[PATCH v1 4/4] mfd: tps6594-pfsm: Add driver for TI TPS6594 PFSM

Julien Panis
2023-02-16T11:44:39Z

This patch adds support for TPS6594 PFSM (Pre-configurable Finite
State Machine).

This PFSM controls the operational modes of the PMIC:
- STANDBY and LP_STANDBY,
- ACTIVE state,
- MCU_ONLY state,
- RETENTION state, with or without DDR and/or GPIO retention.
Depending on the current operational mode, some voltage domains
remain energized while others can be off.

This PFSM is also used to trigger a firmware update, and provides
R/W access to device registers.

Signed-off-by: Julien Panis <jpanis@baylibre.com>
---
.../userspace-api/ioctl/ioctl-number.rst | 1 +
drivers/mfd/Kconfig | 11 +
drivers/mfd/Makefile | 1 +
drivers/mfd/tps6594-pfsm.c | 304 ++++++++++++++++++
include/uapi/linux/tps6594_pfsm.h | 45 +++
5 files changed, 362 insertions(+)
create mode 100644 drivers/mfd/tps6594-pfsm.c
create mode 100644 include/uapi/linux/tps6594_pfsm.h

diff --git a/Documentation/userspace-api/ioctl/ioctl-number.rst b/Documentation/userspace-api/ioctl/ioctl-number.rst
index eb045fc495a4..f3098d3800a5 100644
--- a/Documentation/userspace-api/ioctl/ioctl-number.rst
+++ b/Documentation/userspace-api/ioctl/ioctl-number.rst
@@ -180,6 +180,7 @@ Code Seq# Include File Comments
'P' 00-0F drivers/usb/class/usblp.c conflict!
'P' 01-09 drivers/misc/pci_endpoint_test.c conflict!
'P' 00-0F xen/privcmd.h conflict!
+'P' 00-03 linux/tps6594_pfsm.h conflict!
'Q' all linux/soundcard.h
'R' 00-1F linux/random.h conflict!
'R' 01 linux/rfkill.h conflict!
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index cbf7cfb70879..188c949e4eb0 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -1732,6 +1732,17 @@ config MFD_TPS6594_ESM
This driver can also be built as a module. If so, the module
will be called tps6594-esm.

+config MFD_TPS6594_PFSM
+ tristate "TI TPS6594 Pre-configurable Finite State Machine support"
+ depends on MFD_TPS6594
+ help
+ Support PFSM (Pre-configurable Finite State Machine) on TPS6594 PMIC devices.
+ These devices integrate a finite state machine engine, which manages the state
+ of the device during operating state transition.
+
+ This driver can also be built as a module. If so, the module
+ will be called tps6594-pfsm.
+
config TWL4030_CORE
bool "TI TWL4030/TWL5030/TWL6030/TPS659x0 Support"
depends on I2C=y
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index ae2d404cd6b8..c201c186ae38 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -106,6 +106,7 @@ obj-$(CONFIG_MFD_TPS6594) += tps6594-core.o
obj-$(CONFIG_MFD_TPS6594_I2C) += tps6594-i2c.o
obj-$(CONFIG_MFD_TPS6594_SPI) += tps6594-spi.o
obj-$(CONFIG_MFD_TPS6594_ESM) += tps6594-esm.o
+obj-$(CONFIG_MFD_TPS6594_PFSM) += tps6594-pfsm.o
obj-$(CONFIG_MENELAUS) += menelaus.o

