Re: [PATCH v3 1/4] mfd: cros_ec: Get rid of cros_ec_check_features from cros_ec_dev.

From: Gwendal Grignou
Date: Thu Jul 13 2017 - 16:34:18 EST


On Wed, Jul 12, 2017 at 3:13 AM, Enric Balletbo i Serra
<enric.balletbo@xxxxxxxxxxxxx> wrote:
> The cros_ec_dev driver should be used only to expose the Chrome OS Embedded
> Controller to user-space and should not be used to add MFD devices by
> calling mfd_add_devices. This patch moves this logic to the MFD cros_ec
> driver and removes the MFD bits from the character device driver. Also
> makes independent the IIO driver from the character device as also has no
> sense.

cros_ec_dev serves another purpose: it allows to represent an EC that
does not have a cros_ec structure. It happens when there are several
EC in a chromebook, and one EC is connected through another EC.
One example is Samus (Pixel 2): where we have:

(main SOC, Application Processor) AP --> (main Embedded Controller) EC
---> (Power Delivery [PD}) EC

We access to the PD EC via pass-through commands through the main EC.
Each EC has a cros_ec_dev structure, but only the main EC as a
cros_ec_device structure (I will forever regret the structure names).

Now form the AP point of view, both ECs use the same protocol. That
why the sensors and other devcies that are registered by looking at
the feature fields are registered with cros_ec_dev as their parent.
Other devices that are registered from the device tree, predating the
feature field support, are registered with cros_ec_device as their
parent.

Gwendal.

>
> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@xxxxxxxxxxxxx>
> Acked-by: Jonathan Cameron <jic23@xxxxxxxxxx>
> ---
> .../iio/common/cros_ec_sensors/cros_ec_sensors.c | 8 -
> .../common/cros_ec_sensors/cros_ec_sensors_core.c | 8 +-
> drivers/iio/light/cros_ec_light_prox.c | 8 -
> drivers/iio/pressure/cros_ec_baro.c | 8 -
> drivers/mfd/cros_ec.c | 160 ++++++++++++++++++++
> drivers/platform/chrome/cros_ec_dev.c | 161 ---------------------
> include/linux/mfd/cros_ec.h | 6 +-
> 7 files changed, 170 insertions(+), 189 deletions(-)
>
> diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c
> index 38e8783..9b53a01 100644
> --- a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c
> +++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c
> @@ -191,19 +191,11 @@ static const struct iio_info ec_sensors_info = {
> static int cros_ec_sensors_probe(struct platform_device *pdev)
> {
> struct device *dev = &pdev->dev;
> - struct cros_ec_dev *ec_dev = dev_get_drvdata(dev->parent);
> - struct cros_ec_device *ec_device;
> struct iio_dev *indio_dev;
> struct cros_ec_sensors_state *state;
> struct iio_chan_spec *channel;
> int ret, i;
>
> - if (!ec_dev || !ec_dev->ec_dev) {
> - dev_warn(&pdev->dev, "No CROS EC device found.\n");
> - return -EINVAL;
> - }
> - ec_device = ec_dev->ec_dev;
> -
> indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*state));
> if (!indio_dev)
> return -ENOMEM;
> diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
> index 416cae5..0cdb64a 100644
> --- a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
> +++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
> @@ -41,12 +41,13 @@ int cros_ec_sensors_core_init(struct platform_device *pdev,
> {
> 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_device *ec_dev = 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->ec = ec_dev;
> +
> state->msg = devm_kzalloc(&pdev->dev,
> max((u16)sizeof(struct ec_params_motion_sense),
> state->ec->max_response), GFP_KERNEL);
