[PATCH 0/3] cpufreq: bmips-cpufreq: CPUfreq driver for Broadcom's BMIPS SoCs

[PATCH 0/3] cpufreq: bmips-cpufreq: CPUfreq driver for Broadcom's BMIPS SoCs

[Markus Mayer]

From: Markus Mayer <mmayer@broadcom.com>

This series adds a CPUfreq driver for the BMIPS SoCs. In the first
iteration only BMIPS5xxx SoCs are supported.

This series is based on 4.10-rc1.

Markus Mayer (3):
  BMIPS: Enable prerequisites for CPUfreq in MIPS Kconfig.
  cpufreq: bmips-cpufreq: CPUfreq driver for Broadcom's BMIPS SoCs
  MIPS: BMIPS: enable CPUfreq

 arch/mips/Kconfig                     |   2 +
 arch/mips/configs/bmips_stb_defconfig |  10 ++
 drivers/cpufreq/Kconfig               |  10 ++
 drivers/cpufreq/Makefile              |   1 +
 drivers/cpufreq/bmips-cpufreq.c       | 205 ++++++++++++++++++++++++++++++++++
 5 files changed, 228 insertions(+)
 create mode 100644 drivers/cpufreq/bmips-cpufreq.c

-- 
2.7.4

[PATCH 1/3] BMIPS: Enable prerequisites for CPUfreq in MIPS Kconfig.

[Markus Mayer]

From: Markus Mayer <mmayer@broadcom.com>

Turn on CPU_SUPPORTS_CPUFREQ and MIPS_EXTERNAL_TIMER for BMIPS.

Signed-off-by: Markus Mayer <mmayer@broadcom.com>
---
 arch/mips/Kconfig | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index b3c5bde..e137eed 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -1703,6 +1703,8 @@ config CPU_BMIPS
 	select WEAK_ORDERING
 	select CPU_SUPPORTS_HIGHMEM
 	select CPU_HAS_PREFETCH
+	select CPU_SUPPORTS_CPUFREQ
+	select MIPS_EXTERNAL_TIMER
 	help
 	  Support for BMIPS32/3300/4350/4380 and BMIPS5000 processors.
 
-- 
2.7.4

[PATCH 2/3] cpufreq: bmips-cpufreq: CPUfreq driver for Broadcom's BMIPS SoCs

[Markus Mayer]

From: Markus Mayer <mmayer@broadcom.com>

Add the MIPS CPUfreq driver. This driver currently supports CPUfreq on
BMIPS5xxx-based SoCs.

Signed-off-by: Markus Mayer <mmayer@broadcom.com>
---
 drivers/cpufreq/Kconfig         |  10 ++
 drivers/cpufreq/Makefile        |   1 +
 drivers/cpufreq/bmips-cpufreq.c | 205 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 216 insertions(+)
 create mode 100644 drivers/cpufreq/bmips-cpufreq.c

diff --git a/drivers/cpufreq/Kconfig b/drivers/cpufreq/Kconfig
index d8b164a..f21fe81 100644
--- a/drivers/cpufreq/Kconfig
+++ b/drivers/cpufreq/Kconfig
@@ -271,6 +271,16 @@ config IA64_ACPI_CPUFREQ
 endif
 
