| /* SPDX-License-Identifier: GPL-2.0-only */ |
| |
| #include <console/console.h> |
| #include <delay.h> |
| #include "ec.h" |
| #include "ec_commands.h" |
| #include <spi-generic.h> |
| #include <timer.h> |
| |
| 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 |
| |
| static uint8_t req_buf[PROTO3_MAX_PACKET_SIZE]; |
| static uint8_t resp_buf[PROTO3_MAX_PACKET_SIZE]; |
| |
| void *crosec_get_buffer(size_t size, int req) |
| { |
| if (size > PROTO3_MAX_PACKET_SIZE) { |
| printk(BIOS_DEBUG, "Proto v3 buffer request too large: %zu!\n", |
| size); |
| return NULL; |
| } |
| |
| if (req) |
| return req_buf; |
| else |
| return resp_buf; |
| } |
| |
| 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; |
| |
| /* Wait minimum delay between CS assertions. */ |
| stopwatch_wait_until_expired(&cs_cooldown_sw); |
| |
| spi_claim_bus(slave); |
| |
| /* Allow EC to ramp up clock after being awaken. |
| * See chrome-os-partner:32223 for more details. */ |
| udelay(CONFIG_EC_GOOGLE_CHROMEEC_SPI_WAKEUP_DELAY_US); |
| |
| if (spi_xfer(slave, req_buf, req_size, NULL, 0)) { |
| printk(BIOS_ERR, "%s: Failed to send request.\n", __func__); |
| ret = -1; |
| goto out; |
| } |
| |
| uint8_t byte; |
| struct stopwatch sw; |
| // Wait 1s for a framing byte. |
| stopwatch_init_usecs_expire(&sw, USECS_PER_SEC); |
| while (1) { |
| if (spi_xfer(slave, NULL, 0, &byte, sizeof(byte))) { |
| printk(BIOS_ERR, "%s: Failed to receive byte.\n", |
| __func__); |
| ret = -1; |
| goto out; |
| } |
| if (byte == EcFramingByte) |
| break; |
| |
| if (stopwatch_expired(&sw)) { |
| printk(BIOS_ERR, |
| "%s: Timeout waiting for framing byte.\n", |
| __func__); |
| ret = -1; |
| goto out; |
| } |
| } |
| |
| if (spi_xfer(slave, NULL, 0, resp_buf, resp_size)) { |
| printk(BIOS_ERR, "%s: Failed to receive response.\n", __func__); |
| ret = -1; |
| } |
| |
| out: |
| spi_release_bus(slave); |
| stopwatch_init_usecs_expire(&cs_cooldown_sw, cs_cooldown_us); |
| return ret; |
| } |
| |
| int google_chromeec_command(struct chromeec_command *cec_command) |
| { |
| static int done = 0; |
| static struct spi_slave slave; |
| |
| if (!done) { |
| if (spi_setup_slave(CONFIG_EC_GOOGLE_CHROMEEC_SPI_BUS, |
| CONFIG_EC_GOOGLE_CHROMEEC_SPI_CHIP, &slave)) |
| return -1; |
| stopwatch_init(&cs_cooldown_sw); |
| done = 1; |
| } |
| return crosec_command_proto(cec_command, crosec_spi_io, &slave); |
| } |
| |
| enum host_event_code google_chromeec_get_event(void) |
| { |
| printk(BIOS_ERR, "%s: Not supported.\n", __func__); |
| return EC_HOST_EVENT_NONE; |
| } |