Re: [PATCH 07/11] Input: synaptics-rmi4 - f30/f03: Forward mechanical buttons on buttonpads to PS/2 guest

[Andrew Duggan <aduggan@synaptics.com>]

Resending as plain text

Hi Benjamin,

This patch causes standard clickpads without extended buttons to not 
work. I'll explain some more below.

On 08/18/2016 02:24 AM, Benjamin Tissoires wrote:
> From: Lyude Paul <thatslyude@gmail.com>
>
> On the latest series of ThinkPads, the button events for the TrackPoint
> are reported through the touchpad itself as opposed to the TrackPoint
> device. In order to report these buttons properly, we need to forward
> them to the TrackPoint device and send the button presses/releases
> through there instead.
>
> Signed-off-by: Lyude Paul <thatslyude@gmail.com>
> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
> ---
>  drivers/input/rmi4/rmi_driver.h | 13 +++++++++
>  drivers/input/rmi4/rmi_f03.c    | 28 ++++++++++++++++++
>  drivers/input/rmi4/rmi_f30.c    | 64 +++++++++++++++++++++++++++++++++++------
>  3 files changed, 97 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/input/rmi4/rmi_driver.h b/drivers/input/rmi4/rmi_driver.h
> index e4be773..a0b1978 100644
> --- a/drivers/input/rmi4/rmi_driver.h
> +++ b/drivers/input/rmi4/rmi_driver.h
> @@ -99,6 +99,19 @@ struct rmi_function *rmi_find_function(struct rmi_device *rmi_dev, u8 number);
>
>  char *rmi_f01_get_product_ID(struct rmi_function *fn);
>
> +#ifdef CONFIG_RMI4_F03
> +int rmi_f03_overwrite_button(struct rmi_function *fn, unsigned int button,
> +			     int value);
> +void rmi_f03_commit_buttons(struct rmi_function *fn);
> +#else
> +static inline int rmi_f03_overwrite_button(struct rmi_function *fn,
> +					   unsigned int button, int value)
> +{
> +	return 0;
> +}
> +static inline void rmi_f03_commit_buttons(struct rmi_function *fn) {}
> +#endif
> +
>  extern struct rmi_function_handler rmi_f01_handler;
>  extern struct rmi_function_handler rmi_f03_handler;
>  extern struct rmi_function_handler rmi_f11_handler;
> diff --git a/drivers/input/rmi4/rmi_f03.c b/drivers/input/rmi4/rmi_f03.c
> index daae1c95..535f426 100644
> --- a/drivers/input/rmi4/rmi_f03.c
> +++ b/drivers/input/rmi4/rmi_f03.c
> @@ -37,6 +37,34 @@ struct f03_data {
>  	u8 rx_queue_length;
>  };
>
> +int rmi_f03_overwrite_button(struct rmi_function *fn, unsigned int button,
> +			     int value)
> +{
> +	struct f03_data *f03 = dev_get_drvdata(&fn->dev);
> +	unsigned int bit = BIT(button);
> +
> +	if (button > 2)
> +		return -EINVAL;
> +
> +	if (value)
> +		f03->overwrite_buttons |= bit;
> +	else
> +		f03->overwrite_buttons &= ~bit;
> +
> +	return 0;
> +}
> +
> +void rmi_f03_commit_buttons(struct rmi_function *fn)
> +{
> +	struct f03_data *f03 = dev_get_drvdata(&fn->dev);
> +	int i;
> +
> +	f03->serio->extra_byte = f03->overwrite_buttons;
> +
> +	for (i = 0; i < 3; i++)
> +		serio_interrupt(f03->serio, 0x00, 0x00);
> +}
> +
>  static int rmi_f03_pt_write(struct serio *id, unsigned char val)
>  {
>  	struct f03_data *f03 = id->port_data;
> diff --git a/drivers/input/rmi4/rmi_f30.c b/drivers/input/rmi4/rmi_f30.c
> index 7990bb0..14e3221 100644
> --- a/drivers/input/rmi4/rmi_f30.c
> +++ b/drivers/input/rmi4/rmi_f30.c
> @@ -74,8 +74,11 @@ struct f30_data {
>
>  	u8 data_regs[RMI_F30_CTRL_MAX_BYTES];
>  	u16 *gpioled_key_map;
> +	u16 *gpio_passthrough_key_map;
>
>  	struct input_dev *input;
> +	bool trackstick_buttons;
> +	struct rmi_function *f03;
>  };
>
>  static int rmi_f30_read_control_parameters(struct rmi_function *fn,
> @@ -108,6 +111,13 @@ static int rmi_f30_attention(struct rmi_function *fn, unsigned long *irq_bits)
>  	if (!f30->input)
>  		return 0;
>
> +	if (f30->trackstick_buttons && !f30->f03) {
> +		f30->f03 = rmi_find_function(rmi_dev, 3);
> +
> +		if (!f30->f03)
> +			return -EBUSY;
> +	}
> +
>  	/* Read the gpi led data. */
>  	if (rmi_dev->xport->attn_data) {
>  		memcpy(f30->data_regs, rmi_dev->xport->attn_data,
> @@ -128,23 +138,29 @@ static int rmi_f30_attention(struct rmi_function *fn, unsigned long *irq_bits)
>  	for (reg_num = 0; reg_num < f30->register_count; ++reg_num) {
>  		for (i = 0; gpiled < f30->gpioled_count && i < 8; ++i,
>  			++gpiled) {
> -			if (f30->gpioled_key_map[gpiled] != 0) {
> -				/* buttons have pull up resistors */
> -				value = (((f30->data_regs[reg_num] >> i) & 0x01)
> -									== 0);
> +			/* buttons have pull up resistors */
> +			value = (((f30->data_regs[reg_num] >> i) & 0x01) == 0);
>
> +			if (f30->gpioled_key_map[gpiled] != 0) {
>  				rmi_dbg(RMI_DEBUG_FN, &fn->dev,
>  					"%s: call input report key (0x%04x) value (0x%02x)",
>  					__func__,
>  					f30->gpioled_key_map[gpiled], value);
> +
>  				input_report_key(f30->input,
>  						 f30->gpioled_key_map[gpiled],
>  						 value);
> +			} else if (f30->gpio_passthrough_key_map[gpiled]) {
> +				rmi_f03_overwrite_button(f30->f03,
> +						f30->gpio_passthrough_key_map[gpiled] - BTN_LEFT,
> +						value);
>  			}
> -
>  		}
>  	}
>
> +	if (f30->trackstick_buttons)
> +		rmi_f03_commit_buttons(f30->f03);
> +
>  	return 0;
>  }
>
> @@ -242,10 +258,10 @@ static inline int rmi_f30_initialize(struct rmi_function *fn)
>  	int retval = 0;
>  	int control_address;
>  	int i;
> -	int button;
> +	int button, extra_button;
>  	u8 buf[RMI_F30_QUERY_SIZE];
>  	u8 *ctrl_reg;
> -	u8 *map_memory;
> +	u8 *map_memory, *pt_memory;
>
>  	f30 = devm_kzalloc(&fn->dev, sizeof(struct f30_data),
>  			   GFP_KERNEL);
> @@ -343,15 +359,47 @@ static inline int rmi_f30_initialize(struct rmi_function *fn)
>  	map_memory = devm_kzalloc(&fn->dev,
>  				  (f30->gpioled_count * (sizeof(u16))),
>  				  GFP_KERNEL);
> -	if (!map_memory) {
> +	pt_memory = devm_kzalloc(&fn->dev,
> +				 (f30->gpioled_count * (sizeof(u16))),
> +				 GFP_KERNEL);
> +	if (!map_memory || !pt_memory) {
>  		dev_err(&fn->dev, "Failed to allocate gpioled map memory.\n");
>  		return -ENOMEM;
>  	}
>
>  	f30->gpioled_key_map = (u16 *)map_memory;
> +	f30->gpio_passthrough_key_map = (u16 *)pt_memory;
>
>  	pdata = rmi_get_platform_data(rmi_dev);
>  	if (pdata && f30->has_gpio) {

