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Date: Thu, 10 Sep 2020 07:18:56 -0700
From: Guenter Roeck <groeck@...gle.com>
To: Stephen Boyd <swboyd@...omium.org>
Cc: Benson Leung <bleung@...omium.org>,
Enric Balletbo i Serra <enric.balletbo@...labora.com>,
linux-kernel <linux-kernel@...r.kernel.org>,
Gwendal Grignou <gwendal@...omium.org>,
Guenter Roeck <groeck@...omium.org>,
Lee Jones <lee.jones@...aro.org>
Subject: Re: [PATCH v2] platform/chrome: Don't populate lightbar device if it
isn't there
On Wed, Sep 9, 2020 at 3:42 PM Stephen Boyd <swboyd@...omium.org> wrote:
>
> The cros ec lightbar driver has a check in probe to fail early if the ec
> device isn't the cros_ec one or if it can't read the lightbar version
> from the EC. Let's move this check to the place where the lightbar
> device is registered. This way we don't expose devices that aren't
> actually there on devices that don't have a lightbar.
>
> This should improve memory and possibly performance too because struct
> devices don't exactly have a small memory footprint and they contribute
> to suspend/resume regardless of driver attachment.
>
> Cc: Gwendal Grignou <gwendal@...omium.org>
> Cc: Guenter Roeck <groeck@...omium.org>
> Cc: Lee Jones <lee.jones@...aro.org>
> Signed-off-by: Stephen Boyd <swboyd@...omium.org>
> ---
>
> Changes from v1:
> * Rebased on linux-next patches to this file
>
> drivers/mfd/cros_ec_dev.c | 16 ++-
> drivers/platform/chrome/cros_ec_lightbar.c | 102 ++------------------
> drivers/platform/chrome/cros_ec_proto.c | 84 ++++++++++++++++
> include/linux/platform_data/cros_ec_proto.h | 4 +
> 4 files changed, 111 insertions(+), 95 deletions(-)
>
> diff --git a/drivers/mfd/cros_ec_dev.c b/drivers/mfd/cros_ec_dev.c
> index d07b43d7c761..9e98b2ec5d92 100644
> --- a/drivers/mfd/cros_ec_dev.c
> +++ b/drivers/mfd/cros_ec_dev.c
> @@ -74,6 +74,10 @@ static const struct mfd_cell cros_ec_cec_cells[] = {
> { .name = "cros-ec-cec", },
> };
>
> +static const struct mfd_cell cros_ec_lightbar_cells[] = {
> + { .name = "cros-ec-lightbar", },
> +};
> +
> static const struct mfd_cell cros_ec_rtc_cells[] = {
> { .name = "cros-ec-rtc", },
> };
> @@ -112,7 +116,6 @@ static const struct cros_feature_to_cells cros_subdevices[] = {
> static const struct mfd_cell cros_ec_platform_cells[] = {
> { .name = "cros-ec-chardev", },
> { .name = "cros-ec-debugfs", },
> - { .name = "cros-ec-lightbar", },
> { .name = "cros-ec-sysfs", },
> };
>
> @@ -206,6 +209,17 @@ static int ec_device_probe(struct platform_device *pdev)
> }
> }
>
> + if (!strcmp(ec_platform->ec_name, CROS_EC_DEV_NAME) &&
> + !cros_ec_get_lightbar_version(ec, NULL, NULL)) {
Any idea why the lightbar code doesn't use cros_ec_check_features() ?
There is a definition for EC_FEATURE_LIGHTBAR, but it doesn't seem to
be used. It would be much more convenient if that feature check could
be used instead of moving the get_lightbar_version command and its
helper function around.
