Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc

Pull more powerpc bits from Ben Herrenschmidt:
 "Here are a few more powerpc bits for this merge window.  The bulk is
  made of two pull requests from Scott and Anatolij that I had missed
  previously (they arrived while I was away).  Since both their branches
  are in -next independently, and the content has been around for a
  little while, they can still go in.

  The rest is mostly bug and regression fixes, a small series of
  cleanups to our pseries cpuidle code (including moving it to the right
  place), and one new cpuidle bakend for the powernv platform.  I also
  wired up the new sched_attr syscalls"

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (37 commits)
  powerpc: Wire up sched_setattr and sched_getattr syscalls
  powerpc/hugetlb: Replace __get_cpu_var with get_cpu_var
  powerpc: Make sure "cache" directory is removed when offlining cpu
  powerpc/mm: Fix mmap errno when MAP_FIXED is set and mapping exceeds the allowed address space
  powerpc/powernv/cpuidle: Back-end cpuidle driver for powernv platform.
  powerpc/pseries/cpuidle: smt-snooze-delay cleanup.
  powerpc/pseries/cpuidle: Remove MAX_IDLE_STATE macro.
  powerpc/pseries/cpuidle: Make cpuidle-pseries backend driver a non-module.
  powerpc/pseries/cpuidle: Use cpuidle_register() for initialisation.
  powerpc/pseries/cpuidle: Move processor_idle.c to drivers/cpuidle.
  powerpc: Fix 32-bit frames for signals delivered when transactional
  powerpc/iommu: Fix initialisation of DART iommu table
  powerpc/numa: Fix decimal permissions
  powerpc/mm: Fix compile error of pgtable-ppc64.h
  powerpc: Fix hw breakpoints on !HAVE_HW_BREAKPOINT configurations
  clk: corenet: Adds the clock binding
  powerpc/booke64: Guard e6500 tlb handler with CONFIG_PPC_FSL_BOOK3E
  powerpc/512x: dts: add MPC5125 clock specs
  powerpc/512x: clk: support MPC5121/5123/5125 SoC variants
  powerpc/512x: clk: enforce even SDHC divider values
  ...

11 files changed, 720 insertions, 149 deletions

diff --git a/drivers/cpuidle/Kconfig b/drivers/cpuidle/Kconfig
index b3fb81d7cf04..f04e25f6c98d 100644
--- a/drivers/cpuidle/Kconfig
+++ b/drivers/cpuidle/Kconfig
@@ -35,6 +35,11 @@ depends on ARM
 source "drivers/cpuidle/Kconfig.arm"
 endmenu
 
+menu "POWERPC CPU Idle Drivers"
+depends on PPC
+source "drivers/cpuidle/Kconfig.powerpc"
+endmenu
+
 endif
 
