[PATCH v5 0/2] Add cpufreq support for Armada 8K

[PATCH v5 0/2] Add cpufreq support for Armada 8K

[Gregory CLEMENT]

Hi,

this is the fifth version of a the series adding the cpufreq support
for the Marvell Armada 8K SoCs.

Gregory

Changelog:
v4 -> v5:

 - Rebased onto v5.0-rc1

 - Rewrite the clk_get part in armada_8k_get_sharing_cpus()

 - Reverse the call function order in armada_8k_cpufreq_exit()

v3 -> v4:

 - Remove most of the global variable and use the private data of the
   platfrom device to store the freq_tables struct.

 - Remove the clk pointer of the freq_table struct which is no more
   needed with the new way to register the opp

 - Check the get_cpu_device() return.

 - Balance the clk_get() calls.

 - No more use the devm_ function.

 - Base the registration of the opp on the cpu mask updated after each
   iteration to find the shared cpus.

 - Base the free on the NULL or 0 value of the freq_table struct
   members, it allows to remove the global index.

v2 -> v3

 - Make the driver really modular (modprobe;modprobe -r;modprobe; is working)

 - Don't use anymore 100MHz as minimal frequency, but only max frequency/4

 - Fix remaining warning reported by checkpatch

 - Rework the registering of the opp

v1 -> v2:

 - Fix typos in MAINTAINERS (reported by Baruch Siach) and in
   armada-8k-cpufreq.c (reported by Thomas Petazzoni)

 - Fix indentation in Kconfig.arm  (reported by Thomas Petazzoni)

 - Use const for opps_div  (reported by Thomas Petazzoni)

 - Fix memory leak of opps_array  (reported by Thomas Petazzoni)


Gregory CLEMENT (2):
  MAINTAINERS: add new entries for Armada 8K cpufreq driver
  cpufreq: ap806: add cpufreq driver for Armada 8K

 MAINTAINERS                         |   1 +
 drivers/cpufreq/Kconfig.arm         |  11 ++
 drivers/cpufreq/Makefile            |   1 +
 drivers/cpufreq/armada-8k-cpufreq.c | 203 ++++++++++++++++++++++++++++
 4 files changed, 216 insertions(+)
 create mode 100644 drivers/cpufreq/armada-8k-cpufreq.c

-- 
2.20.1


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[PATCH v5 1/2] MAINTAINERS: add new entries for Armada 8K cpufreq driver

[Gregory CLEMENT]

This new driver belongs to the mvebu family, update the MAINTAINER file
to document it.

Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
---
 MAINTAINERS | 1 +
 1 file changed, 1 insertion(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 32d444476a90..4a3d62a83e35 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1737,6 +1737,7 @@ F:	arch/arm/configs/mvebu_*_defconfig
 F:	arch/arm/mach-mvebu/
 F:	arch/arm64/boot/dts/marvell/armada*
 F:	drivers/cpufreq/armada-37xx-cpufreq.c
+F:	drivers/cpufreq/armada-8k-cpufreq.c
 F:	drivers/cpufreq/mvebu-cpufreq.c
 F:	drivers/irqchip/irq-armada-370-xp.c
 F:	drivers/irqchip/irq-mvebu-*
-- 
2.20.1


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[PATCH v5 2/2] cpufreq: ap806: add cpufreq driver for Armada 8K

[Gregory CLEMENT]

Add cpufreq driver for Marvell AP-806 found on Aramda 8K.
The AP-806 has DFS (Dynamic Frequency Scaling) with coupled
clock domain for two clusters, so this driver will directly
use generic cpufreq-dt driver as backend.

Based on the work of Omri Itach <omrii@marvell.com>.

Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
---
 drivers/cpufreq/Kconfig.arm         |  11 ++
 drivers/cpufreq/Makefile            |   1 +
 drivers/cpufreq/armada-8k-cpufreq.c | 203 ++++++++++++++++++++++++++++
 3 files changed, 215 insertions(+)
 create mode 100644 drivers/cpufreq/armada-8k-cpufreq.c

diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
index 688f10227793..10bc5c798d17 100644
--- a/drivers/cpufreq/Kconfig.arm
+++ b/drivers/cpufreq/Kconfig.arm
@@ -25,6 +25,17 @@ config ARM_ARMADA_37XX_CPUFREQ
 	  This adds the CPUFreq driver support for Marvell Armada 37xx SoCs.
 	  The Armada 37xx PMU supports 4 frequency and VDD levels.
 
