Signed-off-by: Finn Thain Acked-by: Geert Uytterhoeven --- This is intended to improve code style and not affect code behaviour. I've tested this on a Quadra 650. I don't know the meanings of the 4 undocumented write protect register bits 0x55, so I decided against defining 4 macros for those bits. --- arch/m68k/mac/misc.c | 59 +++++++++++++++++++++++++++++++++++---------------- 1 file changed, 41 insertions(+), 18 deletions(-) Index: linux/arch/m68k/mac/misc.c =================================================================== --- linux.orig/arch/m68k/mac/misc.c 2015-08-23 20:41:22.000000000 +1000 +++ linux/arch/m68k/mac/misc.c 2015-08-23 20:41:23.000000000 +1000 @@ -242,6 +242,21 @@ 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 @@ -250,13 +265,17 @@ 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; @@ -264,10 +283,10 @@ static void via_pram_command(int command 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(); @@ -306,10 +325,10 @@ static long 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 @@ -317,10 +336,14 @@ static long 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 result.idata - RTC_OFFSET; @@ -356,18 +379,18 @@ static void via_write_time(long time) /* 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 = 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) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/