/*
* Device handling thread implementation for mac80211 ST-Ericsson CW1200 drivers
*
* Copyright (c) 2010, ST-Ericsson
* Author: Dmitry Tarnyagin <dmitry.tarnyagin@lockless.no>
*
* Based on:
* ST-Ericsson UMAC CW1200 driver, which is
* Copyright (c) 2010, ST-Ericsson
* Author: Ajitpal Singh <ajitpal.singh@stericsson.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/module.h>
#include <net/mac80211.h>
#include <linux/kthread.h>
#include <linux/timer.h>
#include "cw1200.h"
#include "bh.h"
#include "hwio.h"
#include "wsm.h"
#include "hwbus.h"
#include "debug.h"
#include "fwio.h"
static int cw1200_bh(void *arg);
#define DOWNLOAD_BLOCK_SIZE_WR (0x1000 - 4)
/* an SPI message cannot be bigger than (2"12-1)*2 bytes
* "*2" to cvt to bytes
*/
#define MAX_SZ_RD_WR_BUFFERS (DOWNLOAD_BLOCK_SIZE_WR*2)
#define PIGGYBACK_CTRL_REG (2)
#define EFFECTIVE_BUF_SIZE (MAX_SZ_RD_WR_BUFFERS - PIGGYBACK_CTRL_REG)
/* Suspend state privates */
enum cw1200_bh_pm_state {
CW1200_BH_RESUMED = 0,
CW1200_BH_SUSPEND,
CW1200_BH_SUSPENDED,
CW1200_BH_RESUME,
};
typedef int (*cw1200_wsm_handler)(struct cw1200_common *priv,
u8 *data, size_t size);
static void cw1200_bh_work(struct work_struct *work)
{
struct cw1200_common *priv =
container_of(work, struct cw1200_common, bh_work);
cw1200_bh(priv);
}
int cw1200_register_bh(struct cw1200_common *priv)
{
int err = 0;
/* Realtime workqueue */
priv->bh_workqueue = alloc_workqueue("cw1200_bh",
WQ_MEM_RECLAIM | WQ_HIGHPRI
| WQ_CPU_INTENSIVE, 1);
if (!priv->bh_workqueue)
return -ENOMEM;
INIT_WORK(&priv->bh_work, cw1200_bh_work);
pr_debug("[BH] register.\n");
atomic_set(&priv->bh_rx, 0);
atomic_set(&priv->bh_tx, 0);
atomic_set(&priv->bh_term, 0);
atomic_set(&priv->bh_suspend, CW1200_BH_RESUMED);
priv->bh_error = 0;
priv->hw_bufs_used = 0;
priv->buf_id_tx = 0;
priv->buf_id_rx = 0;
init_waitqueue_head(&priv->bh_wq);
init_waitqueue_head(&priv->bh_evt_wq);
err = !queue_work(priv->bh_workqueue, &priv->bh_work);
WARN_ON(err);
return err;
}
void cw1200_unregister_bh(struct cw1200_common *priv)
{
atomic_add(1, &priv->bh_term);
wake_up(&priv->bh_wq);
flush_workqueue(priv->bh_workqueue);
destroy_workqueue(priv->bh_workqueue);
priv->bh_workqueue = NULL;
pr_debug("[BH] unregistered.\n");
}
void cw1200_irq_handler(struct cw1200_common *priv)
{
pr_debug("[BH] irq.\n");
/* Disable Interrupts! */
/* NOTE: hwbus_ops->lock already held */
__cw1200_irq_enable(priv, 0);
if (/* WARN_ON */(priv->bh_error))
return;