+config ARM_ARMADA_8K_CPUFREQ
+	tristate "Armada 8K CPUFreq driver"
+	depends on ARCH_MVEBU && CPUFREQ_DT
+	help
+	  This enables the CPUFreq driver support for Marvell
+	  Armada8k SOCs.
+	  Armada8K device has the AP806 which supports scaling
+	  to any full integer divider.
+
+	  If in doubt, say N.
+
 # big LITTLE core layer and glue drivers
 config ARM_BIG_LITTLE_CPUFREQ
 	tristate "Generic ARM big LITTLE CPUfreq driver"
diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
index 08c071be2491..689b26c6f949 100644
--- a/drivers/cpufreq/Makefile
+++ b/drivers/cpufreq/Makefile
@@ -50,6 +50,7 @@ obj-$(CONFIG_X86_SFI_CPUFREQ)		+= sfi-cpufreq.o
 obj-$(CONFIG_ARM_BIG_LITTLE_CPUFREQ)	+= arm_big_little.o
 
 obj-$(CONFIG_ARM_ARMADA_37XX_CPUFREQ)	+= armada-37xx-cpufreq.o
+obj-$(CONFIG_ARM_ARMADA_8K_CPUFREQ)	+= armada-8k-cpufreq.o
 obj-$(CONFIG_ARM_BRCMSTB_AVS_CPUFREQ)	+= brcmstb-avs-cpufreq.o
 obj-$(CONFIG_ACPI_CPPC_CPUFREQ)		+= cppc_cpufreq.o
 obj-$(CONFIG_ARCH_DAVINCI)		+= davinci-cpufreq.o
diff --git a/drivers/cpufreq/armada-8k-cpufreq.c b/drivers/cpufreq/armada-8k-cpufreq.c
new file mode 100644
index 000000000000..80375de4e149
--- /dev/null
+++ b/drivers/cpufreq/armada-8k-cpufreq.c
@@ -0,0 +1,203 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * CPUFreq support for Armada 8K
+ *
+ * Copyright (C) 2018 Marvell
+ *
+ * Omri Itach <omrii@marvell.com>
+ * Gregory Clement <gregory.clement@bootlin.com>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/clk.h>
+#include <linux/cpu.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm_opp.h>
+#include <linux/slab.h>
+
+/*
+ * Setup the opps list with the divider for the max frequency, that
+ * will be filled at runtime.
+ */
+static const int opps_div[] __initconst = {1, 2, 3, 4};
+
+static struct platform_device *armada_8k_pdev;
+
+struct freq_table {
+	struct device *cpu_dev;
+	unsigned int freq[ARRAY_SIZE(opps_div)];
+};
+
+/* If the CPUs share the same clock, then they are in the same cluster. */
+static void __init armada_8k_get_sharing_cpus(struct clk *cur_clk,
+					      struct cpumask *cpumask)
+{
+	int cpu;
+
+	for_each_possible_cpu(cpu) {
+		struct device *cpu_dev;
+		struct clk *clk;
+
+		cpu_dev = get_cpu_device(cpu);
+		if (!cpu_dev) {
+			pr_warn("Failed to get cpu%d device\n", cpu);
+			continue;
+		}
+
+		clk = clk_get(cpu_dev, 0);
+		if (IS_ERR(clk))
+			pr_warn("Cannot get clock for CPU %d\n", cpu);
+		else if (clk_is_match(clk, cur_clk))
+			cpumask_set_cpu(cpu, cpumask);
+
+		if (!IS_ERR(clk))
+			clk_put(clk);
+	}
+}
+
+static int __init armada_8k_add_opp(struct clk *clk, struct device *cpu_dev,
+				    struct freq_table *freq_tables,
+				    int opps_index)
+{
+	unsigned int cur_frequency;
+	unsigned int freq;
+	int i, ret;
+
+	/* Get nominal (current) CPU frequency. */
+	cur_frequency = clk_get_rate(clk);
+	if (!cur_frequency) {
+		dev_err(cpu_dev, "Failed to get clock rate for this CPU\n");
+		return -EINVAL;
+	}
+
+	freq_tables[opps_index].cpu_dev = cpu_dev;
+
+	for (i = 0; i < ARRAY_SIZE(opps_div); i++) {
+		freq = cur_frequency / opps_div[i];
+
+		ret = dev_pm_opp_add(cpu_dev, freq, 0);
+		if (ret)
+			return ret;
+
+		freq_tables[opps_index].freq[i] = freq;
+	}
+
+	return 0;
+}
+
+static void armada_8k_cpufreq_free_table(struct freq_table *freq_tables)
+{
+	int opps_index, nb_cpus = num_possible_cpus();
+
+	for (opps_index = 0 ; opps_index <= nb_cpus; opps_index++) {
+		int i;
+
+		/* If cpu_dev is NULL then we reached the end of the array */
+		if (!freq_tables[opps_index].cpu_dev)
+			break;
+
+		for (i = 0; i < ARRAY_SIZE(opps_div); i++) {
+			/*
+			 * A 0Hz frequency is not valid, this meant
+			 * that it was not yet initialized so there is
+			 * no more opp to free
+			 */
+			if (freq_tables[opps_index].freq[i] == 0)
+				break;
+
+			dev_pm_opp_remove(freq_tables[opps_index].cpu_dev,
+					  freq_tables[opps_index].freq[i]);
+		}
+	}
+
+	kfree(freq_tables);
+}
+
+static int __init armada_8k_cpufreq_init(void)
+{
+	int ret = 0, opps_index = 0, cpu, nb_cpus;
+	struct freq_table *freq_tables;
+	struct device_node *node;
+	struct cpumask cpus;
+
+	node = of_find_compatible_node(NULL, NULL, "marvell,ap806-cpu-clock");
+	if (!node || !of_device_is_available(node))
+		return -ENODEV;
+
+	nb_cpus = num_possible_cpus();
+	freq_tables = kcalloc(nb_cpus, sizeof(*freq_tables), GFP_KERNEL);
+	cpumask_copy(&cpus, cpu_possible_mask);
+
+	/*
+	 * For each CPU, this loop registers the operating points
+	 * supported (which are the nominal CPU frequency and full integer
+	 * divisions of it).
+	 */
+	for_each_cpu(cpu, &cpus) {
+		struct cpumask shared_cpus;
+		struct device *cpu_dev;
+		struct clk *clk;
+
+		cpu_dev = get_cpu_device(cpu);
+
+		if (!cpu_dev) {
+			pr_err("Cannot get CPU %d\n", cpu);
+			continue;
+		}
+
+		clk = clk_get(cpu_dev, 0);
+
+		if (IS_ERR(clk)) {
+			pr_err("Cannot get clock for CPU %d\n", cpu);
+			ret = PTR_ERR(clk);
+			goto remove_opp;
+		}
+
+		ret = armada_8k_add_opp(clk, cpu_dev, freq_tables, opps_index);
+		if (ret) {
+			clk_put(clk);
+			goto remove_opp;
+		}
+
+		opps_index++;
+		cpumask_clear(&shared_cpus);
+		armada_8k_get_sharing_cpus(clk, &shared_cpus);
+		dev_pm_opp_set_sharing_cpus(cpu_dev, &shared_cpus);
+		cpumask_andnot(&cpus, &cpus, &shared_cpus);
+		clk_put(clk);
+	}
+
+	armada_8k_pdev = platform_device_register_simple("cpufreq-dt", -1,
+							 NULL, 0);
+	ret = PTR_ERR_OR_ZERO(armada_8k_pdev);
+	if (ret)
+		goto remove_opp;
+
+	platform_set_drvdata(armada_8k_pdev, freq_tables);
+
+	return 0;
+
+remove_opp:
+	armada_8k_cpufreq_free_table(freq_tables);
+	return ret;
+}
+module_init(armada_8k_cpufreq_init);
+
+static void __exit armada_8k_cpufreq_exit(void)
+{
+	struct freq_table *freq_tables = platform_get_drvdata(armada_8k_pdev);
+
+	armada_8k_cpufreq_free_table(freq_tables);
+	platform_device_unregister(armada_8k_pdev);
+}
+module_exit(armada_8k_cpufreq_exit);
+
+MODULE_AUTHOR("Gregory Clement <gregory.clement@bootlin.com>");
+MODULE_DESCRIPTION("Armada 8K cpufreq driver");
+MODULE_LICENSE("GPL");
-- 
2.20.1


