// SPDX-License-Identifier: GPL-2.0-only
/*
* Qualcomm BAM-DMUX WWAN network driver
* Copyright (c) 2020, Stephan Gerhold <[email protected]>
*/
#include <linux/atomic.h>
#include <linux/bitops.h>
#include <linux/completion.h>
#include <linux/dma-mapping.h>
#include <linux/dmaengine.h>
#include <linux/if_arp.h>
#include <linux/interrupt.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/soc/qcom/smem_state.h>
#include <linux/spinlock.h>
#include <linux/wait.h>
#include <linux/workqueue.h>
#include <net/pkt_sched.h>
#define BAM_DMUX_BUFFER_SIZE SZ_2K
#define BAM_DMUX_HDR_SIZE sizeof(struct bam_dmux_hdr)
#define BAM_DMUX_MAX_DATA_SIZE (BAM_DMUX_BUFFER_SIZE - BAM_DMUX_HDR_SIZE)
#define BAM_DMUX_NUM_SKB 32
#define BAM_DMUX_HDR_MAGIC 0x33fc
#define BAM_DMUX_AUTOSUSPEND_DELAY 1000
#define BAM_DMUX_REMOTE_TIMEOUT msecs_to_jiffies(2000)
enum {
BAM_DMUX_CMD_DATA,
BAM_DMUX_CMD_OPEN,
BAM_DMUX_CMD_CLOSE,
};
enum {
BAM_DMUX_CH_DATA_0,
BAM_DMUX_CH_DATA_1,
BAM_DMUX_CH_DATA_2,
BAM_DMUX_CH_DATA_3,
BAM_DMUX_CH_DATA_4,
BAM_DMUX_CH_DATA_5,
BAM_DMUX_CH_DATA_6,
BAM_DMUX_CH_DATA_7,
BAM_DMUX_NUM_CH
};
struct bam_dmux_hdr {
u16 magic;
u8 signal;
u8 cmd;
u8 pad;
u8 ch;
u16 len;
};
struct bam_dmux_skb_dma {
struct bam_dmux *dmux;
struct sk_buff *skb;
dma_addr_t addr;
};
struct bam_dmux {
struct device *dev;
int pc_irq;
bool pc_state, pc_ack_state;
struct qcom_smem_state *pc, *pc_ack;
u32 pc_mask, pc_ack_mask;
wait_queue_head_t pc_wait;
struct completion pc_ack_completion;
struct dma_chan *rx, *tx;
struct bam_dmux_skb_dma rx_skbs[BAM_DMUX_NUM_SKB];
struct bam_dmux_skb_dma tx_skbs[BAM_DMUX_NUM_SKB];
spinlock_t tx_lock; /* Protect tx_skbs, tx_next_skb */
unsigned int tx_next_skb;
atomic_long_t tx_deferred_skb;
struct work_struct tx_wakeup_work;
DECLARE_BITMAP(remote_channels, BAM_DMUX_NUM_CH);
struct work_struct register_netdev_work;
struct net_device *netdevs[BAM_DMUX_NUM_CH];
};
struct bam_dmux_netdev {
struct bam_dmux *dmux;
u8 ch;
};
static void bam_dmux_pc_vote(struct bam_dmux *dmux, bool enable)
{
reinit_completion(&dmux->pc_ack_completion);
qcom_smem_state_update_bits(dmux->pc, dmux->pc_mask,
enable ? dmux->pc_mask : 0);
}
static void bam_dmux_pc_ack(struct bam_dmux *dmux)
{
qcom_smem_state_update_bits(dmux->pc_ack, dmux->pc_ack_mask,
dmux->pc_ack_state ? 0 : dmux->pc_ack_mask);
dmux->pc_ack_state = !dmux->pc_ack_state;
}
static bool bam_dmux_skb_dma_map(struct bam_dmux_skb_dma *skb_dma,
enum dma_data_direction dir)
{
struct device *dev = skb_dma->dmux->dev;
skb_dma->addr = dma_map_single(dev, skb_dma->skb->data, skb_dma->skb->len, dir);
if (dma_mapping_error(dev, skb_dma->addr)) {
dev_err(dev, "Failed to DMA map buffer\n");
skb_dma->addr = 0;
return false;
}
return true;
}
static void bam_dmux_skb_dma_unmap(struct bam_dmux_skb_dma *skb_dma,
enum dma_data_direction dir)
{
dma_unmap_single(skb_dma->dmux->dev, skb_dma->addr, skb_dma->skb->len, dir);
skb_dma->addr = 0;
}
static void bam_dmux_tx_wake_queues(struct bam_dmux *dmux)
{
int i;
dev_dbg(dmux->dev, "wake queues\n");
for (i = 0; i < BAM_DMUX_NUM_CH; ++i) {
struct net_device *netdev = dmux->netdevs[i];
if (netdev && netif_running(netdev))
netif_wake_queue(netdev);
}
}
static void bam_dmux_tx_stop_queues(struct bam_dmux *dmux)
{
int i;
dev_dbg(dmux->dev, "stop queues\n");
for (i = 0; i < BAM_DMUX_NUM_CH; ++i) {
struct net_device *netdev = dmux->netdevs[i];
if (netdev)
netif_stop_queue(netdev);
}
}
static void bam_dmux_tx_done(struct bam_dmux_skb_dma *skb_dma)
{
struct bam_dmux *dmux = skb_dma->dmux;
unsigned long flags;
pm_runtime_mark_last_busy(dmux->dev);
pm_runtime_put_autosuspend(dmux->dev);
if (skb_dma->addr)
bam_dmux_skb_dma_unmap(skb_dma, DMA_TO_DEVICE);
spin_lock_irqsave(&dmux->tx_lock, flags);
skb_dma->skb = NULL;
if (skb_dma == &dmux->tx_skbs[dmux->tx_next_skb % BAM_DMUX_NUM_SKB])
bam_dmux_tx_wake_queues(dmux);
spin_unlock_irqrestore(&dmux->tx_lock, flags);
}
static void bam_dmux_tx_callback(void *data)
{
struct bam_dmux_skb_dma *skb_dma = data;
struct sk_buff *skb = skb_dma->skb;
bam_dmux_tx_done(skb_dma);
dev_consume_skb_any(skb);
}
static bool bam_dmux_skb_dma_submit_tx(struct bam_dmux_skb_dma *skb_dma)
{
struct bam_dmux *dmux = skb_dma->dmux;
struct dma_async_tx_descriptor *desc;
desc = dmaengine_prep_slave_single(dmux->tx, skb_dma->addr,
skb_dma->skb->len, DMA_MEM_TO_DEV,
DMA_PREP_INTERRUPT);
if (!desc) {
dev_err(dmux->dev, "Failed to prepare TX DMA buffer\n");
return false;
}
desc->callback = bam_dmux_tx_callback;
desc->callback_param = skb_dma;
desc->cookie = dmaengine_submit(desc);
return true;
}
static struct bam_dmux_skb_dma *
bam_dmux_tx_queue(struct bam_dmux *dmux, struct sk_buff *skb)
{
struct bam_dmux_skb_dma *skb_dma;
unsigned long flags;
spin_lock_irqsave(&dmux->tx_lock, flags);
skb_dma = &dmux->tx_skbs[dmux->tx_next_skb % BAM_DMUX_NUM_SKB];
if (skb_dma->skb) {
bam_dmux_tx_stop_queues(dmux);
spin_unlock_irqrestore(&dmux->tx_lock, flags);
return NULL;
}
skb_dma->skb = skb;
dmux->tx_next_skb++;
if (dmux->tx_skbs[dmux->tx_next_skb % BAM_DMUX_NUM_SKB].skb)
bam_dmux_tx_stop_queues(dmux);
spin_unlock_irqrestore(&dmux->tx_lock, flags);
return skb_dma;
}
static int bam_dmux_send_cmd(struct bam_dmux_netdev *bndev, u8 cmd)
{
struct bam_dmux *dmux = bndev->dmux;
struct bam_dmux_skb_dma *skb_dma;
struct bam_dmux_hdr *hdr;
struct sk_buff *skb;
int ret;
skb = alloc_skb(sizeof(*hdr), GFP_KERNEL);
if (!skb)
return -ENOMEM;
hdr = skb_put_zero(skb, sizeof(*hdr));
hdr->magic = BAM_DMUX_HDR_MAGIC;
hdr->cmd = cmd;
hdr->ch = bndev->ch;
skb_dma = bam_dmux_tx_queue(dmux, skb);
if (!skb_dma) {
ret = -EAGAIN;
goto free_skb;
}
ret = pm_runtime_get_sync(dmux->dev);
if (ret < 0)
goto tx_fail;
if (!bam_dmux_skb_dma_map(skb_dma, DMA_TO_DEVICE)) {
ret = -ENOMEM;
goto tx_fail;
}
if (!bam_dmux_skb_dma_submit_tx(skb_dma)) {
ret = -EIO;
goto tx_fail;
}
dma_async_issue_pending(dmux->tx);
return 0;
tx_fail:
bam_dmux_tx_done(skb_dma);
free_skb:
dev_kfree_skb(skb);
return ret;
}
static int bam_dmux_netdev_open(struct net_device *netdev)
{
struct bam_dmux_netdev *bndev = netdev_priv(netdev);
int ret;
