300 lines
6.6 KiB
C
300 lines
6.6 KiB
C
/*
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* wm831x-auxadc.c -- AUXADC for Wolfson WM831x PMICs
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*
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* Copyright 2009-2011 Wolfson Microelectronics PLC.
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*
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* Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2 of the License, or (at your
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* option) any later version.
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*
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/delay.h>
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#include <linux/mfd/core.h>
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#include <linux/slab.h>
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#include <linux/list.h>
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#include <linux/mfd/wm831x/core.h>
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#include <linux/mfd/wm831x/pdata.h>
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#include <linux/mfd/wm831x/irq.h>
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#include <linux/mfd/wm831x/auxadc.h>
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#include <linux/mfd/wm831x/otp.h>
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#include <linux/mfd/wm831x/regulator.h>
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struct wm831x_auxadc_req {
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struct list_head list;
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enum wm831x_auxadc input;
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int val;
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struct completion done;
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};
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static int wm831x_auxadc_read_irq(struct wm831x *wm831x,
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enum wm831x_auxadc input)
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{
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struct wm831x_auxadc_req *req;
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int ret;
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bool ena = false;
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req = kzalloc(sizeof(*req), GFP_KERNEL);
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if (!req)
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return -ENOMEM;
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init_completion(&req->done);
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req->input = input;
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req->val = -ETIMEDOUT;
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mutex_lock(&wm831x->auxadc_lock);
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/* Enqueue the request */
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list_add(&req->list, &wm831x->auxadc_pending);
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ena = !wm831x->auxadc_active;
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if (ena) {
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ret = wm831x_set_bits(wm831x, WM831X_AUXADC_CONTROL,
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WM831X_AUX_ENA, WM831X_AUX_ENA);
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if (ret != 0) {
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dev_err(wm831x->dev, "Failed to enable AUXADC: %d\n",
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ret);
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goto out;
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}
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}
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/* Enable the conversion if not already running */
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if (!(wm831x->auxadc_active & (1 << input))) {
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ret = wm831x_set_bits(wm831x, WM831X_AUXADC_SOURCE,
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1 << input, 1 << input);
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if (ret != 0) {
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dev_err(wm831x->dev,
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"Failed to set AUXADC source: %d\n", ret);
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goto out;
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}
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wm831x->auxadc_active |= 1 << input;
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}
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/* We convert at the fastest rate possible */
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if (ena) {
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ret = wm831x_set_bits(wm831x, WM831X_AUXADC_CONTROL,
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WM831X_AUX_CVT_ENA |
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WM831X_AUX_RATE_MASK,
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WM831X_AUX_CVT_ENA |
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WM831X_AUX_RATE_MASK);
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if (ret != 0) {
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dev_err(wm831x->dev, "Failed to start AUXADC: %d\n",
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ret);
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goto out;
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}
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}
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mutex_unlock(&wm831x->auxadc_lock);
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/* Wait for an interrupt */
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wait_for_completion_timeout(&req->done, msecs_to_jiffies(500));
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mutex_lock(&wm831x->auxadc_lock);
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list_del(&req->list);
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ret = req->val;
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out:
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mutex_unlock(&wm831x->auxadc_lock);
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kfree(req);
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return ret;
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}
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static irqreturn_t wm831x_auxadc_irq(int irq, void *irq_data)
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{
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struct wm831x *wm831x = irq_data;
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struct wm831x_auxadc_req *req;
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int ret, input, val;
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ret = wm831x_reg_read(wm831x, WM831X_AUXADC_DATA);
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if (ret < 0) {
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dev_err(wm831x->dev,
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"Failed to read AUXADC data: %d\n", ret);
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return IRQ_NONE;
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}
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input = ((ret & WM831X_AUX_DATA_SRC_MASK)
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>> WM831X_AUX_DATA_SRC_SHIFT) - 1;
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if (input == 14)
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input = WM831X_AUX_CAL;
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val = ret & WM831X_AUX_DATA_MASK;
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mutex_lock(&wm831x->auxadc_lock);
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/* Disable this conversion, we're about to complete all users */
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wm831x_set_bits(wm831x, WM831X_AUXADC_SOURCE,
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1 << input, 0);
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wm831x->auxadc_active &= ~(1 << input);
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/* Turn off the entire convertor if idle */
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if (!wm831x->auxadc_active)
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wm831x_reg_write(wm831x, WM831X_AUXADC_CONTROL, 0);
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/* Wake up any threads waiting for this request */
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list_for_each_entry(req, &wm831x->auxadc_pending, list) {
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if (req->input == input) {
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req->val = val;
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complete(&req->done);
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}
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}
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mutex_unlock(&wm831x->auxadc_lock);
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return IRQ_HANDLED;
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}
