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-rw-r--r--drivers/macintosh/ams/ams-i2c.c266
1 files changed, 266 insertions, 0 deletions
diff --git a/drivers/macintosh/ams/ams-i2c.c b/drivers/macintosh/ams/ams-i2c.c
new file mode 100644
index 000000000..3ded34069
--- /dev/null
+++ b/drivers/macintosh/ams/ams-i2c.c
@@ -0,0 +1,266 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * 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
+ */
+
+#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_probe(struct i2c_client *client,
+ const struct i2c_device_id *id);
+static void ams_i2c_remove(struct i2c_client *client);
+
+static const struct i2c_device_id ams_id[] = {
+ { "MAC,accelerometer_1", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, ams_id);
+
+static struct i2c_driver ams_i2c_driver = {
+ .driver = {
+ .name = "ams",
+ },
+ .probe = ams_i2c_probe,
+ .remove = ams_i2c_remove,
+ .id_table = ams_id,
+};
+
+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 count = 3;
+
+ ams_i2c_write(AMS_COMMAND, cmd);
+ msleep(5);
+
+ while (count--) {
+ result = ams_i2c_read(AMS_COMMAND);
+ if (result == 0 || result & 0x80)
+ return 0;
+
+ schedule_timeout_uninterruptible(HZ / 20);
+ }
+
+ 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_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ int vmaj, vmin;
+ int result;
+
+ /* There can be only one */
+ if (unlikely(ams_info.has_device))
+ return -ENODEV;
+
+ ams_info.i2c_client = client;
+
+ 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 void ams_i2c_remove(struct i2c_client *client)
+{
+ if (ams_info.has_device) {
+ ams_sensor_detach();
+
+ /* 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;
+ }
+}
+
+static void ams_i2c_exit(void)
+{
+ i2c_del_driver(&ams_i2c_driver);
+}
+
+int __init ams_i2c_init(struct device_node *np)
+{
+ /* 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;
+
+ return i2c_add_driver(&ams_i2c_driver);
+}