ret = bam_dmux_send_cmd(bndev, BAM_DMUX_CMD_OPEN);
if (ret)
return ret;
netif_start_queue(netdev);
return 0;
}
static int bam_dmux_netdev_stop(struct net_device *netdev)
{
struct bam_dmux_netdev *bndev = netdev_priv(netdev);
netif_stop_queue(netdev);
bam_dmux_send_cmd(bndev, BAM_DMUX_CMD_CLOSE);
return 0;
}
static unsigned int needed_room(unsigned int avail, unsigned int needed)
{
if (avail >= needed)
return 0;
return needed - avail;
}
static int bam_dmux_tx_prepare_skb(struct bam_dmux_netdev *bndev,
struct sk_buff *skb)
{
unsigned int head = needed_room(skb_headroom(skb), BAM_DMUX_HDR_SIZE);
unsigned int pad = sizeof(u32) - skb->len % sizeof(u32);
unsigned int tail = needed_room(skb_tailroom(skb), pad);
struct bam_dmux_hdr *hdr;
int ret;
if (head || tail || skb_cloned(skb)) {
ret = pskb_expand_head(skb, head, tail, GFP_ATOMIC);
if (ret)
return ret;
}
hdr = skb_push(skb, sizeof(*hdr));
hdr->magic = BAM_DMUX_HDR_MAGIC;
hdr->signal = 0;
hdr->cmd = BAM_DMUX_CMD_DATA;
hdr->pad = pad;
hdr->ch = bndev->ch;
hdr->len = skb->len - sizeof(*hdr);
if (pad)
skb_put_zero(skb, pad);
return 0;
}
static netdev_tx_t bam_dmux_netdev_start_xmit(struct sk_buff *skb,
struct net_device *netdev)
{
struct bam_dmux_netdev *bndev = netdev_priv(netdev);
struct bam_dmux *dmux = bndev->dmux;
struct bam_dmux_skb_dma *skb_dma;
int active, ret;
skb_dma = bam_dmux_tx_queue(dmux, skb);
if (!skb_dma)
return NETDEV_TX_BUSY;
active = pm_runtime_get(dmux->dev);
if (active < 0 && active != -EINPROGRESS)
goto drop;
ret = bam_dmux_tx_prepare_skb(bndev, skb);
if (ret)
goto drop;
if (!bam_dmux_skb_dma_map(skb_dma, DMA_TO_DEVICE))
goto drop;
if (active <= 0) {
/* Cannot sleep here so mark skb for wakeup handler and return */
if (!atomic_long_fetch_or(BIT(skb_dma - dmux->tx_skbs),
&dmux->tx_deferred_skb))
queue_pm_work(&dmux->tx_wakeup_work);
return NETDEV_TX_OK;
}
if (!bam_dmux_skb_dma_submit_tx(skb_dma))
goto drop;
dma_async_issue_pending(dmux->tx);
return NETDEV_TX_OK;
drop:
bam_dmux_tx_done(skb_dma);
dev_kfree_skb_any(skb);
return NETDEV_TX_OK;
}
static void bam_dmux_tx_wakeup_work(struct work_struct *work)
{
struct bam_dmux *dmux = container_of(work, struct bam_dmux, tx_wakeup_work);
unsigned long pending;
int ret, i;
ret = pm_runtime_resume_and_get(dmux->dev);
if (ret < 0) {
dev_err(dmux->dev, "Failed to resume: %d\n", ret);
return;
}
pending = atomic_long_xchg(&dmux->tx_deferred_skb, 0);
if (!pending)
goto out;
dev_dbg(dmux->dev, "pending skbs after wakeup: %#lx\n", pending);
for_each_set_bit(i, &pending, BAM_DMUX_NUM_SKB) {
bam_dmux_skb_dma_submit_tx(&dmux->tx_skbs[i]);
}
dma_async_issue_pending(dmux->tx);
out:
pm_runtime_mark_last_busy(dmux->dev);
pm_runtime_put_autosuspend(dmux->dev);
}
static const struct net_device_ops bam_dmux_ops = {
.ndo_open = bam_dmux_netdev_open,
.ndo_stop = bam_dmux_netdev_stop,
.ndo_start_xmit = bam_dmux_netdev_start_xmit,
};
static const struct device_type wwan_type = {
.name = "wwan",
};
static void bam_dmux_netdev_setup(struct net_device *dev)
{
dev->netdev_ops = &bam_dmux_ops;