 config ARCH_NEEDS_CPU_IDLE_COUPLED
diff --git a/drivers/cpuidle/Kconfig.powerpc b/drivers/cpuidle/Kconfig.powerpc
new file mode 100644
index 000000000000..66c3a09574e9
--- /dev/null
+++ b/drivers/cpuidle/Kconfig.powerpc
@@ -0,0 +1,20 @@
+#
+# POWERPC CPU Idle Drivers
+#
+config PSERIES_CPUIDLE
+	bool "Cpuidle driver for pSeries platforms"
+	depends on CPU_IDLE
+	depends on PPC_PSERIES
+	default y
+	help
+	  Select this option to enable processor idle state management
+	  through cpuidle subsystem.
+
+config POWERNV_CPUIDLE
+	bool "Cpuidle driver for powernv platforms"
+	depends on CPU_IDLE
+	depends on PPC_POWERNV
+	default y
+	help
+	  Select this option to enable processor idle state management
+	  through cpuidle subsystem.
diff --git a/drivers/cpuidle/Makefile b/drivers/cpuidle/Makefile
index 527be28e5c1e..f71ae1b373c5 100644
--- a/drivers/cpuidle/Makefile
+++ b/drivers/cpuidle/Makefile
@@ -13,3 +13,8 @@ obj-$(CONFIG_ARM_KIRKWOOD_CPUIDLE)	+= cpuidle-kirkwood.o
 obj-$(CONFIG_ARM_ZYNQ_CPUIDLE)		+= cpuidle-zynq.o
 obj-$(CONFIG_ARM_U8500_CPUIDLE)         += cpuidle-ux500.o
 obj-$(CONFIG_ARM_AT91_CPUIDLE)          += cpuidle-at91.o
+
+###############################################################################
+# POWERPC drivers
+obj-$(CONFIG_PSERIES_CPUIDLE)		+= cpuidle-pseries.o
+obj-$(CONFIG_POWERNV_CPUIDLE)		+= cpuidle-powernv.o
diff --git a/drivers/cpuidle/cpuidle-powernv.c b/drivers/cpuidle/cpuidle-powernv.c
new file mode 100644
index 000000000000..78fd174c57e8
--- /dev/null
+++ b/drivers/cpuidle/cpuidle-powernv.c
@@ -0,0 +1,169 @@
+/*
+ *  cpuidle-powernv - idle state cpuidle driver.
+ *  Adapted from drivers/cpuidle/cpuidle-pseries
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/moduleparam.h>
+#include <linux/cpuidle.h>
+#include <linux/cpu.h>
+#include <linux/notifier.h>
+
+#include <asm/machdep.h>
+#include <asm/firmware.h>
+
+struct cpuidle_driver powernv_idle_driver = {
+	.name             = "powernv_idle",
+	.owner            = THIS_MODULE,
+};
+
+static int max_idle_state;
+static struct cpuidle_state *cpuidle_state_table;
+
+static int snooze_loop(struct cpuidle_device *dev,
+			struct cpuidle_driver *drv,
+			int index)
+{
+	local_irq_enable();
+	set_thread_flag(TIF_POLLING_NRFLAG);
+
+	while (!need_resched()) {
+		HMT_low();
+		HMT_very_low();
+	}
+
+	HMT_medium();
+	clear_thread_flag(TIF_POLLING_NRFLAG);
+	smp_mb();
+	return index;
+}
+
+static int nap_loop(struct cpuidle_device *dev,
+			struct cpuidle_driver *drv,
+			int index)
+{
+	power7_idle();
+	return index;
+}
+
+/*
+ * States for dedicated partition case.
+ */
+static struct cpuidle_state powernv_states[] = {
+	{ /* Snooze */
+		.name = "snooze",
+		.desc = "snooze",
+		.flags = CPUIDLE_FLAG_TIME_VALID,
+		.exit_latency = 0,
+		.target_residency = 0,
+		.enter = &snooze_loop },
+	{ /* NAP */
+		.name = "NAP",
+		.desc = "NAP",
+		.flags = CPUIDLE_FLAG_TIME_VALID,
+		.exit_latency = 10,
+		.target_residency = 100,
+		.enter = &nap_loop },
+};
+
+static int powernv_cpuidle_add_cpu_notifier(struct notifier_block *n,
+			unsigned long action, void *hcpu)
+{
+	int hotcpu = (unsigned long)hcpu;
+	struct cpuidle_device *dev =
+				per_cpu(cpuidle_devices, hotcpu);
+
+	if (dev && cpuidle_get_driver()) {
+		switch (action) {
+		case CPU_ONLINE:
+		case CPU_ONLINE_FROZEN:
+			cpuidle_pause_and_lock();
+			cpuidle_enable_device(dev);
+			cpuidle_resume_and_unlock();
+			break;
+
+		case CPU_DEAD:
+		case CPU_DEAD_FROZEN:
+			cpuidle_pause_and_lock();
+			cpuidle_disable_device(dev);
+			cpuidle_resume_and_unlock();
+			break;
+
+		default:
+			return NOTIFY_DONE;
+		}
+	}
+	return NOTIFY_OK;
+}
+
+static struct notifier_block setup_hotplug_notifier = {
+	.notifier_call = powernv_cpuidle_add_cpu_notifier,
+};
+
+/*
+ * powernv_cpuidle_driver_init()
+ */
+static int powernv_cpuidle_driver_init(void)
+{
+	int idle_state;
+	struct cpuidle_driver *drv = &powernv_idle_driver;
+
+	drv->state_count = 0;
+
+	for (idle_state = 0; idle_state < max_idle_state; ++idle_state) {
+		/* Is the state not enabled? */
+		if (cpuidle_state_table[idle_state].enter == NULL)
+			continue;
+
+		drv->states[drv->state_count] =	/* structure copy */
+			cpuidle_state_table[idle_state];
+
+		drv->state_count += 1;
+	}
+
+	return 0;
+}
+
+/*
+ * powernv_idle_probe()
+ * Choose state table for shared versus dedicated partition
+ */
+static int powernv_idle_probe(void)
+{
+
+	if (cpuidle_disable != IDLE_NO_OVERRIDE)
+		return -ENODEV;
+
+	if (firmware_has_feature(FW_FEATURE_OPALv3)) {
+		cpuidle_state_table = powernv_states;
+		max_idle_state = ARRAY_SIZE(powernv_states);
+ 	} else
+ 		return -ENODEV;
+
+	return 0;
+}
+
+static int __init powernv_processor_idle_init(void)
+{
+	int retval;
+
+	retval = powernv_idle_probe();
+	if (retval)
+		return retval;
+
+	powernv_cpuidle_driver_init();
+	retval = cpuidle_register(&powernv_idle_driver, NULL);
+	if (retval) {
+		printk(KERN_DEBUG "Registration of powernv driver failed.\n");
+		return retval;
+	}
+
+	register_cpu_notifier(&setup_hotplug_notifier);
+	printk(KERN_DEBUG "powernv_idle_driver registered\n");
+	return 0;
+}
+
+device_initcall(powernv_processor_idle_init);
diff --git a/drivers/cpuidle/cpuidle-pseries.c b/drivers/cpuidle/cpuidle-pseries.c
new file mode 100644
index 000000000000..7ab564aa0b1c
--- /dev/null
+++ b/drivers/cpuidle/cpuidle-pseries.c
@@ -0,0 +1,267 @@
+/*
+ *  cpuidle-pseries - idle state cpuidle driver.
+ *  Adapted from drivers/idle/intel_idle.c and
+ *  drivers/acpi/processor_idle.c
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/moduleparam.h>
+#include <linux/cpuidle.h>
+#include <linux/cpu.h>
+#include <linux/notifier.h>
+
+#include <asm/paca.h>
+#include <asm/reg.h>
+#include <asm/machdep.h>
+#include <asm/firmware.h>
+#include <asm/plpar_wrappers.h>