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static int wm831x_auxadc_read_polled(struct wm831x *wm831x,
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enum wm831x_auxadc input)
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{
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int ret, src, timeout;
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mutex_lock(&wm831x->auxadc_lock);
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ret = wm831x_set_bits(wm831x, WM831X_AUXADC_CONTROL,
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WM831X_AUX_ENA, WM831X_AUX_ENA);
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if (ret < 0) {
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dev_err(wm831x->dev, "Failed to enable AUXADC: %d\n", ret);
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goto out;
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}
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/* We force a single source at present */
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src = input;
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ret = wm831x_reg_write(wm831x, WM831X_AUXADC_SOURCE,
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1 << src);
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if (ret < 0) {
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dev_err(wm831x->dev, "Failed to set AUXADC source: %d\n", ret);
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goto out;
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}
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ret = wm831x_set_bits(wm831x, WM831X_AUXADC_CONTROL,
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WM831X_AUX_CVT_ENA, WM831X_AUX_CVT_ENA);
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if (ret < 0) {
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dev_err(wm831x->dev, "Failed to start AUXADC: %d\n", ret);
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goto disable;
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}
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/* If we're not using interrupts then poll the
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* interrupt status register */
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timeout = 5;
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while (timeout) {
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msleep(1);
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ret = wm831x_reg_read(wm831x,
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WM831X_INTERRUPT_STATUS_1);
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if (ret < 0) {
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dev_err(wm831x->dev,
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"ISR 1 read failed: %d\n", ret);
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goto disable;
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}
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/* Did it complete? */
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if (ret & WM831X_AUXADC_DATA_EINT) {
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wm831x_reg_write(wm831x,
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WM831X_INTERRUPT_STATUS_1,
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WM831X_AUXADC_DATA_EINT);
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break;
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} else {
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dev_err(wm831x->dev,
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"AUXADC conversion timeout\n");
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ret = -EBUSY;
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goto disable;
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}
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}
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ret = wm831x_reg_read(wm831x, WM831X_AUXADC_DATA);
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if (ret < 0) {
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dev_err(wm831x->dev,
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"Failed to read AUXADC data: %d\n", ret);
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goto disable;
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}
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src = ((ret & WM831X_AUX_DATA_SRC_MASK)
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>> WM831X_AUX_DATA_SRC_SHIFT) - 1;
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if (src == 14)
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src = WM831X_AUX_CAL;
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if (src != input) {
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dev_err(wm831x->dev, "Data from source %d not %d\n",
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src, input);
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ret = -EINVAL;
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} else {
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ret &= WM831X_AUX_DATA_MASK;
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}
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disable:
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wm831x_set_bits(wm831x, WM831X_AUXADC_CONTROL, WM831X_AUX_ENA, 0);
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out:
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mutex_unlock(&wm831x->auxadc_lock);
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return ret;
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}
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/**
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* wm831x_auxadc_read: Read a value from the WM831x AUXADC
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*
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* @wm831x: Device to read from.
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* @input: AUXADC input to read.
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*/
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int wm831x_auxadc_read(struct wm831x *wm831x, enum wm831x_auxadc input)
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{
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return wm831x->auxadc_read(wm831x, input);
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}
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EXPORT_SYMBOL_GPL(wm831x_auxadc_read);
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/**
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* wm831x_auxadc_read_uv: Read a voltage from the WM831x AUXADC
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*
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* @wm831x: Device to read from.
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* @input: AUXADC input to read.
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*/
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int wm831x_auxadc_read_uv(struct wm831x *wm831x, enum wm831x_auxadc input)
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{
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int ret;
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ret = wm831x_auxadc_read(wm831x, input);
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if (ret < 0)
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return ret;
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ret *= 1465;
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return ret;
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}
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EXPORT_SYMBOL_GPL(wm831x_auxadc_read_uv);
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void wm831x_auxadc_init(struct wm831x *wm831x)
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{
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int ret;
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mutex_init(&wm831x->auxadc_lock);
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INIT_LIST_HEAD(&wm831x->auxadc_pending);
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if (wm831x->irq) {
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wm831x->auxadc_read = wm831x_auxadc_read_irq;
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ret = request_threaded_irq(wm831x_irq(wm831x,
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WM831X_IRQ_AUXADC_DATA),
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NULL, wm831x_auxadc_irq, 0,
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"auxadc", wm831x);
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if (ret < 0) {
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dev_err(wm831x->dev, "AUXADC IRQ request failed: %d\n",
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ret);
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wm831x->auxadc_read = NULL;
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}
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}
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if (!wm831x->auxadc_read)
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wm831x->auxadc_read = wm831x_auxadc_read_polled;
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}
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