mfd: cros_ec: Move protocol helpers out of the MFD driver

The MFD driver should only have the logic to instantiate its child devices
and setup any shared resources that will be used by the subdevices drivers.

The cros_ec MFD is more complex than expected since it also has helpers to
communicate with the EC. So the driver will only get more bigger as other
protocols are supported in the future. So move the communication protocol
helpers to its own driver as drivers/platform/chrome/cros_ec_proto.c.

Suggested-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

2 files changed, 4 insertions, 98 deletions

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index d5ad04d..cf3b86d 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -94,6 +94,8 @@ config MFD_AXP20X
 config MFD_CROS_EC
 	tristate "ChromeOS Embedded Controller"
 	select MFD_CORE
+	select CHROME_PLATFORMS
+	select CROS_EC_PROTO
 	help
 	  If you say Y here you get support for the ChromeOS Embedded
 	  Controller (EC) providing keyboard, battery and power services.
@@ -102,7 +104,7 @@ config MFD_CROS_EC
 
 config MFD_CROS_EC_I2C
 	tristate "ChromeOS Embedded Controller (I2C)"
-	depends on MFD_CROS_EC && I2C
+	depends on MFD_CROS_EC && CROS_EC_PROTO && I2C
 
 	help
 	  If you say Y here, you get support for talking to the ChromeOS
@@ -112,7 +114,7 @@ config MFD_CROS_EC_I2C
 
 config MFD_CROS_EC_SPI
 	tristate "ChromeOS Embedded Controller (SPI)"
-	depends on MFD_CROS_EC && SPI && OF
+	depends on MFD_CROS_EC && CROS_EC_PROTO && SPI && OF
 
 	---help---
 	  If you say Y here, you get support for talking to the ChromeOS EC
diff --git a/drivers/mfd/cros_ec.c b/drivers/mfd/cros_ec.c
index 4a0f6df..d857f6a 100644
--- a/drivers/mfd/cros_ec.c
+++ b/drivers/mfd/cros_ec.c
@@ -23,102 +23,6 @@
 #include <linux/module.h>
 #include <linux/mfd/core.h>
 #include <linux/mfd/cros_ec.h>
-#include <linux/mfd/cros_ec_commands.h>
-#include <linux/delay.h>
-
-#define EC_COMMAND_RETRIES	50
-
-int cros_ec_prepare_tx(struct cros_ec_device *ec_dev,
-		       struct cros_ec_command *msg)
-{
-	uint8_t *out;
-	int csum, i;
-
-	BUG_ON(msg->outsize > EC_PROTO2_MAX_PARAM_SIZE);
-	out = ec_dev->dout;
-	out[0] = EC_CMD_VERSION0 + msg->version;
-	out[1] = msg->command;
-	out[2] = msg->outsize;
-	csum = out[0] + out[1] + out[2];
-	for (i = 0; i < msg->outsize; i++)
-		csum += out[EC_MSG_TX_HEADER_BYTES + i] = msg->data[i];
-	out[EC_MSG_TX_HEADER_BYTES + msg->outsize] = (uint8_t)(csum & 0xff);
-
-	return EC_MSG_TX_PROTO_BYTES + msg->outsize;
-}
-EXPORT_SYMBOL(cros_ec_prepare_tx);
-
-int cros_ec_check_result(struct cros_ec_device *ec_dev,
-			 struct cros_ec_command *msg)
-{
-	switch (msg->result) {
-	case EC_RES_SUCCESS:
-		return 0;
-	case EC_RES_IN_PROGRESS:
-		dev_dbg(ec_dev->dev, "command 0x%02x in progress\n",
-			msg->command);
-		return -EAGAIN;
-	default:
-		dev_dbg(ec_dev->dev, "command 0x%02x returned %d\n",
-			msg->command, msg->result);
-		return 0;
-	}
-}
-EXPORT_SYMBOL(cros_ec_check_result);
-
-int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev,
-		     struct cros_ec_command *msg)
-{
-	int ret;
-
-	mutex_lock(&ec_dev->lock);
-	ret = ec_dev->cmd_xfer(ec_dev, msg);
-	if (msg->result == EC_RES_IN_PROGRESS) {
-		int i;
-		struct cros_ec_command *status_msg;
-		struct ec_response_get_comms_status *status;
-
-		status_msg = kmalloc(sizeof(*status_msg) + sizeof(*status),
-				     GFP_KERNEL);
-		if (!status_msg) {
-			ret = -ENOMEM;
-			goto exit;
-		}
-
-		status_msg->version = 0;
-		status_msg->command = EC_CMD_GET_COMMS_STATUS;
-		status_msg->insize = sizeof(*status);
-		status_msg->outsize = 0;
-
-		/*
-		 * Query the EC's status until it's no longer busy or
-		 * we encounter an error.
-		 */
-		for (i = 0; i < EC_COMMAND_RETRIES; i++) {
-			usleep_range(10000, 11000);
-
-			ret = ec_dev->cmd_xfer(ec_dev, status_msg);
-			if (ret < 0)
-				break;
-
-			msg->result = status_msg->result;
-			if (status_msg->result != EC_RES_SUCCESS)
-				break;
-
-			status = (struct ec_response_get_comms_status *)
-				 status_msg->data;
-			if (!(status->flags & EC_COMMS_STATUS_PROCESSING))
-				break;
-		}
-
-		kfree(status_msg);
-	}
-exit:
-	mutex_unlock(&ec_dev->lock);
-
-	return ret;
-}
-EXPORT_SYMBOL(cros_ec_cmd_xfer);
 
 static const struct mfd_cell cros_devs[] = {
 	{