Re: [PATCH RFC 4/8] soc: samsung: Add Exynos Adaptive Supply Voltage driver
From: Krzysztof Kozlowski
Date: Tue Apr 23 2019 - 06:50:32 EST
On Thu, 4 Apr 2019 at 19:22, Sylwester Nawrocki <s.nawrocki@xxxxxxxxxxx> wrote:
>
> The Adaptive Supply Voltage (ASV) on Exynos SoCs is a technique of adjusting
> operating points of devices in order to better match actual capabilities
> of the hardware and optimize power consumption.
>
> This patch adds common code for parsing the ASV tables from devicetree
> and updating CPU OPPs.
>
> Also support for Exynos5422/5800 SoC is added, the Exynos5422 specific part
> of the patch is partially based on code from
> https://github.com/hardkernel/linux repository, branch odroidxu4-4.14.y,
> files: arch/arm/mach-exynos/exynos5422-asv.[ch].
>
> Tested on Odroid XU3, XU4, XU3 Lite.
>
> Signed-off-by: Sylwester Nawrocki <s.nawrocki@xxxxxxxxxxx>
> ---
> drivers/soc/samsung/Kconfig | 11 ++
> drivers/soc/samsung/Makefile | 3 +
> drivers/soc/samsung/exynos-asv.c | 279 +++++++++++++++++++++++++++
> drivers/soc/samsung/exynos-asv.h | 114 +++++++++++
> drivers/soc/samsung/exynos5422-asv.c | 209 ++++++++++++++++++++
> drivers/soc/samsung/exynos5422-asv.h | 25 +++
> 6 files changed, 641 insertions(+)
> create mode 100644 drivers/soc/samsung/exynos-asv.c
> create mode 100644 drivers/soc/samsung/exynos-asv.h
> create mode 100644 drivers/soc/samsung/exynos5422-asv.c
> create mode 100644 drivers/soc/samsung/exynos5422-asv.h
>
> diff --git a/drivers/soc/samsung/Kconfig b/drivers/soc/samsung/Kconfig
> index 2905f5262197..4d121984f71a 100644
> --- a/drivers/soc/samsung/Kconfig
> +++ b/drivers/soc/samsung/Kconfig
> @@ -7,6 +7,17 @@ menuconfig SOC_SAMSUNG
>
> if SOC_SAMSUNG
>
> +config EXYNOS_ASV
> + bool "Exynos Adaptive Supply Voltage support" if COMPILE_TEST
> + depends on ARCH_EXYNOS || ((ARM || ARM64) && COMPILE_TEST)
> + depends on EXYNOS_CHIPID
> + select EXYNOS_ASV_ARM if ARM && ARCH_EXYNOS
> +
> +# There is no need to enable these drivers for ARMv8
> +config EXYNOS_ASV_ARM
> + bool "Exynos ASV ARMv7-specific driver extensions" if COMPILE_TEST
> + depends on EXYNOS_ASV
> +
> config EXYNOS_CHIPID
> bool "Exynos Chipid controller driver" if COMPILE_TEST
> depends on ARCH_EXYNOS || COMPILE_TEST
> diff --git a/drivers/soc/samsung/Makefile b/drivers/soc/samsung/Makefile
> index 3b6a8797416c..edd1d6ea064d 100644
> --- a/drivers/soc/samsung/Makefile
> +++ b/drivers/soc/samsung/Makefile
> @@ -1,5 +1,8 @@
> # SPDX-License-Identifier: GPL-2.0
>
> +obj-$(CONFIG_EXYNOS_ASV) += exynos-asv.o
> +obj-$(CONFIG_EXYNOS_ASV_ARM) += exynos5422-asv.o
> +
> obj-$(CONFIG_EXYNOS_CHIPID) += exynos-chipid.o
> obj-$(CONFIG_EXYNOS_PMU) += exynos-pmu.o
>
> diff --git a/drivers/soc/samsung/exynos-asv.c b/drivers/soc/samsung/exynos-asv.c
> new file mode 100644
> index 000000000000..60532c7eb3aa
> --- /dev/null
> +++ b/drivers/soc/samsung/exynos-asv.c
> @@ -0,0 +1,279 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2018 - 2019 Samsung Electronics Co., Ltd.
