diff options
Diffstat (limited to 'roms/u-boot/drivers/misc/cros_ec_spi.c')
| -rw-r--r-- | roms/u-boot/drivers/misc/cros_ec_spi.c | 175 |
1 files changed, 175 insertions, 0 deletions
diff --git a/roms/u-boot/drivers/misc/cros_ec_spi.c b/roms/u-boot/drivers/misc/cros_ec_spi.c new file mode 100644 index 00000000..7df709cc --- /dev/null +++ b/roms/u-boot/drivers/misc/cros_ec_spi.c @@ -0,0 +1,175 @@ +/* + * Chromium OS cros_ec driver - SPI interface + * + * Copyright (c) 2012 The Chromium OS Authors. + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +/* + * The Matrix Keyboard Protocol driver handles talking to the keyboard + * controller chip. Mostly this is for keyboard functions, but some other + * things have slipped in, so we provide generic services to talk to the + * KBC. + */ + +#include <common.h> +#include <cros_ec.h> +#include <spi.h> + +int cros_ec_spi_packet(struct cros_ec_dev *dev, int out_bytes, int in_bytes) +{ + int rv; + + /* Do the transfer */ + if (spi_claim_bus(dev->spi)) { + debug("%s: Cannot claim SPI bus\n", __func__); + return -1; + } + + rv = spi_xfer(dev->spi, max(out_bytes, in_bytes) * 8, + dev->dout, dev->din, + SPI_XFER_BEGIN | SPI_XFER_END); + + spi_release_bus(dev->spi); + + if (rv) { + debug("%s: Cannot complete SPI transfer\n", __func__); + return -1; + } + + return in_bytes; +} + +/** + * Send a command to a LPC CROS_EC device and return the reply. + * + * The device's internal input/output buffers are used. + * + * @param dev CROS_EC device + * @param cmd Command to send (EC_CMD_...) + * @param cmd_version Version of command to send (EC_VER_...) + * @param dout Output data (may be NULL If dout_len=0) + * @param dout_len Size of output data in bytes + * @param dinp Returns pointer to response data. This will be + * untouched unless we return a value > 0. + * @param din_len Maximum size of response in bytes + * @return number of bytes in response, or -1 on error + */ +int cros_ec_spi_command(struct cros_ec_dev *dev, uint8_t cmd, int cmd_version, + const uint8_t *dout, int dout_len, + uint8_t **dinp, int din_len) +{ + int in_bytes = din_len + 4; /* status, length, checksum, trailer */ + uint8_t *out; + uint8_t *p; + int csum, len; + int rv; + + if (dev->protocol_version != 2) { + debug("%s: Unsupported EC protcol version %d\n", + __func__, dev->protocol_version); + return -1; + } + + /* + * Sanity-check input size to make sure it plus transaction overhead + * fits in the internal device buffer. + */ + if (in_bytes > sizeof(dev->din)) { + debug("%s: Cannot receive %d bytes\n", __func__, din_len); + return -1; + } + + /* We represent message length as a byte */ + if (dout_len > 0xff) { + debug("%s: Cannot send %d bytes\n", __func__, dout_len); + return -1; + } + + /* + * Clear input buffer so we don't get false hits for MSG_HEADER + */ + memset(dev->din, '\0', in_bytes); + + if (spi_claim_bus(dev->spi)) { + debug("%s: Cannot claim SPI bus\n", __func__); + return -1; + } + + out = dev->dout; + out[0] = cmd_version; + out[1] = cmd; + out[2] = (uint8_t)dout_len; + memcpy(out + 3, dout, dout_len); + csum = cros_ec_calc_checksum(out, 3) + + cros_ec_calc_checksum(dout, dout_len); + out[3 + dout_len] = (uint8_t)csum; + + /* + * Send output data and receive input data starting such that the + * message body will be dword aligned. + */ + p = dev->din + sizeof(int64_t) - 2; + len = dout_len + 4; + cros_ec_dump_data("out", cmd, out, len); + rv = spi_xfer(dev->spi, max(len, in_bytes) * 8, out, p, + SPI_XFER_BEGIN | SPI_XFER_END); + + spi_release_bus(dev->spi); + + if (rv) { + debug("%s: Cannot complete SPI transfer\n", __func__); + return -1; + } + + len = min(p[1], din_len); + cros_ec_dump_data("in", -1, p, len + 3); + + /* Response code is first byte of message */ + if (p[0] != EC_RES_SUCCESS) { + printf("%s: Returned status %d\n", __func__, p[0]); + return -(int)(p[0]); + } + + /* Check checksum */ + csum = cros_ec_calc_checksum(p, len + 2); + if (csum != p[len + 2]) { + debug("%s: Invalid checksum rx %#02x, calced %#02x\n", __func__, + p[2 + len], csum); + return -1; + } + + /* Anything else is the response data */ + *dinp = p + 2; + + return len; +} + +int cros_ec_spi_decode_fdt(struct cros_ec_dev *dev, const void *blob) +{ + /* Decode interface-specific FDT params */ + dev->max_frequency = fdtdec_get_int(blob, dev->node, + "spi-max-frequency", 500000); + dev->cs = fdtdec_get_int(blob, dev->node, "reg", 0); + + return 0; +} + +/** + * Initialize SPI protocol. + * + * @param dev CROS_EC device + * @param blob Device tree blob + * @return 0 if ok, -1 on error + */ +int cros_ec_spi_init(struct cros_ec_dev *dev, const void *blob) +{ + dev->spi = spi_setup_slave_fdt(blob, dev->parent_node, dev->node); + if (!dev->spi) { + debug("%s: Could not setup SPI slave\n", __func__); + return -1; + } + + return 0; +} |