 if MIPS
+config BMIPS_CPUFREQ
+	tristate "BMIPS CPUfreq Driver"
+	help
+	  This option adds a CPUfreq driver for BMIPS processors with
+	  support for configurable CPU frequency.
+
+	  For now, BMIPS5 chips are supported (such as the Broadcom 7425).
+
+	  If in doubt, say N.
+
 config LOONGSON2_CPUFREQ
 	tristate "Loongson2 CPUFreq Driver"
 	help
diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
index 1e46c39..b7b3fc7 100644
--- a/drivers/cpufreq/Makefile
+++ b/drivers/cpufreq/Makefile
@@ -98,6 +98,7 @@ obj-$(CONFIG_POWERNV_CPUFREQ)		+= powernv-cpufreq.o
 # Other platform drivers
 obj-$(CONFIG_AVR32_AT32AP_CPUFREQ)	+= at32ap-cpufreq.o
 obj-$(CONFIG_BFIN_CPU_FREQ)		+= blackfin-cpufreq.o
+obj-$(CONFIG_BMIPS_CPUFREQ)		+= bmips-cpufreq.o
 obj-$(CONFIG_CRIS_MACH_ARTPEC3)		+= cris-artpec3-cpufreq.o
 obj-$(CONFIG_ETRAXFS)			+= cris-etraxfs-cpufreq.o
 obj-$(CONFIG_IA64_ACPI_CPUFREQ)		+= ia64-acpi-cpufreq.o
diff --git a/drivers/cpufreq/bmips-cpufreq.c b/drivers/cpufreq/bmips-cpufreq.c
new file mode 100644
index 0000000..c69f382
--- /dev/null
+++ b/drivers/cpufreq/bmips-cpufreq.c
@@ -0,0 +1,205 @@
+/*
+ * CPU frequency scaling for Broadcom BMIPS SoCs
+ *
+ * Copyright (c) 2017 Broadcom
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/cpufreq.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/slab.h>
+
+/* for mips_hpt_frequency */
+#include <asm/time.h>
+
+#define BMIPS_CPUFREQ_PREFIX	"bmips"
+#define BMIPS_CPUFREQ_NAME	BMIPS_CPUFREQ_PREFIX "-cpufreq"
+
+#define TRANSITION_LATENCY	(25 * 1000)	/* 25 us */
+
+#define BMIPS5_CLK_DIV_SET_SHIFT	0x7
+#define BMIPS5_CLK_DIV_SHIFT		0x4
+#define BMIPS5_CLK_DIV_MASK		0xf
+
+enum bmips_type {
+	BMIPS5000,
+	BMIPS5200,
+};
+
+struct cpufreq_compat {
+	const char *compatible;
+	unsigned int bmips_type;
+	unsigned int clk_mult;
+	unsigned int max_freqs;
+};
+
+#define BMIPS(c, t, m, f) { \
+	.compatible = c, \
+	.bmips_type = (t), \
+	.clk_mult = (m), \
+	.max_freqs = (f), \
+}
+
+static struct cpufreq_compat bmips_cpufreq_compat[] = {
+	BMIPS("brcm,bmips5000", BMIPS5000, 8, 4),
+	BMIPS("brcm,bmips5200", BMIPS5200, 8, 4),
+	{ }
+};
+
+static int htp_freq_to_cpu_freq(unsigned int clk_mult)
+{
+	return mips_hpt_frequency * clk_mult / 1000;
+}
+
+static struct cpufreq_frequency_table *
+bmips_cpufreq_get_freq_table(const struct cpufreq_policy *policy)
+{
+	struct cpufreq_frequency_table *table;
+	struct cpufreq_compat *cc;
+	unsigned long cpu_freq;
+	int i;
+
+	cc = policy->driver_data;
+	cpu_freq = htp_freq_to_cpu_freq(cc->clk_mult);
+
+	table = kzalloc((cc->max_freqs + 1) * sizeof(*table), GFP_KERNEL);
+	if (!table)
+		return ERR_PTR(-ENOMEM);
+
+	for (i = 0; i < cc->max_freqs; i++) {
+		table[i].frequency = cpu_freq / (1 << i);
+		table[i].driver_data = i;
+	}
+	table[i].frequency = CPUFREQ_TABLE_END;
+
+	return table;
+}
+
+static unsigned int bmips_cpufreq_get(unsigned int cpu)
+{
+	struct cpufreq_policy *policy;
+	struct cpufreq_compat *cc;
+	unsigned long freq, cpu_freq;
+	unsigned int div;
+	uint32_t mode;
+
+	policy = cpufreq_cpu_get(cpu);
+	cc = policy->driver_data;
+
+	switch (cc->bmips_type) {
+	case BMIPS5200:
+	case BMIPS5000:
+		mode = read_c0_brcm_mode();
+		div = ((mode >> BMIPS5_CLK_DIV_SHIFT) & BMIPS5_CLK_DIV_MASK);
+		break;
+	default:
+		div = 0;
+	}
+
+	cpu_freq = htp_freq_to_cpu_freq(cc->clk_mult);
+	freq = cpu_freq / (1 << div);
+
+	return freq;
+}
+
+static int bmips_cpufreq_target_index(struct cpufreq_policy *policy,
+				      unsigned int index)
+{
+	struct cpufreq_compat *cc;
+	unsigned int div;
+
+	cc = policy->driver_data;
+	div = policy->freq_table[index].driver_data;
+
+	switch (cc->bmips_type) {
+	case BMIPS5200:
+	case BMIPS5000:
+		change_c0_brcm_mode(BMIPS5_CLK_DIV_MASK << BMIPS5_CLK_DIV_SHIFT,
+				    (1 << BMIPS5_CLK_DIV_SET_SHIFT) |
+				    (div << BMIPS5_CLK_DIV_SHIFT));
+		break;
+	default:
+		return -ENOTSUPP;
+	}
+
+	return 0;
+}
+
+static int bmips_cpufreq_exit(struct cpufreq_policy *policy)
+{
+	kfree(policy->freq_table);
+	policy->freq_table = NULL;
+
+	return 0;
+}
+
+static int bmips_cpufreq_init(struct cpufreq_policy *policy)
+{
+	struct cpufreq_frequency_table *freq_table;
+	int ret;
+
+	/* Store the compatibility data with the policy. */
+	policy->driver_data = cpufreq_get_driver_data();
+
+	freq_table = bmips_cpufreq_get_freq_table(policy);
+	if (IS_ERR(freq_table)) {
+		ret = PTR_ERR(freq_table);
+		pr_err("%s: couldn't determine frequency table (%d).\n",
+			BMIPS_CPUFREQ_NAME, ret);
+		return ret;
+	}
+
+	ret = cpufreq_generic_init(policy, freq_table, TRANSITION_LATENCY);
+	if (ret)
+		bmips_cpufreq_exit(policy);
+	else
+		pr_info("%s: registered\n", BMIPS_CPUFREQ_NAME);
+
+	return ret;
+}
+
+static struct cpufreq_driver bmips_cpufreq_driver = {
+	.flags		= CPUFREQ_NEED_INITIAL_FREQ_CHECK,
+	.verify		= cpufreq_generic_frequency_table_verify,
+	.target_index	= bmips_cpufreq_target_index,
+	.get		= bmips_cpufreq_get,
+	.init		= bmips_cpufreq_init,
+	.exit		= bmips_cpufreq_exit,
+	.attr		= cpufreq_generic_attr,
+	.name		= BMIPS_CPUFREQ_PREFIX,
+};
+
+static int __init bmips_cpufreq_probe(void)
+{
+	struct cpufreq_compat *cc;
+	struct device_node *np;
+
+	for (cc = bmips_cpufreq_compat; cc->compatible; cc++) {
+		np = of_find_compatible_node(NULL, "cpu", cc->compatible);
+		if (np) {
+			of_node_put(np);
+			bmips_cpufreq_driver.driver_data = cc;
+			break;
+		}
+	}
+
+	/* We hit the guard element of the array. No compatible CPU found. */
+	if (!cc->compatible)
+		return -ENODEV;
+
+	return cpufreq_register_driver(&bmips_cpufreq_driver);
+}
+device_initcall(bmips_cpufreq_probe);
+
+MODULE_AUTHOR("Markus Mayer <mmayer@broadcom.com>");
+MODULE_DESCRIPTION("CPUfreq driver for Broadcom BMIPS SoCs");
+MODULE_LICENSE("GPL");
-- 
2.7.4

