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[v4,0/2] cpufreq: qcom-fw: Add support for QCOM cpufreq FW driver

Message ID 1528801355-18719-1-git-send-email-tdas@codeaurora.org
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Series cpufreq: qcom-fw: Add support for QCOM cpufreq FW driver | expand

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Taniya Das June 12, 2018, 11:02 a.m. UTC
[v4]
  * Fixed console messages as per comments.
  * Return error from qcom_resources_init()
    in the cases where failed to get frequency domain.
  * Rename cpu_dev to cpu_np in qcom_resources_init,
    qcom_get_related_cpus(). Also use temp variable freq_np in
    qcom_get_related_cpus().
  * Update qcom_cpufreq_fw_get() to use the policy data to incoporate
    the hotplug use case.
  * Update code to use of fast_switching.
  * Check for !c->max_cores instead of cpumask_empty in
    qcom_get_related_cpus().
  * Update the logic of assigning 'c' to qcom_freq_domain_map[cpu].

 [v3]
  * Remove index check from 'qcom_cpufreq_fw_target_index'.
  * Update the Documentation binding to add the platform specific properties in
    the CPU nodes, node name "qcom,freq-domain".
  * Update return value to '0' from -ENODEV from 'qcom_cpufreq_fw_get'.
  * Update the logic for boost frequency to use local variables instead of
    cpufreq driver data in 'qcom_read_lut'.
  * Update the logic in 'qcom_get_related_cpus' to find the related cpus.
  * Update the reg-names to remove "_base" and also update the binding with the
    description of these registers.
  * Update the logic in 'qcom_resources_init' to address the new device tree
    notation of handling the frequency domain phandles.

 [v2]
 * Fixed the alignment issues in "qcom_cpufreq_fw_target_index" for dev_err and
   also for "qcom_cpu_resources_init".
 * Removed ret = 0 from qcom_get_related_cpus and added to check for
   cpu_mask_empty to return -ENOENT.
 * Fixes qcom_cpu_resources_init function
   * Remove initialization of 'index'
   * Check for valid 'c'
 * Removed initialization of 'prev_cc' from 'qcom_read_lut'.
 * Remove initialization of 'ret' from function qcom_resources_init and add
   return -ENODEV based on 'of_get_available_child_count'.
 * Removed initialization of 'rc' from qcom_cpufreq_fw_driver_probe
 * Removed module_exit as this driver would not be used as module, also updated
   the Kconfig to bool from tristate.
 * Updated the subsystem in device tree bindings.

 [v1]
   * Fixed compilation reported by Amit K.

Taniya Das (2):
  dt-bindings: cpufreq: Introduce QCOM CPUFREQ FW bindings
  cpufreq: qcom-fw: Add support for QCOM cpufreq FW driver

 .../bindings/cpufreq/cpufreq-qcom-fw.txt           | 173 +++++++++++
 drivers/cpufreq/Kconfig.arm                        |   9 +
 drivers/cpufreq/Makefile                           |   1 +
 drivers/cpufreq/qcom-cpufreq-fw.c                  | 336 +++++++++++++++++++++
 4 files changed, 519 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/cpufreq/cpufreq-qcom-fw.txt
 create mode 100644 drivers/cpufreq/qcom-cpufreq-fw.c

