[RFC PATCH v2 00/15] DT/core: update cpu device of_node

[RFC PATCH v2 00/15] DT/core: update cpu device of_node

[Sudeep.KarkadaNagesha]

From: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>

As more and more information is getting added into the cpu node, the number
of drivers needing to parse the device tree for CPU nodes are increasing.
Most of the time, the information needed from the cpu node is preferred
in the logical CPU order. Hence many drivers first parse and search the
CPU node, match them to logical index if needed and then search for the
required property inside a particular cpu node. Some of them assume the
logical and physical CPU ordering to be same which is incorrect.

This patch series initialises the of_node in all the cpu devices when
registering the CPU device.
1. This avoids different drivers having to parse the cpu nodes to obtain
   different attributes like operating points, latency,...etc.
2. This handles different physical and logical cpu ordering which is not
   the case in current code.
3. Also all the cpu nodes will have their of_node initialised correctly.
   Currently different drivers assign them partially and incorrectly.
4. Removes all the reduntant parsing in various drivers.

Changes v1->v2:
1. Moved most of arch_of_get_cpu_node to OF/DT core as of_get_cpu_node
   adding a provision for architecture specific hooks for matching
   logical and physical ids.
2. Extended removal of DT cpu node parsing to PPC cpufreq drivers
3. Added Acks from Viresh and Shawn

Regards,
Sudeep

Sudeep KarkadaNagesha (15):
  of: add support for retrieving cpu node for a given logical cpu index
  driver/core: cpu: initialize of_node in cpu's device struture
  ARM: DT/kernel: define ARM specific arch_match_cpu_phys_id
  ARM: topology: remove hwid/MPIDR dependency from cpu_capacity
  ARM: mvebu: remove device tree parsing for cpu nodes
  drivers/bus: arm-cci: avoid parsing DT for cpu device nodes
  cpufreq: imx6q-cpufreq: remove device tree parsing for cpu nodes
  cpufreq: cpufreq-cpu0: remove device tree parsing for cpu nodes
  cpufreq: highbank-cpufreq: remove device tree parsing for cpu nodes
  cpufreq: spear-cpufreq: remove device tree parsing for cpu nodes
  cpufreq: kirkwood-cpufreq: remove device tree parsing for cpu nodes
  cpufreq: arm_big_little: remove device tree parsing for cpu nodes
  cpufreq: maple-cpufreq: remove device tree parsing for cpu nodes
  cpufreq: pmac64-cpufreq: remove device tree parsing for cpu nodes
  cpufreq: pmac32-cpufreq: remove device tree parsing for cpu nodes

 arch/arm/kernel/devtree.c           |  5 +++
 arch/arm/kernel/topology.c          | 61 +++++++++++-----------------------
 arch/arm/mach-imx/mach-imx6q.c      |  3 +-
 arch/arm/mach-mvebu/platsmp.c       | 52 ++++++++++++++---------------
 drivers/base/cpu.c                  |  2 ++
 drivers/bus/arm-cci.c               | 28 ++++------------
 drivers/cpufreq/arm_big_little_dt.c | 39 ++++++++++------------
 drivers/cpufreq/cpufreq-cpu0.c      | 23 +++----------
 drivers/cpufreq/highbank-cpufreq.c  | 18 ++++------
 drivers/cpufreq/imx6q-cpufreq.c     |  4 +--
 drivers/cpufreq/kirkwood-cpufreq.c  | 14 ++++++--
 drivers/cpufreq/maple-cpufreq.c     | 23 ++++---------
 drivers/cpufreq/pmac32-cpufreq.c    | 11 ++++++-
 drivers/cpufreq/pmac64-cpufreq.c    | 54 ++++++++++--------------------
 drivers/cpufreq/spear-cpufreq.c     | 10 +++++-
 drivers/of/base.c                   | 66 +++++++++++++++++++++++++++++++++++++
 include/linux/of.h                  |  5 +++
 17 files changed, 213 insertions(+), 205 deletions(-)

-- 
1.8.1.2

[RFC PATCH v2 01/15] of: add support for retrieving cpu node for a given logical cpu index

[Sudeep.KarkadaNagesha-5wv7dgnIgG8]

From: Sudeep KarkadaNagesha <sudeep.karkadanagesha-5wv7dgnIgG8@public.gmane.org>

Currently different drivers requiring to access cpu device node are
parsing the device tree themselves. Since the ordering in the DT need
not match the logical cpu ordering, the parsing logic needs to consider
that. However, this has resulted in lots of code duplication and in some
cases even incorrect logic.

It's better to consolidate them by adding support for getting cpu
device node for a given logical cpu index in DT core library. However
logical to physical index mapping can be architecture specific.

This patch adds of_get_cpu_node to retrieve a cpu device node for a
given logical cpu index. The default matching of the physical id to the
logical cpu index can be overridden by architecture specific code.

It is recommended to use these helper function only in pre-SMP/early
initialisation stages to retrieve CPU device node pointers in logical
ordering. Once the cpu devices are registered, it can be retrieved easily
from cpu device of_node which avoids unnecessary parsing and matching.

Cc: Rob Herring <rob.herring-bsGFqQB8/DxBDgjK7y7TUQ@public.gmane.org>
Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha-5wv7dgnIgG8@public.gmane.org>
---
 drivers/of/base.c  | 66 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/of.h |  5 +++++
 2 files changed, 71 insertions(+)

diff --git a/drivers/of/base.c b/drivers/of/base.c
index 5c54279..363b8f9 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -230,6 +230,72 @@ const void *of_get_property(const struct device_node *np, const char *name,
 }
 EXPORT_SYMBOL(of_get_property);
 
+/*
+ * arch_match_cpu_phys_id - Match the given logical CPU and physical id
+ *
+ * @cpu: logical index of a cpu
+ * @phys_id: physical identifier of a cpu
+ *
+ * CPU logical to physical index mapping is architecure specific.
+ * However this __weak function provides a default match of physical
+ * id to logical cpu index.
+ *
+ * Returns 1 if the physical identifier and the logical index correspond
+ * to the same cpu, 0 otherwise.
+ */
+int __weak arch_match_cpu_phys_id(int cpu, u64 phys_id)
+{
+	return (u32)phys_id == cpu;
+}
+
+/**
+ * of_get_cpu_node - Get device node associated with the given logical CPU
+ *
+ * @cpu: CPU number(logical index) for which device node is required
+ *
+ * The main purpose of this function is to retrieve the device node for the
+ * given logical CPU index. It should be used to intialise the of_node in
+ * cpu device. Once of_node in cpu device is populated, all the further
+ * references can use that instead.
+ *
+ * CPU logical to physical index mapping is architecure specific and is built
+ * before booting secondary cores. This function uses arch_match_cpu_phys_id
+ * which can be overridden by architecture specific implementation.
+ *
+ * Returns a node pointer for the logical cpu if found, else NULL.
+ */
+struct device_node *of_get_cpu_node(int cpu)
+{
+	struct device_node *cpun, *cpus;
+	const u32 *cell;
+	u64 hwid;
+	int ac, prop_len;
+
+	cpus = of_find_node_by_path("/cpus");
+	if (WARN(!cpus, "Missing cpus node, bailing out\n"))
+		return NULL;
+
+	if (WARN_ON(of_property_read_u32(cpus, "#address-cells", &ac)))
+		ac = of_n_addr_cells(cpus);
+
+	for_each_child_of_node(cpus, cpun) {
+		if (of_node_cmp(cpun->type, "cpu"))
+			continue;
+		cell = of_get_property(cpun, "reg", &prop_len);
+		if (WARN(!cell, "%s: missing reg property\n", cpun->full_name))
+			continue;
+
+		while (prop_len) {
+			hwid = of_read_number(cell, ac);
+			prop_len -= ac;
+			if (arch_match_cpu_phys_id(cpu, hwid))
+				return cpun;
+		}
+	}
+
+	return NULL;
+}
+
 /** Checks if the given "compat" string matches one of the strings in
  * the device's "compatible" property
  */
diff --git a/include/linux/of.h b/include/linux/of.h
index 1fd08ca..150b48e 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -266,6 +266,7 @@ extern int of_device_is_available(const struct device_node *device);
 extern const void *of_get_property(const struct device_node *node,
 				const char *name,
 				int *lenp);
+extern struct device_node *of_get_cpu_node(int cpu);
 #define for_each_property_of_node(dn, pp) \
 	for (pp = dn->properties; pp != NULL; pp = pp->next)
 
@@ -458,6 +459,10 @@ static inline const void *of_get_property(const struct device_node *node,
 {
 	return NULL;
 }
+static inline struct device_node *of_get_cpu_node(int cpu)
+{
+	return NULL;
+}
 
 static inline int of_property_read_u64(const struct device_node *np,
 				       const char *propname, u64 *out_value)
-- 
1.8.1.2

[RFC PATCH v2 02/15] driver/core: cpu: initialize of_node in cpu's device struture

[Sudeep.KarkadaNagesha]

From: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>

CPUs are also registered as devices but the of_node in these cpu
devices are not initialized. Currently different drivers requiring
to access cpu device node are parsing the nodes themselves and
initialising the of_node in cpu device.

The of_node in all the cpu devices needs to be initialized properly
and at one place. The best place to update this is CPU subsystem
driver when registering the cpu devices.

The OF/DT core library now provides of_get_cpu_node to retrieve a cpu
device node for a given logical index by abstracting the architecture
specific details.

This patch uses of_get_cpu_node to assign of_node when registering the
cpu devices.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
---
 drivers/base/cpu.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c
index a16d20e..c0f7a08 100644
--- a/drivers/base/cpu.c
+++ b/drivers/base/cpu.c
@@ -14,6 +14,7 @@
 #include <linux/slab.h>
 #include <linux/percpu.h>
 #include <linux/acpi.h>
+#include <linux/of.h>
 
 #include "base.h"
 
@@ -289,6 +290,7 @@ int __cpuinit register_cpu(struct cpu *cpu, int num)
 	cpu->dev.release = cpu_device_release;
 	cpu->dev.offline_disabled = !cpu->hotpluggable;
 	cpu->dev.offline = !cpu_online(num);
+	cpu->dev.of_node = of_get_cpu_node(num);
 #ifdef CONFIG_ARCH_HAS_CPU_AUTOPROBE
 	cpu->dev.bus->uevent = arch_cpu_uevent;
 #endif
-- 
1.8.1.2

[RFC PATCH v2 03/15] ARM: DT/kernel: define ARM specific arch_match_cpu_phys_id

[Sudeep.KarkadaNagesha]

From: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>

OF/DT core library now provides architecture specific hook to match the
logical cpu index with the corresponding physical identifier. Most of the
cpu DT node parsing and initialisation is contained in devtree.c. So it's
better to define ARM specific arch_match_cpu_phys_id there.

This mainly helps to avoid replication of the code doing CPU node parsing
and physical(MPIDR) to logical mapping.

Cc: Russell King <linux@arm.linux.org.uk>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
---
 arch/arm/kernel/devtree.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/arm/kernel/devtree.c b/arch/arm/kernel/devtree.c
index 5859c8b..5a36f32 100644
--- a/arch/arm/kernel/devtree.c
+++ b/arch/arm/kernel/devtree.c
@@ -169,6 +169,11 @@ void __init arm_dt_init_cpu_maps(void)
 	}
 }
 
+int arch_match_cpu_phys_id(int cpu, u64 phys_id)
+{
+	return (phys_id & MPIDR_HWID_BITMASK) == cpu_logical_map(cpu);
+}
+
 /**
  * setup_machine_fdt - Machine setup when an dtb was passed to the kernel
  * @dt_phys: physical address of dt blob
-- 
1.8.1.2

[RFC PATCH v2 04/15] ARM: topology: remove hwid/MPIDR dependency from cpu_capacity

[Sudeep.KarkadaNagesha-5wv7dgnIgG8]

From: Sudeep KarkadaNagesha <sudeep.karkadanagesha-5wv7dgnIgG8@public.gmane.org>

Currently the topology code computes cpu capacity and stores it in
the list along with hwid(which is MPIDR) as it parses the CPU nodes
in the device tree. This is required as it needs to be mapped to the
logical CPU later.

Since the CPU device nodes can be retrieved in the logical ordering
using DT/OF helpers, its possible to store cpu_capacity also in logical
ordering and avoid storing hwid for each entry.

This patch removes hwid by making use of of_get_cpu_node.

Cc: Russell King <linux-lFZ/pmaqli7XmaaqVzeoHQ@public.gmane.org>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi-5wv7dgnIgG8@public.gmane.org>
Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha-5wv7dgnIgG8@public.gmane.org>
---
 arch/arm/kernel/topology.c | 61 +++++++++++++++-------------------------------
 1 file changed, 19 insertions(+), 42 deletions(-)

diff --git a/arch/arm/kernel/topology.c b/arch/arm/kernel/topology.c
index c5a5954..28ef27a 100644
--- a/arch/arm/kernel/topology.c
+++ b/arch/arm/kernel/topology.c
@@ -74,12 +74,8 @@ struct cpu_efficiency table_efficiency[] = {
 	{NULL, },
 };
 
-struct cpu_capacity {
-	unsigned long hwid;
-	unsigned long capacity;
-};
-
-struct cpu_capacity *cpu_capacity;
+unsigned long *__cpu_capacity;
+#define cpu_capacity(cpu)	__cpu_capacity[cpu]
 
 unsigned long middle_capacity = 1;
 
@@ -100,15 +96,19 @@ static void __init parse_dt_topology(void)
 	unsigned long capacity = 0;
 	int alloc_size, cpu = 0;
 
-	alloc_size = nr_cpu_ids * sizeof(struct cpu_capacity);
-	cpu_capacity = kzalloc(alloc_size, GFP_NOWAIT);
+	alloc_size = nr_cpu_ids * sizeof(*__cpu_capacity);
+	__cpu_capacity = kzalloc(alloc_size, GFP_NOWAIT);
 
-	while ((cn = of_find_node_by_type(cn, "cpu"))) {
-		const u32 *rate, *reg;
+	for_each_possible_cpu(cpu) {
+		const u32 *rate;
 		int len;
 
-		if (cpu >= num_possible_cpus())
-			break;
+		/* too early to use cpu->of_node */
+		cn = of_get_cpu_node(cpu);
+		if (!cn) {
+			pr_err("missing device node for CPU %d\n", cpu);
+			continue;
+		}
 
 		for (cpu_eff = table_efficiency; cpu_eff->compatible; cpu_eff++)
 			if (of_device_is_compatible(cn, cpu_eff->compatible))
@@ -124,12 +124,6 @@ static void __init parse_dt_topology(void)
 			continue;
 		}
 
-		reg = of_get_property(cn, "reg", &len);
-		if (!reg || len != 4) {
-			pr_err("%s missing reg property\n", cn->full_name);
-			continue;
-		}
-
 		capacity = ((be32_to_cpup(rate)) >> 20) * cpu_eff->efficiency;
 
 		/* Save min capacity of the system */
@@ -140,13 +134,9 @@ static void __init parse_dt_topology(void)
 		if (capacity > max_capacity)
 			max_capacity = capacity;
 
-		cpu_capacity[cpu].capacity = capacity;
-		cpu_capacity[cpu++].hwid = be32_to_cpup(reg);
+		cpu_capacity(cpu) = capacity;
 	}
 
-	if (cpu < num_possible_cpus())
-		cpu_capacity[cpu].hwid = (unsigned long)(-1);
-
 	/* If min and max capacities are equals, we bypass the update of the
 	 * cpu_scale because all CPUs have the same capacity. Otherwise, we
 	 * compute a middle_capacity factor that will ensure that the capacity
@@ -154,9 +144,7 @@ static void __init parse_dt_topology(void)
 	 * SCHED_POWER_SCALE, which is the default value, but with the
 	 * constraint explained near table_efficiency[].
 	 */
-	if (min_capacity == max_capacity)
-		cpu_capacity[0].hwid = (unsigned long)(-1);
-	else if (4*max_capacity < (3*(max_capacity + min_capacity)))
+	if (4*max_capacity < (3*(max_capacity + min_capacity)))
 		middle_capacity = (min_capacity + max_capacity)
 				>> (SCHED_POWER_SHIFT+1);
 	else
@@ -170,23 +158,12 @@ static void __init parse_dt_topology(void)
  * boot. The update of all CPUs is in O(n^2) for heteregeneous system but the
  * function returns directly for SMP system.
  */
-void update_cpu_power(unsigned int cpu, unsigned long hwid)
+void update_cpu_power(unsigned int cpu)
 {
-	unsigned int idx = 0;
-
-	/* look for the cpu's hwid in the cpu capacity table */
-	for (idx = 0; idx < num_possible_cpus(); idx++) {
-		if (cpu_capacity[idx].hwid == hwid)
-			break;
-
-		if (cpu_capacity[idx].hwid == -1)
-			return;
-	}
-
-	if (idx == num_possible_cpus())
+	if (!cpu_capacity(cpu))
 		return;
 
-	set_power_scale(cpu, cpu_capacity[idx].capacity / middle_capacity);
+	set_power_scale(cpu, cpu_capacity(cpu) / middle_capacity);
 
 	printk(KERN_INFO "CPU%u: update cpu_power %lu\n",
 		cpu, arch_scale_freq_power(NULL, cpu));
@@ -194,7 +171,7 @@ void update_cpu_power(unsigned int cpu, unsigned long hwid)
 
 #else
 static inline void parse_dt_topology(void) {}
-static inline void update_cpu_power(unsigned int cpuid, unsigned int mpidr) {}
+static inline void update_cpu_power(unsigned int cpuid) {}
 #endif
 
  /*
@@ -281,7 +258,7 @@ void store_cpu_topology(unsigned int cpuid)
 
 	update_siblings_masks(cpuid);
 
-	update_cpu_power(cpuid, mpidr & MPIDR_HWID_BITMASK);
+	update_cpu_power(cpuid);
 
 	printk(KERN_INFO "CPU%u: thread %d, cpu %d, socket %d, mpidr %x\n",
 		cpuid, cpu_topology[cpuid].thread_id,
-- 
1.8.1.2

[RFC PATCH v2 05/15] ARM: mvebu: remove device tree parsing for cpu nodes

[Sudeep.KarkadaNagesha-5wv7dgnIgG8]

From: Sudeep KarkadaNagesha <sudeep.karkadanagesha-5wv7dgnIgG8@public.gmane.org>

Currently set_secondary_cpus_clock assume the CPU logical ordering
and the MPDIR in DT are same, which is incorrect.

Since the CPU device nodes can be retrieved in the logical ordering
using the DT helper, we can remove the devices tree parsing.

This patch removes DT parsing by making use of of_get_cpu_node.

Cc: Gregory Clement <gregory.clement-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
Cc: Andrew Lunn <andrew-g2DYL2Zd6BY@public.gmane.org>
Cc: Jason Cooper <jason-NLaQJdtUoK4Be96aLqz0jA@public.gmane.org>
Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha-5wv7dgnIgG8@public.gmane.org>
---
 arch/arm/mach-mvebu/platsmp.c | 52 ++++++++++++++++++++-----------------------
 1 file changed, 24 insertions(+), 28 deletions(-)

diff --git a/arch/arm/mach-mvebu/platsmp.c b/arch/arm/mach-mvebu/platsmp.c
index 93f2f3a..12585ad 100644
--- a/arch/arm/mach-mvebu/platsmp.c
+++ b/arch/arm/mach-mvebu/platsmp.c
@@ -23,51 +23,47 @@
 #include <linux/of.h>
 #include <linux/mbus.h>
 #include <asm/cacheflush.h>
+#include <asm/prom.h>
 #include <asm/smp_plat.h>
 #include "common.h"
 #include "armada-370-xp.h"
 #include "pmsu.h"
 #include "coherency.h"
 
+static struct clk *__init get_cpu_clk(int cpu)
+{
+	struct clk *cpu_clk;
+	struct device_node *np = of_get_cpu_node(cpu);
+
+	if (WARN(!np, "missing cpu node\n"))
+		return NULL;
+	cpu_clk = of_clk_get(np, 0);
+	if (WARN_ON(IS_ERR(cpu_clk)))
+		return NULL;
+	return cpu_clk;
+}
+
 void __init set_secondary_cpus_clock(void)
 {
-	int thiscpu;
+	int thiscpu, cpu;
 	unsigned long rate;
-	struct clk *cpu_clk = NULL;
-	struct device_node *np = NULL;
+	struct clk *cpu_clk;
 
 	thiscpu = smp_processor_id();
-	for_each_node_by_type(np, "cpu") {
-		int err;
-		int cpu;
-
-		err = of_property_read_u32(np, "reg", &cpu);
-		if (WARN_ON(err))
-			return;
-
-		if (cpu == thiscpu) {
-			cpu_clk = of_clk_get(np, 0);
-			break;
-		}
-	}
-	if (WARN_ON(IS_ERR(cpu_clk)))
+	cpu_clk = get_cpu_clk(thiscpu);
+	if (!cpu_clk)
 		return;
 	clk_prepare_enable(cpu_clk);
 	rate = clk_get_rate(cpu_clk);
 
 	/* set all the other CPU clk to the same rate than the boot CPU */
-	for_each_node_by_type(np, "cpu") {
-		int err;
-		int cpu;
-
-		err = of_property_read_u32(np, "reg", &cpu);
-		if (WARN_ON(err))
+	for_each_possible_cpu(cpu) {
+		if (cpu == thiscpu)
+			continue;
+		cpu_clk = get_cpu_clk(cpu);
+		if (!cpu_clk)
 			return;
-
-		if (cpu != thiscpu) {
-			cpu_clk = of_clk_get(np, 0);
-			clk_set_rate(cpu_clk, rate);
-		}
+		clk_set_rate(cpu_clk, rate);
 	}
 }
 
-- 
1.8.1.2

[RFC PATCH v2 06/15] drivers/bus: arm-cci: avoid parsing DT for cpu device nodes

[Sudeep.KarkadaNagesha]

From: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>

Since the CPU device nodes can be retrieved using arch_of_get_cpu_node,
we can use it to avoid parsing the cpus node searching the cpu nodes and
mapping to logical index.

This patch removes parsing DT for cpu nodes by using of_get_cpu_node.

Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
---
 drivers/bus/arm-cci.c | 28 +++++++---------------------
 1 file changed, 7 insertions(+), 21 deletions(-)

diff --git a/drivers/bus/arm-cci.c b/drivers/bus/arm-cci.c
index 7332889..7dd891c 100644
--- a/drivers/bus/arm-cci.c
+++ b/drivers/bus/arm-cci.c
@@ -122,17 +122,8 @@ EXPORT_SYMBOL_GPL(cci_ace_get_port);
 
 static void __init cci_ace_init_ports(void)
 {
-	int port, ac, cpu;
-	u64 hwid;
-	const u32 *cell;
-	struct device_node *cpun, *cpus;
-
-	cpus = of_find_node_by_path("/cpus");
-	if (WARN(!cpus, "Missing cpus node, bailing out\n"))
-		return;
-
-	if (WARN_ON(of_property_read_u32(cpus, "#address-cells", &ac)))
-		ac = of_n_addr_cells(cpus);
+	int port, cpu;
+	struct device_node *cpun;
 
 	/*
 	 * Port index look-up speeds up the function disabling ports by CPU,
@@ -141,18 +132,13 @@ static void __init cci_ace_init_ports(void)
 	 * The stashed index array is initialized for all possible CPUs
 	 * at probe time.
 	 */
-	for_each_child_of_node(cpus, cpun) {
-		if (of_node_cmp(cpun->type, "cpu"))
-			continue;
-		cell = of_get_property(cpun, "reg", NULL);
-		if (WARN(!cell, "%s: missing reg property\n", cpun->full_name))
-			continue;
-
-		hwid = of_read_number(cell, ac);
-		cpu = get_logical_index(hwid & MPIDR_HWID_BITMASK);
+	for_each_possible_cpu(cpu) {
+		/* too early to use cpu->of_node */
+		cpun = of_get_cpu_node(cpu);
 
-		if (cpu < 0 || !cpu_possible(cpu))
+		if (WARN(!cpun, "Missing cpu device node\n"))
 			continue;
+
 		port = __cci_ace_get_port(cpun, ACE_PORT);
 		if (port < 0)
 			continue;
-- 
1.8.1.2

[RFC PATCH v2 07/15] cpufreq: imx6q-cpufreq: remove device tree parsing for cpu nodes

[Sudeep.KarkadaNagesha-5wv7dgnIgG8]

From: Sudeep KarkadaNagesha <sudeep.karkadanagesha-5wv7dgnIgG8@public.gmane.org>

Now that the cpu device registration initialises the of_node(if available)
appropriately for all the cpus, parsing here is redundant.

This patch removes all DT parsing and uses cpu->of_node instead.

Acked-by: Shawn Guo <shawn.guo-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
Acked-by: Viresh Kumar <viresh.kumar-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha-5wv7dgnIgG8@public.gmane.org>
---
 arch/arm/mach-imx/mach-imx6q.c  | 3 +--
 drivers/cpufreq/imx6q-cpufreq.c | 4 +---
 2 files changed, 2 insertions(+), 5 deletions(-)

diff --git a/arch/arm/mach-imx/mach-imx6q.c b/arch/arm/mach-imx/mach-imx6q.c
index 7be13f8..a02f275 100644
--- a/arch/arm/mach-imx/mach-imx6q.c
+++ b/arch/arm/mach-imx/mach-imx6q.c
@@ -254,13 +254,12 @@ static void __init imx6q_opp_init(struct device *cpu_dev)
 {
 	struct device_node *np;
 
-	np = of_find_node_by_path("/cpus/cpu@0");
+	np = of_node_get(cpu_dev->of_node);
 	if (!np) {
 		pr_warn("failed to find cpu0 node\n");
 		return;
 	}
 
-	cpu_dev->of_node = np;
 	if (of_init_opp_table(cpu_dev)) {
 		pr_warn("failed to init OPP table\n");
 		goto put_node;
diff --git a/drivers/cpufreq/imx6q-cpufreq.c b/drivers/cpufreq/imx6q-cpufreq.c
index e37cdae..b16632b 100644
--- a/drivers/cpufreq/imx6q-cpufreq.c
+++ b/drivers/cpufreq/imx6q-cpufreq.c
@@ -221,14 +221,12 @@ static int imx6q_cpufreq_probe(struct platform_device *pdev)
 
 	cpu_dev = &pdev->dev;
 
-	np = of_find_node_by_path("/cpus/cpu@0");
+	np = of_node_get(cpu_dev->of_node);
 	if (!np) {
 		dev_err(cpu_dev, "failed to find cpu0 node\n");
 		return -ENOENT;
 	}
 
-	cpu_dev->of_node = np;
-
 	arm_clk = devm_clk_get(cpu_dev, "arm");
 	pll1_sys_clk = devm_clk_get(cpu_dev, "pll1_sys");
 	pll1_sw_clk = devm_clk_get(cpu_dev, "pll1_sw");
-- 
1.8.1.2

[RFC PATCH v2 08/15] cpufreq: cpufreq-cpu0: remove device tree parsing for cpu nodes

[Sudeep.KarkadaNagesha-5wv7dgnIgG8]

From: Sudeep KarkadaNagesha <sudeep.karkadanagesha-5wv7dgnIgG8@public.gmane.org>

Now that the cpu device registration initialises the of_node(if available)
appropriately for all the cpus, parsing here is redundant.

This patch removes all DT parsing and uses cpu->of_node instead.

Acked-by: Shawn Guo <shawn.guo-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
Acked-by: Viresh Kumar <viresh.kumar-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha-5wv7dgnIgG8@public.gmane.org>
---
 drivers/cpufreq/cpufreq-cpu0.c | 23 ++++-------------------
 1 file changed, 4 insertions(+), 19 deletions(-)

diff --git a/drivers/cpufreq/cpufreq-cpu0.c b/drivers/cpufreq/cpufreq-cpu0.c
index ad1fde2..5b05c26 100644
--- a/drivers/cpufreq/cpufreq-cpu0.c
+++ b/drivers/cpufreq/cpufreq-cpu0.c
@@ -174,29 +174,17 @@ static struct cpufreq_driver cpu0_cpufreq_driver = {
 
 static int cpu0_cpufreq_probe(struct platform_device *pdev)
 {
-	struct device_node *np, *parent;
+	struct device_node *np;
 	int ret;
 
-	parent = of_find_node_by_path("/cpus");
-	if (!parent) {
-		pr_err("failed to find OF /cpus\n");
-		return -ENOENT;
-	}
-
-	for_each_child_of_node(parent, np) {
-		if (of_get_property(np, "operating-points", NULL))
-			break;
-	}
+	cpu_dev = &pdev->dev;
 
+	np = of_node_get(cpu_dev->of_node);
 	if (!np) {
 		pr_err("failed to find cpu0 node\n");
-		ret = -ENOENT;
-		goto out_put_parent;
+		return -ENOENT;
 	}
 
-	cpu_dev = &pdev->dev;
-	cpu_dev->of_node = np;
-
 	cpu_reg = devm_regulator_get(cpu_dev, "cpu0");
 	if (IS_ERR(cpu_reg)) {
 		/*
@@ -269,15 +257,12 @@ static int cpu0_cpufreq_probe(struct platform_device *pdev)
 	}
 
 	of_node_put(np);
-	of_node_put(parent);
 	return 0;
 
 out_free_table:
 	opp_free_cpufreq_table(cpu_dev, &freq_table);
 out_put_node:
 	of_node_put(np);
-out_put_parent:
-	of_node_put(parent);
 	return ret;
 }
 
-- 
1.8.1.2

[RFC PATCH v2 09/15] cpufreq: highbank-cpufreq: remove device tree parsing for cpu nodes

[Sudeep.KarkadaNagesha]

From: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>

Now that the cpu device registration initialises the of_node(if available)
appropriately for all the cpus, parsing here is redundant.

This patch removes all DT parsing and uses cpu->of_node instead.

Cc: Mark Langsdorf <mark.langsdorf@calxeda.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
---
 drivers/cpufreq/highbank-cpufreq.c | 18 ++++++------------
 1 file changed, 6 insertions(+), 12 deletions(-)

diff --git a/drivers/cpufreq/highbank-cpufreq.c b/drivers/cpufreq/highbank-cpufreq.c
index b61b5a3..794123f 100644
--- a/drivers/cpufreq/highbank-cpufreq.c
+++ b/drivers/cpufreq/highbank-cpufreq.c
@@ -69,23 +69,17 @@ static int hb_cpufreq_driver_init(void)
 	if (!of_machine_is_compatible("calxeda,highbank"))
 		return -ENODEV;
 
-	for_each_child_of_node(of_find_node_by_path("/cpus"), np)
-		if (of_get_property(np, "operating-points", NULL))
-			break;
-
-	if (!np) {
-		pr_err("failed to find highbank cpufreq node\n");
-		return -ENOENT;
-	}
-
 	cpu_dev = get_cpu_device(0);
 	if (!cpu_dev) {
 		pr_err("failed to get highbank cpufreq device\n");
-		ret = -ENODEV;
-		goto out_put_node;
+		return -ENODEV;
 	}
 
-	cpu_dev->of_node = np;
+	np = of_node_get(cpu_dev->of_node);
+	if (!np) {
+		pr_err("failed to find highbank cpufreq node\n");
+		return -ENOENT;
+	}
 
 	cpu_clk = clk_get(cpu_dev, NULL);
 	if (IS_ERR(cpu_clk)) {
-- 
1.8.1.2

[RFC PATCH v2 10/15] cpufreq: spear-cpufreq: remove device tree parsing for cpu nodes

[Sudeep.KarkadaNagesha]

From: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>

Now that the cpu device registration initialises the of_node(if available)
appropriately for all the cpus, parsing here is redundant.

This patch removes all DT parsing and uses cpu->of_node instead.

Cc: Deepak Sikri <deepak.sikri@st.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
---
 drivers/cpufreq/spear-cpufreq.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/cpufreq/spear-cpufreq.c b/drivers/cpufreq/spear-cpufreq.c
index c3efa7f..eb73c47 100644
--- a/drivers/cpufreq/spear-cpufreq.c
+++ b/drivers/cpufreq/spear-cpufreq.c
@@ -14,6 +14,7 @@
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/clk.h>
+#include <linux/cpu.h>
 #include <linux/cpufreq.h>
 #include <linux/err.h>
 #include <linux/init.h>
@@ -218,12 +219,19 @@ static struct cpufreq_driver spear_cpufreq_driver = {
 static int spear_cpufreq_driver_init(void)
 {
 	struct device_node *np;
+	struct device *cpu_dev;
 	const struct property *prop;
 	struct cpufreq_frequency_table *freq_tbl;
 	const __be32 *val;
 	int cnt, i, ret;
 
-	np = of_find_node_by_path("/cpus/cpu@0");
+	cpu_dev = get_cpu_device(0);
+	if (!cpu_dev) {
+		pr_err("failed to get cpu device\n");
+		return -ENODEV;
+	}
+
+	np = of_node_get(cpu_dev->of_node);
 	if (!np) {
 		pr_err("No cpu node found");
 		return -ENODEV;
-- 
1.8.1.2

[RFC PATCH v2 11/15] cpufreq: kirkwood-cpufreq: remove device tree parsing for cpu nodes

[Sudeep.KarkadaNagesha]

From: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>

Now that the cpu device registration initialises the of_node(if available)
appropriately for all the cpus, parsing here is redundant.

This patch removes all DT parsing and uses cpu->of_node instead.

Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Jason Cooper <jason@lakedaemon.net>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
---
 drivers/cpufreq/kirkwood-cpufreq.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/drivers/cpufreq/kirkwood-cpufreq.c b/drivers/cpufreq/kirkwood-cpufreq.c
index c233ea6..18aa3eb 100644
--- a/drivers/cpufreq/kirkwood-cpufreq.c
+++ b/drivers/cpufreq/kirkwood-cpufreq.c
@@ -13,6 +13,7 @@
 #include <linux/module.h>
 #include <linux/clk.h>
 #include <linux/clk-provider.h>
+#include <linux/cpu.h>
 #include <linux/cpufreq.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
@@ -165,6 +166,7 @@ static struct cpufreq_driver kirkwood_cpufreq_driver = {
 static int kirkwood_cpufreq_probe(struct platform_device *pdev)
 {
 	struct device_node *np;
+	struct device *cpu_dev;
 	struct resource *res;
 	int err;
 
@@ -175,9 +177,17 @@ static int kirkwood_cpufreq_probe(struct platform_device *pdev)
 	if (IS_ERR(priv.base))
 		return PTR_ERR(priv.base);
 
-	np = of_find_node_by_path("/cpus/cpu@0");
-	if (!np)
+	cpu_dev = get_cpu_device(0);
+	if (!cpu_dev) {
+		dev_err(&pdev->dev, "failed to get cpu device\n");
 		return -ENODEV;
+	}
+
+	np = of_node_get(cpu_dev->of_node);
+	if (!np) {
+		dev_err(&pdev->dev, "failed to get cpu device node\n");
+		return -ENODEV;
+	}
 
 	priv.cpu_clk = of_clk_get_by_name(np, "cpu_clk");
 	if (IS_ERR(priv.cpu_clk)) {
-- 
1.8.1.2

[RFC PATCH v2 12/15] cpufreq: arm_big_little: remove device tree parsing for cpu nodes

[Sudeep.KarkadaNagesha]

From: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>

Now that the cpu device registration initialises the of_node(if available)
appropriately for all the cpus, parsing here is redundant.

This patch removes all DT parsing and uses cpu->of_node instead.

Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
---
 drivers/cpufreq/arm_big_little_dt.c | 39 ++++++++++++++++---------------------
 1 file changed, 17 insertions(+), 22 deletions(-)

diff --git a/drivers/cpufreq/arm_big_little_dt.c b/drivers/cpufreq/arm_big_little_dt.c
index fd9e3ea..d2648d1 100644
--- a/drivers/cpufreq/arm_big_little_dt.c
+++ b/drivers/cpufreq/arm_big_little_dt.c
@@ -34,27 +34,19 @@
 /* get cpu node with valid operating-points */
 static struct device_node *get_cpu_node_with_valid_op(int cpu)
 {
-	struct device_node *np = NULL, *parent;
-	int count = 0;
+	struct device *cpu_dev = get_cpu_device(cpu);
+	struct device_node *np;
 
-	parent = of_find_node_by_path("/cpus");
-	if (!parent) {
-		pr_err("failed to find OF /cpus\n");
+	if (!cpu_dev) {
+		pr_err("failed to get cpu device\n");
 		return NULL;
 	}
-
-	for_each_child_of_node(parent, np) {
-		if (count++ != cpu)
-			continue;
-		if (!of_get_property(np, "operating-points", NULL)) {
-			of_node_put(np);
-			np = NULL;
-		}
-
-		break;
+	np = of_node_get(cpu_dev->of_node);
+	if (!of_get_property(np, "operating-points", NULL)) {
+		of_node_put(np);
+		np = NULL;
 	}
 
-	of_node_put(parent);
 	return np;
 }
 
@@ -63,11 +55,12 @@ static int dt_init_opp_table(struct device *cpu_dev)
 	struct device_node *np;
 	int ret;
 
-	np = get_cpu_node_with_valid_op(cpu_dev->id);
-	if (!np)
-		return -ENODATA;
+	np = of_node_get(cpu_dev->of_node);
+	if (!np) {
+		pr_err("failed to find cpu%d node\n", cpu_dev->id);
+		return -ENOENT;
+	}
 
-	cpu_dev->of_node = np;
 	ret = of_init_opp_table(cpu_dev);
 	of_node_put(np);
 
@@ -79,9 +72,11 @@ static int dt_get_transition_latency(struct device *cpu_dev)
 	struct device_node *np;
 	u32 transition_latency = CPUFREQ_ETERNAL;
 
-	np = get_cpu_node_with_valid_op(cpu_dev->id);
-	if (!np)
+	np = of_node_get(cpu_dev->of_node);
+	if (!np) {
+		pr_info("Failed to find cpu node. Use CPUFREQ_ETERNAL transition latency\n");
 		return CPUFREQ_ETERNAL;
+	}
 
 	of_property_read_u32(np, "clock-latency", &transition_latency);
 	of_node_put(np);
-- 
1.8.1.2

[RFC PATCH v2 13/15] cpufreq: maple-cpufreq: remove device tree parsing for cpu nodes

[Sudeep.KarkadaNagesha]

From: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>

Now that the cpu device registration initialises the of_node(if available)
appropriately for all the cpus, parsing here is redundant.

This patch removes all DT parsing and uses cpu->of_node instead.

Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
---
 drivers/cpufreq/maple-cpufreq.c | 23 +++++++----------------
 1 file changed, 7 insertions(+), 16 deletions(-)

diff --git a/drivers/cpufreq/maple-cpufreq.c b/drivers/cpufreq/maple-cpufreq.c
index cdd6291..bc7233b 100644
--- a/drivers/cpufreq/maple-cpufreq.c
+++ b/drivers/cpufreq/maple-cpufreq.c
@@ -19,6 +19,7 @@
 #include <linux/kernel.h>
 #include <linux/delay.h>
 #include <linux/sched.h>
+#include <linux/cpu.h>
 #include <linux/cpufreq.h>
 #include <linux/init.h>
 #include <linux/completion.h>
@@ -201,7 +202,7 @@ static struct cpufreq_driver maple_cpufreq_driver = {
 
 static int __init maple_cpufreq_init(void)
 {
-	struct device_node *cpus;
+	struct device *cpu_dev;
 	struct device_node *cpunode;
 	unsigned int psize;
 	unsigned long max_freq;
@@ -217,24 +218,17 @@ static int __init maple_cpufreq_init(void)
 	    !of_machine_is_compatible("Momentum,Apache"))
 		return 0;
 
-	cpus = of_find_node_by_path("/cpus");
-	if (cpus == NULL) {
-		DBG("No /cpus node !\n");
+	cpu_dev = get_cpu_device(0);
+	if (!cpu_dev) {
+		pr_err("failed to get cpu device\n");
 		return -ENODEV;
 	}
 
 	/* Get first CPU node */
-	for (cpunode = NULL;
-	     (cpunode = of_get_next_child(cpus, cpunode)) != NULL;) {
-		const u32 *reg = of_get_property(cpunode, "reg", NULL);
-		if (reg == NULL || (*reg) != 0)
-			continue;
-		if (!strcmp(cpunode->type, "cpu"))
-			break;
-	}
+	cpunode = of_node_get(cpu_dev->of_node);
 	if (cpunode == NULL) {
 		printk(KERN_ERR "cpufreq: Can't find any CPU 0 node\n");
-		goto bail_cpus;
+		goto bail_noprops;
 	}
 
 	/* Check 970FX for now */
@@ -290,14 +284,11 @@ static int __init maple_cpufreq_init(void)
 	rc = cpufreq_register_driver(&maple_cpufreq_driver);
 
 	of_node_put(cpunode);
-	of_node_put(cpus);
 
 	return rc;
 
 bail_noprops:
 	of_node_put(cpunode);
-bail_cpus:
-	of_node_put(cpus);
 
 	return rc;
 }
-- 
1.8.1.2

[RFC PATCH v2 14/15] cpufreq: pmac64-cpufreq: remove device tree parsing for cpu nodes

[Sudeep.KarkadaNagesha]

From: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>

Now that the cpu device registration initialises the of_node(if available)
appropriately for all the cpus, parsing here is redundant.

This patch removes all DT parsing and uses cpu->of_node instead.

Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
---
 drivers/cpufreq/pmac64-cpufreq.c | 54 ++++++++++++++--------------------------
 1 file changed, 18 insertions(+), 36 deletions(-)

diff --git a/drivers/cpufreq/pmac64-cpufreq.c b/drivers/cpufreq/pmac64-cpufreq.c
index 7ba4234..b60ccea 100644
--- a/drivers/cpufreq/pmac64-cpufreq.c
+++ b/drivers/cpufreq/pmac64-cpufreq.c
@@ -18,6 +18,7 @@
 #include <linux/kernel.h>
 #include <linux/delay.h>
 #include <linux/sched.h>
+#include <linux/cpu.h>
 #include <linux/cpufreq.h>
 #include <linux/init.h>
 #include <linux/completion.h>
@@ -383,9 +384,8 @@ static struct cpufreq_driver g5_cpufreq_driver = {
 
 #ifdef CONFIG_PMAC_SMU
 
-static int __init g5_neo2_cpufreq_init(struct device_node *cpus)
+static int __init g5_neo2_cpufreq_init(struct device_node *cpunode)
 {
-	struct device_node *cpunode;
 	unsigned int psize, ssize;
 	unsigned long max_freq;
 	char *freq_method, *volt_method;
@@ -405,20 +405,6 @@ static int __init g5_neo2_cpufreq_init(struct device_node *cpus)
 	else
 		return -ENODEV;
 
-	/* Get first CPU node */
-	for (cpunode = NULL;
-	     (cpunode = of_get_next_child(cpus, cpunode)) != NULL;) {
-		const u32 *reg = of_get_property(cpunode, "reg", NULL);
-		if (reg == NULL || (*reg) != 0)
-			continue;
-		if (!strcmp(cpunode->type, "cpu"))
-			break;
-	}
-	if (cpunode == NULL) {
-		printk(KERN_ERR "cpufreq: Can't find any CPU 0 node\n");
-		return -ENODEV;
-	}
-
 	/* Check 970FX for now */
 	valp = of_get_property(cpunode, "cpu-version", NULL);
 	if (!valp) {
@@ -537,9 +523,9 @@ static int __init g5_neo2_cpufreq_init(struct device_node *cpus)
 #endif /* CONFIG_PMAC_SMU */
 
 
-static int __init g5_pm72_cpufreq_init(struct device_node *cpus)
+static int __init g5_pm72_cpufreq_init(struct device_node *cpunode)
 {
-	struct device_node *cpuid = NULL, *hwclock = NULL, *cpunode = NULL;
+	struct device_node *cpuid = NULL, *hwclock = NULL;
 	const u8 *eeprom = NULL;
 	const u32 *valp;
 	u64 max_freq, min_freq, ih, il;
@@ -548,17 +534,6 @@ static int __init g5_pm72_cpufreq_init(struct device_node *cpus)
 	DBG("cpufreq: Initializing for PowerMac7,2, PowerMac7,3 and"
 	    " RackMac3,1...\n");
 
-	/* Get first CPU node */
-	for (cpunode = NULL;
-	     (cpunode = of_get_next_child(cpus, cpunode)) != NULL;) {
-		if (!strcmp(cpunode->type, "cpu"))
-			break;
-	}
-	if (cpunode == NULL) {
-		printk(KERN_ERR "cpufreq: Can't find any CPU node\n");
-		return -ENODEV;
-	}
-
 	/* Lookup the cpuid eeprom node */
         cpuid = of_find_node_by_path("/u3@0,f8000000/i2c@f8001000/cpuid@a0");
 	if (cpuid != NULL)
@@ -718,25 +693,32 @@ static int __init g5_pm72_cpufreq_init(struct device_node *cpus)
 
 static int __init g5_cpufreq_init(void)
 {
-	struct device_node *cpus;
+	struct device *cpu_dev;
+	struct device_node *cpunode;
 	int rc = 0;
 
-	cpus = of_find_node_by_path("/cpus");
-	if (cpus == NULL) {
-		DBG("No /cpus node !\n");
+	cpu_dev = get_cpu_device(0);
+	if (!cpu_dev) {
+		pr_err("failed to get cpu device\n");
+		return -ENODEV;
+	}
+
+	/* Get first CPU node */
+	cpunode = of_node_get(cpu_dev->of_node);
+	if (cpunode == NULL) {
+		pr_err("cpufreq: Can't find any CPU node\n");
 		return -ENODEV;
 	}
 
 	if (of_machine_is_compatible("PowerMac7,2") ||
 	    of_machine_is_compatible("PowerMac7,3") ||
 	    of_machine_is_compatible("RackMac3,1"))
-		rc = g5_pm72_cpufreq_init(cpus);
+		rc = g5_pm72_cpufreq_init(cpunode);
 #ifdef CONFIG_PMAC_SMU
 	else
-		rc = g5_neo2_cpufreq_init(cpus);
+		rc = g5_neo2_cpufreq_init(cpunode);
 #endif /* CONFIG_PMAC_SMU */
 
-	of_node_put(cpus);
 	return rc;
 }
 
-- 
1.8.1.2

[RFC PATCH v2 15/15] cpufreq: pmac32-cpufreq: remove device tree parsing for cpu nodes

[Sudeep.KarkadaNagesha]

From: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>

Now that the cpu device registration initialises the of_node(if available)
appropriately for all the cpus, parsing here is redundant.

This patch removes DT parsing and uses cpu->of_node instead.

Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
---
 drivers/cpufreq/pmac32-cpufreq.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/cpufreq/pmac32-cpufreq.c b/drivers/cpufreq/pmac32-cpufreq.c
index 3104fad..b6822ee 100644
--- a/drivers/cpufreq/pmac32-cpufreq.c
+++ b/drivers/cpufreq/pmac32-cpufreq.c
@@ -21,6 +21,7 @@
 #include <linux/sched.h>
 #include <linux/adb.h>
 #include <linux/pmu.h>
+#include <linux/cpu.h>
 #include <linux/cpufreq.h>
 #include <linux/init.h>
 #include <linux/device.h>
@@ -643,6 +644,7 @@ static int pmac_cpufreq_init_750FX(struct device_node *cpunode)
  */
 static int __init pmac_cpufreq_setup(void)
 {
+	struct device *cpu_dev;
 	struct device_node	*cpunode;
 	const u32		*value;
 
@@ -650,7 +652,14 @@ static int __init pmac_cpufreq_setup(void)
 		return 0;
 
 	/* Assume only one CPU */
-	cpunode = of_find_node_by_type(NULL, "cpu");
+	cpu_dev = get_cpu_device(0);
+	if (!cpu_dev) {
+		pr_err("failed to get cpu device\n");
+		return -ENODEV;
+	}
+
+	/* Get first CPU node */
+	cpunode = of_node_get(cpu_dev->of_node);
 	if (!cpunode)
 		goto out;
 
-- 
1.8.1.2

Re: [RFC PATCH v2 01/15] of: add support for retrieving cpu node for a given logical cpu index

[Nicolas Pitre]

On Wed, 17 Jul 2013, Sudeep.KarkadaNagesha-5wv7dgnIgG8@public.gmane.org wrote:

> From: Sudeep KarkadaNagesha <sudeep.karkadanagesha-5wv7dgnIgG8@public.gmane.org>
> 
> Currently different drivers requiring to access cpu device node are
> parsing the device tree themselves. Since the ordering in the DT need
> not match the logical cpu ordering, the parsing logic needs to consider
> that. However, this has resulted in lots of code duplication and in some
> cases even incorrect logic.
> 
> It's better to consolidate them by adding support for getting cpu
> device node for a given logical cpu index in DT core library. However
> logical to physical index mapping can be architecture specific.
> 
> This patch adds of_get_cpu_node to retrieve a cpu device node for a
> given logical cpu index. The default matching of the physical id to the
> logical cpu index can be overridden by architecture specific code.
> 
> It is recommended to use these helper function only in pre-SMP/early
> initialisation stages to retrieve CPU device node pointers in logical
> ordering. Once the cpu devices are registered, it can be retrieved easily
> from cpu device of_node which avoids unnecessary parsing and matching.
> 
> Cc: Rob Herring <rob.herring-bsGFqQB8/DxBDgjK7y7TUQ@public.gmane.org>
> Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha-5wv7dgnIgG8@public.gmane.org>
> ---
>  drivers/of/base.c  | 66 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  include/linux/of.h |  5 +++++
>  2 files changed, 71 insertions(+)
> 
> diff --git a/drivers/of/base.c b/drivers/of/base.c
> index 5c54279..363b8f9 100644
> --- a/drivers/of/base.c
> +++ b/drivers/of/base.c
> @@ -230,6 +230,72 @@ const void *of_get_property(const struct device_node *np, const char *name,
>  }
>  EXPORT_SYMBOL(of_get_property);
>  
> +/*
> + * arch_match_cpu_phys_id - Match the given logical CPU and physical id
> + *
> + * @cpu: logical index of a cpu
> + * @phys_id: physical identifier of a cpu
> + *
> + * CPU logical to physical index mapping is architecure specific.

Typo.

> + * However this __weak function provides a default match of physical
> + * id to logical cpu index.
> + *
> + * Returns 1 if the physical identifier and the logical index correspond
> + * to the same cpu, 0 otherwise.
> + */
> +int __weak arch_match_cpu_phys_id(int cpu, u64 phys_id)

Please use a bool return type, and use true/false rather than 1/0 in the 
comment.

> +{
> +	return (u32)phys_id == cpu;
> +}
> +
> +/**
> + * of_get_cpu_node - Get device node associated with the given logical CPU
> + *
> + * @cpu: CPU number(logical index) for which device node is required
> + *
> + * The main purpose of this function is to retrieve the device node for the
> + * given logical CPU index. It should be used to intialise the of_node in

Typo.

> + * cpu device. Once of_node in cpu device is populated, all the further
> + * references can use that instead.
> + *
> + * CPU logical to physical index mapping is architecure specific and is built

Typo.

> + * before booting secondary cores. This function uses arch_match_cpu_phys_id
> + * which can be overridden by architecture specific implementation.
> + *
> + * Returns a node pointer for the logical cpu if found, else NULL.
> + */
> +struct device_node *of_get_cpu_node(int cpu)
> +{
> +	struct device_node *cpun, *cpus;
> +	const u32 *cell;
> +	u64 hwid;
> +	int ac, prop_len;
> +
> +	cpus = of_find_node_by_path("/cpus");
> +	if (WARN(!cpus, "Missing cpus node, bailing out\n"))
> +		return NULL;
> +
> +	if (WARN_ON(of_property_read_u32(cpus, "#address-cells", &ac)))
> +		ac = of_n_addr_cells(cpus);
> +
> +	for_each_child_of_node(cpus, cpun) {
> +		if (of_node_cmp(cpun->type, "cpu"))
> +			continue;
> +		cell = of_get_property(cpun, "reg", &prop_len);
> +		if (WARN(!cell, "%s: missing reg property\n", cpun->full_name))
> +			continue;
> +
> +		while (prop_len) {
> +			hwid = of_read_number(cell, ac);
> +			prop_len -= ac;
> +			if (arch_match_cpu_phys_id(cpu, hwid))
> +				return cpun;
> +		}
> +	}
> +
> +	return NULL;
> +}
> +
>  /** Checks if the given "compat" string matches one of the strings in
>   * the device's "compatible" property
>   */
> diff --git a/include/linux/of.h b/include/linux/of.h
> index 1fd08ca..150b48e 100644
> --- a/include/linux/of.h
> +++ b/include/linux/of.h
> @@ -266,6 +266,7 @@ extern int of_device_is_available(const struct device_node *device);
>  extern const void *of_get_property(const struct device_node *node,
>  				const char *name,
>  				int *lenp);
> +extern struct device_node *of_get_cpu_node(int cpu);
>  #define for_each_property_of_node(dn, pp) \
>  	for (pp = dn->properties; pp != NULL; pp = pp->next)
>  
> @@ -458,6 +459,10 @@ static inline const void *of_get_property(const struct device_node *node,
>  {
>  	return NULL;
>  }
> +static inline struct device_node *of_get_cpu_node(int cpu)
> +{
> +	return NULL;
> +}
>  
>  static inline int of_property_read_u64(const struct device_node *np,
>  				       const char *propname, u64 *out_value)
> -- 
> 1.8.1.2
> 
> 
> _______________________________________________
> devicetree-discuss mailing list
> devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org
> https://lists.ozlabs.org/listinfo/devicetree-discuss
> 

Re: [RFC PATCH v2 11/15] cpufreq: kirkwood-cpufreq: remove device tree parsing for cpu nodes

[Andrew Lunn]

On Wed, Jul 17, 2013 at 03:06:20PM +0100, Sudeep.KarkadaNagesha@arm.com wrote:
> From: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
> 
> Now that the cpu device registration initialises the of_node(if available)
> appropriately for all the cpus, parsing here is redundant.
> 
> This patch removes all DT parsing and uses cpu->of_node instead.
> 
> Cc: Andrew Lunn <andrew@lunn.ch>
> Cc: Jason Cooper <jason@lakedaemon.net>
> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
> Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
> ---
>  drivers/cpufreq/kirkwood-cpufreq.c | 14 ++++++++++++--
>  1 file changed, 12 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/cpufreq/kirkwood-cpufreq.c b/drivers/cpufreq/kirkwood-cpufreq.c
> index c233ea6..18aa3eb 100644
> --- a/drivers/cpufreq/kirkwood-cpufreq.c
> +++ b/drivers/cpufreq/kirkwood-cpufreq.c
> @@ -13,6 +13,7 @@
>  #include <linux/module.h>
>  #include <linux/clk.h>
>  #include <linux/clk-provider.h>
> +#include <linux/cpu.h>
>  #include <linux/cpufreq.h>
>  #include <linux/of.h>
>  #include <linux/platform_device.h>
> @@ -165,6 +166,7 @@ static struct cpufreq_driver kirkwood_cpufreq_driver = {
>  static int kirkwood_cpufreq_probe(struct platform_device *pdev)
>  {
>  	struct device_node *np;
> +	struct device *cpu_dev;
>  	struct resource *res;
>  	int err;
>  
> @@ -175,9 +177,17 @@ static int kirkwood_cpufreq_probe(struct platform_device *pdev)
>  	if (IS_ERR(priv.base))
>  		return PTR_ERR(priv.base);
>  
> -	np = of_find_node_by_path("/cpus/cpu@0");
> -	if (!np)
> +	cpu_dev = get_cpu_device(0);
> +	if (!cpu_dev) {
> +		dev_err(&pdev->dev, "failed to get cpu device\n");
>  		return -ENODEV;
> +	}
> +
> +	np = of_node_get(cpu_dev->of_node);
> +	if (!np) {
> +		dev_err(&pdev->dev, "failed to get cpu device node\n");
> +		return -ENODEV;
> +	}

Hi Sudeep

Are we not going a bit backwards here? You are replacing two lines
with 10 lines.

