From: Nuno Sa <nuno.sa@xxxxxxxxxx>
The LTC4282 hot swap controller allows a board to be safely inserted and
removed from a live backplane. Using one or more external N-channel pass
transistors, board supply voltage and inrush current are ramped up at an
adjustable rate. An I2C interface and onboard ADC allows for monitoring
of board current, voltage, power, energy and fault status.
Signed-off-by: Nuno Sa <nuno.sa@xxxxxxxxxx>
---
Documentation/hwmon/index.rst | 1 +
Documentation/hwmon/ltc4282.rst | 108 +++
MAINTAINERS | 2 +
drivers/hwmon/Kconfig | 11 +
drivers/hwmon/Makefile | 1 +
drivers/hwmon/ltc4282.c | 1705 +++++++++++++++++++++++++++++++++++++++
6 files changed, 1828 insertions(+)
diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst
index 72f4e6065bae..389ced170802 100644
--- a/Documentation/hwmon/index.rst
+++ b/Documentation/hwmon/index.rst
@@ -128,6 +128,7 @@ Hardware Monitoring Kernel Drivers
ltc4245
ltc4260
ltc4261
+ ltc4282
max127
max15301
max16064
diff --git a/Documentation/hwmon/ltc4282.rst b/Documentation/hwmon/ltc4282.rst
new file mode 100644
index 000000000000..1dfd2e54b405
--- /dev/null
+++ b/Documentation/hwmon/ltc4282.rst
@@ -0,0 +1,108 @@
+.. SPDX-License-Identifier: GPL-2.0-only
+
+Kernel drivers ltc4282
+==========================================
+
+Supported chips:
+
+ * Analog Devices LTC4282
+
+ Prefix: 'ltc4282'
+
+ Addresses scanned: - I2C 0x40 - 0x5A (7-bit)
+ Addresses scanned: - I2C 0x80 - 0xB4 with a step of 2 (8-bit)
+
+ Datasheet:
+
+ https://www.analog.com/media/en/technical-documentation/data-sheets/ltc4282.pdf
+
+Author: Nuno Sá <nuno.sa@xxxxxxxxxx>
+
+Description
+___________
+
+The LTC4282 hot swap controller allows a board to be safely inserted and removed
+from a live backplane. Using one or more external N-channel pass transistors,
+board supply voltage and inrush current are ramped up at an adjustable rate. An
+I2C interface and onboard ADC allows for monitoring of board current, voltage,
+power, energy and fault status. The device features analog foldback current
+limiting and supply monitoring for applications from 2.9V to 33V. Dual 12V gate
+drive allows high power applications to either share safe operating area across
+parallel MOSFETs or support a 2-stage start-up that first charges the load
+capacitance followed by enabling a low on-resistance path to the load. The
+LTC4282 is well suited to high power applications because the precise monitoring
+capability and accurate current limiting reduce the extremes in which both loads
+and power supplies must safely operate. Non-volatile configuration allows for
+flexibility in the autonomous generation of alerts and response to faults.
+
+Sysfs entries
+_____________
+
+The following attributes are supported. Limits are read-write and all the other
+attributes are read-only. Note that in0 and in1 are mutually exclusive. Enabling
+one disables the other and disabling one enables the other.
+
+======================= ==========================================
+in0_input Output voltage (mV).
+in0_min Undervoltage threshold
+in0_max Overvoltage threshold
+in0_lowest Lowest measured voltage
+in0_highest Highest measured voltage
+in0_reset_history Write 1 to reset in0 history
+in0_min_alarm Undervoltage alarm
+in0_max_alarm Overvoltage alarm
+in0_enable Enable/Disable VSOURCE monitoring
+in0_label Channel label (VSOURCE)
+
+in1_input Input voltage (mV).
+in1_min Undervoltage threshold
+in1_max Overvoltage threshold
+in1_lowest Lowest measured voltage
+in1_highest Highest measured voltage
+in1_reset_history Write 1 to reset in1 history
+in1_min_alarm Undervoltage alarm
+in1_max_alarm Overvoltage alarm
+in1_lcrit_alarm Critical Undervoltage alarm
+in1_crit_alarm Critical Overvoltage alarm
+in1_enable Enable/Disable VDD monitoring
+in1_label Channel label (VDD)
+
+in2_input GPIO voltage (mV)
+in2_min Undervoltage threshold
+in2_max Overvoltage threshold
+in2_lowest Lowest measured voltage
+in2_highest Highest measured voltage
+in2_reset_history Write 1 to reset in2 history
+in2_min_alarm Undervoltage alarm
+in2_max_alarm Overvoltage alarm
+in2_label Channel label (VGPIO)
+
+curr1_input Sense current (mA)
+curr1_min Undercurrent threshold
+curr1_max Overcurrent threshold
+curr1_lowest Lowest measured current
+curr1_highest Highest measured current
+curr1_reset_history Write 1 to reset curr1 history
+curr1_min_alarm Undercurrent alarm
+curr1_max_alarm Overcurrent alarm
+curr1_crit_alarm Critical Overcurrent alarm
+curr1_label Channel label (ISENSE)
+
+power1_input Power (in uW)
+power1_min Low power threshold
+power1_max High power threshold
+power1_input_lowest Historical minimum power use
+power1_input_highest Historical maximum power use
+power1_reset_history Write 1 to reset power1 history
+power1_min_alarm Low power alarm
+power1_max_alarm High power alarm
+power1_good Power considered good
+power1_label Channel label (Power)
+
+energy1_input Measured energy over time (in microJoule)
+energy1_enable Enable/Disable Energy accumulation
+
+fet_short_fault FET short alarm
+fet_bad_fault FET bad alarm
+fault_logs_reset Clears all the Logged Faults
+======================= ==========================================
diff --git a/MAINTAINERS b/MAINTAINERS
index 1d209f226ffa..a03d85572c80 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -12641,6 +12641,8 @@ M: Nuno Sa <nuno.sa@xxxxxxxxxx>
L: linux-hwmon@xxxxxxxxxxxxxxx
S: Supported
F: Documentation/devicetree/bindings/hwmon/adi,ltc4282.yaml
+F: Documentation/hwmon/ltc4282.rst
+F: drivers/hwmon/ltc4282.c
LTC4306 I2C MULTIPLEXER DRIVER
M: Michael Hennerich <michael.hennerich@xxxxxxxxxx>
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index cf27523eed5a..2f1a0cf2e1e4 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -1027,6 +1027,17 @@ config SENSORS_LTC4261
This driver can also be built as a module. If so, the module will
be called ltc4261.
+config SENSORS_LTC4282
+ tristate "Analog Devices LTC4282"
+ depends on I2C
+ select REGMAP_I2C
+ help
+ If you say yes here you get support for Analog Devices LTC4282
+ High Current Hot Swap Controller I2C interface.
+
+ This driver can also be built as a module. If so, the module will
+ be called ltc4282.
+
config SENSORS_LTQ_CPUTEMP
bool "Lantiq cpu temperature sensor driver"
depends on SOC_XWAY
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index e84bd9685b5c..cbf22d1d736f 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -135,6 +135,7 @@ obj-$(CONFIG_SENSORS_LTC4222) += ltc4222.o
obj-$(CONFIG_SENSORS_LTC4245) += ltc4245.o
obj-$(CONFIG_SENSORS_LTC4260) += ltc4260.o
obj-$(CONFIG_SENSORS_LTC4261) += ltc4261.o
+obj-$(CONFIG_SENSORS_LTC4282) += ltc4282.o
obj-$(CONFIG_SENSORS_LTQ_CPUTEMP) += ltq-cputemp.o
obj-$(CONFIG_SENSORS_MAX1111) += max1111.o
obj-$(CONFIG_SENSORS_MAX127) += max127.o
diff --git a/drivers/hwmon/ltc4282.c b/drivers/hwmon/ltc4282.c
new file mode 100644
index 000000000000..6a5714d25664
--- /dev/null
+++ b/drivers/hwmon/ltc4282.c
@@ -0,0 +1,1705 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Analog Devices LTC4282 I2C High Current Hot Swap Controller over I2C
+ *
+ * Copyright 2023 Analog Devices Inc.
