Merge tag 'char-misc-5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char/misc driver updates from Greg KH:
 "Here is the big char/misc driver patch pull request for 5.1-rc1.

  The largest thing by far is the new habanalabs driver for their AI
  accelerator chip. For now it is in the drivers/misc directory but will
  probably move to a new directory soon along with other drivers of this
  type.

  Other than that, just the usual set of individual driver updates and
  fixes. There's an "odd" merge in here from the DRM tree that they
  asked me to do as the MEI driver is starting to interact with the i915
  driver, and it needed some coordination. All of those patches have
  been properly acked by the relevant subsystem maintainers.

  All of these have been in linux-next with no reported issues, most for
  quite some time"

* tag 'char-misc-5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (219 commits)
  habanalabs: adjust Kconfig to fix build errors
  habanalabs: use %px instead of %p in error print
  habanalabs: use do_div for 64-bit divisions
  intel_th: gth: Fix an off-by-one in output unassigning
  habanalabs: fix little-endian<->cpu conversion warnings
  habanalabs: use NULL to initialize array of pointers
  habanalabs: fix little-endian<->cpu conversion warnings
  habanalabs: soft-reset device if context-switch fails
  habanalabs: print pointer using %p
  habanalabs: fix memory leak with CBs with unaligned size
  habanalabs: return correct error code on MMU mapping failure
  habanalabs: add comments in uapi/misc/habanalabs.h
  habanalabs: extend QMAN0 job timeout
  habanalabs: set DMA0 completion to SOB 1007
  habanalabs: fix validation of WREG32 to DMA completion
  habanalabs: fix mmu cache registers init
  habanalabs: disable CPU access on timeouts
  habanalabs: add MMU DRAM default page mapping
  habanalabs: Dissociate RAZWI info from event types
  misc/habanalabs: adjust Kconfig to fix build errors
  ...

7 files changed, 475 insertions, 67 deletions

diff --git a/arch/m68k/Kconfig.machine b/arch/m68k/Kconfig.machine
index 328ba83d735bc..c01e103492fdc 100644
--- a/arch/m68k/Kconfig.machine
+++ b/arch/m68k/Kconfig.machine
@@ -16,6 +16,7 @@ config ATARI
 	bool "Atari support"
 	depends on MMU
 	select MMU_MOTOROLA if MMU
+	select HAVE_ARCH_NVRAM_OPS
 	help
 	  This option enables support for the 68000-based Atari series of
 	  computers (including the TT, Falcon and Medusa). If you plan to use
@@ -26,6 +27,7 @@ config MAC
 	bool "Macintosh support"
 	depends on MMU
 	select MMU_MOTOROLA if MMU
+	select HAVE_ARCH_NVRAM_OPS
 	help
 	  This option enables support for the Apple Macintosh series of
 	  computers (yes, there is experimental support now, at least for part
diff --git a/arch/m68k/atari/Makefile b/arch/m68k/atari/Makefile
index 0cac723306f93..0b86bb6cfa876 100644
--- a/arch/m68k/atari/Makefile
+++ b/arch/m68k/atari/Makefile
@@ -6,3 +6,5 @@ obj-y		:= config.o time.o debug.o ataints.o stdma.o \
 			atasound.o stram.o
 
