[PATCH v3 2/7] mfd: Add ST Multi-Function eXpander (STMFX) core driver

From: Amelie Delaunay
Date: Thu Sep 27 2018 - 07:41:27 EST


STMicroelectronics Multi-Function eXpander (STMFX) is a slave controller
using I2C for communication with the main MCU. Main features are:
- 16 fast GPIOs individually configurable in input/output
- 8 alternate GPIOs individually configurable in input/output when other
STMFX functions are not used
- Main MCU IDD measurement
- Resistive touchscreen controller

Signed-off-by: Amelie Delaunay <amelie.delaunay@xxxxxx>
Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
---
drivers/mfd/Kconfig | 14 ++
drivers/mfd/Makefile | 2 +-
drivers/mfd/stmfx.c | 626 ++++++++++++++++++++++++++++++++++++++++++++++
include/linux/mfd/stmfx.h | 27 ++
4 files changed, 668 insertions(+), 1 deletion(-)
create mode 100644 drivers/mfd/stmfx.c
create mode 100644 include/linux/mfd/stmfx.h

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index f3a5f8d..8c41342 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -1862,6 +1862,20 @@ config MFD_STM32_TIMERS
for PWM and IIO Timer. This driver allow to share the
registers between the others drivers.

+config MFD_STMFX
+ tristate "Support for STMicroelectronics Multi-Function eXpander (STMFX)"
+ depends on I2C
+ depends on OF || COMPILE_TEST
+ select MFD_CORE
+ select REGMAP_I2C
+ help
+ Support for the STMicroelectronics Multi-Function eXpander.
+
+ This driver provides common support for accessing the device,
+ additional drivers must be enabled in order to use the functionality
+ of the device.
+
+
menu "Multimedia Capabilities Port drivers"
depends on ARCH_SA1100

diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 5856a94..282323b 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -240,4 +240,4 @@ obj-$(CONFIG_MFD_MXS_LRADC) += mxs-lradc.o
obj-$(CONFIG_MFD_SC27XX_PMIC) += sprd-sc27xx-spi.o
obj-$(CONFIG_RAVE_SP_CORE) += rave-sp.o
obj-$(CONFIG_MFD_ROHM_BD718XX) += rohm-bd718x7.o
-
+obj-$(CONFIG_MFD_STMFX) += stmfx.o
diff --git a/drivers/mfd/stmfx.c b/drivers/mfd/stmfx.c
new file mode 100644
index 0000000..cfd4fca
--- /dev/null
+++ b/drivers/mfd/stmfx.c
@@ -0,0 +1,626 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for STMicroelectronics Multi-Function eXpander (STMFX) core
+ *
+ * Copyright (C) 2018 STMicroelectronics
+ * Author(s): Amelie Delaunay <amelie.delaunay@xxxxxx>.
+ */
+#include <linux/bitfield.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/stmfx.h>
+#include <linux/module.h>
+#include <linux/regulator/consumer.h>
+
+/* General */
+#define STMFX_REG_CHIP_ID 0x00 /* R */
+#define STMFX_REG_FW_VERSION_MSB 0x01 /* R */
+#define STMFX_REG_FW_VERSION_LSB 0x02 /* R */
+#define STMFX_REG_SYS_CTRL 0x40 /* RW */
+/* IRQ output management */
+#define STMFX_REG_IRQ_OUT_PIN 0x41 /* RW */
+#define STMFX_REG_IRQ_SRC_EN 0x42 /* RW */
+#define STMFX_REG_IRQ_PENDING 0x08 /* R */
+#define STMFX_REG_IRQ_ACK 0x44 /* RW */
+/* GPIO management */
+#define STMFX_REG_IRQ_GPI_PENDING1 0x0C /* R */
+#define STMFX_REG_IRQ_GPI_PENDING2 0x0D /* R */
