Re: [PATCH v7 1/2] platform/chrome: wilco_ec: Add property helper library

From: Enric Balletbo i Serra
Date: Tue Apr 23 2019 - 10:43:45 EST




On 22/4/19 20:07, Nick Crews wrote:
> A Property is typically a data item that is stored to NVRAM
> by the EC. Each of these data items has an index associated
> with it, known as the Property ID (PID). Properties may have
> variable lengths, up to a max of WILCO_EC_PROPERTY_MAX_SIZE
> bytes. Properties can be simple integers, or they may be more
> complex binary data.
>
> This patch adds support for getting and setting properties.
> This will be useful for setting the charge algorithm and charge
> schedules, which all use properties.
>
> Signed-off-by: Nick Crews <ncrews@xxxxxxxxxxxx>

For my own reference:
Acked-for-chrome-by: Enric Balletbo i Serra <enric.balletbo@xxxxxxxxxxxxx>

That means that this patch is pushed out as testing in for-next branch to let
the autobuilders play with it. If all goes well your patches would be in the
chrome-platform-5.2 or chrome-platform-5.3 (as we're already at rc6) branch
'soonish'.

Sebastian, note that this patch should be picked before you apply

[PATCH v7 2/2] power_supply: platform/chrome: wilco_ec: Add charging config driver

