xref: /linux/drivers/iio/adc/qcom-pm8xxx-xoadc.c (revision d2c9a99135da931377240942d44f3dea104cedb8)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Qualcomm PM8xxx PMIC XOADC driver
4  *
5  * These ADCs are known as HK/XO (house keeping / chrystal oscillator)
6  * "XO" in "XOADC" means Chrystal Oscillator. It's a bunch of
7  * specific-purpose and general purpose ADC converters and channels.
8  *
9  * Copyright (C) 2017 Linaro Ltd.
10  * Author: Linus Walleij <linus.walleij@linaro.org>
11  */
12 
13 #include <linux/iio/adc/qcom-vadc-common.h>
14 #include <linux/iio/iio.h>
15 #include <linux/iio/sysfs.h>
16 #include <linux/module.h>
17 #include <linux/platform_device.h>
18 #include <linux/property.h>
19 #include <linux/regmap.h>
20 #include <linux/init.h>
21 #include <linux/interrupt.h>
22 #include <linux/regulator/consumer.h>
23 
24 /*
25  * Definitions for the "user processor" registers lifted from the v3.4
26  * Qualcomm tree. Their kernel has two out-of-tree drivers for the ADC:
27  * drivers/misc/pmic8058-xoadc.c
28  * drivers/hwmon/pm8xxx-adc.c
29  * None of them contain any complete register specification, so this is
30  * a best effort of combining the information.
31  */
32 
33 /* These appear to be "battery monitor" registers */
34 #define ADC_ARB_BTM_CNTRL1			0x17e
35 #define ADC_ARB_BTM_CNTRL1_EN_BTM		BIT(0)
36 #define ADC_ARB_BTM_CNTRL1_SEL_OP_MODE		BIT(1)
37 #define ADC_ARB_BTM_CNTRL1_MEAS_INTERVAL1	BIT(2)
38 #define ADC_ARB_BTM_CNTRL1_MEAS_INTERVAL2	BIT(3)
39 #define ADC_ARB_BTM_CNTRL1_MEAS_INTERVAL3	BIT(4)
40 #define ADC_ARB_BTM_CNTRL1_MEAS_INTERVAL4	BIT(5)
41 #define ADC_ARB_BTM_CNTRL1_EOC			BIT(6)
42 #define ADC_ARB_BTM_CNTRL1_REQ			BIT(7)
43 
44 #define ADC_ARB_BTM_AMUX_CNTRL			0x17f
45 #define ADC_ARB_BTM_ANA_PARAM			0x180
46 #define ADC_ARB_BTM_DIG_PARAM			0x181
47 #define ADC_ARB_BTM_RSV				0x182
48 #define ADC_ARB_BTM_DATA1			0x183
49 #define ADC_ARB_BTM_DATA0			0x184
50 #define ADC_ARB_BTM_BAT_COOL_THR1		0x185
51 #define ADC_ARB_BTM_BAT_COOL_THR0		0x186
52 #define ADC_ARB_BTM_BAT_WARM_THR1		0x187
53 #define ADC_ARB_BTM_BAT_WARM_THR0		0x188
54 #define ADC_ARB_BTM_CNTRL2			0x18c
55 
56 /* Proper ADC registers */
57 
58 #define ADC_ARB_USRP_CNTRL			0x197
59 #define ADC_ARB_USRP_CNTRL_EN_ARB		BIT(0)
60 #define ADC_ARB_USRP_CNTRL_RSV1			BIT(1)
61 #define ADC_ARB_USRP_CNTRL_RSV2			BIT(2)
62 #define ADC_ARB_USRP_CNTRL_RSV3			BIT(3)
63 #define ADC_ARB_USRP_CNTRL_RSV4			BIT(4)
64 #define ADC_ARB_USRP_CNTRL_RSV5			BIT(5)
65 #define ADC_ARB_USRP_CNTRL_EOC			BIT(6)
66 #define ADC_ARB_USRP_CNTRL_REQ			BIT(7)
67 
68 #define ADC_ARB_USRP_AMUX_CNTRL			0x198
69 /*
70  * The channel mask includes the bits selecting channel mux and prescaler
71  * on PM8058, or channel mux and premux on PM8921.
72  */
73 #define ADC_ARB_USRP_AMUX_CNTRL_CHAN_MASK	0xfc
74 #define ADC_ARB_USRP_AMUX_CNTRL_RSV0		BIT(0)
75 #define ADC_ARB_USRP_AMUX_CNTRL_RSV1		BIT(1)
76 /* On PM8058 this is prescaling, on PM8921 this is premux */
77 #define ADC_ARB_USRP_AMUX_CNTRL_PRESCALEMUX0	BIT(2)
78 #define ADC_ARB_USRP_AMUX_CNTRL_PRESCALEMUX1	BIT(3)
79 #define ADC_ARB_USRP_AMUX_CNTRL_SEL0		BIT(4)
80 #define ADC_ARB_USRP_AMUX_CNTRL_SEL1		BIT(5)
81 #define ADC_ARB_USRP_AMUX_CNTRL_SEL2		BIT(6)
82 #define ADC_ARB_USRP_AMUX_CNTRL_SEL3		BIT(7)
83 #define ADC_AMUX_PREMUX_SHIFT			2
84 #define ADC_AMUX_SEL_SHIFT			4
85 
86 /* We know very little about the bits in this register */
87 #define ADC_ARB_USRP_ANA_PARAM			0x199
88 #define ADC_ARB_USRP_ANA_PARAM_DIS		0xFE
89 #define ADC_ARB_USRP_ANA_PARAM_EN		0xFF
90 
91 #define ADC_ARB_USRP_DIG_PARAM			0x19A
92 #define ADC_ARB_USRP_DIG_PARAM_SEL_SHIFT0	BIT(0)
93 #define ADC_ARB_USRP_DIG_PARAM_SEL_SHIFT1	BIT(1)
94 #define ADC_ARB_USRP_DIG_PARAM_CLK_RATE0	BIT(2)
95 #define ADC_ARB_USRP_DIG_PARAM_CLK_RATE1	BIT(3)
96 #define ADC_ARB_USRP_DIG_PARAM_EOC		BIT(4)
97 /*
98  * On a later ADC the decimation factors are defined as
99  * 00 = 512, 01 = 1024, 10 = 2048, 11 = 4096 so assume this
100  * holds also for this older XOADC.
