diff options
Diffstat (limited to 'drivers/cpufreq/ti-cpufreq.c')
| -rw-r--r-- | drivers/cpufreq/ti-cpufreq.c | 272 |
1 files changed, 272 insertions, 0 deletions
diff --git a/drivers/cpufreq/ti-cpufreq.c b/drivers/cpufreq/ti-cpufreq.c new file mode 100644 index 000000000000..7ff7ae3c3911 --- /dev/null +++ b/drivers/cpufreq/ti-cpufreq.c @@ -0,0 +1,272 @@ +/* + * 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/module.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,am4372", .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); + 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__); + return -ENODEV; + } + + 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; + + of_node_put(opp_data->opp_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; + } + +register_cpufreq_dt: + platform_device_register_simple("cpufreq-dt", -1, NULL, 0); + + return 0; + +fail_put_node: + of_node_put(opp_data->opp_node); + + return ret; +} +module_init(ti_cpufreq_init); + +MODULE_DESCRIPTION("TI CPUFreq/OPP hw-supported driver"); +MODULE_AUTHOR("Dave Gerlach <d-gerlach@ti.com>"); +MODULE_LICENSE("GPL v2"); |