xref: /arm-trusted-firmware/plat/brcm/board/stingray/src/scp_cmd.c (revision 91f16700b400a8c0651d24a598fc48ee2997a0d7)
1*91f16700Schasinglulu /*
2*91f16700Schasinglulu  * Copyright (c) 2017-2020, Broadcom
3*91f16700Schasinglulu  *
4*91f16700Schasinglulu  * SPDX-License-Identifier: BSD-3-Clause
5*91f16700Schasinglulu  */
6*91f16700Schasinglulu 
7*91f16700Schasinglulu #include <arch_helpers.h>
8*91f16700Schasinglulu #include <common/bl_common.h>
9*91f16700Schasinglulu #include <drivers/delay_timer.h>
10*91f16700Schasinglulu 
11*91f16700Schasinglulu #include <platform_def.h>
12*91f16700Schasinglulu #include <scp.h>
13*91f16700Schasinglulu #include <scp_cmd.h>
14*91f16700Schasinglulu 
15*91f16700Schasinglulu #include "m0_ipc.h"
16*91f16700Schasinglulu 
17*91f16700Schasinglulu /*
18*91f16700Schasinglulu  * Reads a response from CRMU MAILBOX
19*91f16700Schasinglulu  * Assumes that access has been granted and locked.
20*91f16700Schasinglulu  * Note that this is just a temporary implementation until
21*91f16700Schasinglulu  * channels are introduced
22*91f16700Schasinglulu  */
23*91f16700Schasinglulu static void scp_read_response(crmu_response_t *resp)
24*91f16700Schasinglulu {
25*91f16700Schasinglulu 	uint32_t code;
26*91f16700Schasinglulu 
27*91f16700Schasinglulu 	code = mmio_read_32(CRMU_MAIL_BOX0);
28*91f16700Schasinglulu 	resp->completed = code & MCU_IPC_CMD_DONE_MASK;
29*91f16700Schasinglulu 	resp->cmd = code & SCP_CMD_MASK;
30*91f16700Schasinglulu 	resp->ret = (code & MCU_IPC_CMD_REPLY_MASK) >> MCU_IPC_CMD_REPLY_SHIFT;
31*91f16700Schasinglulu }
32*91f16700Schasinglulu 
33*91f16700Schasinglulu /*
34*91f16700Schasinglulu  * Send a command to SCP and wait for timeout us.
35*91f16700Schasinglulu  * Return:  0 on success
36*91f16700Schasinglulu  *         -1 if there was no proper reply from SCP
37*91f16700Schasinglulu  *         >0 if there was a response from MCU, but
38*91f16700Schasinglulu  *            command completed with an error.
39*91f16700Schasinglulu  */
40*91f16700Schasinglulu int scp_send_cmd(uint32_t cmd, uint32_t param, uint32_t timeout)
41*91f16700Schasinglulu {
42*91f16700Schasinglulu 	int ret = -1;
43*91f16700Schasinglulu 
44*91f16700Schasinglulu 	mmio_write_32(CRMU_MAIL_BOX0, cmd);
45*91f16700Schasinglulu 	mmio_write_32(CRMU_MAIL_BOX1, param);
46*91f16700Schasinglulu 	do {
47*91f16700Schasinglulu 		crmu_response_t scp_resp;
48*91f16700Schasinglulu 
49*91f16700Schasinglulu 		udelay(1);
50*91f16700Schasinglulu 		scp_read_response(&scp_resp);
51*91f16700Schasinglulu 		if (scp_resp.completed &&
52*91f16700Schasinglulu 			(scp_resp.cmd == cmd)) {
53*91f16700Schasinglulu 			/* This command has completed */
54*91f16700Schasinglulu 			ret = scp_resp.ret;
55*91f16700Schasinglulu 			break;
56*91f16700Schasinglulu 		}
57*91f16700Schasinglulu 	} while (--timeout);
58*91f16700Schasinglulu 
59*91f16700Schasinglulu 	return ret;
60*91f16700Schasinglulu }
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