[11/31] dma: add channel request API that supports deferred probe

Message ID	1384548866-13141-12-git-send-email-swarren@wwwdotorg.org (mailing list archive)
State	New, archived
Headers	show Return-Path: <linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org> From: Stephen Warren <swarren@wwwdotorg.org> To: swarren@wwwdotorg.org Subject: [PATCH 11/31] dma: add channel request API that supports deferred probe Date: Fri, 15 Nov 2013 13:54:06 -0700 Message-Id: <1384548866-13141-12-git-send-email-swarren@wwwdotorg.org> In-Reply-To: <1384548866-13141-1-git-send-email-swarren@wwwdotorg.org> References: <1384548866-13141-1-git-send-email-swarren@wwwdotorg.org> Cc: Stephen Warren <swarren@nvidia.com>, pdeschrijver@nvidia.com, linux-tegra@vger.kernel.org, Dan Williams <dan.j.williams@intel.com>, treding@nvidia.com, linux-arm-kernel@lists.infradead.org Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" <linux-arm-kernel-bounces@lists.infradead.org> Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org

diff --git a/drivers/dma/acpi-dma.c b/drivers/dma/acpi-dma.c index e69b03c0fa50..c83d40f14467 100644 --- a/drivers/dma/acpi-dma.c +++ b/drivers/dma/acpi-dma.c @@ -334,7 +334,7 @@ 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. + * Returns 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) @@ -349,10 +349,10 @@ 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; @@ -367,7 +367,7 @@ 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); @@ -403,7 +403,7 @@ 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. + * Returns 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) @@ -415,7 +415,7 @@ 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); } diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c index ea806bdc12ef..5e7f8af2f0ec 100644 --- a/drivers/dma/dmaengine.c +++ b/drivers/dma/dmaengine.c @@ -540,6 +540,8 @@ EXPORT_SYMBOL_GPL(dma_get_slave_channel); * @mask: capabilities that the channel must satisfy * @fn: optional callback to disposition available channels * @fn_param: opaque parameter to pass to dma_filter_fn + * + * Returns pointer to appropriate dma channel on success or NULL. */ struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask, dma_filter_fn fn, void *fn_param) @@ -588,24 +590,58 @@ struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask, EXPORT_SYMBOL_GPL(__dma_request_channel); /** - * dma_request_slave_channel - try to allocate an exclusive slave channel + * __dma_request_slave_channel - try to allocate an exclusive slave + * channel * @dev: pointer to client device structure * @name: slave channel name + * + * Returns pointer to appropriate dma channel on success or an error pointer. */ -struct dma_chan *dma_request_slave_channel(struct device *dev, const char *name) +static struct dma_chan *__dma_request_slave_channel(struct device *dev, + const char *name, bool defer) { /* If device-tree is present get slave info from here */ if (dev->of_node) - return of_dma_request_slave_channel(dev->of_node, name); + return of_dma_request_slave_channel(dev->of_node, name, defer); /* If device was enumerated by ACPI get slave info from here */ if (ACPI_HANDLE(dev)) return acpi_dma_request_slave_chan_by_name(dev, name); - return NULL; + return ERR_PTR(-ENODEV); +} + +/** + * dma_request_slave_channel - try to allocate an exclusive slave channel + * @dev: pointer to client device structure + * @name: slave channel name + * + * Returns pointer to appropriate dma channel on success or NULL. + */ +struct dma_chan *dma_request_slave_channel(struct device *dev, + const char *name) +{ + struct dma_chan *ch = __dma_request_slave_channel(dev, name, false); + if (IS_ERR(ch)) + return NULL; + return ch; } EXPORT_SYMBOL_GPL(dma_request_slave_channel); +/** + * dma_request_slave_channel_or_err - try