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// SPDX-License-Identifier: GPL-2.0
/*
* cros_ec_sensors_core - Common function for Chrome OS EC sensor driver.
*
* Copyright (C) 2016 Google, Inc
*/
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/iio/buffer.h>
#include <linux/iio/common/cros_ec_sensors_core.h>
#include <linux/iio/iio.h>
#include <linux/iio/kfifo_buf.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/kernel.h>
#include <linux/mfd/cros_ec.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/platform_data/cros_ec_commands.h>
#include <linux/platform_data/cros_ec_proto.h>
#include <linux/platform_device.h>
static char *cros_ec_loc[] = {
[MOTIONSENSE_LOC_BASE] = "base",
[MOTIONSENSE_LOC_LID] = "lid",
[MOTIONSENSE_LOC_MAX] = "unknown",
};
int cros_ec_sensors_core_init(struct platform_device *pdev,
struct iio_dev *indio_dev,
bool physical_device)
{
struct device *dev = &pdev->dev;
struct cros_ec_sensors_core_state *state = iio_priv(indio_dev);
struct cros_ec_dev *ec = dev_get_drvdata(pdev->dev.parent);
struct cros_ec_sensor_platform *sensor_platform = dev_get_platdata(dev);
platform_set_drvdata(pdev, indio_dev);
state->ec = ec->ec_dev;
state->msg = devm_kzalloc(&pdev->dev,
max((u16)sizeof(struct ec_params_motion_sense),
state->ec->max_response), GFP_KERNEL);
if (!state->msg)
return -ENOMEM;
state->resp = (struct ec_response_motion_sense *)state->msg->data;
mutex_init(&state->cmd_lock);
/* Set up the host command structure. */
state->msg->version = 2;
state->msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset;
state->msg->outsize = sizeof(struct ec_params_motion_sense);
indio_dev->dev.parent = &pdev->dev;
indio_dev->name = pdev->name;
if (physical_device) {
indio_dev->modes = INDIO_DIRECT_MODE;
state->param.cmd = MOTIONSENSE_CMD_INFO;
state->param.info.sensor_num = sensor_platform->sensor_num;
if (cros_ec_motion_send_host_cmd(state, 0)) {
dev_warn(dev, "Can not access sensor info\n");
return -EIO;
}
state->type = state->resp->info.type;
state->loc = state->resp->info.location;
}
return 0;
}
EXPORT_SYMBOL_GPL(cros_ec_sensors_core_init);
int cros_ec_motion_send_host_cmd(struct cros_ec_sensors_core_state *state,
u16 opt_length)
{
int ret;
if (opt_length)
state->msg->insize = min(opt_length, state->ec->max_response);
else
state->msg->insize = state->ec->max_response;
memcpy(state->msg->data, &state->param, sizeof(state->param));
ret = cros_ec_cmd_xfer_status(state->ec, state->msg);
if (ret < 0)
return -EIO;
if (ret &&
state->resp != (struct ec_response_motion_sense *)state->msg->data)
memcpy(state->resp, state->msg->data, ret);
return 0;
}
EXPORT_SYMBOL_GPL(cros_ec_motion_send_host_cmd);
static ssize_t cros_ec_sensors_calibrate(struct iio_dev *indio_dev,
uintptr_t private, const struct iio_chan_spec *chan,
const char *buf, size_t len)
{
struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
int ret, i;
bool calibrate;
ret = strtobool(buf, &calibrate);
if (ret < 0)
return ret;
if (!calibrate)
return -EINVAL;
mutex_lock(&st->cmd_lock);
st->param.cmd = MOTIONSENSE_CMD_PERFORM_CALIB;
ret = cros_ec_motion_send_host_cmd(st, 0);
if (ret != 0) {
dev_warn(&indio_dev->dev, "Unable to calibrate sensor\n");
} else {
/* Save values */
