Re: [PATCH 07/13] Input: synaptics-rmi4 - add support for F03

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

Hi Benjamin,

On Tue, Nov 29, 2016 at 11:08:18AM +0100, Benjamin Tissoires wrote:
> From: Lyude Paul <thatslyude@gmail.com>
> 
> This adds basic functionality for PS/2 passthrough on Synaptics
> Touchpads using RMI4 through smbus.
> 
> Reviewed-by: Andrew Duggan <aduggan@synaptics.com>
> Signed-off-by: Lyude Paul <thatslyude@gmail.com>
> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
> 
> ---
>  drivers/input/mouse/psmouse-base.c |   6 +
>  drivers/input/rmi4/Kconfig         |   9 ++
>  drivers/input/rmi4/Makefile        |   1 +
>  drivers/input/rmi4/rmi_bus.c       |   3 +
>  drivers/input/rmi4/rmi_driver.h    |   1 +
>  drivers/input/rmi4/rmi_f03.c       | 227 +++++++++++++++++++++++++++++++++++++
>  include/uapi/linux/serio.h         |   1 +
>  7 files changed, 248 insertions(+)
>  create mode 100644 drivers/input/rmi4/rmi_f03.c
> 
> diff --git a/drivers/input/mouse/psmouse-base.c b/drivers/input/mouse/psmouse-base.c
> index fb4b185..691dd74 100644
> --- a/drivers/input/mouse/psmouse-base.c
> +++ b/drivers/input/mouse/psmouse-base.c
> @@ -1663,6 +1663,12 @@ static struct serio_device_id psmouse_serio_ids[] = {
>  		.id	= SERIO_ANY,
>  		.extra	= SERIO_ANY,
>  	},
> +	{
> +		.type	= SERIO_RMI_PSTHRU,

Why do we need new serio type here? We had SERIO_PS_PSTHRU because we
needed some quirks in how it interacted with the parent PS/2 port, but
here it seems SERIO_I8042 (which could be called SERIO_STANDARD_PS2)
would suffice?

> +		.proto	= SERIO_ANY,
> +		.id	= SERIO_ANY,
> +		.extra	= SERIO_ANY,
> +	},
>  	{ 0 }
>  };
>  
> diff --git a/drivers/input/rmi4/Kconfig b/drivers/input/rmi4/Kconfig
> index a9c36a5..b8189a3 100644
> --- a/drivers/input/rmi4/Kconfig
> +++ b/drivers/input/rmi4/Kconfig
> @@ -39,6 +39,15 @@ config RMI4_SMB
>  	  To compile this driver as a module, choose M here: the module will be
>  	  called rmi_smbus.
>  
> +config RMI4_F03
> +        bool "RMI4 Function 03 (PS2 Guest)"
> +        depends on RMI4_CORE
> +        help
> +          Say Y here if you want to add support for RMI4 function 03.
> +
> +          Function 03 provides PS2 guest support for RMI4 devices. This
> +          includes support for TrackPoints on TouchPads.
> +
>  config RMI4_2D_SENSOR
>  	bool
>  	depends on RMI4_CORE
> diff --git a/drivers/input/rmi4/Makefile b/drivers/input/rmi4/Makefile
> index e7f4ca6..a199cbe 100644
> --- a/drivers/input/rmi4/Makefile
> +++ b/drivers/input/rmi4/Makefile
> @@ -4,6 +4,7 @@ rmi_core-y := rmi_bus.o rmi_driver.o rmi_f01.o
>  rmi_core-$(CONFIG_RMI4_2D_SENSOR) += rmi_2d_sensor.o
>  
>  # Function drivers
> +rmi_core-$(CONFIG_RMI4_F03) += rmi_f03.o
>  rmi_core-$(CONFIG_RMI4_F11) += rmi_f11.o
>  rmi_core-$(CONFIG_RMI4_F12) += rmi_f12.o
>  rmi_core-$(CONFIG_RMI4_F30) += rmi_f30.o
> diff --git a/drivers/input/rmi4/rmi_bus.c b/drivers/input/rmi4/rmi_bus.c
> index 81be9c1..1c40d94 100644
> --- a/drivers/input/rmi4/rmi_bus.c
> +++ b/drivers/input/rmi4/rmi_bus.c
> @@ -305,6 +305,9 @@ struct bus_type rmi_bus_type = {
>  
>  static struct rmi_function_handler *fn_handlers[] = {
>  	&rmi_f01_handler,
> +#ifdef CONFIG_RMI4_F03
> +	&rmi_f03_handler,
> +#endif
>  #ifdef CONFIG_RMI4_F11
>  	&rmi_f11_handler,
>  #endif
> diff --git a/drivers/input/rmi4/rmi_driver.h b/drivers/input/rmi4/rmi_driver.h
> index cc94585..24f8f76 100644
> --- a/drivers/input/rmi4/rmi_driver.h
> +++ b/drivers/input/rmi4/rmi_driver.h
> @@ -121,6 +121,7 @@ static inline void rmi_f34_remove_sysfs(struct rmi_device *rmi_dev)
>  #endif /* CONFIG_RMI_F34 */
>  
>  extern struct rmi_function_handler rmi_f01_handler;
> +extern struct rmi_function_handler rmi_f03_handler;
>  extern struct rmi_function_handler rmi_f11_handler;
>  extern struct rmi_function_handler rmi_f12_handler;
>  extern struct rmi_function_handler rmi_f30_handler;
> diff --git a/drivers/input/rmi4/rmi_f03.c b/drivers/input/rmi4/rmi_f03.c
> new file mode 100644
> index 0000000..a7e1b98
> --- /dev/null
> +++ b/drivers/input/rmi4/rmi_f03.c
> @@ -0,0 +1,227 @@
> +/*
> + * Copyright (C) 2015-2016 Red Hat
> + * Copyright (C) 2015 Lyude Paul <thatslyude@gmail.com>
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License version 2 as published by
> + * the Free Software Foundation.
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/slab.h>
> +#include <linux/serio.h>
> +#include <linux/notifier.h>
> +#include "rmi_driver.h"
> +
> +#define RMI_F03_RX_DATA_OFB		0x01
> +#define RMI_F03_OB_SIZE			2
> +
> +#define RMI_F03_OB_OFFSET		2
> +#define RMI_F03_OB_DATA_OFFSET		1
> +#define RMI_F03_OB_FLAG_TIMEOUT		(1 << 6)
> +#define RMI_F03_OB_FLAG_PARITY		(1 << 7)

