Re: [PATCH v4 3/3] iio: adc: mt6360: Add ADC driver for MT6360
From: Gene Chen <hidden>
Date: 2020-09-18 08:04:57
Also in:
linux-iio, linux-mediatek, lkml
Jonathan Cameron [off-list ref] 於 2020年9月18日 週五 上午1:53寫道：
On Wed, 16 Sep 2020 01:36:09 +0800 Gene Chen [off-list ref] wrote:quoted
From: Gene Chen <redacted> Add MT6360 ADC driver include Charger Current, Voltage, and Temperature. Signed-off-by: Gene Chen <redacted>Comments inline.quoted
--- 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.cdiff --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_TESTdiff --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.odiff --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;Please add a comment to document what the scope of the lock is.
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quoted
+ 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,Shouldn't be any need to cast a pointer explicitly to void *
ACK
quoted
+ sizeof(__be16));sizeof(adc_enable) preferred.
ACK
quoted
+ 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));To be entirely safe, probably need that to be an unaligned read?
Maybe I can change to "*val = rpt[1] << 8 | rpt[2];". It's more abvious.
quoted
+ 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));sizeof(adc_enable)
ACK
quoted
+ 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;I don't think we need fallthrough for cases with nothing in them.
Every channel needs set " *val = 2500" for scale.
Do you mean change as below?
switch (channel) {
case MT6360_CHAN_USBID:
case MT6360_CHAN_VSYS:
case MT6360_CHAN_VBAT:
case MT6360_CHAN_CHG_VDDP:
case MT6360_CHAN_VREF_TS:
fallthrough;
case MT6360_CHAN_TS:
*val = 1250;
return IIO_VAL_INT;
quoted
+ case MT6360_CHAN_USBID:
quoted
+ 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, ®val); + 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) | \Docs in patch 1 need to reflect this change. Currently they have processed channels.
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quoted
+ 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];There is a hole in here I think? (MT6360_CHAN_MAX is 11?) If so we need to explicitly memset the structure to avoid any risk of kernel data leakage to userspace.quoted
+ int64_t timestamp; + } data;I guess we know this is on a platform with 64bit alignment for int64_t's (unlike x86_64 for example)
Do you mean change as below?
struct {
u16 values[MT6360_CHAN_MAX];
int64_t timestamp; __aligned(8)
} data;
quoted
+ 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 [off-list ref]"); +MODULE_DESCRIPTION("MT6360 ADC Driver"); +MODULE_LICENSE("GPL v2");
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