[PATCH 3/3] MIPS: BMIPS: enable CPUfreq

[Markus Mayer]

From: Markus Mayer <mmayer@broadcom.com>

Enable all applicable CPUfreq options.

Signed-off-by: Markus Mayer <mmayer@broadcom.com>
---
 arch/mips/configs/bmips_stb_defconfig | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/arch/mips/configs/bmips_stb_defconfig b/arch/mips/configs/bmips_stb_defconfig
index 4eb5d6e..6fda604 100644
--- a/arch/mips/configs/bmips_stb_defconfig
+++ b/arch/mips/configs/bmips_stb_defconfig
@@ -26,6 +26,16 @@ CONFIG_INET=y
 # CONFIG_INET_XFRM_MODE_BEET is not set
 # CONFIG_INET_LRO is not set
 # CONFIG_INET_DIAG is not set
+CONFIG_CPU_FREQ=y
+CONFIG_CPU_FREQ_STAT=y
+CONFIG_CPU_FREQ_STAT_DETAILS=y
+CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE=y
+CONFIG_CPU_FREQ_GOV_PERFORMANCE=y
+CONFIG_CPU_FREQ_GOV_ONDEMAND=y
+CONFIG_CPU_FREQ_GOV_POWERSAVE=y
+CONFIG_CPU_FREQ_GOV_USERSPACE=y
+CONFIG_CPU_FREQ_GOV_CONSERVATIVE=y
+CONFIG_BMIPS_CPUFREQ=y
 CONFIG_CFG80211=y
 CONFIG_NL80211_TESTMODE=y
 CONFIG_MAC80211=y
-- 
2.7.4

Re: [PATCH 2/3] cpufreq: bmips-cpufreq: CPUfreq driver for Broadcom's BMIPS SoCs

[Viresh Kumar]

You must be a cpufreq driver expert by now. What's the count? Is this the 3rd
one you have written ? :)

On 01-02-17, 17:06, Markus Mayer wrote:
> diff --git a/drivers/cpufreq/bmips-cpufreq.c b/drivers/cpufreq/bmips-cpufreq.c
> +static struct cpufreq_frequency_table *
> +bmips_cpufreq_get_freq_table(const struct cpufreq_policy *policy)

Maybe call it bmips_cpufreq_create_freq_table() as that's what you are doing.
But its all up to you only.

> +{
> +	struct cpufreq_frequency_table *table;
> +	struct cpufreq_compat *cc;
> +	unsigned long cpu_freq;
> +	int i;
> +
> +	cc = policy->driver_data;
> +	cpu_freq = htp_freq_to_cpu_freq(cc->clk_mult);
> +
> +	table = kzalloc((cc->max_freqs + 1) * sizeof(*table), GFP_KERNEL);

Maybe kmalloc as you are updating all the entries.