+#define STMFX_REG_IRQ_GPI_PENDING3 0x0E /* R */
+#define STMFX_REG_GPIO_STATE1 0x10 /* R */
+#define STMFX_REG_GPIO_STATE2 0x11 /* R */
+#define STMFX_REG_GPIO_STATE3 0x12 /* R */
+#define STMFX_REG_IRQ_GPI_SRC1 0x48 /* RW */
+#define STMFX_REG_IRQ_GPI_SRC2 0x49 /* RW */
+#define STMFX_REG_IRQ_GPI_SRC3 0x4A /* RW */
+#define STMFX_REG_GPO_SET1 0x6C /* RW */
+#define STMFX_REG_GPO_SET2 0x6D /* RW */
+#define STMFX_REG_GPO_SET3 0x6E /* RW */
+#define STMFX_REG_GPO_CLR1 0x70 /* RW */
+#define STMFX_REG_GPO_CLR2 0x71 /* RW */
+#define STMFX_REG_GPO_CLR3 0x72 /* RW */
+
+#define STMFX_REG_MAX 0xB0
+
+/* MFX boot time is around 10ms, so after reset, we have to wait this delay */
+#define STMFX_BOOT_TIME_MS 10
+
+/* STMFX_REG_CHIP_ID bitfields */
+#define STMFX_REG_CHIP_ID_MASK GENMASK(7, 0)
+
+/* STMFX_REG_SYS_CTRL bitfields */
+#define STMFX_REG_SYS_CTRL_GPIO_EN BIT(0)
+#define STMFX_REG_SYS_CTRL_TS_EN BIT(1)
+#define STMFX_REG_SYS_CTRL_IDD_EN BIT(2)
+#define STMFX_REG_SYS_CTRL_ALTGPIO_EN BIT(3)
+#define STMFX_REG_SYS_CTRL_SWRST BIT(7)
+
+/* STMFX_REG_IRQ_OUT_PIN bitfields */
+#define STMFX_REG_IRQ_OUT_PIN_TYPE BIT(0) /* 0-OD 1-PP */
+#define STMFX_REG_IRQ_OUT_PIN_POL BIT(1) /* 0-active LOW 1-active HIGH */
+
+/* STMFX_REG_IRQ_(SRC_EN/PENDING/ACK) bit shift */
+enum stmfx_irqs {
+ STMFX_REG_IRQ_SRC_EN_GPIO = 0,
+ STMFX_REG_IRQ_SRC_EN_IDD,
+ STMFX_REG_IRQ_SRC_EN_ERROR,
+ STMFX_REG_IRQ_SRC_EN_TS_DET,
+ STMFX_REG_IRQ_SRC_EN_TS_NE,
+ STMFX_REG_IRQ_SRC_EN_TS_TH,
+ STMFX_REG_IRQ_SRC_EN_TS_FULL,
+ STMFX_REG_IRQ_SRC_EN_TS_OVF,
+ STMFX_REG_IRQ_SRC_MAX,
+};
+
+/**
+ * struct stmfx_ddata - STMFX MFD private structure
+ * @stmfx: state holder with device for logs and register map
+ * @vdd: STMFX power supply
+ * @irq_domain: IRQ domain
+ * @lock: IRQ bus lock
+ * @irq_src: cache of IRQ_SRC_EN register for bus_lock
+ * @bkp_sysctrl: backup of SYS_CTRL register for suspend/resume
+ * @bkp_irqoutpin: backup of IRQ_OUT_PIN register for suspend/resume
+ */
+struct stmfx_ddata {
+ struct stmfx *stmfx;
+ struct regulator *vdd;
+ struct irq_domain *irq_domain;
+ struct mutex lock; /* IRQ bus lock */
+ u8 irq_src;
+#ifdef CONFIG_PM
+ u8 bkp_sysctrl;
+ u8 bkp_irqoutpin;
+#endif
+};
+
+static u8 stmfx_func_to_mask(u32 func)
+{
+ u8 mask = 0;
+
+ if (func & STMFX_FUNC_GPIO)
+ mask |= STMFX_REG_SYS_CTRL_GPIO_EN;
+
+ if ((func & STMFX_FUNC_ALTGPIO_LOW) || (func & STMFX_FUNC_ALTGPIO_HIGH))
+ mask |= STMFX_REG_SYS_CTRL_ALTGPIO_EN;
+
+ if (func & STMFX_FUNC_TS)
+ mask |= STMFX_REG_SYS_CTRL_TS_EN;
+
+ if (func & STMFX_FUNC_IDD)
+ mask |= STMFX_REG_SYS_CTRL_IDD_EN;
+
+ return mask;
+}
+
+int stmfx_function_enable(struct stmfx *stmfx, u32 func)
+{
+ u32 sys_ctrl;
+ u8 mask;
+ int ret;
+
+ ret = regmap_read(stmfx->map, STMFX_REG_SYS_CTRL, &sys_ctrl);
+ if (ret)
+ return ret;
+
+ /*
+ * IDD and TS have priority in STMFX FW, so if IDD and TS are enabled,
+ * ALTGPIO function is disabled by STMFX FW. If IDD or TS is enabled,
+ * the number of aGPIO available decreases. To avoid GPIO management
+ * disturbance, abort IDD or TS function enable in this case.