So let me know if you plan to pick that for 5.2 or is more suitable for 5.3

Thanks,
Enric

> ---
> v7 changes:
> -Remove bogus gerrit FROMLIST tag in commit title
> v6 changes:
> -Add EC_* prefix to enum property_ops so they are more unique.
> -Split up the commit so properties are added in a first commit
> v5 changes:
> -Remove OP_SYNC, it has no immediate use case.
> -Merge properties.h into wilco-ec.h
> -Remove enum get_set_sync_op from the public interface,
> since without OP_SYNC they are irrelevant.
> -Fix Kconfigs and Makefiles so they actually work
> with the v4 changes
> -Tweak some formatting, spacing, and comments
> -Fix validation of charge_type so illegal values
> can't be set. Before negative error codes were
> accidentally getting casted to positive numbers
> -Remove more unneeded parentheses.
> v4 changes:
> -Use put_unaligned_le32() to store PID in request.
> -Move implementation from
> drivers/platform/chrome/wilco_ec/charge_config.c to
> drivers/power/supply/wilco_charger.c
> -Move drivers/platform/chrome/wilco_ec/properties.h to
> include/linux/platform_data/wilco-ec-properties.h
> -Remove parentheses in switch statement in psp_val_to_charge_mode()
> -Check for any negatvie return code from psp_val_to_charge_mode()
> instead of just -EINVAL so its less brittle
> -Tweak comments in wilco-ec-properties.h
> v3 changes:
> -Add this changelog
> -Fix commit message tags
> v2 changes:
> -Update Documentation to say KernelVersion 5.2
> -Update Documentation to explain Trickle mode better.
> -rename things from using *PCC* to *CHARGE*
> -Split up conversions between POWER_SUPPLY_PROP_CHARGE_TYPE values
> and Wilco EC codes
> -Use devm_ flavor of power_supply_register(), which simplifies things
> -Add extra error checking on property messages received from the EC
> -Fix bug in memcpy() calls in properties.c
> -Refactor fill_property_id()
> -Add valid input checks to charge_type
> -Properly convert charge_type when get()ting
>
> drivers/platform/chrome/wilco_ec/Makefile | 2 +-
> drivers/platform/chrome/wilco_ec/properties.c | 132 ++++++++++++++++++
> include/linux/platform_data/wilco-ec.h | 71 ++++++++++
> 3 files changed, 204 insertions(+), 1 deletion(-)
> create mode 100644 drivers/platform/chrome/wilco_ec/properties.c
>
> diff --git a/drivers/platform/chrome/wilco_ec/Makefile b/drivers/platform/chrome/wilco_ec/Makefile
> index 063e7fb4ea17..29b734137786 100644
> --- a/drivers/platform/chrome/wilco_ec/Makefile
> +++ b/drivers/platform/chrome/wilco_ec/Makefile
> @@ -1,6 +1,6 @@
> # SPDX-License-Identifier: GPL-2.0
>
> -wilco_ec-objs := core.o mailbox.o
> +wilco_ec-objs := core.o mailbox.o properties.o
> obj-$(CONFIG_WILCO_EC) += wilco_ec.o
> wilco_ec_debugfs-objs := debugfs.o
> obj-$(CONFIG_WILCO_EC_DEBUGFS) += wilco_ec_debugfs.o
> diff --git a/drivers/platform/chrome/wilco_ec/properties.c b/drivers/platform/chrome/wilco_ec/properties.c
> new file mode 100644
> index 000000000000..e69682c95ea2
> --- /dev/null
> +++ b/drivers/platform/chrome/wilco_ec/properties.c
> @@ -0,0 +1,132 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright 2019 Google LLC
> + */
> +
> +#include <linux/platform_data/wilco-ec.h>
> +#include <linux/string.h>
> +#include <linux/unaligned/le_memmove.h>
> +
> +/* Operation code; what the EC should do with the property */
> +enum ec_property_op {
> + EC_OP_GET = 0,
> + EC_OP_SET = 1,
> +};
> +
> +struct ec_property_request {
> + u8 op; /* One of enum ec_property_op */
> + u8 property_id[4]; /* The 32 bit PID is stored Little Endian */
> + u8 length;
> + u8 data[WILCO_EC_PROPERTY_MAX_SIZE];
> +} __packed;
> +
> +struct ec_property_response {
> + u8 reserved[2];
> + u8 op; /* One of enum ec_property_op */
> + u8 property_id[4]; /* The 32 bit PID is stored Little Endian */
> + u8 length;
> + u8 data[WILCO_EC_PROPERTY_MAX_SIZE];
> +} __packed;
> +
> +static int send_property_msg(struct wilco_ec_device *ec,
> + struct ec_property_request *rq,
> + struct ec_property_response *rs)
> +{
> + struct wilco_ec_message ec_msg;
> + int ret;
> +
> + memset(&ec_msg, 0, sizeof(ec_msg));
> + ec_msg.type = WILCO_EC_MSG_PROPERTY;
> + ec_msg.request_data = rq;
> + ec_msg.request_size = sizeof(*rq);
> + ec_msg.response_data = rs;
> + ec_msg.response_size = sizeof(*rs);
> +
> + ret = wilco_ec_mailbox(ec, &ec_msg);
> + if (ret < 0)
> + return ret;
> + if (rs->op != rq->op)
> + return -EBADMSG;
> + if (memcmp(rq->property_id, rs->property_id, sizeof(rs->property_id)))
> + return -EBADMSG;
> +
> + return 0;
> +}
> +
> +int wilco_ec_get_property(struct wilco_ec_device *ec,
> + struct wilco_ec_property_msg *prop_msg)
> +{
> + struct ec_property_request rq;
