This patch adds LPC support for carrying out the cros_ec protocol. Signed-off-by: Randall Spangler <rspangler@chromium.org> Signed-off-by: Simon Glass <sjg@chromium.org> Signed-off-by: Hung-ying Tyan <tyanh@chromium.org> Acked-by: Simon Glass <sjg@chromium.org> Tested-by: Simon Glass <sjg@chromium.org>master
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/*
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* Chromium OS cros_ec driver - LPC 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 <command.h> |
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#include <cros_ec.h> |
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#include <asm/io.h> |
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#ifdef DEBUG_TRACE |
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#define debug_trace(fmt, b...) debug(fmt, ##b) |
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#else |
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#define debug_trace(fmt, b...) |
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#endif |
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static int wait_for_sync(struct cros_ec_dev *dev) |
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{ |
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unsigned long start; |
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start = get_timer(0); |
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while (inb(EC_LPC_ADDR_HOST_CMD) & EC_LPC_STATUS_BUSY_MASK) { |
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if (get_timer(start) > 1000) { |
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debug("%s: Timeout waiting for CROS_EC sync\n", |
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__func__); |
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return -1; |
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} |
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} |
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return 0; |
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} |
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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 Place to put pointer to response data |
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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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static int old_lpc_command(struct cros_ec_dev *dev, uint8_t cmd, |
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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 ret, i; |
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if (dout_len > EC_OLD_PARAM_SIZE) { |
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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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if (din_len > EC_OLD_PARAM_SIZE) { |
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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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if (wait_for_sync(dev)) { |
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debug("%s: Timeout waiting ready\n", __func__); |
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return -1; |
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} |
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debug_trace("cmd: %02x, ", cmd); |
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for (i = 0; i < dout_len; i++) { |
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debug_trace("%02x ", dout[i]); |
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outb(dout[i], EC_LPC_ADDR_OLD_PARAM + i); |
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} |
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outb(cmd, EC_LPC_ADDR_HOST_CMD); |
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debug_trace("\n"); |
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if (wait_for_sync(dev)) { |
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debug("%s: Timeout waiting ready\n", __func__); |
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return -1; |
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} |
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ret = inb(EC_LPC_ADDR_HOST_DATA); |
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if (ret) { |
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debug("%s: CROS_EC result code %d\n", __func__, ret); |
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return -ret; |
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} |
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debug_trace("resp: %02x, ", ret); |
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for (i = 0; i < din_len; i++) { |
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dev->din[i] = inb(EC_LPC_ADDR_OLD_PARAM + i); |
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debug_trace("%02x ", dev->din[i]); |
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} |
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debug_trace("\n"); |
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*dinp = dev->din; |
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return din_len; |
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} |
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int cros_ec_lpc_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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const int cmd_addr = EC_LPC_ADDR_HOST_CMD; |
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const int data_addr = EC_LPC_ADDR_HOST_DATA; |
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const int args_addr = EC_LPC_ADDR_HOST_ARGS; |
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const int param_addr = EC_LPC_ADDR_HOST_PARAM; |
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struct ec_lpc_host_args args; |
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uint8_t *d; |
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int csum; |
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int i; |
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/* Fall back to old-style command interface if args aren't supported */ |
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if (!dev->cmd_version_is_supported) |
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return old_lpc_command(dev, cmd, dout, dout_len, dinp, |
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din_len); |
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if (dout_len > EC_HOST_PARAM_SIZE) { |
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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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/* Fill in args */ |
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args.flags = EC_HOST_ARGS_FLAG_FROM_HOST; |
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args.command_version = cmd_version; |
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args.data_size = dout_len; |
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/* Calculate checksum */ |
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csum = cmd + args.flags + args.command_version + args.data_size; |
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for (i = 0, d = (uint8_t *)dout; i < dout_len; i++, d++) |
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csum += *d; |
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args.checksum = (uint8_t)csum; |
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if (wait_for_sync(dev)) { |
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debug("%s: Timeout waiting ready\n", __func__); |
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return -1; |
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} |
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/* Write args */ |
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for (i = 0, d = (uint8_t *)&args; i < sizeof(args); i++, d++) |
