summaryrefslogtreecommitdiffstats
path: root/drivers/firmware/imx/imx-scu.c
blob: f71eaa5bf52d411c750aa359aa13f4a00d88130c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright 2018 NXP
 *  Author: Dong Aisheng <aisheng.dong@nxp.com>
 *
 * Implementation of the SCU IPC functions using MUs (client side).
 *
 */

#include <linux/err.h>
#include <linux/firmware/imx/types.h>
#include <linux/firmware/imx/ipc.h>
#include <linux/firmware/imx/sci.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/kernel.h>
#include <linux/mailbox_client.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>

#define SCU_MU_CHAN_NUM		8
#define MAX_RX_TIMEOUT		(msecs_to_jiffies(30))

struct imx_sc_chan {
	struct imx_sc_ipc *sc_ipc;

	struct mbox_client cl;
	struct mbox_chan *ch;
	int idx;
	struct completion tx_done;
};

struct imx_sc_ipc {
	/* SCU uses 4 Tx and 4 Rx channels */
	struct imx_sc_chan chans[SCU_MU_CHAN_NUM];
	struct device *dev;
	struct mutex lock;
	struct completion done;

	/* temporarily store the SCU msg */
	u32 *msg;
	u8 rx_size;
	u8 count;
};

/*
 * This type is used to indicate error response for most functions.
 */
enum imx_sc_error_codes {
	IMX_SC_ERR_NONE = 0,	/* Success */
	IMX_SC_ERR_VERSION = 1,	/* Incompatible API version */
	IMX_SC_ERR_CONFIG = 2,	/* Configuration error */
	IMX_SC_ERR_PARM = 3,	/* Bad parameter */
	IMX_SC_ERR_NOACCESS = 4,	/* Permission error (no access) */
	IMX_SC_ERR_LOCKED = 5,	/* Permission error (locked) */
	IMX_SC_ERR_UNAVAILABLE = 6,	/* Unavailable (out of resources) */
	IMX_SC_ERR_NOTFOUND = 7,	/* Not found */
	IMX_SC_ERR_NOPOWER = 8,	/* No power */
	IMX_SC_ERR_IPC = 9,		/* Generic IPC error */
	IMX_SC_ERR_BUSY = 10,	/* Resource is currently busy/active */
	IMX_SC_ERR_FAIL = 11,	/* General I/O failure */
	IMX_SC_ERR_LAST
};

static int imx_sc_linux_errmap[IMX_SC_ERR_LAST] = {
	0,	 /* IMX_SC_ERR_NONE */
	-EINVAL, /* IMX_SC_ERR_VERSION */
	-EINVAL, /* IMX_SC_ERR_CONFIG */
	-EINVAL, /* IMX_SC_ERR_PARM */
	-EACCES, /* IMX_SC_ERR_NOACCESS */
	-EACCES, /* IMX_SC_ERR_LOCKED */
	-ERANGE, /* IMX_SC_ERR_UNAVAILABLE */
	-EEXIST, /* IMX_SC_ERR_NOTFOUND */
	-EPERM,	 /* IMX_SC_ERR_NOPOWER */
	-EPIPE,	 /* IMX_SC_ERR_IPC */
	-EBUSY,	 /* IMX_SC_ERR_BUSY */
	-EIO,	 /* IMX_SC_ERR_FAIL */
};

static struct imx_sc_ipc *imx_sc_ipc_handle;

static inline int imx_sc_to_linux_errno(int errno)
{
	if (errno >= IMX_SC_ERR_NONE && errno < IMX_SC_ERR_LAST)
		return imx_sc_linux_errmap[errno];
	return -EIO;
}

/*
 * Get the default handle used by SCU
 */
int imx_scu_get_handle(struct imx_sc_ipc **ipc)
{
	if (!imx_sc_ipc_handle)
		return -EPROBE_DEFER;

	*ipc = imx_sc_ipc_handle;
	return 0;
}
EXPORT_SYMBOL(imx_scu_get_handle);

