| Etienne Carriere | 240720e | 2020-09-09 18:44:01 +0200 | [diff] [blame^] | 1 | // SPDX-License-Identifier: GPL-2.0+ |
| 2 | /* |
| 3 | * Copyright (C) 2020 Linaro Limited. |
| 4 | */ |
| 5 | |
| 6 | #include <common.h> |
| 7 | #include <dm.h> |
| 8 | #include <errno.h> |
| 9 | #include <mailbox.h> |
| 10 | #include <scmi_agent.h> |
| 11 | #include <scmi_agent-uclass.h> |
| 12 | #include <dm/devres.h> |
| 13 | #include <linux/compat.h> |
| 14 | |
| 15 | #include "smt.h" |
| 16 | |
| 17 | #define TIMEOUT_US_10MS 10000 |
| 18 | |
| 19 | /** |
| 20 | * struct scmi_mbox_channel - Description of an SCMI mailbox transport |
| 21 | * @smt: Shared memory buffer |
| 22 | * @mbox: Mailbox channel description |
| 23 | * @timeout_us: Timeout in microseconds for the mailbox transfer |
| 24 | */ |
| 25 | struct scmi_mbox_channel { |
| 26 | struct scmi_smt smt; |
| 27 | struct mbox_chan mbox; |
| 28 | ulong timeout_us; |
| 29 | }; |
| 30 | |
| 31 | static int scmi_mbox_process_msg(struct udevice *dev, struct scmi_msg *msg) |
| 32 | { |
| 33 | struct scmi_mbox_channel *chan = dev_get_priv(dev); |
| 34 | int ret; |
| 35 | |
| 36 | ret = scmi_write_msg_to_smt(dev, &chan->smt, msg); |
| 37 | if (ret) |
| 38 | return ret; |
| 39 | |
| 40 | /* Give shm addr to mbox in case it is meaningful */ |
| 41 | ret = mbox_send(&chan->mbox, chan->smt.buf); |
| 42 | if (ret) { |
| 43 | dev_err(dev, "Message send failed: %d\n", ret); |
| 44 | goto out; |
| 45 | } |
| 46 | |
| 47 | /* Receive the response */ |
| 48 | ret = mbox_recv(&chan->mbox, chan->smt.buf, chan->timeout_us); |
| 49 | if (ret) { |
| 50 | dev_err(dev, "Response failed: %d, abort\n", ret); |
| 51 | goto out; |
| 52 | } |
| 53 | |
| 54 | ret = scmi_read_resp_from_smt(dev, &chan->smt, msg); |
| 55 | |
| 56 | out: |
| 57 | scmi_clear_smt_channel(&chan->smt); |
| 58 | |
| 59 | return ret; |
| 60 | } |
| 61 | |
| 62 | int scmi_mbox_probe(struct udevice *dev) |
| 63 | { |
| 64 | struct scmi_mbox_channel *chan = dev_get_priv(dev); |
| 65 | int ret; |
| 66 | |
| 67 | chan->timeout_us = TIMEOUT_US_10MS; |
| 68 | |
| 69 | ret = mbox_get_by_index(dev, 0, &chan->mbox); |
| 70 | if (ret) { |
| 71 | dev_err(dev, "Failed to find mailbox: %d\n", ret); |
| 72 | goto out; |
| 73 | } |
| 74 | |
| 75 | ret = scmi_dt_get_smt_buffer(dev, &chan->smt); |
| 76 | if (ret) |
| 77 | dev_err(dev, "Failed to get shm resources: %d\n", ret); |
| 78 | |
| 79 | out: |
| 80 | if (ret) |
| 81 | devm_kfree(dev, chan); |
| 82 | |
| 83 | return ret; |
| 84 | } |
| 85 | |
| 86 | static const struct udevice_id scmi_mbox_ids[] = { |
| 87 | { .compatible = "arm,scmi" }, |
| 88 | { } |
| 89 | }; |
| 90 | |
| 91 | static const struct scmi_agent_ops scmi_mbox_ops = { |
| 92 | .process_msg = scmi_mbox_process_msg, |
| 93 | }; |
| 94 | |
| 95 | U_BOOT_DRIVER(scmi_mbox) = { |
| 96 | .name = "scmi-over-mailbox", |
| 97 | .id = UCLASS_SCMI_AGENT, |
| 98 | .of_match = scmi_mbox_ids, |
| 99 | .priv_auto_alloc_size = sizeof(struct scmi_mbox_channel), |
| 100 | .probe = scmi_mbox_probe, |
| 101 | .ops = &scmi_mbox_ops, |
| 102 | }; |