hwmon: New AMS hardware monitoring driver

This driver adds support for the Apple Motion Sensor (AMS) as found in 2005
revisions of Apple PowerBooks and iBooks.  It implements both the PMU and
I2C variants.  The I2C driver and mouse emulation is based on code by
Stelian Pop, while the PMU driver has been developped by Michael Hanselmann.
HD parking support will be added later.

Various people contributed fixes to this driver, including
Aristeu Sergio Rozanski Filho and Jean Delvare.

Signed-off-by: Stelian Pop <stelian@popies.net>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Robert Love <rml@novell.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

1 files changed, 207 insertions, 0 deletions

diff --git a/drivers/hwmon/ams/ams-pmu.c b/drivers/hwmon/ams/ams-pmu.c
new file mode 100644
index 000000000000..4636ae031a53
--- /dev/null
+++ b/drivers/hwmon/ams/ams-pmu.c
@@ -0,0 +1,207 @@
+/*
+ * Apple Motion Sensor driver (PMU variant)
+ *
+ * Copyright (C) 2006 Michael Hanselmann (linux-kernel@hansmi.ch)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/adb.h>
+#include <linux/pmu.h>
+
+#include "ams.h"
+
+/* Attitude */
+#define AMS_X			0x00
+#define AMS_Y			0x01
+#define AMS_Z			0x02
+
+/* Not exactly known, maybe chip vendor */
+#define AMS_VENDOR		0x03
+
+/* Freefall registers */
+#define AMS_FF_CLEAR		0x04
+#define AMS_FF_ENABLE		0x05
+#define AMS_FF_LOW_LIMIT	0x06
+#define AMS_FF_DEBOUNCE		0x07
+
+/* Shock registers */
+#define AMS_SHOCK_CLEAR		0x08
+#define AMS_SHOCK_ENABLE	0x09
+#define AMS_SHOCK_HIGH_LIMIT	0x0a
+#define AMS_SHOCK_DEBOUNCE	0x0b
+
+/* Global interrupt and power control register */
+#define AMS_CONTROL		0x0c
+
+static u8 ams_pmu_cmd;
+
+static void ams_pmu_req_complete(struct adb_request *req)
+{
+	complete((struct completion *)req->arg);
+}
+
+/* Only call this function from task context */
+static void ams_pmu_set_register(u8 reg, u8 value)
+{
+	static struct adb_request req;
+	DECLARE_COMPLETION(req_complete);
+
+	req.arg = &req_complete;
+	if (pmu_request(&req, ams_pmu_req_complete, 4, ams_pmu_cmd, 0x00, reg, value))
+		return;
+
+	wait_for_completion(&req_complete);
+}
+
+/* Only call this function from task context */
+static u8 ams_pmu_get_register(u8 reg)
+{
+	static struct adb_request req;
+	DECLARE_COMPLETION(req_complete);
+
+	req.arg = &req_complete;
+	if (pmu_request(&req, ams_pmu_req_complete, 3, ams_pmu_cmd, 0x01, reg))
+		return 0;
+
+	wait_for_completion(&req_complete);
+
+	if (req.reply_len > 0)
+		return req.reply[0];
+	else
+		return 0;
+}
+
+/* Enables or disables the specified interrupts */
+static void ams_pmu_set_irq(enum ams_irq reg, char enable)
+{
+	if (reg & AMS_IRQ_FREEFALL) {
