1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Interrupt bottom half (BH).
4 *
5 * Copyright (c) 2017-2020, Silicon Laboratories, Inc.
6 * Copyright (c) 2010, ST-Ericsson
7 */
8 #include <linux/gpio/consumer.h>
9 #include <net/mac80211.h>
10
11 #include "bh.h"
12 #include "wfx.h"
13 #include "hwio.h"
14 #include "traces.h"
15 #include "hif_rx.h"
16 #include "hif_api_cmd.h"
17
device_wakeup(struct wfx_dev * wdev)18 static void device_wakeup(struct wfx_dev *wdev)
19 {
20 int max_retry = 3;
21
22 if (!wdev->pdata.gpio_wakeup)
23 return;
24 if (gpiod_get_value_cansleep(wdev->pdata.gpio_wakeup) > 0)
25 return;
26
27 if (wfx_api_older_than(wdev, 1, 4)) {
28 gpiod_set_value_cansleep(wdev->pdata.gpio_wakeup, 1);
29 if (!completion_done(&wdev->hif.ctrl_ready))
30 usleep_range(2000, 2500);
31 return;
32 }
33 for (;;) {
34 gpiod_set_value_cansleep(wdev->pdata.gpio_wakeup, 1);
35 /* completion.h does not provide any function to wait completion without consume it
36 * (a kind of wait_for_completion_done_timeout()). So we have to emulate it.
37 */
38 if (wait_for_completion_timeout(&wdev->hif.ctrl_ready, msecs_to_jiffies(2))) {
39 complete(&wdev->hif.ctrl_ready);
40 return;
41 } else if (max_retry-- > 0) {
42 /* Older firmwares have a race in sleep/wake-up process. Redo the process
43 * is sufficient to unfreeze the chip.
44 */
45 dev_err(wdev->dev, "timeout while wake up chip\n");
46 gpiod_set_value_cansleep(wdev->pdata.gpio_wakeup, 0);
47 usleep_range(2000, 2500);
48 } else {
49 dev_err(wdev->dev, "max wake-up retries reached\n");
50 return;
51 }
52 }
53 }
54
device_release(struct wfx_dev * wdev)55 static void device_release(struct wfx_dev *wdev)
56 {
57 if (!wdev->pdata.gpio_wakeup)
58 return;
59
60 gpiod_set_value_cansleep(wdev->pdata.gpio_wakeup, 0);
61 }
62
rx_helper(struct wfx_dev * wdev,size_t read_len,int * is_cnf)63 static int rx_helper(struct wfx_dev *wdev, size_t read_len, int *is_cnf)
64 {
65 struct sk_buff *skb;
66 struct wfx_hif_msg *hif;
67 size_t alloc_len;
68 size_t computed_len;
69 int release_count;
70 int piggyback = 0;
71
72 WARN(read_len > round_down(0xFFF, 2) * sizeof(u16), "request exceed the chip capability");
73
74 /* Add 2 to take into account piggyback size */
75 alloc_len = wdev->hwbus_ops->align_size(wdev->hwbus_priv, read_len + 2);
76 skb = dev_alloc_skb(alloc_len);
77 if (!skb)
78 return -ENOMEM;
79
80 if (wfx_data_read(wdev, skb->data, alloc_len))
81 goto err;
82
83 piggyback = le16_to_cpup((__le16 *)(skb->data + alloc_len - 2));
84 _trace_piggyback(piggyback, false);
85
86 hif = (struct wfx_hif_msg *)skb->data;
87 WARN(hif->encrypted & 0x3, "encryption is unsupported");
88 if (WARN(read_len < sizeof(struct wfx_hif_msg), "corrupted read"))
89 goto err;
90 computed_len = le16_to_cpu(hif->len);
91 computed_len = round_up(computed_len, 2);
92 if (computed_len != read_len) {
93 dev_err(wdev->dev, "inconsistent message length: %zu != %zu\n",
94 computed_len, read_len);
95 print_hex_dump(KERN_INFO, "hif: ", DUMP_PREFIX_OFFSET, 16, 1,
96 hif, read_len, true);
97 goto err;
98 }
99
100 if (!(hif->id & HIF_ID_IS_INDICATION)) {
101 (*is_cnf)++;
102 if (hif->id == HIF_CNF_ID_MULTI_TRANSMIT)
103 release_count =
104 ((struct wfx_hif_cnf_multi_transmit *)hif->body)->num_tx_confs;
105 else
106 release_count = 1;
107 WARN(wdev->hif.tx_buffers_used < release_count, "corrupted buffer counter");
108 wdev->hif.tx_buffers_used -= release_count;
109 }
