[POWERPC] bootwrapper: Add CPM serial driver

This serial port is used on all 8xx, many 82xx, and some 85xx chips.

The driver requires that the port has already been set up by the firmware
and/or platform code.

Signed-off-by: Scott Wood <scottwood@freescale.com>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 249 insertions, 0 deletions

diff --git a/arch/powerpc/boot/cpm-serial.c b/arch/powerpc/boot/cpm-serial.c
new file mode 100644
index 000000000000..fcb8b5e956bd
--- /dev/null
+++ b/arch/powerpc/boot/cpm-serial.c
@@ -0,0 +1,249 @@
+/*
+ * CPM serial console support.
+ *
+ * Copyright 2007 Freescale Semiconductor, Inc.
+ * Author: Scott Wood <scottwood@freescale.com>
+ *
+ * It is assumed that the firmware (or the platform file) has already set
+ * up the port.
+ */
+
+#include "types.h"
+#include "io.h"
+#include "ops.h"
+
+struct cpm_scc {
+	u32 gsmrl;
+	u32 gsmrh;
+	u16 psmr;
+	u8 res1[2];
+	u16 todr;
+	u16 dsr;
+	u16 scce;
+	u8 res2[2];
+	u16 sccm;
+	u8 res3;
+	u8 sccs;
+	u8 res4[8];
+};
+
+struct cpm_smc {
+	u8 res1[2];
+	u16 smcmr;
+	u8 res2[2];
+	u8 smce;
+	u8 res3[3];
+	u8 smcm;
+	u8 res4[5];
+};
+
+struct cpm_param {
+	u16 rbase;
+	u16 tbase;
+	u8 rfcr;
+	u8 tfcr;
+};
+
+struct cpm_bd {
+	u16 sc;   /* Status and Control */
+	u16 len;  /* Data length in buffer */
+	u8 *addr; /* Buffer address in host memory */
+};
+
+static void *cpcr;
+static struct cpm_param *param;
+static struct cpm_smc *smc;
+static struct cpm_scc *scc;
+struct cpm_bd *tbdf, *rbdf;
+static u32 cpm_cmd;
+static u8 *dpram_start;
+
+static void (*do_cmd)(int op);
+static void (*enable_port)(void);
+static void (*disable_port)(void);
+
+#define CPM_CMD_STOP_TX     4
+#define CPM_CMD_RESTART_TX  6
+#define CPM_CMD_INIT_RX_TX  0
+
+static void cpm1_cmd(int op)
+{
+	while (in_be16(cpcr) & 1)
+		;
+
+	out_be16(cpcr, (op << 8) | cpm_cmd | 1);
+
+	while (in_be16(cpcr) & 1)
+		;
+}
+
+static void cpm2_cmd(int op)
+{
+	while (in_be32(cpcr) & 0x10000)
+		;
+
+	out_be32(cpcr, op | cpm_cmd | 0x10000);
+
+	while (in_be32(cpcr) & 0x10000)
+		;
+}
+
+static void smc_disable_port(void)
+{
+	do_cmd(CPM_CMD_STOP_TX);
+	out_be16(&smc->smcmr, in_be16(&smc->smcmr) & ~3);
+}
+
+static void scc_disable_port(void)
+{
+	do_cmd(CPM_CMD_STOP_TX);
+	out_be32(&scc->gsmrl, in_be32(&scc->gsmrl) & ~0x30);
+}
+
+static void smc_enable_port(void)
+{
+	out_be16(&smc->smcmr, in_be16(&smc->smcmr) | 3);
+	do_cmd(CPM_CMD_RESTART_TX);
+}
+
+static void scc_enable_port(void)
+{
+	out_be32(&scc->gsmrl, in_be32(&scc->gsmrl) | 0x30);
+	do_cmd(CPM_CMD_RESTART_TX);
