This patch adds SPI support for carrying out the cros_ec protocol. Signed-off-by: Hung-ying Tyan <tyanh@chromium.org> Signed-off-by: Randall Spangler <rspangler@chromium.org> Signed-off-by: Simon Glass <sjg@chromium.org> Acked-by: Simon Glass <sjg@chromium.org>master
Hung-ying Tyan
12 years ago
committed by
Tom Rini
parent
78764a4e11
commit
f3424c554c
@ -0,0 +1,161 @@ |
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/*
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* Chromium OS cros_ec driver - SPI interface |
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* |
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* Copyright (c) 2012 The Chromium OS Authors. |
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* See file CREDITS for list of people who contributed to this |
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* project. |
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* |
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* This program is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU General Public License as |
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* published by the Free Software Foundation; either version 2 of |
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* the License, or (at your option) any later version. |
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* |
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* This program is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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* GNU General Public License for more details. |
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* |
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* You should have received a copy of the GNU General Public License |
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* along with this program; if not, write to the Free Software |
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, |
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* MA 02111-1307 USA |
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*/ |
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/*
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* The Matrix Keyboard Protocol driver handles talking to the keyboard |
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* controller chip. Mostly this is for keyboard functions, but some other |
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* things have slipped in, so we provide generic services to talk to the |
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* KBC. |
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*/ |
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#include <common.h> |
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#include <cros_ec.h> |
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#include <spi.h> |
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/**
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* Send a command to a LPC CROS_EC device and return the reply. |
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* |
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* The device's internal input/output buffers are used. |
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* |
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* @param dev CROS_EC device |
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* @param cmd Command to send (EC_CMD_...) |
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* @param cmd_version Version of command to send (EC_VER_...) |
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* @param dout Output data (may be NULL If dout_len=0) |
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* @param dout_len Size of output data in bytes |
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* @param dinp Returns pointer to response data. This will be |
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* untouched unless we return a value > 0. |
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* @param din_len Maximum size of response in bytes |
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* @return number of bytes in response, or -1 on error |
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*/ |
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int cros_ec_spi_command(struct cros_ec_dev *dev, uint8_t cmd, int cmd_version, |
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const uint8_t *dout, int dout_len, |
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uint8_t **dinp, int din_len) |
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{ |
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int in_bytes = din_len + 4; /* status, length, checksum, trailer */ |
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uint8_t *out; |
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uint8_t *p; |
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int csum, len; |
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int rv; |
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/*
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* Sanity-check input size to make sure it plus transaction overhead |
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* fits in the internal device buffer. |
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*/ |
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if (in_bytes > sizeof(dev->din)) { |
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debug("%s: Cannot receive %d bytes\n", __func__, din_len); |
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return -1; |
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} |
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/* We represent message length as a byte */ |
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if (dout_len > 0xff) { |
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debug("%s: Cannot send %d bytes\n", __func__, dout_len); |
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return -1; |
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} |
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/*
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* Clear input buffer so we don't get false hits for MSG_HEADER |
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*/ |
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memset(dev->din, '\0', in_bytes); |
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if (spi_claim_bus(dev->spi)) { |
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debug("%s: Cannot claim SPI bus\n", __func__); |
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return -1; |
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} |
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out = dev->dout; |
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out[0] = cmd_version; |
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out[1] = cmd; |
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out[2] = (uint8_t)dout_len; |
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memcpy(out + 3, dout, dout_len); |
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csum = cros_ec_calc_checksum(out, 3) |
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+ cros_ec_calc_checksum(dout, dout_len); |
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out[3 + dout_len] = (uint8_t)csum; |
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/*
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* Send output data and receive input data starting such that the |
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* message body will be dword aligned. |
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*/ |
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p = dev->din + sizeof(int64_t) - 2; |
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len = dout_len + 4; |
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cros_ec_dump_data("out", cmd, out, len); |
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rv = spi_xfer(dev->spi, max(len, in_bytes) * 8, out, p, |
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SPI_XFER_BEGIN | SPI_XFER_END); |
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spi_release_bus(dev->spi); |
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if (rv) { |
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debug("%s: Cannot complete SPI transfer\n", __func__); |
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return -1; |
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} |
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len = min(p[1], din_len); |
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cros_ec_dump_data("in", -1, p, len + 3); |
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/* Response code is first byte of message */ |
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if (p[0] != EC_RES_SUCCESS) { |
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printf("%s: Returned status %d\n", __func__, p[0]); |
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return -(int)(p[0]); |
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} |
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/* Check checksum */ |
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csum = cros_ec_calc_checksum(p, len + 2); |
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if (csum != p[len + 2]) { |
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debug("%s: Invalid checksum rx %#02x, calced %#02x\n", __func__, |
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p[2 + len], csum); |
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return -1; |
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} |
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/* Anything else is the response data */ |
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*dinp = p + 2; |
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return len; |
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} |
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int cros_ec_spi_decode_fdt(struct cros_ec_dev *dev, const void *blob) |
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{ |
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/* Decode interface-specific FDT params */ |
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dev->max_frequency = fdtdec_get_int(blob, dev->node, |
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"spi-max-frequency", 500000); |
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dev->cs = fdtdec_get_int(blob, dev->node, "reg", 0); |
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return 0; |
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} |
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/**
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* Initialize SPI protocol. |
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* |
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* @param dev CROS_EC device |
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* @param blob Device tree blob |
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* @return 0 if ok, -1 on error |
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*/ |
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int cros_ec_spi_init(struct cros_ec_dev *dev, const void *blob) |
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{ |
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dev->spi = spi_setup_slave_fdt(blob, dev->parent_node, |
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dev->cs, dev->max_frequency, 0); |
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if (!dev->spi) { |
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debug("%s: Could not setup SPI slave\n", __func__); |
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return -1; |
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} |
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return 0; |
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} |
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