1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Copyright 2018 NXP
4 * Author: Dong Aisheng <aisheng.dong@nxp.com>
5 *
6 * Implementation of the SCU IPC functions using MUs (client side).
7 *
8 */
9
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>
22
23 #define SCU_MU_CHAN_NUM 8
24 #define MAX_RX_TIMEOUT (msecs_to_jiffies(30))
25
26 struct imx_sc_chan {
27 struct imx_sc_ipc *sc_ipc;
28
29 struct mbox_client cl;
30 struct mbox_chan *ch;
31 int idx;
32 };
33
34 struct imx_sc_ipc {
35 /* SCU uses 4 Tx and 4 Rx channels */
36 struct imx_sc_chan chans[SCU_MU_CHAN_NUM];
37 struct device *dev;
38 struct mutex lock;
39 struct completion done;
40
41 /* temporarily store the SCU msg */
42 u32 *msg;
43 u8 rx_size;
44 u8 count;
45 };
46
47 /*
48 * This type is used to indicate error response for most functions.
49 */
50 enum imx_sc_error_codes {
51 IMX_SC_ERR_NONE = 0, /* Success */
52 IMX_SC_ERR_VERSION = 1, /* Incompatible API version */
53 IMX_SC_ERR_CONFIG = 2, /* Configuration error */
54 IMX_SC_ERR_PARM = 3, /* Bad parameter */
55 IMX_SC_ERR_NOACCESS = 4, /* Permission error (no access) */
56 IMX_SC_ERR_LOCKED = 5, /* Permission error (locked) */
57 IMX_SC_ERR_UNAVAILABLE = 6, /* Unavailable (out of resources) */
58 IMX_SC_ERR_NOTFOUND = 7, /* Not found */
59 IMX_SC_ERR_NOPOWER = 8, /* No power */
60 IMX_SC_ERR_IPC = 9, /* Generic IPC error */
61 IMX_SC_ERR_BUSY = 10, /* Resource is currently busy/active */
62 IMX_SC_ERR_FAIL = 11, /* General I/O failure */
63 IMX_SC_ERR_LAST
64 };
65
66 static int imx_sc_linux_errmap[IMX_SC_ERR_LAST] = {
67 0, /* IMX_SC_ERR_NONE */
68 -EINVAL, /* IMX_SC_ERR_VERSION */
69 -EINVAL, /* IMX_SC_ERR_CONFIG */
70 -EINVAL, /* IMX_SC_ERR_PARM */
71 -EACCES, /* IMX_SC_ERR_NOACCESS */
72 -EACCES, /* IMX_SC_ERR_LOCKED */
73 -ERANGE, /* IMX_SC_ERR_UNAVAILABLE */
74 -EEXIST, /* IMX_SC_ERR_NOTFOUND */
75 -EPERM, /* IMX_SC_ERR_NOPOWER */
76 -EPIPE, /* IMX_SC_ERR_IPC */
77 -EBUSY, /* IMX_SC_ERR_BUSY */
78 -EIO, /* IMX_SC_ERR_FAIL */
79 };
80
81 static struct imx_sc_ipc *imx_sc_ipc_handle;
82
imx_sc_to_linux_errno(int errno)83 static inline int imx_sc_to_linux_errno(int errno)
84 {
85 if (errno >= IMX_SC_ERR_NONE && errno < IMX_SC_ERR_LAST)
86 return imx_sc_linux_errmap[errno];
87 return -EIO;
88 }
89
90 /*
91 * Get the default handle used by SCU
92 */
imx_scu_get_handle(struct imx_sc_ipc ** ipc)93 int imx_scu_get_handle(struct imx_sc_ipc **ipc)
94 {
95 if (!imx_sc_ipc_handle)
96 return -EPROBE_DEFER;
97
98 *ipc = imx_sc_ipc_handle;
99 return 0;
100 }
101 EXPORT_SYMBOL(imx_scu_get_handle);
102
imx_scu_rx_callback(struct mbox_client * c,void * msg)103 static void imx_scu_rx_callback(struct mbox_client *c, void *msg)
104 {
105 struct imx_sc_chan *sc_chan = container_of(c, struct imx_sc_chan, cl);
106 struct imx_sc_ipc *sc_ipc = sc_chan->sc_ipc;
107 struct imx_sc_rpc_msg *hdr;
108 u32 *data = msg;
109
110 if (sc_chan->idx == 0) {
111 hdr = msg;
112 sc_ipc->rx_size = hdr->size;
113 dev_dbg(sc_ipc->dev, "msg rx size %u\n", sc_ipc->rx_size);
114 if (sc_ipc->rx_size > 4)
115 dev_warn(sc_ipc->dev, "RPC does not support receiving over 4 words: %u\n",
116 sc_ipc->rx_size);
117 }
118
119 sc_ipc->msg[sc_chan->idx] = *data;
120 sc_ipc->count++;
121
122 dev_dbg(sc_ipc->dev, "mu %u msg %u 0x%x\n", sc_chan->idx,
123 sc_ipc->count, *data);
124
125 if ((sc_ipc->rx_size != 0) && (sc_ipc->count == sc_ipc->rx_size))
126 complete(&sc_ipc->done);
127 }
128
imx_scu_ipc_write(struct imx_sc_ipc * sc_ipc,void * msg)129 static int imx_scu_ipc_write(struct imx_sc_ipc *sc_ipc, void *msg)
130 {
131 struct imx_sc_rpc_msg *hdr = msg;
132 struct imx_sc_chan *sc_chan;
