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    Subject[PATCH v7 5/8] mfd: cros_ec: add bus-specific proto v3 code
    Date
    From: Stephen Barber <smbarber@chromium.org>

    Add proto v3 support to the SPI, I2C, and LPC.

    Signed-off-by: Stephen Barber <smbarber@chromium.org>
    Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
    Tested-by: Heiko Stuebner <heiko@sntech.de>
    Reviewed-by: Gwendal Grignou <gwendal@chromium.org>
    Tested-by: Gwendal Grignou <gwendal@chromium.org>
    Acked-by: Lee Jones <lee.jones@linaro.org>
    Acked-by: Olof Johansson <olof@lixom.net>
    ---

    Changes since v6:
    - Add Olof Johansson Acked-by tag

    Changes since v5: None

    Changes since v4: None

    Changes since v3:
    - Added acked-by tag from Lee Jones.

    Changes since v2: None

    Changes since v1:
    - Added Gwendal Grignou Reviewed-by and Tested-by tags
    ---
    drivers/mfd/cros_ec_i2c.c | 166 ++++++++++++++-
    drivers/mfd/cros_ec_spi.c | 382 +++++++++++++++++++++++++++++-----
    drivers/platform/chrome/cros_ec_lpc.c | 73 ++++++-
    include/linux/mfd/cros_ec.h | 6 +
    4 files changed, 569 insertions(+), 58 deletions(-)

    diff --git a/drivers/mfd/cros_ec_i2c.c b/drivers/mfd/cros_ec_i2c.c
    index b400bfa2772a..22e8a4ae1711 100644
    --- a/drivers/mfd/cros_ec_i2c.c
    +++ b/drivers/mfd/cros_ec_i2c.c
    @@ -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)
    {
    @@ -121,9 +276,12 @@ static int cros_ec_cmd_xfer_i2c(struct cros_ec_device *ec_dev,
    }

    ret = len;
    - done:
    +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) {
    diff --git a/drivers/mfd/cros_ec_spi.c b/drivers/mfd/cros_ec_spi.c
    index 04da2f288ef8..4e6f2f6b1095 100644
    --- a/drivers/mfd/cros_ec_spi.c
    +++ b/drivers/mfd/cros_ec_spi.c
    @@ -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
    *
    @@ -87,7 +81,7 @@ struct cros_ec_spi {
    };

    static void debug_packet(struct device *dev, const char *name, u8 *ptr,
    - int len)
    + int len)
    {
    #ifdef DEBUG
    int i;
    @@ -100,6 +94,172 @@ 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;
    +}
    +
    +/**
    + * 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
    + * 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_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_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.
    *
    @@ -115,34 +275,27 @@ static void debug_packet(struct device *dev, const char *name, u8 *ptr,
    static int cros_ec_spi_receive_response(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;
    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;
    -
    - 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);
    + 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;
    @@ -187,21 +340,9 @@ 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);

    - memset(&trans, 0, sizeof(trans));
    - 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) {
    - dev_err(ec_dev->dev, "spi transfer failed: %d\n", ret);
    + ret = receive_n_bytes(ec_dev, ptr, todo);
    + if (ret < 0)
    return ret;
    - }

    debug_packet(ec_dev->dev, "interim", ptr, todo);
    ptr += todo;
    @@ -214,6 +355,128 @@ static int cros_ec_spi_receive_response(struct cros_ec_device *ec_dev,
    }

    /**
    + * 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;
    + spi_message_init(&msg);
    + spi_message_add_tail(&trans, &msg);
    + ret = spi_sync(ec_spi->spi, &msg);
    +
    + /* 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);
    + }
    +
    + 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;
    + }
    +
    + 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
    @@ -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) {
    - ret = cros_ec_spi_receive_response(ec_dev,
    - ec_msg->insize + EC_MSG_TX_PROTO_BYTES);
    + /* 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");
    diff --git a/drivers/platform/chrome/cros_ec_lpc.c b/drivers/platform/chrome/cros_ec_lpc.c
    index 06c5790b2c28..92b633324aaa 100644
    --- a/drivers/platform/chrome/cros_ec_lpc.c
    +++ b/drivers/platform/chrome/cros_ec_lpc.c
    @@ -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)
    {
    @@ -205,7 +276,7 @@ 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);
    diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h
    index 59d909434efd..92e13aaa450c 100644
    --- a/include/linux/mfd/cros_ec.h
    +++ b/include/linux/mfd/cros_ec.h
    @@ -22,6 +22,12 @@
    #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.
    * I2C requires 2 additional bytes for responses.
    --
    2.1.4


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