to allocate an exclusive slave channel + * @dev: pointer to client device structure + * @name: slave channel name + * + * Returns pointer to appropriate dma channel on success or an error pointer. + */ +struct dma_chan *dma_request_slave_channel_or_err(struct device *dev, + const char *name) +{ + return __dma_request_slave_channel(dev, name, true); +} +EXPORT_SYMBOL_GPL(dma_request_slave_channel_or_err); + void dma_release_channel(struct dma_chan *chan) { mutex_lock(&dma_list_mutex); diff --git a/drivers/dma/of-dma.c b/drivers/dma/of-dma.c index 0b88dd3d05f4..928141f6f21b 100644 --- a/drivers/dma/of-dma.c +++ b/drivers/dma/of-dma.c @@ -143,10 +143,10 @@ static int of_dma_match_channel(struct device_node *np, const char *name, * @np: device node to get DMA request from * @name: name of desired channel * - * Returns pointer to appropriate dma channel on success or NULL on error. + * Returns pointer to appropriate dma channel on success or an error pointer. */ struct dma_chan *of_dma_request_slave_channel(struct device_node *np, - const char *name) + const char *name, bool defer) { struct of_phandle_args dma_spec; struct of_dma *ofdma; @@ -155,14 +155,14 @@ struct dma_chan *of_dma_request_slave_channel(struct device_node *np, if (!np || !name) { pr_err("%s: not enough information provided\n", __func__); - return NULL; + return ERR_PTR(-ENODEV); } count = of_property_count_strings(np, "dma-names"); if (count < 0) { pr_err("%s: dma-names property of node '%s' missing or empty\n", __func__, np->full_name); - return NULL; + return ERR_PTR(-ENODEV); } for (i = 0; i < count; i++) { @@ -181,11 +181,13 @@ struct dma_chan *of_dma_request_slave_channel(struct device_node *np, of_node_put(dma_spec.np); + if (!ofdma && defer) + return ERR_PTR(-EPROBE_DEFER); if (chan) return chan; } - return NULL; + return ERR_PTR(-ENODEV); } /** diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h index 41cf0c399288..b908b0fda72b 100644 --- a/include/linux/dmaengine.h +++ b/include/linux/dmaengine.h @@ -1041,6 +1041,8 @@ void dma_issue_pending_all(void); struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask, dma_filter_fn fn, void *fn_param); struct dma_chan *dma_request_slave_channel(struct device *dev, const char *name); +struct dma_chan *dma_request_slave_channel_or_err(struct device *dev, + const char *name); void dma_release_channel(struct dma_chan *chan); #else static inline struct dma_chan *dma_find_channel(enum dma_transaction_type tx_type) @@ -1068,6 +1070,11 @@ static inline struct dma_chan *dma_request_slave_channel(struct device *dev, { return NULL; } +static inline struct dma_chan *dma_request_slave_channel_or_err( + struct device *dev, const char *name) +{ + return ERR_PTR(-ENODEV); +} static inline void dma_release_channel(struct dma_chan *chan) { } diff --git a/include/linux/of_dma.h b/include/linux/of_dma.h index ae36298ba076..0504461574c6 100644 --- a/include/linux/of_dma.h +++ b/include/linux/of_dma.h @@ -38,7 +38,8 @@ extern int of_dma_controller_register(struct device_node *np, void *data); extern void of_dma_controller_free(struct device_node *np); extern struct dma_chan *of_dma_request_slave_channel(struct device_node *np, - const char *name); + const char *name, + bool defer); extern struct dma_chan *of_dma_simple_xlate(struct of_phandle_args *dma_spec, struct of_dma *ofdma); #else @@ -54,8 +55,10 @@ static inline void of_dma_controller_free(struct device_node *np) { } -static inline struct dma_chan *of_dma_request_slave_channel(struct device_node *np, - const char *name) +static inline struct dma_chan *of_dma_request_slave_channel( + struct device_node *np, + const char *name, + bool defer) { return NULL; }

[11/31] dma: add channel request API that supports deferred probe

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