 obj-$(CONFIG_ATARI_KBD_CORE)	+= atakeyb.o
+
+obj-$(CONFIG_NVRAM:m=y)		+= nvram.o
diff --git a/arch/m68k/atari/nvram.c b/arch/m68k/atari/nvram.c
new file mode 100644
index 0000000000000..7000d2443aa38
--- /dev/null
+++ b/arch/m68k/atari/nvram.c
@@ -0,0 +1,272 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * CMOS/NV-RAM driver for Atari. Adapted from drivers/char/nvram.c.
+ * Copyright (C) 1997 Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de>
+ * idea by and with help from Richard Jelinek <rj@suse.de>
+ * Portions copyright (c) 2001,2002 Sun Microsystems (thockin@sun.com)
+ * Further contributions from Cesar Barros, Erik Gilling, Tim Hockin and
+ * Wim Van Sebroeck.
+ */
+
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/mc146818rtc.h>
+#include <linux/module.h>
+#include <linux/nvram.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+#include <asm/atarihw.h>
+#include <asm/atariints.h>
+
+#define NVRAM_BYTES		50
+
+/* It is worth noting that these functions all access bytes of general
+ * purpose memory in the NVRAM - that is to say, they all add the
+ * NVRAM_FIRST_BYTE offset. Pass them offsets into NVRAM as if you did not
+ * know about the RTC cruft.
+ */
+
+/* Note that *all* calls to CMOS_READ and CMOS_WRITE must be done with
+ * rtc_lock held. Due to the index-port/data-port design of the RTC, we
+ * don't want two different things trying to get to it at once. (e.g. the
+ * periodic 11 min sync from kernel/time/ntp.c vs. this driver.)
+ */
+
+static unsigned char __nvram_read_byte(int i)
+{
+	return CMOS_READ(NVRAM_FIRST_BYTE + i);
+}
+
+/* This races nicely with trying to read with checksum checking */
+static void __nvram_write_byte(unsigned char c, int i)
+{
+	CMOS_WRITE(c, NVRAM_FIRST_BYTE + i);
+}
+
+/* On Ataris, the checksum is over all bytes except the checksum bytes
+ * themselves; these are at the very end.
+ */
+#define ATARI_CKS_RANGE_START	0
+#define ATARI_CKS_RANGE_END	47
+#define ATARI_CKS_LOC		48
+
+static int __nvram_check_checksum(void)
+{
+	int i;
+	unsigned char sum = 0;
+
+	for (i = ATARI_CKS_RANGE_START; i <= ATARI_CKS_RANGE_END; ++i)
+		sum += __nvram_read_byte(i);
+	return (__nvram_read_byte(ATARI_CKS_LOC) == (~sum & 0xff)) &&
+	       (__nvram_read_byte(ATARI_CKS_LOC + 1) == (sum & 0xff));
+}
+
+static void __nvram_set_checksum(void)
+{
+	int i;
+	unsigned char sum = 0;
+
+	for (i = ATARI_CKS_RANGE_START; i <= ATARI_CKS_RANGE_END; ++i)
+		sum += __nvram_read_byte(i);
+	__nvram_write_byte(~sum, ATARI_CKS_LOC);
+	__nvram_write_byte(sum, ATARI_CKS_LOC + 1);
+}
+
+long atari_nvram_set_checksum(void)
+{
+	spin_lock_irq(&rtc_lock);
+	__nvram_set_checksum();
+	spin_unlock_irq(&rtc_lock);
+	return 0;
+}
+
+long atari_nvram_initialize(void)
+{
+	loff_t i;
+
+	spin_lock_irq(&rtc_lock);
+	for (i = 0; i < NVRAM_BYTES; ++i)
+		__nvram_write_byte(0, i);
+	__nvram_set_checksum();
+	spin_unlock_irq(&rtc_lock);
+	return 0;
+}
+
+ssize_t atari_nvram_read(char *buf, size_t count, loff_t *ppos)
+{
+	char *p = buf;
+	loff_t i;
+
+	spin_lock_irq(&rtc_lock);
+	if (!__nvram_check_checksum()) {
+		spin_unlock_irq(&rtc_lock);
+		return -EIO;
+	}
+	for (i = *ppos; count > 0 && i < NVRAM_BYTES; --count, ++i, ++p)
+		*p = __nvram_read_byte(i);
+	spin_unlock_irq(&rtc_lock);
+
+	*ppos = i;
+	return p - buf;
+}
+
+ssize_t atari_nvram_write(char *buf, size_t count, loff_t *ppos)
+{
+	char *p = buf;
+	loff_t i;
+
+	spin_lock_irq(&rtc_lock);
+	if (!__nvram_check_checksum()) {
+		spin_unlock_irq(&rtc_lock);
+		return -EIO;
+	}
+	for (i = *ppos; count > 0 && i < NVRAM_BYTES; --count, ++i, ++p)
+		__nvram_write_byte(*p, i);
+	__nvram_set_checksum();
+	spin_unlock_irq(&rtc_lock);
+
+	*ppos = i;
+	return p - buf;
+}
+
+ssize_t atari_nvram_get_size(void)
+{