+ */
+ if (((func & STMFX_FUNC_IDD) || (func & STMFX_FUNC_TS)) &&
+ (sys_ctrl & STMFX_REG_SYS_CTRL_ALTGPIO_EN)) {
+ dev_err(stmfx->dev, "ALTGPIO function already enabled\n");
+ return -EBUSY;
+ }
+
+ /* If TS is enabled, aGPIO[3:0] cannot be used */
+ if ((func & STMFX_FUNC_ALTGPIO_LOW) &&
+ (sys_ctrl & STMFX_REG_SYS_CTRL_TS_EN)) {
+ dev_err(stmfx->dev, "TS in use, aGPIO[3:0] unavailable\n");
+ return -EBUSY;
+ }
+
+ /* If IDD is enabled, aGPIO[7:4] cannot be used */
+ if ((func & STMFX_FUNC_ALTGPIO_HIGH) &&
+ (sys_ctrl & STMFX_REG_SYS_CTRL_IDD_EN)) {
+ dev_err(stmfx->dev, "IDD in use, aGPIO[7:4] unavailable\n");
+ return -EBUSY;
+ }
+
+ mask = stmfx_func_to_mask(func);
+
+ return regmap_update_bits(stmfx->map, STMFX_REG_SYS_CTRL, mask, mask);
+}
+EXPORT_SYMBOL_GPL(stmfx_function_enable);
+
+int stmfx_function_disable(struct stmfx *stmfx, u32 func)
+{
+ u8 mask = stmfx_func_to_mask(func);
+
+ return regmap_update_bits(stmfx->map, STMFX_REG_SYS_CTRL, mask, 0);
+}
+EXPORT_SYMBOL_GPL(stmfx_function_disable);
+
+static void stmfx_irq_bus_lock(struct irq_data *data)
+{
+ struct stmfx_ddata *ddata = irq_data_get_irq_chip_data(data);
+
+ mutex_lock(&ddata->lock);
+}
+
+static void stmfx_irq_bus_sync_unlock(struct irq_data *data)
+{
+ struct stmfx_ddata *ddata = irq_data_get_irq_chip_data(data);
+
+ regmap_write(ddata->stmfx->map, STMFX_REG_IRQ_SRC_EN, ddata->irq_src);
+
+ mutex_unlock(&ddata->lock);
+}
+
+static void stmfx_irq_mask(struct irq_data *data)
+{
+ struct stmfx_ddata *ddata = irq_data_get_irq_chip_data(data);
+
+ ddata->irq_src &= ~BIT(data->hwirq % 8);
+}
+
+static void stmfx_irq_unmask(struct irq_data *data)
+{
+ struct stmfx_ddata *ddata = irq_data_get_irq_chip_data(data);
+
+ ddata->irq_src |= BIT(data->hwirq % 8);
+}
+
+static struct irq_chip stmfx_irq_chip = {
+ .name = "stmfx-core",
+ .irq_bus_lock = stmfx_irq_bus_lock,
+ .irq_bus_sync_unlock = stmfx_irq_bus_sync_unlock,
+ .irq_mask = stmfx_irq_mask,
+ .irq_unmask = stmfx_irq_unmask,
+};
+
+static irqreturn_t stmfx_irq_handler(int irq, void *data)
+{
+ struct stmfx_ddata *ddata = data;
+ unsigned long n, pending;
+ u32 ack;
+ int ret;
+
+ ret = regmap_read(ddata->stmfx->map, STMFX_REG_IRQ_PENDING,
+ (u32 *)&pending);
+ if (ret)
+ return IRQ_NONE;
+
+ /*
+ * There is no ACK for GPIO, MFX_REG_IRQ_PENDING_GPIO is a logical OR
+ * of MFX_REG_IRQ_GPI _PENDING1/_PENDING2/_PENDING3
+ */
+ ack = pending & ~BIT(STMFX_REG_IRQ_SRC_EN_GPIO);
+ if (ack) {
+ ret = regmap_write(ddata->stmfx->map, STMFX_REG_IRQ_ACK, ack);
+ if (ret)
+ return IRQ_NONE;
+ }
+