+ */
+#include <linux/bitfield.h>
+#include <linux/cleanup.h>
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/debugfs.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/i2c.h>
+#include <linux/math.h>
+#include <linux/minmax.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/mutex.h>
+#include <linux/regmap.h>
+#include <linux/property.h>
+#include <linux/string.h>
+#include <linux/units.h>
+#include <linux/util_macros.h>
+
+#define LTC4282_CTRL_LSB 0x00
+ #define LTC4282_CTRL_OV_RETRY_MASK BIT(0)
+ #define LTC4282_CTRL_UV_RETRY_MASK BIT(1)
+ #define LTC4282_CTRL_OC_RETRY_MASK BIT(2)
+ #define LTC4282_CTRL_ON_ACTIVE_LOW_MASK BIT(5)
+ #define LTC4282_CTRL_ON_DELAY_MASK BIT(6)
+#define LTC4282_CTRL_MSB 0x01
+ #define LTC4282_CTRL_VIN_MODE_MASK GENMASK(1, 0)
+ #define LTC4282_CTRL_OV_MODE_MASK GENMASK(3, 2)
+ #define LTC4282_CTRL_UV_MODE_MASK GENMASK(5, 4)
+#define LTC4282_FAULT_LOG 0x04
+ #define LTC4282_OV_FAULT_MASK BIT(0)
+ #define LTC4282_UV_FAULT_MASK BIT(1)
+ #define LTC4282_OC_FAULT_MASK BIT(2)
+ #define LTC4282_POWER_BAD_FAULT_MASK BIT(3)
+ #define LTC4282_FET_SHORT_FAULT_MASK BIT(5)
+ #define LTC4282_FET_BAD_FAULT_MASK BIT(6)
+#define LTC4282_ADC_ALERT_LOG 0x05
+ #define LTC4282_GPIO_ALARM_L_MASK BIT(0)
+ #define LTC4282_GPIO_ALARM_H_MASK BIT(1)
+ #define LTC4282_VSOURCE_ALARM_L_MASK BIT(2)
+ #define LTC4282_VSOURCE_ALARM_H_MASK BIT(3)
+ #define LTC4282_VSENSE_ALARM_L_MASK BIT(4)
+ #define LTC4282_VSENSE_ALARM_H_MASK BIT(5)
+ #define LTC4282_POWER_ALARM_L_MASK BIT(6)
+ #define LTC4282_POWER_ALARM_H_MASK BIT(7)
+#define LTC4282_FET_BAD_FAULT_TIMEOUT 0x06
+ #define LTC4282_FET_BAD_MAX_TIMEOUT 255
+#define LTC4282_GPIO_CONFIG 0x07
+ #define LTC4282_GPIO_2_FET_STRESS_MASK BIT(1)
+ #define LTC4282_GPIO_1_CONFIG_MASK GENMASK(5, 4)
+#define LTC4282_VGPIO_MIN 0x08
+#define LTC4282_VGPIO_MAX 0x09
+#define LTC4282_VSOURCE_MIN 0x0a
+#define LTC4282_VSOURCE_MAX 0x0b
+#define LTC4282_VSENSE_MIN 0x0c
+#define LTC4282_VSENSE_MAX 0x0d
+#define LTC4282_POWER_MIN 0x0e
+#define LTC4282_POWER_MAX 0x0f
+#define LTC4282_CLK_DIV 0x10
+ #define LTC4282_CLK_DIV_MASK GENMASK(4, 0)
+ #define LTC4282_CLKOUT_MASK GENMASK(6, 5)
+#define LTC4282_ILIM_ADJUST 0x11
+ #define LTC4282_GPIO_MODE_MASK BIT(1)
+ #define LTC4282_VDD_MONITOR_MASK BIT(2)
+ #define LTC4282_FOLDBACK_MODE_MASK GENMASK(4, 3)
+ #define LTC4282_ILIM_ADJUST_MASK GENMASK(7, 5)
+#define LTC4282_ENERGY 0x12
+#define LTC4282_TIME_COUNTER 0x18
+#define LTC4282_ALERT_CTRL 0x1c
+ #define LTC4282_ALERT_OUT_MASK BIT(6)
+#define LTC4282_ADC_CTRL 0x1d
+ #define LTC4282_FAULT_LOG_EN_MASK BIT(2)
+ #define LTC4282_METER_HALT_MASK BIT(5)
+ #define LTC4282_METER_RESET_MASK BIT(6)
+ #define LTC4282_RESET_MASK BIT(7)
+#define LTC4282_STATUS_LSB 0x1e
+ #define LTC4282_OV_STATUS_MASK BIT(0)
+ #define LTC4282_UV_STATUS_MASK BIT(1)
+ #define LTC4282_VDD_STATUS_MASK \
+ (LTC4282_OV_STATUS_MASK | LTC4282_UV_STATUS_MASK)
+ #define LTC4282_OC_STATUS_MASK BIT(2)
+ #define LTC4282_POWER_GOOD_MASK BIT(3)
+ #define LTC4282_FET_SHORT_MASK BIT(5)
+ #define LTC4282_FET_BAD_STATUS_MASK BIT(6)
+#define LTC4282_STATUS_MSB 0x1f
+#define LTC4282_RESERVED_1 0x32
+#define LTC4282_RESERVED_2 0x33
+#define LTC4282_VGPIO 0x34
+#define LTC4282_VGPIO_LOWEST 0x36
+#define LTC4282_VGPIO_HIGHEST 0x38
+#define LTC4282_VSOURCE 0x3a
+#define LTC4282_VSOURCE_LOWEST 0x3c
+#define LTC4282_VSOURCE_HIGHEST 0x3e
+#define LTC4282_VSENSE 0x40
+#define LTC4282_VSENSE_LOWEST 0x42
+#define LTC4282_VSENSE_HIGHEST 0x44
+#define LTC4282_POWER 0x46
+#define LTC4282_POWER_LOWEST 0x48
+#define LTC4282_POWER_HIGHEST 0x4a
+#define LTC4282_RESERVED_3 0x50
+
+#define LTC4282_CLKIN_MIN (250 * KILO)
+#define LTC4282_CLKIN_MAX (15500 * KILO)
+#define LTC4282_CLKIN_RANGE (LTC4282_CLKIN_MAX - LTC4282_CLKIN_MIN + 1)
+#define LTC4282_CLKOUT_SYSTEM (250 * KILO)
+#define LTC4282_CLKOUT_CNV 15
+
+enum {
+ LTC4282_CHAN_VSOURCE,
+ LTC4282_CHAN_VDD,
+ LTC4282_CHAN_VGPIO,
+};
+
+struct ltc4282_cache {
+ u32 in_max_raw;
+ u32 in_min_raw;
+ long in_highest;
+ long in_lowest;
+ bool en;
+};
+
+struct ltc4282_state {
+ struct regmap *map;
+ /* Protect against multiple accesses to the device registers */
+ struct mutex lock;
+ struct clk_hw clk_hw;
+ /*
+ * Used to cache values for VDD/VSOURCE depending which will be used
+ * when hwmon is not enabled for that channel. Needed because they share
+ * the same registers.
+ */
+ struct ltc4282_cache in0_1_cache[LTC4282_CHAN_VGPIO];
+ long power_max;
+ u32 rsense;
+ u32 vin_mode;
+ u16 vfs_out;
+ bool energy_en;
+};
+
+enum {
+ LTC4282_VIN_3_3V,
+ LTC4282_VIN_5V,
+ LTC4282_VIN_12V,
+ LTC4282_VIN_24V,
+};
+
+enum {
+ LTC4282_CLKOUT_NONE,
+ LTC4282_CLKOUT_INT,
+ LTC4282_CLKOUT_TICK,
+};
+
+static int ltc4282_set_rate(struct clk_hw *hw,
+ unsigned long rate, unsigned long parent_rate)
+{
+ struct ltc4282_state *st = container_of(hw, struct ltc4282_state,
+ clk_hw);
+ u32 val = LTC4282_CLKOUT_INT;
+
+ if (rate == LTC4282_CLKOUT_CNV)
+ val = LTC4282_CLKOUT_TICK;
+
+ return regmap_update_bits(st->map, LTC4282_CLK_DIV, LTC4282_CLKOUT_MASK,
+ FIELD_PREP(LTC4282_CLKOUT_MASK, val));
+}
+
+/*
+ * Note the 15HZ conversion rate assumes 12bit ADC which is what we are
+ * supporting for now.
+ */
+static unsigned int ltc4282_out_rates[] = {
+ LTC4282_CLKOUT_CNV, LTC4282_CLKOUT_SYSTEM
+};
+
+static long ltc4282_round_rate(struct clk_hw *hw, unsigned long rate,
+ unsigned long *parent_rate)
+{
+ int idx = find_closest(rate, ltc4282_out_rates,
+ ARRAY_SIZE(ltc4282_out_rates));
+
+ return ltc4282_out_rates[idx];
+}
+
+static unsigned long ltc4282_recalc_rate(struct clk_hw *hw,
+ unsigned long parent)
+{
+ struct ltc4282_state *st = container_of(hw, struct ltc4282_state,
+ clk_hw);
+ u32 clkdiv;
+ int ret;
+
+ ret = regmap_read(st->map, LTC4282_CLK_DIV, &clkdiv);
+ if (ret)
+ return 0;
+
+ clkdiv = FIELD_GET(LTC4282_CLKOUT_MASK, clkdiv);
+ if (!clkdiv)
+ return 0;
+ if (clkdiv == LTC4282_CLKOUT_INT)
+ return LTC4282_CLKOUT_SYSTEM;
+
+ return LTC4282_CLKOUT_CNV;
+}
+
+static void ltc4282_disable(struct clk_hw *clk_hw)
+{
+ struct ltc4282_state *st = container_of(clk_hw, struct ltc4282_state,
+ clk_hw);
+
+ regmap_clear_bits(st->map, LTC4282_CLK_DIV, LTC4282_CLKOUT_MASK);
+}
+
+static int ltc4282_read_voltage_word(const struct ltc4282_state *st, u32 reg,
+ u32 fs, long *val)
+{
+ __be16 in;
+ int ret;
+
+ ret = regmap_bulk_read(st->map, reg, &in, sizeof(in));
+ if (ret)
+ return ret;
+
+ /*
+ * This is also used to calculate current in which case fs comes in
+ * 10 * uV. Hence the ULL usage.
