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
36 // completion without consume it (a kind of
37 // wait_for_completion_done_timeout()). So we have to emulate
38 // it.
39 if (wait_for_completion_timeout(&wdev->hif.ctrl_ready,
40 msecs_to_jiffies(2))) {
41 complete(&wdev->hif.ctrl_ready);
42 return;
43 } else if (max_retry-- > 0) {
44 // Older firmwares have a race in sleep/wake-up process.
45 // Redo the process is sufficient to unfreeze the
46 // chip.
47 dev_err(wdev->dev, "timeout while wake up chip\n");
48 gpiod_set_value_cansleep(wdev->pdata.gpio_wakeup, 0);
49 usleep_range(2000, 2500);
50 } else {
51 dev_err(wdev->dev, "max wake-up retries reached\n");
52 return;
53 }
54 }
55 }
56
device_release(struct wfx_dev * wdev)57 static void device_release(struct wfx_dev *wdev)
58 {
59 if (!wdev->pdata.gpio_wakeup)
60 return;
61
62 gpiod_set_value_cansleep(wdev->pdata.gpio_wakeup, 0);
63 }
64
rx_helper(struct wfx_dev * wdev,size_t read_len,int * is_cnf)65 static int rx_helper(struct wfx_dev *wdev, size_t read_len, int *is_cnf)
66 {
67 struct sk_buff *skb;
68 struct hif_msg *hif;
69 size_t alloc_len;
70 size_t computed_len;
71 int release_count;
72 int piggyback = 0;
73
74 WARN(read_len > round_down(0xFFF, 2) * sizeof(u16),
75 "%s: request exceed WFx capability", __func__);
76
77 // Add 2 to take into account piggyback size
78 alloc_len = wdev->hwbus_ops->align_size(wdev->hwbus_priv, read_len + 2);
79 skb = dev_alloc_skb(alloc_len);
80 if (!skb)
81 return -ENOMEM;
82
83 if (wfx_data_read(wdev, skb->data, alloc_len))
84 goto err;
85
86 piggyback = le16_to_cpup((__le16 *)(skb->data + alloc_len - 2));
87 _trace_piggyback(piggyback, false);
88
89 hif = (struct hif_msg *)skb->data;
90 WARN(hif->encrypted & 0x3, "encryption is unsupported");
91 if (WARN(read_len < sizeof(struct hif_msg), "corrupted read"))
92 goto err;
93 computed_len = le16_to_cpu(hif->len);
94 computed_len = round_up(computed_len, 2);
95 if (computed_len != read_len) {
96 dev_err(wdev->dev, "inconsistent message length: %zu != %zu\n",
97 computed_len, read_len);
98 print_hex_dump(KERN_INFO, "hif: ", DUMP_PREFIX_OFFSET, 16, 1,
99 hif, read_len, true);
100 goto err;
101 }
102
103 if (!(hif->id & HIF_ID_IS_INDICATION)) {
104 (*is_cnf)++;
105 if (hif->id == HIF_CNF_ID_MULTI_TRANSMIT)
106 release_count = ((struct hif_cnf_multi_transmit *)hif->body)->num_tx_confs;
107 else
108 release_count = 1;
109 WARN(wdev->hif.tx_buffers_used < release_count, "corrupted buffer counter");
110 wdev->hif.tx_buffers_used -= release_count;
111 }
112 _trace_hif_recv(hif, wdev->hif.tx_buffers_used);
113
114 if (hif->id != HIF_IND_ID_EXCEPTION && hif->id != HIF_IND_ID_ERROR) {
115 if (hif->seqnum != wdev->hif.rx_seqnum)
116 dev_warn(wdev->dev, "wrong message sequence: %d != %d\n",
117 hif->seqnum, wdev->hif.rx_seqnum);
118 wdev->hif.rx_seqnum = (hif->seqnum + 1) % (HIF_COUNTER_MAX + 1);
119 }
120
121 skb_put(skb, le16_to_cpu(hif->len));
122 // wfx_handle_rx takes care on SKB livetime
