Commit 2c7589af authored by Stephen Barber's avatar Stephen Barber Committed by Lee Jones

mfd: cros_ec: add proto v3 skeleton

Add support in cros_ec.c to handle EC host command protocol v3.
For v3+, probe for maximum shared protocol version and max
request, response, and passthrough sizes. For now, this will
always fall back to v2, since there is no bus-specific code
for handling proto v3 packets.
Signed-off-by: default avatarStephen Barber <smbarber@chromium.org>
Signed-off-by: default avatarJavier Martinez Canillas <javier.martinez@collabora.co.uk>
Reviewed-by: default avatarGwendal Grignou <gwendal@chromium.org>
Tested-by: default avatarGwendal Grignou <gwendal@chromium.org>
Tested-by: default avatarHeiko Stuebner <heiko@sntech.de>
Acked-by: default avatarLee Jones <lee.jones@linaro.org>
Acked-by: default avatarOlof Johansson <olof@lixom.net>
Signed-off-by: default avatarLee Jones <lee.jones@linaro.org>
parent 062476f2
......@@ -36,19 +36,22 @@ int cros_ec_register(struct cros_ec_device *ec_dev)
struct device *dev = ec_dev->dev;
int err = 0;
if (ec_dev->din_size) {
ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL);
if (!ec_dev->din)
return -ENOMEM;
}
if (ec_dev->dout_size) {
ec_dev->dout = devm_kzalloc(dev, ec_dev->dout_size, GFP_KERNEL);
if (!ec_dev->dout)
return -ENOMEM;
}
ec_dev->max_request = sizeof(struct ec_params_hello);
ec_dev->max_response = sizeof(struct ec_response_get_protocol_info);
ec_dev->max_passthru = 0;
ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL);
if (!ec_dev->din)
return -ENOMEM;
ec_dev->dout = devm_kzalloc(dev, ec_dev->dout_size, GFP_KERNEL);
if (!ec_dev->dout)
return -ENOMEM;
mutex_init(&ec_dev->lock);
cros_ec_query_all(ec_dev);
err = mfd_add_devices(dev, 0, cros_devs,
ARRAY_SIZE(cros_devs),
NULL, ec_dev->irq, NULL);
......
......@@ -143,8 +143,12 @@ static int cros_ec_i2c_probe(struct i2c_client *client,
ec_dev->priv = client;
ec_dev->irq = client->irq;
ec_dev->cmd_xfer = cros_ec_cmd_xfer_i2c;
ec_dev->pkt_xfer = NULL;
ec_dev->ec_name = client->name;
ec_dev->phys_name = client->adapter->name;
ec_dev->din_size = sizeof(struct ec_host_response) +
sizeof(struct ec_response_get_protocol_info);
ec_dev->dout_size = sizeof(struct ec_host_request);
err = cros_ec_register(ec_dev);
if (err) {
......
......@@ -361,10 +361,13 @@ static int cros_ec_spi_probe(struct spi_device *spi)
ec_dev->priv = ec_spi;
ec_dev->irq = spi->irq;
ec_dev->cmd_xfer = cros_ec_cmd_xfer_spi;
ec_dev->pkt_xfer = NULL;
ec_dev->ec_name = ec_spi->spi->modalias;
ec_dev->phys_name = dev_name(&ec_spi->spi->dev);
ec_dev->din_size = EC_MSG_BYTES + EC_MSG_PREAMBLE_COUNT;
ec_dev->dout_size = EC_MSG_BYTES;
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);
err = cros_ec_register(ec_dev);
if (err) {
......
......@@ -215,7 +215,11 @@ static int cros_ec_lpc_probe(struct platform_device *pdev)
ec_dev->ec_name = pdev->name;
ec_dev->phys_name = dev_name(dev);
ec_dev->cmd_xfer = cros_ec_cmd_xfer_lpc;
ec_dev->pkt_xfer = NULL;
ec_dev->cmd_readmem = cros_ec_lpc_readmem;
ec_dev->din_size = sizeof(struct ec_host_response) +
sizeof(struct ec_response_get_protocol_info);
ec_dev->dout_size = sizeof(struct ec_host_request);
ret = cros_ec_register(ec_dev);
if (ret) {
......
