1 // SPDX-License-Identifier: GPL-2.0
2 //
3 // Copyright (c) 2018 MediaTek Inc.
4 
5 #include <linux/completion.h>
6 #include <linux/errno.h>
7 #include <linux/dma-mapping.h>
8 #include <linux/module.h>
9 #include <linux/mailbox_controller.h>
10 #include <linux/soc/mediatek/mtk-cmdq.h>
11 
12 #define CMDQ_ARG_A_WRITE_MASK	0xffff
13 #define CMDQ_WRITE_ENABLE_MASK	BIT(0)
14 #define CMDQ_EOC_IRQ_EN		BIT(0)
15 #define CMDQ_EOC_CMD		((u64)((CMDQ_CODE_EOC << CMDQ_OP_CODE_SHIFT)) \
16 				<< 32 | CMDQ_EOC_IRQ_EN)
17 
18 static void cmdq_client_timeout(struct timer_list *t)
19 {
20 	struct cmdq_client *client = from_timer(client, t, timer);
21 
22 	dev_err(client->client.dev, "cmdq timeout!\n");
23 }
24 
25 struct cmdq_client *cmdq_mbox_create(struct device *dev, int index, u32 timeout)
26 {
27 	struct cmdq_client *client;
28 
29 	client = kzalloc(sizeof(*client), GFP_KERNEL);
30 	if (!client)
31 		return (struct cmdq_client *)-ENOMEM;
32 
33 	client->timeout_ms = timeout;
34 	if (timeout != CMDQ_NO_TIMEOUT) {
35 		spin_lock_init(&client->lock);
36 		timer_setup(&client->timer, cmdq_client_timeout, 0);
37 	}
38 	client->pkt_cnt = 0;
39 	client->client.dev = dev;
40 	client->client.tx_block = false;
41 	client->chan = mbox_request_channel(&client->client, index);
42 
43 	if (IS_ERR(client->chan)) {
44 		long err;
45 
46 		dev_err(dev, "failed to request channel\n");
47 		err = PTR_ERR(client->chan);
48 		kfree(client);
49 
50 		return ERR_PTR(err);
51 	}
52 
53 	return client;
54 }
55 EXPORT_SYMBOL(cmdq_mbox_create);
56 
57 void cmdq_mbox_destroy(struct cmdq_client *client)
58 {
59 	if (client->timeout_ms != CMDQ_NO_TIMEOUT) {
60 		spin_lock(&client->lock);
61 		del_timer_sync(&client->timer);
62 		spin_unlock(&client->lock);
63 	}
64 	mbox_free_channel(client->chan);
65 	kfree(client);
66 }
67 EXPORT_SYMBOL(cmdq_mbox_destroy);
68 
69 struct cmdq_pkt *cmdq_pkt_create(struct cmdq_client *client, size_t size)
70 {
71 	struct cmdq_pkt *pkt;
72 	struct device *dev;
73 	dma_addr_t dma_addr;
74 
75 	pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
76 	if (!pkt)
77 		return ERR_PTR(-ENOMEM);
78 	pkt->va_base = kzalloc(size, GFP_KERNEL);
79 	if (!pkt->va_base) {
80 		kfree(pkt);
81 		return ERR_PTR(-ENOMEM);
82 	}
83 	pkt->buf_size = size;
84 	pkt->cl = (void *)client;
85 
86 	dev = client->chan->mbox->dev;
87 	dma_addr = dma_map_single(dev, pkt->va_base, pkt->buf_size,
88 				  DMA_TO_DEVICE);
89 	if (dma_mapping_error(dev, dma_addr)) {
90 		dev_err(dev, "dma map failed, size=%u\n", (u32)(u64)size);
91 		kfree(pkt->va_base);
92 		kfree(pkt);
93 		return ERR_PTR(-ENOMEM);
94 	}
95 
96 	pkt->pa_base = dma_addr;
97 
98 	return pkt;
99 }
100 EXPORT_SYMBOL(cmdq_pkt_create);
101 
102 void cmdq_pkt_destroy(struct cmdq_pkt *pkt)
103 {
104 	struct cmdq_client *client = (struct cmdq_client *)pkt->cl;
105 
106 	dma_unmap_single(client->chan->mbox->dev, pkt->pa_base, pkt->buf_size,
107 			 DMA_TO_DEVICE);
108 	kfree(pkt->va_base);
109 	kfree(pkt);
110 }
111 EXPORT_SYMBOL(cmdq_pkt_destroy);
112 
113 static int cmdq_pkt_append_command(struct cmdq_pkt *pkt, enum cmdq_code code,
114 				   u32 arg_a, u32 arg_b)
115 {
116 	u64 *cmd_ptr;
117 
118 	if (unlikely(pkt->cmd_buf_size + CMDQ_INST_SIZE > pkt->buf_size)) {
119 		/*
120 		 * In the case of allocated buffer size (pkt->buf_size) is used
121 		 * up, the real required size (pkt->cmdq_buf_size) is still
122 		 * increased, so that the user knows how much memory should be
123 		 * ultimately allocated after appending all commands and
124 		 * flushing the command packet. Therefor, the user can call
125 		 * cmdq_pkt_create() again with the real required buffer size.
