The Qualcomm PM8xxx PMICs contain a simpler ADC than its
successors (already in the kernel as qcom-spmi-adc.c):
the HK/XO ADC (Housekeeping/Chrystal oscillator ADC).
As far as I can understand this is equal to the PMICs
using SSBI transport and encompass PM8018, PM8038,
PM8058, PM8917 and PM8921, so this is shortly named
PM8xxx.
This ADC monitors a bunch of on-board voltages and the die
temperature of the PMIC itself, but it can also be routed
to convert a few external MPPs (multi-purpose pins). On
the APQ8060 DragonBoard this feature is used to let this
ADC convert an analog ALS (Ambient Light Sensor) voltage
signal from a Capella CM3605 ALS into a LUX value.
Developed and tested with APQ8060 DragonBoard based on
Ivan's driver. The SPMI VADC driver is quite different,
but share enough minor functionality that I have split
out to the common file in a previous patch.
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: linux-arm-msm@xxxxxxxxxxxxxxx
Cc: Ivan T. Ivanov <iivanov.xz@xxxxxxxxx>
Cc: Andy Gross <andy.gross@xxxxxxxxxx>
Cc: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
Cc: Stephen Boyd <sboyd@xxxxxxxxxxxxxx>
Cc: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
---
ChangeLog v1->v2:
- Introduce a mutex to avoid different clients stepping on each others'
toes
- Add an of_xlate function to be sure to match the right ADC
- Add all compatible strings, not just PM8058
---
drivers/iio/adc/Kconfig | 10 +
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/qcom-pm8xxx-xoadc.c | 786 ++++++++++++++++++++++++++++++++++++
3 files changed, 797 insertions(+)
create mode 100644 drivers/iio/adc/qcom-pm8xxx-xoadc.c
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 7edcf3238620..f0b0cbdb9519 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -380,6 +380,16 @@ config PALMAS_GPADC
is used in smartphones and tablets and supports a 16 channel
general purpose ADC.
+config QCOM_PM8XXX_XOADC
+ tristate "Qualcomm SSBI PM8xxx PMIC XOADCs"
+ depends on MFD_PM8XXX
+ help
+ ADC driver for the XOADC portions of the Qualcomm PM8xxx PMICs
+ using SSBI transport: PM8018, PM8038, PM8058, PM8917, PM8921.
+
+ To compile this driver as a module, choose M here: the module
+ will be called qcom-pm8xxx-xoadc.
+
config QCOM_SPMI_IADC
tristate "Qualcomm SPMI PMIC current ADC"
depends on SPMI
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index f9468d228b1e..234d45c805f9 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -40,6 +40,7 @@ obj-$(CONFIG_PALMAS_GPADC) += palmas_gpadc.o
obj-$(CONFIG_QCOM_SPMI_IADC) += qcom-spmi-iadc.o
qcom-vadc-y := qcom-vadc-common.o
obj-$(CONFIG_QCOM_SPMI_VADC) += qcom-vadc.o qcom-spmi-vadc.o
+obj-$(CONFIG_QCOM_PM8XXX_XOADC) += qcom-vadc.o qcom-pm8xxx-xoadc.o
obj-$(CONFIG_ROCKCHIP_SARADC) += rockchip_saradc.o
obj-$(CONFIG_STX104) += stx104.o
obj-$(CONFIG_TI_ADC081C) += ti-adc081c.o
diff --git a/drivers/iio/adc/qcom-pm8xxx-xoadc.c b/drivers/iio/adc/qcom-pm8xxx-xoadc.c
new file mode 100644
index 000000000000..32500d5d2989
--- /dev/null
+++ b/drivers/iio/adc/qcom-pm8xxx-xoadc.c
@@ -0,0 +1,786 @@
+/*
+ * Qualcomm PM8xxx PMIC XOADC driver
+ *
+ * These ADCs are known as HK/XO (house keeping / chrystal oscillator)
+ * "XO" in "XOADC" means Chrystal Oscillator. It's a bunch of
+ * specific-purpose and general purpose ADC converters and channels.
+ *
+ * Copyright (C) 2016 Linaro Ltd.
+ * Author: Linus Walleij <linus.walleij@xxxxxxxxxx>
+ */
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.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/init.h>
+#include <linux/interrupt.h>
+#include <linux/regulator/consumer.h>
+
+#include "qcom-vadc-common.h"
+
+/*
+ * Definitions for the "user processor" registers lifted from the v3.4
+ * Qualcomm tree. Their kernel has two out-of-tree drivers for the ADC:
+ * drivers/misc/pmic8058-xoadc.c
+ * drivers/hwmon/pm8xxx-adc.c
+ * None of them contain any complete register specification, so this is
+ * a best effort of combining the information.
