On 2020/12/01 21:18, Ben Dooks wrote:
> On 01/12/2020 12:00, Damien Le Moal wrote:
>> On 2020/12/01 20:03, conor.dooley@xxxxxxxxxxxxx wrote:
>>> From: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
>>>
>>> This driver provides an interface for other drivers to access the
>>> functions of the system controller on the Microchip PolarFire SoC.
>>>
>>> Signed-off-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
>>> ---
>>> drivers/soc/Kconfig | 1 +
>>> drivers/soc/Makefile | 1 +
>>> drivers/soc/microchip/Kconfig | 10 ++
>>> drivers/soc/microchip/Makefile | 1 +
>>> drivers/soc/microchip/mpfs_sys_controller.c | 135 ++++++++++++++++++++
>>> 5 files changed, 148 insertions(+)
>>> create mode 100644 drivers/soc/microchip/Kconfig
>>> create mode 100644 drivers/soc/microchip/Makefile
>>> create mode 100644 drivers/soc/microchip/mpfs_sys_controller.c
>>>
>>> diff --git a/drivers/soc/Kconfig b/drivers/soc/Kconfig
>>> index 425ab6f7e375..22cb097bcbdc 100644
>>> --- a/drivers/soc/Kconfig
>>> +++ b/drivers/soc/Kconfig
>>> @@ -9,6 +9,7 @@ source "drivers/soc/bcm/Kconfig"
>>> source "drivers/soc/fsl/Kconfig"
>>> source "drivers/soc/imx/Kconfig"
>>> source "drivers/soc/ixp4xx/Kconfig"
>>> +source "drivers/soc/microchip/Kconfig"
>>> source "drivers/soc/mediatek/Kconfig"
>>> source "drivers/soc/qcom/Kconfig"
>>> source "drivers/soc/renesas/Kconfig"
>>> diff --git a/drivers/soc/Makefile b/drivers/soc/Makefile
>>> index 36452bed86ef..fb084cf2d12e 100644
>>> --- a/drivers/soc/Makefile
>>> +++ b/drivers/soc/Makefile
>>> @@ -14,6 +14,7 @@ obj-$(CONFIG_ARCH_GEMINI) += gemini/
>>> obj-y += imx/
>>> obj-$(CONFIG_ARCH_IXP4XX) += ixp4xx/
>>> obj-$(CONFIG_SOC_XWAY) += lantiq/
>>> +obj-$(CONFIG_SOC_MICROCHIP_POLARFIRE) += microchip/
>>> obj-y += mediatek/
>>> obj-y += amlogic/
>>> obj-y += qcom/
>>> diff --git a/drivers/soc/microchip/Kconfig b/drivers/soc/microchip/Kconfig
>>> new file mode 100644
>>> index 000000000000..40e5203c8ba0
>>> --- /dev/null
>>> +++ b/drivers/soc/microchip/Kconfig
>>> @@ -0,0 +1,10 @@
>>> +config MPFS_SYS_CONTROLLER
>>> + tristate "MPFS_SYS_CONTROLLER"
>>> + depends on MPFS_MBOX
>>> + help
>>> + This driver adds support for the Polarfire SoC system controller.
>>> +
>>> + To compile this driver as a module, choose M here. the
>>> + module will be called mpfs_system_controller.
>>> +
>>> + If unsure, say N.
>>> diff --git a/drivers/soc/microchip/Makefile b/drivers/soc/microchip/Makefile
>>> new file mode 100644
>>> index 000000000000..23b1f42a37db
>>> --- /dev/null
>>> +++ b/drivers/soc/microchip/Makefile
>>> @@ -0,0 +1 @@
>>> +obj-$(CONFIG_MPFS_SYS_CONTROLLER) += mpfs_sys_controller.o
>>> diff --git a/drivers/soc/microchip/mpfs_sys_controller.c b/drivers/soc/microchip/mpfs_sys_controller.c
>>> new file mode 100644
>>> index 000000000000..875a0671e196
>>> --- /dev/null
>>> +++ b/drivers/soc/microchip/mpfs_sys_controller.c
>>> @@ -0,0 +1,135 @@
>>> +// SPDX-License-Identifier: GPL-2.0
>>> +/*
>>> + * Microchip MPFS system controller driver
>>> + *
>>> + * Copyright (c) 2020 Microchip Corporation. All rights reserved.
