#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>
/**
* 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
* @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;
/**
* struct ep93xx_spi_chip - SPI device hardware settings
* @spi: back pointer to the SPI device
- * @rate: max rate in hz this chip supports
- * @div_cpsr: cpsr (pre-scaler) divider
- * @div_scr: scr divider
- * @dss: bits per word (4 - 16 bits)
* @ops: private chip operations
- *
- * This structure is used to store hardware register specific settings for each
- * SPI device. Settings are written to hardware by function
- * ep93xx_spi_chip_setup().
*/
struct ep93xx_spi_chip {
const struct spi_device *spi;
- unsigned long rate;
- u8 div_cpsr;
- u8 div_scr;
- u8 dss;
struct ep93xx_spi_chip_ops *ops;
};
/* converts bits per word to CR0.DSS value */
#define bits_per_word_to_dss(bpw) ((bpw) - 1)
-static inline void
-ep93xx_spi_write_u8(const struct ep93xx_spi *espi, u16 reg, u8 value)
+static void ep93xx_spi_write_u8(const struct ep93xx_spi *espi,
+ u16 reg, u8 value)
{
- __raw_writeb(value, espi->regs_base + reg);
+ writeb(value, espi->regs_base + reg);
}
-static inline u8
-ep93xx_spi_read_u8(const struct ep93xx_spi *spi, u16 reg)
+static u8 ep93xx_spi_read_u8(const struct ep93xx_spi *spi, u16 reg)
{
- return __raw_readb(spi->regs_base + reg);
+ return readb(spi->regs_base + reg);
}
-static inline void
-ep93xx_spi_write_u16(const struct ep93xx_spi *espi, u16 reg, u16 value)
+static void ep93xx_spi_write_u16(const struct ep93xx_spi *espi,
+ u16 reg, u16 value)
{
- __raw_writew(value, espi->regs_base + reg);
+ writew(value, espi->regs_base + reg);
}
-static inline u16
-ep93xx_spi_read_u16(const struct ep93xx_spi *spi, u16 reg)
+static u16 ep93xx_spi_read_u16(const struct ep93xx_spi *spi, u16 reg)
{
- return __raw_readw(spi->regs_base + reg);
+ return readw(spi->regs_base + reg);
}
static int ep93xx_spi_enable(const struct ep93xx_spi *espi)
/**
* ep93xx_spi_calc_divisors() - calculates SPI clock divisors
* @espi: ep93xx SPI controller struct
- * @chip: divisors are calculated for this chip
* @rate: desired SPI output clock rate
- *
- * Function calculates cpsr (clock pre-scaler) and scr divisors based on
- * given @rate and places them to @chip->div_cpsr and @chip->div_scr. If,
- * for some reason, divisors cannot be calculated nothing is stored and
- * %-EINVAL is returned.
+ * @div_cpsr: pointer to return the cpsr (pre-scaler) divider
+ * @div_scr: pointer to return the scr divider
*/
static int ep93xx_spi_calc_divisors(const struct ep93xx_spi *espi,
- struct ep93xx_spi_chip *chip,
- unsigned long rate)
+ unsigned long rate,
+ u8 *div_cpsr, u8 *div_scr)
{
unsigned long spi_clk_rate = clk_get_rate(espi->clk);
int cpsr, scr;
/*
* 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);
for (cpsr = 2; cpsr <= 254; cpsr += 2) {
for (scr = 0; scr <= 255; scr++) {
if ((spi_clk_rate / (cpsr * (scr + 1))) <= rate) {
- chip->div_scr = (u8)scr;
- chip->div_cpsr = (u8)cpsr;
+ *div_scr = (u8)scr;
+ *div_cpsr = (u8)cpsr;
return 0;
}
}
spi_set_ctldata(spi, chip);
}
- if (spi->max_speed_hz != chip->rate) {
- int err;
-
- err = ep93xx_spi_calc_divisors(espi, chip, spi->max_speed_hz);
- if (err != 0) {
- spi_set_ctldata(spi, NULL);
- kfree(chip);
- return err;
- }
- chip->rate = spi->max_speed_hz;
- }
-
- chip->dss = bits_per_word_to_dss(spi->bits_per_word);
-
ep93xx_spi_cs_control(spi, false);
return 0;
}
-/**
- * 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
* ep93xx_spi_chip_setup() - configures hardware according to given @chip
* @espi: ep93xx SPI controller struct
* @chip: chip specific settings
- *
- * This function sets up the actual hardware registers with settings given in
- * @chip. Note that no validation is done so make sure that callers validate
- * settings before calling this.
