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 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 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 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 } 132 133 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 } 167 168 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 } 195 196 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 */ 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 } 232 233 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 */ 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 */ 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 */ 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 } 313 314 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 } 320 321 void wfx_bh_unregister(struct wfx_dev *wdev) 322 { 323 flush_work(&wdev->hif.bh); 324 } 325