Merge tag 'omap-fixes-a-for-v3.8-window' of git://git.kernel.org/pub/scm/linux/kernel/git/pjw/omap-pending into fixes

From Paul Walmsley per Tony Lindgrens request:

Fix some OMAP4 clock problems, and deal with some sparse warnings from
the OMAP CPUIdle code.

* tag 'omap-fixes-a-for-v3.8-window' of git://git.kernel.org/pub/scm/linux/kernel/git/pjw/omap-pending:
  ARM: OMAP3/4: cpuidle: fix sparse and checkpatch warnings
  ARM: OMAP4: clock data: DPLLs are missing bypass clocks in their parent lists
  ARM: OMAP4: clock data: div_iva_hs_clk is a power-of-two divider
  ARM: OMAP4: Fix EMU clock domain always on
  ARM: OMAP4460: Workaround ABE DPLL failing to turn-on
  ARM: OMAP4: Enhance support for DPLLs with 4X multiplier
  ARM: OMAP4: Add function table for non-M4X dplls
  ARM: OMAP4: Update timer clock aliases

7 files changed, 189 insertions, 54 deletions

diff --git a/arch/arm/mach-omap2/cclock44xx_data.c b/arch/arm/mach-omap2/cclock44xx_data.c
index aa56c3e5bb34..5789a5e25563 100644
--- a/arch/arm/mach-omap2/cclock44xx_data.c
+++ b/arch/arm/mach-omap2/cclock44xx_data.c
@@ -40,6 +40,14 @@
 #define OMAP4430_MODULEMODE_HWCTRL_SHIFT		0
 #define OMAP4430_MODULEMODE_SWCTRL_SHIFT		1
 
+/*
+ * OMAP4 ABE DPLL default frequency. In OMAP4460 TRM version V, section
+ * "3.6.3.2.3 CM1_ABE Clock Generator" states that the "DPLL_ABE_X2_CLK
+ * must be set to 196.608 MHz" and hence, the DPLL locked frequency is
+ * half of this value.
+ */
+#define OMAP4_DPLL_ABE_DEFFREQ				98304000
+
 /* Root clocks */
 
 DEFINE_CLK_FIXED_RATE(extalt_clkin_ck, CLK_IS_ROOT, 59000000, 0x0);
@@ -124,6 +132,8 @@ static struct dpll_data dpll_abe_dd = {
 	.enable_mask	= OMAP4430_DPLL_EN_MASK,
 	.autoidle_mask	= OMAP4430_AUTO_DPLL_MODE_MASK,
 	.idlest_mask	= OMAP4430_ST_DPLL_CLK_MASK,
+	.m4xen_mask	= OMAP4430_DPLL_REGM4XEN_MASK,
+	.lpmode_mask	= OMAP4430_DPLL_LPMODE_EN_MASK,
 	.max_multiplier	= 2047,
 	.max_divider	= 128,
 	.min_divider	= 1,
@@ -233,7 +243,7 @@ static struct dpll_data dpll_core_dd = {
 
 
 static const char *dpll_core_ck_parents[] = {
-	"sys_clkin_ck",
+	"sys_clkin_ck", "core_hsd_byp_clk_mux_ck"
 };
 
 static struct clk dpll_core_ck;
@@ -286,9 +296,9 @@ DEFINE_CLK_DIVIDER(div_core_ck, "dpll_core_m5x2_ck", &dpll_core_m5x2_ck, 0x0,
 		   OMAP4430_CM_CLKSEL_CORE, OMAP4430_CLKSEL_CORE_SHIFT,
 		   OMAP4430_CLKSEL_CORE_WIDTH, 0x0, NULL);
 
-DEFINE_CLK_OMAP_HSDIVIDER(div_iva_hs_clk, "dpll_core_m5x2_ck",
-			  &dpll_core_m5x2_ck, 0x0, OMAP4430_CM_BYPCLK_DPLL_IVA,
-			  OMAP4430_CLKSEL_0_1_MASK);
+DEFINE_CLK_DIVIDER(div_iva_hs_clk, "dpll_core_m5x2_ck", &dpll_core_m5x2_ck,
+		   0x0, OMAP4430_CM_BYPCLK_DPLL_IVA, OMAP4430_CLKSEL_0_1_SHIFT,
+		   OMAP4430_CLKSEL_0_1_WIDTH, CLK_DIVIDER_POWER_OF_TWO, NULL);
 
