Re: [PATCH v8 6/7] power: cros_usbpd-charger: Add EC-based USB PD charger driver

[Enric Balletbo i Serra]

Hi Tomeu,

Thanks for the patch, looks good, a few comments below.

On 20/04/16 09:42, Tomeu Vizoso wrote:
> Hi Sebastian,
>
> is there any chance that you could review this patch?
>
> Thanks,
>
> Tomeu
>
> On 12 April 2016 at 14:32, Tomeu Vizoso <tomeu.vizoso@xxxxxxxxxxxxx> wrote:
> > From: Sameer Nanda <snanda@xxxxxxxxxxxx>
> >
> > This driver exposes the charger functionality in the PD EC to userspace.
> >
> > Signed-off-by: Tomeu Vizoso <tomeu.vizoso@xxxxxxxxxxxxx>
> > Cc: Sameer Nanda <snanda@xxxxxxxxxxxx>
> > Cc: Benson Leung <bleung@xxxxxxxxxxxx>
> > Cc: Shawn Nematbakhsh <shawnn@xxxxxxxxxxxx>
> > ---
> >
> > Changes in v8: None
> > Changes in v7: None
> > Changes in v6: None
> > Changes in v5:
> > - Fix type of variable passed to do_div.
> >
> > Changes in v4:
> > - Declare size parameters in ec_command as size_t
> >
> > Changes in v3:
> > - Use do_div so it builds on 32bit (suggested by 0-day kbuild bot).
> > - Remove sysfs attributes ext_current_lim and ext_voltage_lim because
> >    I don't know yet where they should be placed (and don't have HW to
> >    test them).
> > - Remove superfluous pre-allocated buffers ec_inbuf and ec_outbuf.
> > - Lots of misc comments from Stephen Boyd were addressed.
> > - Unregister notification listener in .remove callback.
> >
> > Changes in v2:
> > - Split out changes to cros_ec_commands.h and the helpers added to
> >    mfd/cros_ec.h from the patch that adds the charger driver, as
> >    suggested by Lee.
> > - Actually call get_ec_num_ports.
> >
> >   drivers/power/Kconfig              |  10 +
> >   drivers/power/Makefile             |   1 +
> >   drivers/power/cros_usbpd-charger.c | 780 +++++++++++++++++++++++++++++++++++++
> >   3 files changed, 791 insertions(+)
> >   create mode 100644 drivers/power/cros_usbpd-charger.c
> >
> > diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig
> > index 421770ddafa3..d096e76ed822 100644
> > --- a/drivers/power/Kconfig
> > +++ b/drivers/power/Kconfig
> > @@ -509,6 +509,16 @@ config AXP20X_POWER
> >            This driver provides support for the power supply features of
> >            AXP20x PMIC.
> >
> > +config CHARGER_CROS_USB_PD
> > +       tristate "Chrome OS EC based USB PD charger"
> > +       depends on MFD_CROS_EC
> > +       default y

Guess you should not set default to yes here.