+ */
+
+/* These appear to be "battery monitor" registers */
+#define ADC_ARB_BTM_CNTRL1 0x17e
+#define ADC_ARB_BTM_CNTRL1_EN_BTM BIT(0)
+#define ADC_ARB_BTM_CNTRL1_SEL_OP_MODE BIT(1)
+#define ADC_ARB_BTM_CNTRL1_MEAS_INTERVAL1 BIT(2)
+#define ADC_ARB_BTM_CNTRL1_MEAS_INTERVAL2 BIT(3)
+#define ADC_ARB_BTM_CNTRL1_MEAS_INTERVAL3 BIT(4)
+#define ADC_ARB_BTM_CNTRL1_MEAS_INTERVAL4 BIT(5)
+#define ADC_ARB_BTM_CNTRL1_EOC BIT(6)
+#define ADC_ARB_BTM_CNTRL1_REQ BIT(7)
+
+#define ADC_ARB_BTM_AMUX_CNTRL 0x17f
+#define ADC_ARB_BTM_ANA_PARAM 0x180
+#define ADC_ARB_BTM_DIG_PARAM 0x181
+#define ADC_ARB_BTM_RSV 0x182
+#define ADC_ARB_BTM_DATA1 0x183
+#define ADC_ARB_BTM_DATA0 0x184
+#define ADC_ARB_BTM_BAT_COOL_THR1 0x185
+#define ADC_ARB_BTM_BAT_COOL_THR0 0x186
+#define ADC_ARB_BTM_BAT_WARM_THR1 0x187
+#define ADC_ARB_BTM_BAT_WARM_THR0 0x188
+#define ADC_ARB_BTM_CNTRL2 0x18c
+
+/* Proper ADC registers */
+
+#define ADC_ARB_USRP_CNTRL 0x197
+#define ADC_ARB_USRP_CNTRL_EN_ARB BIT(0)
+#define ADC_ARB_USRP_CNTRL_RSV1 BIT(1)
+#define ADC_ARB_USRP_CNTRL_RSV2 BIT(2)
+#define ADC_ARB_USRP_CNTRL_RSV3 BIT(3)
+#define ADC_ARB_USRP_CNTRL_RSV4 BIT(4)
+#define ADC_ARB_USRP_CNTRL_RSV5 BIT(5)
+#define ADC_ARB_USRP_CNTRL_EOC BIT(6)
+#define ADC_ARB_USRP_CNTRL_REQ BIT(7)
+
+#define ADC_ARB_USRP_AMUX_CNTRL 0x198
+#define ADC_ARB_USRP_AMUX_CNTRL_RSV0 BIT(0)
+#define ADC_ARB_USRP_AMUX_CNTRL_RSV1 BIT(1)
+#define ADC_ARB_USRP_AMUX_CNTRL_PREMUX0 BIT(2)
+#define ADC_ARB_USRP_AMUX_CNTRL_PREMUX1 BIT(3)
+#define ADC_ARB_USRP_AMUX_CNTRL_SEL0 BIT(4)
+#define ADC_ARB_USRP_AMUX_CNTRL_SEL1 BIT(5)
+#define ADC_ARB_USRP_AMUX_CNTRL_SEL2 BIT(6)
+#define ADC_ARB_USRP_AMUX_CNTRL_SEL3 BIT(7)
+#define ADC_AMUX_PREMUX_SHIFT 2
+#define ADC_AMUX_SEL_SHIFT 4
+
+/* We know very little about the bits in this register */
+#define ADC_ARB_USRP_ANA_PARAM 0x199
+#define ADC_ARB_USRP_ANA_PARAM_DIS 0xFE
+#define ADC_ARB_USRP_ANA_PARAM_EN 0xFF
+
+#define ADC_ARB_USRP_DIG_PARAM 0x19A
+#define ADC_ARB_USRP_DIG_PARAM_SEL_SHIFT0 BIT(0)
+#define ADC_ARB_USRP_DIG_PARAM_SEL_SHIFT1 BIT(1)
+#define ADC_ARB_USRP_DIG_PARAM_CLK_RATE0 BIT(2)
+#define ADC_ARB_USRP_DIG_PARAM_CLK_RATE1 BIT(3)
+#define ADC_ARB_USRP_DIG_PARAM_EOC BIT(4)
+/*
+ * On a later ADC the decimation factors are defined as
+ * 00 = 512, 01 = 1024, 10 = 2048, 11 = 4096 so assume this
+ * holds also for this older XOADC.
