Messages in this thread Patch in this message | | | From | Gwendal Grignou <> | Date | Tue, 28 May 2019 14:53:08 -0700 | Subject | Re: [PATCH v5] mfd: cros_ec_dev: Register cros_ec_accel_legacy driver as a subdevice |
| |
On Mon, Apr 1, 2019 at 8:46 PM Lee Jones <lee.jones@linaro.org> wrote: > > On Wed, 27 Feb 2019, Gwendal Grignou wrote: > > > From: Enric Balletbo i Serra <enric.balletbo@collabora.com> > > > > With this patch, the cros_ec_ctl driver will register the legacy > > accelerometer driver (named cros_ec_accel_legacy) if it fails to > > register sensors through the usual path cros_ec_sensors_register(). > > This legacy device is present on Chromebook devices with older EC > > firmware only supporting deprecated EC commands (Glimmer based devices). > > > > Tested-by: Gwendal Grignou <gwendal@chromium.org> > > Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com> > > Reviewed-by: Gwendal Grignou <gwendal@chromium.org> > > Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> > > --- > > Changes in v5: > > - Remove unnecessary white lines. > > > > Changes in v4: > > - [5/8] Nit: EC -> ECs (Lee Jones) > > - [5/8] Statically define cros_ec_accel_legacy_cells (Lee Jones) > > > > Changes in v3: > > - [5/8] Add the Reviewed-by Andy Shevchenko. > > > > Changes in v2: > > - [5/8] Add the Reviewed-by Gwendal. > > > > drivers/mfd/cros_ec_dev.c | 66 +++++++++++++++++++++++++++++++++++++++ > > 1 file changed, 66 insertions(+) > > > > diff --git a/drivers/mfd/cros_ec_dev.c b/drivers/mfd/cros_ec_dev.c > > index d275deaecb12..64567bd0a081 100644 > > --- a/drivers/mfd/cros_ec_dev.c > > +++ b/drivers/mfd/cros_ec_dev.c > > @@ -376,6 +376,69 @@ static void cros_ec_sensors_register(struct cros_ec_dev *ec) > > kfree(msg); > > } > > > > +static struct cros_ec_sensor_platform sensor_platforms[] = { > > + { .sensor_num = 0 }, > > + { .sensor_num = 1 } > > +}; > > I'm still very uncomfortable with this struct. > > Other than these indices, the sensors have no other distinguishing > features, thus there should be no need to identify or distinguish > between them in this way. When initializing the sensors, the IIO driver expect to find in the data structure pointed by dev_get_platdata(dev), in field sensor_num is stored the index assigned by the embedded controller to talk to a given sensor. cros_ec_sensors_register() use the same mechanism; in that function, the sensor_num field is populated from the output of an EC command MOTIONSENSE_CMD_INFO. In case of legacy mode, that command may not be available and in any case we know the EC has only either 2 accelerometers present or nothing.
For instance, let's compare a legacy device with a more recent one:
legacy: type | id | sensor_num | device name accelerometer | 0 | 0 | cros-ec-accel.0 accelerometer | 1 | 1 | cros-ec-accel.1
Modern: type | id | sensor_num | device name accelerometer | 0 | 0 | cros-ec-accel.0 accelerometer | 1 | 1 | cros-ec-accel.1 gyroscope | 0 | 2 | cros-ec-gyro.0 magnetometer | 0 | 3 | cros-ec-mag.0 light | 0 | 4 | cros-ec-light.0 ...
Gwendal.
> > > +static const struct mfd_cell cros_ec_accel_legacy_cells[] = { > > + { > > + .name = "cros-ec-accel-legacy", > > + .id = 0, > > + .platform_data = &sensor_platforms[0], > > + .pdata_size = sizeof(struct cros_ec_sensor_platform), > > + }, > > + { > > + .name = "cros-ec-accel-legacy", > > + .id = 1, > > + .platform_data = &sensor_platforms[1], > > + .pdata_size = sizeof(struct cros_ec_sensor_platform), > > + } > > +}; > > + > > +static void cros_ec_accel_legacy_register(struct cros_ec_dev *ec) > > +{ > > + struct cros_ec_device *ec_dev = ec->ec_dev; > > + u8 status; > > + int ret; > > + > > + /* > > + * ECs that need legacy support are the main EC, directly connected to > > + * the AP. > > + */ > > + if (ec->cmd_offset != 0) > > + return; > > + > > + /* > > + * Check if EC supports direct memory reads and if EC has > > + * accelerometers. > > + */ > > + if (!ec_dev->cmd_readmem) > > + return; > > + > > + ret = ec_dev->cmd_readmem(ec_dev, EC_MEMMAP_ACC_STATUS, 1, &status); > > + if (ret < 0) { > > + dev_warn(ec->dev, "EC does not support direct reads.\n"); > > + return; > > + } > > + > > + /* Check if EC has accelerometers. */ > > + if (!(status & EC_MEMMAP_ACC_STATUS_PRESENCE_BIT)) { > > + dev_info(ec->dev, "EC does not have accelerometers.\n"); > > + return; > > + } > > + > > + /* > > + * Register 2 accelerometers > > + */ > > + ret = mfd_add_devices(ec->dev, PLATFORM_DEVID_AUTO, > > Using PLATFORM_DEVID_AUTO whilst providing the MFD cells with IDs > doesn't make any sense. Please remove the IDs from the cells. Removed in V6. > > > + cros_ec_accel_legacy_cells, > > + ARRAY_SIZE(cros_ec_accel_legacy_cells), > > + NULL, 0, NULL); > > + if (ret) > > + dev_err(ec_dev->dev, "failed to add EC sensors\n"); > > +} > > + > > static const struct mfd_cell cros_ec_cec_cells[] = { > > { .name = "cros-ec-cec" } > > }; > > @@ -437,6 +500,9 @@ static int ec_device_probe(struct platform_device *pdev) > > /* check whether this EC is a sensor hub. */ > > if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE)) > > cros_ec_sensors_register(ec); > > + else > > + /* Workaroud for older EC firmware */ > > + cros_ec_accel_legacy_register(ec); > > > > /* Check whether this EC instance has CEC host command support */ > > if (cros_ec_check_features(ec, EC_FEATURE_CEC)) { > > -- > Lee Jones [李琼斯] > Linaro Services Technical Lead > Linaro.org │ Open source software for ARM SoCs > Follow Linaro: Facebook | Twitter | Blog
| |