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/*
* TI CPUFreq/OPP hw-supported driver
*
* Copyright (C) 2016-2017 Texas Instruments, Inc.
* Dave Gerlach <d-gerlach@ti.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/cpu.h>
#include <linux/io.h>
#include <linux/mfd/syscon.h>
#include <linux/init.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/pm_opp.h>
#include <linux/regmap.h>
#include <linux/slab.h>
#define REVISION_MASK 0xF
#define REVISION_SHIFT 28
#define AM33XX_800M_ARM_MPU_MAX_FREQ 0x1E2F
#define AM43XX_600M_ARM_MPU_MAX_FREQ 0xFFA
#define DRA7_EFUSE_HAS_OD_MPU_OPP 11
#define DRA7_EFUSE_HAS_HIGH_MPU_OPP 15
#define DRA7_EFUSE_HAS_ALL_MPU_OPP 23
#define DRA7_EFUSE_NOM_MPU_OPP BIT(0)
#define DRA7_EFUSE_OD_MPU_OPP BIT(1)
#define DRA7_EFUSE_HIGH_MPU_OPP BIT(2)
#define VERSION_COUNT 2
struct ti_cpufreq_data;
struct ti_cpufreq_soc_data {
unsigned long (*efuse_xlate)(struct ti_cpufreq_data *opp_data,
unsigned long efuse);
unsigned long efuse_fallback;
unsigned long efuse_offset;
unsigned long efuse_mask;
unsigned long efuse_shift;
unsigned long rev_offset;
};
struct ti_cpufreq_data {
struct device *cpu_dev;
struct device_node *opp_node;
struct regmap *syscon;
const struct ti_cpufreq_soc_data *soc_data;
};
static unsigned long amx3_efuse_xlate(struct ti_cpufreq_data *opp_data,
unsigned long efuse)
{
if (!efuse)
efuse = opp_data->soc_data->efuse_fallback;
/* AM335x and AM437x use "OPP disable" bits, so invert */
return ~efuse;
}
static unsigned long dra7_efuse_xlate(struct ti_cpufreq_data *opp_data,
unsigned long efuse)
{
unsigned long calculated_efuse = DRA7_EFUSE_NOM_MPU_OPP;
/*
* The efuse on dra7 and am57 parts contains a specific
* value indicating the highest available OPP.
*/
switch (efuse) {
case DRA7_EFUSE_HAS_ALL_MPU_OPP:
case DRA7_EFUSE_HAS_HIGH_MPU_OPP:
calculated_efuse |= DRA7_EFUSE_HIGH_MPU_OPP;
case DRA7_EFUSE_HAS_OD_MPU_OPP:
calculated_efuse |= DRA7_EFUSE_OD_MPU_OPP;
}
return calculated_efuse;
}
static struct ti_cpufreq_soc_data am3x_soc_data = {
.efuse_xlate = amx3_efuse_xlate,
.efuse_fallback = AM33XX_800M_ARM_MPU_MAX_FREQ,
.efuse_offset = 0x07fc,
.efuse_mask = 0x1fff,
.rev_offset = 0x600,
};
static struct ti_cpufreq_soc_data am4x_soc_data = {
.efuse_xlate = amx3_efuse_xlate,
.efuse_fallback = AM43XX_600M_ARM_MPU_MAX_FREQ,
.efuse_offset = 0x0610,
.efuse_mask = 0x3f,
.rev_offset = 0x600,
};
static struct ti_cpufreq_soc_data dra7_soc_data = {
.efuse_xlate = dra7_efuse_xlate,
.efuse_offset = 0x020c,
.efuse_mask = 0xf80000,
.efuse_shift = 19,
.rev_offset = 0x204,
};
/**
* ti_cpufreq_get_efuse() - Parse and return efuse value present on SoC
* @opp_data: pointer to ti_cpufreq_data context
* @efuse_value: Set to the value parsed from efuse
*
* Returns error code if efuse not read properly.