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Comments

Amit Kucheria June 15, 2018, 12:02 p.m. UTC | #1
On Tue, Jun 12, 2018 at 2:02 PM, Taniya Das <tdas@codeaurora.org> wrote:
> The CPUfreq FW present in some QCOM chipsets offloads the steps necessary
> for changing the frequency of CPUs. The driver implements the cpufreq
> driver interface for this firmware.
>
> Signed-off-by: Saravana Kannan <skannan@codeaurora.org>
> Signed-off-by: Taniya Das <tdas@codeaurora.org>
> ---
>  drivers/cpufreq/Kconfig.arm       |   9 +
>  drivers/cpufreq/Makefile          |   1 +
>  drivers/cpufreq/qcom-cpufreq-fw.c | 336 ++++++++++++++++++++++++++++++++++++++
>  3 files changed, 346 insertions(+)
>  create mode 100644 drivers/cpufreq/qcom-cpufreq-fw.c
>
> diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
> index 52f5f1a..2683716 100644
> --- a/drivers/cpufreq/Kconfig.arm
> +++ b/drivers/cpufreq/Kconfig.arm
> @@ -312,3 +312,12 @@ config ARM_PXA2xx_CPUFREQ
>           This add the CPUFreq driver support for Intel PXA2xx SOCs.
>
>           If in doubt, say N.
> +
> +config ARM_QCOM_CPUFREQ_FW
> +       bool "QCOM CPUFreq FW driver"
> +       help
> +        Support for the CPUFreq FW driver.
> +        The CPUfreq FW preset in some QCOM chipsets offloads the steps

s/preset/present

> +        necessary for changing the frequency of CPUs. The driver

I'd rephrase this a bit to address Sudeep's comment. Something like:

"Some QCOM chipsets have a HW engine to offload the steps necessary
for changing the frequency of the CPUs. Firmware loaded in this engine
exposes a programming interface to the high-level OS. This driver
exposes a cpufreq abstraction for this HW engine. Say Y ....."

> +        implements the cpufreq driver interface for this firmware.
> +        Say Y if you want to support CPUFreq FW.
> diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
> index fb4a2ec..34691a2 100644
> --- a/drivers/cpufreq/Makefile
> +++ b/drivers/cpufreq/Makefile
> @@ -86,6 +86,7 @@ obj-$(CONFIG_ARM_TEGRA124_CPUFREQ)    += tegra124-cpufreq.o
>  obj-$(CONFIG_ARM_TEGRA186_CPUFREQ)     += tegra186-cpufreq.o
>  obj-$(CONFIG_ARM_TI_CPUFREQ)           += ti-cpufreq.o
>  obj-$(CONFIG_ARM_VEXPRESS_SPC_CPUFREQ) += vexpress-spc-cpufreq.o
> +obj-$(CONFIG_ARM_QCOM_CPUFREQ_FW)      += qcom-cpufreq-fw.o
>

<snip>

> +static const struct of_device_id match_table[] = {
> +       { .compatible = "qcom,cpufreq-fw" },
> +       {}
> +};
> +
> +static struct platform_driver qcom_cpufreq_fw_driver = {
> +       .probe = qcom_cpufreq_fw_driver_probe,
> +       .driver = {
> +               .name = "qcom-cpufreq-fw",
> +               .of_match_table = match_table,
> +               .owner = THIS_MODULE,
> +       },
> +};
> +
> +static int __init qcom_cpufreq_fw_init(void)
> +{
> +       return platform_driver_register(&qcom_cpufreq_fw_driver);
> +}
> +subsys_initcall(qcom_cpufreq_fw_init);
> +
> +MODULE_DESCRIPTION("QCOM CPU Frequency FW");

This can be a bit more descriptive, e.g.

"QCOM firmware-based CPU Frequency  driver"