> +	if (!table)
> +		return ERR_PTR(-ENOMEM);
> +
> +	for (i = 0; i < cc->max_freqs; i++) {
> +		table[i].frequency = cpu_freq / (1 << i);
> +		table[i].driver_data = i;
> +	}
> +	table[i].frequency = CPUFREQ_TABLE_END;
> +
> +	return table;
> +}
> +
> +static unsigned int bmips_cpufreq_get(unsigned int cpu)
> +{
> +	struct cpufreq_policy *policy;
> +	struct cpufreq_compat *cc;
> +	unsigned long freq, cpu_freq;
> +	unsigned int div;
> +	uint32_t mode;
> +
> +	policy = cpufreq_cpu_get(cpu);

You need to do a corresponding cpufreq_cpu_put().

> +	cc = policy->driver_data;
> +
> +	switch (cc->bmips_type) {
> +	case BMIPS5200:
> +	case BMIPS5000:
> +		mode = read_c0_brcm_mode();
> +		div = ((mode >> BMIPS5_CLK_DIV_SHIFT) & BMIPS5_CLK_DIV_MASK);
> +		break;
> +	default:
> +		div = 0;
> +	}
> +
> +	cpu_freq = htp_freq_to_cpu_freq(cc->clk_mult);
> +	freq = cpu_freq / (1 << div);
> +
> +	return freq;
> +}
> +
> +static int bmips_cpufreq_target_index(struct cpufreq_policy *policy,
> +				      unsigned int index)
> +{
> +	struct cpufreq_compat *cc;
> +	unsigned int div;
> +
> +	cc = policy->driver_data;
> +	div = policy->freq_table[index].driver_data;
> +
> +	switch (cc->bmips_type) {
> +	case BMIPS5200:
> +	case BMIPS5000:
> +		change_c0_brcm_mode(BMIPS5_CLK_DIV_MASK << BMIPS5_CLK_DIV_SHIFT,
> +				    (1 << BMIPS5_CLK_DIV_SET_SHIFT) |
> +				    (div << BMIPS5_CLK_DIV_SHIFT));
> +		break;
> +	default:
> +		return -ENOTSUPP;
> +	}
> +
> +	return 0;
> +}
> +
> +static int bmips_cpufreq_exit(struct cpufreq_policy *policy)
> +{
> +	kfree(policy->freq_table);
> +	policy->freq_table = NULL;

No need to set it to NULL.

> +
> +	return 0;
> +}
> +
> +static int bmips_cpufreq_init(struct cpufreq_policy *policy)
> +{
> +	struct cpufreq_frequency_table *freq_table;
> +	int ret;
> +
> +	/* Store the compatibility data with the policy. */
> +	policy->driver_data = cpufreq_get_driver_data();

Hmm, I wouldn't mind keeping a global variable for this. This driver will be
probed only once and so we can simplify the code a bit. Up to you.

> +
> +	freq_table = bmips_cpufreq_get_freq_table(policy);
> +	if (IS_ERR(freq_table)) {
> +		ret = PTR_ERR(freq_table);
> +		pr_err("%s: couldn't determine frequency table (%d).\n",
> +			BMIPS_CPUFREQ_NAME, ret);
> +		return ret;
> +	}
> +
> +	ret = cpufreq_generic_init(policy, freq_table, TRANSITION_LATENCY);
> +	if (ret)
> +		bmips_cpufreq_exit(policy);
> +	else
> +		pr_info("%s: registered\n", BMIPS_CPUFREQ_NAME);
> +
> +	return ret;
> +}
> +
> +static struct cpufreq_driver bmips_cpufreq_driver = {
> +	.flags		= CPUFREQ_NEED_INITIAL_FREQ_CHECK,
> +	.verify		= cpufreq_generic_frequency_table_verify,
> +	.target_index	= bmips_cpufreq_target_index,
> +	.get		= bmips_cpufreq_get,
> +	.init		= bmips_cpufreq_init,
> +	.exit		= bmips_cpufreq_exit,
> +	.attr		= cpufreq_generic_attr,
> +	.name		= BMIPS_CPUFREQ_PREFIX,
> +};
> +
> +static int __init bmips_cpufreq_probe(void)
> +{
> +	struct cpufreq_compat *cc;
> +	struct device_node *np;
> +
> +	for (cc = bmips_cpufreq_compat; cc->compatible; cc++) {
> +		np = of_find_compatible_node(NULL, "cpu", cc->compatible);
> +		if (np) {
> +			of_node_put(np);
> +			bmips_cpufreq_driver.driver_data = cc;
> +			break;
> +		}
> +	}
> +
> +	/* We hit the guard element of the array. No compatible CPU found. */
> +	if (!cc->compatible)
> +		return -ENODEV;
> +
> +	return cpufreq_register_driver(&bmips_cpufreq_driver);
> +}
> +device_initcall(bmips_cpufreq_probe);
> +
> +MODULE_AUTHOR("Markus Mayer <mmayer@broadcom.com>");
> +MODULE_DESCRIPTION("CPUfreq driver for Broadcom BMIPS SoCs");
> +MODULE_LICENSE("GPL");
> -- 
> 2.7.4

