From f4b323905d8b3e28b2a9cef9325dbec1b0f7f064 Mon Sep 17 00:00:00 2001 From: Lukasz Majewski Date: Tue, 24 Sep 2019 13:05:47 +0200 Subject: spi: Introduce dspi_slave_abort() function for NXP's dspi SPI driver This change provides the dspi_slave_abort() function, which is a callback for slave_abort() method of SPI controller generic driver. As in the SPI slave mode the transmission is driven by master, any distortion may cause the slave to enter undefined internal state. To avoid this problem the dspi_slave_abort() terminates all pending and ongoing DMA transactions (with sync) and clears internal FIFOs. Signed-off-by: Lukasz Majewski Link: https://lore.kernel.org/r/20190924110547.14770-3-lukma@denx.de Signed-off-by: Mark Brown --- drivers/spi/spi-fsl-dspi.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) (limited to 'drivers/spi/spi-fsl-dspi.c') diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c index bec758e978fb..2c0f211eed87 100644 --- a/drivers/spi/spi-fsl-dspi.c +++ b/drivers/spi/spi-fsl-dspi.c @@ -1006,6 +1006,25 @@ static void dspi_init(struct fsl_dspi *dspi) SPI_CTARE_FMSZE(0) | SPI_CTARE_DTCP(1)); } +static int dspi_slave_abort(struct spi_master *master) +{ + struct fsl_dspi *dspi = spi_master_get_devdata(master); + + /* + * Terminate all pending DMA transactions for the SPI working + * in SLAVE mode. + */ + dmaengine_terminate_sync(dspi->dma->chan_rx); + dmaengine_terminate_sync(dspi->dma->chan_tx); + + /* Clear the internal DSPI RX and TX FIFO buffers */ + regmap_update_bits(dspi->regmap, SPI_MCR, + SPI_MCR_CLR_TXF | SPI_MCR_CLR_RXF, + SPI_MCR_CLR_TXF | SPI_MCR_CLR_RXF); + + return 0; +} + static int dspi_probe(struct platform_device *pdev) { struct device_node *np = pdev->dev.of_node; @@ -1030,6 +1049,7 @@ static int dspi_probe(struct platform_device *pdev) ctlr->dev.of_node = pdev->dev.of_node; ctlr->cleanup = dspi_cleanup; + ctlr->slave_abort = dspi_slave_abort; ctlr->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST; pdata = dev_get_platdata(&pdev->dev); -- cgit v1.2.3 From 3c0f9d8bcf47ed33f479cf9dc933d405020aefe4 Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Tue, 1 Oct 2019 23:52:16 +0300 Subject: spi: spi-fsl-dspi: Always use the TCFQ devices in poll mode With this patch, the "interrupts" property from the device tree bindings is ignored, even if present, if the driver runs in TCFQ mode. Switching to using the DSPI in poll mode has several distinct benefits: - With interrupts, the DSPI driver in TCFQ mode raises an IRQ after each transmitted word. There is more time wasted for the "waitq" event than for actual I/O. And the DSPI IRQ count can easily get the largest in /proc/interrupts on Freescale boards with attached SPI devices. - The SPI I/O time is both lower, and more consistently so. Attached to some Freescale devices are either PTP switches, or SPI RTCs. For reading time off of a SPI slave device, it is important that all SPI transfers take a deterministic time to complete. - In poll mode there is much less time spent by the CPU in hardirq context, which helps with the response latency of the system, and at the same time there is more control over when interrupts must be disabled (to get a precise timestamp measurement, which will come in a future patch): win-win. On the LS1021A-TSN board, where the SPI device is a SJA1105 PTP switch (with a bits_per_word=8 driver), I created a "benchmark" where I periodically transferred a 12-byte message once per second, for 120 seconds. I then recorded the time before putting the first byte in the TX