> @@ -59,7 +60,8 @@ int cros_ec_sensors_core_init(struct platform_device *pdev,
>
> /* Set up the host command structure. */
> state->msg->version = 2;
> - state->msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset;
> + state->msg->command = EC_CMD_MOTION_SENSE_CMD +
> + sensor_platform->cmd_offset;
> state->msg->outsize = sizeof(struct ec_params_motion_sense);
>
> indio_dev->dev.parent = &pdev->dev;
> diff --git a/drivers/iio/light/cros_ec_light_prox.c b/drivers/iio/light/cros_ec_light_prox.c
> index 7217223..2133ddc 100644
> --- a/drivers/iio/light/cros_ec_light_prox.c
> +++ b/drivers/iio/light/cros_ec_light_prox.c
> @@ -181,19 +181,11 @@ static const struct iio_info cros_ec_light_prox_info = {
> static int cros_ec_light_prox_probe(struct platform_device *pdev)
> {
> struct device *dev = &pdev->dev;
> - struct cros_ec_dev *ec_dev = dev_get_drvdata(dev->parent);
> - struct cros_ec_device *ec_device;
> struct iio_dev *indio_dev;
> struct cros_ec_light_prox_state *state;
> struct iio_chan_spec *channel;
> int ret;
>
> - if (!ec_dev || !ec_dev->ec_dev) {
> - dev_warn(dev, "No CROS EC device found.\n");
> - return -EINVAL;
> - }
> - ec_device = ec_dev->ec_dev;
> -
> indio_dev = devm_iio_device_alloc(dev, sizeof(*state));
> if (!indio_dev)
> return -ENOMEM;
> diff --git a/drivers/iio/pressure/cros_ec_baro.c b/drivers/iio/pressure/cros_ec_baro.c
> index 48b2a30..dbea18b 100644
> --- a/drivers/iio/pressure/cros_ec_baro.c
> +++ b/drivers/iio/pressure/cros_ec_baro.c
> @@ -126,19 +126,11 @@ static const struct iio_info cros_ec_baro_info = {
> static int cros_ec_baro_probe(struct platform_device *pdev)
> {
> struct device *dev = &pdev->dev;
> - struct cros_ec_dev *ec_dev = dev_get_drvdata(dev->parent);
> - struct cros_ec_device *ec_device;
> struct iio_dev *indio_dev;
> struct cros_ec_baro_state *state;
> struct iio_chan_spec *channel;
> int ret;
>
> - if (!ec_dev || !ec_dev->ec_dev) {
> - dev_warn(dev, "No CROS EC device found.\n");
> - return -EINVAL;
> - }
> - ec_device = ec_dev->ec_dev;
> -
> indio_dev = devm_iio_device_alloc(dev, sizeof(*state));
> if (!indio_dev)
> return -ENOMEM;
> diff --git a/drivers/mfd/cros_ec.c b/drivers/mfd/cros_ec.c
> index b0ca5a4c..75a27a6 100644
> --- a/drivers/mfd/cros_ec.c
> +++ b/drivers/mfd/cros_ec.c
> @@ -91,6 +91,160 @@ static int cros_ec_sleep_event(struct cros_ec_device *ec_dev, u8 sleep_event)
> return cros_ec_cmd_xfer(ec_dev, &buf.msg);
> }
>
> +static int cros_ec_check_features(struct cros_ec_device *ec_dev, int feature)
> +{
> + struct cros_ec_command *msg;
> + int ret;
> +
> + if (ec_dev->features[0] == -1U && ec_dev->features[1] == -1U) {
> + /* features bitmap not read yet */
> +
> + msg = kmalloc(sizeof(*msg) + sizeof(ec_dev->features),
> + GFP_KERNEL);
> + if (!msg)
> + return -ENOMEM;
> +
> + msg->version = 0;
> + msg->command = EC_CMD_GET_FEATURES + ec_p.cmd_offset;
> + msg->insize = sizeof(ec_dev->features);
> + msg->outsize = 0;
> +
> + ret = cros_ec_cmd_xfer(ec_dev, msg);
> + if (ret < 0 || msg->result != EC_RES_SUCCESS) {
> + dev_warn(ec_dev->dev, "cannot get EC features: %d/%d\n",
> + ret, msg->result);
> + memset(ec_dev->features, 0, sizeof(ec_dev->features));
> + }
> +
> + memcpy(ec_dev->features, msg->data, sizeof(ec_dev->features));
> +
> + dev_dbg(ec_dev->dev, "EC features %08x %08x\n",
> + ec_dev->features[0], ec_dev->features[1]);
> +
> + kfree(msg);
> + }
> +
> + return ec_dev->features[feature / 32] & EC_FEATURE_MASK_0(feature);
> +}
> +
> +static void cros_ec_sensors_register(struct cros_ec_device *ec_dev)
> +{
> + /*
> + * Issue a command to get the number of sensor reported.
