mfd: cros_ec: add bus-specific proto v3 code (d3654070) · Commits · 戴 / test

drivers/mfd/cros_ec_i2c.c

+162 −4

Original line number	Diff line number	Diff line
		@@ -13,6 +13,7 @@
		* GNU General Public License for more details.
		*/

		#include <linux/delay.h>
		#include <linux/kernel.h>
		#include <linux/module.h>
		#include <linux/i2c.h>
		@@ -22,6 +23,32 @@
		#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);
		@@ -29,6 +56,134 @@ static inline struct cros_ec_device to_ec_dev(struct device 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)
		{
		@@ -124,6 +279,9 @@ static int cros_ec_cmd_xfer_i2c(struct cros_ec_device *ec_dev,
		done:
		kfree(in_buf);
		kfree(out_buf);
		if (msg->command == EC_CMD_REBOOT_EC)
		msleep(EC_REBOOT_DELAY_MS);

		return ret;
		}

		@@ -143,12 +301,12 @@ 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->pkt_xfer = cros_ec_pkt_xfer_i2c;
		ec_dev->ec_name = client->name;
		ec_dev->phys_name = client->adapter->name;
		ec_dev->din_size = sizeof(struct ec_host_response) +
		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);
		ec_dev->dout_size = sizeof(struct ec_host_request_i2c);

		err = cros_ec_register(ec_dev);
		if (err) {

drivers/mfd/cros_ec_spi.c

+329 −53

Original line number	Diff line number	Diff line
		@@ -65,12 +65,6 @@
		*/
		#define EC_SPI_RECOVERY_TIME_NS (200 * 1000)

		/*
		* The EC is unresponsive for a time after a reboot command. Add a
		* simple delay to make sure that the bus stays locked.
		*/
		#define EC_REBOOT_DELAY_MS 50

		/**
		* struct cros_ec_spi - information about a SPI-connected EC
		*
		@@ -100,8 +94,65 @@ static void debug_packet(struct device dev, const char name, u8 *ptr,
		#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(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;
		}

		/**
		* cros_ec_spi_receive_response - Receive a response from the EC.
		* 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(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
		@@ -112,37 +163,139 @@ static void debug_packet(struct device dev, const char name, u8 *ptr,
		* @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,
		static int cros_ec_spi_receive_packet(struct cros_ec_device *ec_dev,
		int need_len)
		{
		struct cros_ec_spi *ec_spi = ec_dev->priv;
		struct spi_transfer trans;
		struct spi_message msg;
		struct ec_host_response *response;
		u8 ptr, end;
		int ret;
		unsigned long deadline;
		int todo;

		BUG_ON(EC_MSG_PREAMBLE_COUNT > ec_dev->din_size);

		/* Receive data until we see the header byte */
		deadline = jiffies + msecs_to_jiffies(EC_MSG_DEADLINE_MS);
		while (true) {
		unsigned long start_jiffies = jiffies;

		memset(&trans, 0, sizeof(trans));
		trans.cs_change = 1;
		trans.rx_buf = ptr = ec_dev->din;
		trans.len = EC_MSG_PREAMBLE_COUNT;
		ret = receive_n_bytes(ec_dev,
		ec_dev->din,
		EC_MSG_PREAMBLE_COUNT);
		if (ret < 0)
		return ret;

		spi_message_init(&msg);
		spi_message_add_tail(&trans, &msg);
		ret = spi_sync(ec_spi->spi, &msg);
		if (ret < 0) {
		dev_err(ec_dev->dev, "spi transfer failed: %d\n", 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_MSG_PREAMBLE_COUNT > ec_dev->din_size);

		/* 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_MSG_HEADER) {
		if (*ptr == EC_SPI_FRAME_START) {
		dev_dbg(ec_dev->dev, "msg found at %zd\n",
		ptr - ec_dev->din);
		break;
		@@ -187,30 +340,140 @@ static int cros_ec_spi_receive_response(struct cros_ec_device *ec_dev,
		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_request *request;
		struct ec_host_response *response;
		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 sum;
		int ret = 0, final_ret;

		len = cros_ec_prepare_tx(ec_dev, ec_msg);
		request = (struct ec_host_request *)ec_dev->dout;
		dev_dbg(ec_dev->dev, "prepared, len=%d\n", len);

		/* If it's too soon to do another transaction, wait */
		if (ec_spi->last_transfer_ns) {
		unsigned long delay; /* The delay completed so far */

		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) {
		ret = -ENOMEM;
		goto exit;
		}

		/* 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;
		trans.rx_buf = ptr;
		trans.len = todo;
		spi_message_init(&msg);
		spi_message_add_tail(&trans, &msg);

		/* send command to EC and read answer */
		BUG_ON((u8 *)trans.rx_buf - ec_dev->din + todo >
		ec_dev->din_size);
		ret = spi_sync(ec_spi->spi, &msg);
		if (ret < 0) {

		/* Get the response */
		if (!ret) {
		/* Verify that EC can process command */
		for (i = 0; i < len; i++) {
		switch (rx_buf[i]) {
		case EC_SPI_PAST_END:
		case EC_SPI_RX_BAD_DATA:
		case EC_SPI_NOT_READY:
		ret = -EAGAIN;
		ec_msg->result = EC_RES_IN_PROGRESS;
		default:
		break;
		}
		if (ret)
		break;
		}
		if (!ret)
		ret = cros_ec_spi_receive_packet(ec_dev,
		ec_msg->insize + sizeof(*response));
		} else {
		dev_err(ec_dev->dev, "spi transfer failed: %d\n", ret);
		return ret;
		}

		debug_packet(ec_dev->dev, "interim", ptr, todo);
		ptr += todo;
		need_len -= todo;
		final_ret = terminate_request(ec_dev);
		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;
		}

		dev_dbg(ec_dev->dev, "loop done, ptr=%zd\n", ptr - ec_dev->din);
		for (i = 0; i < sizeof(*response); i++)
		sum += ptr[i];

		return 0;
		/* 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;
		}

		/**
		@@ -227,6 +490,7 @@ static int cros_ec_cmd_xfer_spi(struct cros_ec_device *ec_dev,
		struct spi_message msg;
		int i, len;
		u8 *ptr;
		u8 *rx_buf;
		int sum;
		int ret = 0, final_ret;

		@@ -242,10 +506,17 @@ static int cros_ec_cmd_xfer_spi(struct cros_ec_device *ec_dev,
		ndelay(EC_SPI_RECOVERY_TIME_NS - delay);
		}

		rx_buf = kzalloc(len, GFP_KERNEL);
		if (!rx_buf) {
		ret = -ENOMEM;
		goto exit;
		}

		/* 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);
		@@ -254,29 +525,32 @@ static int cros_ec_cmd_xfer_spi(struct cros_ec_device *ec_dev,

		/* Get the response */
		if (!ret) {
		/* Verify that EC can process command */
		for (i = 0; i < len; i++) {
		switch (rx_buf[i]) {
		case EC_SPI_PAST_END:
		case EC_SPI_RX_BAD_DATA:
		case EC_SPI_NOT_READY:
		ret = -EAGAIN;
		ec_msg->result = EC_RES_IN_PROGRESS;
		default:
		break;
		}
		if (ret)
		break;
		}
		if (!ret)
		ret = cros_ec_spi_receive_response(ec_dev,
		ec_msg->insize + EC_MSG_TX_PROTO_BYTES);
		} else {
		dev_err(ec_dev->dev, "spi transfer failed: %d\n", 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);

		final_ret = spi_sync(ec_spi->spi, &msg);
		ec_spi->last_transfer_ns = ktime_get_ns();
		final_ret = terminate_request(ec_dev);
		if (!ret)
		ret = final_ret;
		if (ret < 0) {
		dev_err(ec_dev->dev, "spi transfer failed: %d\n", ret);
		if (ret < 0)
		goto exit;
		}

		ptr = ec_dev->din;

