Merge tag 'armsoc-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc

Pull ARM SoC platform updates from Arnd Bergmann:
 "We get support for three new 32-bit SoC platforms this time.

  The amount of changes in arch/arm for any of them is miniscule, as all
  the interesting code is in device driver subsystems (irqchip, clk,
  pinctrl, ...) these days.  I'm listing them here, as the addition of
  the Kconfig statement is the main relevant milestone for a new
  platform.  In each case, some drivers are are shared with existing
  platforms, while other drivers are added for v4.7 as well, or come in
  a later release.

   - The Aspeed platform is probably the most interesting one, this is
     what most whitebox servers use as their baseboard management
     controller.  We get support for the very common ast2400 and ast2500
     SoCs.  The OpenBMC project focuses on this chip, and the LWN
     article about their ELC 2016 presentation at

        https://lwn.net/Articles/683320/

     triggered the submission, but the code comes from IBM's OpenPOWER
     team rather than the team at Facebook.  There are still a lot more
     drivers that need to get added over time, and I hope both teams can
     work together on that.

   - OXNAS is an old platform for Network Attached Storage devices from
     Oxford Semiconductor.  There are models with ARM10 (!) and
     ARM11MPCore cores, but for now, we only support the original ARM9
     based versions.  The product lineup was subsequently part of PLX,
     Avago and now the new Broadcom Ltd.

        https://wiki.openwrt.org/doc/hardware/soc/soc.oxnas

     has some more information.

   - V2M-MPS2 is a prototyping platform from ARM for their Cortex-M
     cores and is related to the existing Realview / Versatile Express
     lineup, but without MMU.

     We now support various NOMMU platforms, so adding a new one is
     fairly straightforward.

        http://infocenter.arm.com/help/topic/com.arm.doc.100112_0100_03_en/

     has detailed information about the platform.

  Other noteworthy updates:

   - Work on LPC32xx has resumed, and Vladimir Zapolskiy and Sylvain
     Lemieux are now maintaining the platform.

     This is an older ARM9 based platform from NXP (not Freescale), but
     it remains in use in embedded markets.

   - Kevin Hilman is now co-maintaining the Amlogic Meson platform for
     both 32-bit and 64-bit ARM, and started contributing some patches.

   - As is often the case, work on the OMAP platforms makes up the bulk
     of the actual SoC code changes in arch/arm, but there isn't a lot
     of that either"

* tag 'armsoc-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (42 commits)
  MAINTAINERS: ARM/Amlogic: add co-maintainer, misc. updates
  MAINTAINERS: add ARM/NXP LPC32XX SoC specific drivers to the section
  MAINTAINERS: add new maintainers of NXP LPC32xx SoC
  MAINTAINERS: move ARM/NXP LPC32xx record to ARM section
  arm: Add Aspeed machine
  ARM: lpc32xx: remove duplicate const on lpc32xx_auxdata_lookup
  ARM: lpc32xx: remove leftovers of legacy clock source and provider drivers
  ARM: lpc32xx: remove reboot header file
  ARM: dove: Remove CLK_IS_ROOT
  ARM: orion5x: Remove CLK_IS_ROOT
  ARM: mv78xx0: Remove CLK_IS_ROOT
  ARM: davinci: da850: use clk->set_parent for async3
  ARM: davinci: Move clock init after ioremap.
  MAINTAINERS: Update ARM Versatile Express platform entry
  ARM: vexpress/mps2: introduce MPS2 platform
  MAINTAINERS: add maintainer entry for ARM/OXNAS platform
  ARM: Add new mach-oxnas
  irqchip: versatile-fpga: add new compatible for OX810SE SoC
  ARM: uniphier: correct the call order of of_node_put()
  MAINTAINERS: fix stale TI DaVinci entries
  ...

1 files changed, 65 insertions, 0 deletions

diff --git a/arch/arm/mach-omap2/omap_hwmod_reset.c b/arch/arm/mach-omap2/omap_hwmod_reset.c
index 65e186c9df55..b68f9c0aff0b 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 +61,58 @@ 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 microseconds 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_BUSY, OMAP_RTC_MAX_READY_TIME, i);
+	/* now we have ~15 microseconds 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();
+}
+
+/**
+ * omap_hwmod_rtc_lock - Lock the Kicker mechanism.
+ * @oh: struct omap_hwmod *
+ *
+ * RTC IP have kicker feature. This prevents spurious writes to its registers.
+ * Once the RTC registers are written, KICK mechanism needs to be locked,
+ * in order to prevent any spurious writes. This function locks back the RTC
+ * registers once hwmod completes its write into sysconfig register.
+ */
+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();
+}