Initial import

1 files changed, 299 insertions, 0 deletions

diff --git a/drivers/mfd/wm831x-auxadc.c b/drivers/mfd/wm831x-auxadc.c
new file mode 100644
index 000000000..6ee3018d8
--- /dev/null
+++ b/drivers/mfd/wm831x-auxadc.c
@@ -0,0 +1,299 @@
+/*
+ * wm831x-auxadc.c  --  AUXADC for Wolfson WM831x PMICs
+ *
+ * Copyright 2009-2011 Wolfson Microelectronics PLC.
+ *
+ * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
+ *
+ *  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/kernel.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/mfd/core.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+
+#include <linux/mfd/wm831x/core.h>
+#include <linux/mfd/wm831x/pdata.h>
+#include <linux/mfd/wm831x/irq.h>
+#include <linux/mfd/wm831x/auxadc.h>
+#include <linux/mfd/wm831x/otp.h>
+#include <linux/mfd/wm831x/regulator.h>
+
+struct wm831x_auxadc_req {
+	struct list_head list;
+	enum wm831x_auxadc input;
+	int val;
+	struct completion done;
+};
+
+static int wm831x_auxadc_read_irq(struct wm831x *wm831x,
+				  enum wm831x_auxadc input)
+{
+	struct wm831x_auxadc_req *req;
+	int ret;
+	bool ena = false;
+
+	req = kzalloc(sizeof(*req), GFP_KERNEL);
+	if (!req)
+		return -ENOMEM;
+
+	init_completion(&req->done);
+	req->input = input;
+	req->val = -ETIMEDOUT;
+
+	mutex_lock(&wm831x->auxadc_lock);
+
+	/* Enqueue the request */
+	list_add(&req->list, &wm831x->auxadc_pending);
+
+	ena = !wm831x->auxadc_active;
+
+	if (ena) {
+		ret = wm831x_set_bits(wm831x, WM831X_AUXADC_CONTROL,
+				      WM831X_AUX_ENA, WM831X_AUX_ENA);
+		if (ret != 0) {
+			dev_err(wm831x->dev, "Failed to enable AUXADC: %d\n",
+				ret);
+			goto out;
+		}
+	}
+
+	/* Enable the conversion if not already running */
+	if (!(wm831x->auxadc_active & (1 << input))) {
+		ret = wm831x_set_bits(wm831x, WM831X_AUXADC_SOURCE,
+				      1 << input, 1 << input);
+		if (ret != 0) {
+			dev_err(wm831x->dev,
+				"Failed to set AUXADC source: %d\n", ret);
+			goto out;
+		}
+
+		wm831x->auxadc_active |= 1 << input;
+	}
+
+	/* We convert at the fastest rate possible */
+	if (ena) {
+		ret = wm831x_set_bits(wm831x, WM831X_AUXADC_CONTROL,
+				      WM831X_AUX_CVT_ENA |
+				      WM831X_AUX_RATE_MASK,
+				      WM831X_AUX_CVT_ENA |
+				      WM831X_AUX_RATE_MASK);
+		if (ret != 0) {
+			dev_err(wm831x->dev, "Failed to start AUXADC: %d\n",
+				ret);
+			goto out;
+		}
+	}
+
+	mutex_unlock(&wm831x->auxadc_lock);
+
+	/* Wait for an interrupt */
+	wait_for_completion_timeout(&req->done, msecs_to_jiffies(500));
+
+	mutex_lock(&wm831x->auxadc_lock);
+
+	list_del(&req->list);
+	ret = req->val;
+
+out:
+	mutex_unlock(&wm831x->auxadc_lock);
+
+	kfree(req);
+
+	return ret;
+}
+
+static irqreturn_t wm831x_auxadc_irq(int irq, void *irq_data)
+{
+	struct wm831x *wm831x = irq_data;
+	struct wm831x_auxadc_req *req;
+	int ret, input, val;
+
+	ret = wm831x_reg_read(wm831x, WM831X_AUXADC_DATA);
+	if (ret < 0) {
+		dev_err(wm831x->dev,
+			"Failed to read AUXADC data: %d\n", ret);
+		return IRQ_NONE;
+	}
+
+	input = ((ret & WM831X_AUX_DATA_SRC_MASK)
+		 >> WM831X_AUX_DATA_SRC_SHIFT) - 1;
+
+	if (input == 14)
+		input = WM831X_AUX_CAL;
+
+	val = ret & WM831X_AUX_DATA_MASK;
+
+	mutex_lock(&wm831x->auxadc_lock);
+
+	/* Disable this conversion, we're about to complete all users */
+	wm831x_set_bits(wm831x, WM831X_AUXADC_SOURCE,
+			1 << input, 0);
+	wm831x->auxadc_active &= ~(1 << input);
+
+	/* Turn off the entire convertor if idle */
+	if (!wm831x->auxadc_active)
+		wm831x_reg_write(wm831x, WM831X_AUXADC_CONTROL, 0);
+
+	/* Wake up any threads waiting for this request */
