Merge git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivial
[linux-3.10.git] / drivers / spi / spi_bitbang.c
index 0525c99..a23862e 100644 (file)
@@ -16,7 +16,6 @@
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
 
-#include <linux/config.h>
 #include <linux/init.h>
 #include <linux/spinlock.h>
 #include <linux/workqueue.h>
@@ -138,8 +137,7 @@ static unsigned bitbang_txrx_32(
        return t->len - count;
 }
 
-static int
-bitbang_transfer_setup(struct spi_device *spi, struct spi_transfer *t)
+int spi_bitbang_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
 {
        struct spi_bitbang_cs   *cs = spi->controller_state;
        u8                      bits_per_word;
@@ -168,12 +166,15 @@ bitbang_transfer_setup(struct spi_device *spi, struct spi_transfer *t)
        /* nsecs = (clock period)/2 */
        if (!hz)
                hz = spi->max_speed_hz;
-       cs->nsecs = (1000000000/2) / hz;
-       if (cs->nsecs > MAX_UDELAY_MS * 1000)
-               return -EINVAL;
+       if (hz) {
+               cs->nsecs = (1000000000/2) / hz;
+               if (cs->nsecs > (MAX_UDELAY_MS * 1000 * 1000))
+                       return -EINVAL;
+       }
 
        return 0;
 }
+EXPORT_SYMBOL_GPL(spi_bitbang_setup_transfer);
 
 /**
  * spi_bitbang_setup - default setup for per-word I/O loops
@@ -184,7 +185,14 @@ int spi_bitbang_setup(struct spi_device *spi)
        struct spi_bitbang      *bitbang;
        int                     retval;
 
-       if (!spi->max_speed_hz)
+       bitbang = spi_master_get_devdata(spi->master);
+
+       /* REVISIT: some systems will want to support devices using lsb-first
+        * bit encodings on the wire.  In pure software that would be trivial,
+        * just bitbang_txrx_le_cphaX() routines shifting the other way, and
+        * some hardware controllers also have this support.
+        */
+       if ((spi->mode & SPI_LSB_FIRST) != 0)
                return -EINVAL;
 
        if (!cs) {
@@ -193,7 +201,6 @@ int spi_bitbang_setup(struct spi_device *spi)
                        return -ENOMEM;
                spi->controller_state = cs;
        }
-       bitbang = spi_master_get_devdata(spi->master);
 
        if (!spi->bits_per_word)
                spi->bits_per_word = 8;
@@ -203,11 +210,11 @@ int spi_bitbang_setup(struct spi_device *spi)
        if (!cs->txrx_word)
                return -EINVAL;
 
-       retval = bitbang_transfer_setup(spi, NULL);
+       retval = spi_bitbang_setup_transfer(spi, NULL);
        if (retval < 0)
                return retval;
 
-       dev_dbg(&spi->dev, "%s, mode %d, %u bits/w, %u nsec\n",
+       dev_dbg(&spi->dev, "%s, mode %d, %u bits/w, %u nsec/bit\n",
                        __FUNCTION__, spi->mode & (SPI_CPOL | SPI_CPHA),
                        spi->bits_per_word, 2 * cs->nsecs);
 
@@ -396,6 +403,7 @@ int spi_bitbang_transfer(struct spi_device *spi, struct spi_message *m)
 {
        struct spi_bitbang      *bitbang;
        unsigned long           flags;
+       int                     status = 0;
 
        m->actual_length = 0;
        m->status = -EINPROGRESS;
@@ -405,11 +413,15 @@ int spi_bitbang_transfer(struct spi_device *spi, struct spi_message *m)
                return -ESHUTDOWN;
 
        spin_lock_irqsave(&bitbang->lock, flags);
-       list_add_tail(&m->queue, &bitbang->queue);
-       queue_work(bitbang->workqueue, &bitbang->work);
+       if (!spi->max_speed_hz)
+               status = -ENETDOWN;
+       else {
+               list_add_tail(&m->queue, &bitbang->queue);
+               queue_work(bitbang->workqueue, &bitbang->work);
+       }
        spin_unlock_irqrestore(&bitbang->lock, flags);
 
-       return 0;
+       return status;
 }
 EXPORT_SYMBOL_GPL(spi_bitbang_transfer);
 
@@ -454,7 +466,9 @@ int spi_bitbang_start(struct spi_bitbang *bitbang)
                bitbang->use_dma = 0;
                bitbang->txrx_bufs = spi_bitbang_bufs;
                if (!bitbang->master->setup) {
-                       bitbang->setup_transfer = bitbang_transfer_setup;
+                       if (!bitbang->setup_transfer)
+                               bitbang->setup_transfer =
+                                        spi_bitbang_setup_transfer;
                        bitbang->master->setup = spi_bitbang_setup;
                        bitbang->master->cleanup = spi_bitbang_cleanup;
                }