diff options
Diffstat (limited to 'drivers/spi/spi.c')
-rw-r--r-- | drivers/spi/spi.c | 332 |
1 files changed, 293 insertions, 39 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index f9502dbbb5c1..5e4c4532f7f3 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -92,7 +92,7 @@ static ssize_t driver_override_store(struct device *dev, if (len) { spi->driver_override = driver_override; } else { - /* Emptry string, disable driver override */ + /* Empty string, disable driver override */ spi->driver_override = NULL; kfree(driver_override); } @@ -469,7 +469,7 @@ static LIST_HEAD(board_list); static LIST_HEAD(spi_controller_list); /* - * Used to protect add/del opertion for board_info list and + * Used to protect add/del operation for board_info list and * spi_controller list, and their matching process * also used to protect object of type struct idr */ @@ -775,6 +775,15 @@ int spi_register_board_info(struct spi_board_info const *info, unsigned n) static void spi_set_cs(struct spi_device *spi, bool enable) { + bool enable1 = enable; + + if (!spi->controller->set_cs_timing) { + if (enable1) + spi_delay_exec(&spi->controller->cs_setup, NULL); + else + spi_delay_exec(&spi->controller->cs_hold, NULL); + } + if (spi->mode & SPI_CS_HIGH) enable = !enable; @@ -800,6 +809,11 @@ static void spi_set_cs(struct spi_device *spi, bool enable) } else if (spi->controller->set_cs) { spi->controller->set_cs(spi, !enable); } + + if (!spi->controller->set_cs_timing) { + if (!enable1) + spi_delay_exec(&spi->controller->cs_inactive, NULL); + } } #ifdef CONFIG_HAS_DMA @@ -1106,42 +1120,79 @@ static void _spi_transfer_delay_ns(u32 ns) } } -static void _spi_transfer_cs_change_delay(struct spi_message *msg, - struct spi_transfer *xfer) +int spi_delay_to_ns(struct spi_delay *_delay, struct spi_transfer *xfer) { - u32 delay = xfer->cs_change_delay; - u32 unit = xfer->cs_change_delay_unit; + u32 delay = _delay->value; + u32 unit = _delay->unit; u32 hz; - /* return early on "fast" mode - for everything but USECS */ - if (!delay && unit != SPI_DELAY_UNIT_USECS) - return; + if (!delay) + return 0; switch (unit) { case SPI_DELAY_UNIT_USECS: - /* for compatibility use default of 10us */ - if (!delay) - delay = 10000; - else - delay *= 1000; + delay *= 1000; break; case SPI_DELAY_UNIT_NSECS: /* nothing to do here */ break; case SPI_DELAY_UNIT_SCK: + /* clock cycles need to be obtained from spi_transfer */ + if (!xfer) + return -EINVAL; /* if there is no effective speed know, then approximate * by underestimating with half the requested hz */ hz = xfer->effective_speed_hz ?: xfer->speed_hz / 2; + if (!hz) + return -EINVAL; delay *= DIV_ROUND_UP(1000000000, hz); break; default: + return -EINVAL; + } + + return delay; +} +EXPORT_SYMBOL_GPL(spi_delay_to_ns); + +int spi_delay_exec(struct spi_delay *_delay, struct spi_transfer *xfer) +{ + int delay; + + if (!_delay) + return -EINVAL; + + delay = spi_delay_to_ns(_delay, xfer); + if (delay < 0) + return delay; + + _spi_transfer_delay_ns(delay); + + return 0; +} +EXPORT_SYMBOL_GPL(spi_delay_exec); + +static void _spi_transfer_cs_change_delay(struct spi_message *msg, + struct spi_transfer *xfer) +{ + u32 delay = xfer->cs_change_delay.value; + u32 unit = xfer->cs_change_delay.unit; + int ret; + + /* return early on "fast" mode - for everything but USECS */ + if (!delay) { + if (unit == SPI_DELAY_UNIT_USECS) + _spi_transfer_delay_ns(10000); + return; + } + + ret = spi_delay_exec(&xfer->cs_change_delay, xfer); + if (ret) { dev_err_once(&msg->spi->dev, "Use of unsupported delay unit %i, using default of 10us\n", - xfer->cs_change_delay_unit); - delay = 10000; + unit); + _spi_transfer_delay_ns(10000); } - /* now sleep for the requested amount of time */ - _spi_transfer_delay_ns(delay); } /* @@ -1171,6 +1222,11 @@ static int spi_transfer_one_message(struct spi_controller *ctlr, spi_statistics_add_transfer_stats(statm, xfer, ctlr); spi_statistics_add_transfer_stats(stats, xfer, ctlr); + if (!ctlr->ptp_sts_supported) { + xfer->ptp_sts_word_pre = 0; + ptp_read_system_prets(xfer->ptp_sts); + } + if (xfer->tx_buf || xfer->rx_buf) { reinit_completion(&ctlr->xfer_completion); @@ -1197,13 +1253,17 @@ static int spi_transfer_one_message(struct spi_controller *ctlr, xfer->len); } + if (!ctlr->ptp_sts_supported) { + ptp_read_system_postts(xfer->ptp_sts); + xfer->ptp_sts_word_post = xfer->len; + } + trace_spi_transfer_stop(msg, xfer); if (msg->status != -EINPROGRESS) goto out; - if (xfer->delay_usecs) - _spi_transfer_delay_ns(xfer->delay_usecs * 1000); + spi_transfer_delay_exec(xfer); if (xfer->cs_change) { if (list_is_last(&xfer->transfer_list, @@ -1265,6 +1325,7 @@ EXPORT_SYMBOL_GPL(spi_finalize_current_transfer); */ static void __spi_pump_messages(struct spi_controller *ctlr, bool in_kthread) { + struct spi_transfer *xfer; struct spi_message *msg; bool was_busy = false; unsigned long flags; @@ -1391,6 +1452,13 @@ static void __spi_pump_messages(struct spi_controller *ctlr, bool in_kthread) goto out; } + if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) { + list_for_each_entry(xfer, &msg->transfers, transfer_list) { + xfer->ptp_sts_word_pre = 0; + ptp_read_system_prets(xfer->ptp_sts); + } + } + ret = ctlr->transfer_one_message(ctlr, msg); if (ret) { dev_err(&ctlr->dev, @@ -1419,6 +1487,99 @@ static void spi_pump_messages(struct kthread_work *work) } /** + * spi_take_timestamp_pre - helper for drivers to collect the beginning of the + * TX timestamp for the requested byte from the SPI + * transfer. The frequency with which this function + * must be called (once per word, once for the whole + * transfer, once per batch of words etc) is arbitrary + * as long as the @tx buffer offset is greater than or + * equal to the requested byte at the time of the + * call. The timestamp is only taken once, at the + * first such call. It is assumed that the driver + * advances its @tx buffer pointer monotonically. + * @ctlr: Pointer to the spi_controller structure of the driver + * @xfer: Pointer to the transfer being timestamped + * @tx: Pointer to the current word within the xfer->tx_buf that the driver is + * preparing to transmit right now. + * @irqs_off: If true, will disable IRQs and preemption for the duration of the + * transfer, for less jitter in time measurement. Only compatible + * with PIO drivers. If true, must follow up with + * spi_take_timestamp_post or otherwise system will crash. + * WARNING: for fully predictable results, the CPU frequency must + * also be under control (governor). + */ +void spi_take_timestamp_pre(struct spi_controller *ctlr, + struct spi_transfer *xfer, + const void *tx, bool irqs_off) +{ + u8 bytes_per_word = DIV_ROUND_UP(xfer->bits_per_word, 8); + + if (!xfer->ptp_sts) + return; + + if (xfer->timestamped_pre) + return; + + if (tx < (xfer->tx_buf + xfer->ptp_sts_word_pre * bytes_per_word)) + return; + + /* Capture the resolution of the timestamp */ + xfer->ptp_sts_word_pre = (tx - xfer->tx_buf) / bytes_per_word; + + xfer->timestamped_pre = true; + + if (irqs_off) { + local_irq_save(ctlr->irq_flags); + preempt_disable(); + } + + ptp_read_system_prets(xfer->ptp_sts); +} +EXPORT_SYMBOL_GPL(spi_take_timestamp_pre); + +/** + * spi_take_timestamp_post - helper for drivers to collect the end of the + * TX timestamp for the requested byte from the SPI + * transfer. Can be called with an arbitrary + * frequency: only the first call where @tx exceeds + * or is equal to the requested word will be + * timestamped. + * @ctlr: Pointer to the spi_controller structure of the driver + * @xfer: Pointer to the transfer being timestamped + * @tx: Pointer to the current word within the xfer->tx_buf that the driver has + * just transmitted. + * @irqs_off: If true, will re-enable IRQs and preemption for the local CPU. + */ +void spi_take_timestamp_post(struct spi_controller *ctlr, + struct spi_transfer *xfer, + const void *tx, bool irqs_off) +{ + u8 bytes_per_word = DIV_ROUND_UP(xfer->bits_per_word, 8); + + if (!xfer->ptp_sts) + return; + + if (xfer->timestamped_post) + return; + + if (tx < (xfer->tx_buf + xfer->ptp_sts_word_post * bytes_per_word)) + return; + + ptp_read_system_postts(xfer->ptp_sts); + + if (irqs_off) { + local_irq_restore(ctlr->irq_flags); + preempt_enable(); + } + + /* Capture the resolution of the timestamp */ + xfer->ptp_sts_word_post = (tx - xfer->tx_buf) / bytes_per_word; + + xfer->timestamped_post = true; +} +EXPORT_SYMBOL_GPL(spi_take_timestamp_post); + +/** * spi_set_thread_rt - set the controller to pump at realtime priority * @ctlr: controller to boost priority of * @@ -1503,6 +1664,7 @@ EXPORT_SYMBOL_GPL(spi_get_next_queued_message); */ void spi_finalize_current_message(struct spi_controller *ctlr) { + struct spi_transfer *xfer; struct spi_message *mesg; unsigned long flags; int ret; @@ -1511,6 +1673,13 @@ void spi_finalize_current_message(struct spi_controller *ctlr) mesg = ctlr->cur_msg; spin_unlock_irqrestore(&ctlr->queue_lock, flags); + if (!ctlr->ptp_sts_supported && !ctlr->transfer_one) { + list_for_each_entry(xfer, &mesg->transfers, transfer_list) { + ptp_read_system_postts(xfer->ptp_sts); + xfer->ptp_sts_word_post = xfer->len; + } + } + spi_unmap_msg(ctlr, mesg); if (ctlr->cur_msg_prepared && ctlr->unprepare_message) { @@ -1711,15 +1880,7 @@ static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi, spi->mode |= SPI_3WIRE; if (of_property_read_bool(nc, "spi-lsb-first")) spi->mode |= SPI_LSB_FIRST; - - /* - * For descriptors associated with the device, polarity inversion is - * handled in the gpiolib, so all chip selects are "active high" in - * the logical sense, the gpiolib will invert the line if need be. - */ - if (ctlr->use_gpio_descriptors) - spi->mode |= SPI_CS_HIGH; - else if (of_property_read_bool(nc, "spi-cs-high")) + if (of_property_read_bool(nc, "spi-cs-high")) spi->mode |= SPI_CS_HIGH; /* Device DUAL/QUAD mode */ @@ -1783,6 +1944,15 @@ static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi, } spi->chip_select = value; + /* + * For descriptors associated with the device, polarity inversion is + * handled in the gpiolib, so all gpio chip selects are "active high" + * in the logical sense, the gpiolib will invert the line if need be. + */ + if ((ctlr->use_gpio_descriptors) && ctlr->cs_gpiods && + ctlr->cs_gpiods[spi->chip_select]) + spi->mode |= SPI_CS_HIGH; + /* Device speed */ rc = of_property_read_u32(nc, "spi-max-frequency", &value); if (rc) { @@ -2871,10 +3041,11 @@ struct spi_replaced_transfers *spi_replace_transfers( /* add to list */ list_add(&xfer->transfer_list, rxfer->replaced_after); - /* clear cs_change and delay_usecs for all but the last */ + /* clear cs_change and delay for all but the last */ if (i) { xfer->cs_change = false; xfer->delay_usecs = 0; + xfer->delay.value = 0; } } @@ -3091,7 +3262,29 @@ int spi_setup(struct spi_device *spi) if (spi->controller->setup) status = spi->controller->setup(spi); - spi_set_cs(spi, false); + if (spi->controller->auto_runtime_pm && spi->controller->set_cs) { + status = pm_runtime_get_sync(spi->controller->dev.parent); + if (status < 0) { + pm_runtime_put_noidle(spi->controller->dev.parent); + dev_err(&spi->controller->dev, "Failed to power device: %d\n", + status); + return status; + } + + /* + * We do not want to return positive