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|
/*
* CPU frequency scaling for Broadcom SoCs with AVS firmware that
* supports DVS or DVFS
*
* Copyright (c) 2016 Broadcom
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation version 2.
*
* This program is distributed "as is" WITHOUT ANY WARRANTY of any
* kind, whether express or implied; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
/*
* "AVS" is the name of a firmware developed at Broadcom. It derives
* its name from the technique called "Adaptive Voltage Scaling".
* Adaptive voltage scaling was the original purpose of this firmware.
* The AVS firmware still supports "AVS mode", where all it does is
* adaptive voltage scaling. However, on some newer Broadcom SoCs, the
* AVS Firmware, despite its unchanged name, also supports DFS mode and
* DVFS mode.
*
* In the context of this document and the related driver, "AVS" by
* itself always means the Broadcom firmware and never refers to the
* technique called "Adaptive Voltage Scaling".
*
* The Broadcom STB AVS CPUfreq driver provides voltage and frequency
* scaling on Broadcom SoCs using AVS firmware with support for DFS and
* DVFS. The AVS firmware is running on its own co-processor. The
* driver supports both uniprocessor (UP) and symmetric multiprocessor
* (SMP) systems which share clock and voltage across all CPUs.
*
* Actual voltage and frequency scaling is done solely by the AVS
* firmware. This driver does not change frequency or voltage itself.
* It provides a standard CPUfreq interface to the rest of the kernel
* and to userland. It interfaces with the AVS firmware to effect the
* requested changes and to report back the current system status in a
* way that is expected by existing tools.
*/
#include <linux/cpufreq.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/semaphore.h>
#ifdef CONFIG_ARM_BRCMSTB_AVS_CPUFREQ_DEBUG
#include <linux/ctype.h>
#include <linux/debugfs.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#endif
/* Max number of arguments AVS calls take */
#define AVS_MAX_CMD_ARGS 4
/*
* This macro is used to generate AVS parameter register offsets. For
* x >= AVS_MAX_CMD_ARGS, it returns 0 to protect against accidental memory
* access outside of the parameter range. (Offset 0 is the first parameter.)
*/
#define AVS_PARAM_MULT(x) ((x) < AVS_MAX_CMD_ARGS ? (x) : 0)
/* AVS Mailbox Register offsets */
#define AVS_MBOX_COMMAND 0x00
#define AVS_MBOX_STATUS 0x04
#define AVS_MBOX_VOLTAGE0 0x08
#define AVS_MBOX_TEMP0 0x0c
#define AVS_MBOX_PV0 0x10
#define AVS_MBOX_MV0 0x14
#define AVS_MBOX_PARAM(x) (0x18 + AVS_PARAM_MULT(x) * sizeof(u32))
#define AVS_MBOX_REVISION 0x28
#define AVS_MBOX_PSTATE 0x2c
#define AVS_MBOX_HEARTBEAT 0x30
#define AVS_MBOX_MAGIC 0x34
#define AVS_MBOX_SIGMA_HVT 0x38
#define AVS_MBOX_SIGMA_SVT 0x3c
#define AVS_MBOX_VOLTAGE1 0x40
#define AVS_MBOX_TEMP1 0x44
#define AVS_MBOX_PV1 0x48
#define AVS_MBOX_MV1 0x4c
#define AVS_MBOX_FREQUENCY 0x50
/* AVS Commands */
#define AVS_CMD_AVAILABLE 0x00
#define AVS_CMD_DISABLE 0x10
#define AVS_CMD_ENABLE 0x11
#define AVS_CMD_S2_ENTER 0x12
#define AVS_CMD_S2_EXIT 0x13
#define AVS_CMD_BBM_ENTER 0x14
#define AVS_CMD_BBM_EXIT 0x15
#define AVS_CMD_S3_ENTER 0x16
#define AVS_CMD_S3_EXIT 0x17
#define AVS_CMD_BALANCE 0x18
/* PMAP and P-STATE commands */
#define AVS_CMD_GET_PMAP 0x30
#define AVS_CMD_SET_PMAP 0x31
#define AVS_CMD_GET_PSTATE 0x40
#define AVS_CMD_SET_PSTATE 0x41
/* Different modes AVS supports (for GET_PMAP/SET_PMAP) */
#define AVS_MODE_AVS 0x0
#define AVS_MODE_DFS 0x1
#define AVS_MODE_DVS 0x2
#define AVS_MODE_DVFS 0x3
/*
* PMAP parameter p1
* unused:31-24, mdiv_p0:23-16, unused:15-14, pdiv:13-10 , ndiv_int:9-0