 DEFINE_CLK_DIVIDER(div_mpu_hs_clk, "dpll_core_m5x2_ck", &dpll_core_m5x2_ck,
 		   0x0, OMAP4430_CM_BYPCLK_DPLL_MPU, OMAP4430_CLKSEL_0_1_SHIFT,
@@ -363,8 +373,21 @@ static struct dpll_data dpll_iva_dd = {
 	.min_divider	= 1,
 };
 
+static const char *dpll_iva_ck_parents[] = {
+	"sys_clkin_ck", "iva_hsd_byp_clk_mux_ck"
+};
+
 static struct clk dpll_iva_ck;
 
+static const struct clk_ops dpll_ck_ops = {
+	.enable		= &omap3_noncore_dpll_enable,
+	.disable	= &omap3_noncore_dpll_disable,
+	.recalc_rate	= &omap3_dpll_recalc,
+	.round_rate	= &omap2_dpll_round_rate,
+	.set_rate	= &omap3_noncore_dpll_set_rate,
+	.get_parent	= &omap2_init_dpll_parent,
+};
+
 static struct clk_hw_omap dpll_iva_ck_hw = {
 	.hw = {
 		.clk = &dpll_iva_ck,
@@ -373,7 +396,7 @@ static struct clk_hw_omap dpll_iva_ck_hw = {
 	.ops		= &clkhwops_omap3_dpll,
 };
 
-DEFINE_STRUCT_CLK(dpll_iva_ck, dpll_core_ck_parents, dpll_abe_ck_ops);
+DEFINE_STRUCT_CLK(dpll_iva_ck, dpll_iva_ck_parents, dpll_ck_ops);
 
 static const char *dpll_iva_x2_ck_parents[] = {
 	"dpll_iva_ck",
@@ -416,6 +439,10 @@ static struct dpll_data dpll_mpu_dd = {
 	.min_divider	= 1,
 };
 
+static const char *dpll_mpu_ck_parents[] = {
+	"sys_clkin_ck", "div_mpu_hs_clk"
+};
+
 static struct clk dpll_mpu_ck;
 
 static struct clk_hw_omap dpll_mpu_ck_hw = {
@@ -426,7 +453,7 @@ static struct clk_hw_omap dpll_mpu_ck_hw = {
 	.ops		= &clkhwops_omap3_dpll,
 };
 
-DEFINE_STRUCT_CLK(dpll_mpu_ck, dpll_core_ck_parents, dpll_abe_ck_ops);
+DEFINE_STRUCT_CLK(dpll_mpu_ck, dpll_mpu_ck_parents, dpll_ck_ops);
 
 DEFINE_CLK_FIXED_FACTOR(mpu_periphclk, "dpll_mpu_ck", &dpll_mpu_ck, 0x0, 1, 2);
 
@@ -464,6 +491,9 @@ static struct dpll_data dpll_per_dd = {
 	.min_divider	= 1,
 };
 
+static const char *dpll_per_ck_parents[] = {
+	"sys_clkin_ck", "per_hsd_byp_clk_mux_ck"
+};
 
 static struct clk dpll_per_ck;
 
@@ -475,7 +505,7 @@ static struct clk_hw_omap dpll_per_ck_hw = {
 	.ops		= &clkhwops_omap3_dpll,
 };
 
-DEFINE_STRUCT_CLK(dpll_per_ck, dpll_core_ck_parents, dpll_abe_ck_ops);
+DEFINE_STRUCT_CLK(dpll_per_ck, dpll_per_ck_parents, dpll_ck_ops);
 
 DEFINE_CLK_DIVIDER(dpll_per_m2_ck, "dpll_per_ck", &dpll_per_ck, 0x0,
 		   OMAP4430_CM_DIV_M2_DPLL_PER, OMAP4430_DPLL_CLKOUT_DIV_SHIFT,
@@ -559,6 +589,10 @@ static struct dpll_data dpll_usb_dd = {
 	.min_divider	= 1,
 };
 