How about putting these 10 lines into some helper,
of_get_cpu_device()?  It would be useful for spear, kirkwood and
imx6q, and maybe others.

    Thanks
	Andrew

Re: [RFC PATCH v2 01/15] of: add support for retrieving cpu node for a given logical cpu index

[Rob Herring]

On 07/17/2013 09:06 AM, Sudeep.KarkadaNagesha@arm.com wrote:
> From: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
> 
> Currently different drivers requiring to access cpu device node are
> parsing the device tree themselves. Since the ordering in the DT need
> not match the logical cpu ordering, the parsing logic needs to consider
> that. However, this has resulted in lots of code duplication and in some
> cases even incorrect logic.
> 
> It's better to consolidate them by adding support for getting cpu
> device node for a given logical cpu index in DT core library. However
> logical to physical index mapping can be architecture specific.
> 
> This patch adds of_get_cpu_node to retrieve a cpu device node for a
> given logical cpu index. The default matching of the physical id to the
> logical cpu index can be overridden by architecture specific code.
> 
> It is recommended to use these helper function only in pre-SMP/early
> initialisation stages to retrieve CPU device node pointers in logical
> ordering. Once the cpu devices are registered, it can be retrieved easily
> from cpu device of_node which avoids unnecessary parsing and matching.
> 
> Cc: Rob Herring <rob.herring@calxeda.com>
> Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>

One comment below, but otherwise for patches 1-4, 8 and 9:

Acked-by: Rob Herring <rob.herring@calxeda.com>

Also, patch 3 needs to come before patch 2 or the matching will be wrong
if patch 3 is not applied.

> ---
>  drivers/of/base.c  | 66 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  include/linux/of.h |  5 +++++
>  2 files changed, 71 insertions(+)
> 
> diff --git a/drivers/of/base.c b/drivers/of/base.c
> index 5c54279..363b8f9 100644
> --- a/drivers/of/base.c
> +++ b/drivers/of/base.c
> @@ -230,6 +230,72 @@ const void *of_get_property(const struct device_node *np, const char *name,
>  }
>  EXPORT_SYMBOL(of_get_property);
>  
> +/*
> + * arch_match_cpu_phys_id - Match the given logical CPU and physical id
> + *
> + * @cpu: logical index of a cpu
> + * @phys_id: physical identifier of a cpu
> + *
> + * CPU logical to physical index mapping is architecure specific.
> + * However this __weak function provides a default match of physical
> + * id to logical cpu index.
> + *
> + * Returns 1 if the physical identifier and the logical index correspond
> + * to the same cpu, 0 otherwise.
> + */
> +int __weak arch_match_cpu_phys_id(int cpu, u64 phys_id)
> +{
> +	return (u32)phys_id == cpu;
> +}
> +
> +/**
> + * of_get_cpu_node - Get device node associated with the given logical CPU
> + *
> + * @cpu: CPU number(logical index) for which device node is required
> + *
> + * The main purpose of this function is to retrieve the device node for the
> + * given logical CPU index. It should be used to intialise the of_node in
> + * cpu device. Once of_node in cpu device is populated, all the further
> + * references can use that instead.
> + *
> + * CPU logical to physical index mapping is architecure specific and is built
> + * before booting secondary cores. This function uses arch_match_cpu_phys_id
> + * which can be overridden by architecture specific implementation.
> + *
> + * Returns a node pointer for the logical cpu if found, else NULL.
> + */
> +struct device_node *of_get_cpu_node(int cpu)
> +{
> +	struct device_node *cpun, *cpus;
> +	const u32 *cell;
> +	u64 hwid;
> +	int ac, prop_len;
> +
> +	cpus = of_find_node_by_path("/cpus");
> +	if (WARN(!cpus, "Missing cpus node, bailing out\n"))

What happens on a system with no /cpus nodes? Seems like this is another
case of adding new warnings to existing working systems.

I'd replace all the WARN's with a single pr_warn on any errors below.
For missing /cpus, I would just silently return.

Rob

> +		return NULL;
> +
> +	if (WARN_ON(of_property_read_u32(cpus, "#address-cells", &ac)))
> +		ac = of_n_addr_cells(cpus);
> +
> +	for_each_child_of_node(cpus, cpun) {
> +		if (of_node_cmp(cpun->type, "cpu"))
> +			continue;
> +		cell = of_get_property(cpun, "reg", &prop_len);
> +		if (WARN(!cell, "%s: missing reg property\n", cpun->full_name))
> +			continue;
> +
> +		while (prop_len) {
> +			hwid = of_read_number(cell, ac);
> +			prop_len -= ac;
> +			if (arch_match_cpu_phys_id(cpu, hwid))
> +				return cpun;
> +		}
> +	}
> +
> +	return NULL;
> +}

Re: [RFC PATCH v2 01/15] of: add support for retrieving cpu node for a given logical cpu index

[Sudeep KarkadaNagesha]

On 17/07/13 15:50, Rob Herring wrote:
> On 07/17/2013 09:06 AM, Sudeep.KarkadaNagesha@arm.com wrote:
>> From: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
>>
>> Currently different drivers requiring to access cpu device node are
>> parsing the device tree themselves. Since the ordering in the DT need
>> not match the logical cpu ordering, the parsing logic needs to consider
>> that. However, this has resulted in lots of code duplication and in some
>> cases even incorrect logic.
>>
>> It's better to consolidate them by adding support for getting cpu
>> device node for a given logical cpu index in DT core library. However
>> logical to physical index mapping can be architecture specific.
>>
>> This patch adds of_get_cpu_node to retrieve a cpu device node for a
>> given logical cpu index. The default matching of the physical id to the
>> logical cpu index can be overridden by architecture specific code.
>>
>> It is recommended to use these helper function only in pre-SMP/early
>> initialisation stages to retrieve CPU device node pointers in logical
>> ordering. Once the cpu devices are registered, it can be retrieved easily
>> from cpu device of_node which avoids unnecessary parsing and matching.
>>
>> Cc: Rob Herring <rob.herring@calxeda.com>
>> Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
> 
> One comment below, but otherwise for patches 1-4, 8 and 9:
> 
> Acked-by: Rob Herring <rob.herring@calxeda.com>
> 
> Also, patch 3 needs to come before patch 2 or the matching will be wrong
> if patch 3 is not applied.
Ah, correct will fix it in next version.

> 
>> ---
>>  drivers/of/base.c  | 66 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
>>  include/linux/of.h |  5 +++++
>>  2 files changed, 71 insertions(+)
>>
>> diff --git a/drivers/of/base.c b/drivers/of/base.c
>> index 5c54279..363b8f9 100644
>> --- a/drivers/of/base.c
>> +++ b/drivers/of/base.c
>> @@ -230,6 +230,72 @@ const void *of_get_property(const struct device_node *np, const char *name,
>>  }
>>  EXPORT_SYMBOL(of_get_property);
>>  
>> +/*
>> + * arch_match_cpu_phys_id - Match the given logical CPU and physical id
>> + *
>> + * @cpu: logical index of a cpu
>> + * @phys_id: physical identifier of a cpu
>> + *
>> + * CPU logical to physical index mapping is architecure specific.
>> + * However this __weak function provides a default match of physical
>> + * id to logical cpu index.
>> + *
>> + * Returns 1 if the physical identifier and the logical index correspond
>> + * to the same cpu, 0 otherwise.
>> + */
>> +int __weak arch_match_cpu_phys_id(int cpu, u64 phys_id)
>> +{
>> +	return (u32)phys_id == cpu;
>> +}
>> +
>> +/**
>> + * of_get_cpu_node - Get device node associated with the given logical CPU
>> + *
>> + * @cpu: CPU number(logical index) for which device node is required
>> + *
>> + * The main purpose of this function is to retrieve the device node for the
>> + * given logical CPU index. It should be used to intialise the of_node in
>> + * cpu device. Once of_node in cpu device is populated, all the further
>> + * references can use that instead.
>> + *
>> + * CPU logical to physical index mapping is architecure specific and is built
>> + * before booting secondary cores. This function uses arch_match_cpu_phys_id
>> + * which can be overridden by architecture specific implementation.
>> + *
>> + * Returns a node pointer for the logical cpu if found, else NULL.
>> + */
>> +struct device_node *of_get_cpu_node(int cpu)
>> +{
>> +	struct device_node *cpun, *cpus;
>> +	const u32 *cell;
>> +	u64 hwid;
>> +	int ac, prop_len;
>> +
>> +	cpus = of_find_node_by_path("/cpus");
>> +	if (WARN(!cpus, "Missing cpus node, bailing out\n"))
> 
> What happens on a system with no /cpus nodes? Seems like this is another
> case of adding new warnings to existing working systems.
> 
> I'd replace all the WARN's with a single pr_warn on any errors below.
> For missing /cpus, I would just silently return.