+
+struct cpuidle_driver pseries_idle_driver = {
+	.name             = "pseries_idle",
+	.owner            = THIS_MODULE,
+};
+
+static int max_idle_state;
+static struct cpuidle_state *cpuidle_state_table;
+
+static inline void idle_loop_prolog(unsigned long *in_purr)
+{
+	*in_purr = mfspr(SPRN_PURR);
+	/*
+	 * Indicate to the HV that we are idle. Now would be
+	 * a good time to find other work to dispatch.
+	 */
+	get_lppaca()->idle = 1;
+}
+
+static inline void idle_loop_epilog(unsigned long in_purr)
+{
+	u64 wait_cycles;
+
+	wait_cycles = be64_to_cpu(get_lppaca()->wait_state_cycles);
+	wait_cycles += mfspr(SPRN_PURR) - in_purr;
+	get_lppaca()->wait_state_cycles = cpu_to_be64(wait_cycles);
+	get_lppaca()->idle = 0;
+}
+
+static int snooze_loop(struct cpuidle_device *dev,
+			struct cpuidle_driver *drv,
+			int index)
+{
+	unsigned long in_purr;
+
+	idle_loop_prolog(&in_purr);
+	local_irq_enable();
+	set_thread_flag(TIF_POLLING_NRFLAG);
+
+	while (!need_resched()) {
+		HMT_low();
+		HMT_very_low();
+	}
+
+	HMT_medium();
+	clear_thread_flag(TIF_POLLING_NRFLAG);
+	smp_mb();
+
+	idle_loop_epilog(in_purr);
+
+	return index;
+}
+
+static void check_and_cede_processor(void)
+{
+	/*
+	 * Ensure our interrupt state is properly tracked,
+	 * also checks if no interrupt has occurred while we
+	 * were soft-disabled
+	 */
+	if (prep_irq_for_idle()) {
+		cede_processor();
+#ifdef CONFIG_TRACE_IRQFLAGS
+		/* Ensure that H_CEDE returns with IRQs on */
+		if (WARN_ON(!(mfmsr() & MSR_EE)))
+			__hard_irq_enable();
+#endif
+	}
+}
+
+static int dedicated_cede_loop(struct cpuidle_device *dev,
+				struct cpuidle_driver *drv,
+				int index)
+{
+	unsigned long in_purr;
+
+	idle_loop_prolog(&in_purr);
+	get_lppaca()->donate_dedicated_cpu = 1;
+
+	HMT_medium();
+	check_and_cede_processor();
+
+	get_lppaca()->donate_dedicated_cpu = 0;
+
+	idle_loop_epilog(in_purr);
+
+	return index;
+}
+
+static int shared_cede_loop(struct cpuidle_device *dev,
+			struct cpuidle_driver *drv,
+			int index)
+{
+	unsigned long in_purr;
+
+	idle_loop_prolog(&in_purr);
+
+	/*
+	 * Yield the processor to the hypervisor.  We return if
+	 * an external interrupt occurs (which are driven prior
+	 * to returning here) or if a prod occurs from another
+	 * processor. When returning here, external interrupts
+	 * are enabled.
+	 */
+	check_and_cede_processor();
+
+	idle_loop_epilog(in_purr);
+
+	return index;
+}
+
+/*
+ * States for dedicated partition case.
+ */
+static struct cpuidle_state dedicated_states[] = {
+	{ /* Snooze */
+		.name = "snooze",
+		.desc = "snooze",
+		.flags = CPUIDLE_FLAG_TIME_VALID,
+		.exit_latency = 0,
+		.target_residency = 0,
+		.enter = &snooze_loop },
+	{ /* CEDE */
+		.name = "CEDE",
+		.desc = "CEDE",
+		.flags = CPUIDLE_FLAG_TIME_VALID,
+		.exit_latency = 10,
+		.target_residency = 100,
+		.enter = &dedicated_cede_loop },
+};
+
+/*
+ * States for shared partition case.
+ */
+static struct cpuidle_state shared_states[] = {
+	{ /* Shared Cede */
+		.name = "Shared Cede",
+		.desc = "Shared Cede",
+		.flags = CPUIDLE_FLAG_TIME_VALID,
+		.exit_latency = 0,
+		.target_residency = 0,
+		.enter = &shared_cede_loop },
+};
+
+static int pseries_cpuidle_add_cpu_notifier(struct notifier_block *n,
+			unsigned long action, void *hcpu)
+{
+	int hotcpu = (unsigned long)hcpu;
+	struct cpuidle_device *dev =
+				per_cpu(cpuidle_devices, hotcpu);
+
+	if (dev && cpuidle_get_driver()) {
+		switch (action) {
+		case CPU_ONLINE:
+		case CPU_ONLINE_FROZEN:
+			cpuidle_pause_and_lock();
+			cpuidle_enable_device(dev);
+			cpuidle_resume_and_unlock();
+			break;
+
+		case CPU_DEAD:
+		case CPU_DEAD_FROZEN:
+			cpuidle_pause_and_lock();
+			cpuidle_disable_device(dev);
+			cpuidle_resume_and_unlock();
+			break;
+
+		default:
+			return NOTIFY_DONE;
+		}
+	}
+	return NOTIFY_OK;
+}
+
+static struct notifier_block setup_hotplug_notifier = {
+	.notifier_call = pseries_cpuidle_add_cpu_notifier,
+};
+
+/*
+ * pseries_cpuidle_driver_init()
+ */
+static int pseries_cpuidle_driver_init(void)
+{
+	int idle_state;
+	struct cpuidle_driver *drv = &pseries_idle_driver;
+
+	drv->state_count = 0;
+
+	for (idle_state = 0; idle_state < max_idle_state; ++idle_state) {
+		/* Is the state not enabled? */
+		if (cpuidle_state_table[idle_state].enter == NULL)
+			continue;
+
+		drv->states[drv->state_count] =	/* structure copy */
+			cpuidle_state_table[idle_state];
+
+		drv->state_count += 1;
+	}
+
+	return 0;
+}
+
+/*
+ * pseries_idle_probe()
+ * Choose state table for shared versus dedicated partition
+ */
+static int pseries_idle_probe(void)
+{
+
+	if (cpuidle_disable != IDLE_NO_OVERRIDE)
+		return -ENODEV;
+
+	if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
+		if (lppaca_shared_proc(get_lppaca())) {
+			cpuidle_state_table = shared_states;
+			max_idle_state = ARRAY_SIZE(shared_states);
+		} else {
+			cpuidle_state_table = dedicated_states;
+			max_idle_state = ARRAY_SIZE(dedicated_states);
+		}
+	} else
+		return -ENODEV;
+
+	return 0;
+}
+
+static int __init pseries_processor_idle_init(void)
+{
+	int retval;
+
+	retval = pseries_idle_probe();
+	if (retval)
+		return retval;
+
+	pseries_cpuidle_driver_init();
+	retval = cpuidle_register(&pseries_idle_driver, NULL);
+	if (retval) {
+		printk(KERN_DEBUG "Registration of pseries driver failed.\n");
+		return retval;
+	}
+
+	register_cpu_notifier(&setup_hotplug_notifier);
+	printk(KERN_DEBUG "pseries_idle_driver registered\n");
+	return 0;
+}
+
+device_initcall(pseries_processor_idle_init);
diff --git a/drivers/media/platform/fsl-viu.c b/drivers/media/platform/fsl-viu.c
index 6a232239ee8c..dbf0ce38a8e7 100644
--- a/drivers/media/platform/fsl-viu.c
+++ b/drivers/media/platform/fsl-viu.c
@@ -1580,7 +1580,7 @@ static int viu_of_probe(struct platform_device *op)
 	}
 
 	/* enable VIU clock */
-	clk = devm_clk_get(&op->dev, "viu_clk");
+	clk = devm_clk_get(&op->dev, "ipg");
 	if (IS_ERR(clk)) {
 		dev_err(&op->dev, "failed to lookup the clock!\n");
 		ret = PTR_ERR(clk);
diff --git a/drivers/mtd/nand/mpc5121_nfc.c b/drivers/mtd/nand/mpc5121_nfc.c
index 61e2abc216ad..31ee7cfbc12b 100644
--- a/drivers/mtd/nand/mpc5121_nfc.c
+++ b/drivers/mtd/nand/mpc5121_nfc.c
@@ -729,7 +729,7 @@ static int mpc5121_nfc_probe(struct platform_device *op)
 	of_node_put(rootnode);
 
 	/* Enable NFC clock */
-	clk = devm_clk_get(dev, "nfc_clk");
+	clk = devm_clk_get(dev, "ipg");
 	if (IS_ERR(clk)) {
 		dev_err(dev, "Unable to acquire NFC clock!\n");
 		retval = PTR_ERR(clk);
diff --git a/drivers/net/can/mscan/mpc5xxx_can.c b/drivers/net/can/mscan/mpc5xxx_can.c
index 035e235e3118..44725296f72a 100644
--- a/drivers/net/can/mscan/mpc5xxx_can.c
+++ b/drivers/net/can/mscan/mpc5xxx_can.c
@@ -108,135 +108,170 @@ static u32 mpc52xx_can_get_clock(struct platform_device *ofdev,
 #endif /* CONFIG_PPC_MPC52xx */
 
 #ifdef CONFIG_PPC_MPC512x
-struct mpc512x_clockctl {
-	u32 spmr;		/* System PLL Mode Reg */
-	u32 sccr[2];		/* System Clk Ctrl Reg 1 & 2 */
-	u32 scfr1;		/* System Clk Freq Reg 1 */
-	u32 scfr2;		/* System Clk Freq Reg 2 */
-	u32 reserved;
-	u32 bcr;		/* Bread Crumb Reg */
-	u32 pccr[12];		/* PSC Clk Ctrl Reg 0-11 */
-	u32 spccr;		/* SPDIF Clk Ctrl Reg */
-	u32 cccr;		/* CFM Clk Ctrl Reg */
-	u32 dccr;		/* DIU Clk Cnfg Reg */
-	u32 mccr[4];		/* MSCAN Clk Ctrl Reg 1-3 */
-};
-
-static struct of_device_id mpc512x_clock_ids[] = {
-	{ .compatible = "fsl,mpc5121-clock", },
-	{}
-};
-
 static u32 mpc512x_can_get_clock(struct platform_device *ofdev,
-				 const char *clock_name, int *mscan_clksrc)
+				 const char *clock_source, int *mscan_clksrc)
 {
-	struct mpc512x_clockctl __iomem *clockctl;
-	struct device_node *np_clock;
-	struct clk *sys_clk, *ref_clk;
-	int plen, clockidx, clocksrc = -1;
-	u32 sys_freq, val, clockdiv = 1, freq = 0;
-	const u32 *pval;
-
-	np_clock = of_find_matching_node(NULL, mpc512x_clock_ids);
-	if (!np_clock) {
-		dev_err(&ofdev->dev, "couldn't find clock node\n");
-		return 0;
-	}
-	clockctl = of_iomap(np_clock, 0);
-	if (!clockctl) {
-		dev_err(&ofdev->dev, "couldn't map clock registers\n");
-		goto exit_put;
-	}
+	struct device_node *np;
+	u32 clockdiv;
+	enum {
+		CLK_FROM_AUTO,
+		CLK_FROM_IPS,
+		CLK_FROM_SYS,
+		CLK_FROM_REF,
+	} clk_from;
+	struct clk *clk_in, *clk_can;
+	unsigned long freq_calc;
+	struct mscan_priv *priv;
+	struct clk *clk_ipg;
 
