You also need to enable the driver for the bus you are using. The
protocol for talking to the EC is defined by the bus driver.
-config MFD_CROS_EC_I2C
- tristate "ChromeOS Embedded Controller (I2C)"
- depends on MFD_CROS_EC && I2C
-
- help
- If you say Y here, you get support for talking to the ChromeOS
- EC through an I2C bus. This uses a simple byte-level protocol with
- a checksum. Failing accesses will be retried three times to
- improve reliability.
-
-config MFD_CROS_EC_SPI
- tristate "ChromeOS Embedded Controller (SPI)"
- depends on MFD_CROS_EC && SPI
-
- ---help---
- If you say Y here, you get support for talking to the ChromeOS EC
- through a SPI bus, using a byte-level protocol. Since the EC's
- response time cannot be guaranteed, we support ignoring
- 'pre-amble' bytes before the response actually starts.
-
config MFD_CROS_EC_CHARDEV
tristate "Chrome OS Embedded Controller userspace device interface"
depends on MFD_CROS_EC
obj-$(CONFIG_MFD_BD9571MWV) += bd9571mwv.o
cros_ec_core-objs := cros_ec.o
obj-$(CONFIG_MFD_CROS_EC) += cros_ec_core.o
-obj-$(CONFIG_MFD_CROS_EC_I2C) += cros_ec_i2c.o
-obj-$(CONFIG_MFD_CROS_EC_SPI) += cros_ec_spi.o
obj-$(CONFIG_MFD_CROS_EC_CHARDEV) += cros_ec_dev.o
obj-$(CONFIG_MFD_EXYNOS_LPASS) += exynos-lpass.o
+++ /dev/null
-/*
- * ChromeOS EC multi-function device (I2C)
- *
- * Copyright (C) 2012 Google, Inc
- *
- * This software is licensed under the terms of the GNU General Public
- * License version 2, as published by the Free Software Foundation, and
- * may be copied, distributed, and modified under those terms.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- */
-
-#include <linux/acpi.h>
-#include <linux/delay.h>
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/i2c.h>
-#include <linux/interrupt.h>
-#include <linux/mfd/cros_ec.h>
-#include <linux/mfd/cros_ec_commands.h>
-#include <linux/platform_device.h>
-#include <linux/slab.h>
-
-/**
- * Request format for protocol v3
- * byte 0 0xda (EC_COMMAND_PROTOCOL_3)
- * byte 1-8 struct ec_host_request
- * byte 10- response data
- */
-struct ec_host_request_i2c {
- /* Always 0xda to backward compatible with v2 struct */
- uint8_t command_protocol;
- struct ec_host_request ec_request;
-} __packed;
-
-
-/*
- * Response format for protocol v3
- * byte 0 result code
- * byte 1 packet_length
- * byte 2-9 struct ec_host_response
- * byte 10- response data
- */
-struct ec_host_response_i2c {
- uint8_t result;
- uint8_t packet_length;
- struct ec_host_response ec_response;
-} __packed;
-
-static inline struct cros_ec_device *to_ec_dev(struct device *dev)
-{
- struct i2c_client *client = to_i2c_client(dev);
-
- return i2c_get_clientdata(client);
-}
-
-static int cros_ec_pkt_xfer_i2c(struct cros_ec_device *ec_dev,
- struct cros_ec_command *msg)
-{
- struct i2c_client *client = ec_dev->priv;
- int ret = -ENOMEM;
- int i;
- int packet_len;
- u8 *out_buf = NULL;
- u8 *in_buf = NULL;
- u8 sum;
- struct i2c_msg i2c_msg[2];
- struct ec_host_response *ec_response;
- struct ec_host_request_i2c *ec_request_i2c;
- struct ec_host_response_i2c *ec_response_i2c;
- int request_header_size = sizeof(struct ec_host_request_i2c);
- int response_header_size = sizeof(struct ec_host_response_i2c);
-
- i2c_msg[0].addr = client->addr;
- i2c_msg[0].flags = 0;
- i2c_msg[1].addr = client->addr;
- i2c_msg[1].flags = I2C_M_RD;
-
- packet_len = msg->insize + response_header_size;
- BUG_ON(packet_len > ec_dev->din_size);
- in_buf = ec_dev->din;
- i2c_msg[1].len = packet_len;
- i2c_msg[1].buf = (char *) in_buf;
-
- packet_len = msg->outsize + request_header_size;
- BUG_ON(packet_len > ec_dev->dout_size);
- out_buf = ec_dev->dout;
- i2c_msg[0].len = packet_len;
- i2c_msg[0].buf = (char *) out_buf;
-
- /* create request data */
- ec_request_i2c = (struct ec_host_request_i2c *) out_buf;
- ec_request_i2c->command_protocol = EC_COMMAND_PROTOCOL_3;
-
- ec_dev->dout++;
- ret = cros_ec_prepare_tx(ec_dev, msg);
- ec_dev->dout--;
-
- /* send command to EC and read answer */
- ret = i2c_transfer(client->adapter, i2c_msg, 2);
- if (ret < 0) {
- dev_dbg(ec_dev->dev, "i2c transfer failed: %d\n", ret);
- goto done;
- } else if (ret != 2) {
- dev_err(ec_dev->dev, "failed to get response: %d\n", ret);
- ret = -EIO;
- goto done;
- }
-
- ec_response_i2c = (struct ec_host_response_i2c *) in_buf;
- msg->result = ec_response_i2c->result;
- ec_response = &ec_response_i2c->ec_response;
-
- switch (msg->result) {
- case EC_RES_SUCCESS:
- break;
- case EC_RES_IN_PROGRESS:
- ret = -EAGAIN;
- dev_dbg(ec_dev->dev, "command 0x%02x in progress\n",
- msg->command);
- goto done;
-
- default:
- dev_dbg(ec_dev->dev, "command 0x%02x returned %d\n",
- msg->command, msg->result);
- /*
- * When we send v3 request to v2 ec, ec won't recognize the
- * 0xda (EC_COMMAND_PROTOCOL_3) and will return with status
- * EC_RES_INVALID_COMMAND with zero data length.
- *
- * In case of invalid command for v3 protocol the data length
- * will be at least sizeof(struct ec_host_response)
- */
- if (ec_response_i2c->result == EC_RES_INVALID_COMMAND &&
- ec_response_i2c->packet_length == 0) {
- ret = -EPROTONOSUPPORT;
- goto done;
- }
- }
-
- if (ec_response_i2c->packet_length < sizeof(struct ec_host_response)) {
- dev_err(ec_dev->dev,
- "response of %u bytes too short; not a full header\n",
- ec_response_i2c->packet_length);
- ret = -EBADMSG;
- goto done;
- }
-
- if (msg->insize < ec_response->data_len) {
- dev_err(ec_dev->dev,
- "response data size is too large: expected %u, got %u\n",
- msg->insize,
- ec_response->data_len);
- ret = -EMSGSIZE;
- goto done;
- }
-
- /* copy response packet payload and compute checksum */
- sum = 0;
- for (i = 0; i < sizeof(struct ec_host_response); i++)
- sum += ((u8 *)ec_response)[i];
-
- memcpy(msg->data,
- in_buf + response_header_size,
- ec_response->data_len);
- for (i = 0; i < ec_response->data_len; i++)
- sum += msg->data[i];
-
- /* All bytes should sum to zero */
- if (sum) {
- dev_err(ec_dev->dev, "bad packet checksum\n");
- ret = -EBADMSG;
- goto done;
- }
-
- ret = ec_response->data_len;
-
-done:
- if (msg->command == EC_CMD_REBOOT_EC)
- msleep(EC_REBOOT_DELAY_MS);
-
- return ret;
-}
-
-static int cros_ec_cmd_xfer_i2c(struct cros_ec_device *ec_dev,
- struct cros_ec_command *msg)
-{
- struct i2c_client *client = ec_dev->priv;
- int ret = -ENOMEM;
- int i;
- int len;
- int packet_len;
- u8 *out_buf = NULL;
- u8 *in_buf = NULL;
- u8 sum;
- struct i2c_msg i2c_msg[2];
-
- i2c_msg[0].addr = client->addr;
- i2c_msg[0].flags = 0;
- i2c_msg[1].addr = client->addr;
- i2c_msg[1].flags = I2C_M_RD;
-
- /*
- * allocate larger packet (one byte for checksum, one byte for
- * length, and one for result code)
- */
- packet_len = msg->insize + 3;
- in_buf = kzalloc(packet_len, GFP_KERNEL);
- if (!in_buf)
- goto done;
- i2c_msg[1].len = packet_len;
- i2c_msg[1].buf = (char *)in_buf;
-
- /*
- * allocate larger packet (one byte for checksum, one for
- * command code, one for length, and one for command version)
- */
- packet_len = msg->outsize + 4;
- out_buf = kzalloc(packet_len, GFP_KERNEL);
- if (!out_buf)
- goto done;
- i2c_msg[0].len = packet_len;
- i2c_msg[0].buf = (char *)out_buf;
-
- out_buf[0] = EC_CMD_VERSION0 + msg->version;
- out_buf[1] = msg->command;
- out_buf[2] = msg->outsize;
-
- /* copy message payload and compute checksum */
- sum = out_buf[0] + out_buf[1] + out_buf[2];
- for (i = 0; i < msg->outsize; i++) {
- out_buf[3 + i] = msg->data[i];
- sum += out_buf[3 + i];
- }
- out_buf[3 + msg->outsize] = sum;
-
- /* send command to EC and read answer */
- ret = i2c_transfer(client->adapter, i2c_msg, 2);
- if (ret < 0) {
- dev_err(ec_dev->dev, "i2c transfer failed: %d\n", ret);
- goto done;
- } else if (ret != 2) {
- dev_err(ec_dev->dev, "failed to get response: %d\n", ret);
- ret = -EIO;
- goto done;
- }
-
- /* check response error code */
- msg->result = i2c_msg[1].buf[0];
- ret = cros_ec_check_result(ec_dev, msg);
- if (ret)
