linux/drivers/platform/chrome/cros_ec_rpmsg.c

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// SPDX-License-Identifier: GPL-2.0
//
// Copyright 2018 Google LLC.
#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
mfd / platform: cros_ec: Reorganize platform and mfd includes There is a bit of mess between cros-ec mfd includes and platform includes. For example, we have a linux/mfd/cros_ec.h include that exports the interface implemented in platform/chrome/cros_ec_proto.c. Or we have a linux/mfd/cros_ec_commands.h file that is non related to the multifunction device (in the sense that is not exporting any function of the mfd device). This causes crossed includes between mfd and platform/chrome subsystems and makes the code difficult to read, apart from creating 'curious' situations where a platform/chrome driver includes a linux/mfd/cros_ec.h file just to get the exported functions that are implemented in another platform/chrome driver. In order to have a better separation on what the cros-ec multifunction driver does and what the cros-ec core provides move and rework the affected includes doing: - Move cros_ec_commands.h to include/linux/platform_data/cros_ec_commands.h - Get rid of the parts that are implemented in the platform/chrome/cros_ec_proto.c driver from include/linux/mfd/cros_ec.h to a new file include/linux/platform_data/cros_ec_proto.h - Update all the drivers with the new includes, so - Drivers that only need to know about the protocol include - linux/platform_data/cros_ec_proto.h - linux/platform_data/cros_ec_commands.h - Drivers that need to know about the cros-ec mfd device also include - linux/mfd/cros_ec.h Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com> Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Mark Brown <broonie@kernel.org> Acked-by: Wolfram Sang <wsa@the-dreams.de> Acked-by: Neil Armstrong <narmstrong@baylibre.com> Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Acked-by: Sebastian Reichel <sebastian.reichel@collabora.com> Acked-by: Chanwoo Choi <cw00.choi@samsung.com> Reviewed-by: Gwendal Grignou <gwendal@chromium.org> Tested-by: Gwendal Grignou <gwendal@chromium.org> Series changes: 3 - Fix dereferencing pointer to incomplete type 'struct cros_ec_dev' (lkp) Signed-off-by: Lee Jones <lee.jones@linaro.org>
2019-09-02 09:53:05 +00:00
#include <linux/platform_data/cros_ec_commands.h>
#include <linux/platform_data/cros_ec_proto.h>
#include <linux/platform_device.h>
#include <linux/rpmsg.h>
#include <linux/slab.h>
#define EC_MSG_TIMEOUT_MS 200
#define HOST_COMMAND_MARK 1
#define HOST_EVENT_MARK 2
/**
* struct cros_ec_rpmsg_response - rpmsg message format from from EC.
*
* @type: The type of message, should be either HOST_COMMAND_MARK or
* HOST_EVENT_MARK, representing that the message is a response to
* host command, or a host event.
* @data: ec_host_response for host command.
*/
struct cros_ec_rpmsg_response {
u8 type;
u8 data[] __aligned(4);
};
/**
* struct cros_ec_rpmsg - information about a EC over rpmsg.
*
* @rpdev: rpmsg device we are connected to
* @xfer_ack: completion for host command transfer.
* @host_event_work: Work struct for pending host event.
*/
struct cros_ec_rpmsg {
struct rpmsg_device *rpdev;
struct completion xfer_ack;
struct work_struct host_event_work;
struct rpmsg_endpoint *ept;
};
/**
* cros_ec_cmd_xfer_rpmsg - Transfer a message over rpmsg and receive the reply
*
* @ec_dev: ChromeOS EC device
* @ec_msg: Message to transfer
*
* This is only used for old EC proto version, and is not supported for this
* driver.
*
* Return: -EINVAL
*/
static int cros_ec_cmd_xfer_rpmsg(struct cros_ec_device *ec_dev,
struct cros_ec_command *ec_msg)
{
return -EINVAL;
}
/**
* cros_ec_pkt_xfer_rpmsg - Transfer a packet over rpmsg and receive the reply
*
* @ec_dev: ChromeOS EC device
* @ec_msg: Message to transfer
*
* Return: number of bytes of the reply on success or negative error code.
