[PATCH v4] platform: chrome: Add ChromeOS EC ISHTP driver

Rushikesh S Kadam
2019-04-17T10:18:45Z

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@intel.com>
---
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 response 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@intel.com>");
+
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("ishtp:*");
--
1.9.1