12874c5fdSThomas Gleixner // SPDX-License-Identifier: GPL-2.0-or-later
2e69b6de1SMark Brown /*
3e69b6de1SMark Brown * wm831x-auxadc.c -- AUXADC for Wolfson WM831x PMICs
4e69b6de1SMark Brown *
5e69b6de1SMark Brown * Copyright 2009-2011 Wolfson Microelectronics PLC.
6e69b6de1SMark Brown *
7e69b6de1SMark Brown * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
8e69b6de1SMark Brown */
9e69b6de1SMark Brown
10e69b6de1SMark Brown #include <linux/kernel.h>
11e69b6de1SMark Brown #include <linux/module.h>
12e69b6de1SMark Brown #include <linux/delay.h>
13e69b6de1SMark Brown #include <linux/mfd/core.h>
14e69b6de1SMark Brown #include <linux/slab.h>
1578bb3688SMark Brown #include <linux/list.h>
16e69b6de1SMark Brown
17e69b6de1SMark Brown #include <linux/mfd/wm831x/core.h>
18e69b6de1SMark Brown #include <linux/mfd/wm831x/pdata.h>
19e69b6de1SMark Brown #include <linux/mfd/wm831x/irq.h>
20e69b6de1SMark Brown #include <linux/mfd/wm831x/auxadc.h>
21e69b6de1SMark Brown #include <linux/mfd/wm831x/otp.h>
22e69b6de1SMark Brown #include <linux/mfd/wm831x/regulator.h>
23e69b6de1SMark Brown
2478bb3688SMark Brown struct wm831x_auxadc_req {
2578bb3688SMark Brown struct list_head list;
2678bb3688SMark Brown enum wm831x_auxadc input;
2778bb3688SMark Brown int val;
2878bb3688SMark Brown struct completion done;
2978bb3688SMark Brown };
30e69b6de1SMark Brown
wm831x_auxadc_read_irq(struct wm831x * wm831x,enum wm831x_auxadc input)3178bb3688SMark Brown static int wm831x_auxadc_read_irq(struct wm831x *wm831x,
3278bb3688SMark Brown enum wm831x_auxadc input)
3378bb3688SMark Brown {
3478bb3688SMark Brown struct wm831x_auxadc_req *req;
3578bb3688SMark Brown int ret;
3678bb3688SMark Brown bool ena = false;
3778bb3688SMark Brown
3878bb3688SMark Brown req = kzalloc(sizeof(*req), GFP_KERNEL);
3978bb3688SMark Brown if (!req)
4078bb3688SMark Brown return -ENOMEM;
4178bb3688SMark Brown
4278bb3688SMark Brown init_completion(&req->done);
4378bb3688SMark Brown req->input = input;
4478bb3688SMark Brown req->val = -ETIMEDOUT;
4578bb3688SMark Brown
4678bb3688SMark Brown mutex_lock(&wm831x->auxadc_lock);
4778bb3688SMark Brown
4878bb3688SMark Brown /* Enqueue the request */
4978bb3688SMark Brown list_add(&req->list, &wm831x->auxadc_pending);
5078bb3688SMark Brown
5178bb3688SMark Brown ena = !wm831x->auxadc_active;
5278bb3688SMark Brown
5378bb3688SMark Brown if (ena) {
5478bb3688SMark Brown ret = wm831x_set_bits(wm831x, WM831X_AUXADC_CONTROL,
5578bb3688SMark Brown WM831X_AUX_ENA, WM831X_AUX_ENA);
5678bb3688SMark Brown if (ret != 0) {
5778bb3688SMark Brown dev_err(wm831x->dev, "Failed to enable AUXADC: %d\n",
5878bb3688SMark Brown ret);
5978bb3688SMark Brown goto out;
6078bb3688SMark Brown }
6178bb3688SMark Brown }
6278bb3688SMark Brown
6378bb3688SMark Brown /* Enable the conversion if not already running */
6478bb3688SMark Brown if (!(wm831x->auxadc_active & (1 << input))) {
6578bb3688SMark Brown ret = wm831x_set_bits(wm831x, WM831X_AUXADC_SOURCE,
6678bb3688SMark Brown 1 << input, 1 << input);
6778bb3688SMark Brown if (ret != 0) {
6878bb3688SMark Brown dev_err(wm831x->dev,
6978bb3688SMark Brown "Failed to set AUXADC source: %d\n", ret);
7078bb3688SMark Brown goto out;
7178bb3688SMark Brown }
7278bb3688SMark Brown
7378bb3688SMark Brown wm831x->auxadc_active |= 1 << input;
7478bb3688SMark Brown }
7578bb3688SMark Brown
7678bb3688SMark Brown /* We convert at the fastest rate possible */
7778bb3688SMark Brown if (ena) {
7878bb3688SMark Brown ret = wm831x_set_bits(wm831x, WM831X_AUXADC_CONTROL,
7978bb3688SMark Brown WM831X_AUX_CVT_ENA |