+static const char *dpll_usb_ck_parents[] = {
+	"sys_clkin_ck", "usb_hs_clk_div_ck"
+};
+
 static struct clk dpll_usb_ck;
 
 static struct clk_hw_omap dpll_usb_ck_hw = {
@@ -569,7 +603,7 @@ static struct clk_hw_omap dpll_usb_ck_hw = {
 	.ops		= &clkhwops_omap3_dpll,
 };
 
-DEFINE_STRUCT_CLK(dpll_usb_ck, dpll_core_ck_parents, dpll_abe_ck_ops);
+DEFINE_STRUCT_CLK(dpll_usb_ck, dpll_usb_ck_parents, dpll_ck_ops);
 
 static const char *dpll_usb_clkdcoldo_ck_parents[] = {
 	"dpll_usb_ck",
@@ -696,9 +730,13 @@ DEFINE_CLK_DIVIDER(syc_clk_div_ck, "sys_clkin_ck", &sys_clkin_ck, 0x0,
 		   OMAP4430_CM_ABE_DSS_SYS_CLKSEL, OMAP4430_CLKSEL_0_0_SHIFT,
 		   OMAP4430_CLKSEL_0_0_WIDTH, 0x0, NULL);
 
+static const char *dbgclk_mux_ck_parents[] = {
+	"sys_clkin_ck"
+};
+
 static struct clk dbgclk_mux_ck;
 DEFINE_STRUCT_CLK_HW_OMAP(dbgclk_mux_ck, NULL);
-DEFINE_STRUCT_CLK(dbgclk_mux_ck, dpll_core_ck_parents,
+DEFINE_STRUCT_CLK(dbgclk_mux_ck, dbgclk_mux_ck_parents,
 		  dpll_usb_clkdcoldo_ck_ops);
 
 /* Leaf clocks controlled by modules */
@@ -1935,10 +1973,10 @@ static struct omap_clk omap44xx_clks[] = {
 	CLK("4803e000.timer",	"timer_sys_ck",	&sys_clkin_ck,	CK_443X),
 	CLK("48086000.timer",	"timer_sys_ck",	&sys_clkin_ck,	CK_443X),
 	CLK("48088000.timer",	"timer_sys_ck",	&sys_clkin_ck,	CK_443X),
-	CLK("49038000.timer",	"timer_sys_ck",	&syc_clk_div_ck,	CK_443X),
-	CLK("4903a000.timer",	"timer_sys_ck",	&syc_clk_div_ck,	CK_443X),
-	CLK("4903c000.timer",	"timer_sys_ck",	&syc_clk_div_ck,	CK_443X),
-	CLK("4903e000.timer",	"timer_sys_ck",	&syc_clk_div_ck,	CK_443X),
+	CLK("40138000.timer",	"timer_sys_ck",	&syc_clk_div_ck,	CK_443X),
+	CLK("4013a000.timer",	"timer_sys_ck",	&syc_clk_div_ck,	CK_443X),
+	CLK("4013c000.timer",	"timer_sys_ck",	&syc_clk_div_ck,	CK_443X),
+	CLK("4013e000.timer",	"timer_sys_ck",	&syc_clk_div_ck,	CK_443X),
 	CLK(NULL,	"cpufreq_ck",	&dpll_mpu_ck,	CK_443X),
 };
 
@@ -1955,6 +1993,7 @@ int __init omap4xxx_clk_init(void)
 {
 	u32 cpu_clkflg;
 	struct omap_clk *c;
+	int rc;
 
 	if (cpu_is_omap443x()) {
 		cpu_mask = RATE_IN_4430;
@@ -1983,5 +2022,18 @@ int __init omap4xxx_clk_init(void)
 	omap2_clk_enable_init_clocks(enable_init_clks,
 				     ARRAY_SIZE(enable_init_clks));
 