for (i = CROS_EC_SENSOR_X; i < CROS_EC_SENSOR_MAX_AXIS; i++)
st->calib[i] = st->resp->perform_calib.offset[i];
}
mutex_unlock(&st->cmd_lock);
return ret ? ret : len;
}
static ssize_t cros_ec_sensors_id(struct iio_dev *indio_dev,
uintptr_t private,
const struct iio_chan_spec *chan, char *buf)
{
struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
return snprintf(buf, PAGE_SIZE, "%d\n", st->param.info.sensor_num);
}
static ssize_t cros_ec_sensors_loc(struct iio_dev *indio_dev,
uintptr_t private, const struct iio_chan_spec *chan,
char *buf)
{
struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
return snprintf(buf, PAGE_SIZE, "%s\n", cros_ec_loc[st->loc]);
}
const struct iio_chan_spec_ext_info cros_ec_sensors_ext_info[] = {
{
.name = "calibrate",
.shared = IIO_SHARED_BY_ALL,
.write = cros_ec_sensors_calibrate
},
{
.name = "id",
.shared = IIO_SHARED_BY_ALL,
.read = cros_ec_sensors_id
},
{
.name = "location",
.shared = IIO_SHARED_BY_ALL,
.read = cros_ec_sensors_loc
},
{ },
};
EXPORT_SYMBOL_GPL(cros_ec_sensors_ext_info);
/**
* cros_ec_sensors_idx_to_reg - convert index into offset in shared memory
* @st: pointer to state information for device
* @idx: sensor index (should be element of enum sensor_index)
*
* Return: address to read at
*/
static unsigned int cros_ec_sensors_idx_to_reg(
struct cros_ec_sensors_core_state *st,
unsigned int idx)
{
/*
* When using LPC interface, only space for 2 Accel and one Gyro.
* First halfword of MOTIONSENSE_TYPE_ACCEL is used by angle.
*/
if (st->type == MOTIONSENSE_TYPE_ACCEL)
return EC_MEMMAP_ACC_DATA + sizeof(u16) *
(1 + idx + st->param.info.sensor_num *
CROS_EC_SENSOR_MAX_AXIS);
return EC_MEMMAP_GYRO_DATA + sizeof(u16) * idx;
}
static int cros_ec_sensors_cmd_read_u8(struct cros_ec_device *ec,
unsigned int offset, u8 *dest)
{
return ec->cmd_readmem(ec, offset, 1, dest);
}
static int cros_ec_sensors_cmd_read_u16(struct cros_ec_device *ec,
unsigned int offset, u16 *dest)
{
__le16 tmp;
int ret = ec->cmd_readmem(ec, offset, 2, &tmp);
if (ret >= 0)
*dest = le16_to_cpu(tmp);
return ret;
}
/**
* cros_ec_sensors_read_until_not_busy() - read until is not busy
*
* @st: pointer to state information for device
*
* Read from EC status byte until it reads not busy.
* Return: 8-bit status if ok, -errno on failure.
*/
static int cros_ec_sensors_read_until_not_busy(
struct cros_ec_sensors_core_state *st)
{
struct cros_ec_device *ec = st->ec;
u8 status;
int ret, attempts = 0;
ret = cros_ec_sensors_cmd_read_u8(ec, EC_MEMMAP_ACC_STATUS, &status);
if (ret < 0)
return ret;
while (status & EC_MEMMAP_ACC_STATUS_BUSY_BIT) {
/* Give up after enough attempts, return error. */
if (attempts++ >= 50)
return -EIO;
/* Small delay every so often. */
if (attempts % 5 == 0)
msleep(25);
ret = cros_ec_sensors_cmd_read_u8(ec, EC_MEMMAP_ACC_STATUS,
&status);
if (ret < 0)
return ret;
}
return status;
}
/**
* read_ec_sensors_data_unsafe() - read acceleration data from EC shared memory
* @indio_dev: pointer to IIO device
* @scan_mask: bitmap of the sensor indices to scan
* @data: location to store data
*
* This is the unsafe function for reading the EC data. It does not guarantee
* that the EC will not modify the data as it is being read in.
*
* Return: 0 on success, -errno on failure.
