Initial import

1 files changed, 596 insertions, 0 deletions

diff --git a/drivers/iio/adc/qcom-spmi-iadc.c b/drivers/iio/adc/qcom-spmi-iadc.c
new file mode 100644
index 000000000..fabd24edc
--- /dev/null
+++ b/drivers/iio/adc/qcom-spmi-iadc.c
@@ -0,0 +1,596 @@
+/*
+ * 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;
+}
+
+static int iadc_write(struct iadc_chip *iadc, u16 offset, u8 data)
+{
+	return regmap_write(iadc->regmap, iadc->base + offset, data);
+}
+
+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);
+}
+
+static int iadc_set_state(struct iadc_chip *iadc, bool state)
+{
+	return iadc_write(iadc, IADC_EN_CTL1, state ? IADC_EN_CTL1_SET : 0);
+}
+
+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);
+}
+
+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);
+}
+
+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;
+}
+
+static int iadc_read_result(struct iadc_chip *iadc, u16 *data)
+{
+	return regmap_bulk_read(iadc->regmap, iadc->base + IADC_DATA, data, 2);
+}
+
+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;
+}
+
+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;
+}
+
+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;
+}
+
+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;
+}
+
+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;
+}
+
+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;
+}
+
+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);
+}
+
+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>");