+	/*
+	 * On OMAP4460 the ABE DPLL fails to turn on if in idle low-power
+	 * state when turning the ABE clock domain. Workaround this by
+	 * locking the ABE DPLL on boot.
+	 */
+	if (cpu_is_omap446x()) {
+		rc = clk_set_parent(&abe_dpll_refclk_mux_ck, &sys_32k_ck);
+		if (!rc)
+			rc = clk_set_rate(&dpll_abe_ck, OMAP4_DPLL_ABE_DEFFREQ);
+		if (rc)
+			pr_err("%s: failed to configure ABE DPLL!\n", __func__);
+	}
+
 	return 0;
 }
diff --git a/arch/arm/mach-omap2/clock.h b/arch/arm/mach-omap2/clock.h
index 9917f793c3b6..b40204837bd7 100644
--- a/arch/arm/mach-omap2/clock.h
+++ b/arch/arm/mach-omap2/clock.h
@@ -195,6 +195,10 @@ struct clksel {
  * @enable_mask: mask of the DPLL mode bitfield in @control_reg
  * @last_rounded_rate: cache of the last rate result of omap2_dpll_round_rate()
  * @last_rounded_m: cache of the last M result of omap2_dpll_round_rate()
+ * @last_rounded_m4xen: cache of the last M4X result of
+ *			omap4_dpll_regm4xen_round_rate()
+ * @last_rounded_lpmode: cache of the last lpmode result of
+ *			 omap4_dpll_lpmode_recalc()
  * @max_multiplier: maximum valid non-bypass multiplier value (actual)
  * @last_rounded_n: cache of the last N result of omap2_dpll_round_rate()
  * @min_divider: minimum valid non-bypass divider value (actual)
@@ -205,6 +209,8 @@ struct clksel {
  * @autoidle_mask: mask of the DPLL autoidle mode bitfield in @autoidle_reg
  * @freqsel_mask: mask of the DPLL jitter correction bitfield in @control_reg
  * @idlest_mask: mask of the DPLL idle status bitfield in @idlest_reg
+ * @lpmode_mask: mask of the DPLL low-power mode bitfield in @control_reg
+ * @m4xen_mask: mask of the DPLL M4X multiplier bitfield in @control_reg
  * @auto_recal_bit: bitshift of the driftguard enable bit in @control_reg
  * @recal_en_bit: bitshift of the PRM_IRQENABLE_* bit for recalibration IRQs
  * @recal_st_bit: bitshift of the PRM_IRQSTATUS_* bit for recalibration IRQs
@@ -233,6 +239,8 @@ struct dpll_data {
 	u32			enable_mask;
 	unsigned long		last_rounded_rate;
 	u16			last_rounded_m;
+	u8			last_rounded_m4xen;
+	u8			last_rounded_lpmode;
 	u16			max_multiplier;
 	u8			last_rounded_n;
 	u8			min_divider;
@@ -245,6 +253,8 @@ struct dpll_data {
 	u32			idlest_mask;
 	u32			dco_mask;
 	u32			sddiv_mask;
+	u32			lpmode_mask;
+	u32			m4xen_mask;
 	u8			auto_recal_bit;
 	u8			recal_en_bit;
 	u8			recal_st_bit;
diff --git a/arch/arm/mach-omap2/clockdomain.c b/arch/arm/mach-omap2/clockdomain.c
index 384873580b23..7faf82d4e85c 100644
--- a/arch/arm/mach-omap2/clockdomain.c
+++ b/arch/arm/mach-omap2/clockdomain.c
@@ -998,7 +998,8 @@ int clkdm_clk_disable(struct clockdomain *clkdm, struct clk *clk)
 	spin_lock_irqsave(&clkdm->lock, flags);
 
 	/* corner case: disabling unused clocks */
-	if (__clk_get_enable_count(clk) == 0)
+	if ((__clk_get_enable_count(clk) == 0) &&
+	    (atomic_read(&clkdm->usecount) == 0))
 		goto ccd_exit;
 
 	if (atomic_read(&clkdm->usecount) == 0) {
diff --git a/arch/arm/mach-omap2/cpuidle34xx.c b/arch/arm/mach-omap2/cpuidle34xx.c
index bca7a8885703..22590dbe8f14 100644
--- a/arch/arm/mach-omap2/cpuidle34xx.c
+++ b/arch/arm/mach-omap2/cpuidle34xx.c
@@ -40,6 +40,8 @@ struct omap3_idle_statedata {
 	u32 core_state;
 };
 