- goto done;
-
- len = in_buf[1];
- if (len > msg->insize) {
- dev_err(ec_dev->dev, "packet too long (%d bytes, expected %d)",
- len, msg->insize);
- ret = -ENOSPC;
- goto done;
- }
-
- /* copy response packet payload and compute checksum */
- sum = in_buf[0] + in_buf[1];
- for (i = 0; i < len; i++) {
- msg->data[i] = in_buf[2 + i];
- sum += in_buf[2 + i];
- }
- dev_dbg(ec_dev->dev, "packet: %*ph, sum = %02x\n",
- i2c_msg[1].len, in_buf, sum);
- if (sum != in_buf[2 + len]) {
- dev_err(ec_dev->dev, "bad packet checksum\n");
- ret = -EBADMSG;
- goto done;
- }
-
- ret = len;
-done:
- kfree(in_buf);
- kfree(out_buf);
- if (msg->command == EC_CMD_REBOOT_EC)
- msleep(EC_REBOOT_DELAY_MS);
-
- return ret;
-}
-
-static int cros_ec_i2c_probe(struct i2c_client *client,
- const struct i2c_device_id *dev_id)
-{
- struct device *dev = &client->dev;
- struct cros_ec_device *ec_dev = NULL;
- int err;
-
- ec_dev = devm_kzalloc(dev, sizeof(*ec_dev), GFP_KERNEL);
- if (!ec_dev)
- return -ENOMEM;
-
- i2c_set_clientdata(client, ec_dev);
- ec_dev->dev = dev;
- ec_dev->priv = client;
- ec_dev->irq = client->irq;
- ec_dev->cmd_xfer = cros_ec_cmd_xfer_i2c;
- ec_dev->pkt_xfer = cros_ec_pkt_xfer_i2c;
- ec_dev->phys_name = client->adapter->name;
- ec_dev->din_size = sizeof(struct ec_host_response_i2c) +
- sizeof(struct ec_response_get_protocol_info);
- ec_dev->dout_size = sizeof(struct ec_host_request_i2c);
-
- err = cros_ec_register(ec_dev);
- if (err) {
- dev_err(dev, "cannot register EC\n");
- return err;
- }
-
- return 0;
-}
-
-static int cros_ec_i2c_remove(struct i2c_client *client)
-{
- struct cros_ec_device *ec_dev = i2c_get_clientdata(client);
-
- cros_ec_remove(ec_dev);
-
- return 0;
-}
-
-#ifdef CONFIG_PM_SLEEP
-static int cros_ec_i2c_suspend(struct device *dev)
-{
- struct cros_ec_device *ec_dev = to_ec_dev(dev);
-
- return cros_ec_suspend(ec_dev);
-}
-
-static int cros_ec_i2c_resume(struct device *dev)
-{
- struct cros_ec_device *ec_dev = to_ec_dev(dev);
-
- return cros_ec_resume(ec_dev);
-}
-#endif
-
-static const struct dev_pm_ops cros_ec_i2c_pm_ops = {
- SET_LATE_SYSTEM_SLEEP_PM_OPS(cros_ec_i2c_suspend, cros_ec_i2c_resume)
-};
-
-#ifdef CONFIG_OF
-static const struct of_device_id cros_ec_i2c_of_match[] = {
- { .compatible = "google,cros-ec-i2c", },
- { /* sentinel */ },
-};
-MODULE_DEVICE_TABLE(of, cros_ec_i2c_of_match);
-#endif
-
-static const struct i2c_device_id cros_ec_i2c_id[] = {
- { "cros-ec-i2c", 0 },
- { }
-};
-MODULE_DEVICE_TABLE(i2c, cros_ec_i2c_id);
-
-#ifdef CONFIG_ACPI
-static const struct acpi_device_id cros_ec_i2c_acpi_id[] = {
- { "GOOG0008", 0 },
- { /* sentinel */ }
-};
-MODULE_DEVICE_TABLE(acpi, cros_ec_i2c_acpi_id);
-#endif
-
-static struct i2c_driver cros_ec_driver = {
- .driver = {
- .name = "cros-ec-i2c",
- .acpi_match_table = ACPI_PTR(cros_ec_i2c_acpi_id),
- .of_match_table = of_match_ptr(cros_ec_i2c_of_match),
- .pm = &cros_ec_i2c_pm_ops,
- },
- .probe = cros_ec_i2c_probe,
- .remove = cros_ec_i2c_remove,
- .id_table = cros_ec_i2c_id,
-};
-
-module_i2c_driver(cros_ec_driver);
-
-MODULE_LICENSE("GPL");
-MODULE_DESCRIPTION("ChromeOS EC multi function device");
+++ /dev/null
-/*
- * ChromeOS EC multi-function device (SPI)
- *
- * Copyright (C) 2012 Google, Inc
- *
- * This software is licensed under the terms of the GNU General Public
- * License version 2, as published by the Free Software Foundation, and
- * may be copied, distributed, and modified under those terms.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- */
-
-#include <linux/delay.h>
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/mfd/cros_ec.h>
-#include <linux/mfd/cros_ec_commands.h>
-#include <linux/of.h>
-#include <linux/platform_device.h>
-#include <linux/slab.h>
-#include <linux/spi/spi.h>
-
-
-/* The header byte, which follows the preamble */
-#define EC_MSG_HEADER 0xec
-
-/*
- * Number of EC preamble bytes we read at a time. Since it takes
- * about 400-500us for the EC to respond there is not a lot of
- * point in tuning this. If the EC could respond faster then
- * we could increase this so that might expect the preamble and
- * message to occur in a single transaction. However, the maximum
- * SPI transfer size is 256 bytes, so at 5MHz we need a response
- * time of perhaps <320us (200 bytes / 1600 bits).
- */
-#define EC_MSG_PREAMBLE_COUNT 32
-
-/*
- * Allow for a long time for the EC to respond. We support i2c
- * tunneling and support fairly long messages for the tunnel (249
- * bytes long at the moment). If we're talking to a 100 kHz device
- * on the other end and need to transfer ~256 bytes, then we need:
- * 10 us/bit * ~10 bits/byte * ~256 bytes = ~25ms
- *
- * We'll wait 8 times that to handle clock stretching and other
- * paranoia. Note that some battery gas gauge ICs claim to have a
- * clock stretch of 144ms in rare situations. That's incentive for
- * not directly passing i2c through, but it's too late for that for
- * existing hardware.
- *
- * It's pretty unlikely that we'll really see a 249 byte tunnel in
- * anything other than testing. If this was more common we might
- * consider having slow commands like this require a GET_STATUS
- * wait loop. The 'flash write' command would be another candidate
- * for this, clocking in at 2-3ms.
- */
-#define EC_MSG_DEADLINE_MS 200
-
-/*
- * Time between raising the SPI chip select (for the end of a
- * transaction) and dropping it again (for the next transaction).
- * If we go too fast, the EC will miss the transaction. We know that we
- * need at least 70 us with the 16 MHz STM32 EC, so go with 200 us to be
- * safe.
- */
-#define EC_SPI_RECOVERY_TIME_NS (200 * 1000)
-
-/**
- * struct cros_ec_spi - information about a SPI-connected EC
- *
- * @spi: SPI device we are connected to
- * @last_transfer_ns: time that we last finished a transfer.
- * @start_of_msg_delay: used to set the delay_usecs on the spi_transfer that
- * is sent when we want to turn on CS at the start of a transaction.
- * @end_of_msg_delay: used to set the delay_usecs on the spi_transfer that
- * is sent when we want to turn off CS at the end of a transaction.
- */
-struct cros_ec_spi {
- struct spi_device *spi;
- s64 last_transfer_ns;
- unsigned int start_of_msg_delay;
- unsigned int end_of_msg_delay;
-};
-
-static void debug_packet(struct device *dev, const char *name, u8 *ptr,
- int len)
-{
-#ifdef DEBUG
- int i;
-
- dev_dbg(dev, "%s: ", name);
- for (i = 0; i < len; i++)
- pr_cont(" %02x", ptr[i]);
-
- pr_cont("\n");
-#endif
-}
-
-static int terminate_request(struct cros_ec_device *ec_dev)
-{
- struct cros_ec_spi *ec_spi = ec_dev->priv;
- struct spi_message msg;
- struct spi_transfer trans;
- int ret;
-
- /*
- * Turn off CS, possibly adding a delay to ensure the rising edge
- * doesn't come too soon after the end of the data.
- */
- spi_message_init(&msg);
- memset(&trans, 0, sizeof(trans));
- trans.delay_usecs = ec_spi->end_of_msg_delay;
- spi_message_add_tail(&trans, &msg);
-
- ret = spi_sync_locked(ec_spi->spi, &msg);
-
- /* Reset end-of-response timer */
- ec_spi->last_transfer_ns = ktime_get_ns();
- if (ret < 0) {
- dev_err(ec_dev->dev,
- "cs-deassert spi transfer failed: %d\n",
- ret);
- }
-
- return ret;
-}
-
-/**
- * receive_n_bytes - receive n bytes from the EC.
- *
- * Assumes buf is a pointer into the ec_dev->din buffer
- */
-static int receive_n_bytes(struct cros_ec_device *ec_dev, u8 *buf, int n)
-{
- struct cros_ec_spi *ec_spi = ec_dev->priv;
- struct spi_transfer trans;
- struct spi_message msg;
- int ret;
-
- BUG_ON(buf - ec_dev->din + n > ec_dev->din_size);
-
- memset(&trans, 0, sizeof(trans));
- trans.cs_change = 1;
- trans.rx_buf = buf;
- trans.len = n;
-
- spi_message_init(&msg);
- spi_message_add_tail(&trans, &msg);
- ret = spi_sync_locked(ec_spi->spi, &msg);
- if (ret < 0)
- dev_err(ec_dev->dev, "spi transfer failed: %d\n", ret);
-
- return ret;
-}
-
-/**
- * cros_ec_spi_receive_packet - Receive a packet from the EC.
