--- /dev/null
+/*
+ * 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>");
Code Review / kvmfornfv.git / blobdiff