+static struct powerdomain *mpu_pd, *core_pd, *per_pd, *cam_pd;
+
 static struct omap3_idle_statedata omap3_idle_data[] = {
 	{
 		.mpu_state = PWRDM_POWER_ON,
@@ -71,7 +73,7 @@ static struct omap3_idle_statedata omap3_idle_data[] = {
 	},
 };
 
-static struct powerdomain *mpu_pd, *core_pd, *per_pd, *cam_pd;
+/* Private functions */
 
 static int __omap3_enter_idle(struct cpuidle_device *dev,
 				struct cpuidle_driver *drv,
@@ -260,11 +262,11 @@ static int omap3_enter_idle_bm(struct cpuidle_device *dev,
 	return ret;
 }
 
-DEFINE_PER_CPU(struct cpuidle_device, omap3_idle_dev);
+static DEFINE_PER_CPU(struct cpuidle_device, omap3_idle_dev);
 
-struct cpuidle_driver omap3_idle_driver = {
-	.name = 	"omap3_idle",
-	.owner = 	THIS_MODULE,
+static struct cpuidle_driver omap3_idle_driver = {
+	.name =		"omap3_idle",
+	.owner =	THIS_MODULE,
 	.states = {
 		{
 			.enter		  = omap3_enter_idle_bm,
@@ -327,6 +329,8 @@ struct cpuidle_driver omap3_idle_driver = {
 	.safe_state_index = 0,
 };
 
+/* Public functions */
+
 /**
  * omap3_idle_init - Init routine for OMAP3 idle
  *
diff --git a/arch/arm/mach-omap2/cpuidle44xx.c b/arch/arm/mach-omap2/cpuidle44xx.c
index 288bee6cbb76..d639aef0deda 100644
--- a/arch/arm/mach-omap2/cpuidle44xx.c
+++ b/arch/arm/mach-omap2/cpuidle44xx.c
@@ -54,6 +54,8 @@ static struct clockdomain *cpu_clkdm[NR_CPUS];
 static atomic_t abort_barrier;
 static bool cpu_done[NR_CPUS];
 
+/* Private functions */
+
 /**
  * omap4_enter_idle_coupled_[simple/coupled] - OMAP4 cpuidle entry functions
  * @dev: cpuidle device
@@ -161,9 +163,19 @@ fail:
 	return index;
 }
 
-DEFINE_PER_CPU(struct cpuidle_device, omap4_idle_dev);
+/*
+ * For each cpu, setup the broadcast timer because local timers
+ * stops for the states above C1.
+ */
+static void omap_setup_broadcast_timer(void *arg)
+{
+	int cpu = smp_processor_id();
+	clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ON, &cpu);
+}
+
+static DEFINE_PER_CPU(struct cpuidle_device, omap4_idle_dev);
 
-struct cpuidle_driver omap4_idle_driver = {
+static struct cpuidle_driver omap4_idle_driver = {
 	.name				= "omap4_idle",
 	.owner				= THIS_MODULE,
 	.en_core_tk_irqen		= 1,
@@ -178,7 +190,7 @@ struct cpuidle_driver omap4_idle_driver = {
 			.desc = "MPUSS ON"
 		},
 		{
-                        /* C2 - CPU0 OFF + CPU1 OFF + MPU CSWR */
+			/* C2 - CPU0 OFF + CPU1 OFF + MPU CSWR */
 			.exit_latency = 328 + 440,
 			.target_residency = 960,
 			.flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_COUPLED,
@@ -200,15 +212,7 @@ struct cpuidle_driver omap4_idle_driver = {
 	.safe_state_index = 0,
 };
 
-/*
- * For each cpu, setup the broadcast timer because local timers
- * stops for the states above C1.
- */
-static void omap_setup_broadcast_timer(void *arg)
-{
-	int cpu = smp_processor_id();
-	clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ON, &cpu);
-}
+/* Public functions */
 
 /**
  * omap4_idle_init - Init routine for OMAP4 idle
diff --git a/arch/arm/mach-omap2/dpll3xxx.c b/arch/arm/mach-omap2/dpll3xxx.c
index fafb28c0dcbc..2bb18838cba9 100644
--- a/arch/arm/mach-omap2/dpll3xxx.c
+++ b/arch/arm/mach-omap2/dpll3xxx.c
@@ -291,16 +291,13 @@ static void _lookup_sddiv(struct clk_hw_omap *clk, u8 *sd_div, u16 m, u8 n)
 