- *
- * This function has two phases: reading the preamble bytes (since if we read
- * data from the EC before it is ready to send, we just get preamble) and
- * reading the actual message.
- *
- * The received data is placed into ec_dev->din.
- *
- * @ec_dev: ChromeOS EC device
- * @need_len: Number of message bytes we need to read
- */
-static int cros_ec_spi_receive_packet(struct cros_ec_device *ec_dev,
- int need_len)
-{
- struct ec_host_response *response;
- u8 *ptr, *end;
- int ret;
- unsigned long deadline;
- int todo;
-
- BUG_ON(ec_dev->din_size < EC_MSG_PREAMBLE_COUNT);
-
- /* Receive data until we see the header byte */
- deadline = jiffies + msecs_to_jiffies(EC_MSG_DEADLINE_MS);
- while (true) {
- unsigned long start_jiffies = jiffies;
-
- ret = receive_n_bytes(ec_dev,
- ec_dev->din,
- EC_MSG_PREAMBLE_COUNT);
- if (ret < 0)
- return ret;
-
- ptr = ec_dev->din;
- for (end = ptr + EC_MSG_PREAMBLE_COUNT; ptr != end; ptr++) {
- if (*ptr == EC_SPI_FRAME_START) {
- dev_dbg(ec_dev->dev, "msg found at %zd\n",
- ptr - ec_dev->din);
- break;
- }
- }
- if (ptr != end)
- break;
-
- /*
- * Use the time at the start of the loop as a timeout. This
- * gives us one last shot at getting the transfer and is useful
- * in case we got context switched out for a while.
- */
- if (time_after(start_jiffies, deadline)) {
- dev_warn(ec_dev->dev, "EC failed to respond in time\n");
- return -ETIMEDOUT;
- }
- }
-
- /*
- * ptr now points to the header byte. Copy any valid data to the
- * start of our buffer
- */
- todo = end - ++ptr;
- BUG_ON(todo < 0 || todo > ec_dev->din_size);
- todo = min(todo, need_len);
- memmove(ec_dev->din, ptr, todo);
- ptr = ec_dev->din + todo;
- dev_dbg(ec_dev->dev, "need %d, got %d bytes from preamble\n",
- need_len, todo);
- need_len -= todo;
-
- /* If the entire response struct wasn't read, get the rest of it. */
- if (todo < sizeof(*response)) {
- ret = receive_n_bytes(ec_dev, ptr, sizeof(*response) - todo);
- if (ret < 0)
- return -EBADMSG;
- ptr += (sizeof(*response) - todo);
- todo = sizeof(*response);
- }
-
- response = (struct ec_host_response *)ec_dev->din;
-
- /* Abort if data_len is too large. */
- if (response->data_len > ec_dev->din_size)
- return -EMSGSIZE;
-
- /* Receive data until we have it all */
- while (need_len > 0) {
- /*
- * We can't support transfers larger than the SPI FIFO size
- * unless we have DMA. We don't have DMA on the ISP SPI ports
- * for Exynos. We need a way of asking SPI driver for
- * maximum-supported transfer size.
- */
- todo = min(need_len, 256);
- dev_dbg(ec_dev->dev, "loop, todo=%d, need_len=%d, ptr=%zd\n",
- todo, need_len, ptr - ec_dev->din);
-
- ret = receive_n_bytes(ec_dev, ptr, todo);
- if (ret < 0)
- return ret;
-
- ptr += todo;
- need_len -= todo;
- }
-
- dev_dbg(ec_dev->dev, "loop done, ptr=%zd\n", ptr - ec_dev->din);
-
- return 0;
-}
-
-/**
- * cros_ec_spi_receive_response - Receive a response from the EC.
- *
- * This function has two phases: reading the preamble bytes (since if we read
- * data from the EC before it is ready to send, we just get preamble) and
- * reading the actual message.
- *
- * The received data is placed into ec_dev->din.
- *
- * @ec_dev: ChromeOS EC device
- * @need_len: Number of message bytes we need to read
- */
-static int cros_ec_spi_receive_response(struct cros_ec_device *ec_dev,
- int need_len)
-{
- u8 *ptr, *end;
- int ret;
- unsigned long deadline;
- int todo;
-
- BUG_ON(ec_dev->din_size < EC_MSG_PREAMBLE_COUNT);
-
- /* Receive data until we see the header byte */
- deadline = jiffies + msecs_to_jiffies(EC_MSG_DEADLINE_MS);
- while (true) {
- unsigned long start_jiffies = jiffies;
-
- ret = receive_n_bytes(ec_dev,
- ec_dev->din,
- EC_MSG_PREAMBLE_COUNT);
- if (ret < 0)
- return ret;
-
- ptr = ec_dev->din;
- for (end = ptr + EC_MSG_PREAMBLE_COUNT; ptr != end; ptr++) {
- if (*ptr == EC_SPI_FRAME_START) {
- dev_dbg(ec_dev->dev, "msg found at %zd\n",
- ptr - ec_dev->din);
- break;
- }
- }
- if (ptr != end)
- break;
-
- /*
- * Use the time at the start of the loop as a timeout. This
- * gives us one last shot at getting the transfer and is useful
- * in case we got context switched out for a while.
- */
- if (time_after(start_jiffies, deadline)) {
- dev_warn(ec_dev->dev, "EC failed to respond in time\n");
- return -ETIMEDOUT;
- }
- }
-
- /*
- * ptr now points to the header byte. Copy any valid data to the
- * start of our buffer
- */
- todo = end - ++ptr;
- BUG_ON(todo < 0 || todo > ec_dev->din_size);
- todo = min(todo, need_len);
- memmove(ec_dev->din, ptr, todo);
- ptr = ec_dev->din + todo;
- dev_dbg(ec_dev->dev, "need %d, got %d bytes from preamble\n",
- need_len, todo);
- need_len -= todo;
-
- /* Receive data until we have it all */
- while (need_len > 0) {
- /*
- * We can't support transfers larger than the SPI FIFO size
- * unless we have DMA. We don't have DMA on the ISP SPI ports
- * for Exynos. We need a way of asking SPI driver for
- * maximum-supported transfer size.
- */
- todo = min(need_len, 256);
- dev_dbg(ec_dev->dev, "loop, todo=%d, need_len=%d, ptr=%zd\n",
- todo, need_len, ptr - ec_dev->din);
-
- ret = receive_n_bytes(ec_dev, ptr, todo);
- if (ret < 0)
- return ret;
-
- debug_packet(ec_dev->dev, "interim", ptr, todo);
- ptr += todo;
- need_len -= todo;
- }
-
- dev_dbg(ec_dev->dev, "loop done, ptr=%zd\n", ptr - ec_dev->din);
-
- return 0;
-}
-
-/**
- * cros_ec_pkt_xfer_spi - Transfer a packet over SPI and receive the reply
- *
- * @ec_dev: ChromeOS EC device
- * @ec_msg: Message to transfer
- */
-static int cros_ec_pkt_xfer_spi(struct cros_ec_device *ec_dev,
- struct cros_ec_command *ec_msg)
-{
- struct ec_host_response *response;
- struct cros_ec_spi *ec_spi = ec_dev->priv;
- struct spi_transfer trans, trans_delay;
- struct spi_message msg;
- int i, len;
- u8 *ptr;
- u8 *rx_buf;
- u8 sum;
- u8 rx_byte;
- int ret = 0, final_ret;
- unsigned long delay;
-
- len = cros_ec_prepare_tx(ec_dev, ec_msg);
- dev_dbg(ec_dev->dev, "prepared, len=%d\n", len);
-
- /* If it's too soon to do another transaction, wait */
- delay = ktime_get_ns() - ec_spi->last_transfer_ns;
- if (delay < EC_SPI_RECOVERY_TIME_NS)
- ndelay(EC_SPI_RECOVERY_TIME_NS - delay);
-
- rx_buf = kzalloc(len, GFP_KERNEL);
- if (!rx_buf)
- return -ENOMEM;
-
- spi_bus_lock(ec_spi->spi->master);
-
- /*
- * Leave a gap between CS assertion and clocking of data to allow the
- * EC time to wakeup.
- */
- spi_message_init(&msg);
- if (ec_spi->start_of_msg_delay) {
- memset(&trans_delay, 0, sizeof(trans_delay));
- trans_delay.delay_usecs = ec_spi->start_of_msg_delay;
- spi_message_add_tail(&trans_delay, &msg);
- }
-
- /* Transmit phase - send our message */
- memset(&trans, 0, sizeof(trans));
- trans.tx_buf = ec_dev->dout;
- trans.rx_buf = rx_buf;
- trans.len = len;
- trans.cs_change = 1;
- spi_message_add_tail(&trans, &msg);
- ret = spi_sync_locked(ec_spi->spi, &msg);
-
- /* Get the response */
- if (!ret) {
- /* Verify that EC can process command */
- for (i = 0; i < len; i++) {
- rx_byte = rx_buf[i];
- /*
- * Seeing the PAST_END, RX_BAD_DATA, or NOT_READY
- * markers are all signs that the EC didn't fully
- * receive our command. e.g., if the EC is flashing
- * itself, it can't respond to any commands and instead
- * clocks out EC_SPI_PAST_END from its SPI hardware
- * buffer. Similar occurrences can happen if the AP is
- * too slow to clock out data after asserting CS -- the
- * EC will abort and fill its buffer with
- * EC_SPI_RX_BAD_DATA.
- *
- * In all cases, these errors should be safe to retry.
- * Report -EAGAIN and let the caller decide what to do
- * about that.
- */
- if (rx_byte == EC_SPI_PAST_END ||
- rx_byte == EC_SPI_RX_BAD_DATA ||
- rx_byte == EC_SPI_NOT_READY) {
- ret = -EAGAIN;
- break;
- }
- }
- }
-
- if (!ret)
- ret = cros_ec_spi_receive_packet(ec_dev,
- ec_msg->insize + sizeof(*response));
- else if (ret != -EAGAIN)
- dev_err(ec_dev->dev, "spi transfer failed: %d\n", ret);
-
- final_ret = terminate_request(ec_dev);
-
- spi_bus_unlock(ec_spi->spi->master);
-
- if (!ret)
- ret = final_ret;
- if (ret < 0)
- goto exit;
-
- ptr = ec_dev->din;
-
- /* check response error code */
- response = (struct ec_host_response *)ptr;
- ec_msg->result = response->result;
-
- ret = cros_ec_check_result(ec_dev, ec_msg);
- if (ret)
- goto exit;
-
- len = response->data_len;
- sum = 0;
- if (len > ec_msg->insize) {
- dev_err(ec_dev->dev, "packet too long (%d bytes, expected %d)",
- len, ec_msg->insize);
- ret = -EMSGSIZE;
- goto exit;
- }
-
- for (i = 0; i < sizeof(*response); i++)
- sum += ptr[i];
-
- /* copy response packet payload and compute checksum */
- memcpy(ec_msg->data, ptr + sizeof(*response), len);
- for (i = 0; i < len; i++)
- sum += ec_msg->data[i];
-
- if (sum) {
- dev_err(ec_dev->dev,
- "bad packet checksum, calculated %x\n",
- sum);
- ret = -EBADMSG;
- goto exit;
- }
-
- ret = len;
-exit:
- kfree(rx_buf);
- if (ec_msg->command == EC_CMD_REBOOT_EC)
- msleep(EC_REBOOT_DELAY_MS);
-
- return ret;
-}
-
-/**
- * cros_ec_cmd_xfer_spi - Transfer a message over SPI and receive the reply
- *
- * @ec_dev: ChromeOS EC device
- * @ec_msg: Message to transfer
- */
-static int cros_ec_cmd_xfer_spi(struct cros_ec_device *ec_dev,
- struct cros_ec_command *ec_msg)
-{
- struct cros_ec_spi *ec_spi = ec_dev->priv;
- struct spi_transfer trans;
- struct spi_message msg;
- int i, len;
- u8 *ptr;
- u8 *rx_buf;
- u8 rx_byte;
- int sum;
- int ret = 0, final_ret;
- unsigned long delay;
-
- len = cros_ec_prepare_tx(ec_dev, ec_msg);
- dev_dbg(ec_dev->dev, "prepared, len=%d\n", len);
-
- /* If it's too soon to do another transaction, wait */
- delay = ktime_get_ns() - ec_spi->last_transfer_ns;
- if (delay < EC_SPI_RECOVERY_TIME_NS)
- ndelay(EC_SPI_RECOVERY_TIME_NS - delay);
-
- rx_buf = kzalloc(len, GFP_KERNEL);
- if (!rx_buf)
- return -ENOMEM;
-
- spi_bus_lock(ec_spi->spi->master);
-
- /* Transmit phase - send our message */
- debug_packet(ec_dev->dev, "out", ec_dev->dout, len);
- memset(&trans, 0, sizeof(trans));
- trans.tx_buf = ec_dev->dout;
- trans.rx_buf = rx_buf;
- trans.len = len;
- trans.cs_change = 1;
- spi_message_init(&msg);
- spi_message_add_tail(&trans, &msg);
- ret = spi_sync_locked(ec_spi->spi, &msg);
-
- /* Get the response */
- if (!ret) {
- /* Verify that EC can process command */
- for (i = 0; i < len; i++) {
- rx_byte = rx_buf[i];
- /* See comments in cros_ec_pkt_xfer_spi() */
- if (rx_byte == EC_SPI_PAST_END ||
- rx_byte == EC_SPI_RX_BAD_DATA ||
- rx_byte == EC_SPI_NOT_READY) {
- ret = -EAGAIN;
- break;
- }
- }
- }
-
- if (!ret)
- ret = cros_ec_spi_receive_response(ec_dev,
- ec_msg->insize + EC_MSG_TX_PROTO_BYTES);
- else if (ret != -EAGAIN)
- dev_err(ec_dev->dev, "spi transfer failed: %d\n", ret);
-
- final_ret = terminate_request(ec_dev);
-
- spi_bus_unlock(ec_spi->spi->master);
-
- if (!ret)
- ret = final_ret;
- if (ret < 0)
- goto exit;
-
- ptr = ec_dev->din;
-
- /* check response error code */
- ec_msg->result = ptr[0];
- ret = cros_ec_check_result(ec_dev, ec_msg);
- if (ret)
- goto exit;
-
- len = ptr[1];
- sum = ptr[0] + ptr[1];
- if (len > ec_msg->insize) {
- dev_err(ec_dev->dev, "packet too long (%d bytes, expected %d)",
- len, ec_msg->insize);
- ret = -ENOSPC;
- goto exit;
- }
-
- /* copy response packet payload and compute checksum */
- for (i = 0; i < len; i++) {
- sum += ptr[i + 2];
- if (ec_msg->insize)
- ec_msg->data[i] = ptr[i + 2];
- }
- sum &= 0xff;
-
- debug_packet(ec_dev->dev, "in", ptr, len + 3);
-
- if (sum != ptr[len + 2]) {
- dev_err(ec_dev->dev,
- "bad packet checksum, expected %02x, got %02x\n",
- sum, ptr[len + 2]);
- ret = -EBADMSG;
- goto exit;
- }
-
- ret = len;
-exit:
- kfree(rx_buf);
- if (ec_msg->command == EC_CMD_REBOOT_EC)
- msleep(EC_REBOOT_DELAY_MS);
-
- return ret;
-}
-
-static void cros_ec_spi_dt_probe(struct cros_ec_spi *ec_spi, struct device *dev)
-{
- struct device_node *np = dev->of_node;
- u32 val;
- int ret;
-
- ret = of_property_read_u32(np, "google,cros-ec-spi-pre-delay", &val);
- if (!ret)
- ec_spi->start_of_msg_delay = val;
-
- ret = of_property_read_u32(np, "google,cros-ec-spi-msg-delay", &val);
- if (!ret)
- ec_spi->end_of_msg_delay = val;
-}
-
-static int cros_ec_spi_probe(struct spi_device *spi)
-{
- struct device *dev = &spi->dev;
- struct cros_ec_device *ec_dev;
- struct cros_ec_spi *ec_spi;
- int err;
-
- spi->bits_per_word = 8;
- spi->mode = SPI_MODE_0;
- err = spi_setup(spi);
- if (err < 0)
- return err;
-
- ec_spi = devm_kzalloc(dev, sizeof(*ec_spi), GFP_KERNEL);
- if (ec_spi == NULL)
- return -ENOMEM;
- ec_spi->spi = spi;
- ec_dev = devm_kzalloc(dev, sizeof(*ec_dev), GFP_KERNEL);
- if (!ec_dev)
- return -ENOMEM;
-
- /* Check for any DT properties */
- cros_ec_spi_dt_probe(ec_spi, dev);
-
- spi_set_drvdata(spi, ec_dev);
- ec_dev->dev = dev;
- ec_dev->priv = ec_spi;
- ec_dev->irq = spi->irq;
- ec_dev->cmd_xfer = cros_ec_cmd_xfer_spi;
- ec_dev->pkt_xfer = cros_ec_pkt_xfer_spi;
- ec_dev->phys_name = dev_name(&ec_spi->spi->dev);
- ec_dev->din_size = EC_MSG_PREAMBLE_COUNT +
- sizeof(struct ec_host_response) +
- sizeof(struct ec_response_get_protocol_info);
- ec_dev->dout_size = sizeof(struct ec_host_request);
-
- ec_spi->last_transfer_ns = ktime_get_ns();
-
- err = cros_ec_register(ec_dev);
- if (err) {
- dev_err(dev, "cannot register EC\n");
- return err;
- }
-
- device_init_wakeup(&spi->dev, true);
-
- return 0;
-}
-
-static int cros_ec_spi_remove(struct spi_device *spi)
-{
- struct cros_ec_device *ec_dev;
-
- ec_dev = spi_get_drvdata(spi);
- cros_ec_remove(ec_dev);
-
- return 0;
-}
-
-#ifdef CONFIG_PM_SLEEP
-static int cros_ec_spi_suspend(struct device *dev)
-{
- struct cros_ec_device *ec_dev = dev_get_drvdata(dev);
-
- return cros_ec_suspend(ec_dev);
-}
-
-static int cros_ec_spi_resume(struct device *dev)
-{
- struct cros_ec_device *ec_dev = dev_get_drvdata(dev);
-
- return cros_ec_resume(ec_dev);
-}
-#endif
-
-static SIMPLE_DEV_PM_OPS(cros_ec_spi_pm_ops, cros_ec_spi_suspend,
- cros_ec_spi_resume);
-
-static const struct of_device_id cros_ec_spi_of_match[] = {
- { .compatible = "google,cros-ec-spi", },
- { /* sentinel */ },
-};
-MODULE_DEVICE_TABLE(of, cros_ec_spi_of_match);
-
-static const struct spi_device_id cros_ec_spi_id[] = {
- { "cros-ec-spi", 0 },
- { }
-};
-MODULE_DEVICE_TABLE(spi, cros_ec_spi_id);
-
-static struct spi_driver cros_ec_driver_spi = {
- .driver = {
- .name = "cros-ec-spi",
- .of_match_table = of_match_ptr(cros_ec_spi_of_match),
- .pm = &cros_ec_spi_pm_ops,
- },
- .probe = cros_ec_spi_probe,
- .remove = cros_ec_spi_remove,
- .id_table = cros_ec_spi_id,
-};
-
-module_spi_driver(cros_ec_driver_spi);
-
-MODULE_LICENSE("GPL v2");
-MODULE_DESCRIPTION("ChromeOS EC multi function device (SPI)");
config CROS_EC_CTL
tristate
+config CROS_EC_I2C
+ tristate "ChromeOS Embedded Controller (I2C)"
+ depends on MFD_CROS_EC && I2C
+
+ help
+ If you say Y here, you get support for talking to the ChromeOS
+ EC through an I2C bus. This uses a simple byte-level protocol with
+ a checksum. Failing accesses will be retried three times to
+ improve reliability.
+
+config CROS_EC_SPI
+ tristate "ChromeOS Embedded Controller (SPI)"
+ depends on MFD_CROS_EC && SPI
+
+ ---help---
+ If you say Y here, you get support for talking to the ChromeOS EC
+ through a SPI bus, using a byte-level protocol. Since the EC's
+ response time cannot be guaranteed, we support ignoring
+ 'pre-amble' bytes before the response actually starts.
+
config CROS_EC_LPC
tristate "ChromeOS Embedded Controller (LPC)"
depends on MFD_CROS_EC && ACPI && (X86 || COMPILE_TEST)
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-$(CONFIG_CROS_EC_SPI) += cros_ec_spi.o
cros_ec_lpcs-objs := cros_ec_lpc.o cros_ec_lpc_reg.o
cros_ec_lpcs-$(CONFIG_CROS_EC_LPC_MEC) += cros_ec_lpc_mec.o
obj-$(CONFIG_CROS_EC_LPC) += cros_ec_lpcs.o
--- /dev/null
+/*
+ * ChromeOS EC multi-function device (I2C)
+ *
+ * Copyright (C) 2012 Google, Inc
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/acpi.h>
+#include <linux/delay.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/mfd/cros_ec.h>
+#include <linux/mfd/cros_ec_commands.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+/**
+ * Request format for protocol v3
+ * byte 0 0xda (EC_COMMAND_PROTOCOL_3)
+ * byte 1-8 struct ec_host_request
+ * byte 10- response data
+ */
+struct ec_host_request_i2c {
+ /* Always 0xda to backward compatible with v2 struct */
+ uint8_t command_protocol;
+ struct ec_host_request ec_request;
+} __packed;
+
+
+/*
+ * Response format for protocol v3
+ * byte 0 result code
+ * byte 1 packet_length
+ * byte 2-9 struct ec_host_response
+ * byte 10- response data
+ */
+struct ec_host_response_i2c {
+ uint8_t result;
+ uint8_t packet_length;
+ struct ec_host_response ec_response;
+} __packed;
+
+static inline struct cros_ec_device *to_ec_dev(struct device *dev)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+
+ return i2c_get_clientdata(client);
+}
+
+static int cros_ec_pkt_xfer_i2c(struct cros_ec_device *ec_dev,
+ struct cros_ec_command *msg)
+{
+ struct i2c_client *client = ec_dev->priv;
+ int ret = -ENOMEM;
+ int i;
+ int packet_len;
+ u8 *out_buf = NULL;
+ u8 *in_buf = NULL;
+ u8 sum;
+ struct i2c_msg i2c_msg[2];
+ struct ec_host_response *ec_response;
+ struct ec_host_request_i2c *ec_request_i2c;
+ struct ec_host_response_i2c *ec_response_i2c;
+ int request_header_size = sizeof(struct ec_host_request_i2c);
+ int response_header_size = sizeof(struct ec_host_response_i2c);
+
+ i2c_msg[0].addr = client->addr;
+ i2c_msg[0].flags = 0;
+ i2c_msg[1].addr = client->addr;
+ i2c_msg[1].flags = I2C_M_RD;
+
+ packet_len = msg->insize + response_header_size;
+ BUG_ON(packet_len > ec_dev->din_size);
+ in_buf = ec_dev->din;
+ i2c_msg[1].len = packet_len;
+ i2c_msg[1].buf = (char *) in_buf;
+
+ packet_len = msg->outsize + request_header_size;
+ BUG_ON(packet_len > ec_dev->dout_size);
+ out_buf = ec_dev->dout;
+ i2c_msg[0].len = packet_len;
+ i2c_msg[0].buf = (char *) out_buf;
+
+ /* create request data */
+ ec_request_i2c = (struct ec_host_request_i2c *) out_buf;
+ ec_request_i2c->command_protocol = EC_COMMAND_PROTOCOL_3;
+
+ ec_dev->dout++;
+ ret = cros_ec_prepare_tx(ec_dev, msg);
+ ec_dev->dout--;
+
+ /* send command to EC and read answer */
+ ret = i2c_transfer(client->adapter, i2c_msg, 2);
+ if (ret < 0) {
+ dev_dbg(ec_dev->dev, "i2c transfer failed: %d\n", ret);
+ goto done;
+ } else if (ret != 2) {
+ dev_err(ec_dev->dev, "failed to get response: %d\n", ret);
+ ret = -EIO;
+ goto done;
+ }
+
+ ec_response_i2c = (struct ec_host_response_i2c *) in_buf;
+ msg->result = ec_response_i2c->result;
+ ec_response = &ec_response_i2c->ec_response;
+
+ switch (msg->result) {
+ case EC_RES_SUCCESS:
+ break;
+ case EC_RES_IN_PROGRESS:
+ ret = -EAGAIN;
+ dev_dbg(ec_dev->dev, "command 0x%02x in progress\n",
+ msg->command);
+ goto done;
+
+ default:
+ dev_dbg(ec_dev->dev, "command 0x%02x returned %d\n",
+ msg->command, msg->result);
+ /*
+ * When we send v3 request to v2 ec, ec won't recognize the
+ * 0xda (EC_COMMAND_PROTOCOL_3) and will return with status
+ * EC_RES_INVALID_COMMAND with zero data length.
+ *
+ * In case of invalid command for v3 protocol the data length
+ * will be at least sizeof(struct ec_host_response)
+ */
+ if (ec_response_i2c->result == EC_RES_INVALID_COMMAND &&
+ ec_response_i2c->packet_length == 0) {
+ ret = -EPROTONOSUPPORT;
+ goto done;
+ }
+ }
+
+ if (ec_response_i2c->packet_length < sizeof(struct ec_host_response)) {
+ dev_err(ec_dev->dev,
+ "response of %u bytes too short; not a full header\n",
+ ec_response_i2c->packet_length);
+ ret = -EBADMSG;
+ goto done;
+ }
+
+ if (msg->insize < ec_response->data_len) {
+ dev_err(ec_dev->dev,
+ "response data size is too large: expected %u, got %u\n",
+ msg->insize,
+ ec_response->data_len);
+ ret = -EMSGSIZE;
+ goto done;
+ }
+
+ /* copy response packet payload and compute checksum */
+ sum = 0;
+ for (i = 0; i < sizeof(struct ec_host_response); i++)
+ sum += ((u8 *)ec_response)[i];
+
+ memcpy(msg->data,
+ in_buf + response_header_size,
+ ec_response->data_len);
+ for (i = 0; i < ec_response->data_len; i++)
+ sum += msg->data[i];
+
+ /* All bytes should sum to zero */
+ if (sum) {
+ dev_err(ec_dev->dev, "bad packet checksum\n");
+ ret = -EBADMSG;
+ goto done;
+ }
+
+ ret = ec_response->data_len;
+
+done:
+ if (msg->command == EC_CMD_REBOOT_EC)
+ msleep(EC_REBOOT_DELAY_MS);
+
+ return ret;
+}
+
+static int cros_ec_cmd_xfer_i2c(struct cros_ec_device *ec_dev,
+ struct cros_ec_command *msg)
+{
+ struct i2c_client *client = ec_dev->priv;
+ int ret = -ENOMEM;
+ int i;
+ int len;
+ int packet_len;
+ u8 *out_buf = NULL;
+ u8 *in_buf = NULL;
+ u8 sum;
+ struct i2c_msg i2c_msg[2];
+
+ i2c_msg[0].addr = client->addr;
+ i2c_msg[0].flags = 0;
+ i2c_msg[1].addr = client->addr;
+ i2c_msg[1].flags = I2C_M_RD;
+
+ /*
+ * allocate larger packet (one byte for checksum, one byte for
+ * length, and one for result code)
+ */
+ packet_len = msg->insize + 3;
+ in_buf = kzalloc(packet_len, GFP_KERNEL);
+ if (!in_buf)
+ goto done;
+ i2c_msg[1].len = packet_len;
+ i2c_msg[1].buf = (char *)in_buf;
+
+ /*
+ * allocate larger packet (one byte for checksum, one for
+ * command code, one for length, and one for command version)
+ */
+ packet_len = msg->outsize + 4;
+ out_buf = kzalloc(packet_len, GFP_KERNEL);
+ if (!out_buf)
+ goto done;
+ i2c_msg[0].len = packet_len;
+ i2c_msg[0].buf = (char *)out_buf;
+
+ out_buf[0] = EC_CMD_VERSION0 + msg->version;
+ out_buf[1] = msg->command;
+ out_buf[2] = msg->outsize;
+
+ /* copy message payload and compute checksum */
+ sum = out_buf[0] + out_buf[1] + out_buf[2];
+ for (i = 0; i < msg->outsize; i++) {
+ out_buf[3 + i] = msg->data[i];
+ sum += out_buf[3 + i];
+ }
+ out_buf[3 + msg->outsize] = sum;
+
+ /* send command to EC and read answer */
+ ret = i2c_transfer(client->adapter, i2c_msg, 2);
+ if (ret < 0) {
+ dev_err(ec_dev->dev, "i2c transfer failed: %d\n", ret);
+ goto done;
+ } else if (ret != 2) {
+ dev_err(ec_dev->dev, "failed to get response: %d\n", ret);
+ ret = -EIO;
+ goto done;
+ }
+
+ /* check response error code */
+ msg->result = i2c_msg[1].buf[0];
+ ret = cros_ec_check_result(ec_dev, msg);
+ if (ret)
+ goto done;
+
+ len = in_buf[1];
+ if (len > msg->insize) {
+ dev_err(ec_dev->dev, "packet too long (%d bytes, expected %d)",
+ len, msg->insize);
+ ret = -ENOSPC;
+ goto done;
+ }
+
+ /* copy response packet payload and compute checksum */
+ sum = in_buf[0] + in_buf[1];
+ for (i = 0; i < len; i++) {
+ msg->data[i] = in_buf[2 + i];
+ sum += in_buf[2 + i];
+ }
+ dev_dbg(ec_dev->dev, "packet: %*ph, sum = %02x\n",