8078bb3688SMark Brown WM831X_AUX_RATE_MASK,
8178bb3688SMark Brown WM831X_AUX_CVT_ENA |
8278bb3688SMark Brown WM831X_AUX_RATE_MASK);
8378bb3688SMark Brown if (ret != 0) {
8478bb3688SMark Brown dev_err(wm831x->dev, "Failed to start AUXADC: %d\n",
8578bb3688SMark Brown ret);
8678bb3688SMark Brown goto out;
8778bb3688SMark Brown }
8878bb3688SMark Brown }
8978bb3688SMark Brown
9078bb3688SMark Brown mutex_unlock(&wm831x->auxadc_lock);
9178bb3688SMark Brown
9278bb3688SMark Brown /* Wait for an interrupt */
9378bb3688SMark Brown wait_for_completion_timeout(&req->done, msecs_to_jiffies(500));
9478bb3688SMark Brown
9578bb3688SMark Brown mutex_lock(&wm831x->auxadc_lock);
9678bb3688SMark Brown ret = req->val;
9778bb3688SMark Brown
9878bb3688SMark Brown out:
99*26783d74SDan Carpenter list_del(&req->list);
10078bb3688SMark Brown mutex_unlock(&wm831x->auxadc_lock);
10178bb3688SMark Brown
10278bb3688SMark Brown kfree(req);
10378bb3688SMark Brown
10478bb3688SMark Brown return ret;
10578bb3688SMark Brown }
10678bb3688SMark Brown
wm831x_auxadc_irq(int irq,void * irq_data)10778bb3688SMark Brown static irqreturn_t wm831x_auxadc_irq(int irq, void *irq_data)
10878bb3688SMark Brown {
10978bb3688SMark Brown struct wm831x *wm831x = irq_data;
11078bb3688SMark Brown struct wm831x_auxadc_req *req;
11178bb3688SMark Brown int ret, input, val;
11278bb3688SMark Brown
11378bb3688SMark Brown ret = wm831x_reg_read(wm831x, WM831X_AUXADC_DATA);
11478bb3688SMark Brown if (ret < 0) {
11578bb3688SMark Brown dev_err(wm831x->dev,
11678bb3688SMark Brown "Failed to read AUXADC data: %d\n", ret);
11778bb3688SMark Brown return IRQ_NONE;
11878bb3688SMark Brown }
11978bb3688SMark Brown
12078bb3688SMark Brown input = ((ret & WM831X_AUX_DATA_SRC_MASK)
12178bb3688SMark Brown >> WM831X_AUX_DATA_SRC_SHIFT) - 1;
12278bb3688SMark Brown
12378bb3688SMark Brown if (input == 14)
12478bb3688SMark Brown input = WM831X_AUX_CAL;
12578bb3688SMark Brown
12678bb3688SMark Brown val = ret & WM831X_AUX_DATA_MASK;
12778bb3688SMark Brown
12878bb3688SMark Brown mutex_lock(&wm831x->auxadc_lock);
12978bb3688SMark Brown
13078bb3688SMark Brown /* Disable this conversion, we're about to complete all users */
13178bb3688SMark Brown wm831x_set_bits(wm831x, WM831X_AUXADC_SOURCE,
13278bb3688SMark Brown 1 << input, 0);
13378bb3688SMark Brown wm831x->auxadc_active &= ~(1 << input);
13478bb3688SMark Brown
13578bb3688SMark Brown /* Turn off the entire convertor if idle */
13678bb3688SMark Brown if (!wm831x->auxadc_active)
13778bb3688SMark Brown wm831x_reg_write(wm831x, WM831X_AUXADC_CONTROL, 0);
13878bb3688SMark Brown
13978bb3688SMark Brown /* Wake up any threads waiting for this request */
14078bb3688SMark Brown list_for_each_entry(req, &wm831x->auxadc_pending, list) {
14178bb3688SMark Brown if (req->input == input) {
14278bb3688SMark Brown req->val = val;
14378bb3688SMark Brown complete(&req->done);
14478bb3688SMark Brown }
14578bb3688SMark Brown }
14678bb3688SMark Brown
14778bb3688SMark Brown mutex_unlock(&wm831x->auxadc_lock);
14878bb3688SMark Brown
14978bb3688SMark Brown return IRQ_HANDLED;
15078bb3688SMark Brown }
15178bb3688SMark Brown
wm831x_auxadc_read_polled(struct wm831x * wm831x,enum wm831x_auxadc input)15278bb3688SMark Brown static int wm831x_auxadc_read_polled(struct wm831x *wm831x,
15378bb3688SMark Brown enum wm831x_auxadc input)
15478bb3688SMark Brown {
15578bb3688SMark Brown int ret, src, timeout;
156e69b6de1SMark Brown
157e69b6de1SMark Brown mutex_lock(&wm831x->auxadc_lock);
158e69b6de1SMark Brown
159e69b6de1SMark Brown ret = wm831x_set_bits(wm831x, WM831X_AUXADC_CONTROL,