Thanks,
Guenter
> + retval = mfd_add_hotplug_devices(ec->dev,
> + cros_ec_lightbar_cells,
> + ARRAY_SIZE(cros_ec_lightbar_cells));
> + if (retval)
> + dev_err(ec->dev,
> + "failed to add lightbar device: %d\n",
> + retval);
> + }
> +
> /*
> * The PD notifier driver cell is separate since it only needs to be
> * explicitly added on platforms that don't have the PD notifier ACPI
> diff --git a/drivers/platform/chrome/cros_ec_lightbar.c b/drivers/platform/chrome/cros_ec_lightbar.c
> index de8dfb12e486..a7cfde90c8e5 100644
> --- a/drivers/platform/chrome/cros_ec_lightbar.c
> +++ b/drivers/platform/chrome/cros_ec_lightbar.c
> @@ -82,77 +82,6 @@ static int lb_throttle(void)
> return ret;
> }
>
> -static struct cros_ec_command *alloc_lightbar_cmd_msg(struct cros_ec_dev *ec)
> -{
> - struct cros_ec_command *msg;
> - int len;
> -
> - len = max(sizeof(struct ec_params_lightbar),
> - sizeof(struct ec_response_lightbar));
> -
> - msg = kmalloc(sizeof(*msg) + len, GFP_KERNEL);
> - if (!msg)
> - return NULL;
> -
> - msg->version = 0;
> - msg->command = EC_CMD_LIGHTBAR_CMD + ec->cmd_offset;
> - msg->outsize = sizeof(struct ec_params_lightbar);
> - msg->insize = sizeof(struct ec_response_lightbar);
> -
> - return msg;
> -}
> -
> -static int get_lightbar_version(struct cros_ec_dev *ec,
> - uint32_t *ver_ptr, uint32_t *flg_ptr)
> -{
> - struct ec_params_lightbar *param;
> - struct ec_response_lightbar *resp;
> - struct cros_ec_command *msg;
> - int ret;
> -
> - msg = alloc_lightbar_cmd_msg(ec);
> - if (!msg)
> - return 0;
> -
> - param = (struct ec_params_lightbar *)msg->data;
> - param->cmd = LIGHTBAR_CMD_VERSION;
> - msg->outsize = sizeof(param->cmd);
> - msg->result = sizeof(resp->version);
> - ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
> - if (ret < 0 && ret != -EINVAL) {
> - ret = 0;
> - goto exit;
> - }
> -
> - switch (msg->result) {
> - case EC_RES_INVALID_PARAM:
> - /* Pixel had no version command. */
> - if (ver_ptr)
> - *ver_ptr = 0;
> - if (flg_ptr)
> - *flg_ptr = 0;
> - ret = 1;
> - goto exit;
> -
> - case EC_RES_SUCCESS:
> - resp = (struct ec_response_lightbar *)msg->data;
> -
> - /* Future devices w/lightbars should implement this command */
> - if (ver_ptr)
> - *ver_ptr = resp->version.num;
> - if (flg_ptr)
> - *flg_ptr = resp->version.flags;
> - ret = 1;
> - goto exit;
> - }
> -
> - /* Anything else (ie, EC_RES_INVALID_COMMAND) - no lightbar */
> - ret = 0;
> -exit:
> - kfree(msg);
> - return ret;
> -}
> -
> static ssize_t version_show(struct device *dev,
> struct device_attribute *attr, char *buf)
> {
> @@ -165,7 +94,7 @@ static ssize_t version_show(struct device *dev,
> return ret;
>