+ */
+#define ADC_ARB_USRP_DIG_PARAM_DEC_RATE0 BIT(5)
+#define ADC_ARB_USRP_DIG_PARAM_DEC_RATE1 BIT(6)
+#define ADC_ARB_USRP_DIG_PARAM_EN BIT(7)
+#define ADC_DIG_PARAM_DEC_SHIFT 5
+
+#define ADC_ARB_USRP_RSV 0x19B
+#define ADC_ARB_USRP_RSV_RST BIT(0)
+#define ADC_ARB_USRP_RSV_DTEST0 BIT(1)
+#define ADC_ARB_USRP_RSV_DTEST1 BIT(2)
+#define ADC_ARB_USRP_RSV_OP BIT(3)
+#define ADC_ARB_USRP_RSV_IP_SEL0 BIT(4)
+#define ADC_ARB_USRP_RSV_IP_SEL1 BIT(5)
+#define ADC_ARB_USRP_RSV_IP_SEL2 BIT(6)
+#define ADC_ARB_USRP_RSV_TRM BIT(7)
+#define ADC_RSV_IP_SEL_SHIFT 4
+
+#define ADC_ARB_USRP_DATA0 0x19D
+#define ADC_ARB_USRP_DATA1 0x19C
+
+/* Physical channels. MPP = Multi-Purpose Pin */
+#define CHANNEL_VCOIN 0x0 /* Coincell */
+#define CHANNEL_VBAT 0x1 /* Battery voltage */
+#define CHANNEL_VCHG 0x2 /* Charger voltage */
+#define CHANNEL_CHG_MONITOR 0x3 /* Charger current monitor */
+#define CHANNEL_VPH_PWR 0x4 /* Main system power VPH */
+#define CHANNEL_MPP5 0x5 /* "Battery charge current" */
+#define CHANNEL_MPP6 0x6 /* "MPP1" */
+#define CHANNEL_MPP7 0x7 /* "MPP2" */
+#define CHANNEL_MPP8 0x8 /* Battery temperature */
+#define CHANNEL_MPP9 0x9 /* Battery detection */
+#define CHANNEL_USB_VBUS 0xa /* USB charger voltage */
+#define CHANNEL_DIE_TEMP 0xb /* PMIC die temperature */
+#define CHANNEL_INTERNAL 0xc /* 625mV reference channel */
+#define CHANNEL_125V 0xd /* 1.25V reference channel */
+#define CHANNEL_INTERNAL_2 0xe /* Charger temperature */
+#define CHANNEL_MUXOFF 0xf /* Channel to reduce input load on mux */
+
+#define XOADC_CHAN_MAX 15 /* 4 bits */
+
+/* MPP = Multi-Purpose Pins */
+#define PREMUX_MPP_SCALE_0 0x0 /* No scaling on the signal */
+#define PREMUX_MPP_SCALE_1 0x1 /* Unity scaling selected by the user */
+#define PREMUX_MPP_SCALE_1_DIV3 0x2 /* 1/3 prescaler on the input from MPP */
+
+/* Defines reference voltage for the XOADC */
+#define AMUX_RSV0 0x0 /* XO_IN/XOADC_GND */
+#define AMUX_RSV1 0x1 /* PMIC_IN/XOADC_GND */
+#define AMUX_RSV2 0x2 /* PMIC_IN/BMS_CSP */
+#define AMUX_RSV3 0x3 /* not used */
+#define AMUX_RSV4 0x4 /* XOADC_GND/XOADC_GND */
+#define AMUX_RSV5 0x5 /* XOADC_VREF/XOADC_GND */
+#define XOADC_RSV_MAX 5 /* 3 bits 0..7, 3 and 6,7 are invalid */
+
+/*
+ * The different channels have hard-coded prescale ratios defined
+ * by the hardware.
+ */
+static const struct vadc_prescale_ratio adc_prescale_ratios[] = {
+ { .num = 1, .den = 2 }, /* CHANNEL_VCOIN */
+ { .num = 1, .den = 3 }, /* CHANNEL_VBAT */
+ { .num = 1, .den = 10 }, /* CHANNEL_VCHG */
+ { .num = 1, .den = 1 }, /* CHANNEL_CHG_MONITOR */
+ { .num = 1, .den = 3 }, /* CHANNEL_VPH_PWR */
+ { .num = 1, .den = 1 }, /* CHANNEL_MPP5 */
+ { .num = 1, .den = 1 }, /* CHANNEL_MPP6 */
+ { .num = 1, .den = 2 }, /* CHANNEL_MPP7 */
+ { .num = 1, .den = 2 }, /* CHANNEL_MPP8 */
+ { .num = 1, .den = 3 }, /* CHANNEL_MPP9 */
+ { .num = 1, .den = 3 }, /* CHANNEL_USB_VBUS */
+ { .num = 1, .den = 1 }, /* CHANNEL_DIE_TEMP */
+ { .num = 1, .den = 1 }, /* CHANNEL_INTERNAL */
+ { .num = 1, .den = 1 }, /* CHANNEL_125V */
+ { .num = 1, .den = 1 }, /* CHANNEL_INTERNAL_2 */
+ { .num = 1, .den = 1 }, /* CHANNEL_MUXOFF */
+};
+
+/**
+ * struct pm8xxx_chan_info - ADC channel information
+ * @name: name of this channel
+ * @calibration: whether to use absolute or ratiometric calibration
+ * @amux_channel: channel 0..15
+ * @decimation: 0,1,2,3
+ * @amux_mpp_channel: MPP channel 0..3
+ * @amux_ip_rsv: ratiometric scale value if using ratiometric
+ * calibration: 0, 1, 2, 4, 5.
