[PATCH v6 2/7] mfd: Add driver for ASUS Transformer embedded controller

Svyatoslav Ryhel
2026-05-02T12:41:19Z

Support Nuvoton NPCE795-based ECs as used in Asus Transformer TF201,
TF300T, TF300TG, TF300TL and TF700T pad and dock, as well as TF101 dock
and TF600T, P1801-T and TF701T pad. This is a glue driver handling
detection and common operations for EC's functions.

Co-developed-by: Svyatoslav Ryhel <clamor95@gmail.com>
Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
---
drivers/mfd/Kconfig | 14 +
drivers/mfd/Makefile | 1 +
drivers/mfd/asus-transformer-ec.c | 762 ++++++++++++++++++++++++
include/linux/mfd/asus-transformer-ec.h | 162 +++++
4 files changed, 939 insertions(+)
create mode 100644 drivers/mfd/asus-transformer-ec.c
create mode 100644 include/linux/mfd/asus-transformer-ec.h

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 7192c9d1d268..5aa4facfd2df 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -137,6 +137,20 @@ config MFD_AAT2870_CORE
additional drivers must be enabled in order to use the
functionality of the device.

+config MFD_ASUS_TRANSFORMER_EC
+ tristate "ASUS Transformer's embedded controller"
+ depends on I2C && OF
+ help
+ Support ECs found in ASUS Transformer's Pad and Mobile Dock.
+
+ This provides shared glue for functional part drivers:
+ asus-transformer-ec-kbc, asus-transformer-ec-keys,
+ leds-asus-transformer-ec, asus-transformer-ec-battery
+ and asus-transformer-ec-charger.
+
+ This driver can also be built as a module. If so, the module
+ will be called asus-transformer-ec.
+
config MFD_AT91_USART
tristate "AT91 USART Driver"
select MFD_CORE
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index e75e8045c28a..fd80088d8a9a 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -10,6 +10,7 @@ obj-$(CONFIG_MFD_88PM805) += 88pm805.o 88pm80x.o
obj-$(CONFIG_MFD_88PM886_PMIC) += 88pm886.o
obj-$(CONFIG_MFD_ACT8945A) += act8945a.o
obj-$(CONFIG_MFD_SM501) += sm501.o
+obj-$(CONFIG_MFD_ASUS_TRANSFORMER_EC) += asus-transformer-ec.o
obj-$(CONFIG_ARCH_BCM2835) += bcm2835-pm.o
obj-$(CONFIG_MFD_BCM590XX) += bcm590xx.o
obj-$(CONFIG_MFD_BD9571MWV) += bd9571mwv.o
diff --git a/drivers/mfd/asus-transformer-ec.c b/drivers/mfd/asus-transformer-ec.c
new file mode 100644
index 000000000000..75aa7ab99387
--- /dev/null
+++ b/drivers/mfd/asus-transformer-ec.c
@@ -0,0 +1,762 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <linux/array_size.h>
+#include <linux/debugfs.h>
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/mfd/asus-transformer-ec.h>
+#include <linux/mfd/core.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/property.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/unaligned.h>
+
+#define ASUSEC_RSP_BUFFER_SIZE 8
+
+struct asus_ec_chip_data {
+ const char *name;
+ const struct mfd_cell *mfd_devices;
+ unsigned int num_devices;
+ bool clr_fmode; /* clear Factory Mode bit in EC control register */
+};
+
+struct asus_ec_data {
+ struct asusec_info info;
+ struct mutex ecreq_lock; /* prevent simultaneous access */
+ struct gpio_desc *ecreq;
+ struct i2c_client *self;
+ const struct asus_ec_chip_data *data;
+ char ec_data[DOCKRAM_ENTRY_BUFSIZE];
+ bool logging_disabled;
+};
+
+struct dockram_ec_data {
+ struct mutex ctl_lock; /* prevent simultaneous access */
+ char ctl_data[DOCKRAM_ENTRY_BUFSIZE];
+};
+
+#define to_ec_data(ec) \
+ container_of(ec, struct asus_ec_data, info)
+
+/**
+ * asus_dockram_read - Read a register from the DockRAM device.
+ * @client: Handle to the DockRAM device.
+ * @reg: Register to read.
+ * @buf: Byte array into which data will be read; must be large enough to
+ * hold the data returned by the DockRAM.
+ *
+ * This executes the DockRAM read based on the SMBus "block read" protocol
+ * or its emulation. It extracts DOCKRAM_ENTRY_SIZE bytes from the set
+ * register address.
+ *
+ * Returns a negative errno code else zero on success.