value from pm_runtime_get, + * there are many instances of devices calling spi_setup() and + * checking for a non-zero return value instead of a negative + * return value. + */ + status = 0; + + spi_set_cs(spi, false); + pm_runtime_mark_last_busy(spi->controller->dev.parent); + pm_runtime_put_autosuspend(spi->controller->dev.parent); + } else { + spi_set_cs(spi, false); + } if (spi->rt && !spi->controller->rt) { spi->controller->rt = true; @@ -3114,18 +3307,71 @@ EXPORT_SYMBOL_GPL(spi_setup); /** * spi_set_cs_timing - configure CS setup, hold, and inactive delays * @spi: the device that requires specific CS timing configuration - * @setup: CS setup time in terms of clock count - * @hold: CS hold time in terms of clock count - * @inactive_dly: CS inactive delay between transfers in terms of clock count + * @setup: CS setup time specified via @spi_delay + * @hold: CS hold time specified via @spi_delay + * @inactive: CS inactive delay between transfers specified via @spi_delay + * + * Return: zero on success, else a negative error code. */ -void spi_set_cs_timing(struct spi_device *spi, u8 setup, u8 hold, - u8 inactive_dly) +int spi_set_cs_timing(struct spi_device *spi, struct spi_delay *setup, + struct spi_delay *hold, struct spi_delay *inactive) { + size_t len; + if (spi->controller->set_cs_timing) - spi->controller->set_cs_timing(spi, setup, hold, inactive_dly); + return spi->controller->set_cs_timing(spi, setup, hold, + inactive); + + if ((setup && setup->unit == SPI_DELAY_UNIT_SCK) || + (hold && hold->unit == SPI_DELAY_UNIT_SCK) || + (inactive && inactive->unit == SPI_DELAY_UNIT_SCK)) { + dev_err(&spi->dev, + "Clock-cycle delays for CS not supported in SW mode\n"); + return -ENOTSUPP; + } + + len = sizeof(struct spi_delay); + + /* copy delays to controller */ + if (setup) + memcpy(&spi->controller->cs_setup, setup, len); + else + memset(&spi->controller->cs_setup, 0, len); + + if (hold) + memcpy(&spi->controller->cs_hold, hold, len); + else + memset(&spi->controller->cs_hold, 0, len); + + if (inactive) + memcpy(&spi->controller->cs_inactive, inactive, len); + else + memset(&spi->controller->cs_inactive, 0, len); + + return 0; } EXPORT_SYMBOL_GPL(spi_set_cs_timing); +static int _spi_xfer_word_delay_update(struct spi_transfer *xfer, + struct spi_device *spi) +{ + int delay1, delay2; + + delay1 = spi_delay_to_ns(&xfer->word_delay, xfer); + if (delay1 < 0) + return delay1; + + delay2 = spi_delay_to_ns(&spi->word_delay, xfer); + if (delay2 < 0) + return delay2; + + if (delay1 < delay2) + memcpy(&xfer->word_delay, &spi->word_delay, + sizeof(xfer->word_delay)); + + return 0; +} + static int __spi_validate(struct spi_device *spi, struct spi_message *message) { struct spi_controller *ctlr = spi->controller; @@ -3261,8 +3507,8 @@ static int __spi_validate(struct spi_device *spi, struct spi_message *message) return -EINVAL; } - if (xfer->word_delay_usecs < spi->word_delay_usecs) - xfer->word_delay_usecs = spi->word_delay_usecs; + if (_spi_xfer_word_delay_update(xfer, spi)) + return -EINVAL; } message->status = -EINPROGRESS; @@ -3273,6 +3519,7 @@ static int __spi_validate(struct spi_device *spi, struct spi_message *message) static int __spi_async(struct spi_device *spi, struct spi_message *message) { struct spi_controller *ctlr = spi->controller; + struct spi_transfer *xfer; /* * Some controllers do not support doing regular SPI transfers. Return @@ -3288,6 +3535,13 @@ static int __spi_async(struct spi_device *spi, struct spi_message *message) trace_spi_message_submit(message); + if (!ctlr->ptp_sts_supported) { + list_for_each_entry(xfer, &message->transfers, transfer_list) { + xfer->ptp_sts_word_pre = 0; + ptp_read_system_prets(xfer->ptp_sts); + } + } + return ctlr->transfer(spi, message); } |