diff options
Diffstat (limited to 'drivers/spi/spi.c')
-rw-r--r-- | drivers/spi/spi.c | 275 |
1 files changed, 153 insertions, 122 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index e353b7a9e54e..c99181165321 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -363,6 +363,10 @@ static int spi_uevent(struct device *dev, struct kobj_uevent_env *env) const struct spi_device *spi = to_spi_device(dev); int rc; + rc = of_device_uevent_modalias(dev, env); + if (rc != -ENODEV) + return rc; + rc = acpi_device_uevent_modalias(dev, env); if (rc != -ENODEV) return rc; @@ -560,49 +564,23 @@ static void spi_cleanup(struct spi_device *spi) spi->controller->cleanup(spi); } -/** - * spi_add_device - Add spi_device allocated with spi_alloc_device - * @spi: spi_device to register - * - * Companion function to spi_alloc_device. Devices allocated with - * spi_alloc_device can be added onto the spi bus with this function. - * - * Return: 0 on success; negative errno on failure - */ -int spi_add_device(struct spi_device *spi) +static int __spi_add_device(struct spi_device *spi) { struct spi_controller *ctlr = spi->controller; struct device *dev = ctlr->dev.parent; int status; - /* Chipselects are numbered 0..max; validate. */ - if (spi->chip_select >= ctlr->num_chipselect) { - dev_err(dev, "cs%d >= max %d\n", spi->chip_select, - ctlr->num_chipselect); - return -EINVAL; - } - - /* Set the bus ID string */ - spi_dev_set_name(spi); - - /* We need to make sure there's no other device with this - * chipselect **BEFORE** we call setup(), else we'll trash - * its configuration. Lock against concurrent add() calls. - */ - mutex_lock(&spi_add_lock); - status = bus_for_each_dev(&spi_bus_type, NULL, spi, spi_dev_check); if (status) { dev_err(dev, "chipselect %d already in use\n", spi->chip_select); - goto done; + return status; } /* Controller may unregister concurrently */ if (IS_ENABLED(CONFIG_SPI_DYNAMIC) && !device_is_registered(&ctlr->dev)) { - status = -ENODEV; - goto done; + return -ENODEV; } /* Descriptors take precedence */ @@ -619,7 +597,7 @@ int spi_add_device(struct spi_device *spi) if (status < 0) { dev_err(dev, "can't setup %s, status %d\n", dev_name(&spi->dev), status); - goto done; + return status; } /* Device may be bound to an active driver when this returns */ @@ -632,12 +610,64 @@ int spi_add_device(struct spi_device *spi) dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev)); } -done: + return status; +} + +/** + * spi_add_device - Add spi_device allocated with spi_alloc_device + * @spi: spi_device to register + * + * Companion function to spi_alloc_device. Devices allocated with + * spi_alloc_device can be added onto the spi bus with this function. + * + * Return: 0 on success; negative errno on failure + */ +int spi_add_device(struct spi_device *spi) +{ + struct spi_controller *ctlr = spi->controller; + struct device *dev = ctlr->dev.parent; + int status; + + /* Chipselects are numbered 0..max; validate. */ + if (spi->chip_select >= ctlr->num_chipselect) { + dev_err(dev, "cs%d >= max %d\n", spi->chip_select, + ctlr->num_chipselect); + return -EINVAL; + } + + /* Set the bus ID string */ + spi_dev_set_name(spi); + + /* We need to make sure there's no other device with this + * chipselect **BEFORE** we call setup(), else we'll trash + * its configuration. Lock against concurrent add() calls. + */ + mutex_lock(&spi_add_lock); + status = __spi_add_device(spi); mutex_unlock(&spi_add_lock); return status; } EXPORT_SYMBOL_GPL(spi_add_device); +static int spi_add_device_locked(struct spi_device *spi) +{ + struct spi_controller *ctlr = spi->controller; + struct device *dev = ctlr->dev.parent; + + /* Chipselects are numbered 0..max; validate. */ + if (spi->chip_select >= ctlr->num_chipselect) { + dev_err(dev, "cs%d >= max %d\n", spi->chip_select, + ctlr->num_chipselect); + return -EINVAL; + } + + /* Set the bus ID string */ + spi_dev_set_name(spi); + + WARN_ON(!mutex_is_locked(&spi_add_lock)); + return __spi_add_device(spi); +} + /** * spi_new_device - instantiate one new SPI device * @ctlr: Controller to which device is connected @@ -804,6 +834,8 @@ static void spi_set_cs(struct spi_device *spi, bool enable, bool force) (spi->controller->last_cs_mode_high == (spi->mode & SPI_CS_HIGH))) return; + trace_spi_set_cs(spi, activate); + spi->controller->last_cs_enable = enable; spi->controller->last_cs_mode_high = spi->mode & SPI_CS_HIGH; @@ -961,11 +993,15 @@ static int __spi_map_msg(struct spi_controller *ctlr, struct spi_message *msg) if (ctlr->dma_tx) tx_dev = ctlr->dma_tx->device->dev; + else if (ctlr->dma_map_dev) + tx_dev = ctlr->dma_map_dev; else tx_dev = ctlr->dev.parent; if (ctlr->dma_rx) rx_dev = ctlr->dma_rx->device->dev; + else if (ctlr->dma_map_dev) + rx_dev = ctlr->dma_map_dev; else rx_dev = ctlr->dev.parent; @@ -1132,10 +1168,20 @@ static int spi_transfer_wait(struct spi_controller *ctlr, if (!speed_hz) speed_hz = 100000; - ms = 8LL * 1000LL * xfer->len; + /* + * For each byte we wait for 8 cycles of the SPI clock. + * Since speed is defined in Hz and we want milliseconds, + * use respective multiplier, but before the division, + * otherwise we may get 0 for short transfers. + */ + ms = 8LL * MSEC_PER_SEC * xfer->len; do_div(ms, speed_hz); - ms += ms + 200; /* some tolerance */ + /* + * Increase it twice and add 200 ms tolerance, use + * predefined maximum in case of overflow. + */ + ms += ms + 200; if (ms > UINT_MAX) ms = UINT_MAX; @@ -1158,10 +1204,10 @@ static void _spi_transfer_delay_ns(u32 ns) { if (!ns) return; - if (ns <= 1000) { + if (ns <= NSEC_PER_USEC) { ndelay(ns); } else { - u32 us = DIV_ROUND_UP(ns, 1000); + u32 us = DIV_ROUND_UP(ns, NSEC_PER_USEC); if (us <= 10) udelay(us); @@ -1181,21 +1227,25 @@ int spi_delay_to_ns(struct spi_delay *_delay, struct spi_transfer *xfer) switch (unit) { case SPI_DELAY_UNIT_USECS: - delay *= 1000; + delay *= NSEC_PER_USEC; break; - case SPI_DELAY_UNIT_NSECS: /* nothing to do here */ + 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 + /* + * If there is unknown effective speed, approximate it + * by underestimating with half of the requested hz. */ hz = xfer->effective_speed_hz ?: xfer->speed_hz / 2; if (!hz) return -EINVAL; - delay *= DIV_ROUND_UP(1000000000, hz); + + /* Convert delay to nanoseconds */ + delay *= DIV_ROUND_UP(NSEC_PER_SEC, hz); break; default: return -EINVAL; @@ -1227,6 +1277,7 @@ EXPORT_SYMBOL_GPL(spi_delay_exec); static void _spi_transfer_cs_change_delay(struct spi_message *msg, struct spi_transfer *xfer) { + u32 default_delay_ns = 10 * NSEC_PER_USEC; u32 delay = xfer->cs_change_delay.value; u32 unit = xfer->cs_change_delay.unit; int ret; @@ -1234,16 +1285,16 @@ static void _spi_transfer_cs_change_delay(struct spi_message *msg, /* return early on "fast" mode - for everything but USECS */ if (!delay) { if (unit == SPI_DELAY_UNIT_USECS) - _spi_transfer_delay_ns(10000); + _spi_transfer_delay_ns(default_delay_ns); 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", - unit); - _spi_transfer_delay_ns(10000); + "Use of unsupported delay unit %i, using default of %luus\n", + unit, default_delay_ns / NSEC_PER_USEC); + _spi_transfer_delay_ns(default_delay_ns); } } @@ -2057,6 +2108,7 @@ of_register_spi_device(struct spi_controller *ctlr, struct device_node *nc) /* Store a pointer to the node in the device structure */ of_node_get(nc); spi->dev.of_node = nc; + spi->dev.fwnode = of_fwnode_handle(nc); /* Register the new device */ rc = spi_add_device(spi); @@ -2104,6 +2156,55 @@ static