101  */
102 #define ADC_ARB_USRP_DIG_PARAM_DEC_RATE0	BIT(5)
103 #define ADC_ARB_USRP_DIG_PARAM_DEC_RATE1	BIT(6)
104 #define ADC_ARB_USRP_DIG_PARAM_EN		BIT(7)
105 #define ADC_DIG_PARAM_DEC_SHIFT			5
106 
107 #define ADC_ARB_USRP_RSV			0x19B
108 #define ADC_ARB_USRP_RSV_RST			BIT(0)
109 #define ADC_ARB_USRP_RSV_DTEST0			BIT(1)
110 #define ADC_ARB_USRP_RSV_DTEST1			BIT(2)
111 #define ADC_ARB_USRP_RSV_OP			BIT(3)
112 #define ADC_ARB_USRP_RSV_IP_SEL0		BIT(4)
113 #define ADC_ARB_USRP_RSV_IP_SEL1		BIT(5)
114 #define ADC_ARB_USRP_RSV_IP_SEL2		BIT(6)
115 #define ADC_ARB_USRP_RSV_TRM			BIT(7)
116 #define ADC_RSV_IP_SEL_SHIFT			4
117 
118 #define ADC_ARB_USRP_DATA0			0x19D
119 #define ADC_ARB_USRP_DATA1			0x19C
120 
121 /*
122  * Physical channels which MUST exist on all PM variants in order to provide
123  * proper reference points for calibration.
124  *
125  * @PM8XXX_CHANNEL_INTERNAL: 625mV reference channel
126  * @PM8XXX_CHANNEL_125V: 1250mV reference channel
127  * @PM8XXX_CHANNEL_INTERNAL_2: 325mV reference channel
128  * @PM8XXX_CHANNEL_MUXOFF: channel to reduce input load on mux, apparently also
129  * measures XO temperature
130  */
131 #define PM8XXX_CHANNEL_INTERNAL		0x0c
132 #define PM8XXX_CHANNEL_125V		0x0d
133 #define PM8XXX_CHANNEL_INTERNAL_2	0x0e
134 #define PM8XXX_CHANNEL_MUXOFF		0x0f
135 
136 /*
137  * PM8058 AMUX premux scaling, two bits. This is done of the channel before
138  * reaching the AMUX.
139  */
140 #define PM8058_AMUX_PRESCALE_0 0x0 /* No scaling on the signal */
141 #define PM8058_AMUX_PRESCALE_1 0x1 /* Unity scaling selected by the user */
142 #define PM8058_AMUX_PRESCALE_1_DIV3 0x2 /* 1/3 prescaler on the input */
143 
144 /* Defines reference voltage for the XOADC */
145 #define AMUX_RSV0 0x0 /* XO_IN/XOADC_GND, special selection to read XO temp */
146 #define AMUX_RSV1 0x1 /* PMIC_IN/XOADC_GND */
147 #define AMUX_RSV2 0x2 /* PMIC_IN/BMS_CSP */
148 #define AMUX_RSV3 0x3 /* not used */
149 #define AMUX_RSV4 0x4 /* XOADC_GND/XOADC_GND */
150 #define AMUX_RSV5 0x5 /* XOADC_VREF/XOADC_GND */
151 #define XOADC_RSV_MAX 5 /* 3 bits 0..7, 3 and 6,7 are invalid */
152 
153 /**
154  * struct xoadc_channel - encodes channel properties and defaults
155  * @datasheet_name: the hardwarename of this channel
156  * @pre_scale_mux: prescale (PM8058) or premux (PM8921) for selecting
157  * this channel. Both this and the amux channel is needed to uniquely
158  * identify a channel. Values 0..3.
159  * @amux_channel: value of the ADC_ARB_USRP_AMUX_CNTRL register for this
160  * channel, bits 4..7, selects the amux, values 0..f
161  * @prescale: the channels have hard-coded prescale ratios defined
162  * by the hardware, this tells us what it is
163  * @type: corresponding IIO channel type, usually IIO_VOLTAGE or
164  * IIO_TEMP
165  * @scale_fn_type: the liner interpolation etc to convert the
166  * ADC code to the value that IIO expects, in uV or millicelsius
167  * etc. This scale function can be pretty elaborate if different
168  * thermistors are connected or other hardware characteristics are
169  * deployed.
170  * @amux_ip_rsv: ratiometric scale value used by the analog muxer: this
171  * selects the reference voltage for ratiometric scaling
172  */
173 struct xoadc_channel {
174 	const char *datasheet_name;
175 	u8 pre_scale_mux:2;
176 	u8 amux_channel:4;
177 	const struct u32_fract prescale;
178 	enum iio_chan_type type;
179 	enum vadc_scale_fn_type scale_fn_type;
180 	u8 amux_ip_rsv:3;
181 };
182 
183 /**
184  * struct xoadc_variant - encodes the XOADC variant characteristics
185  * @name: name of this PMIC variant
186  * @channels: the hardware channels and respective settings and defaults
187  * @broken_ratiometric: if the PMIC has broken ratiometric scaling (this
188  * is a known problem on PM8058)
189  * @prescaling: this variant uses AMUX bits 2 & 3 for prescaling (PM8058)
190  * @second_level_mux: this variant uses AMUX bits 2 & 3 for a second level
191  * mux
192  */
193 struct xoadc_variant {
194 	const char name[16];
195 	const struct xoadc_channel *channels;
196 	bool broken_ratiometric;
197 	bool prescaling;
198 	bool second_level_mux;
199 };
200 
201 /*
202  * XOADC_CHAN macro parameters:
203  * _dname: the name of the channel
204  * _presmux: prescaler (PM8058) or premux (PM8921) setting for this channel
205  * _amux: the value in bits 2..7 of the ADC_ARB_USRP_AMUX_CNTRL register
206  * for this channel. On some PMICs some of the bits select a prescaler, and
207  * on some PMICs some of the bits select various complex multiplex settings.
208  * _type: IIO channel type
209  * _prenum: prescaler numerator (dividend)
210  * _preden: prescaler denominator (divisor)
211  * _scale: scaling function type, this selects how the raw valued is mangled
212  * to output the actual processed measurement
213  * _amip: analog mux input parent when using ratiometric measurements
214  */
215 #define XOADC_CHAN(_dname, _presmux, _amux, _type, _prenum, _preden, _scale, _amip) \
216 	{								\
217 		.datasheet_name = __stringify(_dname),			\
218 		.pre_scale_mux = _presmux,				\
219 		.amux_channel = _amux,					\
220 		.prescale = {						\
221 			.numerator = _prenum, .denominator = _preden,	\
222 		},							\
223 		.type = _type,						\
224 		.scale_fn_type = _scale,				\
225 		.amux_ip_rsv = _amip,					\
226 	}
227 
228 /*
229  * Taken from arch/arm/mach-msm/board-9615.c in the vendor tree:
230  * TODO: incomplete, needs testing.
