1 /*
2 * Copyright (c) 2020, Google LLC. All rights reserved.
3 *
4 * SPDX-License-Identifier: BSD-3-Clause
5 */
6
7 #include <common/debug.h>
8 #include <drivers/delay_timer.h>
9 #include <lib/mmio.h>
10
11 #include <spmi_arb.h>
12
13 #define REG_APID_MAP(apid) (0x0C440900U + sizeof(uint32_t) * apid)
14 #define NUM_APID ((0x1100U - 0x900U) / sizeof(uint32_t))
15
16 #define PPID_MASK (0xfffU << 8)
17
18 #define REG_ARB_CMD(apid) (0x0C600000U + 0x10000U * apid)
19 /* These are opcodes specific to this SPMI arbitrator, *not* SPMI commands. */
20 #define OPC_EXT_WRITEL 0
21 #define OPC_EXT_READL 1
22
23 #define REG_ARB_STATUS(apid) (0x0C600008U + 0x10000U * apid)
24 #define ARB_STATUS_DONE BIT(0)
25 #define ARB_STATUS_FAILURE BIT(1)
26 #define ARB_STATUS_DENIED BIT(2)
27 #define ARB_STATUS_DROPPED BIT(3)
28
29 /* Fake status to report driver errors. */
30 #define ARB_FAKE_STATUS_TIMEOUT BIT(8)
31
32 #define REG_ARB_RDATA0(apid) (0x0C600018U + 0x10000U * apid)
33 #define REG_ARB_WDATA0(apid) (0x0C600010U + 0x10000U * apid)
34
addr_to_apid(uint32_t addr)35 static int addr_to_apid(uint32_t addr)
36 {
37 unsigned int i;
38
39 for (i = 0U; i < NUM_APID; i++) {
40 uint32_t reg = mmio_read_32(REG_APID_MAP(i));
41 if ((reg != 0U) && ((addr & PPID_MASK) == (reg & PPID_MASK))) {
42 return i;
43 }
44 }
45
46 return -1;
47 }
48
wait_for_done(uint16_t apid)49 static int wait_for_done(uint16_t apid)
50 {
51 unsigned int timeout = 100;
52
53 while (timeout-- != 0U) {
54 uint32_t status = mmio_read_32(REG_ARB_STATUS(apid));
55 if ((status & ARB_STATUS_DONE) != 0U) {
56 if ((status & ARB_STATUS_FAILURE) != 0U ||
57 (status & ARB_STATUS_DENIED) != 0U ||
58 (status & ARB_STATUS_DROPPED) != 0U) {
59 return status & 0xff;
60 }
61 return 0;
62 }
63 mdelay(1);
64 }
65 ERROR("SPMI_ARB timeout!\n");
66 return ARB_FAKE_STATUS_TIMEOUT;
67 }
68
arb_command(uint16_t apid,uint8_t opcode,uint32_t addr,uint8_t bytes)69 static void arb_command(uint16_t apid, uint8_t opcode, uint32_t addr,
70 uint8_t bytes)
71 {
72 mmio_write_32(REG_ARB_CMD(apid), (uint32_t)opcode << 27 |
73 (addr & 0xff) << 4 | (bytes - 1));
74 }
75
spmi_arb_read8(uint32_t addr)76 int spmi_arb_read8(uint32_t addr)
77 {
78 int apid = addr_to_apid(addr);
79
80 if (apid < 0) {
81 return apid;
82 }
83
84 arb_command(apid, OPC_EXT_READL, addr, 1);
85
86 int ret = wait_for_done(apid);
87 if (ret != 0) {
88 ERROR("SPMI_ARB read error [0x%x]: 0x%x\n", addr, ret);
89 return ret;
90 }
91
92 return mmio_read_32(REG_ARB_RDATA0(apid)) & 0xff;
93 }
94
spmi_arb_write8(uint32_t addr,uint8_t data)95 int spmi_arb_write8(uint32_t addr, uint8_t data)
96 {
97 int apid = addr_to_apid(addr);
98
99 if (apid < 0) {
100 return apid;
101 }
102
103 mmio_write_32(REG_ARB_WDATA0(apid), data);
104 arb_command(apid, OPC_EXT_WRITEL, addr, 1);
105
106 int ret = wait_for_done(apid);
107 if (ret != 0) {
108 ERROR("SPMI_ARB write error [0x%x] = 0x%x: 0x%x\n",
109 addr, data, ret);
110 }
111
112 return ret;
113 }
114