> + * Build an array of sensors driver and register them all.
> + */
> + int ret, i, id, sensor_num;
> + struct mfd_cell *sensor_cells;
> + struct cros_ec_sensor_platform *sensor_platforms;
> + int sensor_type[MOTIONSENSE_TYPE_MAX];
> + struct ec_params_motion_sense *params;
> + struct ec_response_motion_sense *resp;
> + struct cros_ec_command *msg;
> +
> + msg = kzalloc(sizeof(struct cros_ec_command) +
> + max(sizeof(*params), sizeof(*resp)), GFP_KERNEL);
> + if (msg == NULL)
> + return;
> +
> + msg->version = 2;
> + msg->command = EC_CMD_MOTION_SENSE_CMD + ec_p.cmd_offset;
> + msg->outsize = sizeof(*params);
> + msg->insize = sizeof(*resp);
> +
> + params = (struct ec_params_motion_sense *)msg->data;
> + params->cmd = MOTIONSENSE_CMD_DUMP;
> +
> + ret = cros_ec_cmd_xfer(ec_dev, msg);
> + if (ret < 0 || msg->result != EC_RES_SUCCESS) {
> + dev_warn(ec_dev->dev, "cannot get EC sensor information: %d/%d\n",
> + ret, msg->result);
> + goto error;
> + }
> +
> + resp = (struct ec_response_motion_sense *)msg->data;
> + sensor_num = resp->dump.sensor_count;
> + /* Allocate 2 extra sensors in case lid angle or FIFO are needed */
> + sensor_cells = kzalloc(sizeof(struct mfd_cell) * (sensor_num + 2),
> + GFP_KERNEL);
> + if (sensor_cells == NULL)
> + goto error;
> +
> + sensor_platforms = kzalloc(sizeof(struct cros_ec_sensor_platform) *
> + (sensor_num + 1), GFP_KERNEL);
> + if (sensor_platforms == NULL)
> + goto error_platforms;
> +
> + memset(sensor_type, 0, sizeof(sensor_type));
> + id = 0;
> + for (i = 0; i < sensor_num; i++) {
> + params->cmd = MOTIONSENSE_CMD_INFO;
> + params->info.sensor_num = i;
> + ret = cros_ec_cmd_xfer(ec_dev, msg);
> + if (ret < 0 || msg->result != EC_RES_SUCCESS) {
> + dev_warn(ec_dev->dev, "no info for EC sensor %d : %d/%d\n",
> + i, ret, msg->result);
> + continue;
> + }
> + switch (resp->info.type) {
> + case MOTIONSENSE_TYPE_ACCEL:
> + sensor_cells[id].name = "cros-ec-accel";
> + break;
> + case MOTIONSENSE_TYPE_BARO:
> + sensor_cells[id].name = "cros-ec-baro";
> + break;
> + case MOTIONSENSE_TYPE_GYRO:
> + sensor_cells[id].name = "cros-ec-gyro";
> + break;
> + case MOTIONSENSE_TYPE_MAG:
> + sensor_cells[id].name = "cros-ec-mag";
> + break;
> + case MOTIONSENSE_TYPE_PROX:
> + sensor_cells[id].name = "cros-ec-prox";
> + break;
> + case MOTIONSENSE_TYPE_LIGHT:
> + sensor_cells[id].name = "cros-ec-light";
> + break;
> + case MOTIONSENSE_TYPE_ACTIVITY:
> + sensor_cells[id].name = "cros-ec-activity";
> + break;
> + default:
> + dev_warn(ec_dev->dev, "unknown type %d\n",
> + resp->info.type);
> + continue;
> + }
> + sensor_platforms[id].sensor_num = i;
> + sensor_platforms[id].cmd_offset = ec_p.cmd_offset;
> + sensor_cells[id].id = sensor_type[resp->info.type];
> + sensor_cells[id].platform_data = &sensor_platforms[id];
> + sensor_cells[id].pdata_size =
> + sizeof(struct cros_ec_sensor_platform);
> +
> + sensor_type[resp->info.type]++;
> + id++;
> + }
> + if (sensor_type[MOTIONSENSE_TYPE_ACCEL] >= 2) {
> + sensor_platforms[id].sensor_num = sensor_num;