+ */
+ *val = DIV_ROUND_CLOSEST_ULL(be16_to_cpu(in) * (u64)fs, U16_MAX);
+ return 0;
+}
+
+static int ltc4282_read_voltage_byte_cached(const struct ltc4282_state *st,
+ u32 reg, u32 fs, long *val,
+ u32 *cached_raw)
+{
+ int ret;
+ u32 in;
+
+ if (cached_raw) {
+ in = *cached_raw;
+ } else {
+ ret = regmap_read(st->map, reg, &in);
+ if (ret)
+ return ret;
+ }
+
+ *val = DIV_ROUND_CLOSEST(in * fs, U8_MAX);
+ return 0;
+}
+
+static int ltc4282_read_voltage_byte(const struct ltc4282_state *st, u32 reg,
+ u32 fs, long *val)
+{
+ return ltc4282_read_voltage_byte_cached(st, reg, fs, val, NULL);
+}
+
+static int __ltc4282_read_alarm(struct ltc4282_state *st, u32 reg, u32 mask,
+ long *val)
+{
+ u32 alarm;
+ int ret;
+
+ ret = regmap_read(st->map, reg, &alarm);
+ if (ret)
+ return ret;
+
+ *val = !!(alarm & mask);
+
+ /* if not status/fault logs, clear the alarm after reading it */
+ if (reg != LTC4282_STATUS_LSB && reg != LTC4282_FAULT_LOG)
+ return regmap_clear_bits(st->map, reg, mask);
+
+ return 0;
+}
+
+static int ltc4282_read_alarm(struct ltc4282_state *st, u32 reg, u32 mask,
+ long *val)
+{
+ guard(mutex)(&st->lock);
+ return __ltc4282_read_alarm(st, reg, mask, val);
+}
+
+static int ltc4282_vdd_source_read_in(struct ltc4282_state *st, u32 channel,
+ long *val)
+{
+ guard(mutex)(&st->lock);
+ if (!st->in0_1_cache[channel].en)
+ return -ENODATA;
+
+ return ltc4282_read_voltage_word(st, LTC4282_VSOURCE, st->vfs_out, val);
+}
+
+static int ltc4282_vdd_source_read_hist(struct ltc4282_state *st, u32 reg,
+ u32 channel, long *cached, long *val)
+{
+ int ret;
+
+ guard(mutex)(&st->lock);
+ if (!st->in0_1_cache[channel].en) {
+ *val = *cached;
+ return 0;
+ }
+
+ ret = ltc4282_read_voltage_word(st, reg, st->vfs_out, val);
+ if (ret)
+ return ret;
+
+ *cached = *val;
+ return 0;
+}
+
+static int ltc4282_vdd_source_read_lim(struct ltc4282_state *st, u32 reg,
+ u32 channel, u32 *cached, long *val)
+{
+ guard(mutex)(&st->lock);
+ if (!st->in0_1_cache[channel].en)
+ return ltc4282_read_voltage_byte_cached(st, reg, st->vfs_out,
+ val, cached);
+
+ return ltc4282_read_voltage_byte(st, reg, st->vfs_out, val);
+}
+
+static int ltc4282_vdd_source_read_alm(struct ltc4282_state *st, u32 mask,
+ u32 channel, long *val)
+{
+ guard(mutex)(&st->lock);
+ if (!st->in0_1_cache[channel].en) {
+ /*
+ * Do this otherwise alarms can get confused because we clear
+ * them after reading them. So, if someone mistakenly reads
+ * VSOURCE right before VDD (or the other way around), we might
+ * get no alarm just because it was cleared when reading VSOURCE
+ * and had no time for a new conversion and thus having the
+ * alarm again.
+ */
+ *val = 0;
+ return 0;
+ }
+
+ return __ltc4282_read_alarm(st, LTC4282_ADC_ALERT_LOG, mask, val);
+}
+
+static int ltc4282_read_in(struct ltc4282_state *st, u32 attr, long *val,
+ u32 channel)
+{
+ switch (attr) {
+ case hwmon_in_input:
+ if (channel == LTC4282_CHAN_VGPIO)
+ return ltc4282_read_voltage_word(st, LTC4282_VGPIO,
+ 1280, val);
+
+ return ltc4282_vdd_source_read_in(st, channel, val);
+ case hwmon_in_highest:
+ if (channel == LTC4282_CHAN_VGPIO)
+ return ltc4282_read_voltage_word(st,
+ LTC4282_VGPIO_HIGHEST,
+ 1280, val);
+
+ return ltc4282_vdd_source_read_hist(st, LTC4282_VSOURCE_HIGHEST,
+ channel,
+ &st->in0_1_cache[channel].in_highest, val);
+ case hwmon_in_lowest:
+ if (channel == LTC4282_CHAN_VGPIO)
+ ltc4282_read_voltage_word(st, LTC4282_VGPIO_LOWEST,
+ 1280, val);
+
+ return ltc4282_vdd_source_read_hist(st, LTC4282_VSOURCE_LOWEST,
+ channel,
+ &st->in0_1_cache[channel].in_lowest, val);
+ case hwmon_in_max_alarm:
+ if (channel == LTC4282_CHAN_VGPIO)
+ return ltc4282_read_alarm(st, LTC4282_ADC_ALERT_LOG,
+ LTC4282_GPIO_ALARM_H_MASK,
+ val);
+
+ return ltc4282_vdd_source_read_alm(st,
+ LTC4282_VSOURCE_ALARM_H_MASK,
+ channel, val);
+ case hwmon_in_min_alarm:
+ if (channel == LTC4282_CHAN_VGPIO)
+ ltc4282_read_alarm(st, LTC4282_ADC_ALERT_LOG,
+ LTC4282_GPIO_ALARM_L_MASK, val);
+
+ return ltc4282_vdd_source_read_alm(st,
+ LTC4282_VSOURCE_ALARM_L_MASK,
+ channel, val);
+ case hwmon_in_crit_alarm:
+ return ltc4282_read_alarm(st, LTC4282_STATUS_LSB,
+ LTC4282_OV_STATUS_MASK, val);
+ case hwmon_in_lcrit_alarm:
+ return ltc4282_read_alarm(st, LTC4282_STATUS_LSB,
+ LTC4282_UV_STATUS_MASK, val);
+ case hwmon_in_max:
+ if (channel == LTC4282_CHAN_VGPIO)
+ return ltc4282_read_voltage_byte(st, LTC4282_VGPIO_MAX,
+ 1280, val);
+
+ return ltc4282_vdd_source_read_lim(st, LTC4282_VSOURCE_MAX,
+ channel,
+ &st->in0_1_cache[channel].in_max_raw, val);
+ case hwmon_in_min:
+ if (channel == LTC4282_CHAN_VGPIO)
+ return ltc4282_read_voltage_byte(st, LTC4282_VGPIO_MIN,
+ 1280, val);
+
+ return ltc4282_vdd_source_read_lim(st, LTC4282_VSOURCE_MIN,
+ channel,
+ &st->in0_1_cache[channel].in_min_raw, val);
+ case hwmon_in_enable:
+ scoped_guard(mutex, &st->lock) {
+ *val = st->in0_1_cache[channel].en;
+ }
+ return 0;
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
+static int ltc4282_read_current_word(const struct ltc4282_state *st, u32 reg,
+ long *val)
+{
+ long in;
+ int ret;
+
+ /*
+ * We pass in full scale in 10 * micro (note that 40 is already
+ * millivolt) so we have better approximations to calculate current.
