can: at91_can: convert derived mailbox constants into functions

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>

1 files changed, 83 insertions, 42 deletions

diff --git a/drivers/net/can/at91_can.c b/drivers/net/can/at91_can.c
index 86994845a1d4..900ff67ed7f3 100644
--- a/drivers/net/can/at91_can.c
+++ b/drivers/net/can/at91_can.c
@@ -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 {
@@ -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)
@@ -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)
@@ -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 */
@@ -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);
 }
@@ -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
@@ -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 */
@@ -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);
 }
 
@@ -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);
 
@@ -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;
@@ -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);
 
         /*
@@ -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);
@@ -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++;
                 }
         }
@@ -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);
 }
 
@@ -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);
@@ -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;