bcma: add Broadcom specific AMBA bus driver

Broadcom has released cards based on a new AMBA-based bus type. From a
programming point of view, this new bus type differs from AMBA and does
not use AMBA common registers. It also differs enough from SSB. We
decided that a new bus driver is needed to keep the code clean.

In its current form, the driver detects devices present on the bus and
registers them in the system. It allows registering BCMA drivers for
specified bus devices and provides them basic operations. The bus driver
itself includes two important bus managing drivers: ChipCommon core
driver and PCI(c) core driver. They are early used to allow correct
initialization.

Currently code is limited to supporting buses on PCI(e) devices, however
the driver is designed to be used also on other hosts. The host
abstraction layer is implemented and already used for PCI(e).

Support for PCI(e) hosts is working and seems to be stable (access to
80211 core was tested successfully on a few devices). We can still
optimize it by using some fixed windows, but this can be done later
without affecting any external code. Windows are just ranges in MMIO
used for accessing cores on the bus.

Cc: Greg KH <greg@kroah.com>
Cc: Michael Büsch <mb@bu3sch.de>
Cc: Larry Finger <Larry.Finger@lwfinger.net>
Cc: George Kashperko <george@znau.edu.ua>
Cc: Arend van Spriel <arend@broadcom.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Andy Botting <andy@andybotting.com>
Cc: linuxdriverproject <devel@linuxdriverproject.org>
Cc: linux-kernel@vger.kernel.org <linux-kernel@vger.kernel.org>
Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 196 insertions, 0 deletions