+ */
+ ret = ltc4282_read_voltage_word(st, reg, DECA * 40 * MILLI, &in);
+ if (ret)
+ return ret;
+
+ *val = DIV_ROUND_CLOSEST(in * MILLI, st->rsense);
+
+ return 0;
+}
+
+static int ltc4282_read_current_byte(const struct ltc4282_state *st, u32 reg,
+ long *val)
+{
+ long in;
+ int ret;
+
+ ret = ltc4282_read_voltage_byte(st, reg, DECA * 40 * MILLI, &in);
+ if (ret)
+ return ret;
+
+ *val = DIV_ROUND_CLOSEST(in * MILLI, st->rsense);
+
+ return 0;
+}
+
+static int ltc4282_read_curr(struct ltc4282_state *st, const u32 attr,
+ long *val)
+{
+ switch (attr) {
+ case hwmon_curr_input:
+ return ltc4282_read_current_word(st, LTC4282_VSENSE, val);
+ case hwmon_curr_highest:
+ return ltc4282_read_current_word(st, LTC4282_VSENSE_HIGHEST,
+ val);
+ case hwmon_curr_lowest:
+ return ltc4282_read_current_word(st, LTC4282_VSENSE_LOWEST,
+ val);
+ case hwmon_curr_max:
+ return ltc4282_read_current_byte(st, LTC4282_VSENSE_MAX, val);
+ case hwmon_curr_min:
+ return ltc4282_read_current_byte(st, LTC4282_VSENSE_MIN, val);
+ case hwmon_curr_max_alarm:
+ return ltc4282_read_alarm(st, LTC4282_ADC_ALERT_LOG,
+ LTC4282_VSENSE_ALARM_H_MASK, val);
+ case hwmon_curr_min_alarm:
+ return ltc4282_read_alarm(st, LTC4282_ADC_ALERT_LOG,
+ LTC4282_VSENSE_ALARM_L_MASK, val);
+ case hwmon_curr_crit_alarm:
+ return ltc4282_read_alarm(st, LTC4282_STATUS_LSB,
+ LTC4282_OC_STATUS_MASK, val);
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
+static int ltc4282_read_power_word(const struct ltc4282_state *st, u32 reg,
+ long *val)
+{
+ u64 temp = DECA * 40ULL * st->vfs_out * BIT(16), temp_2;
+ __be16 raw;
+ u16 power;
+ int ret;
+
+ ret = regmap_bulk_read(st->map, reg, &raw, sizeof(raw));
+ if (ret)
+ return ret;
+
+ power = be16_to_cpu(raw);
+ /*
+ * Power is given by:
+ * P = CODE(16b) * 0.040 * Vfs(out) * 2^16 / ((2^16 - 1)^2 * Rsense)
+ */
+ if (check_mul_overflow(power * temp, MICRO, &temp_2)) {
+ temp = DIV_ROUND_CLOSEST_ULL(power * temp, U16_MAX);
+ *val = DIV64_U64_ROUND_CLOSEST(temp * MICRO,
+ U16_MAX * (u64)st->rsense);
+ return 0;
+ }
+
+ *val = DIV64_U64_ROUND_CLOSEST(temp_2,
+ st->rsense * int_pow(U16_MAX, 2));
+
+ return 0;
+}
+
+static int ltc4282_read_power_byte(const struct ltc4282_state *st, u32 reg,
+ long *val)
+{
+ u32 power;
+ u64 temp;
+ int ret;
+
+ ret = regmap_read(st->map, reg, &power);
+ if (ret)
+ return ret;
+
+ temp = power * 40 * DECA * st->vfs_out * BIT_ULL(8);
+ *val = DIV64_U64_ROUND_CLOSEST(temp * MICRO,
+ int_pow(U8_MAX, 2) * st->rsense);
+
+ return 0;
+}
+
+static int ltc4282_read_energy(const struct ltc4282_state *st, u64 *val)
+{
+ u64 temp, energy;
+ __be64 raw;
+ int ret;
+
+ ret = regmap_bulk_read(st->map, LTC4282_ENERGY, &raw, 6);
+ if (ret)
+ return ret;
+
+ energy = be64_to_cpu(raw) >> 16;
+ /*
+ * The formula for energy is given by:
+ * E = CODE(48b) * 0.040 * Vfs(out) * Tconv * 256 /
+ * ((2^16 - 1)^2 * Rsense)
+ *
+ * Since we only support 12bit ADC, Tconv = 0.065535s. Passing Vfs(out)
+ * and 0.040 to mV and Tconv to us, we can simplify the formula to:
+ * E = CODE(48b) * 40 * Vfs(out) * 256 / (U16_MAX * Rsense)
+ *
+ * As Rsense can have tenths of micro-ohm resolution, we need to
+ * multiply by DECA to get microujoule.
+ */
+ if (check_mul_overflow(DECA * st->vfs_out * 40 * BIT(8), energy, &temp)) {
+ temp = DIV_ROUND_CLOSEST(DECA * st->vfs_out * 40 * BIT(8), U16_MAX);
+ *val = DIV_ROUND_CLOSEST_ULL(temp * energy, st->rsense);
+ return 0;
+ }
+
+ *val = DIV64_U64_ROUND_CLOSEST(temp, U16_MAX * (u64)st->rsense);
+
+ return 0;
+}
+
+static int ltc4282_read_power(struct ltc4282_state *st, const u32 attr,
+ long *val)
+{
+ switch (attr) {
+ case hwmon_power_input:
+ return ltc4282_read_power_word(st, LTC4282_POWER, val);
+ case hwmon_power_input_highest:
+ return ltc4282_read_power_word(st, LTC4282_POWER_HIGHEST, val);
+ case hwmon_power_input_lowest:
+ return ltc4282_read_power_word(st, LTC4282_POWER_LOWEST, val);
+ case hwmon_power_max_alarm:
+ return ltc4282_read_alarm(st, LTC4282_ADC_ALERT_LOG,
+ LTC4282_POWER_ALARM_H_MASK, val);
+ case hwmon_power_min_alarm:
+ return ltc4282_read_alarm(st, LTC4282_ADC_ALERT_LOG,
+ LTC4282_POWER_ALARM_L_MASK, val);
+ case hwmon_power_max:
+ return ltc4282_read_power_byte(st, LTC4282_POWER_MAX, val);
+ case hwmon_power_min:
+ return ltc4282_read_power_byte(st, LTC4282_POWER_MIN, val);
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
+static int ltc4282_read(struct device *dev, enum hwmon_sensor_types type,
+ u32 attr, int channel, long *val)
+{
+ struct ltc4282_state *st = dev_get_drvdata(dev);
+
+ switch (type) {
+ case hwmon_in:
+ return ltc4282_read_in(st, attr, val, channel);
+ case hwmon_curr:
+ return ltc4282_read_curr(st, attr, val);
+ case hwmon_power:
+ return ltc4282_read_power(st, attr, val);
+ case hwmon_energy:
+ scoped_guard(mutex, &st->lock) {
+ *val = st->energy_en;
+ }
+ return 0;
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
+static int ltc4282_write_power_byte(const struct ltc4282_state *st, u32 reg,
+ long val)
+{
+ u32 power;
+ u64 temp;
+
+ if (val > st->power_max)
+ val = st->power_max;
+
+ temp = val * int_pow(U8_MAX, 2) * st->rsense;
+ power = DIV64_U64_ROUND_CLOSEST(temp,
+ MICRO * DECA * 256ULL * st->vfs_out * 40);
+
+ return regmap_write(st->map, reg, power);
+}
+
+static int __ltc4282_write_history(const struct ltc4282_state *st, u32 reg,
+ long lowest, long highest)
+{
+ __be16 __raw;
+ u16 tmp;
+ int ret;
+
+ tmp = DIV_ROUND_CLOSEST(U16_MAX * lowest, st->vfs_out);
+
+ __raw = cpu_to_be16(tmp);
+
+ ret = regmap_bulk_write(st->map, reg, &__raw, 2);
+ if (ret)
+ return ret;
+
+ tmp = DIV_ROUND_CLOSEST(U16_MAX * highest, st->vfs_out);
+
+ __raw = cpu_to_be16(tmp);
+
+ return regmap_bulk_write(st->map, reg + 2, &__raw, 2);
+}
+
+static int ltc4282_write_history(struct ltc4282_state *st, u32 reg, long lowest,
+ long highest)
+{
+ guard(mutex)(&st->lock);
+ return __ltc4282_write_history(st, reg, lowest, highest);
+}
+
+static int ltc4282_write_power(struct ltc4282_state *st, u32 attr,
+ long val)
+{
+ switch (attr) {
+ case hwmon_power_max:
+ return ltc4282_write_power_byte(st, LTC4282_POWER_MAX, val);
+ case hwmon_power_min:
+ return ltc4282_write_power_byte(st, LTC4282_POWER_MIN, val);
+ case hwmon_power_reset_history:
+ return ltc4282_write_history(st, LTC4282_POWER_LOWEST, 0, 0);
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
+static int ltc4282_write_voltage_byte_cached(const struct ltc4282_state *st,
+ u32 reg, u32 fs, long val,
+ u32 *cache_raw)
+{
+ u32 in;
+
+ if (val >= fs)
+ in = U8_MAX;
+ else
+ in = DIV_ROUND_CLOSEST(val * U8_MAX, fs);
+
+ if (cache_raw) {
+ *cache_raw = in;
+ return 0;
+ }
+
+ return regmap_write(st->map, reg, in);
+}
+
+static int ltc4282_write_voltage_byte(const struct ltc4282_state *st, u32 reg,
+ u32 fs, long val)
+{
+ return ltc4282_write_voltage_byte_cached(st, reg, fs, val, NULL);
+}
+
+static int ltc4282_cache_history(struct ltc4282_state *st, u32 channel)
+{
+ long val;
+ int ret;
+
+ ret = ltc4282_read_voltage_word(st, LTC4282_VSOURCE_LOWEST, st->vfs_out,
+ &val);
+ if (ret)
+ return ret;
+
+ st->in0_1_cache[channel].in_lowest = val;
+
+ ret = ltc4282_read_voltage_word(st, LTC4282_VSOURCE_HIGHEST,
+ st->vfs_out, &val);
+ if (ret)
+ return ret;
+
+ st->in0_1_cache[channel].in_highest = val;
+
+ ret = regmap_read(st->map, LTC4282_VSOURCE_MIN,
+ &st->in0_1_cache[channel].in_min_raw);
+ if (ret)
+ return ret;
+
+ return regmap_read(st->map, LTC4282_VSOURCE_MAX,
+ &st->in0_1_cache[channel].in_max_raw);
+}
+
+static int ltc4282_cache_sync(struct ltc4282_state *st, u32 channel)
+{
+ int ret;
+
+ ret = __ltc4282_write_history(st, LTC4282_VSOURCE_LOWEST,
+ st->in0_1_cache[channel].in_lowest,
+ st->in0_1_cache[channel].in_highest);
+ if (ret)
+ return ret;
+
+ ret = regmap_write(st->map, LTC4282_VSOURCE_MIN,
+ st->in0_1_cache[channel].in_min_raw);
+
+ return regmap_write(st->map, LTC4282_VSOURCE_MAX,
+ st->in0_1_cache[channel].in_max_raw);
+}
+
+static int ltc4282_vdd_source_write_lim(struct ltc4282_state *st, u32 reg,
+ int channel, u32 *cache, long val)
+{
+ int ret;
+
+ guard(mutex)(&st->lock);
+ if (st->in0_1_cache[channel].en)
+ ret = ltc4282_write_voltage_byte(st, reg, st->vfs_out, val);
+ else
+ ret = ltc4282_write_voltage_byte_cached(st, reg, st->vfs_out,
+ val, cache);
+
+ return ret;
+}
+
+static int ltc4282_vdd_source_write_hist(struct ltc4282_state *st, int channel)
+{
+ int ret;
+
+ guard(mutex)(&st->lock);
+ if (st->in0_1_cache[channel].en) {
+ ret = __ltc4282_write_history(st, LTC4282_VSOURCE_LOWEST, 0, 0);
+ if (ret)
+ return ret;
+ }
+
+ st->in0_1_cache[channel].in_lowest = 0;
+ st->in0_1_cache[channel].in_highest = 0;
+
+ return 0;
+}
+
+/*
+ * We need to mux between VSOURCE and VDD which means they are mutually
+ * exclusive. Moreover, we can't really disable both VDD and VSOURCE as the ADC
+ * is continuously running (we cannot independently halt it without also
+ * stopping VGPIO). Hence, the logic is that disabling or enabling VDD will
+ * automatically have the reverse effect on VSOURCE and vice-versa.