+ */
+int asus_dockram_read(struct i2c_client *client, int reg, char *buf)
+{
+ struct device *dev = &client->dev;
+ int ret;
+
+ memset(buf, 0, DOCKRAM_ENTRY_BUFSIZE);
+ ret = i2c_smbus_read_i2c_block_data(client, reg,
+ DOCKRAM_ENTRY_BUFSIZE, buf);
+ if (ret < 0)
+ return ret;
+
+ if (buf[0] > DOCKRAM_ENTRY_SIZE) {
+ dev_err(dev, "bad data len; buffer: %*ph; ret: %d\n",
+ DOCKRAM_ENTRY_BUFSIZE, buf, ret);
+ return -EPROTO;
+ }
+
+ dev_dbg(dev, "got data; buffer: %*ph; ret: %d\n",
+ DOCKRAM_ENTRY_BUFSIZE, buf, ret);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(asus_dockram_read);
+
+/**
+ * asus_dockram_write - Write a byte array to a register of the DockRAM device.
+ * @client: Handle to the DockRAM device.
+ * @reg: Register to write to.
+ * @buf: Byte array to be written (up to DOCKRAM_ENTRY_SIZE bytes).
+ *
+ * This executes the DockRAM write based on the SMBus "block write"
+ * protocol or its emulation. It writes DOCKRAM_ENTRY_SIZE bytes to the
+ * specified register address.
+ *
+ * Returns a negative errno code else zero on success.
+ */
+int asus_dockram_write(struct i2c_client *client, int reg, const char *buf)
+{
+ if (buf[0] > DOCKRAM_ENTRY_SIZE)
+ return -EINVAL;
+
+ dev_dbg(&client->dev, "sending data; buffer: %*ph\n", buf[0] + 1, buf);
+
+ return i2c_smbus_write_i2c_block_data(client, reg, buf[0] + 1, buf);
+}
+EXPORT_SYMBOL_GPL(asus_dockram_write);
+
+/**
+ * asus_dockram_access_ctl - Read from or write to the DockRAM control register.
+ * @client: Handle to the DockRAM device.
+ * @out: Pointer to a variable where the register value will be stored.
+ * @mask: Bitmask of bits to be cleared.
+ * @xor: Bitmask of bits to be set (via XOR).
+ *
+ * This performs a control register read if @out is provided and both @mask
+ * and @xor are zero. Otherwise, it performs a control register update if
+ * @mask and @xor are provided.
+ *
+ * Returns a negative errno code else zero on success.
+ */
+int asus_dockram_access_ctl(struct i2c_client *client, u64 *out, u64 mask,
+ u64 xor)
+{
+ struct dockram_ec_data *priv = i2c_get_clientdata(client);
+ char *buf = priv->ctl_data;
+ u64 val;
+ int ret = 0;
+
+ guard(mutex)(&priv->ctl_lock);
+
+ ret = asus_dockram_read(client, ASUSEC_DOCKRAM_CONTROL, buf);
+ if (ret < 0)
+ goto exit;
+
+ if (buf[0] != ASUSEC_CTL_SIZE) {
+ ret = -EPROTO;
+ goto exit;
+ }
+
+ val = get_unaligned_le64(buf + 1);
+
+ if (out)
+ *out = val;
+
+ if (mask || xor) {
+ put_unaligned_le64((val & ~mask) ^ xor, buf + 1);
+ ret = asus_dockram_write(client, ASUSEC_DOCKRAM_CONTROL, buf);
+ }
+
+exit:
+ if (ret < 0)
+ dev_err(&client->dev, "Failed to access control flags: %d\n",
+ ret);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(asus_dockram_access_ctl);
+
+static void asus_ec_remove_notifier(struct device *dev, void *res)
+{
+ struct asusec_info *ec = dev_get_drvdata(dev->parent);
+ struct notifier_block **nb = res;
+
+ blocking_notifier_chain_unregister(&ec->notify_list, *nb);
+}
+
+/**
+ * devm_asus_ec_register_notifier - Managed registration of notifier to an
+ * ASUS EC blocking notifier chain.
+ * @pdev: Device requesting the notifier (used for resource management).
+ * @nb: Notifier block to be registered.
+ *
+ * Register a notifier to the ASUS EC blocking notifier chain. The notifier
+ * will be automatically unregistered when the requesting device is detached.
+ *
+ * Return: 0 on success or a negative error code on failure.