if (atomic_add_return(1, &priv->bh_rx) == 1)
wake_up(&priv->bh_wq);
}
EXPORT_SYMBOL_GPL(cw1200_irq_handler);
void cw1200_bh_wakeup(struct cw1200_common *priv)
{
pr_debug("[BH] wakeup.\n");
if (priv->bh_error) {
pr_err("[BH] wakeup failed (BH error)\n");
return;
}
if (atomic_add_return(1, &priv->bh_tx) == 1)
wake_up(&priv->bh_wq);
}
int cw1200_bh_suspend(struct cw1200_common *priv)
{
pr_debug("[BH] suspend.\n");
if (priv->bh_error) {
wiphy_warn(priv->hw->wiphy, "BH error -- can't suspend\n");
return -EINVAL;
}
atomic_set(&priv->bh_suspend, CW1200_BH_SUSPEND);
wake_up(&priv->bh_wq);
return wait_event_timeout(priv->bh_evt_wq, priv->bh_error ||
(CW1200_BH_SUSPENDED == atomic_read(&priv->bh_suspend)),
1 * HZ) ? 0 : -ETIMEDOUT;
}
int cw1200_bh_resume(struct cw1200_common *priv)
{
pr_debug("[BH] resume.\n");
if (priv->bh_error) {
wiphy_warn(priv->hw->wiphy, "BH error -- can't resume\n");
return -EINVAL;
}
atomic_set(&priv->bh_suspend, CW1200_BH_RESUME);
wake_up(&priv->bh_wq);
return wait_event_timeout(priv->bh_evt_wq, priv->bh_error ||
(CW1200_BH_RESUMED == atomic_read(&priv->bh_suspend)),
1 * HZ) ? 0 : -ETIMEDOUT;
}
static inline void wsm_alloc_tx_buffer(struct cw1200_common *priv)
{
++priv->hw_bufs_used;
}
int wsm_release_tx_buffer(struct cw1200_common *priv, int count)
{
int ret = 0;
int hw_bufs_used = priv->hw_bufs_used;
priv->hw_bufs_used -= count;
if (WARN_ON(priv->hw_bufs_used < 0))
ret = -1;
else if (hw_bufs_used >= priv->wsm_caps.input_buffers)
ret = 1;
if (!priv->hw_bufs_used)
wake_up(&priv->bh_evt_wq);
return ret;
}
static int cw1200_bh_read_ctrl_reg(struct cw1200_common *priv,
u16 *ctrl_reg)
{
int ret;
ret = cw1200_reg_read_16(priv,
ST90TDS_CONTROL_REG_ID, ctrl_reg);
if (ret) {
ret = cw1200_reg_read_16(priv,
ST90TDS_CONTROL_REG_ID, ctrl_reg);
if (ret)
pr_err("[BH] Failed to read control register.\n");
}
return ret;
}
static int cw1200_device_wakeup(struct cw1200_common *priv)
{
u16 ctrl_reg;
int ret;
pr_debug("[BH] Device wakeup.\n");
/* First, set the dpll register */
ret = cw1200_reg_write_32(priv, ST90TDS_TSET_GEN_R_W_REG_ID,
cw1200_dpll_from_clk(priv->hw_refclk));
if (WARN_ON(ret))
return ret;
/* To force the device to be always-on, the host sets WLAN_UP to 1 */
ret = cw1200_reg_write_16(priv, ST90TDS_CONTROL_REG_ID,
ST90TDS_CONT_WUP_BIT);
if (WARN_ON(ret))
return ret;
ret = cw1200_bh_read_ctrl_reg(priv, &ctrl_reg);
if (WARN_ON(ret))
return ret;
/* If the device returns WLAN_RDY as 1, the device is active and will
* remain active.
