/* M_CMD OP codes for SPI */
#define SPI_TX_ONLY 1
#define SPI_RX_ONLY 2
-#define SPI_FULL_DUPLEX 3
#define SPI_TX_RX 7
#define SPI_CS_ASSERT 8
#define SPI_CS_DEASSERT 9
#define TIMESTAMP_AFTER BIT(3)
#define POST_CMD_DELAY BIT(4)
-enum spi_m_cmd_opcode {
- CMD_NONE,
- CMD_XFER,
- CMD_CS,
- CMD_CANCEL,
-};
-
struct spi_geni_master {
struct geni_se se;
struct device *dev;
unsigned int tx_rem_bytes;
unsigned int rx_rem_bytes;
const struct spi_transfer *cur_xfer;
- struct completion xfer_done;
+ struct completion cs_done;
+ struct completion cancel_done;
+ struct completion abort_done;
unsigned int oversampling;
spinlock_t lock;
- enum spi_m_cmd_opcode cur_mcmd;
int irq;
+ bool cs_flag;
};
static int get_spi_clk_cfg(unsigned int speed_hz,
struct spi_message *msg)
{
struct spi_geni_master *mas = spi_master_get_devdata(spi);
- unsigned long time_left, flags;
+ unsigned long time_left;
struct geni_se *se = &mas->se;
- spin_lock_irqsave(&mas->lock, flags);
- reinit_completion(&mas->xfer_done);
- mas->cur_mcmd = CMD_CANCEL;
- geni_se_cancel_m_cmd(se);
+ spin_lock_irq(&mas->lock);
+ reinit_completion(&mas->cancel_done);
writel(0, se->base + SE_GENI_TX_WATERMARK_REG);
- spin_unlock_irqrestore(&mas->lock, flags);
- time_left = wait_for_completion_timeout(&mas->xfer_done, HZ);
+ mas->cur_xfer = NULL;
+ geni_se_cancel_m_cmd(se);
+ spin_unlock_irq(&mas->lock);
+
+ time_left = wait_for_completion_timeout(&mas->cancel_done, HZ);
if (time_left)
return;
- spin_lock_irqsave(&mas->lock, flags);
- reinit_completion(&mas->xfer_done);
+ spin_lock_irq(&mas->lock);
+ reinit_completion(&mas->abort_done);
geni_se_abort_m_cmd(se);
- spin_unlock_irqrestore(&mas->lock, flags);
- time_left = wait_for_completion_timeout(&mas->xfer_done, HZ);
+ spin_unlock_irq(&mas->lock);
+
+ time_left = wait_for_completion_timeout(&mas->abort_done, HZ);
if (!time_left)
dev_err(mas->dev, "Failed to cancel/abort m_cmd\n");
}
struct geni_se *se = &mas->se;
unsigned long time_left;
- reinit_completion(&mas->xfer_done);
- pm_runtime_get_sync(mas->dev);
if (!(slv->mode & SPI_CS_HIGH))
set_flag = !set_flag;
- mas->cur_mcmd = CMD_CS;
+ if (set_flag == mas->cs_flag)
+ return;
+
+ mas->cs_flag = set_flag;
+
+ pm_runtime_get_sync(mas->dev);
+ spin_lock_irq(&mas->lock);
+ reinit_completion(&mas->cs_done);
if (set_flag)
geni_se_setup_m_cmd(se, SPI_CS_ASSERT, 0);
else
geni_se_setup_m_cmd(se, SPI_CS_DEASSERT, 0);
+ spin_unlock_irq(&mas->lock);
- time_left = wait_for_completion_timeout(&mas->xfer_done, HZ);
+ time_left = wait_for_completion_timeout(&mas->cs_done, HZ);
if (!time_left)
handle_fifo_timeout(spi, NULL);
* Hardware programming guide suggests to configure
* RX FIFO RFR level to fifo_depth-2.
