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);
101 mutex_unlock(&wm831x->auxadc_lock);
108 static irqreturn_t wm831x_auxadc_irq(int irq, void *irq_data)
110 struct wm831x *wm831x = irq_data;
111 struct wm831x_auxadc_req *req;
114 ret = wm831x_reg_read(wm831x, WM831X_AUXADC_DATA);
117 "Failed to read AUXADC data: %d\n", ret);
121 input = ((ret & WM831X_AUX_DATA_SRC_MASK)
122 >> WM831X_AUX_DATA_SRC_SHIFT) - 1;
125 input = WM831X_AUX_CAL;
127 val = ret & WM831X_AUX_DATA_MASK;
129 mutex_lock(&wm831x->auxadc_lock);
131 /* Disable this conversion, we're about to complete all users */
132 wm831x_set_bits(wm831x, WM831X_AUXADC_SOURCE,
134 wm831x->auxadc_active &= ~(1 << input);
136 /* Turn off the entire convertor if idle */
137 if (!wm831x->auxadc_active)
138 wm831x_reg_write(wm831x, WM831X_AUXADC_CONTROL, 0);
140 /* Wake up any threads waiting for this request */
141 list_for_each_entry(req, &wm831x->auxadc_pending, list) {
142 if (req->input == input) {
144 complete(&req->done);
148 mutex_unlock(&wm831x->auxadc_lock);
153 static int wm831x_auxadc_read_polled(struct wm831x *wm831x,
154 enum wm831x_auxadc input)
156 int ret, src, timeout;
158 mutex_lock(&wm831x->auxadc_lock);
160 ret = wm831x_set_bits(wm831x, WM831X_AUXADC_CONTROL,
161 WM831X_AUX_ENA, WM831X_AUX_ENA);
163 dev_err(wm831x->dev, "Failed to enable AUXADC: %d\n", ret);
167 /* We force a single source at present */
169 ret = wm831x_reg_write(wm831x, WM831X_AUXADC_SOURCE,
172 dev_err(wm831x->dev, "Failed to set AUXADC source: %d\n", ret);
176 ret = wm831x_set_bits(wm831x, WM831X_AUXADC_CONTROL,
177 WM831X_AUX_CVT_ENA, WM831X_AUX_CVT_ENA);
179 dev_err(wm831x->dev, "Failed to start AUXADC: %d\n", ret);
183 /* If we're not using interrupts then poll the
184 * interrupt status register */
189 ret = wm831x_reg_read(wm831x,
190 WM831X_INTERRUPT_STATUS_1);
193 "ISR 1 read failed: %d\n", ret);
197 /* Did it complete? */
198 if (ret & WM831X_AUXADC_DATA_EINT) {
199 wm831x_reg_write(wm831x,
200 WM831X_INTERRUPT_STATUS_1,
201 WM831X_AUXADC_DATA_EINT);
205 "AUXADC conversion timeout\n");
211 ret = wm831x_reg_read(wm831x, WM831X_AUXADC_DATA);
214 "Failed to read AUXADC data: %d\n", ret);
218 src = ((ret & WM831X_AUX_DATA_SRC_MASK)
219 >> WM831X_AUX_DATA_SRC_SHIFT) - 1;
222 src = WM831X_AUX_CAL;
225 dev_err(wm831x->dev, "Data from source %d not %d\n",
229 ret &= WM831X_AUX_DATA_MASK;
233 wm831x_set_bits(wm831x, WM831X_AUXADC_CONTROL, WM831X_AUX_ENA, 0);
235 mutex_unlock(&wm831x->auxadc_lock);
240 * wm831x_auxadc_read: Read a value from the WM831x AUXADC
242 * @wm831x: Device to read from.
243 * @input: AUXADC input to read.
245 int wm831x_auxadc_read(struct wm831x *wm831x, enum wm831x_auxadc input)
247 return wm831x->auxadc_read(wm831x, input);
249 EXPORT_SYMBOL_GPL(wm831x_auxadc_read);
252 * wm831x_auxadc_read_uv: Read a voltage from the WM831x AUXADC
254 * @wm831x: Device to read from.
255 * @input: AUXADC input to read.
257 int wm831x_auxadc_read_uv(struct wm831x *wm831x, enum wm831x_auxadc input)
261 ret = wm831x_auxadc_read(wm831x, input);
269 EXPORT_SYMBOL_GPL(wm831x_auxadc_read_uv);
271 void wm831x_auxadc_init(struct wm831x *wm831x)
275 mutex_init(&wm831x->auxadc_lock);
276 INIT_LIST_HEAD(&wm831x->auxadc_pending);
279 wm831x->auxadc_read = wm831x_auxadc_read_irq;
281 ret = request_threaded_irq(wm831x_irq(wm831x,
282 WM831X_IRQ_AUXADC_DATA),
283 NULL, wm831x_auxadc_irq,
287 dev_err(wm831x->dev, "AUXADC IRQ request failed: %d\n",
289 wm831x->auxadc_read = NULL;
293 if (!wm831x->auxadc_read)
294 wm831x->auxadc_read = wm831x_auxadc_read_polled;