --- a/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
> +++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
> @@ -124,6 +124,40 @@ struct inv_mpu6050_hw {
> const struct inv_mpu6050_chip_config *config;
> };
>
> +#define INV_MPU6050_MAX_EXT_SENSORS 4
> +
> +/* Specification for an external sensor */
> +struct inv_mpu6050_ext_sens_spec {
> + unsigned short addr;
> + u8 reg, len;
> +
> + int num_ext_channels;
> + int *ext_channels;
> +};
> +
> +/* Driver state for each external sensor */
> +struct inv_mpu6050_ext_sens_state {
> + struct iio_dev *orig_dev;
> +
> + /* Mask of all channels in this sensor */
> + unsigned long scan_mask;
> +
> + /* Length of reading. */
> + int data_len;
> +};
> +
> +/* Driver state for each external channel */
> +struct inv_mpu6050_ext_chan_state {
> + /* Index inside state->ext_sens */
> + int ext_sens_index;
> +
> + /* Index inside orig_dev->channels */
> + int orig_chan_index;
> +
> + /* Relative to EXT_SENS_DATA_00 */
> + int data_offset;
> +};
> +
> /*
> * struct inv_mpu6050_state - Driver state variables.
> * @TIMESTAMP_FIFO_SIZE: fifo size for timestamp.
> @@ -164,6 +198,10 @@ struct inv_mpu6050_state {
> struct i2c_adapter aux_master_adapter;
> struct completion slv4_done;
> #endif
> +
> + struct inv_mpu6050_ext_sens_spec ext_sens_spec[INV_MPU6050_MAX_EXT_SENSORS];
> + struct inv_mpu6050_ext_sens_state ext_sens[INV_MPU6050_MAX_EXT_SENSORS];
> + struct inv_mpu6050_ext_chan_state *ext_chan;
> };
>
> /*register and associated bit definition*/
> @@ -178,6 +216,24 @@ struct inv_mpu6050_state {
> #define INV_MPU6050_REG_FIFO_EN 0x23
> #define INV_MPU6050_BIT_ACCEL_OUT 0x08
> #define INV_MPU6050_BITS_GYRO_OUT 0x70
> +#define INV_MPU6050_BIT_SLV0_FIFO_EN 0x01
> +#define INV_MPU6050_BIT_SLV1_FIFO_EN 0x02
> +#define INV_MPU6050_BIT_SLV2_FIFO_EN 0x04
> +#define INV_MPU6050_BIT_SLV2_FIFO_EN 0x04
> +
> +/* SLV3 fifo enabling is not in REG_FIFO_EN */
> +#define INV_MPU6050_REG_MST_CTRL 0x24
> +#define INV_MPU6050_BIT_SLV3_FIFO_EN 0x10
> +
> +/* For slaves 0-3 */
> +#define INV_MPU6050_REG_I2C_SLV_ADDR(i) (0x25 + 3 * (i))
> +#define INV_MPU6050_REG_I2C_SLV_REG(i) (0x26 + 3 * (i))
> +#define INV_MPU6050_REG_I2C_SLV_CTRL(i) (0x27 + 3 * (i))
> +#define INV_MPU6050_BIT_I2C_SLV_RW 0x80
> +#define INV_MPU6050_BIT_I2C_SLV_EN 0x80
> +#define INV_MPU6050_BIT_I2C_SLV_BYTE_SW 0x40
> +#define INV_MPU6050_BIT_I2C_SLV_REG_DIS 0x20
> +#define INV_MPU6050_BIT_I2C_SLV_REG_GRP 0x10
>
> #define INV_MPU6050_REG_I2C_SLV4_ADDR 0x31
> #define INV_MPU6050_BIT_I2C_SLV4_R 0x80
> @@ -252,8 +308,8 @@ struct inv_mpu6050_state {
> #define INV_MPU6050_GYRO_CONFIG_FSR_SHIFT 3
> #define INV_MPU6050_ACCL_CONFIG_FSR_SHIFT 3
>
> -/* 6 + 6 round up and plus 8 */
> -#define INV_MPU6050_OUTPUT_DATA_SIZE 24
> +/* max is 3*2 accel + 3*2 gyro + 24 external + 8 ts */
> +#define INV_MPU6050_OUTPUT_DATA_SIZE 44
>
> #define INV_MPU6050_REG_INT_PIN_CFG 0x37
> #define INV_MPU6050_BIT_BYPASS_EN 0x2
> @@ -266,6 +322,9 @@ struct inv_mpu6050_state {
> #define INV_MPU6050_MIN_FIFO_RATE 4
> #define INV_MPU6050_ONE_K_HZ 1000
>
> +#define INV_MPU6050_REG_EXT_SENS_DATA_00 0x49
> +#define INV_MPU6050_CNT_EXT_SENS_DATA 24
> +
> #define INV_MPU6050_REG_WHOAMI 117
>
> #define INV_MPU6000_WHOAMI_VALUE 0x68
> diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c
> index e8bda7f..8fa5c3d 100644
> --- a/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c
> +++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c
> @@ -52,6 +52,10 @@ int inv_reset_fifo(struct iio_dev *indio_dev)
> result = regmap_write(st->map, st->reg->fifo_en, 0);
> if (result)
> goto reset_fifo_fail;
> + result = regmap_update_bits(st->map, INV_MPU6050_REG_MST_CTRL,
> + INV_MPU6050_BIT_SLV3_FIFO_EN, 0);
> + if (result)
> + goto reset_fifo_fail;
> /* disable fifo reading */
> st->chip_config.user_ctrl &= ~INV_MPU6050_BIT_FIFO_EN;
> result = regmap_write(st->map, st->reg->user_ctrl,
> @@ -70,7 +74,8 @@ int inv_reset_fifo(struct iio_dev *indio_dev)
>
> /* enable interrupt */
> if (st->chip_config.accl_fifo_enable ||
> - st->chip_config.gyro_fifo_enable) {
> + st->chip_config.gyro_fifo_enable ||
> + true) {
> result = regmap_update_bits(st->map, st->reg->int_enable,
> INV_MPU6050_BIT_DATA_RDY_EN,
> INV_MPU6050_BIT_DATA_RDY_EN);
> @@ -89,10 +94,23 @@ int inv_reset_fifo(struct iio_dev *indio_dev)
> d |= INV_MPU6050_BITS_GYRO_OUT;
> if (st->chip_config.accl_fifo_enable)
> d |= INV_MPU6050_BIT_ACCEL_OUT;
> + if (*indio_dev->active_scan_mask & st->ext_sens[0].scan_mask)
> + d |= INV_MPU6050_BIT_SLV0_FIFO_EN;
> + if (*indio_dev->active_scan_mask & st->ext_sens[1].scan_mask)
> + d |= INV_MPU6050_BIT_SLV1_FIFO_EN;
> + if (*indio_dev->active_scan_mask & st->ext_sens[2].scan_mask)
> + d |= INV_MPU6050_BIT_SLV2_FIFO_EN;
> result = regmap_write(st->map, st->reg->fifo_en, d);
> if (result)
> goto reset_fifo_fail;
> -
> + if (*indio_dev->active_scan_mask & st->ext_sens[3].scan_mask)
> + {
> + result = regmap_update_bits(st->map, INV_MPU6050_REG_MST_CTRL,
> + INV_MPU6050_BIT_SLV3_FIFO_EN,
> + INV_MPU6050_BIT_SLV3_FIFO_EN);
> + if (result)
> + goto reset_fifo_fail;
> + }
> return 0;
>
> reset_fifo_fail:
> @@ -129,8 +147,9 @@ irqreturn_t inv_mpu6050_read_fifo(int irq, void *p)