 /*
  * _omap3_noncore_dpll_program - set non-core DPLL M,N values directly
- * @clk: struct clk * of DPLL to set
- * @m: DPLL multiplier to set
- * @n: DPLL divider to set
- * @freqsel: FREQSEL value to set
+ * @clk:	struct clk * of DPLL to set
+ * @freqsel:	FREQSEL value to set
  *
- * Program the DPLL with the supplied M, N values, and wait for the DPLL to
- * lock..  Returns -EINVAL upon error, or 0 upon success.
+ * Program the DPLL with the last M, N values calculated, and wait for
+ * the DPLL to lock. Returns -EINVAL upon error, or 0 upon success.
  */
-static int omap3_noncore_dpll_program(struct clk_hw_omap *clk, u16 m, u8 n,
-				      u16 freqsel)
+static int omap3_noncore_dpll_program(struct clk_hw_omap *clk, u16 freqsel)
 {
 	struct dpll_data *dd = clk->dpll_data;
 	u8 dco, sd_div;
@@ -323,23 +320,45 @@ static int omap3_noncore_dpll_program(struct clk_hw_omap *clk, u16 m, u8 n,
 	/* Set DPLL multiplier, divider */
 	v = __raw_readl(dd->mult_div1_reg);
 	v &= ~(dd->mult_mask | dd->div1_mask);
-	v |= m << __ffs(dd->mult_mask);
-	v |= (n - 1) << __ffs(dd->div1_mask);
+	v |= dd->last_rounded_m << __ffs(dd->mult_mask);
+	v |= (dd->last_rounded_n - 1) << __ffs(dd->div1_mask);
 
 	/* Configure dco and sd_div for dplls that have these fields */
 	if (dd->dco_mask) {
-		_lookup_dco(clk, &dco, m, n);
+		_lookup_dco(clk, &dco, dd->last_rounded_m, dd->last_rounded_n);
 		v &= ~(dd->dco_mask);
 		v |= dco << __ffs(dd->dco_mask);
 	}
 	if (dd->sddiv_mask) {
-		_lookup_sddiv(clk, &sd_div, m, n);
+		_lookup_sddiv(clk, &sd_div, dd->last_rounded_m,
+			      dd->last_rounded_n);
 		v &= ~(dd->sddiv_mask);
 		v |= sd_div << __ffs(dd->sddiv_mask);
 	}
 
 	__raw_writel(v, dd->mult_div1_reg);
 
+	/* Set 4X multiplier and low-power mode */
+	if (dd->m4xen_mask || dd->lpmode_mask) {
+		v = __raw_readl(dd->control_reg);
+
+		if (dd->m4xen_mask) {
+			if (dd->last_rounded_m4xen)
+				v |= dd->m4xen_mask;
+			else
+				v &= ~dd->m4xen_mask;
+		}
+
+		if (dd->lpmode_mask) {
+			if (dd->last_rounded_lpmode)
+				v |= dd->lpmode_mask;
+			else
+				v &= ~dd->lpmode_mask;
+		}
+
+		__raw_writel(v, dd->control_reg);
+	}
+
 	/* We let the clock framework set the other output dividers later */
 
 	/* REVISIT: Set ramp-up delay? */
@@ -492,8 +511,7 @@ int omap3_noncore_dpll_set_rate(struct clk_hw *hw, unsigned long rate,
 		pr_debug("%s: %s: set rate: locking rate to %lu.\n",
 			 __func__, __clk_get_name(hw->clk), rate);
 
-		ret = omap3_noncore_dpll_program(clk, dd->last_rounded_m,
-						dd->last_rounded_n, freqsel);
+		ret = omap3_noncore_dpll_program(clk, freqsel);
 		if (!ret)
 			new_parent = dd->clk_ref;
 	}
diff --git a/arch/arm/mach-omap2/dpll44xx.c b/arch/arm/mach-omap2/dpll44xx.c
index d3326c474fdc..d28b0f726715 100644
--- a/arch/arm/mach-omap2/dpll44xx.c
+++ b/arch/arm/mach-omap2/dpll44xx.c
@@ -20,6 +20,15 @@
 #include "clock44xx.h"
 #include "cm-regbits-44xx.h"
 