231  */
232 static const struct xoadc_channel pm8018_xoadc_channels[] = {
233 	XOADC_CHAN(VCOIN, 0x00, 0x00, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
234 	XOADC_CHAN(VBAT, 0x00, 0x01, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
235 	XOADC_CHAN(VPH_PWR, 0x00, 0x02, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
236 	XOADC_CHAN(DIE_TEMP, 0x00, 0x0b, IIO_TEMP, 1, 1, SCALE_PMIC_THERM, AMUX_RSV1),
237 	/* Used for battery ID or battery temperature */
238 	XOADC_CHAN(AMUX8, 0x00, 0x08, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV2),
239 	XOADC_CHAN(INTERNAL, 0x00, 0x0c, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
240 	XOADC_CHAN(125V, 0x00, 0x0d, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
241 	XOADC_CHAN(MUXOFF, 0x00, 0x0f, IIO_TEMP, 1, 1, SCALE_XOTHERM, AMUX_RSV0),
242 	{ }, /* Sentinel */
243 };
244 
245 /*
246  * Taken from arch/arm/mach-msm/board-8930-pmic.c in the vendor tree:
247  * TODO: needs testing.
248  */
249 static const struct xoadc_channel pm8038_xoadc_channels[] = {
250 	XOADC_CHAN(VCOIN, 0x00, 0x00, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
251 	XOADC_CHAN(VBAT, 0x00, 0x01, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
252 	XOADC_CHAN(DCIN, 0x00, 0x02, IIO_VOLTAGE, 1, 6, SCALE_DEFAULT, AMUX_RSV1),
253 	XOADC_CHAN(ICHG, 0x00, 0x03, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
254 	XOADC_CHAN(VPH_PWR, 0x00, 0x04, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
255 	XOADC_CHAN(AMUX5, 0x00, 0x05, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
256 	XOADC_CHAN(AMUX6, 0x00, 0x06, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
257 	XOADC_CHAN(AMUX7, 0x00, 0x07, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
258 	/* AMUX8 used for battery temperature in most cases */
259 	XOADC_CHAN(AMUX8, 0x00, 0x08, IIO_TEMP, 1, 1, SCALE_THERM_100K_PULLUP, AMUX_RSV2),
260 	XOADC_CHAN(AMUX9, 0x00, 0x09, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
261 	XOADC_CHAN(USB_VBUS, 0x00, 0x0a, IIO_VOLTAGE, 1, 4, SCALE_DEFAULT, AMUX_RSV1),
262 	XOADC_CHAN(DIE_TEMP, 0x00, 0x0b, IIO_TEMP, 1, 1, SCALE_PMIC_THERM, AMUX_RSV1),
263 	XOADC_CHAN(INTERNAL, 0x00, 0x0c, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
264 	XOADC_CHAN(125V, 0x00, 0x0d, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
265 	XOADC_CHAN(INTERNAL_2, 0x00, 0x0e, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
266 	XOADC_CHAN(MUXOFF, 0x00, 0x0f, IIO_TEMP, 1, 1, SCALE_XOTHERM, AMUX_RSV0),
267 	{ }, /* Sentinel */
268 };
269 
270 /*
271  * This was created by cross-referencing the vendor tree
272  * arch/arm/mach-msm/board-msm8x60.c msm_adc_channels_data[]
273  * with the "channel types" (first field) to find the right
274  * configuration for these channels on an MSM8x60 i.e. PM8058
275  * setup.
276  */
277 static const struct xoadc_channel pm8058_xoadc_channels[] = {
278 	XOADC_CHAN(VCOIN, 0x00, 0x00, IIO_VOLTAGE, 1, 2, SCALE_DEFAULT, AMUX_RSV1),
279 	XOADC_CHAN(VBAT, 0x00, 0x01, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
280 	XOADC_CHAN(DCIN, 0x00, 0x02, IIO_VOLTAGE, 1, 10, SCALE_DEFAULT, AMUX_RSV1),
281 	XOADC_CHAN(ICHG, 0x00, 0x03, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
282 	XOADC_CHAN(VPH_PWR, 0x00, 0x04, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
283 	/*
284 	 * AMUX channels 5 thru 9 are referred to as MPP5 thru MPP9 in
285 	 * some code and documentation. But they are really just 5
286 	 * channels just like any other. They are connected to a switching
287 	 * matrix where they can be routed to any of the MPPs, not just
288 	 * 1-to-1 onto MPP5 thru 9, so naming them MPP5 thru MPP9 is
289 	 * very confusing.
290 	 */
291 	XOADC_CHAN(AMUX5, 0x00, 0x05, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
292 	XOADC_CHAN(AMUX6, 0x00, 0x06, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
293 	XOADC_CHAN(AMUX7, 0x00, 0x07, IIO_VOLTAGE, 1, 2, SCALE_DEFAULT, AMUX_RSV1),
294 	XOADC_CHAN(AMUX8, 0x00, 0x08, IIO_VOLTAGE, 1, 2, SCALE_DEFAULT, AMUX_RSV1),
295 	XOADC_CHAN(AMUX9, 0x00, 0x09, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
296 	XOADC_CHAN(USB_VBUS, 0x00, 0x0a, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
297 	XOADC_CHAN(DIE_TEMP, 0x00, 0x0b, IIO_TEMP, 1, 1, SCALE_PMIC_THERM, AMUX_RSV1),
298 	XOADC_CHAN(INTERNAL, 0x00, 0x0c, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
299 	XOADC_CHAN(125V, 0x00, 0x0d, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
300 	XOADC_CHAN(INTERNAL_2, 0x00, 0x0e, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
301 	XOADC_CHAN(MUXOFF, 0x00, 0x0f, IIO_TEMP, 1, 1, SCALE_XOTHERM, AMUX_RSV0),
302 	/* There are also "unity" and divided by 3 channels (prescaler) but noone is using them */
303 	{ }, /* Sentinel */
304 };
305 
306 /*
307  * The PM8921 has some pre-muxing on its channels, this comes from the vendor tree
308  * include/linux/mfd/pm8xxx/pm8xxx-adc.h
309  * board-flo-pmic.c (Nexus 7) and board-8064-pmic.c
310  */
311 static const struct xoadc_channel pm8921_xoadc_channels[] = {
