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Date: Thu, 11 Apr 2019 15:54:25 +0200
From: Enric Balletbo i Serra <enric.balletbo@...labora.com>
To: Rushikesh S Kadam <rushikesh.s.kadam@...el.com>
Cc: Jett Rink <jettrink@...omium.org>,
Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>,
Benson Leung <bleung@...omium.org>,
Guenter Roeck <groeck@...omium.org>,
Nick Crews <ncrews@...omium.org>,
Gwendal Grignou <gwendal@...gle.com>,
linux-kernel <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v3] platform: chrome: Add ChromeOS EC ISHTP driver
Hi,
On 11/4/19 13:10, Rushikesh S Kadam wrote:
> Hi Enric, Srinivas
>
> On Thu, Apr 11, 2019 at 12:55:13PM +0200, Enric Balletbo i Serra wrote:
>> Hi,
>>
>> On 10/4/19 17:31, Jett Rink wrote:
>>> Reviewed-by: Jett Rink <jettrink@...omium.org>
>>> Tested-by: Jett Rink <jettrink@...omium.org>
>>>
>>>
>>> On Sun, Apr 7, 2019 at 6:10 AM Rushikesh S Kadam
>>> <rushikesh.s.kadam@...el.com> wrote:
>>>>
>>>> This driver implements a slim layer to enable the ChromeOS
>>>> EC kernel stack (cros_ec) to communicate with ChromeOS EC
>>>> firmware running on the Intel Integrated Sensor Hub (ISH).
>>>>
>>>> The driver registers a ChromeOS EC MFD device to connect
>>>> with cros_ec kernel stack (upper layer), and it registers a
>>>> client with the ISH Transport Protocol bus (lower layer) to
>>>> talk with the ISH firwmare. See description of the ISHTP
>>>> protocol at Documentation/hid/intel-ish-hid.txt
>>>>
>>>> Signed-off-by: Rushikesh S Kadam <rushikesh.s.kadam@...el.com>
>>>> ---
>>>>
>>>> v3
>>>> - Made several changes to improve code readability. Replaced
>>>> multiple cl_data_to_dev(client_data) with dev variable. Use
>>>> reverse Xmas tree for variable defintion where it made sense.
>>>> Dropped few debug prints. Add docstring for function
>>>> prepare_cros_ec_rx().
>>>> - Fix code in function prepare_cros_ec_rx() under label
>>>> end_cros_ec_dev_init_error.
>>>> - Recycle buffer in process_recv() on failing to obtain the
>>>> semaphore.
>>>> - Increase ISHTP TX/RX ring buffer size to 8.
>>>> - Alphabetically ordered CROS_EC_ISHTP entries in Makefile and
>>>> Kconfig.
>>>> - Updated commit message.
>>>>
>>>> v2
>>>> - Dropped unused "reset" parameter in function cros_ec_init()
>>>> - Change driver name to cros_ec_ishtp to be consistent with other
>>>> references in the code.
>>>> - Fixed a few typos.
>>>>
>>>> v1
>>>> - Initial version
>>>>
>>>> drivers/platform/chrome/Kconfig | 13 +
>>>> drivers/platform/chrome/Makefile | 1 +
>>>> drivers/platform/chrome/cros_ec_ishtp.c | 765 ++++++++++++++++++++++++++++++++
>>>> 3 files changed, 779 insertions(+)
>>>> create mode 100644 drivers/platform/chrome/cros_ec_ishtp.c
>>>>
>>>> diff --git a/drivers/platform/chrome/Kconfig b/drivers/platform/chrome/Kconfig
>>>> index 16b1615..5848179 100644
>>>> --- a/drivers/platform/chrome/Kconfig
>>>> +++ b/drivers/platform/chrome/Kconfig
>>>> @@ -62,6 +62,19 @@ config CROS_EC_I2C
>>>> a checksum. Failing accesses will be retried three times to
>>>> improve reliability.
>>>>
>>>> +config CROS_EC_ISHTP
>>>> + tristate "ChromeOS Embedded Controller (ISHTP)"
>>>> + depends on MFD_CROS_EC
>>>> + depends on INTEL_ISH_HID
>>>> + help
>>>> + If you say Y here, you get support for talking to the ChromeOS EC
>>>> + firmware running on Intel Integrated Sensor Hub (ISH), using the
>>>> + ISH Transport protocol (ISH-TP). This uses a simple byte-level
>>>> + protocol with a checksum.
>>>> +
>>>> + To compile this driver as a module, choose M here: the
>>>> + module will be called cros_ec_ishtp.