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[PATCH v5 2/2] cpufreq: ap806: add cpufreq driver for Armada 8K

[Gregory CLEMENT]

Add cpufreq driver for Marvell AP-806 found on Aramda 8K.
The AP-806 has DFS (Dynamic Frequency Scaling) with coupled
clock domain for two clusters, so this driver will directly
use generic cpufreq-dt driver as backend.

Based on the work of Omri Itach <omrii@marvell.com>.

Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
---
Hi,

This one is the correct version, in the previous one the change were
not merged.

Sorry for the noise,

Gregory


 drivers/cpufreq/Kconfig.arm         |  11 ++
 drivers/cpufreq/Makefile            |   1 +
 drivers/cpufreq/armada-8k-cpufreq.c | 204 ++++++++++++++++++++++++++++
 3 files changed, 216 insertions(+)
 create mode 100644 drivers/cpufreq/armada-8k-cpufreq.c

diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
index 688f10227793..10bc5c798d17 100644
--- a/drivers/cpufreq/Kconfig.arm
+++ b/drivers/cpufreq/Kconfig.arm
@@ -25,6 +25,17 @@ config ARM_ARMADA_37XX_CPUFREQ
 	  This adds the CPUFreq driver support for Marvell Armada 37xx SoCs.
 	  The Armada 37xx PMU supports 4 frequency and VDD levels.
 
+config ARM_ARMADA_8K_CPUFREQ
+	tristate "Armada 8K CPUFreq driver"
+	depends on ARCH_MVEBU && CPUFREQ_DT
+	help
+	  This enables the CPUFreq driver support for Marvell
+	  Armada8k SOCs.
+	  Armada8K device has the AP806 which supports scaling
+	  to any full integer divider.
+
+	  If in doubt, say N.
+
 # big LITTLE core layer and glue drivers
 config ARM_BIG_LITTLE_CPUFREQ
 	tristate "Generic ARM big LITTLE CPUfreq driver"
diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
index 08c071be2491..689b26c6f949 100644
--- a/drivers/cpufreq/Makefile
+++ b/drivers/cpufreq/Makefile
@@ -50,6 +50,7 @@ obj-$(CONFIG_X86_SFI_CPUFREQ)		+= sfi-cpufreq.o
 obj-$(CONFIG_ARM_BIG_LITTLE_CPUFREQ)	+= arm_big_little.o
 
 obj-$(CONFIG_ARM_ARMADA_37XX_CPUFREQ)	+= armada-37xx-cpufreq.o
+obj-$(CONFIG_ARM_ARMADA_8K_CPUFREQ)	+= armada-8k-cpufreq.o
 obj-$(CONFIG_ARM_BRCMSTB_AVS_CPUFREQ)	+= brcmstb-avs-cpufreq.o
 obj-$(CONFIG_ACPI_CPPC_CPUFREQ)		+= cppc_cpufreq.o
 obj-$(CONFIG_ARCH_DAVINCI)		+= davinci-cpufreq.o
diff --git a/drivers/cpufreq/armada-8k-cpufreq.c b/drivers/cpufreq/armada-8k-cpufreq.c
new file mode 100644
index 000000000000..8a5ddb93fc58
--- /dev/null
+++ b/drivers/cpufreq/armada-8k-cpufreq.c
@@ -0,0 +1,204 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * CPUFreq support for Armada 8K
+ *
+ * Copyright (C) 2018 Marvell
+ *
+ * Omri Itach <omrii@marvell.com>
+ * Gregory Clement <gregory.clement@bootlin.com>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/clk.h>
+#include <linux/cpu.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm_opp.h>
+#include <linux/slab.h>
+
+/*
+ * Setup the opps list with the divider for the max frequency, that
+ * will be filled at runtime.
+ */
+static const int opps_div[] __initconst = {1, 2, 3, 4};
+
+static struct platform_device *armada_8k_pdev;
+
+struct freq_table {
+	struct device *cpu_dev;
+	unsigned int freq[ARRAY_SIZE(opps_div)];
+};
+
+/* If the CPUs share the same clock, then they are in the same cluster. */
+static void __init armada_8k_get_sharing_cpus(struct clk *cur_clk,
+					      struct cpumask *cpumask)
+{
+	int cpu;
+
+	for_each_possible_cpu(cpu) {
+		struct device *cpu_dev;
+		struct clk *clk;
+
+		cpu_dev = get_cpu_device(cpu);
+		if (!cpu_dev) {
+			pr_warn("Failed to get cpu%d device\n", cpu);
+			continue;
+		}
+
+		clk = clk_get(cpu_dev, 0);
+		if (IS_ERR(clk)) {
+			pr_warn("Cannot get clock for CPU %d\n", cpu);
+		} else {
+			if (clk_is_match(clk, cur_clk))
+				cpumask_set_cpu(cpu, cpumask);
+
+			clk_put(clk);
+		}
+	}
+}
+
+static int __init armada_8k_add_opp(struct clk *clk, struct device *cpu_dev,
+				    struct freq_table *freq_tables,
+				    int opps_index)
+{
+	unsigned int cur_frequency;
+	unsigned int freq;
+	int i, ret;
+
+	/* Get nominal (current) CPU frequency. */
+	cur_frequency = clk_get_rate(clk);
+	if (!cur_frequency) {
+		dev_err(cpu_dev, "Failed to get clock rate for this CPU\n");
+		return -EINVAL;
+	}
+
+	freq_tables[opps_index].cpu_dev = cpu_dev;
+
+	for (i = 0; i < ARRAY_SIZE(opps_div); i++) {
+		freq = cur_frequency / opps_div[i];
+
+		ret = dev_pm_opp_add(cpu_dev, freq, 0);
+		if (ret)
+			return ret;
+
+		freq_tables[opps_index].freq[i] = freq;
+	}
+