+ */
+int devm_asus_ec_register_notifier(struct platform_device *pdev,
+ struct notifier_block *nb)
+{
+ struct asusec_info *ec = dev_get_drvdata(pdev->dev.parent);
+ struct notifier_block **res;
+ int ret;
+
+ res = devres_alloc(asus_ec_remove_notifier, sizeof(*res), GFP_KERNEL);
+ if (!res)
+ return -ENOMEM;
+
+ *res = nb;
+ ret = blocking_notifier_chain_register(&ec->notify_list, nb);
+ if (ret) {
+ devres_free(res);
+ return ret;
+ }
+
+ devres_add(&pdev->dev, res);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(devm_asus_ec_register_notifier);
+
+static int asus_ec_signal_request(const struct asusec_info *ec)
+{
+ struct asus_ec_data *priv = to_ec_data(ec);
+
+ guard(mutex)(&priv->ecreq_lock);
+
+ dev_dbg(&priv->self->dev, "EC request\n");
+
+ gpiod_set_value_cansleep(priv->ecreq, 1);
+ msleep(50);
+
+ gpiod_set_value_cansleep(priv->ecreq, 0);
+ msleep(200);
+
+ return 0;
+}
+
+static int asus_ec_write(struct asus_ec_data *priv, u16 data)
+{
+ int ret = i2c_smbus_write_word_data(priv->self, ASUSEC_WRITE_BUF, data);
+
+ dev_dbg(&priv->self->dev, "EC write: %04x, ret = %d\n", data, ret);
+
+ return ret;
+}
+
+static int asus_ec_read(struct asus_ec_data *priv, bool in_irq)
+{
+ int ret = i2c_smbus_read_i2c_block_data(priv->self, ASUSEC_READ_BUF,
+ sizeof(priv->ec_data),
+ priv->ec_data);
+
+ dev_dbg(&priv->self->dev, "EC read: %*ph, ret = %d%s\n",
+ sizeof(priv->ec_data), priv->ec_data,
+ ret, in_irq ? "; in irq" : "");
+
+ return ret;
+}
+
+/**
+ * asus_ec_i2c_command - Send a 16-bit command to the ASUS EC.
+ * @ec: Pointer to the shared ASUS EC structure.
+ * @data: The 16-bit command (word) to be sent.
+ *
+ * Return: 0 on success or a negative error code on failure.
+ */
+int asus_ec_i2c_command(const struct asusec_info *ec, u16 data)
+{
+ return asus_ec_write(to_ec_data(ec), data);
+}
+EXPORT_SYMBOL_GPL(asus_ec_i2c_command);
+
+static void asus_ec_clear_buffer(struct asus_ec_data *priv)
+{
+ int retry = ASUSEC_RSP_BUFFER_SIZE;
+
+ while (retry--) {
+ if (asus_ec_read(priv, false) < 0)
+ continue;
+
+ if (priv->ec_data[1] & ASUSEC_OBF_MASK)
+ continue;
+
+ break;
+ }
+}
+
+static int asus_ec_log_info(struct asus_ec_data *priv, unsigned int reg,
+ const char *name, char **out)
+{
+ char buf[DOCKRAM_ENTRY_BUFSIZE];
+ int ret;
+
+ ret = asus_dockram_read(priv->info.dockram, reg, buf);
+ if (ret < 0)
+ return ret;
+
+ if (!priv->logging_disabled)
+ dev_info(&priv->self->dev, "%-14s: %.*s\n", name,
+ buf[0], buf + 1);
+
+ if (out)
+ *out = kstrndup(buf + 1, buf[0], GFP_KERNEL);
+
+ return 0;
+}
+
+static int asus_ec_reset(struct asus_ec_data *priv)
+{
+ int retry, ret;
+
+ for (retry = 0; retry < 3; retry++) {
+ ret = asus_ec_write(priv, 0);
+ if (!ret)
+ return 0;
+
+ msleep(300);
+ }
+
+ return ret;
+}
+
+static int asus_ec_magic_debug(struct asus_ec_data *priv)
+{
+ u64 flag;
+ int ret;
+
+ ret = asus_ec_get_ctl(&priv->info, &flag);
+ if (ret < 0)
+ return ret;
+
+ flag &= ASUSEC_CTL_SUSB_MODE;
+ dev_info(&priv->self->dev, "EC FW behaviour: %s\n",
+ flag ? "susb on when receive ec_req" :
+ "susb on when system wakeup");
+
+ return 0;
+}
+
+static int asus_ec_set_factory_mode(struct asus_ec_data *priv, bool on)
+{
+ dev_info(&priv->self->dev, "Entering %s mode.\n", on ? "factory" :
