[PATCH] iio: accel: mma8452: code improvements to handle more than one event

From: Harinath Nampally
Date: Fri Aug 18 2017 - 22:09:01 EST


This driver supports multiple devices like mma8653, mma8652, mma8452, mma8453 and
fxls8471. Almost all these devices have more than one event. Current driver design
hardcodes the event specific information, so only one event can be supported by this
driver and current design doesn't have the flexibility to add more events.

This patch improves by detaching the event related information from chip_info struct,
and based on channel type and event direction the corresponding event configuration registers
are picked dynamically. Hence both transient and freefall events can be handled in read/write callbacks.

Changes are thoroughly tested on fxls8471 device on imx6UL Eval board using iio_event_monitor user space program.

After this fix both Freefall and Transient events are handled by the driver without any conflicts.

Changes since v2 -> v3
-Fix typo in commit message
-Replace word 'Bugfix' with 'Improvements'
-Describe more accurate commit message
-Replace breaks with returns
-Initialise transient event threshold mask
-Remove unrelated change of IIO_ACCEL channel type check in read/write event callbacks

Changes since v1 -> v2
-Fix indentations
-Remove unused fields in mma8452_event_regs struct
-Remove redundant return statement
-Remove unrelated changes like checkpatch.pl warning fixes

Signed-off-by: Harinath Nampally <harinath922@xxxxxxxxx>
---
drivers/iio/accel/mma8452.c | 272 +++++++++++++++++++-------------------------
1 file changed, 118 insertions(+), 154 deletions(-)

diff --git a/drivers/iio/accel/mma8452.c b/drivers/iio/accel/mma8452.c
index eb6e3dc..8de9928 100644
--- a/drivers/iio/accel/mma8452.c
+++ b/drivers/iio/accel/mma8452.c
@@ -59,7 +59,9 @@
#define MMA8452_FF_MT_THS 0x17
#define MMA8452_FF_MT_THS_MASK 0x7f
#define MMA8452_FF_MT_COUNT 0x18
+#define MMA8452_FF_MT_CHAN_SHIFT 3
#define MMA8452_TRANSIENT_CFG 0x1d
+#define MMA8452_TRANSIENT_CFG_CHAN(chan) BIT(chan + 1)
#define MMA8452_TRANSIENT_CFG_HPF_BYP BIT(0)
#define MMA8452_TRANSIENT_CFG_ELE BIT(4)
#define MMA8452_TRANSIENT_SRC 0x1e
@@ -69,6 +71,7 @@
#define MMA8452_TRANSIENT_THS 0x1f
#define MMA8452_TRANSIENT_THS_MASK GENMASK(6, 0)
#define MMA8452_TRANSIENT_COUNT 0x20
+#define MMA8452_TRANSIENT_CHAN_SHIFT 1
#define MMA8452_CTRL_REG1 0x2a
#define MMA8452_CTRL_ACTIVE BIT(0)
#define MMA8452_CTRL_DR_MASK GENMASK(5, 3)
@@ -107,6 +110,26 @@ struct mma8452_data {
const struct mma_chip_info *chip_info;
};