BIT()?

> +
> +#define RMI_F03_DEVICE_COUNT		0x07
> +#define RMI_F03_BYTES_PER_DEVICE_MASK	0x70
> +#define RMI_F03_BYTES_PER_DEVICE_SHIFT	4
> +#define RMI_F03_QUEUE_LENGTH		0x0F
> +
> +struct f03_data {
> +	struct rmi_function *fn;
> +
> +	struct serio *serio;
> +
> +	unsigned int overwrite_buttons;

Unused?

> +
> +	u8 device_count;
> +	u8 rx_queue_length;
> +};
> +
> +static int rmi_f03_pt_write(struct serio *id, unsigned char val)
> +{
> +	struct f03_data *f03 = id->port_data;
> +	int rc;
> +
> +	rmi_dbg(RMI_DEBUG_FN, &f03->fn->dev,
> +		"%s: Wrote %.2hhx to PS/2 passthrough address",
> +		__func__, val);
> +
> +	rc = rmi_write(f03->fn->rmi_dev, f03->fn->fd.data_base_addr, val);

error = rmi_write()?

> +	if (rc) {
> +		dev_err(&f03->fn->dev,
> +			"%s: Failed to write to F03 TX register.\n", __func__);

Please report error code as well.

> +		return rc;
> +	}
> +
> +	return 0;
> +}
> +
> +static inline int rmi_f03_initialize(struct rmi_function *fn)

Why inline?

> +{
> +	struct f03_data *f03;
> +	struct device *dev = &fn->dev;
> +	int rc;
> +	u8 bytes_per_device;
> +	u8 query1;
> +	size_t query2_len;
> +
> +	rc = rmi_read(fn->rmi_dev, fn->fd.query_base_addr, &query1);

error = rmi_read()?

> +	if (rc) {
> +		dev_err(dev, "Failed to read query register.\n");
> +		return rc;
> +	}
> +
> +	f03 = devm_kzalloc(dev, sizeof(struct f03_data), GFP_KERNEL);
> +	if (!f03)
> +		return -ENOMEM;
> +
> +	f03->device_count = query1 & RMI_F03_DEVICE_COUNT;
> +	bytes_per_device = (query1 & RMI_F03_BYTES_PER_DEVICE_MASK) >>
> +		RMI_F03_BYTES_PER_DEVICE_SHIFT;
> +
> +	query2_len = f03->device_count * bytes_per_device;
> +
> +	/*
> +	 * The first generation of image sensors don't have a second part to
> +	 * their f03 query, as such we have to set some of these values manually
> +	 */
> +	if (query2_len < 1) {
> +		f03->device_count = 1;
> +		f03->rx_queue_length = 7;
> +	} else {
> +		u8 query2[query2_len];
> +
> +		rc = rmi_read_block(fn->rmi_dev, fn->fd.query_base_addr + 1,
> +				    query2, query2_len);
> +		if (rc) {
> +			dev_err(dev, "Failed to read second set of query registers.\n");
> +			return rc;
> +		}
> +
> +		f03->rx_queue_length = query2[0] & RMI_F03_QUEUE_LENGTH;
> +	}
> +
> +	f03->fn = fn;
> +
> +	dev_set_drvdata(dev, f03);
> +
> +	return f03->device_count;

I'd rather we returned customary 0 here.