+	return 0;
+}
+
+static void armada_8k_cpufreq_free_table(struct freq_table *freq_tables)
+{
+	int opps_index, nb_cpus = num_possible_cpus();
+
+	for (opps_index = 0 ; opps_index <= nb_cpus; opps_index++) {
+		int i;
+
+		/* If cpu_dev is NULL then we reached the end of the array */
+		if (!freq_tables[opps_index].cpu_dev)
+			break;
+
+		for (i = 0; i < ARRAY_SIZE(opps_div); i++) {
+			/*
+			 * A 0Hz frequency is not valid, this meant
+			 * that it was not yet initialized so there is
+			 * no more opp to free
+			 */
+			if (freq_tables[opps_index].freq[i] == 0)
+				break;
+
+			dev_pm_opp_remove(freq_tables[opps_index].cpu_dev,
+					  freq_tables[opps_index].freq[i]);
+		}
+	}
+
+	kfree(freq_tables);
+}
+
+static int __init armada_8k_cpufreq_init(void)
+{
+	int ret = 0, opps_index = 0, cpu, nb_cpus;
+	struct freq_table *freq_tables;
+	struct device_node *node;
+	struct cpumask cpus;
+
+	node = of_find_compatible_node(NULL, NULL, "marvell,ap806-cpu-clock");
+	if (!node || !of_device_is_available(node))
+		return -ENODEV;
+
+	nb_cpus = num_possible_cpus();
+	freq_tables = kcalloc(nb_cpus, sizeof(*freq_tables), GFP_KERNEL);
+	cpumask_copy(&cpus, cpu_possible_mask);
+
+	/*
+	 * For each CPU, this loop registers the operating points
+	 * supported (which are the nominal CPU frequency and full integer
+	 * divisions of it).
+	 */
+	for_each_cpu(cpu, &cpus) {
+		struct cpumask shared_cpus;
+		struct device *cpu_dev;
+		struct clk *clk;
+
+		cpu_dev = get_cpu_device(cpu);
+
+		if (!cpu_dev) {
+			pr_err("Cannot get CPU %d\n", cpu);
+			continue;
+		}
+
+		clk = clk_get(cpu_dev, 0);
+
+		if (IS_ERR(clk)) {
+			pr_err("Cannot get clock for CPU %d\n", cpu);
+			ret = PTR_ERR(clk);
+			goto remove_opp;
+		}
+
+		ret = armada_8k_add_opp(clk, cpu_dev, freq_tables, opps_index);
+		if (ret) {
+			clk_put(clk);
+			goto remove_opp;
+		}
+
+		opps_index++;
+		cpumask_clear(&shared_cpus);
+		armada_8k_get_sharing_cpus(clk, &shared_cpus);
+		dev_pm_opp_set_sharing_cpus(cpu_dev, &shared_cpus);
+		cpumask_andnot(&cpus, &cpus, &shared_cpus);
+		clk_put(clk);
+	}
+
+	armada_8k_pdev = platform_device_register_simple("cpufreq-dt", -1,
+							 NULL, 0);
+	ret = PTR_ERR_OR_ZERO(armada_8k_pdev);
+	if (ret)
+		goto remove_opp;
+
+	platform_set_drvdata(armada_8k_pdev, freq_tables);
+
+	return 0;
+
+remove_opp:
+	armada_8k_cpufreq_free_table(freq_tables);
+	return ret;
+}
+module_init(armada_8k_cpufreq_init);
+
+static void __exit armada_8k_cpufreq_exit(void)
+{
+	struct freq_table *freq_tables = platform_get_drvdata(armada_8k_pdev);
+
+	platform_device_unregister(armada_8k_pdev);
+	armada_8k_cpufreq_free_table(freq_tables);
+}
+module_exit(armada_8k_cpufreq_exit);
+
+MODULE_AUTHOR("Gregory Clement <gregory.clement@bootlin.com>");
+MODULE_DESCRIPTION("Armada 8K cpufreq driver");
+MODULE_LICENSE("GPL");
-- 
2.20.1


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Re: [PATCH v5 0/2] Add cpufreq support for Armada 8K

[Viresh Kumar]

On 18-01-19, 15:11, Gregory CLEMENT wrote:
> Hi,
> 
> this is the fifth version of a the series adding the cpufreq support
> for the Marvell Armada 8K SoCs.

Applied. Thanks.

-- 
viresh

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