+ i2c_msg[1].len, in_buf, sum);
+ if (sum != in_buf[2 + len]) {
+ dev_err(ec_dev->dev, "bad packet checksum\n");
+ ret = -EBADMSG;
+ goto done;
+ }
+
+ ret = len;
+done:
+ kfree(in_buf);
+ kfree(out_buf);
+ if (msg->command == EC_CMD_REBOOT_EC)
+ msleep(EC_REBOOT_DELAY_MS);
+
+ return ret;
+}
+
+static int cros_ec_i2c_probe(struct i2c_client *client,
+ const struct i2c_device_id *dev_id)
+{
+ struct device *dev = &client->dev;
+ struct cros_ec_device *ec_dev = NULL;
+ int err;
+
+ ec_dev = devm_kzalloc(dev, sizeof(*ec_dev), GFP_KERNEL);
+ if (!ec_dev)
+ return -ENOMEM;
+
+ i2c_set_clientdata(client, ec_dev);
+ ec_dev->dev = dev;
+ ec_dev->priv = client;
+ ec_dev->irq = client->irq;
+ ec_dev->cmd_xfer = cros_ec_cmd_xfer_i2c;
+ ec_dev->pkt_xfer = cros_ec_pkt_xfer_i2c;
+ ec_dev->phys_name = client->adapter->name;
+ ec_dev->din_size = sizeof(struct ec_host_response_i2c) +
+ sizeof(struct ec_response_get_protocol_info);
+ ec_dev->dout_size = sizeof(struct ec_host_request_i2c);
+
+ err = cros_ec_register(ec_dev);
+ if (err) {
+ dev_err(dev, "cannot register EC\n");
+ return err;
+ }
+
+ return 0;
+}
+
+static int cros_ec_i2c_remove(struct i2c_client *client)
+{
+ struct cros_ec_device *ec_dev = i2c_get_clientdata(client);
+
+ cros_ec_remove(ec_dev);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int cros_ec_i2c_suspend(struct device *dev)
+{
+ struct cros_ec_device *ec_dev = to_ec_dev(dev);
+
+ return cros_ec_suspend(ec_dev);
+}
+
+static int cros_ec_i2c_resume(struct device *dev)
+{
+ struct cros_ec_device *ec_dev = to_ec_dev(dev);
+
+ return cros_ec_resume(ec_dev);
+}
+#endif
+
+static const struct dev_pm_ops cros_ec_i2c_pm_ops = {
+ SET_LATE_SYSTEM_SLEEP_PM_OPS(cros_ec_i2c_suspend, cros_ec_i2c_resume)
+};
+
+#ifdef CONFIG_OF
+static const struct of_device_id cros_ec_i2c_of_match[] = {
+ { .compatible = "google,cros-ec-i2c", },
+ { /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, cros_ec_i2c_of_match);
+#endif
+
+static const struct i2c_device_id cros_ec_i2c_id[] = {
+ { "cros-ec-i2c", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, cros_ec_i2c_id);
+
+#ifdef CONFIG_ACPI
+static const struct acpi_device_id cros_ec_i2c_acpi_id[] = {
+ { "GOOG0008", 0 },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(acpi, cros_ec_i2c_acpi_id);
+#endif
+
+static struct i2c_driver cros_ec_driver = {
+ .driver = {
+ .name = "cros-ec-i2c",
+ .acpi_match_table = ACPI_PTR(cros_ec_i2c_acpi_id),
+ .of_match_table = of_match_ptr(cros_ec_i2c_of_match),
+ .pm = &cros_ec_i2c_pm_ops,
+ },
+ .probe = cros_ec_i2c_probe,
+ .remove = cros_ec_i2c_remove,
+ .id_table = cros_ec_i2c_id,
+};
+
+module_i2c_driver(cros_ec_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("ChromeOS EC multi function device");
--- /dev/null
+/*
+ * ChromeOS EC multi-function device (SPI)
+ *
+ * Copyright (C) 2012 Google, Inc
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/delay.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mfd/cros_ec.h>
+#include <linux/mfd/cros_ec_commands.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/spi/spi.h>
+
+
+/* The header byte, which follows the preamble */
+#define EC_MSG_HEADER 0xec
+
+/*
+ * Number of EC preamble bytes we read at a time. Since it takes
+ * about 400-500us for the EC to respond there is not a lot of
+ * point in tuning this. If the EC could respond faster then
+ * we could increase this so that might expect the preamble and
+ * message to occur in a single transaction. However, the maximum
+ * SPI transfer size is 256 bytes, so at 5MHz we need a response
+ * time of perhaps <320us (200 bytes / 1600 bits).
+ */
+#define EC_MSG_PREAMBLE_COUNT 32
+
+/*
+ * Allow for a long time for the EC to respond. We support i2c
+ * tunneling and support fairly long messages for the tunnel (249
+ * bytes long at the moment). If we're talking to a 100 kHz device
+ * on the other end and need to transfer ~256 bytes, then we need:
+ * 10 us/bit * ~10 bits/byte * ~256 bytes = ~25ms
+ *
+ * We'll wait 8 times that to handle clock stretching and other
+ * paranoia. Note that some battery gas gauge ICs claim to have a
+ * clock stretch of 144ms in rare situations. That's incentive for
+ * not directly passing i2c through, but it's too late for that for
+ * existing hardware.
+ *
+ * It's pretty unlikely that we'll really see a 249 byte tunnel in
+ * anything other than testing. If this was more common we might
+ * consider having slow commands like this require a GET_STATUS
+ * wait loop. The 'flash write' command would be another candidate
+ * for this, clocking in at 2-3ms.
+ */
+#define EC_MSG_DEADLINE_MS 200
+
+/*
+ * Time between raising the SPI chip select (for the end of a
+ * transaction) and dropping it again (for the next transaction).
+ * If we go too fast, the EC will miss the transaction. We know that we
+ * need at least 70 us with the 16 MHz STM32 EC, so go with 200 us to be
+ * safe.
+ */
+#define EC_SPI_RECOVERY_TIME_NS (200 * 1000)
+
+/**
+ * struct cros_ec_spi - information about a SPI-connected EC
+ *
+ * @spi: SPI device we are connected to
+ * @last_transfer_ns: time that we last finished a transfer.
+ * @start_of_msg_delay: used to set the delay_usecs on the spi_transfer that
+ * is sent when we want to turn on CS at the start of a transaction.
+ * @end_of_msg_delay: used to set the delay_usecs on the spi_transfer that
+ * is sent when we want to turn off CS at the end of a transaction.
+ */
+struct cros_ec_spi {
+ struct spi_device *spi;
+ s64 last_transfer_ns;
+ unsigned int start_of_msg_delay;
+ unsigned int end_of_msg_delay;
+};
+
+static void debug_packet(struct device *dev, const char *name, u8 *ptr,
+ int len)
+{
+#ifdef DEBUG
+ int i;
+
+ dev_dbg(dev, "%s: ", name);
+ for (i = 0; i < len; i++)
+ pr_cont(" %02x", ptr[i]);
+
+ pr_cont("\n");
+#endif
+}
+
+static int terminate_request(struct cros_ec_device *ec_dev)
+{
+ struct cros_ec_spi *ec_spi = ec_dev->priv;
+ struct spi_message msg;
+ struct spi_transfer trans;
+ int ret;
+
+ /*
+ * Turn off CS, possibly adding a delay to ensure the rising edge
+ * doesn't come too soon after the end of the data.
+ */
+ spi_message_init(&msg);
+ memset(&trans, 0, sizeof(trans));
+ trans.delay_usecs = ec_spi->end_of_msg_delay;
+ spi_message_add_tail(&trans, &msg);
+
+ ret = spi_sync_locked(ec_spi->spi, &msg);
+
+ /* Reset end-of-response timer */
+ ec_spi->last_transfer_ns = ktime_get_ns();
+ if (ret < 0) {
+ dev_err(ec_dev->dev,
+ "cs-deassert spi transfer failed: %d\n",
+ ret);
+ }
+
+ return ret;
+}
+
+/**
+ * receive_n_bytes - receive n bytes from the EC.
+ *
+ * Assumes buf is a pointer into the ec_dev->din buffer
+ */
+static int receive_n_bytes(struct cros_ec_device *ec_dev, u8 *buf, int n)
+{
+ struct cros_ec_spi *ec_spi = ec_dev->priv;
+ struct spi_transfer trans;
+ struct spi_message msg;
+ int ret;
+
+ BUG_ON(buf - ec_dev->din + n > ec_dev->din_size);
+
+ memset(&trans, 0, sizeof(trans));
+ trans.cs_change = 1;
+ trans.rx_buf = buf;
+ trans.len = n;
+
+ spi_message_init(&msg);
+ spi_message_add_tail(&trans, &msg);
+ ret = spi_sync_locked(ec_spi->spi, &msg);
+ if (ret < 0)
+ dev_err(ec_dev->dev, "spi transfer failed: %d\n", ret);
+
+ return ret;
+}
+
+/**
+ * cros_ec_spi_receive_packet - Receive a packet from the EC.
+ *
+ * This function has two phases: reading the preamble bytes (since if we read
+ * data from the EC before it is ready to send, we just get preamble) and
+ * reading the actual message.
+ *
+ * The received data is placed into ec_dev->din.