+ */
+static int ltc4282_vdd_source_enable(struct ltc4282_state *st, int channel,
+ long val)
+{
+ int ret, other_chan = ~channel & 0x1;
+ u8 __val = val;
+
+ guard(mutex)(&st->lock);
+ if (st->in0_1_cache[channel].en == !!val)
+ return 0;
+
+ /* clearing the bit makes the ADC to monitor VDD */
+ if (channel == LTC4282_CHAN_VDD)
+ __val = !__val;
+
+ ret = regmap_update_bits(st->map, LTC4282_ILIM_ADJUST,
+ LTC4282_VDD_MONITOR_MASK,
+ FIELD_PREP(LTC4282_VDD_MONITOR_MASK, !!__val));
+ if (ret)
+ return ret;
+
+ st->in0_1_cache[channel].en = !!val;
+ st->in0_1_cache[other_chan].en = !val;
+
+ if (st->in0_1_cache[channel].en) {
+ /*
+ * Then, we are disabling @other_chan. Let's save it's current
+ * history.
+ */
+ ret = ltc4282_cache_history(st, other_chan);
+ if (ret)
+ return ret;
+
+ return ltc4282_cache_sync(st, channel);
+ }
+ /*
+ * Then, we are enabling @other_chan. We need to do the opposite from
+ * above.
+ */
+ ret = ltc4282_cache_history(st, channel);
+ if (ret)
+ return ret;
+
+ return ltc4282_cache_sync(st, other_chan);
+}
+
+static int ltc4282_write_in(struct ltc4282_state *st, u32 attr, long val,
+ int channel)
+{
+ switch (attr) {
+ case hwmon_in_max:
+ if (channel == LTC4282_CHAN_VGPIO)
+ return ltc4282_write_voltage_byte(st, LTC4282_VGPIO_MAX,
+ 1280, val);
+
+ return ltc4282_vdd_source_write_lim(st, LTC4282_VSOURCE_MAX,
+ channel,
+ &st->in0_1_cache[channel].in_max_raw, val);
+ case hwmon_in_min:
+ if (channel == LTC4282_CHAN_VGPIO)
+ return ltc4282_write_voltage_byte(st, LTC4282_VGPIO_MIN,
+ 1280, val);
+
+ return ltc4282_vdd_source_write_lim(st, LTC4282_VSOURCE_MIN,
+ channel,
+ &st->in0_1_cache[channel].in_min_raw, val);
+ case hwmon_in_reset_history:
+ if (channel == LTC4282_CHAN_VGPIO)
+ return ltc4282_write_history(st, LTC4282_VGPIO_LOWEST,
+ 0, 0);
+
+ return ltc4282_vdd_source_write_hist(st, channel);
+ case hwmon_in_enable:
+ return ltc4282_vdd_source_enable(st, channel, val);
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
+static int ltc4282_write_curr(struct ltc4282_state *st, u32 attr,
+ long val)
+{
+ /* need to pass it in millivolt */
+ u32 in = DIV_ROUND_CLOSEST_ULL((u64)val * st->rsense, DECA * MICRO);
+
+ switch (attr) {
+ case hwmon_curr_max:
+ return ltc4282_write_voltage_byte(st, LTC4282_VSENSE_MAX, 40,
+ in);
+ case hwmon_curr_min:
+ return ltc4282_write_voltage_byte(st, LTC4282_VSENSE_MIN, 40,
+ in);
+ case hwmon_curr_reset_history:
+ return ltc4282_write_history(st, LTC4282_VSENSE_LOWEST, 0, 0);
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
+static int ltc4282_energy_enable_set(struct ltc4282_state *st, long val)
+{
+ int ret;
+
+ guard(mutex)(&st->lock);
+ /* setting the bit halts the meter */
+ ret = regmap_update_bits(st->map, LTC4282_ADC_CTRL,
+ LTC4282_METER_HALT_MASK,
+ FIELD_PREP(LTC4282_METER_HALT_MASK, !val));
+ if (ret)
+ return ret;
+
+ st->energy_en = !!val;
+
+ return 0;
+}
+
+static int ltc4282_write(struct device *dev,
+ enum hwmon_sensor_types type,
+ u32 attr, int channel, long val)
+{
+ struct ltc4282_state *st = dev_get_drvdata(dev);
+
+ switch (type) {
+ case hwmon_power:
+ return ltc4282_write_power(st, attr, val);
+ case hwmon_in:
+ return ltc4282_write_in(st, attr, val, channel);
+ case hwmon_curr:
+ return ltc4282_write_curr(st, attr, val);
+ case hwmon_energy:
+ return ltc4282_energy_enable_set(st, val);
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
+static umode_t ltc4282_in_is_visible(const struct ltc4282_state *st, u32 attr)
+{
+ switch (attr) {
+ case hwmon_in_input:
+ case hwmon_in_highest:
+ case hwmon_in_lowest:
+ case hwmon_in_max_alarm:
+ case hwmon_in_min_alarm:
+ case hwmon_in_label:
+ case hwmon_in_lcrit_alarm:
+ case hwmon_in_crit_alarm:
+ return 0444;
+ case hwmon_in_max:
+ case hwmon_in_min:
+ case hwmon_in_enable:
+ case hwmon_in_reset_history:
+ return 0644;
+ default:
+ return 0;
+ }
+}
+
+static umode_t ltc4282_curr_is_visible(u32 attr)
+{
+ switch (attr) {
+ case hwmon_curr_input:
+ case hwmon_curr_highest:
+ case hwmon_curr_lowest:
+ case hwmon_curr_max_alarm:
+ case hwmon_curr_min_alarm:
+ case hwmon_curr_crit_alarm:
+ case hwmon_curr_label:
+ return 0444;
+ case hwmon_curr_max:
+ case hwmon_curr_min:
+ case hwmon_curr_reset_history:
+ return 0644;
+ default:
+ return 0;
+ }
+}
+
+static umode_t ltc4282_power_is_visible(u32 attr)
+{
+ switch (attr) {
+ case hwmon_power_input:
+ case hwmon_power_input_highest:
+ case hwmon_power_input_lowest:
+ case hwmon_power_label:
+ case hwmon_power_max_alarm:
+ case hwmon_power_min_alarm:
+ return 0444;
+ case hwmon_power_max:
+ case hwmon_power_min:
+ case hwmon_power_reset_history:
+ return 0644;
+ default:
+ return 0;
+ }
+}
+
+static umode_t ltc4282_is_visible(const void *data,
+ enum hwmon_sensor_types type,
+ u32 attr, int channel)
+{
+ switch (type) {
+ case hwmon_in:
+ return ltc4282_in_is_visible(data, attr);
+ case hwmon_curr:
+ return ltc4282_curr_is_visible(attr);
+ case hwmon_power:
+ return ltc4282_power_is_visible(attr);
+ case hwmon_energy:
+ /* hwmon_energy_enable */
+ return 0644;
+ default:
+ return 0;
+ }
+}
+
+static const char * const ltc4282_in_strs[] = {
+ "VSOURCE", "VDD", "VGPIO"
+};
+
+static int ltc4282_read_labels(struct device *dev,
+ enum hwmon_sensor_types type,
+ u32 attr, int channel, const char **str)
+{
+ switch (type) {
+ case hwmon_in:
+ *str = ltc4282_in_strs[channel];
+ return 0;
+ case hwmon_curr:
+ *str = "ISENSE";
+ return 0;
+ case hwmon_power:
+ *str = "Power";
+ return 0;
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
+static ssize_t ltc4282_energy_show(struct device *dev,
+ struct device_attribute *da, char *buf)
+{
+ struct ltc4282_state *st = dev_get_drvdata(dev);
+ u64 energy;
+ int ret;
+
+ guard(mutex)(&st->lock);
+ if (!st->energy_en)
+ return -ENODATA;
+
+ ret = ltc4282_read_energy(st, &energy);
+ if (ret < 0)
+ return ret;
+
+ return sysfs_emit(buf, "%llu\n", energy);
+}
+
+static ssize_t ltc4282_status_show(struct device *dev,
+ struct device_attribute *da, char *buf)
+{
+ struct ltc4282_state *st = dev_get_drvdata(dev);
+ struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
+ long alarm;
+ int ret;
+
+ ret = ltc4282_read_alarm(st, LTC4282_STATUS_LSB, attr->index, &alarm);
