@@ -0,0 +1,551 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <linux/array_size.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/mfd/asus-transformer-ec.h>
+#include <linux/mfd/core.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_ACCESS_TIMEOUT 300
+#define ASUSEC_DOCKRAM_OFFSET 2
+#define ASUSEC_ECREQ_DELAY 50
+#define ASUSEC_ECREQ_TIMEOUT 200
+#define ASUSEC_RESET 0
+#define ASUSEC_RETRY_MAX 3
+#define ASUSEC_RSP_BUFFER_SIZE (ASUSEC_ENTRIES / ASUSEC_ENTRY_SIZE)
+#define ASUSEC_SL101_ENTRY_SIZE 8
+
+enum asusec_variant {
+ ASUSEC_SL101_DOCK = 1,
+ ASUSEC_TF101_DOCK,
+ ASUSEC_TF201_PAD,
+ ASUSEC_TF600T_PAD,
+ ASUSEC_MAX
+};
+
+enum asusec_mode {
+ ASUSEC_MODE_NONE,
+ ASUSEC_MODE_NORMAL,
+ ASUSEC_MODE_FACTORY,
+ ASUSEC_MODE_MAX
+};
+
+/**
+ * struct asus_ec_chip_info
+ *
+ * @name: prefix associated with the EC
+ * @variant: id of programming model of EC
+ * @fmode: state of Factory Mode bit in EC control register
+ * @read_size: size of block to read
+ * @keyboard_mask: mask of keyboard packets
+ */
+struct asus_ec_chip_info {
+ const char *name;
+ enum asusec_variant variant;
+ enum asusec_mode fmode;
+ u8 read_size;
+ u8 keyboard_mask;
+};
+
+/**
+ * struct asus_ec_data
+ *
+ * @ec: public part shared with all cells (must be first)
+ * @ecreq_lock: prevents simultaneous access to EC
+ * @ecreq_gpio: EC request GPIO
+ * @client: pointer to EC's i2c_client
+ * @info: pointer to EC's version description
+ * @ec_buf: buffer for EC read
+ */
+struct asus_ec_data {
+ struct asusec_core ec;
+ struct mutex ecreq_lock;
+ struct gpio_desc *ecreq_gpio;
+ struct i2c_client *client;
+ const struct asus_ec_chip_info *info;
+ u8 ec_buf[ASUSEC_ENTRY_BUFSIZE];
+};
+
+/**
+ * struct dockram_ec_data
+ *
+ * @ctl_lock: prevent simultaneous access to Dockram
+ * @ctl_buf: buffer for Dockram read
+ */
+struct dockram_ec_data {
+ struct mutex ctl_lock;
+ u8 ctl_buf[ASUSEC_ENTRY_BUFSIZE];
+};
+
+/**
+ * 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 *ddata;
+ u8 *buf;
+ u64 val;
+ int ret = 0;
+
+ if (!client)
+ return -EINVAL;
+
+ ddata = i2c_get_clientdata(client);
+ if (!ddata)
+ return -ENODEV;
+
+ buf = ddata->ctl_buf;
+
+ guard(mutex)(&ddata->ctl_lock);
+
+ memset(buf, 0, ASUSEC_ENTRY_BUFSIZE);
+ ret = i2c_smbus_read_i2c_block_data(client, ASUSEC_DOCKRAM_CONTROL, ASUSEC_ENTRY_SIZE,
+ buf);
+ if (ret < ASUSEC_ENTRY_SIZE) {
+ dev_err(&client->dev, "failed to access control buffer: %d\n", ret);
+ return ret < 0 ? ret : -EIO;
+ }
+
+ if (buf[0] != ASUSEC_CTL_SIZE) {
+ dev_err(&client->dev, "buffer size exceeds %d: %d\n", ASUSEC_CTL_SIZE, buf[0]);
