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Message-Id: <1357555480-24022-3-git-send-email-mika.westerberg@linux.intel.com>
Date: Mon, 7 Jan 2013 12:44:31 +0200
From: Mika Westerberg <mika.westerberg@...ux.intel.com>
To: linux-kernel@...r.kernel.org
Cc: grant.likely@...retlab.ca, linus.walleij@...aro.org,
eric.y.miao@...il.com, linux@....linux.org.uk,
haojian.zhuang@...il.com, broonie@...nsource.wolfsonmicro.com,
chao.bi@...el.com,
"Rafael J. Wysocki" <rafael.j.wysocki@...el.com>,
Mika Westerberg <mika.westerberg@...ux.intel.com>
Subject: [PATCH 02/11] spi/pxa2xx: convert to the pump message infrastructure
The SPI core provides infrastructure for standard message queueing so use
that instead of handling everything in the driver. This simplifies the
driver.
Signed-off-by: Mika Westerberg <mika.westerberg@...ux.intel.com>
---
drivers/spi/spi-pxa2xx.c | 212 +++-------------------------------------------
1 file changed, 12 insertions(+), 200 deletions(-)
diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c
index 7fac65d..ad842eb 100644
--- a/drivers/spi/spi-pxa2xx.c
+++ b/drivers/spi/spi-pxa2xx.c
@@ -85,9 +85,6 @@ DEFINE_SSP_REG(SSPSP, 0x2c)
#define DONE_STATE ((void*)2)
#define ERROR_STATE ((void*)-1)
-#define QUEUE_RUNNING 0
-#define QUEUE_STOPPED 1
-
struct driver_data {
/* Driver model hookup */
struct platform_device *pdev;
@@ -117,14 +114,6 @@ struct driver_data {
u32 clear_sr;
u32 mask_sr;
- /* Driver message queue */
- struct workqueue_struct *workqueue;
- struct work_struct pump_messages;
- spinlock_t lock;
- struct list_head queue;
- int busy;
- int run;
-
/* Message Transfer pump */
struct tasklet_struct pump_transfers;
@@ -173,8 +162,6 @@ struct chip_data {
void (*cs_control)(u32 command);
};
-static void pump_messages(struct work_struct *work);
-
static void cs_assert(struct driver_data *drv_data)
{
struct chip_data *chip = drv_data->cur_chip;
@@ -444,15 +431,11 @@ static void unmap_dma_buffers(struct driver_data *drv_data)
static void giveback(struct driver_data *drv_data)
{
struct spi_transfer* last_transfer;
- unsigned long flags;
struct spi_message *msg;
- spin_lock_irqsave(&drv_data->lock, flags);
msg = drv_data->cur_msg;
drv_data->cur_msg = NULL;
drv_data->cur_transfer = NULL;
- queue_work(drv_data->workqueue, &drv_data->pump_messages);
- spin_unlock_irqrestore(&drv_data->lock, flags);
last_transfer = list_entry(msg->transfers.prev,
struct spi_transfer,
@@ -481,13 +464,7 @@ static void giveback(struct driver_data *drv_data)
*/
/* get a pointer to the next message, if any */
- spin_lock_irqsave(&drv_data->lock, flags);
- if (list_empty(&drv_data->queue))
- next_msg = NULL;
- else
- next_msg = list_entry(drv_data->queue.next,
- struct spi_message, queue);
- spin_unlock_irqrestore(&drv_data->lock, flags);
+ next_msg = spi_get_next_queued_message(drv_data->master);
/* see if the next and current messages point
* to the same chip
@@ -498,10 +475,7 @@ static void giveback(struct driver_data *drv_data)
cs_deassert(drv_data);
}
- msg->state = NULL;
- if (msg->complete)
- msg->complete(msg->context);
-
+ spi_finalize_current_message(drv_data->master);
drv_data->cur_chip = NULL;
}
@@ -1176,31 +1150,12 @@ static void pump_transfers(unsigned long data)
write_SSCR1(cr1, reg);
}
