[PATCH 1/3] iio: Add ADM1177 Hot Swap Controller and Digital Power Monitor driver
Jonathan Cameron
jonathan.cameron at huawei.com
Tue Nov 12 17:37:57 UTC 2019
On Tue, 12 Nov 2019 17:35:50 +0200
Beniamin Bia <beniamin.bia at analog.com> wrote:
> From: Michael Hennerich <michael.hennerich at analog.com>
>
> ADM1177 is a Hot Swap Controller and Digital Power Monitor with
> Soft Start Pin.
>
> Datasheet:
> Link: https://www.analog.com/media/en/technical-documentation/data-sheets/ADM1177.pdf
>
> Signed-off-by: Michael Hennerich <michael.hennerich at analog.com>
> Co-developed-by: Beniamin Bia <beniamin.bia at analog.com>
> Signed-off-by: Beniamin Bia <beniamin.bia at analog.com>
Hi Beniamin,
A couple immediate thoughts.
1. That cc list has some rather non obvious people on it. Unless something
fairly surprising is going on, probably better to cut it back a bit.
2. Why IIO? Not entirely obvious to me. From first glance this is definitely
doing hardware monitoring. If there is a reason there should be a clear
statement here on why.
+CC Guenter and Jean as hwmon maintainers.
Whilst I'm here, a very quick review below.
> ---
> drivers/iio/adc/Kconfig | 12 ++
> drivers/iio/adc/Makefile | 1 +
> drivers/iio/adc/adm1177.c | 257 ++++++++++++++++++++++++++++++++++++++
> 3 files changed, 270 insertions(+)
> create mode 100644 drivers/iio/adc/adm1177.c
>
> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> index 9554890a3200..4db8c6dcb595 100644
> --- a/drivers/iio/adc/Kconfig
> +++ b/drivers/iio/adc/Kconfig
> @@ -228,6 +228,18 @@ config ASPEED_ADC
> To compile this driver as a module, choose M here: the module will be
> called aspeed_adc.
>
> +config ADM1177
> + tristate "Analog Devices ADM1177 Digital Power Monitor driver"
> + depends on I2C
> + help
> + Say yes here to build support for Analog Devices:
> + ADM1177 Hot Swap Controller and Digital Power Monitor
> + with Soft Start Pin. Provides direct access
> + via sysfs.
> +
> + To compile this driver as a module, choose M here: the
> + module will be called adm1177.
> +
> config AT91_ADC
> tristate "Atmel AT91 ADC"
> depends on ARCH_AT91
> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
> index 5ecc481c2967..7899d6a158f3 100644
> --- a/drivers/iio/adc/Makefile
> +++ b/drivers/iio/adc/Makefile
> @@ -24,6 +24,7 @@ obj-$(CONFIG_AD7887) += ad7887.o
> obj-$(CONFIG_AD7949) += ad7949.o
> obj-$(CONFIG_AD799X) += ad799x.o
> obj-$(CONFIG_ASPEED_ADC) += aspeed_adc.o
> +obj-$(CONFIG_ADM1177) += adm1177.o
> obj-$(CONFIG_AT91_ADC) += at91_adc.o
> obj-$(CONFIG_AT91_SAMA5D2_ADC) += at91-sama5d2_adc.o
> obj-$(CONFIG_AXP20X_ADC) += axp20x_adc.o
> diff --git a/drivers/iio/adc/adm1177.c b/drivers/iio/adc/adm1177.c
> new file mode 100644
> index 000000000000..daec34566a65
> --- /dev/null
> +++ b/drivers/iio/adc/adm1177.c
> @@ -0,0 +1,257 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * ADM1177 Hot Swap Controller and Digital Power Monitor with Soft Start Pin
> + *
> + * Copyright 2015-2019 Analog Devices Inc.
