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Release 4.11 drivers/iio/adc/qcom-spmi-iadc.c

Directory: drivers/iio/adc
/*
 * Copyright (c) 2012-2014, The Linux Foundation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 and
 * only version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/bitops.h>
#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/iio/iio.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/mutex.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/slab.h>

/* IADC register and bit definition */

#define IADC_REVISION2				0x1

#define IADC_REVISION2_SUPPORTED_IADC		1


#define IADC_PERPH_TYPE				0x4

#define IADC_PERPH_TYPE_ADC			8


#define IADC_PERPH_SUBTYPE			0x5

#define IADC_PERPH_SUBTYPE_IADC			3


#define IADC_STATUS1				0x8

#define IADC_STATUS1_OP_MODE			4

#define IADC_STATUS1_REQ_STS			BIT(1)

#define IADC_STATUS1_EOC			BIT(0)

#define IADC_STATUS1_REQ_STS_EOC_MASK		0x3


#define IADC_MODE_CTL				0x40

#define IADC_OP_MODE_SHIFT			3

#define IADC_OP_MODE_NORMAL			0

#define IADC_TRIM_EN				BIT(0)


#define IADC_EN_CTL1				0x46

#define IADC_EN_CTL1_SET			BIT(7)


#define IADC_CH_SEL_CTL				0x48


#define IADC_DIG_PARAM				0x50

#define IADC_DIG_DEC_RATIO_SEL_SHIFT		2


#define IADC_HW_SETTLE_DELAY			0x51


#define IADC_CONV_REQ				0x52

#define IADC_CONV_REQ_SET			BIT(7)


#define IADC_FAST_AVG_CTL			0x5a

#define IADC_FAST_AVG_EN			0x5b

#define IADC_FAST_AVG_EN_SET			BIT(7)


#define IADC_PERH_RESET_CTL3			0xda

#define IADC_FOLLOW_WARM_RB			BIT(2)


#define IADC_DATA				0x60	
/* 16 bits */


#define IADC_SEC_ACCESS				0xd0

#define IADC_SEC_ACCESS_DATA			0xa5


#define IADC_NOMINAL_RSENSE			0xf4

#define IADC_NOMINAL_RSENSE_SIGN_MASK		BIT(7)


#define IADC_REF_GAIN_MICRO_VOLTS		17857


#define IADC_INT_RSENSE_DEVIATION		15625	
/* nano Ohms per bit */


#define IADC_INT_RSENSE_IDEAL_VALUE		10000	
/* micro Ohms */

#define IADC_INT_RSENSE_DEFAULT_VALUE		7800	
/* micro Ohms */

#define IADC_INT_RSENSE_DEFAULT_GF		9000	
/* micro Ohms */

#define IADC_INT_RSENSE_DEFAULT_SMIC		9700	
/* micro Ohms */


#define IADC_CONV_TIME_MIN_US			2000

#define IADC_CONV_TIME_MAX_US			2100


#define IADC_DEF_PRESCALING			0 
/* 1:1 */

#define IADC_DEF_DECIMATION			0 
/* 512 */

#define IADC_DEF_HW_SETTLE_TIME			0 
/* 0 us */

#define IADC_DEF_AVG_SAMPLES			0 
/* 1 sample */

/* IADC channel list */

#define IADC_INT_RSENSE				0

#define IADC_EXT_RSENSE				1

#define IADC_GAIN_17P857MV			3

#define IADC_EXT_OFFSET_CSP_CSN			5

#define IADC_INT_OFFSET_CSP2_CSN2		6

/**
 * struct iadc_chip - IADC Current ADC device structure.
 * @regmap: regmap for register read/write.
 * @dev: This device pointer.
 * @base: base offset for the ADC peripheral.
 * @rsense: Values of the internal and external sense resister in micro Ohms.
 * @poll_eoc: Poll for end of conversion instead of waiting for IRQ.
 * @offset: Raw offset values for the internal and external channels.
 * @gain: Raw gain of the channels.
 * @lock: ADC lock for access to the peripheral.
 * @complete: ADC notification after end of conversion interrupt is received.
 */

struct iadc_chip {
	
struct regmap	*regmap;
	
struct device	*dev;
	
u16		base;
	
bool		poll_eoc;
	
u32		rsense[2];
	
u16		offset[2];
	
u16		gain;
	
struct mutex	lock;
	
struct completion complete;
};


static int iadc_read(struct iadc_chip *iadc, u16 offset, u8 *data) { unsigned int val; int ret; ret = regmap_read(iadc->regmap, iadc->base + offset, &val); if (ret < 0) return ret; *data = val; return 0; }