> +
> + sensor_cells[id].name = "cros-ec-angle";
> + sensor_cells[id].id = 0;
> + sensor_cells[id].platform_data = &sensor_platforms[id];
> + sensor_cells[id].pdata_size =
> + sizeof(struct cros_ec_sensor_platform);
> + id++;
> + }
> +
> + ret = mfd_add_devices(ec_dev->dev, PLATFORM_DEVID_AUTO, sensor_cells,
> + id, NULL, 0, NULL);
> + if (ret)
> + dev_err(ec_dev->dev, "failed to add EC sensors\n");
> +
> + kfree(sensor_platforms);
> +error_platforms:
> + kfree(sensor_cells);
> +error:
> + kfree(msg);
> +}
> +
> int cros_ec_register(struct cros_ec_device *ec_dev)
> {
> struct device *dev = ec_dev->dev;
> @@ -101,6 +255,8 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
> ec_dev->max_request = sizeof(struct ec_params_hello);
> ec_dev->max_response = sizeof(struct ec_response_get_protocol_info);
> ec_dev->max_passthru = 0;
> + ec_dev->features[0] = -1U; /* Not cached yet */
> + ec_dev->features[1] = -1U; /* Not cached yet */
>
> ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL);
> if (!ec_dev->din)
> @@ -134,6 +290,10 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
> goto fail_mfd;
> }
>
> + /* Check whether this EC is a sensor hub. */
> + if (cros_ec_check_features(ec_dev, EC_FEATURE_MOTION_SENSE))
> + cros_ec_sensors_register(ec_dev);
> +
> if (ec_dev->max_passthru) {
> /*
> * Register a PD device as well on top of this device.
> diff --git a/drivers/platform/chrome/cros_ec_dev.c b/drivers/platform/chrome/cros_ec_dev.c
> index cf6c4f0..bd07df5 100644
> --- a/drivers/platform/chrome/cros_ec_dev.c
> +++ b/drivers/platform/chrome/cros_ec_dev.c
> @@ -90,41 +90,6 @@ static int ec_get_version(struct cros_ec_dev *ec, char *str, int maxlen)
> return ret;
> }
>
> -static int cros_ec_check_features(struct cros_ec_dev *ec, int feature)
> -{
> - struct cros_ec_command *msg;
> - int ret;
> -
> - if (ec->features[0] == -1U && ec->features[1] == -1U) {
> - /* features bitmap not read yet */
> -
> - msg = kmalloc(sizeof(*msg) + sizeof(ec->features), GFP_KERNEL);
> - if (!msg)
> - return -ENOMEM;
> -
> - msg->version = 0;
> - msg->command = EC_CMD_GET_FEATURES + ec->cmd_offset;
> - msg->insize = sizeof(ec->features);
> - msg->outsize = 0;
> -
> - ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
> - if (ret < 0 || msg->result != EC_RES_SUCCESS) {
> - dev_warn(ec->dev, "cannot get EC features: %d/%d\n",
> - ret, msg->result);
> - memset(ec->features, 0, sizeof(ec->features));
> - }
> -
> - memcpy(ec->features, msg->data, sizeof(ec->features));
> -
> - dev_dbg(ec->dev, "EC features %08x %08x\n",
> - ec->features[0], ec->features[1]);
> -
> - kfree(msg);
> - }
> -
> - return ec->features[feature / 32] & EC_FEATURE_MASK_0(feature);
> -}
> -
> /* Device file ops */
> static int ec_device_open(struct inode *inode, struct file *filp)
> {
> @@ -268,126 +233,6 @@ static void __remove(struct device *dev)
> kfree(ec);
> }
>
> -static void cros_ec_sensors_register(struct cros_ec_dev *ec)
> -{
> - /*
> - * Issue a command to get the number of sensor reported.