+ "normal");
+
+ return asus_ec_update_ctl(&priv->info, ASUSEC_CTL_FACTORY_MODE,
+ on ? ASUSEC_CTL_FACTORY_MODE : 0);
+}
+
+static int asus_ec_detect(struct asus_ec_data *priv)
+{
+ char *model = NULL;
+ int ret;
+
+ ret = asus_ec_reset(priv);
+ if (ret)
+ goto err_exit;
+
+ asus_ec_clear_buffer(priv);
+
+ ret = asus_ec_log_info(priv, ASUSEC_DOCKRAM_INFO_MODEL, "model", &model);
+ if (ret)
+ goto err_exit;
+
+ ret = asus_ec_log_info(priv, ASUSEC_DOCKRAM_INFO_FW, "FW version", NULL);
+ if (ret)
+ goto err_exit;
+
+ ret = asus_ec_log_info(priv, ASUSEC_DOCKRAM_INFO_CFGFMT, "Config format", NULL);
+ if (ret)
+ goto err_exit;
+
+ ret = asus_ec_log_info(priv, ASUSEC_DOCKRAM_INFO_HW, "HW version", NULL);
+ if (ret)
+ goto err_exit;
+
+ priv->logging_disabled = true;
+
+ ret = asus_ec_magic_debug(priv);
+ if (ret)
+ goto err_exit;
+
+ priv->info.model = model;
+ priv->info.name = priv->data->name;
+
+ if (priv->data->clr_fmode)
+ asus_ec_set_factory_mode(priv, false);
+
+err_exit:
+ if (ret)
+ dev_err(&priv->self->dev, "failed to access EC: %d\n", ret);
+
+ return ret;
+}
+
+static void asus_ec_handle_smi(struct asus_ec_data *priv, unsigned int code)
+{
+ dev_dbg(&priv->self->dev, "SMI interrupt: 0x%02x\n", code);
+
+ switch (code) {
+ case ASUSEC_SMI_HANDSHAKE:
+ case ASUSEC_SMI_RESET:
+ asus_ec_detect(priv);
+ break;
+ }
+}
+
+static irqreturn_t asus_ec_interrupt(int irq, void *dev_id)
+{
+ struct asus_ec_data *priv = dev_id;
+ unsigned long notify_action;
+ int ret;
+
+ ret = asus_ec_read(priv, true);
+ if (ret <= 0 || !(priv->ec_data[1] & ASUSEC_OBF_MASK))
+ return IRQ_NONE;
+
+ notify_action = priv->ec_data[1];
+ if (notify_action & ASUSEC_SMI_MASK) {
+ unsigned int code = priv->ec_data[2];
+
+ asus_ec_handle_smi(priv, code);
+
+ notify_action |= code << 8;
+ dev_dbg(&priv->self->dev, "SMI code: 0x%02x\n", code);
+ }
+
+ blocking_notifier_call_chain(&priv->info.notify_list,
+ notify_action, priv->ec_data);
+
+ return IRQ_HANDLED;
+}
+
+static ssize_t dockram_read(struct file *filp, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct i2c_client *client = filp->private_data;
+ unsigned int reg, rsize;
+ ssize_t n_read = 0, val;
+ loff_t off = *ppos;
+ char *data;
+ int ret;
+
+ reg = off / DOCKRAM_ENTRY_SIZE;
+ off %= DOCKRAM_ENTRY_SIZE;
+ rsize = DOCKRAM_ENTRIES * DOCKRAM_ENTRY_SIZE;
+
+ if (!count)
+ return 0;
+
+ data = kmalloc(DOCKRAM_ENTRY_BUFSIZE, GFP_KERNEL);
+
+ while (reg < DOCKRAM_ENTRIES) {
+ unsigned int len = DOCKRAM_ENTRY_SIZE - off;
+
+ if (len > rsize)
+ len = rsize;
+
+ ret = asus_dockram_read(client, reg, data);
+ if (ret < 0) {
+ if (!n_read)
+ n_read = ret;
+ break;
+ }
+
+ val = copy_to_user(buf, data + 1 + off, len);
+ if (val == len)
+ return -EFAULT;
+
+ *ppos += len;
+ n_read += len;
+
+ if (len == rsize)
+ break;
+
+ rsize -= len;
+ buf += len;
+ off = 0;
+ ++reg;
+ }
+
+ kfree(data);
+
+ return n_read;
+}
+
+static int dockram_write_one(struct i2c_client *client, int reg,
+ const char __user *buf, size_t count)
+{
+ struct dockram_ec_data *priv = i2c_get_clientdata(client);
+ int ret;
+
+ if (!count || count > DOCKRAM_ENTRY_SIZE)
+ return -EINVAL;
+ if (buf[0] != count - 1)
+ return -EINVAL;
+
+ guard(mutex)(&priv->ctl_lock);
+