+ if (ret)
+ return ret;
+
+ return sysfs_emit(buf, "%lu\n", alarm);
+}
+
+static ssize_t ltc4282_clear_faults_store(struct device *dev,
+ struct device_attribute *da,
+ const char *buf, size_t len)
+{
+ struct ltc4282_state *st = dev_get_drvdata(dev);
+ int ret;
+
+ ret = regmap_write(st->map, LTC4282_FAULT_LOG, 0);
+ if (ret)
+ return ret;
+
+ return len;
+}
+
+static const struct clk_ops ltc4282_ops = {
+ .recalc_rate = ltc4282_recalc_rate,
+ .round_rate = ltc4282_round_rate,
+ .set_rate = ltc4282_set_rate,
+ .disable = ltc4282_disable,
+};
+
+static int ltc428_clk_provider_setup(struct ltc4282_state *st,
+ struct device *dev)
+{
+ struct clk_init_data init;
+ int ret;
+
+ if (!IS_ENABLED(CONFIG_COMMON_CLK))
+ return 0;
+
+ init.name = "ltc4282-clk";
+ init.ops = <c4282_ops;
+ init.flags = CLK_GET_RATE_NOCACHE;
+ st->clk_hw.init = &init;
+
+ ret = devm_clk_hw_register(dev, &st->clk_hw);
+ if (ret)
+ return ret;
+
+ return devm_of_clk_add_hw_provider(dev, of_clk_hw_simple_get,
+ &st->clk_hw);
+}
+
+static int ltc428_clks_setup(struct ltc4282_state *st, struct device *dev)
+{
+ unsigned long rate;
+ struct clk *clkin;
+ u32 val;
+ int ret;
+
+ ret = ltc428_clk_provider_setup(st, dev);
+ if (ret)
+ return ret;
+
+ clkin = devm_clk_get_optional_enabled(dev, NULL);
+ if (IS_ERR(clkin))
+ return dev_err_probe(dev, PTR_ERR(clkin),
+ "Failed to get clkin");
+ if (!clkin)
+ return 0;
+
+ rate = clk_get_rate(clkin);
+ if (in_range(rate, LTC4282_CLKIN_MIN, LTC4282_CLKIN_RANGE))
+ return dev_err_probe(dev, -EINVAL,
+ "Invalid clkin range(%lu) [%lu %lu]\n",
+ rate, LTC4282_CLKIN_MIN,
+ LTC4282_CLKIN_MAX);
+
+ /*
+ * Clocks faster than 250KHZ should be reduced to 250KHZ. The clock
+ * frequency is divided by twice the value in the register.
+ */
+ val = rate / (2 * LTC4282_CLKIN_MIN);
+
+ return regmap_update_bits(st->map, LTC4282_CLK_DIV,
+ LTC4282_CLK_DIV_MASK,
+ FIELD_PREP(LTC4282_CLK_DIV_MASK, val));
+}
+
+static const int ltc4282_curr_lim_uv[] = {
+ 12500, 15625, 18750, 21875, 25000, 28125, 31250, 34375
+};
+
+static int ltc4282_get_defaults(struct ltc4282_state *st, u32 *curr_lim_uv)
+{
+ u32 reg_val, ilm_adjust;
+ int ret;
+
+ ret = regmap_read(st->map, LTC4282_ADC_CTRL, ®_val);
+ if (ret)
+ return ret;
+
+ st->energy_en = !FIELD_GET(LTC4282_METER_HALT_MASK, reg_val);
+
+ ret = regmap_read(st->map, LTC4282_CTRL_MSB, ®_val);
+ if (ret)
+ return ret;
+
+ st->vin_mode = FIELD_GET(LTC4282_CTRL_VIN_MODE_MASK, reg_val);
+
+ ret = regmap_read(st->map, LTC4282_ILIM_ADJUST, ®_val);
+ if (ret)
+ return ret;
+
+ ilm_adjust = FIELD_GET(LTC4282_ILIM_ADJUST_MASK, reg_val);
+ *curr_lim_uv = ltc4282_curr_lim_uv[ilm_adjust];
+
+ st->in0_1_cache[LTC4282_CHAN_VSOURCE].en = FIELD_GET(LTC4282_VDD_MONITOR_MASK,
+ ilm_adjust);
+ if (!st->in0_1_cache[LTC4282_CHAN_VSOURCE].en) {
+ st->in0_1_cache[LTC4282_CHAN_VDD].en = true;
+ return regmap_read(st->map, LTC4282_VSOURCE_MAX,
+ &st->in0_1_cache[LTC4282_CHAN_VSOURCE].in_max_raw);
+ }
+
+ return regmap_read(st->map, LTC4282_VSOURCE_MAX,
+ &st->in0_1_cache[LTC4282_CHAN_VDD].in_max_raw);
+}
+
+/*
+ * Set max limits for ISENSE and Power as that depends on the max voltage on
+ * rsense that is defined in ILIM_ADJUST. This is specially important for power
+ * because for some rsense and vfsout values, if we allow the default raw 255
+ * value, that would overflow long in 32bit archs when reading back the max
+ * power limit.
+ */
+static int ltc4282_set_max_limits(struct ltc4282_state *st, u32 val_uv)
+{
+ int ret;
+
+ ret = ltc4282_write_voltage_byte(st, LTC4282_VSENSE_MAX, 40 * MILLI,
+ val_uv);
+ if (ret)
+ return ret;
+
+ /* Power is given by ISENSE * Vout. */
+ st->power_max = DIV_ROUND_CLOSEST(val_uv * DECA * MILLI, st->rsense) * st->vfs_out;
+ return ltc4282_write_power_byte(st, LTC4282_POWER_MAX, st->power_max);
+}
+
+static const char * const ltc4282_gpio1_modes[] = {
+ "power_bad", "power_good"
+};
+
+static const char * const ltc4282_gpio2_modes[] = {
+ "adc_input", "stress_fet"
+};
+
+static int ltc4282_gpio_setup(struct ltc4282_state *st, struct device *dev)
+{
+ const char *func;
+ int ret;
+
+ ret = device_property_read_string(dev, "adi,gpio1-mode", &func);
+ if (!ret) {
+ ret = match_string(ltc4282_gpio1_modes,
+ ARRAY_SIZE(ltc4282_gpio1_modes), func);
+ if (ret < 0)
+ return dev_err_probe(dev, ret,
+ "Invalid func(%s) for gpio1\n",
+ func);
+
+ ret = regmap_update_bits(st->map, LTC4282_GPIO_CONFIG,
+ LTC4282_GPIO_1_CONFIG_MASK,
+ FIELD_PREP(LTC4282_GPIO_1_CONFIG_MASK, ret));
+ if (ret)
+ return ret;
+ }
+
+ ret = device_property_read_string(dev, "adi,gpio2-mode", &func);
+ if (ret)
+ return 0;
+
+ ret = match_string(ltc4282_gpio2_modes, ARRAY_SIZE(ltc4282_gpio2_modes),
+ func);
+ if (ret < 0)
+ return dev_err_probe(dev, ret, "Invalid func(%s) for gpio2\n",
+ func);
+ if (!ret)
+ /* setting the bit to 1 cause the ADC to monitor GPIO2 */
+ return regmap_set_bits(st->map, LTC4282_ILIM_ADJUST,
+ LTC4282_GPIO_MODE_MASK);
+
+ return regmap_update_bits(st->map, LTC4282_GPIO_CONFIG,
+ LTC4282_GPIO_2_FET_STRESS_MASK,
+ FIELD_PREP(LTC4282_GPIO_2_FET_STRESS_MASK, 1));
+}
+
+static const char * const ltc4282_dividers[] = {
+ "external", "vdd_5_percent", "vdd_10_percent", "vdd_15_percent"
+};
+
+/* This maps the Vout full scale for the given Vin mode */
+static const u16 ltc4282_vfs_milli[] = { 5540, 8320, 16640, 33280 };
+
+static int ltc4282_setup(struct ltc4282_state *st, struct device *dev)
+{
+ u32 val, curr_lim_uv;
+ const char *divider;
+ int ret;
+
+ /* The part has an eeprom so let's get the needed defaults from it */
+ ret = ltc4282_get_defaults(st, &curr_lim_uv);
+ if (ret)
+ return ret;
+
+ ret = device_property_read_u32(dev, "adi,rsense-nano-ohms",
+ &st->rsense);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "Failed to read adi,rsense-nano-ohms\n");
+ if (st->rsense < CENTI)
+ return dev_err_probe(dev, -EINVAL,
+ "adi,rsense-nano-ohms too small (< %lu)\n",
+ CENTI);
+
+ /*
+ * The resolution for rsense is tenths of micro (eg: 62.5 uOhm) which
+ * means we need nano in the bindings. However, to make things easier to
+ * handle (with respect to overflows) we divide it by 100 as we don't
+ * really need the last two digits.