> + struct ec_property_response rs;
> + int ret;
> +
> + memset(&rq, 0, sizeof(rq));
> + rq.op = EC_OP_GET;
> + put_unaligned_le32(prop_msg->property_id, rq.property_id);
> +
> + ret = send_property_msg(ec, &rq, &rs);
> + if (ret < 0)
> + return ret;
> +
> + prop_msg->length = rs.length;
> + memcpy(prop_msg->data, rs.data, rs.length);
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(wilco_ec_get_property);
> +
> +int wilco_ec_set_property(struct wilco_ec_device *ec,
> + struct wilco_ec_property_msg *prop_msg)
> +{
> + struct ec_property_request rq;
> + struct ec_property_response rs;
> + int ret;
> +
> + memset(&rq, 0, sizeof(rq));
> + rq.op = EC_OP_SET;
> + put_unaligned_le32(prop_msg->property_id, rq.property_id);
> + rq.length = prop_msg->length;
> + memcpy(rq.data, prop_msg->data, prop_msg->length);
> +
> + ret = send_property_msg(ec, &rq, &rs);
> + if (ret < 0)
> + return ret;
> + if (rs.length != prop_msg->length)
> + return -EBADMSG;
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(wilco_ec_set_property);
> +
> +int wilco_ec_get_byte_property(struct wilco_ec_device *ec, u32 property_id,
> + u8 *val)
> +{
> + struct wilco_ec_property_msg msg;
> + int ret;
> +
> + msg.property_id = property_id;
> +
> + ret = wilco_ec_get_property(ec, &msg);
> + if (ret < 0)
> + return ret;
> + if (msg.length != 1)
> + return -EBADMSG;
> +
> + *val = msg.data[0];
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(wilco_ec_get_byte_property);
> +
> +int wilco_ec_set_byte_property(struct wilco_ec_device *ec, u32 property_id,
> + u8 val)
> +{
> + struct wilco_ec_property_msg msg;
> +
> + msg.property_id = property_id;
> + msg.data[0] = val;
> + msg.length = 1;
> +
> + return wilco_ec_set_property(ec, &msg);
> +}
> +EXPORT_SYMBOL_GPL(wilco_ec_set_byte_property);
> diff --git a/include/linux/platform_data/wilco-ec.h b/include/linux/platform_data/wilco-ec.h
> index 1ff224793c99..50a21bd5fd44 100644
> --- a/include/linux/platform_data/wilco-ec.h
> +++ b/include/linux/platform_data/wilco-ec.h
> @@ -123,4 +123,75 @@ struct wilco_ec_message {
> */
> int wilco_ec_mailbox(struct wilco_ec_device *ec, struct wilco_ec_message *msg);
>
> +/*
> + * A Property is typically a data item that is stored to NVRAM
> + * by the EC. Each of these data items has an index associated
> + * with it, known as the Property ID (PID). Properties may have
> + * variable lengths, up to a max of WILCO_EC_PROPERTY_MAX_SIZE
> + * bytes. Properties can be simple integers, or they may be more
> + * complex binary data.
> + */
> +
> +#define WILCO_EC_PROPERTY_MAX_SIZE 4
> +
> +/**
> + * struct ec_property_set_msg - Message to get or set a property.
> + * @property_id: Which property to get or set.
> + * @length: Number of bytes of |data| that are used.
> + * @data: Actual property data.
> + */
> +struct wilco_ec_property_msg {
> + u32 property_id;
> + int length;
> + u8 data[WILCO_EC_PROPERTY_MAX_SIZE];
> +};
> +
> +/**
> + * wilco_ec_get_property() - Retrieve a property from the EC.
> + * @ec: Embedded Controller device.
> + * @prop_msg: Message for request and response.
> + *
> + * The property_id field of |prop_msg| should be filled before calling this
> + * function. The result will be stored in the data and length fields.
> + *
> + * Return: 0 on success, negative error code on failure.
> + */
> +int wilco_ec_get_property(struct wilco_ec_device *ec,
> + struct wilco_ec_property_msg *prop_msg);
> +
> +/**
> + * wilco_ec_set_property() - Store a property on the EC.
> + * @ec: Embedded Controller device.
> + * @prop_msg: Message for request and response.
> + *
> + * The property_id, length, and data fields of |prop_msg| should be
> + * filled before calling this function.
> + *
> + * Return: 0 on success, negative error code on failure.
> + */
> +int wilco_ec_set_property(struct wilco_ec_device *ec,
> + struct wilco_ec_property_msg *prop_msg);
> +
> +/**
> + * wilco_ec_get_byte_property() - Retrieve a byte-size property from the EC.
> + * @ec: Embedded Controller device.
> + * @property_id: Which property to retrieve.
> + * @val: The result value, will be filled by this function.
> + *
> + * Return: 0 on success, negative error code on failure.
> + */
> +int wilco_ec_get_byte_property(struct wilco_ec_device *ec, u32 property_id,
> + u8 *val);
> +
> +/**
> + * wilco_ec_get_byte_property() - Store a byte-size property on the EC.
> + * @ec: Embedded Controller device.
> + * @property_id: Which property to store.
> + * @val: Value to store.
> + *
> + * Return: 0 on success, negative error code on failure.
> + */
> +int wilco_ec_set_byte_property(struct wilco_ec_device *ec, u32 property_id,
> + u8 val);
> +
> #endif /* WILCO_EC_H */
>