> - * Build an array of sensors driver and register them all.
> - */
> - int ret, i, id, sensor_num;
> - struct mfd_cell *sensor_cells;
> - struct cros_ec_sensor_platform *sensor_platforms;
> - int sensor_type[MOTIONSENSE_TYPE_MAX];
> - struct ec_params_motion_sense *params;
> - struct ec_response_motion_sense *resp;
> - struct cros_ec_command *msg;
> -
> - msg = kzalloc(sizeof(struct cros_ec_command) +
> - max(sizeof(*params), sizeof(*resp)), GFP_KERNEL);
> - if (msg == NULL)
> - return;
> -
> - msg->version = 2;
> - msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset;
> - msg->outsize = sizeof(*params);
> - msg->insize = sizeof(*resp);
> -
> - params = (struct ec_params_motion_sense *)msg->data;
> - params->cmd = MOTIONSENSE_CMD_DUMP;
> -
> - ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
> - if (ret < 0 || msg->result != EC_RES_SUCCESS) {
> - dev_warn(ec->dev, "cannot get EC sensor information: %d/%d\n",
> - ret, msg->result);
> - goto error;
> - }
> -
> - resp = (struct ec_response_motion_sense *)msg->data;
> - sensor_num = resp->dump.sensor_count;
> - /* Allocate 2 extra sensors in case lid angle or FIFO are needed */
> - sensor_cells = kzalloc(sizeof(struct mfd_cell) * (sensor_num + 2),
> - GFP_KERNEL);
> - if (sensor_cells == NULL)
> - goto error;
> -
> - sensor_platforms = kzalloc(sizeof(struct cros_ec_sensor_platform) *
> - (sensor_num + 1), GFP_KERNEL);
> - if (sensor_platforms == NULL)
> - goto error_platforms;
> -
> - memset(sensor_type, 0, sizeof(sensor_type));
> - id = 0;
> - for (i = 0; i < sensor_num; i++) {
> - params->cmd = MOTIONSENSE_CMD_INFO;
> - params->info.sensor_num = i;
> - ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
> - if (ret < 0 || msg->result != EC_RES_SUCCESS) {
> - dev_warn(ec->dev, "no info for EC sensor %d : %d/%d\n",
> - i, ret, msg->result);
> - continue;
> - }
> - switch (resp->info.type) {
> - case MOTIONSENSE_TYPE_ACCEL:
> - sensor_cells[id].name = "cros-ec-accel";
> - break;
> - case MOTIONSENSE_TYPE_BARO:
> - sensor_cells[id].name = "cros-ec-baro";
> - break;
> - case MOTIONSENSE_TYPE_GYRO:
> - sensor_cells[id].name = "cros-ec-gyro";
> - break;
> - case MOTIONSENSE_TYPE_MAG:
> - sensor_cells[id].name = "cros-ec-mag";
> - break;
> - case MOTIONSENSE_TYPE_PROX:
> - sensor_cells[id].name = "cros-ec-prox";
> - break;
> - case MOTIONSENSE_TYPE_LIGHT:
> - sensor_cells[id].name = "cros-ec-light";
> - break;
> - case MOTIONSENSE_TYPE_ACTIVITY:
> - sensor_cells[id].name = "cros-ec-activity";
> - break;
> - default:
> - dev_warn(ec->dev, "unknown type %d\n", resp->info.type);
> - continue;
> - }
> - sensor_platforms[id].sensor_num = i;
> - sensor_cells[id].id = sensor_type[resp->info.type];
> - sensor_cells[id].platform_data = &sensor_platforms[id];
> - sensor_cells[id].pdata_size =
> - sizeof(struct cros_ec_sensor_platform);