123 wfx_handle_rx(wdev, skb);
124 if (!wdev->hif.tx_buffers_used)
125 wake_up(&wdev->hif.tx_buffers_empty);
126
127 return piggyback;
128
129 err:
130 if (skb)
131 dev_kfree_skb(skb);
132 return -EIO;
133 }
134
bh_work_rx(struct wfx_dev * wdev,int max_msg,int * num_cnf)135 static int bh_work_rx(struct wfx_dev *wdev, int max_msg, int *num_cnf)
136 {
137 size_t len;
138 int i;
139 int ctrl_reg, piggyback;
140
141 piggyback = 0;
142 for (i = 0; i < max_msg; i++) {
143 if (piggyback & CTRL_NEXT_LEN_MASK)
144 ctrl_reg = piggyback;
145 else if (try_wait_for_completion(&wdev->hif.ctrl_ready))
146 ctrl_reg = atomic_xchg(&wdev->hif.ctrl_reg, 0);
147 else
148 ctrl_reg = 0;
149 if (!(ctrl_reg & CTRL_NEXT_LEN_MASK))
150 return i;
151 // ctrl_reg units are 16bits words
152 len = (ctrl_reg & CTRL_NEXT_LEN_MASK) * 2;
153 piggyback = rx_helper(wdev, len, num_cnf);
154 if (piggyback < 0)
155 return i;
156 if (!(piggyback & CTRL_WLAN_READY))
157 dev_err(wdev->dev, "unexpected piggyback value: ready bit not set: %04x\n",
158 piggyback);
159 }
160 if (piggyback & CTRL_NEXT_LEN_MASK) {
161 ctrl_reg = atomic_xchg(&wdev->hif.ctrl_reg, piggyback);
162 complete(&wdev->hif.ctrl_ready);
163 if (ctrl_reg)
164 dev_err(wdev->dev, "unexpected IRQ happened: %04x/%04x\n",
165 ctrl_reg, piggyback);
166 }
167 return i;
168 }
169
tx_helper(struct wfx_dev * wdev,struct hif_msg * hif)170 static void tx_helper(struct wfx_dev *wdev, struct hif_msg *hif)
171 {
172 int ret;
173 void *data;
174 bool is_encrypted = false;
175 size_t len = le16_to_cpu(hif->len);
176
177 WARN(len < sizeof(*hif), "try to send corrupted data");
178
179 hif->seqnum = wdev->hif.tx_seqnum;
180 wdev->hif.tx_seqnum = (wdev->hif.tx_seqnum + 1) % (HIF_COUNTER_MAX + 1);
181
182 data = hif;
183 WARN(len > wdev->hw_caps.size_inp_ch_buf,
184 "%s: request exceed WFx capability: %zu > %d\n", __func__,
185 len, wdev->hw_caps.size_inp_ch_buf);
186 len = wdev->hwbus_ops->align_size(wdev->hwbus_priv, len);
187 ret = wfx_data_write(wdev, data, len);
188 if (ret)
189 goto end;
190
191 wdev->hif.tx_buffers_used++;
192 _trace_hif_send(hif, wdev->hif.tx_buffers_used);
193 end:
194 if (is_encrypted)
195 kfree(data);
196 }
197
bh_work_tx(struct wfx_dev * wdev,int max_msg)198 static int bh_work_tx(struct wfx_dev *wdev, int max_msg)
199 {
200 struct hif_msg *hif;
201 int i;
202
203 for (i = 0; i < max_msg; i++) {
204 hif = NULL;
205 if (wdev->hif.tx_buffers_used < wdev->hw_caps.num_inp_ch_bufs) {
206 if (try_wait_for_completion(&wdev->hif_cmd.ready)) {
207 WARN(!mutex_is_locked(&wdev->hif_cmd.lock), "data locking error");
208 hif = wdev->hif_cmd.buf_send;
209 } else {
210 hif = wfx_tx_queues_get(wdev);
211 }
212 }
213 if (!hif)
214 return i;
215 tx_helper(wdev, hif);
216 }
217 return i;
218 }
219
220 /* In SDIO mode, it is necessary to make an access to a register to acknowledge
221 * last received message. It could be possible to restrict this acknowledge to
222 * SDIO mode and only if last operation was rx.