+	return NVRAM_BYTES;
+}
+
+#ifdef CONFIG_PROC_FS
+static struct {
+	unsigned char val;
+	const char *name;
+} boot_prefs[] = {
+	{ 0x80, "TOS" },
+	{ 0x40, "ASV" },
+	{ 0x20, "NetBSD (?)" },
+	{ 0x10, "Linux" },
+	{ 0x00, "unspecified" },
+};
+
+static const char * const languages[] = {
+	"English (US)",
+	"German",
+	"French",
+	"English (UK)",
+	"Spanish",
+	"Italian",
+	"6 (undefined)",
+	"Swiss (French)",
+	"Swiss (German)",
+};
+
+static const char * const dateformat[] = {
+	"MM%cDD%cYY",
+	"DD%cMM%cYY",
+	"YY%cMM%cDD",
+	"YY%cDD%cMM",
+	"4 (undefined)",
+	"5 (undefined)",
+	"6 (undefined)",
+	"7 (undefined)",
+};
+
+static const char * const colors[] = {
+	"2", "4", "16", "256", "65536", "??", "??", "??"
+};
+
+static void atari_nvram_proc_read(unsigned char *nvram, struct seq_file *seq,
+				  void *offset)
+{
+	int checksum;
+	int i;
+	unsigned int vmode;
+
+	spin_lock_irq(&rtc_lock);
+	checksum = __nvram_check_checksum();
+	spin_unlock_irq(&rtc_lock);
+
+	seq_printf(seq, "Checksum status  : %svalid\n", checksum ? "" : "not ");
+
+	seq_puts(seq, "Boot preference  : ");
+	for (i = ARRAY_SIZE(boot_prefs) - 1; i >= 0; --i)
+		if (nvram[1] == boot_prefs[i].val) {
+			seq_printf(seq, "%s\n", boot_prefs[i].name);
+			break;
+		}
+	if (i < 0)
+		seq_printf(seq, "0x%02x (undefined)\n", nvram[1]);
+
+	seq_printf(seq, "SCSI arbitration : %s\n",
+		   (nvram[16] & 0x80) ? "on" : "off");
+	seq_puts(seq, "SCSI host ID     : ");
+	if (nvram[16] & 0x80)
+		seq_printf(seq, "%d\n", nvram[16] & 7);
+	else
+		seq_puts(seq, "n/a\n");
+
+	if (!MACH_IS_FALCON)
+		return;
+
+	seq_puts(seq, "OS language      : ");
+	if (nvram[6] < ARRAY_SIZE(languages))
+		seq_printf(seq, "%s\n", languages[nvram[6]]);
+	else
+		seq_printf(seq, "%u (undefined)\n", nvram[6]);
+	seq_puts(seq, "Keyboard language: ");
+	if (nvram[7] < ARRAY_SIZE(languages))
+		seq_printf(seq, "%s\n", languages[nvram[7]]);
+	else
+		seq_printf(seq, "%u (undefined)\n", nvram[7]);
+	seq_puts(seq, "Date format      : ");
+	seq_printf(seq, dateformat[nvram[8] & 7],
+		   nvram[9] ? nvram[9] : '/', nvram[9] ? nvram[9] : '/');
+	seq_printf(seq, ", %dh clock\n", nvram[8] & 16 ? 24 : 12);
+	seq_puts(seq, "Boot delay       : ");
+	if (nvram[10] == 0)
+		seq_puts(seq, "default\n");
+	else
+		seq_printf(seq, "%ds%s\n", nvram[10],
+			   nvram[10] < 8 ? ", no memory test" : "");
+
+	vmode = (nvram[14] << 8) | nvram[15];
+	seq_printf(seq,
+		   "Video mode       : %s colors, %d columns, %s %s monitor\n",
+		   colors[vmode & 7], vmode & 8 ? 80 : 40,
+		   vmode & 16 ? "VGA" : "TV", vmode & 32 ? "PAL" : "NTSC");
+	seq_printf(seq,
+		   "                   %soverscan, compat. mode %s%s\n",
+		   vmode & 64 ? "" : "no ", vmode & 128 ? "on" : "off",
+		   vmode & 256 ?
+		   (vmode & 16 ? ", line doubling" : ", half screen") : "");
+}
+
+static int nvram_proc_read(struct seq_file *seq, void *offset)
+{
+	unsigned char contents[NVRAM_BYTES];
+	int i;
+
+	spin_lock_irq(&rtc_lock);
+	for (i = 0; i < NVRAM_BYTES; ++i)
+		contents[i] = __nvram_read_byte(i);
+	spin_unlock_irq(&rtc_lock);
+
+	atari_nvram_proc_read(contents, seq, offset);
+
+	return 0;
+}
+
+static int __init atari_nvram_init(void)
+{
+	if (!(MACH_IS_ATARI && ATARIHW_PRESENT(TT_CLK)))
+		return -ENODEV;
+
+	if (!proc_create_single("driver/nvram", 0, NULL, nvram_proc_read)) {
+		pr_err("nvram: can't create /proc/driver/nvram\n");
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+device_initcall(atari_nvram_init);
+#endif /* CONFIG_PROC_FS */
diff --git a/arch/m68k/include/asm/atarihw.h b/arch/m68k/include/asm/atarihw.h
index 9000b249d225e..533008262b691 100644
--- a/arch/m68k/include/asm/atarihw.h
+++ b/arch/m68k/include/asm/atarihw.h
@@ -33,6 +33,12 @@ extern int atari_dont_touch_floppy_select;
 
