linux/drivers/misc/smpro-misc.c
Quan Nguyen 763dc90e9a misc: smpro-misc: Add Ampere's Altra SMpro misc driver
Add driver support for accessing various information reported by
Ampere's SMpro co-processor such as Boot Progress and other
miscellaneous data.

Signed-off-by: Quan Nguyen <quan@os.amperecomputing.com>
Link: https://lore.kernel.org/r/20221031024442.2490881-4-quan@os.amperecomputing.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-10 19:03:03 +01:00

146 lines
3.2 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Ampere Computing SoC's SMpro Misc Driver
*
* Copyright (c) 2022, Ampere Computing LLC
*/
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
/* Boot Stage/Progress Registers */
#define BOOTSTAGE 0xB0
#define BOOTSTAGE_LO 0xB1
#define CUR_BOOTSTAGE 0xB2
#define BOOTSTAGE_HI 0xB3
/* SOC State Registers */
#define SOC_POWER_LIMIT 0xE5
struct smpro_misc {
struct regmap *regmap;
};
static ssize_t boot_progress_show(struct device *dev, struct device_attribute *da, char *buf)
{
struct smpro_misc *misc = dev_get_drvdata(dev);
u16 boot_progress[3] = { 0 };
u32 bootstage;
u8 boot_stage;
u8 cur_stage;
u32 reg_lo;
u32 reg;
int ret;
/* Read current boot stage */
ret = regmap_read(misc->regmap, CUR_BOOTSTAGE, &reg);
if (ret)
return ret;
cur_stage = reg & 0xff;
ret = regmap_read(misc->regmap, BOOTSTAGE, &bootstage);
if (ret)
return ret;
boot_stage = (bootstage >> 8) & 0xff;
if (boot_stage > cur_stage)
return -EINVAL;
ret = regmap_read(misc->regmap, BOOTSTAGE_LO, &reg_lo);
if (!ret)
ret = regmap_read(misc->regmap, BOOTSTAGE_HI, &reg);
if (ret)
return ret;
/* Firmware to report new boot stage next time */
if (boot_stage < cur_stage) {
ret = regmap_write(misc->regmap, BOOTSTAGE, ((bootstage & 0xff00) | 0x1));
if (ret)
return ret;
}
boot_progress[0] = bootstage;
boot_progress[1] = swab16(reg);
boot_progress[2] = swab16(reg_lo);
return sysfs_emit(buf, "%*phN\n", (int)sizeof(boot_progress), boot_progress);
}
static DEVICE_ATTR_RO(boot_progress);
static ssize_t soc_power_limit_show(struct device *dev, struct device_attribute *da, char *buf)
{
struct smpro_misc *misc = dev_get_drvdata(dev);
unsigned int value;
int ret;
ret = regmap_read(misc->regmap, SOC_POWER_LIMIT, &value);
if (ret)
return ret;
return sysfs_emit(buf, "%d\n", value);
}
static ssize_t soc_power_limit_store(struct device *dev, struct device_attribute *da,
const char *buf, size_t count)
{
struct smpro_misc *misc = dev_get_drvdata(dev);
unsigned long val;
s32 ret;
ret = kstrtoul(buf, 0, &val);
if (ret)
return ret;
ret = regmap_write(misc->regmap, SOC_POWER_LIMIT, (unsigned int)val);
if (ret)
return -EPROTO;
return count;
}
static DEVICE_ATTR_RW(soc_power_limit);
static struct attribute *smpro_misc_attrs[] = {
&dev_attr_boot_progress.attr,
&dev_attr_soc_power_limit.attr,
NULL
};
ATTRIBUTE_GROUPS(smpro_misc);
static int smpro_misc_probe(struct platform_device *pdev)
{
struct smpro_misc *misc;
misc = devm_kzalloc(&pdev->dev, sizeof(struct smpro_misc), GFP_KERNEL);
if (!misc)
return -ENOMEM;
platform_set_drvdata(pdev, misc);
misc->regmap = dev_get_regmap(pdev->dev.parent, NULL);
if (!misc->regmap)
return -ENODEV;
return 0;
}
static struct platform_driver smpro_misc_driver = {
.probe = smpro_misc_probe,
.driver = {
.name = "smpro-misc",
.dev_groups = smpro_misc_groups,
},
};
module_platform_driver(smpro_misc_driver);
MODULE_AUTHOR("Tung Nguyen <tungnguyen@os.amperecomputing.com>");
MODULE_AUTHOR("Quan Nguyen <quan@os.amperecomputing.com>");
MODULE_DESCRIPTION("Ampere Altra SMpro Misc driver");
MODULE_LICENSE("GPL");