312 	XOADC_CHAN(VCOIN, 0x00, 0x00, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
313 	XOADC_CHAN(VBAT, 0x00, 0x01, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
314 	XOADC_CHAN(DCIN, 0x00, 0x02, IIO_VOLTAGE, 1, 6, SCALE_DEFAULT, AMUX_RSV1),
315 	/* channel "ICHG" is reserved and not used on PM8921 */
316 	XOADC_CHAN(VPH_PWR, 0x00, 0x04, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
317 	XOADC_CHAN(IBAT, 0x00, 0x05, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
318 	/* CHAN 6 & 7 (MPP1 & MPP2) are reserved for MPP channels on PM8921 */
319 	XOADC_CHAN(BATT_THERM, 0x00, 0x08, IIO_TEMP, 1, 1, SCALE_THERM_100K_PULLUP, AMUX_RSV1),
320 	XOADC_CHAN(BATT_ID, 0x00, 0x09, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
321 	XOADC_CHAN(USB_VBUS, 0x00, 0x0a, IIO_VOLTAGE, 1, 4, SCALE_DEFAULT, AMUX_RSV1),
322 	XOADC_CHAN(DIE_TEMP, 0x00, 0x0b, IIO_TEMP, 1, 1, SCALE_PMIC_THERM, AMUX_RSV1),
323 	XOADC_CHAN(INTERNAL, 0x00, 0x0c, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
324 	XOADC_CHAN(125V, 0x00, 0x0d, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
325 	/* FIXME: look into the scaling of this temperature */
326 	XOADC_CHAN(CHG_TEMP, 0x00, 0x0e, IIO_TEMP, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
327 	XOADC_CHAN(MUXOFF, 0x00, 0x0f, IIO_TEMP, 1, 1, SCALE_XOTHERM, AMUX_RSV0),
328 	/* The following channels have premux bit 0 set to 1 (all end in 4) */
329 	XOADC_CHAN(ATEST_8, 0x01, 0x00, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
330 	/* Set scaling to 1/2 based on the name for these two */
331 	XOADC_CHAN(USB_SNS_DIV20, 0x01, 0x01, IIO_VOLTAGE, 1, 2, SCALE_DEFAULT, AMUX_RSV1),
332 	XOADC_CHAN(DCIN_SNS_DIV20, 0x01, 0x02, IIO_VOLTAGE, 1, 2, SCALE_DEFAULT, AMUX_RSV1),
333 	XOADC_CHAN(AMUX3, 0x01, 0x03, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
334 	XOADC_CHAN(AMUX4, 0x01, 0x04, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
335 	XOADC_CHAN(AMUX5, 0x01, 0x05, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
336 	XOADC_CHAN(AMUX6, 0x01, 0x06, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
337 	XOADC_CHAN(AMUX7, 0x01, 0x07, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
338 	XOADC_CHAN(AMUX8, 0x01, 0x08, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
339 	/* Internal test signals, I think */
340 	XOADC_CHAN(ATEST_1, 0x01, 0x09, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
341 	XOADC_CHAN(ATEST_2, 0x01, 0x0a, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
342 	XOADC_CHAN(ATEST_3, 0x01, 0x0b, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
343 	XOADC_CHAN(ATEST_4, 0x01, 0x0c, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
344 	XOADC_CHAN(ATEST_5, 0x01, 0x0d, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
345 	XOADC_CHAN(ATEST_6, 0x01, 0x0e, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
346 	XOADC_CHAN(ATEST_7, 0x01, 0x0f, IIO_VOLTAGE, 1, 1, SCALE_DEFAULT, AMUX_RSV1),
347 	/* The following channels have premux bit 1 set to 1 (all end in 8) */
348 	/* I guess even ATEST8 will be divided by 3 here */
349 	XOADC_CHAN(ATEST_8, 0x02, 0x00, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
350 	/* I guess div 2 div 3 becomes div 6 */
351 	XOADC_CHAN(USB_SNS_DIV20_DIV3, 0x02, 0x01, IIO_VOLTAGE, 1, 6, SCALE_DEFAULT, AMUX_RSV1),
352 	XOADC_CHAN(DCIN_SNS_DIV20_DIV3, 0x02, 0x02, IIO_VOLTAGE, 1, 6, SCALE_DEFAULT, AMUX_RSV1),
353 	XOADC_CHAN(AMUX3_DIV3, 0x02, 0x03, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
354 	XOADC_CHAN(AMUX4_DIV3, 0x02, 0x04, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
355 	XOADC_CHAN(AMUX5_DIV3, 0x02, 0x05, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
356 	XOADC_CHAN(AMUX6_DIV3, 0x02, 0x06, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
357 	XOADC_CHAN(AMUX7_DIV3, 0x02, 0x07, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
358 	XOADC_CHAN(AMUX8_DIV3, 0x02, 0x08, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
359 	XOADC_CHAN(ATEST_1_DIV3, 0x02, 0x09, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
360 	XOADC_CHAN(ATEST_2_DIV3, 0x02, 0x0a, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
361 	XOADC_CHAN(ATEST_3_DIV3, 0x02, 0x0b, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
362 	XOADC_CHAN(ATEST_4_DIV3, 0x02, 0x0c, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
363 	XOADC_CHAN(ATEST_5_DIV3, 0x02, 0x0d, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
364 	XOADC_CHAN(ATEST_6_DIV3, 0x02, 0x0e, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
365 	XOADC_CHAN(ATEST_7_DIV3, 0x02, 0x0f, IIO_VOLTAGE, 1, 3, SCALE_DEFAULT, AMUX_RSV1),
366 	{ }, /* Sentinel */
367 };
368 
369 /**
370  * struct pm8xxx_chan_info - ADC channel information
371  * @label: label of this channel from device tree (defaults to datasheet name if not specified)
372  * @hwchan: pointer to hardware channel information (muxing & scaling settings)
373  * @calibration: whether to use absolute or ratiometric calibration
374  * @decimation: 0,1,2,3
375  * @amux_ip_rsv: ratiometric scale value if using ratiometric
376  * calibration: 0, 1, 2, 4, 5.