void of_register_spi_devices(struct spi_controller *ctlr) static void of_register_spi_devices(struct spi_controller *ctlr) { } #endif +/** + * spi_new_ancillary_device() - Register ancillary SPI device + * @spi: Pointer to the main SPI device registering the ancillary device + * @chip_select: Chip Select of the ancillary device + * + * Register an ancillary SPI device; for example some chips have a chip-select + * for normal device usage and another one for setup/firmware upload. + * + * This may only be called from main SPI device's probe routine. + * + * Return: 0 on success; negative errno on failure + */ +struct spi_device *spi_new_ancillary_device(struct spi_device *spi, + u8 chip_select) +{ + struct spi_device *ancillary; + int rc = 0; + + /* Alloc an spi_device */ + ancillary = spi_alloc_device(spi->controller); + if (!ancillary) { + rc = -ENOMEM; + goto err_out; + } + + strlcpy(ancillary->modalias, "dummy", sizeof(ancillary->modalias)); + + /* Use provided chip-select for ancillary device */ + ancillary->chip_select = chip_select; + + /* Take over SPI mode/speed from SPI main device */ + ancillary->max_speed_hz = spi->max_speed_hz; + ancillary->mode = spi->mode; + + /* Register the new device */ + rc = spi_add_device_locked(ancillary); + if (rc) { + dev_err(&spi->dev, "failed to register ancillary device\n"); + goto err_out; + } + + return ancillary; + +err_out: + spi_dev_put(ancillary); + return ERR_PTR(rc); +} +EXPORT_SYMBOL_GPL(spi_new_ancillary_device); + #ifdef CONFIG_ACPI struct acpi_spi_lookup { struct spi_controller *ctlr; @@ -2621,9 +2722,10 @@ static int spi_get_gpio_descs(struct spi_controller *ctlr) native_cs_mask |= BIT(i); } - ctlr->unused_native_cs = ffz(native_cs_mask); - if (num_cs_gpios && ctlr->max_native_cs && - ctlr->unused_native_cs >= ctlr->max_native_cs) { + ctlr->unused_native_cs = ffs(~native_cs_mask) - 1; + + if ((ctlr->flags & SPI_MASTER_GPIO_SS) && num_cs_gpios && + ctlr->max_native_cs && ctlr->unused_native_cs >= ctlr->max_native_cs) { dev_err(dev, "No unused native chip select available\n"); return -EINVAL; } @@ -3440,8 +3542,10 @@ int spi_setup(struct spi_device *spi) spi_set_thread_rt(spi->controller); } - dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n", - (int) (spi->mode & (SPI_CPOL | SPI_CPHA)), + trace_spi_setup(spi, status); + + dev_dbg(&spi->dev, "setup mode %lu, %s%s%s%s%u bits/w, %u Hz max --> %d\n", + spi->mode & SPI_MODE_X_MASK, (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "", (spi->mode & SPI_LSB_FIRST) ? "lsb, " : "", (spi->mode & SPI_3WIRE) ? "3wire, " : "", @@ -3453,79 +3557,6 @@ int spi_setup(struct spi_device *spi) } 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 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. - */ -int spi_set_cs_timing(struct spi_device *spi, struct spi_delay *setup, - struct spi_delay *hold, struct spi_delay *inactive) -{ - struct device *parent = spi->controller->dev.parent; - size_t len; - int status; - - if (spi->controller->set_cs_timing && - !(spi->cs_gpiod || gpio_is_valid(spi->cs_gpio))) { - mutex_lock(&spi->controller->io_mutex); - - if (spi->controller->auto_runtime_pm) { - status = pm_runtime_get_sync(parent); - if (status < 0) { - mutex_unlock(&spi->controller->io_mutex); - pm_runtime_put_noidle(parent); - dev_err(&spi->controller->dev, "Failed to power device: %d\n", - status); - return status; - } - - status = spi->controller->set_cs_timing(spi, setup, - hold, inactive); - pm_runtime_mark_last_busy(parent); - pm_runtime_put_autosuspend(parent); - } else { - status = spi->controller->set_cs_timing(spi, setup, hold, - inactive); - } - - mutex_unlock(&spi->controller->io_mutex); - return status; - } - - 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) { |