> + * http://www.samsung.com/
> + * Author: Sylwester Nawrocki <s.nawrocki@xxxxxxxxxxx>
> + *
> + * Samsung Exynos SoC Adaptive Supply Voltage support
> + */
> +
> +#include <linux/cpu.h>
> +#include <linux/delay.h>
> +#include <linux/device.h>
> +#include <linux/errno.h>
> +#include <linux/init.h>
> +#include <linux/of.h>
> +#include <linux/pm_opp.h>
> +#include <linux/slab.h>
> +
> +#include "exynos-asv.h"
> +#include "exynos5422-asv.h"
> +#include "exynos5433-asv.h"
> +
> +#ifndef MHZ
> +#define MHZ 1000000U
> +#endif
> +
> +static struct exynos_asv *exynos_asv;
> +
> +int exynos_asv_parse_of_table(struct device_node *node,
> + struct exynos_asv_table *table,
> + int index)
> +{
> + u32 table_size, table_id = 0;
> + unsigned int len1, len2 = 0;
> + unsigned int num_cols, num_rows;
> + u32 tmp[20];
> + u32 *buf;
> + int ret;
> +
> + ret = of_property_read_u32(node, "samsung,asv-table-id",
> + &table_id);
> + if (ret < 0) {
> + pr_err("ASV: Missing table id in %pOF\n", node);
> + return ret;
> + }
> + table->id = table_id;
> +
> + if (index >= 0 && asv_table_to_index(table_id) != index)
> + return -EBADR;
> +
> + ret = of_property_read_u32_array(node, "samsung,asv-table-size",
> + tmp, 2);
> + if (ret < 0)
> + return ret;
> +
> + num_rows = tmp[0];
> + num_cols = tmp[1];
> + if (num_rows > EXYNOS_ASV_MAX_LEVELS ||
> + num_cols > (EXYNOS_ASV_MAX_GROUPS + 1)) {
> + pr_err("ASV: Unsupported ASV table size (%d x %d)\n",
> + num_rows, num_cols);
> + return -EINVAL;
> + }
> +
> + table_size = num_rows * num_cols;
> + buf = kcalloc(table_size, sizeof(u32), GFP_KERNEL);
> + if (!buf)
> + return -ENOMEM;
> +
> + ret = of_property_read_variable_u32_array(node, "samsung,asv-data",
> + buf, 0, table_size);
> + if (ret < 0)
> + goto err_free_buf;
> +
> + len1 = ret;
> +
> + if (ret < table_size) {
> + u32 *dst, *src;
> + ret = of_property_read_variable_u32_array(node,
> + "samsung,asv-common-data",
> + (u32 *)tmp, 0,
> + ARRAY_SIZE(tmp));
> + if (ret < 0) {
> + pr_err("ASV: Not enough data for table #%x (%d x %d)\n",
> + table_id, num_rows, num_cols);
> + goto err_free_buf;
> + }
> + len2 = ret;
> +
> + if (len1 + ((len2 / 2) * num_cols) > table_size) {
> + pr_err("ASV: Incorrect table %#x definition\n",
> + table_id);
> + ret = -EINVAL;
> + goto err_free_buf;
> + }
> + /*
> + * Copy data common to all ASV levels to first and second column
> + * in the main buffer. We don't replicate data to further
> + * columns, instead they are left initialized to 0 (invalid,
> + * unused frequency value). We assume that users of the table
> + * will refer to voltage data in column 1 if 0 is encountered
> + * in any further column (2, 3,...).
