[PATCH 1/2] mn10300: use RTC_DRV_CMOS instead of CONFIG_RTC

From: Arnd Bergmann
Date: Wed Jun 01 2016 - 10:47:39 EST


nn10300 has a dependency on mc146818_get_time/mc146818_set_time,
which we want to move from the mc146818rtc.h header into the
rtc subsystem, which in turn is not usable on mn10300.

This changes mn10300 to use the modern rtc-cmos driver instead
of the old RTC driver, and that in turn lets us completely
remove the read_persistent_clock/update_persistent_clock callbacks.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
We should probably get both these patches through the rtc tree, but
it would be nice to have some confirmation from the mn10300 maintainer
that this is a reasonable patch.

arch/mn10300/Kconfig | 4 +-
arch/mn10300/include/asm/rtc-regs.h | 4 +-
arch/mn10300/kernel/rtc.c | 104 +++-----------------------------
arch/mn10300/proc-mn103e010/proc-init.c | 1 +
drivers/char/Kconfig | 2 +-
drivers/rtc/Kconfig | 2 +-
drivers/rtc/rtc-cmos.c | 2 +-
7 files changed, 18 insertions(+), 101 deletions(-)

diff --git a/arch/mn10300/Kconfig b/arch/mn10300/Kconfig
index 9627e81a6cbb..38e3494bfb63 100644
--- a/arch/mn10300/Kconfig
+++ b/arch/mn10300/Kconfig
@@ -236,7 +236,9 @@ source "kernel/Kconfig.hz"
config MN10300_RTC
bool "Using MN10300 RTC"
depends on MN10300_PROC_MN103E010 || MN10300_PROC_MN2WS0050
- select GENERIC_CMOS_UPDATE
+ select RTC_CLASS
+ select RTC_DRV_CMOS
+ select RTC_SYSTOHC
default n
help
This option enables support for the RTC, thus enabling time to be
diff --git a/arch/mn10300/include/asm/rtc-regs.h b/arch/mn10300/include/asm/rtc-regs.h
index c42deefaec11..c81cacecb6e3 100644
--- a/arch/mn10300/include/asm/rtc-regs.h
+++ b/arch/mn10300/include/asm/rtc-regs.h
@@ -75,9 +75,9 @@
#define RTC_PORT(x) 0xd8600000
#define RTC_ALWAYS_BCD 1 /* RTC operates in binary mode */

-#define CMOS_READ(addr) __SYSREG(0xd8600000 + (addr), u8)
+#define CMOS_READ(addr) __SYSREG(0xd8600000 + (u32)(addr), u8)
#define CMOS_WRITE(val, addr) \
- do { __SYSREG(0xd8600000 + (addr), u8) = val; } while (0)
+ do { __SYSREG(0xd8600000 + (u32)(addr), u8) = val; } while (0)

#define RTC_IRQ RTIRQ

diff --git a/arch/mn10300/kernel/rtc.c b/arch/mn10300/kernel/rtc.c
index 77e0be4d92ea..f81f37025072 100644
--- a/arch/mn10300/kernel/rtc.c
+++ b/arch/mn10300/kernel/rtc.c
@@ -12,107 +12,19 @@
#include <linux/module.h>
#include <linux/init.h>
#include <linux/mc146818rtc.h>
-#include <linux/bcd.h>
-#include <linux/timex.h>
+#include <linux/ioport.h>
+#include <linux/platform_device.h>
+
#include <asm/rtc-regs.h>
#include <asm/rtc.h>

DEFINE_SPINLOCK(rtc_lock);
EXPORT_SYMBOL(rtc_lock);

