[PATCH v4 3/3] iio: adc: mt6360: Add ADC driver for MT6360

Gene Chen
2020-09-15T18:42:12Z

From: Gene Chen <gene_chen@richtek.com>

Add MT6360 ADC driver include Charger Current, Voltage, and
Temperature.

Signed-off-by: Gene Chen <gene_chen@richtek.com>
---
drivers/iio/adc/Kconfig | 11 ++
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/mt6360-adc.c | 357 +++++++++++++++++++++++++++++++++++++++++++
3 files changed, 369 insertions(+)
create mode 100644 drivers/iio/adc/mt6360-adc.c

diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 66d9cc0..8d36b66 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -703,6 +703,17 @@ config MCP3911
This driver can also be built as a module. If so, the module will be
called mcp3911.

+config MEDIATEK_MT6360_ADC
+ tristate "Mediatek MT6360 ADC driver"
+ depends on MFD_MT6360
+ select IIO_BUFFER
+ select IIO_TRIGGERED_BUFFER
+ help
+ Say Y here to enable MT6360 ADC support.
+ Integrated for System Monitoring includes
+ is used in smartphones and tablets and supports a 11 channel
+ general purpose ADC.
+
config MEDIATEK_MT6577_AUXADC
tristate "MediaTek AUXADC driver"
depends on ARCH_MEDIATEK || COMPILE_TEST
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index 90f94ad..5fca90a 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -65,6 +65,7 @@ obj-$(CONFIG_MAX9611) += max9611.o
obj-$(CONFIG_MCP320X) += mcp320x.o
obj-$(CONFIG_MCP3422) += mcp3422.o
obj-$(CONFIG_MCP3911) += mcp3911.o
+obj-$(CONFIG_MEDIATEK_MT6360_ADC) += mt6360-adc.o
obj-$(CONFIG_MEDIATEK_MT6577_AUXADC) += mt6577_auxadc.o
obj-$(CONFIG_MEN_Z188_ADC) += men_z188_adc.o
obj-$(CONFIG_MESON_SARADC) += meson_saradc.o
diff --git a/drivers/iio/adc/mt6360-adc.c b/drivers/iio/adc/mt6360-adc.c
new file mode 100644
index 0000000..b256d0a
--- /dev/null
+++ b/drivers/iio/adc/mt6360-adc.c
@@ -0,0 +1,357 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/delay.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/ktime.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#include <linux/iio/buffer.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+
+#define MT6360_REG_PMUCHGCTRL3 0x313
+#define MT6360_REG_PMUADCCFG 0x356
+#define MT6360_REG_PMUADCIDLET 0x358
+#define MT6360_REG_PMUADCRPT1 0x35A
+
+/* PMUCHGCTRL3 0x313 */
+#define MT6360_AICR_MASK GENMASK(7, 2)
+#define MT6360_AICR_SHFT 2
+#define MT6360_AICR_400MA 0x6
+/* PMUADCCFG 0x356 */
+#define MT6360_ADCEN_MASK 0x8000
+/* PMUADCRPT1 0x35A */
+#define MT6360_PREFERCH_MASK GENMASK(7, 4)
+#define MT6360_PREFERCH_SHFT 4
+#define MT6360_RPTCH_MASK GENMASK(3, 0)
+#define MT6360_NO_PREFER 15
+
+/* Time in ms */
+#define ADC_WAIT_TIME_MS 25
+
+enum {
+ MT6360_CHAN_USBID = 0,
+ MT6360_CHAN_VBUSDIV5,
+ MT6360_CHAN_VBUSDIV2,
+ MT6360_CHAN_VSYS,
+ MT6360_CHAN_VBAT,
+ MT6360_CHAN_IBUS,
+ MT6360_CHAN_IBAT,
+ MT6360_CHAN_CHG_VDDP,
