[PATCH v2 0/3] ARM: OMAP2+: hwmod: RTC: Add lock and unlock hooks

[PATCH v2 0/3] ARM: OMAP2+: hwmod: RTC: Add lock and unlock hooks

[Lokesh Vutla]

This series implements lock and unlock functions for RTC and hooks
the same to DRA7 and AMx3xx hwmod.
This is dependent on the patch https://patchwork.kernel.org/patch/6578281/,
which is queued recently by Paul.

Tested on DRA72-evm: http://pastebin.ubuntu.com/11892356/

Lokesh Vutla (3):
  ARM: hwmod: RTC: Add lock and unlock functions
  ARM: DRA7: RTC: Add lock and unlock functions
  ARM: AMx3xx: RTC: Add lock and unlock functions

 arch/arm/mach-omap2/omap_hwmod.h                   |  2 +
 .../mach-omap2/omap_hwmod_33xx_43xx_ipblock_data.c |  2 +
 arch/arm/mach-omap2/omap_hwmod_7xx_data.c          |  2 +
 arch/arm/mach-omap2/omap_hwmod_reset.c             | 56 ++++++++++++++++++++++
 4 files changed, 62 insertions(+)

-- 
2.1.4

[PATCH v2 1/3] ARM: hwmod: RTC: Add lock and unlock functions

[Lokesh Vutla]

RTC IP have kicker feature which prevents spurious writes to its registers.
In order to write into any of the RTC registers, KICK values has to be
written to KICK registers.
Introduce omap_hwmod_rtc_unlock/lock functions, which  writes into these
KICK registers inorder to lock and unlock RTC registers.

Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
---
 arch/arm/mach-omap2/omap_hwmod.h       |  2 ++
 arch/arm/mach-omap2/omap_hwmod_reset.c | 56 ++++++++++++++++++++++++++++++++++
 2 files changed, 58 insertions(+)

diff --git a/arch/arm/mach-omap2/omap_hwmod.h b/arch/arm/mach-omap2/omap_hwmod.h
index c697b57..173a31e 100644
--- a/arch/arm/mach-omap2/omap_hwmod.h
+++ b/arch/arm/mach-omap2/omap_hwmod.h
@@ -748,6 +748,8 @@ const char *omap_hwmod_get_main_clk(struct omap_hwmod *oh);
  */
 
 extern int omap_hwmod_aess_preprogram(struct omap_hwmod *oh);
+void omap_hwmod_rtc_unlock(struct omap_hwmod *oh);
+void omap_hwmod_rtc_lock(struct omap_hwmod *oh);
 
 /*
  * Chip variant-specific hwmod init routines - XXX should be converted
diff --git a/arch/arm/mach-omap2/omap_hwmod_reset.c b/arch/arm/mach-omap2/omap_hwmod_reset.c
index 65e186c..eebadb2 100644
--- a/arch/arm/mach-omap2/omap_hwmod_reset.c
+++ b/arch/arm/mach-omap2/omap_hwmod_reset.c
@@ -29,6 +29,16 @@
 #include <sound/aess.h>
 
 #include "omap_hwmod.h"
+#include "common.h"
+
+#define OMAP_RTC_STATUS_REG	0x44
+#define OMAP_RTC_KICK0_REG	0x6c
+#define OMAP_RTC_KICK1_REG	0x70
+
+#define OMAP_RTC_KICK0_VALUE	0x83E70B13
+#define OMAP_RTC_KICK1_VALUE	0x95A4F1E0
+#define OMAP_RTC_STATUS_BUSY	BIT(0)
+#define OMAP_RTC_MAX_READY_TIME	50
 
 /**
  * omap_hwmod_aess_preprogram - enable AESS internal autogating
@@ -51,3 +61,49 @@ int omap_hwmod_aess_preprogram(struct omap_hwmod *oh)
 