+	list_for_each_entry(req, &wm831x->auxadc_pending, list) {
+		if (req->input == input) {
+			req->val = val;
+			complete(&req->done);
+		}
+	}
+
+	mutex_unlock(&wm831x->auxadc_lock);
+
+	return IRQ_HANDLED;
+}
+
+static int wm831x_auxadc_read_polled(struct wm831x *wm831x,
+				     enum wm831x_auxadc input)
+{
+	int ret, src, timeout;
+
+	mutex_lock(&wm831x->auxadc_lock);
+
+	ret = wm831x_set_bits(wm831x, WM831X_AUXADC_CONTROL,
+			      WM831X_AUX_ENA, WM831X_AUX_ENA);
+	if (ret < 0) {
+		dev_err(wm831x->dev, "Failed to enable AUXADC: %d\n", ret);
+		goto out;
+	}
+
+	/* We force a single source at present */
+	src = input;
+	ret = wm831x_reg_write(wm831x, WM831X_AUXADC_SOURCE,
+			       1 << src);
+	if (ret < 0) {
+		dev_err(wm831x->dev, "Failed to set AUXADC source: %d\n", ret);
+		goto out;
+	}
+
+	ret = wm831x_set_bits(wm831x, WM831X_AUXADC_CONTROL,
+			      WM831X_AUX_CVT_ENA, WM831X_AUX_CVT_ENA);
+	if (ret < 0) {
+		dev_err(wm831x->dev, "Failed to start AUXADC: %d\n", ret);
+		goto disable;
+	}
+
+	/* If we're not using interrupts then poll the
+	 * interrupt status register */
+	timeout = 5;
+	while (timeout) {
+		msleep(1);
+
+		ret = wm831x_reg_read(wm831x,
+				      WM831X_INTERRUPT_STATUS_1);
+		if (ret < 0) {
+			dev_err(wm831x->dev,
+				"ISR 1 read failed: %d\n", ret);
+			goto disable;
+		}
+
+		/* Did it complete? */
+		if (ret & WM831X_AUXADC_DATA_EINT) {
+			wm831x_reg_write(wm831x,
+					 WM831X_INTERRUPT_STATUS_1,
+					 WM831X_AUXADC_DATA_EINT);
+			break;
+		} else {
+			dev_err(wm831x->dev,
+				"AUXADC conversion timeout\n");
+			ret = -EBUSY;
+			goto disable;
+		}
+	}
+
+	ret = wm831x_reg_read(wm831x, WM831X_AUXADC_DATA);
+	if (ret < 0) {
+		dev_err(wm831x->dev,
+			"Failed to read AUXADC data: %d\n", ret);
+		goto disable;
+	}
+
+	src = ((ret & WM831X_AUX_DATA_SRC_MASK)
+	       >> WM831X_AUX_DATA_SRC_SHIFT) - 1;
+
+	if (src == 14)
+		src = WM831X_AUX_CAL;
+
+	if (src != input) {
+		dev_err(wm831x->dev, "Data from source %d not %d\n",
+			src, input);
+		ret = -EINVAL;
+	} else {
+		ret &= WM831X_AUX_DATA_MASK;
+	}
+
+disable:
+	wm831x_set_bits(wm831x, WM831X_AUXADC_CONTROL, WM831X_AUX_ENA, 0);
+out:
+	mutex_unlock(&wm831x->auxadc_lock);
+	return ret;
+}
+
+/**
+ * wm831x_auxadc_read: Read a value from the WM831x AUXADC
+ *
+ * @wm831x: Device to read from.
+ * @input: AUXADC input to read.
+ */
+int wm831x_auxadc_read(struct wm831x *wm831x, enum wm831x_auxadc input)
+{
+	return wm831x->auxadc_read(wm831x, input);
+}
+EXPORT_SYMBOL_GPL(wm831x_auxadc_read);
+
+/**
+ * wm831x_auxadc_read_uv: Read a voltage from the WM831x AUXADC
+ *
+ * @wm831x: Device to read from.
+ * @input: AUXADC input to read.
+ */
+int wm831x_auxadc_read_uv(struct wm831x *wm831x, enum wm831x_auxadc input)
+{
+	int ret;
+
+	ret = wm831x_auxadc_read(wm831x, input);
+	if (ret < 0)
+		return ret;
+
+	ret *= 1465;
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(wm831x_auxadc_read_uv);
+
+void wm831x_auxadc_init(struct wm831x *wm831x)
+{
+	int ret;
+
+	mutex_init(&wm831x->auxadc_lock);
+	INIT_LIST_HEAD(&wm831x->auxadc_pending);
+
+	if (wm831x->irq) {
+		wm831x->auxadc_read = wm831x_auxadc_read_irq;
+
+		ret = request_threaded_irq(wm831x_irq(wm831x,
+						      WM831X_IRQ_AUXADC_DATA),
+					   NULL, wm831x_auxadc_irq, 0,
+					   "auxadc", wm831x);
+		if (ret < 0) {
+			dev_err(wm831x->dev, "AUXADC IRQ request failed: %d\n",
+				ret);
+			wm831x->auxadc_read = NULL;
+		}
+	}
+
+	if (!wm831x->auxadc_read)
+		wm831x->auxadc_read = wm831x_auxadc_read_polled;
+}