> /* This should always succeed, because we check during init. */
> - if (!get_lightbar_version(ec, &version, &flags))
> + if (cros_ec_get_lightbar_version(ec, &version, &flags))
> return -EIO;
>
> return scnprintf(buf, PAGE_SIZE, "%d %d\n", version, flags);
> @@ -184,7 +113,7 @@ static ssize_t brightness_store(struct device *dev,
> if (kstrtouint(buf, 0, &val))
> return -EINVAL;
>
> - msg = alloc_lightbar_cmd_msg(ec);
> + msg = cros_ec_alloc_lightbar_cmd_msg(ec);
> if (!msg)
> return -ENOMEM;
>
> @@ -222,7 +151,7 @@ static ssize_t led_rgb_store(struct device *dev, struct device_attribute *attr,
> unsigned int val[4];
> int ret, i = 0, j = 0, ok = 0;
>
> - msg = alloc_lightbar_cmd_msg(ec);
> + msg = cros_ec_alloc_lightbar_cmd_msg(ec);
> if (!msg)
> return -ENOMEM;
>
> @@ -289,7 +218,7 @@ static ssize_t sequence_show(struct device *dev,
> int ret;
> struct cros_ec_dev *ec = to_cros_ec_dev(dev);
>
> - msg = alloc_lightbar_cmd_msg(ec);
> + msg = cros_ec_alloc_lightbar_cmd_msg(ec);
> if (!msg)
> return -ENOMEM;
>
> @@ -324,7 +253,7 @@ static int lb_send_empty_cmd(struct cros_ec_dev *ec, uint8_t cmd)
> struct cros_ec_command *msg;
> int ret;
>
> - msg = alloc_lightbar_cmd_msg(ec);
> + msg = cros_ec_alloc_lightbar_cmd_msg(ec);
> if (!msg)
> return -ENOMEM;
>
> @@ -352,7 +281,7 @@ static int lb_manual_suspend_ctrl(struct cros_ec_dev *ec, uint8_t enable)
> struct cros_ec_command *msg;
> int ret;
>
> - msg = alloc_lightbar_cmd_msg(ec);
> + msg = cros_ec_alloc_lightbar_cmd_msg(ec);
> if (!msg)
> return -ENOMEM;
>
> @@ -399,7 +328,7 @@ static ssize_t sequence_store(struct device *dev, struct device_attribute *attr,
> return ret;
> }
>
> - msg = alloc_lightbar_cmd_msg(ec);
> + msg = cros_ec_alloc_lightbar_cmd_msg(ec);
> if (!msg)
> return -ENOMEM;
>
> @@ -444,7 +373,7 @@ static ssize_t program_store(struct device *dev, struct device_attribute *attr,
> return -EINVAL;
> }
>
> - msg = alloc_lightbar_cmd_msg(ec);
> + msg = cros_ec_alloc_lightbar_cmd_msg(ec);
> if (!msg)
> return -ENOMEM;
>
> @@ -531,24 +460,9 @@ static struct attribute_group cros_ec_lightbar_attr_group = {
> static int cros_ec_lightbar_probe(struct platform_device *pd)
> {
> struct cros_ec_dev *ec_dev = dev_get_drvdata(pd->dev.parent);
> - struct cros_ec_platform *pdata = dev_get_platdata(ec_dev->dev);
> struct device *dev = &pd->dev;
> int ret;
>
> - /*
> - * Only instantiate the lightbar if the EC name is 'cros_ec'. Other EC
> - * devices like 'cros_pd' doesn't have a lightbar.
> - */
> - if (strcmp(pdata->ec_name, CROS_EC_DEV_NAME) != 0)
> - return -ENODEV;
> -
> - /*
> - * Ask then for the lightbar version, if it's 0 then the 'cros_ec'
> - * doesn't have a lightbar.