*/
static int cros_ec_pkt_xfer_rpmsg(struct cros_ec_device *ec_dev,
struct cros_ec_command *ec_msg)
{
struct cros_ec_rpmsg *ec_rpmsg = ec_dev->priv;
struct ec_host_response *response;
unsigned long timeout;
int len;
int ret;
u8 sum;
int i;
ec_msg->result = 0;
len = cros_ec_prepare_tx(ec_dev, ec_msg);
dev_dbg(ec_dev->dev, "prepared, len=%d\n", len);
reinit_completion(&ec_rpmsg->xfer_ack);
ret = rpmsg_send(ec_rpmsg->ept, ec_dev->dout, len);
if (ret) {
dev_err(ec_dev->dev, "rpmsg send failed\n");
return ret;
}
timeout = msecs_to_jiffies(EC_MSG_TIMEOUT_MS);
ret = wait_for_completion_timeout(&ec_rpmsg->xfer_ack, timeout);
if (!ret) {
dev_err(ec_dev->dev, "rpmsg send timeout\n");
return -EIO;
}
/* check response error code */
response = (struct ec_host_response *)ec_dev->din;
ec_msg->result = response->result;
ret = cros_ec_check_result(ec_dev, ec_msg);
if (ret)
goto exit;
if (response->data_len > ec_msg->insize) {
dev_err(ec_dev->dev, "packet too long (%d bytes, expected %d)",
response->data_len, ec_msg->insize);
ret = -EMSGSIZE;
goto exit;
}
/* copy response packet payload and compute checksum */
memcpy(ec_msg->data, ec_dev->din + sizeof(*response),
response->data_len);
sum = 0;
for (i = 0; i < sizeof(*response) + response->data_len; i++)
sum += ec_dev->din[i];
if (sum) {
dev_err(ec_dev->dev, "bad packet checksum, calculated %x\n",
sum);
ret = -EBADMSG;
goto exit;
}
ret = response->data_len;
exit:
if (ec_msg->command == EC_CMD_REBOOT_EC)
msleep(EC_REBOOT_DELAY_MS);
return ret;
}
static void
cros_ec_rpmsg_host_event_function(struct work_struct *host_event_work)
{
struct cros_ec_rpmsg *ec_rpmsg = container_of(host_event_work,
struct cros_ec_rpmsg,
host_event_work);
struct cros_ec_device *ec_dev = dev_get_drvdata(&ec_rpmsg->rpdev->dev);
bool wake_event = true;
int ret;
ret = cros_ec_get_next_event(ec_dev, &wake_event);
/*
* Signal only if wake host events or any interrupt if
* cros_ec_get_next_event() returned an error (default value for
* wake_event is true)
*/
if (wake_event && device_may_wakeup(ec_dev->dev))
pm_wakeup_event(ec_dev->dev, 0);
if (ret > 0)
blocking_notifier_call_chain(&ec_dev->event_notifier,
0, ec_dev);
}
static int cros_ec_rpmsg_callback(struct rpmsg_device *rpdev, void *data,
int len, void *priv, u32 src)
{
struct cros_ec_device *ec_dev = dev_get_drvdata(&rpdev->dev);
struct cros_ec_rpmsg *ec_rpmsg = ec_dev->priv;
struct cros_ec_rpmsg_response *resp;
if (!len) {
dev_warn(ec_dev->dev, "rpmsg received empty response");
return -EINVAL;
}
resp = data;
len -= offsetof(struct cros_ec_rpmsg_response, data);
if (resp->type == HOST_COMMAND_MARK) {
if (len > ec_dev->din_size) {
dev_warn(ec_dev->dev,
"received length %d > din_size %d, truncating",
len, ec_dev->din_size);
len = ec_dev->din_size;
}
memcpy(ec_dev->din, resp->data, len);
complete(&ec_rpmsg->xfer_ack);
} else if (resp->type == HOST_EVENT_MARK) {
schedule_work(&ec_rpmsg->host_event_work);
} else {
dev_warn(ec_dev->dev, "rpmsg received invalid type = %d",
resp->type);
return -EINVAL;
}
return 0;
}
static struct rpmsg_endpoint *
cros_ec_rpmsg_create_ept(struct rpmsg_device *rpdev)
{
struct rpmsg_channel_info chinfo = {};
strscpy(chinfo.name, rpdev->id.name, RPMSG_NAME_SIZE);
chinfo.src = rpdev->src;
chinfo.dst = RPMSG_ADDR_ANY;
return rpmsg_create_ept(rpdev, cros_ec_rpmsg_callback, NULL, chinfo);
}
static int cros_ec_rpmsg_probe(struct rpmsg_device *rpdev)
{
struct device *dev = &rpdev->dev;
struct cros_ec_rpmsg *ec_rpmsg;
struct cros_ec_device *ec_dev;
int ret;
ec_dev = devm_kzalloc(dev, sizeof(*ec_dev), GFP_KERNEL);
if (!ec_dev)
return -ENOMEM;
ec_rpmsg = devm_kzalloc(dev, sizeof(*ec_rpmsg), GFP_KERNEL);
if (!ec_rpmsg)
return -ENOMEM;
ec_dev->dev = dev;
ec_dev->priv = ec_rpmsg;
ec_dev->cmd_xfer = cros_ec_cmd_xfer_rpmsg;
ec_dev->pkt_xfer = cros_ec_pkt_xfer_rpmsg;
ec_dev->phys_name = dev_name(&rpdev->dev);
ec_dev->din_size = sizeof(struct ec_host_response) +
sizeof(struct ec_response_get_protocol_info);
ec_dev->dout_size = sizeof(struct ec_host_request);
dev_set_drvdata(dev, ec_dev);
ec_rpmsg->rpdev = rpdev;
init_completion(&ec_rpmsg->xfer_ack);
INIT_WORK(&ec_rpmsg->host_event_work,
cros_ec_rpmsg_host_event_function);
ec_rpmsg->ept = cros_ec_rpmsg_create_ept(rpdev);
if (!ec_rpmsg->ept)
return -ENOMEM;
ret = cros_ec_register(ec_dev);
if (ret < 0) {
rpmsg_destroy_ept(ec_rpmsg->ept);
cancel_work_sync(&ec_rpmsg->host_event_work);
return ret;
}
return 0;
}
static void cros_ec_rpmsg_remove(struct rpmsg_device *rpdev)
{
struct cros_ec_device *ec_dev = dev_get_drvdata(&rpdev->dev);
struct cros_ec_rpmsg *ec_rpmsg = ec_dev->priv;
mfd / platform: cros_ec: Handle chained ECs as platform devices An MFD is a device that contains several sub-devices (cells). For instance, the ChromeOS EC fits in this description as usually contains a charger and can have other devices with different functions like a Real-Time Clock, an Audio codec, a Real-Time Clock, ... If you look at the driver, though, we're doing something odd. We have two MFD cros-ec drivers where one of them (cros-ec-core) instantiates another MFD driver as sub-driver (cros-ec-dev), and the latest instantiates the different sub-devices (Real-Time Clock, Audio codec, etc). MFD ------------------------------------------ cros-ec-core |___ mfd-cellA (cros-ec-dev) | |__ mfd-cell0 | |__ mfd-cell1 | |__ ... | |___ mfd-cellB (cros-ec-dev) |__ mfd-cell0 |__ mfd-cell1 |__ ... The problem that was trying to solve is to describe some kind of topology for the case where we have an EC (cros-ec) chained with another EC (cros-pd). Apart from that this extends the bounds of what MFD was designed to do we might be interested on have other kinds of topology that can't be implemented in that way. Let's prepare the code to move the cros-ec-core part from MFD to platform/chrome as this is clearly a platform specific thing non-related to a MFD device. platform/chrome | MFD ------------------------------------------ | cros-ec ________|___ cros-ec-dev | |__ mfd-cell0 | |__ mfd-cell1 | |__ ... | cros-pd ________|___ cros-ec-dev | |__ mfd-cell0 | |__ mfd-cell1 | |__ ... Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com> Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Gwendal Grignou <gwendal@chromium.org> Tested-by: Gwendal Grignou <gwendal@chromium.org> Signed-off-by: Lee Jones <lee.jones@linaro.org>
2019-09-02 09:53:00 +00:00
cros_ec_unregister(ec_dev);
rpmsg_destroy_ept(ec_rpmsg->ept);
cancel_work_sync(&ec_rpmsg->host_event_work);
}
#ifdef CONFIG_PM_SLEEP
static int cros_ec_rpmsg_suspend(struct device *dev)
{
struct cros_ec_device *ec_dev = dev_get_drvdata(dev);
return cros_ec_suspend(ec_dev);
}
static int cros_ec_rpmsg_resume(struct device *dev)
{
struct cros_ec_device *ec_dev = dev_get_drvdata(dev);
return cros_ec_resume(ec_dev);
}
#endif
static SIMPLE_DEV_PM_OPS(cros_ec_rpmsg_pm_ops, cros_ec_rpmsg_suspend,
cros_ec_rpmsg_resume);
static const struct of_device_id cros_ec_rpmsg_of_match[] = {
{ .compatible = "google,cros-ec-rpmsg", },
{ }
};
MODULE_DEVICE_TABLE(of, cros_ec_rpmsg_of_match);
static struct rpmsg_driver cros_ec_driver_rpmsg = {
.drv = {
.name = "cros-ec-rpmsg",
.of_match_table = cros_ec_rpmsg_of_match,
.pm = &cros_ec_rpmsg_pm_ops,
},
.probe = cros_ec_rpmsg_probe,
.remove = cros_ec_rpmsg_remove,
};
module_rpmsg_driver(cros_ec_driver_rpmsg);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("ChromeOS EC multi function device (rpmsg)");