alistair23-linux/drivers/cpufreq/imx-cpufreq-dt.c
Anson Huang 75c000c4bc cpufreq: imx-cpufreq-dt: Add i.MX8MN support
i.MX8MN has different speed grading definition as below, it has 4 bits
to define speed grading, add support for it.

 SPEED_GRADE[3:0]    MHz
    0000            2300
    0001            2200
    0010            2100
    0011            2000
    0100            1900
    0101            1800
    0110            1700
    0111            1600
    1000            1500
    1001            1400
    1010            1300
    1011            1200
    1100            1100
    1101            1000
    1110             900
    1111             800

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Reviewed-by: Leonard Crestez <leonard.crestez@nxp.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2019-08-22 11:31:04 +05:30

105 lines
3 KiB
C

// 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 IMX8MN_OCOTP_CFG3_SPEED_GRADE_MASK (0xf << 8)
#define OCOTP_CFG3_MKT_SEGMENT_SHIFT 6
#define OCOTP_CFG3_MKT_SEGMENT_MASK (0x3 << 6)
/* 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);
u32 cell_value, supported_hw[2];
int speed_grade, mkt_segment;
int ret;
ret = nvmem_cell_read_u32(cpu_dev, "speed_grade", &cell_value);
if (ret)
return ret;
if (of_machine_is_compatible("fsl,imx8mn"))
speed_grade = (cell_value & IMX8MN_OCOTP_CFG3_SPEED_GRADE_MASK)
>> OCOTP_CFG3_SPEED_GRADE_SHIFT;
else
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;
/*
* Early samples without fuses written report "0 0" which means
* consumer segment and minimum speed grading.
*
* According to datasheet minimum speed grading is not supported for
* consumer parts so clamp to 1 to avoid warning for "no OPPs"
*
* Applies to i.MX8M series SoCs.
*/
if (mkt_segment == 0 && speed_grade == 0 && (
of_machine_is_compatible("fsl,imx8mm") ||
of_machine_is_compatible("fsl,imx8mn") ||
of_machine_is_compatible("fsl,imx8mq")))
speed_grade = 1;
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");