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// 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 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),
"%s: request exceed the chip capability", __func__);
/* 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 hif_msg *)skb->data;
WARN(hif->encrypted & 0x3, "encryption is unsupported");
if (WARN(read_len < sizeof(struct 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 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 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 > wdev->hw_caps.size_inp_ch_buf,
"%s: request exceed the chip capability: %zu > %d\n", __func__,
len, 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 hif_msg *hif;
int i;
for (i = 0; i < max_msg; i++) {
hif = NULL;
if (wdev->hif.tx_buffers_used < 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;
config_reg_read(wdev, &cfg_reg);
if (cfg_reg & 0xFF) {
dev_warn(wdev->dev, "chip reports errors: %02x\n",
cfg_reg & 0xFF);
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;
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");
start = ktime_get();
for (;;) {
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);
}
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