133 u32 *data = msg;
134 int ret;
135 int i;
136
137 /* Check size */
138 if (hdr->size > IMX_SC_RPC_MAX_MSG)
139 return -EINVAL;
140
141 dev_dbg(sc_ipc->dev, "RPC SVC %u FUNC %u SIZE %u\n", hdr->svc,
142 hdr->func, hdr->size);
143
144 for (i = 0; i < hdr->size; i++) {
145 sc_chan = &sc_ipc->chans[i % 4];
146 ret = mbox_send_message(sc_chan->ch, &data[i]);
147 if (ret < 0)
148 return ret;
149 }
150
151 return 0;
152 }
153
154 /*
155 * RPC command/response
156 */
imx_scu_call_rpc(struct imx_sc_ipc * sc_ipc,void * msg,bool have_resp)157 int imx_scu_call_rpc(struct imx_sc_ipc *sc_ipc, void *msg, bool have_resp)
158 {
159 struct imx_sc_rpc_msg *hdr;
160 int ret;
161
162 if (WARN_ON(!sc_ipc || !msg))
163 return -EINVAL;
164
165 mutex_lock(&sc_ipc->lock);
166 reinit_completion(&sc_ipc->done);
167
168 sc_ipc->msg = msg;
169 sc_ipc->count = 0;
170 ret = imx_scu_ipc_write(sc_ipc, msg);
171 if (ret < 0) {
172 dev_err(sc_ipc->dev, "RPC send msg failed: %d\n", ret);
173 goto out;
174 }
175
176 if (have_resp) {
177 if (!wait_for_completion_timeout(&sc_ipc->done,
178 MAX_RX_TIMEOUT)) {
179 dev_err(sc_ipc->dev, "RPC send msg timeout\n");
180 mutex_unlock(&sc_ipc->lock);
181 return -ETIMEDOUT;
182 }
183
184 /* response status is stored in hdr->func field */
185 hdr = msg;
186 ret = hdr->func;
187 }
188
189 out:
190 mutex_unlock(&sc_ipc->lock);
191
192 dev_dbg(sc_ipc->dev, "RPC SVC done\n");
193
194 return imx_sc_to_linux_errno(ret);
195 }
196 EXPORT_SYMBOL(imx_scu_call_rpc);
197
imx_scu_probe(struct platform_device * pdev)198 static int imx_scu_probe(struct platform_device *pdev)
199 {
200 struct device *dev = &pdev->dev;
201 struct imx_sc_ipc *sc_ipc;
202 struct imx_sc_chan *sc_chan;
203 struct mbox_client *cl;
204 char *chan_name;
205 int ret;
206 int i;
207
208 sc_ipc = devm_kzalloc(dev, sizeof(*sc_ipc), GFP_KERNEL);
209 if (!sc_ipc)
210 return -ENOMEM;
211
212 for (i = 0; i < SCU_MU_CHAN_NUM; i++) {
213 if (i < 4)
214 chan_name = kasprintf(GFP_KERNEL, "tx%d", i);
215 else
216 chan_name = kasprintf(GFP_KERNEL, "rx%d", i - 4);
217
218 if (!chan_name)
219 return -ENOMEM;
220
221 sc_chan = &sc_ipc->chans[i];
222 cl = &sc_chan->cl;
223 cl->dev = dev;
224 cl->tx_block = false;
225 cl->knows_txdone = true;
226 cl->rx_callback = imx_scu_rx_callback;
227
228 sc_chan->sc_ipc = sc_ipc;
229 sc_chan->idx = i % 4;
230 sc_chan->ch = mbox_request_channel_byname(cl, chan_name);
231 if (IS_ERR(sc_chan->ch)) {
232 ret = PTR_ERR(sc_chan->ch);
233 if (ret != -EPROBE_DEFER)
234 dev_err(dev, "Failed to request mbox chan %s ret %d\n",
235 chan_name, ret);
236 return ret;
237 }
238
239 dev_dbg(dev, "request mbox chan %s\n", chan_name);
240 /* chan_name is not used anymore by framework */
241 kfree(chan_name);
242 }
243
244 sc_ipc->dev = dev;
245 mutex_init(&sc_ipc->lock);
246 init_completion(&sc_ipc->done);
247
248 imx_sc_ipc_handle = sc_ipc;
249
250 ret = imx_scu_enable_general_irq_channel(dev);
251 if (ret)
252 dev_warn(dev,
253 "failed to enable general irq channel: %d\n", ret);
254
255 dev_info(dev, "NXP i.MX SCU Initialized\n");
256
257 return devm_of_platform_populate(dev);
258 }
259
260 static const struct of_device_id imx_scu_match[] = {
261 { .compatible = "fsl,imx-scu", },
262 { /* Sentinel */ }
263 };
264
265 static struct platform_driver imx_scu_driver = {
266 .driver = {
267 .name = "imx-scu",
268 .of_match_table = imx_scu_match,
269 },
270 .probe = imx_scu_probe,
271 };
272 builtin_platform_driver(imx_scu_driver);
273
274 MODULE_AUTHOR("Dong Aisheng <aisheng.dong@nxp.com>");
275 MODULE_DESCRIPTION("IMX SCU firmware protocol driver");
276 MODULE_LICENSE("GPL v2");
277
