smsc911x: add dynamic bus configuration

Convert the driver to select 16-bit or 32-bit bus access at runtime,
at a small performance cost.

Signed-off-by: Steve Glendinning <steve.glendinning@smsc.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 84 insertions, 80 deletions

diff --git a/drivers/net/smsc911x.c b/drivers/net/smsc911x.c
index fe517880fc97..4b8ff843e300 100644
--- a/drivers/net/smsc911x.c
+++ b/drivers/net/smsc911x.c
@@ -77,19 +77,16 @@ struct smsc911x_data {
         unsigned int generation;
 
         /* device configuration (copied from platform_data during probe) */
-        unsigned int irq_polarity;
-        unsigned int irq_type;
-        phy_interface_t phy_interface;
+        struct smsc911x_platform_config config;
 
         /* This needs to be acquired before calling any of below:
          * smsc911x_mac_read(), smsc911x_mac_write()
          */
         spinlock_t mac_lock;
 
-#if (!SMSC_CAN_USE_32BIT)
-        /* spinlock to ensure 16-bit accesses are serialised */
+        /* spinlock to ensure 16-bit accesses are serialised.
+         * unused with a 32-bit bus */
         spinlock_t dev_lock;
-#endif
 
         struct phy_device *phy_dev;
         struct mii_bus *mii_bus;
@@ -121,70 +118,56 @@ struct smsc911x_data {
         unsigned int hashlo;
 };
 
-#if SMSC_CAN_USE_32BIT
-
-static inline u32 smsc911x_reg_read(struct smsc911x_data *pdata, u32 reg)
-{
-        return readl(pdata->ioaddr + reg);
-}
-
-static inline void smsc911x_reg_write(struct smsc911x_data *pdata, u32 reg,
-                                      u32 val)
-{
-        writel(val, pdata->ioaddr + reg);
-}
-
-/* Writes a packet to the TX_DATA_FIFO */
-static inline void
-smsc911x_tx_writefifo(struct smsc911x_data *pdata, unsigned int *buf,
-                      unsigned int wordcount)
-{
-        writesl(pdata->ioaddr + TX_DATA_FIFO, buf, wordcount);
-}
-
-/* Reads a packet out of the RX_DATA_FIFO */
-static inline void
-smsc911x_rx_readfifo(struct smsc911x_data *pdata, unsigned int *buf,
-                     unsigned int wordcount)
-{
-        readsl(pdata->ioaddr + RX_DATA_FIFO, buf, wordcount);
-}
-
-#else                           /* SMSC_CAN_USE_32BIT */
-
-/* These 16-bit access functions are significantly slower, due to the locking
+/* The 16-bit access functions are significantly slower, due to the locking
  * necessary.  If your bus hardware can be configured to do this for you
  * (in response to a single 32-bit operation from software), you should use
  * the 32-bit access functions instead. */
 
 static inline u32 smsc911x_reg_read(struct smsc911x_data *pdata, u32 reg)
 {
-        unsigned long flags;
-        u32 data;
-
-        /* these two 16-bit reads must be performed consecutively, so must
-         * not be interrupted by our own ISR (which would start another
-         * read operation) */
-        spin_lock_irqsave(&pdata->dev_lock, flags);
-        data = ((readw(pdata->ioaddr + reg) & 0xFFFF) |
-                ((readw(pdata->ioaddr + reg + 2) & 0xFFFF) << 16));
-        spin_unlock_irqrestore(&pdata->dev_lock, flags);
+        if (pdata->config.flags & SMSC911X_USE_32BIT)
+                return readl(pdata->ioaddr + reg);
+
+        if (pdata->config.flags & SMSC911X_USE_16BIT) {
+                u32 data;
+                unsigned long flags;
+
+                /* these two 16-bit reads must be performed consecutively, so
+                 * must not be interrupted by our own ISR (which would start
+                 * another read operation) */
+                spin_lock_irqsave(&pdata->dev_lock, flags);
+                data = ((readw(pdata->ioaddr + reg) & 0xFFFF) |
+                        ((readw(pdata->ioaddr + reg + 2) & 0xFFFF) << 16));
+                spin_unlock_irqrestore(&pdata->dev_lock, flags);
+
+                return data;
+        }
 
