cpufreq: Add imx-cpufreq-dt driver

Right now in upstream imx8m cpufreq support just lists a common subset
of OPPs because the higher ones should only be attempted after checking
speed grading in fuses.

Add a small driver which checks speed grading from nvmem cells before
registering cpufreq-dt.

This driver allows unlocking all frequencies for imx8mm and imx8mq and
could be applied to other chips like imx7d

Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
This commit is contained in:
Leonard Crestez 2019-05-13 11:01:38 +00:00 committed by Viresh Kumar
parent a188339ca5
commit 4d28ba1d62
5 changed files with 112 additions and 0 deletions

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@ -92,6 +92,15 @@ config ARM_IMX6Q_CPUFREQ
If in doubt, say N.
config ARM_IMX_CPUFREQ_DT
tristate "Freescale i.MX8M cpufreq support"
depends on ARCH_MXC && CPUFREQ_DT
help
This adds cpufreq driver support for Freescale i.MX8M series SoCs,
based on cpufreq-dt.
If in doubt, say N.
config ARM_KIRKWOOD_CPUFREQ
def_bool MACH_KIRKWOOD
help

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@ -56,6 +56,7 @@ obj-$(CONFIG_ACPI_CPPC_CPUFREQ) += cppc_cpufreq.o
obj-$(CONFIG_ARCH_DAVINCI) += davinci-cpufreq.o
obj-$(CONFIG_ARM_HIGHBANK_CPUFREQ) += highbank-cpufreq.o
obj-$(CONFIG_ARM_IMX6Q_CPUFREQ) += imx6q-cpufreq.o
obj-$(CONFIG_ARM_IMX_CPUFREQ_DT) += imx-cpufreq-dt.o
obj-$(CONFIG_ARM_KIRKWOOD_CPUFREQ) += kirkwood-cpufreq.o
obj-$(CONFIG_ARM_MEDIATEK_CPUFREQ) += mediatek-cpufreq.o
obj-$(CONFIG_MACH_MVEBU_V7) += mvebu-cpufreq.o

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@ -108,6 +108,9 @@ static const struct of_device_id blacklist[] __initconst = {
{ .compatible = "calxeda,highbank", },
{ .compatible = "calxeda,ecx-2000", },
{ .compatible = "fsl,imx8mq", },
{ .compatible = "fsl,imx8mm", },
{ .compatible = "marvell,armadaxp", },
{ .compatible = "mediatek,mt2701", },

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@ -0,0 +1,96 @@
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright 2019 NXP
*/
#include <linux/cpu.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/nvmem-consumer.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pm_opp.h>
#include <linux/slab.h>
#define OCOTP_CFG3_SPEED_GRADE_SHIFT 8
#define OCOTP_CFG3_SPEED_GRADE_MASK (0x3 << 8)
#define OCOTP_CFG3_MKT_SEGMENT_SHIFT 6
#define OCOTP_CFG3_MKT_SEGMENT_MASK (0x3 << 6)
static const struct of_device_id imx_cpufreq_dt_match_list[] = {
{ .compatible = "fsl,imx8mm" },
{ .compatible = "fsl,imx8mq" },
{}
};
/* cpufreq-dt device registered by imx-cpufreq-dt */
static struct platform_device *cpufreq_dt_pdev;
static struct opp_table *cpufreq_opp_table;
static int imx_cpufreq_dt_probe(struct platform_device *pdev)
{
struct device *cpu_dev = get_cpu_device(0);
struct device_node *np;
const struct of_device_id *match;
u32 cell_value, supported_hw[2];
int speed_grade, mkt_segment;
int ret;
np = of_find_node_by_path("/");
match = of_match_node(imx_cpufreq_dt_match_list, np);
of_node_put(np);
if (!match)
return -ENODEV;
ret = nvmem_cell_read_u32(cpu_dev, "speed_grade", &cell_value);
if (ret)
return ret;
speed_grade = (cell_value & OCOTP_CFG3_SPEED_GRADE_MASK) >> OCOTP_CFG3_SPEED_GRADE_SHIFT;
mkt_segment = (cell_value & OCOTP_CFG3_MKT_SEGMENT_MASK) >> OCOTP_CFG3_MKT_SEGMENT_SHIFT;
supported_hw[0] = BIT(speed_grade);
supported_hw[1] = BIT(mkt_segment);
dev_info(&pdev->dev, "cpu speed grade %d mkt segment %d supported-hw %#x %#x\n",
speed_grade, mkt_segment, supported_hw[0], supported_hw[1]);
cpufreq_opp_table = dev_pm_opp_set_supported_hw(cpu_dev, supported_hw, 2);
if (IS_ERR(cpufreq_opp_table)) {
ret = PTR_ERR(cpufreq_opp_table);
dev_err(&pdev->dev, "Failed to set supported opp: %d\n", ret);
return ret;
}
cpufreq_dt_pdev = platform_device_register_data(
&pdev->dev, "cpufreq-dt", -1, NULL, 0);
if (IS_ERR(cpufreq_dt_pdev)) {
dev_pm_opp_put_supported_hw(cpufreq_opp_table);
ret = PTR_ERR(cpufreq_dt_pdev);
dev_err(&pdev->dev, "Failed to register cpufreq-dt: %d\n", ret);
return ret;
}
return 0;
}
static int imx_cpufreq_dt_remove(struct platform_device *pdev)
{
platform_device_unregister(cpufreq_dt_pdev);
dev_pm_opp_put_supported_hw(cpufreq_opp_table);
return 0;
}
static struct platform_driver imx_cpufreq_dt_driver = {
.probe = imx_cpufreq_dt_probe,
.remove = imx_cpufreq_dt_remove,
.driver = {
.name = "imx-cpufreq-dt",
},
};
module_platform_driver(imx_cpufreq_dt_driver);
MODULE_ALIAS("platform:imx-cpufreq-dt");
MODULE_DESCRIPTION("Freescale i.MX cpufreq speed grading driver");
MODULE_LICENSE("GPL v2");

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@ -103,6 +103,9 @@ static int __init imx8_soc_init(void)
if (IS_ERR(soc_dev))
goto free_rev;
if (IS_ENABLED(CONFIG_ARM_IMX_CPUFREQ_DT))
platform_device_register_simple("imx-cpufreq-dt", -1, NULL, 0);
return 0;
free_rev: