usb: gadget: udc: amd5536: split core and PCI layer

This patch splits the amd5536udc driver into two -- one that does
pci device registration and the other file that does the rest of
the driver tasks like the gadget/ep ops etc for Synopsys UDC.

This way of splitting helps in exporting core driver symbols which
can be used by any other platform/pci driver that is written for
the same Synopsys USB device controller.

The current patch also includes a change in the Kconfig and Makefile.
A new config option USB_SNP_CORE will be selected automatically when
any one of the platform or pci driver for the same UDC is selected.

Main changes:
- amd5536udc_pci.c: PCI device registration is moved to this file.

- amd5536udc.c:
  This file does rest of the core UDC fucntionality.
  9 symbols are exported so as to be used by amd5536udc_pci.c.
  Module parameter definitions are moved to header file.

- amd5536udc.h:
  Function declarations, module parameters definitions and few common
  header file includes are added to this file

- Kconfig:
  New USB_SNP_CORE option is added which will be auto selected when
  any pci or platform driver config option for the UDC is chosen.

- Makefile:
  Compiles the core and pci files separately.

Signed-off-by: Raviteja Garimella <raviteja.garimella@broadcom.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

1 files changed, 217 insertions, 0 deletions

diff --git a/drivers/usb/gadget/udc/amd5536udc_pci.c b/drivers/usb/gadget/udc/amd5536udc_pci.c
new file mode 100644
index 000000000000..2a2d0a96fe24
--- /dev/null
+++ b/drivers/usb/gadget/udc/amd5536udc_pci.c
@@ -0,0 +1,217 @@
+/*
+ * amd5536udc_pci.c -- AMD 5536 UDC high/full speed USB device controller
+ *
+ * Copyright (C) 2005-2007 AMD (http://www.amd.com)
+ * Author: Thomas Dahlmann
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+/*
+ * The AMD5536 UDC is part of the x86 southbridge AMD Geode CS5536.
+ * It is a USB Highspeed DMA capable USB device controller. Beside ep0 it
+ * provides 4 IN and 4 OUT endpoints (bulk or interrupt type).
+ *
+ * Make sure that UDC is assigned to port 4 by BIOS settings (port can also
+ * be used as host port) and UOC bits PAD_EN and APU are set (should be done
+ * by BIOS init).
+ *
+ * UDC DMA requires 32-bit aligned buffers so DMA with gadget ether does not
+ * work without updating NET_IP_ALIGN. Or PIO mode (module param "use_dma=0")
+ * can be used with gadget ether.
+ *
+ * This file does pci device registration, and the core driver implementation
+ * is done in amd5536udc.c
+ *
+ * The driver is split so as to use the core UDC driver which is based on
+ * Synopsys device controller IP (different than HS OTG IP) in UDCs
+ * integrated to SoC platforms.
+ *
+ */
+
+/* Driver strings */
+#define UDC_MOD_DESCRIPTION		"AMD 5536 UDC - USB Device Controller"
+
+/* system */
+#include <linux/device.h>
+#include <linux/dmapool.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/prefetch.h>
+#include <linux/pci.h>
+
+/* udc specific */
+#include "amd5536udc.h"
+
+/* pointer to device object */
+static struct udc *udc;
+
+/* description */
+static const char mod_desc[] = UDC_MOD_DESCRIPTION;
+static const char name[] = "amd5536udc-pci";
+
+/* Reset all pci context */
+static void udc_pci_remove(struct pci_dev *pdev)
+{
+	struct udc		*dev;
+
+	dev = pci_get_drvdata(pdev);
+
+	usb_del_gadget_udc(&udc->gadget);
