Message-ID: <s5hy6ggxb91.wl%tiwai@suse.de>
Date:	Thu, 22 Apr 2010 08:16:42 +0200
From:	Takashi Iwai <tiwai@...e.de>
To:	Dmitry Torokhov <dmitry.torokhov@...il.com>
Cc:	Pavel Machek <pavel@....cz>, Richard Purdie <rpurdie@...ys.net>,
	linux-input@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH v4] input: Add LED support to Synaptics device

The new Synaptics devices have an LED on the top-left corner.
This patch adds a new LED class device to control it.  It's created
dynamically upon synaptics device probing.

The LED is controlled via the command 0x0a with parameters 0x88 or 0x10.
This seems only on/off control although other value might be accepted.

The detection of the LED isn't clear yet.  It should have been the new
capability bits that indicate the presence, but on real machines, it
doesn't fit.  So, for the time being, the driver checks the product id
in the ext capability bits and assumes that LED exists on the known
devices.

Signed-off-by: Takashi Iwai <tiwai@...e.de>
---

Changes from v3:
 - Now it has a new Kconfig and the conditional select for LED class.
   Can be built without LED support, too.
 - The led cdev brightness value is used instead of keeping the value in
   synaptics privately.
 - Add explicit protection of LED ps2 command sequence.

 drivers/input/mouse/Kconfig     |    9 +++
 drivers/input/mouse/synaptics.c |  111 +++++++++++++++++++++++++++++++++++++++
 drivers/input/mouse/synaptics.h |    3 +
 3 files changed, 123 insertions(+), 0 deletions(-)

diff --git a/drivers/input/mouse/Kconfig b/drivers/input/mouse/Kconfig
index c714ca2..91d3517 100644
--- a/drivers/input/mouse/Kconfig
+++ b/drivers/input/mouse/Kconfig
@@ -19,6 +19,7 @@ config MOUSE_PS2
 	select SERIO_LIBPS2
 	select SERIO_I8042 if X86
 	select SERIO_GSCPS2 if GSC
+	select LEDS_CLASS if MOUSE_PS2_SYNAPICS_LED
 	help
 	  Say Y here if you have a PS/2 mouse connected to your system. This
 	  includes the standard 2 or 3-button PS/2 mouse, as well as PS/2
@@ -67,6 +68,14 @@ config MOUSE_PS2_SYNAPTICS
 
 	  If unsure, say Y.
 
+config MOUSE_PS2_SYNAPTICS_LED
+	bool "Support embedded LED on Synaptics devices"
+	depends on MOUSE_PS2_SYNAPTICS
+	select NEW_LEDS
+	help
+	  Say Y here if you have a Synaptics device with an embedded LED.
+	  This will enable LED class driver to control the LED device.
+
 config MOUSE_PS2_LIFEBOOK
 	bool "Fujitsu Lifebook PS/2 mouse protocol extension" if EMBEDDED
 	default y
diff --git a/drivers/input/mouse/synaptics.c b/drivers/input/mouse/synaptics.c
index c7b5285..8dc1fb5 100644
--- a/drivers/input/mouse/synaptics.c
+++ b/drivers/input/mouse/synaptics.c
@@ -28,6 +28,7 @@
 #include <linux/input.h>
 #include <linux/serio.h>
 #include <linux/libps2.h>
+#include <linux/leds.h>
 #include <linux/slab.h>
 #include "psmouse.h"
 #include "synaptics.h"
@@ -335,6 +336,110 @@ static void synaptics_pt_create(struct psmouse *psmouse)
 	serio_register_port(serio);
 }
 