*/
- geni_se_init(se, 0x0, mas->tx_fifo_depth - 2);
+ geni_se_init(se, mas->tx_fifo_depth / 2, mas->tx_fifo_depth - 2);
/* Transmit an entire FIFO worth of data per IRQ */
mas->tx_wm = 1;
ver = geni_se_get_qup_hw_version(se);
struct geni_se *se = &mas->se;
int ret;
+ /*
+ * Ensure that our interrupt handler isn't still running from some
+ * prior command before we start messing with the hardware behind
+ * its back. We don't need to _keep_ the lock here since we're only
+ * worried about racing with out interrupt handler. The SPI core
+ * already handles making sure that we're not trying to do two
+ * transfers at once or setting a chip select and doing a transfer
+ * concurrently.
+ *
+ * NOTE: we actually _can't_ hold the lock here because possibly we
+ * might call clk_set_rate() which needs to be able to sleep.
+ */
+ spin_lock_irq(&mas->lock);
+ spin_unlock_irq(&mas->lock);
+
spi_tx_cfg = readl(se->base + SE_SPI_TRANS_CFG);
if (xfer->bits_per_word != mas->cur_bits_per_word) {
spi_setup_word_len(mas, mode, xfer->bits_per_word);
mas->tx_rem_bytes = 0;
mas->rx_rem_bytes = 0;
- if (xfer->tx_buf && xfer->rx_buf)
- m_cmd = SPI_FULL_DUPLEX;
- else if (xfer->tx_buf)
- m_cmd = SPI_TX_ONLY;
- else if (xfer->rx_buf)
- m_cmd = SPI_RX_ONLY;
spi_tx_cfg &= ~CS_TOGGLE;
len &= TRANS_LEN_MSK;
mas->cur_xfer = xfer;
- if (m_cmd & SPI_TX_ONLY) {
+ if (xfer->tx_buf) {
+ m_cmd |= SPI_TX_ONLY;
mas->tx_rem_bytes = xfer->len;
writel(len, se->base + SE_SPI_TX_TRANS_LEN);
}
- if (m_cmd & SPI_RX_ONLY) {
+ if (xfer->rx_buf) {
+ m_cmd |= SPI_RX_ONLY;
writel(len, se->base + SE_SPI_RX_TRANS_LEN);
mas->rx_rem_bytes = xfer->len;
}
writel(spi_tx_cfg, se->base + SE_SPI_TRANS_CFG);
- mas->cur_mcmd = CMD_XFER;
+
+ /*
+ * Lock around right before we start the transfer since our
+ * interrupt could come in at any time now.
+ */
+ spin_lock_irq(&mas->lock);
geni_se_setup_m_cmd(se, m_cmd, FRAGMENTATION);
/*
*/
if (m_cmd & SPI_TX_ONLY)
writel(mas->tx_wm, se->base + SE_GENI_TX_WATERMARK_REG);
+ spin_unlock_irq(&mas->lock);
}
static int spi_geni_transfer_one(struct spi_master *spi,
struct spi_geni_master *mas = spi_master_get_devdata(spi);
struct geni_se *se = &mas->se;
u32 m_irq;
- unsigned long flags;
- if (mas->cur_mcmd == CMD_NONE)
+ m_irq = readl(se->base + SE_GENI_M_IRQ_STATUS);
+ if (!m_irq)
return IRQ_NONE;
- spin_lock_irqsave(&mas->lock, flags);
- m_irq = readl(se->base + SE_GENI_M_IRQ_STATUS);
+ if (m_irq & (M_CMD_OVERRUN_EN | M_ILLEGAL_CMD_EN | M_CMD_FAILURE_EN |
+ M_RX_FIFO_RD_ERR_EN | M_RX_FIFO_WR_ERR_EN |
+ M_TX_FIFO_RD_ERR_EN | M_TX_FIFO_WR_ERR_EN))
+ dev_warn(mas->dev, "Unexpected IRQ err status %#010x\n", m_irq);
+
+ spin_lock(&mas->lock);
if ((m_irq & M_RX_FIFO_WATERMARK_EN) || (m_irq & M_RX_FIFO_LAST_EN))
geni_spi_handle_rx(mas);
geni_spi_handle_tx(mas);
if (m_irq & M_CMD_DONE_EN) {
- if (mas->cur_mcmd == CMD_XFER)
+ if (mas->cur_xfer) {
spi_finalize_current_transfer(spi);
- else if (mas->cur_mcmd == CMD_CS)
- complete(&mas->xfer_done);
- mas->cur_mcmd = CMD_NONE;
- /*
- * If this happens, then a CMD_DONE came before all the Tx
- * buffer bytes were sent out. This is unusual, log this
- * condition and disable the WM interrupt to prevent the
- * system from stalling due an interrupt storm.