-/*
- * Read the current RTC time
- */
-void read_persistent_clock(struct timespec *ts)
-{
- struct rtc_time tm;
-
- mc146818_set_time(&tm);
-
- ts->tv_nsec = 0;
- ts->tv_sec = mktime(tm.tm_year, tm.tm_mon, tm.tm_mday,
- tm.tm_hour, tm.tm_min, tm.tm_sec);
-
- /* if rtc is way off in the past, set something reasonable */
- if (ts->tv_sec < 0)
- ts->tv_sec = mktime(2009, 1, 1, 12, 0, 0);
-}
-
-/*
- * In order to set the CMOS clock precisely, set_rtc_mmss has to be called 500
- * ms after the second nowtime has started, because when nowtime is written
- * into the registers of the CMOS clock, it will jump to the next second
- * precisely 500 ms later. Check the Motorola MC146818A or Dallas DS12887 data
- * sheet for details.
- *
- * BUG: This routine does not handle hour overflow properly; it just
- * sets the minutes. Usually you'll only notice that after reboot!
- */
-static int set_rtc_mmss(unsigned long nowtime)
-{
- unsigned char save_control, save_freq_select;
- int retval = 0;
- int real_seconds, real_minutes, cmos_minutes;
-
- /* gets recalled with irq locally disabled */
- spin_lock(&rtc_lock);
- save_control = CMOS_READ(RTC_CONTROL); /* tell the clock it's being
- * set */
- CMOS_WRITE(save_control | RTC_SET, RTC_CONTROL);
-
- save_freq_select = CMOS_READ(RTC_FREQ_SELECT); /* stop and reset
- * prescaler */
- CMOS_WRITE(save_freq_select | RTC_DIV_RESET2, RTC_FREQ_SELECT);
-
- cmos_minutes = CMOS_READ(RTC_MINUTES);
- if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
- cmos_minutes = bcd2bin(cmos_minutes);
-
- /*
- * since we're only adjusting minutes and seconds,
- * don't interfere with hour overflow. This avoids
- * messing with unknown time zones but requires your
- * RTC not to be off by more than 15 minutes
- */
- real_seconds = nowtime % 60;
- real_minutes = nowtime / 60;
- if (((abs(real_minutes - cmos_minutes) + 15) / 30) & 1)
- /* correct for half hour time zone */
- real_minutes += 30;
- real_minutes %= 60;
-
- if (abs(real_minutes - cmos_minutes) < 30) {
- if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
- real_seconds = bin2bcd(real_seconds);
- real_minutes = bin2bcd(real_minutes);
- }
- CMOS_WRITE(real_seconds, RTC_SECONDS);
- CMOS_WRITE(real_minutes, RTC_MINUTES);
- } else {
- printk_once(KERN_NOTICE
- "set_rtc_mmss: can't update from %d to %d\n",
- cmos_minutes, real_minutes);
- retval = -1;
- }
-
- /* The following flags have to be released exactly in this order,
- * otherwise the DS12887 (popular MC146818A clone with integrated
- * battery and quartz) will not reset the oscillator and will not
- * update precisely 500 ms later. You won't find this mentioned in
- * the Dallas Semiconductor data sheets, but who believes data
- * sheets anyway ... -- Markus Kuhn
- */
- CMOS_WRITE(save_control, RTC_CONTROL);
- CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT);
- spin_unlock(&rtc_lock);
-
- return retval;
-}
-
-int update_persistent_clock(struct timespec now)
-{
- return set_rtc_mmss(now.tv_sec);
-}
+static const __initdata struct resource res[] = {
+ DEFINE_RES_IO(RTC_PORT(0), RTC_IO_EXTENT),
+ DEFINE_RES_IRQ(RTC_IRQ),
+};

/*
* calibrate the TSC clock against the RTC
@@ -129,4 +41,6 @@ void __init calibrate_clock(void)
RTCRA |= RTCRA_DVR;
RTCRA &= ~RTCRA_DVR;
RTCRB &= ~RTCRB_SET;
+
+ platform_device_register_simple("rtc_cmos", -1, res, ARRAY_SIZE(res));
}
diff --git a/arch/mn10300/proc-mn103e010/proc-init.c b/arch/mn10300/proc-mn103e010/proc-init.c
index d4dcb0c56b35..f4990dffff94 100644
--- a/arch/mn10300/proc-mn103e010/proc-init.c
+++ b/arch/mn10300/proc-mn103e010/proc-init.c
@@ -9,6 +9,7 @@
* 2 of the Licence, or (at your option) any later version.
*/
#include <linux/kernel.h>
+#include <linux/irq.h>
#include <asm/cacheflush.h>
#include <asm/fpu.h>
#include <asm/rtc.h>
diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig
index 0ec91cc6c2fb..273b5492fbcf 100644
--- a/drivers/char/Kconfig
+++ b/drivers/char/Kconfig
@@ -279,7 +279,7 @@ if RTC_LIB=n

config RTC
tristate "Enhanced Real Time Clock Support (legacy PC RTC driver)"
- depends on ALPHA || (MIPS && MACH_LOONGSON64) || MN10300
+ depends on ALPHA || (MIPS && MACH_LOONGSON64)
---help---
If you say Y here and create a character special file /dev/rtc with
major number 10 and minor number 135 using mknod ("man mknod"), you
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 18639e0cb6e2..e8ef709f3945 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -795,7 +795,7 @@ comment "Platform RTC drivers"

config RTC_DRV_CMOS
tristate "PC-style 'CMOS'"
- depends on X86 || ARM || M32R || PPC || MIPS || SPARC64
+ depends on X86 || ARM || M32R || PPC || MIPS || SPARC64 || MN10300
default y if X86
help
Say "yes" here to get direct support for the real time clock
diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c
index cf8eb98382ce..f9fdb6fc641c 100644
--- a/drivers/rtc/rtc-cmos.c
+++ b/drivers/rtc/rtc-cmos.c
@@ -630,7 +630,7 @@ cmos_do_probe(struct device *dev, struct resource *ports, int rtc_irq)
address_space = 64;
#elif defined(__i386__) || defined(__x86_64__) || defined(__arm__) \
|| defined(__sparc__) || defined(__mips__) \
- || defined(__powerpc__)
+ || defined(__powerpc__) || defined(CONFIG_MN10300)
address_space = 128;
#else
#warning Assuming 128 bytes of RTC+NVRAM address space, not 64 bytes.
--
2.7.0