diff options
Diffstat (limited to 'drivers/spi/spi.c')
| -rw-r--r-- | drivers/spi/spi.c | 219 |
1 files changed, 94 insertions, 125 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 9291b2a0e887..8d6304cb061e 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -4,36 +4,36 @@ // Copyright (C) 2005 David Brownell // Copyright (C) 2008 Secret Lab Technologies Ltd. -#include <linux/kernel.h> -#include <linux/device.h> -#include <linux/init.h> +#include <linux/acpi.h> #include <linux/cache.h> -#include <linux/dma-mapping.h> +#include <linux/clk/clk-conf.h> +#include <linux/delay.h> +#include <linux/device.h> #include <linux/dmaengine.h> +#include <linux/dma-mapping.h> +#include <linux/export.h> +#include <linux/gpio/consumer.h> +#include <linux/highmem.h> +#include <linux/idr.h> +#include <linux/init.h> +#include <linux/ioport.h> +#include <linux/kernel.h> +#include <linux/kthread.h> +#include <linux/mod_devicetable.h> #include <linux/mutex.h> #include <linux/of_device.h> #include <linux/of_irq.h> -#include <linux/clk/clk-conf.h> -#include <linux/slab.h> -#include <linux/mod_devicetable.h> -#include <linux/spi/spi.h> -#include <linux/spi/spi-mem.h> -#include <linux/gpio/consumer.h> -#include <linux/pm_runtime.h> +#include <linux/percpu.h> +#include <linux/platform_data/x86/apple.h> #include <linux/pm_domain.h> +#include <linux/pm_runtime.h> #include <linux/property.h> -#include <linux/export.h> +#include <linux/ptp_clock_kernel.h> #include <linux/sched/rt.h> +#include <linux/slab.h> +#include <linux/spi/spi.h> +#include <linux/spi/spi-mem.h> #include <uapi/linux/sched/types.h> -#include <linux/delay.h> -#include <linux/kthread.h> -#include <linux/ioport.h> -#include <linux/acpi.h> -#include <linux/highmem.h> -#include <linux/idr.h> -#include <linux/platform_data/x86/apple.h> -#include <linux/ptp_clock_kernel.h> -#include <linux/percpu.h> #define CREATE_TRACE_POINTS #include <trace/events/spi.h> @@ -64,7 +64,7 @@ modalias_show(struct device *dev, struct device_attribute *a, char *buf) if (len != -ENODEV) return len; - return sprintf(buf, "%s%s\n", SPI_MODULE_PREFIX, spi->modalias); + return sysfs_emit(buf, "%s%s\n", SPI_MODULE_PREFIX, spi->modalias); } static DEVICE_ATTR_RO(modalias); @@ -89,7 +89,7 @@ static ssize_t driver_override_show(struct device *dev, ssize_t len; device_lock(dev); - len = snprintf(buf, PAGE_SIZE, "%s\n", spi->driver_override ? : ""); + len = sysfs_emit(buf, "%s\n", spi->driver_override ? : ""); device_unlock(dev); return len; } @@ -631,6 +631,16 @@ static int __spi_add_device(struct spi_device *spi) struct device *dev = ctlr->dev.parent; int status; + /* Chipselects are numbered 0..max; validate. */ + if (spi_get_chipselect(spi, 0) >= ctlr->num_chipselect) { + dev_err(dev, "cs%d >= max %d\n", spi_get_chipselect(spi, 0), + 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 @@ -682,26 +692,15 @@ static int __spi_add_device(struct spi_device *spi) * @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. + * 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_get_chipselect(spi, 0) >= ctlr->num_chipselect) { - dev_err(dev, "cs%d >= max %d\n", spi_get_chipselect(spi, 0), - ctlr->num_chipselect); - return -EINVAL; - } - - /* Set the bus ID string */ - spi_dev_set_name(spi); - mutex_lock(&ctlr->add_lock); status = __spi_add_device(spi); mutex_unlock(&ctlr->add_lock); @@ -709,25 +708,6 @@ int spi_add_device(struct spi_device *spi) } 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_get_chipselect(spi, 