 extern int atari_SCC_reset_done;
 
+extern ssize_t atari_nvram_read(char *, size_t, loff_t *);
+extern ssize_t atari_nvram_write(char *, size_t, loff_t *);
+extern ssize_t atari_nvram_get_size(void);
+extern long atari_nvram_set_checksum(void);
+extern long atari_nvram_initialize(void);
+
 /* convenience macros for testing machine type */
 #define MACH_IS_ST	((atari_mch_cookie >> 16) == ATARI_MCH_ST)
 #define MACH_IS_STE	((atari_mch_cookie >> 16) == ATARI_MCH_STE && \
diff --git a/arch/m68k/include/asm/macintosh.h b/arch/m68k/include/asm/macintosh.h
index 08cee11180e69..d9a08bed4b128 100644
--- a/arch/m68k/include/asm/macintosh.h
+++ b/arch/m68k/include/asm/macintosh.h
@@ -19,6 +19,10 @@ extern void mac_init_IRQ(void);
 extern void mac_irq_enable(struct irq_data *data);
 extern void mac_irq_disable(struct irq_data *data);
 
+extern unsigned char mac_pram_read_byte(int);
+extern void mac_pram_write_byte(unsigned char, int);
+extern ssize_t mac_pram_get_size(void);
+
 /*
  *	Macintosh Table
  */
diff --git a/arch/m68k/kernel/setup_mm.c b/arch/m68k/kernel/setup_mm.c
index ad0195cbe0425..528484feff800 100644
--- a/arch/m68k/kernel/setup_mm.c
+++ b/arch/m68k/kernel/setup_mm.c
@@ -24,6 +24,7 @@
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
 #include <linux/module.h>
+#include <linux/nvram.h>
 #include <linux/initrd.h>
 
 #include <asm/bootinfo.h>
@@ -37,13 +38,14 @@
 #ifdef CONFIG_AMIGA
 #include <asm/amigahw.h>
 #endif
-#ifdef CONFIG_ATARI
 #include <asm/atarihw.h>
+#ifdef CONFIG_ATARI
 #include <asm/atari_stram.h>
 #endif
 #ifdef CONFIG_SUN3X
 #include <asm/dvma.h>
 #endif
+#include <asm/macintosh.h>
 #include <asm/natfeat.h>
 
 #if !FPSTATESIZE || !NR_IRQS
@@ -547,3 +549,81 @@ static int __init adb_probe_sync_enable (char *str) {
 