+ */
+struct pm8xxx_chan_info {
+ const char *name;
+ enum vadc_calibration calibration;
+ u8 amux_channel:4;
+ u8 decimation:2;
+ u8 amux_mpp_channel:2;
+ u8 amux_ip_rsv:3;
+};
+
+/**
+ * struct pm8xxx_xoadc - state container for the XOADC
+ * @dev: pointer to device
+ * @map: regmap to access registers
+ * @vref: reference voltage regulator
+ * @nchans: number of channels
+ * @chans: the channel information per-channel
+ * @iio_chans: IIO channel specifiers
+ * @graph: linear calibration parameters for absolute and
+ * ratiometric measurements
+ * @complete: completion to indicate end of conversion
+ * @lock: lock to restrict access to the hardware to one client at the time
+ */
+struct pm8xxx_xoadc {
+ struct device *dev;
+ struct regmap *map;
+ struct regulator *vref;
+ unsigned int nchans;
+ struct pm8xxx_chan_info *chans;
+ struct iio_chan_spec *iio_chans;
+ struct vadc_linear_graph graph[2];
+ struct completion complete;
+ struct mutex lock;
+};
+
+static irqreturn_t pm8xxx_eoc_irq(int irq, void *d)
+{
+ struct iio_dev *indio_dev = d;
+ struct pm8xxx_xoadc *adc = iio_priv(indio_dev);
+
+ complete(&adc->complete);
+
+ return IRQ_HANDLED;
+}
+
+static struct pm8xxx_chan_info *
+pm8xxx_get_channel(struct pm8xxx_xoadc *adc, u8 chan)
+{
+ struct pm8xxx_chan_info *ch;
+ int i;
+
+ for (i = 0; i < adc->nchans; i++) {
+ ch = &adc->chans[i];
+ if (ch->amux_channel == chan)
+ break;
+ }
+ if (i == adc->nchans)
+ return NULL;
+
+ return ch;
+}
+
+static int pm8xxx_read_channel_rsv(struct pm8xxx_xoadc *adc,
+ const struct pm8xxx_chan_info *ch,
+ u8 rsv, u16 *adc_code)
+{
+ int ret;
+ unsigned int val;
+ u8 rsvmask, rsvval;
+ u8 lsb, msb;
+
+ dev_dbg(adc->dev, "read channel \"%s\", amux %d, mpp %d, rsv %d\n",
+ ch->name, ch->amux_channel, ch->amux_mpp_channel, rsv);
+
+ mutex_lock(&adc->lock);
+
+ /* Mux in this channel */
+ ret = regmap_write(adc->map, ADC_ARB_USRP_AMUX_CNTRL,
+ ch->amux_channel << ADC_AMUX_SEL_SHIFT |
+ ch->amux_mpp_channel << ADC_AMUX_PREMUX_SHIFT);
+ if (ret)
+ goto unlock;
+
+ /* Set up ratiometric scale value */
+ rsvmask = (ADC_ARB_USRP_RSV_RST | ADC_ARB_USRP_RSV_DTEST0 |
+ ADC_ARB_USRP_RSV_DTEST1 | ADC_ARB_USRP_RSV_OP);
+ if (ch->calibration == VADC_CALIB_RATIOMETRIC) {
+ if (rsv == 0xff)
+ rsvval = (ch->amux_ip_rsv << ADC_RSV_IP_SEL_SHIFT) |