+ * @speed_hz: transfer speed
+ * @bits_per_word: transfer bits_per_word
*/
-static void ep93xx_spi_chip_setup(const struct ep93xx_spi *espi,
- const struct ep93xx_spi_chip *chip)
+static int ep93xx_spi_chip_setup(const struct ep93xx_spi *espi,
+ const struct ep93xx_spi_chip *chip,
+ u32 speed_hz, u8 bits_per_word)
{
+ u8 dss = bits_per_word_to_dss(bits_per_word);
+ u8 div_cpsr = 0;
+ u8 div_scr = 0;
u16 cr0;
+ int err;
- cr0 = chip->div_scr << SSPCR0_SCR_SHIFT;
+ err = ep93xx_spi_calc_divisors(espi, speed_hz, &div_cpsr, &div_scr);
+ if (err)
+ return err;
+
+ cr0 = div_scr << SSPCR0_SCR_SHIFT;
cr0 |= (chip->spi->mode & (SPI_CPHA|SPI_CPOL)) << SSPCR0_MODE_SHIFT;
- cr0 |= chip->dss;
+ cr0 |= dss;
dev_dbg(&espi->pdev->dev, "setup: mode %d, cpsr %d, scr %d, dss %d\n",
- chip->spi->mode, chip->div_cpsr, chip->div_scr, chip->dss);
+ chip->spi->mode, div_cpsr, div_scr, dss);
dev_dbg(&espi->pdev->dev, "setup: cr0 %#x", cr0);
- ep93xx_spi_write_u8(espi, SSPCPSR, chip->div_cpsr);
+ ep93xx_spi_write_u8(espi, SSPCPSR, div_cpsr);
ep93xx_spi_write_u16(espi, SSPCR0, cr0);
-}
-
-static inline int bits_per_word(const struct ep93xx_spi *espi)
-{
- struct spi_message *msg = espi->current_msg;
- struct spi_transfer *t = msg->state;
- return t->bits_per_word;
+ return 0;
}
static void ep93xx_do_write(struct ep93xx_spi *espi, struct spi_transfer *t)
{
- if (bits_per_word(espi) > 8) {
+ if (t->bits_per_word > 8) {
u16 tx_val = 0;
if (t->tx_buf)
static void ep93xx_do_read(struct ep93xx_spi *espi, struct spi_transfer *t)
{
- if (bits_per_word(espi) > 8) {
+ if (t->bits_per_word > 8) {
u16 rx_val;
rx_val = ep93xx_spi_read_u16(espi, SSPDR);
size_t len = t->len;
int i, ret, nents;
- if (bits_per_word(espi) > 8)
+ if (t->bits_per_word > 8)
buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
else
buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE;
}
if (WARN_ON(len)) {
- dev_warn(&espi->pdev->dev, "len = %d expected 0!", len);
+ dev_warn(&espi->pdev->dev, "len = %zu expected 0!", len);
return ERR_PTR(-EINVAL);
}
struct spi_transfer *t)
{
struct ep93xx_spi_chip *chip = spi_get_ctldata(msg->spi);
+ int err;
msg->state = t;
- /*
- * Handle any transfer specific settings if needed. We use
- * temporary chip settings here and restore original later when
- * the transfer is finished.
- */
- if (t->speed_hz || t->bits_per_word) {
- struct ep93xx_spi_chip tmp_chip = *chip;
-
- if (t->speed_hz) {
- int err;
-
- err = ep93xx_spi_calc_divisors(espi, &tmp_chip,
- t->speed_hz);
- if (err) {
- dev_err(&espi->pdev->dev,
- "failed to adjust speed\n");
- msg->status = err;
- return;
- }
- }
-
- if (t->bits_per_word)
- tmp_chip.dss = bits_per_word_to_dss(t->bits_per_word);
-
- /*
- * Set up temporary new hw settings for this transfer.
- */
- ep93xx_spi_chip_setup(espi, &tmp_chip);
+ err = ep93xx_spi_chip_setup(espi, chip, t->speed_hz, t->bits_per_word);
+ if (err) {
+ dev_err(&espi->pdev->dev,
+ "failed to setup chip for transfer\n");
+ msg->status = err;
+ return;
}
espi->rx = 0;
ep93xx_spi_cs_control(msg->spi, true);
}
}
-
- if (t->speed_hz || t->bits_per_word)
- ep93xx_spi_chip_setup(espi, chip);
}
/*
espi->fifo_level = 0;
/*
- * Update SPI controller registers according to spi device and assert
- * the chipselect.
+ * Assert the chipselect.
*/
- ep93xx_spi_chip_setup(espi, spi_get_ctldata(msg->spi));
ep93xx_spi_cs_control(msg->spi, true);
list_for_each_entry(t, &msg->transfers, transfer_list) {
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)
info = dev_get_platdata(&pdev->dev);
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0) {
+ dev_err(&pdev->dev, "failed to get irq resources\n");
+ return -EBUSY;
+ }
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ dev_err(&pdev->dev, "unable to get iomem resource\n");
+ return -ENODEV;
+ }
+
master = spi_alloc_master(&pdev->dev, sizeof(*espi));
- if (!master) {
- dev_err(&pdev->dev, "failed to allocate spi master\n");
+ if (!master)
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;
espi = spi_master_get_devdata(master);
- espi->clk = clk_get(&pdev->dev, NULL);
+ espi->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(espi->clk)) {
dev_err(&pdev->dev, "unable to get spi clock\n");
error = PTR_ERR(espi->clk);
goto fail_release_master;
}
- spin_lock_init(&espi->lock);
init_completion(&espi->wait);
/*
espi->min_rate = clk_get_rate(espi->clk) / (254 * 256);
espi->pdev = pdev;
- irq = platform_get_irq(pdev, 0);
- if (irq < 0) {
- error = -EBUSY;
- dev_err(&pdev->dev, "failed to get irq resources\n");
- goto fail_put_clock;
- }
-
- res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
- if (!res) {
- dev_err(&pdev->dev, "unable to get iomem resource\n");
- error = -ENODEV;
- goto fail_put_clock;
- }
-
espi->sspdr_phys = res->start + SSPDR;
espi->regs_base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(espi->regs_base)) {
error = PTR_ERR(espi->regs_base);
- goto fail_put_clock;
+ goto fail_release_master;
}
error = devm_request_irq(&pdev->dev, irq, ep93xx_spi_interrupt,
0, "ep93xx-spi", espi);
if (error) {
dev_err(&pdev->dev, "failed to request irq\n");
- goto fail_put_clock;
+ goto fail_release_master;
}
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",
return 0;
-fail_free_queue:
- destroy_workqueue(espi->wq);
fail_free_dma:
ep93xx_spi_release_dma(espi);
-fail_put_clock:
- clk_put(espi->clk);
fail_release_master:
spi_master_put(master);
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);
- clk_put(espi->clk);
spi_unregister_master(master);
return 0;
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