alistair23-linux/drivers/usb/host/ehci-ppc-of.c

// SPDX-License-Identifier: GPL-1.0+
/*
 * EHCI HCD (Host Controller Driver) for USB.
 *
 * Bus Glue for PPC On-Chip EHCI driver on the of_platform bus
 * Tested on AMCC PPC 440EPx
 *
 * Valentine Barshak <vbarshak@ru.mvista.com>
 *
 * Based on "ehci-ppc-soc.c" by Stefan Roese <sr@denx.de>
 * and "ohci-ppc-of.c" by Sylvain Munaut <tnt@246tNt.com>
 *
 * This file is licenced under the GPL.
 */

#include <linux/err.h>
#include <linux/signal.h>

#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/of_platform.h>


static const struct hc_driver ehci_ppc_of_hc_driver = {
	.description		= hcd_name,
	.product_desc		= "OF EHCI",
	.hcd_priv_size		= sizeof(struct ehci_hcd),

	/*
	 * generic hardware linkage
	 */
	.irq			= ehci_irq,
	.flags			= HCD_MEMORY | HCD_DMA | HCD_USB2 | HCD_BH,

	/*
	 * basic lifecycle operations
	 */
	.reset			= ehci_setup,
	.start			= ehci_run,
	.stop			= ehci_stop,
	.shutdown		= ehci_shutdown,

	/*
	 * managing i/o requests and associated device resources
	 */
	.urb_enqueue		= ehci_urb_enqueue,
	.urb_dequeue		= ehci_urb_dequeue,
	.endpoint_disable	= ehci_endpoint_disable,
	.endpoint_reset		= ehci_endpoint_reset,

	/*
	 * scheduling support
	 */
	.get_frame_number	= ehci_get_frame,

	/*
	 * root hub support
	 */
	.hub_status_data	= ehci_hub_status_data,
	.hub_control		= ehci_hub_control,
#ifdef	CONFIG_PM
	.bus_suspend		= ehci_bus_suspend,
	.bus_resume		= ehci_bus_resume,
#endif
	.relinquish_port	= ehci_relinquish_port,
	.port_handed_over	= ehci_port_handed_over,

	.clear_tt_buffer_complete	= ehci_clear_tt_buffer_complete,
};


/*
 * 440EPx Errata USBH_3
 * Fix: Enable Break Memory Transfer (BMT) in INSNREG3
 */
#define PPC440EPX_EHCI0_INSREG_BMT	(0x1 << 0)
static int
ppc44x_enable_bmt(struct device_node *dn)
{
	__iomem u32 *insreg_virt;

	insreg_virt = of_iomap(dn, 1);
	if (!insreg_virt)
		return  -EINVAL;

	out_be32(insreg_virt + 3, PPC440EPX_EHCI0_INSREG_BMT);

	iounmap(insreg_virt);
	return 0;
}


static int ehci_hcd_ppc_of_probe(struct platform_device *op)
{
	struct device_node *dn = op->dev.of_node;
	struct usb_hcd *hcd;
	struct ehci_hcd	*ehci = NULL;
	struct resource res;
	int irq;
	int rv;

	struct device_node *np;

	if (usb_disabled())
		return -ENODEV;

	dev_dbg(&op->dev, "initializing PPC-OF USB Controller\n");

	rv = of_address_to_resource(dn, 0, &res);
	if (rv)
		return rv;

	hcd = usb_create_hcd(&ehci_ppc_of_hc_driver, &op->dev, "PPC-OF USB");
	if (!hcd)
		return -ENOMEM;

	hcd->rsrc_start = res.start;
	hcd->rsrc_len = resource_size(&res);

	irq = irq_of_parse_and_map(dn, 0);
	if (irq == NO_IRQ) {
		dev_err(&op->dev, "%s: irq_of_parse_and_map failed\n",
			__FILE__);
		rv = -EBUSY;
		goto err_irq;
	}

	hcd->regs = devm_ioremap_resource(&op->dev, &res);
	if (IS_ERR(hcd->regs)) {
		rv = PTR_ERR(hcd->regs);
		goto err_ioremap;
	}

	ehci = hcd_to_ehci(hcd);
	np = of_find_compatible_node(NULL, NULL, "ibm,usb-ohci-440epx");
	if (np != NULL) {
		/* claim we really affected by usb23 erratum */
		if (!of_address_to_resource(np, 0, &res))
			ehci->ohci_hcctrl_reg =
				devm_ioremap(&op->dev,
					     res.start + OHCI_HCCTRL_OFFSET,
					     OHCI_HCCTRL_LEN);
		else
			pr_debug("%s: no ohci offset in fdt\n", __FILE__);
		if (!ehci->ohci_hcctrl_reg) {
			pr_debug("%s: ioremap for ohci hcctrl failed\n", __FILE__);
		} else {
			ehci->has_amcc_usb23 = 1;
		}
	}

	if (of_get_property(dn, "big-endian", NULL)) {
		ehci->big_endian_mmio = 1;
		ehci->big_endian_desc = 1;
	}
	if (of_get_property(dn, "big-endian-regs", NULL))
		ehci->big_endian_mmio = 1;
	if (of_get_property(dn, "big-endian-desc", NULL))
		ehci->big_endian_desc = 1;

	ehci->caps = hcd->regs;

	if (of_device_is_compatible(dn, "ibm,usb-ehci-440epx")) {
		rv = ppc44x_enable_bmt(dn);
		ehci_dbg(ehci, "Break Memory Transfer (BMT) is %senabled!\n",
				rv ? "NOT ": "");
	}

	rv = usb_add_hcd(hcd, irq, 0);
	if (rv)
		goto err_ioremap;

	device_wakeup_enable(hcd->self.controller);
	return 0;

err_ioremap:
	irq_dispose_mapping(irq);
err_irq:
	usb_put_hcd(hcd);

	return rv;
}


static int ehci_hcd_ppc_of_remove(struct platform_device *op)
{
	struct usb_hcd *hcd = platform_get_drvdata(op);
	struct ehci_hcd *ehci = hcd_to_ehci(hcd);

	struct device_node *np;
	struct resource res;

	dev_dbg(&op->dev, "stopping PPC-OF USB Controller\n");

	usb_remove_hcd(hcd);

	irq_dispose_mapping(hcd->irq);

	/* use request_mem_region to test if the ohci driver is loaded.  if so
	 * ensure the ohci core is operational.
	 */
	if (ehci->has_amcc_usb23) {
		np = of_find_compatible_node(NULL, NULL, "ibm,usb-ohci-440epx");
		if (np != NULL) {
			if (!of_address_to_resource(np, 0, &res))
				if (!request_mem_region(res.start,
							    0x4, hcd_name))
					set_ohci_hcfs(ehci, 1);
				else
					release_mem_region(res.start, 0x4);
			else
				pr_debug("%s: no ohci offset in fdt\n", __FILE__);
			of_node_put(np);
		}
	}
	usb_put_hcd(hcd);

	return 0;
}


static const struct of_device_id ehci_hcd_ppc_of_match[] = {
	{
		.compatible = "usb-ehci",
	},
	{},
};
MODULE_DEVICE_TABLE(of, ehci_hcd_ppc_of_match);


static struct platform_driver ehci_hcd_ppc_of_driver = {
	.probe		= ehci_hcd_ppc_of_probe,
	.remove		= ehci_hcd_ppc_of_remove,
	.shutdown	= usb_hcd_platform_shutdown,
	.driver = {
		.name = "ppc-of-ehci",
		.of_match_table = ehci_hcd_ppc_of_match,
	},
};