+ *
+ * @ec_dev: ChromeOS EC device
+ * @need_len: Number of message bytes we need to read
+ */
+static int cros_ec_spi_receive_packet(struct cros_ec_device *ec_dev,
+ int need_len)
+{
+ struct ec_host_response *response;
+ u8 *ptr, *end;
+ int ret;
+ unsigned long deadline;
+ int todo;
+
+ BUG_ON(ec_dev->din_size < EC_MSG_PREAMBLE_COUNT);
+
+ /* Receive data until we see the header byte */
+ deadline = jiffies + msecs_to_jiffies(EC_MSG_DEADLINE_MS);
+ while (true) {
+ unsigned long start_jiffies = jiffies;
+
+ ret = receive_n_bytes(ec_dev,
+ ec_dev->din,
+ EC_MSG_PREAMBLE_COUNT);
+ if (ret < 0)
+ return ret;
+
+ ptr = ec_dev->din;
+ for (end = ptr + EC_MSG_PREAMBLE_COUNT; ptr != end; ptr++) {
+ if (*ptr == EC_SPI_FRAME_START) {
+ dev_dbg(ec_dev->dev, "msg found at %zd\n",
+ ptr - ec_dev->din);
+ break;
+ }
+ }
+ if (ptr != end)
+ break;
+
+ /*
+ * Use the time at the start of the loop as a timeout. This
+ * gives us one last shot at getting the transfer and is useful
+ * in case we got context switched out for a while.
+ */
+ if (time_after(start_jiffies, deadline)) {
+ dev_warn(ec_dev->dev, "EC failed to respond in time\n");
+ return -ETIMEDOUT;
+ }
+ }
+
+ /*
+ * ptr now points to the header byte. Copy any valid data to the
+ * start of our buffer
+ */
+ todo = end - ++ptr;
+ BUG_ON(todo < 0 || todo > ec_dev->din_size);
+ todo = min(todo, need_len);
+ memmove(ec_dev->din, ptr, todo);
+ ptr = ec_dev->din + todo;
+ dev_dbg(ec_dev->dev, "need %d, got %d bytes from preamble\n",
+ need_len, todo);
+ need_len -= todo;
+
+ /* If the entire response struct wasn't read, get the rest of it. */
+ if (todo < sizeof(*response)) {
+ ret = receive_n_bytes(ec_dev, ptr, sizeof(*response) - todo);
+ if (ret < 0)
+ return -EBADMSG;
+ ptr += (sizeof(*response) - todo);
+ todo = sizeof(*response);
+ }
+
+ response = (struct ec_host_response *)ec_dev->din;
+
+ /* Abort if data_len is too large. */
+ if (response->data_len > ec_dev->din_size)
+ return -EMSGSIZE;
+
+ /* Receive data until we have it all */
+ while (need_len > 0) {
+ /*
+ * We can't support transfers larger than the SPI FIFO size
+ * unless we have DMA. We don't have DMA on the ISP SPI ports
+ * for Exynos. We need a way of asking SPI driver for
+ * maximum-supported transfer size.
+ */
+ todo = min(need_len, 256);
+ dev_dbg(ec_dev->dev, "loop, todo=%d, need_len=%d, ptr=%zd\n",
+ todo, need_len, ptr - ec_dev->din);
+
+ ret = receive_n_bytes(ec_dev, ptr, todo);
+ if (ret < 0)
+ return ret;
+
+ ptr += todo;
+ need_len -= todo;
+ }
+
+ dev_dbg(ec_dev->dev, "loop done, ptr=%zd\n", ptr - ec_dev->din);
+
+ return 0;
+}
+
+/**
+ * cros_ec_spi_receive_response - Receive a response from the EC.
+ *
+ * This function has two phases: reading the preamble bytes (since if we read
+ * data from the EC before it is ready to send, we just get preamble) and
+ * reading the actual message.
+ *
+ * The received data is placed into ec_dev->din.
+ *
+ * @ec_dev: ChromeOS EC device
+ * @need_len: Number of message bytes we need to read
+ */
+static int cros_ec_spi_receive_response(struct cros_ec_device *ec_dev,
+ int need_len)
+{
+ u8 *ptr, *end;
+ int ret;
+ unsigned long deadline;
+ int todo;
+
+ BUG_ON(ec_dev->din_size < EC_MSG_PREAMBLE_COUNT);
+
+ /* Receive data until we see the header byte */
+ deadline = jiffies + msecs_to_jiffies(EC_MSG_DEADLINE_MS);
+ while (true) {
+ unsigned long start_jiffies = jiffies;
+
+ ret = receive_n_bytes(ec_dev,
+ ec_dev->din,
+ EC_MSG_PREAMBLE_COUNT);
+ if (ret < 0)
+ return ret;
+
+ ptr = ec_dev->din;
+ for (end = ptr + EC_MSG_PREAMBLE_COUNT; ptr != end; ptr++) {
+ if (*ptr == EC_SPI_FRAME_START) {
+ dev_dbg(ec_dev->dev, "msg found at %zd\n",
+ ptr - ec_dev->din);
+ break;
+ }
+ }
+ if (ptr != end)
+ break;
+
+ /*
+ * Use the time at the start of the loop as a timeout. This
+ * gives us one last shot at getting the transfer and is useful
+ * in case we got context switched out for a while.
+ */
+ if (time_after(start_jiffies, deadline)) {
+ dev_warn(ec_dev->dev, "EC failed to respond in time\n");
+ return -ETIMEDOUT;
+ }
+ }
+
+ /*
+ * ptr now points to the header byte. Copy any valid data to the
+ * start of our buffer
+ */
+ todo = end - ++ptr;
+ BUG_ON(todo < 0 || todo > ec_dev->din_size);
+ todo = min(todo, need_len);
+ memmove(ec_dev->din, ptr, todo);
+ ptr = ec_dev->din + todo;
+ dev_dbg(ec_dev->dev, "need %d, got %d bytes from preamble\n",
+ need_len, todo);
+ need_len -= todo;
+
+ /* Receive data until we have it all */
+ while (need_len > 0) {
+ /*
+ * We can't support transfers larger than the SPI FIFO size
+ * unless we have DMA. We don't have DMA on the ISP SPI ports
+ * for Exynos. We need a way of asking SPI driver for
+ * maximum-supported transfer size.
+ */
+ todo = min(need_len, 256);
+ dev_dbg(ec_dev->dev, "loop, todo=%d, need_len=%d, ptr=%zd\n",
+ todo, need_len, ptr - ec_dev->din);
+
+ ret = receive_n_bytes(ec_dev, ptr, todo);
+ if (ret < 0)
+ return ret;
+
+ debug_packet(ec_dev->dev, "interim", ptr, todo);
+ ptr += todo;
+ need_len -= todo;
+ }
+
+ dev_dbg(ec_dev->dev, "loop done, ptr=%zd\n", ptr - ec_dev->din);
+
+ return 0;
+}
+
+/**
+ * cros_ec_pkt_xfer_spi - Transfer a packet over SPI and receive the reply
+ *
+ * @ec_dev: ChromeOS EC device
+ * @ec_msg: Message to transfer
+ */
+static int cros_ec_pkt_xfer_spi(struct cros_ec_device *ec_dev,
+ struct cros_ec_command *ec_msg)
+{
+ struct ec_host_response *response;
+ struct cros_ec_spi *ec_spi = ec_dev->priv;
+ struct spi_transfer trans, trans_delay;
+ struct spi_message msg;
+ int i, len;
+ u8 *ptr;
+ u8 *rx_buf;
+ u8 sum;
+ u8 rx_byte;
+ int ret = 0, final_ret;
+ unsigned long delay;
+
+ len = cros_ec_prepare_tx(ec_dev, ec_msg);
+ dev_dbg(ec_dev->dev, "prepared, len=%d\n", len);
+
+ /* If it's too soon to do another transaction, wait */
+ delay = ktime_get_ns() - ec_spi->last_transfer_ns;
+ if (delay < EC_SPI_RECOVERY_TIME_NS)
+ ndelay(EC_SPI_RECOVERY_TIME_NS - delay);
+
+ rx_buf = kzalloc(len, GFP_KERNEL);
+ if (!rx_buf)
+ return -ENOMEM;
+
+ spi_bus_lock(ec_spi->spi->master);
+
+ /*
+ * Leave a gap between CS assertion and clocking of data to allow the
+ * EC time to wakeup.
+ */
+ spi_message_init(&msg);
+ if (ec_spi->start_of_msg_delay) {
+ memset(&trans_delay, 0, sizeof(trans_delay));
+ trans_delay.delay_usecs = ec_spi->start_of_msg_delay;
+ spi_message_add_tail(&trans_delay, &msg);
+ }
+
+ /* Transmit phase - send our message */
+ memset(&trans, 0, sizeof(trans));
+ trans.tx_buf = ec_dev->dout;
+ trans.rx_buf = rx_buf;
+ trans.len = len;
+ trans.cs_change = 1;
+ spi_message_add_tail(&trans, &msg);
+ ret = spi_sync_locked(ec_spi->spi, &msg);
+
+ /* Get the response */
+ if (!ret) {
+ /* Verify that EC can process command */
+ for (i = 0; i < len; i++) {
+ rx_byte = rx_buf[i];
+ /*
+ * Seeing the PAST_END, RX_BAD_DATA, or NOT_READY
+ * markers are all signs that the EC didn't fully
+ * receive our command. e.g., if the EC is flashing
+ * itself, it can't respond to any commands and instead
+ * clocks out EC_SPI_PAST_END from its SPI hardware
+ * buffer. Similar occurrences can happen if the AP is
+ * too slow to clock out data after asserting CS -- the
+ * EC will abort and fill its buffer with
+ * EC_SPI_RX_BAD_DATA.
+ *
+ * In all cases, these errors should be safe to retry.
+ * Report -EAGAIN and let the caller decide what to do
+ * about that.