dev->type = ARPHRD_RAWIP;
SET_NETDEV_DEVTYPE(dev, &wwan_type);
dev->flags = IFF_POINTOPOINT | IFF_NOARP;
dev->mtu = ETH_DATA_LEN;
dev->max_mtu = BAM_DMUX_MAX_DATA_SIZE;
dev->needed_headroom = sizeof(struct bam_dmux_hdr);
dev->needed_tailroom = sizeof(u32); /* word-aligned */
dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN;
/* This perm addr will be used as interface identifier by IPv6 */
dev->addr_assign_type = NET_ADDR_RANDOM;
eth_random_addr(dev->perm_addr);
}
static void bam_dmux_register_netdev_work(struct work_struct *work)
{
struct bam_dmux *dmux = container_of(work, struct bam_dmux, register_netdev_work);
struct bam_dmux_netdev *bndev;
struct net_device *netdev;
int ch, ret;
for_each_set_bit(ch, dmux->remote_channels, BAM_DMUX_NUM_CH) {
if (dmux->netdevs[ch])
continue;
netdev = alloc_netdev(sizeof(*bndev), "wwan%d", NET_NAME_ENUM,
bam_dmux_netdev_setup);
if (!netdev)
return;
SET_NETDEV_DEV(netdev, dmux->dev);
netdev->dev_port = ch;
bndev = netdev_priv(netdev);
bndev->dmux = dmux;
bndev->ch = ch;
ret = register_netdev(netdev);
if (ret) {
dev_err(dmux->dev, "Failed to register netdev for channel %u: %d\n",
ch, ret);
free_netdev(netdev);
return;
}
dmux->netdevs[ch] = netdev;
}
}
static void bam_dmux_rx_callback(void *data);
static bool bam_dmux_skb_dma_submit_rx(struct bam_dmux_skb_dma *skb_dma)
{
struct bam_dmux *dmux = skb_dma->dmux;
struct dma_async_tx_descriptor *desc;
desc = dmaengine_prep_slave_single(dmux->rx, skb_dma->addr,
skb_dma->skb->len, DMA_DEV_TO_MEM,
DMA_PREP_INTERRUPT);
if (!desc) {
dev_err(dmux->dev, "Failed to prepare RX DMA buffer\n");
return false;
}
desc->callback = bam_dmux_rx_callback;
desc->callback_param = skb_dma;
desc->cookie = dmaengine_submit(desc);
return true;
}
static bool bam_dmux_skb_dma_queue_rx(struct bam_dmux_skb_dma *skb_dma, gfp_t gfp)
{
if (!skb_dma->skb) {
skb_dma->skb = __netdev_alloc_skb(NULL, BAM_DMUX_BUFFER_SIZE, gfp);
if (!skb_dma->skb)
return false;
skb_put(skb_dma->skb, BAM_DMUX_BUFFER_SIZE);
}
return bam_dmux_skb_dma_map(skb_dma, DMA_FROM_DEVICE) &&
bam_dmux_skb_dma_submit_rx(skb_dma);
}
static void bam_dmux_cmd_data(struct bam_dmux_skb_dma *skb_dma)
{
struct bam_dmux *dmux = skb_dma->dmux;
struct sk_buff *skb = skb_dma->skb;
struct bam_dmux_hdr *hdr = (struct bam_dmux_hdr *)skb->data;
struct net_device *netdev = dmux->netdevs[hdr->ch];
if (!netdev || !netif_running(netdev)) {
dev_warn(dmux->dev, "Data for inactive channel %u\n", hdr->ch);
return;
}
if (hdr->len > BAM_DMUX_MAX_DATA_SIZE) {
dev_err(dmux->dev, "Data larger than buffer? (%u > %u)\n",
hdr->len, (u16)BAM_DMUX_MAX_DATA_SIZE);
return;
}
skb_dma->skb = NULL; /* Hand over to network stack */
skb_pull(skb, sizeof(*hdr));
skb_trim(skb, hdr->len);
skb->dev = netdev;
/* Only Raw-IP/QMAP is supported by this driver */
switch (skb->data[0] & 0xf0) {
case 0x40:
skb->protocol = htons(ETH_P_IP);
break;
case 0x60:
skb->protocol = htons(ETH_P_IPV6);
break;
default:
skb->protocol = htons(ETH_P_MAP);
break;
}
netif_receive_skb(skb);
}