/* Callback called when the word of a message is ack-ed, eg read by SCU */
static void imx_scu_tx_done(struct mbox_client *cl, void *mssg, int r)
{
	struct imx_sc_chan *sc_chan = container_of(cl, struct imx_sc_chan, cl);

	complete(&sc_chan->tx_done);
}

static void imx_scu_rx_callback(struct mbox_client *c, void *msg)
{
	struct imx_sc_chan *sc_chan = container_of(c, struct imx_sc_chan, cl);
	struct imx_sc_ipc *sc_ipc = sc_chan->sc_ipc;
	struct imx_sc_rpc_msg *hdr;
	u32 *data = msg;

	if (!sc_ipc->msg) {
		dev_warn(sc_ipc->dev, "unexpected rx idx %d 0x%08x, ignore!\n",
				sc_chan->idx, *data);
		return;
	}

	if (sc_chan->idx == 0) {
		hdr = msg;
		sc_ipc->rx_size = hdr->size;
		dev_dbg(sc_ipc->dev, "msg rx size %u\n", sc_ipc->rx_size);
		if (sc_ipc->rx_size > 4)
			dev_warn(sc_ipc->dev, "RPC does not support receiving over 4 words: %u\n",
				 sc_ipc->rx_size);
	}

	sc_ipc->msg[sc_chan->idx] = *data;
	sc_ipc->count++;

	dev_dbg(sc_ipc->dev, "mu %u msg %u 0x%x\n", sc_chan->idx,
		sc_ipc->count, *data);

	if ((sc_ipc->rx_size != 0) && (sc_ipc->count == sc_ipc->rx_size))
		complete(&sc_ipc->done);
}

static int imx_scu_ipc_write(struct imx_sc_ipc *sc_ipc, void *msg)
{
	struct imx_sc_rpc_msg *hdr = msg;
	struct imx_sc_chan *sc_chan;
	u32 *data = msg;
	int ret;
	int i;

	/* Check size */
	if (hdr->size > IMX_SC_RPC_MAX_MSG)
		return -EINVAL;

	dev_dbg(sc_ipc->dev, "RPC SVC %u FUNC %u SIZE %u\n", hdr->svc,
		hdr->func, hdr->size);

	for (i = 0; i < hdr->size; i++) {
		sc_chan = &sc_ipc->chans[i % 4];

		/*
		 * SCU requires that all messages words are written
		 * sequentially but linux MU driver implements multiple
		 * independent channels for each register so ordering between
		 * different channels must be ensured by SCU API interface.
		 *
		 * Wait for tx_done before every send to ensure that no
		 * queueing happens at the mailbox channel level.
		 */
		wait_for_completion(&sc_chan->tx_done);
		reinit_completion(&sc_chan->tx_done);

		ret = mbox_send_message(sc_chan->ch, &data[i]);
		if (ret < 0)
			return ret;
	}

	return 0;
}

/*
 * RPC command/response
 */
int imx_scu_call_rpc(struct imx_sc_ipc *sc_ipc, void *msg, bool have_resp)
{
	uint8_t saved_svc, saved_func;
	struct imx_sc_rpc_msg *hdr;
	int ret;

	if (WARN_ON(!sc_ipc || !msg))
		return -EINVAL;

	mutex_lock(&sc_ipc->lock);
	reinit_completion(&sc_ipc->done);

	if (have_resp) {
		sc_ipc->msg = msg;
		saved_svc = ((struct imx_sc_rpc_msg *)msg)->svc;
		saved_func = ((struct imx_sc_rpc_msg *)msg)->func;
	}
	sc_ipc->count = 0;
	ret = imx_scu_ipc_write(sc_ipc, msg);
	if (ret < 0) {
		dev_err(sc_ipc->dev, "RPC send msg failed: %d\n", ret);
		goto out;
	}

	if (have_resp) {
		if (!wait_for_completion_timeout(&sc_ipc->done,
						 MAX_RX_TIMEOUT)) {
			dev_err(sc_ipc->dev, "RPC send msg timeout\n");
			mutex_unlock(&sc_ipc->lock);
			return -ETIMEDOUT;
		}

