add raspberry pi kernel (from sources)

1 files changed, 413 insertions, 0 deletions

diff --git a/sys/src/9/bcm/uartmini.c b/sys/src/9/bcm/uartmini.c
new file mode 100644
index 000000000..aa9b87f13
--- /dev/null
+++ b/sys/src/9/bcm/uartmini.c
@@ -0,0 +1,413 @@
+/*
+ * bcm2835 mini uart (UART1)
+ */
+
+#include "u.h"
+#include "../port/lib.h"
+#include "../port/error.h"
+#include "mem.h"
+#include "dat.h"
+#include "fns.h"
+#include "io.h"
+
+#define GPIOREGS	(VIRTIO+0x200000)
+#define AUXREGS		(VIRTIO+0x215000)
+#define	OkLed		16
+#define	TxPin		14
+#define	RxPin		15
+
+/* GPIO regs */
+enum {
+	Fsel0	= 0x00>>2,
+		FuncMask= 0x7,
+		Input	= 0x0,
+		Output	= 0x1,
+		Alt0	= 0x4,
+		Alt1	= 0x5,
+		Alt2	= 0x6,
+		Alt3	= 0x7,
+		Alt4	= 0x3,
+		Alt5	= 0x2,
+	Set0	= 0x1c>>2,
+	Clr0	= 0x28>>2,
+	Lev0	= 0x34>>2,
+	PUD	= 0x94>>2,
+		Off	= 0x0,
+		Pulldown= 0x1,
+		Pullup	= 0x2,
+	PUDclk0	= 0x98>>2,
+	PUDclk1	= 0x9c>>2,
+};
+
+/* AUX regs */
+enum {
+	Irq	= 0x00>>2,
+		UartIrq	= 1<<0,
+	Enables	= 0x04>>2,
+		UartEn	= 1<<0,
+	MuIo	= 0x40>>2,
+	MuIer	= 0x44>>2,
+		RxIen	= 1<<0,
+		TxIen	= 1<<1,
+	MuIir	= 0x48>>2,
+	MuLcr	= 0x4c>>2,
+		Bitsmask= 3<<0,
+		Bits7	= 2<<0,
+		Bits8	= 3<<0,
+	MuMcr	= 0x50>>2,
+		RtsN	= 1<<1,
+	MuLsr	= 0x54>>2,
+		TxDone	= 1<<6,
+		TxRdy	= 1<<5,
+		RxRdy	= 1<<0,
+	MuCntl	= 0x60>>2,
+		CtsFlow	= 1<<3,
+		TxEn	= 1<<1,
+		RxEn	= 1<<0,
+	MuBaud	= 0x68>>2,
+};
+
+extern PhysUart miniphysuart;
+
+static Uart miniuart = {
+	.regs	= (u32int*)AUXREGS,
+	.name	= "uart0",
+	.freq	= 250000000,
+	.phys	= &miniphysuart,
+};
+
+void
+gpiosel(uint pin, int func)
+{	
+	u32int *gp, *fsel;
+	int off;
+
+	gp = (u32int*)GPIOREGS;
+	fsel = &gp[Fsel0 + pin/10];
+	off = (pin % 10) * 3;
+	*fsel = (*fsel & ~(FuncMask << off)) | func << off;
+}
+
+void
+gpiopulloff(uint pin)
+{
+	u32int *gp, *reg;
+	u32int mask;
+
+	gp = (u32int*)GPIOREGS;
+	reg = &gp[PUDclk0 + pin/32];
+	mask = 1 << (pin % 32);
+	gp[PUD] = Off;
+	microdelay(1);
+	*reg = mask;
+	microdelay(1);
+	*reg = 0;
+}
+
+void
+gpioout(uint pin, int set)
+{
+	u32int *gp;
+	int v;
+
+	gp = (u32int*)GPIOREGS;
+	v = set? Set0: Clr0;
+	gp[v + pin/32] = 1 << (pin % 32);
+}
+
+int
+gpioin(uint pin)
+{
+	u32int *gp;
+
+	gp = (u32int*)GPIOREGS;
+	return (gp[Lev0 + pin/32] & (1 << (pin % 32))) != 0;
+}
+
+static void
+interrupt(Ureg*, void *arg)
+{
+	Uart *uart;
+	u32int *ap;
+
+	uart = arg;
+	ap = (u32int*)uart->regs;
+
+	coherence();
+	if(0 && (ap[Irq] & UartIrq) == 0)
+		return;
+	if(ap[MuLsr] & TxRdy)
+		uartkick(uart);
+	if(ap[MuLsr] & RxRdy){
+		do{
+			uartrecv(uart, ap[MuIo] & 0xFF);
+		}while(ap[MuLsr] & RxRdy);
+	}
+	coherence();
+}
+
+static Uart*
+pnp(void)
+{
+	return &miniuart;
+}
+
+static void
+enable(Uart *uart, int ie)
+{
+	u32int *ap;
+
+	ap = (u32int*)uart->regs;
+	delay(10);
+	gpiosel(TxPin, Alt5);
+	gpiosel(RxPin, Alt5);
+	gpiopulloff(TxPin);
+	gpiopulloff(RxPin);
+	ap[Enables] |= UartEn;
+	ap[MuIir] = 6;
+	ap[MuLcr] = Bits8;
+	ap[MuCntl] = TxEn|RxEn;
+	ap[MuBaud] = 250000000 / (115200 * 8) - 1;
+	if(ie){
+		intrenable(IRQaux, interrupt, uart, 0, "uart");
+		ap[MuIer] = RxIen|TxIen;
+	}else
+		ap[MuIer] = 0;
+}
+
+static void
+disable(Uart *uart)
+{
+	u32int *ap;
+
+	ap = (u32int*)uart->regs;
+	ap[MuCntl] = 0;
+	ap[MuIer] = 0;
+}
+