223 */
ack_sdio_data(struct wfx_dev * wdev)224 static void ack_sdio_data(struct wfx_dev *wdev)
225 {
226 u32 cfg_reg;
227
228 config_reg_read(wdev, &cfg_reg);
229 if (cfg_reg & 0xFF) {
230 dev_warn(wdev->dev, "chip reports errors: %02x\n",
231 cfg_reg & 0xFF);
232 config_reg_write_bits(wdev, 0xFF, 0x00);
233 }
234 }
235
bh_work(struct work_struct * work)236 static void bh_work(struct work_struct *work)
237 {
238 struct wfx_dev *wdev = container_of(work, struct wfx_dev, hif.bh);
239 int stats_req = 0, stats_cnf = 0, stats_ind = 0;
240 bool release_chip = false, last_op_is_rx = false;
241 int num_tx, num_rx;
242
243 device_wakeup(wdev);
244 do {
245 num_tx = bh_work_tx(wdev, 32);
246 stats_req += num_tx;
247 if (num_tx)
248 last_op_is_rx = false;
249 num_rx = bh_work_rx(wdev, 32, &stats_cnf);
250 stats_ind += num_rx;
251 if (num_rx)
252 last_op_is_rx = true;
253 } while (num_rx || num_tx);
254 stats_ind -= stats_cnf;
255
256 if (last_op_is_rx)
257 ack_sdio_data(wdev);
258 if (!wdev->hif.tx_buffers_used && !work_pending(work)) {
259 device_release(wdev);
260 release_chip = true;
261 }
262 _trace_bh_stats(stats_ind, stats_req, stats_cnf,
263 wdev->hif.tx_buffers_used, release_chip);
264 }
265
266 /*
267 * An IRQ from chip did occur
268 */
wfx_bh_request_rx(struct wfx_dev * wdev)269 void wfx_bh_request_rx(struct wfx_dev *wdev)
270 {
271 u32 cur, prev;
272
273 control_reg_read(wdev, &cur);
274 prev = atomic_xchg(&wdev->hif.ctrl_reg, cur);
275 complete(&wdev->hif.ctrl_ready);
276 queue_work(system_highpri_wq, &wdev->hif.bh);
277
278 if (!(cur & CTRL_NEXT_LEN_MASK))
279 dev_err(wdev->dev, "unexpected control register value: length field is 0: %04x\n",
280 cur);
281 if (prev != 0)
282 dev_err(wdev->dev, "received IRQ but previous data was not (yet) read: %04x/%04x\n",
283 prev, cur);
284 }
285
286 /*
287 * Driver want to send data
288 */
wfx_bh_request_tx(struct wfx_dev * wdev)289 void wfx_bh_request_tx(struct wfx_dev *wdev)
290 {
291 queue_work(system_highpri_wq, &wdev->hif.bh);
292 }
293
294 /*
295 * If IRQ is not available, this function allow to manually poll the control
296 * register and simulate an IRQ ahen an event happened.
297 *
298 * Note that the device has a bug: If an IRQ raise while host read control
299 * register, the IRQ is lost. So, use this function carefully (only duing
300 * device initialisation).
301 */
wfx_bh_poll_irq(struct wfx_dev * wdev)302 void wfx_bh_poll_irq(struct wfx_dev *wdev)
303 {
304 ktime_t now, start;
305 u32 reg;
306
307 WARN(!wdev->poll_irq, "unexpected IRQ polling can mask IRQ");
308 start = ktime_get();
309 for (;;) {
310 control_reg_read(wdev, ®);
311 now = ktime_get();
312 if (reg & 0xFFF)
313 break;
314 if (ktime_after(now, ktime_add_ms(start, 1000))) {
315 dev_err(wdev->dev, "time out while polling control register\n");
316 return;
317 }
318 udelay(200);
319 }
320 wfx_bh_request_rx(wdev);
321 }
322
wfx_bh_register(struct wfx_dev * wdev)323 void wfx_bh_register(struct wfx_dev *wdev)
324 {
325 INIT_WORK(&wdev->hif.bh, bh_work);
326 init_completion(&wdev->hif.ctrl_ready);
327 init_waitqueue_head(&wdev->hif.tx_buffers_empty);
328 }
329
wfx_bh_unregister(struct wfx_dev * wdev)330 void wfx_bh_unregister(struct wfx_dev *wdev)
331 {
332 flush_work(&wdev->hif.bh);
333 }
334