*/
if (ctrl_reg & ST90TDS_CONT_RDY_BIT) {
pr_debug("[BH] Device awake.\n");
return 1;
}
return 0;
}
/* Must be called from BH thraed. */
void cw1200_enable_powersave(struct cw1200_common *priv,
bool enable)
{
pr_debug("[BH] Powerave is %s.\n",
enable ? "enabled" : "disabled");
priv->powersave_enabled = enable;
}
static int cw1200_bh_rx_helper(struct cw1200_common *priv,
uint16_t *ctrl_reg,
int *tx)
{
size_t read_len = 0;
struct sk_buff *skb_rx = NULL;
struct wsm_hdr *wsm;
size_t wsm_len;
u16 wsm_id;
u8 wsm_seq;
int rx_resync = 1;
size_t alloc_len;
u8 *data;
read_len = (*ctrl_reg & ST90TDS_CONT_NEXT_LEN_MASK) * 2;
if (!read_len)
return 0; /* No more work */
if (WARN_ON((read_len < sizeof(struct wsm_hdr)) ||
(read_len > EFFECTIVE_BUF_SIZE))) {
pr_debug("Invalid read len: %zu (%04x)",
read_len, *ctrl_reg);
goto err;
}
/* Add SIZE of PIGGYBACK reg (CONTROL Reg)
* to the NEXT Message length + 2 Bytes for SKB
*/
read_len = read_len + 2;
alloc_len = priv->hwbus_ops->align_size(
priv->hwbus_priv, read_len);
/* Check if not exceeding CW1200 capabilities */
if (WARN_ON_ONCE(alloc_len > EFFECTIVE_BUF_SIZE)) {
pr_debug("Read aligned len: %zu\n",
alloc_len);
}
skb_rx = dev_alloc_skb(alloc_len);
if (WARN_ON(!skb_rx))
goto err;
skb_trim(skb_rx, 0);
skb_put(skb_rx, read_len);
data = skb_rx->data;
if (WARN_ON(!data))
goto err;
if (WARN_ON(cw1200_data_read(priv, data, alloc_len))) {
pr_err("rx blew up, len %zu\n", alloc_len);
goto err;
}
/* Piggyback */
*ctrl_reg = __le16_to_cpu(
((__le16 *)data)[alloc_len / 2 - 1]);
wsm = (struct wsm_hdr *)data;
wsm_len = __le16_to_cpu(wsm->len);
if (WARN_ON(wsm_len > read_len))
goto err;
if (priv->wsm_enable_wsm_dumps)
print_hex_dump_bytes("<-- ",
DUMP_PREFIX_NONE,
data, wsm_len);
wsm_id = __le16_to_cpu(wsm->id) & 0xFFF;
wsm_seq = (__le16_to_cpu(wsm->id) >> 13) & 7;
skb_trim(skb_rx, wsm_len);
if (wsm_id == 0x0800) {
wsm_handle_exception(priv,
&data[sizeof(*wsm)],
wsm_len - sizeof(*wsm));
goto err;
} else if (!rx_resync) {
if (WARN_ON(wsm_seq != priv->wsm_rx_seq))
goto err;
}
priv->wsm_rx_seq = (wsm_seq + 1) & 7;
rx_resync = 0;
if (wsm_id & 0x0400) {
int rc = wsm_release_tx_buffer(priv, 1);
if (WARN_ON(rc < 0))
return rc;
else if (rc > 0)
*tx = 1;
}
/* cw1200_wsm_rx takes care on SKB livetime */
if (WARN_ON(wsm_handle_rx(priv, wsm_id, wsm, &skb_rx)))
goto err;
if (skb_rx) {
dev_kfree_skb(skb_rx);
skb_rx = NULL;
}
return 0;
err:
if (skb_rx) {
dev_kfree_skb(skb_rx);
skb_rx = NULL;
}
return -1;
}
static int cw1200_bh_tx_helper(struct cw1200_common *priv,
int *pending_tx,
int *tx_burst)
{
size_t tx_len;
u8 *data;
int ret;
struct wsm_hdr *wsm;
if (priv->device_can_sleep) {
ret = cw1200_device_wakeup(priv);
if (WARN_ON(ret < 0)) { /* Error in wakeup */
*pending_tx = 1;
return 0;
} else if (ret) { /* Woke up */
priv->device_can_sleep = false;
} else { /* Did not awake */
*pending_tx = 1;
return 0;
}
}
wsm_alloc_tx_buffer(priv);
ret = wsm_get_tx(priv, &data, &tx_len, tx_burst);
