diff options
Diffstat (limited to 'drivers/spi/spi.c')
| -rw-r--r-- | drivers/spi/spi.c | 206 |
1 files changed, 182 insertions, 24 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 84c2861d6f4d..ab095acdb2a8 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -30,11 +30,14 @@ #include <linux/slab.h> #include <linux/mod_devicetable.h> #include <linux/spi/spi.h> +#include <linux/of_gpio.h> #include <linux/pm_runtime.h> #include <linux/export.h> #include <linux/sched.h> #include <linux/delay.h> #include <linux/kthread.h> +#include <linux/ioport.h> +#include <linux/acpi.h> static void spidev_release(struct device *dev) { @@ -93,6 +96,10 @@ static int spi_match_device(struct device *dev, struct device_driver *drv) if (of_driver_match_device(dev, drv)) return 1; + /* Then try ACPI */ + if (acpi_driver_match_device(dev, drv)) + return 1; + if (sdrv->id_table) return !!spi_match_id(sdrv->id_table, spi); @@ -327,6 +334,7 @@ struct spi_device *spi_alloc_device(struct spi_master *master) spi->dev.parent = &master->dev; spi->dev.bus = &spi_bus_type; spi->dev.release = spidev_release; + spi->cs_gpio = -EINVAL; device_initialize(&spi->dev); return spi; } @@ -344,15 +352,16 @@ EXPORT_SYMBOL_GPL(spi_alloc_device); int spi_add_device(struct spi_device *spi) { static DEFINE_MUTEX(spi_add_lock); - struct device *dev = spi->master->dev.parent; + struct spi_master *master = spi->master; + struct device *dev = master->dev.parent; struct device *d; int status; /* Chipselects are numbered 0..max; validate. */ - if (spi->chip_select >= spi->master->num_chipselect) { + if (spi->chip_select >= master->num_chipselect) { dev_err(dev, "cs%d >= max %d\n", spi->chip_select, - spi->master->num_chipselect); + master->num_chipselect); return -EINVAL; } @@ -376,6 +385,9 @@ int spi_add_device(struct spi_device *spi) goto done; } + if (master->cs_gpios) + spi->cs_gpio = master->cs_gpios[spi->chip_select]; + /* Drivers may modify this initial i/o setup, but will * normally rely on the device being setup. Devices * using SPI_CS_HIGH can't coexist well otherwise... @@ -486,8 +498,7 @@ static void spi_match_master_to_boardinfo(struct spi_master *master, * The board info passed can safely be __initdata ... but be careful of * any embedded pointers (platform_data, etc), they're copied as-is. */ -int __devinit -spi_register_board_info(struct spi_board_info const *info, unsigned n) +int spi_register_board_info(struct spi_board_info const *info, unsigned n) { struct boardinfo *bi; int i; @@ -800,7 +811,7 @@ err_init_queue: /*-------------------------------------------------------------------------*/ -#if defined(CONFIG_OF) && !defined(CONFIG_SPARC) +#if defined(CONFIG_OF) /** * of_register_spi_devices() - Register child devices onto the SPI bus * @master: Pointer to spi_master device @@ -819,7 +830,7 @@ static void of_register_spi_devices(struct spi_master *master) if (!master->dev.of_node) return; - for_each_child_of_node(master->dev.of_node, nc) { + for_each_available_child_of_node(master->dev.of_node, nc) { /* Alloc an spi_device */ spi = spi_alloc_device(master); if (!spi) { @@ -855,6 +866,8 @@ static void of_register_spi_devices(struct spi_master *master) spi->mode |= SPI_CPOL; if (of_find_property(nc, "spi-cs-high", NULL)) spi->mode |= SPI_CS_HIGH; + if (of_find_property(nc, "spi-3wire", NULL)) + spi->mode |= SPI_3WIRE; /* Device speed */ prop = of_get_property(nc, "spi-max-frequency", &len); @@ -888,6 +901,100 @@ static void of_register_spi_devices(struct spi_master *master) static void of_register_spi_devices(struct spi_master *master) { } #endif +#ifdef CONFIG_ACPI +static int acpi_spi_add_resource(struct acpi_resource *ares, void *data) +{ + struct spi_device *spi = data; + + if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) { + struct acpi_resource_spi_serialbus *sb; + + sb = &ares->data.spi_serial_bus; + if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_SPI) { + spi->chip_select = sb->device_selection; + spi->max_speed_hz = sb->connection_speed; + + if (sb->clock_phase == ACPI_SPI_SECOND_PHASE) + spi->mode |= SPI_CPHA; + if (sb->clock_polarity == ACPI_SPI_START_HIGH) + spi->mode |= SPI_CPOL; + if (sb->device_polarity == ACPI_SPI_ACTIVE_HIGH) + spi->mode |= SPI_CS_HIGH; + } + } else if (spi->irq < 0) { + struct resource r; + + if (acpi_dev_resource_interrupt(ares, 0, &r)) + spi->irq = r.start; + } + + /* Always tell the ACPI core to skip this resource */ + return 1; +} + +static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level, + void *data, void **return_value) +{ + struct spi_master *master = data; + struct list_head resource_list; + struct acpi_device *adev; + struct spi_device *spi; + int ret; + + if (acpi_bus_get_device(handle, &adev)) + return AE_OK; + if (acpi_bus_get_status(adev) || !adev->status.present) + return AE_OK; + + spi = spi_alloc_device(master); + if (!spi) { + dev_err(&master->dev, "failed to allocate SPI device for %s\n", + dev_name(&adev->dev)); + return AE_NO_MEMORY; + } + + ACPI_HANDLE_SET(&spi->dev, handle); + spi->irq = -1; + + INIT_LIST_HEAD(&resource_list); + ret = acpi_dev_get_resources(adev, &resource_list, + acpi_spi_add_resource, spi); + acpi_dev_free_resource_list(&resource_list); + + if (ret < 0 || !spi->max_speed_hz) { + spi_dev_put(spi); + return AE_OK; + } + + strlcpy(spi->modalias, dev_name(&adev->dev), sizeof(spi->modalias)); + if (spi_add_device(spi)) { + dev_err(&master->dev, "failed to add SPI device %s from ACPI\n", + dev_name(&adev->dev)); + spi_dev_put(spi); + } + + return AE_OK; +} + +static void acpi_register_spi_devices(struct spi_master *master) +{ + acpi_status status; + acpi_handle handle; + + handle = ACPI_HANDLE(&master->dev); + if (!handle) + return; + + status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1, + acpi_spi_add_device, NULL, + master, NULL); + if (ACPI_FAILURE(status)) + dev_warn(&master->dev, "failed to enumerate SPI slaves\n"); +} +#else +static inline void acpi_register_spi_devices(struct spi_master *master) {} +#endif /* CONFIG_ACPI */ + static void spi_master_release(struct device *dev) { struct spi_master *master; @@ -946,6 +1053,44 @@ struct spi_master *spi_alloc_master(struct device *dev, unsigned size) } EXPORT_SYMBOL_GPL(spi_alloc_master); +#ifdef CONFIG_OF +static int of_spi_register_master(struct spi_master *master) +{ + u16 nb; + int i, *cs; + struct device_node *np = master->dev.of_node; + + if (!np) + return 0; + + nb = of_gpio_named_count(np, "cs-gpios"); + master->num_chipselect = max(nb, master->num_chipselect); + + if (nb < 1) + return 0; + + cs = devm_kzalloc(&master->dev, + sizeof(int) * master->num_chipselect, + GFP_KERNEL); + master->cs_gpios = cs; + + if (!master->cs_gpios) + return -ENOMEM; + + memset(cs, -EINVAL, master->num_chipselect); + + for (i = 0; i < nb; i++) + cs[i] = of_get_named_gpio(np, "cs-gpios", i); + + return 0; +} +#else +static int of_spi_register_master(struct spi_master *master) +{ + return 0; +} +#endif + /** * spi_register_master - register SPI master controller * @master: initialized master, originally