Input: cyapa - add sysfs interfaces support in the cyapa driver

Introduce control interfaces that are commonly used in pre- and after
production, for trackpad device state checking, managing and firmware image
updating.  These interfaces include mode, firmware_version and product_id
interfaces for reading firmware version and trackpad device product id
values, and update_fw interface to command firmware image update process.
There are also baseline and calibrate interfaces for reading and checking
trackpad device's sensors states.
Signed-off-by: Dudley Du <dudl@cypress.com>
Tested-by: Jeremiah Mahler <jmmahler@gmail.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/mouse/cyapa.c

@@ -32,6 +32,8 @@
 #define CYAPA_ADAPTER_FUNC_SMBUS  2
 #define CYAPA_ADAPTER_FUNC_BOTH   3
 
+#define CYAPA_FW_NAME		"cyapa.bin"
+
 const char product_id[] = "CYTRA";
 
 static int cyapa_reinitialize(struct cyapa *cyapa);
@@ -476,6 +478,38 @@ static int cyapa_create_input_dev(struct cyapa *cyapa)
 	return 0;
 }
 
+static void cyapa_enable_irq_for_cmd(struct cyapa *cyapa)
+{
+	struct input_dev *input = cyapa->input;
+
+	if (!input || !input->users) {
+		/*
+		 * When input is NULL, TP must be in deep sleep mode.
+		 * In this mode, later non-power I2C command will always failed
+		 * if not bring it out of deep sleep mode firstly,
+		 * so must command TP to active mode here.
+		 */
+		if (!input || cyapa->operational)
+			cyapa->ops->set_power_mode(cyapa,
+				PWR_MODE_FULL_ACTIVE, 0);
+		/* Gen3 always using polling mode for command. */
+		if (cyapa->gen >= CYAPA_GEN5)
+			enable_irq(cyapa->client->irq);
+	}
+}
+
+static void cyapa_disable_irq_for_cmd(struct cyapa *cyapa)
+{
+	struct input_dev *input = cyapa->input;
+
+	if (!input || !input->users) {
+		if (cyapa->gen >= CYAPA_GEN5)
+			disable_irq(cyapa->client->irq);
+		if (!input || cyapa->operational)
+			cyapa->ops->set_power_mode(cyapa, PWR_MODE_OFF, 0);
+	}
+}
+
 /*
  * cyapa_sleep_time_to_pwr_cmd and cyapa_pwr_cmd_to_sleep_time
  *
@@ -877,6 +911,269 @@ static inline int cyapa_start_runtime(struct cyapa *cyapa)
 }
 #endif /* CONFIG_PM */
 
+static ssize_t cyapa_show_fm_ver(struct device *dev,
+				 struct device_attribute *attr, char *buf)
+{
+	int error;
+	struct cyapa *cyapa = dev_get_drvdata(dev);
+
+	error = mutex_lock_interruptible(&cyapa->state_sync_lock);
+	if (error)
+		return error;
+	error = scnprintf(buf, PAGE_SIZE, "%d.%d\n", cyapa->fw_maj_ver,
+			 cyapa->fw_min_ver);
+	mutex_unlock(&cyapa->state_sync_lock);
+	return error;
+}
+
+static ssize_t cyapa_show_product_id(struct device *dev,
+				     struct device_attribute *attr, char *buf)
+{
+	struct cyapa *cyapa = dev_get_drvdata(dev);
+	int size;
+	int error;
+
+	error = mutex_lock_interruptible(&cyapa->state_sync_lock);
+	if (error)
+		return error;
+	size = scnprintf(buf, PAGE_SIZE, "%s\n", cyapa->product_id);
+	mutex_unlock(&cyapa->state_sync_lock);
+	return size;
+}
+
+static int cyapa_firmware(struct cyapa *cyapa, const char *fw_name)
+{
+	struct device *dev = &cyapa->client->dev;
+	const struct firmware *fw;
+	int error;
+
+	error = request_firmware(&fw, fw_name, dev);
+	if (error) {
+		dev_err(dev, "Could not load firmware from %s: %d\n",
+			fw_name, error);
+		return error;
+	}
+
+	error = cyapa->ops->check_fw(cyapa, fw);
+	if (error) {
+		dev_err(dev, "Invalid CYAPA firmware image: %s\n",
+				fw_name);
+		goto done;
+	}
+
+	/*
+	 * Resume the potentially suspended device because doing FW
+	 * update on a device not in the FULL mode has a chance to
+	 * fail.
+	 */
+	pm_runtime_get_sync(dev);
+
+	/* Require IRQ support for firmware update commands. */
+	cyapa_enable_irq_for_cmd(cyapa);
+
+	error = cyapa->ops->bl_enter(cyapa);
+	if (error) {
+		dev_err(dev, "bl_enter failed, %d\n", error);
+		goto err_detect;
+	}
+
+	error = cyapa->ops->bl_activate(cyapa);
+	if (error) {
+		dev_err(dev, "bl_activate failed, %d\n", error);
+		goto err_detect;
+	}
+
+	error = cyapa->ops->bl_initiate(cyapa, fw);
+	if (error) {
+		dev_err(dev, "bl_initiate failed, %d\n", error);
+		goto err_detect;
+	}
+
+	error = cyapa->ops->update_fw(cyapa, fw);
+	if (error) {
+		dev_err(dev, "update_fw failed, %d\n", error);
+		goto err_detect;
+	}
+
+err_detect:
+	cyapa_disable_irq_for_cmd(cyapa);
+	pm_runtime_put_noidle(dev);
+
+done:
+	release_firmware(fw);
+	return error;
+}
+
+static ssize_t cyapa_update_fw_store(struct device *dev,
+				     struct device_attribute *attr,
+				     const char *buf, size_t count)
+{
+	struct cyapa *cyapa = dev_get_drvdata(dev);
+	char fw_name[NAME_MAX];
+	int ret, error;
+
+	if (count > NAME_MAX) {
+		dev_err(dev, "File name too long\n");
+		return -EINVAL;
+	}
+
+	memcpy(fw_name, buf, count);
+	if (fw_name[count - 1] == '\n')
+		fw_name[count - 1] = '\0';
+	else
+		fw_name[count] = '\0';
+
+	if (cyapa->input) {
+		/*
+		 * Force the input device to be registered after the firmware
+		 * image is updated, so if the corresponding parameters updated
+		 * in the new firmware image can taken effect immediately.
+		 */
+		input_unregister_device(cyapa->input);
+		cyapa->input = NULL;
+	}
+
+	error = mutex_lock_interruptible(&cyapa->state_sync_lock);
+	if (error) {
+		/*
+		 * Whatever, do reinitialize to try to recover TP state to
+		 * previous state just as it entered fw update entrance.
+		 */
+		cyapa_reinitialize(cyapa);
+		return error;
+	}
+
+	error = cyapa_firmware(cyapa, fw_name);
+	if (error)
+		dev_err(dev, "firmware update failed: %d\n", error);
+	else
+		dev_dbg(dev, "firmware update successfully done.\n");
+
+	/*
+	 * Redetect trackpad device states because firmware update process
+	 * will reset trackpad device into bootloader mode.
+	 */
+	ret = cyapa_reinitialize(cyapa);
+	if (ret) {
+		dev_err(dev, "failed to redetect after updated: %d\n", ret);
+		error = error ? error : ret;
+	}
+
+	mutex_unlock(&cyapa->state_sync_lock);