This existing check of pdata is not needed because pdata is embedded in 
the transport device and will never be NULL. That means that in this 
patch the else case will never be called.

> +		/*
> +		 * For touchpads the buttons are mapped as:
> +		 * - bit 0 = Left, bit 1 = right, bit 2 = middle / clickbutton
> +		 * - 3, 4, 5 are extended buttons and
> +		 * - 6 and 7 are other sorts of GPIOs
> +		 */
> +		button = BTN_LEFT;
> +		extra_button = BTN_LEFT;
> +		for (i = 0; i < f30->gpioled_count - 2 && i < 3; i++) {

Subtracting 2 from gpioled_count does not have the intended affect. The 
name gpioled_count comes from the spec, but that byte is really a bit 
map. On a typical clickpad bit two is set as mentioned in the new 
comment. The result is that this for loop only runs once and it only 
checks the first bit of ctrl 2 and ctrl 3 for a valid button. Since bit 
0 is not set then no valid buttons are reported for the clickpad.

It looks like the Lenovo systems which this patch is targeting actually 
have 6 gpios defined (bits 2 - 7 are set) so this code works on those 
system since the "count" is sufficiently large. Also, maybe it's time to 
rename gpioled_count to something like gpioled_map.

> +			if (rmi_f30_is_valid_button(i, f30->ctrl))
> +				f30->gpioled_key_map[i] = button++;
> +		}
> +
> +		f30->trackstick_buttons = pdata &&
> +				pdata->f30_data.trackstick_buttons;
> +
> +		if (f30->trackstick_buttons) {
> +			for (i = 3; i < f30->gpioled_count - 2; i++) {
> +				if (rmi_f30_is_valid_button(i, f30->ctrl))
> +					f30->gpio_passthrough_key_map[i] = extra_button++;
> +			}
> +		} else {
> +			for (i = 3; i < f30->gpioled_count - 2; i++) {
> +				if (rmi_f30_is_valid_button(i, f30->ctrl))
> +					f30->gpioled_key_map[i] = button++;
> +			}
> +		}
> +	} else if (f30->has_gpio) {

As noted above this else block is never called.

Andrew

>  		button = BTN_LEFT;
>  		for (i = 0; i < f30->gpioled_count; i++) {
>  			if (rmi_f30_is_valid_button(i, f30->ctrl)) {
>