+ MT6360_CHAN_TEMP_JC,
+ MT6360_CHAN_VREF_TS,
+ MT6360_CHAN_TS,
+ MT6360_CHAN_MAX
+};
+
+struct mt6360_adc_data {
+ struct device *dev;
+ struct regmap *regmap;
+ struct mutex adc_lock;
+ ktime_t last_off_timestamps[MT6360_CHAN_MAX];
+};
+
+static int mt6360_adc_read_channel(struct mt6360_adc_data *mad, int channel, int *val)
+{
+ __be16 adc_enable;
+ u8 rpt[3];
+ ktime_t start_t, predict_end_t;
+ unsigned int pre_wait_time;
+ int ret;
+
+ mutex_lock(&mad->adc_lock);
+
+ /* Select the preferred ADC channel */
+ ret = regmap_update_bits(mad->regmap, MT6360_REG_PMUADCRPT1, MT6360_PREFERCH_MASK,
+ channel << MT6360_PREFERCH_SHFT);
+ if (ret)
+ goto out_adc_lock;
+
+ adc_enable = cpu_to_be16(MT6360_ADCEN_MASK | BIT(channel));
+ ret = regmap_raw_write(mad->regmap, MT6360_REG_PMUADCCFG, (void *)&adc_enable,
+ sizeof(__be16));
+ if (ret)
+ goto out_adc_lock;
+
+ start_t = ktime_get();
+ predict_end_t = ktime_add_ms(mad->last_off_timestamps[channel], 2 * ADC_WAIT_TIME_MS);
+
+ if (ktime_after(start_t, predict_end_t))
+ pre_wait_time = ADC_WAIT_TIME_MS;
+ else
+ pre_wait_time = 3 * ADC_WAIT_TIME_MS;
+
+ msleep(pre_wait_time);
+
+ while (true) {
+ ret = regmap_raw_read(mad->regmap, MT6360_REG_PMUADCRPT1, rpt, sizeof(rpt));
+ if (ret)
+ goto out_adc_conv;
+
+ /*
+ * There are two functions, ZCV and TypeC OTP, running ADC VBAT and TS in
+ * background, and ADC samples are taken on a fixed frequency no matter read the
+ * previous one or not.
+ * To avoid conflict, We set minimum time threshold after enable ADC and
+ * check report channel is the same.
+ * The worst case is run the same ADC twice and background function is also running,
+ * ADC conversion sequence is desire channel before start ADC, background ADC,
+ * desire channel after start ADC.
+ * So the minimum correct data is three times of typical conversion time.
+ */
+ if ((rpt[0] & MT6360_RPTCH_MASK) == channel)
+ break;
+
+ msleep(ADC_WAIT_TIME_MS);
+ }
+
+ /* rpt[1]: ADC_HI_BYTE, rpt[2]: ADC_LOW_BYTE */
+ *val = be16_to_cpup((__be16 *)(rpt + 1));
+ ret = IIO_VAL_INT;
+
+out_adc_conv:
+ /* Only keep ADC enable */
+ adc_enable = cpu_to_be16(MT6360_ADCEN_MASK);
+ regmap_raw_write(mad->regmap, MT6360_REG_PMUADCCFG, (void *)&adc_enable, sizeof(__be16));
+ mad->last_off_timestamps[channel] = ktime_get();
+ /* Config prefer channel to NO_PREFER */
+ regmap_update_bits(mad->regmap, MT6360_REG_PMUADCRPT1, MT6360_PREFERCH_MASK,
+ MT6360_NO_PREFER << MT6360_PREFERCH_SHFT);
+out_adc_lock:
+ mutex_unlock(&mad->adc_lock);
+
+ return ret;
+}
+
+static int mt6360_adc_read_scale(struct mt6360_adc_data *mad, int channel, int *val, int *val2)
+{
+ unsigned int regval;
+ int ret;
+
+ switch (channel) {
+ case MT6360_CHAN_USBID:
+ fallthrough;
+ case MT6360_CHAN_VSYS:
+ fallthrough;
+ case MT6360_CHAN_VBAT:
+ fallthrough;
+ case MT6360_CHAN_CHG_VDDP:
+ fallthrough;