> + */
> + dst = buf + len1;
> + src = tmp;
> +
> + while (len2 >= 2) {
> + memcpy(dst, src, 2 * sizeof(u32));
> + dst += num_cols;
> + src += 2;
> + len2 -= 2;
> + }
> + }
> +
> + table->num_cols = num_cols;
> + table->num_rows = num_rows;
> + table->buf = buf;
> + return 0;
> +
> +err_free_buf:
> + kfree(buf);
> + return ret;
> +}
> +
> +int exynos_asv_parse_cpu_tables(struct exynos_asv *asv, struct device_node *np,
> + int table_index)
> +{
> + struct exynos_asv_subsys *subsys;
> + struct exynos_asv_table table;
> + struct device_node *child;
> + int ret;
> +
> + for_each_child_of_node(np, child) {
> + ret = exynos_asv_parse_of_table(child, &table, table_index);
> + if (ret < 0) {
> + if (ret == -EBADR)
> + continue;
> + of_node_put(child);
> + return ret;
> + }
> +
> + pr_debug("%s: Matching table: id: %#x at %pOF\n",
> + __func__, table.id, child);
> +
> + switch(asv_table_to_subsys_id(table.id)) {
> + case EXYNOS_ASV_SUBSYS_ID_ARM:
> + subsys = &asv->arm;
> + break;
> + case EXYNOS_ASV_SUBSYS_ID_KFC:
> + subsys = &asv->kfc;
> + break;
> + default:
> + of_node_put(child);
> + return -EINVAL;
> + }
> +
> + subsys->num_asv_levels = table.num_rows;
> + subsys->num_asv_groups = table.num_cols - 1;
> + subsys->table = table;
> + subsys->id = asv_table_to_subsys_id(table.id);
> + }
> +
> + return 0;
> +}
> +
> +static int exynos_asv_update_cpu_opps(struct device *cpu)
> +{
> + struct exynos_asv_subsys *subsys = NULL;
> + struct dev_pm_opp *opp;
> + unsigned int opp_freq;
> + int i;
> +
> + if (of_device_is_compatible(cpu->of_node,
> + exynos_asv->arm.cpu_dt_compat))
> + subsys = &exynos_asv->arm;
> + else if (of_device_is_compatible(cpu->of_node,
> + exynos_asv->kfc.cpu_dt_compat))
> + subsys = &exynos_asv->kfc;
> +
> + if (!subsys)
> + return -EINVAL;
> +
> + for (i = 0; i < subsys->num_asv_levels; i++) {
> + unsigned int new_voltage;
> + unsigned int voltage;
> + int timeout = 1000;
> + int err;
> +
> + opp_freq = exynos_asv_opp_get_frequency(subsys, i);
> +
> + opp = dev_pm_opp_find_freq_exact(cpu, opp_freq * MHZ, true);
> + if (IS_ERR(opp)) {
> + pr_info("%s cpu%d opp%d, freq: %u missing\n",
> + __func__, cpu->id, i, opp_freq);
> +
> + continue;
> + }
> +
> + voltage = dev_pm_opp_get_voltage(opp);
> + new_voltage = exynos_asv->opp_get_voltage(subsys, i, voltage);
> + dev_pm_opp_put(opp);
> +
> + opp_freq *= MHZ;
> + dev_pm_opp_remove(cpu, opp_freq);
> +
> + while (--timeout) {
> + opp = dev_pm_opp_find_freq_exact(cpu, opp_freq, true);
> + if (IS_ERR(opp))
> + break;
> + dev_pm_opp_put(opp);
> + msleep(1);
> + }
> +
> + err = dev_pm_opp_add(cpu, opp_freq, new_voltage);
> + if (err < 0)
> + pr_err("%s: Failed to add OPP %u Hz/%u uV for cpu%d\n",
> + __func__, opp_freq, new_voltage, cpu->id);
> + }
> +
> + return 0;
> +}
> +
> +static int exynos_asv_update_opps(void)
> +{
> + struct opp_table *last_opp_table = NULL;
> + struct device *cpu;