static void bam_dmux_cmd_open(struct bam_dmux *dmux, struct bam_dmux_hdr *hdr)
{
struct net_device *netdev = dmux->netdevs[hdr->ch];
dev_dbg(dmux->dev, "open channel: %u\n", hdr->ch);
if (__test_and_set_bit(hdr->ch, dmux->remote_channels)) {
dev_warn(dmux->dev, "Channel already open: %u\n", hdr->ch);
return;
}
if (netdev) {
netif_device_attach(netdev);
} else {
/* Cannot sleep here, schedule work to register the netdev */
schedule_work(&dmux->register_netdev_work);
}
}
static void bam_dmux_cmd_close(struct bam_dmux *dmux, struct bam_dmux_hdr *hdr)
{
struct net_device *netdev = dmux->netdevs[hdr->ch];
dev_dbg(dmux->dev, "close channel: %u\n", hdr->ch);
if (!__test_and_clear_bit(hdr->ch, dmux->remote_channels)) {
dev_err(dmux->dev, "Channel not open: %u\n", hdr->ch);
return;
}
if (netdev)
netif_device_detach(netdev);
}
static void bam_dmux_rx_callback(void *data)
{
struct bam_dmux_skb_dma *skb_dma = data;
struct bam_dmux *dmux = skb_dma->dmux;
struct sk_buff *skb = skb_dma->skb;
struct bam_dmux_hdr *hdr = (struct bam_dmux_hdr *)skb->data;
bam_dmux_skb_dma_unmap(skb_dma, DMA_FROM_DEVICE);
if (hdr->magic != BAM_DMUX_HDR_MAGIC) {
dev_err(dmux->dev, "Invalid magic in header: %#x\n", hdr->magic);
goto out;
}
if (hdr->ch >= BAM_DMUX_NUM_CH) {
dev_dbg(dmux->dev, "Unsupported channel: %u\n", hdr->ch);
goto out;
}
switch (hdr->cmd) {
case BAM_DMUX_CMD_DATA:
bam_dmux_cmd_data(skb_dma);
break;
case BAM_DMUX_CMD_OPEN:
bam_dmux_cmd_open(dmux, hdr);
break;
case BAM_DMUX_CMD_CLOSE:
bam_dmux_cmd_close(dmux, hdr);
break;
default:
dev_err(dmux->dev, "Unsupported command %u on channel %u\n",
hdr->cmd, hdr->ch);
break;
}
out:
if (bam_dmux_skb_dma_queue_rx(skb_dma, GFP_ATOMIC))
dma_async_issue_pending(dmux->rx);
}
static bool bam_dmux_power_on(struct bam_dmux *dmux)
{
struct device *dev = dmux->dev;
struct dma_slave_config dma_rx_conf = {
.direction = DMA_DEV_TO_MEM,
.src_maxburst = BAM_DMUX_BUFFER_SIZE,
};
int i;
dmux->rx = dma_request_chan(dev, "rx");
if (IS_ERR(dmux->rx)) {
dev_err(dev, "Failed to request RX DMA channel: %pe\n", dmux->rx);
dmux->rx = NULL;
return false;
}
dmaengine_slave_config(dmux->rx, &dma_rx_conf);
for (i = 0; i < BAM_DMUX_NUM_SKB; i++) {
if (!bam_dmux_skb_dma_queue_rx(&dmux->rx_skbs[i], GFP_KERNEL))
return false;
}
dma_async_issue_pending(dmux->rx);
return true;
}
static void bam_dmux_free_skbs(struct bam_dmux_skb_dma skbs[],
enum dma_data_direction dir)
{
int i;
for (i = 0; i < BAM_DMUX_NUM_SKB; i++) {
struct bam_dmux_skb_dma *skb_dma = &skbs[i];
if (skb_dma->addr)
bam_dmux_skb_dma_unmap(skb_dma, dir);
if (skb_dma->skb) {
dev_kfree_skb(skb_dma->skb);
skb_dma->skb = NULL;
}
}
}
static void bam_dmux_power_off(struct bam_dmux *dmux)
{
if (dmux->tx) {
dmaengine_terminate_sync(dmux->tx);
dma_release_channel(dmux->tx);
dmux->tx = NULL;
}
if (dmux->rx) {
dmaengine_terminate_sync(dmux->rx);
dma_release_channel(dmux->rx);
dmux->rx = NULL;
}
bam_dmux_free_skbs(dmux->rx_skbs, DMA_FROM_DEVICE);
}
static irqreturn_t bam_dmux_pc_irq(int irq, void *data)
{
struct bam_dmux *dmux = data;
