diff options
Diffstat (limited to 'drivers/net/wireless/silabs/wfx/bh.c')
| -rw-r--r-- | drivers/net/wireless/silabs/wfx/bh.c | 324 |
1 files changed, 324 insertions, 0 deletions
diff --git a/drivers/net/wireless/silabs/wfx/bh.c b/drivers/net/wireless/silabs/wfx/bh.c new file mode 100644 index 000000000000..bcea9d5b119c --- /dev/null +++ b/drivers/net/wireless/silabs/wfx/bh.c @@ -0,0 +1,324 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Interrupt bottom half (BH). + * + * Copyright (c) 2017-2020, Silicon Laboratories, Inc. + * Copyright (c) 2010, ST-Ericsson + */ +#include <linux/gpio/consumer.h> +#include <net/mac80211.h> + +#include "bh.h" +#include "wfx.h" +#include "hwio.h" +#include "traces.h" +#include "hif_rx.h" +#include "hif_api_cmd.h" + +static void device_wakeup(struct wfx_dev *wdev) +{ + int max_retry = 3; + + if (!wdev->pdata.gpio_wakeup) + return; + if (gpiod_get_value_cansleep(wdev->pdata.gpio_wakeup) > 0) + return; + + if (wfx_api_older_than(wdev, 1, 4)) { + gpiod_set_value_cansleep(wdev->pdata.gpio_wakeup, 1); + if (!completion_done(&wdev->hif.ctrl_ready)) + usleep_range(2000, 2500); + return; + } + for (;;) { + gpiod_set_value_cansleep(wdev->pdata.gpio_wakeup, 1); + /* completion.h does not provide any function to wait completion without consume it + * (a kind of wait_for_completion_done_timeout()). So we have to emulate it. + */ + if (wait_for_completion_timeout(&wdev->hif.ctrl_ready, msecs_to_jiffies(2))) { + complete(&wdev->hif.ctrl_ready); + return; + } else if (max_retry-- > 0) { + /* Older firmwares have a race in sleep/wake-up process. Redo the process + * is sufficient to unfreeze the chip. + */ + dev_err(wdev->dev, "timeout while wake up chip\n"); + gpiod_set_value_cansleep(wdev->pdata.gpio_wakeup, 0); + usleep_range(2000, 2500); + } else { + dev_err(wdev->dev, "max wake-up retries reached\n"); + return; + } + } +} + +static void device_release(struct wfx_dev *wdev) +{ + if (!wdev->pdata.gpio_wakeup) + return; + + gpiod_set_value_cansleep(wdev->pdata.gpio_wakeup, 0); +} + +static int rx_helper(struct wfx_dev *wdev, size_t read_len, int *is_cnf) +{ + struct sk_buff *skb; + struct wfx_hif_msg *hif; + size_t alloc_len; + size_t computed_len; + int release_count; + int piggyback = 0; + + WARN(read_len > round_down(0xFFF, 2) * sizeof(u16), "request exceed the chip capability"); + + /* Add 2 to take into account piggyback size */ + alloc_len = wdev->hwbus_ops->align_size(wdev->hwbus_priv, read_len + 2); + skb = dev_alloc_skb(alloc_len); + if (!skb) + return -ENOMEM; + + if (wfx_data_read(wdev, skb->data, alloc_len)) + goto err; + + piggyback = le16_to_cpup((__le16 *)(skb->data + alloc_len - 2)); + _trace_piggyback(piggyback, false); + + hif = (struct wfx_hif_msg *)skb->data; + WARN(hif->encrypted & 0x3, "encryption is unsupported"); + if (WARN(read_len < sizeof(struct wfx_hif_msg), "corrupted read")) + goto err; + computed_len = le16_to_cpu(hif->len); + computed_len = round_up(computed_len, 2); + if (computed_len != read_len) { + dev_err(wdev->dev, "inconsistent message length: %zu != %zu\n", + computed_len, read_len); + print_hex_dump(KERN_INFO, "hif: ", DUMP_PREFIX_OFFSET, 16, 1, + hif, read_len, true); + goto err; + } + + if (!