From mboxrd@z Thu Jan 1 00:00:00 1970 From: nm@ti.com (Nishanth Menon) Date: Fri, 22 Aug 2014 09:02:28 -0500 Subject: [PATCH 04/10] ARM: OMAP5 / DRA7: PM: Enable Mercury retention mode on CPUx powerdomains In-Reply-To: <1408716154-26101-1-git-send-email-nm@ti.com> References: <1408716154-26101-1-git-send-email-nm@ti.com> Message-ID: <1408716154-26101-5-git-send-email-nm@ti.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org From: Santosh Shilimkar In addition to the standard power-management technique, the OMAP5 / DRA7 MPU subsystem also employs an SR3-APG (mercury) power management technology to reduce leakage. It allows for full logic and memories retention on MPU_C0 and MPU_C1 and is controlled by the PRCM_MPU. Only "Fast-mode" is supported on the OMAP5 and DRA7 family of processors. Signed-off-by: Santosh Shilimkar [nm at ti.com: minor consolidation] Signed-off-by: Nishanth Menon --- This has a minor checkpatch warning for aligning with '(', but that when fixed results in over 80 char warning. So choose '(' check instead :D. arch/arm/mach-omap2/omap-mpuss-lowpower.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/arch/arm/mach-omap2/omap-mpuss-lowpower.c b/arch/arm/mach-omap2/omap-mpuss-lowpower.c index 63a1dd7..fad6e8c 100644 --- a/arch/arm/mach-omap2/omap-mpuss-lowpower.c +++ b/arch/arm/mach-omap2/omap-mpuss-lowpower.c @@ -321,6 +321,21 @@ int omap4_hotplug_cpu(unsigned int cpu, unsigned int power_state) /* + * Enable Mercury Fast HG retention mode by default. + */ +static void enable_mercury_retention_mode(void) +{ + u32 reg; + + reg = omap4_prcm_mpu_read_inst_reg(OMAP54XX_PRCM_MPU_DEVICE_INST, + OMAP54XX_PRCM_MPU_PRM_PSCON_COUNT_OFFSET); + /* Enable HG_EN, HG_RAMPUP = fast mode */ + reg |= BIT(24) | BIT(25); + omap4_prcm_mpu_write_inst_reg(reg, OMAP54XX_PRCM_MPU_DEVICE_INST, + OMAP54XX_PRCM_MPU_PRM_PSCON_COUNT_OFFSET); +} + +/* * Initialise OMAP4 MPUSS */ int __init omap4_mpuss_init(void) @@ -397,6 +412,7 @@ int __init omap4_mpuss_init(void) cpu_context_offset = OMAP4_RM_CPU0_CPU0_CONTEXT_OFFSET; } else if (soc_is_omap54xx() || soc_is_dra7xx()) { cpu_context_offset = OMAP54XX_RM_CPU0_CPU0_CONTEXT_OFFSET; + enable_mercury_retention_mode(); } return 0; -- 1.7.9.5