>>>> +
>>>> config CROS_EC_SPI
>>>> tristate "ChromeOS Embedded Controller (SPI)"
>>>> depends on MFD_CROS_EC && SPI
>>>> diff --git a/drivers/platform/chrome/Makefile b/drivers/platform/chrome/Makefile
>>>> index cd591bf..4efe102 100644
>>>> --- a/drivers/platform/chrome/Makefile
>>>> +++ b/drivers/platform/chrome/Makefile
>>>> @@ -7,6 +7,7 @@ cros_ec_ctl-objs := cros_ec_sysfs.o cros_ec_lightbar.o \
>>>> cros_ec_vbc.o cros_ec_debugfs.o
>>>> obj-$(CONFIG_CROS_EC_CTL) += cros_ec_ctl.o
>>>> obj-$(CONFIG_CROS_EC_I2C) += cros_ec_i2c.o
>>>> +obj-$(CONFIG_CROS_EC_ISHTP) += cros_ec_ishtp.o
>>>> obj-$(CONFIG_CROS_EC_SPI) += cros_ec_spi.o
>>>> cros_ec_lpcs-objs := cros_ec_lpc.o cros_ec_lpc_reg.o
>>>> cros_ec_lpcs-$(CONFIG_CROS_EC_LPC_MEC) += cros_ec_lpc_mec.o
>>>> diff --git a/drivers/platform/chrome/cros_ec_ishtp.c b/drivers/platform/chrome/cros_ec_ishtp.c
>>>> new file mode 100644
>>>> index 0000000..b1d19c4
>>>> --- /dev/null
>>>> +++ b/drivers/platform/chrome/cros_ec_ishtp.c
>>>> @@ -0,0 +1,765 @@
>>>> +// SPDX-License-Identifier: GPL-2.0
>>>> +/*
>>>> + * ISHTP client driver for talking to the Chrome OS EC firmware running
>>>> + * on Intel Integrated Sensor Hub (ISH) using the ISH Transport protocol
>>>> + * (ISH-TP).
>>>> + *
>>>> + * Copyright (c) 2019, Intel Corporation.
>>>> + */
>>>> +
>>>> +#include <linux/delay.h>
>>>> +#include <linux/mfd/core.h>
>>>> +#include <linux/mfd/cros_ec.h>
>>>> +#include <linux/mfd/cros_ec_commands.h>
>>>> +#include <linux/module.h>
>>>> +#include <linux/pci.h>
>>>> +#include <linux/intel-ish-client-if.h>
>>>> +
>>
>> I think that this patch depends on another patchset that's in linux-next but
>> diddn't land yet to mainline. Do you know if the dependencies are queued for
>> next merge window? Can you provide the exact patches that this patch depends on?
>
> Enric,
> Sorry I missed mentioning this.
>
> The patch have dependency on intel-ish-hid stack on hid git tree,
> branch for-5.2/ish
> https://git.kernel.org/pub/scm/linux/kernel/git/hid/hid.git/log/?h=for-5.2/ish
>
> Srinivas,
> Could you tell if the patches are queued for next merge window?
>
If you can provide an immutable branch I can queue the patch to the
chrome-platform now, otherwise I'll wait to see this merged and then apply. I
did some minor style modifications but from my side the patch is fine to go for
chrome-platform-5.2
Thanks,
Enric
> Thanks
> Rushikesh
>
>
>>
>> Thanks,
>> Enric
>>
>>
>>>> +/*
>>>> + * ISH TX/RX ring buffer pool size
>>>> + *
>>>> + * The AP->ISH messages and corresponding ISH->AP responses are
>>>> + * serialized. We need 1 TX and 1 RX buffer for these.
>>>> + *
>>>> + * The MKBP ISH->AP events are serialized. We need one additional RX
>>>> + * buffer for them.
>>>> + */
>>>> +#define CROS_ISH_CL_TX_RING_SIZE 8
>>>> +#define CROS_ISH_CL_RX_RING_SIZE 8
>>>> +
>>>> +/* ISH CrOS EC Host Commands */
>>>> +enum cros_ec_ish_channel {
>>>> + CROS_EC_COMMAND = 1, /* AP->ISH message */
>>>> + CROS_MKBP_EVENT = 2, /* ISH->AP events */
>>>> +};
>>>> +
>>>> +/*
>>>> + * ISH firmware timeout for 1 message send failure is 1Hz, and the
>>>> + * firmware will retry 2 times, so 3Hz is used for timeout.
>>>> + */
>>>> +#define ISHTP_SEND_TIMEOUT (3 * HZ)
>>>> +
>>>> +/* ISH Transport CrOS EC ISH client unique GUID */
>>>> +static const guid_t cros_ish_guid =
>>>> + GUID_INIT(0x7b7154d0, 0x56f4, 0x4bdc,
>>>> + 0xb0, 0xd8, 0x9e, 0x7c, 0xda, 0xe0, 0xd6, 0xa0);
>>>> +
>>>> +struct header {
>>>> + u8 channel;
>>>> + u8 status;
>>>> + u8 reserved[2];
>>>> +} __packed;
>>>> +
>>>> +struct cros_ish_out_msg {
>>>> + struct header hdr;
>>>> + struct ec_host_request ec_request;
>>>> +} __packed;
>>>> +
>>>> +struct cros_ish_in_msg {
>>>> + struct header hdr;
>>>> + struct ec_host_response ec_response;
>>>> +} __packed;
>>>> +
>>>> +#define IN_MSG_EC_RESPONSE_PREAMBLE \
>>>> + offsetof(struct cros_ish_in_msg, ec_response)
>>>> +
>>>> +#define OUT_MSG_EC_REQUEST_PREAMBLE \
>>>> + offsetof(struct cros_ish_out_msg, ec_request)
>>>> +
>>>> +#define cl_data_to_dev(client_data) ishtp_device((client_data)->cl_device)
>>>> +
>>>> +/*
>>>> + * The Read-Write Semaphore is used to prevent message TX or RX while
>>>> + * the ishtp client is being initialized or undergoing reset.