+ ADC_ARB_USRP_RSV_TRM;
+ else
+ rsvval = (rsv << ADC_RSV_IP_SEL_SHIFT) |
+ ADC_ARB_USRP_RSV_TRM;
+ } else {
+ /* We are not ratiometric so turn this off */
+ rsvval = ADC_ARB_USRP_RSV_IP_SEL1;
+ }
+
+ ret = regmap_update_bits(adc->map,
+ ADC_ARB_USRP_RSV,
+ ~rsvmask,
+ rsvval);
+ if (ret)
+ goto unlock;
+
+ ret = regmap_write(adc->map, ADC_ARB_USRP_ANA_PARAM,
+ ADC_ARB_USRP_ANA_PARAM_DIS);
+ if (ret)
+ goto unlock;
+
+ /* Decimation factor */
+ ret = regmap_write(adc->map, ADC_ARB_USRP_DIG_PARAM,
+ ADC_ARB_USRP_DIG_PARAM_SEL_SHIFT0 |
+ ADC_ARB_USRP_DIG_PARAM_SEL_SHIFT1 |
+ ch->decimation << ADC_DIG_PARAM_DEC_SHIFT);
+ if (ret)
+ goto unlock;
+
+ ret = regmap_write(adc->map, ADC_ARB_USRP_ANA_PARAM,
+ ADC_ARB_USRP_ANA_PARAM_EN);
+ if (ret)
+ goto unlock;
+
+ /* Enable the arbiter, the Qualcomm code does it twice like this */
+ ret = regmap_write(adc->map, ADC_ARB_USRP_CNTRL,
+ ADC_ARB_USRP_CNTRL_EN_ARB);
+ if (ret)
+ goto unlock;
+ ret = regmap_write(adc->map, ADC_ARB_USRP_CNTRL,
+ ADC_ARB_USRP_CNTRL_EN_ARB);
+ if (ret)
+ goto unlock;
+
+
+ /* Fire a request! */
+ reinit_completion(&adc->complete);
+ ret = regmap_write(adc->map, ADC_ARB_USRP_CNTRL,
+ ADC_ARB_USRP_CNTRL_EN_ARB |
+ ADC_ARB_USRP_CNTRL_REQ);
+ if (ret)
+ goto unlock;
+
+ /* Next the interrupt occurs */
+ ret = wait_for_completion_timeout(&adc->complete,
+ VADC_CONV_TIME_MAX_US);
+ if (!ret) {
+ dev_err(adc->dev, "conversion timed out\n");
+ ret = -ETIMEDOUT;
+ goto unlock;
+ }
+
+ ret = regmap_read(adc->map, ADC_ARB_USRP_DATA0, &val);
+ if (ret)
+ goto unlock;
+ lsb = val;
+ ret = regmap_read(adc->map, ADC_ARB_USRP_DATA1, &val);
+ if (ret)
+ goto unlock;
+ msb = val;
+ *adc_code = (msb << 8) | lsb;
+
+ /* Turn off the ADC by setting the arbiter to 0 twice */
+ ret = regmap_write(adc->map, ADC_ARB_USRP_CNTRL, 0);
+ if (ret)
+ goto unlock;
+ ret = regmap_write(adc->map, ADC_ARB_USRP_CNTRL, 0);
+ if (ret)
+ goto unlock;
+
+unlock:
+ mutex_unlock(&adc->lock);
+ return ret;
+}
+
+static int pm8xxx_read_channel(struct pm8xxx_xoadc *adc,
+ const struct pm8xxx_chan_info *ch,
+ u16 *adc_code)
+{
+ /*
+ * Normally we just use the ratiometric scale value (RSV) predefined
+ * for the channel, but during calibration we need to modify this
+ * so this wrapper is a helper hiding the more complex version.
