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author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2019-06-26 10:51:27 +0200 |
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committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2019-06-26 10:51:27 +0200 |
commit | fba7402017f95c75281991c58d25f1836c04d9bd (patch) | |
tree | 6bf288a6eb99c7fee3cb59cb5ed8b4fefbbe84f2 /drivers/cpufreq/raspberrypi-cpufreq.c | |
parent | 2d4a79ae34048996906e585375c2e3e699e1e11a (diff) | |
parent | f9020441dbc39133591ff72b420f21f51896afc5 (diff) |
Merge branch 'cpufreq/arm/linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/pm
Pull ARM cpufreq changes for v5.3 from Viresh Kumar:
"This pull request contains:
- Minor fixes for brcmstb driver (Florian).
- New imx-cpufreq driver, its bindings and code around it (Leonard).
- New Raspberry Pi driver (Nicolas).
- Minor fix for s5pv210 driver (Pawel).
- Minor cleanup for armada driver (YueHaibing)."
* 'cpufreq/arm/linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/vireshk/pm:
cpufreq: s5pv210: Don't flood kernel log after cpufreq change
cpufreq: add driver for Raspberry Pi
cpufreq: Switch imx7d to imx-cpufreq-dt for speed grading
cpufreq: imx-cpufreq-dt: Remove global platform match list
cpufreq: brcmstb-avs-cpufreq: Fix types for voltage/frequency
cpufreq: brcmstb-avs-cpufreq: Fix initial command check
cpufreq: armada-37xx: Remove set but not used variable 'freq'
cpufreq: imx-cpufreq-dt: Fix no OPPs available on unfused parts
dt-bindings: imx-cpufreq-dt: Document opp-supported-hw usage
cpufreq: Add imx-cpufreq-dt driver
Diffstat (limited to 'drivers/cpufreq/raspberrypi-cpufreq.c')
-rw-r--r-- | drivers/cpufreq/raspberrypi-cpufreq.c | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/drivers/cpufreq/raspberrypi-cpufreq.c b/drivers/cpufreq/raspberrypi-cpufreq.c new file mode 100644 index 000000000000..2bc7d9734272 --- /dev/null +++ b/drivers/cpufreq/raspberrypi-cpufreq.c @@ -0,0 +1,97 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Raspberry Pi cpufreq driver + * + * Copyright (C) 2019, Nicolas Saenz Julienne <nsaenzjulienne@suse.de> + */ + +#include <linux/clk.h> +#include <linux/cpu.h> +#include <linux/cpufreq.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/pm_opp.h> + +#define RASPBERRYPI_FREQ_INTERVAL 100000000 + +static struct platform_device *cpufreq_dt; + +static int raspberrypi_cpufreq_probe(struct platform_device *pdev) +{ + struct device *cpu_dev; + unsigned long min, max; + unsigned long rate; + struct clk *clk; + int ret; + + cpu_dev = get_cpu_device(0); + if (!cpu_dev) { + pr_err("Cannot get CPU for cpufreq driver\n"); + return -ENODEV; + } + + clk = clk_get(cpu_dev, NULL); + if (IS_ERR(clk)) { + dev_err(cpu_dev, "Cannot get clock for CPU0\n"); + return PTR_ERR(clk); + } + + /* + * The max and min frequencies are configurable in the Raspberry Pi + * firmware, so we query them at runtime. + */ + min = roundup(clk_round_rate(clk, 0), RASPBERRYPI_FREQ_INTERVAL); + max = roundup(clk_round_rate(clk, ULONG_MAX), RASPBERRYPI_FREQ_INTERVAL); + clk_put(clk); + + for (rate = min; rate <= max; rate += RASPBERRYPI_FREQ_INTERVAL) { + ret = dev_pm_opp_add(cpu_dev, rate, 0); + if (ret) + goto remove_opp; + } + + cpufreq_dt = platform_device_register_simple("cpufreq-dt", -1, NULL, 0); + ret = PTR_ERR_OR_ZERO(cpufreq_dt); + if (ret) { + dev_err(cpu_dev, "Failed to create platform device, %d\n", ret); + goto remove_opp; + } + + return 0; + +remove_opp: + dev_pm_opp_remove_all_dynamic(cpu_dev); + + return ret; +} + +static int raspberrypi_cpufreq_remove(struct platform_device *pdev) +{ + struct device *cpu_dev; + + cpu_dev = get_cpu_device(0); + if (cpu_dev) + dev_pm_opp_remove_all_dynamic(cpu_dev); + + platform_device_unregister(cpufreq_dt); + + return 0; +} + +/* + * Since the driver depends on clk-raspberrypi, which may return EPROBE_DEFER, + * all the activity is performed in the probe, which may be defered as well. + */ +static struct platform_driver raspberrypi_cpufreq_driver = { + .driver = { + .name = "raspberrypi-cpufreq", + }, + .probe = raspberrypi_cpufreq_probe, + .remove = raspberrypi_cpufreq_remove, +}; +module_platform_driver(raspberrypi_cpufreq_driver); + +MODULE_AUTHOR("Nicolas Saenz Julienne <nsaenzjulienne@suse.de"); +MODULE_DESCRIPTION("Raspberry Pi cpufreq driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:raspberrypi-cpufreq"); |