 __setup("adb_sync", adb_probe_sync_enable);
 #endif /* CONFIG_ADB */
+
+#if IS_ENABLED(CONFIG_NVRAM)
+#ifdef CONFIG_MAC
+static unsigned char m68k_nvram_read_byte(int addr)
+{
+	if (MACH_IS_MAC)
+		return mac_pram_read_byte(addr);
+	return 0xff;
+}
+
+static void m68k_nvram_write_byte(unsigned char val, int addr)
+{
+	if (MACH_IS_MAC)
+		mac_pram_write_byte(val, addr);
+}
+#endif /* CONFIG_MAC */
+
+#ifdef CONFIG_ATARI
+static ssize_t m68k_nvram_read(char *buf, size_t count, loff_t *ppos)
+{
+	if (MACH_IS_ATARI)
+		return atari_nvram_read(buf, count, ppos);
+	else if (MACH_IS_MAC)
+		return nvram_read_bytes(buf, count, ppos);
+	return -EINVAL;
+}
+
+static ssize_t m68k_nvram_write(char *buf, size_t count, loff_t *ppos)
+{
+	if (MACH_IS_ATARI)
+		return atari_nvram_write(buf, count, ppos);
+	else if (MACH_IS_MAC)
+		return nvram_write_bytes(buf, count, ppos);
+	return -EINVAL;
+}
+
+static long m68k_nvram_set_checksum(void)
+{
+	if (MACH_IS_ATARI)
+		return atari_nvram_set_checksum();
+	return -EINVAL;
+}
+
+static long m68k_nvram_initialize(void)
+{
+	if (MACH_IS_ATARI)
+		return atari_nvram_initialize();
+	return -EINVAL;
+}
+#endif /* CONFIG_ATARI */
+
+static ssize_t m68k_nvram_get_size(void)
+{
+	if (MACH_IS_ATARI)
+		return atari_nvram_get_size();
+	else if (MACH_IS_MAC)
+		return mac_pram_get_size();
+	return -ENODEV;
+}
+
+/* Atari device drivers call .read (to get checksum validation) whereas
+ * Mac and PowerMac device drivers just use .read_byte.
+ */
+const struct nvram_ops arch_nvram_ops = {
+#ifdef CONFIG_MAC
+	.read_byte      = m68k_nvram_read_byte,
+	.write_byte     = m68k_nvram_write_byte,
+#endif
+#ifdef CONFIG_ATARI
+	.read           = m68k_nvram_read,
+	.write          = m68k_nvram_write,
+	.set_checksum   = m68k_nvram_set_checksum,
+	.initialize     = m68k_nvram_initialize,
+#endif
+	.get_size       = m68k_nvram_get_size,
+};
+EXPORT_SYMBOL(arch_nvram_ops);
+#endif /* CONFIG_NVRAM */
diff --git a/arch/m68k/mac/misc.c b/arch/m68k/mac/misc.c
index 1423e1fe02618..90f4e9ca1276b 100644
--- a/arch/m68k/mac/misc.c
+++ b/arch/m68k/mac/misc.c
@@ -36,8 +36,9 @@
 
 static void (*rom_reset)(void);
 
+#if IS_ENABLED(CONFIG_NVRAM)
 #ifdef CONFIG_ADB_CUDA
-static __u8 cuda_read_pram(int offset)
+static unsigned char cuda_pram_read_byte(int offset)
 {
 	struct adb_request req;
 
@@ -49,7 +50,7 @@ static __u8 cuda_read_pram(int offset)
 	return req.reply[3];
 }
 
-static void cuda_write_pram(int offset, __u8 data)
+static void cuda_pram_write_byte(unsigned char data, int offset)
 {
 	struct adb_request req;
 
@@ -62,29 +63,29 @@ static void cuda_write_pram(int offset, __u8 data)
 #endif /* CONFIG_ADB_CUDA */
 
 #ifdef CONFIG_ADB_PMU
-static __u8 pmu_read_pram(int offset)
+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_write_pram(int offset, __u8 data)
+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 */
+#endif /* CONFIG_NVRAM */
 
 /*
  * VIA PRAM/RTC access routines
@@ -93,7 +94,7 @@ static void pmu_write_pram(int offset, __u8 data)
  * the RTC should be enabled.
  */
 
-static __u8 via_pram_readbyte(void)
+static __u8 via_rtc_recv(void)
 {
 	int i, reg;
 	__u8 data;
@@ -120,7 +121,7 @@ static __u8 via_pram_readbyte(void)
 	return data;
 }
 
-static void via_pram_writebyte(__u8 data)
+static void via_rtc_send(__u8 data)
 {
 	int i, reg, bit;
 