> + int ret, cpuid;
> +
> + for_each_possible_cpu(cpuid) {
> + struct opp_table *opp_table;
> +
> + cpu = get_cpu_device(cpuid);
> + if (!cpu)
> + continue;
> +
> + opp_table = dev_pm_opp_get_opp_table(cpu);
> + if (IS_ERR(opp_table))
> + continue;
> +
> + if (!last_opp_table || opp_table != last_opp_table) {
> + last_opp_table = opp_table;
> +
> + ret = exynos_asv_update_cpu_opps(cpu);
> + if (ret < 0)
> + pr_err("%s: Couldn't udate OPPs for cpu%d\n",
> + __func__, cpuid);
> + }
> +
> + dev_pm_opp_put_opp_table(opp_table);
> + }
> +
> + return 0;
> +}
> +
> +static int __init exynos_asv_init(void)
> +{
> + int ret;
> +
> + exynos_asv = kcalloc(1, sizeof(struct exynos_asv), GFP_KERNEL);
> + if (!exynos_asv)
> + return -ENOMEM;
> +
> + if (of_machine_is_compatible("samsung,exynos5800") ||
> + of_machine_is_compatible("samsung,exynos5420"))
> + ret = exynos5422_asv_init(exynos_asv);
> + else
> + return 0;
> +
> + if (ret < 0)
> + return ret;
> +
> + ret = exynos_asv_update_opps();
> +
> + if (exynos_asv->release)
> + exynos_asv->release(exynos_asv);
> +
> + return ret;
> +}
> +late_initcall(exynos_asv_init)
> diff --git a/drivers/soc/samsung/exynos-asv.h b/drivers/soc/samsung/exynos-asv.h
> new file mode 100644
> index 000000000000..3444b361e5e3
> --- /dev/null
> +++ b/drivers/soc/samsung/exynos-asv.h
> @@ -0,0 +1,114 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2018 - 2019 Samsung Electronics Co., Ltd.
> + * http://www.samsung.com/
> + * Author: Sylwester Nawrocki <s.nawrocki@xxxxxxxxxxx>
> + *
> + * Samsung Exynos SoC Adaptive Supply Voltage support
> + */
> +#ifndef __EXYNOS_ASV_H
> +#define __EXYNOS_ASV_H
> +
> +#define EXYNOS_ASV_MAX_GROUPS 16
> +#define EXYNOS_ASV_MAX_LEVELS 24
> +
> +#define EXYNOS_ASV_TABLE_INDEX_MASK (0xff)
> +#define EXYNOS_ASV_SUBSYS_ID_MASK (0xff << 8)
> +
> +#define asv_table_to_subsys_id(_id) ((_id >> 8) & 0xff)
> +#define asv_table_to_index(_id) ((_id) & 0xff)
> +
> +#define EXYNOS_ASV_SUBSYS_ID_ARM 0x0
> +#define EXYNOS_ASV_SUBSYS_ID_EGL EXYNOS_ASV_SUBSYS_ID_ARM
> +#define EXYNOS_ASV_SUBSYS_ID_KFC 0x1
> +#define EXYNOS_ASV_SUBSYS_ID_INT 0x2
> +#define EXYNOS_ASV_SUBSYS_ID_MIF 0x3
> +#define EXYNOS_ASV_SUBSYS_ID_G3D 0x4
> +#define EXYNOS_ASV_SUBSYS_ID_CAM 0x5
> +#define EXYNOS_ASV_SUBSYS_ID_MAX 0x6
> +
> +struct device_node;
> +
> +/* HPM, IDS values to select target group */
> +struct asv_limit_entry {
> + unsigned int hpm;
> + unsigned int ids;
> +};
> +
> +struct exynos_asv_table {
> + unsigned int num_rows;
> + unsigned int num_cols;
> + unsigned int id;
> + u32 *buf;
> +};
> +
> +struct exynos_asv_subsys {
> + int id;
> + char *cpu_dt_compat;
> +
> + unsigned int base_volt;
> + unsigned int num_asv_levels;
> + unsigned int num_asv_groups;
> + unsigned int offset_volt_h;
> + unsigned int offset_volt_l;
> + struct exynos_asv_table table;
> +};
> +
> +struct exynos_asv {
> + struct device_node *chipid_node;
