From d0a8ce08199b40e29a7c7b3642c56e7158b1ca09 Mon Sep 17 00:00:00 2001
From: Mark Rages <mrages@sram.com>
Date: Fri, 27 Jul 2018 16:07:19 -0600
Subject: [PATCH] Add extra port for mass erasing / unprotecting nRF52 with
 APPROTECT set.

Mostly copied from the equivalent in kinetis.c and
https://devzone.nordicsemi.com/f/nordic-q-a/12484/approtect-and-dap/47301
---
 src/target/adiv5.c   |  3 ++
 src/target/kinetis.c |  2 +-
 src/target/nrf51.c   | 78 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 82 insertions(+), 1 deletion(-)

diff --git a/src/target/adiv5.c b/src/target/adiv5.c
index 109cab3..08baf30 100644
--- a/src/target/adiv5.c
+++ b/src/target/adiv5.c
@@ -445,6 +445,9 @@ void adiv5_dp_init(ADIv5_DP_t *dp)
 		extern void kinetis_mdm_probe(ADIv5_AP_t *);
 		kinetis_mdm_probe(ap);
 
+		extern void nrf51_mdm_probe(ADIv5_AP_t *);
+		nrf51_mdm_probe(ap);
+
 		if (ap->base == 0xffffffff) {
 			/* No debug entries... useless AP */
 			adiv5_ap_unref(ap);
diff --git a/src/target/kinetis.c b/src/target/kinetis.c
index 4770773..d9f4d0a 100644
--- a/src/target/kinetis.c
+++ b/src/target/kinetis.c
@@ -341,7 +341,7 @@ const struct command_s kinetis_mdm_cmd_list[] = {
 	{NULL, NULL, NULL}
 };
 
-bool nop_function(void)
+static bool nop_function(void)
 {
 	return true;
 }
diff --git a/src/target/nrf51.c b/src/target/nrf51.c
index f85d182..9948bb1 100644
--- a/src/target/nrf51.c
+++ b/src/target/nrf51.c
@@ -335,3 +335,81 @@ static bool nrf51_cmd_read(target *t, int argc, const char *argv[])
 
 	return nrf51_cmd_read_help(t);
 }
+
+#include "adiv5.h"
+#define NRF52_MDM_IDR 0x02880000
+
+static bool nrf51_mdm_cmd_erase_mass(target *t);
+
+const struct command_s nrf51_mdm_cmd_list[] = {
+	{"erase_mass", (cmd_handler)nrf51_mdm_cmd_erase_mass, "Erase entire flash memory"},
+	{NULL, NULL, NULL}
+};
+
+static bool nop_function(void)
+{
+	return true;
+}
+
+void nrf51_mdm_probe(ADIv5_AP_t *ap)
+{
+	switch(ap->idr) {
+	case NRF52_MDM_IDR:
+		break;
+	default:
+		return;
+	}
+
+	target *t = target_new();
+	adiv5_ap_ref(ap);
+	t->priv = ap;
+	t->priv_free = (void*)adiv5_ap_unref;
+
+	t->driver = "Nordic nRF52 Access Port";
+	t->attach = (void*)nop_function;
+	t->detach = (void*)nop_function;
+	t->check_error = (void*)nop_function;
+	t->mem_read = (void*)nop_function;
+	t->mem_write = (void*)nop_function;
+	t->regs_size = 4;
+	t->regs_read = (void*)nop_function;
+	t->regs_write = (void*)nop_function;
+	t->reset = (void*)nop_function;
+	t->halt_request = (void*)nop_function;
+	//t->halt_poll = mdm_halt_poll;
+	t->halt_resume = (void*)nop_function;
+
+	target_add_commands(t, nrf51_mdm_cmd_list, t->driver);
+}
+
+#define MDM_POWER_EN ADIV5_DP_REG(0x01)
+#define MDM_SELECT_AP ADIV5_DP_REG(0x02)
+#define MDM_STATUS  ADIV5_AP_REG(0x08)
+#define MDM_CONTROL ADIV5_AP_REG(0x04)
+#define MDM_PROT_EN  ADIV5_AP_REG(0x0C)
+
+
+static bool nrf51_mdm_cmd_erase_mass(target *t)
+{
+	ADIv5_AP_t *ap = t->priv;
+
+	uint32_t status = adiv5_ap_read(ap, MDM_STATUS);
+
+	adiv5_dp_write(ap->dp, MDM_POWER_EN, 0x50000000);
+
+	adiv5_dp_write(ap->dp, MDM_SELECT_AP, 0x01000000);
+
+	adiv5_ap_write(ap, MDM_CONTROL, 0x00000001);
+
+	// Read until 0, probably should have a timeout here...
+	do {
+		status = adiv5_ap_read(ap, MDM_STATUS);
+	} while (status);
+
+	// The second read will provide true prot status
+	status = adiv5_ap_read(ap, MDM_PROT_EN);
+	status = adiv5_ap_read(ap, MDM_PROT_EN);
+
+	// should we return the prot status here?
+	return true;
+}