diff options
| -rw-r--r-- | src/ec/google/chromeec/ec_spi.c | 32 |
1 files changed, 21 insertions, 11 deletions
diff --git a/src/ec/google/chromeec/ec_spi.c b/src/ec/google/chromeec/ec_spi.c index e93d038213..a0049c6860 100644 --- a/src/ec/google/chromeec/ec_spi.c +++ b/src/ec/google/chromeec/ec_spi.c @@ -20,6 +20,11 @@ #include <spi-generic.h> #include <timer.h> +/* This is assuming that this driver is not used on x86. If that changes, this + might need to become a CAR_GLOBAL or maybe even more complicated. */ +static struct stopwatch cs_cooldown_sw; +static const long cs_cooldown_us = 200; + static const uint8_t EcFramingByte = 0xec; #define PROTO3_MAX_PACKET_SIZE 268 @@ -44,7 +49,10 @@ void *crosec_get_buffer(size_t size, int req) static int crosec_spi_io(size_t req_size, size_t resp_size, void *context) { struct spi_slave *slave = (struct spi_slave *)context; + int ret = 0; + while (!stopwatch_expired(&cs_cooldown_sw)) + /* Wait minimum delay between CS assertions. */; spi_claim_bus(slave); /* Allow EC to ramp up clock after being awaken. @@ -53,8 +61,8 @@ static int crosec_spi_io(size_t req_size, size_t resp_size, void *context) if (spi_xfer(slave, req_buf, req_size, NULL, 0)) { printk(BIOS_ERR, "%s: Failed to send request.\n", __func__); - spi_release_bus(slave); - return -1; + ret = -1; + goto out; } uint8_t byte; @@ -65,8 +73,8 @@ static int crosec_spi_io(size_t req_size, size_t resp_size, void *context) if (spi_xfer(slave, NULL, 0, &byte, sizeof(byte))) { printk(BIOS_ERR, "%s: Failed to receive byte.\n", __func__); - spi_release_bus(slave); - return -1; + ret = -1; + goto out; } if (byte == EcFramingByte) break; @@ -75,28 +83,30 @@ static int crosec_spi_io(size_t req_size, size_t resp_size, void *context) printk(BIOS_ERR, "%s: Timeout waiting for framing byte.\n", __func__); - spi_release_bus(slave); - return -1; + ret = -1; + goto out; } } if (spi_xfer(slave, NULL, 0, resp_buf, resp_size)) { printk(BIOS_ERR, "%s: Failed to receive response.\n", __func__); - spi_release_bus(slave); - return -1; + ret = -1; } +out: spi_release_bus(slave); - - return 0; + stopwatch_init_usecs_expire(&cs_cooldown_sw, cs_cooldown_us); + return ret; } int google_chromeec_command(struct chromeec_command *cec_command) { static struct spi_slave *slave = NULL; - if (!slave) + if (!slave) { slave = spi_setup_slave(CONFIG_EC_GOOGLE_CHROMEEC_SPI_BUS, CONFIG_EC_GOOGLE_CHROMEEC_SPI_CHIP); + stopwatch_init(&cs_cooldown_sw); + } return crosec_command_proto(cec_command, crosec_spi_io, slave); } |