+		u8 val = ams_pmu_get_register(AMS_FF_ENABLE);
+		if (enable)
+			val |= 0x80;
+		else
+			val &= ~0x80;
+		ams_pmu_set_register(AMS_FF_ENABLE, val);
+	}
+
+	if (reg & AMS_IRQ_SHOCK) {
+		u8 val = ams_pmu_get_register(AMS_SHOCK_ENABLE);
+		if (enable)
+			val |= 0x80;
+		else
+			val &= ~0x80;
+		ams_pmu_set_register(AMS_SHOCK_ENABLE, val);
+	}
+
+	if (reg & AMS_IRQ_GLOBAL) {
+		u8 val = ams_pmu_get_register(AMS_CONTROL);
+		if (enable)
+			val |= 0x80;
+		else
+			val &= ~0x80;
+		ams_pmu_set_register(AMS_CONTROL, val);
+	}
+}
+
+static void ams_pmu_clear_irq(enum ams_irq reg)
+{
+	if (reg & AMS_IRQ_FREEFALL)
+		ams_pmu_set_register(AMS_FF_CLEAR, 0x00);
+
+	if (reg & AMS_IRQ_SHOCK)
+		ams_pmu_set_register(AMS_SHOCK_CLEAR, 0x00);
+}
+
+static u8 ams_pmu_get_vendor(void)
+{
+	return ams_pmu_get_register(AMS_VENDOR);
+}
+
+static void ams_pmu_get_xyz(s8 *x, s8 *y, s8 *z)
+{
+	*x = ams_pmu_get_register(AMS_X);
+	*y = ams_pmu_get_register(AMS_Y);
+	*z = ams_pmu_get_register(AMS_Z);
+}
+
+static void ams_pmu_exit(void)
+{
+	/* Disable interrupts */
+	ams_pmu_set_irq(AMS_IRQ_ALL, 0);
+
+	/* Clear interrupts */
+	ams_pmu_clear_irq(AMS_IRQ_ALL);
+
+	ams_info.has_device = 0;
+
+	printk(KERN_INFO "ams: Unloading\n");
+}
+
+int __init ams_pmu_init(struct device_node *np)
+{
+	u32 *prop;
+	int result;
+
+	mutex_lock(&ams_info.lock);
+
+	/* Set implementation stuff */
+	ams_info.of_node = np;
+	ams_info.exit = ams_pmu_exit;
+	ams_info.get_vendor = ams_pmu_get_vendor;
+	ams_info.get_xyz = ams_pmu_get_xyz;
+	ams_info.clear_irq = ams_pmu_clear_irq;
+	ams_info.bustype = BUS_HOST;
+
+	/* Get PMU command, should be 0x4e, but we can never know */
+	prop = (u32*)get_property(ams_info.of_node, "reg", NULL);
+	if (!prop) {
+		result = -ENODEV;
+		goto exit;
+	}
+	ams_pmu_cmd = ((*prop) >> 8) & 0xff;
+
+	/* Disable interrupts */
+	ams_pmu_set_irq(AMS_IRQ_ALL, 0);
+
+	/* Clear interrupts */
+	ams_pmu_clear_irq(AMS_IRQ_ALL);
+
+	result = ams_sensor_attach();
+	if (result < 0)
+		goto exit;
+
+	/* Set default values */
+	ams_pmu_set_register(AMS_FF_LOW_LIMIT, 0x15);
+	ams_pmu_set_register(AMS_FF_ENABLE, 0x08);
+	ams_pmu_set_register(AMS_FF_DEBOUNCE, 0x14);
+
+	ams_pmu_set_register(AMS_SHOCK_HIGH_LIMIT, 0x60);
+	ams_pmu_set_register(AMS_SHOCK_ENABLE, 0x0f);
+	ams_pmu_set_register(AMS_SHOCK_DEBOUNCE, 0x14);
+
+	ams_pmu_set_register(AMS_CONTROL, 0x4f);
+
+	/* Clear interrupts */
+	ams_pmu_clear_irq(AMS_IRQ_ALL);
+
+	ams_info.has_device = 1;
+
+	/* Enable interrupts */
+	ams_pmu_set_irq(AMS_IRQ_ALL, 1);
+
+	printk(KERN_INFO "ams: Found PMU based motion sensor\n");
+
+	result = 0;
+
+exit:
+	mutex_unlock(&ams_info.lock);
+
+	return result;
+}