From 7f24467f3b357ab6abc146c47fcedd7d57a189b6 Mon Sep 17 00:00:00 2001 From: Octavian Purdila Date: Fri, 8 Jul 2016 19:13:11 +0300 Subject: [PATCH] spi / ACPI: add support for ACPI reconfigure notifications This patch adds supports for SPI device enumeration and removal via ACPI reconfiguration notifications that are send as a result of an ACPI table load or unload operation. The code is very similar with the device tree reconfiguration code with only small differences in the way we test and set the enumerated state of the device: * the equivalent of device tree's OF_POPULATED flag is the flags.visited field in the ACPI device and the following wrappers are used to manipulate it: acpi_device_enumerated(), acpi_device_set_enumerated() and acpi_device_clear_enumerated() * the device tree code checks of status of the OF_POPULATED flag to avoid trying to create duplicate Linux devices in two places: once when the controller is probed, and once when the reconfigure event is received; in the ACPI code the check is performed only once when the ACPI namespace is searched because this code path is invoked in both of the two mentioned cases The rest of the enumeration handling is similar with device tree: when the Linux device is unregistered the ACPI device is marked as not enumerated; also, when a device remove notification is received we check that the device is in the enumerated state before continuing with the removal of the Linux device. Signed-off-by: Octavian Purdila Reviewed-by: Mika Westerberg Acked-by: Mark Brown Signed-off-by: Rafael J. Wysocki --- drivers/spi/spi.c | 100 ++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 93 insertions(+), 7 deletions(-) diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 77e6e45951f4..7589c8af4368 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -622,6 +622,8 @@ void spi_unregister_device(struct spi_device *spi) if (spi->dev.of_node) of_node_clear_flag(spi->dev.of_node, OF_POPULATED); + if (ACPI_COMPANION(&spi->dev)) + acpi_device_clear_enumerated(ACPI_COMPANION(&spi->dev)); device_unregister(&spi->dev); } EXPORT_SYMBOL_GPL(spi_unregister_device); @@ -1646,18 +1648,15 @@ static int acpi_spi_add_resource(struct acpi_resource *ares, void *data) return 1; } -static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level, - void *data, void **return_value) +static acpi_status acpi_register_spi_device(struct spi_master *master, + struct acpi_device *adev) { - 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) + if (acpi_bus_get_status(adev) || !adev->status.present || + acpi_device_enumerated(adev)) return AE_OK; spi = spi_alloc_device(master); @@ -1683,6 +1682,8 @@ static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level, if (spi->irq < 0) spi->irq = acpi_dev_gpio_irq_get(adev, 0); + acpi_device_set_enumerated(adev); + adev->power.flags.ignore_parent = true; strlcpy(spi->modalias, acpi_device_hid(adev), sizeof(spi->modalias)); if (spi_add_device(spi)) { @@ -1695,6 +1696,18 @@ static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level, return AE_OK; } +static acpi_status acpi_spi_add_device(acpi_handle handle, u32 level, + void *data, void **return_value) +{ + struct spi_master *master = data; + struct acpi_device *adev; + + if (acpi_bus_get_device(handle, &adev)) + return AE_OK; + + return acpi_register_spi_device(master, adev); +} + static void acpi_register_spi_devices(struct spi_master *master) { acpi_status status; @@ -3107,6 +3120,77 @@ static struct notifier_block spi_of_notifier = { extern struct notifier_block spi_of_notifier; #endif /* IS_ENABLED(CONFIG_OF_DYNAMIC) */ +#if IS_ENABLED(CONFIG_ACPI) +static int spi_acpi_master_match(struct device *dev, const void *data) +{ + return ACPI_COMPANION(dev->parent) == data; +} + +static int spi_acpi_device_match(struct device *dev, void *data) +{ + return ACPI_COMPANION(dev) == data; +} + +static struct spi_master *acpi_spi_find_master_by_adev(struct acpi_device *adev) +{ + struct device *dev; + + dev = class_find_device(&spi_master_class, NULL, adev, + spi_acpi_master_match); + if (!dev) + return NULL; + + return container_of(dev, struct spi_master, dev); +} + +static struct spi_device *acpi_spi_find_device_by_adev(struct acpi_device *adev) +{ + struct device *dev; + + dev = bus_find_device(&spi_bus_type, NULL, adev, spi_acpi_device_match); + + return dev ? to_spi_device(dev) : NULL; +} + +static int acpi_spi_notify(struct notifier_block *nb, unsigned long value, + void *arg) +{ + struct acpi_device *adev = arg; + struct spi_master *master; + struct spi_device *spi; + + switch (value) { + case ACPI_RECONFIG_DEVICE_ADD: + master = acpi_spi_find_master_by_adev(adev->parent); + if (!master) + break; + + acpi_register_spi_device(master, adev); + put_device(&master->dev); + break; + case ACPI_RECONFIG_DEVICE_REMOVE: + if (!acpi_device_enumerated(adev)) + break; + + spi = acpi_spi_find_device_by_adev(adev); + if (!spi) + break; + + spi_unregister_device(spi); + put_device(&spi->dev); + break; + } + + return NOTIFY_OK; +} + +static struct notifier_block spi_acpi_notifier = { + .notifier_call = acpi_spi_notify, +}; +#else +extern struct notifier_block spi_acpi_notifier; +#endif + static int __init spi_init(void) { int status; @@ -3127,6 +3211,8 @@ static int __init spi_init(void) if (IS_ENABLED(CONFIG_OF_DYNAMIC)) WARN_ON(of_reconfig_notifier_register(&spi_of_notifier)); + if (IS_ENABLED(CONFIG_ACPI)) + WARN_ON(acpi_reconfig_notifier_register(&spi_acpi_notifier)); return 0; -- 2.20.1