-static void pump_messages(struct work_struct *work)
+static int pxa2xx_spi_transfer_one_message(struct spi_master *master,
+ struct spi_message *msg)
{
- struct driver_data *drv_data =
- container_of(work, struct driver_data, pump_messages);
- unsigned long flags;
-
- /* Lock queue and check for queue work */
- spin_lock_irqsave(&drv_data->lock, flags);
- if (list_empty(&drv_data->queue) || drv_data->run == QUEUE_STOPPED) {
- drv_data->busy = 0;
- spin_unlock_irqrestore(&drv_data->lock, flags);
- return;
- }
-
- /* Make sure we are not already running a message */
- if (drv_data->cur_msg) {
- spin_unlock_irqrestore(&drv_data->lock, flags);
- return;
- }
-
- /* Extract head of queue */
- drv_data->cur_msg = list_entry(drv_data->queue.next,
- struct spi_message, queue);
- list_del_init(&drv_data->cur_msg->queue);
+ struct driver_data *drv_data = spi_master_get_devdata(master);
+ drv_data->cur_msg = msg;
/* Initial message state*/
drv_data->cur_msg->state = START_STATE;
drv_data->cur_transfer = list_entry(drv_data->cur_msg->transfers.next,
@@ -1213,34 +1168,6 @@ static void pump_messages(struct work_struct *work)
/* Mark as busy and launch transfers */
tasklet_schedule(&drv_data->pump_transfers);
-
- drv_data->busy = 1;
- spin_unlock_irqrestore(&drv_data->lock, flags);
-}
-
-static int transfer(struct spi_device *spi, struct spi_message *msg)
-{
- struct driver_data *drv_data = spi_master_get_devdata(spi->master);
- unsigned long flags;
-
- spin_lock_irqsave(&drv_data->lock, flags);
-
- if (drv_data->run == QUEUE_STOPPED) {
- spin_unlock_irqrestore(&drv_data->lock, flags);
- return -ESHUTDOWN;
- }
-
- msg->actual_length = 0;
- msg->status = -EINPROGRESS;
- msg->state = START_STATE;
-
- list_add_tail(&msg->queue, &drv_data->queue);
-
- if (drv_data->run == QUEUE_RUNNING && !drv_data->busy)
- queue_work(drv_data->workqueue, &drv_data->pump_messages);
-
- spin_unlock_irqrestore(&drv_data->lock, flags);
-
return 0;
}
@@ -1438,94 +1365,6 @@ static void cleanup(struct spi_device *spi)
kfree(chip);
}
-static int init_queue(struct driver_data *drv_data)
-{
- INIT_LIST_HEAD(&drv_data->queue);
- spin_lock_init(&drv_data->lock);
-
- drv_data->run = QUEUE_STOPPED;
- drv_data->busy = 0;
-
- tasklet_init(&drv_data->pump_transfers,
- pump_transfers, (unsigned long)drv_data);
-
- INIT_WORK(&drv_data->pump_messages, pump_messages);
- drv_data->workqueue = create_singlethread_workqueue(
- dev_name(drv_data->master->dev.parent));
- if (drv_data->workqueue == NULL)
- return -EBUSY;
-
- return 0;
-}
-
-static int start_queue(struct driver_data *drv_data)
-{
- unsigned long flags;
-
- spin_lock_irqsave(&drv_data->lock, flags);
-
- if (drv_data->run == QUEUE_RUNNING || drv_data->busy) {
- spin_unlock_irqrestore(&drv_data->lock, flags);
- return -EBUSY;
- }
-
- drv_data->run = QUEUE_RUNNING;
- drv_data->cur_msg = NULL;
- drv_data->cur_transfer = NULL;
- drv_data->cur_chip = NULL;
- spin_unlock_irqrestore(&drv_data->lock, flags);
-
- queue_work(drv_data->workqueue, &drv_data->pump_messages);
-
- return 0;
-}
-
-static int stop_queue(struct driver_data *drv_data)
-{
- unsigned long flags;
- unsigned limit = 500;
- int status = 0;
-
- spin_lock_irqsave(&drv_data->lock, flags);
-
- /* This is a bit lame, but is optimized for the common execution path.