		@@ -315,6 +589,7 @@ static int cros_ec_cmd_xfer_spi(struct cros_ec_device *ec_dev,

		ret = len;
		exit:
		kfree(rx_buf);
		if (ec_msg->command == EC_CMD_REBOOT_EC)
		msleep(EC_REBOOT_DELAY_MS);

		@@ -361,7 +636,7 @@ 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->pkt_xfer = cros_ec_pkt_xfer_spi;
		ec_dev->ec_name = ec_spi->spi->modalias;
		ec_dev->phys_name = dev_name(&ec_spi->spi->dev);
		ec_dev->din_size = EC_MSG_PREAMBLE_COUNT +
		@@ -369,6 +644,7 @@ static int cros_ec_spi_probe(struct spi_device *spi)
		sizeof(struct ec_response_get_protocol_info);
		ec_dev->dout_size = sizeof(struct ec_host_request);


		err = cros_ec_register(ec_dev);
		if (err) {
		dev_err(dev, "cannot register EC\n");

drivers/platform/chrome/cros_ec_lpc.c

+72 −1

Original line number	Diff line number	Diff line
		@@ -46,6 +46,77 @@ static int ec_response_timed_out(void)
		return 1;
		}

		static int cros_ec_pkt_xfer_lpc(struct cros_ec_device *ec,
		struct cros_ec_command *msg)
		{
		struct ec_host_request *request;
		struct ec_host_response response;
		u8 sum = 0;
		int i;
		int ret = 0;
		u8 *dout;

		ret = cros_ec_prepare_tx(ec, msg);

		/* Write buffer */
		for (i = 0; i < ret; i++)
		outb(ec->dout[i], EC_LPC_ADDR_HOST_PACKET + i);

		request = (struct ec_host_request *)ec->dout;

		/* Here we go */
		outb(EC_COMMAND_PROTOCOL_3, EC_LPC_ADDR_HOST_CMD);

		if (ec_response_timed_out()) {
		dev_warn(ec->dev, "EC responsed timed out\n");
		ret = -EIO;
		goto done;
		}

		/* Check result */
		msg->result = inb(EC_LPC_ADDR_HOST_DATA);
		ret = cros_ec_check_result(ec, msg);
		if (ret)
		goto done;

		/* Read back response */
		dout = (u8 *)&response;
		for (i = 0; i < sizeof(response); i++) {
		dout[i] = inb(EC_LPC_ADDR_HOST_PACKET + i);
		sum += dout[i];
		}

		msg->result = response.result;

		if (response.data_len > msg->insize) {
		dev_err(ec->dev,
		"packet too long (%d bytes, expected %d)",
		response.data_len, msg->insize);
		ret = -EMSGSIZE;
		goto done;
		}

		/* Read response and process checksum */
		for (i = 0; i < response.data_len; i++) {
		msg->data[i] =
		inb(EC_LPC_ADDR_HOST_PACKET + sizeof(response) + i);
		sum += msg->data[i];
		}

		if (sum) {
		dev_err(ec->dev,
		"bad packet checksum %02x\n",
		response.checksum);
		ret = -EBADMSG;
		goto done;
		}

		/* Return actual amount of data received */
		ret = response.data_len;
		done:
		return ret;
		}

		static int cros_ec_cmd_xfer_lpc(struct cros_ec_device *ec,
		struct cros_ec_command *msg)
		{
		@@ -215,7 +286,7 @@ 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->pkt_xfer = cros_ec_pkt_xfer_lpc;
		ec_dev->cmd_readmem = cros_ec_lpc_readmem;
		ec_dev->din_size = sizeof(struct ec_host_response) +
		sizeof(struct ec_response_get_protocol_info);

include/linux/mfd/cros_ec.h

+6 −0

Original line number	Diff line number	Diff line
		@@ -21,6 +21,12 @@
		#include <linux/mfd/cros_ec_commands.h>
		#include <linux/mutex.h>

		/*
		* The EC is unresponsive for a time after a reboot command. Add a
		* simple delay to make sure that the bus stays locked.
		*/
		#define EC_REBOOT_DELAY_MS 50

		/*
		* Max bus-specific overhead incurred by request/responses.
		* I2C requires 1 additional byte for requests.

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