+ */
+ if (rx_byte == EC_SPI_PAST_END ||
+ rx_byte == EC_SPI_RX_BAD_DATA ||
+ rx_byte == EC_SPI_NOT_READY) {
+ ret = -EAGAIN;
+ break;
+ }
+ }
+ }
+
+ if (!ret)
+ ret = cros_ec_spi_receive_packet(ec_dev,
+ ec_msg->insize + sizeof(*response));
+ else if (ret != -EAGAIN)
+ dev_err(ec_dev->dev, "spi transfer failed: %d\n", ret);
+
+ final_ret = terminate_request(ec_dev);
+
+ spi_bus_unlock(ec_spi->spi->master);
+
+ if (!ret)
+ ret = final_ret;
+ if (ret < 0)
+ goto exit;
+
+ ptr = ec_dev->din;
+
+ /* check response error code */
+ response = (struct ec_host_response *)ptr;
+ ec_msg->result = response->result;
+
+ ret = cros_ec_check_result(ec_dev, ec_msg);
+ if (ret)
+ goto exit;
+
+ len = response->data_len;
+ sum = 0;
+ if (len > ec_msg->insize) {
+ dev_err(ec_dev->dev, "packet too long (%d bytes, expected %d)",
+ len, ec_msg->insize);
+ ret = -EMSGSIZE;
+ goto exit;
+ }
+
+ for (i = 0; i < sizeof(*response); i++)
+ sum += ptr[i];
+
+ /* copy response packet payload and compute checksum */
+ memcpy(ec_msg->data, ptr + sizeof(*response), len);
+ for (i = 0; i < len; i++)
+ sum += ec_msg->data[i];
+
+ if (sum) {
+ dev_err(ec_dev->dev,
+ "bad packet checksum, calculated %x\n",
+ sum);
+ ret = -EBADMSG;
+ goto exit;
+ }
+
+ ret = len;
+exit:
+ kfree(rx_buf);
+ if (ec_msg->command == EC_CMD_REBOOT_EC)
+ msleep(EC_REBOOT_DELAY_MS);
+
+ return ret;
+}
+
+/**
+ * cros_ec_cmd_xfer_spi - Transfer a message over SPI and receive the reply
+ *
+ * @ec_dev: ChromeOS EC device
+ * @ec_msg: Message to transfer
+ */
+static int cros_ec_cmd_xfer_spi(struct cros_ec_device *ec_dev,
+ struct cros_ec_command *ec_msg)
+{
+ struct cros_ec_spi *ec_spi = ec_dev->priv;
+ struct spi_transfer trans;
+ struct spi_message msg;
+ int i, len;
+ u8 *ptr;
+ u8 *rx_buf;
+ u8 rx_byte;
+ int sum;
+ int ret = 0, final_ret;
+ unsigned long delay;
+
+ len = cros_ec_prepare_tx(ec_dev, ec_msg);
+ dev_dbg(ec_dev->dev, "prepared, len=%d\n", len);
+
+ /* If it's too soon to do another transaction, wait */
+ delay = ktime_get_ns() - ec_spi->last_transfer_ns;
+ if (delay < EC_SPI_RECOVERY_TIME_NS)
+ ndelay(EC_SPI_RECOVERY_TIME_NS - delay);
+
+ rx_buf = kzalloc(len, GFP_KERNEL);
+ if (!rx_buf)
+ return -ENOMEM;
+
+ spi_bus_lock(ec_spi->spi->master);
+
+ /* Transmit phase - send our message */
+ debug_packet(ec_dev->dev, "out", ec_dev->dout, len);
+ memset(&trans, 0, sizeof(trans));
+ trans.tx_buf = ec_dev->dout;
+ trans.rx_buf = rx_buf;
+ trans.len = len;
+ trans.cs_change = 1;
+ spi_message_init(&msg);
+ spi_message_add_tail(&trans, &msg);
+ ret = spi_sync_locked(ec_spi->spi, &msg);
+
+ /* Get the response */
+ if (!ret) {
+ /* Verify that EC can process command */
+ for (i = 0; i < len; i++) {
+ rx_byte = rx_buf[i];
+ /* See comments in cros_ec_pkt_xfer_spi() */
+ if (rx_byte == EC_SPI_PAST_END ||
+ rx_byte == EC_SPI_RX_BAD_DATA ||
+ rx_byte == EC_SPI_NOT_READY) {
+ ret = -EAGAIN;
+ break;
+ }
+ }
+ }
+
+ if (!ret)
+ ret = cros_ec_spi_receive_response(ec_dev,
+ ec_msg->insize + EC_MSG_TX_PROTO_BYTES);
+ else if (ret != -EAGAIN)
+ dev_err(ec_dev->dev, "spi transfer failed: %d\n", ret);
+
+ final_ret = terminate_request(ec_dev);
+
+ spi_bus_unlock(ec_spi->spi->master);
+
+ if (!ret)
+ ret = final_ret;
+ if (ret < 0)
+ goto exit;
+
+ ptr = ec_dev->din;
+
+ /* check response error code */
+ ec_msg->result = ptr[0];
+ ret = cros_ec_check_result(ec_dev, ec_msg);
+ if (ret)
+ goto exit;
+
+ len = ptr[1];
+ sum = ptr[0] + ptr[1];
+ if (len > ec_msg->insize) {
+ dev_err(ec_dev->dev, "packet too long (%d bytes, expected %d)",
+ len, ec_msg->insize);
+ ret = -ENOSPC;
+ goto exit;
+ }
+
+ /* copy response packet payload and compute checksum */
+ for (i = 0; i < len; i++) {
+ sum += ptr[i + 2];
+ if (ec_msg->insize)
+ ec_msg->data[i] = ptr[i + 2];
+ }
+ sum &= 0xff;
+
+ debug_packet(ec_dev->dev, "in", ptr, len + 3);
+
+ if (sum != ptr[len + 2]) {
+ dev_err(ec_dev->dev,
+ "bad packet checksum, expected %02x, got %02x\n",
+ sum, ptr[len + 2]);
+ ret = -EBADMSG;
+ goto exit;
+ }
+
+ ret = len;
+exit:
+ kfree(rx_buf);
+ if (ec_msg->command == EC_CMD_REBOOT_EC)
+ msleep(EC_REBOOT_DELAY_MS);
+
+ return ret;
+}
+
+static void cros_ec_spi_dt_probe(struct cros_ec_spi *ec_spi, struct device *dev)
+{
+ struct device_node *np = dev->of_node;
+ u32 val;
+ int ret;
+
+ ret = of_property_read_u32(np, "google,cros-ec-spi-pre-delay", &val);
+ if (!ret)
+ ec_spi->start_of_msg_delay = val;
+
+ ret = of_property_read_u32(np, "google,cros-ec-spi-msg-delay", &val);
+ if (!ret)
+ ec_spi->end_of_msg_delay = val;
+}
+
+static int cros_ec_spi_probe(struct spi_device *spi)
+{
+ struct device *dev = &spi->dev;
+ struct cros_ec_device *ec_dev;
+ struct cros_ec_spi *ec_spi;
+ int err;
+
+ spi->bits_per_word = 8;
+ spi->mode = SPI_MODE_0;
+ err = spi_setup(spi);
+ if (err < 0)
+ return err;
+
+ ec_spi = devm_kzalloc(dev, sizeof(*ec_spi), GFP_KERNEL);
+ if (ec_spi == NULL)
+ return -ENOMEM;
+ ec_spi->spi = spi;
+ ec_dev = devm_kzalloc(dev, sizeof(*ec_dev), GFP_KERNEL);
+ if (!ec_dev)
+ return -ENOMEM;
+
+ /* Check for any DT properties */
+ cros_ec_spi_dt_probe(ec_spi, dev);
+
+ spi_set_drvdata(spi, ec_dev);
+ ec_dev->dev = dev;
+ ec_dev->priv = ec_spi;
+ ec_dev->irq = spi->irq;
+ ec_dev->cmd_xfer = cros_ec_cmd_xfer_spi;
+ ec_dev->pkt_xfer = cros_ec_pkt_xfer_spi;
+ ec_dev->phys_name = dev_name(&ec_spi->spi->dev);
+ ec_dev->din_size = EC_MSG_PREAMBLE_COUNT +
+ sizeof(struct ec_host_response) +
+ sizeof(struct ec_response_get_protocol_info);
+ ec_dev->dout_size = sizeof(struct ec_host_request);
+
+ ec_spi->last_transfer_ns = ktime_get_ns();
+
+ err = cros_ec_register(ec_dev);
+ if (err) {
+ dev_err(dev, "cannot register EC\n");
+ return err;
+ }
+
+ device_init_wakeup(&spi->dev, true);
+
+ return 0;
+}
+
+static int cros_ec_spi_remove(struct spi_device *spi)
+{
+ struct cros_ec_device *ec_dev;
+
+ ec_dev = spi_get_drvdata(spi);
+ cros_ec_remove(ec_dev);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int cros_ec_spi_suspend(struct device *dev)
+{
+ struct cros_ec_device *ec_dev = dev_get_drvdata(dev);
+
+ return cros_ec_suspend(ec_dev);
+}
+
+static int cros_ec_spi_resume(struct device *dev)
+{
+ struct cros_ec_device *ec_dev = dev_get_drvdata(dev);
+
+ return cros_ec_resume(ec_dev);
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(cros_ec_spi_pm_ops, cros_ec_spi_suspend,
+ cros_ec_spi_resume);
+
+static const struct of_device_id cros_ec_spi_of_match[] = {
+ { .compatible = "google,cros-ec-spi", },
+ { /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, cros_ec_spi_of_match);
+
+static const struct spi_device_id cros_ec_spi_id[] = {
+ { "cros-ec-spi", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(spi, cros_ec_spi_id);
+
+static struct spi_driver cros_ec_driver_spi = {
+ .driver = {
+ .name = "cros-ec-spi",
+ .of_match_table = of_match_ptr(cros_ec_spi_of_match),
+ .pm = &cros_ec_spi_pm_ops,
+ },
+ .probe = cros_ec_spi_probe,
+ .remove = cros_ec_spi_remove,
+ .id_table = cros_ec_spi_id,
+};
+
+module_spi_driver(cros_ec_driver_spi);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("ChromeOS EC multi function device (SPI)");
projects / linux-2.6-block.git / commitdiff