bool new_state = !dmux->pc_state;
dev_dbg(dmux->dev, "pc: %u\n", new_state);
if (new_state) {
if (bam_dmux_power_on(dmux))
bam_dmux_pc_ack(dmux);
else
bam_dmux_power_off(dmux);
} else {
bam_dmux_power_off(dmux);
bam_dmux_pc_ack(dmux);
}
dmux->pc_state = new_state;
wake_up_all(&dmux->pc_wait);
return IRQ_HANDLED;
}
static irqreturn_t bam_dmux_pc_ack_irq(int irq, void *data)
{
struct bam_dmux *dmux = data;
dev_dbg(dmux->dev, "pc ack\n");
complete_all(&dmux->pc_ack_completion);
return IRQ_HANDLED;
}
static int bam_dmux_runtime_suspend(struct device *dev)
{
struct bam_dmux *dmux = dev_get_drvdata(dev);
dev_dbg(dev, "runtime suspend\n");
bam_dmux_pc_vote(dmux, false);
return 0;
}
static int __maybe_unused bam_dmux_runtime_resume(struct device *dev)
{
struct bam_dmux *dmux = dev_get_drvdata(dev);
dev_dbg(dev, "runtime resume\n");
/* Wait until previous power down was acked */
if (!wait_for_completion_timeout(&dmux->pc_ack_completion,
BAM_DMUX_REMOTE_TIMEOUT))
return -ETIMEDOUT;
/* Vote for power state */
bam_dmux_pc_vote(dmux, true);
/* Wait for ack */
if (!wait_for_completion_timeout(&dmux->pc_ack_completion,
BAM_DMUX_REMOTE_TIMEOUT)) {
bam_dmux_pc_vote(dmux, false);
return -ETIMEDOUT;
}
/* Wait until we're up */
if (!wait_event_timeout(dmux->pc_wait, dmux->pc_state,
BAM_DMUX_REMOTE_TIMEOUT)) {
bam_dmux_pc_vote(dmux, false);
return -ETIMEDOUT;
}
/* Ensure that we actually initialized successfully */
if (!dmux->rx) {
bam_dmux_pc_vote(dmux, false);
return -ENXIO;
}
/* Request TX channel if necessary */
if (dmux->tx)
return 0;
dmux->tx = dma_request_chan(dev, "tx");
if (IS_ERR(dmux->tx)) {
dev_err(dev, "Failed to request TX DMA channel: %pe\n", dmux->tx);
dmux->tx = NULL;
bam_dmux_runtime_suspend(dev);
return -ENXIO;
}
return 0;
}
static int bam_dmux_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct bam_dmux *dmux;
int ret, pc_ack_irq, i;
unsigned int bit;
dmux = devm_kzalloc(dev, sizeof(*dmux), GFP_KERNEL);
if (!dmux)
return -ENOMEM;
dmux->dev = dev;
platform_set_drvdata(pdev, dmux);
dmux->pc_irq = platform_get_irq_byname(pdev, "pc");
if (dmux->pc_irq < 0)
return dmux->pc_irq;
pc_ack_irq = platform_get_irq_byname(pdev, "pc-ack");
if (pc_ack_irq < 0)
return pc_ack_irq;
dmux->pc = devm_qcom_smem_state_get(dev, "pc", &bit);
if (IS_ERR(dmux->pc))
return dev_err_probe(dev, PTR_ERR(dmux->pc),
"Failed to get pc state\n");
dmux->pc_mask = BIT(bit);
dmux->pc_ack = devm_qcom_smem_state_get(dev, "pc-ack", &bit);
if (IS_ERR(dmux->pc_ack))
return dev_err_probe(dev, PTR_ERR(dmux->pc_ack),
"Failed to get pc-ack state\n");
dmux->pc_ack_mask = BIT(bit);
init_waitqueue_head(&dmux->pc_wait);
init_completion(&dmux->pc_ack_completion);
complete_all(&dmux->pc_ack_completion);
spin_lock_init(&dmux->tx_lock);
INIT_WORK(&dmux->tx_wakeup_work, bam_dmux_tx_wakeup_work);
INIT_WORK(&dmux->register_netdev_work, bam_dmux_register_netdev_work);
for (i = 0; i < BAM_DMUX_NUM_SKB; i++) {
dmux->rx_skbs[i].dmux = dmux;
dmux->tx_skbs[i].dmux = dmux;
}
/* Runtime PM manages our own power vote.
