diff options
Diffstat (limited to 'arch/m68k/mac/misc.c')
| -rw-r--r-- | arch/m68k/mac/misc.c | 59 |
1 files changed, 41 insertions, 18 deletions
diff --git a/arch/m68k/mac/misc.c b/arch/m68k/mac/misc.c index 78c807025436..af000a015f68 100644 --- a/arch/m68k/mac/misc.c +++ b/arch/m68k/mac/misc.c @@ -137,6 +137,21 @@ static void via_rtc_send(__u8 data) } /* + * These values can be found in Inside Macintosh vol. III ch. 2 + * which has a description of the RTC chip in the original Mac. + */ + +#define RTC_FLG_READ BIT(7) +#define RTC_FLG_WRITE_PROTECT BIT(7) +#define RTC_CMD_READ(r) (RTC_FLG_READ | (r << 2)) +#define RTC_CMD_WRITE(r) (r << 2) +#define RTC_REG_SECONDS_0 0 +#define RTC_REG_SECONDS_1 1 +#define RTC_REG_SECONDS_2 2 +#define RTC_REG_SECONDS_3 3 +#define RTC_REG_WRITE_PROTECT 13 + +/* * Execute a VIA PRAM/RTC command. For read commands * data should point to a one-byte buffer for the * resulting data. For write commands it should point @@ -145,13 +160,17 @@ static void via_rtc_send(__u8 data) * This function disables all interrupts while running. */ -static void via_pram_command(int command, __u8 *data) +static void via_rtc_command(int command, __u8 *data) { unsigned long flags; int is_read; local_irq_save(flags); + /* The least significant bits must be 0b01 according to Inside Mac */ + + command = (command & ~3) | 1; + /* Enable the RTC and make sure the strobe line is high */ via1[vBufB] = (via1[vBufB] | VIA1B_vRTCClk) & ~VIA1B_vRTCEnb; @@ -159,10 +178,10 @@ static void via_pram_command(int command, __u8 *data) if (command & 0xFF00) { /* extended (two-byte) command */ via_rtc_send((command & 0xFF00) >> 8); via_rtc_send(command & 0xFF); - is_read = command & 0x8000; + is_read = command & (RTC_FLG_READ << 8); } else { /* one-byte command */ via_rtc_send(command); - is_read = command & 0x80; + is_read = command & RTC_FLG_READ; } if (is_read) { *data = via_rtc_recv(); @@ -201,10 +220,10 @@ static time64_t via_read_time(void) } result, last_result; int count = 1; - via_pram_command(0x81, &last_result.cdata[3]); - via_pram_command(0x85, &last_result.cdata[2]); - via_pram_command(0x89, &last_result.cdata[1]); - via_pram_command(0x8D, &last_result.cdata[0]); + via_rtc_command(RTC_CMD_READ(RTC_REG_SECONDS_0), &last_result.cdata[3]); + via_rtc_command(RTC_CMD_READ(RTC_REG_SECONDS_1), &last_result.cdata[2]); + via_rtc_command(RTC_CMD_READ(RTC_REG_SECONDS_2), &last_result.cdata[1]); + via_rtc_command(RTC_CMD_READ(RTC_REG_SECONDS_3), &last_result.cdata[0]); /* * The NetBSD guys say to loop until you get the same reading @@ -212,10 +231,14 @@ static time64_t via_read_time(void) */ while (1) { - via_pram_command(0x81, &result.cdata[3]); - via_pram_command(0x85, &result.cdata[2]); - via_pram_command(0x89, &result.cdata[1]); - via_pram_command(0x8D, &result.cdata[0]); + via_rtc_command(RTC_CMD_READ(RTC_REG_SECONDS_0), + &result.cdata[3]); + via_rtc_command(RTC_CMD_READ(RTC_REG_SECONDS_1), + &result.cdata[2]); + via_rtc_command(RTC_CMD_READ(RTC_REG_SECONDS_2), + &result.cdata[1]); + via_rtc_command(RTC_CMD_READ(RTC_REG_SECONDS_3), + &result.cdata[0]); if (result.idata == last_result.idata) return (time64_t)result.idata - RTC_OFFSET; @@ -254,18 +277,18 @@ static void via_set_rtc_time(struct rtc_time *tm) /* Clear the write protect bit */ temp = 0x55; - via_pram_command(0x35, &temp); + via_rtc_command(RTC_CMD_WRITE(RTC_REG_WRITE_PROTECT), &temp); data.idata = lower_32_bits(time + RTC_OFFSET); - via_pram_command(0x01, &data.cdata[3]); - via_pram_command(0x05, &data.cdata[2]); - via_pram_command(0x09, &data.cdata[1]); - via_pram_command(0x0D, &data.cdata[0]); + via_rtc_command(RTC_CMD_WRITE(RTC_REG_SECONDS_0), &data.cdata[3]); + via_rtc_command(RTC_CMD_WRITE(RTC_REG_SECONDS_1), &data.cdata[2]); + via_rtc_command(RTC_CMD_WRITE(RTC_REG_SECONDS_2), &data.cdata[1]); + via_rtc_command(RTC_CMD_WRITE(RTC_REG_SECONDS_3), &data.cdata[0]); /* Set the write protect bit */ - temp = 0xD5; - via_pram_command(0x35, &temp); + temp = 0x55 | RTC_FLG_WRITE_PROTECT; + via_rtc_command(RTC_CMD_WRITE(RTC_REG_WRITE_PROTECT), &temp); } static void via_shutdown(void) |