>>>> + *
>>>> + * The readers are the kernel function calls responsible for IA->ISH
>>>> + * and ISH->AP messaging.
>>>> + *
>>>> + * The writers are .reset() and .probe() function.
>>>> + */
>>>> +DECLARE_RWSEM(init_lock);
>>>> +
>>>> +/**
>>>> + * struct response_info - Encapsulate firmware response related
>>>> + * information for passing between function
>>>> + * ish_send() and process_recv() callback.
>>>> + * @data: Copy the data received from firmware here.
>>>> + * @max_size: Max size allocated for the @data buffer. If the
>>>> + * received data exceeds this value, we log an
>>>> + * error.
>>>> + * @size: Actual size of data received from firmware.
>>>> + * @error: 0 for success, negative error code for a
>>>> + * failure in function process_recv().
>>>> + * @received: Set to true on receiving a valid firmware
>>>> + * response to host command
>>>> + * @wait_queue: Wait queue for Host firmware loading where the
>>>> + * client sends message to ISH firmware and waits
>>>> + * for response
>>>> + */
>>>> +struct response_info {
>>>> + void *data;
>>>> + size_t max_size;
>>>> + size_t size;
>>>> + int error;
>>>> + bool received;
>>>> + wait_queue_head_t wait_queue;
>>>> +};
>>>> +
>>>> +/**
>>>> + * struct ishtp_cl_data - Encapsulate per ISH TP Client.
>>>> + * @cros_ish_cl: ISHTP firmware client instance.
>>>> + * @cl_device: ISHTP client device instance.
>>>> + * @response: Firmware response information for passing
>>>> + * between function ish_send() and process_recv()
>>>> + * callback.
>>>> + * @work_ishtp_reset: Work queue reset handling.
>>>> + * @work_ec_evt: Work queue for EC events.
>>>> + * @ec_dev: CrOS EC MFD device.
>>>> + *
>>>> + * This structure is used to store per client data.
>>>> + */
>>>> +struct ishtp_cl_data {
>>>> + struct ishtp_cl *cros_ish_cl;
>>>> + struct ishtp_cl_device *cl_device;
>>>> +
>>>> + /*
>>>> + * Used for passing firmware response information between
>>>> + * ish_send() and process_recv() callback.
>>>> + */
>>>> + struct response_info response;
>>>> +
>>>> + struct work_struct work_ishtp_reset;
>>>> + struct work_struct work_ec_evt;
>>>> + struct cros_ec_device *ec_dev;
>>>> +};
>>>> +
>>>> +/**
>>>> + * ish_evt_handler - ISH to AP event handler
>>>> + * @work: Work struct
>>>> + */
>>>> +static void ish_evt_handler(struct work_struct *work)
>>>> +{
>>>> + struct ishtp_cl_data *client_data =
>>>> + container_of(work, struct ishtp_cl_data, work_ec_evt);
>>>> + struct cros_ec_device *ec_dev = client_data->ec_dev;
>>>> +
>>>> + if (cros_ec_get_next_event(ec_dev, NULL) > 0) {
>>>> + blocking_notifier_call_chain(&ec_dev->event_notifier,
>>>> + 0, ec_dev);
>>>> + }
>>>> +}
>>>> +
>>>> +/**
>>>> + * ish_send() - Send message from host to firmware
>>>> + * @client_data: Client data instance
>>>> + * @out_msg: Message buffer to be sent to firmware
>>>> + * @out_size: Size of out going message
>>>> + * @in_msg: Message buffer where the incoming data copied.
>>>> + * This buffer is allocated by calling
>>>> + * @in_size: Max size of incoming message
>>>> + *
>>>> + * Return: Number of bytes copied in the in_msg on success, negative
>>>> + * error code on failure.
>>>> + */
>>>> +static int ish_send(struct ishtp_cl_data *client_data,
>>>> + u8 *out_msg, size_t out_size,
>>>> + u8 *in_msg, size_t in_size)
>>>> +{
>>>> + int rv;
>>>> + struct header *out_hdr = (struct header *)out_msg;
>>>> + struct ishtp_cl *cros_ish_cl = client_data->cros_ish_cl;
>>>> +
>>>> + dev_dbg(cl_data_to_dev(client_data),
>>>> + "%s: channel=%02u status=%02u\n",
>>>> + __func__, out_hdr->channel, out_hdr->status);
>>>> +
>>>> + /* Setup for incoming response */
>>>> + client_data->response.data = in_msg;
>>>> + client_data->response.max_size = in_size;
>>>> + client_data->response.error = 0;
>>>> + client_data->response.received = false;
>>>> +
>>>> + rv = ishtp_cl_send(cros_ish_cl, out_msg, out_size);
>>>> + if (rv) {
>>>> + dev_err(cl_data_to_dev(client_data),
>>>> + "ishtp_cl_send error %d\n", rv);
>>>> + return rv;
>>>> + }
>>>> +
>>>> + wait_event_interruptible_timeout(client_data->response.wait_queue,
>>>> + client_data->response.received,
>>>> + ISHTP_SEND_TIMEOUT);
>>>> + if (!client_data->response.received) {
>>>> + dev_err(cl_data_to_dev(client_data),
>>>> + "Timed out for response to host message\n");
>>>> + return -ETIMEDOUT;
>>>> + }
>>>> +
>>>> + if (client_data->response.error < 0)
>>>> + return client_data->response.error;
>>>> +
>>>> + return client_data->response.size;
>>>> +}
>>>> +
>>>> +/**
>>>> + * process_recv() - Received and parse incoming packet
>>>> + * @cros_ish_cl: Client instance to get stats
>>>> + * @rb_in_proc: Host interface message buffer
>>>> + *
>>>> + * Parse the incoming packet. If it is a response packet then it will
>>>> + * update per instance flags and wake up the caller waiting to for the
>>>> + * response. If it is an event packet then it will schedule event work.
