Merge git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6

[safe/jmp/linux-2.6] / drivers / spi / spi_bitbang.c

diff --git a/drivers/spi/spi_bitbang.c b/drivers/spi/spi_bitbang.c
index 24a330d..5265330 100644 (file)
--- a/drivers/spi/spi_bitbang.c
+++ b/drivers/spi/spi_bitbang.c
@@ -23,6 +23,7 @@
 #include <linux/delay.h>
 #include <linux/errno.h>
 #include <linux/platform_device.h>
+#include <linux/slab.h>
 
 #include <linux/spi/spi.h>
 #include <linux/spi/spi_bitbang.h>
@@ -184,17 +185,10 @@ int spi_bitbang_setup(struct spi_device *spi)
        struct spi_bitbang_cs   *cs = spi->controller_state;
        struct spi_bitbang      *bitbang;
        int                     retval;
+       unsigned long           flags;
 
        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) {
                cs = kzalloc(sizeof *cs, GFP_KERNEL);
                if (!cs)
@@ -202,9 +196,6 @@ int spi_bitbang_setup(struct spi_device *spi)
                spi->controller_state = cs;
        }
 
-       if (!spi->bits_per_word)
-               spi->bits_per_word = 8;
-
        /* per-word shift register access, in hardware or bitbanging */
        cs->txrx_word = bitbang->txrx_word[spi->mode & (SPI_CPOL|SPI_CPHA)];
        if (!cs->txrx_word)
@@ -214,9 +205,7 @@ int spi_bitbang_setup(struct spi_device *spi)
        if (retval < 0)
                return retval;
 
-       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);
+       dev_dbg(&spi->dev, "%s, %u nsec/bit\n", __func__, 2 * cs->nsecs);
 
        /* NOTE we _need_ to call chipselect() early, ideally with adapter
         * setup, unless the hardware defaults cooperate to avoid confusion
@@ -224,12 +213,12 @@ int spi_bitbang_setup(struct spi_device *spi)
         */
 
        /* deselect chip (low or high) */
-       spin_lock(&bitbang->lock);
+       spin_lock_irqsave(&bitbang->lock, flags);
        if (!bitbang->busy) {
                bitbang->chipselect(spi, BITBANG_CS_INACTIVE);
                ndelay(cs->nsecs);
        }
-       spin_unlock(&bitbang->lock);
+       spin_unlock_irqrestore(&bitbang->lock, flags);
 
        return 0;
 }
@@ -270,6 +259,11 @@ static void bitbang_work(struct work_struct *work)
        struct spi_bitbang      *bitbang =
                container_of(work, struct spi_bitbang, work);
        unsigned long           flags;
+       int                     do_setup = -1;
+       int                     (*setup_transfer)(struct spi_device *,
+                                       struct spi_transfer *);
+
+       setup_transfer = bitbang->setup_transfer;
 
        spin_lock_irqsave(&bitbang->lock, flags);
        bitbang->busy = 1;
@@ -281,8 +275,6 @@ static void bitbang_work(struct work_struct *work)
                unsigned                tmp;
                unsigned                cs_change;
                int                     status;
-               int                     (*setup_transfer)(struct spi_device *,
-                                               struct spi_transfer *);
 
                m = container_of(bitbang->queue.next, struct spi_message,
                                queue);
@@ -299,23 +291,19 @@ static void bitbang_work(struct work_struct *work)
                tmp = 0;
                cs_change = 1;
                status = 0;
-               setup_transfer = NULL;
 
                list_for_each_entry (t, &m->transfers, transfer_list) {
-                       if (bitbang->shutdown) {
-                               status = -ESHUTDOWN;
-                               break;
-                       }
 
