From ae89a65956f95c2bee652396286d97b47ff804b6 Mon Sep 17 00:00:00 2001
From: Kevin O'Connor <kevin@koconnor.net>
Date: Wed, 24 Mar 2021 19:49:08 -0400
Subject: [PATCH] lpc176x: Do not modify PCLKSELx at runtime

The lpc176x has an errata that could cause updates to PCLKSELx to not
take effect.  Rework the code to use the default peripheral clock
speed (25Mhz or 30Mhz) so that this register does not need to be
updated at runtime.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
---
 src/lpc176x/main.c | 9 +--------
 1 file changed, 1 insertion(+), 8 deletions(-)

diff --git a/src/lpc176x/main.c b/src/lpc176x/main.c
index b35e31eee..d12bcd57d 100644
--- a/src/lpc176x/main.c
+++ b/src/lpc176x/main.c
@@ -49,20 +49,13 @@ void
 enable_pclock(uint32_t pclk)
 {
     LPC_SC->PCONP |= 1<<pclk;
-    if (pclk < 16) {
-        uint32_t shift = pclk * 2;
-        LPC_SC->PCLKSEL0 = (LPC_SC->PCLKSEL0 & ~(0x3<<shift)) | (0x1<<shift);
-    } else {
-        uint32_t shift = (pclk - 16) * 2;
-        LPC_SC->PCLKSEL1 = (LPC_SC->PCLKSEL1 & ~(0x3<<shift)) | (0x1<<shift);
-    }
 }
 
 // Return the frequency of the given peripheral clock
 uint32_t
 get_pclock_frequency(uint32_t pclk)
 {
-    return CONFIG_CLOCK_FREQ;
+    return CONFIG_CLOCK_FREQ / 4;
 }
 
 // Main entry point - called from armcm_boot.c:ResetHandler()