-        return data;
+        BUG();
 }
 
 static inline void smsc911x_reg_write(struct smsc911x_data *pdata, u32 reg,
                                       u32 val)
 {
-        unsigned long flags;
+        if (pdata->config.flags & SMSC911X_USE_32BIT) {
+                writel(val, pdata->ioaddr + reg);
+                return;
+        }
+
+        if (pdata->config.flags & SMSC911X_USE_16BIT) {
+                unsigned long flags;
+
+                /* these two 16-bit writes must be performed consecutively, so
+                 * must not be interrupted by our own ISR (which would start
+                 * another read operation) */
+                spin_lock_irqsave(&pdata->dev_lock, flags);
+                writew(val & 0xFFFF, pdata->ioaddr + reg);
+                writew((val >> 16) & 0xFFFF, pdata->ioaddr + reg + 2);
+                spin_unlock_irqrestore(&pdata->dev_lock, flags);
+                return;
+        }
 
-        /* these two 16-bit writes must be performed consecutively, so must
-         * not be interrupted by our own ISR (which would start another
-         * read operation) */
-        spin_lock_irqsave(&pdata->dev_lock, flags);
-        writew(val & 0xFFFF, pdata->ioaddr + reg);
-        writew((val >> 16) & 0xFFFF, pdata->ioaddr + reg + 2);
-        spin_unlock_irqrestore(&pdata->dev_lock, flags);
+        BUG();
 }
 
 /* Writes a packet to the TX_DATA_FIFO */
@@ -192,8 +175,18 @@ static inline void
 smsc911x_tx_writefifo(struct smsc911x_data *pdata, unsigned int *buf,
                       unsigned int wordcount)
 {
-        while (wordcount--)
-                smsc911x_reg_write(pdata, TX_DATA_FIFO, *buf++);
+        if (pdata->config.flags & SMSC911X_USE_32BIT) {
+                writesl(pdata->ioaddr + TX_DATA_FIFO, buf, wordcount);
+                return;
+        }
+
+        if (pdata->config.flags & SMSC911X_USE_16BIT) {
+                while (wordcount--)
+                        smsc911x_reg_write(pdata, TX_DATA_FIFO, *buf++);
+                return;
+        }
+
+        BUG();
 }
 
 /* Reads a packet out of the RX_DATA_FIFO */
@@ -201,11 +194,19 @@ static inline void
 smsc911x_rx_readfifo(struct smsc911x_data *pdata, unsigned int *buf,
                      unsigned int wordcount)
 {
-        while (wordcount--)
-                *buf++ = smsc911x_reg_read(pdata, RX_DATA_FIFO);
-}
+        if (pdata->config.flags & SMSC911X_USE_32BIT) {
+                readsl(pdata->ioaddr + RX_DATA_FIFO, buf, wordcount);
+                return;
+        }
 
-#endif                          /* SMSC_CAN_USE_32BIT */
+        if (pdata->config.flags & SMSC911X_USE_16BIT) {
+                while (wordcount--)
+                        *buf++ = smsc911x_reg_read(pdata, RX_DATA_FIFO);
+                return;
+        }
+
+        BUG();
+}
 
 /* waits for MAC not busy, with timeout.  Only called by smsc911x_mac_read
  * and smsc911x_mac_write, so assumes mac_lock is held */
@@ -790,7 +791,7 @@ static int smsc911x_mii_probe(struct net_device *dev)
         }
 
         phydev = phy_connect(dev, phydev->dev.bus_id,
-                &smsc911x_phy_adjust_link, 0, pdata->phy_interface);
+                &smsc911x_phy_adjust_link, 0, pdata->config.phy_interface);
 
         if (IS_ERR(phydev)) {
                 pr_err("%s: Could not attach to PHY\n", dev->name);
@@ -1205,14 +1206,14 @@ static int smsc911x_open(struct net_device *dev)
         /* Set interrupt deassertion to 100uS */
         intcfg = ((10 << 24) | INT_CFG_IRQ_EN_);
 
-        if (pdata->irq_polarity) {
+        if (pdata->config.irq_polarity) {
                 SMSC_TRACE(IFUP, "irq polarity: active high");
                 intcfg |= INT_CFG_IRQ_POL_;
         } else {
                 SMSC_TRACE(IFUP, "irq polarity: active low");
         }
 
-        if (pdata->irq_type) {
+        if (pdata->config.irq_type) {
                 SMSC_TRACE(IFUP, "irq type: push-pull");
                 intcfg |= INT_CFG_IRQ_TYPE_;
         } else {
@@ -1767,9 +1768,7 @@ static int __devinit smsc911x_init(struct net_device *dev)
         SMSC_TRACE(PROBE, "IRQ: %d", dev->irq);
         SMSC_TRACE(PROBE, "PHY will be autodetected.");
 