from spi_alloc_master() @@ -977,6 +1122,10 @@ int spi_register_master(struct spi_master *master) if (!dev) return -ENODEV; + status = of_spi_register_master(master); + if (status) + return status; + /* even if it's just one always-selected device, there must * be at least one chipselect */ @@ -1023,8 +1172,9 @@ int spi_register_master(struct spi_master *master) spi_match_master_to_boardinfo(master, &bi->board_info); mutex_unlock(&board_lock); - /* Register devices from the device tree */ + /* Register devices from the device tree and ACPI */ of_register_spi_devices(master); + acpi_register_spi_devices(master); done: return status; } @@ -1156,7 +1306,7 @@ EXPORT_SYMBOL_GPL(spi_busnum_to_master); int spi_setup(struct spi_device *spi) { unsigned bad_bits; - int status; + int status = 0; /* help drivers fail *cleanly* when they need options * that aren't supported with their current master @@ -1171,7 +1321,8 @@ int spi_setup(struct spi_device *spi) if (!spi->bits_per_word) spi->bits_per_word = 8; - status = spi->master->setup(spi); + if (spi->master->setup) + status = spi->master->setup(spi); dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s" "%u bits/w, %u Hz max --> %d\n", @@ -1190,6 +1341,7 @@ EXPORT_SYMBOL_GPL(spi_setup); static int __spi_async(struct spi_device *spi, struct spi_message *message) { struct spi_master *master = spi->master; + struct spi_transfer *xfer; /* Half-duplex links include original MicroWire, and ones with * only one data pin like SPI_3WIRE (switches direction) or where @@ -1198,7 +1350,6 @@ static int __spi_async(struct spi_device *spi, struct spi_message *message) */ if ((master->flags & SPI_MASTER_HALF_DUPLEX) || (spi->mode & SPI_3WIRE)) { - struct spi_transfer *xfer; unsigned flags = master->flags; list_for_each_entry(xfer, &message->transfers, transfer_list) { @@ -1211,6 +1362,15 @@ static int __spi_async(struct spi_device *spi, struct spi_message *message) } } + /** + * Set transfer bits_per_word as spi device default if it is not + * set for this transfer. + */ + list_for_each_entry(xfer, &message->transfers, transfer_list) { + if (!xfer->bits_per_word) + xfer->bits_per_word = spi->bits_per_word; + } + message->spi = spi; message->status = -EINPROGRESS; return master->transfer(spi, message); @@ -1487,12 +1647,18 @@ int spi_write_then_read(struct spi_device *spi, struct spi_transfer x[2]; u8 *local_buf; - /* Use preallocated DMA-safe buffer. We can't avoid copying here, - * (as a pure convenience thing), but we can keep heap costs - * out of the hot path ... + /* Use preallocated DMA-safe buffer if we can. We can't avoid + * copying here, (as a pure convenience thing), but we can + * keep heap costs out of the hot path unless someone else is + * using the pre-allocated buffer or the transfer is too large. */ - if ((n_tx + n_rx) > SPI_BUFSIZ) - return -EINVAL; + if ((n_tx + n_rx) > SPI_BUFSIZ || !mutex_trylock(&lock)) { + local_buf = kmalloc(max((unsigned)SPI_BUFSIZ, n_tx + n_rx), GFP_KERNEL); + if (!local_buf) + return -ENOMEM; + } else { + local_buf = buf; + } spi_message_init(&message); memset(x, 0, sizeof x); @@ -1505,14 +1671,6 @@ int spi_write_then_read(struct spi_device *spi, spi_message_add_tail(&x[1], &message); } - /* ... unless someone else is using the pre-allocated buffer */ - if (!mutex_trylock(&lock)) { - local_buf = kmalloc(SPI_BUFSIZ, GFP_KERNEL); - if (!local_buf) - return -ENOMEM; - } else - local_buf = buf; - memcpy(local_buf, txbuf, n_tx); x[0].tx_buf = local_buf; x[1].rx_buf = local_buf + n_tx; |