+#ifdef CONFIG_MOUSE_PS2_SYNAPTICS_LED
+/*
+ * LED handling:
+ * Some Synaptics devices have an embeded LED at the top-left corner.
+ */
+
+struct synaptics_led {
+	struct psmouse *psmouse;
+	struct work_struct work;
+	struct led_classdev cdev;
+};
+
+static void synaptics_set_led(struct psmouse *psmouse, int on)
+{
+	int i;
+	unsigned char cmd = on ? 0x88 : 0x10;
+
+	ps2_begin_command(&psmouse->ps2dev);
+	if (__ps2_command(&psmouse->ps2dev, NULL, PSMOUSE_CMD_SETSCALE11))
+		goto out;
+	for (i = 6; i >= 0; i -= 2) {
+		unsigned char d = (cmd >> i) & 3;
+		if (__ps2_command(&psmouse->ps2dev, &d, PSMOUSE_CMD_SETRES))
+			goto out;
+	}
+	cmd = 0x0a;
+	__ps2_command(&psmouse->ps2dev, &cmd, PSMOUSE_CMD_SETRATE);
+ out:
+	ps2_end_command(&psmouse->ps2dev);
+}
+
+static void synaptics_led_work(struct work_struct *work)
+{
+	struct synaptics_led *led;
+
+	led = container_of(work, struct synaptics_led, work);
+	synaptics_set_led(led->psmouse, led->cdev.brightness);
+}
+
+static void synaptics_led_cdev_brightness_set(struct led_classdev *cdev,
+					      enum led_brightness value)
+{
+	struct synaptics_led *led;
+
+	led = container_of(cdev, struct synaptics_led, cdev);
+	schedule_work(&led->work);
+}
+
+static void synaptics_sync_led(struct psmouse *psmouse)
+{
+	struct synaptics_data *priv = psmouse->private;
+
+	if (priv->led)
+		synaptics_set_led(psmouse, priv->led->cdev.brightness);
+}
+
+static int synaptics_init_led(struct psmouse *psmouse)
+{
+	struct synaptics_data *priv = psmouse->private;
+	struct synaptics_led *led;
+	int err;
+
+	/* FIXME: LED is supposedly detectable in cap0c[1] 0x20, but it seems
+	 * not working on real machines.
+	 * So we check the product id to be sure.
+	 */
+	if (!priv->ext_cap_0c || SYN_CAP_PRODUCT_ID(priv->ext_cap) != 0xe4)
+		return 0;
+
+	printk(KERN_INFO "synaptics: support LED control\n");
+	led = kzalloc(sizeof(struct synaptics_led), GFP_KERNEL);
+	if (!led)
+		return -ENOMEM;
+	led->psmouse = psmouse;
+	INIT_WORK(&led->work, synaptics_led_work);
+	led->cdev.name = "psmouse::synaptics";
+	led->cdev.brightness_set = synaptics_led_cdev_brightness_set;
+	led->cdev.flags = LED_CORE_SUSPENDRESUME;
+	err = led_classdev_register(NULL, &led->cdev);
+	if (err < 0) {
+		kfree(led);
+		return err;
+	}
+	priv->led = led;
+	return 0;
+}
+
+static void synaptics_free_led(struct psmouse *psmouse)
+{
+	struct synaptics_data *priv = psmouse->private;
+
+	if (!priv->led)
+		return;
+	cancel_work_sync(&priv->led->work);
+	synaptics_set_led(psmouse, 0);
+	led_classdev_unregister(&priv->led->cdev);
+	kfree(priv->led);
+}
+#else
+#define synaptics_init_led(ps)	0
+#define synaptics_free_led(ps)	do {} while (0)
+#define synaptics_sync_led(ps)	do {} while (0)
+#endif
+
 /*****************************************************************************
  *	Functions to interpret the absolute mode packets
  ****************************************************************************/
@@ -622,6 +727,7 @@ static void set_input_params(struct input_dev *dev, struct synaptics_data *priv)
 
 static void synaptics_disconnect(struct psmouse *psmouse)
 {
+	synaptics_free_led(psmouse);
 	synaptics_reset(psmouse);
 	kfree(psmouse->private);
 	psmouse->private = NULL;
@@ -653,6 +759,8 @@ static int synaptics_reconnect(struct psmouse *psmouse)
 		return -1;
 	}
 
+	synaptics_sync_led(psmouse);
+
 	return 0;
 }
 
@@ -727,6 +835,9 @@ int synaptics_init(struct psmouse *psmouse)
 		SYN_ID_MAJOR(priv->identity), SYN_ID_MINOR(priv->identity),
 		priv->model_id, priv->capabilities, priv->ext_cap, priv->ext_cap_0c);
 
+	if (synaptics_init_led(psmouse) < 0)
+		goto init_fail;
+
 	set_input_params(psmouse->dev, priv);
 
 	/*
diff --git a/drivers/input/mouse/synaptics.h b/drivers/input/mouse/synaptics.h
index ae37c5d..d5bb8f4 100644
--- a/drivers/input/mouse/synaptics.h
+++ b/drivers/input/mouse/synaptics.h
@@ -94,6 +94,8 @@ struct synaptics_hw_state {
 	signed char scroll;
 };
 
+struct synaptics_led;
+
 struct synaptics_data {
 	/* Data read from the touchpad */
 	unsigned long int model_id;		/* Model-ID */
@@ -107,6 +109,7 @@ struct synaptics_data {
 	unsigned char pkt_type;			/* packet type - old, new, etc */
 	unsigned char mode;			/* current mode byte */
 	int scroll;
+	struct synaptics_led *led;
 };
 
 void synaptics_module_init(void);
-- 
1.7.0.4

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