diff options
| -rw-r--r-- | Documentation/devicetree/bindings/dma/dma.txt | 28 | ||||
| -rw-r--r-- | drivers/dma/dmaengine.c | 7 | ||||
| -rw-r--r-- | drivers/dma/of-dma.c | 89 | ||||
| -rw-r--r-- | include/linux/dmaengine.h | 17 | ||||
| -rw-r--r-- | include/linux/of_dma.h | 21 |
5 files changed, 162 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/dma/dma.txt b/Documentation/devicetree/bindings/dma/dma.txt index 82104271e754..6312fb00ce8d 100644 --- a/Documentation/devicetree/bindings/dma/dma.txt +++ b/Documentation/devicetree/bindings/dma/dma.txt @@ -31,6 +31,34 @@ Example: dma-requests = <127>; }; +* DMA router + +DMA routers are transparent IP blocks used to route DMA request lines from +devices to the DMA controller. Some SoCs (like TI DRA7x) have more peripherals +integrated with DMA requests than what the DMA controller can handle directly. + +Required property: +- dma-masters: phandle of the DMA controller or list of phandles for + the DMA controllers the router can direct the signal to. +- #dma-cells: Must be at least 1. Used to provide DMA router specific + information. See DMA client binding below for more + details. + +Optional properties: +- dma-requests: Number of incoming request lines the router can handle. +- In the node pointed by the dma-masters: + - dma-requests: The router driver might need to look for this in order + to configure the routing. + +Example: + sdma_xbar: dma-router@4a002b78 { + compatible = "ti,dra7-dma-crossbar"; + reg = <0x4a002b78 0xfc>; + #dma-cells = <1>; + dma-requests = <205>; + ti,dma-safe-map = <0>; + dma-masters = <&sdma>; + }; * DMA client diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c index 0e035a8cf401..9e5949696b1b 100644 --- a/drivers/dma/dmaengine.c +++ b/drivers/dma/dmaengine.c @@ -267,6 +267,13 @@ static void dma_chan_put(struct dma_chan *chan) /* This channel is not in use anymore, free it */ if (!chan->client_count && chan->device->device_free_chan_resources) chan->device->device_free_chan_resources(chan); + + /* If the channel is used via a DMA request router, free the mapping */ + if (chan->router && chan->router->route_free) { + chan->router->route_free(chan->router->dev, chan->route_data); + chan->router = NULL; + chan->route_data = NULL; + } } enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie) diff --git a/drivers/dma/of-dma.c b/drivers/dma/of-dma.c index cbd4a8aff120..1e1f2986eba8 100644 --- a/drivers/dma/of-dma.c +++ b/drivers/dma/of-dma.c @@ -45,6 +45,50 @@ static struct of_dma *of_dma_find_controller(struct of_phandle_args *dma_spec) } /** + * of_dma_router_xlate - translation function for router devices + * @dma_spec: pointer to DMA specifier as found in the device tree + * @of_dma: pointer to DMA controller data (router information) + * + * The function creates new dma_spec to be passed to the router driver's + * of_dma_route_allocate() function to prepare a dma_spec which will be used + * to request channel from the real DMA controller. + */ +static struct dma_chan *of_dma_router_xlate(struct of_phandle_args *dma_spec, + struct of_dma *ofdma) +{ + struct dma_chan *chan; + struct of_dma *ofdma_target; + struct of_phandle_args dma_spec_target; + void *route_data; + + /* translate the request for the real DMA controller */ + memcpy(&dma_spec_target, dma_spec, sizeof(dma_spec_target)); + route_data = ofdma->of_dma_route_allocate(&dma_spec_target, ofdma); + if (IS_ERR(route_data)) + return NULL; + + ofdma_target = of_dma_find_controller(&dma_spec_target); + if (!ofdma_target) + return NULL; + + chan = ofdma_target->of_dma_xlate(&dma_spec_target, ofdma_target); + if (chan) { + chan->router = ofdma->dma_router; + chan->route_data = route_data; + } else { + ofdma->dma_router->route_free(ofdma->dma_router->dev, + route_data); + } + + /* + * Need to put the node back since the ofdma->of_dma_route_allocate + * has taken it for generating the new, translated dma_spec + */ + of_node_put(dma_spec_target.np); + return chan; +} + +/** * of_dma_controller_register - Register a DMA controller to DT DMA helpers * @np: device node of DMA controller * @of_dma_xlate: translation function which converts a phandle @@ -110,6 +154,51 @@ void of_dma_controller_free(struct device_node *np) EXPORT_SYMBOL_GPL(of_dma_controller_free); /** + * of_dma_router_register - Register a DMA router to DT DMA helpers as a + * controller + * @np: device node of DMA router + * @of_dma_route_allocate: setup function for the router which need to + * modify the dma_spec for the DMA controller to + * use and to set up the requested route. + * @dma_router: pointer to dma_router structure to be used when + * the route need to be free up. + * + * Returns 0 on success or appropriate errno value on error. + * + * Allocated memory should be freed with appropriate of_dma_controller_free() + * call. + */ +int of_dma_router_register(struct device_node *np, + void *(*of_dma_route_allocate) + (struct of_phandle_args *, struct of_dma *), + struct dma_router *dma_router) +{ + struct of_dma *ofdma; + + if (!np || !of_dma_route_allocate || !dma_router) { + pr_err("%s: not enough information provided\n", __func__); + return -EINVAL; + } + + ofdma = kzalloc(sizeof(*ofdma), GFP_KERNEL); + if (!ofdma) + return -ENOMEM; + + ofdma->of_node = np; + ofdma->of_dma_xlate = of_dma_router_xlate; + ofdma->of_dma_route_allocate = of_dma_route_allocate; + ofdma->dma_router = dma_router; + + /* Now queue of_dma controller structure in list */ + mutex_lock(&of_dma_lock); + list_add_tail(&ofdma->of_dma_controllers, &of_dma_list); + mutex_unlock(&of_dma_lock); + + return 0; +} +EXPORT_SYMBOL_GPL(of_dma_router_register); + +/** * of_dma_match_channel - Check if a DMA specifier matches name * @np: device node to look for DMA channels * @name: channel name to be matched diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h index ad419757241f..abf63ceabef9 100644 --- a/include/linux/dmaengine.h +++ b/include/linux/dmaengine.h @@ -222,6 +222,16 @@ struct dma_chan_percpu { }; /** + * struct dma_router - DMA router structure + * @dev: pointer to the DMA router device + * @route_free: function to be called when the route can be disconnected + */ +struct dma_router { + struct device *dev; + void (*route_free)(struct device *dev, void *route_data); +}; + +/** * struct dma_chan - devices supply DMA channels, clients use them * @device: ptr to the dma device who supplies this channel, always !%NULL * @cookie: last cookie value returned to client @@ -232,6 +242,8 @@ struct dma_chan_percpu { * @local: per-cpu pointer to a struct dma_chan_percpu * @client_count: how many clients are using this channel * @table_count: number of appearances in the mem-to-mem allocation table + * @router: pointer to the DMA router structure + * @route_data: channel specific data for the router * @private: private data for certain client-channel associations */ struct dma_chan { @@ -247,6 +259,11 @@ struct dma_chan { struct dma_chan_percpu __percpu *local; int client_count; int table_count; + + /* DMA router */ + struct dma_router *router; + void *route_data; + void *private; }; diff --git a/include/linux/of_dma.h b/include/linux/of_dma.h index 56bc026c143f..98ba7525929e 100644 --- a/include/linux/of_dma.h +++ b/include/linux/of_dma.h @@ -23,6 +23,9 @@ struct of_dma { struct device_node *of_node; struct dma_chan *(*of_dma_xlate) (struct of_phandle_args *, struct of_dma *); + void *(*of_dma_route_allocate) + (struct of_phandle_args *, struct of_dma *); + struct dma_router *dma_router; void *of_dma_data; }; @@ -37,12 +40,20 @@ extern int of_dma_controller_register(struct device_node *np, (struct of_phandle_args *, struct of_dma *), void *data); extern void of_dma_controller_free(struct device_node *np); + +extern int of_dma_router_register(struct device_node *np, + void *(*of_dma_route_allocate) + (struct of_phandle_args *, struct of_dma *), + struct dma_router *dma_router); +#define of_dma_router_free of_dma_controller_free + extern struct dma_chan *of_dma_request_slave_channel(struct device_node *np, const char *name); extern struct dma_chan *of_dma_simple_xlate(struct of_phandle_args *dma_spec, struct of_dma *ofdma); extern struct dma_chan *of_dma_xlate_by_chan_id(struct of_phandle_args *dma_spec, struct of_dma *ofdma); + #else static inline int of_dma_controller_register(struct device_node *np, struct dma_chan *(*of_dma_xlate) @@ -56,6 +67,16 @@ static inline void of_dma_controller_free(struct device_node *np) { } +static inline int of_dma_router_register(struct device_node *np, + void *(*of_dma_route_allocate) + (struct of_phandle_args *, struct of_dma *), + struct dma_router *dma_router) +{ + return -ENODEV; +} + +#define of_dma_router_free of_dma_controller_free + static inline struct dma_chan *of_dma_request_slave_channel(struct device_node *np, const char *name) { |