From: Stephen Boyd <swboyd@chromium.org>
To: "Rafael J. Wysocki" <rjw@rjwysocki.net>,
Taniya Das <tdas@codeaurora.org>,
Viresh Kumar <viresh.kumar@linaro.org>,
linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org
Cc: Rajendra Nayak <rnayak@codeaurora.org>,
devicetree@vger.kernel.org, robh@kernel.org,
skannan@codeaurora.org, linux-arm-msm@vger.kernel.org,
amit.kucheria@linaro.org, evgreen@google.com,
Taniya Das <tdas@codeaurora.org>
Subject: Re: [PATCH 2/2] cpufreq: qcom-hw: Add support for QCOM cpufreq HW driver
Date: Wed, 17 Oct 2018 16:32:33 -0700 [thread overview]
Message-ID: <153981915373.5275.15971019914218464179@swboyd.mtv.corp.google.com> (raw)
In-Reply-To: <1539257761-23023-3-git-send-email-tdas@codeaurora.org>
Quoting Taniya Das (2018-10-11 04:36:01)
> --- a/drivers/cpufreq/Kconfig.arm
> +++ b/drivers/cpufreq/Kconfig.arm
> @@ -121,6 +121,17 @@ config ARM_QCOM_CPUFREQ_KRYO
>
> If in doubt, say N.
>
> +config ARM_QCOM_CPUFREQ_HW
> + bool "QCOM CPUFreq HW driver"
Is there any reason this can't be a module?
> + depends on ARCH_QCOM || COMPILE_TEST
> + help
> + Support for the CPUFreq HW driver.
> + 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 OS.
> + The driver implements the cpufreq interface for this HW engine.
> + Say Y if you want to support CPUFreq HW.
> +
> config ARM_S3C_CPUFREQ
> bool
> help
> diff --git a/drivers/cpufreq/qcom-cpufreq-hw.c b/drivers/cpufreq/qcom-cpufreq-hw.c
> new file mode 100644
> index 0000000..fe1c264
> --- /dev/null
> +++ b/drivers/cpufreq/qcom-cpufreq-hw.c
> @@ -0,0 +1,354 @@
> +// 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/of_address.h>
> +#include <linux/of_platform.h>
> +
> +#define LUT_MAX_ENTRIES 40U
> +#define CORE_COUNT_VAL(val) (((val) & (GENMASK(18, 16))) >> 16)
> +#define LUT_ROW_SIZE 32
> +#define CLK_HW_DIV 2
> +
> +enum {
> + REG_ENABLE,
> + REG_LUT_TABLE,
> + REG_PERF_STATE,
> +
> + REG_ARRAY_SIZE,
> +};
> +
> +struct cpufreq_qcom {
> + struct cpufreq_frequency_table *table;
> + void __iomem *reg_bases[REG_ARRAY_SIZE];
> + cpumask_t related_cpus;
> + unsigned int max_cores;
> + unsigned long xo_rate;
> + unsigned long cpu_hw_rate;
> +};
> +
> +static const u16 cpufreq_qcom_std_offsets[REG_ARRAY_SIZE] = {
Is this going to change in the future?
> + [REG_ENABLE] = 0x0,
> + [REG_LUT_TABLE] = 0x110,
> + [REG_PERF_STATE] = 0x920,
> +};
> +
> +static struct cpufreq_qcom *qcom_freq_domain_map[NR_CPUS];
> +
> +static int
> +qcom_cpufreq_hw_target_index(struct cpufreq_policy *policy,
> + unsigned int index)
> +{
> + struct cpufreq_qcom *c = policy->driver_data;
> +
> + writel_relaxed(index, c->reg_bases[REG_PERF_STATE]);
Why can't we avoid the indirection here and store the perf_state pointer
in probe? Then we don't have to indirect through a table to perform the
register write.
> +
> + return 0;
> +}
> +
[..]
> +static int qcom_resources_init(struct platform_device *pdev)
> +{
> + struct device_node *cpu_np;
> + struct of_phandle_args args;
> + struct clk *clk;
> + unsigned int cpu;
> + unsigned long xo_rate, cpu_hw_rate;
> + int ret;
> +
> + clk = clk_get(&pdev->dev, "xo");
> + if (IS_ERR(clk))
> + return PTR_ERR(clk);
> +
> + xo_rate = clk_get_rate(clk);
> +
> + clk_put(clk);
> +
> + clk = clk_get(&pdev->dev, "cpu_clk");
Sad that the name is cpu_clk, instead of something like 'backup' or
whatever the name really is in hardware.
next prev parent reply other threads:[~2018-10-17 23:32 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-11 11:35 [PATCH v9 0/2] cpufreq: qcom-hw: Add support for QCOM cpufreq HW driver Taniya Das
2018-10-11 11:36 ` [PATCH 1/2] dt-bindings: cpufreq: Introduce QCOM CPUFREQ Firmware bindings Taniya Das
2018-10-17 19:57 ` Rob Herring
2018-10-17 23:17 ` Stephen Boyd
2018-10-19 21:30 ` Matthias Kaehlcke
2018-10-23 11:53 ` Amit Kucheria
2018-10-25 22:43 ` Matthias Kaehlcke
2018-11-13 0:28 ` Matthias Kaehlcke
2018-10-11 11:36 ` [PATCH 2/2] cpufreq: qcom-hw: Add support for QCOM cpufreq HW driver Taniya Das
2018-10-17 23:32 ` Stephen Boyd [this message]
2018-11-03 3:06 ` Taniya Das
2018-11-04 4:20 ` Stephen Boyd
2018-11-11 12:42 ` Taniya Das
2018-11-16 0:23 ` Matthias Kaehlcke
2018-11-21 0:59 ` Stephen Boyd
2018-11-05 10:38 ` Sudeep Holla
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