+ */
+ st->rsense /= CENTI;
+
+ ret = device_property_read_u32(dev, "adi,vin-mode-microvolt", &val);
+ if (!ret) {
+ switch (val) {
+ case 3300000:
+ st->vin_mode = LTC4282_VIN_3_3V;
+ break;
+ case 5000000:
+ st->vin_mode = LTC4282_VIN_5V;
+ break;
+ case 12000000:
+ st->vin_mode = LTC4282_VIN_12V;
+ break;
+ case 24000000:
+ st->vin_mode = LTC4282_VIN_24V;
+ break;
+ default:
+ return dev_err_probe(dev, -EINVAL,
+ "Invalid val(%u) for vin-mode-microvolt\n",
+ val);
+ }
+
+ ret = regmap_update_bits(st->map, LTC4282_CTRL_MSB,
+ LTC4282_CTRL_VIN_MODE_MASK,
+ FIELD_PREP(LTC4282_CTRL_VIN_MODE_MASK, st->vin_mode));
+ if (ret)
+ return ret;
+
+ /* Foldback mode should also be set to the input voltage */
+ ret = regmap_update_bits(st->map, LTC4282_ILIM_ADJUST,
+ LTC4282_FOLDBACK_MODE_MASK,
+ FIELD_PREP(LTC4282_FOLDBACK_MODE_MASK, st->vin_mode));
+ if (ret)
+ return ret;
+ }
+
+ st->vfs_out = ltc4282_vfs_milli[st->vin_mode];
+
+ ret = device_property_read_u32(dev, "adi,current-limit-sense-microvolt",
+ &curr_lim_uv);
+ if (!ret) {
+ int reg_val;
+
+ switch (val) {
+ case 12500:
+ reg_val = 0;
+ break;
+ case 15625:
+ reg_val = 1;
+ break;
+ case 18750:
+ reg_val = 2;
+ break;
+ case 21875:
+ reg_val = 3;
+ break;
+ case 25000:
+ reg_val = 4;
+ break;
+ case 28125:
+ reg_val = 5;
+ break;
+ case 31250:
+ reg_val = 6;
+ break;
+ case 34375:
+ reg_val = 7;
+ break;
+ default:
+ return dev_err_probe(dev, -EINVAL,
+ "Invalid val(%u) for adi,current-limit-microvolt\n",
+ val);
+ }
+
+ ret = regmap_update_bits(st->map, LTC4282_ILIM_ADJUST,
+ LTC4282_ILIM_ADJUST_MASK,
+ FIELD_PREP(LTC4282_ILIM_ADJUST_MASK, reg_val));
+ if (ret)
+ return ret;
+ }
+
+ ret = ltc4282_set_max_limits(st, curr_lim_uv);
+ if (ret)
+ return ret;
+
+ ret = device_property_read_string(dev, "adi,overvoltage-dividers",
+ ÷r);
+ if (!ret) {
+ int div = match_string(ltc4282_dividers,
+ ARRAY_SIZE(ltc4282_dividers), divider);
+ if (div < 0)
+ return dev_err_probe(dev, -EINVAL,
+ "Invalid val(%s) for adi,overvoltage-divider\n",
+ divider);
+
+ ret = regmap_update_bits(st->map, LTC4282_CTRL_MSB,
+ LTC4282_CTRL_OV_MODE_MASK,
+ FIELD_PREP(LTC4282_CTRL_OV_MODE_MASK, div));
+ }
+
+ ret = device_property_read_string(dev, "adi,undervoltage-dividers",
+ ÷r);
+ if (!ret) {
+ int div = match_string(ltc4282_dividers,
+ ARRAY_SIZE(ltc4282_dividers), divider);
+ if (div < 0)
+ return dev_err_probe(dev, -EINVAL,
+ "Invalid val(%s) for adi,undervoltage-divider\n",
+ divider);
+
+ ret = regmap_update_bits(st->map, LTC4282_CTRL_MSB,
+ LTC4282_CTRL_UV_MODE_MASK,
+ FIELD_PREP(LTC4282_CTRL_UV_MODE_MASK, div));
+ }
+
+ if (device_property_read_bool(dev, "adi,overcurrent-retry")) {
+ ret = regmap_set_bits(st->map, LTC4282_CTRL_LSB,
+ LTC4282_CTRL_OC_RETRY_MASK);
+ if (ret)
+ return ret;
+ }
+
+ if (device_property_read_bool(dev, "adi,overvoltage-retry-disable")) {
+ ret = regmap_clear_bits(st->map, LTC4282_CTRL_LSB,
+ LTC4282_CTRL_OV_RETRY_MASK);
+ if (ret)
+ return ret;
+ }
+
+ if (device_property_read_bool(dev, "adi,undervoltage-retry-disable")) {
+ ret = regmap_clear_bits(st->map, LTC4282_CTRL_LSB,
+ LTC4282_CTRL_UV_RETRY_MASK);
+ if (ret)
+ return ret;
+ }
+
+ if (device_property_read_bool(dev, "adi,fault-log-enable")) {
+ ret = regmap_set_bits(st->map, LTC4282_ADC_CTRL,
+ LTC4282_FAULT_LOG_EN_MASK);
+ if (ret)
+ return ret;
+ }
+
+ if (device_property_read_bool(dev, "adi,fault-log-enable")) {
+ ret = regmap_set_bits(st->map, LTC4282_ADC_CTRL, LTC4282_FAULT_LOG_EN_MASK);
+ if (ret)
+ return ret;
+ }
+
+ ret = device_property_read_u32(dev, "adi,fet-bad-timeout-ms", &val);
+ if (!ret) {
+ if (val > LTC4282_FET_BAD_MAX_TIMEOUT)
+ return dev_err_probe(dev, -EINVAL,
+ "Invalid value(%u) for adi,fet-bad-timeout-ms",
+ val);
+
+ ret = regmap_write(st->map, LTC4282_FET_BAD_FAULT_TIMEOUT, val);
+ if (ret)
+ return ret;
+ }
+
+ return ltc4282_gpio_setup(st, dev);
+}
+
+static bool ltc4282_readable_reg(struct device *dev, unsigned int reg)
+{
+ if (reg == LTC4282_RESERVED_1 || reg == LTC4282_RESERVED_2)
+ return false;
+
+ return true;
+}
+
+static bool ltc4282_writable_reg(struct device *dev, unsigned int reg)
+{
+ if (reg == LTC4282_STATUS_LSB || reg == LTC4282_STATUS_MSB)
+ return false;
+ if (reg == LTC4282_RESERVED_1 || reg == LTC4282_RESERVED_2)
+ return false;
+
+ return true;
+}
+
+static const struct regmap_config ltc4282_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .max_register = LTC4282_RESERVED_3,
+ .readable_reg = ltc4282_readable_reg,
+ .writeable_reg = ltc4282_writable_reg,
+};
+
+static const struct hwmon_channel_info * const ltc4282_info[] = {
+ HWMON_CHANNEL_INFO(in,
+ HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST |
+ HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM |
+ HWMON_I_MAX_ALARM | HWMON_I_ENABLE |
+ HWMON_I_RESET_HISTORY | HWMON_I_LABEL,
+ HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST |
+ HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM |
+ HWMON_I_MAX_ALARM | HWMON_I_LCRIT_ALARM |
+ HWMON_I_CRIT_ALARM | HWMON_I_ENABLE |
+ HWMON_I_RESET_HISTORY | HWMON_I_LABEL,
+ HWMON_I_INPUT | HWMON_I_LOWEST | HWMON_I_HIGHEST |
+ HWMON_I_MAX | HWMON_I_MIN | HWMON_I_MIN_ALARM |
+ HWMON_I_MAX_ALARM | HWMON_I_LABEL),
+ HWMON_CHANNEL_INFO(curr,
+ HWMON_C_INPUT | HWMON_C_LOWEST | HWMON_C_HIGHEST |
+ HWMON_C_MAX | HWMON_C_MIN | HWMON_C_MIN_ALARM |
+ HWMON_C_MAX_ALARM | HWMON_C_CRIT_ALARM |
+ HWMON_I_RESET_HISTORY | HWMON_C_LABEL),
+ HWMON_CHANNEL_INFO(power,
+ HWMON_P_INPUT | HWMON_P_INPUT_LOWEST |
+ HWMON_P_INPUT_HIGHEST | HWMON_P_MAX | HWMON_P_MIN |
+ HWMON_P_MAX_ALARM | HWMON_P_MIN_ALARM |
+ HWMON_I_RESET_HISTORY | HWMON_P_LABEL),
+ HWMON_CHANNEL_INFO(energy,
+ HWMON_E_ENABLE),
+ NULL
+};
+
+static const struct hwmon_ops ltc4282_hwmon_ops = {
+ .read = ltc4282_read,
+ .write = ltc4282_write,
+ .is_visible = ltc4282_is_visible,
+ .read_string = ltc4282_read_labels,
+};
+
+static const struct hwmon_chip_info ltc2947_chip_info = {
+ .ops = <c4282_hwmon_ops,
+ .info = ltc4282_info,
+};
+
+/* energy attributes are 6bytes wide so we need u64 */
+static SENSOR_DEVICE_ATTR_RO(energy1_input, ltc4282_energy, 0);
+/* power1_fault */
+static SENSOR_DEVICE_ATTR_RO(power1_good, ltc4282_status,
+ LTC4282_POWER_GOOD_MASK);
+/* FET faults */
+static SENSOR_DEVICE_ATTR_RO(fet_short_fault, ltc4282_status,
+ LTC4282_FET_SHORT_MASK);
+static SENSOR_DEVICE_ATTR_RO(fet_bad_fault, ltc4282_status,
+ LTC4282_FET_BAD_STATUS_MASK);
+/*
+ * Fault log failures. These faults might be important in systems where
+ * auto-retry is not enabled since they will cause the part to latch off until
+ * they are cleared. Typically that happens when the system admin is close
+ * enough so he can check what happened and manually clear the faults. Hence, we
+ * provide an attribute to clear all fauls at once while still capable of
+ * checking individual faults in debugfs.