(hif->id & HIF_ID_IS_INDICATION)) { + (*is_cnf)++; + if (hif->id == HIF_CNF_ID_MULTI_TRANSMIT) + release_count = + ((struct wfx_hif_cnf_multi_transmit *)hif->body)->num_tx_confs; + else + release_count = 1; + WARN(wdev->hif.tx_buffers_used < release_count, "corrupted buffer counter"); + wdev->hif.tx_buffers_used -= release_count; + } + _trace_hif_recv(hif, wdev->hif.tx_buffers_used); + + if (hif->id != HIF_IND_ID_EXCEPTION && hif->id != HIF_IND_ID_ERROR) { + if (hif->seqnum != wdev->hif.rx_seqnum) + dev_warn(wdev->dev, "wrong message sequence: %d != %d\n", + hif->seqnum, wdev->hif.rx_seqnum); + wdev->hif.rx_seqnum = (hif->seqnum + 1) % (HIF_COUNTER_MAX + 1); + } + + skb_put(skb, le16_to_cpu(hif->len)); + /* wfx_handle_rx takes care on SKB livetime */ + wfx_handle_rx(wdev, skb); + if (!wdev->hif.tx_buffers_used) + wake_up(&wdev->hif.tx_buffers_empty); + + return piggyback; + +err: + if (skb) + dev_kfree_skb(skb); + return -EIO; +} + +static int bh_work_rx(struct wfx_dev *wdev, int max_msg, int *num_cnf) +{ + size_t len; + int i; + int ctrl_reg, piggyback; + + piggyback = 0; + for (i = 0; i < max_msg; i++) { + if (piggyback & CTRL_NEXT_LEN_MASK) + ctrl_reg = piggyback; + else if (try_wait_for_completion(&wdev->hif.ctrl_ready)) + ctrl_reg = atomic_xchg(&wdev->hif.ctrl_reg, 0); + else + ctrl_reg = 0; + if (!(ctrl_reg & CTRL_NEXT_LEN_MASK)) + return i; + /* ctrl_reg units are 16bits words */ + len = (ctrl_reg & CTRL_NEXT_LEN_MASK) * 2; + piggyback = rx_helper(wdev, len, num_cnf); + if (piggyback < 0) + return i; + if (!(piggyback & CTRL_WLAN_READY)) + dev_err(wdev->dev, "unexpected piggyback value: ready bit not set: %04x\n", + piggyback); + } + if (piggyback & CTRL_NEXT_LEN_MASK) { + ctrl_reg = atomic_xchg(&wdev->hif.ctrl_reg, piggyback); + complete(&wdev->hif.ctrl_ready); + if (ctrl_reg) + dev_err(wdev->dev, "unexpected IRQ happened: %04x/%04x\n", + ctrl_reg, piggyback); + } + return i; +} + +static void tx_helper(struct wfx_dev *wdev, struct wfx_hif_msg *hif) +{ + int ret; + void *data; + bool is_encrypted = false; + size_t len = le16_to_cpu(hif->len); + + WARN(len < sizeof(*hif), "try to send corrupted data"); + + hif->seqnum = wdev->hif.tx_seqnum; + wdev->hif.tx_seqnum = (wdev->hif.tx_seqnum + 1) % (HIF_COUNTER_MAX + 1); + + data = hif; + WARN(len > le16_to_cpu(wdev->hw_caps.size_inp_ch_buf), + "request exceed the chip capability: %zu > %d\n", + len, le16_to_cpu(wdev->hw_caps.size_inp_ch_buf)); + len = wdev->hwbus_ops->align_size(wdev->hwbus_priv, len); + ret = wfx_data_write(wdev, data, len); + if (ret) + goto end; + + wdev->hif.tx_buffers_used++; + _trace_hif_send(hif, wdev->hif.tx_buffers_used); +end: + if (is_encrypted) + kfree(data); +} + +static int bh_work_tx(struct wfx_dev *wdev, int max_msg) +{ + struct wfx_hif_msg *hif; + int i; + + for (i = 0; i < max_msg; i++) { + hif = NULL; + if (wdev->hif.tx_buffers_used < le16_to_cpu(wdev->hw_caps.num_inp_ch_bufs)) { + if (try_wait_for_completion(&wdev->hif_cmd.ready)) { + WARN(!mutex_is_locked(&wdev->hif_cmd.lock), "data locking error"); + hif = wdev->hif_cmd.buf_send; + } else { + hif = wfx_tx_queues_get(wdev); + } + } + if (!hif) + return i; + tx_helper(wdev, hif); + } + return i; +} + +/* In SDIO mode, it is necessary to make an access to a register to acknowledge last received + * message. It could be possible to restrict this acknowledge to SDIO mode and only if last + * operation was rx. + */ +static void ack_sdio_data(struct wfx_dev *wdev) +{ + u32 cfg_reg; + + wfx_config_reg_read(wdev, &cfg_reg); + if (cfg_reg & 0xFF) { + dev_warn(wdev->dev, "chip reports errors: %02x\n", cfg_reg & 0xFF); + wfx_config_reg_write_bits(wdev, 0xFF, 0x00); + } +} + +static void bh_work(struct work_struct *work) +{ + struct wfx_dev *wdev = container_of(work, struct wfx_dev, hif.bh); + int stats_req = 0, stats_cnf = 0, stats_ind = 0; + bool release_chip = false, last_op_is_rx = false; + int num_tx, num_rx; + + device_wakeup(wdev); + do { + num_tx = bh_work_tx(wdev, 32); + stats_req += num_tx; + if (num_tx) + last_op_is_rx = false; + num_rx = bh_work_rx(wdev, 32, &stats_cnf); + stats_ind += num_rx; + if (num_rx) + last_op_is_rx = true; + } while (num_rx || num_tx); + stats_ind -= stats_cnf; + + if (last_op_is_rx) + ack_sdio_data(wdev); + if (!wdev->hif.tx_buffers_used && !work_pending(work)) { + device_release(wdev); + release_chip = true; + } + _trace_bh_stats(stats_ind, stats_req, stats_cnf, wdev->hif.tx_buffers_used, release_chip); +} + +/* An IRQ from chip did occur */ +void wfx_bh_request_rx(struct wfx_dev *wdev) +{ + u32 cur, prev; + + wfx_control_reg_read(wdev, &cur); + prev = atomic_xchg(&wdev->hif.ctrl_reg, cur); + complete(&wdev->hif.ctrl_ready); + queue_work(system_highpri_wq, &wdev->hif.bh); + + if (!(cur & CTRL_NEXT_LEN_MASK)) + dev_err(wdev->dev, "unexpected control register value: length field is 0: %04x\n", + cur); + if (prev != 0) + dev_err(wdev->dev, "received IRQ but previous data was not (yet) read: %04x/%04x\n", + prev, cur); +} + +/* Driver want to send data */ +void wfx_bh_request_tx(struct wfx_dev *wdev) +{ + queue_work(system_highpri_wq, &wdev->hif.bh); +} + +/* If IRQ is not available, this function allow to manually poll the control register and simulate + * an IRQ ahen an event happened. + * + * Note that the device has a bug: If an IRQ raise while host read control register, the IRQ is + * lost. So, use this function carefully (only duing device initialisation). + */ +void wfx_bh_poll_irq(struct wfx_dev *wdev) +{ + ktime_t now, start; + u32 reg; + + WARN(!wdev->poll_irq, "unexpected IRQ polling can mask IRQ"); + flush_workqueue(system_highpri_wq); + start = ktime_get(); + for (;;) { + wfx_control_reg_read(wdev, ®); + now = ktime_get(); + if (reg & 0xFFF) + break; + if (ktime_after(now, ktime_add_ms(start, 1000))) { + dev_err(wdev->dev, "time out while polling control register\n"); + return; + } + udelay(200); + } + wfx_bh_request_rx(wdev); +} + +void wfx_bh_register(struct wfx_dev *wdev) +{ + INIT_WORK(&wdev->hif.bh, bh_work); + init_completion(&wdev->hif.ctrl_ready); + init_waitqueue_head(&wdev->hif.tx_buffers_empty); +} + +void wfx_bh_unregister(struct wfx_dev *wdev) +{ + flush_work(&wdev->hif.bh); +} |