diff options
Diffstat (limited to 'drivers/dma/acpi-dma.c')
| -rw-r--r-- | drivers/dma/acpi-dma.c | 53 |
1 files changed, 32 insertions, 21 deletions
diff --git a/drivers/dma/acpi-dma.c b/drivers/dma/acpi-dma.c index 5a18f82f732..de361a156b3 100644 --- a/drivers/dma/acpi-dma.c +++ b/drivers/dma/acpi-dma.c @@ -13,6 +13,7 @@ */ #include <linux/device.h> +#include <linux/err.h> #include <linux/module.h> #include <linux/list.h> #include <linux/mutex.h> @@ -30,11 +31,12 @@ static DEFINE_MUTEX(acpi_dma_lock); * @adev: ACPI device to match with * @adma: struct acpi_dma of the given DMA controller * - * Returns 1 on success, 0 when no information is available, or appropriate - * errno value on error. - * * In order to match a device from DSDT table to the corresponding CSRT device * we use MMIO address and IRQ. + * + * Return: + * 1 on success, 0 when no information is available, or appropriate errno value + * on error. */ static int acpi_dma_parse_resource_group(const struct acpi_csrt_group *grp, struct acpi_device *adev, struct acpi_dma *adma) @@ -43,7 +45,6 @@ static int acpi_dma_parse_resource_group(const struct acpi_csrt_group *grp, struct list_head resource_list; struct resource_list_entry *rentry; resource_size_t mem = 0, irq = 0; - u32 vendor_id; int ret; if (grp->shared_info_length != sizeof(struct acpi_csrt_shared_info)) @@ -73,9 +74,8 @@ static int acpi_dma_parse_resource_group(const struct acpi_csrt_group *grp, if (si->mmio_base_low != mem || si->gsi_interrupt != irq) return 0; - vendor_id = le32_to_cpu(grp->vendor_id); dev_dbg(&adev->dev, "matches with %.4s%04X (rev %u)\n", - (char *)&vendor_id, grp->device_id, grp->revision); + (char *)&grp->vendor_id, grp->device_id, grp->revision); /* Check if the request line range is available */ if (si->base_request_line == 0 && si->num_handshake_signals == 0) @@ -103,7 +103,6 @@ static int acpi_dma_parse_resource_group(const struct acpi_csrt_group *grp, * * We are using this table to get the request line range of the specific DMA * controller to be used later. - * */ static void acpi_dma_parse_csrt(struct acpi_device *adev, struct acpi_dma *adma) { @@ -143,10 +142,11 @@ static void acpi_dma_parse_csrt(struct acpi_device *adev, struct acpi_dma *adma) * @data pointer to controller specific data to be used by * translation function * - * Returns 0 on success or appropriate errno value on error. - * * Allocated memory should be freed with appropriate acpi_dma_controller_free() * call. + * + * Return: + * 0 on success or appropriate errno value on error. */ int acpi_dma_controller_register(struct device *dev, struct dma_chan *(*acpi_dma_xlate) @@ -190,6 +190,9 @@ EXPORT_SYMBOL_GPL(acpi_dma_controller_register); * @dev: struct device of DMA controller * * Memory allocated by acpi_dma_controller_register() is freed here. + * + * Return: + * 0 on success or appropriate errno value on error. */ int acpi_dma_controller_free(struct device *dev) { @@ -227,6 +230,9 @@ static void devm_acpi_dma_release(struct device *dev, void *res) * Managed acpi_dma_controller_register(). DMA controller registered by this * function are automatically freed on driver detach. See * acpi_dma_controller_register() for more information. + * + * Return: + * 0 on success or appropriate errno value on error. */ int devm_acpi_dma_controller_register(struct device *dev, struct dma_chan *(*acpi_dma_xlate) @@ -260,7 +266,7 @@ EXPORT_SYMBOL_GPL(devm_acpi_dma_controller_register); */ void devm_acpi_dma_controller_free(struct device *dev) { - WARN_ON(devres_destroy(dev, devm_acpi_dma_release, NULL, NULL)); + WARN_ON(devres_release(dev, devm_acpi_dma_release, NULL, NULL)); } EXPORT_SYMBOL_GPL(devm_acpi_dma_controller_free); @@ -269,8 +275,6 @@ EXPORT_SYMBOL_GPL(devm_acpi_dma_controller_free); * @adma: struct acpi_dma of DMA controller * @dma_spec: dma specifier to update * - * Returns 0, if no information is avaiable, -1 on mismatch, and 1 otherwise. - * * Accordingly to ACPI 5.0 Specification Table 6-170 "Fixed DMA Resource * Descriptor": * DMA Request Line bits is a platform-relative number uniquely @@ -278,6 +282,9 @@ EXPORT_SYMBOL_GPL(devm_acpi_dma_controller_free); * mapping is done in a controller-specific OS driver. * That's why we can safely adjust slave_id when the appropriate controller is * found. + * + * Return: + * 0, if no information is avaiable, -1 on mismatch, and 1 otherwise. */ static int acpi_dma_update_dma_spec(struct acpi_dma *adma, struct acpi_dma_spec *dma_spec) @@ -336,7 +343,8 @@ static int acpi_dma_parse_fixed_dma(struct acpi_resource *res, void *data) * @dev: struct device to get DMA request from * @index: index of FixedDMA descriptor for @dev * - * Returns pointer to appropriate dma channel on success or NULL on error. + * Return: + * Pointer to appropriate dma channel on success or an error pointer. */ struct dma_chan *acpi_dma_request_slave_chan_by_index(struct device *dev, size_t index) @@ -351,10 +359,10 @@ struct dma_chan *acpi_dma_request_slave_chan_by_index(struct device *dev, /* Check if the device was enumerated by ACPI */ if (!dev || !ACPI_HANDLE(dev)) - return NULL; + return ERR_PTR(-ENODEV); if (acpi_bus_get_device(ACPI_HANDLE(dev), &adev)) - return NULL; + return ERR_PTR(-ENODEV); memset(&pdata, 0, sizeof(pdata)); pdata.index = index; @@ -369,7 +377,7 @@ struct dma_chan *acpi_dma_request_slave_chan_by_index(struct device *dev, acpi_dev_free_resource_list(&resource_list); if (dma_spec->slave_id < 0 || dma_spec->chan_id < 0) - return NULL; + return ERR_PTR(-ENODEV); mutex_lock(&acpi_dma_lock); @@ -392,7 +400,7 @@ struct dma_chan *acpi_dma_request_slave_chan_by_index(struct device *dev, } mutex_unlock(&acpi_dma_lock); - return chan; + return chan ? chan : ERR_PTR(-EPROBE_DEFER); } EXPORT_SYMBOL_GPL(acpi_dma_request_slave_chan_by_index); @@ -405,7 +413,8 @@ EXPORT_SYMBOL_GPL(acpi_dma_request_slave_chan_by_index); * translate the names "tx" and "rx" here based on the most common case where * the first FixedDMA descriptor is TX and second is RX. * - * Returns pointer to appropriate dma channel on success or NULL on error. + * Return: + * Pointer to appropriate dma channel on success or an error pointer. */ struct dma_chan *acpi_dma_request_slave_chan_by_name(struct device *dev, const char *name) @@ -417,7 +426,7 @@ struct dma_chan *acpi_dma_request_slave_chan_by_name(struct device *dev, else if (!strcmp(name, "rx")) index = 1; else - return NULL; + return ERR_PTR(-ENODEV); return acpi_dma_request_slave_chan_by_index(dev, index); } @@ -429,8 +438,10 @@ EXPORT_SYMBOL_GPL(acpi_dma_request_slave_chan_by_name); * @adma: pointer to ACPI DMA controller data * * A simple translation function for ACPI based devices. Passes &struct - * dma_spec to the DMA controller driver provided filter function. Returns - * pointer to the channel if found or %NULL otherwise. + * dma_spec to the DMA controller driver provided filter function. + * + * Return: + * Pointer to the channel if found or %NULL otherwise. */ struct dma_chan *acpi_dma_simple_xlate(struct acpi_dma_spec *dma_spec, struct acpi_dma *adma) |