+ priv->ctl_data[0] = (u8)count;
+ memcpy(priv->ctl_data + 1, buf, count);
+ ret = asus_dockram_write(client, reg, priv->ctl_data);
+
+ return ret;
+}
+
+static ssize_t dockram_write(struct file *filp, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ struct i2c_client *client = filp->private_data;
+ unsigned int reg;
+ loff_t off = *ppos;
+ int ret;
+
+ if (off % DOCKRAM_ENTRY_SIZE != 0)
+ return -EINVAL;
+
+ reg = off / DOCKRAM_ENTRY_SIZE;
+ if (reg >= DOCKRAM_ENTRIES)
+ return -EINVAL;
+
+ ret = dockram_write_one(client, reg, buf, count);
+
+ return ret < 0 ? ret : count;
+}
+
+static const struct debugfs_short_fops dockram_fops = {
+ .read = dockram_read,
+ .write = dockram_write,
+ .llseek = default_llseek,
+};
+
+static int control_reg_get(void *ec, u64 *val)
+{
+ return asus_ec_get_ctl(ec, val);
+}
+
+static int control_reg_set(void *ec, u64 val)
+{
+ return asus_ec_update_ctl(ec, ~0ull, val);
+}
+
+DEFINE_DEBUGFS_ATTRIBUTE(control_reg_fops, control_reg_get,
+ control_reg_set, "%016llx\n");
+
+static int ec_request_set(void *ec, u64 val)
+{
+ if (val)
+ asus_ec_signal_request(ec);
+
+ return 0;
+}
+
+DEFINE_DEBUGFS_ATTRIBUTE(ec_request_fops, NULL, ec_request_set, "%llu\n");
+
+static int ec_irq_set(void *ec, u64 val)
+{
+ struct asus_ec_data *priv = to_ec_data(ec);
+
+ if (val)
+ irq_wake_thread(priv->self->irq, priv);
+
+ return 0;
+}
+
+DEFINE_DEBUGFS_ATTRIBUTE(ec_irq_fops, NULL, ec_irq_set, "%llu\n");
+
+static void asus_ec_debugfs_remove(void *debugfs_root)
+{
+ debugfs_remove_recursive(debugfs_root);
+}
+
+static void devm_asus_ec_debugfs_init(struct device *dev)
+{
+ struct asusec_info *ec = dev_get_drvdata(dev);
+ struct asus_ec_data *priv = to_ec_data(ec);
+ struct dentry *debugfs_root, *dockram_dir;
+ char *name = devm_kasprintf(dev, GFP_KERNEL, "asus-ec-%s",
+ priv->data->name);
+
+ debugfs_root = debugfs_create_dir(name, NULL);
+ dockram_dir = debugfs_create_dir("dockram", debugfs_root);
+
+ debugfs_create_file("ec_irq", 0200, debugfs_root, ec,
+ &ec_irq_fops);
+ debugfs_create_file("ec_request", 0200, debugfs_root, ec,
+ &ec_request_fops);
+ debugfs_create_file("control_reg", 0644, dockram_dir, ec,
+ &control_reg_fops);
+ debugfs_create_file("dockram", 0644, dockram_dir,
+ priv->info.dockram, &dockram_fops);
+
+ devm_add_action_or_reset(dev, asus_ec_debugfs_remove, debugfs_root);
+}
+
+static void asus_ec_release_dockram_dev(void *client)
+{
+ i2c_unregister_device(client);
+}
+
+static struct i2c_client *devm_asus_dockram_get(struct device *dev)
+{
+ struct i2c_client *parent = to_i2c_client(dev);
+ struct i2c_client *dockram;
+ struct dockram_ec_data *priv;
+ int ret;
+
+ dockram = i2c_new_ancillary_device(parent, "dockram",
+ parent->addr + 2);
+ if (IS_ERR(dockram))
+ return dockram;
+
+ ret = devm_add_action_or_reset(dev, asus_ec_release_dockram_dev,
+ dockram);
+ if (ret)
+ return ERR_PTR(ret);
+
+ priv = devm_kzalloc(&dockram->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return ERR_PTR(-ENOMEM);
+
+ i2c_set_clientdata(dockram, priv);
+ mutex_init(&priv->ctl_lock);
+
+ return dockram;
+}
+
+static int asus_ec_probe(struct i2c_client *client)
+{
+ struct device *dev = &client->dev;
+ struct asus_ec_data *priv;
+ int ret;
+
