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

[Andrew Duggan <aduggan@synaptics.com>]

On 07/09/2015 03:40 PM, Gabriele Mazzotta wrote:
> 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@gmail.com>

Thanks for testing!

>> Signed-off-by: Andrew Duggan <aduggan@synaptics.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?
>

Another option would be to create a local buffer for the read and only 
copy it to data->f11_ctrl_regs if we get all of the bytes. That way we 
can ensure that rmi_post_reset will have a valid set of registers to 
restore. Or we could also just remove the read from the suspend callback 
altogether and just write the values we set in rmi_populate_f11 and not 
worry about changes made outside the driver.

>> +
>> +
>>   	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?

That makes sense. I can make this change in my v2.

>> -	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);
>>
Andrew