diff --git a/drivers/bcma/host_pci.c b/drivers/bcma/host_pci.c
new file mode 100644
index 00000000000..99dd36e8500
--- /dev/null
+++ b/drivers/bcma/host_pci.c
@@ -0,0 +1,196 @@
+/*
+ * Broadcom specific AMBA
+ * PCI Host
+ *
+ * Licensed under the GNU/GPL. See COPYING for details.
+ */
+
+#include "bcma_private.h"
+#include <linux/bcma/bcma.h>
+#include <linux/pci.h>
+
+static void bcma_host_pci_switch_core(struct bcma_device *core)
+{
+	pci_write_config_dword(core->bus->host_pci, BCMA_PCI_BAR0_WIN,
+			       core->addr);
+	pci_write_config_dword(core->bus->host_pci, BCMA_PCI_BAR0_WIN2,
+			       core->wrap);
+	core->bus->mapped_core = core;
+	pr_debug("Switched to core: 0x%X\n", core->id.id);
+}
+
+static u8 bcma_host_pci_read8(struct bcma_device *core, u16 offset)
+{
+	if (core->bus->mapped_core != core)
+		bcma_host_pci_switch_core(core);
+	return ioread8(core->bus->mmio + offset);
+}
+
+static u16 bcma_host_pci_read16(struct bcma_device *core, u16 offset)
+{
+	if (core->bus->mapped_core != core)
+		bcma_host_pci_switch_core(core);
+	return ioread16(core->bus->mmio + offset);
+}
+
+static u32 bcma_host_pci_read32(struct bcma_device *core, u16 offset)
+{
+	if (core->bus->mapped_core != core)
+		bcma_host_pci_switch_core(core);
+	return ioread32(core->bus->mmio + offset);
+}
+
+static void bcma_host_pci_write8(struct bcma_device *core, u16 offset,
+				 u8 value)
+{
+	if (core->bus->mapped_core != core)
+		bcma_host_pci_switch_core(core);
+	iowrite8(value, core->bus->mmio + offset);
+}
+
+static void bcma_host_pci_write16(struct bcma_device *core, u16 offset,
+				 u16 value)
+{
+	if (core->bus->mapped_core != core)
+		bcma_host_pci_switch_core(core);
+	iowrite16(value, core->bus->mmio + offset);
+}
+
+static void bcma_host_pci_write32(struct bcma_device *core, u16 offset,
+				 u32 value)
+{
+	if (core->bus->mapped_core != core)
+		bcma_host_pci_switch_core(core);
+	iowrite32(value, core->bus->mmio + offset);
+}
+
+static u32 bcma_host_pci_aread32(struct bcma_device *core, u16 offset)
+{
+	if (core->bus->mapped_core != core)
+		bcma_host_pci_switch_core(core);
+	return ioread32(core->bus->mmio + (1 * BCMA_CORE_SIZE) + offset);
+}
+
+static void bcma_host_pci_awrite32(struct bcma_device *core, u16 offset,
+				  u32 value)
+{
+	if (core->bus->mapped_core != core)
+		bcma_host_pci_switch_core(core);
+	iowrite32(value, core->bus->mmio + (1 * BCMA_CORE_SIZE) + offset);
+}
+
+const struct bcma_host_ops bcma_host_pci_ops = {
+	.read8		= bcma_host_pci_read8,
+	.read16		= bcma_host_pci_read16,
+	.read32		= bcma_host_pci_read32,
+	.write8		= bcma_host_pci_write8,
+	.write16	= bcma_host_pci_write16,
+	.write32	= bcma_host_pci_write32,
+	.aread32	= bcma_host_pci_aread32,
+	.awrite32	= bcma_host_pci_awrite32,
+};
+
+static int bcma_host_pci_probe(struct pci_dev *dev,
+			     const struct pci_device_id *id)
+{
+	struct bcma_bus *bus;
+	int err = -ENOMEM;
+	const char *name;
+	u32 val;
+
+	/* Alloc */
+	bus = kzalloc(sizeof(*bus), GFP_KERNEL);
+	if (!bus)
+		goto out;
+
+	/* Basic PCI configuration */
+	err = pci_enable_device(dev);
+	if (err)
+		goto err_kfree_bus;
+
+	name = dev_name(&dev->dev);
+	if (dev->driver && dev->driver->name)
+		name = dev->driver->name;
+	err = pci_request_regions(dev, name);
+	if (err)
+		goto err_pci_disable;
+	pci_set_master(dev);
+
+	/* Disable the RETRY_TIMEOUT register (0x41) to keep
+	 * PCI Tx retries from interfering with C3 CPU state */
+	pci_read_config_dword(dev, 0x40, &val);
+	if ((val & 0x0000ff00) != 0)
+		pci_write_config_dword(dev, 0x40, val & 0xffff00ff);
+
+	/* SSB needed additional powering up, do we have any AMBA PCI cards? */
+	if (!pci_is_pcie(dev))
+		pr_err("PCI card detected, report problems.\n");
+
+	/* Map MMIO */
+	err = -ENOMEM;
+	bus->mmio = pci_iomap(dev, 0, ~0UL);
+	if (!bus->mmio)
+		goto err_pci_release_regions;
+
+	/* Host specific */
+	bus->host_pci = dev;
+	bus->hosttype = BCMA_HOSTTYPE_PCI;
+	bus->ops = &bcma_host_pci_ops;
+
+	/* Register */
+	err = bcma_bus_register(bus);
+	if (err)
+		goto err_pci_unmap_mmio;
+
+	pci_set_drvdata(dev, bus);
+
+out:
+	return err;
+
+err_pci_unmap_mmio:
+	pci_iounmap(dev, bus->mmio);
+err_pci_release_regions:
+	pci_release_regions(dev);
+err_pci_disable:
+	pci_disable_device(dev);
+err_kfree_bus:
+	kfree(bus);
+	return err;
+}
+
+static void bcma_host_pci_remove(struct pci_dev *dev)
+{
+	struct bcma_bus *bus = pci_get_drvdata(dev);
+
+	bcma_bus_unregister(bus);
+	pci_iounmap(dev, bus->mmio);
+	pci_release_regions(dev);
+	pci_disable_device(dev);
+	kfree(bus);
+	pci_set_drvdata(dev, NULL);
+}
+
+static DEFINE_PCI_DEVICE_TABLE(bcma_pci_bridge_tbl) = {
+	{ PCI_DEVICE(PCI_VENDOR_ID_BROADCOM, 0x4331) },
+	{ PCI_DEVICE(PCI_VENDOR_ID_BROADCOM, 0x4353) },
+	{ PCI_DEVICE(PCI_VENDOR_ID_BROADCOM, 0x4727) },
+	{ 0, },
+};
+MODULE_DEVICE_TABLE(pci, bcma_pci_bridge_tbl);
+
+static struct pci_driver bcma_pci_bridge_driver = {
+	.name = "bcma-pci-bridge",
+	.id_table = bcma_pci_bridge_tbl,
+	.probe = bcma_host_pci_probe,
+	.remove = bcma_host_pci_remove,
+};
+
+int __init bcma_host_pci_init(void)
+{
+	return pci_register_driver(&bcma_pci_bridge_driver);
+}
+
+void __exit bcma_host_pci_exit(void)
+{
+	pci_unregister_driver(&bcma_pci_bridge_driver);
+}