> +}
> +
> +static inline int rmi_f03_register_pt(struct rmi_function *fn)
> +{
> +	struct f03_data *f03 = dev_get_drvdata(&fn->dev);
> +	struct serio *serio = kzalloc(sizeof(struct serio), GFP_KERNEL);

Please do not do allocations at declaration; limit to declarations with
initialization to operations without side effect. So:

	struct serio *serio;

	serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
	if (!serio)
		return -ENOMEM;

> +
> +	if (!serio)
> +		return -ENOMEM;
> +
> +	serio->id.type = SERIO_RMI_PSTHRU;
> +	serio->write = rmi_f03_pt_write;
> +	serio->port_data = f03;
> +
> +	strlcpy(serio->name, "Synaptics RMI4 PS2 pass-through",
> +		sizeof(serio->name));
> +	strlcpy(serio->phys, "synaptics-rmi4-pt/serio1",
> +		sizeof(serio->phys));
> +	 serio->dev.parent = &fn->dev;

Extra space after tab in indentation.

> +
> +	f03->serio = serio;
> +
> +	serio_register_port(serio);
> +
> +	return 0;
> +}
> +
> +static int rmi_f03_probe(struct rmi_function *fn)
> +{
> +	int rc;

int error;

Maybe allocate the memory here...

> +
> +	rc = rmi_f03_initialize(fn);
> +	if (rc < 0)
> +		return rc;
> +
> +	rmi_dbg(RMI_DEBUG_FN, &fn->dev, "%d devices on PS/2 passthrough", rc);

so you can use f03->device_count here.

Do we need to warn if we see device count greater than 1?

> +
> +	rc = rmi_f03_register_pt(fn);
> +	if (rc)
> +		return rc;
> +
> +	return 0;
> +}
> +
> +static int rmi_f03_config(struct rmi_function *fn)
> +{
> +	fn->rmi_dev->driver->set_irq_bits(fn->rmi_dev, fn->irq_mask);
> +
> +	return 0;
> +}
> +
> +static int rmi_f03_attention(struct rmi_function *fn, unsigned long *irq_bits)
> +{
> +	struct f03_data *f03 = dev_get_drvdata(&fn->dev);
> +	u16 data_addr = fn->fd.data_base_addr;
> +	const u8 ob_len = f03->rx_queue_length * RMI_F03_OB_SIZE;
> +	u8 obs[ob_len];
> +	u8 ob_status;
> +	u8 ob_data;
> +	unsigned int serio_flags;
> +	int i;
> +	int retval;
> +
> +	/* Grab all of the data registers, and check them for data */
> +	retval = rmi_read_block(fn->rmi_dev, data_addr + RMI_F03_OB_OFFSET,
> +				&obs, ob_len);
> +	if (retval) {
> +		dev_err(&fn->dev, "%s: Failed to read F03 output buffers.\n",
> +			__func__);
> +		serio_interrupt(f03->serio, 0, SERIO_TIMEOUT);
> +		return retval;
> +	}
> +
> +	for (i = 0; i < ob_len; i += RMI_F03_OB_SIZE) {
> +		ob_status = obs[i];
> +		ob_data = obs[i + RMI_F03_OB_DATA_OFFSET];
> +		serio_flags = 0;
> +
> +		if (!(ob_status & RMI_F03_RX_DATA_OFB))
> +			continue;
> +
> +		if (ob_status & RMI_F03_OB_FLAG_TIMEOUT)
> +			serio_flags |= SERIO_TIMEOUT;
> +		if (ob_status & RMI_F03_OB_FLAG_PARITY)
> +			serio_flags |= SERIO_PARITY;
> +
> +		rmi_dbg(RMI_DEBUG_FN, &fn->dev,
> +			"%s: Received %.2hhx from PS2 guest T: %c P: %c\n",
> +			__func__, ob_data,
> +			serio_flags & SERIO_TIMEOUT ?  'Y' : 'N',
> +			serio_flags & SERIO_PARITY ? 'Y' : 'N');
> +
> +		serio_interrupt(f03->serio, ob_data, serio_flags);
> +	}
> +
> +	return 0;
> +}
> +
> +static void rmi_f03_remove(struct rmi_function *fn)
> +{
> +	struct f03_data *f03 = dev_get_drvdata(&fn->dev);
> +
> +	serio_unregister_port(f03->serio);
> +}
> +
> +struct rmi_function_handler rmi_f03_handler = {
> +	.driver = {
> +		.name = "rmi4_f03",
> +	},
> +	.func = 0x03,
> +	.probe = rmi_f03_probe,
> +	.config = rmi_f03_config,
> +	.attention = rmi_f03_attention,
> +	.remove = rmi_f03_remove,
> +};
> +
> +MODULE_AUTHOR("Lyude Paul <thatslyude@gmail.com>");
> +MODULE_DESCRIPTION("RMI F03 module");
> +MODULE_LICENSE("GPL");
> diff --git a/include/uapi/linux/serio.h b/include/uapi/linux/serio.h
> index f2447a8..7012178 100644
> --- a/include/uapi/linux/serio.h
> +++ b/include/uapi/linux/serio.h
> @@ -30,6 +30,7 @@
>  #define SERIO_HIL_MLC	0x03
>  #define SERIO_PS_PSTHRU	0x05
>  #define SERIO_8042_XL	0x06
> +#define SERIO_RMI_PSTHRU	0x07
>  
>  /*
>   * Serio protocols
> -- 
> 2.7.4
> 

Thanks.

-- 
Dmitry