>>>> + */
>>>> +static void process_recv(struct ishtp_cl *cros_ish_cl,
>>>> + struct ishtp_cl_rb *rb_in_proc)
>>>> +{
>>>> + size_t data_len = rb_in_proc->buf_idx;
>>>> + struct ishtp_cl_data *client_data =
>>>> + ishtp_get_client_data(cros_ish_cl);
>>>> + struct device *dev = cl_data_to_dev(client_data);
>>>> + struct cros_ish_in_msg *in_msg =
>>>> + (struct cros_ish_in_msg *)rb_in_proc->buffer.data;
>>>> +
>>>> + /* Proceed only if reset or init is not in progress */
>>>> + if (!down_read_trylock(&init_lock)) {
>>>> + /* Free the buffer */
>>>> + ishtp_cl_io_rb_recycle(rb_in_proc);
>>>> + dev_warn(dev,
>>>> + "Host is not ready to receive incoming messages\n");
>>>> + return;
>>>> + }
>>>> +
>>>> + /*
>>>> + * All firmware messages contain a header. Check the buffer size
>>>> + * before accessing elements inside.
>>>> + */
>>>> + if (!rb_in_proc->buffer.data) {
>>>> + dev_warn(dev, "rb_in_proc->buffer.data returned null");
>>>> + client_data->response.error = -EBADMSG;
>>>> + goto end_error;
>>>> + }
>>>> +
>>>> + if (data_len < sizeof(struct header)) {
>>>> + dev_err(dev, "data size %zu is less than header %zu\n",
>>>> + data_len, sizeof(struct header));
>>>> + client_data->response.error = -EMSGSIZE;
>>>> + goto end_error;
>>>> + }
>>>> +
>>>> + dev_dbg(dev, "channel=%02u status=%02u\n",
>>>> + in_msg->hdr.channel, in_msg->hdr.status);
>>>> +
>>>> + switch (in_msg->hdr.channel) {
>>>> + case CROS_EC_COMMAND:
>>>> + /* Sanity check */
>>>> + if (!client_data->response.data) {
>>>> + dev_err(dev,
>>>> + "Receiving buffer is null. Should be allocated by calling function\n");
>>>> + client_data->response.error = -EINVAL;
>>>> + goto error_wake_up;
>>>> + }
>>>> +
>>>> + if (client_data->response.received) {
>>>> + dev_err(dev,
>>>> + "Previous firmware message not yet processed\n");
>>>> + client_data->response.error = -EINVAL;
>>>> + goto error_wake_up;
>>>> + }
>>>> +
>>>> + if (data_len > client_data->response.max_size) {
>>>> + dev_err(dev,
>>>> + "Received buffer size %zu is larger than allocated buffer %zu\n",
>>>> + data_len, client_data->response.max_size);
>>>> + client_data->response.error = -EMSGSIZE;
>>>> + goto error_wake_up;
>>>> + }
>>>> +
>>>> + if (in_msg->hdr.status) {
>>>> + dev_err(dev, "firmware returned status %d\n",
>>>> + in_msg->hdr.status);
>>>> + client_data->response.error = -EIO;
>>>> + goto error_wake_up;
>>>> + }
>>>> +
>>>> + /* Update the actual received buffer size */
>>>> + client_data->response.size = data_len;
>>>> +
>>>> + /*
>>>> + * Copy the buffer received in firmware response for the
>>>> + * calling thread.
>>>> + */
>>>> + memcpy(client_data->response.data,
>>>> + rb_in_proc->buffer.data, data_len);
>>>> +
>>>> + /* Set flag before waking up the caller */
>>>> + client_data->response.received = true;
>>>> +error_wake_up:
>>>> + /* Wake the calling thread */
>>>> + wake_up_interruptible(&client_data->response.wait_queue);
>>>> +
>>>> + break;
>>>> +
>>>> + case CROS_MKBP_EVENT:
>>>> + /* The event system doesn't send any data in buffer */
>>>> + schedule_work(&client_data->work_ec_evt);
>>>> +
>>>> + break;
>>>> +
>>>> + default:
>>>> + dev_err(dev, "Invalid channel=%02d\n", in_msg->hdr.channel);
>>>> + }
>>>> +
>>>> +end_error:
>>>> + /* Free the buffer */
>>>> + ishtp_cl_io_rb_recycle(rb_in_proc);
>>>> +
>>>> + up_read(&init_lock);
>>>> +}
>>>> +
>>>> +/**
>>>> + * ish_event_cb() - bus driver callback for incoming message
>>>> + * @cl_device: ISHTP client device for which this message is
>>>> + * targeted.
>>>> + *
>>>> + * Remove the packet from the list and process the message by calling
>>>> + * process_recv.
>>>> + */
>>>> +static void ish_event_cb(struct ishtp_cl_device *cl_device)
>>>> +{
>>>> + struct ishtp_cl_rb *rb_in_proc;
>>>> + struct ishtp_cl *cros_ish_cl = ishtp_get_drvdata(cl_device);
>>>> +
>>>> + while ((rb_in_proc = ishtp_cl_rx_get_rb(cros_ish_cl)) != NULL) {
>>>> + /* Decide what to do with received data */
>>>> + process_recv(cros_ish_cl, rb_in_proc);
>>>> + }
>>>> +}
>>>> +
>>>> +/**
>>>> + * cros_ish_init() - Init function for ISHTP client
>>>> + * @cros_ish_cl: ISHTP client instance
>>>> + *
>>>> + * This function complete the initializtion of the client.
>>>> + *
>>>> + * Return: 0 for success, negative error code for failure.
>>>> + */
>>>> +static int cros_ish_init(struct ishtp_cl *cros_ish_cl)
>>>> +{
>>>> + int rv;
>>>> + struct ishtp_device *dev;
>>>> + struct ishtp_fw_client *fw_client;
>>>> + struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl);
>>>> +
>>>> + rv = ishtp_cl_link(cros_ish_cl);
>>>> + if (rv) {
>>>> + dev_err(cl_data_to_dev(client_data),
>>>> + "ishtp_cl_link failed\n");
>>>> + return rv;
>>>> + }
>>>> +
>>>> + dev = ishtp_get_ishtp_device(cros_ish_cl);
>>>> +
>>>> + /* Connect to firmware client */
>>>> + ishtp_set_tx_ring_size(cros_ish_cl, CROS_ISH_CL_TX_RING_SIZE);
>>>> + ishtp_set_rx_ring_size(cros_ish_cl, CROS_ISH_CL_RX_RING_SIZE);
>>>> +
>>>> + fw_client = ishtp_fw_cl_get_client(dev, &cros_ish_guid);
>>>> + if (!fw_client) {
>>>> + dev_err(cl_data_to_dev(client_data),
>>>> + "ish client uuid not found\n");
>>>> + rv = -ENOENT;
>>>> + goto err_cl_unlink;
>>>> + }
>>>> +
>>>> + ishtp_cl_set_fw_client_id(cros_ish_cl,
>>>> + ishtp_get_fw_client_id(fw_client));
>>>> + ishtp_set_connection_state(cros_ish_cl, ISHTP_CL_CONNECTING);
>>>> +
>>>> + rv = ishtp_cl_connect(cros_ish_cl);
>>>> + if (rv) {
>>>> + dev_err(cl_data_to_dev(client_data),
>>>> + "client connect fail\n");
>>>> + goto err_cl_unlink;
>>>> + }
>>>> +
>>>> + ishtp_register_event_cb(client_data->cl_device, ish_event_cb);
>>>> + return 0;
>>>> +
>>>> +err_cl_unlink:
>>>> + ishtp_cl_unlink(cros_ish_cl);
>>>> + return rv;
>>>> +}
>>>> +
>>>> +/**
>>>> + * cros_ish_deinit() - Deinit function for ISHTP client
>>>> + * @cros_ish_cl: ISHTP client instance
>>>> + *
>>>> + * Unlink and free cros_ec client
>>>> + */
>>>> +static void cros_ish_deinit(struct ishtp_cl *cros_ish_cl)
>>>> +{
>>>> + ishtp_set_connection_state(cros_ish_cl, ISHTP_CL_DISCONNECTING);
>>>> + ishtp_cl_disconnect(cros_ish_cl);
>>>> + ishtp_cl_unlink(cros_ish_cl);
>>>> + ishtp_cl_flush_queues(cros_ish_cl);
>>>> +
>>>> + /* Disband and free all Tx and Rx client-level rings */
>>>> + ishtp_cl_free(cros_ish_cl);
>>>> +}
>>>> +
>>>> +/**
>>>> + * prepare_cros_ec_rx() - Check & prepare receive buffer
>>>> + * @in_msg: Incoming message buffer
>>>> + * @cros_ec_command cros_ec command used to send & receive data
>>>> + *
>>>> + * Check the received buffer. Convert to cros_ec_command format.
>>>> + */
>>>> +static int prepare_cros_ec_rx(struct cros_ec_device *ec_dev,
>>>> + const struct cros_ish_in_msg *in_msg,
>>>> + struct cros_ec_command *msg)
>>>> +{
>>>> + u8 sum = 0;
>>>> + int i, rv, offset;
>>>> +
>>>> + /* Check response error code */
>>>> + msg->result = in_msg->ec_response.result;
>>>> + rv = cros_ec_check_result(ec_dev, msg);
>>>> + if (rv < 0)
>>>> + return rv;
>>>> +
>>>> + if (in_msg->ec_response.data_len > msg->insize) {
>>>> + dev_err(ec_dev->dev, "Packet too long (%d bytes, expected %d)",
>>>> + in_msg->ec_response.data_len, msg->insize);
>>>> + return -ENOSPC;
>>>> + }
>>>> +
>>>> + /* Copy response packet payload and compute checksum */
>>>> + for (i = 0; i < sizeof(struct ec_host_response); i++)
>>>> + sum += ((u8 *)in_msg)[IN_MSG_EC_RESPONSE_PREAMBLE + i];
>>>> +
>>>> + offset = sizeof(struct cros_ish_in_msg);
>>>> + for (i = 0; i < in_msg->ec_response.data_len; i++)
>>>> + sum += msg->data[i] = ((u8 *)in_msg)[offset + i];
>>>> +
>>>> + if (sum) {
>>>> + dev_dbg(ec_dev->dev, "Bad received packet checksum %d\n", sum);
>>>> + return -EBADMSG;
>>>> + }
>>>> +
>>>> + return 0;
>>>> +}
>>>> +
>>>> +static int cros_ec_pkt_xfer_ish(struct cros_ec_device *ec_dev,
>>>> + struct cros_ec_command *msg)
>>>> +{
>>>> + int rv;
>>>> + struct ishtp_cl *cros_ish_cl = ec_dev->priv;
>>>> + struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl);
>>>> + struct device *dev = cl_data_to_dev(client_data);
>>>> + struct cros_ish_in_msg *in_msg = (struct cros_ish_in_msg *)ec_dev->din;
>>>> + struct cros_ish_out_msg *out_msg =
>>>> + (struct cros_ish_out_msg *)ec_dev->dout;
>>>> + size_t in_size = sizeof(struct cros_ish_in_msg) + msg->insize;
>>>> + size_t out_size = sizeof(struct cros_ish_out_msg) + msg->outsize;
>>>> +
>>>> + /* Proceed only if reset-init is not in progress */
>>>> + if (!down_read_trylock(&init_lock)) {
>>>> + dev_warn(dev,
>>>> + "Host is not ready to send messages to ISH. Try again\n");
>>>> + return -EAGAIN;
>>>> + }
>>>> +
>>>> + /* Sanity checks */
>>>> + if (in_size > ec_dev->din_size) {
>>>> + dev_err(dev,
>>>> + "Incoming payload size %zu is too large for ec_dev->din_size %d\n",
>>>> + in_size, ec_dev->din_size);
>>>> + return -EMSGSIZE;
>>>> + }
>>>> +
>>>> + if (out_size > ec_dev->dout_size) {
>>>> + dev_err(dev,
>>>> + "Outgoing payload size %zu is too large for ec_dev->dout_size %d\n",
>>>> + out_size, ec_dev->dout_size);
>>>> + return -EMSGSIZE;
>>>> + }
>>>> +
>>>> + /* Prepare the package to be sent over ISH TP */
>>>> + out_msg->hdr.channel = CROS_EC_COMMAND;
>>>> + out_msg->hdr.status = 0;
>>>> +
>>>> + ec_dev->dout += OUT_MSG_EC_REQUEST_PREAMBLE;
>>>> + cros_ec_prepare_tx(ec_dev, msg);
>>>> + ec_dev->dout -= OUT_MSG_EC_REQUEST_PREAMBLE;
>>>> +
>>>> + dev_dbg(dev,
>>>> + "out_msg: struct_ver=0x%x checksum=0x%x command=0x%x command_ver=0x%x data_len=0x%x\n",
>>>> + out_msg->ec_request.struct_version,
>>>> + out_msg->ec_request.checksum,
>>>> + out_msg->ec_request.command,
>>>> + out_msg->ec_request.command_version,
>>>> + out_msg->ec_request.data_len);
>>>> +
>>>> + /* Send command to ISH EC firmware and read response */
>>>> + rv = ish_send(client_data,
>>>> + (u8 *)out_msg, out_size,
>>>> + (u8 *)in_msg, in_size);
>>>> + if (rv < 0)
>>>> + goto end_error;
>>>> +
>>>> + rv = prepare_cros_ec_rx(ec_dev, in_msg, msg);
>>>> + if (rv)
>>>> + goto end_error;
>>>> +
>>>> + rv = in_msg->ec_response.data_len;
>>>> +
>>>> + dev_dbg(dev,
>>>> + "in_msg: struct_ver=0x%x checksum=0x%x result=0x%x data_len=0x%x\n",
>>>> + in_msg->ec_response.struct_version,
>>>> + in_msg->ec_response.checksum,
>>>> + in_msg->ec_response.result,
>>>> + in_msg->ec_response.data_len);
>>>> +
>>>> +end_error:
>>>> + if (msg->command == EC_CMD_REBOOT_EC)
>>>> + msleep(EC_REBOOT_DELAY_MS);
>>>> +
>>>> + up_read(&init_lock);
