| Message ID | 1557916721-31315-1-git-send-email-rushikesh.s.kadam@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v6] platform: chrome: Add ChromeOS EC ISHTP driver | expand |
Hi, Missatge de Rushikesh S Kadam <rushikesh.s.kadam@intel.com> del dia dc., 15 de maig 2019 a les 12:41: > > 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> > Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> > Acked-by: Enric Balletbo i Serra <enric.balletbo@collabora.com> > Reviewed-by: Jett Rink <jettrink@chromium.org> > Tested-by: Jett Rink <jettrink@chromium.org> > --- The following patch is queued to the for-next branch for the autobuilders to play with, if all goes well I'll add the patch for 5.3 when current merge window closes. Thanks, Enric > > Submitting the patch to linux-input@ per the discussion here > https://lkml.org/lkml/2019/5/2/339 > > The patch is 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 > > v6 > - Moved the sanity checks in cros_ec_pkt_xfer_ish() to before > the point we take the lock (Bug fix). > > v5 > - Submitting with all Acked-by & Tested-bys. No other changes. > > 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..e504d25 > --- /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; > + > + /* 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; > + } > + > + /* 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; > + } > + > + /* 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 >
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..e504d25 --- /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; + + /* 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; + } + + /* 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; + } + + /* 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:*");