spi: spi-ep93xx: convert to the queued driver infrastructure

The SPI core provides infrastructure for standard message queueing. Use
that instead of handling it in the driver.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Mika Westerberg <mika.westerberg@iki.fi>
Signed-off-by: Mark Brown <broonie@linaro.org>

1 files changed, 19 insertions, 146 deletions

diff --git a/drivers/spi/spi-ep93xx.c b/drivers/spi/spi-ep93xx.c
index 2e64806b40af..4c9a50ce4f6c 100644
--- a/drivers/spi/spi-ep93xx.c
+++ b/drivers/spi/spi-ep93xx.c
@@ -26,7 +26,6 @@
 #include <linux/interrupt.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
-#include <linux/workqueue.h>
 #include <linux/sched.h>
 #include <linux/scatterlist.h>
 #include <linux/spi/spi.h>
@@ -70,19 +69,13 @@
 
 /**
  * struct ep93xx_spi - EP93xx SPI controller structure
- * @lock: spinlock that protects concurrent accesses to fields @running,
- *        @current_msg and @msg_queue
  * @pdev: pointer to platform device
  * @clk: clock for the controller
  * @regs_base: pointer to ioremap()'d registers
  * @sspdr_phys: physical address of the SSPDR register
  * @min_rate: minimum clock rate (in Hz) supported by the controller
  * @max_rate: maximum clock rate (in Hz) supported by the controller
- * @running: is the queue running
- * @wq: workqueue used by the driver
- * @msg_work: work that is queued for the driver
  * @wait: wait here until given transfer is completed
- * @msg_queue: queue for the messages
  * @current_msg: message that is currently processed (or %NULL if none)
  * @tx: current byte in transfer to transmit
  * @rx: current byte in transfer to receive
@@ -96,30 +89,15 @@
  * @tx_sgt: sg table for TX transfers
  * @zeropage: dummy page used as RX buffer when only TX buffer is passed in by
  *            the client
- *
- * This structure holds EP93xx SPI controller specific information. When
- * @running is %true, driver accepts transfer requests from protocol drivers.
- * @current_msg is used to hold pointer to the message that is currently
- * processed. If @current_msg is %NULL, it means that no processing is going
- * on.
- *
- * Most of the fields are only written once and they can be accessed without
- * taking the @lock. Fields that are accessed concurrently are: @current_msg,
- * @running, and @msg_queue.
  */
 struct ep93xx_spi {
-        spinlock_t                      lock;
         const struct platform_device    *pdev;
         struct clk                      *clk;
         void __iomem                    *regs_base;
         unsigned long                   sspdr_phys;
         unsigned long                   min_rate;
         unsigned long                   max_rate;
-        bool                            running;
-        struct workqueue_struct         *wq;
-        struct work_struct              msg_work;
         struct completion               wait;
-        struct list_head                msg_queue;
         struct spi_message              *current_msg;
         size_t                          tx;
         size_t                          rx;
@@ -230,7 +208,7 @@ static int ep93xx_spi_calc_divisors(const struct ep93xx_spi *espi,
         /*
          * Make sure that max value is between values supported by the
          * controller. Note that minimum value is already checked in
-         * ep93xx_spi_transfer().
+         * ep93xx_spi_transfer_one_message().
          */
         rate = clamp(rate, espi->min_rate, espi->max_rate);
 
@@ -306,54 +284,6 @@ static int ep93xx_spi_setup(struct spi_device *spi)
 }
 
 /**
- * ep93xx_spi_transfer() - queue message to be transferred
- * @spi: target SPI device
- * @msg: message to be transferred
- *
- * This function is called by SPI device drivers when they are going to transfer
- * a new message. It simply puts the message in the queue and schedules
- * workqueue to perform the actual transfer later on.
- *
- * Returns %0 on success and negative error in case of failure.
- */
-static int ep93xx_spi_transfer(struct spi_device *spi, struct spi_message *msg)
-{
-        struct ep93xx_spi *espi = spi_master_get_devdata(spi->master);
-        struct spi_transfer *t;
-        unsigned long flags;
-
-        if (!msg || !msg->complete)
-                return -EINVAL;
-
-        /* first validate each transfer */
-        list_for_each_entry(t, &msg->transfers, transfer_list) {
-                if (t->speed_hz && t->speed_hz < espi->min_rate)
-                                return -EINVAL;
-        }
-
-        /*
-         * Now that we own the message, let's initialize it so that it is
-         * suitable for us. We use @msg->status to signal whether there was
-         * error in transfer and @msg->state is used to hold pointer to the
-         * current transfer (or %NULL if no active current transfer).
-         */
-        msg->state = NULL;
-        msg->status = 0;
-        msg->actual_length = 0;
-
-        spin_lock_irqsave(&espi->lock, flags);
-        if (!espi->running) {
-                spin_unlock_irqrestore(&espi->lock, flags);
-                return -ESHUTDOWN;
-        }
-        list_add_tail(&msg->queue, &espi->msg_queue);
-        queue_work(espi->wq, &espi->msg_work);
-        spin_unlock_irqrestore(&espi->lock, flags);
-
-        return 0;
-}
-
-/**
  * ep93xx_spi_cleanup() - cleans up master controller specific state
  * @spi: SPI device to cleanup
  *
@@ -801,50 +731,29 @@ static void ep93xx_spi_process_message(struct ep93xx_spi *espi,
         ep93xx_spi_disable(espi);
 }
 
-#define work_to_espi(work) (container_of((work), struct ep93xx_spi, msg_work))
-
-/**
- * ep93xx_spi_work() - EP93xx SPI workqueue worker function
- * @work: work struct
- *
- * Workqueue worker function. This function is called when there are new
- * SPI messages to be processed. Message is taken out from the queue and then
- * passed to ep93xx_spi_process_message().
- *
- * After message is transferred, protocol driver is notified by calling
- * @msg->complete(). In case of error, @msg->status is set to negative error
- * number, otherwise it contains zero (and @msg->actual_length is updated).
- */
-static void ep93xx_spi_work(struct work_struct *work)
+static int ep93xx_spi_transfer_one_message(struct spi_master *master,
+                                           struct spi_message *msg)
 {
-        struct ep93xx_spi *espi = work_to_espi(work);
-        struct spi_message *msg;
+        struct ep93xx_spi *espi = spi_master_get_devdata(master);
+        struct spi_transfer *t;
 
-        spin_lock_irq(&espi->lock);
-        if (!espi->running || espi->current_msg ||
-                list_empty(&espi->msg_queue)) {
-                spin_unlock_irq(&espi->lock);
-                return;
+        /* first validate each transfer */
+        list_for_each_entry(t, &msg->transfers, transfer_list) {
+                if (t->speed_hz < espi->min_rate)
+                        return -EINVAL;
         }
-        msg = list_first_entry(&espi->msg_queue, struct spi_message, queue);
-        list_del_init(&msg->queue);
-        espi->current_msg = msg;
-        spin_unlock_irq(&espi->lock);
 
-        ep93xx_spi_process_message(espi, msg);
+        msg->state = NULL;
+        msg->status = 0;
+        msg->actual_length = 0;
 
-        /*
-         * Update the current message and re-schedule ourselves if there are
-         * more messages in the queue.
-         */
-        spin_lock_irq(&espi->lock);
+        espi->current_msg = msg;
+        ep93xx_spi_process_message(espi, msg);
         espi->current_msg = NULL;
-        if (espi->running && !list_empty(&espi->msg_queue))
-                queue_work(espi->wq, &espi->msg_work);
-        spin_unlock_irq(&espi->lock);
 
-        /* notify the protocol driver that we are done with this message */
-        msg->complete(msg->context);
+        spi_finalize_current_message(master);
+
+        return 0;
 }
 
 static irqreturn_t ep93xx_spi_interrupt(int irq, void *dev_id)
@@ -984,7 +893,7 @@ static int ep93xx_spi_probe(struct platform_device *pdev)
                 return -ENOMEM;
 
         master->setup = ep93xx_spi_setup;
-        master->transfer = ep93xx_spi_transfer;
+        master->transfer_one_message = ep93xx_spi_transfer_one_message;
         master->cleanup = ep93xx_spi_cleanup;
         master->bus_num = pdev->id;
         master->num_chipselect = info->num_chipselect;
@@ -1002,7 +911,6 @@ static int ep93xx_spi_probe(struct platform_device *pdev)
                 goto fail_release_master;
         }
 
-        spin_lock_init(&espi->lock);
         init_completion(&espi->wait);
 
         /*
@@ -1031,23 +939,13 @@ static int ep93xx_spi_probe(struct platform_device *pdev)
         if (info->use_dma && ep93xx_spi_setup_dma(espi))
                 dev_warn(&pdev->dev, "DMA setup failed. Falling back to PIO\n");
 
-        espi->wq = create_singlethread_workqueue("ep93xx_spid");
-        if (!espi->wq) {
-                dev_err(&pdev->dev, "unable to create workqueue\n");
-                error = -ENOMEM;
-                goto fail_free_dma;
-        }
-        INIT_WORK(&espi->msg_work, ep93xx_spi_work);
-        INIT_LIST_HEAD(&espi->msg_queue);
-        espi->running = true;
-
         /* make sure that the hardware is disabled */
         ep93xx_spi_write_u8(espi, SSPCR1, 0);
 
         error = spi_register_master(master);
         if (error) {
                 dev_err(&pdev->dev, "failed to register SPI master\n");
-                goto fail_free_queue;
+                goto fail_free_dma;
         }
 
         dev_info(&pdev->dev, "EP93xx SPI Controller at 0x%08lx irq %d\n",
@@ -1055,8 +953,6 @@ static int ep93xx_spi_probe(struct platform_device *pdev)
 
         return 0;
 
-fail_free_queue:
-        destroy_workqueue(espi->wq);
 fail_free_dma:
         ep93xx_spi_release_dma(espi);
 fail_release_master:
@@ -1070,29 +966,6 @@ static int ep93xx_spi_remove(struct platform_device *pdev)
         struct spi_master *master = platform_get_drvdata(pdev);
         struct ep93xx_spi *espi = spi_master_get_devdata(master);
 
-        spin_lock_irq(&espi->lock);
-        espi->running = false;
-        spin_unlock_irq(&espi->lock);
-
-        destroy_workqueue(espi->wq);
-
-        /*
-         * Complete remaining messages with %-ESHUTDOWN status.
-         */
-        spin_lock_irq(&espi->lock);
-        while (!list_empty(&espi->msg_queue)) {
-                struct spi_message *msg;
-
-                msg = list_first_entry(&espi->msg_queue,
-                                       struct spi_message, queue);
-                list_del_init(&msg->queue);
-                msg->status = -ESHUTDOWN;
-                spin_unlock_irq(&espi->lock);
-                msg->complete(msg->context);
-                spin_lock_irq(&espi->lock);
-        }
-        spin_unlock_irq(&espi->lock);
-
         ep93xx_spi_release_dma(espi);
 
         spi_unregister_master(master);