sdhc: add ipc call IPC_SDHC_EXIT

In some cases it is desirable to let the Broadway processor take complete
control of hardware initially managed by 'mini'.
Add a new IPC call to instruct 'mini' to relinquish control of the
SD Host Controller.

One immediate user of this IPC call is Linux on the Nintendo Wii which
takes complete control of the SDHC hardware.

Signed-off-by: Albert Herranz <[email protected]>

Author: herraa1

ipc.h

@@ -77,6 +77,7 @@ Copyright (C) 2009		John Kelley <[email protected]>
 // etc.
 
 #define IPC_SDHC_DISCOVER 0x0000
+#define IPC_SDHC_EXIT 	  0x0001
 
 #define IPC_SDMMC_ACK	0x0000
 #define IPC_SDMMC_READ	0x0001

sdhc.c

@@ -1033,13 +1033,24 @@ void sdhc_init(void)
 //	sdhc_host_found(&__softc, 0, 0x0d080000, 1);
 }
 
+void sdhc_exit(void)
+{
+#ifdef CAN_HAZ_IRQ
+	irq_disable(IRQ_SDHC);
+#endif
+	sdhc_shutdown(&__softc);
+}
+
 #ifdef CAN_HAZ_IPC
 void sdhc_ipc(volatile ipc_request *req)
 {
 	switch (req->req) {
 	case IPC_SDHC_DISCOVER:
 		sdmmc_needs_discover((struct device *)req->args[0]);
 		break;
+	case IPC_SDHC_EXIT:
+		sdhc_exit();
+		ipc_post(req->code, req->tag, 0);
 	}
 }
 #endif

sdhcvar.h

@@ -57,6 +57,7 @@ void	sdhc_power(int, void *);
 void	sdhc_shutdown(void *);
 int	sdhc_intr(void *);
 void	sdhc_init(void);
+void	sdhc_exit(void);
 void	sdhc_irq(void);
 #ifdef CAN_HAZ_IPC
 void	sdhc_ipc(volatile ipc_request *req);