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>
This commit is contained in:
parent
f7ef1da9e2
commit
84ddb3c1df
drivers/spi
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@ -26,7 +26,6 @@
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#include <linux/interrupt.h>
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#include <linux/interrupt.h>
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#include <linux/module.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/platform_device.h>
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#include <linux/workqueue.h>
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#include <linux/sched.h>
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#include <linux/sched.h>
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#include <linux/scatterlist.h>
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#include <linux/scatterlist.h>
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#include <linux/spi/spi.h>
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#include <linux/spi/spi.h>
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@ -70,19 +69,13 @@
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/**
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/**
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* struct ep93xx_spi - EP93xx SPI controller structure
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* struct ep93xx_spi - EP93xx SPI controller structure
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* @lock: spinlock that protects concurrent accesses to fields @running,
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* @current_msg and @msg_queue
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* @pdev: pointer to platform device
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* @pdev: pointer to platform device
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* @clk: clock for the controller
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* @clk: clock for the controller
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* @regs_base: pointer to ioremap()'d registers
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* @regs_base: pointer to ioremap()'d registers
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* @sspdr_phys: physical address of the SSPDR register
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* @sspdr_phys: physical address of the SSPDR register
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* @min_rate: minimum clock rate (in Hz) supported by the controller
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* @min_rate: minimum clock rate (in Hz) supported by the controller
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* @max_rate: maximum clock rate (in Hz) supported by the controller
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* @max_rate: maximum clock rate (in Hz) supported by the controller
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* @running: is the queue running
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* @wq: workqueue used by the driver
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* @msg_work: work that is queued for the driver
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* @wait: wait here until given transfer is completed
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* @wait: wait here until given transfer is completed
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* @msg_queue: queue for the messages
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* @current_msg: message that is currently processed (or %NULL if none)
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* @current_msg: message that is currently processed (or %NULL if none)
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* @tx: current byte in transfer to transmit
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* @tx: current byte in transfer to transmit
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* @rx: current byte in transfer to receive
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* @rx: current byte in transfer to receive
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@ -96,30 +89,15 @@
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* @tx_sgt: sg table for TX transfers
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* @tx_sgt: sg table for TX transfers
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* @zeropage: dummy page used as RX buffer when only TX buffer is passed in by
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* @zeropage: dummy page used as RX buffer when only TX buffer is passed in by
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* the client
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* the client
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*
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* This structure holds EP93xx SPI controller specific information. When
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* @running is %true, driver accepts transfer requests from protocol drivers.
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* @current_msg is used to hold pointer to the message that is currently
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* processed. If @current_msg is %NULL, it means that no processing is going
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* on.
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*
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* Most of the fields are only written once and they can be accessed without
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* taking the @lock. Fields that are accessed concurrently are: @current_msg,
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* @running, and @msg_queue.
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*/
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*/
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struct ep93xx_spi {
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struct ep93xx_spi {
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spinlock_t lock;
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const struct platform_device *pdev;
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const struct platform_device *pdev;
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struct clk *clk;
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struct clk *clk;
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void __iomem *regs_base;
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void __iomem *regs_base;
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unsigned long sspdr_phys;
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unsigned long sspdr_phys;
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unsigned long min_rate;
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unsigned long min_rate;
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unsigned long max_rate;
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unsigned long max_rate;
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bool running;
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struct workqueue_struct *wq;
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struct work_struct msg_work;
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struct completion wait;
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struct completion wait;
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struct list_head msg_queue;
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struct spi_message *current_msg;
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struct spi_message *current_msg;
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size_t tx;
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size_t tx;
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size_t rx;
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size_t rx;
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@ -230,7 +208,7 @@ static int ep93xx_spi_calc_divisors(const struct ep93xx_spi *espi,
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/*
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/*
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* Make sure that max value is between values supported by the
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* Make sure that max value is between values supported by the
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* controller. Note that minimum value is already checked in
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* controller. Note that minimum value is already checked in
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* ep93xx_spi_transfer().
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* ep93xx_spi_transfer_one_message().
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*/
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*/
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rate = clamp(rate, espi->min_rate, espi->max_rate);
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rate = clamp(rate, espi->min_rate, espi->max_rate);
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@ -305,54 +283,6 @@ static int ep93xx_spi_setup(struct spi_device *spi)
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return 0;
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return 0;
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}
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}
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/**
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* ep93xx_spi_transfer() - queue message to be transferred
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* @spi: target SPI device
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* @msg: message to be transferred
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*
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* This function is called by SPI device drivers when they are going to transfer
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* a new message. It simply puts the message in the queue and schedules
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* workqueue to perform the actual transfer later on.