+ case MT6360_CHAN_VREF_TS:
+ fallthrough;
+ case MT6360_CHAN_TS:
+ *val = 1250;
+ return IIO_VAL_INT;
+ case MT6360_CHAN_VBUSDIV5:
+ *val = 6250;
+ return IIO_VAL_INT;
+ case MT6360_CHAN_VBUSDIV2:
+ fallthrough;
+ case MT6360_CHAN_IBUS:
+ fallthrough;
+ case MT6360_CHAN_IBAT:
+ *val = 2500;
+
+ if (channel == MT6360_CHAN_IBUS) {
+ /* IBUS will be affected by input current limit for the different Ron */
+ /* Check whether the config is <400mA or not */
+ ret = regmap_read(mad->regmap, MT6360_REG_PMUCHGCTRL3, &regval);
+ if (ret)
+ return ret;
+
+ regval = (regval & MT6360_AICR_MASK) >> MT6360_AICR_SHFT;
+ if (regval < MT6360_AICR_400MA)
+ *val = 1900;
+ }
+
+ return IIO_VAL_INT;
+ case MT6360_CHAN_TEMP_JC:
+ *val = 105;
+ *val2 = 100;
+ return IIO_VAL_FRACTIONAL;
+ }
+
+ return -EINVAL;
+}
+
+static int mt6360_adc_read_offset(struct mt6360_adc_data *mad, int channel, int *val)
+{
+ *val = (channel == MT6360_CHAN_TEMP_JC) ? -80 : 0;
+ return IIO_VAL_INT;
+
+}
+
+static int mt6360_adc_read_raw(struct iio_dev *iio_dev, const struct iio_chan_spec *chan,
+ int *val, int *val2, long mask)
+{
+ struct mt6360_adc_data *mad = iio_priv(iio_dev);
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ return mt6360_adc_read_channel(mad, chan->channel, val);
+ case IIO_CHAN_INFO_SCALE:
+ return mt6360_adc_read_scale(mad, chan->channel, val, val2);
+ case IIO_CHAN_INFO_OFFSET:
+ return mt6360_adc_read_offset(mad, chan->channel, val);
+ }
+
+ return -EINVAL;
+}
+
+static const struct iio_info mt6360_adc_iio_info = {
+ .read_raw = mt6360_adc_read_raw,
+};
+
+#define MT6360_ADC_CHAN(_idx, _type) { \
+ .type = _type, \
+ .channel = MT6360_CHAN_##_idx, \
+ .scan_index = MT6360_CHAN_##_idx, \
+ .extend_name = #_idx, \
+ .datasheet_name = #_idx, \
+ .scan_type = { \
+ .sign = 'u', \
+ .realbits = 16, \
+ .storagebits = 16, \
+ .endianness = IIO_CPU, \
+ }, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
+ BIT(IIO_CHAN_INFO_SCALE) | \
+ BIT(IIO_CHAN_INFO_OFFSET), \
+}
+
+static const struct iio_chan_spec mt6360_adc_channels[] = {
+ MT6360_ADC_CHAN(USBID, IIO_VOLTAGE),
+ MT6360_ADC_CHAN(VBUSDIV5, IIO_VOLTAGE),
+ MT6360_ADC_CHAN(VBUSDIV2, IIO_VOLTAGE),
+ MT6360_ADC_CHAN(VSYS, IIO_VOLTAGE),
+ MT6360_ADC_CHAN(VBAT, IIO_VOLTAGE),
+ MT6360_ADC_CHAN(IBUS, IIO_CURRENT),
+ MT6360_ADC_CHAN(IBAT, IIO_CURRENT),
+ MT6360_ADC_CHAN(CHG_VDDP, IIO_VOLTAGE),
+ MT6360_ADC_CHAN(TEMP_JC, IIO_TEMP),
+ MT6360_ADC_CHAN(VREF_TS, IIO_VOLTAGE),
+ MT6360_ADC_CHAN(TS, IIO_VOLTAGE),
+ IIO_CHAN_SOFT_TIMESTAMP(MT6360_CHAN_MAX),
+};
+
+static irqreturn_t mt6360_adc_trigger_handler(int irq, void *p)
+{
+ struct iio_poll_func *pf = p;
+ struct iio_dev *indio_dev = pf->indio_dev;
+ struct mt6360_adc_data *mad = iio_priv(indio_dev);
+ struct {
+ u16 values[MT6360_CHAN_MAX];
+ int64_t timestamp;
+ } data;
+ int i = 0, bit, val, ret;