126 		 */
127 		pkt->cmd_buf_size += CMDQ_INST_SIZE;
128 		WARN_ONCE(1, "%s: buffer size %u is too small !\n",
129 			__func__, (u32)pkt->buf_size);
130 		return -ENOMEM;
131 	}
132 	cmd_ptr = pkt->va_base + pkt->cmd_buf_size;
133 	(*cmd_ptr) = (u64)((code << CMDQ_OP_CODE_SHIFT) | arg_a) << 32 | arg_b;
134 	pkt->cmd_buf_size += CMDQ_INST_SIZE;
135 
136 	return 0;
137 }
138 
139 int cmdq_pkt_write(struct cmdq_pkt *pkt, u8 subsys, u16 offset, u32 value)
140 {
141 	u32 arg_a = (offset & CMDQ_ARG_A_WRITE_MASK) |
142 		    (subsys << CMDQ_SUBSYS_SHIFT);
143 
144 	return cmdq_pkt_append_command(pkt, CMDQ_CODE_WRITE, arg_a, value);
145 }
146 EXPORT_SYMBOL(cmdq_pkt_write);
147 
148 int cmdq_pkt_write_mask(struct cmdq_pkt *pkt, u8 subsys,
149 			u16 offset, u32 value, u32 mask)
150 {
151 	u32 offset_mask = offset;
152 	int err = 0;
153 
154 	if (mask != 0xffffffff) {
155 		err = cmdq_pkt_append_command(pkt, CMDQ_CODE_MASK, 0, ~mask);
156 		offset_mask |= CMDQ_WRITE_ENABLE_MASK;
157 	}
158 	err |= cmdq_pkt_write(pkt, subsys, offset_mask, value);
159 
160 	return err;
161 }
162 EXPORT_SYMBOL(cmdq_pkt_write_mask);
163 
164 int cmdq_pkt_wfe(struct cmdq_pkt *pkt, u16 event)
165 {
166 	u32 arg_b;
167 
168 	if (event >= CMDQ_MAX_EVENT)
169 		return -EINVAL;
170 
171 	/*
172 	 * WFE arg_b
173 	 * bit 0-11: wait value
174 	 * bit 15: 1 - wait, 0 - no wait
175 	 * bit 16-27: update value
176 	 * bit 31: 1 - update, 0 - no update
177 	 */
178 	arg_b = CMDQ_WFE_UPDATE | CMDQ_WFE_WAIT | CMDQ_WFE_WAIT_VALUE;
179 
180 	return cmdq_pkt_append_command(pkt, CMDQ_CODE_WFE, event, arg_b);
181 }
182 EXPORT_SYMBOL(cmdq_pkt_wfe);
183 
184 int cmdq_pkt_clear_event(struct cmdq_pkt *pkt, u16 event)
185 {
186 	if (event >= CMDQ_MAX_EVENT)
187 		return -EINVAL;
188 
189 	return cmdq_pkt_append_command(pkt, CMDQ_CODE_WFE, event,
190 				       CMDQ_WFE_UPDATE);
191 }
192 EXPORT_SYMBOL(cmdq_pkt_clear_event);
193 
194 static int cmdq_pkt_finalize(struct cmdq_pkt *pkt)
195 {
196 	int err;
197 
198 	/* insert EOC and generate IRQ for each command iteration */
199 	err = cmdq_pkt_append_command(pkt, CMDQ_CODE_EOC, 0, CMDQ_EOC_IRQ_EN);
200 
201 	/* JUMP to end */
202 	err |= cmdq_pkt_append_command(pkt, CMDQ_CODE_JUMP, 0, CMDQ_JUMP_PASS);
203 
204 	return err;
205 }
206 
207 static void cmdq_pkt_flush_async_cb(struct cmdq_cb_data data)
208 {
209 	struct cmdq_pkt *pkt = (struct cmdq_pkt *)data.data;
210 	struct cmdq_task_cb *cb = &pkt->cb;