+ /**
+ * struct mma8452_event_regs - chip specific data related to events
+ * @ev_cfg: event config register address
+ * @ev_src: event source register address
+ * @ev_ths: event threshold register address
+ * @ev_ths_mask: mask for the threshold value
+ * @ev_count: event count (period) register address
+ *
+ * Since not all chips supported by the driver support comparing high pass
+ * filtered data for events (interrupts), different interrupt sources are
+ * used for different chips and the relevant registers are included here.
+ */
+struct mma8452_event_regs {
+ u8 ev_cfg;
+ u8 ev_src;
+ u8 ev_ths;
+ u8 ev_ths_mask;
+ u8 ev_count;
+};
+
/**
* struct mma_chip_info - chip specific data
* @chip_id: WHO_AM_I register's value
@@ -116,40 +139,12 @@ struct mma8452_data {
* @mma_scales: scale factors for converting register values
* to m/s^2; 3 modes: 2g, 4g, 8g; 2 integers
* per mode: m/s^2 and micro m/s^2
- * @ev_cfg: event config register address
- * @ev_cfg_ele: latch bit in event config register
- * @ev_cfg_chan_shift: number of the bit to enable events in X
- * direction; in event config register
- * @ev_src: event source register address
- * @ev_src_xe: bit in event source register that indicates
- * an event in X direction
- * @ev_src_ye: bit in event source register that indicates
- * an event in Y direction
- * @ev_src_ze: bit in event source register that indicates
- * an event in Z direction
- * @ev_ths: event threshold register address
- * @ev_ths_mask: mask for the threshold value
- * @ev_count: event count (period) register address
- *
- * Since not all chips supported by the driver support comparing high pass
- * filtered data for events (interrupts), different interrupt sources are
- * used for different chips and the relevant registers are included here.
*/
struct mma_chip_info {
u8 chip_id;
const struct iio_chan_spec *channels;
int num_channels;
const int mma_scales[3][2];
- u8 ev_cfg;
- u8 ev_cfg_ele;
- u8 ev_cfg_chan_shift;
- u8 ev_src;
- u8 ev_src_xe;
- u8 ev_src_ye;
- u8 ev_src_ze;
- u8 ev_ths;
- u8 ev_ths_mask;
- u8 ev_count;
};

enum {
@@ -602,9 +597,8 @@ static int mma8452_set_power_mode(struct mma8452_data *data, u8 mode)
static int mma8452_freefall_mode_enabled(struct mma8452_data *data)
{
int val;
- const struct mma_chip_info *chip = data->chip_info;

- val = i2c_smbus_read_byte_data(data->client, chip->ev_cfg);
+ val = i2c_smbus_read_byte_data(data->client, MMA8452_FF_MT_CFG);
if (val < 0)
return val;

@@ -614,29 +608,28 @@ static int mma8452_freefall_mode_enabled(struct mma8452_data *data)
static int mma8452_set_freefall_mode(struct mma8452_data *data, bool state)
{
int val;
- const struct mma_chip_info *chip = data->chip_info;

if ((state && mma8452_freefall_mode_enabled(data)) ||
(!state && !(mma8452_freefall_mode_enabled(data))))
return 0;

- val = i2c_smbus_read_byte_data(data->client, chip->ev_cfg);
+ val = i2c_smbus_read_byte_data(data->client, MMA8452_FF_MT_CFG);
if (val < 0)
return val;

if (state) {
- val |= BIT(idx_x + chip->ev_cfg_chan_shift);
- val |= BIT(idx_y + chip->ev_cfg_chan_shift);
- val |= BIT(idx_z + chip->ev_cfg_chan_shift);
+ val |= BIT(idx_x + MMA8452_FF_MT_CHAN_SHIFT);
+ val |= BIT(idx_y + MMA8452_FF_MT_CHAN_SHIFT);
+ val |= BIT(idx_z + MMA8452_FF_MT_CHAN_SHIFT);
val &= ~MMA8452_FF_MT_CFG_OAE;
} else {
- val &= ~BIT(idx_x + chip->ev_cfg_chan_shift);
- val &= ~BIT(idx_y + chip->ev_cfg_chan_shift);
- val &= ~BIT(idx_z + chip->ev_cfg_chan_shift);
+ val &= ~BIT(idx_x + MMA8452_FF_MT_CHAN_SHIFT);
+ val &= ~BIT(idx_y + MMA8452_FF_MT_CHAN_SHIFT);
+ val &= ~BIT(idx_z + MMA8452_FF_MT_CHAN_SHIFT);
val |= MMA8452_FF_MT_CFG_OAE;
}

- return mma8452_change_config(data, chip->ev_cfg, val);
+ return mma8452_change_config(data, MMA8452_FF_MT_CFG, val);
}

static int mma8452_set_hp_filter_frequency(struct mma8452_data *data,
@@ -740,6 +733,39 @@ static int mma8452_write_raw(struct iio_dev *indio_dev,
return ret;
}