*/
#define NDIV_INT_SHIFT 0
#define NDIV_INT_MASK 0x3ff
#define PDIV_SHIFT 10
#define PDIV_MASK 0xf
#define MDIV_P0_SHIFT 16
#define MDIV_P0_MASK 0xff
/*
* PMAP parameter p2
* mdiv_p4:31-24, mdiv_p3:23-16, mdiv_p2:15:8, mdiv_p1:7:0
*/
#define MDIV_P1_SHIFT 0
#define MDIV_P1_MASK 0xff
#define MDIV_P2_SHIFT 8
#define MDIV_P2_MASK 0xff
#define MDIV_P3_SHIFT 16
#define MDIV_P3_MASK 0xff
#define MDIV_P4_SHIFT 24
#define MDIV_P4_MASK 0xff
/* Different P-STATES AVS supports (for GET_PSTATE/SET_PSTATE) */
#define AVS_PSTATE_P0 0x0
#define AVS_PSTATE_P1 0x1
#define AVS_PSTATE_P2 0x2
#define AVS_PSTATE_P3 0x3
#define AVS_PSTATE_P4 0x4
#define AVS_PSTATE_MAX AVS_PSTATE_P4
/* CPU L2 Interrupt Controller Registers */
#define AVS_CPU_L2_SET0 0x04
#define AVS_CPU_L2_INT_MASK BIT(31)
/* AVS Command Status Values */
#define AVS_STATUS_CLEAR 0x00
/* Command/notification accepted */
#define AVS_STATUS_SUCCESS 0xf0
/* Command/notification rejected */
#define AVS_STATUS_FAILURE 0xff
/* Invalid command/notification (unknown) */
#define AVS_STATUS_INVALID 0xf1
/* Non-AVS modes are not supported */
#define AVS_STATUS_NO_SUPP 0xf2
/* Cannot set P-State until P-Map supplied */
#define AVS_STATUS_NO_MAP 0xf3
/* Cannot change P-Map after initial P-Map set */
#define AVS_STATUS_MAP_SET 0xf4
/* Max AVS status; higher numbers are used for debugging */
#define AVS_STATUS_MAX 0xff
/* Other AVS related constants */
#define AVS_LOOP_LIMIT 10000
#define AVS_TIMEOUT 300 /* in ms; expected completion is < 10ms */
#define AVS_FIRMWARE_MAGIC 0xa11600d1
#define BRCM_AVS_CPUFREQ_PREFIX "brcmstb-avs"
#define BRCM_AVS_CPUFREQ_NAME BRCM_AVS_CPUFREQ_PREFIX "-cpufreq"
#define BRCM_AVS_CPU_DATA "brcm,avs-cpu-data-mem"
#define BRCM_AVS_CPU_INTR "brcm,avs-cpu-l2-intr"
#define BRCM_AVS_HOST_INTR "sw_intr"
struct pmap {
unsigned int mode;
unsigned int p1;
unsigned int p2;
unsigned int state;
};
struct private_data {
void __iomem *base;
void __iomem *avs_intr_base;
struct device *dev;
#ifdef CONFIG_ARM_BRCMSTB_AVS_CPUFREQ_DEBUG
struct dentry *debugfs;
#endif
struct completion done;
struct semaphore sem;
struct pmap pmap;
};
#ifdef CONFIG_ARM_BRCMSTB_AVS_CPUFREQ_DEBUG
enum debugfs_format {
DEBUGFS_NORMAL,
DEBUGFS_FLOAT,
DEBUGFS_REV,
};
struct debugfs_data {
struct debugfs_entry *entry;
struct private_data *priv;
};
struct debugfs_entry {
char *name;
u32 offset;
fmode_t mode;
enum debugfs_format format;
};
#define DEBUGFS_ENTRY(name, mode, format) { \
#name, AVS_MBOX_##name, mode, format \
}
/*
* These are used for debugfs only. Otherwise we use AVS_MBOX_PARAM() directly.
*/
#define AVS_MBOX_PARAM1 AVS_MBOX_PARAM(0)
#define AVS_MBOX_PARAM2 AVS_MBOX_PARAM(1)
#define AVS_MBOX_PARAM3 AVS_MBOX_PARAM(2)
#define AVS_MBOX_PARAM4 AVS_MBOX_PARAM(3)
/*
* This table stores the name, access permissions and offset for each hardware
* register and is used to generate debugfs entries.
*/
static struct debugfs_entry debugfs_entries[] = {
DEBUGFS_ENTRY(COMMAND, S_IWUSR, DEBUGFS_NORMAL),
DEBUGFS_ENTRY(STATUS, S_IWUSR, DEBUGFS_NORMAL),
DEBUGFS_ENTRY(VOLTAGE0, 0, DEBUGFS_FLOAT),
DEBUGFS_ENTRY(TEMP0, 0, DEBUGFS_FLOAT),
DEBUGFS_ENTRY(PV0, 0, DEBUGFS_FLOAT),
DEBUGFS_ENTRY(MV0, 0, DEBUGFS_FLOAT),
DEBUGFS_ENTRY(PARAM1, S_IWUSR, DEBUGFS_NORMAL),
DEBUGFS_ENTRY(PARAM2, S_IWUSR, DEBUGFS_NORMAL),
DEBUGFS_ENTRY(PARAM3, S_IWUSR, DEBUGFS_NORMAL),
DEBUGFS_ENTRY(PARAM4, S_IWUSR, DEBUGFS_NORMAL),
DEBUGFS_ENTRY(REVISION, 0, DEBUGFS_REV),
DEBUGFS_ENTRY(PSTATE, 0, DEBUGFS_NORMAL),
DEBUGFS_ENTRY(HEARTBEAT, 0, DEBUGFS_NORMAL),
DEBUGFS_ENTRY(MAGIC, S_IWUSR, DEBUGFS_NORMAL),
DEBUGFS_ENTRY(SIGMA_HVT, 0, DEBUGFS_NORMAL),
DEBUGFS_ENTRY
|