-	/* Determine the MSCAN device index from the peripheral's
-	 * physical address. Register address offsets against the
-	 * IMMR base are:  0x1300, 0x1380, 0x2300, 0x2380
+	/* the caller passed in the clock source spec that was read from
+	 * the device tree, get the optional clock divider as well
 	 */
-	pval = of_get_property(ofdev->dev.of_node, "reg", &plen);
-	BUG_ON(!pval || plen < sizeof(*pval));
-	clockidx = (*pval & 0x80) ? 1 : 0;
-	if (*pval & 0x2000)
-		clockidx += 2;
+	np = ofdev->dev.of_node;
+	clockdiv = 1;
+	of_property_read_u32(np, "fsl,mscan-clock-divider", &clockdiv);
+	dev_dbg(&ofdev->dev, "device tree specs: clk src[%s] div[%d]\n",
+		clock_source ? clock_source : "<NULL>", clockdiv);
+
+	/* when clock-source is 'ip', the CANCTL1[CLKSRC] bit needs to
+	 * get set, and the 'ips' clock is the input to the MSCAN
+	 * component
+	 *
+	 * for clock-source values of 'ref' or 'sys' the CANCTL1[CLKSRC]
+	 * bit needs to get cleared, an optional clock-divider may have
+	 * been specified (the default value is 1), the appropriate
+	 * MSCAN related MCLK is the input to the MSCAN component
+	 *
+	 * in the absence of a clock-source spec, first an optimal clock
+	 * gets determined based on the 'sys' clock, if that fails the
+	 * 'ref' clock is used
+	 */
+	clk_from = CLK_FROM_AUTO;
+	if (clock_source) {
+		/* interpret the device tree's spec for the clock source */
+		if (!strcmp(clock_source, "ip"))
+			clk_from = CLK_FROM_IPS;
+		else if (!strcmp(clock_source, "sys"))
+			clk_from = CLK_FROM_SYS;
+		else if (!strcmp(clock_source, "ref"))
+			clk_from = CLK_FROM_REF;
+		else
+			goto err_invalid;
+		dev_dbg(&ofdev->dev, "got a clk source spec[%d]\n", clk_from);
+	}
+	if (clk_from == CLK_FROM_AUTO) {
+		/* no spec so far, try the 'sys' clock; round to the
+		 * next MHz and see if we can get a multiple of 16MHz
+		 */
+		dev_dbg(&ofdev->dev, "no clk source spec, trying SYS\n");
+		clk_in = devm_clk_get(&ofdev->dev, "sys");
+		if (IS_ERR(clk_in))
+			goto err_notavail;
+		freq_calc = clk_get_rate(clk_in);
+		freq_calc +=  499999;
+		freq_calc /= 1000000;
+		freq_calc *= 1000000;
+		if ((freq_calc % 16000000) == 0) {
+			clk_from = CLK_FROM_SYS;
+			clockdiv = freq_calc / 16000000;
+			dev_dbg(&ofdev->dev,
+				"clk fit, sys[%lu] div[%d] freq[%lu]\n",
+				freq_calc, clockdiv, freq_calc / clockdiv);
+		}
+	}
+	if (clk_from == CLK_FROM_AUTO) {
+		/* no spec so far, use the 'ref' clock */
+		dev_dbg(&ofdev->dev, "no clk source spec, trying REF\n");
+		clk_in = devm_clk_get(&ofdev->dev, "ref");
+		if (IS_ERR(clk_in))
+			goto err_notavail;
+		clk_from = CLK_FROM_REF;
+		freq_calc = clk_get_rate(clk_in);
+		dev_dbg(&ofdev->dev,
+			"clk fit, ref[%lu] (no div) freq[%lu]\n",
+			freq_calc, freq_calc);
+	}
 
