diff options
| -rw-r--r-- | drivers/spi/spi.c | 103 |
1 files changed, 102 insertions, 1 deletions
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 84c2861d6f4d..1ab05234729f 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -35,6 +35,8 @@ #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 +95,10 @@ 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); @@ -888,6 +894,100 @@ 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; @@ -1023,8 +1123,9 @@ 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; } |