-- 
viresh

Re: [PATCH 3/3] MIPS: BMIPS: enable CPUfreq

[Viresh Kumar]

On 01-02-17, 17:06, Markus Mayer wrote:
> From: Markus Mayer <mmayer@broadcom.com>
> 
> Enable all applicable CPUfreq options.
> 
> Signed-off-by: Markus Mayer <mmayer@broadcom.com>
> ---
>  arch/mips/configs/bmips_stb_defconfig | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/arch/mips/configs/bmips_stb_defconfig b/arch/mips/configs/bmips_stb_defconfig
> index 4eb5d6e..6fda604 100644
> --- a/arch/mips/configs/bmips_stb_defconfig
> +++ b/arch/mips/configs/bmips_stb_defconfig
> @@ -26,6 +26,16 @@ CONFIG_INET=y
>  # CONFIG_INET_XFRM_MODE_BEET is not set
>  # CONFIG_INET_LRO is not set
>  # CONFIG_INET_DIAG is not set
> +CONFIG_CPU_FREQ=y
> +CONFIG_CPU_FREQ_STAT=y
> +CONFIG_CPU_FREQ_STAT_DETAILS=y
> +CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE=y
> +CONFIG_CPU_FREQ_GOV_PERFORMANCE=y
> +CONFIG_CPU_FREQ_GOV_ONDEMAND=y
> +CONFIG_CPU_FREQ_GOV_POWERSAVE=y
> +CONFIG_CPU_FREQ_GOV_USERSPACE=y
> +CONFIG_CPU_FREQ_GOV_CONSERVATIVE=y
> +CONFIG_BMIPS_CPUFREQ=y
>  CONFIG_CFG80211=y
>  CONFIG_NL80211_TESTMODE=y
>  CONFIG_MAC80211=y

Rebase your stuff over pm/linux-next and you will see some changes here. Also
schedutil is the new governor in town, you must give it a try.

-- 
viresh

Re: [PATCH 3/3] MIPS: BMIPS: enable CPUfreq

[Markus Mayer]

On 2 February 2017 at 20:29, Viresh Kumar <viresh.kumar@linaro.org> wrote:
> On 01-02-17, 17:06, Markus Mayer wrote:
>> From: Markus Mayer <mmayer@broadcom.com>
>>
>> Enable all applicable CPUfreq options.
>>
>> Signed-off-by: Markus Mayer <mmayer@broadcom.com>
>> ---
>>  arch/mips/configs/bmips_stb_defconfig | 10 ++++++++++
>>  1 file changed, 10 insertions(+)
>>
>> diff --git a/arch/mips/configs/bmips_stb_defconfig b/arch/mips/configs/bmips_stb_defconfig
>> index 4eb5d6e..6fda604 100644
>> --- a/arch/mips/configs/bmips_stb_defconfig
>> +++ b/arch/mips/configs/bmips_stb_defconfig
>> @@ -26,6 +26,16 @@ CONFIG_INET=y
>>  # CONFIG_INET_XFRM_MODE_BEET is not set
>>  # CONFIG_INET_LRO is not set
>>  # CONFIG_INET_DIAG is not set
>> +CONFIG_CPU_FREQ=y
>> +CONFIG_CPU_FREQ_STAT=y
>> +CONFIG_CPU_FREQ_STAT_DETAILS=y
>> +CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE=y
>> +CONFIG_CPU_FREQ_GOV_PERFORMANCE=y
>> +CONFIG_CPU_FREQ_GOV_ONDEMAND=y
>> +CONFIG_CPU_FREQ_GOV_POWERSAVE=y
>> +CONFIG_CPU_FREQ_GOV_USERSPACE=y
>> +CONFIG_CPU_FREQ_GOV_CONSERVATIVE=y
>> +CONFIG_BMIPS_CPUFREQ=y
>>  CONFIG_CFG80211=y
>>  CONFIG_NL80211_TESTMODE=y
>>  CONFIG_MAC80211=y
>
> Rebase your stuff over pm/linux-next and you will see some changes here. Also
> schedutil is the new governor in town, you must give it a try.

I'll definitely turn on SCHEDUTIL. As for the changes in next, I don't
see any conflicts. My series applied fine on top of linux-next from
https://git.kernel.org/cgit/linux/kernel/git/rafael/linux-pm.git/. Did
I use the wrong tree?

$ git log

commit f81d425292d7d14d45eedc16b9f59066e6640500
Author: Markus Mayer <mmayer@broadcom.com>
Date:   Wed Feb 1 16:45:06 2017 -0800

    MIPS: BMIPS: enable CPUfreq

    Enable all applicable CPUfreq options.