>>>> +
>>>> + return rv;
>>>> +}
>>>> +
>>>> +static int cros_ec_dev_init(struct ishtp_cl_data *client_data)
>>>> +{
>>>> + struct cros_ec_device *ec_dev;
>>>> + struct device *dev = cl_data_to_dev(client_data);
>>>> +
>>>> + ec_dev = devm_kzalloc(dev, sizeof(*ec_dev), GFP_KERNEL);
>>>> + if (!ec_dev)
>>>> + return -ENOMEM;
>>>> +
>>>> + client_data->ec_dev = ec_dev;
>>>> + dev->driver_data = ec_dev;
>>>> +
>>>> + ec_dev->dev = dev;
>>>> + ec_dev->priv = client_data->cros_ish_cl;
>>>> + ec_dev->cmd_xfer = NULL;
>>>> + ec_dev->pkt_xfer = cros_ec_pkt_xfer_ish;
>>>> + ec_dev->phys_name = dev_name(dev);
>>>> + ec_dev->din_size = sizeof(struct cros_ish_in_msg) +
>>>> + sizeof(struct ec_response_get_protocol_info);
>>>> + ec_dev->dout_size = sizeof(struct cros_ish_out_msg);
>>>> +
>>>> + return cros_ec_register(ec_dev);
>>>> +}
>>>> +
>>>> +static void reset_handler(struct work_struct *work)
>>>> +{
>>>> + int rv;
>>>> + struct device *dev;
>>>> + struct ishtp_cl *cros_ish_cl;
>>>> + struct ishtp_cl_device *cl_device;
>>>> + struct ishtp_cl_data *client_data =
>>>> + container_of(work, struct ishtp_cl_data, work_ishtp_reset);
>>>> +
>>>> + /* Lock for reset to complete */
>>>> + down_write(&init_lock);
>>>> +
>>>> + cros_ish_cl = client_data->cros_ish_cl;
>>>> + cl_device = client_data->cl_device;
>>>> +
>>>> + /* Unlink, flush queues & start again */
>>>> + ishtp_cl_unlink(cros_ish_cl);
>>>> + ishtp_cl_flush_queues(cros_ish_cl);
>>>> + ishtp_cl_free(cros_ish_cl);
>>>> +
>>>> + cros_ish_cl = ishtp_cl_allocate(cl_device);
>>>> + if (!cros_ish_cl) {
>>>> + up_write(&init_lock);
>>>> + return;
>>>> + }
>>>> +
>>>> + ishtp_set_drvdata(cl_device, cros_ish_cl);
>>>> + ishtp_set_client_data(cros_ish_cl, client_data);
>>>> + client_data->cros_ish_cl = cros_ish_cl;
>>>> +
>>>> + rv = cros_ish_init(cros_ish_cl);
>>>> + if (rv) {
>>>> + ishtp_cl_free(cros_ish_cl);
>>>> + dev_err(cl_data_to_dev(client_data), "Reset Failed\n");
>>>> + up_write(&init_lock);
>>>> + return;
>>>> + }
>>>> +
>>>> + /* Refresh ec_dev device pointers */
>>>> + client_data->ec_dev->priv = client_data->cros_ish_cl;
>>>> + dev = cl_data_to_dev(client_data);
>>>> + dev->driver_data = client_data->ec_dev;
>>>> +
>>>> + dev_info(cl_data_to_dev(client_data), "Chrome EC ISH reset done\n");
>>>> +
>>>> + up_write(&init_lock);
>>>> +}
>>>> +
>>>> +/**
>>>> + * cros_ec_ishtp_probe() - ISHTP client driver probe callback
>>>> + * @cl_device: ISHTP client device instance
>>>> + *
>>>> + * Return: 0 for success, negative error code for failure.
>>>> + */
>>>> +static int cros_ec_ishtp_probe(struct ishtp_cl_device *cl_device)
>>>> +{
>>>> + int rv;
>>>> + struct ishtp_cl *cros_ish_cl;
>>>> + struct ishtp_cl_data *client_data =
>>>> + devm_kzalloc(ishtp_device(cl_device),
>>>> + sizeof(*client_data), GFP_KERNEL);
>>>> + if (!client_data)
>>>> + return -ENOMEM;
>>>> +
>>>> + /* Lock for initialization to complete */
>>>> + down_write(&init_lock);
>>>> +
>>>> + cros_ish_cl = ishtp_cl_allocate(cl_device);
>>>> + if (!cros_ish_cl) {
>>>> + rv = -ENOMEM;
>>>> + goto end_ishtp_cl_alloc_error;
>>>> + }
>>>> +
>>>> + ishtp_set_drvdata(cl_device, cros_ish_cl);
>>>> + ishtp_set_client_data(cros_ish_cl, client_data);
>>>> + client_data->cros_ish_cl = cros_ish_cl;
>>>> + client_data->cl_device = cl_device;
>>>> +
>>>> + init_waitqueue_head(&client_data->response.wait_queue);
>>>> +
>>>> + INIT_WORK(&client_data->work_ishtp_reset,
>>>> + reset_handler);
>>>> + INIT_WORK(&client_data->work_ec_evt,
>>>> + ish_evt_handler);
>>>> +
>>>> + rv = cros_ish_init(cros_ish_cl);
>>>> + if (rv)
>>>> + goto end_ishtp_cl_init_error;
>>>> +
>>>> + ishtp_get_device(cl_device);
>>>> +
>>>> + up_write(&init_lock);
>>>> +
>>>> + /* Register croc_ec_dev mfd */
>>>> + rv = cros_ec_dev_init(client_data);
>>>> + if (rv)