+static int mma8452_get_event_regs(const struct iio_chan_spec *chan,
+ enum iio_event_direction dir,
+ struct mma8452_event_regs *ev_regs
+ )
+{
+ if (!chan)
+ return -EINVAL;
+ switch (chan->type) {
+ case IIO_ACCEL:
+ switch (dir) {
+ case IIO_EV_DIR_FALLING:
+ ev_regs->ev_cfg = MMA8452_FF_MT_CFG;
+ ev_regs->ev_src = MMA8452_FF_MT_SRC;
+ ev_regs->ev_ths = MMA8452_FF_MT_THS;
+ ev_regs->ev_ths_mask = MMA8452_FF_MT_THS_MASK;
+ ev_regs->ev_count = MMA8452_FF_MT_COUNT;
+ return 0;
+ case IIO_EV_DIR_RISING:
+ ev_regs->ev_cfg = MMA8452_TRANSIENT_CFG;
+ ev_regs->ev_src = MMA8452_TRANSIENT_SRC;
+ ev_regs->ev_ths = MMA8452_TRANSIENT_THS;
+ ev_regs->ev_ths_mask = MMA8452_TRANSIENT_THS_MASK;
+ ev_regs->ev_count = MMA8452_TRANSIENT_COUNT;
+ return 0;
+ default:
+ return -EINVAL;
+ }
+ break;
+ default:
+ return -EINVAL;
+ }
+}
+
static int mma8452_read_thresh(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan,
enum iio_event_type type,
@@ -749,21 +775,23 @@ static int mma8452_read_thresh(struct iio_dev *indio_dev,
{
struct mma8452_data *data = iio_priv(indio_dev);
int ret, us, power_mode;
+ struct mma8452_event_regs ev_regs;

+ ret = mma8452_get_event_regs(chan, dir, &ev_regs);
+ if (ret)
+ return ret;
switch (info) {
case IIO_EV_INFO_VALUE:
- ret = i2c_smbus_read_byte_data(data->client,
- data->chip_info->ev_ths);
+ ret = i2c_smbus_read_byte_data(data->client, ev_regs.ev_ths);
if (ret < 0)
return ret;

- *val = ret & data->chip_info->ev_ths_mask;
+ *val = ret & ev_regs.ev_ths_mask;

return IIO_VAL_INT;

case IIO_EV_INFO_PERIOD:
- ret = i2c_smbus_read_byte_data(data->client,
- data->chip_info->ev_count);
+ ret = i2c_smbus_read_byte_data(data->client, ev_regs.ev_count);
if (ret < 0)
return ret;

@@ -809,14 +837,18 @@ static int mma8452_write_thresh(struct iio_dev *indio_dev,
{
struct mma8452_data *data = iio_priv(indio_dev);
int ret, reg, steps;
+ struct mma8452_event_regs ev_regs;
+
+ ret = mma8452_get_event_regs(chan, dir, &ev_regs);
+ if (ret)
+ return ret;

switch (info) {
case IIO_EV_INFO_VALUE:
- if (val < 0 || val > MMA8452_TRANSIENT_THS_MASK)
+ if (val < 0 || val > ev_regs.ev_ths_mask)
return -EINVAL;

- return mma8452_change_config(data, data->chip_info->ev_ths,
- val);
+ return mma8452_change_config(data, ev_regs.ev_ths, val);

case IIO_EV_INFO_PERIOD:
ret = mma8452_get_power_mode(data);
@@ -830,8 +862,7 @@ static int mma8452_write_thresh(struct iio_dev *indio_dev,
if (steps < 0 || steps > 0xff)
return -EINVAL;

- return mma8452_change_config(data, data->chip_info->ev_count,
- steps);
+ return mma8452_change_config(data, ev_regs.ev_count, steps);

case IIO_EV_INFO_HIGH_PASS_FILTER_3DB:
reg = i2c_smbus_read_byte_data(data->client,
@@ -861,23 +892,18 @@ static int mma8452_read_event_config(struct iio_dev *indio_dev,
enum iio_event_direction dir)
{
struct mma8452_data *data = iio_priv(indio_dev);
- const struct mma_chip_info *chip = data->chip_info;
int ret;

switch (dir) {
case IIO_EV_DIR_FALLING:
return mma8452_freefall_mode_enabled(data);
case IIO_EV_DIR_RISING:
- if (mma8452_freefall_mode_enabled(data))
- return 0;
-
- ret = i2c_smbus_read_byte_data(data->client,
- data->chip_info->ev_cfg);
+ ret = i2c_smbus_read_byte_data(data->client, MMA8452_TRANSIENT_CFG);
if (ret < 0)
return ret;