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outb(*d, args_addr + i); |
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/* Write data, if any */ |
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debug_trace("cmd: %02x, ver: %02x", cmd, cmd_version); |
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for (i = 0, d = (uint8_t *)dout; i < dout_len; i++, d++) { |
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outb(*d, param_addr + i); |
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debug_trace("%02x ", *d); |
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} |
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outb(cmd, cmd_addr); |
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debug_trace("\n"); |
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if (wait_for_sync(dev)) { |
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debug("%s: Timeout waiting for response\n", __func__); |
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return -1; |
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} |
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/* Check result */ |
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i = inb(data_addr); |
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if (i) { |
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debug("%s: CROS_EC result code %d\n", __func__, i); |
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return -i; |
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} |
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/* Read back args */ |
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for (i = 0, d = (uint8_t *)&args; i < sizeof(args); i++, d++) |
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*d = inb(args_addr + i); |
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/*
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* If EC didn't modify args flags, then somehow we sent a new-style |
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* command to an old EC, which means it would have read its params |
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* from the wrong place. |
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*/ |
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if (!(args.flags & EC_HOST_ARGS_FLAG_TO_HOST)) { |
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debug("%s: CROS_EC protocol mismatch\n", __func__); |
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return -EC_RES_INVALID_RESPONSE; |
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} |
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if (args.data_size > din_len) { |
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debug("%s: CROS_EC returned too much data %d > %d\n", |
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__func__, args.data_size, din_len); |
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return -EC_RES_INVALID_RESPONSE; |
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} |
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/* Read data, if any */ |
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for (i = 0, d = (uint8_t *)dev->din; i < args.data_size; i++, d++) { |
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*d = inb(param_addr + i); |
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debug_trace("%02x ", *d); |
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} |
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debug_trace("\n"); |
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/* Verify checksum */ |
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csum = cmd + args.flags + args.command_version + args.data_size; |
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for (i = 0, d = (uint8_t *)dev->din; i < args.data_size; i++, d++) |
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csum += *d; |
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if (args.checksum != (uint8_t)csum) { |
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debug("%s: CROS_EC response has invalid checksum\n", __func__); |
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return -EC_RES_INVALID_CHECKSUM; |
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} |
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*dinp = dev->din; |
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/* Return actual amount of data received */ |
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return args.data_size; |
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} |
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/**
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* Initialize LPC 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_lpc_init(struct cros_ec_dev *dev, const void *blob) |
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{ |
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int byte, i; |
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/* See if we can find an EC at the other end */ |
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byte = 0xff; |
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byte &= inb(EC_LPC_ADDR_HOST_CMD); |
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byte &= inb(EC_LPC_ADDR_HOST_DATA); |
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for (i = 0; i < EC_HOST_PARAM_SIZE && (byte == 0xff); i++) |
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byte &= inb(EC_LPC_ADDR_HOST_PARAM + i); |
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if (byte == 0xff) { |
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debug("%s: CROS_EC device not found on LPC bus\n", |
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__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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/*
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* Test if LPC command args are supported. |
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* |
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* The cheapest way to do this is by looking for the memory-mapped |
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* flag. This is faster than sending a new-style 'hello' command and |
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* seeing whether the EC sets the EC_HOST_ARGS_FLAG_FROM_HOST flag |
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* in args when it responds. |
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*/ |
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int cros_ec_lpc_check_version(struct cros_ec_dev *dev) |
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{ |
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if (inb(EC_LPC_ADDR_MEMMAP + EC_MEMMAP_ID) == 'E' && |
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inb(EC_LPC_ADDR_MEMMAP + EC_MEMMAP_ID + 1) |
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== 'C' && |
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(inb(EC_LPC_ADDR_MEMMAP + |
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EC_MEMMAP_HOST_CMD_FLAGS) & |
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EC_HOST_CMD_FLAG_LPC_ARGS_SUPPORTED)) { |
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dev->cmd_version_is_supported = 1; |
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} else { |
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/* We are going to use the old IO ports */ |
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dev->cmd_version_is_supported = 0; |
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} |
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debug("lpc: version %s\n", dev->cmd_version_is_supported ? |
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"new" : "old"); |
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return 0; |
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} |
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