Ah, forgot recent discussions on this, will fix it.

Regards,
Sudeep

Re: [RFC PATCH v2 11/15] cpufreq: kirkwood-cpufreq: remove device tree parsing for cpu nodes

[Viresh Kumar]

On 17 July 2013 20:13, Andrew Lunn <andrew@lunn.ch> wrote:
> Are we not going a bit backwards here? You are replacing two lines
> with 10 lines.
>
> How about putting these 10 lines into some helper,
> of_get_cpu_device()?  It would be useful for spear, kirkwood and
> imx6q, and maybe others.

+1

Re: [RFC PATCH v2 00/15] DT/core: update cpu device of_node

[Viresh Kumar]

On 17 July 2013 19:36,  <Sudeep.KarkadaNagesha@arm.com> wrote:
> 3. Added Acks from Viresh and Shawn

Add it for the new cpufreq drivers included in this patchset too..

Re: [RFC PATCH v2 11/15] cpufreq: kirkwood-cpufreq: remove device tree parsing for cpu nodes

[Sudeep KarkadaNagesha]

On 17/07/13 15:43, Andrew Lunn wrote:
> On Wed, Jul 17, 2013 at 03:06:20PM +0100, Sudeep.KarkadaNagesha@arm.com wrote:
>> From: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
>>
>> Now that the cpu device registration initialises the of_node(if available)
>> appropriately for all the cpus, parsing here is redundant.
>>
>> This patch removes all DT parsing and uses cpu->of_node instead.
>>
>> Cc: Andrew Lunn <andrew@lunn.ch>
>> Cc: Jason Cooper <jason@lakedaemon.net>
>> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
>> Signed-off-by: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
>> ---
>>  drivers/cpufreq/kirkwood-cpufreq.c | 14 ++++++++++++--
>>  1 file changed, 12 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/cpufreq/kirkwood-cpufreq.c b/drivers/cpufreq/kirkwood-cpufreq.c
>> index c233ea6..18aa3eb 100644
>> --- a/drivers/cpufreq/kirkwood-cpufreq.c
>> +++ b/drivers/cpufreq/kirkwood-cpufreq.c
>> @@ -13,6 +13,7 @@
>>  #include <linux/module.h>
>>  #include <linux/clk.h>
>>  #include <linux/clk-provider.h>
>> +#include <linux/cpu.h>
>>  #include <linux/cpufreq.h>
>>  #include <linux/of.h>
>>  #include <linux/platform_device.h>
>> @@ -165,6 +166,7 @@ static struct cpufreq_driver kirkwood_cpufreq_driver = {
>>  static int kirkwood_cpufreq_probe(struct platform_device *pdev)
>>  {
>>  	struct device_node *np;
>> +	struct device *cpu_dev;
>>  	struct resource *res;
>>  	int err;
>>  
>> @@ -175,9 +177,17 @@ static int kirkwood_cpufreq_probe(struct platform_device *pdev)
>>  	if (IS_ERR(priv.base))
>>  		return PTR_ERR(priv.base);
>>  
>> -	np = of_find_node_by_path("/cpus/cpu@0");
>> -	if (!np)
>> +	cpu_dev = get_cpu_device(0);
>> +	if (!cpu_dev) {
>> +		dev_err(&pdev->dev, "failed to get cpu device\n");
>>  		return -ENODEV;
>> +	}
>> +
>> +	np = of_node_get(cpu_dev->of_node);
>> +	if (!np) {
>> +		dev_err(&pdev->dev, "failed to get cpu device node\n");
>> +		return -ENODEV;
>> +	}
> 
> Hi Sudeep
> 
> Are we not going a bit backwards here? You are replacing two lines
> with 10 lines.
> 
> How about putting these 10 lines into some helper,
> of_get_cpu_device()?  It would be useful for spear, kirkwood and
> imx6q, and maybe others.
> 
Yes I realised that after making changes to this and pmac32 drivers. I
have already made those changes in v3. I am waiting for more response
before posting them.

Regards,
Sudeep

Re: [RFC PATCH v2 11/15] cpufreq: kirkwood-cpufreq: remove device tree parsing for cpu nodes

[Sudeep KarkadaNagesha]

On 18/07/13 09:24, Sudeep KarkadaNagesha wrote:
> On 17/07/13 15:43, Andrew Lunn wrote:
>> On Wed, Jul 17, 2013 at 03:06:20PM +0100, Sudeep.KarkadaNagesha@arm.com wrote:
>>> From: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
>>>
[...]
>>> diff --git a/drivers/cpufreq/kirkwood-cpufreq.c b/drivers/cpufreq/kirkwood-cpufreq.c
>>> index c233ea6..18aa3eb 100644
>>> --- a/drivers/cpufreq/kirkwood-cpufreq.c
>>> +++ b/drivers/cpufreq/kirkwood-cpufreq.c
>>> @@ -13,6 +13,7 @@
>>>  #include <linux/module.h>
>>>  #include <linux/clk.h>
>>>  #include <linux/clk-provider.h>
>>> +#include <linux/cpu.h>
>>>  #include <linux/cpufreq.h>
>>>  #include <linux/of.h>
>>>  #include <linux/platform_device.h>
>>> @@ -165,6 +166,7 @@ static struct cpufreq_driver kirkwood_cpufreq_driver = {
>>>  static int kirkwood_cpufreq_probe(struct platform_device *pdev)
>>>  {
>>>  	struct device_node *np;
>>> +	struct device *cpu_dev;
>>>  	struct resource *res;
>>>  	int err;
>>>  
>>> @@ -175,9 +177,17 @@ static int kirkwood_cpufreq_probe(struct platform_device *pdev)
>>>  	if (IS_ERR(priv.base))
>>>  		return PTR_ERR(priv.base);
>>>  
>>> -	np = of_find_node_by_path("/cpus/cpu@0");
>>> -	if (!np)
>>> +	cpu_dev = get_cpu_device(0);
>>> +	if (!cpu_dev) {
>>> +		dev_err(&pdev->dev, "failed to get cpu device\n");
>>>  		return -ENODEV;
>>> +	}
>>> +
>>> +	np = of_node_get(cpu_dev->of_node);
>>> +	if (!np) {
>>> +		dev_err(&pdev->dev, "failed to get cpu device node\n");
>>> +		return -ENODEV;
>>> +	}
>>
>> Hi Sudeep
>>
>> Are we not going a bit backwards here? You are replacing two lines
>> with 10 lines.
>>
>> How about putting these 10 lines into some helper,
>> of_get_cpu_device()?  It would be useful for spear, kirkwood and
>> imx6q, and maybe others.
>>
> Yes I realised that after making changes to this and pmac32 drivers. I
> have already made those changes in v3. I am waiting for more response
> before posting them.
> 
I thought of placing this helper in include/linux/of_device.h but I see:
#include <linux/of_platform.h> /* temporary until merge */

Does this mean of_platform.h and of_device.h will be merged ?
If so, which will be the final merged one ? I would like to avoid
changing all the header file inclusions later in users of this new helper.

Regards,
Sudeep

Re: [RFC PATCH v2 11/15] cpufreq: kirkwood-cpufreq: remove device tree parsing for cpu nodes

[Rob Herring]

On 07/18/2013 05:14 AM, Sudeep KarkadaNagesha wrote:
> On 18/07/13 09:24, Sudeep KarkadaNagesha wrote:
>> On 17/07/13 15:43, Andrew Lunn wrote:
>>> On Wed, Jul 17, 2013 at 03:06:20PM +0100, Sudeep.KarkadaNagesha@arm.com wrote:
>>>> From: Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
>>>>
> [...]

>>> Are we not going a bit backwards here? You are replacing two lines
>>> with 10 lines.
>>>
>>> How about putting these 10 lines into some helper,
>>> of_get_cpu_device()?  It would be useful for spear, kirkwood and
>>> imx6q, and maybe others.
>>>
>> Yes I realised that after making changes to this and pmac32 drivers. I
>> have already made those changes in v3. I am waiting for more response
>> before posting them.
>>
> I thought of placing this helper in include/linux/of_device.h but I see:
> #include <linux/of_platform.h> /* temporary until merge */
> 
> Does this mean of_platform.h and of_device.h will be merged ?

No, I think that was probably to avoid adding includes of of_platform.h
for 100's of files. Maybe things are cleaned up enough to remove this line.

> If so, which will be the final merged one ? I would like to avoid
> changing all the header file inclusions later in users of this new helper.

of_device.h is the right place.

Rob

> 
> Regards,
> Sudeep
> 
> 
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