diff options
author | Chun-Ta Lin <itspeter@google.com> | 2017-05-18 14:44:55 +0800 |
---|---|---|
committer | chrome-bot <chrome-bot@chromium.org> | 2017-06-05 07:55:32 -0700 |
commit | d5c08763e12cff3207696ec53232cf6eb3303096 (patch) | |
tree | cfa7abd458a477260d2621066bd5af9fed24d2b4 /common/usb_i2c.c | |
parent | ce65199e5ed75bf8ab4cc3a4f9abae85f63f1a02 (diff) | |
download | chrome-ec-d5c08763e12cff3207696ec53232cf6eb3303096.tar.gz |
usb_i2c: extend the protocol to support larger payload
The default USB packet has a maximum size of 64 bytes, however, we need
to support some USB over I2C write transaction that exceed this default.
To support so with protocol backwards-compatible in mind, we enable a
config option CONFIG_USB_I2C_MAX_WRITE_COUNT that will enlarge the USB
RX queue.
BRANCH=none
BUG=b:35587174
TEST=Complete presubmit test.
TEST=Manually update elan trackpad firmware with interrupt disabled.
Change-Id: Ia8983b036b7297f7ca673459ae34b7e5ecd2ee01
Reviewed-on: https://chromium-review.googlesource.com/513642
Commit-Ready: Chun-ta Lin <itspeter@chromium.org>
Tested-by: Chun-ta Lin <itspeter@chromium.org>
Reviewed-by: Chun-ta Lin <itspeter@chromium.org>
Reviewed-by: Nicolas Boichat <drinkcat@chromium.org>
Diffstat (limited to 'common/usb_i2c.c')
-rw-r--r-- | common/usb_i2c.c | 38 |
1 files changed, 32 insertions, 6 deletions
diff --git a/common/usb_i2c.c b/common/usb_i2c.c index 4c8350e910..64d7135a89 100644 --- a/common/usb_i2c.c +++ b/common/usb_i2c.c @@ -50,12 +50,32 @@ static void usb_i2c_write_packet(struct usb_i2c_config const *config, QUEUE_ADD_UNITS(config->tx_queue, config->buffer, count); } -void usb_i2c_deferred(struct usb_i2c_config const *config) +static uint8_t usb_i2c_executable(struct usb_i2c_config const *config) { /* - * And if there is a USB packet waiting we process it and generate a - * response. + * In order to support larger write payload, we need to peek + * the queue to see if we need to wait for more data. */ + + uint8_t write_count; + + if (queue_peek_units(config->consumer.queue, &write_count, 2, 1) == 1 + && (write_count + 4) > queue_count(config->consumer.queue)) { + /* + * Feed me more data, please. + * Reuse the buffer in usb_i2c_config to send ACK packet. + */ + config->buffer[0] = USB_I2C_SUCCESS; + config->buffer[1] = 0; + usb_i2c_write_packet(config, 4); + return 0; + } + return 1; +} + +void usb_i2c_execute(struct usb_i2c_config const *config) +{ + /* Payload is ready to execute. */ uint8_t count = usb_i2c_read_packet(config); int portindex = (config->buffer[0] >> 0) & 0xff; /* Convert 7-bit slave address to chromium EC 8-bit address. */ @@ -70,8 +90,8 @@ void usb_i2c_deferred(struct usb_i2c_config const *config) if (!count || (!read_count && !write_count)) return; - if (write_count > USB_I2C_MAX_WRITE_COUNT || - write_count != (count - 4)) { + if (write_count > CONFIG_USB_I2C_MAX_WRITE_COUNT || + write_count != (count - 4)) { config->buffer[0] = USB_I2C_WRITE_COUNT_INVALID; } else if (read_count > USB_I2C_MAX_READ_COUNT) { config->buffer[0] = USB_I2C_READ_COUNT_INVALID; @@ -86,10 +106,16 @@ void usb_i2c_deferred(struct usb_i2c_config const *config) (uint8_t *)(config->buffer + 2), read_count, I2C_XFER_SINGLE)); } - usb_i2c_write_packet(config, read_count + 4); } +void usb_i2c_deferred(struct usb_i2c_config const *config) +{ + /* Check if we can proceed the queue. */ + if (usb_i2c_executable(config)) + usb_i2c_execute(config); +} + static void usb_i2c_written(struct consumer const *consumer, size_t count) { struct usb_i2c_config const *config = |