> struct iio_poll_func *pf = p;
> struct iio_dev *indio_dev = pf->indio_dev;
> struct inv_mpu6050_state *st = iio_priv(indio_dev);
> - size_t bytes_per_datum;
> + size_t bytes_per_datum = 0;
> int result;
> + int i;
> u8 data[INV_MPU6050_OUTPUT_DATA_SIZE];
> u16 fifo_count;
> s64 timestamp;
> @@ -143,15 +162,18 @@ irqreturn_t inv_mpu6050_read_fifo(int irq, void *p)
> spi = i2c ? NULL: to_spi_device(regmap_dev);
>
> mutex_lock(&indio_dev->mlock);
> - if (!(st->chip_config.accl_fifo_enable |
> - st->chip_config.gyro_fifo_enable))
> - goto end_session;
> +
> + /* Compute bytes_per_datum */
> bytes_per_datum = 0;
> if (st->chip_config.accl_fifo_enable)
> bytes_per_datum += INV_MPU6050_BYTES_PER_3AXIS_SENSOR;
> -
> if (st->chip_config.gyro_fifo_enable)
> bytes_per_datum += INV_MPU6050_BYTES_PER_3AXIS_SENSOR;
> + for (i = 0; i < INV_MPU6050_MAX_EXT_SENSORS; ++i)
> + if (st->ext_sens[i].scan_mask & *indio_dev->active_scan_mask)
> + bytes_per_datum += st->ext_sens[i].data_len;
> + if (!bytes_per_datum)
> + return 0;
>
> /*
> * read fifo_count register to know how many bytes inside FIFO
> @@ -228,6 +250,7 @@ static int inv_mpu_buffer_preenable(struct iio_dev *indio_dev)
> {
> struct inv_mpu6050_state *st = iio_priv(indio_dev);
> unsigned long mask = *indio_dev->active_scan_mask;
> + int i;
>
> if ((mask & INV_MPU6050_SCAN_MASK_GYRO) &&
> (mask & INV_MPU6050_SCAN_MASK_GYRO) != INV_MPU6050_SCAN_MASK_GYRO)
> @@ -245,6 +268,17 @@ static int inv_mpu_buffer_preenable(struct iio_dev *indio_dev)
> return -EINVAL;
> }
>
> + for (i = 0; i < INV_MPU6050_MAX_EXT_SENSORS; ++i) {
> + if ((mask & st->ext_sens[i].scan_mask) &&
> + (mask & st->ext_sens[i].scan_mask) != st->ext_sens[i].scan_mask)
> + {
> + dev_warn(regmap_get_device(st->map),
> + "External channels from the same reading "
> + "can only be enabled together\n");
> + return -EINVAL;
> + }
> + }
> +
> return 0;
> }
>
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [RFC 7/7] iio: inv_mpu6050: Add support for external sensors
2016-05-01 17:54 ` [RFC 7/7] iio: inv_mpu6050: Add support for external sensors Jonathan Cameron
@ 2016-05-02 12:15 ` Rob Herring
0 siblings, 0 replies; 5+ messages in thread
From: Rob Herring @ 2016-05-02 12:15 UTC (permalink / raw)
To: Jonathan Cameron
Cc: Crestez Dan Leonard, linux-iio@vger.kernel.org,
linux-kernel@vger.kernel.org, Hartmut Knaack, Lars-Peter Clausen,
Peter Meerwald-Stadler, Daniel Baluta, Ge Gao,
devicetree@vger.kernel.org, Mark Rutland, Pawel Moll,
Ian Campbell, Kumar Gala, Linux I2C, Wolfram Sang, Peter Rosin,
Mark Brown
On Sun, May 1, 2016 at 12:54 PM, Jonathan Cameron <jic23@kernel.org> wrote:
> On 29/04/16 20:02, Crestez Dan Leonard wrote:
>> This works by copying their channels at probe time.
>>
>> Signed-off-by: Crestez Dan Leonard <leonard.crestez@intel.com>
> This is some mixture of deeply nefarious and rather cool.
> Great bit of work all in all.
>
> Cc'd device tree list and maintainers - to them - this is downright mad
> hardware - basically a partial i2c offload engine sitting on either i2c or
> spi buses with lots of iritating restrictions but useful stuff like a fifo
> between it and the rest of the world - upshot it's much much faster than
> actually addressing these devices directly...
>
> First time I read the datasheet for this part - I thought no one would ever
> figure out / go to the effort of supporting this functionality. Turns
> out I was wrong!
Versions of the vendor driver
>
> It is the only part I know of allowing this level of flexibility as a sensor
> hub. Most sensor hubs hide entirely what is going on behind them whereas this
> one exposes what is going on...
>
> Also cc'd the i2c list / Peter, Wolfram and Mark (just because they might be
> interested!)
>
> Jonathan
>> ---
>> .../devicetree/bindings/iio/imu/inv_mpu6050.txt | 37 +-
>> drivers/iio/imu/inv_mpu6050/inv_mpu_core.c | 420 ++++++++++++++++++++-
>> drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h | 63 +++-
>> drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c | 48 ++-
>> 4 files changed, 555 insertions(+), 13 deletions(-)
>>
>> diff --git a/Documentation/devicetree/bindings/iio/imu/inv_mpu6050.txt b/Documentation/devicetree/bindings/iio/imu/inv_mpu6050.txt
>> index aaf12b4..79b8326 100644
>> --- a/Documentation/devicetree/bindings/iio/imu/inv_mpu6050.txt
>> +++ b/Documentation/devicetree/bindings/iio/imu/inv_mpu6050.txt
>> @@ -23,6 +23,28 @@ Devices connected in "bypass" mode must be listed behind i2c@0 with the address
>>
>> Devices connected in "master" mode must be listed behind i2c@1 with the address 1
>>
>> +It is possible to configure the MPU to automatically fetch reading for
>> +devices connected on the auxiliary i2c bus without CPU intervention. When this
>> +is done the driver will present the channels of the slaved devices as if they
>> +belong to the MPU device itself.
>> +
>> +Reads and write to config values (like scaling factors) are forwarded to the
>> +other driver while data reads are handled from MPU registers. The channels are
>> +also available through the MPU's iio triggered buffer mechanism. This feature
>> +can allow sampling up to 24 bytes from 4 slaves at a much higher rate.
