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can: at91_can: convert derived mailbox constants into functions
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This is the first of two patches converting the at91_can driver from a
compile time mailbox setup to a dynamic one.

This patch converts all derived mailbox constants to functions.

Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
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Marc Kleine-Budde committed Jun 6, 2011
1 parent b049994 commit 7900899
Showing 1 changed file with 83 additions and 42 deletions.
125 changes: 83 additions & 42 deletions drivers/net/can/at91_can.c
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Original file line number Diff line number Diff line change
Expand Up @@ -54,18 +54,7 @@

#define AT91_MB_MASK(i) ((1 << (i)) - 1)
#define AT91_MB_RX_SPLIT 8
#define AT91_MB_RX_LOW_LAST (AT91_MB_RX_SPLIT - 1)
#define AT91_MB_RX_LOW_MASK (AT91_MB_MASK(AT91_MB_RX_SPLIT) & \
~AT91_MB_MASK(AT91_MB_RX_FIRST))

#define AT91_MB_TX_NUM (1 << AT91_MB_TX_SHIFT)
#define AT91_MB_TX_FIRST (AT91_MB_RX_LAST + 1)
#define AT91_MB_TX_LAST (AT91_MB_TX_FIRST + AT91_MB_TX_NUM - 1)

#define AT91_NEXT_PRIO_SHIFT (AT91_MB_TX_SHIFT)
#define AT91_NEXT_PRIO_MASK (0xf << AT91_MB_TX_SHIFT)
#define AT91_NEXT_MB_MASK (AT91_MB_MASK(AT91_MB_TX_SHIFT))
#define AT91_NEXT_MASK ((AT91_MB_TX_NUM - 1) | AT91_NEXT_PRIO_MASK)

/* Common registers */
enum at91_reg {
Expand Down Expand Up @@ -127,12 +116,6 @@ enum at91_mb_mode {
};

/* Interrupt mask bits */
#define AT91_IRQ_MB_RX (AT91_MB_MASK(AT91_MB_RX_LAST + 1) & \
~AT91_MB_MASK(AT91_MB_RX_FIRST))
#define AT91_IRQ_MB_TX (AT91_MB_MASK(AT91_MB_TX_LAST + 1) & \
~AT91_MB_MASK(AT91_MB_TX_FIRST))
#define AT91_IRQ_MB_ALL (AT91_IRQ_MB_RX | AT91_IRQ_MB_TX)

#define AT91_IRQ_ERRA (1 << 16)
#define AT91_IRQ_WARN (1 << 17)
#define AT91_IRQ_ERRP (1 << 18)
Expand Down Expand Up @@ -185,19 +168,77 @@ static struct can_bittiming_const at91_bittiming_const = {
.brp_inc = 1,
};

static inline unsigned int get_mb_rx_low_last(const struct at91_priv *priv)
{
return AT91_MB_RX_SPLIT - 1;
}

static inline unsigned int get_mb_rx_low_mask(const struct at91_priv *priv)
{
return AT91_MB_MASK(AT91_MB_RX_SPLIT) &
~AT91_MB_MASK(AT91_MB_RX_FIRST);
}

static inline unsigned int get_mb_tx_num(const struct at91_priv *priv)
{
return 1 << AT91_MB_TX_SHIFT;
}

static inline unsigned int get_mb_tx_first(const struct at91_priv *priv)
{
return AT91_MB_RX_LAST + 1;
}

static inline unsigned int get_mb_tx_last(const struct at91_priv *priv)
{
return get_mb_tx_first(priv) + get_mb_tx_num(priv) - 1;
}

static inline unsigned int get_next_prio_shift(const struct at91_priv *priv)
{
return AT91_MB_TX_SHIFT;
}

static inline unsigned int get_next_prio_mask(const struct at91_priv *priv)
{
return 0xf << AT91_MB_TX_SHIFT;
}

static inline unsigned int get_next_mb_mask(const struct at91_priv *priv)
{
return AT91_MB_MASK(AT91_MB_TX_SHIFT);
}

static inline unsigned int get_next_mask(const struct at91_priv *priv)
{
return get_next_mb_mask(priv) | get_next_prio_mask(priv);
}

static inline unsigned int get_irq_mb_rx(const struct at91_priv *priv)
{
return AT91_MB_MASK(AT91_MB_RX_LAST + 1) &
~AT91_MB_MASK(AT91_MB_RX_FIRST);
}

static inline unsigned int get_irq_mb_tx(const struct at91_priv *priv)
{
return AT91_MB_MASK(get_mb_tx_last(priv) + 1) &
~AT91_MB_MASK(get_mb_tx_first(priv));
}