......@@ -22,11 +22,100 @@
#define EC_COMMAND_RETRIES 50
static int prepare_packet(struct cros_ec_device *ec_dev,
struct cros_ec_command *msg)
{
struct ec_host_request *request;
u8 *out;
int i;
u8 csum = 0;
BUG_ON(ec_dev->proto_version != EC_HOST_REQUEST_VERSION);
BUG_ON(msg->outsize + sizeof(*request) > ec_dev->dout_size);
out = ec_dev->dout;
request = (struct ec_host_request *)out;
request->struct_version = EC_HOST_REQUEST_VERSION;
request->checksum = 0;
request->command = msg->command;
request->command_version = msg->version;
request->reserved = 0;
request->data_len = msg->outsize;
for (i = 0; i < sizeof(*request); i++)
csum += out[i];
/* Copy data and update checksum */
memcpy(out + sizeof(*request), msg->data, msg->outsize);
for (i = 0; i < msg->outsize; i++)
csum += msg->data[i];
request->checksum = -csum;
return sizeof(*request) + msg->outsize;
}
static int send_command(struct cros_ec_device *ec_dev,
struct cros_ec_command *msg)
{
int ret;
if (ec_dev->proto_version > 2)
ret = ec_dev->pkt_xfer(ec_dev, msg);
else
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)
return -ENOMEM;
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);
}
return ret;
}
int cros_ec_prepare_tx(struct cros_ec_device *ec_dev,
struct cros_ec_command *msg)
{
uint8_t *out;
int csum, i;
u8 *out;
u8 csum;
int i;
if (ec_dev->proto_version > 2)
return prepare_packet(ec_dev, msg);
BUG_ON(msg->outsize > EC_PROTO2_MAX_PARAM_SIZE);
out = ec_dev->dout;
......@@ -36,7 +125,7 @@ int cros_ec_prepare_tx(struct cros_ec_device *ec_dev,
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);
out[EC_MSG_TX_HEADER_BYTES + msg->outsize] = csum;
return EC_MSG_TX_PROTO_BYTES + msg->outsize;
}
......@@ -60,54 +149,232 @@ int cros_ec_check_result(struct cros_ec_device *ec_dev,
}
EXPORT_SYMBOL(cros_ec_check_result);
int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev,
struct cros_ec_command *msg)
static int cros_ec_host_command_proto_query(struct cros_ec_device *ec_dev,
int devidx,
struct cros_ec_command *msg)
{
/*
* Try using v3+ to query for supported protocols. If this
* command fails, fall back to v2. Returns the highest protocol
* supported by the EC.
* Also sets the max request/response/passthru size.
*/
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;
if (!ec_dev->pkt_xfer)
return -EPROTONOSUPPORT;
status_msg = kmalloc(sizeof(*status_msg) + sizeof(*status),
GFP_KERNEL);
if (!status_msg) {
ret = -ENOMEM;
goto exit;
}
memset(msg, 0, sizeof(*msg));
msg->command = EC_CMD_PASSTHRU_OFFSET(devidx) | EC_CMD_GET_PROTOCOL_INFO;
msg->insize = sizeof(struct ec_response_get_protocol_info);
status_msg->version = 0;
status_msg->command = EC_CMD_GET_COMMS_STATUS;
status_msg->insize = sizeof(*status);
status_msg->outsize = 0;
ret = send_command(ec_dev, msg);
if (ret < 0) {
dev_dbg(ec_dev->dev,
"failed to check for EC[%d] protocol version: %d\n",
devidx, ret);
return ret;
}
if (devidx > 0 && msg->result == EC_RES_INVALID_COMMAND)
return -ENODEV;
else if (msg->result != EC_RES_SUCCESS)
return msg->result;
return 0;
}
static int cros_ec_host_command_proto_query_v2(struct cros_ec_device *ec_dev)
{
struct cros_ec_command *msg;
struct ec_params_hello *hello_params;
struct ec_response_hello *hello_response;
int ret;
int len = max(sizeof(*hello_params), sizeof(*hello_response));
