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, 299 insertions, 0 deletions

diff --git a/drivers/hwmon/ams/ams-i2c.c b/drivers/hwmon/ams/ams-i2c.c
new file mode 100644
index 000000000000..0d24bdfea53e
--- /dev/null
+++ b/drivers/hwmon/ams/ams-i2c.c
@@ -0,0 +1,299 @@
+/*
+ * Apple Motion Sensor driver (I2C variant)
+ *
+ * Copyright (C) 2005 Stelian Pop (stelian@popies.net)
+ * Copyright (C) 2006 Michael Hanselmann (linux-kernel@hansmi.ch)
+ *
+ * Clean room implementation based on the reverse engineered Mac OS X driver by
+ * Johannes Berg <johannes@sipsolutions.net>, documentation available at
+ * http://johannes.sipsolutions.net/PowerBook/Apple_Motion_Sensor_Specification
+ *
+ * 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/delay.h>
+
+#include "ams.h"
+
+/* AMS registers */
+#define AMS_COMMAND     0x00    /* command register */
+#define AMS_STATUS      0x01    /* status register */
+#define AMS_CTRL1       0x02    /* read control 1 (number of values) */
+#define AMS_CTRL2       0x03    /* read control 2 (offset?) */
+#define AMS_CTRL3       0x04    /* read control 3 (size of each value?) */
+#define AMS_DATA1       0x05    /* read data 1 */
+#define AMS_DATA2       0x06    /* read data 2 */
+#define AMS_DATA3       0x07    /* read data 3 */
+#define AMS_DATA4       0x08    /* read data 4 */
+#define AMS_DATAX       0x20    /* data X */
+#define AMS_DATAY       0x21    /* data Y */
+#define AMS_DATAZ       0x22    /* data Z */
+#define AMS_FREEFALL    0x24    /* freefall int control */
+#define AMS_SHOCK       0x25    /* shock int control */
+#define AMS_SENSLOW     0x26    /* sensitivity low limit */
+#define AMS_SENSHIGH    0x27    /* sensitivity high limit */
+#define AMS_CTRLX       0x28    /* control X */
+#define AMS_CTRLY       0x29    /* control Y */
+#define AMS_CTRLZ       0x2A    /* control Z */
+#define AMS_UNKNOWN1    0x2B    /* unknown 1 */
+#define AMS_UNKNOWN2    0x2C    /* unknown 2 */
+#define AMS_UNKNOWN3    0x2D    /* unknown 3 */
+#define AMS_VENDOR      0x2E    /* vendor */
+
+/* AMS commands - use with the AMS_COMMAND register */
+enum ams_i2c_cmd {
+        AMS_CMD_NOOP = 0,
+        AMS_CMD_VERSION,
+        AMS_CMD_READMEM,
+        AMS_CMD_WRITEMEM,
+        AMS_CMD_ERASEMEM,
+        AMS_CMD_READEE,
+        AMS_CMD_WRITEEE,
+        AMS_CMD_RESET,
+        AMS_CMD_START,
+};
+
+static int ams_i2c_attach(struct i2c_adapter *adapter);
+static int ams_i2c_detach(struct i2c_adapter *adapter);
+
+static struct i2c_driver ams_i2c_driver = {
+        .driver = {
+                .name   = "ams",
+                .owner  = THIS_MODULE,
+        },
+        .attach_adapter = ams_i2c_attach,
+        .detach_adapter = ams_i2c_detach,
+};
+
+static s32 ams_i2c_read(u8 reg)
+{
+        return i2c_smbus_read_byte_data(&ams_info.i2c_client, reg);
+}
+
+static int ams_i2c_write(u8 reg, u8 value)
+{
+        return i2c_smbus_write_byte_data(&ams_info.i2c_client, reg, value);
+}
+
+static int ams_i2c_cmd(enum ams_i2c_cmd cmd)
+{
+        s32 result;
+        int remaining = HZ / 20;
+
+        ams_i2c_write(AMS_COMMAND, cmd);
+        mdelay(5);
+
+        while (remaining) {
+                result = ams_i2c_read(AMS_COMMAND);
+                if (result == 0 || result & 0x80)
+                        return 0;
+
+                remaining = schedule_timeout(remaining);
+        }
+
+        return -1;
+}
+
+static void ams_i2c_set_irq(enum ams_irq reg, char enable)
+{
+        if (reg & AMS_IRQ_FREEFALL) {
+                u8 val = ams_i2c_read(AMS_CTRLX);
+                if (enable)
+                        val |= 0x80;
+                else
+                        val &= ~0x80;
+                ams_i2c_write(AMS_CTRLX, val);
+        }
+
+        if (reg & AMS_IRQ_SHOCK) {
+                u8 val = ams_i2c_read(AMS_CTRLY);
+                if (enable)
+                        val |= 0x80;
+                else
+                        val &= ~0x80;
+                ams_i2c_write(AMS_CTRLY, val);
+        }
+
+        if (reg & AMS_IRQ_GLOBAL) {
+                u8 val = ams_i2c_read(AMS_CTRLZ);
+                if (enable)
+                        val |= 0x80;
+                else
+                        val &= ~0x80;
+                ams_i2c_write(AMS_CTRLZ, val);
+        }
+}
+
+static void ams_i2c_clear_irq(enum ams_irq reg)
+{
+        if (reg & AMS_IRQ_FREEFALL)
+                ams_i2c_write(AMS_FREEFALL, 0);
+
+        if (reg & AMS_IRQ_SHOCK)