+ if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_I2C_BLOCK))
+ return dev_err_probe(dev, -ENXIO,
+ "I2C bus is missing required SMBus block mode support\n");
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->data = device_get_match_data(dev);
+ if (!priv->data)
+ return -ENODEV;
+
+ i2c_set_clientdata(client, priv);
+ priv->self = client;
+
+ priv->info.dockram = devm_asus_dockram_get(dev);
+ if (IS_ERR(priv->info.dockram))
+ return dev_err_probe(dev, PTR_ERR(priv->info.dockram),
+ "failed to get dockram\n");
+
+ priv->ecreq = devm_gpiod_get(dev, "request", GPIOD_OUT_LOW);
+ if (IS_ERR(priv->ecreq))
+ return dev_err_probe(dev, PTR_ERR(priv->ecreq),
+ "failed to get request GPIO\n");
+
+ BLOCKING_INIT_NOTIFIER_HEAD(&priv->info.notify_list);
+ mutex_init(&priv->ecreq_lock);
+
+ asus_ec_signal_request(&priv->info);
+
+ ret = asus_ec_detect(priv);
+ if (ret)
+ return dev_err_probe(dev, ret, "failed to detect EC version\n");
+
+ ret = devm_request_threaded_irq(dev, client->irq, NULL,
+ &asus_ec_interrupt,
+ IRQF_ONESHOT | IRQF_SHARED,
+ client->name, priv);
+ if (ret)
+ return dev_err_probe(dev, ret, "failed to register IRQ\n");
+
+ /* Parent I2C controller uses DMA, ASUS EC and child devices do not */
+ client->dev.coherent_dma_mask = 0;
+ client->dev.dma_mask = &client->dev.coherent_dma_mask;
+
+ if (IS_ENABLED(CONFIG_DEBUG_FS))
+ devm_asus_ec_debugfs_init(dev);
+
+ return devm_mfd_add_devices(dev, 0, priv->data->mfd_devices,
+ priv->data->num_devices, NULL, 0, NULL);
+}
+
+static const struct mfd_cell asus_ec_sl101_dock_mfd_devices[] = {
+ {
+ .name = "asus-transformer-ec-kbc",
+ },
+};
+
+static const struct asus_ec_chip_data asus_ec_sl101_dock_data = {
+ .name = "dock",
+ .mfd_devices = asus_ec_sl101_dock_mfd_devices,
+ .num_devices = ARRAY_SIZE(asus_ec_sl101_dock_mfd_devices),
+ .clr_fmode = false,
+};
+
+static const struct mfd_cell asus_ec_tf101_dock_mfd_devices[] = {
+ {
+ .name = "asus-transformer-ec-battery",
+ .id = 1,
+ }, {
+ .name = "asus-transformer-ec-charger",
+ .id = 1,
+ }, {
+ .name = "asus-transformer-ec-led",
+ .id = 1,
+ }, {
+ .name = "asus-transformer-ec-keys",
+ }, {
+ .name = "asus-transformer-ec-kbc",
+ },
+};
+
+static const struct asus_ec_chip_data asus_ec_tf101_dock_data = {
+ .name = "dock",
+ .mfd_devices = asus_ec_tf101_dock_mfd_devices,
+ .num_devices = ARRAY_SIZE(asus_ec_tf101_dock_mfd_devices),
+ .clr_fmode = false,
+};
+
+static const struct mfd_cell asus_ec_tf201_pad_mfd_devices[] = {
+ {
+ .name = "asus-transformer-ec-battery",
+ .id = 0,
+ }, {
+ .name = "asus-transformer-ec-led",
+ .id = 0,
+ },
+};
+
+static const struct asus_ec_chip_data asus_ec_tf201_pad_data = {
+ .name = "pad",
+ .mfd_devices = asus_ec_tf201_pad_mfd_devices,
+ .num_devices = ARRAY_SIZE(asus_ec_tf201_pad_mfd_devices),
+ .clr_fmode = true,
+};
+
+static const struct mfd_cell asus_ec_tf600t_pad_mfd_devices[] = {
+ {
+ .name = "asus-transformer-ec-battery",
+ .id = 0,
+ }, {
+ .name = "asus-transformer-ec-charger",
+ .id = 0,
+ }, {
+ .name = "asus-transformer-ec-led",
+ .id = 0,
+ },
+};
+
+static const struct asus_ec_chip_data asus_ec_tf600t_pad_data = {
+ .name = "pad",
+ .mfd_devices = asus_ec_tf600t_pad_mfd_devices,
+ .num_devices = ARRAY_SIZE(asus_ec_tf600t_pad_mfd_devices),