msg = kmalloc(sizeof(*msg) + len, GFP_KERNEL);
if (!msg)
return -ENOMEM;
msg->version = 0;
msg->command = EC_CMD_HELLO;
hello_params = (struct ec_params_hello *)msg->data;
msg->outsize = sizeof(*hello_params);
hello_response = (struct ec_response_hello *)msg->data;
msg->insize = sizeof(*hello_response);
hello_params->in_data = 0xa0b0c0d0;
ret = send_command(ec_dev, msg);
if (ret < 0) {
dev_dbg(ec_dev->dev,
"EC failed to respond to v2 hello: %d\n",
ret);
goto exit;
} else if (msg->result != EC_RES_SUCCESS) {
dev_err(ec_dev->dev,
"EC responded to v2 hello with error: %d\n",
msg->result);
ret = msg->result;
goto exit;
} else if (hello_response->out_data != 0xa1b2c3d4) {
dev_err(ec_dev->dev,
"EC responded to v2 hello with bad result: %u\n",
hello_response->out_data);
ret = -EBADMSG;
goto exit;
}
ret = 0;
exit:
kfree(msg);
return ret;
}
int cros_ec_query_all(struct cros_ec_device *ec_dev)
{
struct device *dev = ec_dev->dev;
struct cros_ec_command *proto_msg;
struct ec_response_get_protocol_info *proto_info;
int ret;
proto_msg = kzalloc(sizeof(*proto_msg) + sizeof(*proto_info),
GFP_KERNEL);
if (!proto_msg)
return -ENOMEM;
/* First try sending with proto v3. */
ec_dev->proto_version = 3;
ret = cros_ec_host_command_proto_query(ec_dev, 0, proto_msg);
if (ret == 0) {
proto_info = (struct ec_response_get_protocol_info *)
proto_msg->data;
ec_dev->max_request = proto_info->max_request_packet_size -
sizeof(struct ec_host_request);
ec_dev->max_response = proto_info->max_response_packet_size -
sizeof(struct ec_host_response);
ec_dev->proto_version =
min(EC_HOST_REQUEST_VERSION,
fls(proto_info->protocol_versions) - 1);
dev_dbg(ec_dev->dev,
"using proto v%u\n",
ec_dev->proto_version);
ec_dev->din_size = ec_dev->max_response +
sizeof(struct ec_host_response) +
EC_MAX_RESPONSE_OVERHEAD;
ec_dev->dout_size = ec_dev->max_request +
sizeof(struct ec_host_request) +
EC_MAX_REQUEST_OVERHEAD;
/*
* Query the EC's status until it's no longer busy or
* we encounter an error.
* Check for PD
*/
for (i = 0; i < EC_COMMAND_RETRIES; i++) {
usleep_range(10000, 11000);
ret = cros_ec_host_command_proto_query(ec_dev, 1, proto_msg);
ret = ec_dev->cmd_xfer(ec_dev, status_msg);
if (ret < 0)
break;
if (ret) {
dev_dbg(ec_dev->dev, "no PD chip found: %d\n", ret);
ec_dev->max_passthru = 0;
} else {
dev_dbg(ec_dev->dev, "found PD chip\n");
ec_dev->max_passthru =
proto_info->max_request_packet_size -
sizeof(struct ec_host_request);
}
} else {
/* Try querying with a v2 hello message. */
ec_dev->proto_version = 2;
ret = cros_ec_host_command_proto_query_v2(ec_dev);
msg->result = status_msg->result;
if (status_msg->result != EC_RES_SUCCESS)
break;
if (ret == 0) {
/* V2 hello succeeded. */
dev_dbg(ec_dev->dev, "falling back to proto v2\n");
status = (struct ec_response_get_comms_status *)
status_msg->data;
if (!(status->flags & EC_COMMS_STATUS_PROCESSING))
break;
ec_dev->max_request = EC_PROTO2_MAX_PARAM_SIZE;
ec_dev->max_response = EC_PROTO2_MAX_PARAM_SIZE;
ec_dev->max_passthru = 0;
ec_dev->pkt_xfer = NULL;
ec_dev->din_size = EC_MSG_BYTES;
ec_dev->dout_size = EC_MSG_BYTES;
} else {
/*
* It's possible for a test to occur too early when
* the EC isn't listening. If this happens, we'll
* test later when the first command is run.
