5  * This file implements a DMA  interface using TI's CPPI DMA.
6  * For now it's DaVinci-only, but CPPI isn't specific to DaVinci or USB.
7  * The TUSB6020, using VLYNQ, has CPPI that looks much like DaVinci.
21 /* CPPI DMA status 7-mar-2006:
37  * REVISIT:  the "transfer DMA" glue between CPPI and USB fifos will
110 static void cppi_pool_init(struct cppi *cppi, struct cppi_channel *c)  in cppi_pool_init()  argument
119 	c->controller = cppi;  in cppi_pool_init()
128 		bd = dma_pool_alloc(cppi->pool, GFP_KERNEL, &dma);  in cppi_pool_init()
138 	struct cppi		*cppi = c->controller;  in cppi_pool_free()  local
149 			dma_pool_free(cppi->pool, bd, bd->dma);  in cppi_pool_free()
155 static void cppi_controller_start(struct cppi *controller)  in cppi_controller_start()
201 	/* enable individual cppi channels */  in cppi_controller_start()
207 	/* enable tx/rx CPPI control */  in cppi_controller_start()
222 static void cppi_controller_stop(struct cppi *controller)  in cppi_controller_stop()
247 	 * Tx/Rx CPPI after cleanup of Tx channels. Before TX teardown is  in cppi_controller_stop()
248 	 * complete TX CPPI cannot be disabled.  in cppi_controller_stop()
250 	/*disable tx/rx cppi */  in cppi_controller_stop()
261  * REVISIT same issue applies to pure PIO usage too, and non-cppi dma...
275  * Allocate a CPPI Channel for DMA.  With CPPI, channels are bound to
284 	struct cppi		*controller;  in cppi_channel_allocate()
290 	controller = container_of(c, struct cppi, controller);  in cppi_channel_allocate()
294 	/* ep0 doesn't use DMA; remember cppi indices are 0..N-1 */  in cppi_channel_allocate()
297 	/* return the corresponding CPPI Channel Handle, and  in cppi_channel_allocate()
298 	 * probably disable the non-CPPI irq until we need it.  in cppi_channel_allocate()
302 			musb_dbg(musb, "no %cX%d CPPI channel", 'T', index);  in cppi_channel_allocate()
308 			musb_dbg(musb, "no %cX%d CPPI channel", 'R', index);  in cppi_channel_allocate()
325 	musb_dbg(musb, "Allocate CPPI%d %cX", index, transmit ? 'T' : 'R');  in cppi_channel_allocate()
329 /* Release a CPPI Channel.  */
345 	/* for now, leave its cppi IRQ enabled (we won't trigger it) */  in cppi_channel_release()
413 	/* we may need to change the rndis flag for this cppi channel */  in cppi_rndis_update()
451  * so we won't ever use it (see "CPPI RX Woes" below).
528  * That's true even in the CPPI- friendly iso case, where most urbs have
534  * CPPI TX:
545  * written?) boiling down to not being able to rely on CPPI writing any
556  * REVISIT try to handle terminating zero length packets using CPPI
572 	/* TX can use the CPPI "rndis" mode, where we can probably fit this  in cppi_next_tx_segment()
670  * CPPI RX Woes:
678  * the buffer with 1024 bytes.  How to do that with CPPI?
689  *   converse problems:  (b) is handled right, but (a) loses badly.  CPPI RX
706  * But there seems to be no way to identify the cases where CPPI RNDIS mode
714  * since CPPI penalizes our need for a "true RNDIS" default mode.
727  *	- less than 64KB (max per cppi descriptor)
952 	struct cppi		*controller;  in cppi_channel_program()
1001 static bool cppi_rx_scan(struct cppi *cppi, unsigned ch)  in cppi_rx_scan()  argument
1003 	struct cppi_channel		*rx = &cppi->rx[ch];  in cppi_rx_scan()
1012 	struct musb			*musb = cppi->controller.musb;  in cppi_rx_scan()
1026 		/* catch latest BD writes from CPPI */  in cppi_rx_scan()
1050 			 * CPPI ignores those BDs even though OWN is still set.  in cppi_rx_scan()
1059 		 * CPPI may completing other BDs while we scan this list...  in cppi_rx_scan()
1061 		 * RACE: we can notice OWN cleared before CPPI raises the  in cppi_rx_scan()
1100 		musb_ep_select(cppi->mregs, rx->index + 1);  in cppi_rx_scan()
1124 		if (is_host_active(cppi->controller.musb)  in cppi_rx_scan()
1144 	struct cppi		*cppi;  in cppi_interrupt()  local
1151 	cppi = container_of(musb->dma_controller, struct cppi, controller);  in cppi_interrupt()
1152 	if (cppi->irq)  in cppi_interrupt()
1161 		if (cppi->irq)  in cppi_interrupt()
1166 	musb_dbg(musb, "CPPI IRQ Tx%x Rx%x", tx, rx);  in cppi_interrupt()
1178 		tx_ch = cppi->tx + index;  in cppi_interrupt()
1204 			/* catch latest BD writes from CPPI */  in cppi_interrupt()
1264 			rx_ch = cppi->rx + index;  in cppi_interrupt()
1267 			if (!cppi_rx_scan(cppi, index))  in cppi_interrupt()
1288 	/* write to CPPI EOI register to re-enable interrupts */  in cppi_interrupt()
1291 	if (cppi->irq)  in cppi_interrupt()
1302 	struct cppi		*controller;  in cppi_dma_controller_create()
1325 	controller->pool = dma_pool_create("cppi",  in cppi_dma_controller_create()
1335 		if (request_irq(irq, cppi_interrupt, 0, "cppi-dma", musb)) {  in cppi_dma_controller_create()
1353 	struct cppi	*cppi;  in cppi_dma_controller_destroy()  local
1355 	cppi = container_of(c, struct cppi, controller);  in cppi_dma_controller_destroy()
1357 	cppi_controller_stop(cppi);  in cppi_dma_controller_destroy()
1359 	if (cppi->irq)  in cppi_dma_controller_destroy()
1360 		free_irq(cppi->irq, cppi->controller.musb);  in cppi_dma_controller_destroy()
1363 	dma_pool_destroy(cppi->pool);  in cppi_dma_controller_destroy()
1365 	kfree(cppi);  in cppi_dma_controller_destroy()
1375 	struct cppi		*controller;  in cppi_channel_abort()
1464 		 * expect that if the usb core stops telling the cppi core  in cppi_channel_abort()
1518 		/* next DMA request _should_ load cppi head ptr */  in cppi_channel_abort()
1545  * Power Management ... probably turn off cppi during suspend, restart;