>> +
>> +This is be specified in device tree as an "inv,external-sensors" node which
>> +have children indexed by slave ids 0 to 3. The child node identifying each
>> +external sensor reading has the following properties:
>> + - reg: 0 to 3 slave index
>> + - inv,addr : the I2C address to read from
>> + - inv,reg : the I2C register to read from
>> + - inv,len : read length from the device
>> + - inv,external-channels : list of slaved channels specified by config index.
> I wonder if we want to try and make these generic - probably not until we have
> at least one more device doing something similar...
>> +
>> +The sum of storagebits for external channels must equal the read length. Only
>> +16bit channels are currently supported.
>> +
>> Example:
>> mpu6050@68 {
>> compatible = "invensense,mpu6050";
>> @@ -61,7 +83,8 @@ Example describing mpu9150 (which includes an ak9875 on chip):
>> };
>> };
>>
>> -Example describing a mpu6500 via SPI with an hmc5883l on auxiliary i2c:
>> +Example describing a mpu6500 via SPI with an hmc5883l on aux i2c configured for
>> +automatic external readings as slave 0:
>> mpu6500@0 {
>> compatible = "inv,mpu6500";
>> reg = <0x0>;
>> @@ -80,4 +103,16 @@ Example describing a mpu6500 via SPI with an hmc5883l on auxiliary i2c:
>> reg = <0x1e>;
>> };
>> };
>> +
>> + inv,external-sensors {
>> + #address-cells = <1>;
>> + #size-cells = <0>;
>> + hmc5833l@0 {
>> + reg = <0>;
>> + inv,addr = <0x1e>;
>> + inv,reg = <3>;
>> + inv,len = <6>;
>> + inv,external-channels = <0 1 2>;
>> + };
>> + };
>> };
>> diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
>> index 712e901..224be3c 100644
>> --- a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
>> +++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
>> @@ -41,6 +41,8 @@ static const int gyro_scale_6050[] = {133090, 266181, 532362, 1064724};
>> */
>> static const int accel_scale[] = {598, 1196, 2392, 4785};
>>
>> +#define INV_MPU6050_NUM_INT_CHAN 8
>> +
>> static const struct inv_mpu6050_reg_map reg_set_6500 = {
>> .sample_rate_div = INV_MPU6050_REG_SAMPLE_RATE_DIV,
>> .lpf = INV_MPU6050_REG_CONFIG,
>> @@ -136,6 +138,9 @@ static bool inv_mpu6050_volatile_reg(struct device *dev, unsigned int reg)
>> return true;
>> if (reg >= INV_MPU6050_REG_RAW_GYRO && reg < INV_MPU6050_REG_RAW_GYRO + 6)
>> return true;
>> + if (reg < INV_MPU6050_REG_EXT_SENS_DATA_00 + INV_MPU6050_CNT_EXT_SENS_DATA &&
>> + reg >= INV_MPU6050_REG_EXT_SENS_DATA_00)
>> + return true;
>> switch (reg) {
>> case INV_MPU6050_REG_TEMPERATURE:
>> case INV_MPU6050_REG_TEMPERATURE + 1:
>> @@ -340,13 +345,115 @@ static int inv_mpu6050_sensor_show(struct inv_mpu6050_state *st, int reg,
>> return IIO_VAL_INT;
>> }
>>
>> +static bool iio_chan_needs_swab(const struct iio_chan_spec *chan)
>> +{
>> +#if defined(__LITTLE_ENDIAN)
>> + return chan->scan_type.endianness == IIO_BE;
>> +#elif defined(__BIG_ENDIAN)
>> + return chan->scan_type.endianness == IIO_LE;
>> +#else
>> + #error undefined endianness
>> +#endif
>> +}
>> +
>> +/* Convert iio buffer format to IIO_CHAN_INFO_RAW value */
>> +static int iio_bufval_to_rawval(const struct iio_chan_spec *chan, void *buf, int *val)
>> +{
>> + switch (chan->scan_type.storagebits) {
>> + case 8: *val = *((u8*)buf); break;
>> + case 16: *val = *(u16*)buf; break;
>> + case 32: *val = *(u32*)buf; break;
>> + default: return -EINVAL;
>> + }
>> +
>> + *val >>= chan->scan_type.shift;
>> + *val &= (1 << chan->scan_type.realbits) - 1;
>> + if (iio_chan_needs_swab(chan)) {
>> + if (chan->scan_type.storagebits == 16)
>> + *val = swab16(*val);
>> + else if (chan->scan_type.storagebits == 32)
>> + *val = swab32(*val);
> This needs some explanatory comments!
>> + }
>> + if (chan->scan_type.sign == 's')
>> + *val = sign_extend32(*val, chan->scan_type.storagebits - 1);
>> +
>> + return 0;
>> +}
>> +
>> +static int
>> +inv_mpu6050_read_raw_external(struct iio_dev *indio_dev,
>> + struct iio_chan_spec const *chan,
>> + int *val, int *val2, long mask)
>> +{
>> + int result;
>> + struct inv_mpu6050_state *st = iio_priv(indio_dev);
>> + int chan_index = chan - indio_dev->channels;
>> + struct inv_mpu6050_ext_chan_state *ext_chan_state =
>> + &st->ext_chan[chan_index - INV_MPU6050_NUM_INT_CHAN];
>> + struct inv_mpu6050_ext_sens_state *ext_sens_state =
>> + &st->ext_sens[ext_chan_state->ext_sens_index];
>> + struct iio_dev *orig_dev = ext_sens_state->orig_dev;
>> + const struct iio_chan_spec *orig_chan = &orig_dev->channels[ext_chan_state->orig_chan_index];
>> + int data_offset;
>> + int data_length;
>> + u8 buf[4];
>> +
>> + /* Everything but raw data reads is forwarded. */
>> + if (mask != IIO_CHAN_INFO_RAW)
>> + return orig_dev->info->read_raw(orig_dev, orig_chan, val, val2, mask);
> Obviously this is useful for testing, but on a polled interface do we actually
> care that it is quicker to go directly? I'd be tempted to not bother except
> for the buffered mode.