> > +       help
> > +         Say Y here to enable Chrome OS EC based USB PD charger driver. This
> > +         driver gets various bits of information about what is connected to
> > +         USB PD ports from the EC and converts that into power_supply
> > +         properties.
> > +
> >   endif # POWER_SUPPLY
> >
> >   source "drivers/power/reset/Kconfig"
> > diff --git a/drivers/power/Makefile b/drivers/power/Makefile
> > index e46b75d448a5..c9eca1f9bfb0 100644
> > --- a/drivers/power/Makefile
> > +++ b/drivers/power/Makefile
> > @@ -74,3 +74,4 @@ obj-$(CONFIG_CHARGER_TPS65217)        += tps65217_charger.o
> >   obj-$(CONFIG_POWER_RESET)      += reset/
> >   obj-$(CONFIG_AXP288_FUEL_GAUGE) += axp288_fuel_gauge.o
> >   obj-$(CONFIG_AXP288_CHARGER)   += axp288_charger.o
> > +obj-$(CONFIG_CHARGER_CROS_USB_PD)      += cros_usbpd-charger.o
> > diff --git a/drivers/power/cros_usbpd-charger.c b/drivers/power/cros_usbpd-charger.c
> > new file mode 100644
> > index 000000000000..e7366660c093
> > --- /dev/null
> > +++ b/drivers/power/cros_usbpd-charger.c
> > @@ -0,0 +1,780 @@
> > +/*
> > + * Power supply driver for ChromeOS EC based USB PD Charger.
> > + *
> > + * Copyright (c) 2014 Google, Inc
> > + *
> > + * This software is licensed under the terms of the GNU General Public
> > + * License version 2, as published by the Free Software Foundation, and
> > + * may be copied, distributed, and modified under those terms.
> > + *
> > + * This program is distributed in the hope that it will be useful,
> > + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> > + * GNU General Public License for more details.
> > + */
> > +
> > +#include <linux/ktime.h>
> > +#include <linux/module.h>
> > +#include <linux/mfd/cros_ec.h>
> > +#include <linux/mfd/cros_ec_commands.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/power_supply.h>
> > +#include <linux/rtc.h>
> > +#include <linux/slab.h>
> > +
> > +#define CROS_USB_PD_MAX_PORTS          8
> > +#define CROS_USB_PD_MAX_LOG_ENTRIES    30
> > +
> > +#define CROS_USB_PD_LOG_UPDATE_DELAY msecs_to_jiffies(60000)
> > +#define CROS_USB_PD_CACHE_UPDATE_DELAY msecs_to_jiffies(500)
> > +
> > +/* Buffer + macro for building PDLOG string */
> > +#define BUF_SIZE 80
> > +#define APPEND_STRING(buf, len, str, ...) ((len) += \
> > +       snprintf((buf) + (len), max(BUF_SIZE - (len), 0), (str), ##__VA_ARGS__))
> > +
> > +#define CHARGER_DIR_NAME               "CROS_USB_PD_CHARGER%d"
> > +#define CHARGER_DIR_NAME_LENGTH                sizeof(CHARGER_DIR_NAME)
> > +
> > +#define MANUFACTURER_MODEL_LENGTH      32
> > +
> > +struct port_data {
> > +       int port_number;
> > +       char name[CHARGER_DIR_NAME_LENGTH];
> > +       char manufacturer[MANUFACTURER_MODEL_LENGTH];
> > +       char model_name[MANUFACTURER_MODEL_LENGTH];
> > +       struct power_supply *psy;
> > +       struct power_supply_desc psy_desc;
> > +       int psy_type;
> > +       int psy_online;
> > +       int psy_status;
> > +       int psy_current_max;
> > +       int psy_voltage_max_design;
> > +       int psy_voltage_now;
> > +       int psy_power_max;
> > +       struct charger_data *charger;
> > +       unsigned long last_update;
> > +};
> > +
> > +struct charger_data {
> > +       struct device *dev;
> > +       struct cros_ec_dev *ec_dev;
> > +       struct cros_ec_device *ec_device;
> > +       int num_charger_ports;
> > +       int num_registered_psy;
> > +       struct port_data *ports[CROS_USB_PD_MAX_PORTS];
> > +       struct delayed_work log_work;
> > +       struct workqueue_struct *log_workqueue;
> > +       struct notifier_block notifier;
> > +       bool suspended;
> > +};
> > +
> > +static enum power_supply_property cros_usb_pd_charger_props[] = {
> > +       POWER_SUPPLY_PROP_ONLINE,
> > +       POWER_SUPPLY_PROP_STATUS,
> > +       POWER_SUPPLY_PROP_CURRENT_MAX,
> > +       POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,
> > +       POWER_SUPPLY_PROP_VOLTAGE_NOW,
> > +       POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT_MAX,
> > +       POWER_SUPPLY_PROP_MODEL_NAME,
> > +       POWER_SUPPLY_PROP_MANUFACTURER,
> > +};
> > +
> > +static int ec_command(struct cros_ec_dev *ec_dev, int version, int command,
> > +                     uint8_t *outdata, size_t outsize, uint8_t *indata,
> > +                     size_t insize)
> > +{
> > +       struct cros_ec_device *ec_device = ec_dev->ec_dev;
> > +       struct cros_ec_command *msg;
> > +       int ret;
> > +
> > +       msg = kmalloc(sizeof(*msg) + max(outsize, insize), GFP_KERNEL);
> > +       if (!msg)
> > +               return -ENOMEM;
> > +
> > +       msg->version = version;
> > +       msg->command = ec_dev->cmd_offset + command;
> > +       msg->outsize = outsize;
> > +       msg->insize = insize;
> > +
> > +       memcpy(msg->data, outdata, outsize);
> > +       ret = cros_ec_cmd_xfer_status(ec_device, msg);
> > +       memcpy(indata, msg->data, insize);
> > +
> > +       kfree(msg);
> > +
> > +       return ret;
> > +}
> > +
> > +static int set_ec_usb_pd_override_ports(struct charger_data *charger,
> > +                                       int port_num)
> > +{
> > +       struct device *dev = charger->dev;
> > +       struct ec_params_charge_port_override req;
> > +       int ret;
> > +
> > +       req.override_port = port_num;
> > +
> > +       ret = ec_command(charger->ec_dev, 0, EC_CMD_PD_CHARGE_PORT_OVERRIDE,
> > +                        (uint8_t *)&req, sizeof(req),
> > +                        NULL, 0);
> > +       if (ret < 0) {
> > +               dev_err(dev, "Port Override command returned 0x%x\n", ret);
> > +               return -EINVAL;
> > +       }
> > +
> > +       return 0;
> > +}
> > +
> > +static int get_ec_num_ports(struct charger_data *charger, int *num_ports)
> > +{
> > +       struct device *dev = charger->dev;
> > +       struct ec_response_usb_pd_ports resp;
> > +       int ret;
> > +
> > +       *num_ports = 0;
> > +       ret = ec_command(charger->ec_dev, 0, EC_CMD_USB_PD_PORTS, NULL, 0,
> > +                        (uint8_t *)&resp, sizeof(resp));
> > +       if (ret < 0) {
> > +               dev_err(dev, "Unable to query PD ports (err:0x%x)\n", ret);
> > +               return ret;

Generally you return -EINVAL instead of ret when ec_command fails, any 
reason why here is different?