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static int iadc_write(struct iadc_chip *iadc, u16 offset, u8 data) { return regmap_write(iadc->regmap, iadc->base + offset, data); }

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static int iadc_reset(struct iadc_chip *iadc) { u8 data; int ret; ret = iadc_write(iadc, IADC_SEC_ACCESS, IADC_SEC_ACCESS_DATA); if (ret < 0) return ret; ret = iadc_read(iadc, IADC_PERH_RESET_CTL3, &data); if (ret < 0) return ret; ret = iadc_write(iadc, IADC_SEC_ACCESS, IADC_SEC_ACCESS_DATA); if (ret < 0) return ret; data |= IADC_FOLLOW_WARM_RB; return iadc_write(iadc, IADC_PERH_RESET_CTL3, data); }

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static int iadc_set_state(struct iadc_chip *iadc, bool state) { return iadc_write(iadc, IADC_EN_CTL1, state ? IADC_EN_CTL1_SET : 0); }

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static void iadc_status_show(struct iadc_chip *iadc) { u8 mode, sta1, chan, dig, en, req; int ret; ret = iadc_read(iadc, IADC_MODE_CTL, &mode); if (ret < 0) return; ret = iadc_read(iadc, IADC_DIG_PARAM, &dig); if (ret < 0) return; ret = iadc_read(iadc, IADC_CH_SEL_CTL, &chan); if (ret < 0) return; ret = iadc_read(iadc, IADC_CONV_REQ, &req); if (ret < 0) return; ret = iadc_read(iadc, IADC_STATUS1, &sta1); if (ret < 0) return; ret = iadc_read(iadc, IADC_EN_CTL1, &en); if (ret < 0) return; dev_err(iadc->dev, "mode:%02x en:%02x chan:%02x dig:%02x req:%02x sta1:%02x\n", mode, en, chan, dig, req, sta1); }

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static int iadc_configure(struct iadc_chip *iadc, int channel) { u8 decim, mode; int ret; /* Mode selection */ mode = (IADC_OP_MODE_NORMAL << IADC_OP_MODE_SHIFT) | IADC_TRIM_EN; ret = iadc_write(iadc, IADC_MODE_CTL, mode); if (ret < 0) return ret; /* Channel selection */ ret = iadc_write(iadc, IADC_CH_SEL_CTL, channel); if (ret < 0) return ret; /* Digital parameter setup */ decim = IADC_DEF_DECIMATION << IADC_DIG_DEC_RATIO_SEL_SHIFT; ret = iadc_write(iadc, IADC_DIG_PARAM, decim); if (ret < 0) return ret; /* HW settle time delay */ ret = iadc_write(iadc, IADC_HW_SETTLE_DELAY, IADC_DEF_HW_SETTLE_TIME); if (ret < 0) return ret; ret = iadc_write(iadc, IADC_FAST_AVG_CTL, IADC_DEF_AVG_SAMPLES); if (ret < 0) return ret; if (IADC_DEF_AVG_SAMPLES) ret = iadc_write(iadc, IADC_FAST_AVG_EN, IADC_FAST_AVG_EN_SET); else ret = iadc_write(iadc, IADC_FAST_AVG_EN, 0); if (ret < 0) return ret; if (!iadc->poll_eoc) reinit_completion(&iadc->complete); ret = iadc_set_state(iadc, true); if (ret < 0) return ret; /* Request conversion */ return iadc_write(iadc, IADC_CONV_REQ, IADC_CONV_REQ_SET); }

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static int iadc_poll_wait_eoc(struct iadc_chip *iadc, unsigned int interval_us) { unsigned int count, retry; int ret; u8 sta1; retry = interval_us / IADC_CONV_TIME_MIN_US; for (count = 0; count < retry; count++) { ret = iadc_read(iadc, IADC_STATUS1, &sta1); if (ret < 0) return ret; sta1 &= IADC_STATUS1_REQ_STS_EOC_MASK; if (sta1 == IADC_STATUS1_EOC) return 0; usleep_range(IADC_CONV_TIME_MIN_US, IADC_CONV_TIME_MAX_US); } iadc_status_show(iadc); return -ETIMEDOUT; }

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static int iadc_read_result(struct iadc_chip *iadc, u16 *data) { return regmap_bulk_read(iadc->regmap, iadc->base + IADC_DATA, data, 2); }