>> +
>> + /* Raw reads are handled directly. */
>> + data_offset = INV_MPU6050_REG_EXT_SENS_DATA_00 + ext_chan_state->data_offset;
>> + data_length = chan->scan_type.storagebits / 8;
>> + if (data_length > sizeof(buf)) {
>> + return -EINVAL;
>> + }
>> +
>> + mutex_lock(&indio_dev->mlock);
>> + if (!st->chip_config.enable) {
>> + result = inv_mpu6050_set_power_itg(st, true);
>> + if (result)
>> + goto error_unlock;
>> + }
>> + result = regmap_bulk_read(st->map, data_offset, buf, data_length);
>> + if (result)
>> + goto error_unpower;
>> + if (!st->chip_config.enable) {
>> + result = inv_mpu6050_set_power_itg(st, false);
>> + if (result)
>> + goto error_unlock;
>> + }
>> + mutex_unlock(&indio_dev->mlock);
>> +
>> + /* Convert buf to val and return success */
>> + result = iio_bufval_to_rawval(chan, buf, val);
>> + if (result)
>> + return result;
>> + return IIO_VAL_INT;
>> +
>> +error_unpower:
>> + if (!st->chip_config.enable)
>> + inv_mpu6050_set_power_itg(st, false);
>> +error_unlock:
>> + mutex_unlock(&indio_dev->mlock);
>> + return result;
>> +}
>> +
>> static int
>> inv_mpu6050_read_raw(struct iio_dev *indio_dev,
>> struct iio_chan_spec const *chan,
>> int *val, int *val2, long mask)
>> {
>> - struct inv_mpu6050_state *st = iio_priv(indio_dev);
>> + struct inv_mpu6050_state *st = iio_priv(indio_dev);
>> int ret = 0;
>> + int chan_index;
>> +
>> + if (chan < indio_dev->channels || chan > indio_dev->channels + indio_dev->num_channels) {
>> + return -EINVAL;
>> + }
>> + chan_index = chan - indio_dev->channels;
>> + if (chan_index >= INV_MPU6050_NUM_INT_CHAN)
>> + return inv_mpu6050_read_raw_external(indio_dev, chan, val, val2, mask);
>>
>> switch (mask) {
>> case IIO_CHAN_INFO_RAW:
>> @@ -819,6 +926,309 @@ static const struct iio_info mpu_info = {
>> .validate_trigger = inv_mpu6050_validate_trigger,
>> };
>>
>> +extern struct device_type iio_device_type;
>> +
>> +static int iio_device_from_i2c_client_match(struct device *dev, void *data)
>> +{
>> + return dev->type == &iio_device_type;
>> +}
>> +
>> +static struct iio_dev* iio_device_from_i2c_client(struct i2c_client* i2c)
>> +{
>> + struct device *child;
>> +
>> + child = device_find_child(&i2c->dev, NULL, iio_device_from_i2c_client_match);
>> +
>> + return (child ? dev_to_iio_dev(child) : NULL);
>> +}
>> +
>> +static int inv_mpu_set_external_reads_enabled(struct inv_mpu6050_state *st, bool en)
>> +{
>> + int i, result, error = 0;
>> +
>> + /* Even if there are errors try to disable all slaves. */
>> + for (i = 0; i < INV_MPU6050_MAX_EXT_SENSORS; ++i) {
>> + result = regmap_update_bits(st->map, INV_MPU6050_REG_I2C_SLV_CTRL(i),
>> + INV_MPU6050_BIT_I2C_SLV_EN,
>> + en ? INV_MPU6050_BIT_I2C_SLV_EN : 0);
>> + if (result) {
>> + error = result;
>> + }
>> + }
>> +
>> + return error;
>> +}
>> +
>> +static int inv_mpu_parse_one_ext_sens(struct device *dev,
>> + struct device_node *np,
>> + struct inv_mpu6050_ext_sens_spec *spec)
>> +{
>> + int result;
>> + u32 addr, reg, len;
>> +
>> + result = of_property_read_u32(np, "inv,addr", &addr);
>> + if (result)
>> + return result;
>> + result = of_property_read_u32(np, "inv,reg", ®);
>> + if (result)
>> + return result;
>> + result = of_property_read_u32(np, "inv,len", &len);
>> + if (result)
>> + return result;
>> +
>> + spec->addr = addr;
>> + spec->reg = reg;
>> + spec->len = len;
>> +
>> + result = of_property_count_u32_elems(np, "inv,external-channels");
>> + if (result < 0)
>> + return result;
>> + spec->num_ext_channels = result;
>> + spec->ext_channels = devm_kmalloc(dev, spec->num_ext_channels * sizeof(*spec->ext_channels), GFP_KERNEL);
>> + if (!spec->ext_channels)
>> + return -ENOMEM;
>> + result = of_property_read_u32_array(np, "inv,external-channels",
>> + spec->ext_channels,
>> + spec->num_ext_channels);
>> + if (result)
>> + return result;
>> +
>> + return 0;
>> +}
>> +
>> +static int inv_mpu_parse_ext_sens(struct device *dev,
>> + struct device_node *node,
>> + struct inv_mpu6050_ext_sens_spec *specs)
>> +{
>> + struct device_node *child;
>> + int result;
>> + u32 reg;
>> +
>> + for_each_available_child_of_node(node, child) {
>> + result = of_property_read_u32(child, "reg", ®);
>> + if (result)
>> + return result;
>> + if (reg > INV_MPU6050_MAX_EXT_SENSORS) {
>> + dev_err(dev, "External sensor index %u out of range, max %d\n",
>> + reg, INV_MPU6050_MAX_EXT_SENSORS);
>> + return -EINVAL;
>> + }
>> + result = inv_mpu_parse_one_ext_sens(dev, child, &specs[reg]);
>> + if (result)
>> + return result;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static int inv_mpu_get_ext_sens_spec(struct iio_dev *indio_dev)
>> +{
>> + struct inv_mpu6050_state *st = iio_priv(indio_dev);
>> + struct device *dev = regmap_get_device(st->map);
>> + struct device_node *node;
>> + int result;
>> +
>> + node = of_get_child_by_name(dev->of_node, "inv,external-sensors");
>> + if (node) {
>> + result = inv_mpu_parse_ext_sens(dev, node, st->ext_sens_spec);
>> + if (result)
>> + dev_err(dev, "Failed to parsing external-sensors devicetree data\n");
>> + return result;
>> + }
>> +
>> + /* Maybe some other way to deal with this? */
> Probably not ;)
>> +
>> + return 0;
>> +}
>> +
>> +/* Struct used while enumerating devices and matching them */
>> +struct inv_mpu_handle_ext_sensor_fnarg
>> +{
>> + struct iio_dev *indio_dev;
>> +
>> + /* Next scan index */
>> + int scan_index;
>> + /* Index among external channels */
>> + int chan_index;
>> + /* Offset in EXTDATA */
>> + int data_offset;
>> + struct iio_chan_spec *channels;
>> +};
>> +
>> +static int inv_mpu_config_external_read(struct inv_mpu6050_state *st, int index,
>> + const struct inv_mpu6050_ext_sens_spec *spec)
>> +{
>> + int result;
>> +
>> + result = regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_ADDR(index),
>> + INV_MPU6050_BIT_I2C_SLV_RW | spec->addr);
>> + if (result)
>> + return result;
>> + result = regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_REG(index), spec->reg);
>> + if (result)
>> + return result;
>> + result = regmap_write(st->map, INV_MPU6050_REG_I2C_SLV_CTRL(index),