+ for_each_set_bit(n, &pending, STMFX_REG_IRQ_SRC_MAX)
+ handle_nested_irq(irq_find_mapping(ddata->irq_domain, n));
+
+ return IRQ_HANDLED;
+}
+
+static int stmfx_irq_map(struct irq_domain *d, unsigned int virq,
+ irq_hw_number_t hwirq)
+{
+ irq_set_chip_data(virq, d->host_data);
+ irq_set_chip_and_handler(virq, &stmfx_irq_chip, handle_simple_irq);
+ irq_set_nested_thread(virq, 1);
+ irq_set_noprobe(virq);
+
+ return 0;
+}
+
+static void stmfx_irq_unmap(struct irq_domain *d, unsigned int virq)
+{
+ irq_set_chip_and_handler(virq, NULL, NULL);
+ irq_set_chip_data(virq, NULL);
+}
+
+static const struct irq_domain_ops stmfx_irq_ops = {
+ .map = stmfx_irq_map,
+ .unmap = stmfx_irq_unmap,
+};
+
+static void stmfx_irq_exit(struct stmfx_ddata *ddata)
+{
+ int hwirq;
+
+ for (hwirq = 0; hwirq < STMFX_REG_IRQ_SRC_MAX; hwirq++)
+ irq_dispose_mapping(irq_find_mapping(ddata->irq_domain, hwirq));
+ irq_domain_remove(ddata->irq_domain);
+}
+
+static int stmfx_irq_init(struct stmfx_ddata *ddata, int irq)
+{
+ struct device *dev = ddata->stmfx->dev;
+ u32 irqoutpin = 0, irqtrigger;
+ int ret;
+
+ ddata->irq_domain = irq_domain_add_simple(dev->of_node,
+ STMFX_REG_IRQ_SRC_MAX, 0,
+ &stmfx_irq_ops, ddata);
+ if (!ddata->irq_domain) {
+ dev_err(dev, "failed to create irq domain\n");
+ return -EINVAL;
+ }
+
+ if (!of_property_read_bool(dev->of_node, "drive-open-drain"))
+ irqoutpin |= STMFX_REG_IRQ_OUT_PIN_TYPE;
+
+ irqtrigger = irq_get_trigger_type(irq);
+ if ((irqtrigger & IRQ_TYPE_EDGE_RISING) ||
+ (irqtrigger & IRQ_TYPE_LEVEL_HIGH))
+ irqoutpin |= STMFX_REG_IRQ_OUT_PIN_POL;
+
+ ret = regmap_write(ddata->stmfx->map, STMFX_REG_IRQ_OUT_PIN, irqoutpin);
+ if (ret)
+ return ret;
+
+ ret = devm_request_threaded_irq(dev, irq, NULL, stmfx_irq_handler,
+ irqtrigger | IRQF_ONESHOT,
+ "stmfx", ddata);
+ if (ret)
+ stmfx_irq_exit(ddata);
+
+ return ret;
+}
+
+static int stmfx_chip_reset(struct stmfx_ddata *ddata)
+{
+ int ret;
+
+ ret = regmap_write(ddata->stmfx->map, STMFX_REG_SYS_CTRL,
+ STMFX_REG_SYS_CTRL_SWRST);
+ if (ret)
+ return ret;
+
+ msleep(STMFX_BOOT_TIME_MS);
+
+ return ret;
+}
+
+static int stmfx_chip_init(struct stmfx_ddata *ddata, struct i2c_client *client)
+{
+ u32 id;
+ u8 version[2];
+ int ret;
+
+ ddata->vdd = devm_regulator_get_optional(&client->dev, "vdd");
+ if (IS_ERR(ddata->vdd)) {
+ ret = PTR_ERR(ddata->vdd);
+ if (ret != -ENODEV) {
+ if (ret != -EPROBE_DEFER)
+ dev_err(&client->dev,
+ "no vdd regulator found:%d\n", ret);
+ return ret;
+ }
+ }
+
+ if (!IS_ERR(ddata->vdd)) {
+ ret = regulator_enable(ddata->vdd);
+ if (ret) {