if (ret <= 0) {
wsm_release_tx_buffer(priv, 1);
if (WARN_ON(ret < 0))
return ret; /* Error */
return 0; /* No work */
}
wsm = (struct wsm_hdr *)data;
BUG_ON(tx_len < sizeof(*wsm));
BUG_ON(__le16_to_cpu(wsm->len) != tx_len);
atomic_add(1, &priv->bh_tx);
tx_len = priv->hwbus_ops->align_size(
priv->hwbus_priv, tx_len);
/* Check if not exceeding CW1200 capabilities */
if (WARN_ON_ONCE(tx_len > EFFECTIVE_BUF_SIZE))
pr_debug("Write aligned len: %zu\n", tx_len);
wsm->id &= __cpu_to_le16(0xffff ^ WSM_TX_SEQ(WSM_TX_SEQ_MAX));
wsm->id |= __cpu_to_le16(WSM_TX_SEQ(priv->wsm_tx_seq));
if (WARN_ON(cw1200_data_write(priv, data, tx_len))) {
pr_err("tx blew up, len %zu\n", tx_len);
wsm_release_tx_buffer(priv, 1);
return -1; /* Error */
}
if (priv->wsm_enable_wsm_dumps)
print_hex_dump_bytes("--> ",
DUMP_PREFIX_NONE,
data,
__le16_to_cpu(wsm->len));
wsm_txed(priv, data);
priv->wsm_tx_seq = (priv->wsm_tx_seq + 1) & WSM_TX_SEQ_MAX;
if (*tx_burst > 1) {
cw1200_debug_tx_burst(priv);
return 1; /* Work remains */
}
return 0;
}
static int cw1200_bh(void *arg)
{
struct cw1200_common *priv = arg;
int rx, tx, term, suspend;
u16 ctrl_reg = 0;
int tx_allowed;
int pending_tx = 0;
int tx_burst;
long status;
u32 dummy;
int ret;
for (;;) {
if (!priv->hw_bufs_used &&
priv->powersave_enabled &&
!priv->device_can_sleep &&
!atomic_read(&priv->recent_scan)) {
status = 1 * HZ;
pr_debug("[BH] Device wakedown. No data.\n");
cw1200_reg_write_16(priv, ST90TDS_CONTROL_REG_ID, 0);
priv->device_can_sleep = true;
} else if (priv->hw_bufs_used) {
/* Interrupt loss detection */
status = 1 * HZ;
} else {
status = MAX_SCHEDULE_TIMEOUT;
}
/* Dummy Read for SDIO retry mechanism*/
if ((priv->hw_type != -1) &&
(atomic_read(&priv->bh_rx) == 0) &&
(atomic_read(&priv->bh_tx) == 0))
cw1200_reg_read(priv, ST90TDS_CONFIG_REG_ID,
&dummy, sizeof(dummy));
pr_debug("[BH] waiting ...\n");
status = wait_event_interruptible_timeout(priv->bh_wq, ({
rx = atomic_xchg(&priv->bh_rx, 0);
tx = atomic_xchg(&priv->bh_tx, 0);
term = atomic_xchg(&priv->bh_term, 0);
suspend = pending_tx ?
0 : atomic_read(&priv->bh_suspend);
(rx || tx || term || suspend || priv->bh_error);
}), status);
pr_debug("[BH] - rx: %d, tx: %d, term: %d, bh_err: %d, suspend: %d, status: %ld\n",
rx, tx, term, suspend, priv->bh_error, status);
/* Did an error occur? */
if ((status < 0 && status != -ERESTARTSYS) ||
term || priv->bh_error) {
break;
}
if (!status) { /* wait_event timed out */
unsigned long timestamp = jiffies;
long timeout;
int pending = 0;
int i;
/* Check to see if we have any outstanding frames */
if (priv->hw_bufs_used && (!rx || !tx)) {
wiphy_warn(priv->hw->wiphy,
"Missed interrupt? (%d frames outstanding)\n",
priv->hw_bufs_used);
rx = 1;
/* Get a timestamp of "oldest" frame */
for (i = 0; i < 4; ++i)
pending += cw1200_queue_get_xmit_timestamp(
&priv->tx_queue[i],
×tamp,
priv->pending_frame_id);
/* Check if frame transmission is timed out.