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*
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* Returns %0 on success and negative error in case of failure.
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*/
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static int ep93xx_spi_transfer(struct spi_device *spi, struct spi_message *msg)
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{
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struct ep93xx_spi *espi = spi_master_get_devdata(spi->master);
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struct spi_transfer *t;
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unsigned long flags;
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if (!msg || !msg->complete)
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return -EINVAL;
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/* first validate each transfer */
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list_for_each_entry(t, &msg->transfers, transfer_list) {
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if (t->speed_hz && t->speed_hz < espi->min_rate)
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return -EINVAL;
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}
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/*
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* Now that we own the message, let's initialize it so that it is
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* suitable for us. We use @msg->status to signal whether there was
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* error in transfer and @msg->state is used to hold pointer to the
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* current transfer (or %NULL if no active current transfer).
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*/
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msg->state = NULL;
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msg->status = 0;
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msg->actual_length = 0;
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spin_lock_irqsave(&espi->lock, flags);
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if (!espi->running) {
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spin_unlock_irqrestore(&espi->lock, flags);
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return -ESHUTDOWN;
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}
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list_add_tail(&msg->queue, &espi->msg_queue);
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queue_work(espi->wq, &espi->msg_work);
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spin_unlock_irqrestore(&espi->lock, flags);
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return 0;
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}
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/**
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/**
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* ep93xx_spi_cleanup() - cleans up master controller specific state
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* ep93xx_spi_cleanup() - cleans up master controller specific state
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* @spi: SPI device to cleanup
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* @spi: SPI device to cleanup
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@ -801,50 +731,29 @@ static void ep93xx_spi_process_message(struct ep93xx_spi *espi,
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ep93xx_spi_disable(espi);
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ep93xx_spi_disable(espi);
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}
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}
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#define work_to_espi(work) (container_of((work), struct ep93xx_spi, msg_work))
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static int ep93xx_spi_transfer_one_message(struct spi_master *master,
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struct spi_message *msg)
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/**
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* ep93xx_spi_work() - EP93xx SPI workqueue worker function
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* @work: work struct
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*
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* Workqueue worker function. This function is called when there are new
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* SPI messages to be processed. Message is taken out from the queue and then
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* passed to ep93xx_spi_process_message().
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*
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* After message is transferred, protocol driver is notified by calling
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* @msg->complete(). In case of error, @msg->status is set to negative error
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* number, otherwise it contains zero (and @msg->actual_length is updated).
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*/
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static void ep93xx_spi_work(struct work_struct *work)
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{
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{
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struct ep93xx_spi *espi = work_to_espi(work);
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struct ep93xx_spi *espi = spi_master_get_devdata(master);
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struct spi_message *msg;
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struct spi_transfer *t;
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spin_lock_irq(&espi->lock);
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/* first validate each transfer */
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if (!espi->running || espi->current_msg ||
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list_for_each_entry(t, &msg->transfers, transfer_list) {
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list_empty(&espi->msg_queue)) {
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if (t->speed_hz < espi->min_rate)
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spin_unlock_irq(&espi->lock);
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return -EINVAL;
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return;
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}
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}
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msg = list_first_entry(&espi->msg_queue, struct spi_message, queue);
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list_del_init(&msg->queue);
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msg->state = NULL;
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msg->status = 0;
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msg->actual_length = 0;
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espi->current_msg = msg;
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espi->current_msg = msg;
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spin_unlock_irq(&espi->lock);
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ep93xx_spi_process_message(espi, msg);
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ep93xx_spi_process_message(espi, msg);
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/*
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* Update the current message and re-schedule ourselves if there are
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* more messages in the queue.