+ .clr_fmode = true,
+};
+
+static const struct of_device_id asus_ec_match[] = {
+ { .compatible = "asus,sl101-ec-dock", .data = &asus_ec_sl101_dock_data },
+ { .compatible = "asus,tf101-ec-dock", .data = &asus_ec_tf101_dock_data },
+ { .compatible = "asus,tf201-ec-pad", .data = &asus_ec_tf201_pad_data },
+ { .compatible = "asus,tf600t-ec-pad", .data = &asus_ec_tf600t_pad_data },
+ { }
+};
+MODULE_DEVICE_TABLE(of, asus_ec_match);
+
+static struct i2c_driver asus_ec_driver = {
+ .driver = {
+ .name = "asus-transformer-ec",
+ .of_match_table = asus_ec_match,
+ },
+ .probe = asus_ec_probe,
+};
+module_i2c_driver(asus_ec_driver);
+
+MODULE_AUTHOR("Michał Mirosław <mirq-linux@rere.qmqm.pl>");
+MODULE_AUTHOR("Svyatoslav Ryhel <clamor95@gmail.com>");
+MODULE_DESCRIPTION("ASUS Transformer's EC driver");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/mfd/asus-transformer-ec.h b/include/linux/mfd/asus-transformer-ec.h
new file mode 100644
index 000000000000..0a72de40352e
--- /dev/null
+++ b/include/linux/mfd/asus-transformer-ec.h
@@ -0,0 +1,162 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef __MFD_ASUS_TRANSFORMER_EC_H
+#define __MFD_ASUS_TRANSFORMER_EC_H
+
+#include <linux/notifier.h>
+#include <linux/platform_device.h>
+#include <linux/workqueue.h>
+
+struct i2c_client;
+
+struct asusec_info {
+ const char *model;
+ const char *name;
+ struct i2c_client *dockram;
+ struct workqueue_struct *wq;
+ struct blocking_notifier_head notify_list;
+};
+
+#define DOCKRAM_ENTRIES 0x100
+#define DOCKRAM_ENTRY_SIZE 32
+#define DOCKRAM_ENTRY_BUFSIZE (DOCKRAM_ENTRY_SIZE + 1)
+
+/* interrupt sources */
+#define ASUSEC_OBF_MASK BIT(0)
+#define ASUSEC_KEY_MASK BIT(2)
+#define ASUSEC_KBC_MASK BIT(3)
+#define ASUSEC_AUX_MASK BIT(5)
+#define ASUSEC_SCI_MASK BIT(6)
+#define ASUSEC_SMI_MASK BIT(7)
+
+/* SMI notification codes */
+#define ASUSEC_SMI_POWER_NOTIFY 0x31 /* [un]plugging USB cable */
+#define ASUSEC_SMI_HANDSHAKE 0x50 /* response to ec_req edge */
+#define ASUSEC_SMI_WAKE 0x53
+#define ASUSEC_SMI_RESET 0x5f
+#define ASUSEC_SMI_ADAPTER_EVENT 0x60 /* [un]plugging charger to dock */
+#define ASUSEC_SMI_BACKLIGHT_ON 0x63
+#define ASUSEC_SMI_AUDIO_DOCK_IN 0x70
+
+#define ASUSEC_SMI_ACTION(code) (ASUSEC_SMI_MASK | ASUSEC_OBF_MASK | \
+ (ASUSEC_SMI_##code << 8))
+
+/* control register [0x0a] layout */
+#define ASUSEC_CTL_SIZE 8
+
+/*
+ * EC reports power from 40-pin connector in the LSB of the control
+ * register. The following values have been observed (xor 0x02):
+ *
+ * PAD-ec no-plug 0x40 / PAD-ec DOCK 0x20 / DOCK-ec no-plug 0x40
+ * PAD-ec AC 0x25 / PAD-ec DOCK+AC 0x24 / DOCK-ec AC 0x25
+ * PAD-ec USB 0x45 / PAD-ec DOCK+USB 0x24 / DOCK-ec USB 0x41
+ */
+
+#define ASUSEC_CTL_DIRECT_POWER_SOURCE BIT_ULL(0)
+#define ASUSEC_STAT_CHARGING BIT_ULL(2)
+#define ASUSEC_CTL_FULL_POWER_SOURCE BIT_ULL(5)
+#define ASUSEC_CTL_SUSB_MODE BIT_ULL(9)
+#define ASUSEC_CMD_SUSPEND_S3 BIT_ULL(33)
+#define ASUSEC_CTL_TEST_DISCHARGE BIT_ULL(35)
+#define ASUSEC_CMD_SUSPEND_INHIBIT BIT_ULL(37)
+#define ASUSEC_CTL_FACTORY_MODE BIT_ULL(38)
+#define ASUSEC_CTL_KEEP_AWAKE BIT_ULL(39)
+#define ASUSEC_CTL_USB_CHARGE BIT_ULL(40)
+#define ASUSEC_CTL_LED_BLINK BIT_ULL(40)
+#define ASUSEC_CTL_LED_AMBER BIT_ULL(41)