160e69b6de1SMark Brown WM831X_AUX_ENA, WM831X_AUX_ENA);
161e69b6de1SMark Brown if (ret < 0) {
162e69b6de1SMark Brown dev_err(wm831x->dev, "Failed to enable AUXADC: %d\n", ret);
163e69b6de1SMark Brown goto out;
164e69b6de1SMark Brown }
165e69b6de1SMark Brown
166e69b6de1SMark Brown /* We force a single source at present */
167e69b6de1SMark Brown src = input;
168e69b6de1SMark Brown ret = wm831x_reg_write(wm831x, WM831X_AUXADC_SOURCE,
169e69b6de1SMark Brown 1 << src);
170e69b6de1SMark Brown if (ret < 0) {
171e69b6de1SMark Brown dev_err(wm831x->dev, "Failed to set AUXADC source: %d\n", ret);
172e69b6de1SMark Brown goto out;
173e69b6de1SMark Brown }
174e69b6de1SMark Brown
175e69b6de1SMark Brown ret = wm831x_set_bits(wm831x, WM831X_AUXADC_CONTROL,
176e69b6de1SMark Brown WM831X_AUX_CVT_ENA, WM831X_AUX_CVT_ENA);
177e69b6de1SMark Brown if (ret < 0) {
178e69b6de1SMark Brown dev_err(wm831x->dev, "Failed to start AUXADC: %d\n", ret);
179e69b6de1SMark Brown goto disable;
180e69b6de1SMark Brown }
181e69b6de1SMark Brown
182e69b6de1SMark Brown /* If we're not using interrupts then poll the
183e69b6de1SMark Brown * interrupt status register */
184e69b6de1SMark Brown timeout = 5;
185e69b6de1SMark Brown while (timeout) {
186e69b6de1SMark Brown msleep(1);
187e69b6de1SMark Brown
188e69b6de1SMark Brown ret = wm831x_reg_read(wm831x,
189e69b6de1SMark Brown WM831X_INTERRUPT_STATUS_1);
190e69b6de1SMark Brown if (ret < 0) {
191e69b6de1SMark Brown dev_err(wm831x->dev,
192e69b6de1SMark Brown "ISR 1 read failed: %d\n", ret);
193e69b6de1SMark Brown goto disable;
194e69b6de1SMark Brown }
195e69b6de1SMark Brown
196e69b6de1SMark Brown /* Did it complete? */
197e69b6de1SMark Brown if (ret & WM831X_AUXADC_DATA_EINT) {
198e69b6de1SMark Brown wm831x_reg_write(wm831x,
199e69b6de1SMark Brown WM831X_INTERRUPT_STATUS_1,
200e69b6de1SMark Brown WM831X_AUXADC_DATA_EINT);
201e69b6de1SMark Brown break;
202e69b6de1SMark Brown } else {
203e69b6de1SMark Brown dev_err(wm831x->dev,
204e69b6de1SMark Brown "AUXADC conversion timeout\n");
205e69b6de1SMark Brown ret = -EBUSY;
206e69b6de1SMark Brown goto disable;
207e69b6de1SMark Brown }
208e69b6de1SMark Brown }
209e69b6de1SMark Brown
210e69b6de1SMark Brown ret = wm831x_reg_read(wm831x, WM831X_AUXADC_DATA);
211e69b6de1SMark Brown if (ret < 0) {
212e69b6de1SMark Brown dev_err(wm831x->dev,
213e69b6de1SMark Brown "Failed to read AUXADC data: %d\n", ret);
214e69b6de1SMark Brown goto disable;
215e69b6de1SMark Brown }
216e69b6de1SMark Brown
21778bb3688SMark Brown src = ((ret & WM831X_AUX_DATA_SRC_MASK)
218e69b6de1SMark Brown >> WM831X_AUX_DATA_SRC_SHIFT) - 1;
219e69b6de1SMark Brown
220e69b6de1SMark Brown if (src == 14)
221e69b6de1SMark Brown src = WM831X_AUX_CAL;
222e69b6de1SMark Brown
223e69b6de1SMark Brown if (src != input) {
224e69b6de1SMark Brown dev_err(wm831x->dev, "Data from source %d not %d\n",
225e69b6de1SMark Brown src, input);
226e69b6de1SMark Brown ret = -EINVAL;
227e69b6de1SMark Brown } else {
22878bb3688SMark Brown ret &= WM831X_AUX_DATA_MASK;
229e69b6de1SMark Brown }
230e69b6de1SMark Brown
231e69b6de1SMark Brown disable:
232e69b6de1SMark Brown wm831x_set_bits(wm831x, WM831X_AUXADC_CONTROL, WM831X_AUX_ENA, 0);
233e69b6de1SMark Brown out:
234e69b6de1SMark Brown mutex_unlock(&wm831x->auxadc_lock);
235e69b6de1SMark Brown return ret;
236e69b6de1SMark Brown }
237e69b6de1SMark Brown
23878bb3688SMark Brown /**
23978bb3688SMark Brown * wm831x_auxadc_read: Read a value from the WM831x AUXADC
24078bb3688SMark Brown *
24178bb3688SMark Brown * @wm831x: Device to read from.
