[PATCH] POWERPC: Added RTC support for mpc8313RDB and utilize "clock-frequency"

[PATCH] POWERPC: Added RTC support for mpc8313RDB and utilize "clock-frequency"

[Vitaly Bordug]

This enables DS1337 embedded RTC and uses "clock-frequency"
property to configure loops_per_jiffy. Fixed spaces vs tabs issue
in couple of places.

Signed-off-by: Vitaly Bordug <vitb@kernel.crashing.org>

---

 arch/powerpc/platforms/83xx/mpc8313_rdb.c |   52 ++++++++++++++++++++++++++++-
 1 files changed, 50 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/platforms/83xx/mpc8313_rdb.c b/arch/powerpc/platforms/83xx/mpc8313_rdb.c
index 3edfe17..b410e67 100644
--- a/arch/powerpc/platforms/83xx/mpc8313_rdb.c
+++ b/arch/powerpc/platforms/83xx/mpc8313_rdb.c
@@ -14,6 +14,8 @@
  */
 
 #include <linux/pci.h>
+#include <linux/delay.h>
+#include <linux/rtc.h>
 
 #include <asm/time.h>
 #include <asm/ipic.h>
@@ -42,6 +44,17 @@ static void __init mpc8313_rdb_setup_arch(void)
 	if (ppc_md.progress)
 		ppc_md.progress("mpc8313_rdb_setup_arch()", 0);
 
+	np = of_find_node_by_type(NULL, "cpu");
+	if (np != 0) {
+		const unsigned int *fp =
+			get_property(np, "clock-frequency", NULL);
+		if (fp != 0)
+			loops_per_jiffy = *fp / HZ;
+		else
+			loops_per_jiffy = 50000000 / HZ;
+		of_node_put(np);
+	}
+
 #ifdef CONFIG_PCI
 	for (np = NULL; (np = of_find_node_by_type(np, "pci")) != NULL;)
 		mpc83xx_add_bridge(np);
@@ -67,14 +80,49 @@ void __init mpc8313_rdb_init_IRQ(void)
 	ipic_set_default_priority();
 }
 
+#if defined (CONFIG_SENSORS_DS1337) && defined (CONFIG_I2C)
+
+extern int ds1337_do_command(int id, int cmd, void *arg);
+extern spinlock_t rtc_lock;
+#define DS1337_GET_DATE		0
+#define DS1337_SET_DATE		1
+
+static void mpc8313rdb_get_rtc_time(struct rtc_time *tm)
+{
+	int result;
+
+	result = ds1337_do_command(0, DS1337_GET_DATE, tm);
+
+	if (result == 0)
+		result = mktime(tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_hour, tm->tm_min, tm->tm_sec);
+}
+
+static int mpc8313rdb_set_rtc_time(struct rtc_time *tm)
+{
+	int result;
+
+	result = ds1337_do_command(0, DS1337_SET_DATE, tm);
+
+	return result;
+}
+
+static int __init rtc_hookup(void)
+{
+	ppc_md.get_rtc_time = mpc8313rdb_get_rtc_time;
+	ppc_md.set_rtc_time = mpc8313rdb_set_rtc_time;
+	return 0;
+}
+late_initcall(rtc_hookup);
+#endif
+
 /*
  * Called very early, MMU is off, device-tree isn't unflattened
  */
 static int __init mpc8313_rdb_probe(void)
 {
-        unsigned long root = of_get_flat_dt_root();
+	unsigned long root = of_get_flat_dt_root();
 
-        return of_flat_dt_is_compatible(root, "MPC8313ERDB");
+	return of_flat_dt_is_compatible(root, "MPC8313ERDB");
 }
 
 define_machine(mpc8313_rdb) {

Re: [PATCH] POWERPC: Added RTC support for mpc8313RDB and utilize "clock-frequency"

[Scott Wood]

On Tue, Jul 17, 2007 at 04:49:13AM +0400, Vitaly Bordug wrote:
> +	np = of_find_node_by_type(NULL, "cpu");
> +	if (np != 0) {
> +		const unsigned int *fp =
> +			get_property(np, "clock-frequency", NULL);
> +		if (fp != 0)
> +			loops_per_jiffy = *fp / HZ;
> +		else
> +			loops_per_jiffy = 50000000 / HZ;
> +		of_node_put(np);
> +	}

This is not necessary.  It's only used for /proc/cpuinfo (delays are done
using tb_ticks_per_usec), and it'll be overwritten by the generic
calibrate_delay() anyway.

We should be removing this from board files that have it, not adding it
to ones that don't.

> +#if defined (CONFIG_SENSORS_DS1337) && defined (CONFIG_I2C)
> +
> +extern int ds1337_do_command(int id, int cmd, void *arg);
> +extern spinlock_t rtc_lock;
> +#define DS1337_GET_DATE		0
> +#define DS1337_SET_DATE		1
> +
> +static void mpc8313rdb_get_rtc_time(struct rtc_time *tm)
> +{
> +	int result;
> +
> +	result = ds1337_do_command(0, DS1337_GET_DATE, tm);
> +
> +	if (result == 0)
> +		result = mktime(tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_hour, tm->tm_min, tm->tm_sec);
> +}
> +
> +static int mpc8313rdb_set_rtc_time(struct rtc_time *tm)
> +{
> +	int result;
> +
> +	result = ds1337_do_command(0, DS1337_SET_DATE, tm);
> +
> +	return result;
> +}
> +
> +static int __init rtc_hookup(void)
> +{
> +	ppc_md.get_rtc_time = mpc8313rdb_get_rtc_time;
> +	ppc_md.set_rtc_time = mpc8313rdb_set_rtc_time;
> +	return 0;
> +}
> +late_initcall(rtc_hookup);
> +#endif

Please don't do this; drivers/i2c/chips/ds1337.c is deprecated.  You
should be using the RTC-class driver in drivers/rtc/rtc-ds1307.c, which
has a non-device-specific API that can be used.

The ppc_md RTC functions should really just go away, though -- setting
the clock on bootup can be done by generic code, and periodically
updating the RTC when using NTP can be done from userspace.

-Scott

Re: [PATCH] POWERPC: Added RTC support for mpc8313RDB and utilize "clock-frequency"

[Vitaly Bordug]

On Tue, 17 Jul 2007 11:36:45 -0500
Scott Wood <scottwood@freescale.com> wrote:

> On Tue, Jul 17, 2007 at 04:49:13AM +0400, Vitaly Bordug wrote:
> > +	np = of_find_node_by_type(NULL, "cpu");
> > +	if (np != 0) {
> > +		const unsigned int *fp =
> > +			get_property(np, "clock-frequency", NULL);
> > +		if (fp != 0)
> > +			loops_per_jiffy = *fp / HZ;
> > +		else
> > +			loops_per_jiffy = 50000000 / HZ;
> > +		of_node_put(np);
> > +	}
> 
> This is not necessary.  It's only used for /proc/cpuinfo (delays are done
> using tb_ticks_per_usec), and it'll be overwritten by the generic
> calibrate_delay() anyway.
> 
> We should be removing this from board files that have it, not adding it
> to ones that don't.
> 
Yet many boards still have this stuff (like pretty recent 86xx) - should
we at least add some comments or clean that up?

> > +#if defined (CONFIG_SENSORS_DS1337) && defined (CONFIG_I2C)
> > +
> > +extern int ds1337_do_command(int id, int cmd, void *arg);
> > +extern spinlock_t rtc_lock;
> > +#define DS1337_GET_DATE		0
> > +#define DS1337_SET_DATE		1
> > +
> > +static void mpc8313rdb_get_rtc_time(struct rtc_time *tm)
> > +{
> > +	int result;
> > +
> > +	result = ds1337_do_command(0, DS1337_GET_DATE, tm);
> > +
> > +	if (result == 0)
> > +		result = mktime(tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_hour, tm->tm_min, tm->tm_sec);
> > +}
> > +
> > +static int mpc8313rdb_set_rtc_time(struct rtc_time *tm)
> > +{
> > +	int result;
> > +
> > +	result = ds1337_do_command(0, DS1337_SET_DATE, tm);
> > +
> > +	return result;
> > +}
> > +
> > +static int __init rtc_hookup(void)
> > +{
> > +	ppc_md.get_rtc_time = mpc8313rdb_get_rtc_time;
> > +	ppc_md.set_rtc_time = mpc8313rdb_set_rtc_time;
> > +	return 0;
> > +}
> > +late_initcall(rtc_hookup);
> > +#endif
> 
> Please don't do this; drivers/i2c/chips/ds1337.c is deprecated.  You
> should be using the RTC-class driver in drivers/rtc/rtc-ds1307.c, which
> has a non-device-specific API that can be used.
> 
> The ppc_md RTC functions should really just go away, though -- setting
> the clock on bootup can be done by generic code, and periodically
> updating the RTC when using NTP can be done from userspace.
> 