+ */
+static SENSOR_DEVICE_ATTR_WO(fault_logs_reset, ltc4282_clear_faults, 0);
+
+static struct attribute *ltc4282_attrs[] = {
+ &sensor_dev_attr_energy1_input.dev_attr.attr,
+ &sensor_dev_attr_power1_good.dev_attr.attr,
+ &sensor_dev_attr_fet_bad_fault.dev_attr.attr,
+ &sensor_dev_attr_fet_short_fault.dev_attr.attr,
+ &sensor_dev_attr_fault_logs_reset.dev_attr.attr,
+ NULL
+};
+ATTRIBUTE_GROUPS(ltc4282);
+
+static int ltc4282_show_fault_log(void *arg, u64 *val, u32 mask)
+{
+ struct ltc4282_state *st = arg;
+ long alarm;
+ int ret;
+
+ ret = ltc4282_read_alarm(st, LTC4282_FAULT_LOG, mask, &alarm);
+ if (ret)
+ return ret;
+
+ *val = alarm;
+
+ return 0;
+}
+
+static int ltc4282_show_curr1_crit_fault_log(void *arg, u64 *val)
+{
+ return ltc4282_show_fault_log(arg, val, LTC4282_OC_FAULT_MASK);
+}
+DEFINE_DEBUGFS_ATTRIBUTE(ltc4282_curr1_crit_fault_log,
+ ltc4282_show_curr1_crit_fault_log, NULL, "%llu\n");
+
+static int ltc4282_show_in1_lcrit_fault_log(void *arg, u64 *val)
+{
+ return ltc4282_show_fault_log(arg, val, LTC4282_UV_FAULT_MASK);
+}
+DEFINE_DEBUGFS_ATTRIBUTE(ltc4282_in1_lcrit_fault_log,
+ ltc4282_show_in1_lcrit_fault_log, NULL, "%llu\n");
+
+static int ltc4282_show_in1_crit_fault_log(void *arg, u64 *val)
+{
+ return ltc4282_show_fault_log(arg, val, LTC4282_OV_FAULT_MASK);
+}
+DEFINE_DEBUGFS_ATTRIBUTE(ltc4282_in1_crit_fault_log,
+ ltc4282_show_in1_crit_fault_log, NULL, "%llu\n");
+
+static int ltc4282_show_fet_bad_fault_log(void *arg, u64 *val)
+{
+ return ltc4282_show_fault_log(arg, val, LTC4282_FET_BAD_FAULT_MASK);
+}
+DEFINE_DEBUGFS_ATTRIBUTE(ltc4282_fet_bad_fault_log,
+ ltc4282_show_fet_bad_fault_log, NULL, "%llu\n");
+
+static int ltc4282_show_fet_short_fault_log(void *arg, u64 *val)
+{
+ return ltc4282_show_fault_log(arg, val, LTC4282_FET_SHORT_FAULT_MASK);
+}
+DEFINE_DEBUGFS_ATTRIBUTE(ltc4282_fet_short_fault_log,
+ ltc4282_show_fet_short_fault_log, NULL, "%llu\n");
+
+static int ltc4282_show_power1_bad_fault_log(void *arg, u64 *val)
+{
+ return ltc4282_show_fault_log(arg, val, LTC4282_POWER_BAD_FAULT_MASK);
+}
+DEFINE_DEBUGFS_ATTRIBUTE(ltc4282_power1_bad_fault_log,
+ ltc4282_show_power1_bad_fault_log, NULL, "%llu\n");
+
+static void ltc4282_debugfs_remove(void *dir)
+{
+ debugfs_remove_recursive(dir);
+}
+
+static void ltc4282_debugfs_init(struct ltc4282_state *st,
+ struct i2c_client *i2c,
+ const struct device *hwmon)
+{
+ const char *debugfs_name;
+ struct dentry *dentry;
+ int ret;
+
+ if (!IS_ENABLED(CONFIG_DEBUG_FS))
+ return;
+
+ debugfs_name = devm_kasprintf(&i2c->dev, GFP_KERNEL, "%s-%s",
+ i2c->name, dev_name(hwmon));
+ if (!debugfs_name)
+ return;
+
+ dentry = debugfs_create_dir(debugfs_name, NULL);
+ if (IS_ERR(dentry))
+ return;
+
+ ret = devm_add_action_or_reset(&i2c->dev, ltc4282_debugfs_remove,
+ dentry);
+ if (ret)
+ return;
+
+ debugfs_create_file_unsafe("power1_bad_fault_log", 0400, dentry, st,
+ <c4282_power1_bad_fault_log);
+ debugfs_create_file_unsafe("fet_short_fault_log", 0400, dentry, st,
+ <c4282_fet_short_fault_log);
+ debugfs_create_file_unsafe("fet_bad_fault_log", 0400, dentry, st,
+ <c4282_fet_bad_fault_log);
+ debugfs_create_file_unsafe("in1_crit_fault_log", 0400, dentry, st,
+ <c4282_in1_crit_fault_log);
+ debugfs_create_file_unsafe("in1_lcrit_fault_log", 0400, dentry, st,
+ <c4282_in1_lcrit_fault_log);
+ debugfs_create_file_unsafe("curr1_crit_fault_log", 0400, dentry, st,
+ <c4282_curr1_crit_fault_log);
+}
+
+static int ltc4282_probe(struct i2c_client *i2c)
+{
+ struct device *dev = &i2c->dev, *hwmon;
+ struct ltc4282_state *st;
+ int ret;
+
+ st = devm_kzalloc(dev, sizeof(*st), GFP_KERNEL);
+ if (!st)
+ return dev_err_probe(dev, -ENOMEM,
+ "Failed to allocate memory\n");
+
+ st->map = devm_regmap_init_i2c(i2c, <c4282_regmap_config);
+ if (IS_ERR(st->map))
+ return dev_err_probe(dev, PTR_ERR(st->map),
+ "failed regmap init\n");
+
+ /* Soft reset */
+ ret = regmap_set_bits(st->map, LTC4282_ADC_CTRL, LTC4282_RESET_MASK);
+ if (ret)
+ return ret;
+
+ /* Yes, it's big but it is as specified in the datasheet */
+ msleep(3200);
+
+ ret = ltc428_clks_setup(st, dev);
+ if (ret)
+ return ret;
+
+ ret = ltc4282_setup(st, dev);
+ if (ret)
+ return ret;
+
+ mutex_init(&st->lock);
+ hwmon = devm_hwmon_device_register_with_info(dev, "ltc4282", st,
+ <c2947_chip_info,
+ ltc4282_groups);
+ if (IS_ERR(hwmon))
+ return PTR_ERR(hwmon);
+
+ ltc4282_debugfs_init(st, i2c, hwmon);
+
+ return 0;
+}
+
+static const struct of_device_id ltc4282_of_match[] = {
+ { .compatible = "adi,ltc4282" },
+ {}
+};
+MODULE_DEVICE_TABLE(of, ltc4282_of_match);
+
+static struct i2c_driver ltc4282_driver = {
+ .driver = {
+ .name = "ltc4282",
+ .of_match_table = ltc4282_of_match,
+ },
+ .probe = ltc4282_probe,
+};
+module_i2c_driver(ltc4282_driver);
+
+MODULE_AUTHOR("Nuno Sa <nuno.sa@xxxxxxxxxx>");
+MODULE_DESCRIPTION("LTC4282 I2C High Current Hot Swap Controller");
+MODULE_LICENSE("GPL");
--
2.43.0