+ */
+ return pm8xxx_read_channel_rsv(adc, ch, 0xff, adc_code);
+}
+
+static s32 pm8xxx_calibrate(struct pm8xxx_xoadc *adc,
+ const struct pm8xxx_chan_info *ch,
+ u16 adc_code)
+{
+ return qcom_vadc_calibrate(&adc_prescale_ratios[ch->amux_channel],
+ &adc->graph[ch->calibration],
+ (ch->calibration == VADC_CALIB_ABSOLUTE),
+ adc_code);
+}
+
+static int pm8xxx_calibrate_device(struct pm8xxx_xoadc *adc)
+{
+ const struct pm8xxx_chan_info *ch;
+ u16 read_1250v;
+ u16 read_0625v;
+ u16 read_nomux_rsv5;
+ u16 read_nomux_rsv4;
+ int ret;
+
+
+ adc->graph[VADC_CALIB_ABSOLUTE].dx = VADC_ABSOLUTE_RANGE_UV;
+ adc->graph[VADC_CALIB_RATIOMETRIC].dx = VADC_RATIOMETRIC_RANGE_UV;
+
+ /* Common reference channel calibration */
+ ch = pm8xxx_get_channel(adc, CHANNEL_125V);
+ if (!ch)
+ return -ENODEV;
+ ret = pm8xxx_read_channel(adc, ch, &read_1250v);
+ if (ret) {
+ dev_err(adc->dev, "could not read 1.25V reference channel\n");
+ return -ENODEV;
+ }
+ ch = pm8xxx_get_channel(adc, CHANNEL_INTERNAL);
+ if (!ch)
+ return -ENODEV;
+ ret = pm8xxx_read_channel(adc, ch, &read_0625v);
+ if (ret) {
+ dev_err(adc->dev, "could not read 0.625V reference channel\n");
+ return -ENODEV;
+ }
+ if (read_1250v == read_0625v) {
+ dev_err(adc->dev, "read same ADC code for 1.25V and 0.625V\n");
+ return -ENODEV;
+ }
+
+ adc->graph[VADC_CALIB_ABSOLUTE].dy = read_1250v - read_0625v;
+ adc->graph[VADC_CALIB_ABSOLUTE].gnd = read_0625v;
+
+ dev_info(adc->dev, "absolute calibration dx = %d uV, dy = %d units\n",
+ VADC_ABSOLUTE_RANGE_UV, adc->graph[VADC_CALIB_ABSOLUTE].dy);
+
+ /* Ratiometric calibration */
+ ch = pm8xxx_get_channel(adc, CHANNEL_MUXOFF);
+ if (!ch)
+ return -ENODEV;
+ ret = pm8xxx_read_channel_rsv(adc, ch, AMUX_RSV5, &read_nomux_rsv5);
+ if (ret) {
+ dev_err(adc->dev, "could not read MUXOFF reference channel\n");
+ return -ENODEV;
+ }
+ ret = pm8xxx_read_channel_rsv(adc, ch, AMUX_RSV4, &read_nomux_rsv4);
+ if (ret) {
+ dev_err(adc->dev, "could not read MUXOFF reference channel\n");
+ return -ENODEV;
+ }
+ adc->graph[VADC_CALIB_RATIOMETRIC].dy =
+ read_nomux_rsv5 - read_nomux_rsv4;
+ adc->graph[VADC_CALIB_RATIOMETRIC].gnd = read_nomux_rsv4;
+
+ dev_info(adc->dev, "ratiometric calibration dx = %d uV, dy = %d units\n",
+ VADC_RATIOMETRIC_RANGE_UV,
+ adc->graph[VADC_CALIB_RATIOMETRIC].dy);
+
+ return 0;
+}
+
+static int pm8xxx_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ struct pm8xxx_xoadc *adc = iio_priv(indio_dev);
+ const struct pm8xxx_chan_info *ch;
+ u16 adc_code;
+ int ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_PROCESSED:
+ /* Only die temperature ends up here */
+ ch = pm8xxx_get_channel(adc, chan->address);
+ if (!ch) {
+ dev_err(adc->dev, "no such channel %lu\n",
+ chan->address);
+ return -EINVAL;
+ }
+ ret = pm8xxx_read_channel(adc, ch, &adc_code);
+ if (ret)
+ return ret;
+ *val = pm8xxx_calibrate(adc, ch, adc_code);
+ /* 2mV/K, return milli Celsius */
+ *val /= 2;
+ *val -= KELVINMIL_CELSIUSMIL;
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_RAW:
+ switch (chan->type) {
+ case IIO_VOLTAGE:
+ ch = pm8xxx_get_channel(adc, chan->address);
+ if (!ch) {
+ dev_err(adc->dev, "no such channel %lu\n",
+ chan->address);
+ return -EINVAL;
+ }
+ ret = pm8xxx_read_channel(adc, ch, &adc_code);
+ if (ret)
+ return ret;
+ *val = pm8xxx_calibrate(adc, ch, adc_code);
+ return IIO_VAL_INT;
+ default:
+ return -EINVAL;
+ }
+ case IIO_CHAN_INFO_SCALE:
+ /*
+ * Applies to all voltage channels: we scale the microvolts
+ * to millivolts as required by the userspace ABI.
