linux/drivers/misc/tps6594-pfsm.c

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// SPDX-License-Identifier: GPL-2.0
/*
* PFSM (Pre-configurable Finite State Machine) driver for TI TPS6594/TPS6593/LP8764 PMICs
*
* Copyright (C) 2023 BayLibre Incorporated - https://www.baylibre.com/
*/
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/interrupt.h>
#include <linux/ioctl.h>
#include <linux/miscdevice.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/mfd/tps6594.h>
#include <linux/tps6594_pfsm.h>
#define TPS6594_STARTUP_DEST_MCU_ONLY_VAL 2
#define TPS6594_STARTUP_DEST_ACTIVE_VAL 3
#define TPS6594_STARTUP_DEST_SHIFT 5
#define TPS6594_STARTUP_DEST_MCU_ONLY (TPS6594_STARTUP_DEST_MCU_ONLY_VAL \
<< TPS6594_STARTUP_DEST_SHIFT)
#define TPS6594_STARTUP_DEST_ACTIVE (TPS6594_STARTUP_DEST_ACTIVE_VAL \
<< TPS6594_STARTUP_DEST_SHIFT)
/*
* To update the PMIC firmware, the user must be able to access
* page 0 (user registers) and page 1 (NVM control and configuration).
*/
#define TPS6594_PMIC_MAX_POS 0x200
#define TPS6594_FILE_TO_PFSM(f) container_of((f)->private_data, struct tps6594_pfsm, miscdev)
/**
* struct tps6594_pfsm - device private data structure
*
* @miscdev: misc device infos
* @regmap: regmap for accessing the device registers
*/
struct tps6594_pfsm {
struct miscdevice miscdev;
struct regmap *regmap;
};
static ssize_t tps6594_pfsm_read(struct file *f, char __user *buf,
size_t count, loff_t *ppos)
{
struct tps6594_pfsm *pfsm = TPS6594_FILE_TO_PFSM(f);
loff_t pos = *ppos;
unsigned int val;
int ret;
int i;
if (pos < 0)
return -EINVAL;
if (pos >= TPS6594_PMIC_MAX_POS)
return 0;
if (count > TPS6594_PMIC_MAX_POS - pos)
count = TPS6594_PMIC_MAX_POS - pos;
for (i = 0 ; i < count ; i++) {
ret = regmap_read(pfsm->regmap, pos + i, &val);
if (ret)
return ret;
if (put_user(val, buf + i))
return -EFAULT;
}
*ppos = pos + count;
return count;
}
static ssize_t tps6594_pfsm_write(struct file *f, const char __user *buf,
size_t count, loff_t *ppos)
{
struct tps6594_pfsm *pfsm = TPS6594_FILE_TO_PFSM(f);
loff_t pos = *ppos;
char val;
int ret;
int i;
if (pos < 0)
return -EINVAL;
if (pos >= TPS6594_PMIC_MAX_POS || !count)
return 0;
if (count > TPS6594_PMIC_MAX_POS - pos)
count = TPS6594_PMIC_MAX_POS - pos;
for (i = 0 ; i < count ; i++) {
if (get_user(val, buf + i))
return -EFAULT;
ret = regmap_write(pfsm->regmap, pos + i, val);
if (ret)
return ret;
}
*ppos = pos + count;
return count;
}
static int tps6594_pfsm_configure_ret_trig(struct regmap *regmap, u8 gpio_ret, u8 ddr_ret)
{
int ret;
if (gpio_ret)
ret = regmap_set_bits(regmap, TPS6594_REG_FSM_I2C_TRIGGERS,
TPS6594_BIT_TRIGGER_I2C(5) | TPS6594_BIT_TRIGGER_I2C(6));
else
ret = regmap_clear_bits(regmap, TPS6594_REG_FSM_I2C_TRIGGERS,
TPS6594_BIT_TRIGGER_I2C(5) | TPS6594_BIT_TRIGGER_I2C(6));
if (ret)
return ret;
if (ddr_ret)
ret = regmap_set_bits(regmap, TPS6594_REG_FSM_I2C_TRIGGERS,
TPS6594_BIT_TRIGGER_I2C(7));
else
ret = regmap_clear_bits(regmap, TPS6594_REG_FSM_I2C_TRIGGERS,
TPS6594_BIT_TRIGGER_I2C(7));
return ret;
}
static long tps6594_pfsm_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
{
struct tps6594_pfsm *pfsm = TPS6594_FILE_TO_PFSM(f);
struct pmic_state_opt state_opt;
void __user *argp = (void __user *)arg;
int ret = -ENOIOCTLCMD;
switch (cmd) {
case PMIC_GOTO_STANDBY:
/* Disable LP mode */
ret = regmap_clear_bits(pfsm->regmap, TPS6594_REG_RTC_CTRL_2,
TPS6594_BIT_LP_STANDBY_SEL);
if (ret)
return ret;
/* Force trigger */
ret = regmap_write_bits(pfsm->regmap, TPS6594_REG_FSM_I2C_TRIGGERS,
TPS6594_BIT_TRIGGER_I2C(0), TPS6594_BIT_TRIGGER_I2C(0));
break;
case PMIC_GOTO_LP_STANDBY:
/* Enable LP mode */
ret = regmap_set_bits(pfsm->regmap, TPS6594_REG_RTC_CTRL_2,
TPS6594_BIT_LP_STANDBY_SEL);
if (ret)
return ret;
/* Force trigger */
ret = regmap_write_bits(pfsm->regmap, TPS6594_REG_FSM_I2C_TRIGGERS,
TPS6594_BIT_TRIGGER_I2C(0), TPS6594_BIT_TRIGGER_I2C(0));
break;
case PMIC_UPDATE_PGM:
/* Force trigger */
ret = regmap_write_bits(pfsm->regmap, TPS6594_REG_FSM_I2C_TRIGGERS,
TPS6594_BIT_TRIGGER_I2C(3), TPS6594_BIT_TRIGGER_I2C(3));
break;
case PMIC_SET_ACTIVE_STATE:
/* Modify NSLEEP1-2 bits */
ret = regmap_set_bits(pfsm->regmap, TPS6594_REG_FSM_NSLEEP_TRIGGERS,
TPS6594_BIT_NSLEEP1B | TPS6594_BIT_NSLEEP2B);
break;
case PMIC_SET_MCU_ONLY_STATE:
if (copy_from_user(&state_opt, argp, sizeof(state_opt)))
return -EFAULT;
/* Configure retention triggers */
ret = tps6594_pfsm_configure_ret_trig(pfsm->regmap, state_opt.gpio_retention,
state_opt.ddr_retention);
if (ret)
return ret;
/* Modify NSLEEP1-2 bits */
ret = regmap_clear_bits(pfsm->regmap, TPS6594_REG_FSM_NSLEEP_TRIGGERS,
TPS6594_BIT_NSLEEP1B);
if (ret)
return ret;
ret = regmap_set_bits(pfsm->regmap, TPS6594_REG_FSM_NSLEEP_TRIGGERS,
TPS6594_BIT_NSLEEP2B);
break;
case PMIC_SET_RETENTION_STATE:
if (copy_from_user(&state_opt, argp, sizeof(state_opt)))
return -EFAULT;
/* Configure wake-up destination */
if (state_opt.mcu_only_startup_dest)
ret = regmap_write_bits(pfsm->regmap, TPS6594_REG_RTC_CTRL_2,
TPS6594_MASK_STARTUP_DEST,
TPS6594_STARTUP_DEST_MCU_ONLY);
else
ret = regmap_write_bits(pfsm->regmap, TPS6594_REG_RTC_CTRL_2,
TPS6594_MASK_STARTUP_DEST,
TPS6594_STARTUP_DEST_ACTIVE);
if (ret)
return ret;
/* Configure retention triggers */
ret = tps6594_pfsm_configure_ret_trig(pfsm->regmap, state_opt.gpio_retention,
state_opt.ddr_retention);
if (ret)
return ret;
/* Modify NSLEEP1-2 bits */
ret = regmap_clear_bits(pfsm->regmap, TPS6594_REG_FSM_NSLEEP_TRIGGERS,
TPS6594_BIT_NSLEEP2B);
break;
}
return ret;
}
static const struct file_operations tps6594_pfsm_fops = {
.owner = THIS_MODULE,
.llseek = generic_file_llseek,
.read = tps6594_pfsm_read,
.write = tps6594_pfsm_write,
.unlocked_ioctl = tps6594_pfsm_ioctl,
.compat_ioctl = compat_ptr_ioctl,
};
static irqreturn_t tps6594_pfsm_isr(int irq, void *dev_id)
{
struct platform_device *pdev = dev_id;
int i;
for (i = 0 ; i < pdev->num_resources ; i++) {
if (irq == platform_get_irq_byname(pdev, pdev->resource[i].name)) {
dev_err(pdev->dev.parent, "%s event detected\n", pdev->resource[i].name);
return IRQ_HANDLED;
}
}
return IRQ_NONE;
}
static int tps6594_pfsm_probe(struct platform_device *pdev)
{
struct tps6594_pfsm *pfsm;
struct tps6594 *tps = dev_get_drvdata(pdev->dev.parent);
struct device *dev = &pdev->dev;
int irq;
int ret;
int i;
pfsm = devm_kzalloc(dev, sizeof(struct tps6594_pfsm), GFP_KERNEL);
if (!pfsm)
return -ENOMEM;
pfsm->regmap = tps->regmap;
pfsm->miscdev.minor = MISC_DYNAMIC_MINOR;
pfsm->miscdev.name = devm_kasprintf(dev, GFP_KERNEL, "pfsm-%ld-0x%02x",
tps->chip_id, tps->reg);
pfsm->miscdev.fops = &tps6594_pfsm_fops;
pfsm->miscdev.parent = dev->parent;
for (i = 0 ; i < pdev->num_resources ; i++) {
irq = platform_get_irq_byname(pdev, pdev->resource[i].name);
if (irq < 0)
return irq;
ret = devm_request_threaded_irq(dev, irq, NULL,
tps6594_pfsm_isr, IRQF_ONESHOT,
pdev->resource[i].name, pdev);
if (ret)
return dev_err_probe(dev, ret, "Failed to request irq\n");
}
platform_set_drvdata(pdev, pfsm);
return misc_register(&pfsm->miscdev);
}
static void tps6594_pfsm_remove(struct platform_device *pdev)
{
struct tps6594_pfsm *pfsm = platform_get_drvdata(pdev);
misc_deregister(&pfsm->miscdev);
}
static struct platform_driver tps6594_pfsm_driver = {
.driver = {
.name = "tps6594-pfsm",
},
.probe = tps6594_pfsm_probe,
.remove_new = tps6594_pfsm_remove,
};
module_platform_driver(tps6594_pfsm_driver);
MODULE_ALIAS("platform:tps6594-pfsm");
MODULE_AUTHOR("Julien Panis <jpanis@baylibre.com>");
MODULE_DESCRIPTION("TPS6594 Pre-configurable Finite State Machine Driver");
MODULE_LICENSE("GPL");