+	/* gadget driver must not be registered */
+	if (WARN_ON(dev->driver))
+		return;
+
+	/* dma pool cleanup */
+	free_dma_pools(dev);
+
+	/* reset controller */
+	writel(AMD_BIT(UDC_DEVCFG_SOFTRESET), &dev->regs->cfg);
+	free_irq(pdev->irq, dev);
+	iounmap(dev->virt_addr);
+	release_mem_region(pci_resource_start(pdev, 0),
+			   pci_resource_len(pdev, 0));
+	pci_disable_device(pdev);
+
+	udc_remove(dev);
+}
+
+/* Called by pci bus driver to init pci context */
+static int udc_pci_probe(
+	struct pci_dev *pdev,
+	const struct pci_device_id *id
+)
+{
+	struct udc		*dev;
+	unsigned long		resource;
+	unsigned long		len;
+	int			retval = 0;
+
+	/* one udc only */
+	if (udc) {
+		dev_dbg(&pdev->dev, "already probed\n");
+		return -EBUSY;
+	}
+
+	/* init */
+	dev = kzalloc(sizeof(struct udc), GFP_KERNEL);
+	if (!dev)
+		return -ENOMEM;
+
+	/* pci setup */
+	if (pci_enable_device(pdev) < 0) {
+		retval = -ENODEV;
+		goto err_pcidev;
+	}
+
+	/* PCI resource allocation */
+	resource = pci_resource_start(pdev, 0);
+	len = pci_resource_len(pdev, 0);
+
+	if (!request_mem_region(resource, len, name)) {
+		dev_dbg(&pdev->dev, "pci device used already\n");
+		retval = -EBUSY;
+		goto err_memreg;
+	}
+
+	dev->virt_addr = ioremap_nocache(resource, len);
+	if (!dev->virt_addr) {
+		dev_dbg(&pdev->dev, "start address cannot be mapped\n");
+		retval = -EFAULT;
+		goto err_ioremap;
+	}
+
+	if (!pdev->irq) {
+		dev_err(&pdev->dev, "irq not set\n");
+		retval = -ENODEV;
+		goto err_irq;
+	}
+
+	spin_lock_init(&dev->lock);
+	/* udc csr registers base */
+	dev->csr = dev->virt_addr + UDC_CSR_ADDR;
+	/* dev registers base */
+	dev->regs = dev->virt_addr + UDC_DEVCFG_ADDR;
+	/* ep registers base */
+	dev->ep_regs = dev->virt_addr + UDC_EPREGS_ADDR;
+	/* fifo's base */
+	dev->rxfifo = (u32 __iomem *)(dev->virt_addr + UDC_RXFIFO_ADDR);
+	dev->txfifo = (u32 __iomem *)(dev->virt_addr + UDC_TXFIFO_ADDR);
+
+	if (request_irq(pdev->irq, udc_irq, IRQF_SHARED, name, dev) != 0) {
+		dev_dbg(&pdev->dev, "request_irq(%d) fail\n", pdev->irq);
+		retval = -EBUSY;
+		goto err_irq;
+	}
+
+	pci_set_drvdata(pdev, dev);
+
+	/* chip revision for Hs AMD5536 */
+	dev->chiprev = pdev->revision;
+
+	pci_set_master(pdev);
+	pci_try_set_mwi(pdev);
+
+	/* init dma pools */
+	if (use_dma) {
+		retval = init_dma_pools(dev);
+		if (retval != 0)
+			goto err_dma;
+	}
+
+	dev->phys_addr = resource;
+	dev->irq = pdev->irq;
+	dev->pdev = pdev;
+
+	/* general probing */
+	if (udc_probe(dev)) {
+		retval = -ENODEV;
+		goto err_probe;
+	}
+	return 0;
+
+err_probe:
+	if (use_dma)
+		free_dma_pools(dev);
+err_dma:
+	free_irq(pdev->irq, dev);
+err_irq:
+	iounmap(dev->virt_addr);
+err_ioremap:
+	release_mem_region(resource, len);
+err_memreg:
+	pci_disable_device(pdev);
+err_pcidev:
+	kfree(dev);
+	return retval;
+}
+
+/* PCI device parameters */
+static const struct pci_device_id pci_id[] = {
+	{
+		PCI_DEVICE(PCI_VENDOR_ID_AMD, 0x2096),
+		.class =	PCI_CLASS_SERIAL_USB_DEVICE,
+		.class_mask =	0xffffffff,
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(pci, pci_id);
+
+/* PCI functions */
+static struct pci_driver udc_pci_driver = {
+	.name =		(char *) name,
+	.id_table =	pci_id,
+	.probe =	udc_pci_probe,
+	.remove =	udc_pci_remove,
+};
+module_pci_driver(udc_pci_driver);
+
+MODULE_DESCRIPTION(UDC_MOD_DESCRIPTION);
+MODULE_AUTHOR("Thomas Dahlmann");
+MODULE_LICENSE("GPL");