- * A wait_queue on the drv_data->busy could be used, but then the common
- * execution path (pump_messages) would be required to call wake_up or
- * friends on every SPI message. Do this instead */
- drv_data->run = QUEUE_STOPPED;
- while ((!list_empty(&drv_data->queue) || drv_data->busy) && limit--) {
- spin_unlock_irqrestore(&drv_data->lock, flags);
- msleep(10);
- spin_lock_irqsave(&drv_data->lock, flags);
- }
-
- if (!list_empty(&drv_data->queue) || drv_data->busy)
- status = -EBUSY;
-
- spin_unlock_irqrestore(&drv_data->lock, flags);
-
- return status;
-}
-
-static int destroy_queue(struct driver_data *drv_data)
-{
- int status;
-
- status = stop_queue(drv_data);
- /* we are unloading the module or failing to load (only two calls
- * to this routine), and neither call can handle a return value.
- * However, destroy_workqueue calls flush_workqueue, and that will
- * block until all work is done. If the reason that stop_queue
- * timed out is that the work will never finish, then it does no
- * good to call destroy_workqueue, so return anyway. */
- if (status != 0)
- return status;
-
- destroy_workqueue(drv_data->workqueue);
-
- return 0;
-}
-
static int pxa2xx_spi_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
@@ -1566,7 +1405,7 @@ static int pxa2xx_spi_probe(struct platform_device *pdev)
master->dma_alignment = DMA_ALIGNMENT;
master->cleanup = cleanup;
master->setup = setup;
- master->transfer = transfer;
+ master->transfer_one_message = pxa2xx_spi_transfer_one_message;
drv_data->ssp_type = ssp->type;
drv_data->null_dma_buf = (u32 *)PTR_ALIGN(drv_data + 1, 8);
@@ -1639,31 +1478,19 @@ static int pxa2xx_spi_probe(struct platform_device *pdev)
write_SSTO(0, drv_data->ioaddr);
write_SSPSP(0, drv_data->ioaddr);
- /* Initial and start queue */
- status = init_queue(drv_data);
- if (status != 0) {
- dev_err(&pdev->dev, "problem initializing queue\n");
- goto out_error_clock_enabled;
- }
- status = start_queue(drv_data);
- if (status != 0) {
- dev_err(&pdev->dev, "problem starting queue\n");
- goto out_error_clock_enabled;
- }
+ tasklet_init(&drv_data->pump_transfers, pump_transfers,
+ (unsigned long)drv_data);
/* Register with the SPI framework */
platform_set_drvdata(pdev, drv_data);
status = spi_register_master(master);
if (status != 0) {
dev_err(&pdev->dev, "problem registering spi master\n");
- goto out_error_queue_alloc;
+ goto out_error_clock_enabled;
}
return status;
-out_error_queue_alloc:
- destroy_queue(drv_data);
-
out_error_clock_enabled:
clk_disable(ssp->clk);
@@ -1686,26 +1513,11 @@ static int pxa2xx_spi_remove(struct platform_device *pdev)
{
struct driver_data *drv_data = platform_get_drvdata(pdev);
struct ssp_device *ssp;
- int status = 0;
if (!drv_data)
return 0;
ssp = drv_data->ssp;
- /* Remove the queue */
- status = destroy_queue(drv_data);
- if (status != 0)
- /* the kernel does not check the return status of this
- * this routine (mod->exit, within the kernel). Therefore
- * nothing is gained by returning from here, the module is
- * going away regardless, and we should not leave any more
- * resources allocated than necessary. We cannot free the
- * message memory in drv_data->queue, but we can release the
- * resources below. I think the kernel should honor -EBUSY
- * returns but... */
- dev_err(&pdev->dev, "pxa2xx_spi_remove: workqueue will not "
- "complete, message memory not freed\n");
-
/* Disable the SSP at the peripheral and SOC level */
write_SSCR0(0, drv_data->ioaddr);
clk_disable(ssp->clk);
@@ -1748,7 +1560,7 @@ static int pxa2xx_spi_suspend(struct device *dev)
struct ssp_device *ssp = drv_data->ssp;
int status = 0;
- status = stop_queue(drv_data);
+ status = spi_master_suspend(drv_data->master);
if (status != 0)
return status;
write_SSCR0(0, drv_data->ioaddr);
@@ -1774,7 +1586,7 @@ static int pxa2xx_spi_resume(struct device *dev)
clk_enable(ssp->clk);
/* Start the queue running */
- status = start_queue(drv_data);
+ status = spi_master_resume(drv_data->master);
if (status != 0) {
dev_err(dev, "problem starting queue (%d)\n", status);
return status;
--
1.7.10.4
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