platform/chrome: Move cros-ec transport drivers to drivers/platform.

There are some cros-ec transport drivers (I2C, SPI) living in MFD, while
others (LPC) living in drivers/platform. The transport drivers are more
platform specific. So, move the I2C and SPI transport drivers to the
platform/chrome directory. The patch also removes the MFD_ prefix of
their Kconfig symbols.

Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Reviewed-by: Guenter Roeck <groeck@chromium.org>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Benson Leung <bleung@chromium.org>

4 files changed, 0 insertions, 1151 deletions

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index b860eb5aa194..013458e728dc 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -202,26 +202,6 @@ config MFD_CROS_EC
 	  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
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index e9fd20dba18d..d13e859d7c1e 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -14,8 +14,6 @@ obj-$(CONFIG_MFD_BCM590XX)	+= bcm590xx.o
 obj-$(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
 
diff --git a/drivers/mfd/cros_ec_i2c.c b/drivers/mfd/cros_ec_i2c.c
deleted file mode 100644
index ef9b4763356f..000000000000
--- a/drivers/mfd/cros_ec_i2c.c
+++ /dev/null
@@ -1,386 +0,0 @@
-/*
- * 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");
diff --git a/drivers/mfd/cros_ec_spi.c b/drivers/mfd/cros_ec_spi.c
deleted file mode 100644
index 2060d1483043..000000000000
--- a/drivers/mfd/cros_ec_spi.c
+++ /dev/null
@@ -1,743 +0,0 @@
-/*
- * 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)");