*/
ec_dev->proto_version = EC_PROTO_VERSION_UNKNOWN;
dev_dbg(ec_dev->dev, "EC query failed: %d\n", ret);
goto exit;
}
}
kfree(status_msg);
devm_kfree(dev, ec_dev->din);
devm_kfree(dev, ec_dev->dout);
ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL);
if (!ec_dev->din) {
ret = -ENOMEM;
goto exit;
}
ec_dev->dout = devm_kzalloc(dev, ec_dev->dout_size, GFP_KERNEL);
if (!ec_dev->dout) {
devm_kfree(dev, ec_dev->din);
ret = -ENOMEM;
goto exit;
}
exit:
kfree(proto_msg);
return ret;
}
EXPORT_SYMBOL(cros_ec_query_all);
int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev,
struct cros_ec_command *msg)
{
int ret;
mutex_lock(&ec_dev->lock);
if (ec_dev->proto_version == EC_PROTO_VERSION_UNKNOWN) {
ret = cros_ec_query_all(ec_dev);
if (ret) {
dev_err(ec_dev->dev,
"EC version unknown and query failed; aborting command\n");
mutex_unlock(&ec_dev->lock);
return ret;
}
}
if (msg->insize > ec_dev->max_response) {
dev_dbg(ec_dev->dev, "clamping message receive buffer\n");
msg->insize = ec_dev->max_response;
}
if (msg->command < EC_CMD_PASSTHRU_OFFSET(1)) {
if (msg->outsize > ec_dev->max_request) {
dev_err(ec_dev->dev,
"request of size %u is too big (max: %u)\n",
msg->outsize,
ec_dev->max_request);
mutex_unlock(&ec_dev->lock);
return -EMSGSIZE;
}
} else {
if (msg->outsize > ec_dev->max_passthru) {
dev_err(ec_dev->dev,
"passthru rq of size %u is too big (max: %u)\n",
msg->outsize,
ec_dev->max_passthru);
mutex_unlock(&ec_dev->lock);
return -EMSGSIZE;
}
}
ret = send_command(ec_dev, msg);
mutex_unlock(&ec_dev->lock);
return ret;
......
......@@ -21,6 +21,15 @@
#include <linux/mfd/cros_ec_commands.h>
#include <linux/mutex.h>
/*
* Max bus-specific overhead incurred by request/responses.
* I2C requires 1 additional byte for requests.
* I2C requires 2 additional bytes for responses.
* */
#define EC_PROTO_VERSION_UNKNOWN 0
#define EC_MAX_REQUEST_OVERHEAD 1
#define EC_MAX_RESPONSE_OVERHEAD 2
/*
* Command interface between EC and AP, for LPC, I2C and SPI interfaces.
*/
......@@ -88,6 +97,7 @@ struct cros_ec_command {
* Returns the number of bytes received if the communication succeeded, but
* that doesn't mean the EC was happy with the command. The caller
* should check msg.result for the EC's result code.
* @pkt_xfer: send packet to EC and get response
* @lock: one transaction at a time
*/
struct cros_ec_device {
......@@ -104,15 +114,21 @@ struct cros_ec_device {
unsigned int bytes, void *dest);
/* These are used to implement the platform-specific interface */
u16 max_request;
u16 max_response;
u16 max_passthru;
u16 proto_version;
void *priv;
int irq;
uint8_t *din;
uint8_t *dout;
u8 *din;
u8 *dout;
int din_size;
int dout_size;
bool wake_enabled;
int (*cmd_xfer)(struct cros_ec_device *ec,
struct cros_ec_command *msg);
int (*pkt_xfer)(struct cros_ec_device *ec,
struct cros_ec_command *msg);
struct mutex lock;
};
......@@ -194,4 +210,12 @@ int cros_ec_remove(struct cros_ec_device *ec_dev);
*/
int cros_ec_register(struct cros_ec_device *ec_dev);
/**
* cros_ec_register - Query the protocol version supported by the ChromeOS EC
*
* @ec_dev: Device to register
* @return 0 if ok, -ve on error
*/
int cros_ec_query_all(struct cros_ec_device *ec_dev);
#endif /* __LINUX_MFD_CROS_EC_H */
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