+ */
+ *val = 0;
+ *val2 = 1000;
+ return IIO_VAL_INT_PLUS_MICRO;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int pm8xxx_of_xlate(struct iio_dev *indio_dev,
+ const struct of_phandle_args *iiospec)
+{
+ struct pm8xxx_xoadc *adc = iio_priv(indio_dev);
+ unsigned int i;
+
+ for (i = 0; i < adc->nchans; i++)
+ if (adc->iio_chans[i].channel == iiospec->args[0])
+ return i;
+
+ return -EINVAL;
+}
+
+static const struct iio_info pm8xxx_xoadc_info = {
+ .driver_module = THIS_MODULE,
+ .of_xlate = pm8xxx_of_xlate,
+ .read_raw = pm8xxx_read_raw,
+};
+
+static int pm8xxx_xoadc_parse_channel(struct device *dev,
+ struct device_node *np,
+ struct pm8xxx_chan_info *ch)
+{
+ const char *name = np->name;
+ u32 chan, rsv, dec;
+ int ret;
+
+ ret = of_property_read_u32(np, "reg", &chan);
+ if (ret) {
+ dev_err(dev, "invalid channel number %s\n", name);
+ return ret;
+ }
+ if (chan > XOADC_CHAN_MAX) {
+ dev_err(dev, "%s too big channel number %d\n", name, chan);
+ return -EINVAL;
+ }
+
+ if (of_property_read_bool(np, "qcom,ratiometric")) {
+ ch->calibration = VADC_CALIB_RATIOMETRIC;
+ ret = of_property_read_u32(np, "qcom,ratiometric-ref", &rsv);
+ if (ret) {
+ dev_err(dev, "invalid RSV %s\n", name);
+ return ret;
+ }
+ if (rsv > XOADC_RSV_MAX) {
+ dev_err(dev, "%s too large RSV value %d\n", name, rsv);
+ return -EINVAL;
+ }
+ if (rsv == AMUX_RSV3) {
+ dev_err(dev, "%s invalid RSV value %d\n", name, rsv);
+ return -EINVAL;
+ }
+ } else {
+ ch->calibration = VADC_CALIB_ABSOLUTE;
+ rsv = 0;
+ }
+
+ ret = of_property_read_u32(np, "qcom,decimation", &dec);
+ if (!ret) {
+ /* It's OK to skip this ... */
+ ret = qcom_vadc_decimation_from_dt(dec);
+ if (ret < 0) {
+ dev_err(dev, "%s invalid decimation %d\n",
+ name, dec);
+ return ret;
+ }
+ ch->decimation = ret;
+ } else {
+ ch->decimation = VADC_DEF_DECIMATION;
+ }
+
+ ch->amux_channel = chan;
+ ch->name = name;
+ ch->amux_ip_rsv = rsv;
+ ch->amux_mpp_channel = PREMUX_MPP_SCALE_0; /* FIXME: get from DT */
+
+ dev_dbg(dev, "channel %d \"%s\" ref voltage: %d, decimation %d\n",
+ ch->amux_channel,
+ ch->name,
+ ch->amux_ip_rsv,
+ ch->decimation);
+ return 0;
+}
+
+static int pm8xxx_xoadc_parse_channels(struct pm8xxx_xoadc *adc,
+ struct device_node *np)
+{
+ struct device_node *child;
+ struct pm8xxx_chan_info *ch;
+ int ret;
+ int i;
+
+ adc->nchans = of_get_available_child_count(np);
+ if (!adc->nchans) {
+ dev_err(adc->dev, "no channel children\n");
+ return -ENODEV;
+ }
+ dev_dbg(adc->dev, "found %d ADC channels\n", adc->nchans);
+
+ adc->iio_chans = devm_kcalloc(adc->dev, adc->nchans,
+ sizeof(*adc->iio_chans), GFP_KERNEL);
+ if (!adc->iio_chans)
+ return -ENOMEM;
+
+ adc->chans = devm_kcalloc(adc->dev, adc->nchans,
+ sizeof(*adc->chans), GFP_KERNEL);
+ if (!adc->chans)
+ return -ENOMEM;
+
+ i = 0;
+ for_each_available_child_of_node(np, child) {
+ struct iio_chan_spec *iio_chan;
+
+ ch = &adc->chans[i];
+ ret = pm8xxx_xoadc_parse_channel(adc->dev, child, ch);
+ if (ret) {
+ of_node_put(child);
+ return ret;
+ }
+
+ iio_chan = &adc->iio_chans[i];
+ iio_chan->channel = ch->amux_channel;
+ iio_chan->datasheet_name = ch->name;
+ /* A single temperature channel, the rest are voltages */
+ if (ch->amux_channel == CHANNEL_DIE_TEMP) {
+ iio_chan->type = IIO_TEMP;
+ iio_chan->info_mask_separate =
+ BIT(IIO_CHAN_INFO_PROCESSED);
+ } else {
+ iio_chan->type = IIO_VOLTAGE;
+ iio_chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_SCALE);
+ }
+ iio_chan->indexed = 1;
+ iio_chan->address = ch->amux_channel;
+
+ i++;
+ }
+
+ /* Check for required channels */