377  */
378 struct pm8xxx_chan_info {
379 	const char *label;
380 	const struct xoadc_channel *hwchan;
381 	enum vadc_calibration calibration;
382 	u8 decimation:2;
383 	u8 amux_ip_rsv:3;
384 };
385 
386 /**
387  * struct pm8xxx_xoadc - state container for the XOADC
388  * @dev: pointer to device
389  * @map: regmap to access registers
390  * @variant: XOADC variant characteristics
391  * @vref: reference voltage regulator
392  * characteristics of the channels, and sensible default settings
393  * @nchans: number of channels, configured by the device tree
394  * @chans: the channel information per-channel, configured by the device tree
395  * @iio_chans: IIO channel specifiers
396  * @graph: linear calibration parameters for absolute and
397  * ratiometric measurements
398  * @complete: completion to indicate end of conversion
399  * @lock: lock to restrict access to the hardware to one client at the time
400  */
401 struct pm8xxx_xoadc {
402 	struct device *dev;
403 	struct regmap *map;
404 	const struct xoadc_variant *variant;
405 	struct regulator *vref;
406 	unsigned int nchans;
407 	struct pm8xxx_chan_info *chans;
408 	struct iio_chan_spec *iio_chans;
409 	struct vadc_linear_graph graph[2];
410 	struct completion complete;
411 	struct mutex lock;
412 };
413 
pm8xxx_eoc_irq(int irq,void * d)414 static irqreturn_t pm8xxx_eoc_irq(int irq, void *d)
415 {
416 	struct iio_dev *indio_dev = d;
417 	struct pm8xxx_xoadc *adc = iio_priv(indio_dev);
418 
419 	complete(&adc->complete);
420 
421 	return IRQ_HANDLED;
422 }
423 
424 static struct pm8xxx_chan_info *
pm8xxx_get_channel(struct pm8xxx_xoadc * adc,u8 chan)425 pm8xxx_get_channel(struct pm8xxx_xoadc *adc, u8 chan)
426 {
427 	int i;
428 
429 	for (i = 0; i < adc->nchans; i++) {
430 		struct pm8xxx_chan_info *ch = &adc->chans[i];
431 		if (ch->hwchan->amux_channel == chan)
432 			return ch;
433 	}
434 	return NULL;
435 }
436 
pm8xxx_read_channel_rsv(struct pm8xxx_xoadc * adc,const struct pm8xxx_chan_info * ch,u8 rsv,u16 * adc_code,bool force_ratiometric)437 static int pm8xxx_read_channel_rsv(struct pm8xxx_xoadc *adc,
438 				   const struct pm8xxx_chan_info *ch,
439 				   u8 rsv, u16 *adc_code,
440 				   bool force_ratiometric)
441 {
442 	int ret;
443 	unsigned int val;
444 	u8 rsvmask, rsvval;
445 	u8 lsb, msb;
446 
447 	dev_dbg(adc->dev, "read channel \"%s\", amux %d, prescale/mux: %d, rsv %d\n",
448 		ch->label, ch->hwchan->amux_channel, ch->hwchan->pre_scale_mux, rsv);
449 
450 	mutex_lock(&adc->lock);
451 
452 	/* Mux in this channel */
453 	val = ch->hwchan->amux_channel << ADC_AMUX_SEL_SHIFT;
454 	val |= ch->hwchan->pre_scale_mux << ADC_AMUX_PREMUX_SHIFT;
455 	ret = regmap_write(adc->map, ADC_ARB_USRP_AMUX_CNTRL, val);
456 	if (ret)
457 		goto unlock;
458 
459 	/* Set up ratiometric scale value, mask off all bits except these */
460 	rsvmask = (ADC_ARB_USRP_RSV_RST | ADC_ARB_USRP_RSV_DTEST0 |
461 		   ADC_ARB_USRP_RSV_DTEST1 | ADC_ARB_USRP_RSV_OP);
462 	if (adc->variant->broken_ratiometric && !force_ratiometric) {
463 		/*
464 		 * Apparently the PM8058 has some kind of bug which is
465 		 * reflected in the vendor tree drivers/misc/pmix8058-xoadc.c
466 		 * which just hardcodes the RSV selector to SEL1 (0x20) for
467 		 * most cases and SEL0 (0x10) for the MUXOFF channel only.
468 		 * If we force ratiometric (currently only done when attempting
469 		 * to do ratiometric calibration) this doesn't seem to work
470 		 * very well and I suspect ratiometric conversion is simply
471 		 * broken or not supported on the PM8058.
472 		 *
473 		 * Maybe IO_SEL2 doesn't exist on PM8058 and bits 4 & 5 select
474 		 * the mode alone.
475 		 *
476 		 * Some PM8058 register documentation would be nice to get
477 		 * this right.
478 		 */
479 		if (ch->hwchan->amux_channel == PM8XXX_CHANNEL_MUXOFF)
480 			rsvval = ADC_ARB_USRP_RSV_IP_SEL0;
481 		else
482 			rsvval = ADC_ARB_USRP_RSV_IP_SEL1;
483 	} else {
484 		if (rsv == 0xff)
485 			rsvval = (ch->amux_ip_rsv << ADC_RSV_IP_SEL_SHIFT) |
486 				ADC_ARB_USRP_RSV_TRM;
487 		else
488 			rsvval = (rsv << ADC_RSV_IP_SEL_SHIFT) |
489 				ADC_ARB_USRP_RSV_TRM;
490 	}
491 
492 	ret = regmap_update_bits(adc->map,
493 				 ADC_ARB_USRP_RSV,
494 				 ~rsvmask,
495 				 rsvval);
496 	if (ret)
497 		goto unlock;
498 
499 	ret = regmap_write(adc->map, ADC_ARB_USRP_ANA_PARAM,
500 			   ADC_ARB_USRP_ANA_PARAM_DIS);
501 	if (ret)
502 		goto unlock;
503 
504 	/* Decimation factor */
505 	ret = regmap_write(adc->map, ADC_ARB_USRP_DIG_PARAM,
506 			   ADC_ARB_USRP_DIG_PARAM_SEL_SHIFT0 |
507 			   ADC_ARB_USRP_DIG_PARAM_SEL_SHIFT1 |
508 			   ch->decimation << ADC_DIG_PARAM_DEC_SHIFT);
509 	if (ret)
510 		goto unlock;
511 
512 	ret = regmap_write(adc->map, ADC_ARB_USRP_ANA_PARAM,
513 			   ADC_ARB_USRP_ANA_PARAM_EN);
514 	if (ret)
515 		goto unlock;
516 
517 	/* Enable the arbiter, the Qualcomm code does it twice like this */
518 	ret = regmap_write(adc->map, ADC_ARB_USRP_CNTRL,
519 			   ADC_ARB_USRP_CNTRL_EN_ARB);
520 	if (ret)
521 		goto unlock;
522 	ret = regmap_write(adc->map, ADC_ARB_USRP_CNTRL,
523 			   ADC_ARB_USRP_CNTRL_EN_ARB);
524 	if (ret)
525 		goto unlock;
526 
527 
528 	/* Fire a request! */
529 	reinit_completion(&adc->complete);
530 	ret = regmap_write(adc->map, ADC_ARB_USRP_CNTRL,
531 			   ADC_ARB_USRP_CNTRL_EN_ARB |
532 			   ADC_ARB_USRP_CNTRL_REQ);
533 	if (ret)
534 		goto unlock;
535 
536 	/* Next the interrupt occurs */
537 	if (!wait_for_completion_timeout(&adc->complete, VADC_CONV_TIME_MAX_US)) {
538 		ret = -ETIMEDOUT;
539 		goto unlock;
540 	}
541 
542 	ret = regmap_read(adc->map, ADC_ARB_USRP_DATA0, &val);
543 	if (ret)
544 		goto unlock;
545 	lsb = val;
546 	ret = regmap_read(adc->map, ADC_ARB_USRP_DATA1, &val);
547 	if (ret)
548 		goto unlock;
549 	msb = val;
550 	*adc_code = (msb << 8) | lsb;
551 
552 	/* Turn off the ADC by setting the arbiter to 0 twice */
553 	ret = regmap_write(adc->map, ADC_ARB_USRP_CNTRL, 0);
554 	if (ret)
555 		goto unlock;
556 	ret = regmap_write(adc->map, ADC_ARB_USRP_CNTRL, 0);
557 	if (ret)
558 		goto unlock;
559 
560 unlock:
561 	mutex_unlock(&adc->lock);
562 	return ret;
563 }
564 
pm8xxx_read_channel(struct pm8xxx_xoadc * adc,const struct pm8xxx_chan_info * ch,u16 * adc_code)565 static int pm8xxx_read_channel(struct pm8xxx_xoadc *adc,
566 			       const struct pm8xxx_chan_info *ch,
567 			       u16 *adc_code)
568 {
569 	/*
570 	 * Normally we just use the ratiometric scale value (RSV) predefined
571 	 * for the channel, but during calibration we need to modify this
572 	 * so this wrapper is a helper hiding the more complex version.