- * If this happens when all Rx bytes haven't been received, log
- * the condition.
- * The only known time this can happen is if bits_per_word != 8
- * and some registers that expect xfer lengths in num spi_words
- * weren't written correctly.
- */
- if (mas->tx_rem_bytes) {
- writel(0, se->base + SE_GENI_TX_WATERMARK_REG);
- dev_err(mas->dev, "Premature done. tx_rem = %d bpw%d\n",
- mas->tx_rem_bytes, mas->cur_bits_per_word);
+ mas->cur_xfer = NULL;
+ /*
+ * If this happens, then a CMD_DONE came before all the
+ * Tx buffer bytes were sent out. This is unusual, log
+ * this condition and disable the WM interrupt to
+ * prevent the system from stalling due an interrupt
+ * storm.
+ *
+ * If this happens when all Rx bytes haven't been
+ * received, log the condition. The only known time
+ * this can happen is if bits_per_word != 8 and some
+ * registers that expect xfer lengths in num spi_words
+ * weren't written correctly.
+ */
+ if (mas->tx_rem_bytes) {
+ writel(0, se->base + SE_GENI_TX_WATERMARK_REG);
+ dev_err(mas->dev, "Premature done. tx_rem = %d bpw%d\n",
+ mas->tx_rem_bytes, mas->cur_bits_per_word);
+ }
+ if (mas->rx_rem_bytes)
+ dev_err(mas->dev, "Premature done. rx_rem = %d bpw%d\n",
+ mas->rx_rem_bytes, mas->cur_bits_per_word);
+ } else {
+ complete(&mas->cs_done);
}
- if (mas->rx_rem_bytes)
- dev_err(mas->dev, "Premature done. rx_rem = %d bpw%d\n",
- mas->rx_rem_bytes, mas->cur_bits_per_word);
}
- if ((m_irq & M_CMD_CANCEL_EN) || (m_irq & M_CMD_ABORT_EN)) {
- mas->cur_mcmd = CMD_NONE;
- complete(&mas->xfer_done);
- }
+ if (m_irq & M_CMD_CANCEL_EN)
+ complete(&mas->cancel_done);
+ if (m_irq & M_CMD_ABORT_EN)
+ complete(&mas->abort_done);
+ /*
+ * It's safe or a good idea to Ack all of our our interrupts at the
+ * end of the function. Specifically:
+ * - M_CMD_DONE_EN / M_RX_FIFO_LAST_EN: Edge triggered interrupts and
+ * clearing Acks. Clearing at the end relies on nobody else having
+ * started a new transfer yet or else we could be clearing _their_
+ * done bit, but everyone grabs the spinlock before starting a new
+ * transfer.
+ * - M_RX_FIFO_WATERMARK_EN / M_TX_FIFO_WATERMARK_EN: These appear
+ * to be "latched level" interrupts so it's important to clear them
+ * _after_ you've handled the condition and always safe to do so
+ * since they'll re-assert if they're still happening.
+ */
writel(m_irq, se->base + SE_GENI_M_IRQ_CLEAR);
- spin_unlock_irqrestore(&mas->lock, flags);
+
+ spin_unlock(&mas->lock);
+
return IRQ_HANDLED;
}
spi->handle_err = handle_fifo_timeout;
spi->set_cs = spi_geni_set_cs;
- init_completion(&mas->xfer_done);
+ init_completion(&mas->cs_done);
+ init_completion(&mas->cancel_done);
+ init_completion(&mas->abort_done);
spin_lock_init(&mas->lock);
+ pm_runtime_use_autosuspend(&pdev->dev);
+ pm_runtime_set_autosuspend_delay(&pdev->dev, 250);
pm_runtime_enable(dev);
ret = geni_icc_get(&mas->se, NULL);
projects / linux-2.6-microblaze.git / blobdiff