diff options
Diffstat (limited to 'drivers/platform/chrome/cros_ec_lpc_mec.c')
| -rw-r--r-- | drivers/platform/chrome/cros_ec_lpc_mec.c | 78 |
1 files changed, 47 insertions, 31 deletions
diff --git a/drivers/platform/chrome/cros_ec_lpc_mec.c b/drivers/platform/chrome/cros_ec_lpc_mec.c index c4edfa83e493..d8890bafb55d 100644 --- a/drivers/platform/chrome/cros_ec_lpc_mec.c +++ b/drivers/platform/chrome/cros_ec_lpc_mec.c @@ -1,29 +1,10 @@ -/* - * cros_ec_lpc_mec - LPC variant I/O for Microchip EC - * - * Copyright (C) 2016 Google, Inc - * - * This software is licensed under the terms of the GNU General Public - * License version 2, as published by the Free Software Foundation, and - * may be copied, distributed, and modified under those terms. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * This driver uses the Chrome OS EC byte-level message-based protocol for - * communicating the keyboard state (which keys are pressed) from a keyboard EC - * to the AP over some bus (such as i2c, lpc, spi). The EC does debouncing, - * but everything else (including deghosting) is done here. The main - * motivation for this is to keep the EC firmware as simple as possible, since - * it cannot be easily upgraded and EC flash/IRAM space is relatively - * expensive. - */ +// SPDX-License-Identifier: GPL-2.0 +// LPC variant I/O for Microchip EC +// +// Copyright (C) 2016 Google, Inc #include <linux/delay.h> #include <linux/io.h> -#include <linux/mfd/cros_ec_commands.h> #include <linux/mutex.h> #include <linux/types.h> @@ -34,6 +15,7 @@ * EC mutex because memmap data may be accessed without it being held. */ static struct mutex io_mutex; +static u16 mec_emi_base, mec_emi_end; /* * cros_ec_lpc_mec_emi_write_address @@ -46,10 +28,37 @@ static struct mutex io_mutex; static void cros_ec_lpc_mec_emi_write_address(u16 addr, enum cros_ec_lpc_mec_emi_access_mode access_type) { - /* Address relative to start of EMI range */ - addr -= MEC_EMI_RANGE_START; - outb((addr & 0xfc) | access_type, MEC_EMI_EC_ADDRESS_B0); - outb((addr >> 8) & 0x7f, MEC_EMI_EC_ADDRESS_B1); + outb((addr & 0xfc) | access_type, MEC_EMI_EC_ADDRESS_B0(mec_emi_base)); + outb((addr >> 8) & 0x7f, MEC_EMI_EC_ADDRESS_B1(mec_emi_base)); +} + +/** + * cros_ec_lpc_mec_in_range() - Determine if addresses are in MEC EMI range. + * + * @offset: Address offset + * @length: Number of bytes to check + * + * Return: 1 if in range, 0 if not, and -EINVAL on failure + * such as the mec range not being initialized + */ +int cros_ec_lpc_mec_in_range(unsigned int offset, unsigned int length) +{ + if (length == 0) + return -EINVAL; + + if (WARN_ON(mec_emi_base == 0 || mec_emi_end == 0)) + return -EINVAL; + + if (offset >= mec_emi_base && offset < mec_emi_end) { + if (WARN_ON(offset + length - 1 >= mec_emi_end)) + return -EINVAL; + return 1; + } + + if (WARN_ON(offset + length > mec_emi_base && offset < mec_emi_end)) + return -EINVAL; + + return 0; } /* @@ -71,6 +80,11 @@ u8 cros_ec_lpc_io_bytes_mec(enum cros_ec_lpc_mec_io_type io_type, u8 sum = 0; enum cros_ec_lpc_mec_emi_access_mode access, new_access; + /* Return checksum of 0 if window is not initialized */ + WARN_ON(mec_emi_base == 0 || mec_emi_end == 0); + if (mec_emi_base == 0 || mec_emi_end == 0) + return 0; + /* * Long access cannot be used on misaligned data since reading B0 loads * the data register and writing B3 flushes. @@ -86,9 +100,9 @@ u8 cros_ec_lpc_io_bytes_mec(enum cros_ec_lpc_mec_io_type io_type, cros_ec_lpc_mec_emi_write_address(offset, access); /* Skip bytes in case of misaligned offset */ - io_addr = MEC_EMI_EC_DATA_B0 + (offset & 0x3); + io_addr = MEC_EMI_EC_DATA_B0(mec_emi_base) + (offset & 0x3); while (i < length) { - while (io_addr <= MEC_EMI_EC_DATA_B3) { + while (io_addr <= MEC_EMI_EC_DATA_B3(mec_emi_base)) { if (io_type == MEC_IO_READ) buf[i] = inb(io_addr++); else @@ -118,7 +132,7 @@ u8 cros_ec_lpc_io_bytes_mec(enum cros_ec_lpc_mec_io_type io_type, } /* Access [B0, B3] on each loop pass */ - io_addr = MEC_EMI_EC_DATA_B0; + io_addr = MEC_EMI_EC_DATA_B0(mec_emi_base); } done: @@ -128,9 +142,11 @@ done: } EXPORT_SYMBOL(cros_ec_lpc_io_bytes_mec); -void cros_ec_lpc_mec_init(void) +void cros_ec_lpc_mec_init(unsigned int base, unsigned int end) { mutex_init(&io_mutex); + mec_emi_base = base; + mec_emi_end = end; } EXPORT_SYMBOL(cros_ec_lpc_mec_init); |