--- /dev/null
+/*
+ * 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;
+}
Code Review / kvmfornfv.git / blobdiff