>>> + *
>>> + * Author: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
>>> + *
>>> + */
>>> +
>>> +#include <linux/slab.h>
>>> +#include <linux/module.h>
>>> +#include <linux/interrupt.h>
>>> +#include <linux/of_platform.h>
>>> +#include <linux/mailbox_client.h>
>>> +#include <linux/platform_device.h>
>>> +#include <soc/microchip/mpfs.h>
>>> +
>>> +static DEFINE_MUTEX(transaction_lock);
>>> +
>>> +struct mpfs_sys_controller {
>>> + struct mbox_client client;
>>> + struct mbox_chan *chan;
>>> + struct completion c;
>>> + u32 enabled;
>>> + void *response;
>>> + u16 response_size_bytes;
>>> +};
>>> +
>>> +int mpfs_blocking_transaction(struct mpfs_sys_controller *mpfs_client, void *msg,
>>> + void *response, u16 response_size_bytes)
>>> +{
>>> + int ret;
>>> +
>>> + mpfs_client->response = response;
>>> + mpfs_client->response_size_bytes = response_size_bytes;
>>> +
>>> + mutex_lock_interruptible(&transaction_lock);
>>> +
>>> + reinit_completion(&mpfs_client->c);
>>> +
>>> + ret = mbox_send_message(mpfs_client->chan, msg);
>>> + if (ret >= 0) {
>>> + if (wait_for_completion_timeout(&mpfs_client->c, HZ)) {
>>> + ret = 0;
>>> + } else {
>>> + ret = -ETIMEDOUT;
>>> + dev_warn(mpfs_client->client.dev, "MPFS sys controller transaction timeout");
>>> + }
>>> + } else {
>>> + dev_err(mpfs_client->client.dev,
>>> + "mpfs sys controller transaction returned %d\r\n", ret);
>>> + }
>>> +
>>> + mutex_unlock(&transaction_lock);
>>> +
>>> + return ret;
>>> +}
>>> +EXPORT_SYMBOL(mpfs_blocking_transaction);
>>> +
>>> +static void rx_callback(struct mbox_client *client, void *msg)
>>> +{
>>> + struct mpfs_sys_controller *mpfs_client =
>>> + container_of(client, struct mpfs_sys_controller, client);
>>> +
>>> + memcpy(mpfs_client->response, (u8 *)msg,
>>> + mpfs_client->response_size_bytes);
>>> +
>>> + complete(&mpfs_client->c);
>>> +}
>>> +
>>> +static int mpfs_sys_controller_probe(struct platform_device *pdev)
>>> +{
>>> + struct device *dev = &pdev->dev;
>>> + struct mpfs_sys_controller *mpfs_client;
>>> +
>>> + mpfs_client = devm_kzalloc(dev, sizeof(*mpfs_client), GFP_KERNEL);
>>> + if (!mpfs_client)
>>> + return -ENOMEM;
>>> +
>>> + mpfs_client->client.dev = dev;
>>> + mpfs_client->client.rx_callback = rx_callback;
>>> + mpfs_client->client.tx_block = 1U;
>>> +
>>> + mpfs_client->chan = mbox_request_channel_byname(&mpfs_client->client,
>>> + "mbox-mpfs");
>>> + if (IS_ERR(mpfs_client->chan)) {
>>> + int ret = PTR_ERR(mpfs_client->chan);
>>> +
>>> + if (ret != -EPROBE_DEFER)
>>> + dev_err(dev, "Failed to get mbox channel: %d\n", ret);
>>> + return ret;
>>
>> You can replace all of this with
>>
>> return dev_err_probe(dev, PTR_ERR(mpfs_client->chan),
>> ""Failed to get mbox channel\n");
>
> you'll spam the error log if you get a lot of probe defferals.
> I think the code as is fine.
Please look at that function code: it does not print anything if the error is
-EPROBE_DEFER.
--
Damien Le Moal
Western Digital Research