If those ppc_md hookups would be declared deprecated, there's no much sense in the upper,
apparently. But I am not sure they will be... I'm inclined to let this patch floating since
interacting with rtc class from within BSP code just does not worth it.

-- 
Sincerely, 
Vitaly

Re: [PATCH] POWERPC: Added RTC support for mpc8313RDB and utilize "clock-frequency"

[Scott Wood]

Vitaly Bordug wrote:
> On Tue, 17 Jul 2007 11:36:45 -0500
> Scott Wood <scottwood@freescale.com> wrote:
>>We should be removing this from board files that have it, not adding it
>>to ones that don't.
> 
> Yet many boards still have this stuff (like pretty recent 86xx) - should
> we at least add some comments or clean that up?

See above. :-)

AFAICT, it's just copied from board to board without thought.  It should 
be removed.

>>The ppc_md RTC functions should really just go away, though -- setting
>>the clock on bootup can be done by generic code, and periodically
>>updating the RTC when using NTP can be done from userspace.
> 
> If those ppc_md hookups would be declared deprecated, there's no much sense in the upper,
> apparently. But I am not sure they will be... I'm inclined to let this patch floating since
> interacting with rtc class from within BSP code just does not worth it.

I'm not sure they will either; I just wish they would be. :-)

In the meantime, some sort of workqueue-based hookup to the RTC class 
API should be used.  I believe there have been patches along those lines 
posted in the past.

-Scott

Re: [PATCH] POWERPC: Added RTC support for mpc8313RDB and utilize "clock-frequency"

[Jon Loeliger]

On Tue, 2007-07-17 at 12:48, Vitaly Bordug wrote:
> 't.
> > 
> Yet many boards still have this stuff (like pretty recent 86xx) - should
> we at least add some comments or clean that up?

Hrm.  Alright.  I'm on deck for a patch here, I see... :-)

But you might notice that the most recent board port
that I added, mpc8544_ds.c, does NOT have it:

        static void __init mpc8544_ds_setup_arch(void)
        {
                if (ppc_md.progress)
                        ppc_md.progress("mpc8544_ds_setup_arch()", 0);
         
                printk("MPC8544 DS board from Freescale Semiconductor\n");
        }

Thanks,
jdl

Re: [PATCH] POWERPC: Added RTC support for mpc8313RDB and utilize "clock-frequency"

[Guennadi Liakhovetski]

On Tue, 17 Jul 2007, Vitaly Bordug wrote:

> > Please don't do this; drivers/i2c/chips/ds1337.c is deprecated.  You
> > should be using the RTC-class driver in drivers/rtc/rtc-ds1307.c, which
> > has a non-device-specific API that can be used.
> > 
> > The ppc_md RTC functions should really just go away, though -- setting
> > the clock on bootup can be done by generic code, and periodically
> > updating the RTC when using NTP can be done from userspace.
> 
> If those ppc_md hookups would be declared deprecated, there's no much sense in the upper,
> apparently. But I am not sure they will be... I'm inclined to let this patch floating since
> interacting with rtc class from within BSP code just does not worth it.

Exactly! Don't interact with it. Just leave it alone. No need to re-write 
[sg]et_rtc_time, bother with setting system time on bootup... Just let the 
rtc driver and framework do it for you.

Thanks
Guennadi
---
Guennadi Liakhovetski