FIFO, and the time after reading the last byte from the RX FIFO. That is the transfer delay in nanoseconds. Interrupt mode: delay: min 125120 max 168320 mean 150286 std dev 17675.3 Poll mode: delay: min 69440 max 119040 mean 70312.9 std dev 8065.34 Both the mean latency and the standard deviation are more than 50% lower in poll mode than in interrupt mode, and the 'max' in poll mode is lower than the 'min' in interrupt mode. This is with an 'ondemand' governor on an otherwise idle system - therefore running mostly at 600 MHz out of a max of 1200 MHz. Signed-off-by: Vladimir Oltean Link: https://lore.kernel.org/r/20191001205216.32115-1-olteanv@gmail.com Signed-off-by: Mark Brown --- drivers/spi/spi-fsl-dspi.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'drivers/spi/spi-fsl-dspi.c') diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c index 2c0f211eed87..c61074502145 100644 --- a/drivers/spi/spi-fsl-dspi.c +++ b/drivers/spi/spi-fsl-dspi.c @@ -707,7 +707,7 @@ static irqreturn_t dspi_interrupt(int irq, void *dev_id) regmap_read(dspi->regmap, SPI_SR, &spi_sr); regmap_write(dspi->regmap, SPI_SR, spi_sr); - if (!(spi_sr & (SPI_SR_EOQF | SPI_SR_TCFQF))) + if (!(spi_sr & SPI_SR_EOQF)) return IRQ_NONE; if (dspi_rxtx(dspi) == 0) { @@ -1134,6 +1134,9 @@ static int dspi_probe(struct platform_device *pdev) dspi_init(dspi); + if (dspi->devtype_data->trans_mode == DSPI_TCFQ_MODE) + goto poll_mode; + dspi->irq = platform_get_irq(pdev, 0); if (dspi->irq <= 0) { dev_info(&pdev->dev, -- cgit v1.2.3 From d6b71dfaeeba115dd61a7f367cf04c2d0ca77ebb Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Thu, 5 Sep 2019 04:01:13 +0300 Subject: spi: spi-fsl-dspi: Implement the PTP system timestamping for TCFQ mode In this mode, the DSPI controller uses PIO to transfer word by word. In comparison, in EOQ mode the 4-word deep FIFO is being used, hence the current logic will need some adaptation for which I do not have the hardware (Coldfire) to test. It is not clear what is the timing of DMA transfers and whether timestamping in the driver brings any overall performance increase compared to regular timestamping done in the core. Short phc2sys summary after 58 minutes of running on LS1021A-TSN with interrupts disabled during the critical section: offset: min -26251 max 16416 mean -21.8672 std dev 863.416 delay: min 4720 max 57280 mean 5182.49 std dev 1607.19 lost servo lock 3 times Summary of the same phc2sys service running for 120 minutes with interrupts disabled: offset: min -378 max 381 mean -0.0083089 std dev 101.495 delay: min 4720 max 5920 mean 5129.38 std dev 154.899 lost servo lock 0 times The minimum delay (pre to post time) in nanoseconds is the same, but the maximum delay is quite a bit higher, due to interrupts getting sometimes executed and interfering with the measurement. Hence set disable_irqs whenever possible (aka when the driver runs in poll mode - otherwise it would be a contradiction in terms). Signed-off-by: Vladimir Oltean Link: https://lore.kernel.org/r/20190905010114.26718-4-olteanv@gmail.com Signed-off-by: Mark Brown --- drivers/spi/spi-fsl-dspi.