+ return -EPROTO;
+ }
+
+ val = get_unaligned_le64(buf + 1);
+
+ if (out)
+ *out = val;
+
+ if (mask || xor) {
+ put_unaligned_le64((val & ~mask) ^ xor, buf + 1);
+ ret = i2c_smbus_write_i2c_block_data(client, ASUSEC_DOCKRAM_CONTROL,
+ ASUSEC_ENTRY_SIZE, buf);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(asus_dockram_access_ctl);
+
+static int asus_ec_signal_request(struct asus_ec_data *ddata)
+{
+ guard(mutex)(&ddata->ecreq_lock);
+
+ gpiod_set_value_cansleep(ddata->ecreq_gpio, 1);
+ msleep(ASUSEC_ECREQ_DELAY);
+
+ gpiod_set_value_cansleep(ddata->ecreq_gpio, 0);
+ msleep(ASUSEC_ECREQ_TIMEOUT);
+
+ return 0;
+}
+
+static int asus_ec_log_info(struct asus_ec_data *ddata, unsigned int reg, const char *name)
+{
+ struct device *dev = &ddata->client->dev;
+ u8 buf[ASUSEC_ENTRY_BUFSIZE];
+ int ret;
+
+ memset(buf, 0, ASUSEC_ENTRY_BUFSIZE);
+ ret = i2c_smbus_read_i2c_block_data(ddata->ec.dockram, reg, ASUSEC_ENTRY_SIZE, buf);
+ if (ret < ASUSEC_ENTRY_SIZE)
+ return ret < 0 ? ret : -EIO;
+
+ if (buf[0] > ASUSEC_ENTRY_SIZE) {
+ dev_err(dev, "bad data len; buffer: %*ph; ret: %d\n", ASUSEC_ENTRY_BUFSIZE, buf,
+ ret);
+ return -EPROTO;
+ }
+
+ dev_info(dev, "%-14s: %.*s\n", name, buf[0], buf + 1);
+
+ if (!ddata->ec.model) {
+ ddata->ec.model = devm_kasprintf(dev, GFP_KERNEL, "%.*s", buf[0], buf + 1);
+ if (!ddata->ec.model)
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+
+static int asus_ec_detect(struct asus_ec_data *ddata)
+{
+ int ret;
+
+ ret = asus_ec_log_info(ddata, ASUSEC_DOCKRAM_INFO_MODEL, "Model");
+ if (ret)
+ return ret;
+
+ ret = asus_ec_log_info(ddata, ASUSEC_DOCKRAM_INFO_FW, "FW version");
+ if (ret)
+ return ret;
+
+ ret = asus_ec_log_info(ddata, ASUSEC_DOCKRAM_INFO_CFGFMT, "Config format");
+ if (ret)
+ return ret;
+
+ ret = asus_ec_log_info(ddata, ASUSEC_DOCKRAM_INFO_HW, "HW version");
+ if (ret)
+ return ret;
+
+ ddata->ec.name = ddata->info->name;
+ ddata->ec.keyboard_mask = ddata->info->keyboard_mask;
+
+ return 0;
+}
+
+static int asus_ec_reset(struct asus_ec_data *ddata)
+{
+ int ret;
+
+ guard(mutex)(&ddata->ecreq_lock);
+
+ for (int retry = 0; retry < ASUSEC_RETRY_MAX; retry++) {
+ ret = i2c_smbus_write_word_data(ddata->client, ASUSEC_WRITE_BUF, ASUSEC_RESET);
+ if (!ret)
+ return 0;
+
+ msleep(ASUSEC_ACCESS_TIMEOUT);
+ }
+
+ return ret;
+}
+
+static void asus_ec_clear_buffer(struct asus_ec_data *ddata)
+{
+ int ret, retry = ASUSEC_RSP_BUFFER_SIZE;
+
+ /*
+ * Read the buffer till we get valid data by checking ASUSEC_OBF_MASK
+ * of the status byte or till we reach end of the 256 byte buffer.
