ssb: Implement SDIO host bus support

Add support for communicating with a Sonics Silicon Backplane through a
SDIO interface, as found in the Nintendo Wii WLAN daughter card.

The Nintendo Wii WLAN card includes a custom Broadcom 4318 chip with
a SDIO host interface.
Signed-off-by: Albert Herranz <albert_herranz@yahoo.es>
Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/ssb/Kconfig

@@ -66,6 +66,20 @@ config SSB_PCMCIAHOST
 
 	  If unsure, say N
 
+config SSB_SDIOHOST_POSSIBLE
+	bool
+	depends on SSB && (MMC = y || MMC = SSB)
+	default y
+
+config SSB_SDIOHOST
+	bool "Support for SSB on SDIO-bus host"
+	depends on SSB_SDIOHOST_POSSIBLE
+	help
+	  Support for a Sonics Silicon Backplane on top
+	  of a SDIO device.
+
+	  If unsure, say N
+
 config SSB_SILENT
 	bool "No SSB kernel messages"
 	depends on SSB && EMBEDDED

drivers/ssb/Makefile

@@ -6,6 +6,7 @@ ssb-$(CONFIG_SSB_SPROM)			+= sprom.o
 # host support
 ssb-$(CONFIG_SSB_PCIHOST)		+= pci.o pcihost_wrapper.o
 ssb-$(CONFIG_SSB_PCMCIAHOST)		+= pcmcia.o
+ssb-$(CONFIG_SSB_SDIOHOST)		+= sdio.o
 
 # built-in drivers
 ssb-y					+= driver_chipcommon.o

drivers/ssb/main.c

@@ -17,6 +17,7 @@
 #include <linux/ssb/ssb_driver_gige.h>
 #include <linux/dma-mapping.h>
 #include <linux/pci.h>
+#include <linux/mmc/sdio_func.h>
 
 #include <pcmcia/cs_types.h>
 #include <pcmcia/cs.h>
@@ -88,6 +89,25 @@ found:
 }
 #endif /* CONFIG_SSB_PCMCIAHOST */
 
+#ifdef CONFIG_SSB_SDIOHOST
+struct ssb_bus *ssb_sdio_func_to_bus(struct sdio_func *func)
+{
+	struct ssb_bus *bus;
+
+	ssb_buses_lock();
+	list_for_each_entry(bus, &buses, list) {
+		if (bus->bustype == SSB_BUSTYPE_SDIO &&
+		    bus->host_sdio == func)
+			goto found;
+	}
+	bus = NULL;
+found:
+	ssb_buses_unlock();
+
+	return bus;
+}
+#endif /* CONFIG_SSB_SDIOHOST */
+
 int ssb_for_each_bus_call(unsigned long data,
 			  int (*func)(struct ssb_bus *bus, unsigned long data))
 {
@@ -467,6 +487,12 @@ static int ssb_devices_register(struct ssb_bus *bus)
 #ifdef CONFIG_SSB_PCMCIAHOST
 			sdev->irq = bus->host_pcmcia->irq.AssignedIRQ;
 			dev->parent = &bus->host_pcmcia->dev;
+#endif
+			break;
+		case SSB_BUSTYPE_SDIO:
+#ifdef CONFIG_SSB_SDIO
+			sdev->irq = bus->host_sdio->dev.irq;
+			dev->parent = &bus->host_sdio->dev;
 #endif
 			break;
 		case SSB_BUSTYPE_SSB:
@@ -724,12 +750,18 @@ static int ssb_bus_register(struct ssb_bus *bus,
 	err = ssb_pci_xtal(bus, SSB_GPIO_XTAL | SSB_GPIO_PLL, 1);
 	if (err)
 		goto out;
+
+	/* Init SDIO-host device (if any), before the scan */
+	err = ssb_sdio_init(bus);
+	if (err)
+		goto err_disable_xtal;
+
 	ssb_buses_lock();
 	bus->busnumber = next_busnumber;
 	/* Scan for devices (cores) */
 	err = ssb_bus_scan(bus, baseaddr);
 	if (err)
-		goto err_disable_xtal;
+		goto err_sdio_exit;
 
