Hung-ying Tyan | 78764a4 | 2013-05-15 18:27:29 +0800 | [diff] [blame] | 1 | /* |
| 2 | * Chromium OS cros_ec driver - I2C interface |
| 3 | * |
| 4 | * Copyright (c) 2012 The Chromium OS Authors. |
Hung-ying Tyan | 78764a4 | 2013-05-15 18:27:29 +0800 | [diff] [blame] | 5 | * |
Wolfgang Denk | 1a45966 | 2013-07-08 09:37:19 +0200 | [diff] [blame^] | 6 | * SPDX-License-Identifier: GPL-2.0+ |
Hung-ying Tyan | 78764a4 | 2013-05-15 18:27:29 +0800 | [diff] [blame] | 7 | */ |
| 8 | |
| 9 | /* |
| 10 | * The Matrix Keyboard Protocol driver handles talking to the keyboard |
| 11 | * controller chip. Mostly this is for keyboard functions, but some other |
| 12 | * things have slipped in, so we provide generic services to talk to the |
| 13 | * KBC. |
| 14 | */ |
| 15 | |
| 16 | #include <common.h> |
| 17 | #include <i2c.h> |
| 18 | #include <cros_ec.h> |
| 19 | |
| 20 | #ifdef DEBUG_TRACE |
| 21 | #define debug_trace(fmt, b...) debug(fmt, #b) |
| 22 | #else |
| 23 | #define debug_trace(fmt, b...) |
| 24 | #endif |
| 25 | |
| 26 | int cros_ec_i2c_command(struct cros_ec_dev *dev, uint8_t cmd, int cmd_version, |
| 27 | const uint8_t *dout, int dout_len, |
| 28 | uint8_t **dinp, int din_len) |
| 29 | { |
| 30 | int old_bus = 0; |
| 31 | /* version8, cmd8, arglen8, out8[dout_len], csum8 */ |
| 32 | int out_bytes = dout_len + 4; |
| 33 | /* response8, arglen8, in8[din_len], checksum8 */ |
| 34 | int in_bytes = din_len + 3; |
| 35 | uint8_t *ptr; |
| 36 | /* Receive input data, so that args will be dword aligned */ |
| 37 | uint8_t *in_ptr; |
| 38 | int ret; |
| 39 | |
| 40 | old_bus = i2c_get_bus_num(); |
| 41 | |
| 42 | /* |
| 43 | * Sanity-check I/O sizes given transaction overhead in internal |
| 44 | * buffers. |
| 45 | */ |
| 46 | if (out_bytes > sizeof(dev->dout)) { |
| 47 | debug("%s: Cannot send %d bytes\n", __func__, dout_len); |
| 48 | return -1; |
| 49 | } |
| 50 | if (in_bytes > sizeof(dev->din)) { |
| 51 | debug("%s: Cannot receive %d bytes\n", __func__, din_len); |
| 52 | return -1; |
| 53 | } |
| 54 | assert(dout_len >= 0); |
| 55 | assert(dinp); |
| 56 | |
| 57 | /* |
| 58 | * Copy command and data into output buffer so we can do a single I2C |
| 59 | * burst transaction. |
| 60 | */ |
| 61 | ptr = dev->dout; |
| 62 | |
| 63 | /* |
| 64 | * in_ptr starts of pointing to a dword-aligned input data buffer. |
| 65 | * We decrement it back by the number of header bytes we expect to |
| 66 | * receive, so that the first parameter of the resulting input data |
| 67 | * will be dword aligned. |
| 68 | */ |
| 69 | in_ptr = dev->din + sizeof(int64_t); |
| 70 | if (!dev->cmd_version_is_supported) { |
| 71 | /* Send an old-style command */ |
| 72 | *ptr++ = cmd; |
| 73 | out_bytes = dout_len + 1; |
| 74 | in_bytes = din_len + 2; |
| 75 | in_ptr--; /* Expect just a status byte */ |
| 76 | } else { |
| 77 | *ptr++ = EC_CMD_VERSION0 + cmd_version; |
| 78 | *ptr++ = cmd; |
| 79 | *ptr++ = dout_len; |
| 80 | in_ptr -= 2; /* Expect status, length bytes */ |
| 81 | } |
| 82 | memcpy(ptr, dout, dout_len); |
| 83 | ptr += dout_len; |
| 84 | |
| 85 | if (dev->cmd_version_is_supported) |
| 86 | *ptr++ = (uint8_t) |