>> + INV_MPU6050_BIT_I2C_SLV_EN | spec->len);
>> +
>> + return result;
>> +}
>> +
>> +static int inv_mpu_handle_ext_sensor_fn(struct device *dev, void *data)
>> +{
>> + struct inv_mpu_handle_ext_sensor_fnarg *fnarg = data;
>> + struct iio_dev *indio_dev = fnarg->indio_dev;
>> + struct inv_mpu6050_state *st = iio_priv(indio_dev);
>> + struct device *mydev = regmap_get_device(st->map);
>> + struct i2c_client *client;
>> + struct iio_dev *orig_dev;
>> + int i, j;
>> +
>> + client = i2c_verify_client(dev);
>> + if (!client)
>> + return 0;
>> + orig_dev = iio_device_from_i2c_client(client);
>> + if (!orig_dev)
>> + return 0;
>> + for (i = 0; i < INV_MPU6050_MAX_EXT_SENSORS; ++i) {
>> + int start_data_offset;
>> + struct inv_mpu6050_ext_sens_spec *ext_sens_spec = &st->ext_sens_spec[i];
>> + struct inv_mpu6050_ext_sens_state *ext_sens_state = &st->ext_sens[i];
>> +
>> + if (ext_sens_spec->addr != client->addr)
>> + continue;
>> + if (ext_sens_state->orig_dev) {
>> + dev_warn(&indio_dev->dev, "already found slave with at addr %d\n", client->addr);
>> + continue;
>> + }
>> + dev_info(mydev, "external sensor %d is device %s\n",
>> + i, orig_dev->name ?: dev_name(&orig_dev->dev));
>> + ext_sens_state->orig_dev = orig_dev;
>> + ext_sens_state->scan_mask = 0;
>> + ext_sens_state->data_len = ext_sens_spec->len;
>> + start_data_offset = fnarg->data_offset;
>> +
>> + /* Matched the device (by address). Now process channels: */
>> + for (j = 0; j < ext_sens_spec->num_ext_channels; ++j) {
>> + int orig_chan_index;
>> + const struct iio_chan_spec *orig_chan_spec;
>> + struct iio_chan_spec *chan_spec;
>> + struct inv_mpu6050_ext_chan_state *chan_state;
>> +
>> + orig_chan_index = ext_sens_spec->ext_channels[j];
>> + orig_chan_spec = &orig_dev->channels[orig_chan_index];
>> + chan_spec = &fnarg->channels[INV_MPU6050_NUM_INT_CHAN + fnarg->chan_index];
>> + chan_state = &st->ext_chan[fnarg->chan_index];
>> +
>> + chan_state->ext_sens_index = i;
>> + chan_state->orig_chan_index = orig_chan_index;
>> + chan_state->data_offset = fnarg->data_offset;
>> + memcpy(chan_spec, orig_chan_spec, sizeof(struct iio_chan_spec));
>> + chan_spec->scan_index = fnarg->scan_index;
>> + ext_sens_state->scan_mask |= (1 << chan_spec->scan_index);
>> + if (orig_chan_spec->scan_type.storagebits != 16) {
>> + /*
>> + * Supporting other channels sizes would require data read from the
>> + * hardware fifo to comply with iio alignment.
>> + */
> Or a demux/mux before iio_push_to_buffers.
>> + dev_err(&indio_dev->dev, "All external channels must have 16 storage bits\n");
>> + return -EINVAL;
>> + }
>> +
>> + fnarg->scan_index++;
>> + fnarg->chan_index++;
>> + fnarg->data_offset += chan_spec->scan_type.storagebits / 8;
>> + dev_info(mydev, "Reading external channel #%d scan_index %d data_offset %d"
>> + " from original device %s chan #%d scan_index %d\n",
>> + fnarg->chan_index, chan_spec->scan_index, chan_state->data_offset,
>> + orig_dev->name ?: dev_name(&orig_dev->dev), orig_chan_index, orig_chan_spec->scan_index);
>> + }
>> + if (start_data_offset + ext_sens_spec->len != fnarg->data_offset) {
>> + dev_warn(mydev, "length mismatch between i2c slave read length and slave channel spec\n");
>> + return -EINVAL;
>> + }
>> +
>> + return inv_mpu_config_external_read(st, i, ext_sens_spec);
>> + }
>> + return 0;
>> +}
>> +
>> +static int inv_mpu6050_handle_ext_sensors(struct iio_dev *indio_dev)
>> +{
>> + struct inv_mpu6050_state *st = iio_priv(indio_dev);
>> + struct device *dev = regmap_get_device(st->map);
>> + struct inv_mpu_handle_ext_sensor_fnarg fnarg = {
>> + .indio_dev = indio_dev,
>> + .chan_index = 0,
>> + .data_offset = 0,
>> + .scan_index = INV_MPU6050_SCAN_TIMESTAMP,
>> + };
>> + int i, result;
>> + int num_ext_chan = 0, sum_data_len = 0;
>> +
>> + inv_mpu_get_ext_sens_spec(indio_dev);
>> + for (i = 0; i < INV_MPU6050_MAX_EXT_SENSORS; ++i) {
>> + num_ext_chan += st->ext_sens_spec[i].num_ext_channels;
>> + sum_data_len += st->ext_sens_spec[i].len;
>> + }
>> + if (sum_data_len > INV_MPU6050_CNT_EXT_SENS_DATA) {
>> + dev_err(dev, "Too many bytes from external sensors:"
>> + " requested=%d max=%d\n",
>> + sum_data_len, INV_MPU6050_CNT_EXT_SENS_DATA);
>> + return -EINVAL;
>> + }
>> +
>> + /* Zero length means nothing to do */
>> + if (!sum_data_len) {
>> + indio_dev->channels = inv_mpu_channels;
>> + indio_dev->num_channels = INV_MPU6050_NUM_INT_CHAN;
>> + BUILD_BUG_ON(ARRAY_SIZE(inv_mpu_channels) != INV_MPU6050_NUM_INT_CHAN);
>> + return 0;
>> + }
>> +
>> + fnarg.channels = devm_kmalloc(indio_dev->dev.parent,
>> + (num_ext_chan + INV_MPU6050_NUM_INT_CHAN) *
>> + sizeof(struct iio_chan_spec),
>> + GFP_KERNEL);
>> + if (!fnarg.channels)
>> + return -ENOMEM;
>> + memcpy(fnarg.channels, inv_mpu_channels, sizeof(inv_mpu_channels));
>> + memset(fnarg.channels + INV_MPU6050_NUM_INT_CHAN, 0,
>> + num_ext_chan * sizeof(struct iio_chan_spec));
>> +
>> + st->ext_chan = devm_kzalloc(indio_dev->dev.parent,
>> + (num_ext_chan) * sizeof(*st->ext_chan),
>> + GFP_KERNEL);
>> + if (!st->ext_chan)
>> + return -ENOMEM;
>> +
>> + result = inv_mpu6050_set_power_itg(st, true);
>> + if (result < 0)
>> + return result;
>> +
>> + result = device_for_each_child(&st->aux_master_adapter.dev, &fnarg,
>> + inv_mpu_handle_ext_sensor_fn);
>> + if (result)
>> + goto out_disable;
>> + /* Timestamp channel has index 0 and last scan_index */
>> + fnarg.channels[0].scan_index = fnarg.scan_index;
>> +
>> + if (fnarg.chan_index != num_ext_chan) {
>> + dev_err(&indio_dev->dev, "Failed to match all external channels!\n");
>> + result = -EINVAL;
>> + goto out_disable;
>> + }
>> +
>> + result = inv_mpu6050_set_power_itg(st, false);
>> + indio_dev->channels = fnarg.channels;
>> + indio_dev->num_channels = INV_MPU6050_NUM_INT_CHAN + num_ext_chan;
>> + return result;
>> +
>> +out_disable:
>> + inv_mpu6050_set_power_itg(st, false);
>> + inv_mpu_set_external_reads_enabled(st, false);
>> + return result;
>> +}
>> +
>> /**
>> * inv_check_and_setup_chip() - check and setup chip.