0) >= ctlr->num_chipselect) { - dev_err(dev, "cs%d >= max %d\n", spi_get_chipselect(spi, 0), - ctlr->num_chipselect); - return -EINVAL; - } - - /* Set the bus ID string */ - spi_dev_set_name(spi); - - WARN_ON(!mutex_is_locked(&ctlr->add_lock)); - return __spi_add_device(spi); -} - /** * spi_new_device - instantiate one new SPI device * @ctlr: Controller to which device is connected @@ -889,7 +869,7 @@ int spi_register_board_info(struct spi_board_info const *info, unsigned n) * spi_res_alloc - allocate a spi resource that is life-cycle managed * during the processing of a spi_message while using * spi_transfer_one - * @spi: the spi device for which we allocate memory + * @spi: the SPI device for which we allocate memory * @release: the release code to execute for this resource * @size: size to alloc and return * @gfp: GFP allocation flags @@ -915,7 +895,7 @@ static void *spi_res_alloc(struct spi_device *spi, spi_res_release_t release, } /** - * spi_res_free - free an spi resource + * spi_res_free - free an SPI resource * @res: pointer to the custom data of a resource */ static void spi_res_free(void *res) @@ -931,7 +911,7 @@ static void spi_res_free(void *res) /** * spi_res_add - add a spi_res to the spi_message - * @message: the spi message + * @message: the SPI message * @res: the spi_resource */ static void spi_res_add(struct spi_message *message, void *res) @@ -943,7 +923,7 @@ static void spi_res_add(struct spi_message *message, void *res) } /** - * spi_res_release - release all spi resources for this message + * spi_res_release - release all SPI resources for this message * @ctlr: the @spi_controller * @message: the @spi_message */ @@ -1006,7 +986,7 @@ static void spi_set_cs(struct spi_device *spi, bool enable, bool force) gpiod_set_value_cansleep(spi_get_csgpiod(spi, 0), activate); } /* Some SPI masters need both GPIO CS & slave_select */ - if ((spi->controller->flags & SPI_MASTER_GPIO_SS) && + if ((spi->controller->flags & SPI_CONTROLLER_GPIO_SS) && spi->controller->set_cs) spi->controller->set_cs(spi, !enable); } else if (spi->controller->set_cs) { @@ -1424,7 +1404,7 @@ int spi_delay_to_ns(struct spi_delay *_delay, struct spi_transfer *xfer) return -EINVAL; /* * If there is unknown effective speed, approximate it - * by underestimating with half of the requested hz. + * by underestimating with half of the requested Hz. */ hz = xfer->effective_speed_hz ?: xfer->speed_hz / 2; if (!hz) @@ -1739,11 +1719,11 @@ static int __spi_pump_transfer_message(struct spi_controller *ctlr, } /** - * __spi_pump_messages - function which processes spi message queue + * __spi_pump_messages - function which processes SPI message queue * @ctlr: controller to process queue for * @in_kthread: true if we are in the context of the message pump thread * - * This function checks if there is any spi message in the queue that + * This function checks if there is any SPI message in the queue that * needs processing and if so call out to the driver to initialize hardware * and transfer each message. * @@ -1758,7 +1738,7 @@ static void __spi_pump_messages(struct spi_controller *ctlr, bool in_kthread) unsigned long flags; int ret; - /* Take the IO mutex */ + /* Take the I/O mutex */ mutex_lock(&ctlr->io_mutex); /* Lock queue */ @@ -2169,8 +2149,8 @@ static int __spi_queued_transfer(struct spi_device *spi, /** * spi_queued_transfer - transfer function for queued transfers - * @spi: spi device which is requesting transfer - * @msg: spi message which is to handled is queued to driver