-#if (!SMSC_CAN_USE_32BIT)
         spin_lock_init(&pdata->dev_lock);
-#endif
 
         if (pdata->ioaddr == 0) {
                 SMSC_WARNING(PROBE, "pdata->ioaddr: 0x00000000");
@@ -1910,6 +1909,7 @@ static int __devinit smsc911x_drv_probe(struct platform_device *pdev)
 {
         struct net_device *dev;
         struct smsc911x_data *pdata;
+        struct smsc911x_platform_config *config = pdev->dev.platform_data;
         struct resource *res;
         unsigned int intcfg = 0;
         int res_size;
@@ -1918,6 +1918,13 @@ static int __devinit smsc911x_drv_probe(struct platform_device *pdev)
 
         pr_info("%s: Driver version %s.\n", SMSC_CHIPNAME, SMSC_DRV_VERSION);
 
+        /* platform data specifies irq & dynamic bus configuration */
+        if (!pdev->dev.platform_data) {
+                pr_warning("%s: platform_data not provided\n", SMSC_CHIPNAME);
+                retval = -ENODEV;
+                goto out_0;
+        }
+
         res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
                                            "smsc911x-memory");
         if (!res)
@@ -1949,15 +1956,8 @@ static int __devinit smsc911x_drv_probe(struct platform_device *pdev)
         dev->irq = platform_get_irq(pdev, 0);
         pdata->ioaddr = ioremap_nocache(res->start, res_size);
 
-        /* copy config parameters across if present, otherwise pdata
-         * defaults to zeros */
-        if (pdev->dev.platform_data) {
-                struct smsc911x_platform_config *config =
-                        pdev->dev.platform_data;
-                pdata->irq_polarity = config->irq_polarity;
-                pdata->irq_type  = config->irq_type;
-                pdata->phy_interface = config->phy_interface;
-        }
+        /* copy config parameters across to pdata */
+        memcpy(&pdata->config, config, sizeof(pdata->config));
 
         pdata->dev = dev;
         pdata->msg_enable = ((1 << debug) - 1);
@@ -1974,10 +1974,10 @@ static int __devinit smsc911x_drv_probe(struct platform_device *pdev)
                 goto out_unmap_io_3;
 
         /* configure irq polarity and type before connecting isr */
-        if (pdata->irq_polarity == SMSC911X_IRQ_POLARITY_ACTIVE_HIGH)
+        if (pdata->config.irq_polarity == SMSC911X_IRQ_POLARITY_ACTIVE_HIGH)
                 intcfg |= INT_CFG_IRQ_POL_;
 
-        if (pdata->irq_type == SMSC911X_IRQ_TYPE_PUSH_PULL)
+        if (pdata->config.irq_type == SMSC911X_IRQ_TYPE_PUSH_PULL)
                 intcfg |= INT_CFG_IRQ_TYPE_;
 
         smsc911x_reg_write(pdata, INT_CFG, intcfg);
diff --git a/drivers/net/smsc911x.h b/drivers/net/smsc911x.h
index feb36de274ca..f818cf0415f7 100644
--- a/drivers/net/smsc911x.h
+++ b/drivers/net/smsc911x.h
@@ -21,7 +21,6 @@
 #ifndef __SMSC911X_H__
 #define __SMSC911X_H__
 
-#define SMSC_CAN_USE_32BIT      1
 #define TX_FIFO_LOW_THRESHOLD   ((u32)1600)
 #define SMSC911X_EEPROM_SIZE    ((u32)7)
 #define USE_DEBUG               0
diff --git a/include/linux/smsc911x.h b/include/linux/smsc911x.h
index 47c4ffd10dbb..1cbf0313adde 100644
--- a/include/linux/smsc911x.h
+++ b/include/linux/smsc911x.h
@@ -28,6 +28,7 @@
 struct smsc911x_platform_config {
         unsigned int irq_polarity;
         unsigned int irq_type;
+        unsigned int flags;
         phy_interface_t phy_interface;
 };
 
@@ -39,4 +40,8 @@ struct smsc911x_platform_config {
 #define SMSC911X_IRQ_TYPE_OPEN_DRAIN            0
 #define SMSC911X_IRQ_TYPE_PUSH_PULL             1
 
+/* Constants for flags */
+#define SMSC911X_USE_16BIT                      (BIT(0))
+#define SMSC911X_USE_32BIT                      (BIT(1))
+
 #endif /* __LINUX_SMSC911X_H__ */