> +MODULE_LICENSE("GPL v2");
> --
> Qualcomm INDIA, on behalf of Qualcomm Innovation Center, Inc.is a member
> of the Code Aurora Forum, hosted by the  Linux Foundation.
>
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Viresh Kumar June 19, 2018, 9:30 a.m. UTC | #2
On 12-06-18, 16:32, Taniya Das wrote:
> +static int qcom_get_related_cpus(struct device_node *np, struct cpumask *m)
> +{
> +	struct device_node *cpu_np, *freq_np;
> +	int cpu;
> +
> +	for_each_possible_cpu(cpu) {
> +		cpu_np = of_cpu_device_node_get(cpu);
> +		if (!cpu_np)
> +			continue;
> +		freq_np = of_parse_phandle(cpu_np, "qcom,freq-domain", 0);
> +		if (!freq_np)
> +			continue;
> +		if (freq_np == np)
> +			cpumask_set_cpu(cpu, m);
> +	}
> +
> +	return 0;
> +}
> +
> +static int qcom_cpu_resources_init(struct platform_device *pdev,
> +				   struct device_node *np, unsigned int cpu)
> +{
> +	struct cpufreq_qcom *c;
> +	struct resource res;
> +	struct device *dev = &pdev->dev;
> +	void __iomem *en_base;
> +	int index, ret;
> +
> +	c = devm_kzalloc(dev, sizeof(*c), GFP_KERNEL);
> +	if (!c)
> +		return -ENOMEM;
> +
> +	index = of_property_match_string(np, "reg-names", "enable");
> +	if (index < 0)
> +		return index;
> +
> +	if (of_address_to_resource(np, index, &res))
> +		return -ENOMEM;
> +
> +	en_base = devm_ioremap(dev, res.start, resource_size(&res));
> +	if (!en_base) {
> +		dev_err(dev, "Unable to map %s enable-base\n", np->name);
> +		return -ENOMEM;
> +	}
> +
> +	/* FW should be in enabled state to proceed */
> +	if (!(readl_relaxed(en_base) & 0x1)) {
> +		dev_err(dev, "%s firmware not enabled\n", np->name);
> +		return -ENODEV;
> +	}
> +	devm_iounmap(&pdev->dev, en_base);
> +
> +	index = of_property_match_string(np, "reg-names", "perf");
> +	if (index < 0)
> +		return index;
> +
> +	if (of_address_to_resource(np, index, &res))
> +		return -ENOMEM;
> +
> +	c->perf_base = devm_ioremap(dev, res.start, resource_size(&res));
> +	if (!c->perf_base) {
> +		dev_err(dev, "Unable to map %s perf-base\n", np->name);
> +		return -ENOMEM;
> +	}
> +
> +	index = of_property_match_string(np, "reg-names", "lut");
> +	if (index < 0)
> +		return index;
> +
> +	if (of_address_to_resource(np, index, &res))
> +		return -ENOMEM;
> +
> +	c->lut_base = devm_ioremap(dev, res.start, resource_size(&res));
> +	if (!c->lut_base) {
> +		dev_err(dev, "Unable to map %s lut-base\n", np->name);
> +		return -ENOMEM;
> +	}
> +
> +	ret = qcom_get_related_cpus(np, &c->related_cpus);
> +	if (ret) {
> +		dev_err(dev, "%s failed to get related CPUs\n", np->name);
> +		return ret;
> +	}
> +
> +	c->max_cores = cpumask_weight(&c->related_cpus);
> +	if (!c->max_cores)
> +		return -ENOENT;
> +
> +	ret = qcom_read_lut(pdev, c);
> +	if (ret) {
> +		dev_err(dev, "%s failed to read LUT\n", np->name);
> +		return ret;
> +	}
> +
> +	qcom_freq_domain_map[cpu] = c;

This still looks wrong. You have removed the for-each-cpu loop here, so what
will happen now is that you will allocate a different "struct cpufreq_qcom" for
every CPU, even if they are related. Is that what you should be doing ? I think
there should still be a single copy of that structure which must be used by all
related CPUs.

> +
> +	return 0;
> +}
> +
> +static int qcom_resources_init(struct platform_device *pdev)
> +{
> +	struct device_node *np, *cpu_np;
> +	unsigned int cpu;
> +	int ret;
> +
> +	for_each_possible_cpu(cpu) {
> +		cpu_np = of_cpu_device_node_get(cpu);
> +		if (!cpu_np) {
> +			dev_err(&pdev->dev, "Failed to get cpu %d device\n",
> +				cpu);
> +			continue;
> +		}
> +
> +		np = of_parse_phandle(cpu_np, "qcom,freq-domain", 0);
> +		if (!np) {
> +			dev_err(&pdev->dev, "Failed to get freq-domain device\n");
> +			return -EINVAL;
> +		}
> +
> +		of_node_put(cpu_np);
> +
> +		ret = qcom_cpu_resources_init(pdev, np, cpu);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	return 0;
> +}
Matthias Kaehlcke July 11, 2018, 8:37 p.m. UTC | #3
Hi,

