Re: [RFC v2 23/24] m68k/mac: Fix PRAM accessors
From: Geert Uytterhoeven <geert@linux-m68k.org>
Date: 2015-06-15 08:23:29
Also in:
linux-api, linux-m68k, lkml
Hi Finn, On Sun, Jun 14, 2015 at 9:46 AM, Finn Thain [off-list ref] wrote:
quoted hunk ↗ jump to hunk
--- linux.orig/arch/m68k/mac/misc.c 2015-06-14 17:46:02.000000000 +1000 +++ linux/arch/m68k/mac/misc.c 2015-06-14 17:46:03.000000000 +1000@@ -284,11 +287,31 @@ static void via_pram_command(int command static unsigned char via_pram_read_byte(int offset) { - return 0; + unsigned char temp; + int addr = ((offset & 0xE0) << 3) | ((offset & 0x1F) << 2);
Can you please add #defines for the magic values?
+ + /* Use RTC command 0x38 for XPRAM access, as per MESS source code */ + via_pram_command(addr | 0x3800 | 0x8001, &temp);
It seems 0x38 is already documented in <linux/pmu.h> (see below), or not (it's shifted left by 8 bits?)?
+
+ 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);More magic values...
quoted hunk ↗ jump to hunk
} /* Index: linux/include/uapi/linux/pmu.h ===================================================================--- linux.orig/include/uapi/linux/pmu.h 2015-06-14 17:45:34.000000000 +1000 +++ linux/include/uapi/linux/pmu.h 2015-06-14 17:46:03.000000000 +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 */
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds