1 files changed, 65 insertions, 0 deletions
diff --git a/driver/als_isl29035.c b/driver/als_isl29035.c
new file mode 100644
index 0000000000..13e5d77c14
--- /dev/null
+++ b/driver/als_isl29035.c
@@ -0,0 +1,65 @@
+/* Copyright (c) 2013 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ *
+ * Intersil ILS29035 light sensor driver
+ */
+
+#include "driver/als_isl29035.h"
+#include "common.h"
+#include "i2c.h"
+#include "timer.h"
+
+/* I2C interface */
+#define ILS29035_I2C_ADDR       0x88
+#define ILS29035_REG_COMMAND_I  0
+#define ILS29035_REG_COMMAND_II 1
+#define ILS29035_REG_DATA_LSB   2
+#define ILS29035_REG_DATA_MSB   3
+#define ILS29035_REG_INT_LT_LSB 4
+#define ILS29035_REG_INT_LT_MSB 5
+#define ILS29035_REG_INT_HT_LSB 6
+#define ILS29035_REG_INT_HT_MSB 7
+#define ILS29035_REG_ID         15
+
+int isl29035_read_lux(int *lux)
+{
+	int rv, lsb, msb, data;
+
+	/* Tell it to read once */
+	rv = i2c_write8(I2C_PORT_ALS, ILS29035_I2C_ADDR,
+			ILS29035_REG_COMMAND_I, 0x20);
+	if (rv)
+		return rv;
+
+	/* The highest precision (default) should take ~90ms */
+	usleep(100 * MSEC);
+
+	/* NOTE: It is necessary to read the LSB first, then the MSB. If you do
+	 * it in the opposite order, the results are not correct. This is
+	 * apparently an undocumented "feature".
+	 */
+
+	/* Read lsb */
+	rv = i2c_read8(I2C_PORT_ALS, ILS29035_I2C_ADDR,
+		       ILS29035_REG_DATA_LSB, &lsb);
+	if (rv)
+		return rv;
+
+	/* Read msb */
+	rv = i2c_read8(I2C_PORT_ALS, ILS29035_I2C_ADDR,
+		       ILS29035_REG_DATA_MSB, &msb);
+	if (rv)
+		return rv;
+
+	data = (msb << 8) | lsb;
+
+	/*
+	 * The default power-on values will give 16 bits of precision:
+	 * 0x0000-0xffff indicates 0-1000 lux. If you change the defaults,
+	 * you'll need to change the scale factor accordingly.
+	 */
+	*lux = data * 1000 / 0xffff;
+
+	return EC_SUCCESS;
+}