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*/
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spin_lock_irq(&espi->lock);
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espi->current_msg = NULL;
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espi->current_msg = NULL;
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if (espi->running && !list_empty(&espi->msg_queue))
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queue_work(espi->wq, &espi->msg_work);
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spin_unlock_irq(&espi->lock);
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/* notify the protocol driver that we are done with this message */
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spi_finalize_current_message(master);
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msg->complete(msg->context);
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return 0;
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}
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}
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static irqreturn_t ep93xx_spi_interrupt(int irq, void *dev_id)
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static irqreturn_t ep93xx_spi_interrupt(int irq, void *dev_id)
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@ -984,7 +893,7 @@ static int ep93xx_spi_probe(struct platform_device *pdev)
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return -ENOMEM;
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return -ENOMEM;
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master->setup = ep93xx_spi_setup;
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master->setup = ep93xx_spi_setup;
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master->transfer = ep93xx_spi_transfer;
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master->transfer_one_message = ep93xx_spi_transfer_one_message;
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master->cleanup = ep93xx_spi_cleanup;
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master->cleanup = ep93xx_spi_cleanup;
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master->bus_num = pdev->id;
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master->bus_num = pdev->id;
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master->num_chipselect = info->num_chipselect;
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master->num_chipselect = info->num_chipselect;
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@ -1002,7 +911,6 @@ static int ep93xx_spi_probe(struct platform_device *pdev)
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goto fail_release_master;
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goto fail_release_master;
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}
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}
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spin_lock_init(&espi->lock);
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init_completion(&espi->wait);
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init_completion(&espi->wait);
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/*
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/*
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@ -1031,23 +939,13 @@ static int ep93xx_spi_probe(struct platform_device *pdev)
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if (info->use_dma && ep93xx_spi_setup_dma(espi))
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if (info->use_dma && ep93xx_spi_setup_dma(espi))
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dev_warn(&pdev->dev, "DMA setup failed. Falling back to PIO\n");
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dev_warn(&pdev->dev, "DMA setup failed. Falling back to PIO\n");
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espi->wq = create_singlethread_workqueue("ep93xx_spid");
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if (!espi->wq) {
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dev_err(&pdev->dev, "unable to create workqueue\n");
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error = -ENOMEM;
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goto fail_free_dma;
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}
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INIT_WORK(&espi->msg_work, ep93xx_spi_work);
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INIT_LIST_HEAD(&espi->msg_queue);
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espi->running = true;
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/* make sure that the hardware is disabled */
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/* make sure that the hardware is disabled */
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ep93xx_spi_write_u8(espi, SSPCR1, 0);
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ep93xx_spi_write_u8(espi, SSPCR1, 0);
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error = spi_register_master(master);
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error = spi_register_master(master);
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if (error) {
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if (error) {
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dev_err(&pdev->dev, "failed to register SPI master\n");
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dev_err(&pdev->dev, "failed to register SPI master\n");
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goto fail_free_queue;
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goto fail_free_dma;
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}
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}
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dev_info(&pdev->dev, "EP93xx SPI Controller at 0x%08lx irq %d\n",
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dev_info(&pdev->dev, "EP93xx SPI Controller at 0x%08lx irq %d\n",
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@ -1055,8 +953,6 @@ static int ep93xx_spi_probe(struct platform_device *pdev)
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return 0;
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return 0;
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fail_free_queue:
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destroy_workqueue(espi->wq);
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fail_free_dma:
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fail_free_dma:
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ep93xx_spi_release_dma(espi);
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ep93xx_spi_release_dma(espi);
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fail_release_master:
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fail_release_master:
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@ -1070,29 +966,6 @@ static int ep93xx_spi_remove(struct platform_device *pdev)
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struct spi_master *master = platform_get_drvdata(pdev);
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struct spi_master *master = platform_get_drvdata(pdev);
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struct ep93xx_spi *espi = spi_master_get_devdata(master);
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struct ep93xx_spi *espi = spi_master_get_devdata(master);
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spin_lock_irq(&espi->lock);
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espi->running = false;
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spin_unlock_irq(&espi->lock);
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destroy_workqueue(espi->wq);
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/*
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* Complete remaining messages with %-ESHUTDOWN status.
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*/
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spin_lock_irq(&espi->lock);
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while (!list_empty(&espi->msg_queue)) {
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struct spi_message *msg;
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msg = list_first_entry(&espi->msg_queue,
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struct spi_message, queue);
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list_del_init(&msg->queue);
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msg->status = -ESHUTDOWN;
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spin_unlock_irq(&espi->lock);
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msg->complete(msg->context);
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spin_lock_irq(&espi->lock);
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}
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spin_unlock_irq(&espi->lock);
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ep93xx_spi_release_dma(espi);
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ep93xx_spi_release_dma(espi);
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spi_unregister_master(master);
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spi_unregister_master(master);
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