> > +       }
> > +       *num_ports = resp.num_ports;
> > +       dev_dbg(dev, "Num ports = %d\n", *num_ports);
> > +
> > +       return 0;
> > +}
> > +
> > +static int get_ec_usb_pd_discovery_info(struct port_data *port)
> > +{
> > +       struct charger_data *charger = port->charger;
> > +       struct device *dev = charger->dev;
> > +       struct ec_params_usb_pd_info_request req;
> > +       struct ec_params_usb_pd_discovery_entry resp;
> > +       int ret;
> > +
> > +       req.port = port->port_number;
> > +
> > +       ret = ec_command(charger->ec_dev, 0, EC_CMD_USB_PD_DISCOVERY,
> > +                        (uint8_t *)&req, sizeof(req),
> > +                        (uint8_t *)&resp, sizeof(resp));
> > +       if (ret < 0) {
> > +               dev_err(dev, "Unable to query Discovery info (err:0x%x)\n",
> > +                        ret);
> > +               return -EINVAL;
> > +       }
> > +
> > +       dev_dbg(dev, "Port %d: VID = 0x%x, PID=0x%x, PTYPE=0x%x\n",
> > +               port->port_number, resp.vid, resp.pid, resp.ptype);
> > +
> > +       snprintf(port->manufacturer, MANUFACTURER_MODEL_LENGTH, "%x", resp.vid);

This looks a vendor id code, generally I saw this propietry show the 
manufacturer name.

