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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * wm831x-auxadc.c -- AUXADC for Wolfson WM831x PMICs4 *5 * Copyright 2009-2011 Wolfson Microelectronics PLC.6 *7 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>8 */9 10#include <linux/kernel.h>11#include <linux/module.h>12#include <linux/delay.h>13#include <linux/mfd/core.h>14#include <linux/slab.h>15#include <linux/list.h>16 17#include <linux/mfd/wm831x/core.h>18#include <linux/mfd/wm831x/pdata.h>19#include <linux/mfd/wm831x/irq.h>20#include <linux/mfd/wm831x/auxadc.h>21#include <linux/mfd/wm831x/otp.h>22#include <linux/mfd/wm831x/regulator.h>23 24struct wm831x_auxadc_req {25 struct list_head list;26 enum wm831x_auxadc input;27 int val;28 struct completion done;29};30 31static int wm831x_auxadc_read_irq(struct wm831x *wm831x,32 enum wm831x_auxadc input)33{34 struct wm831x_auxadc_req *req;35 int ret;36 bool ena = false;37 38 req = kzalloc(sizeof(*req), GFP_KERNEL);39 if (!req)40 return -ENOMEM;41 42 init_completion(&req->done);43 req->input = input;44 req->val = -ETIMEDOUT;45 46 mutex_lock(&wm831x->auxadc_lock);47 48 /* Enqueue the request */49 list_add(&req->list, &wm831x->auxadc_pending);50 51 ena = !wm831x->auxadc_active;52 53 if (ena) {54 ret = wm831x_set_bits(wm831x, WM831X_AUXADC_CONTROL,55 WM831X_AUX_ENA, WM831X_AUX_ENA);56 if (ret != 0) {57 dev_err(wm831x->dev, "Failed to enable AUXADC: %d\n",58 ret);59 goto out;60 }61 }62 63 /* Enable the conversion if not already running */64 if (!(wm831x->auxadc_active & (1 << input))) {65 ret = wm831x_set_bits(wm831x, WM831X_AUXADC_SOURCE,66 1 << input, 1 << input);67 if (ret != 0) {68 dev_err(wm831x->dev,69 "Failed to set AUXADC source: %d\n", ret);70 goto out;71 }72 73 wm831x->auxadc_active |= 1 << input;74 }75 76 /* We convert at the fastest rate possible */77 if (ena) {78 ret = wm831x_set_bits(wm831x, WM831X_AUXADC_CONTROL,79 WM831X_AUX_CVT_ENA |80 WM831X_AUX_RATE_MASK,81 WM831X_AUX_CVT_ENA |82 WM831X_AUX_RATE_MASK);83 if (ret != 0) {84 dev_err(wm831x->dev, "Failed to start AUXADC: %d\n",85 ret);86 goto out;87 }88 }89 90 mutex_unlock(&wm831x->auxadc_lock);91 92 /* Wait for an interrupt */93 wait_for_completion_timeout(&req->done, msecs_to_jiffies(500));94 95 mutex_lock(&wm831x->auxadc_lock);96 ret = req->val;97 98out:99 list_del(&req->list);100 mutex_unlock(&wm831x->auxadc_lock);101 102 kfree(req);103 104 return ret;105}106 107static irqreturn_t wm831x_auxadc_irq(int irq, void *irq_data)108{109 struct wm831x *wm831x = irq_data;110 struct wm831x_auxadc_req *req;111 int ret, input, val;112 113 ret = wm831x_reg_read(wm831x, WM831X_AUXADC_DATA);114 if (ret < 0) {115 dev_err(wm831x->dev,116 "Failed to read AUXADC data: %d\n", ret);117 return IRQ_NONE;118 }119 120 input = ((ret & WM831X_AUX_DATA_SRC_MASK)121 >> WM831X_AUX_DATA_SRC_SHIFT) - 1;122 123 if (input == 14)124 input = WM831X_AUX_CAL;125 126 val = ret & WM831X_AUX_DATA_MASK;127 128 mutex_lock(&wm831x->auxadc_lock);129 130 /* Disable this conversion, we're about to complete all users */131 wm831x_set_bits(wm831x, WM831X_AUXADC_SOURCE,132 1 << input, 0);133 wm831x->auxadc_active &= ~(1 << input);134 135 /* Turn off the entire convertor if idle */136 if (!wm831x->auxadc_active)137 wm831x_reg_write(wm831x, WM831X_AUXADC_CONTROL, 0);138 139 /* Wake up any threads waiting for this request */140 list_for_each_entry(req, &wm831x->auxadc_pending, list) {141 