> - */
> - if (!get_lightbar_version(ec_dev, NULL, NULL))
> - return -ENODEV;
> -
> /* Take control of the lightbar from the EC. */
> lb_manual_suspend_ctrl(ec_dev, 1);
>
> diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
> index dda182132a6a..a08747eec36a 100644
> --- a/drivers/platform/chrome/cros_ec_proto.c
> +++ b/drivers/platform/chrome/cros_ec_proto.c
> @@ -922,3 +922,87 @@ int cros_ec_get_sensor_count(struct cros_ec_dev *ec)
> return sensor_count;
> }
> EXPORT_SYMBOL_GPL(cros_ec_get_sensor_count);
> +
> +struct cros_ec_command *cros_ec_alloc_lightbar_cmd_msg(struct cros_ec_dev *ec)
> +{
> + struct cros_ec_command *msg;
> + int len;
> +
> + len = max(sizeof(struct ec_params_lightbar),
> + sizeof(struct ec_response_lightbar));
> +
> + msg = kmalloc(sizeof(*msg) + len, GFP_KERNEL);
> + if (!msg)
> + return NULL;
> +
> + msg->version = 0;
> + msg->command = EC_CMD_LIGHTBAR_CMD + ec->cmd_offset;
> + msg->outsize = sizeof(struct ec_params_lightbar);
> + msg->insize = sizeof(struct ec_response_lightbar);
> +
> + return msg;
> +}
> +EXPORT_SYMBOL_GPL(cros_ec_alloc_lightbar_cmd_msg);
> +
> +/**
> + * cros_ec_get_lightbar_version() - Get the EC lightbar version
> + *
> + * @ec: EC device, does not have to be connected directly to the AP,
> + * can be daisy chained through another device.
> + * @ver_ptr: Detected lightbar version number
> + * @flag_ptr: Detected lightbar flags
> + *
> + * Call this function to determine the EC's lightbar version and flags
> + * information. If it doesn't exist then this function returns a negative
> + * error value.
> + *
> + * Return: 0 on success, negative errno on failure to detect a lightbar.
> + */
> +int cros_ec_get_lightbar_version(struct cros_ec_dev *ec, uint32_t *ver_ptr,
> + uint32_t *flg_ptr)
> +{
> + struct ec_params_lightbar *param;
> + struct ec_response_lightbar *resp;
> + struct cros_ec_command *msg;
> + int ret;
> +
> + msg = cros_ec_alloc_lightbar_cmd_msg(ec);
> + if (!msg)
> + return -ENOMEM;
> +
> + param = (struct ec_params_lightbar *)msg->data;
> + param->cmd = LIGHTBAR_CMD_VERSION;
> + msg->outsize = sizeof(param->cmd);
> + msg->result = sizeof(resp->version);
> + ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
> + if (ret < 0 && ret != -EINVAL)
> + goto exit;
> +
> + switch (msg->result) {
> + case EC_RES_INVALID_PARAM:
> + /* Pixel had no version command. */
> + if (ver_ptr)
> + *ver_ptr = 0;
> + if (flg_ptr)
> + *flg_ptr = 0;
> + ret = 0;
> + break;
> + case EC_RES_SUCCESS:
> + resp = (struct ec_response_lightbar *)msg->data;
> +
> + /* Future devices w/lightbars should implement this command */
> + if (ver_ptr)
> + *ver_ptr = resp->version.num;
> + if (flg_ptr)
> + *flg_ptr = resp->version.flags;
> + ret = 0;
> + break;
> + default:
> + /* Anything else (ie, EC_RES_INVALID_COMMAND) - no lightbar */
> + ret = -ENODEV;
> + }
> +exit:
> + kfree(msg);
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(cros_ec_get_lightbar_version);
> diff --git a/include/linux/platform_data/cros_ec_proto.h b/include/linux/platform_data/cros_ec_proto.h
> index 4a415ae851ef..50221254956c 100644
> --- a/include/linux/platform_data/cros_ec_proto.h
> +++ b/include/linux/platform_data/cros_ec_proto.h
> @@ -229,6 +229,10 @@ u32 cros_ec_get_host_event(struct cros_ec_device *ec_dev);
>
> int cros_ec_check_features(struct cros_ec_dev *ec, int feature);
>
> +struct cros_ec_command *cros_ec_alloc_lightbar_cmd_msg(struct cros_ec_dev *ec);
> +int cros_ec_get_lightbar_version(struct cros_ec_dev *ec, uint32_t *ver_ptr,
> + uint32_t *flg_ptr);
> +
> int cros_ec_get_sensor_count(struct cros_ec_dev *ec);
>
> /**
>
> base-commit: 1e7913ff5f9f1b73146ad8522958bd266f22a510
> --
> Sent by a computer, using git, on the internet
>
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