573 	 */
574 	return pm8xxx_read_channel_rsv(adc, ch, 0xff, adc_code, false);
575 }
576 
pm8xxx_calibrate_device(struct pm8xxx_xoadc * adc)577 static int pm8xxx_calibrate_device(struct pm8xxx_xoadc *adc)
578 {
579 	const struct pm8xxx_chan_info *ch;
580 	u16 read_1250v;
581 	u16 read_0625v;
582 	u16 read_nomux_rsv5;
583 	u16 read_nomux_rsv4;
584 	int ret;
585 
586 	adc->graph[VADC_CALIB_ABSOLUTE].dx = VADC_ABSOLUTE_RANGE_UV;
587 	adc->graph[VADC_CALIB_RATIOMETRIC].dx = VADC_RATIOMETRIC_RANGE;
588 
589 	/* Common reference channel calibration */
590 	ch = pm8xxx_get_channel(adc, PM8XXX_CHANNEL_125V);
591 	if (!ch)
592 		return -ENODEV;
593 	ret = pm8xxx_read_channel(adc, ch, &read_1250v);
594 	if (ret) {
595 		dev_err(adc->dev, "could not read 1.25V reference channel\n");
596 		return -ENODEV;
597 	}
598 	ch = pm8xxx_get_channel(adc, PM8XXX_CHANNEL_INTERNAL);
599 	if (!ch)
600 		return -ENODEV;
601 	ret = pm8xxx_read_channel(adc, ch, &read_0625v);
602 	if (ret) {
603 		dev_err(adc->dev, "could not read 0.625V reference channel\n");
604 		return -ENODEV;
605 	}
606 	if (read_1250v == read_0625v) {
607 		dev_err(adc->dev, "read same ADC code for 1.25V and 0.625V\n");
608 		return -ENODEV;
609 	}
610 
611 	adc->graph[VADC_CALIB_ABSOLUTE].dy = read_1250v - read_0625v;
612 	adc->graph[VADC_CALIB_ABSOLUTE].gnd = read_0625v;
613 
614 	dev_info(adc->dev, "absolute calibration dx = %d uV, dy = %d units\n",
615 		 VADC_ABSOLUTE_RANGE_UV, adc->graph[VADC_CALIB_ABSOLUTE].dy);
616 
617 	/* Ratiometric calibration */
618 	ch = pm8xxx_get_channel(adc, PM8XXX_CHANNEL_MUXOFF);
619 	if (!ch)
620 		return -ENODEV;
621 	ret = pm8xxx_read_channel_rsv(adc, ch, AMUX_RSV5,
622 				      &read_nomux_rsv5, true);
623 	if (ret) {
624 		dev_err(adc->dev, "could not read MUXOFF reference channel\n");
625 		return -ENODEV;
626 	}
627 	ret = pm8xxx_read_channel_rsv(adc, ch, AMUX_RSV4,
628 				      &read_nomux_rsv4, true);
629 	if (ret) {
630 		dev_err(adc->dev, "could not read MUXOFF reference channel\n");
631 		return -ENODEV;
632 	}
633 	adc->graph[VADC_CALIB_RATIOMETRIC].dy =
634 		read_nomux_rsv5 - read_nomux_rsv4;
635 	adc->graph[VADC_CALIB_RATIOMETRIC].gnd = read_nomux_rsv4;
636 
637 	dev_info(adc->dev, "ratiometric calibration dx = %d, dy = %d units\n",
638 		 VADC_RATIOMETRIC_RANGE,
639 		 adc->graph[VADC_CALIB_RATIOMETRIC].dy);
640 
641 	return 0;
642 }
643 
pm8xxx_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)644 static int pm8xxx_read_raw(struct iio_dev *indio_dev,
645 			   struct iio_chan_spec const *chan,
646 			   int *val, int *val2, long mask)
647 {
648 	struct pm8xxx_xoadc *adc = iio_priv(indio_dev);
649 	const struct pm8xxx_chan_info *ch;
650 	u16 adc_code;
651 	int ret;
652 
653 	switch (mask) {
654 	case IIO_CHAN_INFO_PROCESSED:
655 		ch = pm8xxx_get_channel(adc, chan->address);
656 		if (!ch)
657 			return -EINVAL;
658 		ret = pm8xxx_read_channel(adc, ch, &adc_code);
659 		if (ret)
660 			return ret;
661 
662 		ret = qcom_vadc_scale(ch->hwchan->scale_fn_type,
663 				      &adc->graph[ch->calibration],
664 				      &ch->hwchan->prescale,
665 				      (ch->calibration == VADC_CALIB_ABSOLUTE),
666 				      adc_code, val);
667 		if (ret)
668 			return ret;
669 
670 		return IIO_VAL_INT;
671 	case IIO_CHAN_INFO_RAW:
672 		ch = pm8xxx_get_channel(adc, chan->address);
673 		if (!ch)
674 			return -EINVAL;
675 		ret = pm8xxx_read_channel(adc, ch, &adc_code);
676 		if (ret)
677 			return ret;
678 
679 		*val = (int)adc_code;
680 		return IIO_VAL_INT;
681 	default:
682 		return -EINVAL;
683 	}
684 }
685 
pm8xxx_fwnode_xlate(struct iio_dev * indio_dev,const struct fwnode_reference_args * iiospec)686 static int pm8xxx_fwnode_xlate(struct iio_dev *indio_dev,
687 			       const struct fwnode_reference_args *iiospec)
688 {
689 	struct pm8xxx_xoadc *adc = iio_priv(indio_dev);
690 	u8 pre_scale_mux;
691 	u8 amux_channel;
692 	unsigned int i;
693 
694 	/*
695 	 * First cell is prescaler or premux, second cell is analog
696 	 * mux.
697 	 */
698 	if (iiospec->nargs != 2) {
699 		dev_err(&indio_dev->dev, "wrong number of arguments for %pfwP need 2 got %d\n",
700 			iiospec->fwnode,
701 			iiospec->nargs);
702 		return -EINVAL;
703 	}
704 	pre_scale_mux = (u8)iiospec->args[0];
705 	amux_channel = (u8)iiospec->args[1];
706 	dev_dbg(&indio_dev->dev, "pre scale/mux: %02x, amux: %02x\n",
707 		pre_scale_mux, amux_channel);
708 
709 	/* We need to match exactly on the prescale/premux and channel */
710 	for (i = 0; i < adc->nchans; i++)
711 		if (adc->chans[i].hwchan->pre_scale_mux == pre_scale_mux &&
712 		    adc->chans[i].hwchan->amux_channel == amux_channel)
713 			return i;
714 
715 	return -EINVAL;
716 }
717 
pm8xxx_read_label(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,char * label)718 static int pm8xxx_read_label(struct iio_dev *indio_dev,
719 			     struct iio_chan_spec const *chan, char *label)
720 {
721 	struct pm8xxx_xoadc *adc = iio_priv(indio_dev);
722 	const struct pm8xxx_chan_info *ch;
723 
724 	ch = pm8xxx_get_channel(adc, chan->address);
725 	if (!ch)
726 		return -EINVAL;
727 	return sysfs_emit(label, "%s\n", ch->label);
728 }
729 
730 static const struct iio_info pm8xxx_xoadc_info = {
731 	.fwnode_xlate = pm8xxx_fwnode_xlate,
732 	.read_label = pm8xxx_read_label,
733 	.read_raw = pm8xxx_read_raw,
734 };
735 
pm8xxx_xoadc_parse_channel(struct device * dev,struct fwnode_handle * fwnode,const struct xoadc_channel * hw_channels,struct iio_chan_spec * iio_chan,struct pm8xxx_chan_info * ch)736 static int pm8xxx_xoadc_parse_channel(struct device *dev,
737 				      struct fwnode_handle *fwnode,
738 				      const struct xoadc_channel *hw_channels,
739 				      struct iio_chan_spec *iio_chan,
740 				      struct pm8xxx_chan_info *ch)
741 {
742 	const char *name = fwnode_get_name(fwnode);
743 	const struct xoadc_channel *hwchan;
744 	u32 pre_scale_mux, amux_channel, reg[2];
745 	u32 rsv, dec;
746 	int ret;
747 	int chid;
748 
749 	ret = fwnode_property_read_u32_array(fwnode, "reg", reg,
750 					     ARRAY_SIZE(reg));
751 	if (ret) {
752 		dev_err(dev, "invalid pre scale/mux or amux channel number %s\n",
753 			name);
754 		return ret;
755 	}
756 
757 	pre_scale_mux = reg[0];
758 	amux_channel = reg[1];
759 
760 	/* Find the right channel setting */
761 	chid = 0;
762 	hwchan = &hw_channels[0];
763 	while (hwchan->datasheet_name) {
764 		if (hwchan->pre_scale_mux == pre_scale_mux &&
765 		    hwchan->amux_channel == amux_channel)
766 			break;
767 		hwchan++;
768 		chid++;
769 	}
770 	/* The sentinel does not have a name assigned */
771 	if (!hwchan->datasheet_name) {
772 		dev_err(dev, "could not locate channel %02x/%02x\n",
773 			pre_scale_mux, amux_channel);
774 		return -EINVAL;
775 	}
776 	ch->label = hwchan->datasheet_name;
777 	fwnode_property_read_string(fwnode, "label", &ch->label);
778 	ch->hwchan = hwchan;
779 	/* Everyone seems to use absolute calibration except in special cases */
780 	ch->calibration = VADC_CALIB_ABSOLUTE;
781 	/* Everyone seems to use default ("type 2") decimation */
782 	ch->decimation = VADC_DEF_DECIMATION;
783 
784 	if (!fwnode_property_read_u32(fwnode, "qcom,ratiometric", &rsv)) {
785 		ch->calibration = VADC_CALIB_RATIOMETRIC;
786 		if (rsv > XOADC_RSV_MAX) {
787 			dev_err(dev, "%s too large RSV value %d\n", name, rsv);
788 			return -EINVAL;
789 		}
790 		if (rsv == AMUX_RSV3) {
791 			dev_err(dev, "%s invalid RSV value %d\n", name, rsv);
792 			return -EINVAL;
793 		}
794 	}
795 
796 	/* Optional decimation, if omitted we use the default */
797 	ret = fwnode_property_read_u32(fwnode, "qcom,decimation", &dec);
798 	if (!ret) {
799 		ret = qcom_vadc_decimation_from_dt(dec);
800 		if (ret < 0) {
801 			dev_err(dev, "%s invalid decimation %d\n",
802 				name, dec);
803 			return ret;
804 		}
805 		ch->decimation = ret;
806 	}
807 
808 	iio_chan->channel = chid;
809 	iio_chan->address = hwchan->amux_channel;
810 	iio_chan->datasheet_name = hwchan->datasheet_name;
811 	iio_chan->type = hwchan->type;
812 	/* All channels are raw or processed */
813 	iio_chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
814 		BIT(IIO_CHAN_INFO_PROCESSED);
815 	iio_chan->indexed = 1;
816 
817 	dev_dbg(dev,
818 		"channel [PRESCALE/MUX: %02x AMUX: %02x] \"%s\" ref voltage: %d, decimation %d prescale %d/%d, scale function %d\n",
819 		hwchan->pre_scale_mux, hwchan->amux_channel, ch->label,
820 		ch->amux_ip_rsv, ch->decimation, hwchan->prescale.numerator,
821 		hwchan->prescale.denominator, hwchan->scale_fn_type);
822 
823 	return 0;
824 }
825 
pm8xxx_xoadc_parse_channels(struct pm8xxx_xoadc * adc)826 static int pm8xxx_xoadc_parse_channels(struct pm8xxx_xoadc *adc)
827 {
828 	struct pm8xxx_chan_info *ch;
829 	int ret;
830 	int i;
831 
832 	adc->nchans = device_get_child_node_count(adc->dev);
833 	if (!adc->nchans) {
834 		dev_err(adc->dev, "no channel children\n");
835 		return -ENODEV;
836 	}
837 	dev_dbg(adc->dev, "found %d ADC channels\n", adc->nchans);
838 
839 	adc->iio_chans = devm_kcalloc(adc->dev, adc->nchans,
840 				      sizeof(*adc->iio_chans), GFP_KERNEL);
841 	if (!adc->iio_chans)