static inline unsigned int get_tx_next_mb(const struct at91_priv *priv)
{
return (priv->tx_next & AT91_NEXT_MB_MASK) + AT91_MB_TX_FIRST;
return (priv->tx_next & get_next_mb_mask(priv)) + get_mb_tx_first(priv);
}

static inline unsigned int get_tx_next_prio(const struct at91_priv *priv)
{
return (priv->tx_next >> AT91_NEXT_PRIO_SHIFT) & 0xf;
return (priv->tx_next >> get_next_prio_shift(priv)) & 0xf;
}

static inline unsigned int get_tx_echo_mb(const struct at91_priv *priv)
{
return (priv->tx_echo & AT91_NEXT_MB_MASK) + AT91_MB_TX_FIRST;
return (priv->tx_echo & get_next_mb_mask(priv)) + get_mb_tx_first(priv);
}

static inline u32 at91_read(const struct at91_priv *priv, enum at91_reg reg)
Expand Down Expand Up @@ -275,7 +316,7 @@ static void at91_setup_mailboxes(struct net_device *dev)
}

/* The last 4 mailboxes are used for transmitting. */
for (i = AT91_MB_TX_FIRST; i <= AT91_MB_TX_LAST; i++)
for (i = get_mb_tx_first(priv); i <= get_mb_tx_last(priv); i++)
set_mb_mode_prio(priv, i, AT91_MB_MODE_TX, 0);

/* Reset tx and rx helper pointers */
Expand Down Expand Up @@ -335,7 +376,7 @@ static void at91_chip_start(struct net_device *dev)
priv->can.state = CAN_STATE_ERROR_ACTIVE;

/* Enable interrupts */
reg_ier = AT91_IRQ_MB_RX | AT91_IRQ_ERRP | AT91_IRQ_ERR_FRAME;
reg_ier = get_irq_mb_rx(priv) | AT91_IRQ_ERRP | AT91_IRQ_ERR_FRAME;
at91_write(priv, AT91_IDR, AT91_IRQ_ALL);
at91_write(priv, AT91_IER, reg_ier);
}
Expand Down Expand Up @@ -416,7 +457,7 @@ static netdev_tx_t at91_start_xmit(struct sk_buff *skb, struct net_device *dev)
stats->tx_bytes += cf->can_dlc;

/* _NOTE_: subtract AT91_MB_TX_FIRST offset from mb! */
can_put_echo_skb(skb, dev, mb - AT91_MB_TX_FIRST);
can_put_echo_skb(skb, dev, mb - get_mb_tx_first(priv));

/*
* we have to stop the queue and deliver all messages in case
Expand All @@ -429,7 +470,7 @@ static netdev_tx_t at91_start_xmit(struct sk_buff *skb, struct net_device *dev)
priv->tx_next++;
if (!(at91_read(priv, AT91_MSR(get_tx_next_mb(priv))) &
AT91_MSR_MRDY) ||
(priv->tx_next & AT91_NEXT_MASK) == 0)
(priv->tx_next & get_next_mask(priv)) == 0)
netif_stop_queue(dev);

/* Enable interrupt for this mailbox */
Expand All @@ -446,7 +487,7 @@ static netdev_tx_t at91_start_xmit(struct sk_buff *skb, struct net_device *dev)
*/
static inline void at91_activate_rx_low(const struct at91_priv *priv)
{
u32 mask = AT91_MB_RX_LOW_MASK;
u32 mask = get_mb_rx_low_mask(priv);
at91_write(priv, AT91_TCR, mask);
}

Expand Down Expand Up @@ -611,23 +652,23 @@ static int at91_poll_rx(struct net_device *dev, int quota)
unsigned int mb;
int received = 0;

if (priv->rx_next > AT91_MB_RX_LOW_LAST &&
reg_sr & AT91_MB_RX_LOW_MASK)
if (priv->rx_next > get_mb_rx_low_last(priv) &&
reg_sr & get_mb_rx_low_mask(priv))
netdev_info(dev,
"order of incoming frames cannot be guaranteed\n");

again:
for (mb = find_next_bit(addr, AT91_MB_RX_LAST + 1, priv->rx_next);
mb < AT91_MB_RX_LAST + 1 && quota > 0;
for (mb = find_next_bit(addr, get_mb_tx_first(priv), priv->rx_next);
mb < get_mb_tx_first(priv) && quota > 0;
reg_sr = at91_read(priv, AT91_SR),
mb = find_next_bit(addr, AT91_MB_RX_LAST + 1, ++priv->rx_next)) {
mb = find_next_bit(addr, get_mb_tx_first(priv), ++priv->rx_next)) {
at91_read_msg(dev, mb);