+ */
+ while (retry--) {
+ ret = i2c_smbus_read_i2c_block_data(ddata->client, ASUSEC_READ_BUF,
+ ddata->info->read_size, ddata->ec_buf);
+ if (ret < ddata->info->read_size)
+ continue;
+
+ if (ddata->ec_buf[ASUSEC_IRQ_STATUS] & ASUSEC_OBF_MASK)
+ continue;
+
+ break;
+ }
+}
+
+static int asus_ec_susb_on_status(struct asus_ec_data *ddata)
+{
+ u64 flag;
+ int ret;
+
+ ret = asus_dockram_access_ctl(ddata->ec.dockram, &flag, 0, 0);
+ if (ret)
+ return ret;
+
+ flag &= ASUSEC_CTL_SUSB_MODE;
+ dev_info(&ddata->client->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 *ddata,
+ enum asusec_mode fmode)
+{
+ dev_info(&ddata->client->dev, "Entering %s mode.\n",
+ fmode == ASUSEC_MODE_FACTORY ? "factory" : "normal");
+
+ return asus_dockram_access_ctl(ddata->ec.dockram, NULL, ASUSEC_CTL_FACTORY_MODE,
+ fmode == ASUSEC_MODE_FACTORY ? ASUSEC_CTL_FACTORY_MODE : 0);
+}
+
+static int asus_ec_init(struct asus_ec_data *ddata)
+{
+ int ret;
+
+ ret = asus_ec_reset(ddata);
+ if (ret)
+ goto err_exit;
+
+ asus_ec_clear_buffer(ddata);
+
+ /* Check and inform about EC firmware behavior */
+ ret = asus_ec_susb_on_status(ddata);
+ if (ret)
+ goto err_exit;
+
+ /* Some EC require factory mode to be set normal on each request */
+ if (ddata->info->fmode)
+ ret = asus_ec_set_factory_mode(ddata, ddata->info->fmode);
+
+err_exit:
+ if (ret)
+ dev_err(&ddata->client->dev, "failed to access EC: %d\n", ret);
+
+ return ret;
+}
+
+static void asus_ec_handle_smi(struct asus_ec_data *ddata, unsigned int code)
+{
+ switch (code) {
+ case ASUSEC_SMI_HANDSHAKE:
+ case ASUSEC_SMI_RESET:
+ asus_ec_init(ddata);
+ break;
+ }
+}
+
+static irqreturn_t asus_ec_interrupt(int irq, void *dev_id)
+{
+ struct asus_ec_data *ddata = dev_id;
+ unsigned long notify_action;
+ int ret;
+
+ ret = i2c_smbus_read_i2c_block_data(ddata->client, ASUSEC_READ_BUF,
+ ddata->info->read_size, ddata->ec_buf);
+ if (ret < ddata->info->read_size)
+ return IRQ_NONE;
+
+ /* Check status byte with ASUSEC_OBF_MASK if data is valid */
+ ret = ddata->ec_buf[ASUSEC_IRQ_STATUS] & ASUSEC_OBF_MASK;
+ if (!ret)
+ return IRQ_NONE;
+
+ notify_action = ddata->ec_buf[ASUSEC_IRQ_STATUS];
+ if (notify_action & ASUSEC_SMI_MASK) {
+ unsigned int code = ddata->ec_buf[ASUSEC_SMI_CODE];
+
+ asus_ec_handle_smi(ddata, code);
+
+ notify_action |= code << 8;
+ }
+
+ blocking_notifier_call_chain(&ddata->ec.notify_list, notify_action, ddata->ec_buf);
+
+ return IRQ_HANDLED;
+}
+
+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 *ddata;
+ int ret;
+
+ dockram = i2c_new_ancillary_device(parent, "dockram",
+ parent->addr + ASUSEC_DOCKRAM_OFFSET);
+ 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);
+
+ ddata = devm_kzalloc(&dockram->dev, sizeof(*ddata), GFP_KERNEL);
+ if (!ddata)
+ return ERR_PTR(-ENOMEM);
+
+ i2c_set_clientdata(dockram, ddata);
+ mutex_init(&ddata->ctl_lock);
+
+ return dockram;
+}
+
+static const struct mfd_cell asus_ec_sl101_dock_mfd_devices[] = {
+ MFD_CELL_NAME("asus-transformer-ec-kbc"),
+};
+
+static const struct mfd_cell asus_ec_tf101_dock_mfd_devices[] = {
+ MFD_CELL_NAME("asus-transformer-ec-battery"),
+ MFD_CELL_NAME("asus-transformer-ec-charger"),
+ MFD_CELL_NAME("asus-transformer-ec-led"),
+ MFD_CELL_NAME("asus-transformer-ec-kbc"),
+ MFD_CELL_NAME("asus-transformer-ec-keys"),
+};
+
+static const struct mfd_cell asus_ec_tf201_pad_mfd_devices[] = {
+ MFD_CELL_NAME("asus-transformer-ec-battery"),
+ MFD_CELL_NAME("asus-transformer-ec-led"),
+};
+
+static const struct mfd_cell asus_ec_tf600t_pad_mfd_devices[] = {
+ MFD_CELL_NAME("asus-transformer-ec-battery"),