+
+ for_each_set_bit(bit, indio_dev->active_scan_mask, indio_dev->masklength) {
+ ret = mt6360_adc_read_channel(mad, bit, &val);
+ if (ret < 0) {
+ dev_warn(&indio_dev->dev, "Failed to get channel %d conversion val\n", bit);
+ goto out;
+ }
+
+ data.values[i++] = val;
+ }
+ iio_push_to_buffers_with_timestamp(indio_dev, &data, iio_get_time_ns(indio_dev));
+out:
+ iio_trigger_notify_done(indio_dev->trig);
+
+ return IRQ_HANDLED;
+}
+
+static inline int mt6360_adc_reset(struct mt6360_adc_data *info)
+{
+ __be16 adc_enable;
+ ktime_t all_off_time;
+ int i, ret;
+
+ /* Clear ADC idle wait time to 0 */
+ ret = regmap_write(info->regmap, MT6360_REG_PMUADCIDLET, 0);
+ if (ret)
+ return ret;
+
+ /* Only keep ADC enable, but keep all channels off */
+ adc_enable = cpu_to_be16(MT6360_ADCEN_MASK);
+ ret = regmap_raw_write(info->regmap, MT6360_REG_PMUADCCFG, (void *)&adc_enable,
+ sizeof(__be16));
+ if (ret)
+ return ret;
+
+ /* Reset all channel off time to the current one */
+ all_off_time = ktime_get();
+ for (i = 0; i < MT6360_CHAN_MAX; i++)
+ info->last_off_timestamps[i] = all_off_time;
+
+ return 0;
+}
+
+static int mt6360_adc_probe(struct platform_device *pdev)
+{
+ struct mt6360_adc_data *mad;
+ struct regmap *regmap;
+ struct iio_dev *indio_dev;
+ int ret;
+
+ regmap = dev_get_regmap(pdev->dev.parent, NULL);
+ if (!regmap) {
+ dev_err(&pdev->dev, "Failed to get parent regmap\n");
+ return -ENODEV;
+ }
+
+ indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*mad));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ mad = iio_priv(indio_dev);
+ mad->dev = &pdev->dev;
+ mad->regmap = regmap;
+ mutex_init(&mad->adc_lock);
+
+ ret = mt6360_adc_reset(mad);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Failed to reset adc\n");
+ return ret;
+ }
+
+ indio_dev->name = dev_name(&pdev->dev);
+ indio_dev->dev.parent = &pdev->dev;
+ indio_dev->info = &mt6360_adc_iio_info;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->channels = mt6360_adc_channels;
+ indio_dev->num_channels = ARRAY_SIZE(mt6360_adc_channels);
+
+ ret = devm_iio_triggered_buffer_setup(&pdev->dev, indio_dev, NULL,
+ mt6360_adc_trigger_handler, NULL);
+ if (ret) {
+ dev_err(&pdev->dev, "Failed to allocate iio trigger buffer\n");
+ return ret;
+ }
+
+ return devm_iio_device_register(&pdev->dev, indio_dev);
+}
+
+static const struct of_device_id __maybe_unused mt6360_adc_of_id[] = {
+ { .compatible = "mediatek,mt6360-adc", },
+ {}
+};
+MODULE_DEVICE_TABLE(of, mt6360_adc_of_id);
+
+static struct platform_driver mt6360_adc_driver = {
+ .driver = {
+ .name = "mt6360-adc",
+ .of_match_table = mt6360_adc_of_id,
+ },
+ .probe = mt6360_adc_probe,
+};
+module_platform_driver(mt6360_adc_driver);
+
+MODULE_AUTHOR("Gene Chen <gene_chen@richtek.com>");
+MODULE_DESCRIPTION("MT6360 ADC Driver");
+MODULE_LICENSE("GPL v2");
--
2.7.4