+                ams_i2c_write(AMS_SHOCK, 0);
+}
+
+static u8 ams_i2c_get_vendor(void)
+{
+        return ams_i2c_read(AMS_VENDOR);
+}
+
+static void ams_i2c_get_xyz(s8 *x, s8 *y, s8 *z)
+{
+        *x = ams_i2c_read(AMS_DATAX);
+        *y = ams_i2c_read(AMS_DATAY);
+        *z = ams_i2c_read(AMS_DATAZ);
+}
+
+static int ams_i2c_attach(struct i2c_adapter *adapter)
+{
+        unsigned long bus;
+        int vmaj, vmin;
+        int result;
+
+        /* There can be only one */
+        if (unlikely(ams_info.has_device))
+                return -ENODEV;
+
+        if (strncmp(adapter->name, "uni-n", 5))
+                return -ENODEV;
+
+        bus = simple_strtoul(adapter->name + 6, NULL, 10);
+        if (bus != ams_info.i2c_bus)
+                return -ENODEV;
+
+        ams_info.i2c_client.addr = ams_info.i2c_address;
+        ams_info.i2c_client.adapter = adapter;
+        ams_info.i2c_client.driver = &ams_i2c_driver;
+        strcpy(ams_info.i2c_client.name, "Apple Motion Sensor");
+
+        if (ams_i2c_cmd(AMS_CMD_RESET)) {
+                printk(KERN_INFO "ams: Failed to reset the device\n");
+                return -ENODEV;
+        }
+
+        if (ams_i2c_cmd(AMS_CMD_START)) {
+                printk(KERN_INFO "ams: Failed to start the device\n");
+                return -ENODEV;
+        }
+
+        /* get version/vendor information */
+        ams_i2c_write(AMS_CTRL1, 0x02);
+        ams_i2c_write(AMS_CTRL2, 0x85);
+        ams_i2c_write(AMS_CTRL3, 0x01);
+
+        ams_i2c_cmd(AMS_CMD_READMEM);
+
+        vmaj = ams_i2c_read(AMS_DATA1);
+        vmin = ams_i2c_read(AMS_DATA2);
+        if (vmaj != 1 || vmin != 52) {
+                printk(KERN_INFO "ams: Incorrect device version (%d.%d)\n",
+                        vmaj, vmin);
+                return -ENODEV;
+        }
+
+        ams_i2c_cmd(AMS_CMD_VERSION);
+
+        vmaj = ams_i2c_read(AMS_DATA1);
+        vmin = ams_i2c_read(AMS_DATA2);
+        if (vmaj != 0 || vmin != 1) {
+                printk(KERN_INFO "ams: Incorrect firmware version (%d.%d)\n",
+                        vmaj, vmin);
+                return -ENODEV;
+        }
+
+        /* Disable interrupts */
+        ams_i2c_set_irq(AMS_IRQ_ALL, 0);
+
+        result = ams_sensor_attach();
+        if (result < 0)
+                return result;
+
+        /* Set default values */
+        ams_i2c_write(AMS_SENSLOW, 0x15);
+        ams_i2c_write(AMS_SENSHIGH, 0x60);
+        ams_i2c_write(AMS_CTRLX, 0x08);
+        ams_i2c_write(AMS_CTRLY, 0x0F);
+        ams_i2c_write(AMS_CTRLZ, 0x4F);
+        ams_i2c_write(AMS_UNKNOWN1, 0x14);
+
+        /* Clear interrupts */
+        ams_i2c_clear_irq(AMS_IRQ_ALL);
+
+        ams_info.has_device = 1;
+
+        /* Enable interrupts */
+        ams_i2c_set_irq(AMS_IRQ_ALL, 1);
+
+        printk(KERN_INFO "ams: Found I2C based motion sensor\n");
+
+        return 0;
+}
+
+static int ams_i2c_detach(struct i2c_adapter *adapter)
+{
+        if (ams_info.has_device) {
+                /* Disable interrupts */
+                ams_i2c_set_irq(AMS_IRQ_ALL, 0);
+
+                /* Clear interrupts */
+                ams_i2c_clear_irq(AMS_IRQ_ALL);
+
+                printk(KERN_INFO "ams: Unloading\n");
+
+                ams_info.has_device = 0;
+        }
+
+        return 0;
+}
+
+static void ams_i2c_exit(void)
+{
+        i2c_del_driver(&ams_i2c_driver);
+}
+
+int __init ams_i2c_init(struct device_node *np)
+{
+        char *tmp_bus;
+        int result;
+        u32 *prop;
+
+        mutex_lock(&ams_info.lock);
+
+        /* Set implementation stuff */
+        ams_info.of_node = np;
+        ams_info.exit = ams_i2c_exit;
+        ams_info.get_vendor = ams_i2c_get_vendor;
+        ams_info.get_xyz = ams_i2c_get_xyz;
+        ams_info.clear_irq = ams_i2c_clear_irq;
+        ams_info.bustype = BUS_I2C;
+
+        /* look for bus either using "reg" or by path */
+        prop = (u32*)get_property(ams_info.of_node, "reg", NULL);
+        if (!prop) {
+                result = -ENODEV;
+
+                goto exit;
+        }
+
+        tmp_bus = strstr(ams_info.of_node->full_name, "/i2c-bus@");
+        if (tmp_bus)
+                ams_info.i2c_bus = *(tmp_bus + 9) - '0';
+        else
+                ams_info.i2c_bus = ((*prop) >> 8) & 0x0f;
+        ams_info.i2c_address = ((*prop) & 0xff) >> 1;
+
+        result = i2c_add_driver(&ams_i2c_driver);
+
+exit:
+        mutex_unlock(&ams_info.lock);
+
+        return result;
+}