> > +       snprintf(port->model_name, MANUFACTURER_MODEL_LENGTH, "%x", resp.pid);
> > +
> > +       return 0;
> > +}
> > +
> > +static int get_ec_usb_pd_power_info(struct port_data *port)
> > +{
> > +       struct charger_data *charger = port->charger;
> > +       struct device *dev = charger->dev;
> > +       struct ec_params_usb_pd_power_info req;
> > +       struct ec_response_usb_pd_power_info resp;
> > +       char role_str[80];
> > +       int ret, last_psy_status, last_psy_type;
> > +
> > +       req.port = port->port_number;
> > +       ret = ec_command(charger->ec_dev, 0, EC_CMD_USB_PD_POWER_INFO,
> > +                        (uint8_t *)&req, sizeof(req),
> > +                        (uint8_t *)&resp, sizeof(resp));
> > +       if (ret < 0) {
> > +               dev_err(dev, "Unable to query PD power info (err:0x%x)\n", ret);
> > +               return -EINVAL;
> > +       }
> > +
> > +       last_psy_status = port->psy_status;
> > +       last_psy_type = port->psy_type;
> > +
> > +       switch (resp.role) {
> > +       case USB_PD_PORT_POWER_DISCONNECTED:
> > +               snprintf(role_str, sizeof(role_str), "%s", "DISCONNECTED");
> > +               port->psy_status = POWER_SUPPLY_STATUS_NOT_CHARGING;
> > +               port->psy_online = 0;
> > +               break;
> > +       case USB_PD_PORT_POWER_SOURCE:
> > +               snprintf(role_str, sizeof(role_str), "%s", "SOURCE");
> > +               port->psy_status = POWER_SUPPLY_STATUS_NOT_CHARGING;
> > +               port->psy_online = 0;
> > +               break;
> > +       case USB_PD_PORT_POWER_SINK:
> > +               snprintf(role_str, sizeof(role_str), "%s", "SINK");
> > +               port->psy_status = POWER_SUPPLY_STATUS_CHARGING;
> > +               port->psy_online = 1;
> > +               break;
> > +       case USB_PD_PORT_POWER_SINK_NOT_CHARGING:
> > +               snprintf(role_str, sizeof(role_str), "%s", "NOT CHARGING");
> > +               port->psy_status = POWER_SUPPLY_STATUS_NOT_CHARGING;
> > +               port->psy_online = 1;
> > +               break;
> > +       default:
> > +               snprintf(role_str, sizeof(role_str), "%s", "UNKNOWN");
> > +               dev_err(dev, "Unknown role %d\n", resp.role);
> > +               break;
> > +       }
> > +
> > +       port->psy_voltage_max_design = resp.meas.voltage_max;
> > +       port->psy_voltage_now = resp.meas.voltage_now;
> > +       port->psy_current_max = resp.meas.current_max;
> > +       port->psy_power_max = resp.max_power;
> > +
> > +       switch (resp.type) {
> > +       case USB_CHG_TYPE_BC12_SDP:
> > +       case USB_CHG_TYPE_VBUS:
> > +               port->psy_type = POWER_SUPPLY_TYPE_USB;
> > +               break;
> > +       case USB_CHG_TYPE_NONE:
> > +               /*
> > +                * For dual-role devices when we are a source, the firmware
> > +                * reports the type as NONE. Report such chargers as type
> > +                * USB_PD_DRP.
> > +                */
> > +               if (resp.role == USB_PD_PORT_POWER_SOURCE && resp.dualrole)
> > +                       port->psy_type = POWER_SUPPLY_TYPE_USB_PD_DRP;
> > +               else
> > +                       port->psy_type = POWER_SUPPLY_TYPE_USB;
> > +               break;
> > +       case USB_CHG_TYPE_PROPRIETARY:
> > +               port->psy_type = POWER_SUPPLY_TYPE_MAINS;
> > +               break;
> > +       case USB_CHG_TYPE_C:
> > +               port->psy_type = POWER_SUPPLY_TYPE_USB_TYPE_C;
> > +               break;
> > +       case USB_CHG_TYPE_BC12_DCP:
> > +               port->psy_type = POWER_SUPPLY_TYPE_USB_DCP;
> > +               break;
> > +       case USB_CHG_TYPE_BC12_CDP:
> > +               port->psy_type = POWER_SUPPLY_TYPE_USB_CDP;
> > +               break;
> > +       case USB_CHG_TYPE_PD:
> > +               if (resp.dualrole)
> > +                       port->psy_type = POWER_SUPPLY_TYPE_USB_PD_DRP;
> > +               else
> > +                       port->psy_type = POWER_SUPPLY_TYPE_USB_PD;
> > +               break;
> > +       case USB_CHG_TYPE_UNKNOWN:
> > +               /*
> > +                * While the EC is trying to determine the type of charger that
> > +                * has been plugged in, it will report the charger type as
> > +                * unknown. Treat this case as a dedicated charger since we
> > +                * don't know any better just yet. Additionally since the power
> > +                * capabilities are unknown, report the max current and voltage
> > +                * as zero.
> > +                */
> > +               port->psy_type = POWER_SUPPLY_TYPE_MAINS;
> > +               port->psy_voltage_max_design = 0;
> > +               port->psy_current_max = 0;
> > +               break;
> > +       default:
> > +               dev_err(dev, "Port %d: default case!\n",
> > +                       port->port_number);
> > +               port->psy_type = POWER_SUPPLY_TYPE_USB;
> > +       }
> > +
> > +       port->psy_desc.type = port->psy_type;
> > +
> > +       dev_dbg(dev,
> > +               "Port %d: %s type=%d=vmax=%d vnow=%d cmax=%d clim=%d pmax=%d\n",
> > +               port->port_number, role_str, resp.type,
> > +               resp.meas.voltage_max, resp.meas.voltage_now,
> > +               resp.meas.current_max, resp.meas.current_lim,
> > +               resp.max_power);
> > +
> > +       /*
> > +        * If power supply type or status changed, explicitly call
> > +        * power_supply_changed. This results in udev event getting generated
> > +        * and allows user mode apps to react quicker instead of waiting for
> > +        * their next poll of power supply status.
> > +        */
> > +       if (last_psy_type != port->psy_type ||
> > +           last_psy_status != port->psy_status) {
> > +               dev_dbg(dev, "Port %d: Calling power_supply_changed\n",
> > +                       port->port_number);
> > +               power_supply_changed(port->psy);
> > +       }
> > +
> > +       return 0;
> > +}
> > +
> > +static int get_ec_port_status(struct port_data *port, bool ratelimit)
> > +{
> > +       int ret;
> > +
> > +       if (ratelimit &&
> > +           time_is_after_jiffies(port->last_update +
> > +                                 CROS_USB_PD_CACHE_UPDATE_DELAY))
> > +               return 0;
> > +
> > +       ret = get_ec_usb_pd_power_info(port);
> > +       if (ret < 0)
> > +               return ret;
> > +
> > +       ret = get_ec_usb_pd_discovery_info(port);
> > +       port->last_update = jiffies;
> > +
> > +       return ret;
> > +}
> > +
> > +static void cros_usb_pd_charger_power_changed(struct power_supply *psy)
> > +{
> > +       struct port_data *port = power_supply_get_drvdata(psy);
> > +       struct charger_data *charger = port->charger;
> > +       struct device *dev = charger->dev;
> > +       int i;
> > +
> > +       dev_dbg(dev, "cros_usb_pd_charger_power_changed\n");

nit: In my opinion this debug message is not needed and doesn't add any 
information. It only shows that the function is called. You can usethe 
kernel tracing tools for that.