queue + * @spi: SPI device which is requesting transfer + * @msg: SPI message which is to handled is queued to driver queue * * Return: zero on success, else a negative error code. */ @@ -2399,9 +2379,6 @@ static void of_register_spi_devices(struct spi_controller *ctlr) struct spi_device *spi; struct device_node *nc; - if (!ctlr->dev.of_node) - return; - for_each_available_child_of_node(ctlr->dev.of_node, nc) { if (of_node_test_and_set_flag(nc, OF_POPULATED)) continue; @@ -2432,11 +2409,12 @@ static void of_register_spi_devices(struct spi_controller *ctlr) { } struct spi_device *spi_new_ancillary_device(struct spi_device *spi, u8 chip_select) { + struct spi_controller *ctlr = spi->controller; struct spi_device *ancillary; int rc = 0; /* Alloc an spi_device */ - ancillary = spi_alloc_device(spi->controller); + ancillary = spi_alloc_device(ctlr); if (!ancillary) { rc = -ENOMEM; goto err_out; @@ -2451,8 +2429,10 @@ struct spi_device *spi_new_ancillary_device(struct spi_device *spi, ancillary->max_speed_hz = spi->max_speed_hz; ancillary->mode = spi->mode; + WARN_ON(!mutex_is_locked(&ctlr->add_lock)); + /* Register the new device */ - rc = spi_add_device_locked(ancillary); + rc = __spi_add_device(ancillary); if (rc) { dev_err(&spi->dev, "failed to register ancillary device\n"); goto err_out; @@ -2499,7 +2479,7 @@ static int acpi_spi_count(struct acpi_resource *ares, void *data) * acpi_spi_count_resources - Count the number of SpiSerialBus resources * @adev: ACPI device * - * Returns the number of SpiSerialBus resources in the ACPI-device's + * Return: the number of SpiSerialBus resources in the ACPI-device's * resource-list; or a negative error code. */ int acpi_spi_count_resources(struct acpi_device *adev) @@ -2633,10 +2613,10 @@ static int acpi_spi_add_resource(struct acpi_resource *ares, void *data) * @adev: ACPI Device for the spi device * @index: Index of the spi resource inside the ACPI Node * - * This should be used to allocate a new spi device from and ACPI Node. - * The caller is responsible for calling spi_add_device to register the spi device. + * This should be used to allocate a new SPI device from and ACPI Device node. + * The caller is responsible for calling spi_add_device to register the SPI device. * - * If ctlr is set to NULL, the Controller for the spi device will be looked up + * If ctlr is set to NULL, the Controller for the SPI device will be looked up * using the resource. * If index is set to -1, index is not used. * Note: If index is -1, ctlr must be set. @@ -2817,8 +2797,7 @@ static ssize_t slave_show(struct device *dev, struct device_attribute *attr, struct device *child; child = device_find_any_child(&ctlr->dev); - return sprintf(buf, "%s\n", - child ? to_spi_device(child)->modalias : NULL); + return sysfs_emit(buf, "%s\n", child ? to_spi_device(child)->modalias : NULL); } static ssize_t slave_store(struct device *dev, struct device_attribute *attr, @@ -3056,7 +3035,7 @@ static int spi_get_gpio_descs(struct spi_controller *ctlr) ctlr->unused_native_cs = ffs(~native_cs_mask) - 1; - if ((ctlr->flags & SPI_MASTER_GPIO_SS) && num_cs_gpios && + if ((ctlr->flags & SPI_CONTROLLER_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; @@ -3084,6 +3063,20 @@ static int spi_controller_check_ops(struct spi_controller *ctlr) return 0; } +/* Allocate dynamic bus number using Linux idr */ +static int spi_controller_id_alloc(struct spi_controller *ctlr, int start, int end) +{ + int id; + + mutex_lock(&board_lock); + id = idr_alloc(&spi_master_idr, ctlr, start, end, GFP_KERNEL); + mutex_unlock(&board_lock); + if (WARN(id < 0, "couldn't get idr")) + return id == -ENOSPC ? -EBUSY : id; + ctlr->bus_num = id; + return 0; +} + /** * spi_register_controller - register SPI master or slave controller * @ctlr: initialized master, originally from spi_alloc_master() or @@ -3111,8 +3104,8 @@ int spi_register_controller(struct spi_controller *ctlr) { struct device *dev = ctlr->dev.parent; struct boardinfo *bi; + int first_dynamic; int status; - int id, first_dynamic; if (!dev) return -ENODEV; @@ -3125,27 +3118,13 @@ int spi_register_controller(struct spi_controller *ctlr) if (status) return status; + if (ctlr->bus_num < 0) + ctlr->bus_num = of_alias_get_id(ctlr->dev.of_node, "spi"); if (ctlr->bus_num >= 0) { /* Devices with a fixed bus num must check-in with the num */ - mutex_lock(&board_lock); - id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num, - ctlr->bus_num + 1, GFP_KERNEL); - mutex_unlock(&board_lock); - if (WARN(id < 0, "couldn't get idr")) - return id == -ENOSPC ? -EBUSY : id; - ctlr->bus_num = id; - } else if (ctlr->dev.of_node) { - /* Allocate dynamic bus number using Linux idr */ - id = of_alias_get_id(ctlr->dev.of_node, "spi"); - if (id >= 0) { - ctlr->bus_num = id; - mutex_lock(&board_lock); - id = idr_alloc(&spi_master_idr, ctlr, ctlr->bus_num, - ctlr->bus_num + 1, GFP_KERNEL); - mutex_unlock(&board_lock); - if (WARN(id < 0, "couldn't get idr")) - return id == -ENOSPC ? -EBUSY : id; - } + status = spi_controller_id_alloc(ctlr, ctlr->bus_num, ctlr->bus_num + 1); + if (status) + return status; } if (ctlr->bus_num < 0) { first_dynamic = of_alias_get_highest_id("spi"); @@ -3154,13 +3133,9 @@ int spi_register_controller(struct spi_controller *ctlr) else first_dynamic++; - mutex_lock(&board_lock); - id = idr_alloc(&spi_master_idr, ctlr, first_dynamic, - 0, GFP_KERNEL); - mutex_unlock(&board_lock); - if (WARN(id < 0, "couldn't get idr")) - return id; - ctlr->bus_num = id; + status = spi_controller_id_alloc(ctlr, first_dynamic, 0); + if (status) + return status; } ctlr->bus_lock_flag = 0; init_completion(&ctlr->xfer_completion); @@ -3339,7 +3314,8 @@ void spi_unregister_controller(struct spi_controller *ctlr) if (IS_ENABLED(CONFIG_SPI_DYNAMIC)) mutex_unlock(&ctlr->add_lock); - /* Release the last reference on the controller if its driver + /* + * Release the last reference on the controller if its driver * has not yet been converted to devm_spi_alloc_master/slave(). */ if (!ctlr->devm_allocated) @@ -3552,7 +3528,7 @@ static int __spi_split_transfer_maxsize(struct spi_controller *ctlr, /* All the others need rx_buf/tx_buf also set */ for (i = 1, offset = maxsize; i < count; offset += maxsize, i++) { - /* Update rx_buf, tx_buf and dma */ + /* Update rx_buf, tx_buf and DMA */ if (xfers[i].rx_buf) xfers[i].rx_buf += offset; if (xfers[i].rx_dma) @@ -3622,7 +3598,7 @@ EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize); /** - * spi_split_transfers_maxwords - split spi transfers into multiple transfers + * spi_split_transfers_maxwords - split SPI transfers into multiple transfers * when an individual transfer exceeds a * certain number of SPI words * @ctlr: the @spi_controller for this transfer @@ -3650,13 +3626,7 @@ int spi_split_transfers_maxwords(struct spi_controller *ctlr, size_t maxsize; int ret; - if (xfer->bits_per_word <= 8) - maxsize = maxwords; - else if (xfer->bits_per_word <= 16) - maxsize = 2 * maxwords; - else - maxsize = 4 * maxwords; - + maxsize = maxwords * roundup_pow_of_two(BITS_TO_BYTES(xfer->bits_per_word)); if (xfer->len > maxsize) { ret = __spi_split_transfer_maxsize(ctlr, msg, &xfer, maxsize, gfp); @@ -3671,7 +3641,8 @@ EXPORT_SYMBOL_GPL(spi_split_transfers_maxwords); /*-------------------------------------------------------------------------*/ -/* Core methods for SPI controller protocol drivers. Some of the +/* + * Core methods for SPI controller protocol drivers. Some of the * other core methods are currently defined as inline functions. */ @@ -3731,7 +3702,7 @@ static int spi_set_cs_timing(struct spi_device *spi) * changes those settings, and must be called from a context that can sleep. * Except for SPI_CS_HIGH, which takes effect immediately, the changes take * effect the next time the device is selected and data is transferred to - * or from it. When this function returns, the spi device is deselected. + * or from it. When this function returns, the SPI device is deselected. * * Note that this call will fail if the protocol driver specifies an option * that the underlying controller or its driver does not support. For @@ -3906,11 +3877,9 @@ static int __spi_validate(struct spi_device *spi, struct spi_message *message) */ if ((spi->mode & SPI_CS_WORD) && (!(ctlr->mode_bits & SPI_CS_WORD) || spi_get_csgpiod(spi, 0))) { - size_t maxsize; + size_t maxsize = BITS_TO_BYTES(spi->bits_per_word); int ret; - maxsize = (spi->bits_per_word + 7) / 8; - /* spi_split_transfers_maxsize() requires message->spi */ message->spi = spi; @@ -4071,7 +4040,7 @@ static int __spi_async(struct spi_device *spi, struct spi_message *message) * spi_async - asynchronous SPI transfer * @spi: device with which data will be exchanged * @message: describes the data transfers, including completion callback - * Context: any (irqs may be blocked, etc) + * Context: any (IRQs may be blocked, etc) * * This call may be used in_irq and other contexts which can't sleep, * as well as from task contexts which can sleep. @@ -4125,7 +4094,7 @@ EXPORT_SYMBOL_GPL(spi_async); * spi_async_locked - version of spi_async with exclusive bus usage * @spi: device with which data will be exchanged * @message: describes the data transfers, including completion callback - * Context: any (irqs may be blocked, etc) + * Context: any (IRQs may be blocked, etc) * * This call may be used in_irq and other contexts which can't sleep, * as well as from task contexts which can sleep. @@ -4388,9 +4357,9 @@ static u8 *buf; /** * spi_write_then_read - SPI synchronous write followed by read * @spi: device with which data will be exchanged - * @txbuf: data to be written (need not be dma-safe) + * @txbuf: data to be written (need not be DMA-safe) * @n_tx: size of txbuf, in bytes - * @rxbuf: buffer into which data will be read (need not be dma-safe) + * @rxbuf: buffer into which data will be read (need not be DMA-safe) * @n_rx: size of rxbuf, in bytes * Context: can sleep * @@ -4401,7 +4370,7 @@ static u8 *buf; * * Parameters to this routine are always copied using a small buffer. * Performance-sensitive or bulk transfer code should instead use - * spi_{async,sync}() calls with dma-safe buffers. + * spi_{async,sync}() calls with DMA-safe buffers. * * Return: zero on success, else a negative error code. */ @@ -4446,7 +4415,7 @@ int spi_write_then_read(struct spi_device *spi, x[0].tx_buf = local_buf; x[1].rx_buf = local_buf + n_tx; - /* Do the i/o */ + /* Do the I/O */ status = spi_sync(spi, &message); if (status == 0) memcpy(rxbuf, x[1].rx_buf, n_rx); |