From 561ad1494cad32243fa256af8acb755466ef12a7 Mon Sep 17 00:00:00 2001
From: Ian Moffett <ian@osmora.org>
Date: Sun, 21 Sep 2025 14:12:27 -0400
Subject: kern: ahci: Scan for implemented ports with PI reg

Signed-off-by: Ian Moffett <ian@osmora.org>
---
 src/sys/io/ic/ahci.c | 30 ++++++++++++++++++++++++++++--
 1 file changed, 28 insertions(+), 2 deletions(-)

(limited to 'src/sys/io/ic/ahci.c')

diff --git a/src/sys/io/ic/ahci.c b/src/sys/io/ic/ahci.c
index 825306d..9f96a00 100644
--- a/src/sys/io/ic/ahci.c
+++ b/src/sys/io/ic/ahci.c
@@ -143,6 +143,27 @@ ahci_hba_reset(struct ahci_hba *hba)
     return 0;
 }
 
+/*
+ * Initialize the ports of an HBA
+ */
+static int
+ahci_init_ports(struct ahci_hba *hba)
+{
+    volatile struct hba_memspace *io = hba->io;
+    uint32_t pi, nbits;
+
+    pi = hba->pi;
+    for (int i = 0; i < hba->nport; ++i) {
+        if (!ISSET(pi, BIT(i))) {
+            continue;
+        }
+
+        dtrace("port %d implemented\n", i);
+    }
+
+    return 0;
+}
+
 /*
  * Put the HBA as well as its devices in an initialized
  * state so that they may be used for operation.
@@ -151,9 +172,14 @@ static int
 ahci_hba_init(struct ahci_hba *hba)
 {
     volatile struct hba_memspace *io = hba->io;
-    uint32_t ghc;
+    uint32_t ghc, cap;
     int error;
 
+    /* Yoink from firmware before reset */
+    cap = mmio_read32(&io->cap);
+    hba->pi = mmio_read32(&io->pi);
+    hba->nport = AHCI_CAP_NP(cap) + 1;
+
     /*
      * We cannot be so certain what state the BIOS or whatever
      * firmware left the host controller in, therefore the HBA
@@ -173,7 +199,7 @@ ahci_hba_init(struct ahci_hba *hba)
     ghc = mmio_read32(&io->ghc);
     ghc |= AHCI_GHC_AE;
     mmio_write32(&io->ghc, ghc);
-    return 0;
+    return ahci_init_ports(hba);
 }
 
 /*
-- 
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