> > +       for (i = 0; i < charger->num_registered_psy; i++)
> > +               get_ec_port_status(charger->ports[i], false);
> > +}
> > +
> > +static int cros_usb_pd_charger_get_prop(struct power_supply *psy,
> > +                                   enum power_supply_property psp,
> > +                                   union power_supply_propval *val)
> > +{
> > +       struct port_data *port = power_supply_get_drvdata(psy);
> > +       struct charger_data *charger = port->charger;
> > +       struct device *dev = charger->dev;
> > +       int ret;
> > +
> > +
> > +       /* Only refresh ec_port_status for dynamic properties */
> > +       switch (psp) {
> > +       case POWER_SUPPLY_PROP_CURRENT_MAX:
> > +       case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
> > +       case POWER_SUPPLY_PROP_VOLTAGE_NOW:
> > +       case POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT_MAX:
> > +               ret = get_ec_port_status(port, true);
> > +               if (ret < 0) {
> > +                       dev_err(dev, "Failed to get port status (err:0x%x)\n",
> > +                               ret);
> > +                       return -EINVAL;
> > +               }
> > +               break;
> > +       default:
> > +               break;
> > +       }
> > +
> > +       switch (psp) {
> > +       case POWER_SUPPLY_PROP_ONLINE:
> > +               val->intval = port->psy_online;
> > +               break;
> > +       case POWER_SUPPLY_PROP_STATUS:
> > +               val->intval = port->psy_status;
> > +               break;
> > +       case POWER_SUPPLY_PROP_CURRENT_MAX:
> > +               val->intval = port->psy_current_max * 1000;
> > +               break;
> > +       case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
> > +               val->intval = port->psy_voltage_max_design * 1000;
> > +               break;
> > +       case POWER_SUPPLY_PROP_VOLTAGE_NOW:
> > +               val->intval = port->psy_voltage_now * 1000;
> > +               break;
> > +       case POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT_MAX:
> > +               /* TODO: send a TBD host command to the EC. */
> > +               val->intval = 0;

If I'm not mistaken the function below sets the control limit max value, 
but here you always return a 0. This is confusing for me. Seems that 
this is not supported yet? So maybe is better remove the code related to 
this or store the value set in a variable meanwhile you're not able to 
ask the value to the EC.

