Function ti_sdma_attach

freebsd/arm/ti/ti_sdma.c:1150–1232

* ti_sdma_attach - driver attach function * @dev: dma device handle * * Initialises memory mapping/pointers to the DMA register set and requests * IRQs. This is effectively the setup function for the driver. * * RETURNS: * 0 on success or a negative error code failure. */

 *	0 on success or a negative error code failure.
 */
static int
ti_sdma_attach(device_t dev)
{
	struct ti_sdma_softc *sc = device_get_softc(dev);
	unsigned int timeout;
	unsigned int i;
	int      rid;
	void    *ihl;
	int      err;

	/* Setup the basics */
	sc->sc_dev = dev;

	/* No channels active at the moment */
	sc->sc_active_channels = 0x00000000;

	/* Mutex to protect the shared data structures */
	TI_SDMA_LOCK_INIT(sc);

	/* Get the memory resource for the register mapping */
	rid = 0;
	sc->sc_mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid, RF_ACTIVE);
	if (sc->sc_mem_res == NULL)
		panic("%s: Cannot map registers", device_get_name(dev));

	/* Enable the interface and functional clocks */
	ti_sysc_clock_enable(device_get_parent(dev));

	/* Read the sDMA revision register and sanity check it's known */
	sc->sc_hw_rev = ti_sdma_read_4(sc,
	    ti_sysc_get_rev_address_offset_host(device_get_parent(dev)));
	device_printf(dev, "sDMA revision %08x\n", sc->sc_hw_rev);

	if (!ti_sdma_is_omap4_rev(sc) && !ti_sdma_is_omap3_rev(sc)) {
		device_printf(sc->sc_dev, "error - unknown sDMA H/W revision\n");
		return (EINVAL);
	}

	/* Disable all interrupts */
	for (i = 0; i < NUM_DMA_IRQS; i++) {
		ti_sdma_write_4(sc, DMA4_IRQENABLE_L(i), 0x00000000);
	}

	/* Soft-reset is only supported on pre-OMAP44xx devices */
	if (ti_sdma_is_omap3_rev(sc)) {
		/* Soft-reset */
		ti_sdma_write_4(sc, DMA4_OCP_SYSCONFIG, 0x0002);

		/* Set the timeout to 100ms*/
		timeout = (hz < 10) ? 1 : ((100 * hz) / 1000);

		/* Wait for DMA reset to complete */
		while ((ti_sdma_read_4(sc, DMA4_SYSSTATUS) & 0x1) == 0x0) {
			/* Sleep for a tick */
			pause("DMARESET", 1);

			if (timeout-- == 0) {
				device_printf(sc->sc_dev, "sDMA reset operation timed out\n");