| 87 | cros_ec_calc_checksum(dev->dout, dout_len + 3); |
| 88 | |
| 89 | /* Set to the proper i2c bus */ |
| 90 | if (i2c_set_bus_num(dev->bus_num)) { |
| 91 | debug("%s: Cannot change to I2C bus %d\n", __func__, |
| 92 | dev->bus_num); |
| 93 | return -1; |
| 94 | } |
| 95 | |
| 96 | /* Send output data */ |
| 97 | cros_ec_dump_data("out", -1, dev->dout, out_bytes); |
| 98 | ret = i2c_write(dev->addr, 0, 0, dev->dout, out_bytes); |
| 99 | if (ret) { |
| 100 | debug("%s: Cannot complete I2C write to 0x%x\n", |
| 101 | __func__, dev->addr); |
| 102 | ret = -1; |
| 103 | } |
| 104 | |
| 105 | if (!ret) { |
| 106 | ret = i2c_read(dev->addr, 0, 0, in_ptr, in_bytes); |
| 107 | if (ret) { |
| 108 | debug("%s: Cannot complete I2C read from 0x%x\n", |
| 109 | __func__, dev->addr); |
| 110 | ret = -1; |
| 111 | } |
| 112 | } |
| 113 | |
| 114 | /* Return to original bus number */ |
| 115 | i2c_set_bus_num(old_bus); |
| 116 | if (ret) |
| 117 | return ret; |
| 118 | |
| 119 | if (*in_ptr != EC_RES_SUCCESS) { |
| 120 | debug("%s: Received bad result code %d\n", __func__, *in_ptr); |
| 121 | return -(int)*in_ptr; |
| 122 | } |
| 123 | |
| 124 | if (dev->cmd_version_is_supported) { |
| 125 | int len, csum; |
| 126 | |
| 127 | len = in_ptr[1]; |
| 128 | if (len + 3 > sizeof(dev->din)) { |
| 129 | debug("%s: Received length %#02x too large\n", |
| 130 | __func__, len); |
| 131 | return -1; |
| 132 | } |
| 133 | csum = cros_ec_calc_checksum(in_ptr, 2 + len); |
| 134 | if (csum != in_ptr[2 + len]) { |
| 135 | debug("%s: Invalid checksum rx %#02x, calced %#02x\n", |
| 136 | __func__, in_ptr[2 + din_len], csum); |
| 137 | return -1; |
| 138 | } |
| 139 | din_len = min(din_len, len); |
| 140 | cros_ec_dump_data("in", -1, in_ptr, din_len + 3); |
| 141 | } else { |
| 142 | cros_ec_dump_data("in (old)", -1, in_ptr, in_bytes); |
| 143 | } |
| 144 | |
| 145 | /* Return pointer to dword-aligned input data, if any */ |
| 146 | *dinp = dev->din + sizeof(int64_t); |
| 147 | |
| 148 | return din_len; |
| 149 | } |
| 150 | |
| 151 | int cros_ec_i2c_decode_fdt(struct cros_ec_dev *dev, const void *blob) |
| 152 | { |
| 153 | /* Decode interface-specific FDT params */ |
| 154 | dev->max_frequency = fdtdec_get_int(blob, dev->node, |
| 155 | "i2c-max-frequency", 100000); |
| 156 | dev->bus_num = i2c_get_bus_num_fdt(dev->parent_node); |
| 157 | if (dev->bus_num == -1) { |
| 158 | debug("%s: Failed to read bus number\n", __func__); |
| 159 | return -1; |
| 160 | } |
| 161 | dev->addr = fdtdec_get_int(blob, dev->node, "reg", -1); |
| 162 | if (dev->addr == -1) { |
| 163 | debug("%s: Failed to read device address\n", __func__); |
| 164 | return -1; |
| 165 | } |
| 166 | |
| 167 | return 0; |
| 168 | } |
| 169 | |
| 170 | /** |
| 171 | * Initialize I2C protocol. |
| 172 | * |
| 173 | * @param dev CROS_EC device |
| 174 | * @param blob Device tree blob |
| 175 | * @return 0 if ok, -1 on error |
| 176 | */ |
| 177 | int cros_ec_i2c_init(struct cros_ec_dev *dev, const void *blob) |
| 178 | { |
| 179 | i2c_init(dev->max_frequency, dev->addr); |
| 180 | |
| 181 | dev->cmd_version_is_supported = 0; |
| 182 | |
| 183 | return 0; |
| 184 | } |