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'drivers/spi/spi-fsl-dspi.c') diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c index c61074502145..c0e96cc7fc51 100644 --- a/drivers/spi/spi-fsl-dspi.c +++ b/drivers/spi/spi-fsl-dspi.c @@ -129,6 +129,7 @@ enum dspi_trans_mode { struct fsl_dspi_devtype_data { enum dspi_trans_mode trans_mode; u8 max_clock_factor; + bool ptp_sts_supported; bool xspi_mode; }; @@ -140,12 +141,14 @@ static const struct fsl_dspi_devtype_data vf610_data = { static const struct fsl_dspi_devtype_data ls1021a_v1_data = { .trans_mode = DSPI_TCFQ_MODE, .max_clock_factor = 8, + .ptp_sts_supported = true, .xspi_mode = true, }; static const struct fsl_dspi_devtype_data ls2085a_data = { .trans_mode = DSPI_TCFQ_MODE, .max_clock_factor = 8, + .ptp_sts_supported = true, }; static const struct fsl_dspi_devtype_data coldfire_data = { @@ -654,6 +657,9 @@ static int dspi_rxtx(struct fsl_dspi *dspi) u16 spi_tcnt; u32 spi_tcr; + spi_take_timestamp_post(dspi->ctlr, dspi->cur_transfer, + dspi->tx - dspi->bytes_per_word, !dspi->irq); + /* Get transfer counter (in number of SPI transfers). It was * reset to 0 when transfer(s) were started. */ @@ -672,6 +678,9 @@ static int dspi_rxtx(struct fsl_dspi *dspi) /* Success! */ return 0; + spi_take_timestamp_pre(dspi->ctlr, dspi->cur_transfer, + dspi->tx, !dspi->irq); + if (trans_mode == DSPI_EOQ_MODE) dspi_eoq_write(dspi); else if (trans_mode == DSPI_TCFQ_MODE) @@ -779,6 +788,9 @@ static int dspi_transfer_one_message(struct spi_controller *ctlr, SPI_FRAME_EBITS(transfer->bits_per_word) | SPI_CTARE_DTCP(1)); + spi_take_timestamp_pre(dspi->ctlr, dspi->cur_transfer, + dspi->tx, !dspi->irq); + trans_mode = dspi->devtype_data->trans_mode; switch (trans_mode) { case DSPI_EOQ_MODE: @@ -1155,6 +1167,7 @@ static int dspi_probe(struct platform_device *pdev) init_waitqueue_head(&dspi->waitq); poll_mode: + if (dspi->devtype_data->trans_mode == DSPI_DMA_MODE) { ret = dspi_request_dma(dspi, res->start); if (ret < 0) { @@ -1166,6 +1179,8 @@ poll_mode: ctlr->max_speed_hz = clk_get_rate(dspi->clk) / dspi->devtype_data->max_clock_factor; + ctlr->ptp_sts_supported = dspi->devtype_data->ptp_sts_supported; + platform_set_drvdata(pdev, ctlr); ret = spi_register_controller(ctlr); -- cgit v1.2.3 From e74dc5c763448004ec8add422e9db53ee246acce Mon Sep 17 00:00:00 2001 From: Alexandru Ardelean Date: Thu, 26 Sep 2019 13:51:37 +0300 Subject: spi: use new `spi_transfer_delay_exec` helper where straightforward For many places in the spi drivers, using the new `spi_transfer_delay` helper is straightforward. It's just replacing: ``` if (t->delay_usecs) udelay(t->delay_usecs); ``` with `spi_transfer_delay(t)` which handles both `delay_usecs` and the new `delay` field. This change replaces in all places (in the spi drivers) where this change is simple. Signed-off-by: Alexandru Ardelean Link: https://lore.kernel.org/r/20190926105147.7839-10-alexandru.ardelean@analog.com Signed-off-by: Mark Brown --- drivers/spi/spi-atmel.c | 3 +-- drivers/spi/spi-bcm63xx-hsspi.c | 3 +-- drivers/spi/spi-cavium.c | 3 +-- drivers/spi/spi-fsl-dspi.c | 3 +-- drivers/spi/spi-fsl-espi.c | 3 +-- drivers/spi/spi-fsl-spi.c | 3 +-- drivers/spi/spi-mpc512x-psc.c | 3 +-- drivers/spi/spi-mpc52xx-psc.c | 3 +-- drivers/spi/spi-omap-100k.c | 3 +-- drivers/spi/spi-pl022.c | 25 +++++++++++-------------- drivers/spi/spi-sc18is602.c | 3 +-- drivers/spi/spi-sh-hspi.c | 3 +-- drivers/spi/spi-topcliff-pch.c | 7 +------ drivers/spi/spi-txx9.c | 3 +-- drivers/spi/spi-xcomm.c | 3 +-- 15 files changed, 25 insertions(+), 46 deletions(-) (limited to 'drivers/spi/spi-fsl-dspi.c') diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c index 1471b049f99a..e34ab587b980 100644 --- a/drivers/spi/spi-atmel.c +++ b/drivers/spi/spi-atmel.c @@ -1366,8 +1366,7 @@ static int atmel_spi_one_transfer(struct spi_master *master, && as->use_pdc) atmel_spi_dma_unmap_xfer(master, xfer); - if (xfer->delay_usecs) - udelay(xfer->delay_usecs); + spi_transfer_delay_exec(xfer); if (xfer->cs_change) { if (list_is_last(&xfer->transfer_list, diff --git a/drivers/spi/spi-bcm63xx-hsspi.c b/drivers/spi/spi-bcm63xx-hsspi.c index c6836a931dbf..7327309ea3d5 100644 --- a/drivers/spi/spi-bcm63xx-hsspi.c +++ b/drivers/spi/spi-bcm63xx-hsspi.c @@ -291,8 +291,7 @@ static int bcm63xx_hsspi_transfer_one(struct spi_master *master, msg->actual_length += t->len; - if (t->delay_usecs) - udelay(t->delay_usecs); + spi_transfer_delay_exec(t); if (t->cs_change) bcm63xx_hsspi_set_cs(bs, spi->chip_select, false); diff --git a/drivers/spi/spi-cavium.c b/drivers/spi/spi-cavium.c index 5aaf21582cb5..6854c3ce423b 100644 --- a/drivers/spi/spi-cavium.c +++ b/drivers/spi/spi-cavium.c @@ -119,8 +119,7 @@ static int octeon_spi_do_transfer(struct octeon_spi *p, *rx_buf++ = (u8)v; } - if (xfer->delay_usecs) - udelay(xfer->delay_usecs); + spi_transfer_delay_exec(xfer); return xfer->len; } diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c index c0e96cc7fc51..442cff71a0d2 100644 --- a/drivers/spi/spi-fsl-dspi.c +++ b/drivers/spi/spi-fsl-dspi.c @@ -827,8 +827,7 @@ static int dspi_transfer_one_message(struct spi_controller *ctlr, dev_err(&dspi->pdev->dev, "Waiting for transfer to complete failed!\n"); - if (transfer->delay_usecs) - udelay(transfer->delay_usecs); + spi_transfer_delay_exec(transfer); } out: diff --git a/drivers/spi/spi-fsl-espi.c b/drivers/spi/spi-fsl-espi.c index f72daf66f3f3..e60581283a24 100644 --- a/drivers/spi/spi-fsl-espi.c +++ b/drivers/spi/spi-fsl-espi.c @@ -427,8 +427,7 @@ static int fsl_espi_trans(struct spi_message *m, struct spi_transfer *trans) ret = fsl_espi_bufs(spi, trans); - if (trans->delay_usecs) - udelay(trans->delay_usecs); + spi_transfer_delay_exec(trans); return ret; } diff --git a/drivers/spi/spi-fsl-spi.c b/drivers/spi/spi-fsl-spi.c index 4b80ace1d137..114801a32371 100644 --- a/drivers/spi/spi-fsl-spi.c +++ b/drivers/spi/spi-fsl-spi.c @@ -416,8 +416,7 @@ static int fsl_spi_do_one_msg(struct spi_master *master, } m->actual_length += t->len; - if (t->delay_usecs) - udelay(t->delay_usecs); + spi_transfer_delay_exec(t); if (cs_change) { ndelay(nsecs); diff --git a/drivers/spi/spi-mpc512x-psc.c b/drivers/spi/spi-mpc512x-psc.c index a337b842ae8c..ea1b07953d38 100644 --- a/drivers/spi/spi-mpc512x-psc.c +++ b/drivers/spi/spi-mpc512x-psc.c @@ -311,8 +311,7 @@ static int mpc512x_psc_spi_msg_xfer(struct spi_master *master, break; m->actual_length += t->len; - if (t->delay_usecs) - udelay(t->delay_usecs); + spi_transfer_delay_exec(t); if (cs_change) mpc512x_psc_spi_deactivate_cs(spi); diff --git a/drivers/spi/spi-mpc52xx-psc.c b/drivers/spi/spi-mpc52xx-psc.c index c7e478b9b586..17935e71b02f 100644 --- a/drivers/spi/spi-mpc52xx-psc.c +++ b/drivers/spi/spi-mpc52xx-psc.c @@ -234,8 +234,7 @@ static void mpc52xx_psc_spi_work(struct work_struct *work) break; m->actual_length += t->len; - if (t->delay_usecs) - udelay(t->delay_usecs); + spi_transfer_delay_exec(t); if (cs_change) mpc52xx_psc_spi_deactivate_cs(spi); diff --git a/drivers/spi/spi-omap-100k.c b/drivers/spi/spi-omap-100k.c index 43a4785fc89b..5c704ba6d8ea 100644 --- a/drivers/spi/spi-omap-100k.c +++ b/drivers/spi/spi-omap-100k.c @@ -321,8 +321,7 @@ static int omap1_spi100k_transfer_one_message(struct spi_master *master, } } - if (t->delay_usecs) - udelay(t->delay_usecs); + spi_transfer_delay_exec(t); /* ignore the "leave it on after last xfer" hint */ diff --git a/drivers/spi/spi-pl022.c b/drivers/spi/spi-pl022.c index 7fedea67159c..3024c30e7f2e 100644 --- a/drivers/spi/spi-pl022.c +++ b/drivers/spi/spi-pl022.c @@ -485,12 +485,11 @@ static void giveback(struct pl022 *pl022) struct spi_transfer, transfer_list); /* Delay if requested before any change in chip select */ - if (last_transfer->delay_usecs) - /* - * FIXME: This runs in interrupt context. - * Is this really smart? - */ - udelay(last_transfer->delay_usecs); + /* + * FIXME: This runs in interrupt context. + * Is this really smart? + */ + spi_transfer_delay_exec(last_transfer); if (!last_transfer->cs_change) { struct spi_message *next_msg; @@ -1401,12 +1400,11 @@ static void pump_transfers(unsigned long data) previous = list_entry(transfer->transfer_list.prev, struct spi_transfer, transfer_list); - if (previous->delay_usecs) - /* - * FIXME: This runs in interrupt context. - * Is this really smart? - */ - udelay(previous->delay_usecs); + /* + * FIXME: This runs in interrupt context. + * Is this really smart? + */ + spi_transfer_delay_exec(previous); /* Reselect chip select only if cs_change was requested */ if (previous->cs_change) @@ -1520,8 +1518,7 @@ static void do_polling_transfer(struct pl022 *pl022) previous = list_entry(transfer->transfer_list.prev, struct spi_transfer, transfer_list); - if (previous->delay_usecs) - udelay(previous->delay_usecs); + spi_transfer_delay_exec(previous); if (previous->cs_change) pl022_cs_control(pl022, SSP_CHIP_SELECT); } else { diff --git a/drivers/spi/spi-sc18is602.c b/drivers/spi/spi-sc18is602.c index 11acddc83304..5497eeb3bf3e 100644 --- a/drivers/spi/spi-sc18is602.c +++ b/drivers/spi/spi-sc18is602.c @@ -211,8 +211,7 @@ static int sc18is602_transfer_one(struct spi_master *master, } status = 0; - if (t->delay_usecs) - udelay(t->delay_usecs); + spi_transfer_delay_exec(t); } m->status = status; spi_finalize_current_message(master); diff --git a/drivers/spi/spi-sh-hspi.c b/drivers/spi/spi-sh-hspi.c index 7f73f91d412a..a62034e2a7cb 100644 --- a/drivers/spi/spi-sh-hspi.c +++ b/drivers/spi/spi-sh-hspi.c @@ -190,8 +190,7 @@ static int hspi_transfer_one_message(struct spi_controller *ctlr, msg->actual_length += t->len; - if (t->delay_usecs) - udelay(t->delay_usecs); + spi_transfer_delay_exec(t); if (cs_change) { ndelay(nsecs); diff --git a/drivers/spi/spi-topcliff-pch.c b/drivers/spi/spi-topcliff-pch.c index f88cbb94ce12..223353fa2d8a 100644 --- a/drivers/spi/spi-topcliff-pch.c +++ b/drivers/spi/spi-topcliff-pch.c @@ -1229,12 +1229,7 @@ static void pch_spi_process_messages(struct work_struct *pwork) "%s:data->current_msg->actual_length=%d\n", __func__, data->current_msg->actual_length); - /* check for delay */ - if (data->cur_trans->delay_usecs) { - dev_dbg(&data->master->dev, "%s:delay in usec=%d\n", - __func__, data->cur_trans->delay_usecs); - udelay(data->cur_trans->delay_usecs); - } + spi_transfer_delay_exec(data->cur_trans); spin_lock(&data->lock); diff --git a/drivers/spi/spi-txx9.c b/drivers/spi/spi-txx9.c index 51759d3fd45f..83daaa597acc 100644 --- a/drivers/spi/spi-txx9.c +++ b/drivers/spi/spi-txx9.c @@ -248,8 +248,7 @@ static void txx9spi_work_one(struct txx9spi *c, struct spi_message *m) len -= count * wsize; } m->actual_length += t->len; - if (t->delay_usecs) - udelay(t->delay_usecs); + spi_transfer_delay_exec(t); if (!cs_change) continue; diff --git a/drivers/spi/spi-xcomm.c b/drivers/spi/spi-xcomm.c index a3496c46cc1b..1d9b3f03d986 100644 --- a/drivers/spi/spi-xcomm.c +++ b/drivers/spi/spi-xcomm.c @@ -188,8 +188,7 @@ static int spi_xcomm_transfer_one(struct spi_master *master, } status = 0; - if (t->delay_usecs) - udelay(t->delay_usecs); + spi_transfer_delay_exec(t); is_first = false; } -- cgit v1.2.3