+}
+
+static int cpm_serial_open(void)
+{
+	int dpaddr = 0x800;
+	disable_port();
+
+	out_8(&param->rfcr, 0x10);
+	out_8(&param->tfcr, 0x10);
+
+	rbdf = (struct cpm_bd *)(dpram_start + dpaddr);
+	rbdf->addr = (u8 *)(rbdf + 2);
+	rbdf->sc = 0xa000;
+	rbdf->len = 1;
+
+	tbdf = rbdf + 1;
+	tbdf->addr = (u8 *)(rbdf + 2) + 1;
+	tbdf->sc = 0x2000;
+	tbdf->len = 1;
+
+	sync();
+	out_be16(&param->rbase, dpaddr);
+	out_be16(&param->tbase, dpaddr + sizeof(struct cpm_bd));
+
+	do_cmd(CPM_CMD_INIT_RX_TX);
+
+	enable_port();
+	return 0;
+}
+
+static void cpm_serial_putc(unsigned char c)
+{
+	while (tbdf->sc & 0x8000)
+		barrier();
+
+	sync();
+
+	tbdf->addr[0] = c;
+	eieio();
+	tbdf->sc |= 0x8000;
+}
+
+static unsigned char cpm_serial_tstc(void)
+{
+	barrier();
+	return !(rbdf->sc & 0x8000);
+}
+
+static unsigned char cpm_serial_getc(void)
+{
+	unsigned char c;
+
+	while (!cpm_serial_tstc())
+		;
+
+	sync();
+	c = rbdf->addr[0];
+	eieio();
+	rbdf->sc |= 0x8000;
+
+	return c;
+}
+
+int cpm_console_init(void *devp, struct serial_console_data *scdp)
+{
+	void *reg_virt[2];
+	int is_smc = 0, is_cpm2 = 0, n;
+	unsigned long reg_phys;
+	void *parent;
+
+	if (dt_is_compatible(devp, "fsl,cpm1-smc-uart")) {
+		is_smc = 1;
+	} else if (dt_is_compatible(devp, "fsl,cpm2-scc-uart")) {
+		is_cpm2 = 1;
+	} else if (dt_is_compatible(devp, "fsl,cpm2-smc-uart")) {
+		is_cpm2 = 1;
+		is_smc = 1;
+	}
+
+	if (is_smc) {
+		enable_port = smc_enable_port;
+		disable_port = smc_disable_port;
+	} else {
+		enable_port = scc_enable_port;
+		disable_port = scc_disable_port;
+	}
+
+	if (is_cpm2)
+		do_cmd = cpm2_cmd;
+	else
+		do_cmd = cpm1_cmd;
+
+	n = getprop(devp, "fsl,cpm-command", &cpm_cmd, 4);
+	if (n < 4)
+		return -1;
+
+	n = getprop(devp, "virtual-reg", reg_virt, sizeof(reg_virt));
+	if (n < (int)sizeof(reg_virt)) {
+		for (n = 0; n < 2; n++) {
+			if (!dt_xlate_reg(devp, n, &reg_phys, NULL))
+				return -1;
+
+			reg_virt[n] = (void *)reg_phys;
+		}
+	}
+
+	if (is_smc)
+		smc = reg_virt[0];
+	else
+		scc = reg_virt[0];
+
+	param = reg_virt[1];
+
+	parent = get_parent(devp);
+	if (!parent)
+		return -1;
+
+	n = getprop(parent, "virtual-reg", reg_virt, sizeof(reg_virt));
+	if (n < (int)sizeof(reg_virt)) {
+		for (n = 0; n < 2; n++) {
+			if (!dt_xlate_reg(parent, n, &reg_phys, NULL))
+				return -1;
+
+			reg_virt[n] = (void *)reg_phys;
+		}
+	}
+
+	cpcr = reg_virt[0];
+	dpram_start = reg_virt[1];
+
+	scdp->open = cpm_serial_open;
+	scdp->putc = cpm_serial_putc;
+	scdp->getc = cpm_serial_getc;
+	scdp->tstc = cpm_serial_tstc;
+
+	return 0;
+}