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path: root/drivers/mfd/wm831x-auxadc.c
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Diffstat (limited to 'drivers/mfd/wm831x-auxadc.c')
-rw-r--r--drivers/mfd/wm831x-auxadc.c199
1 files changed, 199 insertions, 0 deletions
diff --git a/drivers/mfd/wm831x-auxadc.c b/drivers/mfd/wm831x-auxadc.c
new file mode 100644
index 000000000000..2fc9531b243d
--- /dev/null
+++ b/drivers/mfd/wm831x-auxadc.c
@@ -0,0 +1,199 @@
+/*
+ * 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/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>
+
+/**
+ * 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)
+{
+ int ret, src, irq_masked, timeout;
+
+ /* Are we using the interrupt? */
+ irq_masked = wm831x_reg_read(wm831x, WM831X_INTERRUPT_STATUS_1_MASK);
+ irq_masked &= WM831X_AUXADC_DATA_EINT;
+
+ 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;
+ }
+
+ /* Clear any notification from a very late arriving interrupt */
+ try_wait_for_completion(&wm831x->auxadc_done);
+
+ 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 (irq_masked) {
+ /* 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;
+ }
+
+ wm831x->auxadc_data = ret;
+
+ } else {
+ /* If we are using interrupts then wait for the
+ * interrupt to complete. Use an extremely long
+ * timeout to handle situations with heavy load where
+ * the notification of the interrupt may be delayed by
+ * threaded IRQ handling. */
+ if (!wait_for_completion_timeout(&wm831x->auxadc_done,
+ msecs_to_jiffies(500))) {
+ dev_err(wm831x->dev, "Timed out waiting for AUXADC\n");
+ ret = -EBUSY;
+ goto disable;
+ }
+ }
+
+ src = ((wm831x->auxadc_data & 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->auxadc_data & WM831X_AUX_DATA_MASK;
+ }
+
+disable:
+ wm831x_set_bits(wm831x, WM831X_AUXADC_CONTROL, WM831X_AUX_ENA, 0);
+out:
+ mutex_unlock(&wm831x->auxadc_lock);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(wm831x_auxadc_read);
+
+static irqreturn_t wm831x_auxadc_irq(int irq, void *irq_data)
+{
+ struct wm831x *wm831x = irq_data;
+ int ret;
+
+ ret = wm831x_reg_read(wm831x, WM831X_AUXADC_DATA);
+ if (ret < 0) {
+ dev_err(wm831x->dev,
+ "Failed to read AUXADC data: %d\n", ret);
+ wm831x->auxadc_data = 0xffff;
+ } else {
+ wm831x->auxadc_data = ret;
+ }
+
+ complete(&wm831x->auxadc_done);
+
+ return IRQ_HANDLED;
+}
+
+/**
+ * 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_completion(&wm831x->auxadc_done);
+
+ if (wm831x->irq_base) {
+ ret = request_threaded_irq(wm831x->irq_base +
+ 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);
+ }
+}