 	return 0;
 }
+
+/**
+ * omap_rtc_wait_not_busy - Wait for the RTC BUSY flag
+ * @oh: struct omap_hwmod *
+ *
+ * For updating certain RTC registers, the MPU must wait
+ * for the BUSY status in OMAP_RTC_STATUS_REG to become zero.
+ * Once the BUSY status is zero, there is a 15-?s access
+ * period in which the MPU can program.
+ */
+static void omap_rtc_wait_not_busy(struct omap_hwmod *oh)
+{
+	int i;
+
+	/* BUSY may stay active for 1/32768 second (~30 usec) */
+	omap_test_timeout(omap_hwmod_read(oh, OMAP_RTC_STATUS_REG)
+			  & OMAP_RTC_STATUS_REG, OMAP_RTC_MAX_READY_TIME, i);
+	/* now we have ~15 usec to read/write various registers */
+}
+
+/**
+ * omap_hwmod_rtc_unlock - Unlock the Kicker mechanism.
+ * @oh: struct omap_hwmod *
+ *
+ * RTC IP have kicker feature.  This prevents spurious writes to its registers.
+ * In order to write into any of the RTC registers, KICK values has te be
+ * written in respective KICK registers. This is needed for hwmod to write into
+ * sysconfig register.
+ */
+void omap_hwmod_rtc_unlock(struct omap_hwmod *oh)
+{
+	local_irq_disable();
+	omap_rtc_wait_not_busy(oh);
+	omap_hwmod_write(OMAP_RTC_KICK0_VALUE, oh, OMAP_RTC_KICK0_REG);
+	omap_hwmod_write(OMAP_RTC_KICK1_VALUE, oh, OMAP_RTC_KICK1_REG);
+	local_irq_enable();
+}
+
+void omap_hwmod_rtc_lock(struct omap_hwmod *oh)
+{
+	local_irq_disable();
+	omap_rtc_wait_not_busy(oh);
+	omap_hwmod_write(0x0, oh, OMAP_RTC_KICK0_REG);
+	omap_hwmod_write(0x0, oh, OMAP_RTC_KICK1_REG);
+	local_irq_enable();
+}
-- 
2.1.4

[PATCH v2 2/3] ARM: DRA7: RTC: Add lock and unlock functions

[Lokesh Vutla]

Hook omap_hwmod_rtc_unlock/lock functions into RTC hwmod,
so that SYSCONFIG register is updated properly

Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
---
 arch/arm/mach-omap2/omap_hwmod_7xx_data.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm/mach-omap2/omap_hwmod_7xx_data.c b/arch/arm/mach-omap2/omap_hwmod_7xx_data.c
index 2606c66..95d9bc5c 100644
--- a/arch/arm/mach-omap2/omap_hwmod_7xx_data.c
+++ b/arch/arm/mach-omap2/omap_hwmod_7xx_data.c
@@ -1572,6 +1572,8 @@ static struct omap_hwmod_class_sysconfig dra7xx_rtcss_sysc = {
 static struct omap_hwmod_class dra7xx_rtcss_hwmod_class = {
 	.name	= "rtcss",
 	.sysc	= &dra7xx_rtcss_sysc,
+	.unlock	= &omap_hwmod_rtc_unlock,
+	.lock	= &omap_hwmod_rtc_lock,
 };
 
 /* rtcss */
-- 
2.1.4

[PATCH v2 3/3] ARM: AMx3xx: RTC: Add lock and unlock functions

[Lokesh Vutla]

Hook omap_hwmod_rtc_unlock/lock functions into RTC hwmod,
so that SYSCONFIG register is updated properly.

Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
---
 arch/arm/mach-omap2/omap_hwmod_33xx_43xx_ipblock_data.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm/mach-omap2/omap_hwmod_33xx_43xx_ipblock_data.c b/arch/arm/mach-omap2/omap_hwmod_33xx_43xx_ipblock_data.c
index 907a452b..aed3362 100644
--- a/arch/arm/mach-omap2/omap_hwmod_33xx_43xx_ipblock_data.c
+++ b/arch/arm/mach-omap2/omap_hwmod_33xx_43xx_ipblock_data.c
@@ -918,6 +918,8 @@ static struct omap_hwmod_class_sysconfig am33xx_rtc_sysc = {
 static struct omap_hwmod_class am33xx_rtc_hwmod_class = {
 	.name		= "rtc",
 	.sysc		= &am33xx_rtc_sysc,
+	.unlock		= &omap_hwmod_rtc_unlock,
+	.lock		= &omap_hwmod_rtc_lock,
 };
 
 struct omap_hwmod am33xx_rtc_hwmod = {
-- 
2.1.4

[PATCH v2 1/3] ARM: hwmod: RTC: Add lock and unlock functions

[Paul Walmsley]

Hi

On Fri, 17 Jul 2015, Lokesh Vutla wrote:

> RTC IP have kicker feature which prevents spurious writes to its registers.
> In order to write into any of the RTC registers, KICK values has to be
> written to KICK registers.
> Introduce omap_hwmod_rtc_unlock/lock functions, which  writes into these
> KICK registers inorder to lock and unlock RTC registers.
> 
> Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>

Please add kerneldoc for the omap_hwmod_rtc_lock() function.