On Tue, Jun 12, 2018 at 04:32:35PM +0530, Taniya Das wrote:
> The CPUfreq FW present in some QCOM chipsets offloads the steps necessary
> for changing the frequency of CPUs. The driver implements the cpufreq
> driver interface for this firmware.
> 
> Signed-off-by: Saravana Kannan <skannan@codeaurora.org>
> Signed-off-by: Taniya Das <tdas@codeaurora.org>
> ---
>  drivers/cpufreq/Kconfig.arm       |   9 +
>  drivers/cpufreq/Makefile          |   1 +
>  drivers/cpufreq/qcom-cpufreq-fw.c | 336 ++++++++++++++++++++++++++++++++++++++
>  3 files changed, 346 insertions(+)
>  create mode 100644 drivers/cpufreq/qcom-cpufreq-fw.c
> 
> diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
> index 52f5f1a..2683716 100644
> --- a/drivers/cpufreq/Kconfig.arm
> +++ b/drivers/cpufreq/Kconfig.arm
> @@ -312,3 +312,12 @@ config ARM_PXA2xx_CPUFREQ
>  	  This add the CPUFreq driver support for Intel PXA2xx SOCs.
> 
>  	  If in doubt, say N.
> +
> +config ARM_QCOM_CPUFREQ_FW
> +	bool "QCOM CPUFreq FW driver"
> +	help
> +	 Support for the CPUFreq FW driver.
> +	 The CPUfreq FW preset in some QCOM chipsets offloads the steps
> +	 necessary for changing the frequency of CPUs. The driver
> +	 implements the cpufreq driver interface for this firmware.
> +	 Say Y if you want to support CPUFreq FW.
> diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
> index fb4a2ec..34691a2 100644
> --- a/drivers/cpufreq/Makefile
> +++ b/drivers/cpufreq/Makefile
> @@ -86,6 +86,7 @@ obj-$(CONFIG_ARM_TEGRA124_CPUFREQ)	+= tegra124-cpufreq.o
>  obj-$(CONFIG_ARM_TEGRA186_CPUFREQ)	+= tegra186-cpufreq.o
>  obj-$(CONFIG_ARM_TI_CPUFREQ)		+= ti-cpufreq.o
>  obj-$(CONFIG_ARM_VEXPRESS_SPC_CPUFREQ)	+= vexpress-spc-cpufreq.o
> +obj-$(CONFIG_ARM_QCOM_CPUFREQ_FW)	+= qcom-cpufreq-fw.o
> 
> 
>  ##################################################################################
> diff --git a/drivers/cpufreq/qcom-cpufreq-fw.c b/drivers/cpufreq/qcom-cpufreq-fw.c
> new file mode 100644
> index 0000000..62f4452
> --- /dev/null
> +++ b/drivers/cpufreq/qcom-cpufreq-fw.c
> @@ -0,0 +1,336 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2018, The Linux Foundation. All rights reserved.
> + */
> +
> +#include <linux/cpufreq.h>
> +#include <linux/init.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/of_address.h>
> +#include <linux/of_platform.h>
> +
> +#define INIT_RATE			300000000UL
> +#define XO_RATE				19200000UL
> +#define LUT_MAX_ENTRIES			40U
> +#define CORE_COUNT_VAL(val)		(((val) & (GENMASK(18, 16))) >> 16)
> +#define LUT_ROW_SIZE			32
> +
> +struct cpufreq_qcom {
> +	struct cpufreq_frequency_table *table;
> +	struct device *dev;
> +	void __iomem *perf_base;
> +	void __iomem *lut_base;
> +	cpumask_t related_cpus;
> +	unsigned int max_cores;

Why *max*_cores? This seems to be the number of CPUs in a cluster and
qcom_read_lut() expects the core count read from the LUT to match
exactly.

> +static int qcom_read_lut(struct platform_device *pdev,
> +			 struct cpufreq_qcom *c)
> +{
> +	struct device *dev = &pdev->dev;
> +	u32 data, src, lval, i, core_count, prev_cc, prev_freq, cur_freq;
> +
> +	c->table = devm_kcalloc(dev, LUT_MAX_ENTRIES + 1,
> +				sizeof(*c->table), GFP_KERNEL);
> +	if (!c->table)
> +		return -ENOMEM;
> +
> +	for (i = 0; i < LUT_MAX_ENTRIES; i++) {
> +		data = readl_relaxed(c->lut_base + i * LUT_ROW_SIZE);
> +		src = ((data & GENMASK(31, 30)) >> 30);
> +		lval = (data & GENMASK(7, 0));
> +		core_count = CORE_COUNT_VAL(data);
> +
> +		if (!src)
> +			c->table[i].frequency = INIT_RATE / 1000;
> +		else
> +			c->table[i].frequency = XO_RATE * lval / 1000;

nit: any particular reason to use negative logic here? Why not check
for 'src[ != NULL]', which also seems to be the more common case.

> +static int qcom_get_related_cpus(struct device_node *np, struct cpumask *m)
> +{
> +	struct device_node *cpu_np, *freq_np;
> +	int cpu;
> +
> +	for_each_possible_cpu(cpu) {
> +		cpu_np = of_cpu_device_node_get(cpu);
> +		if (!cpu_np)
> +			continue;
> +		freq_np = of_parse_phandle(cpu_np, "qcom,freq-domain", 0);
> +		if (!freq_np)
> +			continue;
> +		if (freq_np == np)
> +			cpumask_set_cpu(cpu, m);

missing 'of_node_put(cpu_np)'. You might want to do it at the end of
the loop and use a 'goto' above instead of 'continue'.

> +static int qcom_cpu_resources_init(struct platform_device *pdev,
> +				   struct device_node *np, unsigned int cpu)
> +{
> +	struct cpufreq_qcom *c;
> +	struct resource res;
> +	struct device *dev = &pdev->dev;
> +	void __iomem *en_base;
> +	int index, ret;
> +
> +	c = devm_kzalloc(dev, sizeof(*c), GFP_KERNEL);
> +	if (!c)
> +		return -ENOMEM;
> +
> +	index = of_property_match_string(np, "reg-names", "enable");
> +	if (index < 0)
> +		return index;
> +
> +	if (of_address_to_resource(np, index, &res))
> +		return -ENOMEM;
> +
> +	en_base = devm_ioremap(dev, res.start, resource_size(&res));
> +	if (!en_base) {
> +		dev_err(dev, "Unable to map %s enable-base\n", np->name);
> +		return -ENOMEM;
> +	}
> +
> +	/* FW should be in enabled state to proceed */
> +	if (!(readl_relaxed(en_base) & 0x1)) {
> +		dev_err(dev, "%s firmware not enabled\n", np->name);
> +		return -ENODEV;
> +	}
> +	devm_iounmap(&pdev->dev, en_base);
> +
> +	index = of_property_match_string(np, "reg-names", "perf");
> +	if (index < 0)
> +		return index;
> +
> +	if (of_address_to_resource(np, index, &res))
> +		return -ENOMEM;
> +
> +	c->perf_base = devm_ioremap(dev, res.start, resource_size(&res));
> +	if (!c->perf_base) {
> +		dev_err(dev, "Unable to map %s perf-base\n", np->name);
> +		return -ENOMEM;
> +	}
> +
> +	index = of_property_match_string(np, "reg-names", "lut");
> +	if (index < 0)
> +		return index;
> +
> +	if (of_address_to_resource(np, index, &res))
> +		return -ENOMEM;
> +
> +	c->lut_base = devm_ioremap(dev, res.start, resource_size(&res));
> +	if (!c->lut_base) {
> +		dev_err(dev, "Unable to map %s lut-base\n", np->name);
> +		return -ENOMEM;
> +	}

The of_property_match_string() - of_address_to_resource() -
devm_ioremap() pattern is repeated 3x. In case the binding doesn't
change (there is discussion on the DT patch) you might want to move
this to a helper.

> +static int qcom_resources_init(struct platform_device *pdev)
> +{
> +	struct device_node *np, *cpu_np;
> +	unsigned int cpu;
> +	int ret;
> +
> +	for_each_possible_cpu(cpu) {
> +		cpu_np = of_cpu_device_node_get(cpu);
> +		if (!cpu_np) {
> +			dev_err(&pdev->dev, "Failed to get cpu %d device\n",
> +				cpu);
> +			continue;
> +		}
> +
> +		np = of_parse_phandle(cpu_np, "qcom,freq-domain", 0);
> +		if (!np) {
> +			dev_err(&pdev->dev, "Failed to get freq-domain device\n");
			of_node_put(cpu_np);
> +			return -EINVAL;
> +		}
> +
> +		of_node_put(cpu_np);
> +
> +		ret = qcom_cpu_resources_init(pdev, np, cpu);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	return 0;

Cheers

Matthias
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Taniya Das July 12, 2018, 6:06 p.m. UTC | #4
Please help review of the new series[v5] which takes care of the below.

- Remove mapping different register regions of perf/lut/enable,
   instead map the entire HW region.
- Add reg_offset/cpufreq_qcom_std_offsets to be supplied as device data.
- Check of src == 0 during lut read.
- Add of_node_put(cpu_np) in qcom_get_related_cpus
- Update the qcom_cpu_resources_init for register offset data,
   and cleanup the related cpus to keep a single copy of CPUfreq.
- Replace FW with HW, update Kconfig, rename filename qcom-cpufreq-hw.c