> + struct exynos_asv_subsys arm;
> + struct exynos_asv_subsys kfc;
> +
> + int (*opp_get_voltage)(struct exynos_asv_subsys *subs, int level,
> + unsigned int voltage);
> + void (*release)(struct exynos_asv *asv);
> +
> + unsigned int group;
> + unsigned int table;
> +
> + /* TODO: Move member fields below to SoC type specific data structure */
> + unsigned int is_bin2;
> + unsigned int is_special_lot;
> +};
> +
> +static inline u32 __exynos_asv_get_item(struct exynos_asv_table *table,
> + unsigned int row, unsigned int col)
> +{
> + return table->buf[row * (table->num_cols) + col];
> +}
> +
> +static inline u32 exynos_asv_opp_get_frequency(struct exynos_asv_subsys *subsys,
> + unsigned int index)
> +{
> + return __exynos_asv_get_item(&subsys->table, index, 0);
> +}
> +/**
> + * exynos_asv_parse_of_table - Parse ASV table from devicetree
> + *
> + * @node: DT node containing the table
> + * @table: The parsed table data
> + * @index: Used to select table with specific index to parse, if >= 0.
> + * This argument is ignored if the value is less than 0.
> + *
> + * Returns: 0 on success, or negative value on failure. EBADR is returned
> + * when @index is >= 0 but the index value of the parsed table ID is different
> + * than @index.
> + */
> +int exynos_asv_parse_of_table(struct device_node *node,
> + struct exynos_asv_table *table,
> + int index);
> +
> +/**
> + * exynos_asv_parse_cpu_tables - Parse ARM and KFC ASV tables from DT
> + *
> + * @asv: data structure to store the parsed data to
> + * @node: DT node containing the tables
> + * @index: Used to select table with specific index to parse, if >= 0.
> + * This argument is ignored if the value is less than 0.
> + *
> + * Returns: 0 on success, or negative value on failure.
> + */
> +int exynos_asv_parse_cpu_tables(struct exynos_asv *asv, struct device_node *np,
> + int table_index);
> +
> +#endif /* __EXYNOS_ASV_H */
> diff --git a/drivers/soc/samsung/exynos5422-asv.c b/drivers/soc/samsung/exynos5422-asv.c
> new file mode 100644
> index 000000000000..f0b7bdd873a9
> --- /dev/null
> +++ b/drivers/soc/samsung/exynos5422-asv.c
> @@ -0,0 +1,209 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2018 - 2019 Samsung Electronics Co., Ltd.
> + * http://www.samsung.com/
> + *
> + * Samsung Exynos 5422 SoC Adaptive Supply Voltage support
> + */
> +
> +#include <linux/errno.h>
> +#include <linux/init.h>
> +#include <linux/of.h>
> +#include <linux/slab.h>
> +
> +#include "exynos-asv.h"
> +#include "exynos-chipid.h"
> +
> +#define EXYNOS5422_NUM_ASV_GROUPS 14
> +
> +static struct exynos_asv *exynos_asv;
> +
> +static int exynos5422_asv_get_table(void)
> +{
> + unsigned int reg = exynos_chipid_read(EXYNOS_CHIPID_REG_PKG_ID);
One more thought: you read this register multiple times in the same
function. I think it is not needed - just read once, store the value
and use the helpers to parse it.
Best regards,
Krzysztof