[PATCH v2 10/11] spi: spi-ep93xx: convert to the queued driver infrastructure
H Hartley Sweeten
hartleys at visionengravers.com
Mon Jul 8 12:12:37 EDT 2013
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 at visionengravers.com>
Acked-by: Mika Westerberg <mika.westerberg at iki.fi>
Cc: Ryan Mallon <rmallon at gmail.com>
Cc: Mark Brown <broonie at kernel.org>
Cc: Grant Likely <grant.likely at linaro.org>
---
drivers/spi/spi-ep93xx.c | 165 ++++++-----------------------------------------
1 file changed, 19 insertions(+), 146 deletions(-)
diff --git a/drivers/spi/spi-ep93xx.c b/drivers/spi/spi-ep93xx.c
index 2e64806..4c9a50c 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);
--
1.8.1.4
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