On Mon, 29 Sep 2014, Bjorn Andersson wrote:
> Driver for the Resource Power Manager (RPM) found in Qualcomm 8974 based
> devices.
> The driver exposes resources that child drivers can operate on; to
> implementing regulator, clock and bus frequency drivers.
>
> Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxxxxxx>
> ---
>
> Note that the qcom_rpm_smd_write is equivalent of qcom_rpm_write and there is a
> possibility of re-using at least the clock implementation on top of this. This
> would however require some logic for calling the right implementation so I have
> not done it at this time to keep things as clean as possible.
>
> An idea for improvement is that in qcom_rpm_smd_write we put the ack_status and
> completion on the stack and register this with idr using the message id, upon
> receiving the interrupt we would find the right client and complete this.
> Allowing for multiple requests to be in flight at any given time.
>
> I did not implement this because I haven't done any measurements on what kind
> of improvements this could give and it would be a clean iteration ontop of
> this.
>
> drivers/mfd/Kconfig | 14 ++
> drivers/mfd/Makefile | 1 +
> drivers/mfd/qcom-smd-rpm.c | 299 ++++++++++++++++++++++++++++++++++++++
> include/linux/mfd/qcom-smd-rpm.h | 9 ++
> 4 files changed, 323 insertions(+)
> create mode 100644 drivers/mfd/qcom-smd-rpm.c
> create mode 100644 include/linux/mfd/qcom-smd-rpm.h
> +#define RPM_ERR_INVALID_RESOURCE "resource does not exist"
> +
> +static bool qcom_rpm_msg_is_invalid_resource(struct qcom_rpm_message *msg)
> +{
> + size_t msg_len = sizeof(RPM_ERR_INVALID_RESOURCE) - 1;
> +
> + if (msg->length != msg_len)
> + return false;
> +
> + if (memcmp(msg->message, RPM_ERR_INVALID_RESOURCE, msg_len))
> + return false;
> +
> + return true;
> +}
You can save yourself a hell of a lot of code by just doing:
if (memcmp(msg->message, RPM_ERR_INVALID_RESOURCE,
min(msg_len, sizeof(RPM_ERR_INVALID_RESOURCE))))
... in qcom_smd_rpm_callback().
[...]
> +static int qcom_smd_rpm_probe(struct qcom_smd_device *sdev)
> +{
> + const struct of_device_id *match;
> + struct qcom_smd_rpm *rpm;
> +
> + rpm = devm_kzalloc(&sdev->dev, sizeof(*rpm), GFP_KERNEL);
> + if (!rpm)
> + return -ENOMEM;
> +
> + rpm->dev = &sdev->dev;
> + mutex_init(&rpm->lock);
> + init_completion(&rpm->ack);
> +
> + match = of_match_device(qcom_smd_rpm_of_match, &sdev->dev);
You need to check the return value here.
> + rpm->data = match->data;
> + rpm->rpm_channel = sdev->channel;
> +
> + dev_set_drvdata(&sdev->dev, rpm);
> +
> + dev_info(&sdev->dev, "Qualcomm SMD RPM driver probed\n");
Please remove this line.
> + return of_platform_populate(sdev->dev.of_node, NULL, NULL, &sdev->dev);
> +}
> +
> +static void qcom_smd_rpm_remove(struct qcom_smd_device *sdev)
> +{
> + dev_set_drvdata(&sdev->dev, NULL);
If you use the proper platform device interface you don't have to do
this.
> + of_platform_depopulate(&sdev->dev);
> +}
> +
> +static struct qcom_smd_driver qcom_smd_rpm_driver = {
> + .probe = qcom_smd_rpm_probe,
> + .remove = qcom_smd_rpm_remove,
> + .callback = qcom_smd_rpm_callback,
> + .driver = {
> + .name = "qcom_smd_rpm",
> + .owner = THIS_MODULE,
> + .of_match_table = qcom_smd_rpm_of_match,
> + },
> +};
> +
> +module_qcom_smd_driver(qcom_smd_rpm_driver);
I don't like this. What's wrong with the existing platform driver
code?
--
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
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