[RFC 23/24] m68k/mac: Fix PRAM accessors

Finn Thain
2015-05-31T01:21:15Z

[-- Attachment #1: fix-mac-pram-accessors --]
[-- Type: text/plain, Size: 2947 bytes --]

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>

---

Tested on a PowerBook 520 and Quadra 650.

---
arch/m68k/mac/misc.c | 35 +++++++++++++++++++++++++++++------
include/uapi/linux/pmu.h | 2 ++
2 files changed, 31 insertions(+), 6 deletions(-)

Index: linux/arch/m68k/mac/misc.c
===================================================================
--- linux.orig/arch/m68k/mac/misc.c 2015-05-31 11:01:26.000000000 +1000
+++ linux/arch/m68k/mac/misc.c 2015-05-31 11:01:28.000000000 +1000
@@ -124,19 +124,22 @@ static void pmu_write_time(long data)
static unsigned char pmu_pram_read_byte(int offset)
{
struct adb_request req;
- if (pmu_request(&req, NULL, 3, PMU_READ_NVRAM,
- (offset >> 8) & 0xFF, offset & 0xFF) < 0)
+
+ if (pmu_request(&req, NULL, 3, PMU_READ_XPRAM,
+ offset & 0xFF, 1) < 0)
return 0;
while (!req.complete)
pmu_poll();
- return req.reply[3];
+
+ return req.reply[1];
}

static void pmu_pram_write_byte(unsigned char data, int offset)
{
struct adb_request req;
- if (pmu_request(&req, NULL, 4, PMU_WRITE_NVRAM,
- (offset >> 8) & 0xFF, offset & 0xFF, data) < 0)
+
+ if (pmu_request(&req, NULL, 4, PMU_WRITE_XPRAM,
+ offset & 0xFF, 1, data) < 0)
return;
while (!req.complete)
pmu_poll();
@@ -295,11 +298,31 @@ static void via_pram_command(int command
#if IS_ENABLED(CONFIG_NVRAM)
static unsigned char via_pram_read_byte(int offset)
{
- return 0;
+ unsigned char temp;
+ int addr = ((offset & 0xE0) << 3) | ((offset & 0x1F) << 2);
+
+ /* Use RTC command 0x38 for XPRAM access, as per MESS source code */
+ via_pram_command(addr | 0x3800 | 0x8001, &temp);
+
+ return temp;
}

static void via_pram_write_byte(unsigned char data, int offset)
{
+ unsigned char temp;
+ int addr = ((offset & 0xE0) << 3) | ((offset & 0x1F) << 2);
+
+ /* Clear the write protect bit */
+ temp = 0x55;
+ via_pram_command(0x34 | 0x01, &temp);
+
+ /* Write the byte to XPRAM */
+ temp = data;
+ via_pram_command(0x3800 | 0x0001 | addr, &temp);
+
+ /* Set the write protect bit */
+ temp = 0xD5;
+ via_pram_command(0x34 | 0x01, &temp);
}
#endif /* CONFIG_NVRAM */

Index: linux/include/uapi/linux/pmu.h
===================================================================
--- linux.orig/include/uapi/linux/pmu.h 2015-05-31 11:00:59.000000000 +1000
+++ linux/include/uapi/linux/pmu.h 2015-05-31 11:01:28.000000000 +1000
@@ -18,7 +18,9 @@
#define PMU_POWER_CTRL 0x11 /* control power of some devices */
#define PMU_ADB_CMD 0x20 /* send ADB packet */
#define PMU_ADB_POLL_OFF 0x21 /* disable ADB auto-poll */
+#define PMU_WRITE_XPRAM 0x32 /* write eXtended Parameter RAM */
#define PMU_WRITE_NVRAM 0x33 /* write non-volatile RAM */
+#define PMU_READ_XPRAM 0x3a /* read eXtended Parameter RAM */
#define PMU_READ_NVRAM 0x3b /* read non-volatile RAM */
#define PMU_SET_RTC 0x30 /* set real-time clock */
#define PMU_READ_RTC 0x38 /* read real-time clock */