		/* response status is stored in hdr->func field */
		hdr = msg;
		ret = hdr->func;
		/*
		 * Some special SCU firmware APIs do NOT have return value
		 * in hdr->func, but they do have response data, those special
		 * APIs are defined as void function in SCU firmware, so they
		 * should be treated as return success always.
		 */
		if ((saved_svc == IMX_SC_RPC_SVC_MISC) &&
			(saved_func == IMX_SC_MISC_FUNC_UNIQUE_ID ||
			 saved_func == IMX_SC_MISC_FUNC_GET_BUTTON_STATUS))
			ret = 0;
	}

out:
	sc_ipc->msg = NULL;
	mutex_unlock(&sc_ipc->lock);

	dev_dbg(sc_ipc->dev, "RPC SVC done\n");

	return imx_sc_to_linux_errno(ret);
}
EXPORT_SYMBOL(imx_scu_call_rpc);

static int imx_scu_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct imx_sc_ipc *sc_ipc;
	struct imx_sc_chan *sc_chan;
	struct mbox_client *cl;
	char *chan_name;
	int ret;
	int i;

	sc_ipc = devm_kzalloc(dev, sizeof(*sc_ipc), GFP_KERNEL);
	if (!sc_ipc)
		return -ENOMEM;

	for (i = 0; i < SCU_MU_CHAN_NUM; i++) {
		if (i < 4)
			chan_name = kasprintf(GFP_KERNEL, "tx%d", i);
		else
			chan_name = kasprintf(GFP_KERNEL, "rx%d", i - 4);

		if (!chan_name)
			return -ENOMEM;

		sc_chan = &sc_ipc->chans[i];
		cl = &sc_chan->cl;
		cl->dev = dev;
		cl->tx_block = false;
		cl->knows_txdone = true;
		cl->rx_callback = imx_scu_rx_callback;

		/* Initial tx_done completion as "done" */
		cl->tx_done = imx_scu_tx_done;
		init_completion(&sc_chan->tx_done);
		complete(&sc_chan->tx_done);

		sc_chan->sc_ipc = sc_ipc;
		sc_chan->idx = i % 4;
		sc_chan->ch = mbox_request_channel_byname(cl, chan_name);
		if (IS_ERR(sc_chan->ch)) {
			ret = PTR_ERR(sc_chan->ch);
			if (ret != -EPROBE_DEFER)
				dev_err(dev, "Failed to request mbox chan %s ret %d\n",
					chan_name, ret);
			return ret;
		}

		dev_dbg(dev, "request mbox chan %s\n", chan_name);
		/* chan_name is not used anymore by framework */
		kfree(chan_name);
	}

	sc_ipc->dev = dev;
	mutex_init(&sc_ipc->lock);
	init_completion(&sc_ipc->done);

	imx_sc_ipc_handle = sc_ipc;

	ret = imx_scu_enable_general_irq_channel(dev);
	if (ret)
		dev_warn(dev,
			"failed to enable general irq channel: %d\n", ret);

	dev_info(dev, "NXP i.MX SCU Initialized\n");

	return devm_of_platform_populate(dev);
}

static const struct of_device_id imx_scu_match[] = {
	{ .compatible = "fsl,imx-scu", },
	{ /* Sentinel */ }
};

static struct platform_driver imx_scu_driver = {
	.driver = {
		.name = "imx-scu",
		.of_match_table = imx_scu_match,
	},
	.probe = imx_scu_probe,
};
builtin_platform_driver(imx_scu_driver);

MODULE_AUTHOR("Dong Aisheng <aisheng.dong@nxp.com>");
MODULE_DESCRIPTION("IMX SCU firmware protocol driver");
MODULE_LICENSE("GPL v2");