    Signed-off-by: Markus Mayer <mmayer@broadcom.com>

commit 9b71c19f3d9af3867f8ec144305b7f23bfaa42f3
Author: Markus Mayer <mmayer@broadcom.com>
Date:   Wed Feb 1 16:19:01 2017 -0800

    cpufreq: bmips-cpufreq: CPUfreq driver for Broadcom's BMIPS SoCs

    Add the MIPS CPUfreq driver. This driver currently supports CPUfreq on
    BMIPS5xxx-based SoCs.

    Signed-off-by: Markus Mayer <mmayer@broadcom.com>

commit 3a2894802066c8a24da6890bcc2c0b7fae1ccb40
Author: Markus Mayer <mmayer@broadcom.com>
Date:   Wed Feb 1 16:16:55 2017 -0800

    BMIPS: Enable prerequisites for CPUfreq in MIPS Kconfig.

    Turn on CPU_SUPPORTS_CPUFREQ and MIPS_EXTERNAL_TIMER for BMIPS.

    Signed-off-by: Markus Mayer <mmayer@broadcom.com>

commit fd4c9e3a71b4c967731c99525a2e94085a776638
Merge: ba358f6 a9306a6
Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Date:   Sat Feb 4 00:45:12 2017 +0100

    Merge branch 'pm-core-fixes' into linux-next

    * pm-core-fixes:
      PM / runtime: Avoid false-positive warnings from might_sleep_if()

...

Thanks,
-Markus

> --
> viresh

Re: [PATCH 3/3] MIPS: BMIPS: enable CPUfreq

[Viresh Kumar]

On 03-02-17, 17:00, Markus Mayer wrote:
> On 2 February 2017 at 20:29, Viresh Kumar <viresh.kumar@linaro.org> wrote:
> > On 01-02-17, 17:06, Markus Mayer wrote:
> >> From: Markus Mayer <mmayer@broadcom.com>
> >>
> >> Enable all applicable CPUfreq options.
> >>
> >> Signed-off-by: Markus Mayer <mmayer@broadcom.com>
> >> ---
> >>  arch/mips/configs/bmips_stb_defconfig | 10 ++++++++++
> >>  1 file changed, 10 insertions(+)
> >>
> >> diff --git a/arch/mips/configs/bmips_stb_defconfig b/arch/mips/configs/bmips_stb_defconfig
> >> index 4eb5d6e..6fda604 100644
> >> --- a/arch/mips/configs/bmips_stb_defconfig
> >> +++ b/arch/mips/configs/bmips_stb_defconfig
> >> @@ -26,6 +26,16 @@ CONFIG_INET=y
> >>  # CONFIG_INET_XFRM_MODE_BEET is not set
> >>  # CONFIG_INET_LRO is not set
> >>  # CONFIG_INET_DIAG is not set
> >> +CONFIG_CPU_FREQ=y
> >> +CONFIG_CPU_FREQ_STAT=y
> >> +CONFIG_CPU_FREQ_STAT_DETAILS=y
> >> +CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE=y
> >> +CONFIG_CPU_FREQ_GOV_PERFORMANCE=y
> >> +CONFIG_CPU_FREQ_GOV_ONDEMAND=y
> >> +CONFIG_CPU_FREQ_GOV_POWERSAVE=y
> >> +CONFIG_CPU_FREQ_GOV_USERSPACE=y
> >> +CONFIG_CPU_FREQ_GOV_CONSERVATIVE=y
> >> +CONFIG_BMIPS_CPUFREQ=y
> >>  CONFIG_CFG80211=y
> >>  CONFIG_NL80211_TESTMODE=y
> >>  CONFIG_MAC80211=y
> >
> > Rebase your stuff over pm/linux-next and you will see some changes here. Also
> > schedutil is the new governor in town, you must give it a try.
> 
> I'll definitely turn on SCHEDUTIL. As for the changes in next, I don't
> see any conflicts. My series applied fine on top of linux-next from
> https://git.kernel.org/cgit/linux/kernel/git/rafael/linux-pm.git/. Did
> I use the wrong tree?

No, but you didn't follow the right process. You should use 'make
savedefconfig' to update the defconfig.

The symbol CONFIG_CPU_FREQ_STAT_DETAILS is removed from the kernel
now.

-- 
viresh

Re: [PATCH 3/3] MIPS: BMIPS: enable CPUfreq

[Markus Mayer]