*/
static int ti_cpufreq_get_efuse(struct ti_cpufreq_data *opp_data,
u32 *efuse_value)
{
struct device *dev = opp_data->cpu_dev;
u32 efuse;
int ret;
ret = regmap_read(opp_data->syscon, opp_data->soc_data->efuse_offset,
&efuse);
if (ret) {
dev_err(dev,
"Failed to read the efuse value from syscon: %d\n",
ret);
return ret;
}
efuse = (efuse & opp_data->soc_data->efuse_mask);
efuse >>= opp_data->soc_data->efuse_shift;
*efuse_value = opp_data->soc_data->efuse_xlate(opp_data, efuse);
return 0;
}
/**
* ti_cpufreq_get_rev() - Parse and return rev value present on SoC
* @opp_data: pointer to ti_cpufreq_data context
* @revision_value: Set to the value parsed from revision register
*
* Returns error code if revision not read properly.
*/
static int ti_cpufreq_get_rev(struct ti_cpufreq_data *opp_data,
u32 *revision_value)
{
struct device *dev = opp_data->cpu_dev;
u32 revision;
int ret;
ret = regmap_read(opp_data->syscon, opp_data->soc_data->rev_offset,
&revision);
if (ret) {
dev_err(dev,
"Failed to read the revision number from syscon: %d\n",
ret);
return ret;
}
*revision_value = BIT((revision >> REVISION_SHIFT) & REVISION_MASK);
return 0;
}
static int ti_cpufreq_setup_syscon_register(struct ti_cpufreq_data *opp_data)
{
struct device *dev = opp_data->cpu_dev;
struct device_node *np = opp_data->opp_node;
opp_data->syscon = syscon_regmap_lookup_by_phandle(np,
"syscon");
if (IS_ERR(opp_data->syscon)) {
dev_err(dev,
"\"syscon\" is missing, cannot use OPPv2 table.\n");
return PTR_ERR(opp_data->syscon);
}
return 0;
}
static const struct of_device_id ti_cpufreq_of_match[] = {
{ .compatible = "ti,am33xx", .data = &am3x_soc_data, },
{ .compatible = "ti,am43", .data = &am4x_soc_data, },
{ .compatible = "ti,dra7", .data = &dra7_soc_data },
{},
};
static int ti_cpufreq_init(void)
{
u32 version[VERSION_COUNT];
struct device_node *np;
const struct of_device_id *match;
struct ti_cpufreq_data *opp_data;
int ret;
np = of_find_node_by_path("/");
match = of_match_node(ti_cpufreq_of_match, np);
of_node_put(np);
if (!match)
return -ENODEV;
opp_data = kzalloc(sizeof(*opp_data), GFP_KERNEL);
if (!opp_data)
return -ENOMEM;
opp_data->soc_data = match->data;
opp_data->cpu_dev = get_cpu_device(0);
if (!opp_data->cpu_dev) {
pr_err("%s: Failed to get device for CPU0\n", __func__);
ret = ENODEV;
goto free_opp_data;
}
opp_data->opp_node = dev_pm_opp_of_get_opp_desc_node(opp_data->cpu_dev);
if (!opp_data->opp_node) {
dev_info(opp_data->cpu_dev,
"OPP-v2 not supported, cpufreq-dt will attempt to use legacy tables.\n");
goto register_cpufreq_dt;
}
ret = ti_cpufreq_setup_syscon_register(opp_data);
if (ret)
goto fail_put_node;
/*
* OPPs determine whether or not they are supported based on
* two metrics:
* 0 - SoC Revision
* 1 - eFuse value
*/
ret = ti_cpufreq_get_rev(opp_data, &version[0]);
if (ret)
goto fail_put_node;
ret = ti_cpufreq_get_efuse(opp_data, &version[1]);
if (ret)
goto fail_put_node;
ret = PTR_ERR_OR_ZERO(dev_pm_opp_set_supported_hw(opp_data->cpu_dev,
version, VERSION_COUNT));
if (ret) {
dev_err(opp_data->cpu_dev,
"Failed to set supported hardware\n");
goto fail_put_node;
}
of_node_put(opp_data->opp_node);
register_cpufreq_dt:
platform_device_register_simple("cpufreq-dt", -1, NULL, 0);
return 0;
fail_put_node:
of_node_put(opp_data->opp_node);
free_opp_data:
kfree(opp_data);
return ret;
}
device_initcall(ti_cpufreq_init);
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