>> */
>> @@ -1121,8 +1531,6 @@ int inv_mpu_core_probe(struct regmap *regmap, int irq, const char *name,
>> indio_dev->name = name;
>> else
>> indio_dev->name = dev_name(dev);
>> - indio_dev->channels = inv_mpu_channels;
>> - indio_dev->num_channels = ARRAY_SIZE(inv_mpu_channels);
>>
>> indio_dev->info = &mpu_info;
>> indio_dev->modes = INDIO_BUFFER_TRIGGERED;
>> @@ -1160,6 +1568,12 @@ int inv_mpu_core_probe(struct regmap *regmap, int irq, const char *name,
>> }
>> #endif
>>
>> + result = inv_mpu6050_handle_ext_sensors(indio_dev);
>> + if (result < 0) {
>> + dev_err(dev, "failed to configure channels %d\n", result);
>> + goto out_remove_trigger;
>> + }
>> +
>> INIT_KFIFO(st->timestamps);
>> spin_lock_init(&st->time_stamp_lock);
>> result = iio_device_register(indio_dev);
>> diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h b/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
>> index 9d406df..007fe75 100644
>> --- a/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
>> +++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
>> @@ -124,6 +124,40 @@ struct inv_mpu6050_hw {
>> const struct inv_mpu6050_chip_config *config;
>> };
>>
>> +#define INV_MPU6050_MAX_EXT_SENSORS 4
>> +
>> +/* Specification for an external sensor */
>> +struct inv_mpu6050_ext_sens_spec {
>> + unsigned short addr;
>> + u8 reg, len;
>> +
>> + int num_ext_channels;
>> + int *ext_channels;
>> +};
>> +
>> +/* Driver state for each external sensor */
>> +struct inv_mpu6050_ext_sens_state {
>> + struct iio_dev *orig_dev;
>> +
>> + /* Mask of all channels in this sensor */
>> + unsigned long scan_mask;
>> +
>> + /* Length of reading. */
>> + int data_len;
>> +};
>> +
>> +/* Driver state for each external channel */
>> +struct inv_mpu6050_ext_chan_state {
>> + /* Index inside state->ext_sens */
>> + int ext_sens_index;
>> +
>> + /* Index inside orig_dev->channels */
>> + int orig_chan_index;
>> +
>> + /* Relative to EXT_SENS_DATA_00 */
>> + int data_offset;
>> +};
>> +
>> /*
>> * struct inv_mpu6050_state - Driver state variables.
>> * @TIMESTAMP_FIFO_SIZE: fifo size for timestamp.
>> @@ -164,6 +198,10 @@ struct inv_mpu6050_state {
>> struct i2c_adapter aux_master_adapter;
>> struct completion slv4_done;
>> #endif
>> +
>> + struct inv_mpu6050_ext_sens_spec ext_sens_spec[INV_MPU6050_MAX_EXT_SENSORS];
>> + struct inv_mpu6050_ext_sens_state ext_sens[INV_MPU6050_MAX_EXT_SENSORS];
>> + struct inv_mpu6050_ext_chan_state *ext_chan;
>> };
>>
>> /*register and associated bit definition*/
>> @@ -178,6 +216,24 @@ struct inv_mpu6050_state {
>> #define INV_MPU6050_REG_FIFO_EN 0x23
>> #define INV_MPU6050_BIT_ACCEL_OUT 0x08
>> #define INV_MPU6050_BITS_GYRO_OUT 0x70
>> +#define INV_MPU6050_BIT_SLV0_FIFO_EN 0x01
>> +#define INV_MPU6050_BIT_SLV1_FIFO_EN 0x02
>> +#define INV_MPU6050_BIT_SLV2_FIFO_EN 0x04
>> +#define INV_MPU6050_BIT_SLV2_FIFO_EN 0x04
>> +
>> +/* SLV3 fifo enabling is not in REG_FIFO_EN */
>> +#define INV_MPU6050_REG_MST_CTRL 0x24
>> +#define INV_MPU6050_BIT_SLV3_FIFO_EN 0x10
>> +
>> +/* For slaves 0-3 */
>> +#define INV_MPU6050_REG_I2C_SLV_ADDR(i) (0x25 + 3 * (i))
>> +#define INV_MPU6050_REG_I2C_SLV_REG(i) (0x26 + 3 * (i))
>> +#define INV_MPU6050_REG_I2C_SLV_CTRL(i) (0x27 + 3 * (i))
>> +#define INV_MPU6050_BIT_I2C_SLV_RW 0x80
>> +#define INV_MPU6050_BIT_I2C_SLV_EN 0x80
>> +#define INV_MPU6050_BIT_I2C_SLV_BYTE_SW 0x40
>> +#define INV_MPU6050_BIT_I2C_SLV_REG_DIS 0x20
>> +#define INV_MPU6050_BIT_I2C_SLV_REG_GRP 0x10
>>
>> #define INV_MPU6050_REG_I2C_SLV4_ADDR 0x31
>> #define INV_MPU6050_BIT_I2C_SLV4_R 0x80
>> @@ -252,8 +308,8 @@ struct inv_mpu6050_state {
>> #define INV_MPU6050_GYRO_CONFIG_FSR_SHIFT 3
>> #define INV_MPU6050_ACCL_CONFIG_FSR_SHIFT 3
>>
>> -/* 6 + 6 round up and plus 8 */
>> -#define INV_MPU6050_OUTPUT_DATA_SIZE 24
>> +/* max is 3*2 accel + 3*2 gyro + 24 external + 8 ts */
>> +#define INV_MPU6050_OUTPUT_DATA_SIZE 44
>>
>> #define INV_MPU6050_REG_INT_PIN_CFG 0x37
>> #define INV_MPU6050_BIT_BYPASS_EN 0x2
>> @@ -266,6 +322,9 @@ struct inv_mpu6050_state {
>> #define INV_MPU6050_MIN_FIFO_RATE 4
>> #define INV_MPU6050_ONE_K_HZ 1000
>>
>> +#define INV_MPU6050_REG_EXT_SENS_DATA_00 0x49
>> +#define INV_MPU6050_CNT_EXT_SENS_DATA 24
>> +
>> #define INV_MPU6050_REG_WHOAMI 117
>>
>> #define INV_MPU6000_WHOAMI_VALUE 0x68
>> diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c
>> index e8bda7f..8fa5c3d 100644
>> --- a/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c
>> +++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c
>> @@ -52,6 +52,10 @@ int inv_reset_fifo(struct iio_dev *indio_dev)
>> result = regmap_write(st->map, st->reg->fifo_en, 0);
>> if (result)
>> goto reset_fifo_fail;
>> + result = regmap_update_bits(st->map, INV_MPU6050_REG_MST_CTRL,
>> + INV_MPU6050_BIT_SLV3_FIFO_EN, 0);
>> + if (result)
>> + goto reset_fifo_fail;
>> /* disable fifo reading */
>> st->chip_config.user_ctrl &= ~INV_MPU6050_BIT_FIFO_EN;
>> result = regmap_write(st->map, st->reg->user_ctrl,
>> @@ -70,7 +74,8 @@ int inv_reset_fifo(struct iio_dev *indio_dev)
>>
>> /* enable interrupt */
>> if (st->chip_config.accl_fifo_enable ||
>> - st->chip_config.gyro_fifo_enable) {
>> + st->chip_config.gyro_fifo_enable ||
>> + true) {
>> result = regmap_update_bits(st->map, st->reg->int_enable,
>> INV_MPU6050_BIT_DATA_RDY_EN,
>> INV_MPU6050_BIT_DATA_RDY_EN);
>> @@ -89,10 +94,23 @@ int inv_reset_fifo(struct iio_dev *indio_dev)
>> d |= INV_MPU6050_BITS_GYRO_OUT;
>> if (st->chip_config.accl_fifo_enable)
>> d |= INV_MPU6050_BIT_ACCEL_OUT;
>> + if (*indio_dev->active_scan_mask & st->ext_sens[0].scan_mask)
>> + d |= INV_MPU6050_BIT_SLV0_FIFO_EN;
>> + if (*indio_dev->active_scan_mask & st->ext_sens[1].scan_mask)
>> + d |= INV_MPU6050_BIT_SLV1_FIFO_EN;
>> + if (*indio_dev->active_scan_mask & st->ext_sens[2].scan_mask)
>> + d |= INV_MPU6050_BIT_SLV2_FIFO_EN;
>> result = regmap_write(st->map, st->reg->fifo_en, d);
>> if (result)
>> goto reset_fifo_fail;
>> -
>> + if (*indio_dev->active_scan_mask & st->ext_sens[3].scan_mask)
>> + {
>> + result = regmap_update_bits(st->map, INV_MPU6050_REG_MST_CTRL,
>> + INV_MPU6050_BIT_SLV3_FIFO_EN,
>> + INV_MPU6050_BIT_SLV3_FIFO_EN);
>> + if (result)
>> + goto reset_fifo_fail;
>> + }
>> return 0;
>>
>> reset_fifo_fail:
>> @@ -129,8 +147,9 @@ irqreturn_t inv_mpu6050_read_fifo(int irq, void *p)
>> struct iio_poll_func *pf = p;
>> struct iio_dev *indio_dev = pf->indio_dev;
>> struct inv_mpu6050_state *st = iio_priv(indio_dev);
>> - size_t bytes_per_datum;
>> + size_t bytes_per_datum = 0;
>> int result;
>> + int i;
>> u8 data[INV_MPU6050_OUTPUT_DATA_SIZE];
>> u16 fifo_count;
>> s64 timestamp;
>> @@ -143,15 +162,18 @@ irqreturn_t inv_mpu6050_read_fifo(int irq, void *p)
>> spi = i2c ? NULL: to_spi_device(regmap_dev);
>>
>> mutex_lock(&indio_dev->mlock);
>> - if (!(st->chip_config.accl_fifo_enable |
>> - st->chip_config.gyro_fifo_enable))
>> - goto end_session;
>> +
>> + /* Compute bytes_per_datum */
>> bytes_per_datum = 0;
>> if (st->chip_config.accl_fifo_enable)
>> bytes_per_datum += INV_MPU6050_BYTES_PER_3AXIS_SENSOR;
>> -
>> if (st->chip_config.gyro_fifo_enable)
>> bytes_per_datum += INV_MPU6050_BYTES_PER_3AXIS_SENSOR;
>> + for (i = 0; i < INV_MPU6050_MAX_EXT_SENSORS; ++i)
>> + if (st->ext_sens[i].scan_mask & *indio_dev->active_scan_mask)
>> + bytes_per_datum += st->ext_sens[i].data_len;
>> + if (!bytes_per_datum)
>> + return 0;
>>
>> /*
>> * read fifo_count register to know how many bytes inside FIFO
>> @@ -228,6 +250,7 @@ static int inv_mpu_buffer_preenable(struct iio_dev *indio_dev)
>> {
>> struct inv_mpu6050_state *st = iio_priv(indio_dev);
>> unsigned long mask = *indio_dev->active_scan_mask;
>> + int i;
>>
>> if ((mask & INV_MPU6050_SCAN_MASK_GYRO) &&
>> (mask & INV_MPU6050_SCAN_MASK_GYRO) != INV_MPU6050_SCAN_MASK_GYRO)
>> @@ -245,6 +268,17 @@ static int inv_mpu_buffer_preenable(struct iio_dev *indio_dev)
>> return -EINVAL;
>> }
>>
>> + for (i = 0; i < INV_MPU6050_MAX_EXT_SENSORS; ++i) {
>> + if ((mask & st->ext_sens[i].scan_mask) &&
>> + (mask & st->ext_sens[i].scan_mask) != st->ext_sens[i].scan_mask)
>> + {
>> + dev_warn(regmap_get_device(st->map),
>> + "External channels from the same reading "
>> + "can only be enabled together\n");
>> + return -EINVAL;
>> + }
>> + }
>> +
>> return 0;
>> }
>>
>>
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [RFC 5/7] iio: inv_mpu6050: Add support for auxiliary I2C master
2016-05-01 17:27 ` [RFC 5/7] iio: inv_mpu6050: Add support for auxiliary I2C master Jonathan Cameron
@ 2016-05-05 12:38 ` Crestez Dan Leonard
2016-05-05 13:10 ` Rob Herring
0 siblings, 1 reply; 5+ messages in thread
From: Crestez Dan Leonard @ 2016-05-05 12:38 UTC (permalink / raw)
To: Jonathan Cameron, linux-iio
Cc: linux-kernel, Hartmut Knaack, Lars-Peter Clausen,
Peter Meerwald-Stadler, Daniel Baluta, Ge Gao, Peter Rosin,
Linux I2C, Wolfram Sang, devicetree@vger.kernel.org, Mark Rutland,
Rob Herring, Pawel Moll, Ian Campbell, Kumar Gala, Matt Ranostay
On 05/01/2016 08:27 PM, Jonathan Cameron wrote:
> On 29/04/16 20:02, Crestez Dan Leonard wrote:
>> --- a/Documentation/devicetree/bindings/iio/imu/inv_mpu6050.txt
>> +++ b/Documentation/devicetree/bindings/iio/imu/inv_mpu6050.txt
>> @@ -1,16 +1,27 @@
>> InvenSense MPU-6050 Six-Axis (Gyro + Accelerometer) MEMS MotionTracking Device
>>
>> -http://www.invensense.com/mems/gyro/mpu6050.html
> If this is invalid, please add an up to date link if possible.