> + */
> +
> +#include <linux/device.h>
> +#include <linux/err.h>
> +#include <linux/i2c.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/mutex.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/slab.h>
> +#include <linux/sysfs.h>
> +
> +#include <linux/iio/iio.h>
> +#include <linux/iio/sysfs.h>
> +#include <linux/iio/events.h>
> +
> +/* Command Byte Operations */
> +#define ADM1177_CMD_V_CONT BIT(0)
> +#define ADM1177_CMD_V_ONCE BIT(1)
> +#define ADM1177_CMD_I_CONT BIT(2)
> +#define ADM1177_CMD_I_ONCE BIT(3)
> +#define ADM1177_CMD_VRANGE BIT(4)
> +#define ADM1177_CMD_STATUS_RD BIT(6)
> +
> +/* Extended Register */
> +#define ADM1177_REG_ALERT_EN 1
> +#define ADM1177_REG_ALERT_TH 2
> +#define ADM1177_REG_CONTROL 3
> +
> +/* ADM1177_REG_ALERT_EN */
> +#define ADM1177_EN_ADC_OC1 BIT(0)
> +#define ADM1177_EN_ADC_OC4 BIT(1)
> +#define ADM1177_EN_HS_ALERT BIT(2)
> +#define ADM1177_EN_OFF_ALERT BIT(3)
> +#define ADM1177_CLEAR BIT(4)
> +
> +/* ADM1177_REG_CONTROL */
> +#define ADM1177_SWOFF BIT(0)
> +
> +#define ADM1177_BITS 12
> +
> +/**
> + * struct adm1177_state - driver instance specific data
> + * @client pointer to i2c client
> + * @reg regulator info for the the power supply of the device
> + * @command internal control register
> + * @r_sense_uohm current sense resistor value
> + * @alert_threshold_ua current limit for shutdown
> + * @vrange_high internal voltage divider
> + */
> +struct adm1177_state {
> + struct i2c_client *client;
> + struct regulator *reg;
> + u8 command;
> + u32 r_sense_uohm;
> + u32 alert_threshold_ua;
> + bool vrange_high;
> +};
> +
> +static int adm1177_read(struct adm1177_state *st, u8 num, u8 *data)
> +{
> + struct i2c_client *client = st->client;
> + int ret = 0;
> +
> + ret = i2c_master_recv(client, data, num);
> + if (ret < 0) {
> + dev_err(&client->dev, "I2C read error\n");
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int adm1177_write_cmd(struct adm1177_state *st, u8 cmd)
> +{
> + st->command = cmd;
> + return i2c_smbus_write_byte(st->client, cmd);
> +}
> +
> +static int adm1177_write_reg(struct adm1177_state *st, u8 reg, u8 val)
> +{
> + return i2c_smbus_write_byte_data(st->client, reg, val);
These wrappers don't really add anything. I'd just make the i2c
calls directly inline. They will be self explanatory.
> +}
> +
> +static int adm1177_read_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan,
> + int *val,
> + int *val2,
> + long mask)
> +{
> + struct adm1177_state *st = iio_priv(indio_dev);
> + u8 data[3];
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_RAW:
> + adm1177_read(st, 3, data);
> + switch (chan->type) {
> + case IIO_VOLTAGE:
> + *val = (data[0] << 4) | (data[2] >> 4);
> + return IIO_VAL_INT;
> + case IIO_CURRENT:
> + *val = (data[1] << 4) | (data[2] & 0xF);
> + return IIO_VAL_INT;
> + default:
> + return -EINVAL;
> + }
> +
> + case IIO_CHAN_INFO_SCALE:
> + switch (chan->type) {
> + case IIO_VOLTAGE:
> + if (st->command & ADM1177_CMD_VRANGE)
> + *val = 6650;
> + else
> + *val = 26350;
> +
> + *val2 = ADM1177_BITS;
> + return IIO_VAL_FRACTIONAL_LOG2;
> + case IIO_CURRENT:
> + *val = 105840 / st->r_sense_uohm;
> +
> + *val2 = ADM1177_BITS;
> + return IIO_VAL_FRACTIONAL_LOG2;
> + default:
> + return -EINVAL;
> + }
> + default:
> + return -EINVAL;
> + }
> +}
> +
> +static const struct iio_chan_spec adm1177_channels[] = {
> + {
> + .type = IIO_VOLTAGE,
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
> + BIT(IIO_CHAN_INFO_SCALE),
> + .indexed = 1,
> + .channel = 0,
> + },
> + {
> + .type = IIO_CURRENT,
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
> + BIT(IIO_CHAN_INFO_SCALE),
> + .indexed = 1,
> + .channel = 0,
> + },
> +};
> +
> +static const struct iio_info adm1177_info = {
> + .read_raw = &adm1177_read_raw,
> +};
blank line here.