- Paul


> ---
>  arch/arm/mach-omap2/omap_hwmod.h       |  2 ++
>  arch/arm/mach-omap2/omap_hwmod_reset.c | 56 ++++++++++++++++++++++++++++++++++
>  2 files changed, 58 insertions(+)
> 
> diff --git a/arch/arm/mach-omap2/omap_hwmod.h b/arch/arm/mach-omap2/omap_hwmod.h
> index c697b57..173a31e 100644
> --- a/arch/arm/mach-omap2/omap_hwmod.h
> +++ b/arch/arm/mach-omap2/omap_hwmod.h
> @@ -748,6 +748,8 @@ const char *omap_hwmod_get_main_clk(struct omap_hwmod *oh);
>   */
>  
>  extern int omap_hwmod_aess_preprogram(struct omap_hwmod *oh);
> +void omap_hwmod_rtc_unlock(struct omap_hwmod *oh);
> +void omap_hwmod_rtc_lock(struct omap_hwmod *oh);
>  
>  /*
>   * Chip variant-specific hwmod init routines - XXX should be converted
> diff --git a/arch/arm/mach-omap2/omap_hwmod_reset.c b/arch/arm/mach-omap2/omap_hwmod_reset.c
> index 65e186c..eebadb2 100644
> --- a/arch/arm/mach-omap2/omap_hwmod_reset.c
> +++ b/arch/arm/mach-omap2/omap_hwmod_reset.c
> @@ -29,6 +29,16 @@
>  #include <sound/aess.h>
>  
>  #include "omap_hwmod.h"
> +#include "common.h"
> +
> +#define OMAP_RTC_STATUS_REG	0x44
> +#define OMAP_RTC_KICK0_REG	0x6c
> +#define OMAP_RTC_KICK1_REG	0x70
> +
> +#define OMAP_RTC_KICK0_VALUE	0x83E70B13
> +#define OMAP_RTC_KICK1_VALUE	0x95A4F1E0
> +#define OMAP_RTC_STATUS_BUSY	BIT(0)
> +#define OMAP_RTC_MAX_READY_TIME	50
>  
>  /**
>   * omap_hwmod_aess_preprogram - enable AESS internal autogating
> @@ -51,3 +61,49 @@ int omap_hwmod_aess_preprogram(struct omap_hwmod *oh)
>  
>  	return 0;
>  }
> +
> +/**
> + * omap_rtc_wait_not_busy - Wait for the RTC BUSY flag
> + * @oh: struct omap_hwmod *
> + *
> + * For updating certain RTC registers, the MPU must wait
> + * for the BUSY status in OMAP_RTC_STATUS_REG to become zero.
> + * Once the BUSY status is zero, there is a 15-?s access
> + * period in which the MPU can program.
> + */
> +static void omap_rtc_wait_not_busy(struct omap_hwmod *oh)
> +{
> +	int i;
> +
> +	/* BUSY may stay active for 1/32768 second (~30 usec) */
> +	omap_test_timeout(omap_hwmod_read(oh, OMAP_RTC_STATUS_REG)
> +			  & OMAP_RTC_STATUS_REG, OMAP_RTC_MAX_READY_TIME, i);
> +	/* now we have ~15 usec to read/write various registers */
> +}
> +
> +/**
> + * omap_hwmod_rtc_unlock - Unlock the Kicker mechanism.
> + * @oh: struct omap_hwmod *
> + *
> + * RTC IP have kicker feature.  This prevents spurious writes to its registers.
> + * In order to write into any of the RTC registers, KICK values has te be
> + * written in respective KICK registers. This is needed for hwmod to write into
> + * sysconfig register.
> + */
> +void omap_hwmod_rtc_unlock(struct omap_hwmod *oh)
> +{
> +	local_irq_disable();
> +	omap_rtc_wait_not_busy(oh);
> +	omap_hwmod_write(OMAP_RTC_KICK0_VALUE, oh, OMAP_RTC_KICK0_REG);
> +	omap_hwmod_write(OMAP_RTC_KICK1_VALUE, oh, OMAP_RTC_KICK1_REG);
> +	local_irq_enable();
> +}
> +
> +void omap_hwmod_rtc_lock(struct omap_hwmod *oh)
> +{
> +	local_irq_disable();
> +	omap_rtc_wait_not_busy(oh);
> +	omap_hwmod_write(0x0, oh, OMAP_RTC_KICK0_REG);
> +	omap_hwmod_write(0x0, oh, OMAP_RTC_KICK1_REG);
> +	local_irq_enable();
> +}
> -- 
> 2.1.4
> 


- Paul