* Note that the RX path may be active even if we are runtime suspended,
* since it is controlled by the remote side.
*/
pm_runtime_set_autosuspend_delay(dev, BAM_DMUX_AUTOSUSPEND_DELAY);
pm_runtime_use_autosuspend(dev);
pm_runtime_enable(dev);
ret = devm_request_threaded_irq(dev, pc_ack_irq, NULL, bam_dmux_pc_ack_irq,
IRQF_ONESHOT, NULL, dmux);
if (ret)
goto err_disable_pm;
ret = devm_request_threaded_irq(dev, dmux->pc_irq, NULL, bam_dmux_pc_irq,
IRQF_ONESHOT, NULL, dmux);
if (ret)
goto err_disable_pm;
ret = irq_get_irqchip_state(dmux->pc_irq, IRQCHIP_STATE_LINE_LEVEL,
&dmux->pc_state);
if (ret)
goto err_disable_pm;
/* Check if remote finished initialization before us */
if (dmux->pc_state) {
if (bam_dmux_power_on(dmux))
bam_dmux_pc_ack(dmux);
else
bam_dmux_power_off(dmux);
}
return 0;
err_disable_pm:
pm_runtime_disable(dev);
pm_runtime_dont_use_autosuspend(dev);
return ret;
}
static void bam_dmux_remove(struct platform_device *pdev)
{
struct bam_dmux *dmux = platform_get_drvdata(pdev);
struct device *dev = dmux->dev;
LIST_HEAD(list);
int i;
/* Unregister network interfaces */
cancel_work_sync(&dmux->register_netdev_work);
rtnl_lock();
for (i = 0; i < BAM_DMUX_NUM_CH; ++i)
if (dmux->netdevs[i])
unregister_netdevice_queue(dmux->netdevs[i], &list);
unregister_netdevice_many(&list);
rtnl_unlock();
cancel_work_sync(&dmux->tx_wakeup_work);
/* Drop our own power vote */
pm_runtime_disable(dev);
pm_runtime_dont_use_autosuspend(dev);
bam_dmux_runtime_suspend(dev);
pm_runtime_set_suspended(dev);
/* Try to wait for remote side to drop power vote */
if (!wait_event_timeout(dmux->pc_wait, !dmux->rx, BAM_DMUX_REMOTE_TIMEOUT))
dev_err(dev, "Timed out waiting for remote side to suspend\n");
/* Make sure everything is cleaned up before we return */
disable_irq(dmux->pc_irq);
bam_dmux_power_off(dmux);
bam_dmux_free_skbs(dmux->tx_skbs, DMA_TO_DEVICE);
}
static const struct dev_pm_ops bam_dmux_pm_ops = {
SET_RUNTIME_PM_OPS(bam_dmux_runtime_suspend, bam_dmux_runtime_resume, NULL)
};
static const struct of_device_id bam_dmux_of_match[] = {
{ .compatible = "qcom,bam-dmux" },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, bam_dmux_of_match);
static struct platform_driver bam_dmux_driver = {
.probe = bam_dmux_probe,
.remove_new = bam_dmux_remove,
.driver = {
.name = "bam-dmux",
.pm = &bam_dmux_pm_ops,
.of_match_table = bam_dmux_of_match,
},
};
module_platform_driver(bam_dmux_driver);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Qualcomm BAM-DMUX WWAN Network Driver");
MODULE_AUTHOR("Stephan Gerhold <[email protected]>");
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