-	/*
-	 * Clock source and divider selection: 3 different clock sources
-	 * can be selected: "ip", "ref" or "sys". For the latter two, a
-	 * clock divider can be defined as well. If the clock source is
-	 * not specified by the device tree, we first try to find an
-	 * optimal CAN source clock based on the system clock. If that
-	 * is not posslible, the reference clock will be used.
+	/* select IPS or MCLK as the MSCAN input (returned to the caller),
+	 * setup the MCLK mux source and rate if applicable, apply the
+	 * optionally specified or derived above divider, and determine
+	 * the actual resulting clock rate to return to the caller
 	 */
-	if (clock_name && !strcmp(clock_name, "ip")) {
+	switch (clk_from) {
+	case CLK_FROM_IPS:
+		clk_can = devm_clk_get(&ofdev->dev, "ips");
+		if (IS_ERR(clk_can))
+			goto err_notavail;
+		priv = netdev_priv(dev_get_drvdata(&ofdev->dev));
+		priv->clk_can = clk_can;
+		freq_calc = clk_get_rate(clk_can);
 		*mscan_clksrc = MSCAN_CLKSRC_IPS;
-		freq = mpc5xxx_get_bus_frequency(ofdev->dev.of_node);
-	} else {
+		dev_dbg(&ofdev->dev, "clk from IPS, clksrc[%d] freq[%lu]\n",
+			*mscan_clksrc, freq_calc);
+		break;
+	case CLK_FROM_SYS:
+	case CLK_FROM_REF:
+		clk_can = devm_clk_get(&ofdev->dev, "mclk");
+		if (IS_ERR(clk_can))
+			goto err_notavail;
+		priv = netdev_priv(dev_get_drvdata(&ofdev->dev));
+		priv->clk_can = clk_can;
+		if (clk_from == CLK_FROM_SYS)
+			clk_in = devm_clk_get(&ofdev->dev, "sys");
+		if (clk_from == CLK_FROM_REF)
+			clk_in = devm_clk_get(&ofdev->dev, "ref");
+		if (IS_ERR(clk_in))
+			goto err_notavail;
+		clk_set_parent(clk_can, clk_in);
+		freq_calc = clk_get_rate(clk_in);
+		freq_calc /= clockdiv;
+		clk_set_rate(clk_can, freq_calc);
+		freq_calc = clk_get_rate(clk_can);
 		*mscan_clksrc = MSCAN_CLKSRC_BUS;
-
-		pval = of_get_property(ofdev->dev.of_node,
-				       "fsl,mscan-clock-divider", &plen);
-		if (pval && plen == sizeof(*pval))
-			clockdiv = *pval;
-		if (!clockdiv)
-			clockdiv = 1;
-
-		if (!clock_name || !strcmp(clock_name, "sys")) {
-			sys_clk = devm_clk_get(&ofdev->dev, "sys_clk");
-			if (IS_ERR(sys_clk)) {
-				dev_err(&ofdev->dev, "couldn't get sys_clk\n");
-				goto exit_unmap;
-			}
-			/* Get and round up/down sys clock rate */
-			sys_freq = 1000000 *
-				((clk_get_rate(sys_clk) + 499999) / 1000000);
-
-			if (!clock_name) {
-				/* A multiple of 16 MHz would be optimal */
-				if ((sys_freq % 16000000) == 0) {
-					clocksrc = 0;
-					clockdiv = sys_freq / 16000000;
-					freq = sys_freq / clockdiv;
-				}
-			} else {
-				clocksrc = 0;
-				freq = sys_freq / clockdiv;
-			}
-		}
-
-		if (clocksrc < 0) {
-			ref_clk = devm_clk_get(&ofdev->dev, "ref_clk");
-			if (IS_ERR(ref_clk)) {
-				dev_err(&ofdev->dev, "couldn't get ref_clk\n");
-				goto exit_unmap;
-			}
-			clocksrc = 1;
-			freq = clk_get_rate(ref_clk) / clockdiv;
-		}
+		dev_dbg(&ofdev->dev, "clk from MCLK, clksrc[%d] freq[%lu]\n",
+			*mscan_clksrc, freq_calc);
+		break;
+	default:
+		goto err_invalid;
 	}
 
-	/* Disable clock */
-	out_be32(&clockctl->mccr[clockidx], 0x0);
-	if (clocksrc >= 0) {
-		/* Set source and divider */
-		val = (clocksrc << 14) | ((clockdiv - 1) << 17);
-		out_be32(&clockctl->mccr[clockidx], val);
-		/* Enable clock */
-		out_be32(&clockctl->mccr[clockidx], val | 0x10000);
-	}
+	/* the above clk_can item is used for the bitrate, access to
+	 * the peripheral's register set needs the clk_ipg item
+	 */
+	clk_ipg = devm_clk_get(&ofdev->dev, "ipg");
+	if (IS_ERR(clk_ipg))
+		goto err_notavail_ipg;
+	if (clk_prepare_enable(clk_ipg))
+		goto err_notavail_ipg;
+	priv = netdev_priv(dev_get_drvdata(&ofdev->dev));
+	priv->clk_ipg = clk_ipg;
+
+	/* return the determined clock source rate */
+	return freq_calc;
+
+err_invalid:
+	dev_err(&ofdev->dev, "invalid clock source specification\n");
+	/* clock source rate could not get determined */
+	return 0;
 
-	/* Enable MSCAN clock domain */
-	val = in_be32(&clockctl->sccr[1]);
-	if (!(val & (1 << 25)))
-		out_be32(&clockctl->sccr[1], val | (1 << 25));
+err_notavail:
+	dev_err(&ofdev->dev, "cannot acquire or setup bitrate clock source\n");
+	/* clock source rate could not get determined */
+	return 0;
 
-	dev_dbg(&ofdev->dev, "using '%s' with frequency divider %d\n",
-		*mscan_clksrc == MSCAN_CLKSRC_IPS ? "ips_clk" :
-		clocksrc == 1 ? "ref_clk" : "sys_clk", clockdiv);
+err_notavail_ipg:
+	dev_err(&ofdev->dev, "cannot acquire or setup register clock\n");
+	/* clock source rate could not get determined */
+	return 0;
+}
 
