Re: [PATCH v2 04/11] soc: qcom: Add Shared Memory Driver

Georgi Djakov
2015-07-07T13:46:09Z

Hi Bjorn,
Thank you for this patchset! Some nits and a question below.

On 06/27/2015 12:50 AM, bjorn@kryo.se wrote:
> From: Bjorn Andersson <bjorn.andersson@sonymobile.com>
>
> This adds the Qualcomm Shared Memory Driver (SMD) providing
> communication channels to remote processors, ontop of SMEM.
>
> Signed-off-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
> ---
> drivers/soc/qcom/Kconfig | 8 +
> drivers/soc/qcom/Makefile | 1 +
> drivers/soc/qcom/smd.c | 1324 ++++++++++++++++++++++++++++++++++++++++++
> include/linux/soc/qcom/smd.h | 46 ++
> 4 files changed, 1379 insertions(+)
> create mode 100644 drivers/soc/qcom/smd.c
> create mode 100644 include/linux/soc/qcom/smd.h
>
[...]
> --- /dev/null
> +++ b/drivers/soc/qcom/smd.c
> @@ -0,0 +1,1324 @@
> +/*
> + * Copyright (c) 2015, Sony Mobile Communications AB.
> + * Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 and
> + * only version 2 as published by the Free Software Foundation.
> + *
> + * 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/delay.h>

unused?

[...]
> +
> +#define GET_RX_CHANNEL_INFO(channel, param) \
> + (channel->rx_info_word ? \
> + channel->rx_info_word->param : \
> + channel->rx_info->param)
> +
> +#define SET_RX_CHANNEL_INFO(channel, param, value) \
> + (channel->rx_info_word ? \
> + (channel->rx_info_word->param = value) : \
> + (channel->rx_info->param = value))
> +
> +#define GET_TX_CHANNEL_INFO(channel, param) \
> + (channel->rx_info_word ? \

Maybe this should be tx_info_word?

> + channel->tx_info_word->param : \
> + channel->tx_info->param)
> +
> +#define SET_TX_CHANNEL_INFO(channel, param, value) \
> + (channel->rx_info_word ? \

ditto?

> + (channel->tx_info_word->param = value) : \
> + (channel->tx_info->param = value))
> +
[...]
> + ret = qcom_smem_get(edge->edge_id, smem_fifo_item, &fifo_base, &fifo_size);
> + if (ret)
> + goto free_name_and_channel;
> +
> + /* The channel consist of a rx and tx fifo of equal size */
> + fifo_size /= 2;
> +
> + dev_dbg(smd->dev, "new channel '%s' info-size: %d fifo-size: %zu\n",

%zu for info-size?

> + name, info_size, fifo_size);
> +

[...]
> +static int __init qcom_smd_init(void)
> +{
> + int ret;
> +
> + ret = bus_register(&qcom_smd_bus);
> + if (ret) {
> + pr_err("failed to register smd bus: %d\n", ret);
> + return ret;
> + }
> +
> + return platform_driver_register(&qcom_smd_driver);
> +}
> +arch_initcall(qcom_smd_init);
> +
> +static void __exit qcom_smd_exit(void)
> +{
> + platform_driver_unregister(&qcom_smd_driver);
> + bus_unregister(&qcom_smd_bus);
> +}
> +module_exit(qcom_smd_exit);
> +
[...]
> +/**
> + * struct qcom_smd_driver - smd driver struct
> + * @driver: underlying device driver
> + * @probe: invoked when the smd channel is found
> + * @remove: invoked when the smd channel is closed
> + * @callback: invoked when an inbound message is received on the channel,
> + * should return 0 on success or -EBUSY if the data cannot be
> + * consumed at this time
> + */
> +struct qcom_smd_driver {
> + struct device_driver driver;
> + int (*probe)(struct qcom_smd_device *dev);
> + void (*remove)(struct qcom_smd_device *dev);
> + int (*callback)(struct qcom_smd_device *, const void *, size_t);
> +};
> +
> +int qcom_smd_driver_register(struct qcom_smd_driver *drv);
> +void qcom_smd_driver_unregister(struct qcom_smd_driver *drv);
> +
> +#define module_qcom_smd_driver(__smd_driver) \
> + module_driver(__smd_driver, qcom_smd_driver_register, \
> + qcom_smd_driver_unregister)
> +

This comment is mostly related to your RPM over SMD driver patch, as
i have a RPM clock driver based on it. The RPM clock driver registers
some fundamental stuff like XO and i had to hack smd-rpm to probe
earlier, so that most other drivers can initialize. So i was wondering,
what if we register the drivers on the bus earlier? What do you think?

Thanks,
Georgi