+ dev_err(&client->dev, "vdd enable failed: %d\n", ret);
+ return ret;
+ }
+ }
+
+ ret = regmap_read(ddata->stmfx->map, STMFX_REG_CHIP_ID, &id);
+ if (ret) {
+ dev_err(&client->dev, "error reading chip id: %d\n", ret);
+ goto err;
+ }
+
+ /*
+ * Check that ID is the complement of the I2C address:
+ * STMFX I2C address follows the 7-bit format (MSB), that's why
+ * client->addr is shifted.
+ *
+ * STMFX_I2C_ADDR| STMFX | Linux
+ * input pin | I2C device address | I2C device address
+ *---------------------------------------------------------
+ * 0 | b: 1000 010x h:0x84 | 0x42
+ * 1 | b: 1000 011x h:0x86 | 0x43
+ */
+ if (FIELD_GET(STMFX_REG_CHIP_ID_MASK, ~id) != (client->addr << 1)) {
+ dev_err(&client->dev, "unknown chip id: %#x\n", id);
+ ret = -EINVAL;
+ goto err;
+ }
+
+ ret = regmap_bulk_read(ddata->stmfx->map, STMFX_REG_FW_VERSION_MSB,
+ version, ARRAY_SIZE(version));
+ if (ret) {
+ dev_err(&client->dev, "error reading fw version: %d\n", ret);
+ goto err;
+ }
+
+ dev_info(&client->dev, "STMFX id: %#x, fw version: %x.%02x\n",
+ id, version[0], version[1]);
+
+ return stmfx_chip_reset(ddata);
+
+err:
+ if (!IS_ERR(ddata->vdd))
+ return regulator_disable(ddata->vdd);
+
+ return ret;
+}
+
+static int stmfx_chip_exit(struct stmfx_ddata *ddata)
+{
+ regmap_write(ddata->stmfx->map, STMFX_REG_IRQ_SRC_EN, 0);
+ regmap_write(ddata->stmfx->map, STMFX_REG_SYS_CTRL, 0);
+
+ if (!IS_ERR(ddata->vdd))
+ return regulator_disable(ddata->vdd);
+
+ return 0;
+}
+
+static const struct resource stmfx_pinctrl_resources[] = {
+ DEFINE_RES_IRQ(STMFX_REG_IRQ_SRC_EN_GPIO),
+};
+
+static struct mfd_cell stmfx_cells[] = {
+ {
+ .of_compatible = "st,stmfx-0300-pinctrl",
+ .name = "stmfx-pinctrl",
+ .resources = stmfx_pinctrl_resources,
+ .num_resources = ARRAY_SIZE(stmfx_pinctrl_resources),
+ }
+};
+
+static bool stmfx_reg_volatile(struct device *dev, unsigned int reg)
+{
+ switch (reg) {
+ case STMFX_REG_SYS_CTRL:
+ case STMFX_REG_IRQ_SRC_EN:
+ case STMFX_REG_IRQ_PENDING:
+ case STMFX_REG_IRQ_GPI_PENDING1:
+ case STMFX_REG_IRQ_GPI_PENDING2:
+ case STMFX_REG_IRQ_GPI_PENDING3:
+ case STMFX_REG_GPIO_STATE1:
+ case STMFX_REG_GPIO_STATE2:
+ case STMFX_REG_GPIO_STATE3:
+ case STMFX_REG_IRQ_GPI_SRC1:
+ case STMFX_REG_IRQ_GPI_SRC2:
+ case STMFX_REG_IRQ_GPI_SRC3:
+ case STMFX_REG_GPO_SET1:
+ case STMFX_REG_GPO_SET2:
+ case STMFX_REG_GPO_SET3:
+ case STMFX_REG_GPO_CLR1:
+ case STMFX_REG_GPO_CLR2:
+ case STMFX_REG_GPO_CLR3:
+ return true;
+ default:
+ return false;
+ }
+}
+
+static bool stmfx_reg_writeable(struct device *dev, unsigned int reg)
+{