+ MFD_CELL_NAME("asus-transformer-ec-charger"),
+ MFD_CELL_NAME("asus-transformer-ec-led"),
+};
+
+static int asus_ec_probe(struct i2c_client *client)
+{
+ struct device *dev = &client->dev;
+ struct asus_ec_data *ddata;
+ const struct mfd_cell *cells;
+ unsigned int num_cells;
+ unsigned long irqflags;
+ 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");
+
+ ddata = devm_kzalloc(dev, sizeof(*ddata), GFP_KERNEL);
+ if (!ddata)
+ return -ENOMEM;
+
+ ddata->info = device_get_match_data(dev);
+ if (!ddata->info)
+ return -ENODEV;
+
+ switch (ddata->info->variant) {
+ case ASUSEC_SL101_DOCK:
+ cells = asus_ec_sl101_dock_mfd_devices;
+ num_cells = ARRAY_SIZE(asus_ec_sl101_dock_mfd_devices);
+ break;
+ case ASUSEC_TF101_DOCK:
+ cells = asus_ec_tf101_dock_mfd_devices;
+ num_cells = ARRAY_SIZE(asus_ec_tf101_dock_mfd_devices);
+ break;
+ case ASUSEC_TF201_PAD:
+ cells = asus_ec_tf201_pad_mfd_devices;
+ num_cells = ARRAY_SIZE(asus_ec_tf201_pad_mfd_devices);
+ break;
+ case ASUSEC_TF600T_PAD:
+ cells = asus_ec_tf600t_pad_mfd_devices;
+ num_cells = ARRAY_SIZE(asus_ec_tf600t_pad_mfd_devices);
+ break;
+ default:
+ return dev_err_probe(dev, -EINVAL, "Unknown device variant %d\n",
+ ddata->info->variant);
+ }
+
+ i2c_set_clientdata(client, ddata);
+ ddata->client = client;
+
+ ddata->ec.dockram = devm_asus_dockram_get(dev);
+ if (IS_ERR(ddata->ec.dockram))
+ return dev_err_probe(dev, PTR_ERR(ddata->ec.dockram), "Failed to get DockRam\n");
+
+ ddata->ecreq_gpio = devm_gpiod_get(dev, "request", GPIOD_OUT_LOW);
+ if (IS_ERR(ddata->ecreq_gpio))
+ return dev_err_probe(dev, PTR_ERR(ddata->ecreq_gpio),
+ "Failed to get EC request GPIO\n");
+
+ BLOCKING_INIT_NOTIFIER_HEAD(&ddata->ec.notify_list);
+ mutex_init(&ddata->ecreq_lock);
+
+ asus_ec_signal_request(ddata);
+
+ ret = asus_ec_detect(ddata);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to detect EC version\n");
+
+ ret = asus_ec_init(ddata);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to init EC\n");
+
+ /*
+ * Systems using device tree should set up interrupt via DTS,
+ * the rest will use the default low interrupt.
+ */
+ irqflags = dev->of_node ? 0 : IRQF_TRIGGER_LOW;
+
+ ret = devm_request_threaded_irq(dev, client->irq, NULL, &asus_ec_interrupt,
+ IRQF_ONESHOT | irqflags, client->name, ddata);
+ 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;
+
+ return devm_mfd_add_devices(dev, PLATFORM_DEVID_AUTO, cells, num_cells, NULL, 0, NULL);
+}
+
+static const struct asus_ec_chip_info asus_ec_sl101_dock_data = {
+ .name = "dock",
+ .variant = ASUSEC_SL101_DOCK,
+ .fmode = ASUSEC_MODE_NONE,
+ .read_size = ASUSEC_SL101_ENTRY_SIZE,
+ .keyboard_mask = ASUSEC_OBF_MASK,
+};
+
+static const struct asus_ec_chip_info asus_ec_tf101_dock_data = {
+ .name = "dock",
+ .variant = ASUSEC_TF101_DOCK,
+ .fmode = ASUSEC_MODE_NONE,
+ .read_size = ASUSEC_ENTRY_SIZE,
+ .keyboard_mask = ASUSEC_KBC_MASK | ASUSEC_KEY_MASK,
+};
+
+static const struct asus_ec_chip_info asus_ec_tf201_pad_data = {
+ .name = "pad",
+ .variant = ASUSEC_TF201_PAD,
+ .fmode = ASUSEC_MODE_NORMAL,
+ .read_size = ASUSEC_ENTRY_SIZE,
+ .keyboard_mask = ASUSEC_KBC_MASK | ASUSEC_KEY_MASK,
+};
+
+static const struct asus_ec_chip_info asus_ec_tf600t_pad_data = {
+ .name = "pad",
+ .variant = ASUSEC_TF600T_PAD,
+ .fmode = ASUSEC_MODE_NORMAL,
+ .read_size = ASUSEC_ENTRY_SIZE,
+ .keyboard_mask = ASUSEC_KBC_MASK | ASUSEC_KEY_MASK,
+};
+
+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,
+ },
+ { /* sentinel */ }
+};
+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");