X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?p=rpikern;a=blobdiff_plain;f=src%2Frpi.c;fp=src%2Frpi.c;h=ba39596a506b91b4bc46ef2f2ef20c7bb7fb95f5;hp=0000000000000000000000000000000000000000;hb=32ccc707bc0821d7ff4248fe9f58e92e9c6ebef9;hpb=203b43a75a028e9238307bd6e73768eb8e942071

diff --git a/src/rpi.c b/src/rpi.c
new file mode 100644
index 0000000..ba39596
--- /dev/null
+++ b/src/rpi.c
@@ -0,0 +1,111 @@
+#include "rpi.h"
+#include "asm.h"
+
+#define IOREG(offs)		(*(volatile uint32_t*)(rpi_iobase | offs))
+
+/* System timer */
+#define STM_CTL_REG		IOREG(0x3000)
+#define STM_STAT_REG	STM_CTL_REG
+#define STM_LCNT_REG	IOREG(0x3004)
+#define STM_HCNT_REG	IOREG(0x3008)
+#define STM_CMP0_REG	IOREG(0x300c)
+#define STM_CMP1_REG	IOREG(0x3010)
+#define STM_CMP2_REG	IOREG(0x3014)
+#define STM_CMP3_REG	IOREG(0x3018)
+
+#define STMCTL_M0		1
+#define STMCTL_M1		2
+#define STMCTL_M2		4
+#define STMCTL_M3		8
+
+/* TIMER */
+#define TM_LOAD_REG		IOREG(0xb400)
+#define TM_VALUE_REG	IOREG(0xb404)
+#define TM_CTL_REG		IOREG(0xb408)
+#define TM_ICLR_REG		IOREG(0xb40c)
+#define TM_IRAW_REG		IOREG(0xb410)
+#define TM_IMSK_REG		IOREG(0xb414)
+#define TM_RELOAD_REG	IOREG(0xb418)
+#define TM_PREDIV_REG	IOREG(0xb41c)
+#define TM_COUNT_REG	IOREG(0xb420)
+
+#define TMCTL_23BIT		0x000002
+#define TMCTL_DIV16		0x000004
+#define TMCTL_DIV256	0x000008
+#define TMCTL_DIV1		0x00000c
+#define TMCTL_IEN		0x000020
+#define TMCTL_EN		0x000080
+#define TMCTL_DBGHALT	0x000100
+#define TMCTL_CNTEN		0x000200
+
+#define TMCTL_PRESCALER(x)	(((uint32_t)(x) & 0xff) << 16)
+
+
+/* MAILBOX */
+#define MBOX_READ_REG	IOREG(0xb880)
+#define MBOX_POLL_REG	IOREG(0xb890)
+#define MBOX_SENDER_REG	IOREG(0xb894)
+#define MBOX_STATUS_REG	IOREG(0xb898)
+#define MBOX_CFG_REG	IOREG(0xb89c)
+#define MBOX_WRITE_REG	IOREG(0xb8a0)
+
+/* the full bit is set when there's no space to append messages */
+#define MBOX_STAT_FULL	0x80000000
+/* the empty bit is set when there are no pending messages to be read */
+#define MBOX_STAT_EMPTY	0x40000000
+
+static int detect(void);
+
+int rpi_model;
+uint32_t rpi_iobase;
+uint32_t rpi_memsize, rpi_vc_memsize;
+
+void rpi_init(void)
+{
+	if((rpi_model = detect()) == -1) {
+		for(;;) halt_cpu();
+	}
+
+	/* TODO */
+}
+
+static int detect(void)
+{
+	int i, j;
+	uint32_t tm0, tm1;
+	static uint32_t base[] = {0x20000000, 0x3f000000, 0xfe000000};
+
+	for(i=0; i<3; i++) {
+		rpi_iobase = base[i];
+		tm0 = STM_LCNT_REG;
+		for(j=0; j<256; j++) {
+			tm1 = STM_LCNT_REG;
+		}
+		if(tm0 != tm1) {
+			return i + 1;
+		}
+	}
+	return -1;
+}
+
+
+void rpi_mbox_send(int chan, uint32_t msg)
+{
+	while(MBOX_STATUS_REG & MBOX_STAT_FULL);
+	MBOX_WRITE_REG = (msg & 0xfffffff0) | chan;
+}
+
+uint32_t rpi_mbox_recv(int chan)
+{
+	uint32_t msg;
+	do {
+		while(MBOX_STATUS_REG & MBOX_STAT_EMPTY);
+		msg = MBOX_READ_REG;
+	} while((msg & 0xf) != chan);
+	return msg & 0xfffffff0;
+}
+
+int rpi_mbox_pending(int chan)
+{
+	return (MBOX_STATUS_REG & MBOX_STAT_EMPTY) == 0;
+}