obj-$(CONFIG_TWL4030_CORE) += twl-core.o twl4030-irq.o twl6030-irq.o
diff --git a/drivers/mfd/tps6594-pfsm.c b/drivers/mfd/tps6594-pfsm.c
new file mode 100644
index 000000000000..ce7859ac82ab
--- /dev/null
+++ b/drivers/mfd/tps6594-pfsm.c
@@ -0,0 +1,304 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * PFSM (Pre-configurable Finite State Machine) driver for TI TPS6594/TPS6593/LP8764X PMICs
+ *
+ * Copyright (C) 2022 BayLibre Incorporated - https://www.baylibre.com/
+ */
+
+#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 options)
+{
+ int ret;
+
+ if (options & PMIC_GPIO_RETENTION)
+ 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 (options & PMIC_DDR_RETENTION)
+ 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 pfsm_state;
+ void __user *argp = (void __user *)arg;
+ int ret = -EINVAL;
+
+ 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_STATE:
+ if (copy_from_user(&pfsm_state, argp, sizeof(pfsm_state)))
+ return -EFAULT;
+
+ switch (pfsm_state.state) {
+ case PMIC_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_MCU_ONLY_STATE:
+ /* Configure retention triggers */
+ ret = tps6594_pfsm_configure_ret_trig(pfsm->regmap, pfsm_state.options);
+ 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_RETENTION_STATE:
+ /* Configure wake-up destination */
+ if (pfsm_state.options & PMIC_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, pfsm_state.options);
+ if (ret)
+ return ret;
+
+ /* Modify NSLEEP1-2 bits */
+ ret = regmap_clear_bits(pfsm->regmap, TPS6594_REG_FSM_NSLEEP_TRIGGERS,
+ TPS6594_BIT_NSLEEP2B);
+ break;
+ }
+
+ 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,
+};
+
+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 dev_err_probe(dev, irq, "Failed to get %s irq\n",
+ pdev->resource[i].name);
+
+ 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 int tps6594_pfsm_remove(struct platform_device *pdev)
+{
+ struct tps6594_pfsm *pfsm = platform_get_drvdata(pdev);
+
+ misc_deregister(&pfsm->miscdev);
+
+ return 0;
+}
+
+static struct platform_driver tps6594_pfsm_driver = {
+ .driver = {
+ .name = "tps6594-pfsm",
+ },
+ .probe = tps6594_pfsm_probe,
+ .remove = 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");
diff --git a/include/uapi/linux/tps6594_pfsm.h b/include/uapi/linux/tps6594_pfsm.h
new file mode 100644
index 000000000000..e5264af71d2e
--- /dev/null
+++ b/include/uapi/linux/tps6594_pfsm.h
@@ -0,0 +1,45 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * Userspace ABI for TPS6594 PMIC Pre-configurable Finite State Machine
+ *
+ * Copyright (C) 2022 BayLibre Incorporated - https://www.baylibre.com/
+ */
+
+#ifndef __TPS6594_PFSM_H
+#define __TPS6594_PFSM_H
+
+#include <linux/const.h>
+#include <linux/ioctl.h>
+#include <linux/types.h>
+
+/* PFSM state definitions */
+enum pfsm_state {
+ PMIC_ACTIVE_STATE,
+ PMIC_MCU_ONLY_STATE,
+ PMIC_RETENTION_STATE
+};
+
+/**
+ * struct pmic_state - PMIC state identification
+ * @state: PFSM destination state
+ * @options: options for destination state
+ */
+struct pmic_state {
+ enum pfsm_state state;
+ __u8 options;
+};
+
+/* Commands */
+#define PMIC_BASE 'P'
+
+#define PMIC_GOTO_STANDBY _IO(PMIC_BASE, 0)
+#define PMIC_GOTO_LP_STANDBY _IO(PMIC_BASE, 1)
+#define PMIC_UPDATE_PGM _IO(PMIC_BASE, 2)
+#define PMIC_SET_STATE _IOW(PMIC_BASE, 3, struct pmic_state)
+
+/* Options for destination state */
+#define PMIC_GPIO_RETENTION _BITUL(0)
+#define PMIC_DDR_RETENTION _BITUL(1)
+#define PMIC_MCU_ONLY_STARTUP_DEST _BITUL(2)
+
+#endif /* __TPS6594_PFSM_H */
--
2.37.3