- return !!(ret & BIT(chan->scan_index +
- chip->ev_cfg_chan_shift));
+ return !!(ret & MMA8452_TRANSIENT_CFG_CHAN(chan->scan_index));
+
default:
return -EINVAL;
}
@@ -890,7 +916,6 @@ static int mma8452_write_event_config(struct iio_dev *indio_dev,
int state)
{
struct mma8452_data *data = iio_priv(indio_dev);
- const struct mma_chip_info *chip = data->chip_info;
int val, ret;

ret = mma8452_set_runtime_pm_state(data->client, state);
@@ -901,28 +926,18 @@ static int mma8452_write_event_config(struct iio_dev *indio_dev,
case IIO_EV_DIR_FALLING:
return mma8452_set_freefall_mode(data, state);
case IIO_EV_DIR_RISING:
- val = i2c_smbus_read_byte_data(data->client, chip->ev_cfg);
+ val = i2c_smbus_read_byte_data(data->client, MMA8452_TRANSIENT_CFG);
if (val < 0)
return val;

- if (state) {
- if (mma8452_freefall_mode_enabled(data)) {
- val &= ~BIT(idx_x + chip->ev_cfg_chan_shift);
- val &= ~BIT(idx_y + chip->ev_cfg_chan_shift);
- val &= ~BIT(idx_z + chip->ev_cfg_chan_shift);
- val |= MMA8452_FF_MT_CFG_OAE;
- }
- val |= BIT(chan->scan_index + chip->ev_cfg_chan_shift);
- } else {
- if (mma8452_freefall_mode_enabled(data))
- return 0;
+ if (state)
+ val |= MMA8452_TRANSIENT_CFG_CHAN(chan->scan_index);
+ else
+ val &= ~MMA8452_TRANSIENT_CFG_CHAN(chan->scan_index);

- val &= ~BIT(chan->scan_index + chip->ev_cfg_chan_shift);
- }
-
- val |= chip->ev_cfg_ele;
+ val |= MMA8452_TRANSIENT_CFG_ELE;

- return mma8452_change_config(data, chip->ev_cfg, val);
+ return mma8452_change_config(data, MMA8452_TRANSIENT_CFG, val);
default:
return -EINVAL;
}
@@ -934,35 +949,25 @@ static void mma8452_transient_interrupt(struct iio_dev *indio_dev)
s64 ts = iio_get_time_ns(indio_dev);
int src;

- src = i2c_smbus_read_byte_data(data->client, data->chip_info->ev_src);
+ src = i2c_smbus_read_byte_data(data->client, MMA8452_TRANSIENT_SRC);
if (src < 0)
return;

- if (mma8452_freefall_mode_enabled(data)) {
- iio_push_event(indio_dev,
- IIO_MOD_EVENT_CODE(IIO_ACCEL, 0,
- IIO_MOD_X_AND_Y_AND_Z,
- IIO_EV_TYPE_MAG,
- IIO_EV_DIR_FALLING),
- ts);
- return;
- }
-
- if (src & data->chip_info->ev_src_xe)
+ if (src & MMA8452_TRANSIENT_SRC_XTRANSE)
iio_push_event(indio_dev,
IIO_MOD_EVENT_CODE(IIO_ACCEL, 0, IIO_MOD_X,
IIO_EV_TYPE_MAG,
IIO_EV_DIR_RISING),
ts);

- if (src & data->chip_info->ev_src_ye)
+ if (src & MMA8452_TRANSIENT_SRC_YTRANSE)
iio_push_event(indio_dev,
IIO_MOD_EVENT_CODE(IIO_ACCEL, 0, IIO_MOD_Y,
IIO_EV_TYPE_MAG,
IIO_EV_DIR_RISING),
ts);

