On Mon, Apr 19, 2021 at 12:12:51PM +0200, Erik Rosen wrote: > Add pmbus driver support for Maxim MAX15301 InTune Automatically > Compensated Digital PoL Controller with Driver and PMBus Telemetry > > Even though the specification does not specifically mention it, > extensive empirical testing has revealed that auto-detection of > limit-registers will fail in a random fashion unless the delay > parameter is set to above about 80us. The default delay is set > to 100us to include some safety margin. > > This patch is tested on a Flex BMR461 converter module. > > Signed-off-by: Erik Rosen <erik.ro...@metormote.com>
Applied. Note that I added above rationale to the driver header. > --- > Documentation/hwmon/index.rst | 1 + > Documentation/hwmon/max15301.rst | 87 +++++++++++++++ > MAINTAINERS | 7 ++ > drivers/hwmon/pmbus/Kconfig | 9 ++ > drivers/hwmon/pmbus/Makefile | 1 + > drivers/hwmon/pmbus/max15301.c | 183 +++++++++++++++++++++++++++++++ > 6 files changed, 288 insertions(+) > create mode 100644 Documentation/hwmon/max15301.rst > create mode 100644 drivers/hwmon/pmbus/max15301.c > > > base-commit: 1e28eed17697bcf343c6743f0028cc3b5dd88bf0 > > diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst > index 8d5a2df1ecb6..6583a1ea76cb 100644 > --- a/Documentation/hwmon/index.rst > +++ b/Documentation/hwmon/index.rst > @@ -112,6 +112,7 @@ Hardware Monitoring Kernel Drivers > ltc4260 > ltc4261 > max127 > + max15301 > max16064 > max16065 > max1619 > diff --git a/Documentation/hwmon/max15301.rst > b/Documentation/hwmon/max15301.rst > new file mode 100644 > index 000000000000..e3dc22fe1c6d > --- /dev/null > +++ b/Documentation/hwmon/max15301.rst > @@ -0,0 +1,87 @@ > +.. SPDX-License-Identifier: GPL-2.0 > + > +Kernel driver max15301 > +====================== > + > +Supported chips: > + > + * Maxim MAX15301 > + > + Prefix: 'max15301', 'bmr461' > + > + Addresses scanned: - > + > + Datasheet: https://datasheets.maximintegrated.com/en/ds/MAX15301.pdf > + > +Author: Erik Rosen <erik.ro...@metormote.com> > + > + > +Description > +----------- > + > +This driver supports hardware monitoring for Maxim MAX15301 controller chip > and > +compatible modules. > + > +The driver is a client driver to the core PMBus driver. Please see > +Documentation/hwmon/pmbus.rst and Documentation.hwmon/pmbus-core for details > +on PMBus client drivers. > + > + > +Usage Notes > +----------- > + > +This driver does not auto-detect devices. You will have to instantiate the > +devices explicitly. Please see Documentation/i2c/instantiating-devices.rst > for > +details. > + > + > +Platform data support > +--------------------- > + > +The driver supports standard PMBus driver platform data. > + > + > +Module parameters > +----------------- > + > +delay > +----- > + > +The controller requires a minimum interval between I2C bus accesses. > +The default interval is set to 100 us. For manual override, the driver > +provides a writeable module parameter, 'delay', which can be used to > +set the interval to a value between 0 and 65,535 microseconds. > + > + > +Sysfs entries > +------------- > + > +The following attributes are supported. Limits are read-write; all other > +attributes are read-only. > + > +======================= > ======================================================== > +in1_label "vin" > +in1_input Measured input voltage. > +in1_lcrit Critical minimum input voltage. > +in1_crit Critical maximum input voltage. > +in1_lcrit_alarm Input voltage critical low alarm. > +in1_crit_alarm Input voltage critical high alarm. > + > +in2_label "vout1" > +in2_input Measured output voltage. > +in2_lcrit Critical minimum output Voltage. > +in2_crit Critical maximum output voltage. > +in2_lcrit_alarm Critical output voltage critical low