forked from ~ljy/RK356X_SDK_RELEASE

hc
2024-05-11 297b60346df8beafee954a0fd7c2d64f33f3b9bc
kernel/drivers/platform/chrome/cros_ec_lpc_mec.c
....@@ -1,65 +1,73 @@
1
-/*
2
- * cros_ec_lpc_mec - LPC variant I/O for Microchip EC
3
- *
4
- * Copyright (C) 2016 Google, Inc
5
- *
6
- * This software is licensed under the terms of the GNU General Public
7
- * License version 2, as published by the Free Software Foundation, and
8
- * may be copied, distributed, and modified under those terms.
9
- *
10
- * This program is distributed in the hope that it will be useful,
11
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
12
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13
- * GNU General Public License for more details.
14
- *
15
- * This driver uses the Chrome OS EC byte-level message-based protocol for
16
- * communicating the keyboard state (which keys are pressed) from a keyboard EC
17
- * to the AP over some bus (such as i2c, lpc, spi). The EC does debouncing,
18
- * but everything else (including deghosting) is done here. The main
19
- * motivation for this is to keep the EC firmware as simple as possible, since
20
- * it cannot be easily upgraded and EC flash/IRAM space is relatively
21
- * expensive.
22
- */
1
+// SPDX-License-Identifier: GPL-2.0
2
+// LPC variant I/O for Microchip EC
3
+//
4
+// Copyright (C) 2016 Google, Inc
235
246 #include <linux/delay.h>
257 #include <linux/io.h>
26
-#include <linux/mfd/cros_ec_commands.h>
27
-#include <linux/mfd/cros_ec_lpc_mec.h>
288 #include <linux/mutex.h>
299 #include <linux/types.h>
10
+
11
+#include "cros_ec_lpc_mec.h"
3012
3113 /*
3214 * This mutex must be held while accessing the EMI unit. We can't rely on the
3315 * EC mutex because memmap data may be accessed without it being held.
3416 */
3517 static struct mutex io_mutex;
18
+static u16 mec_emi_base, mec_emi_end;
3619
37
-/*
38
- * cros_ec_lpc_mec_emi_write_address
20
+/**
21
+ * cros_ec_lpc_mec_emi_write_address() - Initialize EMI at a given address.
3922 *
40
- * Initialize EMI read / write at a given address.
41
- *
42
- * @addr: Starting read / write address
23
+ * @addr: Starting read / write address
4324 * @access_type: Type of access, typically 32-bit auto-increment
4425 */
4526 static void cros_ec_lpc_mec_emi_write_address(u16 addr,
4627 enum cros_ec_lpc_mec_emi_access_mode access_type)
4728 {
48
- /* Address relative to start of EMI range */
49
- addr -= MEC_EMI_RANGE_START;
50
- outb((addr & 0xfc) | access_type, MEC_EMI_EC_ADDRESS_B0);
51
- outb((addr >> 8) & 0x7f, MEC_EMI_EC_ADDRESS_B1);
29
+ outb((addr & 0xfc) | access_type, MEC_EMI_EC_ADDRESS_B0(mec_emi_base));
30
+ outb((addr >> 8) & 0x7f, MEC_EMI_EC_ADDRESS_B1(mec_emi_base));
5231 }
5332
54
-/*
55
- * cros_ec_lpc_io_bytes_mec - Read / write bytes to MEC EMI port
33
+/**
34
+ * cros_ec_lpc_mec_in_range() - Determine if addresses are in MEC EMI range.
35
+ *
36
+ * @offset: Address offset
37
+ * @length: Number of bytes to check
38
+ *
39
+ * Return: 1 if in range, 0 if not, and -EINVAL on failure
40
+ * such as the mec range not being initialized
41
+ */
42
+int cros_ec_lpc_mec_in_range(unsigned int offset, unsigned int length)
43
+{
44
+ if (length == 0)
45
+ return -EINVAL;
46
+
47
+ if (WARN_ON(mec_emi_base == 0 || mec_emi_end == 0))
48
+ return -EINVAL;
49
+
50
+ if (offset >= mec_emi_base && offset < mec_emi_end) {
51
+ if (WARN_ON(offset + length - 1 >= mec_emi_end))
52
+ return -EINVAL;
53
+ return 1;
54
+ }
55
+
56
+ if (WARN_ON(offset + length > mec_emi_base && offset < mec_emi_end))
57
+ return -EINVAL;
58
+
59
+ return 0;
60
+}
61
+
62
+/**
63
+ * cros_ec_lpc_io_bytes_mec() - Read / write bytes to MEC EMI port.
5664 *
5765 * @io_type: MEC_IO_READ or MEC_IO_WRITE, depending on request
5866 * @offset: Base read / write address
5967 * @length: Number of bytes to read / write
6068 * @buf: Destination / source buffer
6169 *
62
- * @return 8-bit checksum of all bytes read / written
70
+ * Return: 8-bit checksum of all bytes read / written
6371 */
6472 u8 cros_ec_lpc_io_bytes_mec(enum cros_ec_lpc_mec_io_type io_type,
6573 unsigned int offset, unsigned int length,
....@@ -69,6 +77,11 @@
6977 int io_addr;
7078 u8 sum = 0;
7179 enum cros_ec_lpc_mec_emi_access_mode access, new_access;
80
+
81
+ /* Return checksum of 0 if window is not initialized */
82
+ WARN_ON(mec_emi_base == 0 || mec_emi_end == 0);
83
+ if (mec_emi_base == 0 || mec_emi_end == 0)
84
+ return 0;
7285
7386 /*
7487 * Long access cannot be used on misaligned data since reading B0 loads
....@@ -85,9 +98,9 @@
8598 cros_ec_lpc_mec_emi_write_address(offset, access);
8699
87100 /* Skip bytes in case of misaligned offset */
88
- io_addr = MEC_EMI_EC_DATA_B0 + (offset & 0x3);
101
+ io_addr = MEC_EMI_EC_DATA_B0(mec_emi_base) + (offset & 0x3);
89102 while (i < length) {
90
- while (io_addr <= MEC_EMI_EC_DATA_B3) {
103
+ while (io_addr <= MEC_EMI_EC_DATA_B3(mec_emi_base)) {
91104 if (io_type == MEC_IO_READ)
92105 buf[i] = inb(io_addr++);
93106 else
....@@ -117,7 +130,7 @@
117130 }
118131
119132 /* Access [B0, B3] on each loop pass */
120
- io_addr = MEC_EMI_EC_DATA_B0;
133
+ io_addr = MEC_EMI_EC_DATA_B0(mec_emi_base);
121134 }
122135
123136 done:
....@@ -127,9 +140,11 @@
127140 }
128141 EXPORT_SYMBOL(cros_ec_lpc_io_bytes_mec);
129142
130
-void cros_ec_lpc_mec_init(void)
143
+void cros_ec_lpc_mec_init(unsigned int base, unsigned int end)
131144 {
132145 mutex_init(&io_mutex);
146
+ mec_emi_base = base;
147
+ mec_emi_end = end;
133148 }
134149 EXPORT_SYMBOL(cros_ec_lpc_mec_init);
135150