+ ch = pm8xxx_get_channel(adc, CHANNEL_125V);
+ if (!ch) {
+ dev_err(adc->dev, "missing 1.25V reference channel\n");
+ return -ENODEV;
+ }
+ ch = pm8xxx_get_channel(adc, CHANNEL_INTERNAL);
+ if (!ch) {
+ dev_err(adc->dev, "missing 0.625V reference channel\n");
+ return -ENODEV;
+ }
+ ch = pm8xxx_get_channel(adc, CHANNEL_MUXOFF);
+ if (!ch) {
+ dev_err(adc->dev, "missing MUXOFF reference channel\n");
+ return -ENODEV;
+ }
+
+ return 0;
+}
+
+static int pm8xxx_xoadc_probe(struct platform_device *pdev)
+{
+ struct pm8xxx_xoadc *adc;
+ struct iio_dev *indio_dev;
+ struct device_node *np = pdev->dev.of_node;
+ struct regmap *map;
+ struct device *dev = &pdev->dev;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(dev, sizeof(*adc));
+ if (!indio_dev)
+ return -ENOMEM;
+ platform_set_drvdata(pdev, indio_dev);
+
+ adc = iio_priv(indio_dev);
+ adc->dev = dev;
+ init_completion(&adc->complete);
+ mutex_init(&adc->lock);
+
+ ret = pm8xxx_xoadc_parse_channels(adc, np);
+ if (ret)
+ return ret;
+
+ map = dev_get_regmap(dev->parent, NULL);
+ if (!map) {
+ dev_err(dev, "Parent regmap unavailable.\n");
+ return -ENXIO;
+ }
+ adc->map = map;
+
+ /* Bring up regulator */
+ adc->vref = devm_regulator_get(dev, "xoadc-ref");
+ if (IS_ERR(adc->vref)) {
+ dev_err(dev, "failed to get XOADC VREF regulator\n");
+ return PTR_ERR(adc->vref);
+ }
+ /* We strictly require this voltage */
+ ret = regulator_set_voltage(adc->vref, 2200000, 2200000);
+ if (ret) {
+ dev_err(dev, "unable to set LDO18 voltage to 2.2V\n");
+ return ret;
+ }
+ ret = regulator_enable(adc->vref);
+ if (ret) {
+ dev_err(dev, "failed to enable XOADC VREF regulator\n");
+ return ret;
+ }
+
+ ret = devm_request_threaded_irq(dev, platform_get_irq(pdev, 0),
+ pm8xxx_eoc_irq, NULL, 0, "pm8xxx-adc", indio_dev);
+ if (ret) {
+ dev_err(dev, "unable to request IRQ\n");
+ goto out_disable_vref;
+ }
+
+ indio_dev->dev.parent = dev;
+ indio_dev->dev.of_node = np;
+ indio_dev->name = "pm8xxx-xoadc";
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->info = &pm8xxx_xoadc_info;
+ indio_dev->channels = adc->iio_chans;
+ indio_dev->num_channels = adc->nchans;
+
+ ret = iio_device_register(indio_dev);
+ if (ret)
+ goto out_disable_vref;
+
+ ret = pm8xxx_calibrate_device(adc);
+ if (ret)
+ goto out_unreg_device;
+
+ dev_info(dev, "PM8xxx XOADC driver enabled\n");
+
+ return 0;
+
+out_unreg_device:
+ iio_device_unregister(indio_dev);
+out_disable_vref:
+ regulator_disable(adc->vref);
+
+ return ret;
+}
+
+static int pm8xxx_xoadc_remove(struct platform_device *pdev)
+{
+ struct iio_dev *indio_dev = platform_get_drvdata(pdev);
+ struct pm8xxx_xoadc *adc = iio_priv(indio_dev);
+
+ iio_device_unregister(indio_dev);
+
+ regulator_disable(adc->vref);
+
+ return 0;
+}
+
+static const struct of_device_id pm8xxx_xoadc_id_table[] = {
+ {
+ .compatible = "qcom,pm8018-adc",
+ },
+ {
+ .compatible = "qcom,pm8038-adc",
+ },
+ {
+ .compatible = "qcom,pm8058-adc",
+ },
+ {
+ .compatible = "qcom,pm8917-adc",
+ },
+ {
+ .compatible = "qcom,pm8921-adc",
+ },
+ { },
+};
+MODULE_DEVICE_TABLE(of, pm8xxx_xoadc_id_table);
+
+static struct platform_driver pm8xxx_xoadc_driver = {
+ .driver = {
+ .name = "pm8xxx-adc",
+ .of_match_table = pm8xxx_xoadc_id_table,
+ },
+ .probe = pm8xxx_xoadc_probe,
+ .remove = pm8xxx_xoadc_remove,
+};
+module_platform_driver(pm8xxx_xoadc_driver);
+
+MODULE_DESCRIPTION("PM8xxx XOADC driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:pm8xxx-xoadc");
--
2.7.4
--
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