On 7/12/2018 2:07 AM, Matthias Kaehlcke wrote:
> Hi,
> 
> On Tue, Jun 12, 2018 at 04:32:35PM +0530, Taniya Das wrote:
>> The CPUfreq FW present in some QCOM chipsets offloads the steps necessary
>> for changing the frequency of CPUs. The driver implements the cpufreq
>> driver interface for this firmware.
>>
>> Signed-off-by: Saravana Kannan <skannan@codeaurora.org>
>> Signed-off-by: Taniya Das <tdas@codeaurora.org>
>> ---
>>   drivers/cpufreq/Kconfig.arm       |   9 +
>>   drivers/cpufreq/Makefile          |   1 +
>>   drivers/cpufreq/qcom-cpufreq-fw.c | 336 ++++++++++++++++++++++++++++++++++++++
>>   3 files changed, 346 insertions(+)
>>   create mode 100644 drivers/cpufreq/qcom-cpufreq-fw.c
>>
>> diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
>> index 52f5f1a..2683716 100644
>> --- a/drivers/cpufreq/Kconfig.arm
>> +++ b/drivers/cpufreq/Kconfig.arm
>> @@ -312,3 +312,12 @@ config ARM_PXA2xx_CPUFREQ
>>   	  This add the CPUFreq driver support for Intel PXA2xx SOCs.
>>
>>   	  If in doubt, say N.
>> +
>> +config ARM_QCOM_CPUFREQ_FW
>> +	bool "QCOM CPUFreq FW driver"
>> +	help
>> +	 Support for the CPUFreq FW driver.
>> +	 The CPUfreq FW preset in some QCOM chipsets offloads the steps
>> +	 necessary for changing the frequency of CPUs. The driver
>> +	 implements the cpufreq driver interface for this firmware.
>> +	 Say Y if you want to support CPUFreq FW.
>> diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
>> index fb4a2ec..34691a2 100644
>> --- a/drivers/cpufreq/Makefile
>> +++ b/drivers/cpufreq/Makefile
>> @@ -86,6 +86,7 @@ obj-$(CONFIG_ARM_TEGRA124_CPUFREQ)	+= tegra124-cpufreq.o
>>   obj-$(CONFIG_ARM_TEGRA186_CPUFREQ)	+= tegra186-cpufreq.o
>>   obj-$(CONFIG_ARM_TI_CPUFREQ)		+= ti-cpufreq.o
>>   obj-$(CONFIG_ARM_VEXPRESS_SPC_CPUFREQ)	+= vexpress-spc-cpufreq.o
>> +obj-$(CONFIG_ARM_QCOM_CPUFREQ_FW)	+= qcom-cpufreq-fw.o
>>
>>
>>   ##################################################################################
>> diff --git a/drivers/cpufreq/qcom-cpufreq-fw.c b/drivers/cpufreq/qcom-cpufreq-fw.c
>> new file mode 100644
>> index 0000000..62f4452
>> --- /dev/null
>> +++ b/drivers/cpufreq/qcom-cpufreq-fw.c
>> @@ -0,0 +1,336 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * Copyright (c) 2018, The Linux Foundation. All rights reserved.
>> + */
>> +
>> +#include <linux/cpufreq.h>
>> +#include <linux/init.h>
>> +#include <linux/kernel.h>
>> +#include <linux/module.h>
>> +#include <linux/of_address.h>
>> +#include <linux/of_platform.h>
>> +
>> +#define INIT_RATE			300000000UL
>> +#define XO_RATE				19200000UL
>> +#define LUT_MAX_ENTRIES			40U
>> +#define CORE_COUNT_VAL(val)		(((val) & (GENMASK(18, 16))) >> 16)
>> +#define LUT_ROW_SIZE			32
>> +
>> +struct cpufreq_qcom {
>> +	struct cpufreq_frequency_table *table;
>> +	struct device *dev;
>> +	void __iomem *perf_base;
>> +	void __iomem *lut_base;
>> +	cpumask_t related_cpus;
>> +	unsigned int max_cores;
> 
> Why *max*_cores? This seems to be the number of CPUs in a cluster and
> qcom_read_lut() expects the core count read from the LUT to match
> exactly.
> 
>> +static int qcom_read_lut(struct platform_device *pdev,
>> +			 struct cpufreq_qcom *c)
>> +{
>> +	struct device *dev = &pdev->dev;
>> +	u32 data, src, lval, i, core_count, prev_cc, prev_freq, cur_freq;
>> +
>> +	c->table = devm_kcalloc(dev, LUT_MAX_ENTRIES + 1,
>> +				sizeof(*c->table), GFP_KERNEL);
>> +	if (!c->table)
>> +		return -ENOMEM;
>> +
>> +	for (i = 0; i < LUT_MAX_ENTRIES; i++) {
>> +		data = readl_relaxed(c->lut_base + i * LUT_ROW_SIZE);
>> +		src = ((data & GENMASK(31, 30)) >> 30);