110 _trace_hif_recv(hif, wdev->hif.tx_buffers_used);
111
112 if (hif->id != HIF_IND_ID_EXCEPTION && hif->id != HIF_IND_ID_ERROR) {
113 if (hif->seqnum != wdev->hif.rx_seqnum)
114 dev_warn(wdev->dev, "wrong message sequence: %d != %d\n",
115 hif->seqnum, wdev->hif.rx_seqnum);
116 wdev->hif.rx_seqnum = (hif->seqnum + 1) % (HIF_COUNTER_MAX + 1);
117 }
118
119 skb_put(skb, le16_to_cpu(hif->len));
120 /* wfx_handle_rx takes care on SKB livetime */
121 wfx_handle_rx(wdev, skb);
122 if (!wdev->hif.tx_buffers_used)
123 wake_up(&wdev->hif.tx_buffers_empty);
124
125 return piggyback;
126
127 err:
128 if (skb)
129 dev_kfree_skb(skb);
130 return -EIO;
131 }
132
bh_work_rx(struct wfx_dev * wdev,int max_msg,int * num_cnf)133 static int bh_work_rx(struct wfx_dev *wdev, int max_msg, int *num_cnf)
134 {
135 size_t len;
136 int i;
137 int ctrl_reg, piggyback;
138
139 piggyback = 0;
140 for (i = 0; i < max_msg; i++) {
141 if (piggyback & CTRL_NEXT_LEN_MASK)
142 ctrl_reg = piggyback;
143 else if (try_wait_for_completion(&wdev->hif.ctrl_ready))
144 ctrl_reg = atomic_xchg(&wdev->hif.ctrl_reg, 0);
145 else
146 ctrl_reg = 0;
147 if (!(ctrl_reg & CTRL_NEXT_LEN_MASK))
148 return i;
149 /* ctrl_reg units are 16bits words */
150 len = (ctrl_reg & CTRL_NEXT_LEN_MASK) * 2;
151 piggyback = rx_helper(wdev, len, num_cnf);
152 if (piggyback < 0)
153 return i;
154 if (!(piggyback & CTRL_WLAN_READY))
155 dev_err(wdev->dev, "unexpected piggyback value: ready bit not set: %04x\n",
156 piggyback);
157 }
158 if (piggyback & CTRL_NEXT_LEN_MASK) {
159 ctrl_reg = atomic_xchg(&wdev->hif.ctrl_reg, piggyback);
160 complete(&wdev->hif.ctrl_ready);
161 if (ctrl_reg)
162 dev_err(wdev->dev, "unexpected IRQ happened: %04x/%04x\n",
163 ctrl_reg, piggyback);
164 }
165 return i;
166 }
167
tx_helper(struct wfx_dev * wdev,struct wfx_hif_msg * hif)168 static void tx_helper(struct wfx_dev *wdev, struct wfx_hif_msg *hif)
169 {
170 int ret;
171 void *data;
172 bool is_encrypted = false;
173 size_t len = le16_to_cpu(hif->len);
174
175 WARN(len < sizeof(*hif), "try to send corrupted data");
176
177 hif->seqnum = wdev->hif.tx_seqnum;
178 wdev->hif.tx_seqnum = (wdev->hif.tx_seqnum + 1) % (HIF_COUNTER_MAX + 1);
179
180 data = hif;
181 WARN(len > le16_to_cpu(wdev->hw_caps.size_inp_ch_buf),
182 "request exceed the chip capability: %zu > %d\n",
183 len, le16_to_cpu(wdev->hw_caps.size_inp_ch_buf));
184 len = wdev->hwbus_ops->align_size(wdev->hwbus_priv, len);
185 ret = wfx_data_write(wdev, data, len);
186 if (ret)
187 goto end;
188
189 wdev->hif.tx_buffers_used++;
190 _trace_hif_send(hif, wdev->hif.tx_buffers_used);
191 end:
192 if (is_encrypted)
193 kfree(data);
194 }
195
bh_work_tx(struct wfx_dev * wdev,int max_msg)196 static int bh_work_tx(struct wfx_dev *wdev, int max_msg)
197 {
198 struct wfx_hif_msg *hif;
199 int i;
200
201 for (i = 0; i < max_msg; i++) {
202 hif = NULL;
203 if (wdev->hif.tx_buffers_used < le16_to_cpu(wdev->hw_caps.num_inp_ch_bufs)) {
204 if (try_wait_for_completion(&wdev->hif_cmd.ready)) {
205 WARN(!mutex_is_locked(&wdev->hif_cmd.lock), "data locking error");
206 hif = wdev->hif_cmd.buf_send;
207 } else {
208 hif = wfx_tx_queues_get(wdev);
209 }
210 }
211 if (!hif)
212 return i;
213 tx_helper(wdev, hif);
214 }
215 return i;
216 }
217
218 /* In SDIO mode, it is necessary to make an access to a register to acknowledge last received
219 * message. It could be possible to restrict this acknowledge to SDIO mode and only if last
220 * operation was rx.