*/
static int cros_ec_sensors_read_data_unsafe(struct iio_dev *indio_dev,
unsigned long scan_mask, s16 *data)
{
struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
struct cros_ec_device *ec = st->ec;
unsigned int i;
int ret;
/* Read all sensors enabled in scan_mask. Each value is 2 bytes. */
for_each_set_bit(i, &scan_mask, indio_dev->masklength) {
ret = cros_ec_sensors_cmd_read_u16(ec,
cros_ec_sensors_idx_to_reg(st, i),
data);
if (ret < 0)
return ret;
data++;
}
return 0;
}
/**
* cros_ec_sensors_read_lpc() - read acceleration data from EC shared memory.
* @indio_dev: pointer to IIO device.
* @scan_mask: bitmap of the sensor indices to scan.
* @data: location to store data.
*
* Note: this is the safe function for reading the EC data. It guarantees
* that the data sampled was not modified by the EC while being read.
*
* Return: 0 on success, -errno on failure.
*/
int cros_ec_sensors_read_lpc(struct iio_dev *indio_dev,
unsigned long scan_mask, s16 *data)
{
struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
struct cros_ec_device *ec = st->ec;
u8 samp_id = 0xff, status = 0;
int ret, attempts = 0;
/*
* Continually read all data from EC until the status byte after
* all reads reflects that the EC is not busy and the sample id
* matches the sample id from before all reads. This guarantees
* that data read in was not modified by the EC while reading.
*/
while ((status & (EC_MEMMAP_ACC_STATUS_BUSY_BIT |
EC_MEMMAP_ACC_STATUS_SAMPLE_ID_MASK)) != samp_id) {
/* If we have tried to read too many times, return error. */
if (attempts++ >= 5)
return -EIO;
/* Read status byte until EC is not busy. */
ret = cros_ec_sensors_read_until_not_busy(st);
if (ret < 0)
return ret;
/*
* Store the current sample id so that we can compare to the
* sample id after reading the data.
*/
samp_id = ret & EC_MEMMAP_ACC_STATUS_SAMPLE_ID_MASK;
/* Read all EC data, format it, and store it into data. */
ret = cros_ec_sensors_read_data_unsafe(indio_dev, scan_mask,
data);
if (ret < 0)
return ret;
/* Read status byte. */
ret = cros_ec_sensors_cmd_read_u8(ec, EC_MEMMAP_ACC_STATUS,
&status);
if (ret < 0)
return ret;
}
return 0;
}
EXPORT_SYMBOL_GPL(cros_ec_sensors_read_lpc);
int cros_ec_sensors_read_cmd(struct iio_dev *indio_dev,
unsigned long scan_mask, s16 *data)
{
struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
int ret;
unsigned int i;
/* Read all sensor data through a command. */
st->param.cmd = MOTIONSENSE_CMD_DATA;
ret = cros_ec_motion_send_host_cmd(st, sizeof(st->resp->data));
if (ret != 0) {
dev_warn(&indio_dev->dev, "Unable to read sensor data\n");
return ret;
}
for_each_set_bit(i, &scan_mask, indio_dev->masklength) {
*data = st->resp->data.data[i];
data++;
}
return 0;
}
EXPORT_SYMBOL_GPL(cros_ec_sensors_read_cmd);
irqreturn_t cros_ec_sensors_capture(int irq, void *p)
{
struct iio_poll_func *pf = p;
struct iio_dev *indio_dev = pf->indio_dev;
struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
int ret;
mutex_lock(&st->cmd_lock);
/* Clear capture data. */
memset(st->samples, 0, indio_dev->scan_bytes);
/* Read data based on which channels are enabled in scan mask. */
ret = st->read_ec_sensors_data(indio_dev,
*(indio_dev->active_scan_mask),
(s16 *)st->samples);
if (ret < 0)
goto done;
iio_push_to_buffers_with_timestamp(indio_dev, st->samples,
iio_get_time_ns(indio_dev));
done:
/*
* Tell the core we are done with this trigger and ready for the
* next one.