 	/* Init PCI-host device (if any) */
 	err = ssb_pci_init(bus);
@@ -776,6 +808,8 @@ err_pci_exit:
 	ssb_pci_exit(bus);
 err_unmap:
 	ssb_iounmap(bus);
+err_sdio_exit:
+	ssb_sdio_exit(bus);
 err_disable_xtal:
 	ssb_buses_unlock();
 	ssb_pci_xtal(bus, SSB_GPIO_XTAL | SSB_GPIO_PLL, 0);
@@ -825,6 +859,28 @@ int ssb_bus_pcmciabus_register(struct ssb_bus *bus,
 EXPORT_SYMBOL(ssb_bus_pcmciabus_register);
 #endif /* CONFIG_SSB_PCMCIAHOST */
 
+#ifdef CONFIG_SSB_SDIOHOST
+int ssb_bus_sdiobus_register(struct ssb_bus *bus, struct sdio_func *func,
+			     unsigned int quirks)
+{
+	int err;
+
+	bus->bustype = SSB_BUSTYPE_SDIO;
+	bus->host_sdio = func;
+	bus->ops = &ssb_sdio_ops;
+	bus->quirks = quirks;
+
+	err = ssb_bus_register(bus, ssb_sdio_get_invariants, ~0);
+	if (!err) {
+		ssb_printk(KERN_INFO PFX "Sonics Silicon Backplane found on "
+			   "SDIO device %s\n", sdio_func_id(func));
+	}
+
+	return err;
+}
+EXPORT_SYMBOL(ssb_bus_sdiobus_register);
+#endif /* CONFIG_SSB_PCMCIAHOST */
+
 int ssb_bus_ssbbus_register(struct ssb_bus *bus,
 			    unsigned long baseaddr,
 			    ssb_invariants_func_t get_invariants)

drivers/ssb/scan.c

@@ -175,6 +175,9 @@ static u32 scan_read32(struct ssb_bus *bus, u8 current_coreidx,
 		} else
 			ssb_pcmcia_switch_segment(bus, 0);
 		break;
+	case SSB_BUSTYPE_SDIO:
+		offset += current_coreidx * SSB_CORE_SIZE;
+		return ssb_sdio_scan_read32(bus, offset);
 	}
 	return readl(bus->mmio + offset);
 }
@@ -188,6 +191,8 @@ static int scan_switchcore(struct ssb_bus *bus, u8 coreidx)
 		return ssb_pci_switch_coreidx(bus, coreidx);
 	case SSB_BUSTYPE_PCMCIA:
 		return ssb_pcmcia_switch_coreidx(bus, coreidx);
+	case SSB_BUSTYPE_SDIO:
+		return ssb_sdio_scan_switch_coreidx(bus, coreidx);
 	}
 	return 0;
 }
@@ -206,6 +211,8 @@ void ssb_iounmap(struct ssb_bus *bus)
 		SSB_BUG_ON(1); /* Can't reach this code. */
 #endif
 		break;
+	case SSB_BUSTYPE_SDIO:
+		break;
 	}
 	bus->mmio = NULL;
 	bus->mapped_device = NULL;
@@ -230,6 +237,10 @@ static void __iomem *ssb_ioremap(struct ssb_bus *bus,
 		SSB_BUG_ON(1); /* Can't reach this code. */
 #endif
 		break;
+	case SSB_BUSTYPE_SDIO:
+		/* Nothing to ioremap in the SDIO case, just fake it */
+		mmio = (void __iomem *)baseaddr;
+		break;
 	}
 
 	return mmio;

drivers/ssb/ssb_private.h

@@ -114,6 +114,46 @@ static inline int ssb_pcmcia_init(struct ssb_bus *bus)
 }
 #endif /* CONFIG_SSB_PCMCIAHOST */
 
+/* sdio.c */
+#ifdef CONFIG_SSB_SDIOHOST
+extern int ssb_sdio_get_invariants(struct ssb_bus *bus,
+				     struct ssb_init_invariants *iv);
+
+extern u32 ssb_sdio_scan_read32(struct ssb_bus *bus, u16 offset);
+extern int ssb_sdio_switch_core(struct ssb_bus *bus, struct ssb_device *dev);
+extern int ssb_sdio_scan_switch_coreidx(struct ssb_bus *bus, u8 coreidx);
+extern int ssb_sdio_hardware_setup(struct ssb_bus *bus);
+extern void ssb_sdio_exit(struct ssb_bus *bus);
+extern int ssb_sdio_init(struct ssb_bus *bus);
+
+extern const struct ssb_bus_ops ssb_sdio_ops;
+#else /* CONFIG_SSB_SDIOHOST */
+static inline u32 ssb_sdio_scan_read32(struct ssb_bus *bus, u16 offset)
+{
+	return 0;
+}
+static inline int ssb_sdio_switch_core(struct ssb_bus *bus,
+					 struct ssb_device *dev)
+{
+	return 0;
+}
+static inline int ssb_sdio_scan_switch_coreidx(struct ssb_bus *bus, u8 coreidx)
+{
+	return 0;
+}
+static inline int ssb_sdio_hardware_setup(struct ssb_bus *bus)
+{
+	return 0;
+}
+static inline void ssb_sdio_exit(struct ssb_bus *bus)
+{
+}
+static inline int ssb_sdio_init(struct ssb_bus *bus)
+{
+	return 0;
+}
+#endif /* CONFIG_SSB_SDIOHOST */
+
 
 /* scan.c */
 extern const char *ssb_core_name(u16 coreid);

include/linux/ssb/ssb.h

@@ -238,6 +238,7 @@ enum ssb_bustype {
 	SSB_BUSTYPE_SSB,	/* This SSB bus is the system bus */
 	SSB_BUSTYPE_PCI,	/* SSB is connected to PCI bus */
 	SSB_BUSTYPE_PCMCIA,	/* SSB is connected to PCMCIA bus */
+	SSB_BUSTYPE_SDIO,	/* SSB is connected to SDIO bus */
 };
 
 /* board_vendor */
@@ -270,8 +271,12 @@ struct ssb_bus {
 
 	/* The core in the basic address register window. (PCI bus only) */
 	struct ssb_device *mapped_device;
-	/* Currently mapped PCMCIA segment. (bustype == SSB_BUSTYPE_PCMCIA only) */
-	u8 mapped_pcmcia_seg;
+	union {
+		/* Currently mapped PCMCIA segment. (bustype == SSB_BUSTYPE_PCMCIA only) */
+		u8 mapped_pcmcia_seg;
+		/* Current SSB base address window for SDIO. */
+		u32 sdio_sbaddr;
+	};
 	/* Lock for core and segment switching.
 	 * On PCMCIA-host busses this is used to protect the whole MMIO access. */
 	spinlock_t bar_lock;
@@ -282,6 +287,11 @@ struct ssb_bus {
 	struct pci_dev *host_pci;
 	/* Pointer to the PCMCIA device (only if bustype == SSB_BUSTYPE_PCMCIA). */
 	struct pcmcia_device *host_pcmcia;
+	/* Pointer to the SDIO device (only if bustype == SSB_BUSTYPE_SDIO). */
+	struct sdio_func *host_sdio;
+
+	/* See enum ssb_quirks */
+	unsigned int quirks;
 
 #ifdef CONFIG_SSB_SPROM
 	/* Mutex to protect the SPROM writing. */
@@ -336,6 +346,11 @@ struct ssb_bus {
 #endif /* DEBUG */
 };
 
+enum ssb_quirks {
+	/* SDIO connected card requires performing a read after writing a 32-bit value */
+	SSB_QUIRK_SDIO_READ_AFTER_WRITE32	= (1 << 0),
+};
+
 /* The initialization-invariants. */
 struct ssb_init_invariants {
 	/* Versioning information about the PCB. */
@@ -366,6 +381,12 @@ extern int ssb_bus_pcmciabus_register(struct ssb_bus *bus,
 				      struct pcmcia_device *pcmcia_dev,
 				      unsigned long baseaddr);
 #endif /* CONFIG_SSB_PCMCIAHOST */
+#ifdef CONFIG_SSB_SDIOHOST
+extern int ssb_bus_sdiobus_register(struct ssb_bus *bus,
+				    struct sdio_func *sdio_func,
+				    unsigned int quirks);
+#endif /* CONFIG_SSB_SDIOHOST */
+
 
 extern void ssb_bus_unregister(struct ssb_bus *bus);