-exit_unmap:
-	iounmap(clockctl);
-exit_put:
-	of_node_put(np_clock);
-	return freq;
+static void mpc512x_can_put_clock(struct platform_device *ofdev)
+{
+	struct mscan_priv *priv;
+
+	priv = netdev_priv(dev_get_drvdata(&ofdev->dev));
+	if (priv->clk_ipg)
+		clk_disable_unprepare(priv->clk_ipg);
 }
 #else /* !CONFIG_PPC_MPC512x */
 static u32 mpc512x_can_get_clock(struct platform_device *ofdev,
@@ -244,6 +279,7 @@ static u32 mpc512x_can_get_clock(struct platform_device *ofdev,
 {
 	return 0;
 }
+#define mpc512x_can_put_clock NULL
 #endif /* CONFIG_PPC_MPC512x */
 
 static const struct of_device_id mpc5xxx_can_table[];
@@ -385,11 +421,13 @@ static int mpc5xxx_can_resume(struct platform_device *ofdev)
 static const struct mpc5xxx_can_data mpc5200_can_data = {
 	.type = MSCAN_TYPE_MPC5200,
 	.get_clock = mpc52xx_can_get_clock,
+	/* .put_clock not applicable */
 };
 
 static const struct mpc5xxx_can_data mpc5121_can_data = {
 	.type = MSCAN_TYPE_MPC5121,
 	.get_clock = mpc512x_can_get_clock,
+	.put_clock = mpc512x_can_put_clock,
 };
 
 static const struct of_device_id mpc5xxx_can_table[] = {
diff --git a/drivers/spi/spi-mpc512x-psc.c b/drivers/spi/spi-mpc512x-psc.c
index 46d2313f7c6f..5032141eeeec 100644
--- a/drivers/spi/spi-mpc512x-psc.c
+++ b/drivers/spi/spi-mpc512x-psc.c
@@ -40,6 +40,7 @@ struct mpc512x_psc_spi {
 	unsigned int irq;
 	u8 bits_per_word;
 	struct clk *clk_mclk;
+	struct clk *clk_ipg;
 	u32 mclk_rate;
 
 	struct completion txisrdone;
@@ -475,8 +476,6 @@ static int mpc512x_psc_spi_do_probe(struct device *dev, u32 regaddr,
 	struct spi_master *master;
 	int ret;
 	void *tempp;
-	int psc_num;
-	char clk_name[16];
 	struct clk *clk;
 
 	master = spi_alloc_master(dev, sizeof *mps);
@@ -519,9 +518,7 @@ static int mpc512x_psc_spi_do_probe(struct device *dev, u32 regaddr,
 		goto free_master;
 	init_completion(&mps->txisrdone);
 
-	psc_num = master->bus_num;
-	snprintf(clk_name, sizeof(clk_name), "psc%d_mclk", psc_num);
-	clk = devm_clk_get(dev, clk_name);
+	clk = devm_clk_get(dev, "mclk");
 	if (IS_ERR(clk)) {
 		ret = PTR_ERR(clk);
 		goto free_master;
@@ -532,17 +529,29 @@ static int mpc512x_psc_spi_do_probe(struct device *dev, u32 regaddr,
 	mps->clk_mclk = clk;
 	mps->mclk_rate = clk_get_rate(clk);
 
+	clk = devm_clk_get(dev, "ipg");
+	if (IS_ERR(clk)) {
+		ret = PTR_ERR(clk);
+		goto free_mclk_clock;
+	}
+	ret = clk_prepare_enable(clk);
+	if (ret)
+		goto free_mclk_clock;
+	mps->clk_ipg = clk;
+
 	ret = mpc512x_psc_spi_port_config(master, mps);
 	if (ret < 0)
-		goto free_clock;
+		goto free_ipg_clock;
 
 	ret = devm_spi_register_master(dev, master);
 	if (ret < 0)
-		goto free_clock;
+		goto free_ipg_clock;
 
 	return ret;
 
-free_clock:
+free_ipg_clock:
+	clk_disable_unprepare(mps->clk_ipg);
+free_mclk_clock:
 	clk_disable_unprepare(mps->clk_mclk);
 free_master:
 	spi_master_put(master);
@@ -556,6 +565,7 @@ static int mpc512x_psc_spi_do_remove(struct device *dev)
 	struct mpc512x_psc_spi *mps = spi_master_get_devdata(master);
 
 	clk_disable_unprepare(mps->clk_mclk);
+	clk_disable_unprepare(mps->clk_ipg);
 
 	return 0;
 }
diff --git a/drivers/tty/serial/mpc52xx_uart.c b/drivers/tty/serial/mpc52xx_uart.c
index ec06505e3ae6..97888f4900ec 100644
--- a/drivers/tty/serial/mpc52xx_uart.c
+++ b/drivers/tty/serial/mpc52xx_uart.c
@@ -421,6 +421,7 @@ struct psc_fifoc {
 
 static struct psc_fifoc __iomem *psc_fifoc;
 static unsigned int psc_fifoc_irq;
+static struct clk *psc_fifoc_clk;
 
 static void mpc512x_psc_fifo_init(struct uart_port *port)
 {
@@ -568,36 +569,73 @@ static unsigned int mpc512x_psc_set_baudrate(struct uart_port *port,
 /* Init PSC FIFO Controller */
 static int __init mpc512x_psc_fifoc_init(void)
 {
+	int err;
 	struct device_node *np;
+	struct clk *clk;
+
+	/* default error code, potentially overwritten by clock calls */
+	err = -ENODEV;
 
 	np = of_find_compatible_node(NULL, NULL,
 				     "fsl,mpc5121-psc-fifo");
 	if (!np) {
 		pr_err("%s: Can't find FIFOC node\n", __func__);
-		return -ENODEV;
+		goto out_err;
 	}
 