+ return (reg >= STMFX_REG_SYS_CTRL);
+}
+
+static const struct regmap_config stmfx_regmap_config = {
+ .reg_bits = 8,
+ .reg_stride = 1,
+ .val_bits = 8,
+ .max_register = STMFX_REG_MAX,
+ .volatile_reg = stmfx_reg_volatile,
+ .writeable_reg = stmfx_reg_writeable,
+ .cache_type = REGCACHE_RBTREE,
+};
+
+static int stmfx_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct device *dev = &client->dev;
+ struct stmfx_ddata *ddata;
+ int i, ret;
+
+ ddata = devm_kzalloc(dev, sizeof(*ddata), GFP_KERNEL);
+ if (!ddata)
+ return -ENOMEM;
+ /* State holder */
+ ddata->stmfx = devm_kzalloc(dev, sizeof(*ddata->stmfx), GFP_KERNEL);
+ if (!ddata->stmfx)
+ return -ENOMEM;
+
+ i2c_set_clientdata(client, ddata);
+
+ ddata->stmfx->dev = dev;
+
+ ddata->stmfx->map = devm_regmap_init_i2c(client, &stmfx_regmap_config);
+ if (IS_ERR(ddata->stmfx->map)) {
+ ret = PTR_ERR(ddata->stmfx->map);
+ dev_err(dev, "failed to allocate register map: %d\n", ret);
+ return ret;
+ }
+
+ mutex_init(&ddata->lock);
+
+ ret = stmfx_chip_init(ddata, client);
+ if (ret) {
+ if (ret == -ETIMEDOUT)
+ return -EPROBE_DEFER;
+ return ret;
+ }
+
+ if (client->irq < 0) {
+ dev_err(dev, "failed to get irq: %d\n", client->irq);
+ ret = client->irq;
+ goto err_chip_exit;
+ }
+
+ ret = stmfx_irq_init(ddata, client->irq);
+ if (ret)
+ goto err_chip_exit;
+
+ for (i = 0; i < ARRAY_SIZE(stmfx_cells); i++) {
+ stmfx_cells[i].platform_data = ddata->stmfx;
+ stmfx_cells[i].pdata_size = sizeof(struct stmfx);
+ }
+
+ ret = devm_mfd_add_devices(dev, PLATFORM_DEVID_NONE,
+ stmfx_cells, ARRAY_SIZE(stmfx_cells), NULL,
+ 0, ddata->irq_domain);
+ if (ret)
+ goto err_irq_exit;
+
+ return 0;
+
+err_irq_exit:
+ stmfx_irq_exit(ddata);
+err_chip_exit:
+ stmfx_chip_exit(ddata);
+
+ return ret;
+}
+
+static int stmfx_remove(struct i2c_client *client)
+{
+ struct stmfx_ddata *ddata = i2c_get_clientdata(client);
+
+ stmfx_irq_exit(ddata);
+
+ return stmfx_chip_exit(ddata);
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int stmfx_backup_regs(struct stmfx_ddata *ddata)
+{
+ int ret;
+
+ ret = regmap_raw_read(ddata->stmfx->map, STMFX_REG_SYS_CTRL,
+ &ddata->bkp_sysctrl, sizeof(ddata->bkp_sysctrl));
+ if (ret)
+ return ret;
+ ret = regmap_raw_read(ddata->stmfx->map, STMFX_REG_IRQ_OUT_PIN,
+ &ddata->bkp_irqoutpin,
+ sizeof(ddata->bkp_irqoutpin));
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static int stmfx_restore_regs(struct stmfx_ddata *ddata)
+{
+ int ret;
+
+ ret = regmap_raw_write(ddata->stmfx->map, STMFX_REG_SYS_CTRL,
+ &ddata->bkp_sysctrl, sizeof(ddata->bkp_sysctrl));
+ if (ret)