+/*
+ * Maximum DPLL input frequency (FINT) and output frequency (FOUT) that
+ * can supported when using the DPLL low-power mode. Frequencies are
+ * defined in OMAP4430/60 Public TRM section 3.6.3.3.2 "Enable Control,
+ * Status, and Low-Power Operation Mode".
+ */
+#define OMAP4_DPLL_LP_FINT_MAX	1000000
+#define OMAP4_DPLL_LP_FOUT_MAX	100000000
+
 /* Supported only on OMAP4 */
 int omap4_dpllmx_gatectrl_read(struct clk_hw_omap *clk)
 {
@@ -82,6 +91,31 @@ const struct clk_hw_omap_ops clkhwops_omap4_dpllmx = {
 };
 
 /**
+ * omap4_dpll_lpmode_recalc - compute DPLL low-power setting
+ * @dd: pointer to the dpll data structure
+ *
+ * Calculates if low-power mode can be enabled based upon the last
+ * multiplier and divider values calculated. If low-power mode can be
+ * enabled, then the bit to enable low-power mode is stored in the
+ * last_rounded_lpmode variable. This implementation is based upon the
+ * criteria for enabling low-power mode as described in the OMAP4430/60
+ * Public TRM section 3.6.3.3.2 "Enable Control, Status, and Low-Power
+ * Operation Mode".
+ */
+static void omap4_dpll_lpmode_recalc(struct dpll_data *dd)
+{
+	long fint, fout;
+
+	fint = __clk_get_rate(dd->clk_ref) / (dd->last_rounded_n + 1);
+	fout = fint * dd->last_rounded_m;
+
+	if ((fint < OMAP4_DPLL_LP_FINT_MAX) && (fout < OMAP4_DPLL_LP_FOUT_MAX))
+		dd->last_rounded_lpmode = 1;
+	else
+		dd->last_rounded_lpmode = 0;
+}
+
+/**
  * omap4_dpll_regm4xen_recalc - compute DPLL rate, considering REGM4XEN bit
  * @clk: struct clk * of the DPLL to compute the rate for
  *
@@ -130,7 +164,6 @@ long omap4_dpll_regm4xen_round_rate(struct clk_hw *hw,
 				    unsigned long *parent_rate)
 {
 	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
-	u32 v;
 	struct dpll_data *dd;
 	long r;
 
@@ -139,18 +172,31 @@ long omap4_dpll_regm4xen_round_rate(struct clk_hw *hw,
 
 	dd = clk->dpll_data;
 
-	/* regm4xen adds a multiplier of 4 to DPLL calculations */
-	v = __raw_readl(dd->control_reg) & OMAP4430_DPLL_REGM4XEN_MASK;
-
-	if (v)
-		target_rate = target_rate / OMAP4430_REGM4XEN_MULT;
+	dd->last_rounded_m4xen = 0;
 
+	/*
+	 * First try to compute the DPLL configuration for
+	 * target rate without using the 4X multiplier.
+	 */
 	r = omap2_dpll_round_rate(hw, target_rate, NULL);
+	if (r != ~0)
+		goto out;
+
+	/*
+	 * If we did not find a valid DPLL configuration, try again, but
+	 * this time see if using the 4X multiplier can help. Enabling the
+	 * 4X multiplier is equivalent to dividing the target rate by 4.
+	 */
+	r = omap2_dpll_round_rate(hw, target_rate / OMAP4430_REGM4XEN_MULT,
+				  NULL);
 	if (r == ~0)
 		return r;
 
-	if (v)
-		clk->dpll_data->last_rounded_rate *= OMAP4430_REGM4XEN_MULT;
+	dd->last_rounded_rate *= OMAP4430_REGM4XEN_MULT;
+	dd->last_rounded_m4xen = 1;
+
+out:
+	omap4_dpll_lpmode_recalc(dd);
 
-	return clk->dpll_data->last_rounded_rate;
+	return dd->last_rounded_rate;
 }