+	clk = of_clk_get(np, 0);
+	if (IS_ERR(clk)) {
+		/* backwards compat with device trees that lack clock specs */
+		clk = clk_get_sys(np->name, "ipg");
+	}
+	if (IS_ERR(clk)) {
+		pr_err("%s: Can't lookup FIFO clock\n", __func__);
+		err = PTR_ERR(clk);
+		goto out_ofnode_put;
+	}
+	if (clk_prepare_enable(clk)) {
+		pr_err("%s: Can't enable FIFO clock\n", __func__);
+		clk_put(clk);
+		goto out_ofnode_put;
+	}
+	psc_fifoc_clk = clk;
+
 	psc_fifoc = of_iomap(np, 0);
 	if (!psc_fifoc) {
 		pr_err("%s: Can't map FIFOC\n", __func__);
-		of_node_put(np);
-		return -ENODEV;
+		goto out_clk_disable;
 	}
 
 	psc_fifoc_irq = irq_of_parse_and_map(np, 0);
-	of_node_put(np);
 	if (psc_fifoc_irq == 0) {
 		pr_err("%s: Can't get FIFOC irq\n", __func__);
-		iounmap(psc_fifoc);
-		return -ENODEV;
+		goto out_unmap;
 	}
 
+	of_node_put(np);
 	return 0;
+
+out_unmap:
+	iounmap(psc_fifoc);
+out_clk_disable:
+	clk_disable_unprepare(psc_fifoc_clk);
+	clk_put(psc_fifoc_clk);
+out_ofnode_put:
+	of_node_put(np);
+out_err:
+	return err;
 }
 
 static void __exit mpc512x_psc_fifoc_uninit(void)
 {
 	iounmap(psc_fifoc);
+
+	/* disable the clock, errors are not fatal */
+	if (psc_fifoc_clk) {
+		clk_disable_unprepare(psc_fifoc_clk);
+		clk_put(psc_fifoc_clk);
+		psc_fifoc_clk = NULL;
+	}
 }
 
 /* 512x specific interrupt handler. The caller holds the port lock */
@@ -619,29 +657,55 @@ static irqreturn_t mpc512x_psc_handle_irq(struct uart_port *port)
 }
 
 static struct clk *psc_mclk_clk[MPC52xx_PSC_MAXNUM];
+static struct clk *psc_ipg_clk[MPC52xx_PSC_MAXNUM];
 
 /* called from within the .request_port() callback (allocation) */
 static int mpc512x_psc_alloc_clock(struct uart_port *port)
 {
 	int psc_num;
-	char clk_name[16];
 	struct clk *clk;
 	int err;
 
 	psc_num = (port->mapbase & 0xf00) >> 8;
-	snprintf(clk_name, sizeof(clk_name), "psc%d_mclk", psc_num);
-	clk = devm_clk_get(port->dev, clk_name);
+
+	clk = devm_clk_get(port->dev, "mclk");
 	if (IS_ERR(clk)) {
 		dev_err(port->dev, "Failed to get MCLK!\n");
-		return PTR_ERR(clk);
+		err = PTR_ERR(clk);
+		goto out_err;
 	}
 	err = clk_prepare_enable(clk);
 	if (err) {
 		dev_err(port->dev, "Failed to enable MCLK!\n");
-		return err;
+		goto out_err;
 	}
 	psc_mclk_clk[psc_num] = clk;
+
+	clk = devm_clk_get(port->dev, "ipg");
+	if (IS_ERR(clk)) {
+		dev_err(port->dev, "Failed to get IPG clock!\n");
+		err = PTR_ERR(clk);
+		goto out_err;
+	}
+	err = clk_prepare_enable(clk);
+	if (err) {
+		dev_err(port->dev, "Failed to enable IPG clock!\n");
+		goto out_err;
+	}
+	psc_ipg_clk[psc_num] = clk;
+
 	return 0;
+
+out_err:
+	if (psc_mclk_clk[psc_num]) {
+		clk_disable_unprepare(psc_mclk_clk[psc_num]);
+		psc_mclk_clk[psc_num] = NULL;
+	}
+	if (psc_ipg_clk[psc_num]) {
+		clk_disable_unprepare(psc_ipg_clk[psc_num]);
+		psc_ipg_clk[psc_num] = NULL;
+	}
+	return err;
 }
 
 /* called from within the .release_port() callback (release) */
@@ -656,6 +720,10 @@ static void mpc512x_psc_relse_clock(struct uart_port *port)
 		clk_disable_unprepare(clk);
 		psc_mclk_clk[psc_num] = NULL;
 	}
+	if (psc_ipg_clk[psc_num]) {
+		clk_disable_unprepare(psc_ipg_clk[psc_num]);
+		psc_ipg_clk[psc_num] = NULL;
+	}
 }
 
 /* implementation of the .clock() callback (enable/disable) */
diff --git a/drivers/usb/host/fsl-mph-dr-of.c b/drivers/usb/host/fsl-mph-dr-of.c
index abd5050a4899..9162d1b6c0a3 100644
--- a/drivers/usb/host/fsl-mph-dr-of.c
+++ b/drivers/usb/host/fsl-mph-dr-of.c
@@ -261,19 +261,8 @@ int fsl_usb2_mpc5121_init(struct platform_device *pdev)
 	struct fsl_usb2_platform_data *pdata = dev_get_platdata(&pdev->dev);
 	struct clk *clk;
 	int err;
-	char clk_name[10];
-	int base, clk_num;
-
-	base = pdev->resource->start & 0xf000;
-	if (base == 0x3000)
-		clk_num = 1;
-	else if (base == 0x4000)
-		clk_num = 2;
-	else
-		return -ENODEV;
 
-	snprintf(clk_name, sizeof(clk_name), "usb%d_clk", clk_num);
-	clk = devm_clk_get(pdev->dev.parent, clk_name);
+	clk = devm_clk_get(pdev->dev.parent, "ipg");
 	if (IS_ERR(clk)) {
 		dev_err(&pdev->dev, "failed to get clk\n");
 		return PTR_ERR(clk);