@@ -137,6 +138,31 @@ static void via_pram_writebyte(__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
+
+/*
+ * 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
  * resulting data. For write commands it should point
@@ -145,29 +171,33 @@ static void via_pram_writebyte(__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;
 
 	if (command & 0xFF00) {		/* extended (two-byte) command */
-		via_pram_writebyte((command & 0xFF00) >> 8);
-		via_pram_writebyte(command & 0xFF);
-		is_read = command & 0x8000;
+		via_rtc_send((command & 0xFF00) >> 8);
+		via_rtc_send(command & 0xFF);
+		is_read = command & (RTC_FLG_READ << 8);
 	} else {			/* one-byte command */
-		via_pram_writebyte(command);
-		is_read = command & 0x80;
+		via_rtc_send(command);
+		is_read = command & RTC_FLG_READ;
 	}
 	if (is_read) {
-		*data = via_pram_readbyte();
+		*data = via_rtc_recv();
 	} else {
-		via_pram_writebyte(*data);
+		via_rtc_send(*data);
 	}
 
 	/* All done, disable the RTC */
@@ -177,14 +207,30 @@ static void via_pram_command(int command, __u8 *data)
 	local_irq_restore(flags);
 }
 
-static __u8 via_read_pram(int offset)
+#if IS_ENABLED(CONFIG_NVRAM)
+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_write_pram(int offset, __u8 data)
+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);
 }
+#endif /* CONFIG_NVRAM */
 
 /*
  * Return the current time in seconds since January 1, 1904.
@@ -201,10 +247,10 @@ 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 +258,14 @@ 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 +304,18 @@ 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)
@@ -326,66 +376,58 @@ static void cuda_shutdown(void)
  *-------------------------------------------------------------------
  */
 
-void mac_pram_read(int offset, __u8 *buffer, int len)
+#if IS_ENABLED(CONFIG_NVRAM)
+unsigned char mac_pram_read_byte(int addr)
 {
-	__u8 (*func)(int);
-	int i;
-
 	switch (macintosh_config->adb_type) {
 	case MAC_ADB_IOP:
 	case MAC_ADB_II:
 	case MAC_ADB_PB1:
-		func = via_read_pram;
-		break;
+		return via_pram_read_byte(addr);
 #ifdef CONFIG_ADB_CUDA
 	case MAC_ADB_EGRET:
 	case MAC_ADB_CUDA:
-		func = cuda_read_pram;
-		break;
+		return cuda_pram_read_byte(addr);
 #endif
 #ifdef CONFIG_ADB_PMU
 	case MAC_ADB_PB2:
-		func = pmu_read_pram;
-		break;
+		return pmu_pram_read_byte(addr);
 #endif
 	default:
-		return;
-	}
-	for (i = 0 ; i < len ; i++) {
-		buffer[i] = (*func)(offset++);
+		return 0xFF;
 	}
 }
 
-void mac_pram_write(int offset, __u8 *buffer, int len)
+void mac_pram_write_byte(unsigned char val, int addr)
 {
-	void (*func)(int, __u8);
-	int i;
-
 	switch (macintosh_config->adb_type) {
 	case MAC_ADB_IOP:
 	case MAC_ADB_II:
 	case MAC_ADB_PB1:
-		func = via_write_pram;
+		via_pram_write_byte(val, addr);
 		break;
 #ifdef CONFIG_ADB_CUDA
 	case MAC_ADB_EGRET:
 	case MAC_ADB_CUDA:
-		func = cuda_write_pram;
+		cuda_pram_write_byte(val, addr);
 		break;
 #endif
 #ifdef CONFIG_ADB_PMU
 	case MAC_ADB_PB2:
-		func = pmu_write_pram;
+		pmu_pram_write_byte(val, addr);
 		break;
 #endif
 	default:
-		return;
-	}
-	for (i = 0 ; i < len ; i++) {
-		(*func)(offset++, buffer[i]);
+		break;
 	}
 }
 
+ssize_t mac_pram_get_size(void)
+{
+	return 256;
+}
+#endif /* CONFIG_NVRAM */
+
 void mac_poweroff(void)
 {
 	if (oss_present) {