+static void
+kick(Uart *uart)
+{
+	u32int *ap;
+
+	ap = (u32int*)uart->regs;
+	if(uart->blocked)
+		return;
+	coherence();
+	while(ap[MuLsr] & TxRdy){
+		if(uart->op >= uart->oe && uartstageoutput(uart) == 0)
+			break;
+		ap[MuIo] = *(uart->op++);
+	}
+	if(ap[MuLsr] & TxDone)
+		ap[MuIer] &= ~TxIen;
+	else
+		ap[MuIer] |= TxIen;
+	coherence();
+}
+
+/* TODO */
+static void
+dobreak(Uart *uart, int ms)
+{
+	USED(uart, ms);
+}
+
+static int
+baud(Uart *uart, int n)
+{
+	u32int *ap;
+
+	ap = (u32int*)uart->regs;
+	if(uart->freq == 0 || n <= 0)
+		return -1;
+	ap[MuBaud] = (uart->freq + 4*n - 1) / (8 * n) - 1;
+	uart->baud = n;
+	return 0;
+}
+
+static int
+bits(Uart *uart, int n)
+{
+	u32int *ap;
+	int set;
+
+	ap = (u32int*)uart->regs;
+	switch(n){
+	case 7:
+		set = Bits7;
+		break;
+	case 8:
+		set = Bits8;
+		break;
+	default:
+		return -1;
+	}
+	ap[MuLcr] = (ap[MuLcr] & ~Bitsmask) | set;
+	uart->bits = n;
+	return 0;
+}
+
+static int
+stop(Uart *uart, int n)
+{
+	if(n != 1)
+		return -1;
+	uart->stop = n;
+	return 0;
+}
+
+static int
+parity(Uart *uart, int n)
+{
+	if(n != 'n')
+		return -1;
+	uart->parity = n;
+	return 0;
+}
+
+/*
+ * cts/rts flow control
+ *   need to bring signals to gpio pins before enabling this
+ */
+
+static void
+modemctl(Uart *uart, int on)
+{
+	u32int *ap;
+
+	ap = (u32int*)uart->regs;
+	if(on)
+		ap[MuCntl] |= CtsFlow;
+	else
+		ap[MuCntl] &= ~CtsFlow;
+	uart->modem = on;
+}
+
+static void
+rts(Uart *uart, int on)
+{
+	u32int *ap;
+
+	ap = (u32int*)uart->regs;
+	if(on)
+		ap[MuMcr] &= ~RtsN;
+	else
+		ap[MuMcr] |= RtsN;
+}
+
+static long
+status(Uart *uart, void *buf, long n, long offset)
+{
+	char *p;
+
+	p = malloc(READSTR);
+	if(p == nil)
+		error(Enomem);
+	snprint(p, READSTR,
+		"b%d\n"
+		"dev(%d) type(%d) framing(%d) overruns(%d) "
+		"berr(%d) serr(%d)\n",
+
+		uart->baud,
+		uart->dev,
+		uart->type,
+		uart->ferr,
+		uart->oerr,
+		uart->berr,
+		uart->serr
+	);
+	n = readstr(offset, buf, n, p);
+	free(p);
+
+	return n;
+}
+
+static void
+donothing(Uart*, int)
+{
+}
+
+void
+putc(Uart*, int c)
+{
+	u32int *ap;
+
+	ap = (u32int*)AUXREGS;
+	while((ap[MuLsr] & TxRdy) == 0)
+		;
+	ap[MuIo] = c;
+	while((ap[MuLsr] & TxRdy) == 0)
+		;
+}
+
+int
+getc(Uart*)
+{
+	u32int *ap;
+
+	ap = (u32int*)AUXREGS;
+	while((ap[MuLsr] & RxRdy) == 0)
+		;
+	return ap[MuIo] & 0xFF;
+}
+
+void
+uartconsinit(void)
+{
+	Uart *uart;
+	int n;
+	char *p, *cmd;
+
+	if((p = getconf("console")) == nil)
+		return;
+	n = strtoul(p, &cmd, 0);
+	if(p == cmd)
+		return;
+	switch(n){
+	default:
+		return;
+	case 0:
+		uart = &miniuart;
+		break;
+	}
+
+	if(!uart->enabled)
+		(*uart->phys->enable)(uart, 0);
+	uartctl(uart, "b9600 l8 pn s1");
+	if(*cmd != '\0')
+		uartctl(uart, cmd);
+
+	consuart = uart;
+	uart->console = 1;
+}
+
+PhysUart miniphysuart = {
+	.name		= "miniuart",
+	.pnp		= pnp,
+	.enable		= enable,
+	.disable	= disable,
+	.kick		= kick,
+	.dobreak	= dobreak,
+	.baud		= baud,
+	.bits		= bits,
+	.stop		= stop,
+	.parity		= parity,
+	.modemctl	= donothing,
+	.rts		= rts,
+	.dtr		= donothing,
+	.status		= status,
+	.fifo		= donothing,
+	.getc		= getc,
+	.putc		= putc,
+};
+
+void
+okay(int on)
+{
+	static int first;
+
+	if(!first++)
+		gpiosel(OkLed, Output);
+	gpioout(OkLed, !on);
+}