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

From: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Date: 2016-12-01 01:36:43
Also in: lkml

Hi Benjamin,

On Tue, Nov 29, 2016 at 11:08:18AM +0100, Benjamin Tissoires wrote:

quoted hunk ↗ jump to hunk

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 <redacted>
Signed-off-by: Lyude Paul <thatslyude@gmail.com>
Signed-off-by: Benjamin Tissoires <redacted>

---
 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?

quoted hunk ↗ jump to hunk

+		.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?

quoted hunk ↗ jump to hunk

+
+	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 [off-list ref]");
+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

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