linux-kernel - Re: [PATCH] HID: rmi: Write updated F11 control registers after reset

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Date:	Fri, 10 Jul 2015 00:40:18 +0200
From:	Gabriele Mazzotta <gabriele.mzt@...il.com>
To:	Andrew Duggan <aduggan@...aptics.com>
Cc:	linux-input@...r.kernel.org, linux-kernel@...r.kernel.org,
	Jiri Kosina <jkosina@...e.cz>,
	Benjamin Tissoires <benjamin.tissoires@...hat.com>
Subject: Re: [PATCH] HID: rmi: Write updated F11 control registers after reset

On Thursday 09 July 2015 15:14:17 Andrew Duggan wrote:
> When a device is reset the values of control registers will be reset to
> the defaults. This patch reapplies the control register values set for F11
> by the driver.

Hi,

thanks for this, it works as intended. I just added a couple of
comments here below, but other than that

Tested-by: Gabriele Mazzotta <gabriele.mzt@...il.com>

> Signed-off-by: Andrew Duggan <aduggan@...aptics.com>
> ---
>  drivers/hid/hid-rmi.c | 41 ++++++++++++++++++++++++++++++++++-------
>  1 file changed, 34 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/hid/hid-rmi.c b/drivers/hid/hid-rmi.c
> index af191a2..80c068f 100644
> --- a/drivers/hid/hid-rmi.c
> +++ b/drivers/hid/hid-rmi.c
> @@ -40,6 +40,8 @@
>  #define RMI_DEVICE			BIT(0)
>  #define RMI_DEVICE_HAS_PHYS_BUTTONS	BIT(1)
>  
> +#define RMI_F11_CTRL_REG_COUNT		12
> +
>  enum rmi_mode_type {
>  	RMI_MODE_OFF			= 0,
>  	RMI_MODE_ATTN_REPORTS		= 1,
> @@ -116,6 +118,8 @@ struct rmi_data {
>  	unsigned int max_y;
>  	unsigned int x_size_mm;
>  	unsigned int y_size_mm;
> +	bool read_f11_ctrl_regs;
> +	u8 f11_ctrl_regs[RMI_F11_CTRL_REG_COUNT];
>  
>  	unsigned int gpio_led_count;
>  	unsigned int button_count;
> @@ -557,6 +561,15 @@ static int rmi_set_sleep_mode(struct hid_device *hdev, int sleep_mode)
>  
>  static int rmi_suspend(struct hid_device *hdev, pm_message_t message)
>  {
> +	struct rmi_data *data = hid_get_drvdata(hdev);
> +	int ret;
> +
> +	ret = rmi_read_block(hdev, data->f11.control_base_addr,
> +			data->f11_ctrl_regs, RMI_F11_CTRL_REG_COUNT);
> +	if (ret)
> +		hid_warn(hdev, "can not read F11 control registers\n");

It seems that rmi_read_block() can fail because of timeouts after it
has started filling the buffer, so isn't it better to set
read_f11_ctrl_regs to false when it happens?

> +
> +
>  	if (!device_may_wakeup(hdev->dev.parent))
>  		return rmi_set_sleep_mode(hdev, RMI_SLEEP_DEEP_SLEEP);
>  
> @@ -565,6 +578,7 @@ static int rmi_suspend(struct hid_device *hdev, pm_message_t message)
>  
>  static int rmi_post_reset(struct hid_device *hdev)
>  {
> +	struct rmi_data *data = hid_get_drvdata(hdev);
>  	int ret;
>  
>  	ret = rmi_set_mode(hdev, RMI_MODE_ATTN_REPORTS);
> @@ -573,6 +587,14 @@ static int rmi_post_reset(struct hid_device *hdev)
>  		return ret;
>  	}
>  
> +	if (data->read_f11_ctrl_regs) {
> +		ret = rmi_write_block(hdev, data->f11.control_base_addr,
> +				data->f11_ctrl_regs, RMI_F11_CTRL_REG_COUNT);
> +		if (ret)
> +			hid_warn(hdev,
> +				"can not write F11 control registers after reset\n");
> +	}
> +
>  	if (!device_may_wakeup(hdev->dev.parent)) {
>  		ret = rmi_set_sleep_mode(hdev, RMI_SLEEP_NORMAL);
>  		if (ret) {
> @@ -963,18 +985,23 @@ static int rmi_populate_f11(struct hid_device *hdev)
>  	 * and there is no way to know if the first 20 bytes are here or not.
>  	 * We use only the first 12 bytes, so get only them.
>  	 */

Just a suggestion here. What about moving this comment right above the
definition of RMI_F11_CTRL_REG_COUNT?

> -	ret = rmi_read_block(hdev, data->f11.control_base_addr, buf, 12);
> +	ret = rmi_read_block(hdev, data->f11.control_base_addr,
> +			data->f11_ctrl_regs, RMI_F11_CTRL_REG_COUNT);
>  	if (ret) {
>  		hid_err(hdev, "can not read ctrl block of size 11: %d.\n", ret);
>  		return ret;
>  	}
>  
> -	data->max_x = buf[6] | (buf[7] << 8);
> -	data->max_y = buf[8] | (buf[9] << 8);
> +	/* data->f11_ctrl_regs now contains valid register data */
> +	data->read_f11_ctrl_regs = true;
> +
> +	data->max_x = data->f11_ctrl_regs[6] | (data->f11_ctrl_regs[7] << 8);
> +	data->max_y = data->f11_ctrl_regs[8] | (data->f11_ctrl_regs[9] << 8);
>  
>  	if (has_dribble) {
> -		buf[0] = buf[0] & ~BIT(6);
> -		ret = rmi_write(hdev, data->f11.control_base_addr, buf);
> +		data->f11_ctrl_regs[0] = data->f11_ctrl_regs[0] & ~BIT(6);
> +		ret = rmi_write(hdev, data->f11.control_base_addr,
> +				data->f11_ctrl_regs);
>  		if (ret) {
>  			hid_err(hdev, "can not write to control reg 0: %d.\n",
>  				ret);
> @@ -983,9 +1010,9 @@ static int rmi_populate_f11(struct hid_device *hdev)
>  	}
>  
>  	if (has_palm_detect) {
> -		buf[11] = buf[11] & ~BIT(0);
> +		data->f11_ctrl_regs[11] = data->f11_ctrl_regs[11] & ~BIT(0);
>  		ret = rmi_write(hdev, data->f11.control_base_addr + 11,
> -				&buf[11]);
> +				&data->f11_ctrl_regs[11]);
>  		if (ret) {
>  			hid_err(hdev, "can not write to control reg 11: %d.\n",
>  				ret);
> 

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