221 */
ack_sdio_data(struct wfx_dev * wdev)222 static void ack_sdio_data(struct wfx_dev *wdev)
223 {
224 u32 cfg_reg;
225
226 wfx_config_reg_read(wdev, &cfg_reg);
227 if (cfg_reg & 0xFF) {
228 dev_warn(wdev->dev, "chip reports errors: %02x\n", cfg_reg & 0xFF);
229 wfx_config_reg_write_bits(wdev, 0xFF, 0x00);
230 }
231 }
232
bh_work(struct work_struct * work)233 static void bh_work(struct work_struct *work)
234 {
235 struct wfx_dev *wdev = container_of(work, struct wfx_dev, hif.bh);
236 int stats_req = 0, stats_cnf = 0, stats_ind = 0;
237 bool release_chip = false, last_op_is_rx = false;
238 int num_tx, num_rx;
239
240 device_wakeup(wdev);
241 do {
242 num_tx = bh_work_tx(wdev, 32);
243 stats_req += num_tx;
244 if (num_tx)
245 last_op_is_rx = false;
246 num_rx = bh_work_rx(wdev, 32, &stats_cnf);
247 stats_ind += num_rx;
248 if (num_rx)
249 last_op_is_rx = true;
250 } while (num_rx || num_tx);
251 stats_ind -= stats_cnf;
252
253 if (last_op_is_rx)
254 ack_sdio_data(wdev);
255 if (!wdev->hif.tx_buffers_used && !work_pending(work)) {
256 device_release(wdev);
257 release_chip = true;
258 }
259 _trace_bh_stats(stats_ind, stats_req, stats_cnf, wdev->hif.tx_buffers_used, release_chip);
260 }
261
262 /* An IRQ from chip did occur */
wfx_bh_request_rx(struct wfx_dev * wdev)263 void wfx_bh_request_rx(struct wfx_dev *wdev)
264 {
265 u32 cur, prev;
266
267 wfx_control_reg_read(wdev, &cur);
268 prev = atomic_xchg(&wdev->hif.ctrl_reg, cur);
269 complete(&wdev->hif.ctrl_ready);
270 queue_work(wdev->bh_wq, &wdev->hif.bh);
271
272 if (!(cur & CTRL_NEXT_LEN_MASK))
273 dev_err(wdev->dev, "unexpected control register value: length field is 0: %04x\n",
274 cur);
275 if (prev != 0)
276 dev_err(wdev->dev, "received IRQ but previous data was not (yet) read: %04x/%04x\n",
277 prev, cur);
278 }
279
280 /* Driver want to send data */
wfx_bh_request_tx(struct wfx_dev * wdev)281 void wfx_bh_request_tx(struct wfx_dev *wdev)
282 {
283 queue_work(wdev->bh_wq, &wdev->hif.bh);
284 }
285
286 /* If IRQ is not available, this function allow to manually poll the control register and simulate
287 * an IRQ ahen an event happened.
288 *
289 * Note that the device has a bug: If an IRQ raise while host read control register, the IRQ is
290 * lost. So, use this function carefully (only duing device initialisation).
291 */
wfx_bh_poll_irq(struct wfx_dev * wdev)292 void wfx_bh_poll_irq(struct wfx_dev *wdev)
293 {
294 ktime_t now, start;
295 u32 reg;
296
297 WARN(!wdev->poll_irq, "unexpected IRQ polling can mask IRQ");
298 flush_workqueue(wdev->bh_wq);
299 start = ktime_get();
300 for (;;) {
301 wfx_control_reg_read(wdev, ®);
302 now = ktime_get();
303 if (reg & 0xFFF)
304 break;
305 if (ktime_after(now, ktime_add_ms(start, 1000))) {
306 dev_err(wdev->dev, "time out while polling control register\n");
307 return;
308 }
309 udelay(200);
310 }
311 wfx_bh_request_rx(wdev);
312 }
313
wfx_bh_register(struct wfx_dev * wdev)314 void wfx_bh_register(struct wfx_dev *wdev)
315 {
316 INIT_WORK(&wdev->hif.bh, bh_work);
317 init_completion(&wdev->hif.ctrl_ready);
318 init_waitqueue_head(&wdev->hif.tx_buffers_empty);
319 }
320
wfx_bh_unregister(struct wfx_dev * wdev)321 void wfx_bh_unregister(struct wfx_dev *wdev)
322 {
323 flush_work(&wdev->hif.bh);
324 }
325