211 	struct cmdq_client *client = (struct cmdq_client *)pkt->cl;
212 
213 	if (client->timeout_ms != CMDQ_NO_TIMEOUT) {
214 		unsigned long flags = 0;
215 
216 		spin_lock_irqsave(&client->lock, flags);
217 		if (--client->pkt_cnt == 0)
218 			del_timer(&client->timer);
219 		else
220 			mod_timer(&client->timer, jiffies +
221 				  msecs_to_jiffies(client->timeout_ms));
222 		spin_unlock_irqrestore(&client->lock, flags);
223 	}
224 
225 	dma_sync_single_for_cpu(client->chan->mbox->dev, pkt->pa_base,
226 				pkt->cmd_buf_size, DMA_TO_DEVICE);
227 	if (cb->cb) {
228 		data.data = cb->data;
229 		cb->cb(data);
230 	}
231 }
232 
233 int cmdq_pkt_flush_async(struct cmdq_pkt *pkt, cmdq_async_flush_cb cb,
234 			 void *data)
235 {
236 	int err;
237 	unsigned long flags = 0;
238 	struct cmdq_client *client = (struct cmdq_client *)pkt->cl;
239 
240 	err = cmdq_pkt_finalize(pkt);
241 	if (err < 0)
242 		return err;
243 
244 	pkt->cb.cb = cb;
245 	pkt->cb.data = data;
246 	pkt->async_cb.cb = cmdq_pkt_flush_async_cb;
247 	pkt->async_cb.data = pkt;
248 
249 	dma_sync_single_for_device(client->chan->mbox->dev, pkt->pa_base,
250 				   pkt->cmd_buf_size, DMA_TO_DEVICE);
251 
252 	if (client->timeout_ms != CMDQ_NO_TIMEOUT) {
253 		spin_lock_irqsave(&client->lock, flags);
254 		if (client->pkt_cnt++ == 0)
255 			mod_timer(&client->timer, jiffies +
256 				  msecs_to_jiffies(client->timeout_ms));
257 		spin_unlock_irqrestore(&client->lock, flags);
258 	}
259 
260 	mbox_send_message(client->chan, pkt);
261 	/* We can send next packet immediately, so just call txdone. */
262 	mbox_client_txdone(client->chan, 0);
263 
264 	return 0;
265 }
266 EXPORT_SYMBOL(cmdq_pkt_flush_async);
267 
268 struct cmdq_flush_completion {
269 	struct completion cmplt;
270 	bool err;
271 };
272 
273 static void cmdq_pkt_flush_cb(struct cmdq_cb_data data)
274 {
275 	struct cmdq_flush_completion *cmplt;
276 
277 	cmplt = (struct cmdq_flush_completion *)data.data;
278 	if (data.sta != CMDQ_CB_NORMAL)
279 		cmplt->err = true;
280 	else
281 		cmplt->err = false;
282 	complete(&cmplt->cmplt);
283 }
284 
285 int cmdq_pkt_flush(struct cmdq_pkt *pkt)
286 {
287 	struct cmdq_flush_completion cmplt;
288 	int err;
289 
290 	init_completion(&cmplt.cmplt);
291 	err = cmdq_pkt_flush_async(pkt, cmdq_pkt_flush_cb, &cmplt);
292 	if (err < 0)
293 		return err;
294 	wait_for_completion(&cmplt.cmplt);
295 
296 	return cmplt.err ? -EFAULT : 0;
297 }
298 EXPORT_SYMBOL(cmdq_pkt_flush);
299 
300 MODULE_LICENSE("GPL v2");
301