> -
> - sensor_type[resp->info.type]++;
> - id++;
> - }
> - if (sensor_type[MOTIONSENSE_TYPE_ACCEL] >= 2) {
> - sensor_platforms[id].sensor_num = sensor_num;
> -
> - sensor_cells[id].name = "cros-ec-angle";
> - sensor_cells[id].id = 0;
> - sensor_cells[id].platform_data = &sensor_platforms[id];
> - sensor_cells[id].pdata_size =
> - sizeof(struct cros_ec_sensor_platform);
> - id++;
> - }
> - if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO)) {
> - sensor_cells[id].name = "cros-ec-ring";
> - id++;
> - }
> -
> - ret = mfd_add_devices(ec->dev, 0, sensor_cells, id,
> - NULL, 0, NULL);
> - if (ret)
> - dev_err(ec->dev, "failed to add EC sensors\n");
> -
> - kfree(sensor_platforms);
> -error_platforms:
> - kfree(sensor_cells);
> -error:
> - kfree(msg);
> -}
> -
> static int ec_device_probe(struct platform_device *pdev)
> {
> int retval = -ENOMEM;
> @@ -402,8 +247,6 @@ static int ec_device_probe(struct platform_device *pdev)
> ec->ec_dev = dev_get_drvdata(dev->parent);
> ec->dev = dev;
> ec->cmd_offset = ec_platform->cmd_offset;
> - ec->features[0] = -1U; /* Not cached yet */
> - ec->features[1] = -1U; /* Not cached yet */
> device_initialize(&ec->class_dev);
> cdev_init(&ec->cdev, &fops);
>
> @@ -432,10 +275,6 @@ static int ec_device_probe(struct platform_device *pdev)
> if (cros_ec_debugfs_init(ec))
> dev_warn(dev, "failed to create debugfs directory\n");
>
> - /* check whether this EC is a sensor hub. */
> - if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE))
> - cros_ec_sensors_register(ec);
> -
> /* Take control of the lightbar from the EC. */
> lb_manual_suspend_ctrl(ec, 1);
>
> diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h
> index 4e887ba..a4138a5 100644
> --- a/include/linux/mfd/cros_ec.h
> +++ b/include/linux/mfd/cros_ec.h
> @@ -115,6 +115,7 @@ struct cros_ec_command {
> * @event_notifier: interrupt event notifier for transport devices.
> * @event_data: raw payload transferred with the MKBP event.
> * @event_size: size in bytes of the event data.
> + * @features: stores the EC features.
> */
> struct cros_ec_device {
>
> @@ -150,15 +151,19 @@ struct cros_ec_device {
> struct ec_response_get_next_event event_data;
> int event_size;
> u32 host_event_wake_mask;
> + u32 features[2];
> };
>
> /**
> * struct cros_ec_sensor_platform - ChromeOS EC sensor platform information
> *
> * @sensor_num: Id of the sensor, as reported by the EC.
> + * @cmd_offset: offset to apply for each command. Set when
> + * registering a devicde behind another one.
> */
> struct cros_ec_sensor_platform {
> u8 sensor_num;
> + u16 cmd_offset;
> };
>
> /* struct cros_ec_platform - ChromeOS EC platform information
> @@ -192,7 +197,6 @@ struct cros_ec_dev {
> struct device *dev;
> struct cros_ec_debugfs *debug_info;
> u16 cmd_offset;
> - u32 features[2];
> };
>
> /**
> --
> 2.9.3
>