On 5 February 2017 at 19:35, Viresh Kumar <viresh.kumar@linaro.org> wrote:
>
> On 03-02-17, 17:00, Markus Mayer wrote:
> > On 2 February 2017 at 20:29, Viresh Kumar <viresh.kumar@linaro.org> wrote:
> > > On 01-02-17, 17:06, Markus Mayer wrote:
> > >> From: Markus Mayer <mmayer@broadcom.com>
> > >>
> > >> Enable all applicable CPUfreq options.
> > >>
> > >> Signed-off-by: Markus Mayer <mmayer@broadcom.com>
> > >> ---
> > >>  arch/mips/configs/bmips_stb_defconfig | 10 ++++++++++
> > >>  1 file changed, 10 insertions(+)
> > >>
> > >> diff --git a/arch/mips/configs/bmips_stb_defconfig b/arch/mips/configs/bmips_stb_defconfig
> > >> index 4eb5d6e..6fda604 100644
> > >> --- a/arch/mips/configs/bmips_stb_defconfig
> > >> +++ b/arch/mips/configs/bmips_stb_defconfig
> > >> @@ -26,6 +26,16 @@ CONFIG_INET=y
> > >>  # CONFIG_INET_XFRM_MODE_BEET is not set
> > >>  # CONFIG_INET_LRO is not set
> > >>  # CONFIG_INET_DIAG is not set
> > >> +CONFIG_CPU_FREQ=y
> > >> +CONFIG_CPU_FREQ_STAT=y
> > >> +CONFIG_CPU_FREQ_STAT_DETAILS=y
> > >> +CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE=y
> > >> +CONFIG_CPU_FREQ_GOV_PERFORMANCE=y
> > >> +CONFIG_CPU_FREQ_GOV_ONDEMAND=y
> > >> +CONFIG_CPU_FREQ_GOV_POWERSAVE=y
> > >> +CONFIG_CPU_FREQ_GOV_USERSPACE=y
> > >> +CONFIG_CPU_FREQ_GOV_CONSERVATIVE=y
> > >> +CONFIG_BMIPS_CPUFREQ=y
> > >>  CONFIG_CFG80211=y
> > >>  CONFIG_NL80211_TESTMODE=y
> > >>  CONFIG_MAC80211=y
> > >
> > > Rebase your stuff over pm/linux-next and you will see some changes here. Also
> > > schedutil is the new governor in town, you must give it a try.
> >
> > I'll definitely turn on SCHEDUTIL. As for the changes in next, I don't
> > see any conflicts. My series applied fine on top of linux-next from
> > https://git.kernel.org/cgit/linux/kernel/git/rafael/linux-pm.git/. Did
> > I use the wrong tree?
>
> No, but you didn't follow the right process. You should use 'make
> savedefconfig' to update the defconfig.
>
> The symbol CONFIG_CPU_FREQ_STAT_DETAILS is removed from the kernel
> now.

Okay. Got it. Will do.

-Markus

Re: [PATCH 2/3] cpufreq: bmips-cpufreq: CPUfreq driver for Broadcom's BMIPS SoCs

[Markus Mayer]

On 2 February 2017 at 20:28, Viresh Kumar <viresh.kumar@linaro.org> wrote:
> You must be a cpufreq driver expert by now. What's the count? Is this the 3rd
> one you have written ? :)

Indeed. This is #3. We should be done now, though. We have ARM, legacy
ARM and BMIPS covered. :-)

> On 01-02-17, 17:06, Markus Mayer wrote:
>> diff --git a/drivers/cpufreq/bmips-cpufreq.c b/drivers/cpufreq/bmips-cpufreq.c
>> +static struct cpufreq_frequency_table *
>> +bmips_cpufreq_get_freq_table(const struct cpufreq_policy *policy)
>
> Maybe call it bmips_cpufreq_create_freq_table() as that's what you are doing.
> But its all up to you only.

I was about to change the name, but then realized that the other two
drivers use *get_freq_table(), too. So, I'd prefer to keep the name as
is, so we don't get naming oddities between various Broadcom cpufreq
drivers.

>> +{
>> +     struct cpufreq_frequency_table *table;
>> +     struct cpufreq_compat *cc;
>> +     unsigned long cpu_freq;
>> +     int i;
>> +
>> +     cc = policy->driver_data;
>> +     cpu_freq = htp_freq_to_cpu_freq(cc->clk_mult);
>> +
>> +     table = kzalloc((cc->max_freqs + 1) * sizeof(*table), GFP_KERNEL);
>
> Maybe kmalloc as you are updating all the entries.

Done.

>> +     if (!table)
>> +             return ERR_PTR(-ENOMEM);
>> +
>> +     for (i = 0; i < cc->max_freqs; i++) {
>> +             table[i].frequency = cpu_freq / (1 << i);
>> +             table[i].driver_data = i;
>> +     }
>> +     table[i].frequency = CPUFREQ_TABLE_END;
>> +
>> +     return table;
>> +}
>> +
>> +static unsigned int bmips_cpufreq_get(unsigned int cpu)
>> +{
>> +     struct cpufreq_policy *policy;
>> +     struct cpufreq_compat *cc;
>> +     unsigned long freq, cpu_freq;
>> +     unsigned int div;
>> +     uint32_t mode;
>> +
>> +     policy = cpufreq_cpu_get(cpu);
>
> You need to do a corresponding cpufreq_cpu_put().