> > +               break;
> > +       case POWER_SUPPLY_PROP_MODEL_NAME:
> > +               val->strval = port->model_name;
> > +               break;
> > +       case POWER_SUPPLY_PROP_MANUFACTURER:
> > +               val->strval = port->manufacturer;
> > +               break;
> > +       default:
> > +               return -EINVAL;
> > +       }
> > +
> > +       return 0;
> > +}
> > +
> > +static int cros_usb_pd_charger_set_prop(struct power_supply *psy,
> > +                                   enum power_supply_property psp,
> > +                                   const union power_supply_propval *val)
> > +{
> > +       struct port_data *port = power_supply_get_drvdata(psy);
> > +       struct charger_data *charger = port->charger;
> > +       int port_number;
> > +
> > +       switch (psp) {
> > +       case POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT_MAX:
> > +               /*
> > +                * A value of -1 implies switching to battery as the power
> > +                * source. Any other value implies using this port as the
> > +                * power source.
> > +                */
> > +               port_number = val->intval;
> > +               if (port_number != -1)
> > +                       port_number = port->port_number;
> > +               return set_ec_usb_pd_override_ports(charger, port_number);
> > +       default:
> > +               return -EINVAL;
> > +       }
> > +       return 0;
> > +}
> > +
> > +static int cros_usb_pd_charger_is_writeable(struct power_supply *psy,
> > +               enum power_supply_property psp)
> > +{
> > +       int ret;
> > +
> > +       switch (psp) {
> > +       case POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT_MAX:
> > +               ret = 1;
> > +               break;
> > +       default:
> > +               ret = 0;
> > +       }
> > +
> > +       return ret;
> > +}
> > +
> > +static void cros_usb_pd_print_log_entry(struct ec_response_pd_log *r,
> > +                                       ktime_t tstamp)
> > +{
> > +       static const char * const fault_names[] = {
> > +               "---", "OCP", "fast OCP", "OVP", "Discharge"
> > +       };
> > +       static const char * const role_names[] = {
> > +               "Disconnected", "SRC", "SNK", "SNK (not charging)"
> > +       };
> > +       static const char * const chg_type_names[] = {
> > +               "None", "PD", "Type-C", "Proprietary",
> > +               "DCP", "CDP", "SDP", "Other", "VBUS"
> > +       };
> > +       int i;
> > +       int role_idx, type_idx;
> > +       const char *fault, *role, *chg_type;
> > +       struct usb_chg_measures *meas;
> > +       struct mcdp_info *minfo;
> > +       struct rtc_time rt;
> > +       u64 msecs;
> > +       int len = 0;
> > +       char buf[BUF_SIZE + 1];
> > +
> > +       /* the timestamp is the number of 1024th of seconds in the past */
> > +       tstamp = ktime_sub_us(tstamp,
> > +                (uint64_t)r->timestamp_ms << PD_LOG_TIMESTAMP_SHIFT);
> > +       rt = rtc_ktime_to_tm(tstamp);
> > +
> > +       switch (r->type) {
> > +       case PD_EVENT_MCU_CHARGE:
> > +               if (r->data & CHARGE_FLAGS_OVERRIDE)
> > +                       APPEND_STRING(buf, len, "override ");
> > +               if (r->data & CHARGE_FLAGS_DELAYED_OVERRIDE)
> > +                       APPEND_STRING(buf, len, "pending_override ");
> > +               role_idx = r->data & CHARGE_FLAGS_ROLE_MASK;
> > +               role = role_idx < ARRAY_SIZE(role_names) ?
> > +                       role_names[role_idx] : "Unknown";
> > +               type_idx = (r->data & CHARGE_FLAGS_TYPE_MASK)
> > +                        >> CHARGE_FLAGS_TYPE_SHIFT;
> > +               chg_type = type_idx < ARRAY_SIZE(chg_type_names) ?
> > +                       chg_type_names[type_idx] : "???";
> > +
> > +               if ((role_idx == USB_PD_PORT_POWER_DISCONNECTED) ||
> > +                   (role_idx == USB_PD_PORT_POWER_SOURCE)) {
> > +                       APPEND_STRING(buf, len, "%s", role);
> > +                       break;
> > +               }
> > +
> > +               meas = (struct usb_chg_measures *)r->payload;
> > +               APPEND_STRING(buf, len, "%s %s %s %dmV max %dmV / %dmA", role,
> > +                       r->data & CHARGE_FLAGS_DUAL_ROLE ? "DRP" : "Charger",
> > +                       chg_type,
> > +                       meas->voltage_now,
> > +                       meas->voltage_max,
> > +                       meas->current_max);
> > +               break;
> > +       case PD_EVENT_ACC_RW_FAIL:
> > +               APPEND_STRING(buf, len, "RW signature check failed");
> > +               break;
> > +       case PD_EVENT_PS_FAULT:
> > +               fault = r->data < ARRAY_SIZE(fault_names) ? fault_names[r->data]
> > +                                                         : "???";
> > +               APPEND_STRING(buf, len, "Power supply fault: %s", fault);
> > +               break;
> > +       case PD_EVENT_VIDEO_DP_MODE:
> > +               APPEND_STRING(buf, len, "DP mode %sabled",
> > +                             (r->data == 1) ? "en" : "dis");
> > +               break;
> > +       case PD_EVENT_VIDEO_CODEC:
> > +               minfo = (struct mcdp_info *)r->payload;
> > +               APPEND_STRING(buf, len,
> > +                             "HDMI info: family:%04x chipid:%04x irom:%d.%d.%d fw:%d.%d.%d",
> > +                             MCDP_FAMILY(minfo->family),
> > +                             MCDP_CHIPID(minfo->chipid),
> > +                             minfo->irom.major, minfo->irom.minor,
> > +                             minfo->irom.build, minfo->fw.major,
> > +                             minfo->fw.minor, minfo->fw.build);
> > +               break;
> > +       default:
> > +               APPEND_STRING(buf, len,
> > +                       "Event %02x (%04x) [", r->type, r->data);
> > +               for (i = 0; i < PD_LOG_SIZE(r->size_port); i++)
> > +                       APPEND_STRING(buf, len, "%02x ", r->payload[i]);
> > +               APPEND_STRING(buf, len, "]");
> > +               break;
> > +       }
> > +
> > +       msecs = ktime_to_ms(tstamp);
> > +       do_div(msecs, MSEC_PER_SEC);
> > +       pr_info("PDLOG %d/%02d/%02d %02d:%02d:%02d.%03llu P%d %s\n",
> > +               rt.tm_year + 1900, rt.tm_mon + 1, rt.tm_mday,
> > +               rt.tm_hour, rt.tm_min, rt.tm_sec, msecs,
> > +               PD_LOG_PORT(r->size_port), buf);

nit: Maybe is better use a debug print level here. How often is this called?