>> -
>> Required properties:
>> - - compatible : should be "invensense,mpu6050"
>> - - reg : the I2C address of the sensor
>> + - compatible : should be "invensense,mpuXXXX"
> List them all explicitly here rather than wild cards.
>
But the list is a bit long. I'll just write "see below for valid
compatible strings".
>> + - reg : the I2C or SPI address of the sensor
>> - interrupt-parent : should be the phandle for the interrupt controller
>> - interrupts : interrupt mapping for GPIO IRQ
>>
>> Optional properties:
>> - mount-matrix: an optional 3x3 mounting rotation matrix
>> + - inv,i2c-aux-master: operate aux i2c in "master mode" (default is mux).
>> +
>> +Valid compatible strings:
> Vendor prefix? These will work for historical reasons, but now vendor
> prefix should definitely be there as well.
>> + - mpu6000
>> + - mpu6050
>> + - mpu6500
>> + - mpu9150
>
The driver currently only lists i2c_device_id and this will work
ignoring the vendor string. I can prefix all these valid strings with
the vendor prefix but this is not actually a requirement. That would
require a separate unrelated patch adding of_device_id tables.
>> + /*
>> + * Regmap will never ignore writes but it will ignore full-register
>> + * updates to the same value.
> Hmm. I'd missed this distinction. Feels decidely 'interesting'... and makes
> my earlier suggestion invalid as I guess the fields stuff uses update bits
> internally.
>
I will replace this with if (read() != addr) write(addr) to clarify.
Mentioning a regmap implementation quirk this way is silly.
>> diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h b/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
>> index bd2c0fd..9d15633 100644
>> --- a/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
>> +++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
>> @@ -42,6 +42,13 @@
>> * @int_pin_cfg; Controls interrupt pin configuration.
>> * @accl_offset: Controls the accelerometer calibration offset.
>> * @gyro_offset: Controls the gyroscope calibration offset.
>> + * @mst_status: secondary I2C master interrupt source status
>> + * @slv4_addr: I2C slave address for slave 4 transaction
>> + * @slv4_reg: I2C register used with slave 4 transaction
>> + * @slv4_di: I2C data in register for slave 4 transaction
>> + * @slv4_ctrl: I2C slave 4 control register
>> + * @slv4_do: I2C data out register for slave 4 transaction
>> +
I forgot to ask about this but this patch adds registers addresses to
struct inv_mpu6050_reg_map and not others. All the supported models have
the same registers for this functionality.
It seems to me that the simplest approach to supporting multiple models
is to only put the registers that vary in a model struct and use
constants for the rest. Is this the correct approach? If so I will use
constants for SLV4_* in the next patch.
It's not clear that adding this kind of indirection for everything is
useful for supporting new models. Different models can also move bits
around, not just registers.
--
Regards,
Leonard
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [RFC 5/7] iio: inv_mpu6050: Add support for auxiliary I2C master
2016-05-05 12:38 ` Crestez Dan Leonard
@ 2016-05-05 13:10 ` Rob Herring
0 siblings, 0 replies; 5+ messages in thread
From: Rob Herring @ 2016-05-05 13:10 UTC (permalink / raw)
To: Crestez Dan Leonard
Cc: Jonathan Cameron, linux-iio@vger.kernel.org,
linux-kernel@vger.kernel.org, Hartmut Knaack, Lars-Peter Clausen,
Peter Meerwald-Stadler, Daniel Baluta, Ge Gao, Peter Rosin,
Linux I2C, Wolfram Sang, devicetree@vger.kernel.org, Mark Rutland,
Pawel Moll, Ian Campbell, Kumar Gala, Matt Ranostay
On Thu, May 5, 2016 at 7:38 AM, Crestez Dan Leonard
<leonard.crestez@intel.com> wrote:
> On 05/01/2016 08:27 PM, Jonathan Cameron wrote:
>> On 29/04/16 20:02, Crestez Dan Leonard wrote:
>>> --- a/Documentation/devicetree/bindings/iio/imu/inv_mpu6050.txt
>>> +++ b/Documentation/devicetree/bindings/iio/imu/inv_mpu6050.txt
>>> @@ -1,16 +1,27 @@
>>> InvenSense MPU-6050 Six-Axis (Gyro + Accelerometer) MEMS MotionTracking Device
>>>
>>> -http://www.invensense.com/mems/gyro/mpu6050.html
>> If this is invalid, please add an up to date link if possible.
>>> -
>>> Required properties:
>>> - - compatible : should be "invensense,mpu6050"
>>> - - reg : the I2C address of the sensor
>>> + - compatible : should be "invensense,mpuXXXX"
>> List them all explicitly here rather than wild cards.
>>
> But the list is a bit long. I'll just write "see below for valid
> compatible strings".
No, please list here. 4 is not long. A note of which ones are SPI
would be good too.
Can you add 9250 as well as it is commonly available for maker h/w.
>
>>> + - reg : the I2C or SPI address of the sensor
>>> - interrupt-parent : should be the phandle for the interrupt controller
>>> - interrupts : interrupt mapping for GPIO IRQ
>>>
>>> Optional properties:
>>> - mount-matrix: an optional 3x3 mounting rotation matrix
>>> + - inv,i2c-aux-master: operate aux i2c in "master mode" (default is mux).
>>> +
>>> +Valid compatible strings:
>> Vendor prefix? These will work for historical reasons, but now vendor
>> prefix should definitely be there as well.
>>> + - mpu6000
>>> + - mpu6050
>>> + - mpu6500
>>> + - mpu9150
>>
> The driver currently only lists i2c_device_id and this will work
> ignoring the vendor string. I can prefix all these valid strings with
> the vendor prefix but this is not actually a requirement. That would
> require a separate unrelated patch adding of_device_id tables.
What the driver happens to do is irrelevant to the binding. From a
binding standpoint, the vendor prefix is always required.
Rob
^ permalink raw reply [flat|nested] 5+ messages in thread
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2016-05-01 17:27 ` [RFC 5/7] iio: inv_mpu6050: Add support for auxiliary I2C master Jonathan Cameron
2016-05-05 12:38 ` Crestez Dan Leonard
2016-05-05 13:10 ` Rob Herring
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2016-05-02 12:15 ` Rob Herring
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