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

From: Dmitry Torokhov
Date: Wed Nov 30 2016 - 20:36:47 EST


Hi Benjamin,

On Tue, Nov 29, 2016 at 11:08:18AM +0100, Benjamin Tissoires wrote:
> From: Lyude Paul <thatslyude@xxxxxxxxx>
>
> This adds basic functionality for PS/2 passthrough on Synaptics
> Touchpads using RMI4 through smbus.
>
> Reviewed-by: Andrew Duggan <aduggan@xxxxxxxxxxxxx>
> Signed-off-by: Lyude Paul <thatslyude@xxxxxxxxx>
> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
>
> ---
> 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@xxxxxxxxx>
> + *
> + * 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@xxxxxxxxx>");
> +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