>> +		lval = (data & GENMASK(7, 0));
>> +		core_count = CORE_COUNT_VAL(data);
>> +
>> +		if (!src)
>> +			c->table[i].frequency = INIT_RATE / 1000;
>> +		else
>> +			c->table[i].frequency = XO_RATE * lval / 1000;
> 
> nit: any particular reason to use negative logic here? Why not check
> for 'src[ != NULL]', which also seems to be the more common case.
> 
>> +static int qcom_get_related_cpus(struct device_node *np, struct cpumask *m)
>> +{
>> +	struct device_node *cpu_np, *freq_np;
>> +	int cpu;
>> +
>> +	for_each_possible_cpu(cpu) {
>> +		cpu_np = of_cpu_device_node_get(cpu);
>> +		if (!cpu_np)
>> +			continue;
>> +		freq_np = of_parse_phandle(cpu_np, "qcom,freq-domain", 0);
>> +		if (!freq_np)
>> +			continue;
>> +		if (freq_np == np)
>> +			cpumask_set_cpu(cpu, m);
> 
> missing 'of_node_put(cpu_np)'. You might want to do it at the end of
> the loop and use a 'goto' above instead of 'continue'.
> 
>> +static int qcom_cpu_resources_init(struct platform_device *pdev,
>> +				   struct device_node *np, unsigned int cpu)
>> +{
>> +	struct cpufreq_qcom *c;
>> +	struct resource res;
>> +	struct device *dev = &pdev->dev;
>> +	void __iomem *en_base;
>> +	int index, ret;
>> +
>> +	c = devm_kzalloc(dev, sizeof(*c), GFP_KERNEL);
>> +	if (!c)
>> +		return -ENOMEM;
>> +
>> +	index = of_property_match_string(np, "reg-names", "enable");
>> +	if (index < 0)
>> +		return index;
>> +
>> +	if (of_address_to_resource(np, index, &res))
>> +		return -ENOMEM;
>> +
>> +	en_base = devm_ioremap(dev, res.start, resource_size(&res));
>> +	if (!en_base) {
>> +		dev_err(dev, "Unable to map %s enable-base\n", np->name);
>> +		return -ENOMEM;
>> +	}
>> +
>> +	/* FW should be in enabled state to proceed */
>> +	if (!(readl_relaxed(en_base) & 0x1)) {
>> +		dev_err(dev, "%s firmware not enabled\n", np->name);
>> +		return -ENODEV;
>> +	}
>> +	devm_iounmap(&pdev->dev, en_base);
>> +
>> +	index = of_property_match_string(np, "reg-names", "perf");
>> +	if (index < 0)
>> +		return index;
>> +
>> +	if (of_address_to_resource(np, index, &res))
>> +		return -ENOMEM;
>> +
>> +	c->perf_base = devm_ioremap(dev, res.start, resource_size(&res));
>> +	if (!c->perf_base) {
>> +		dev_err(dev, "Unable to map %s perf-base\n", np->name);
>> +		return -ENOMEM;
>> +	}
>> +
>> +	index = of_property_match_string(np, "reg-names", "lut");
>> +	if (index < 0)
>> +		return index;
>> +
>> +	if (of_address_to_resource(np, index, &res))
>> +		return -ENOMEM;
>> +
>> +	c->lut_base = devm_ioremap(dev, res.start, resource_size(&res));
>> +	if (!c->lut_base) {
>> +		dev_err(dev, "Unable to map %s lut-base\n", np->name);
>> +		return -ENOMEM;
>> +	}
> 
> The of_property_match_string() - of_address_to_resource() -
> devm_ioremap() pattern is repeated 3x. In case the binding doesn't
> change (there is discussion on the DT patch) you might want to move
> this to a helper.
> 
>> +static int qcom_resources_init(struct platform_device *pdev)
>> +{
>> +	struct device_node *np, *cpu_np;
>> +	unsigned int cpu;
>> +	int ret;
>> +
>> +	for_each_possible_cpu(cpu) {
>> +		cpu_np = of_cpu_device_node_get(cpu);
>> +		if (!cpu_np) {
>> +			dev_err(&pdev->dev, "Failed to get cpu %d device\n",
>> +				cpu);
>> +			continue;
>> +		}
>> +
>> +		np = of_parse_phandle(cpu_np, "qcom,freq-domain", 0);
>> +		if (!np) {
>> +			dev_err(&pdev->dev, "Failed to get freq-domain device\n");
> 			of_node_put(cpu_np);
>> +			return -EINVAL;
>> +		}
>> +
>> +		of_node_put(cpu_np);
>> +
>> +		ret = qcom_cpu_resources_init(pdev, np, cpu);
>> +		if (ret)
>> +			return ret;
>> +	}
>> +
>> +	return 0;
> 
> Cheers
> 
> Matthias
>