842 		return -ENOMEM;
843 
844 	adc->chans = devm_kcalloc(adc->dev, adc->nchans,
845 				  sizeof(*adc->chans), GFP_KERNEL);
846 	if (!adc->chans)
847 		return -ENOMEM;
848 
849 	i = 0;
850 	device_for_each_child_node_scoped(adc->dev, child) {
851 		ch = &adc->chans[i];
852 		ret = pm8xxx_xoadc_parse_channel(adc->dev, child,
853 						 adc->variant->channels,
854 						 &adc->iio_chans[i],
855 						 ch);
856 		if (ret)
857 			return ret;
858 
859 		i++;
860 	}
861 
862 	/* Check for required channels */
863 	ch = pm8xxx_get_channel(adc, PM8XXX_CHANNEL_125V);
864 	if (!ch) {
865 		dev_err(adc->dev, "missing 1.25V reference channel\n");
866 		return -ENODEV;
867 	}
868 	ch = pm8xxx_get_channel(adc, PM8XXX_CHANNEL_INTERNAL);
869 	if (!ch) {
870 		dev_err(adc->dev, "missing 0.625V reference channel\n");
871 		return -ENODEV;
872 	}
873 	ch = pm8xxx_get_channel(adc, PM8XXX_CHANNEL_MUXOFF);
874 	if (!ch) {
875 		dev_err(adc->dev, "missing MUXOFF reference channel\n");
876 		return -ENODEV;
877 	}
878 
879 	return 0;
880 }
881 
pm8xxx_xoadc_probe(struct platform_device * pdev)882 static int pm8xxx_xoadc_probe(struct platform_device *pdev)
883 {
884 	const struct xoadc_variant *variant;
885 	struct pm8xxx_xoadc *adc;
886 	struct iio_dev *indio_dev;
887 	struct regmap *map;
888 	struct device *dev = &pdev->dev;
889 	int ret;
890 
891 	variant = device_get_match_data(dev);
892 	if (!variant)
893 		return -ENODEV;
894 
895 	indio_dev = devm_iio_device_alloc(dev, sizeof(*adc));
896 	if (!indio_dev)
897 		return -ENOMEM;
898 	platform_set_drvdata(pdev, indio_dev);
899 
900 	adc = iio_priv(indio_dev);
901 	adc->dev = dev;
902 	adc->variant = variant;
903 	init_completion(&adc->complete);
904 	mutex_init(&adc->lock);
905 
906 	ret = pm8xxx_xoadc_parse_channels(adc);
907 	if (ret)
908 		return ret;
909 
910 	map = dev_get_regmap(dev->parent, NULL);
911 	if (!map) {
912 		dev_err(dev, "parent regmap unavailable.\n");
913 		return -ENODEV;
914 	}
915 	adc->map = map;
916 
917 	/* Bring up regulator */
918 	adc->vref = devm_regulator_get(dev, "xoadc-ref");
919 	if (IS_ERR(adc->vref))
920 		return dev_err_probe(dev, PTR_ERR(adc->vref),
921 				     "failed to get XOADC VREF regulator\n");
922 	ret = regulator_enable(adc->vref);
923 	if (ret) {
924 		dev_err(dev, "failed to enable XOADC VREF regulator\n");
925 		return ret;
926 	}
927 
928 	ret = devm_request_threaded_irq(dev, platform_get_irq(pdev, 0),
929 			pm8xxx_eoc_irq, NULL, 0, variant->name, indio_dev);
930 	if (ret) {
931 		dev_err(dev, "unable to request IRQ\n");
932 		goto out_disable_vref;
933 	}
934 
935 	indio_dev->name = variant->name;
936 	indio_dev->modes = INDIO_DIRECT_MODE;
937 	indio_dev->info = &pm8xxx_xoadc_info;
938 	indio_dev->channels = adc->iio_chans;
939 	indio_dev->num_channels = adc->nchans;
940 
941 	ret = iio_device_register(indio_dev);
942 	if (ret)
943 		goto out_disable_vref;
944 
945 	ret = pm8xxx_calibrate_device(adc);
946 	if (ret)
947 		goto out_unreg_device;
948 
949 	dev_info(dev, "%s XOADC driver enabled\n", variant->name);
950 
951 	return 0;
952 
953 out_unreg_device:
954 	iio_device_unregister(indio_dev);
955 out_disable_vref:
956 	regulator_disable(adc->vref);
957 
958 	return ret;
959 }
960 
pm8xxx_xoadc_remove(struct platform_device * pdev)961 static void pm8xxx_xoadc_remove(struct platform_device *pdev)
962 {
963 	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
964 	struct pm8xxx_xoadc *adc = iio_priv(indio_dev);
965 
966 	iio_device_unregister(indio_dev);
967 
968 	regulator_disable(adc->vref);
969 }
970 
971 static const struct xoadc_variant pm8018_variant = {
972 	.name = "PM8018-XOADC",
973 	.channels = pm8018_xoadc_channels,
974 };
975 
976 static const struct xoadc_variant pm8038_variant = {
977 	.name = "PM8038-XOADC",
978 	.channels = pm8038_xoadc_channels,
979 };
980 
981 static const struct xoadc_variant pm8058_variant = {
982 	.name = "PM8058-XOADC",
983 	.channels = pm8058_xoadc_channels,
984 	.broken_ratiometric = true,
985 	.prescaling = true,
986 };
987 
988 static const struct xoadc_variant pm8921_variant = {
989 	.name = "PM8921-XOADC",
990 	.channels = pm8921_xoadc_channels,
991 	.second_level_mux = true,
992 };
993 
994 static const struct of_device_id pm8xxx_xoadc_id_table[] = {
995 	{
996 		.compatible = "qcom,pm8018-adc",
997 		.data = &pm8018_variant,
998 	},
999 	{
1000 		.compatible = "qcom,pm8038-adc",
1001 		.data = &pm8038_variant,
1002 	},
1003 	{
1004 		.compatible = "qcom,pm8058-adc",
1005 		.data = &pm8058_variant,
1006 	},
1007 	{
1008 		.compatible = "qcom,pm8921-adc",
1009 		.data = &pm8921_variant,
1010 	},
1011 	{ }
1012 };
1013 MODULE_DEVICE_TABLE(of, pm8xxx_xoadc_id_table);
1014 
1015 static struct platform_driver pm8xxx_xoadc_driver = {
1016 	.driver		= {
1017 		.name	= "pm8xxx-adc",
1018 		.of_match_table = pm8xxx_xoadc_id_table,
1019 	},
1020 	.probe		= pm8xxx_xoadc_probe,
1021 	.remove		= pm8xxx_xoadc_remove,
1022 };
1023 module_platform_driver(pm8xxx_xoadc_driver);
1024 
1025 MODULE_DESCRIPTION("PM8xxx XOADC driver");
1026 MODULE_LICENSE("GPL v2");
1027 MODULE_ALIAS("platform:pm8xxx-xoadc");
1028