+ return ret;
+ ret = regmap_raw_write(ddata->stmfx->map, STMFX_REG_IRQ_OUT_PIN,
+ &ddata->bkp_irqoutpin,
+ sizeof(ddata->bkp_irqoutpin));
+ if (ret)
+ return ret;
+ ret = regmap_raw_write(ddata->stmfx->map, STMFX_REG_IRQ_SRC_EN,
+ &ddata->irq_src, sizeof(ddata->irq_src));
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static int stmfx_suspend(struct device *dev)
+{
+ struct stmfx_ddata *ddata = dev_get_drvdata(dev);
+ int ret;
+
+ ret = stmfx_backup_regs(ddata);
+ if (ret) {
+ dev_err(ddata->stmfx->dev, "registers backup failure\n");
+ return ret;
+ }
+
+ if (!IS_ERR(ddata->vdd)) {
+ ret = regulator_disable(ddata->vdd);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+static int stmfx_resume(struct device *dev)
+{
+ struct stmfx_ddata *ddata = dev_get_drvdata(dev);
+ int ret;
+
+ if (!IS_ERR(ddata->vdd)) {
+ ret = regulator_enable(ddata->vdd);
+ if (ret) {
+ dev_err(ddata->stmfx->dev,
+ "vdd enable failed: %d\n", ret);
+ return ret;
+ }
+ }
+
+ ret = stmfx_restore_regs(ddata);
+ if (ret) {
+ dev_err(ddata->stmfx->dev, "registers restoration failure\n");
+ return ret;
+ }
+
+ return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(stmfx_dev_pm_ops, stmfx_suspend, stmfx_resume);
+
+static const struct of_device_id stmfx_of_match[] = {
+ { .compatible = "st,stmfx-0300", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, stmfx_of_match);
+
+static struct i2c_driver stmfx_driver = {
+ .driver = {
+ .name = "stmfx-core",
+ .of_match_table = of_match_ptr(stmfx_of_match),
+ .pm = &stmfx_dev_pm_ops,
+ },
+ .probe = stmfx_probe,
+ .remove = stmfx_remove,
+};
+module_i2c_driver(stmfx_driver);
+
+MODULE_DESCRIPTION("STMFX core driver");
+MODULE_AUTHOR("Amelie Delaunay <amelie.delaunay@xxxxxx>");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/mfd/stmfx.h b/include/linux/mfd/stmfx.h
new file mode 100644
index 0000000..35c3d42
--- /dev/null
+++ b/include/linux/mfd/stmfx.h
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2018 STMicroelectronics
+ * Author(s): Amelie Delaunay <amelie.delaunay@xxxxxx>.
+ */
+
+#ifndef MFD_STMFX_H
+#define MFX_STMFX_H
+
+#include <linux/regmap.h>
+
+enum stmfx_functions {
+ STMFX_FUNC_GPIO = BIT(0), /* GPIO[15:0] */
+ STMFX_FUNC_ALTGPIO_LOW = BIT(1), /* aGPIO[3:0] */
+ STMFX_FUNC_ALTGPIO_HIGH = BIT(2), /* aGPIO[7:4] */
+ STMFX_FUNC_TS = BIT(3),
+ STMFX_FUNC_IDD = BIT(4),
+};
+
+struct stmfx {
+ struct device *dev;
+ struct regmap *map;
+};
+
+int stmfx_function_enable(struct stmfx *stmfx, u32 func);
+int stmfx_function_disable(struct stmfx *stmfx, u32 func);
+#endif
--
2.7.4