.. | .. |
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1 | | -/* |
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2 | | - * cros_ec_lpc_mec - LPC variant I/O for Microchip EC |
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3 | | - * |
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4 | | - * Copyright (C) 2016 Google, Inc |
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5 | | - * |
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6 | | - * This software is licensed under the terms of the GNU General Public |
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7 | | - * License version 2, as published by the Free Software Foundation, and |
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8 | | - * may be copied, distributed, and modified under those terms. |
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9 | | - * |
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10 | | - * This program is distributed in the hope that it will be useful, |
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11 | | - * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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12 | | - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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13 | | - * GNU General Public License for more details. |
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14 | | - * |
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15 | | - * This driver uses the Chrome OS EC byte-level message-based protocol for |
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16 | | - * communicating the keyboard state (which keys are pressed) from a keyboard EC |
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17 | | - * to the AP over some bus (such as i2c, lpc, spi). The EC does debouncing, |
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18 | | - * but everything else (including deghosting) is done here. The main |
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19 | | - * motivation for this is to keep the EC firmware as simple as possible, since |
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20 | | - * it cannot be easily upgraded and EC flash/IRAM space is relatively |
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21 | | - * expensive. |
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22 | | - */ |
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| 1 | +// SPDX-License-Identifier: GPL-2.0 |
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| 2 | +// LPC variant I/O for Microchip EC |
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| 3 | +// |
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| 4 | +// Copyright (C) 2016 Google, Inc |
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23 | 5 | |
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24 | 6 | #include <linux/delay.h> |
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25 | 7 | #include <linux/io.h> |
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26 | | -#include <linux/mfd/cros_ec_commands.h> |
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27 | | -#include <linux/mfd/cros_ec_lpc_mec.h> |
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28 | 8 | #include <linux/mutex.h> |
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29 | 9 | #include <linux/types.h> |
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| 10 | + |
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| 11 | +#include "cros_ec_lpc_mec.h" |
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30 | 12 | |
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31 | 13 | /* |
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32 | 14 | * This mutex must be held while accessing the EMI unit. We can't rely on the |
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33 | 15 | * EC mutex because memmap data may be accessed without it being held. |
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34 | 16 | */ |
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35 | 17 | static struct mutex io_mutex; |
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| 18 | +static u16 mec_emi_base, mec_emi_end; |
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36 | 19 | |
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37 | | -/* |
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38 | | - * cros_ec_lpc_mec_emi_write_address |
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| 20 | +/** |
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| 21 | + * cros_ec_lpc_mec_emi_write_address() - Initialize EMI at a given address. |
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39 | 22 | * |
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40 | | - * Initialize EMI read / write at a given address. |
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41 | | - * |
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42 | | - * @addr: Starting read / write address |
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| 23 | + * @addr: Starting read / write address |
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43 | 24 | * @access_type: Type of access, typically 32-bit auto-increment |
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44 | 25 | */ |
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45 | 26 | static void cros_ec_lpc_mec_emi_write_address(u16 addr, |
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46 | 27 | enum cros_ec_lpc_mec_emi_access_mode access_type) |
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47 | 28 | { |
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48 | | - /* Address relative to start of EMI range */ |
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49 | | - addr -= MEC_EMI_RANGE_START; |
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50 | | - outb((addr & 0xfc) | access_type, MEC_EMI_EC_ADDRESS_B0); |
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51 | | - outb((addr >> 8) & 0x7f, MEC_EMI_EC_ADDRESS_B1); |
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| 29 | + outb((addr & 0xfc) | access_type, MEC_EMI_EC_ADDRESS_B0(mec_emi_base)); |
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| 30 | + outb((addr >> 8) & 0x7f, MEC_EMI_EC_ADDRESS_B1(mec_emi_base)); |
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52 | 31 | } |
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53 | 32 | |
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54 | | -/* |
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55 | | - * cros_ec_lpc_io_bytes_mec - Read / write bytes to MEC EMI port |
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| 33 | +/** |
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| 34 | + * cros_ec_lpc_mec_in_range() - Determine if addresses are in MEC EMI range. |
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| 35 | + * |
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| 36 | + * @offset: Address offset |
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| 37 | + * @length: Number of bytes to check |
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| 38 | + * |
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| 39 | + * Return: 1 if in range, 0 if not, and -EINVAL on failure |
