Date: Mon, 15 Dec 2014 06:11:19 -0800
From: Jeremiah Mahler <jmmahler@gmail.com>
To: Dudley Du <dudley.dulixin@gmail.com>
Cc: dmitry.torokhov@gmail.com, rydberg@euromail.se, bleung@google.com,
        linux-input@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v15 05/12] input: cyapa: add sysfs interfaces supported
 in the cyapa driver
Message-ID: <20141215141119.GD918@newt.localdomain>
Mail-Followup-To: Jeremiah Mahler <jmmahler@gmail.com>,
	Dudley Du <dudley.dulixin@gmail.com>, dmitry.torokhov@gmail.com,
	rydberg@euromail.se, bleung@google.com, linux-input@vger.kernel.org,
	linux-kernel@vger.kernel.org
References: <1418624603-19054-1-git-send-email-dudley.dulixin@gmail.com>
 <1418624603-19054-6-git-send-email-dudley.dulixin@gmail.com>
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In-Reply-To: <1418624603-19054-6-git-send-email-dudley.dulixin@gmail.com>
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Sender: linux-kernel-owner@vger.kernel.org

Dudley,

On Mon, Dec 15, 2014 at 02:23:16PM +0800, Dudley Du wrote:
> Add device's basic control and features supported in cyapa driver through
> sysfs file system interfaces. These interfaces are commonly used in
> pre- and after production, for trackpad device state checking, managing
> and firmware image updating.
> These interfaces including mode, firmware_version and product_id interfaces
> for reading firmware version and trackpad device product id values,
> and including update_fw interface to command firmware image update
> process. Also including baseline and calibrate interfaces for
> reading and checking trackpad device's sensors states.

This paragraph isn't aligned very well and is hard to read.
If you use Vim the 'gq' command can help with this.

> TEST=test on Chromebooks.
> 
> Signed-off-by: Dudley Du <dudley.dulixin@gmail.com>
> ---
>  drivers/input/mouse/cyapa.c | 327 ++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 327 insertions(+)
> 
> diff --git a/drivers/input/mouse/cyapa.c b/drivers/input/mouse/cyapa.c
> index 3bcfce3..dac3996 100644
> --- a/drivers/input/mouse/cyapa.c
> +++ b/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";
Yes, I like that better than unique_str :-)

>  
>  static int cyapa_reinitialize(struct cyapa *cyapa);
> @@ -442,6 +444,29 @@ 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) {
> +		if (!CYAPA_BOOTLOADER(cyapa) && cyapa->ops->set_power_mode)
> +			cyapa->ops->set_power_mode(cyapa,
> +				PWR_MODE_FULL_ACTIVE, 0);
> +		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) {
> +		disable_irq(cyapa->client->irq);
> +		if (!CYAPA_BOOTLOADER(cyapa) && cyapa->ops->set_power_mode)
> +			cyapa->ops->set_power_mode(cyapa, PWR_MODE_OFF, 0);
> +	}
> +}
> +
>  /*
>   * cyapa_sleep_time_to_pwr_cmd and cyapa_pwr_cmd_to_sleep_time
>   *
> @@ -783,6 +808,295 @@ static int cyapa_start_runtime(struct cyapa *cyapa)
>  }
>  #endif /* CONFIG_PM_RUNTIME */
>  
> +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;
> +	}
> +
> +	if (cyapa->ops->check_fw) {
> +		error = cyapa->ops->check_fw(cyapa, fw);
> +		if (error) {
> +			dev_err(dev, "Invalid CYAPA firmware image: %s\n",
> +					fw_name);
> +			goto done;
> +		}
> +	} else {
> +		dev_err(dev, "No valid device ops->check_fw handler set.\n");
> +		error = -ENODEV;
> +		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);
> +
> +	if (cyapa->ops->bl_enter) {
> +		error = cyapa->ops->bl_enter(cyapa);
> +		if (error) {
> +			dev_err(dev, "bl_enter failed, %d\n", error);
> +			goto err_detect;
> +		}
> +	}
> +
> +	if (cyapa->ops->bl_activate) {
> +		error = cyapa->ops->bl_activate(cyapa);
> +		if (error) {
> +			dev_err(dev, "bl_activate failed, %d\n", error);
> +			goto err_detect;
> +		}
> +	}
> +
> +	if (cyapa->ops->bl_initiate) {
> +		error = cyapa->ops->bl_initiate(cyapa, fw);
> +		if (error) {
> +			dev_err(dev, "bl_initiate failed, %d\n", error);
> +			goto err_detect;
> +		}
> +	}
> +
> +	if (cyapa->ops->update_fw) {
> +		error = cyapa->ops->update_fw(cyapa, fw);
> +		if (error) {
> +			dev_err(dev, "update_fw failed, %d\n", error);
> +			goto err_detect;
> +		}
> +	}
> +
> +	if (cyapa->ops->bl_verify_app_integrity) {
> +		error = cyapa->ops->bl_verify_app_integrity(cyapa);
> +		if (error) {
> +			dev_err(dev, "bl_verify_app_integrity 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[64];
> +	int ret, error;
> +
What is the significance of 64?
Should it be NAME_MAX or PATH_MAX (see linux/limits.h)?

> +	if (count > 64) {
> +		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->operational = false;
> +		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->ops->calibrate_store) {
> +		dev_err(dev, "Calibrate operation not supported.\n");
> +		error = -ENOTSUPP;
> +	} else {
> +		cyapa_enable_irq_for_cmd(cyapa);
> +		error = cyapa->ops->calibrate_store(dev, attr, buf, count);
> +		cyapa_disable_irq_for_cmd(cyapa);
> +	}
> +
> +	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->ops->show_baseline) {
> +		dev_err(dev, "Calibrate operation not supported.\n");
> +		error = -ENOTSUPP;
> +	} else {
> +		cyapa_enable_irq_for_cmd(cyapa);
> +		error = cyapa->ops->show_baseline(dev, attr, buf);
> +		cyapa_disable_irq_for_cmd(cyapa);
> +	}
> +
> +	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)
>  {
> @@ -822,6 +1136,19 @@ 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;
> +	}
> +
>  #ifdef CONFIG_PM_SLEEP
>  	if (device_can_wakeup(dev)) {
>  		error = sysfs_merge_group(&client->dev.kobj,
> -- 
> 1.9.1
> 
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-- 
- Jeremiah Mahler
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