alarm. > +in2_crit_alarm Critical output voltage critical high alarm. > + > +curr1_label "iout1" > +curr1_input Measured output current. > +curr1_crit Critical maximum output current. > +curr1_crit_alarm Output current critical high alarm. > + > +temp1_input Measured maximum temperature of all phases. > +temp1_max Maximum temperature limit. > +temp1_max_alarm High temperature alarm. > +temp1_crit Critical maximum temperature limit. > +temp1_crit_alarm Critical maximum temperature alarm. > +======================= > ======================================================== > diff --git a/MAINTAINERS b/MAINTAINERS > index aa84121c5611..de2ad7223055 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -10790,6 +10790,13 @@ S: Orphan > F: drivers/video/fbdev/matrox/matroxfb_* > F: include/uapi/linux/matroxfb.h > > +MAX15301 DRIVER > +M: Daniel Nilsson <daniel.nils...@flex.com> > +L: linux-hw...@vger.kernel.org > +S: Maintained > +F: Documentation/hwmon/max15301.rst > +F: drivers/hwmon/pmbus/max15301.c > + > MAX16065 HARDWARE MONITOR DRIVER > M: Guenter Roeck <li...@roeck-us.net> > L: linux-hw...@vger.kernel.org > diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig > index 32d2fc850621..5c9fb1a88cec 100644 > --- a/drivers/hwmon/pmbus/Kconfig > +++ b/drivers/hwmon/pmbus/Kconfig > @@ -148,6 +148,15 @@ config SENSORS_LTC3815 > This driver can also be built as a module. If so, the module will > be called ltc3815. > > +config SENSORS_MAX15301 > + tristate "Maxim MAX15301" > + help > + If you say yes here you get hardware monitoring support for Maxim > + MAX15301, as well as for Flex BMR461. > + > + This driver can also be built as a module. If so, the module will > + be called max15301. > + > config SENSORS_MAX16064 > tristate "Maxim MAX16064" > help > diff --git a/drivers/hwmon/pmbus/Makefile b/drivers/hwmon/pmbus/Makefile > index 6a4ba0fdc1db..6040bc8718e9 100644 > --- a/drivers/hwmon/pmbus/Makefile > +++ b/drivers/hwmon/pmbus/Makefile > @@ -17,6 +17,7 @@ obj-$(CONFIG_SENSORS_ISL68137) += isl68137.o > obj-$(CONFIG_SENSORS_LM25066) += lm25066.o > obj-$(CONFIG_SENSORS_LTC2978) += ltc2978.o > obj-$(CONFIG_SENSORS_LTC3815) += ltc3815.o > +obj-$(CONFIG_SENSORS_MAX15301) += max15301.o > obj-$(CONFIG_SENSORS_MAX16064) += max16064.o > obj-$(CONFIG_SENSORS_MAX16601) += max16601.o > obj-$(CONFIG_SENSORS_MAX20730) += max20730.o > diff --git a/drivers/hwmon/pmbus/max15301.c b/drivers/hwmon/pmbus/max15301.c > new file mode 100644 > index 000000000000..eb9b7a5ef052 > --- /dev/null > +++ b/drivers/hwmon/pmbus/max15301.c > @@ -0,0 +1,183 @@ > +// SPDX-License-Identifier: GPL-2.0-or-later > +/* > + * Hardware monitoring driver for Maxim MAX15301 > + * > + * Copyright (c) 2021 Flextronics International Sweden AB > + */ > + > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/init.h> > +#include <linux/err.h> > +#include <linux/slab.h> > +#include <linux/i2c.h> > +#include <linux/ktime.h> > +#include <linux/delay.h> > +#include <linux/pmbus.h> > +#include "pmbus.h" > + > +static const struct i2c_device_id max15301_id[] = { > + {"bmr461", 0}, > + {"max15301", 0}, > + {} > +}; > +MODULE_DEVICE_TABLE(i2c, max15301_id); > + > +struct max15301_data { > + int id; > + ktime_t access; /* Chip access time */ > + int delay; /* Delay between chip accesses in us */ > + struct pmbus_driver_info info; > +}; > + > +#define to_max15301_data(x) container_of(x, struct max15301_data, info) > + > +#define MAX15301_WAIT_TIME 100 /* us */ > + > +static ushort delay = MAX15301_WAIT_TIME; > +module_param(delay, ushort, 0644); > +MODULE_PARM_DESC(delay, "Delay between chip accesses in us"); > + > +static struct max15301_data max15301_data = { > + .info = { > + .pages = 1, > + .func[0] = PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT > + | PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT > + | PMBUS_HAVE_TEMP | PMBUS_HAVE_TEMP2 > + | PMBUS_HAVE_STATUS_TEMP > + | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT, > + } > +}; > + > +/* This chip needs a delay between accesses */ > +static inline void max15301_wait(const struct max15301_data *data) > +{ > + if (data->delay) { > + s64 delta = ktime_us_delta(ktime_get(), data->access); > + > + if (delta < data->delay) > + udelay(data->delay - delta); > + } > +} > + > +static int max15301_read_word_data(struct i2c_client *client, int page, > + int phase, int reg) > +{ > + const struct pmbus_driver_info *info = pmbus_get_driver_info(client); > + struct max15301_data *data = to_max15301_data(info); > + int ret; > + > + if (page > 0) > + return -ENXIO; > + > + if (reg >= PMBUS_VIRT_BASE) > + return -ENXIO; > + > + max15301_wait(data); > + ret = pmbus_read_word_data(client, page, phase, reg); > + data->access = ktime_get(); > + > + return ret; > +} > + > +static int max15301_read_byte_data(struct i2c_client *client, int page, int > reg) > +{ > + const struct pmbus_driver_info *info = pmbus_get_driver_info(client); > + struct max15301_data *data = to_max15301_data(info); > + int ret; > + > + if (page > 0) > + return -ENXIO; > + > + max15301_wait(data); > + ret = pmbus_read_byte_data(client, page, reg); > + data->access = ktime_get(); > + > + return ret; > +} > + > +static int max15301_write_word_data(struct i2c_client *client, int page, int > reg, > + u16 word) > +{ > + const struct pmbus_driver_info *info = pmbus_get_driver_info(client); > + struct max15301_data *data = to_max15301_data(info); > + int ret; > + > + if (page > 0) > + return -ENXIO; > + > + if (reg >= PMBUS_VIRT_BASE) > + return -ENXIO; > + > + max15301_wait(data); > + ret = pmbus_write_word_data(client, page, reg, word); > + data->access = ktime_get(); > + > + return ret; > +} > + > +static int max15301_write_byte(struct i2c_client *client, int page, u8 value) > +{ > + const struct pmbus_driver_info *info = pmbus_get_driver_info(client); > + struct max15301_data *data = to_max15301_data(info); > + int ret; > + > + if (page > 0) > + return -ENXIO; > + > + max15301_wait(data); > + ret = pmbus_write_byte(client, page, value); > + data->access = ktime_get(); > + > + return ret; > +} > + > +static int max15301_probe(struct i2c_client *client) > +{ > + int status; > + u8 device_id[I2C_SMBUS_BLOCK_MAX + 1]; > + const struct i2c_device_id *mid; > + struct pmbus_driver_info *info = &max15301_data.info; > + > + if (!i2c_check_functionality(client->adapter, > + I2C_FUNC_SMBUS_READ_BYTE_DATA > + | I2C_FUNC_SMBUS_BLOCK_DATA)) > + return -ENODEV; > + > + status = i2c_smbus_read_block_data(client, PMBUS_IC_DEVICE_ID, > device_id); > + if (status < 0) { > + dev_err(&client->dev, "Failed to read Device Id\n"); > + return status; > + } > + for (mid = max15301_id; mid->name[0]; mid++) { > + if (!strncasecmp(mid->name, device_id, strlen(mid->name))) > + break; > + } > + if (!mid->name[0]) { > + dev_err(&client->dev, "Unsupported device\n"); > + return -ENODEV; > + } > + > + max15301_data.delay = delay; > + > + info->read_byte_data = max15301_read_byte_data; > + info->read_word_data = max15301_read_word_data; > + info->write_byte = max15301_write_byte; > + info->write_word_data = max15301_write_word_data; > + > + return pmbus_do_probe(client, info); > +} > + > +static struct i2c_driver max15301_driver = { > + .driver = { > + .name = "max15301", > + }, > + .probe_new = max15301_probe, > + .id_table = max15301_id, > +}; > + > +module_i2c_driver(max15301_driver); > + > +MODULE_AUTHOR("Erik Rosen <erik.ro...@metormote.com>"); > +MODULE_DESCRIPTION("PMBus driver for Maxim MAX15301"); > +MODULE_LICENSE("GPL");