*/
iio_trigger_notify_done(indio_dev->trig);
mutex_unlock(&st->cmd_lock);
return IRQ_HANDLED;
}
EXPORT_SYMBOL_GPL(cros_ec_sensors_capture);
int cros_ec_sensors_core_read(struct cros_ec_sensors_core_state *st,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
int ret = IIO_VAL_INT;
switch (mask) {
case IIO_CHAN_INFO_SAMP_FREQ:
st->param.cmd = MOTIONSENSE_CMD_EC_RATE;
st->param.ec_rate.data =
EC_MOTION_SENSE_NO_VALUE;
if (cros_ec_motion_send_host_cmd(st, 0))
ret = -EIO;
else
*val = st->resp->ec_rate.ret;
break;
case IIO_CHAN_INFO_FREQUENCY:
st->param.cmd = MOTIONSENSE_CMD_SENSOR_ODR;
st->param.sensor_odr.data =
EC_MOTION_SENSE_NO_VALUE;
if (cros_ec_motion_send_host_cmd(st, 0))
ret = -EIO;
else
*val = st->resp->sensor_odr.ret;
break;
default:
break;
}
return ret;
}
EXPORT_SYMBOL_GPL(cros_ec_sensors_core_read);
int cros_ec_sensors_core_write(struct cros_ec_sensors_core_state *st,
struct iio_chan_spec const *chan,
int val, int val2, long mask)
{
int ret = 0;
switch (mask) {
case IIO_CHAN_INFO_FREQUENCY:
st->param.cmd = MOTIONSENSE_CMD_SENSOR_ODR;
st->param.sensor_odr.data = val;
/* Always roundup, so caller gets at least what it asks for. */
st->param.sensor_odr.roundup = 1;
if (cros_ec_motion_send_host_cmd(st, 0))
ret = -EIO;
break;
case IIO_CHAN_INFO_SAMP_FREQ:
st->param.cmd = MOTIONSENSE_CMD_EC_RATE;
st->param.ec_rate.data = val;
if (cros_ec_motion_send_host_cmd(st, 0))
ret = -EIO;
else
st->curr_sampl_freq = val;
break;
default:
ret = -EINVAL;
break;
}
return ret;
}
EXPORT_SYMBOL_GPL(cros_ec_sensors_core_write);
static int __maybe_unused cros_ec_sensors_prepare(struct device *dev)
{
struct iio_dev *indio_dev = dev_get_drvdata(dev);
struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
if (st->curr_sampl_freq == 0)
return 0;
/*
* If the sensors are sampled at high frequency, we will not be able to
* sleep. Set sampling to a long period if necessary.
*/
if (st->curr_sampl_freq < CROS_EC_MIN_SUSPEND_SAMPLING_FREQUENCY) {
mutex_lock(&st->cmd_lock);
st->param.cmd = MOTIONSENSE_CMD_EC_RATE;
st->param.ec_rate.data = CROS_EC_MIN_SUSPEND_SAMPLING_FREQUENCY;
cros_ec_motion_send_host_cmd(st, 0);
mutex_unlock(&st->cmd_lock);
}
return 0;
}
static void __maybe_unused cros_ec_sensors_complete(struct device *dev)
{
struct iio_dev *indio_dev = dev_get_drvdata(dev);
struct cros_ec_sensors_core_state *st = iio_priv(indio_dev);
if (st->curr_sampl_freq == 0)
return;
if (st->curr_sampl_freq < CROS_EC_MIN_SUSPEND_SAMPLING_FREQUENCY) {
mutex_lock(&st->cmd_lock);
st->param.cmd = MOTIONSENSE_CMD_EC_RATE;
st->param.ec_rate.data = st->curr_sampl_freq;
cros_ec_motion_send_host_cmd(st, 0);
mutex_unlock(&st->cmd_lock);
}
}
const struct dev_pm_ops cros_ec_sensors_pm_ops = {
#ifdef CONFIG_PM_SLEEP
.prepare = cros_ec_sensors_prepare,
.complete = cros_ec_sensors_complete
#endif
};
EXPORT_SYMBOL_GPL(cros_ec_sensors_pm_ops);
MODULE_DESCRIPTION("ChromeOS EC sensor hub core functions");
MODULE_LICENSE("GPL v2");
|