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Message-ID: <CAK+PMK5SjXUdr-EKTng63ZNZkqaXH_gX8gsYpWkMKfAoJaBB6g@mail.gmail.com>
Date: Wed, 17 Apr 2019 10:34:40 -0600
From: Jett Rink <jettrink@...omium.org>
To: Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>
Cc: Rushikesh S Kadam <rushikesh.s.kadam@...el.com>,
Benson Leung <bleung@...omium.org>,
Enric Balletbo i Serra <enric.balletbo@...labora.com>,
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 v4] platform: chrome: Add ChromeOS EC ISHTP driver
Reviewed-by: Jett Rink <jettrink@...omium.org>
Tested-by: Jett Rink <jettrink@...omium.org>
On Wed, Apr 17, 2019 at 10:27 AM Srinivas Pandruvada
<srinivas.pandruvada@...ux.intel.com> wrote:
>
> On Wed, 2019-04-17 at 15:48 +0530, Rushikesh S Kadam 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>
> Acked-by: Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>
>
> I think you have some reviewed and tested by.
>
> Also copy to Jiri, as this may have to go via HID pull as this has
> dependency.
>
> Thanks,
> Srinivas
>
> > ---
> > The patches are baselined to 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
> >
> > v4
> > - Coding style related changes. No functional changes. Addresses
> > review comments on v3.
> >
> > 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 | 763
> > ++++++++++++++++++++++++++++++++
> > 3 files changed, 777 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..997503d
> > --- /dev/null
> > +++ b/drivers/platform/chrome/cros_ec_ishtp.c
> > @@ -0,0 +1,763 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +// ISHTP interface for ChromeOS Embedded Controller
> > +//
> > +// Copyright (c) 2019, Intel Corporation.
> > +//
> > +// 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).
> > +
> > +#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>
> > +
> > +/*
> > + * 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
> > process_recv().
> > + * @received: Set to true on receiving a valid firmware respons
> > e to host command
> > + * @wait_queue: Wait queue for host to wait for firmware 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: Response info passing between ish_send() and
> > process_recv().
> > + * @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 is 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
> > + * @ec_dev: CrOS EC MFD device.
> > + * @in_msg: Incoming message buffer
> > + * @msg: cros_ec command used to send & receive data
> > + *
> > + * Return: 0 for success, negative error code for failure.
> > + *
> > + * 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:*");
>
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