1 // SPDX-License-Identifier: GPL-2.0+
4 * Author: Dong Aisheng <aisheng.dong@nxp.com>
6 * Implementation of the SCU IPC functions using MUs (client side).
10 #include <linux/err.h>
11 #include <linux/firmware/imx/types.h>
12 #include <linux/firmware/imx/ipc.h>
13 #include <linux/firmware/imx/sci.h>
14 #include <linux/interrupt.h>
15 #include <linux/irq.h>
16 #include <linux/kernel.h>
17 #include <linux/mailbox_client.h>
18 #include <linux/module.h>
19 #include <linux/mutex.h>
20 #include <linux/of_platform.h>
21 #include <linux/platform_device.h>
23 #define SCU_MU_CHAN_NUM 8
24 #define MAX_RX_TIMEOUT (msecs_to_jiffies(30))
27 struct imx_sc_ipc *sc_ipc;
29 struct mbox_client cl;
32 struct completion tx_done;
36 /* SCU uses 4 Tx and 4 Rx channels */
37 struct imx_sc_chan chans[SCU_MU_CHAN_NUM];
40 struct completion done;
43 /* temporarily store the SCU msg */
50 * This type is used to indicate error response for most functions.
52 enum imx_sc_error_codes {
53 IMX_SC_ERR_NONE = 0, /* Success */
54 IMX_SC_ERR_VERSION = 1, /* Incompatible API version */
55 IMX_SC_ERR_CONFIG = 2, /* Configuration error */
56 IMX_SC_ERR_PARM = 3, /* Bad parameter */
57 IMX_SC_ERR_NOACCESS = 4, /* Permission error (no access) */
58 IMX_SC_ERR_LOCKED = 5, /* Permission error (locked) */
59 IMX_SC_ERR_UNAVAILABLE = 6, /* Unavailable (out of resources) */
60 IMX_SC_ERR_NOTFOUND = 7, /* Not found */
61 IMX_SC_ERR_NOPOWER = 8, /* No power */
62 IMX_SC_ERR_IPC = 9, /* Generic IPC error */
63 IMX_SC_ERR_BUSY = 10, /* Resource is currently busy/active */
64 IMX_SC_ERR_FAIL = 11, /* General I/O failure */
68 static int imx_sc_linux_errmap[IMX_SC_ERR_LAST] = {
69 0, /* IMX_SC_ERR_NONE */
70 -EINVAL, /* IMX_SC_ERR_VERSION */
71 -EINVAL, /* IMX_SC_ERR_CONFIG */
72 -EINVAL, /* IMX_SC_ERR_PARM */
73 -EACCES, /* IMX_SC_ERR_NOACCESS */
74 -EACCES, /* IMX_SC_ERR_LOCKED */
75 -ERANGE, /* IMX_SC_ERR_UNAVAILABLE */
76 -EEXIST, /* IMX_SC_ERR_NOTFOUND */
77 -EPERM, /* IMX_SC_ERR_NOPOWER */
78 -EPIPE, /* IMX_SC_ERR_IPC */
79 -EBUSY, /* IMX_SC_ERR_BUSY */
80 -EIO, /* IMX_SC_ERR_FAIL */
83 static struct imx_sc_ipc *imx_sc_ipc_handle;
85 static inline int imx_sc_to_linux_errno(int errno)
87 if (errno >= IMX_SC_ERR_NONE && errno < IMX_SC_ERR_LAST)
88 return imx_sc_linux_errmap[errno];
93 * Get the default handle used by SCU
95 int imx_scu_get_handle(struct imx_sc_ipc **ipc)
97 if (!imx_sc_ipc_handle)
100 *ipc = imx_sc_ipc_handle;
103 EXPORT_SYMBOL(imx_scu_get_handle);
105 /* Callback called when the word of a message is ack-ed, eg read by SCU */
106 static void imx_scu_tx_done(struct mbox_client *cl, void *mssg, int r)
108 struct imx_sc_chan *sc_chan = container_of(cl, struct imx_sc_chan, cl);
110 complete(&sc_chan->tx_done);
113 static void imx_scu_rx_callback(struct mbox_client *c, void *msg)
115 struct imx_sc_chan *sc_chan = container_of(c, struct imx_sc_chan, cl);
116 struct imx_sc_ipc *sc_ipc = sc_chan->sc_ipc;
117 struct imx_sc_rpc_msg *hdr;
122 dev_warn(sc_ipc->dev, "unexpected rx idx %d 0x%08x, ignore!\n",
123 sc_chan->idx, *data);
127 if (sc_ipc->fast_ipc) {
129 sc_ipc->rx_size = hdr->size;
130 sc_ipc->msg[0] = *data++;
132 for (i = 1; i < sc_ipc->rx_size; i++)
133 sc_ipc->msg[i] = *data++;
135 complete(&sc_ipc->done);
140 if (sc_chan->idx == 0) {
142 sc_ipc->rx_size = hdr->size;
143 dev_dbg(sc_ipc->dev, "msg rx size %u\n", sc_ipc->rx_size);
144 if (sc_ipc->rx_size > 4)
145 dev_warn(sc_ipc->dev, "RPC does not support receiving over 4 words: %u\n",
149 sc_ipc->msg[sc_chan->idx] = *data;
152 dev_dbg(sc_ipc->dev, "mu %u msg %u 0x%x\n", sc_chan->idx,
153 sc_ipc->count, *data);
155 if ((sc_ipc->rx_size != 0) && (sc_ipc->count == sc_ipc->rx_size))
156 complete(&sc_ipc->done);
159 static int imx_scu_ipc_write(struct imx_sc_ipc *sc_ipc, void *msg)
161 struct imx_sc_rpc_msg hdr = *(struct imx_sc_rpc_msg *)msg;
162 struct imx_sc_chan *sc_chan;
169 if (hdr.size > IMX_SC_RPC_MAX_MSG)
172 dev_dbg(sc_ipc->dev, "RPC SVC %u FUNC %u SIZE %u\n", hdr.svc,
175 size = sc_ipc->fast_ipc ? 1 : hdr.size;
176 for (i = 0; i < size; i++) {
177 sc_chan = &sc_ipc->chans[i % 4];
180 * SCU requires that all messages words are written
181 * sequentially but linux MU driver implements multiple
182 * independent channels for each register so ordering between
183 * different channels must be ensured by SCU API interface.