24278bb3688SMark Brown * @input: AUXADC input to read.
24378bb3688SMark Brown */
wm831x_auxadc_read(struct wm831x * wm831x,enum wm831x_auxadc input)24478bb3688SMark Brown int wm831x_auxadc_read(struct wm831x *wm831x, enum wm831x_auxadc input)
245e69b6de1SMark Brown {
24678bb3688SMark Brown return wm831x->auxadc_read(wm831x, input);
247e69b6de1SMark Brown }
24878bb3688SMark Brown EXPORT_SYMBOL_GPL(wm831x_auxadc_read);
249e69b6de1SMark Brown
250e69b6de1SMark Brown /**
251e69b6de1SMark Brown * wm831x_auxadc_read_uv: Read a voltage from the WM831x AUXADC
252e69b6de1SMark Brown *
253e69b6de1SMark Brown * @wm831x: Device to read from.
254e69b6de1SMark Brown * @input: AUXADC input to read.
255e69b6de1SMark Brown */
wm831x_auxadc_read_uv(struct wm831x * wm831x,enum wm831x_auxadc input)256e69b6de1SMark Brown int wm831x_auxadc_read_uv(struct wm831x *wm831x, enum wm831x_auxadc input)
257e69b6de1SMark Brown {
258e69b6de1SMark Brown int ret;
259e69b6de1SMark Brown
260e69b6de1SMark Brown ret = wm831x_auxadc_read(wm831x, input);
261e69b6de1SMark Brown if (ret < 0)
262e69b6de1SMark Brown return ret;
263e69b6de1SMark Brown
264e69b6de1SMark Brown ret *= 1465;
265e69b6de1SMark Brown
266e69b6de1SMark Brown return ret;
267e69b6de1SMark Brown }
268e69b6de1SMark Brown EXPORT_SYMBOL_GPL(wm831x_auxadc_read_uv);
269e69b6de1SMark Brown
wm831x_auxadc_init(struct wm831x * wm831x)270e69b6de1SMark Brown void wm831x_auxadc_init(struct wm831x *wm831x)
271e69b6de1SMark Brown {
272e69b6de1SMark Brown int ret;
273e69b6de1SMark Brown
274e69b6de1SMark Brown mutex_init(&wm831x->auxadc_lock);
27578bb3688SMark Brown INIT_LIST_HEAD(&wm831x->auxadc_pending);
276e69b6de1SMark Brown
277cd99758bSMark Brown if (wm831x->irq) {
27878bb3688SMark Brown wm831x->auxadc_read = wm831x_auxadc_read_irq;
27978bb3688SMark Brown
280cd99758bSMark Brown ret = request_threaded_irq(wm831x_irq(wm831x,
281cd99758bSMark Brown WM831X_IRQ_AUXADC_DATA),
2821a52598cSFabio Estevam NULL, wm831x_auxadc_irq,
2831a52598cSFabio Estevam IRQF_ONESHOT,
284e69b6de1SMark Brown "auxadc", wm831x);
28578bb3688SMark Brown if (ret < 0) {
286e69b6de1SMark Brown dev_err(wm831x->dev, "AUXADC IRQ request failed: %d\n",
287e69b6de1SMark Brown ret);
28878bb3688SMark Brown wm831x->auxadc_read = NULL;
289e69b6de1SMark Brown }
290e69b6de1SMark Brown }
29178bb3688SMark Brown
29278bb3688SMark Brown if (!wm831x->auxadc_read)
29378bb3688SMark Brown wm831x->auxadc_read = wm831x_auxadc_read_polled;
29478bb3688SMark Brown }
295