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| 40 | + * such as the mec range not being initialized |
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| 41 | + */ |
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| 42 | +int cros_ec_lpc_mec_in_range(unsigned int offset, unsigned int length) |
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| 43 | +{ |
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| 44 | + if (length == 0) |
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| 45 | + return -EINVAL; |
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| 46 | + |
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| 47 | + if (WARN_ON(mec_emi_base == 0 || mec_emi_end == 0)) |
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| 48 | + return -EINVAL; |
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| 49 | + |
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| 50 | + if (offset >= mec_emi_base && offset < mec_emi_end) { |
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| 51 | + if (WARN_ON(offset + length - 1 >= mec_emi_end)) |
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| 52 | + return -EINVAL; |
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| 53 | + return 1; |
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| 54 | + } |
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| 55 | + |
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| 56 | + if (WARN_ON(offset + length > mec_emi_base && offset < mec_emi_end)) |
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| 57 | + return -EINVAL; |
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| 58 | + |
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| 59 | + return 0; |
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| 60 | +} |
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| 61 | + |
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| 62 | +/** |
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| 63 | + * cros_ec_lpc_io_bytes_mec() - Read / write bytes to MEC EMI port. |
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56 | 64 | * |
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57 | 65 | * @io_type: MEC_IO_READ or MEC_IO_WRITE, depending on request |
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58 | 66 | * @offset: Base read / write address |
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59 | 67 | * @length: Number of bytes to read / write |
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60 | 68 | * @buf: Destination / source buffer |
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61 | 69 | * |
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62 | | - * @return 8-bit checksum of all bytes read / written |
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| 70 | + * Return: 8-bit checksum of all bytes read / written |
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63 | 71 | */ |
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64 | 72 | u8 cros_ec_lpc_io_bytes_mec(enum cros_ec_lpc_mec_io_type io_type, |
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65 | 73 | unsigned int offset, unsigned int length, |
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.. | .. |
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69 | 77 | int io_addr; |
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70 | 78 | u8 sum = 0; |
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71 | 79 | enum cros_ec_lpc_mec_emi_access_mode access, new_access; |
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| 80 | + |
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| 81 | + /* Return checksum of 0 if window is not initialized */ |
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| 82 | + WARN_ON(mec_emi_base == 0 || mec_emi_end == 0); |
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| 83 | + if (mec_emi_base == 0 || mec_emi_end == 0) |
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| 84 | + return 0; |
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72 | 85 | |
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73 | 86 | /* |
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74 | 87 | * Long access cannot be used on misaligned data since reading B0 loads |
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.. | .. |
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85 | 98 | cros_ec_lpc_mec_emi_write_address(offset, access); |
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86 | 99 | |
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87 | 100 | /* Skip bytes in case of misaligned offset */ |
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88 | | - io_addr = MEC_EMI_EC_DATA_B0 + (offset & 0x3); |
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| 101 | + io_addr = MEC_EMI_EC_DATA_B0(mec_emi_base) + (offset & 0x3); |
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89 | 102 | while (i < length) { |
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90 | | - while (io_addr <= MEC_EMI_EC_DATA_B3) { |
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| 103 | + while (io_addr <= MEC_EMI_EC_DATA_B3(mec_emi_base)) { |
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91 | 104 | if (io_type == MEC_IO_READ) |
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92 | 105 | buf[i] = inb(io_addr++); |
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93 | 106 | else |
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.. | .. |
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117 | 130 | } |
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118 | 131 | |
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119 | 132 | /* Access [B0, B3] on each loop pass */ |
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120 | | - io_addr = MEC_EMI_EC_DATA_B0; |
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| 133 | + io_addr = MEC_EMI_EC_DATA_B0(mec_emi_base); |
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121 | 134 | } |
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122 | 135 | |
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123 | 136 | done: |
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.. | .. |
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127 | 140 | } |
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128 | 141 | EXPORT_SYMBOL(cros_ec_lpc_io_bytes_mec); |
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129 | 142 | |
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130 | | -void cros_ec_lpc_mec_init(void) |
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| 143 | +void cros_ec_lpc_mec_init(unsigned int base, unsigned int end) |
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131 | 144 | { |
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132 | 145 | mutex_init(&io_mutex); |
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| 146 | + mec_emi_base = base; |
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| 147 | + mec_emi_end = end; |
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133 | 148 | } |
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134 | 149 | EXPORT_SYMBOL(cros_ec_lpc_mec_init); |
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135 | 150 | |
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