+
+	return error ? error : count;
+}
+
+static ssize_t cyapa_calibrate_store(struct device *dev,
+				     struct device_attribute *attr,
+				     const char *buf, size_t count)
+{
+	struct cyapa *cyapa = dev_get_drvdata(dev);
+	int error;
+
+	error = mutex_lock_interruptible(&cyapa->state_sync_lock);
+	if (error)
+		return error;
+
+	if (cyapa->operational) {
+		cyapa_enable_irq_for_cmd(cyapa);
+		error = cyapa->ops->calibrate_store(dev, attr, buf, count);
+		cyapa_disable_irq_for_cmd(cyapa);
+	} else {
+		error = -EBUSY;  /* Still running in bootloader mode. */
+	}
+
+	mutex_unlock(&cyapa->state_sync_lock);
+	return error < 0 ? error : count;
+}
+
+static ssize_t cyapa_show_baseline(struct device *dev,
+				   struct device_attribute *attr, char *buf)
+{
+	struct cyapa *cyapa = dev_get_drvdata(dev);
+	ssize_t error;
+
+	error = mutex_lock_interruptible(&cyapa->state_sync_lock);
+	if (error)
+		return error;
+
+	if (cyapa->operational) {
+		cyapa_enable_irq_for_cmd(cyapa);
+		error = cyapa->ops->show_baseline(dev, attr, buf);
+		cyapa_disable_irq_for_cmd(cyapa);
+	} else {
+		error = -EBUSY;  /* Still running in bootloader mode. */
+	}
+
+	mutex_unlock(&cyapa->state_sync_lock);
+	return error;
+}
+
+static char *cyapa_state_to_string(struct cyapa *cyapa)
+{
+	switch (cyapa->state) {
+	case CYAPA_STATE_BL_BUSY:
+		return "bootloader busy";
+	case CYAPA_STATE_BL_IDLE:
+		return "bootloader idle";
+	case CYAPA_STATE_BL_ACTIVE:
+		return "bootloader active";
+	case CYAPA_STATE_GEN5_BL:
+		return "bootloader";
+	case CYAPA_STATE_OP:
+	case CYAPA_STATE_GEN5_APP:
+		return "operational";  /* Normal valid state. */
+	default:
+		return "invalid mode";
+	}
+}
+
+static ssize_t cyapa_show_mode(struct device *dev,
+				   struct device_attribute *attr, char *buf)
+{
+	struct cyapa *cyapa = dev_get_drvdata(dev);
+	int size;
+	int error;
+
+	error = mutex_lock_interruptible(&cyapa->state_sync_lock);
+	if (error)
+		return error;
+
+	size = scnprintf(buf, PAGE_SIZE, "gen%d %s\n",
+			cyapa->gen, cyapa_state_to_string(cyapa));
+
+	mutex_unlock(&cyapa->state_sync_lock);
+	return size;
+}
+
+static DEVICE_ATTR(firmware_version, S_IRUGO, cyapa_show_fm_ver, NULL);
+static DEVICE_ATTR(product_id, S_IRUGO, cyapa_show_product_id, NULL);
+static DEVICE_ATTR(update_fw, S_IWUSR, NULL, cyapa_update_fw_store);
+static DEVICE_ATTR(baseline, S_IRUGO, cyapa_show_baseline, NULL);
+static DEVICE_ATTR(calibrate, S_IWUSR, NULL, cyapa_calibrate_store);
+static DEVICE_ATTR(mode, S_IRUGO, cyapa_show_mode, NULL);
+
+static struct attribute *cyapa_sysfs_entries[] = {
+	&dev_attr_firmware_version.attr,
+	&dev_attr_product_id.attr,
+	&dev_attr_update_fw.attr,
+	&dev_attr_baseline.attr,
+	&dev_attr_calibrate.attr,
+	&dev_attr_mode.attr,
+	NULL,
+};
+
+static const struct attribute_group cyapa_sysfs_group = {
+	.attrs = cyapa_sysfs_entries,
+};
+
+static void cyapa_remove_sysfs_group(void *data)
+{
+	struct cyapa *cyapa = data;
+
+	sysfs_remove_group(&cyapa->client->dev.kobj, &cyapa_sysfs_group);
+}
+
 static int cyapa_probe(struct i2c_client *client,
 		       const struct i2c_device_id *dev_id)
 {
@@ -916,6 +1213,19 @@ static int cyapa_probe(struct i2c_client *client,
 		return error;
 	}
 
+	error = sysfs_create_group(&client->dev.kobj, &cyapa_sysfs_group);
+	if (error) {
+		dev_err(dev, "failed to create sysfs entries: %d\n", error);
+		return error;
+	}
+
+	error = devm_add_action(dev, cyapa_remove_sysfs_group, cyapa);
+	if (error) {
+		cyapa_remove_sysfs_group(cyapa);
+		dev_err(dev, "failed to add sysfs cleanup action: %d\n", error);
+		return error;
+	}
+
 	error = cyapa_prepare_wakeup_controls(cyapa);
 	if (error) {
 		dev_err(dev, "failed to prepare wakeup controls: %d\n", error);