>>>> + goto end_cros_ec_dev_init_error;
>>>> +
>>>> + return 0;
>>>> +
>>>> +end_cros_ec_dev_init_error:
>>>> + ishtp_set_connection_state(cros_ish_cl, ISHTP_CL_DISCONNECTING);
>>>> + ishtp_cl_disconnect(cros_ish_cl);
>>>> + ishtp_cl_unlink(cros_ish_cl);
>>>> + ishtp_cl_flush_queues(cros_ish_cl);
>>>> + ishtp_put_device(cl_device);
>>>> +end_ishtp_cl_init_error:
>>>> + ishtp_cl_free(cros_ish_cl);
>>>> +end_ishtp_cl_alloc_error:
>>>> + up_write(&init_lock);
>>>> + return rv;
>>>> +}
>>>> +
>>>> +/**
>>>> + * cros_ec_ishtp_remove() - ISHTP client driver remove callback
>>>> + * @cl_device: ISHTP client device instance
>>>> + *
>>>> + * Return: 0
>>>> + */
>>>> +static int cros_ec_ishtp_remove(struct ishtp_cl_device *cl_device)
>>>> +{
>>>> + struct ishtp_cl *cros_ish_cl = ishtp_get_drvdata(cl_device);
>>>> + struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl);
>>>> +
>>>> + cancel_work_sync(&client_data->work_ishtp_reset);
>>>> + cancel_work_sync(&client_data->work_ec_evt);
>>>> + cros_ish_deinit(cros_ish_cl);
>>>> + ishtp_put_device(cl_device);
>>>> +
>>>> + return 0;
>>>> +}
>>>> +
>>>> +/**
>>>> + * cros_ec_ishtp_reset() - ISHTP client driver reset callback
>>>> + * @cl_device: ISHTP client device instance
>>>> + *
>>>> + * Return: 0
>>>> + */
>>>> +static int cros_ec_ishtp_reset(struct ishtp_cl_device *cl_device)
>>>> +{
>>>> + struct ishtp_cl *cros_ish_cl = ishtp_get_drvdata(cl_device);
>>>> + struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl);
>>>> +
>>>> + schedule_work(&client_data->work_ishtp_reset);
>>>> +
>>>> + return 0;
>>>> +}
>>>> +
>>>> +/**
>>>> + * cros_ec_ishtp_suspend() - ISHTP client driver suspend callback
>>>> + * @device: device instance
>>>> + *
>>>> + * Return: 0 for success, negative error code for failure.
>>>> + */
>>>> +static int __maybe_unused cros_ec_ishtp_suspend(struct device *device)
>>>> +{
>>>> + struct ishtp_cl_device *cl_device = dev_get_drvdata(device);
>>>> + struct ishtp_cl *cros_ish_cl = ishtp_get_drvdata(cl_device);
>>>> + struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl);
>>>> +
>>>> + return cros_ec_suspend(client_data->ec_dev);
>>>> +}
>>>> +
>>>> +/**
>>>> + * cros_ec_ishtp_resume() - ISHTP client driver resume callback
>>>> + * @device: device instance
>>>> + *
>>>> + * Return: 0 for success, negative error code for failure.
>>>> + */
>>>> +static int __maybe_unused cros_ec_ishtp_resume(struct device *device)
>>>> +{
>>>> + struct ishtp_cl_device *cl_device = dev_get_drvdata(device);
>>>> + struct ishtp_cl *cros_ish_cl = ishtp_get_drvdata(cl_device);
>>>> + struct ishtp_cl_data *client_data = ishtp_get_client_data(cros_ish_cl);
>>>> +
>>>> + return cros_ec_resume(client_data->ec_dev);
>>>> +}
>>>> +
>>>> +static SIMPLE_DEV_PM_OPS(cros_ec_ishtp_pm_ops, cros_ec_ishtp_suspend,
>>>> + cros_ec_ishtp_resume);
>>>> +
>>>> +static struct ishtp_cl_driver cros_ec_ishtp_driver = {
>>>> + .name = "cros_ec_ishtp",
>>>> + .guid = &cros_ish_guid,
>>>> + .probe = cros_ec_ishtp_probe,
>>>> + .remove = cros_ec_ishtp_remove,
>>>> + .reset = cros_ec_ishtp_reset,
>>>> + .driver = {
>>>> + .pm = &cros_ec_ishtp_pm_ops,
>>>> + },
>>>> +};
>>>> +
>>>> +static int __init cros_ec_ishtp_mod_init(void)
>>>> +{
>>>> + return ishtp_cl_driver_register(&cros_ec_ishtp_driver, THIS_MODULE);
>>>> +}
>>>> +
>>>> +static void __exit cros_ec_ishtp_mod_exit(void)
>>>> +{
>>>> + ishtp_cl_driver_unregister(&cros_ec_ishtp_driver);
>>>> +}
>>>> +
>>>> +module_init(cros_ec_ishtp_mod_init);
>>>> +module_exit(cros_ec_ishtp_mod_exit);
>>>> +
>>>> +MODULE_DESCRIPTION("ChromeOS EC ISHTP Client Driver");
>>>> +MODULE_AUTHOR("Rushikesh S Kadam <rushikesh.s.kadam@...el.com>");
>>>> +
>>>> +MODULE_LICENSE("GPL v2");
>>>> +MODULE_ALIAS("ishtp:*");
>>>> --
>>>> 1.9.1
>>>>
>
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