1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * wm831x-auxadc.c -- AUXADC for Wolfson WM831x PMICs
5 * Copyright 2009-2011 Wolfson Microelectronics PLC.
7 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
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>
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>
24 struct wm831x_auxadc_req {
25 struct list_head list;
26 enum wm831x_auxadc input;
28 struct completion done;
31 static int wm831x_auxadc_read_irq(struct wm831x *wm831x,
32 enum wm831x_auxadc input)
34 struct wm831x_auxadc_req *req;
38 req = kzalloc(sizeof(*req), GFP_KERNEL);
42 init_completion(&req->done);
44 req->val = -ETIMEDOUT;
46 mutex_lock(&wm831x->auxadc_lock);
48 /* Enqueue the request */
49 list_add(&req->list, &wm831x->auxadc_pending);
51 ena = !wm831x->auxadc_active;
54 ret = wm831x_set_bits(wm831x, WM831X_AUXADC_CONTROL,
55 WM831X_AUX_ENA, WM831X_AUX_ENA);
57 dev_err(wm831x->dev, "Failed to enable AUXADC: %d\n",
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);
69 "Failed to set AUXADC source: %d\n", ret);
73 wm831x->auxadc_active |= 1 << input;
76 /* We convert at the fastest rate possible */
78 ret = wm831x_set_bits(wm831x, WM831X_AUXADC_CONTROL,
82 WM831X_AUX_RATE_MASK);
84 dev_err(wm831x->dev, "Failed to start AUXADC: %d\n",
90 mutex_unlock(&wm831x->auxadc_lock);
92 /* Wait for an interrupt */
93 wait_for_completion_timeout(&req->done, msecs_to_jiffies(500));
95 mutex_lock(&wm831x->auxadc_lock);
100 mutex_unlock(&wm831x->auxadc_lock);
107 static irqreturn_t wm831x_auxadc_irq(int irq, void *irq_data)
109 struct wm831x *wm831x = irq_data;
110 struct wm831x_auxadc_req *req;
113 ret = wm831x_reg_read(wm831x, WM831X_AUXADC_DATA);
116 "Failed to read AUXADC data: %d\n", ret);
120 input = ((ret & WM831X_AUX_DATA_SRC_MASK)
121 >> WM831X_AUX_DATA_SRC_SHIFT) - 1;
124 input = WM831X_AUX_CAL;
126 val = ret & WM831X_AUX_DATA_MASK;
128 mutex_lock(&wm831x->auxadc_lock);
130 /* Disable this conversion, we're about to complete all users */
131 wm831x_set_bits(wm831x, WM831X_AUXADC_SOURCE,
133 wm831x->auxadc_active &= ~(1 << input);
135 /* Turn off the entire convertor if idle */
136 if (!wm831x->auxadc_active)
137 wm831x_reg_write(wm831x, WM831X_AUXADC_CONTROL, 0);
139 /* Wake up any threads waiting for this request */
140 list_for_each_entry(req, &wm831x->auxadc_pending, list) {
141 if (req->input == input) {
143 complete(&req->done);
147 mutex_unlock(&wm831x->auxadc_lock);
152 static int wm831x_auxadc_read_polled(struct wm831x *wm831x,
153 enum wm831x_auxadc input)
157 mutex_lock(&wm831x->auxadc_lock);
159 ret = wm831x_set_bits(wm831x, WM831X_AUXADC_CONTROL,
160 WM831X_AUX_ENA, WM831X_AUX_ENA);
162 dev_err(wm831x->dev, "Failed to enable AUXADC: %d\n", ret);
166 /* We force a single source at present */
168 ret = wm831x_reg_write(wm831x, WM831X_AUXADC_SOURCE,
171 dev_err(wm831x->dev, "Failed to set AUXADC source: %d\n", ret);
175 ret = wm831x_set_bits(wm831x, WM831X_AUXADC_CONTROL,
176 WM831X_AUX_CVT_ENA, WM831X_AUX_CVT_ENA);
178 dev_err(wm831x->dev, "Failed to start AUXADC: %d\n", ret);
182 /* If we're not using interrupts then read the interrupt status register */
185 ret = wm831x_reg_read(wm831x, WM831X_INTERRUPT_STATUS_1);
188 "ISR 1 read failed: %d\n", ret);
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);
198 "AUXADC conversion timeout\n");
203 ret = wm831x_reg_read(wm831x, WM831X_AUXADC_DATA);
206 "Failed to read AUXADC data: %d\n", ret);
210 src = ((ret & WM831X_AUX_DATA_SRC_MASK)
211 >> WM831X_AUX_DATA_SRC_SHIFT) - 1;
214 src = WM831X_AUX_CAL;
217 dev_err(wm831x->dev, "Data from source %d not %d\n",
221 ret &= WM831X_AUX_DATA_MASK;
225 wm831x_set_bits(wm831x, WM831X_AUXADC_CONTROL, WM831X_AUX_ENA, 0);
227 mutex_unlock(&wm831x->auxadc_lock);
232 * wm831x_auxadc_read: Read a value from the WM831x AUXADC
234 * @wm831x: Device to read from.
235 * @input: AUXADC input to read.
237 int wm831x_auxadc_read(struct wm831x *wm831x, enum wm831x_auxadc input)
239 return wm831x->auxadc_read(wm831x, input);
241 EXPORT_SYMBOL_GPL(wm831x_auxadc_read);
244 * wm831x_auxadc_read_uv: Read a voltage from the WM831x AUXADC
246 * @wm831x: Device to read from.
247 * @input: AUXADC input to read.
249 int wm831x_auxadc_read_uv(struct wm831x *wm831x, enum wm831x_auxadc input)
253 ret = wm831x_auxadc_read(wm831x, input);
261 EXPORT_SYMBOL_GPL(wm831x_auxadc_read_uv);
263 void wm831x_auxadc_init(struct wm831x *wm831x)
267 mutex_init(&wm831x->auxadc_lock);
268 INIT_LIST_HEAD(&wm831x->auxadc_pending);
271 wm831x->auxadc_read = wm831x_auxadc_read_irq;
273 ret = request_threaded_irq(wm831x_irq(wm831x,
274 WM831X_IRQ_AUXADC_DATA),
275 NULL, wm831x_auxadc_irq,
279 dev_err(wm831x->dev, "AUXADC IRQ request failed: %d\n",
281 wm831x->auxadc_read = NULL;
285 if (!wm831x->auxadc_read)
286 wm831x->auxadc_read = wm831x_auxadc_read_polled;