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static int iadc_do_conversion(struct iadc_chip *iadc, int chan, u16 *data) { unsigned int wait; int ret; ret = iadc_configure(iadc, chan); if (ret < 0) goto exit; wait = BIT(IADC_DEF_AVG_SAMPLES) * IADC_CONV_TIME_MIN_US * 2; if (iadc->poll_eoc) { ret = iadc_poll_wait_eoc(iadc, wait); } else { ret = wait_for_completion_timeout(&iadc->complete, usecs_to_jiffies(wait)); if (!ret) ret = -ETIMEDOUT; else /* double check conversion status */ ret = iadc_poll_wait_eoc(iadc, IADC_CONV_TIME_MIN_US); } if (!ret) ret = iadc_read_result(iadc, data); exit: iadc_set_state(iadc, false); if (ret < 0) dev_err(iadc->dev, "conversion failed\n"); return ret; }

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static int iadc_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long mask) { struct iadc_chip *iadc = iio_priv(indio_dev); s32 isense_ua, vsense_uv; u16 adc_raw, vsense_raw; int ret; switch (mask) { case IIO_CHAN_INFO_RAW: mutex_lock(&iadc->lock); ret = iadc_do_conversion(iadc, chan->channel, &adc_raw); mutex_unlock(&iadc->lock); if (ret < 0) return ret; vsense_raw = adc_raw - iadc->offset[chan->channel]; vsense_uv = vsense_raw * IADC_REF_GAIN_MICRO_VOLTS; vsense_uv /= (s32)iadc->gain - iadc->offset[chan->channel]; isense_ua = vsense_uv / iadc->rsense[chan->channel]; dev_dbg(iadc->dev, "off %d gain %d adc %d %duV I %duA\n", iadc->offset[chan->channel], iadc->gain, adc_raw, vsense_uv, isense_ua); *val = isense_ua; return IIO_VAL_INT; case IIO_CHAN_INFO_SCALE: *val = 0; *val2 = 1000; return IIO_VAL_INT_PLUS_MICRO; } return -EINVAL; }

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static const struct iio_info iadc_info = { .read_raw = iadc_read_raw, .driver_module = THIS_MODULE, };
static irqreturn_t iadc_isr(int irq, void *dev_id) { struct iadc_chip *iadc = dev_id; complete(&iadc->complete); return IRQ_HANDLED; }

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static int iadc_update_offset(struct iadc_chip *iadc) { int ret; ret = iadc_do_conversion(iadc, IADC_GAIN_17P857MV, &iadc->gain); if (ret < 0) return ret; ret = iadc_do_conversion(iadc, IADC_INT_OFFSET_CSP2_CSN2, &iadc->offset[IADC_INT_RSENSE]); if (ret < 0) return ret; if (iadc->gain == iadc->offset[IADC_INT_RSENSE]) { dev_err(iadc->dev, "error: internal offset == gain %d\n", iadc->gain); return -EINVAL; } ret = iadc_do_conversion(iadc, IADC_EXT_OFFSET_CSP_CSN, &iadc->offset[IADC_EXT_RSENSE]); if (ret < 0) return ret; if (iadc->gain == iadc->offset[IADC_EXT_RSENSE]) { dev_err(iadc->dev, "error: external offset == gain %d\n", iadc->gain); return -EINVAL; } return 0; }

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static int iadc_version_check(struct iadc_chip *iadc) { u8 val; int ret; ret = iadc_read(iadc, IADC_PERPH_TYPE, &val); if (ret < 0) return ret; if (val < IADC_PERPH_TYPE_ADC) { dev_err(iadc->dev, "%d is not ADC\n", val); return -EINVAL; } ret = iadc_read(iadc, IADC_PERPH_SUBTYPE, &val); if (ret < 0) return ret; if (val < IADC_PERPH_SUBTYPE_IADC) { dev_err(iadc->dev, "%d is not IADC\n", val); return -EINVAL; } ret = iadc_read(iadc, IADC_REVISION2, &val); if (ret < 0) return ret; if (val < IADC_REVISION2_SUPPORTED_IADC) { dev_err(iadc->dev, "revision %d not supported\n", val); return -EINVAL; } return 0; }

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static int iadc_rsense_read(struct iadc_chip *iadc, struct device_node *node) { int ret, sign, int_sense; u8 deviation; ret = of_property_read_u32(node, "qcom,external-resistor-micro-ohms", &iadc->rsense[IADC_EXT_RSENSE]); if (ret < 0) iadc->rsense[IADC_EXT_RSENSE] = IADC_INT_RSENSE_IDEAL_VALUE; if (!iadc->rsense[IADC_EXT_RSENSE]) { dev_err(iadc->dev, "external resistor can't be zero Ohms"); return -EINVAL; } ret = iadc_read(iadc, IADC_NOMINAL_RSENSE, &deviation); if (ret < 0) return ret; /* * Deviation value stored is an offset from 10 mili Ohms, bit 7 is * the sign, the remaining bits have an LSB of 15625 nano Ohms. */ sign = (deviation & IADC_NOMINAL_RSENSE_SIGN_MASK) ? -1 : 1; deviation &= ~IADC_NOMINAL_RSENSE_SIGN_MASK; /* Scale it to nono Ohms */ int_sense = IADC_INT_RSENSE_IDEAL_VALUE * 1000; int_sense += sign * deviation * IADC_INT_RSENSE_DEVIATION; int_sense /= 1000; /* micro Ohms */ iadc->rsense[IADC_INT_RSENSE] = int_sense; return 0; }

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static const struct iio_chan_spec iadc_channels[] = { { .type = IIO_CURRENT, .datasheet_name = "INTERNAL_RSENSE", .channel = 0, .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE), .indexed = 1, }, { .type = IIO_CURRENT, .datasheet_name = "EXTERNAL_RSENSE", .channel = 1, .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE), .indexed = 1, }, };
static int iadc_probe(struct platform_device *pdev) { struct device_node *node = pdev->dev.of_node; struct device *dev = &pdev->dev; struct iio_dev *indio_dev; struct iadc_chip *iadc; int ret, irq_eoc; u32 res; indio_dev = devm_iio_device_alloc(dev, sizeof(*iadc)); if (!indio_dev) return -ENOMEM; iadc = iio_priv(indio_dev); iadc->dev = dev; iadc->regmap = dev_get_regmap(dev->parent, NULL); if (!iadc->regmap) return -ENODEV; init_completion(&iadc->complete); mutex_init(&iadc->lock); ret = of_property_read_u32(node, "reg", &res); if (ret < 0) return -ENODEV; iadc->base = res; ret = iadc_version_check(iadc); if (ret < 0) return -ENODEV; ret = iadc_rsense_read(iadc, node); if (ret < 0) return -ENODEV; dev_dbg(iadc->dev, "sense resistors %d and %d micro Ohm\n", iadc->rsense[IADC_INT_RSENSE], iadc->rsense[IADC_EXT_RSENSE]); irq_eoc = platform_get_irq(pdev, 0); if (irq_eoc == -EPROBE_DEFER) return irq_eoc; if (irq_eoc < 0) iadc->poll_eoc = true; ret = iadc_reset(iadc); if (ret < 0) { dev_err(dev, "reset failed\n"); return ret; } if (!iadc->poll_eoc) { ret = devm_request_irq(dev, irq_eoc, iadc_isr, 0, "spmi-iadc", iadc); if (!ret) enable_irq_wake(irq_eoc); else return ret; } else { device_init_wakeup(iadc->dev, 1); } ret = iadc_update_offset(iadc); if (ret < 0) { dev_err(dev, "failed offset calibration\n"); return ret; } indio_dev->dev.parent = dev; indio_dev->dev.of_node = node; indio_dev->name = pdev->name; indio_dev->modes = INDIO_DIRECT_MODE; indio_dev->info = &iadc_info; indio_dev->channels = iadc_channels; indio_dev->num_channels = ARRAY_SIZE(iadc_channels); return devm_iio_device_register(dev, indio_dev); }

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static const struct of_device_id iadc_match_table[] = { { .compatible = "qcom,spmi-iadc" }, { } }; MODULE_DEVICE_TABLE(of, iadc_match_table); static struct platform_driver iadc_driver = { .driver = { .name = "qcom-spmi-iadc", .of_match_table = iadc_match_table, }, .probe = iadc_probe, }; module_platform_driver(iadc_driver); MODULE_ALIAS("platform:qcom-spmi-iadc"); MODULE_DESCRIPTION("Qualcomm SPMI PMIC current ADC driver"); MODULE_LICENSE("GPL v2"); MODULE_AUTHOR("Ivan T. Ivanov <iivanov@mm-sol.com>");

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Directory: drivers/iio/adc
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