> +static void adm1177_remove(void *data)
> +{
> + struct adm1177_state *st = data;
> +
> + if (st->reg)
> + regulator_disable(st->reg);
Probe and remove should be mirror images of each other.
As you have a mixture of managed and non managed calls that
isn't the case here.
devm_add_action_or_reset will sort this out for you if
used to turn off the regulator at the right point on removal.
> +}
> +
> +static int adm1177_probe(struct i2c_client *client,
> + const struct i2c_device_id *id)
> +{
> + int ret;
> + struct device_node *np;
> + struct adm1177_state *st;
> + struct iio_dev *indio_dev;
> +
> + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*st));
> + if (!indio_dev)
> + return -ENOMEM;
> +
> + st = iio_priv(indio_dev);
> + i2c_set_clientdata(client, indio_dev);
> + st->client = client;
> +
> + np = client->dev.of_node;
> +
> + st->reg = devm_regulator_get_optional(&client->dev, "vref");
> + if (IS_ERR(st->reg)) {
> + if (PTR_ERR(st->reg) == EPROBE_DEFER)
> + return -EPROBE_DEFER;
> +
> + st->reg = NULL;
> + } else {
> + ret = regulator_enable(st->reg);
> + if (ret)
> + return ret;
> + ret = devm_add_action_or_reset(&client->dev, adm1177_remove,
> + st);
> + if (ret)
> + return ret;
> + }
> +
> + of_property_read_u32(np, "adi,r-sense-micro-ohms", &st->r_sense_uohm);
> + of_property_read_u32(np, "adi,shutdown-threshold-microamp",
> + &st->alert_threshold_ua);
> + st->vrange_high = of_property_read_bool(np,
> + "adi,vrange-high-enable");
> + if (st->alert_threshold_ua) {
> + unsigned int val;
> +
> + val = (st->alert_threshold_ua * st->r_sense_uohm * 0xFF);
> + val /= 105840000U;
> + if (val > 0xFF) {
> + dev_err(&client->dev,
> + "Requested shutdown current %d uA above limit\n",
> + st->alert_threshold_ua);
> +
> + val = 0xFF;
> + }
> + adm1177_write_reg(st, ADM1177_REG_ALERT_TH, val);
> + }
> +
> + adm1177_write_cmd(st, ADM1177_CMD_V_CONT |
> + ADM1177_CMD_I_CONT |
> + (st->vrange_high ? 0 : ADM1177_CMD_VRANGE));
> +
> + indio_dev->name = id->name;
> + indio_dev->channels = adm1177_channels;
> + indio_dev->num_channels = ARRAY_SIZE(adm1177_channels);
> +
> + indio_dev->dev.parent = &client->dev;
> + indio_dev->info = &adm1177_info;
> + indio_dev->modes = INDIO_DIRECT_MODE;
> +
> + return devm_iio_device_register(&client->dev, indio_dev);
> +}
> +
> +static const struct i2c_device_id adm1177_ids[] = {
> + { "adm1177", 0 },
> + {}
> +};
> +MODULE_DEVICE_TABLE(i2c, adm1177_ids);
> +
> +static const struct of_device_id adm1177_dt_ids[] = {
> + { .compatible = "adi,adm1177" },
> + {},
> +};
> +MODULE_DEVICE_TABLE(of, adm1177_dt_ids);
> +
> +static struct i2c_driver adm1177_driver = {
> + .driver = {
> + .name = "adm1177",
> + .of_match_table = adm1177_dt_ids,
> + },
> + .probe = adm1177_probe,
> + .id_table = adm1177_ids,
> +};
> +module_i2c_driver(adm1177_driver);
> +
> +MODULE_AUTHOR("Michael Hennerich <michael.hennerich at analog.com>");
> +MODULE_DESCRIPTION("Analog Devices ADM1177 ADC driver");
> +MODULE_LICENSE("GPL v2");
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