* Add an extra second with respect to possible
* interrupt loss.
*/
timeout = timestamp +
WSM_CMD_LAST_CHANCE_TIMEOUT +
1 * HZ -
jiffies;
/* And terminate BH thread if the frame is "stuck" */
if (pending && timeout < 0) {
wiphy_warn(priv->hw->wiphy,
"Timeout waiting for TX confirm (%d/%d pending, %ld vs %lu).\n",
priv->hw_bufs_used, pending,
timestamp, jiffies);
break;
}
} else if (!priv->device_can_sleep &&
!atomic_read(&priv->recent_scan)) {
pr_debug("[BH] Device wakedown. Timeout.\n");
cw1200_reg_write_16(priv,
ST90TDS_CONTROL_REG_ID, 0);
priv->device_can_sleep = true;
}
goto done;
} else if (suspend) {
pr_debug("[BH] Device suspend.\n");
if (priv->powersave_enabled) {
pr_debug("[BH] Device wakedown. Suspend.\n");
cw1200_reg_write_16(priv,
ST90TDS_CONTROL_REG_ID, 0);
priv->device_can_sleep = true;
}
atomic_set(&priv->bh_suspend, CW1200_BH_SUSPENDED);
wake_up(&priv->bh_evt_wq);
status = wait_event_interruptible(priv->bh_wq,
CW1200_BH_RESUME == atomic_read(&priv->bh_suspend));
if (status < 0) {
wiphy_err(priv->hw->wiphy,
"Failed to wait for resume: %ld.\n",
status);
break;
}
pr_debug("[BH] Device resume.\n");
atomic_set(&priv->bh_suspend, CW1200_BH_RESUMED);
wake_up(&priv->bh_evt_wq);
atomic_add(1, &priv->bh_rx);
goto done;
}
rx:
tx += pending_tx;
pending_tx = 0;
if (cw1200_bh_read_ctrl_reg(priv, &ctrl_reg))
break;
/* Don't bother trying to rx unless we have data to read */
if (ctrl_reg & ST90TDS_CONT_NEXT_LEN_MASK) {
ret = cw1200_bh_rx_helper(priv, &ctrl_reg, &tx);
if (ret < 0)
break;
/* Double up here if there's more data.. */
if (ctrl_reg & ST90TDS_CONT_NEXT_LEN_MASK) {
ret = cw1200_bh_rx_helper(priv, &ctrl_reg, &tx);
if (ret < 0)
break;
}
}
tx:
if (tx) {
tx = 0;
BUG_ON(priv->hw_bufs_used > priv->wsm_caps.input_buffers);
tx_burst = priv->wsm_caps.input_buffers - priv->hw_bufs_used;
tx_allowed = tx_burst > 0;
if (!tx_allowed) {
/* Buffers full. Ensure we process tx
* after we handle rx..
*/
pending_tx = tx;
goto done_rx;
}
ret = cw1200_bh_tx_helper(priv, &pending_tx, &tx_burst);
if (ret < 0)
break;
if (ret > 0) /* More to transmit */
tx = ret;
/* Re-read ctrl reg */
if (cw1200_bh_read_ctrl_reg(priv, &ctrl_reg))
break;
}
done_rx:
if (priv->bh_error)
break;
if (ctrl_reg & ST90TDS_CONT_NEXT_LEN_MASK)
goto rx;
if (tx)
goto tx;
done:
/* Re-enable device interrupts */
priv->hwbus_ops->lock(priv->hwbus_priv);
__cw1200_irq_enable(priv, 1);
priv->hwbus_ops->unlock(priv->hwbus_priv);
}
/* Explicitly disable device interrupts */
priv->hwbus_ops->lock(priv->hwbus_priv);
__cw1200_irq_enable(priv, 0);
priv->hwbus_ops->unlock(priv->hwbus_priv);
if (!term) {
pr_err("[BH] Fatal error, exiting.\n");
priv->bh_error = 1;
/* TODO: schedule_work(recovery) */
}
return 0;
}