- if (src & data->chip_info->ev_src_ze)
+ if (src & MMA8452_TRANSIENT_SRC_ZTRANSE)
iio_push_event(indio_dev,
IIO_MOD_EVENT_CODE(IIO_ACCEL, 0, IIO_MOD_Z,
IIO_EV_TYPE_MAG,
@@ -974,23 +979,42 @@ static irqreturn_t mma8452_interrupt(int irq, void *p)
{
struct iio_dev *indio_dev = p;
struct mma8452_data *data = iio_priv(indio_dev);
- const struct mma_chip_info *chip = data->chip_info;
int ret = IRQ_NONE;
int src;
+ int enabled_interrupts;

src = i2c_smbus_read_byte_data(data->client, MMA8452_INT_SRC);
if (src < 0)
return IRQ_NONE;

+ enabled_interrupts = i2c_smbus_read_byte_data(data->client,
+ MMA8452_CTRL_REG4);
+ if (enabled_interrupts < 0)
+ return enabled_interrupts;
+
+ if (!(src & enabled_interrupts))
+ return IRQ_NONE;
+
if (src & MMA8452_INT_DRDY) {
iio_trigger_poll_chained(indio_dev->trig);
ret = IRQ_HANDLED;
}

- if ((src & MMA8452_INT_TRANS &&
- chip->ev_src == MMA8452_TRANSIENT_SRC) ||
- (src & MMA8452_INT_FF_MT &&
- chip->ev_src == MMA8452_FF_MT_SRC)) {
+ if (src & MMA8452_INT_FF_MT) {
+ if (mma8452_freefall_mode_enabled(data)) {
+ s64 ts = iio_get_time_ns(indio_dev);
+
+ iio_push_event(indio_dev,
+ IIO_MOD_EVENT_CODE(IIO_ACCEL, 0,
+ IIO_MOD_X_AND_Y_AND_Z,
+ IIO_EV_TYPE_MAG,
+ IIO_EV_DIR_FALLING),
+ ts);
+ }
+ ret = IRQ_HANDLED;
+ }
+
+ if (src & MMA8452_INT_TRANS) {
mma8452_transient_interrupt(indio_dev);
ret = IRQ_HANDLED;
}
@@ -1222,96 +1246,36 @@ static const struct mma_chip_info mma_chip_info_table[] = {
* g * N * 1000000 / 2048 for N = 2, 4, 8 and g=9.80665
*/
.mma_scales = { {0, 2394}, {0, 4788}, {0, 9577} },
- .ev_cfg = MMA8452_TRANSIENT_CFG,
- .ev_cfg_ele = MMA8452_TRANSIENT_CFG_ELE,
- .ev_cfg_chan_shift = 1,
- .ev_src = MMA8452_TRANSIENT_SRC,
- .ev_src_xe = MMA8452_TRANSIENT_SRC_XTRANSE,
- .ev_src_ye = MMA8452_TRANSIENT_SRC_YTRANSE,
- .ev_src_ze = MMA8452_TRANSIENT_SRC_ZTRANSE,
- .ev_ths = MMA8452_TRANSIENT_THS,
- .ev_ths_mask = MMA8452_TRANSIENT_THS_MASK,
- .ev_count = MMA8452_TRANSIENT_COUNT,
},
[mma8452] = {
.chip_id = MMA8452_DEVICE_ID,
.channels = mma8452_channels,
.num_channels = ARRAY_SIZE(mma8452_channels),
.mma_scales = { {0, 9577}, {0, 19154}, {0, 38307} },
- .ev_cfg = MMA8452_TRANSIENT_CFG,
- .ev_cfg_ele = MMA8452_TRANSIENT_CFG_ELE,
- .ev_cfg_chan_shift = 1,
- .ev_src = MMA8452_TRANSIENT_SRC,
- .ev_src_xe = MMA8452_TRANSIENT_SRC_XTRANSE,
- .ev_src_ye = MMA8452_TRANSIENT_SRC_YTRANSE,