> > +}
> > +
> > +static void cros_usb_pd_log_check(struct work_struct *work)
> > +{
> > +       struct charger_data *charger = container_of(to_delayed_work(work),
> > +               struct charger_data, log_work);
> > +       struct device *dev = charger->dev;
> > +       union {
> > +               struct ec_response_pd_log r;
> > +               uint32_t words[8]; /* space for the payload */
> > +       } u;
> > +       int ret;
> > +       int entries = 0;
> > +       ktime_t now;
> > +
> > +       if (charger->suspended) {
> > +               dev_dbg(dev, "Suspended...bailing out\n");
> > +               return;
> > +       }
> > +
> > +       while (entries++ < CROS_USB_PD_MAX_LOG_ENTRIES) {
> > +               ret = ec_command(charger->ec_dev, 0, EC_CMD_PD_GET_LOG_ENTRY,
> > +                                NULL, 0, (uint8_t *)&u, sizeof(u));
> > +               now = ktime_get_real();
> > +               if (ret < 0) {
> > +                       dev_dbg(dev, "Cannot get PD log %d\n", ret);
> > +                       break;
> > +               }
> > +               if (u.r.type == PD_EVENT_NO_ENTRY)
> > +                       break;
> > +
> > +               cros_usb_pd_print_log_entry(&u.r, now);
> > +       }
> > +
> > +       queue_delayed_work(charger->log_workqueue, &charger->log_work,
> > +               CROS_USB_PD_LOG_UPDATE_DELAY);
> > +}
> > +
> > +static int cros_usb_pd_ec_event(struct notifier_block *nb,
> > +       unsigned long queued_during_suspend, void *_notify)
> > +{
> > +       struct charger_data *charger;
> > +       struct device *dev;
> > +       struct cros_ec_device *ec_device;
> > +       u32 host_event;
> > +
> > +       charger = container_of(nb, struct charger_data, notifier);
> > +       dev = charger->dev;
> > +       ec_device = charger->ec_device;
> > +
> > +       host_event = cros_ec_get_host_event(ec_device);
> > +       if (host_event & EC_HOST_EVENT_MASK(EC_HOST_EVENT_PD_MCU)) {
> > +               cros_usb_pd_charger_power_changed(charger->ports[0]->psy);
> > +               return NOTIFY_OK;
> > +       }
> > +
> > +       return NOTIFY_DONE;
> > +}
> > +
> > +static char *charger_supplied_to[] = {"cros-usb_pd-charger"};
> > +
> > +static int cros_usb_pd_charger_probe(struct platform_device *pd)
> > +{
> > +       struct device *dev = &pd->dev;
> > +       struct cros_ec_dev *ec_dev = dev_get_drvdata(pd->dev.parent);
> > +       struct cros_ec_device *ec_device;
> > +       struct charger_data *charger;
> > +       struct port_data *port;
> > +       struct power_supply_desc *psy_desc;
> > +       struct power_supply_config psy_cfg = {};
> > +       int i;
> > +       int ret = -EINVAL;
> > +
> > +       dev_dbg(dev, "cros_usb_pd_charger_probe\n");

nit: Remove? You can use kernel tracing tools to print functions calls.

> > +       if (!ec_dev) {
> > +               WARN(1, "%s: No EC dev found\n", dev_name(dev));
> > +               return -EINVAL;
> > +       }
> > +
> > +       ec_device = ec_dev->ec_dev;
> > +       if (!ec_device) {
> > +               WARN(1, "%s: No EC device found\n", dev_name(dev));
> > +               return -EINVAL;
> > +       }
> > +
> > +       charger = devm_kzalloc(dev, sizeof(struct charger_data),
> > +                                   GFP_KERNEL);

Alignement should match with parentheses.

> > +       if (!charger)
> > +               return -ENOMEM;
> > +
> > +       charger->dev = dev;
> > +       charger->ec_dev = ec_dev;
> > +       charger->ec_device = ec_device;
> > +
> > +       platform_set_drvdata(pd, charger);
> > +
> > +       if ((get_ec_num_ports(charger, &charger->num_charger_ports) < 0) ||
> > +           !charger->num_charger_ports) {
> > +               dev_err(dev, "No charging ports found\n");
> > +               ret = -ENODEV;
> > +               goto fail;

I think you can return -ENODEV directly here, you don't need to jump to 
fail.

> > +       }
> > +
> > +       for (i = 0; i < charger->num_charger_ports; i++) {
> > +               port = devm_kzalloc(dev, sizeof(struct port_data), GFP_KERNEL);
> > +               if (!port) {
> > +                       ret = -ENOMEM;
> > +                       goto fail;
> > +               }
> > +
> > +               port->charger = charger;
> > +               port->port_number = i;
> > +               sprintf(port->name, CHARGER_DIR_NAME, i);
> > +
> > +               psy_desc = &port->psy_desc;
> > +               psy_desc->name = port->name;
> > +               psy_desc->type = POWER_SUPPLY_TYPE_USB;
> > +               psy_desc->get_property = cros_usb_pd_charger_get_prop;
> > +               psy_desc->set_property = cros_usb_pd_charger_set_prop;
> > +               psy_desc->property_is_writeable =
> > +                       cros_usb_pd_charger_is_writeable;
> > +               psy_desc->external_power_changed =
> > +                       cros_usb_pd_charger_power_changed;
> > +               psy_desc->properties = cros_usb_pd_charger_props;
> > +               psy_desc->num_properties = ARRAY_SIZE(
> > +                       cros_usb_pd_charger_props);
> > +
> > +               psy_cfg.drv_data = port;
> > +               psy_cfg.supplied_to = charger_supplied_to;
> > +               psy_cfg.num_supplicants = ARRAY_SIZE(charger_supplied_to);
> > +
> > +               port->psy = power_supply_register_no_ws(dev, psy_desc,
> > +                                                       &psy_cfg);

Guess you can use devm_power_supply_register_no_ws here.

