[PATCH v9 13/22] m68k/mac: Fix PRAM accessors

Finn Thain
2019-01-15T04:22:59Z

PMU-based m68k Macs pre-date PowerMac-style NVRAM. Use the appropriate
PMU commands. Also implement the missing XPRAM accessors for VIA-based
Macs.

Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: Stan Johnson <userm57@yahoo.com>
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
---
Changed since v7:
- Revised PMU response decoding due to via-pmu68k driver replacement.
---
arch/m68k/mac/misc.c | 43 ++++++++++++++++++++++++++++++----------
include/uapi/linux/pmu.h | 2 ++
2 files changed, 35 insertions(+), 10 deletions(-)

diff --git a/arch/m68k/mac/misc.c b/arch/m68k/mac/misc.c
index af000a015f68..d016ca2e0d10 100644
--- a/arch/m68k/mac/misc.c
+++ b/arch/m68k/mac/misc.c
@@ -66,23 +66,22 @@ 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];
+ pmu_wait_complete(&req);
+
+ return req.reply[0];
}

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();
+ pmu_wait_complete(&req);
}
#endif /* CONFIG_ADB_PMU */

@@ -151,6 +150,16 @@ static void via_rtc_send(__u8 data)
#define RTC_REG_SECONDS_3 3
#define RTC_REG_WRITE_PROTECT 13

+/*
+ * Inside Mac has no information about two-byte RTC commands but
+ * the MAME/MESS source code has the essentials.
+ */
+
+#define RTC_REG_XPRAM 14
+#define RTC_CMD_XPRAM_READ (RTC_CMD_READ(RTC_REG_XPRAM) << 8)
+#define RTC_CMD_XPRAM_WRITE (RTC_CMD_WRITE(RTC_REG_XPRAM) << 8)
+#define RTC_CMD_XPRAM_ARG(a) (((a & 0xE0) << 3) | ((a & 0x1F) << 2))
+
/*
* Execute a VIA PRAM/RTC command. For read commands
* data should point to a one-byte buffer for the
@@ -198,11 +207,25 @@ static void via_rtc_command(int command, __u8 *data)

static unsigned char via_pram_read_byte(int offset)
{
- return 0;
+ unsigned char temp;
+
+ via_rtc_command(RTC_CMD_XPRAM_READ | RTC_CMD_XPRAM_ARG(offset), &temp);
+
+ return temp;
}

static void via_pram_write_byte(unsigned char data, int offset)
{
+ unsigned char temp;
+
+ temp = 0x55;
+ via_rtc_command(RTC_CMD_WRITE(RTC_REG_WRITE_PROTECT), &temp);
+
+ temp = data;
+ via_rtc_command(RTC_CMD_XPRAM_WRITE | RTC_CMD_XPRAM_ARG(offset), &temp);
+
+ temp = 0x55 | RTC_FLG_WRITE_PROTECT;
+ via_rtc_command(RTC_CMD_WRITE(RTC_REG_WRITE_PROTECT), &temp);
}

/*
diff --git a/include/uapi/linux/pmu.h b/include/uapi/linux/pmu.h
index 97256f90e6df..f2fc1bd80017 100644
--- a/include/uapi/linux/pmu.h
+++ b/include/uapi/linux/pmu.h
@@ -19,7 +19,9 @@
#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 */
--
2.19.2