+#define ASUSEC_CTL_LED_GREEN BIT_ULL(42)
+#define ASUSEC_CMD_SWITCH_HDMI BIT_ULL(56)
+#define ASUSEC_CMD_WIN_SHUTDOWN BIT_ULL(62)
+
+#define ASUSEC_DOCKRAM_INFO_MODEL 0x01
+#define ASUSEC_DOCKRAM_INFO_FW 0x02
+#define ASUSEC_DOCKRAM_INFO_CFGFMT 0x03
+#define ASUSEC_DOCKRAM_INFO_HW 0x04
+#define ASUSEC_DOCKRAM_CONTROL 0x0a
+#define ASUSEC_DOCKRAM_BATT_CTL 0x14
+
+#define ASUSEC_WRITE_BUF 0x64
+#define ASUSEC_READ_BUF 0x6a
+
+/* dockram comm */
+int asus_dockram_read(struct i2c_client *client, int reg, char *buf);
+int asus_dockram_write(struct i2c_client *client, int reg, const char *buf);
+int asus_dockram_access_ctl(struct i2c_client *client,
+ u64 *out, u64 mask, u64 xor);
+
+/* EC public API */
+
+/**
+ * cell_to_ec - Request the shared ASUS EC structure via a subdevice's pdev.
+ * @pdev: EC subdevice pdev requesting access to the shared ASUS EC structure.
+ *
+ * Returns a pointer to the asusec_info structure.
+ */
+static inline struct asusec_info *cell_to_ec(struct platform_device *pdev)
+{
+ return dev_get_drvdata(pdev->dev.parent);
+}
+
+/**
+ * asus_ec_get_ctl - Read from the DockRAM control register.
+ * @ec: Pointer to the shared ASUS EC structure.
+ * @out: Pointer to the variable where the register value will be stored.
+ *
+ * Performs a control register read and stores the value in @out.
+ *
+ * Return: 0 on success, or a negative errno code on failure.
+ */
+static inline int asus_ec_get_ctl(const struct asusec_info *ec, u64 *out)
+{
+ return asus_dockram_access_ctl(ec->dockram, out, 0, 0);
+}
+
+/**
+ * asus_ec_update_ctl - Update the DockRAM control register.
+ * @ec: Pointer to the shared ASUS EC structure.
+ * @mask: Bitmask of bits to be cleared.
+ * @xor: Bitmask of bits to be toggled or set (via XOR).
+ *
+ * Performs a read-modify-write update on the control register using
+ * the provided @mask and @xor values.
+ *
+ * Return: 0 on success, or a negative errno code on failure.
+ */
+static inline int asus_ec_update_ctl(const struct asusec_info *ec,
+ u64 mask, u64 xor)
+{
+ return asus_dockram_access_ctl(ec->dockram, NULL, mask, xor);
+}
+
+/**
+ * asus_ec_set_ctl_bits - Sets bits of the DockRAM control register.
+ * @ec: Pointer to the shared ASUS EC structure.
+ * @mask: Bitmask of bits to be set.
+ *
+ * Sets bits of the control register using the provided @mask value.
+ *
+ * Return: 0 on success, or a negative errno code on failure.
+ */
+static inline int asus_ec_set_ctl_bits(const struct asusec_info *ec, u64 mask)
+{
+ return asus_dockram_access_ctl(ec->dockram, NULL, mask, mask);
+}
+
+/**
+ * asus_ec_clear_ctl_bits - Clears bits of the DockRAM control register.
+ * @ec: Pointer to the shared ASUS EC structure.
+ * @mask: Bitmask of bits to be cleared.
+ *
+ * Clears bits of the control register using the provided @mask value.
+ *
+ * Return: 0 on success, or a negative errno code on failure.
+ */
+static inline int asus_ec_clear_ctl_bits(const struct asusec_info *ec, u64 mask)
+{
+ return asus_dockram_access_ctl(ec->dockram, NULL, mask, 0);
+}
+
+int asus_ec_i2c_command(const struct asusec_info *ec, u16 data);
+int devm_asus_ec_register_notifier(struct platform_device *dev,
+ struct notifier_block *nb);
+#endif /* __MFD_ASUS_TRANSFORMER_EC_H */
--
2.51.0