From aa7357861a8ba9762ba1c5ac5fbcb2598abe3cd5 Mon Sep 17 00:00:00 2001
From: Solomon Peachy <pizza@shaftnet.org>
Date: Mon, 22 Apr 2024 21:55:26 -0400
Subject: ipod6g: Issue a FLUSH_CACHE[_EXT] command if device can't sleep.

Additionally, synchronize with the standard ATA driver's feature table

 * Acoustic management set to quietest
 * Set power mode to lowest w/o standby

Change-Id: I12e64354d4c946228e9a55fc8da2114127d08d28
---
 .../target/arm/s5l8702/ipod6g/storage_ata-6g.c     | 49 ++++++++++++++++++++--
 1 file changed, 45 insertions(+), 4 deletions(-)

diff --git a/firmware/target/arm/s5l8702/ipod6g/storage_ata-6g.c b/firmware/target/arm/s5l8702/ipod6g/storage_ata-6g.c
index f77cfcbac6..7a3be20577 100644
--- a/firmware/target/arm/s5l8702/ipod6g/storage_ata-6g.c
+++ b/firmware/target/arm/s5l8702/ipod6g/storage_ata-6g.c
@@ -48,6 +48,8 @@
 #define CMD_READ_DMA               0xC8
 #define CMD_WRITE_DMA              0xCA
 #define CMD_STANDBY_IMMEDIATE      0xE0
+#define CMD_FLUSH_CACHE            0xE7
+#define CMD_FLUSH_CACHE_EXT        0xEA
 #define CMD_IDENTIFY               0xEC
 #define CMD_SET_FEATURES           0xEF
 
@@ -678,10 +680,15 @@ static int ata_power_up(void)
         }
         ata_dma = param ? true : false;
         dma_mode = param;
-        PASS_RC(ata_set_feature(0x03, param), 3, 4);
+        PASS_RC(ata_set_feature(0x03, param), 3, 4); /* Transfer mode */
         if (ata_identify_data[82] & BIT(5))
-            PASS_RC(ata_set_feature(0x02, 0), 3, 5);
-        if (ata_identify_data[82] & BIT(6)) PASS_RC(ata_set_feature(0xaa, 0), 3, 6);
+            PASS_RC(ata_set_feature(0x02, 0), 3, 5); /* Enable volatile write cache */
+        if (ata_identify_data[82] & BIT(6))
+            PASS_RC(ata_set_feature(0xaa, 0), 3, 6); /* Enable read lookahead */
+        if (ata_identify_data[83] & BIT(3))
+            PASS_RC(ata_set_feature(0x05, 0x80), 3, 7); /* Enable lowest power mode w/o standby */
+        if (ata_identify_data[83] & BIT(9))
+            PASS_RC(ata_set_feature(0x42, 0x80), 3, 8); /* Enable lowest noise mode */
         ATA_PIO_TIME = piotime;
         ATA_MDMA_TIME = mdmatime;
         ATA_UDMA_TIME = udmatime;
@@ -692,7 +699,8 @@ static int ata_power_up(void)
                             | (((uint64_t)ata_identify_data[101]) << 16)
                             | (((uint64_t)ata_identify_data[102]) << 32)
                             | (((uint64_t)ata_identify_data[103]) << 48);
-    else ata_total_sectors = ata_identify_data[60] | (((uint32_t)ata_identify_data[61]) << 16);
+    else
+        ata_total_sectors = ata_identify_data[60] | (((uint32_t)ata_identify_data[61]) << 16);
     ata_total_sectors >>= 3;
     ata_powered = true;
     ata_set_active();
@@ -981,12 +989,45 @@ void ata_spindown(int seconds)
     ata_sleep_timeout = seconds * HZ;
 }
 
+static void ata_flush_cache(void)
+{
+    uint8_t cmd;
+
+    if (ata_identify_data[83] & BIT(13)) {
+        cmd = CMD_FLUSH_CACHE_EXT;
+    } else if (ata_identify_data[83] & BIT(12)) {
+        cmd = CMD_FLUSH_CACHE;
+    } else {
+        /* If neither (mandatory!) command is supported
+           then don't issue it. */
+       return;
+    }
+
+    if (ceata)
+    {
+        memset(ceata_taskfile, 0, 16);
+        ceata_taskfile[0xf] = cmd;
+        ceata_wait_idle();
+        ceata_write_multiple_register(0, ceata_taskfile, 16);
+        ceata_wait_idle();
+    }
+    else
+    {
+        ata_wait_for_rdy(1000000);
+        ata_write_cbr(&ATA_PIO_DVR, 0);
+        ata_write_cbr(&ATA_PIO_CSD, cmd);
+        ata_wait_for_rdy(1000000);
+    }
+}
+
 void ata_sleepnow(void)
 {
     mutex_lock(&ata_mutex);
 
     if (ata_disk_can_poweroff())
         ata_power_down();
+    else
+        ata_flush_cache();
 
     mutex_unlock(&ata_mutex);
 }
-- 
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