/* reactivate mailboxes */
if (mb == AT91_MB_RX_LOW_LAST)
if (mb == get_mb_rx_low_last(priv))
/* all lower mailboxed, if just finished it */
at91_activate_rx_low(priv);
else if (mb > AT91_MB_RX_LOW_LAST)
else if (mb > get_mb_rx_low_last(priv))
/* only the mailbox we read */
at91_activate_rx_mb(priv, mb);

Expand All @@ -636,7 +677,7 @@ static int at91_poll_rx(struct net_device *dev, int quota)
}

/* upper group completed, look again in lower */
if (priv->rx_next > AT91_MB_RX_LOW_LAST &&
if (priv->rx_next > get_mb_rx_low_last(priv) &&
quota > 0 && mb > AT91_MB_RX_LAST) {
priv->rx_next = AT91_MB_RX_FIRST;
goto again;
Expand Down Expand Up @@ -721,7 +762,7 @@ static int at91_poll(struct napi_struct *napi, int quota)
u32 reg_sr = at91_read(priv, AT91_SR);
int work_done = 0;

if (reg_sr & AT91_IRQ_MB_RX)
if (reg_sr & get_irq_mb_rx(priv))
work_done += at91_poll_rx(dev, quota - work_done);

/*
Expand All @@ -735,7 +776,7 @@ static int at91_poll(struct napi_struct *napi, int quota)
if (work_done < quota) {
/* enable IRQs for frame errors and all mailboxes >= rx_next */
u32 reg_ier = AT91_IRQ_ERR_FRAME;
reg_ier |= AT91_IRQ_MB_RX & ~AT91_MB_MASK(priv->rx_next);
reg_ier |= get_irq_mb_rx(priv) & ~AT91_MB_MASK(priv->rx_next);

napi_complete(napi);
at91_write(priv, AT91_IER, reg_ier);
Expand Down Expand Up @@ -784,7 +825,7 @@ static void at91_irq_tx(struct net_device *dev, u32 reg_sr)
if (likely(reg_msr & AT91_MSR_MRDY &&
~reg_msr & AT91_MSR_MABT)) {
/* _NOTE_: subtract AT91_MB_TX_FIRST offset from mb! */
can_get_echo_skb(dev, mb - AT91_MB_TX_FIRST);
can_get_echo_skb(dev, mb - get_mb_tx_first(priv));
dev->stats.tx_packets++;
}
}
Expand All @@ -794,8 +835,8 @@ static void at91_irq_tx(struct net_device *dev, u32 reg_sr)
* we get a TX int for the last can frame directly before a
* wrap around.
*/
if ((priv->tx_next & AT91_NEXT_MASK) != 0 ||
(priv->tx_echo & AT91_NEXT_MASK) == 0)
if ((priv->tx_next & get_next_mask(priv)) != 0 ||
(priv->tx_echo & get_next_mask(priv)) == 0)
netif_wake_queue(dev);
}

Expand Down Expand Up @@ -969,19 +1010,19 @@ static irqreturn_t at91_irq(int irq, void *dev_id)
handled = IRQ_HANDLED;

/* Receive or error interrupt? -> napi */
if (reg_sr & (AT91_IRQ_MB_RX | AT91_IRQ_ERR_FRAME)) {
if (reg_sr & (get_irq_mb_rx(priv) | AT91_IRQ_ERR_FRAME)) {
/*
* The error bits are clear on read,
* save for later use.
*/
priv->reg_sr = reg_sr;
at91_write(priv, AT91_IDR,
AT91_IRQ_MB_RX | AT91_IRQ_ERR_FRAME);
get_irq_mb_rx(priv) | AT91_IRQ_ERR_FRAME);
napi_schedule(&priv->napi);
}

/* Transmission complete interrupt */
if (reg_sr & AT91_IRQ_MB_TX)
if (reg_sr & get_irq_mb_tx(priv))
at91_irq_tx(dev, reg_sr);

at91_irq_err(dev);
Expand Down Expand Up @@ -1158,7 +1199,7 @@ static int __devinit at91_can_probe(struct platform_device *pdev)
goto exit_release;
}

dev = alloc_candev(sizeof(struct at91_priv), AT91_MB_TX_NUM);
dev = alloc_candev(sizeof(struct at91_priv), 1 << AT91_MB_TX_SHIFT);
if (!dev) {
err = -ENOMEM;
goto exit_iounmap;
Expand Down

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