if (req->input == input) {142 req->val = val;143 complete(&req->done);144 }145 }146 147 mutex_unlock(&wm831x->auxadc_lock);148 149 return IRQ_HANDLED;150}151 152static int wm831x_auxadc_read_polled(struct wm831x *wm831x,153 enum wm831x_auxadc input)154{155 int ret, src;156 157 mutex_lock(&wm831x->auxadc_lock);158 159 ret = wm831x_set_bits(wm831x, WM831X_AUXADC_CONTROL,160 WM831X_AUX_ENA, WM831X_AUX_ENA);161 if (ret < 0) {162 dev_err(wm831x->dev, "Failed to enable AUXADC: %d\n", ret);163 goto out;164 }165 166 /* We force a single source at present */167 src = input;168 ret = wm831x_reg_write(wm831x, WM831X_AUXADC_SOURCE,169 1 << src);170 if (ret < 0) {171 dev_err(wm831x->dev, "Failed to set AUXADC source: %d\n", ret);172 goto out;173 }174 175 ret = wm831x_set_bits(wm831x, WM831X_AUXADC_CONTROL,176 WM831X_AUX_CVT_ENA, WM831X_AUX_CVT_ENA);177 if (ret < 0) {178 dev_err(wm831x->dev, "Failed to start AUXADC: %d\n", ret);179 goto disable;180 }181 182 /* If we're not using interrupts then read the interrupt status register */183 msleep(20);184 185 ret = wm831x_reg_read(wm831x, WM831X_INTERRUPT_STATUS_1);186 if (ret < 0) {187 dev_err(wm831x->dev,188 "ISR 1 read failed: %d\n", ret);189 goto disable;190 }191 192 /* Did it complete? */193 if (ret & WM831X_AUXADC_DATA_EINT) {194 wm831x_reg_write(wm831x, WM831X_INTERRUPT_STATUS_1,195 WM831X_AUXADC_DATA_EINT);196 } else {197 dev_err(wm831x->dev,198 "AUXADC conversion timeout\n");199 ret = -EBUSY;200 goto disable;201 }202 203 ret = wm831x_reg_read(wm831x, WM831X_AUXADC_DATA);204 if (ret < 0) {205 dev_err(wm831x->dev,206 "Failed to read AUXADC data: %d\n", ret);207 goto disable;208 }209 210 src = ((ret & WM831X_AUX_DATA_SRC_MASK)211 >> WM831X_AUX_DATA_SRC_SHIFT) - 1;212 213 if (src == 14)214 src = WM831X_AUX_CAL;215 216 if (src != input) {217 dev_err(wm831x->dev, "Data from source %d not %d\n",218 src, input);219 ret = -EINVAL;220 } else {221 ret &= WM831X_AUX_DATA_MASK;222 }223 224disable:225 wm831x_set_bits(wm831x, WM831X_AUXADC_CONTROL, WM831X_AUX_ENA, 0);226out:227 mutex_unlock(&wm831x->auxadc_lock);228 return ret;229}230 231/**232 * wm831x_auxadc_read: Read a value from the WM831x AUXADC233 *234 * @wm831x: Device to read from.235 * @input: AUXADC input to read.236 */237int wm831x_auxadc_read(struct wm831x *wm831x, enum wm831x_auxadc input)238{239 return wm831x->auxadc_read(wm831x, input);240}241EXPORT_SYMBOL_GPL(wm831x_auxadc_read);242 243/**244 * wm831x_auxadc_read_uv: Read a voltage from the WM831x AUXADC245 *246 * @wm831x: Device to read from.247 * @input: AUXADC input to read.248 */249int wm831x_auxadc_read_uv(struct wm831x *wm831x, enum wm831x_auxadc input)250{251 int ret;252 253 ret = wm831x_auxadc_read(wm831x, input);254 if (ret < 0)255 return ret;256 257 ret *= 1465;258 259 return ret;260}261EXPORT_SYMBOL_GPL(wm831x_auxadc_read_uv);262 263void wm831x_auxadc_init(struct wm831x *wm831x)264{265 int ret;266 267 mutex_init(&wm831x->auxadc_lock);268 INIT_LIST_HEAD(&wm831x->auxadc_pending);269 270 if (wm831x->irq) {271 wm831x->auxadc_read = wm831x_auxadc_read_irq;272 273 ret = request_threaded_irq(wm831x_irq(wm831x,274 WM831X_IRQ_AUXADC_DATA),275 NULL, wm831x_auxadc_irq,276 IRQF_ONESHOT,277 "auxadc", wm831x);278 if (ret < 0) {279 dev_err(wm831x->dev, "AUXADC IRQ request failed: %d\n",280 ret);281 wm831x->auxadc_read = NULL;282 }283 }284 285 if (!wm831x->auxadc_read)286 wm831x->auxadc_read = wm831x_auxadc_read_polled;287}288