Actually, I don't need the policy at all anymore. I converted to a
global variable (as per suggestion below), which means no more policy
in this function. So, rather than adding cpufreq_cpu_put(), I removed
cpufreq_cpu_get().

>> +     cc = policy->driver_data;
>> +
>> +     switch (cc->bmips_type) {
>> +     case BMIPS5200:
>> +     case BMIPS5000:
>> +             mode = read_c0_brcm_mode();
>> +             div = ((mode >> BMIPS5_CLK_DIV_SHIFT) & BMIPS5_CLK_DIV_MASK);
>> +             break;
>> +     default:
>> +             div = 0;
>> +     }
>> +
>> +     cpu_freq = htp_freq_to_cpu_freq(cc->clk_mult);
>> +     freq = cpu_freq / (1 << div);
>> +
>> +     return freq;
>> +}
>> +
>> +static int bmips_cpufreq_target_index(struct cpufreq_policy *policy,
>> +                                   unsigned int index)
>> +{
>> +     struct cpufreq_compat *cc;
>> +     unsigned int div;
>> +
>> +     cc = policy->driver_data;
>> +     div = policy->freq_table[index].driver_data;
>> +
>> +     switch (cc->bmips_type) {
>> +     case BMIPS5200:
>> +     case BMIPS5000:
>> +             change_c0_brcm_mode(BMIPS5_CLK_DIV_MASK << BMIPS5_CLK_DIV_SHIFT,
>> +                                 (1 << BMIPS5_CLK_DIV_SET_SHIFT) |
>> +                                 (div << BMIPS5_CLK_DIV_SHIFT));
>> +             break;
>> +     default:
>> +             return -ENOTSUPP;
>> +     }
>> +
>> +     return 0;
>> +}
>> +
>> +static int bmips_cpufreq_exit(struct cpufreq_policy *policy)
>> +{
>> +     kfree(policy->freq_table);
>> +     policy->freq_table = NULL;
>
> No need to set it to NULL.

Removed.

>> +
>> +     return 0;
>> +}
>> +
>> +static int bmips_cpufreq_init(struct cpufreq_policy *policy)
>> +{
>> +     struct cpufreq_frequency_table *freq_table;
>> +     int ret;
>> +
>> +     /* Store the compatibility data with the policy. */
>> +     policy->driver_data = cpufreq_get_driver_data();
>
> Hmm, I wouldn't mind keeping a global variable for this. This driver will be
> probed only once and so we can simplify the code a bit. Up to you.

Done. Got rid of 10 lines of code overall.

>> +
>> +     freq_table = bmips_cpufreq_get_freq_table(policy);
>> +     if (IS_ERR(freq_table)) {
>> +             ret = PTR_ERR(freq_table);
>> +             pr_err("%s: couldn't determine frequency table (%d).\n",
>> +                     BMIPS_CPUFREQ_NAME, ret);
>> +             return ret;
>> +     }
>> +
>> +     ret = cpufreq_generic_init(policy, freq_table, TRANSITION_LATENCY);
>> +     if (ret)
>> +             bmips_cpufreq_exit(policy);
>> +     else
>> +             pr_info("%s: registered\n", BMIPS_CPUFREQ_NAME);
>> +
>> +     return ret;
>> +}
>> +
>> +static struct cpufreq_driver bmips_cpufreq_driver = {
>> +     .flags          = CPUFREQ_NEED_INITIAL_FREQ_CHECK,
>> +     .verify         = cpufreq_generic_frequency_table_verify,
>> +     .target_index   = bmips_cpufreq_target_index,
>> +     .get            = bmips_cpufreq_get,
>> +     .init           = bmips_cpufreq_init,
>> +     .exit           = bmips_cpufreq_exit,
>> +     .attr           = cpufreq_generic_attr,
>> +     .name           = BMIPS_CPUFREQ_PREFIX,
>> +};
>> +
>> +static int __init bmips_cpufreq_probe(void)
>> +{
>> +     struct cpufreq_compat *cc;
>> +     struct device_node *np;
>> +
>> +     for (cc = bmips_cpufreq_compat; cc->compatible; cc++) {
>> +             np = of_find_compatible_node(NULL, "cpu", cc->compatible);
>> +             if (np) {
>> +                     of_node_put(np);
>> +                     bmips_cpufreq_driver.driver_data = cc;
>> +                     break;
>> +             }
>> +     }
>> +
>> +     /* We hit the guard element of the array. No compatible CPU found. */
>> +     if (!cc->compatible)
>> +             return -ENODEV;
>> +
>> +     return cpufreq_register_driver(&bmips_cpufreq_driver);
>> +}
>> +device_initcall(bmips_cpufreq_probe);
>> +
>> +MODULE_AUTHOR("Markus Mayer <mmayer@broadcom.com>");
>> +MODULE_DESCRIPTION("CPUfreq driver for Broadcom BMIPS SoCs");
>> +MODULE_LICENSE("GPL");
>> --
>> 2.7.4
>
> --
> viresh