185 * Wait for tx_done before every send to ensure that no
186 * queueing happens at the mailbox channel level.
188 if (!sc_ipc->fast_ipc) {
189 wait_for_completion(&sc_chan->tx_done);
190 reinit_completion(&sc_chan->tx_done);
193 ret = mbox_send_message(sc_chan->ch, &data[i]);
202 * RPC command/response
204 int imx_scu_call_rpc(struct imx_sc_ipc *sc_ipc, void *msg, bool have_resp)
206 struct imx_sc_rpc_msg *hdr;
209 if (WARN_ON(!sc_ipc || !msg))
212 mutex_lock(&sc_ipc->lock);
213 reinit_completion(&sc_ipc->done);
218 ret = imx_scu_ipc_write(sc_ipc, msg);
220 dev_err(sc_ipc->dev, "RPC send msg failed: %d\n", ret);
225 if (!wait_for_completion_timeout(&sc_ipc->done,
227 dev_err(sc_ipc->dev, "RPC send msg timeout\n");
228 mutex_unlock(&sc_ipc->lock);
232 /* response status is stored in hdr->func field */
239 mutex_unlock(&sc_ipc->lock);
241 dev_dbg(sc_ipc->dev, "RPC SVC done\n");
243 return imx_sc_to_linux_errno(ret);
245 EXPORT_SYMBOL(imx_scu_call_rpc);
247 static int imx_scu_probe(struct platform_device *pdev)
249 struct device *dev = &pdev->dev;
250 struct imx_sc_ipc *sc_ipc;
251 struct imx_sc_chan *sc_chan;
252 struct mbox_client *cl;
254 struct of_phandle_args args;
259 sc_ipc = devm_kzalloc(dev, sizeof(*sc_ipc), GFP_KERNEL);
263 ret = of_parse_phandle_with_args(pdev->dev.of_node, "mboxes",
264 "#mbox-cells", 0, &args);
268 sc_ipc->fast_ipc = of_device_is_compatible(args.np, "fsl,imx8-mu-scu");
270 num_channel = sc_ipc->fast_ipc ? 2 : SCU_MU_CHAN_NUM;
271 for (i = 0; i < num_channel; i++) {
272 if (i < num_channel / 2)
273 chan_name = kasprintf(GFP_KERNEL, "tx%d", i);
275 chan_name = kasprintf(GFP_KERNEL, "rx%d",
276 i - num_channel / 2);
281 sc_chan = &sc_ipc->chans[i];
284 cl->tx_block = false;
285 cl->knows_txdone = true;
286 cl->rx_callback = imx_scu_rx_callback;
288 if (!sc_ipc->fast_ipc) {
289 /* Initial tx_done completion as "done" */
290 cl->tx_done = imx_scu_tx_done;
291 init_completion(&sc_chan->tx_done);
292 complete(&sc_chan->tx_done);
295 sc_chan->sc_ipc = sc_ipc;
296 sc_chan->idx = i % (num_channel / 2);
297 sc_chan->ch = mbox_request_channel_byname(cl, chan_name);
298 if (IS_ERR(sc_chan->ch)) {
299 ret = PTR_ERR(sc_chan->ch);
300 if (ret != -EPROBE_DEFER)
301 dev_err(dev, "Failed to request mbox chan %s ret %d\n",
306 dev_dbg(dev, "request mbox chan %s\n", chan_name);
307 /* chan_name is not used anymore by framework */
312 mutex_init(&sc_ipc->lock);
313 init_completion(&sc_ipc->done);
315 imx_sc_ipc_handle = sc_ipc;
317 ret = imx_scu_enable_general_irq_channel(dev);
320 "failed to enable general irq channel: %d\n", ret);
322 dev_info(dev, "NXP i.MX SCU Initialized\n");
324 return devm_of_platform_populate(dev);
327 static const struct of_device_id imx_scu_match[] = {
328 { .compatible = "fsl,imx-scu", },
332 static struct platform_driver imx_scu_driver = {
335 .of_match_table = imx_scu_match,
337 .probe = imx_scu_probe,
339 builtin_platform_driver(imx_scu_driver);
341 MODULE_AUTHOR("Dong Aisheng <aisheng.dong@nxp.com>");
342 MODULE_DESCRIPTION("IMX SCU firmware protocol driver");
343 MODULE_LICENSE("GPL v2");