- .ev_src_ze = MMA8452_TRANSIENT_SRC_ZTRANSE,
- .ev_ths = MMA8452_TRANSIENT_THS,
- .ev_ths_mask = MMA8452_TRANSIENT_THS_MASK,
- .ev_count = MMA8452_TRANSIENT_COUNT,
},
[mma8453] = {
.chip_id = MMA8453_DEVICE_ID,
.channels = mma8453_channels,
.num_channels = ARRAY_SIZE(mma8453_channels),
.mma_scales = { {0, 38307}, {0, 76614}, {0, 153228} },
- .ev_cfg = MMA8452_TRANSIENT_CFG,
- .ev_cfg_ele = MMA8452_TRANSIENT_CFG_ELE,
- .ev_cfg_chan_shift = 1,
- .ev_src = MMA8452_TRANSIENT_SRC,
- .ev_src_xe = MMA8452_TRANSIENT_SRC_XTRANSE,
- .ev_src_ye = MMA8452_TRANSIENT_SRC_YTRANSE,
- .ev_src_ze = MMA8452_TRANSIENT_SRC_ZTRANSE,
- .ev_ths = MMA8452_TRANSIENT_THS,
- .ev_ths_mask = MMA8452_TRANSIENT_THS_MASK,
- .ev_count = MMA8452_TRANSIENT_COUNT,
},
[mma8652] = {
.chip_id = MMA8652_DEVICE_ID,
.channels = mma8652_channels,
.num_channels = ARRAY_SIZE(mma8652_channels),
.mma_scales = { {0, 9577}, {0, 19154}, {0, 38307} },
- .ev_cfg = MMA8452_FF_MT_CFG,
- .ev_cfg_ele = MMA8452_FF_MT_CFG_ELE,
- .ev_cfg_chan_shift = 3,
- .ev_src = MMA8452_FF_MT_SRC,
- .ev_src_xe = MMA8452_FF_MT_SRC_XHE,
- .ev_src_ye = MMA8452_FF_MT_SRC_YHE,
- .ev_src_ze = MMA8452_FF_MT_SRC_ZHE,
- .ev_ths = MMA8452_FF_MT_THS,
- .ev_ths_mask = MMA8452_FF_MT_THS_MASK,
- .ev_count = MMA8452_FF_MT_COUNT,
},
[mma8653] = {
.chip_id = MMA8653_DEVICE_ID,
.channels = mma8653_channels,
.num_channels = ARRAY_SIZE(mma8653_channels),
.mma_scales = { {0, 38307}, {0, 76614}, {0, 153228} },
- .ev_cfg = MMA8452_FF_MT_CFG,
- .ev_cfg_ele = MMA8452_FF_MT_CFG_ELE,
- .ev_cfg_chan_shift = 3,
- .ev_src = MMA8452_FF_MT_SRC,
- .ev_src_xe = MMA8452_FF_MT_SRC_XHE,
- .ev_src_ye = MMA8452_FF_MT_SRC_YHE,
- .ev_src_ze = MMA8452_FF_MT_SRC_ZHE,
- .ev_ths = MMA8452_FF_MT_THS,
- .ev_ths_mask = MMA8452_FF_MT_THS_MASK,
- .ev_count = MMA8452_FF_MT_COUNT,
},
[fxls8471] = {
.chip_id = FXLS8471_DEVICE_ID,
.channels = mma8451_channels,
.num_channels = ARRAY_SIZE(mma8451_channels),
.mma_scales = { {0, 2394}, {0, 4788}, {0, 9577} },
- .ev_cfg = MMA8452_TRANSIENT_CFG,
- .ev_cfg_ele = MMA8452_TRANSIENT_CFG_ELE,
- .ev_cfg_chan_shift = 1,
- .ev_src = MMA8452_TRANSIENT_SRC,
- .ev_src_xe = MMA8452_TRANSIENT_SRC_XTRANSE,
- .ev_src_ye = MMA8452_TRANSIENT_SRC_YTRANSE,
- .ev_src_ze = MMA8452_TRANSIENT_SRC_ZTRANSE,
- .ev_ths = MMA8452_TRANSIENT_THS,
- .ev_ths_mask = MMA8452_TRANSIENT_THS_MASK,
- .ev_count = MMA8452_TRANSIENT_COUNT,
},
};

--
2.7.4