-                       /* override or restore speed and wordsize */
-                       if (t->speed_hz || t->bits_per_word) {
-                               setup_transfer = bitbang->setup_transfer;
+                       /* override speed or wordsize? */
+                       if (t->speed_hz || t->bits_per_word)
+                               do_setup = 1;
+
+                       /* init (-1) or override (1) transfer params */
+                       if (do_setup != 0) {
                                if (!setup_transfer) {
                                        status = -ENOPROTOOPT;
                                        break;
                                }
-                       }
-                       if (setup_transfer) {
                                status = setup_transfer(spi, t);
                                if (status < 0)
                                        break;
@@ -349,12 +337,14 @@ static void bitbang_work(struct work_struct *work)
                                        t->rx_dma = t->tx_dma = 0;
                                status = bitbang->txrx_bufs(spi, t);
                        }
+                       if (status > 0)
+                               m->actual_length += status;
                        if (status != t->len) {
-                               if (status > 0)
-                                       status = -EMSGSIZE;
+                               /* always report some kind of error */
+                               if (status >= 0)
+                                       status = -EREMOTEIO;
                                break;
                        }
-                       m->actual_length += status;
                        status = 0;
 
                        /* protocol tweaks before next transfer */
@@ -377,9 +367,10 @@ static void bitbang_work(struct work_struct *work)
                m->status = status;
                m->complete(m->context);
 
-               /* restore speed and wordsize */
-               if (setup_transfer)
+               /* restore speed and wordsize if it was overridden */
+               if (do_setup == 1)
                        setup_transfer(spi, NULL);
+               do_setup = 0;
 
                /* normally deactivate chipselect ... unless no error and
                 * cs_change has hinted that the next message will probably
@@ -410,8 +401,6 @@ int spi_bitbang_transfer(struct spi_device *spi, struct spi_message *m)
        m->status = -EINPROGRESS;
 
        bitbang = spi_master_get_devdata(spi->master);
-       if (bitbang->shutdown)
-               return -ESHUTDOWN;
 
        spin_lock_irqsave(&bitbang->lock, flags);
        if (!spi->max_speed_hz)
@@ -462,6 +451,9 @@ int spi_bitbang_start(struct spi_bitbang *bitbang)
        spin_lock_init(&bitbang->lock);
        INIT_LIST_HEAD(&bitbang->queue);
 
+       if (!bitbang->master->mode_bits)
+               bitbang->master->mode_bits = SPI_CPOL | SPI_CPHA | bitbang->flags;
+
        if (!bitbang->master->transfer)
                bitbang->master->transfer = spi_bitbang_transfer;
        if (!bitbang->txrx_bufs) {
@@ -480,7 +472,7 @@ int spi_bitbang_start(struct spi_bitbang *bitbang)
        /* this task is the only thing to touch the SPI bits */
        bitbang->busy = 0;
        bitbang->workqueue = create_singlethread_workqueue(
-                       bitbang->master->cdev.dev->bus_id);
+                       dev_name(bitbang->master->dev.parent));
        if (bitbang->workqueue == NULL) {
                status = -EBUSY;
                goto err1;
@@ -507,28 +499,12 @@ EXPORT_SYMBOL_GPL(spi_bitbang_start);
  */
 int spi_bitbang_stop(struct spi_bitbang *bitbang)
 {
-       unsigned        limit = 500;
-
-       spin_lock_irq(&bitbang->lock);
-       bitbang->shutdown = 0;
-       while (!list_empty(&bitbang->queue) && limit--) {
-               spin_unlock_irq(&bitbang->lock);
-
-               dev_dbg(bitbang->master->cdev.dev, "wait for queue\n");
-               msleep(10);
+       spi_unregister_master(bitbang->master);
 
-               spin_lock_irq(&bitbang->lock);
-       }
-       spin_unlock_irq(&bitbang->lock);
-       if (!list_empty(&bitbang->queue)) {
-               dev_err(bitbang->master->cdev.dev, "queue didn't empty\n");
-               return -EBUSY;
-       }
+       WARN_ON(!list_empty(&bitbang->queue));
 
        destroy_workqueue(bitbang->workqueue);
 
-       spi_unregister_master(bitbang->master);
-
        return 0;
 }
 EXPORT_SYMBOL_GPL(spi_bitbang_stop);