> > +               if (IS_ERR(port->psy)) {
> > +                       dev_err(dev, "Failed to register power supply: %ld\n",
> > +                               PTR_ERR(port->psy));
> > +                       continue;
> > +               }
> > +
> > +               charger->ports[charger->num_registered_psy++] = port;
> > +       }
> > +
> > +       if (!charger->num_registered_psy) {
> > +               ret = -ENODEV;
> > +               dev_err(dev, "No power supplies registered\n");
> > +               goto fail;
> > +       }
> > +
> > +       if (ec_device->mkbp_event_supported) {
> > +               /* Get PD events from the EC */
> > +               charger->notifier.notifier_call = cros_usb_pd_ec_event;
> > +               ret = blocking_notifier_chain_register(
> > +                       &ec_device->event_notifier, &charger->notifier);
> > +               if (ret < 0)
> > +                       dev_warn(dev, "failed to register notifier\n");
> > +       }
> > +
> > +       /* Retrieve PD event logs periodically */
> > +       INIT_DELAYED_WORK(&charger->log_work, cros_usb_pd_log_check);
> > +       charger->log_workqueue =
> > +               create_singlethread_workqueue("cros_usb_pd_log");
> > +       queue_delayed_work(charger->log_workqueue, &charger->log_work,
> > +               CROS_USB_PD_LOG_UPDATE_DELAY);
> > +
> > +       return 0;
> > +
> > +fail:
> > +       for (i = 0; i < charger->num_registered_psy; i++) {
> > +               port = charger->ports[i];
> > +               power_supply_unregister(port->psy);

If you use devm_power_supply_register_no_ws this is not needed since it 
would be called by managed resources infrastructure.

> > +               devm_kfree(dev, port);

Guess the managed resources infrastructure will do this for you.

> > +       }
> > +       platform_set_drvdata(pd, NULL);
> > +
> > +       return ret;
> > +}
> > +
> > +static int cros_usb_pd_charger_remove(struct platform_device *pd)
> > +{
> > +       struct charger_data *charger = platform_get_drvdata(pd);
> > +       struct port_data *port;
> > +       int i;
> > +
> > +       if (charger->notifier.notifier_call)
> > +               blocking_notifier_chain_unregister(
> > +                       &charger->ec_device->event_notifier,
> > +                       &charger->notifier);
> > +
> > +       for (i = 0; i < charger->num_registered_psy; i++) {
> > +               port = charger->ports[i];
> > +               power_supply_unregister(port->psy);
> > +       }
> > +       flush_delayed_work(&charger->log_work);
> > +
> > +       return 0;
> > +}
> > +
> > +#ifdef CONFIG_PM_SLEEP
> > +static int cros_usb_pd_charger_resume(struct device *dev)
> > +{
> > +       struct charger_data *charger = dev_get_drvdata(dev);
> > +       int i;
> > +
> > +       if (!charger)
> > +               return 0;
> > +
> > +       charger->suspended = false;
> > +
> > +       dev_dbg(dev, "cros_usb_pd_charger_resume: updating power supplies\n");
> > +       for (i = 0; i < charger->num_registered_psy; i++) {
> > +               power_supply_changed(charger->ports[i]->psy);
> > +               charger->ports[i]->last_update =
> > +                               jiffies - CROS_USB_PD_CACHE_UPDATE_DELAY;
> > +       }
> > +       queue_delayed_work(charger->log_workqueue, &charger->log_work,
> > +               CROS_USB_PD_LOG_UPDATE_DELAY);
> > +
> > +       return 0;
> > +}
> > +
> > +static int cros_usb_pd_charger_suspend(struct device *dev)
> > +{
> > +       struct charger_data *charger = dev_get_drvdata(dev);
> > +
> > +       charger->suspended = true;
> > +
> > +       flush_delayed_work(&charger->log_work);
> > +
> > +       return 0;
> > +}
> > +#endif
> > +
> > +static SIMPLE_DEV_PM_OPS(cros_usb_pd_charger_pm_ops,
> > +       cros_usb_pd_charger_suspend, cros_usb_pd_charger_resume);
> > +
> > +static struct platform_driver cros_usb_pd_charger_driver = {
> > +       .driver = {
> > +               .name = "cros-usb-pd-charger",
> > +               .pm = &cros_usb_pd_charger_pm_ops,
> > +       },
> > +       .probe = cros_usb_pd_charger_probe,
> > +       .remove = cros_usb_pd_charger_remove,
> > +};
> > +
> > +module_platform_driver(cros_usb_pd_charger_driver);
> > +
> > +MODULE_LICENSE("GPL");
> > +MODULE_DESCRIPTION("Chrome USB PD charger");
> > +MODULE_ALIAS("power_supply:cros-usb-pd-charger");
> > --
> > 2.5.5

Best regards,
 Enric