* [PATCH] hwmon: (pmbus/tps53679) Add support for TPS536C7
2026-09-04 22:08 [PATCH 0/3] hwmon: (pmbus/tps53679) Add TPS536C7 Pradhan, Sanman
2026-09-04 22:08 ` [PATCH 1/3] hwmon: (pmbus/tps53679) Fix TPS53676 phase page decoding Pradhan, Sanman
2026-09-04 22:09 ` [PATCH 2/3] dt-bindings: trivial-devices: Add TI TPS536C7 Pradhan, Sanman
@ 2026-09-04 22:09 ` Pradhan, Sanman
2 siblings, 0 replies; 4+ messages in thread
From: Pradhan, Sanman @ 2026-09-04 22:09 UTC (permalink / raw)
To: Guenter Roeck, Jonathan Corbet, Rob Herring, Krzysztof Kozlowski,
Conor Dooley
Cc: linux-hwmon@vger.kernel.org, devicetree@vger.kernel.org,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
Sanman Pradhan, Senthil Muniyappan, Vaibhav Agarwal
From: Sanman Pradhan <psanman@juniper.net>
TPS536C7 is a dual-channel D-CAP+ step-down controller whose channels are
distributed across a configurable number of phases (N+M, up to 12 total).
Whether channel B (PMBus page 1) exists depends on the phase configuration
register, so the page count is derived at probe time.
Factor the TPS53676 phase-map parsing into a shared helper and reuse it
for TPS536C7. Only aggregate per-channel telemetry is exposed: leave
info->phases[] unset so the PMBus core never programs the PHASE selector
on every read (and because TPS536C7 can place up to 12 phases on channel
A, exceeding PMBUS_PHASES). Report VOUT in linear format like TPS53676.
Since the core never programs PHASE, set it to 0xff on each populated
page so READ_IOUT reports the aggregate channel current, and verify it
(PHASE can be write-protected). Fail identification if aggregate
selection cannot be established, since otherwise a single phase current
could be reported as the channel total.
A configuration with no channel-A phase is rejected with -EOPNOTSUPP:
the PMBus core models pages as the contiguous range 0..pages-1 and
cannot represent a channel-A-absent topology.
On the tested TPS536C7 (device ID 54 49 53 6c 70 00, CAPABILITY 0xd0),
block reads of IC_DEVICE_ID and USER_DATA_03 return -EBADMSG with PEC
enabled, while retrying those two reads without PEC returns the expected
6- and 24-byte payloads. Standard byte/word telemetry keeps using PEC,
so only those two identification reads fall back to no-PEC.
Co-developed-by: Senthil Muniyappan <smuniyappan@juniper.net>
Co-developed-by: Vaibhav Agarwal <avaibhav@juniper.net>
Signed-off-by: Sanman Pradhan <psanman@juniper.net>
---
Documentation/hwmon/tps53679.rst | 23 ++++--
drivers/hwmon/pmbus/Kconfig | 2 +-
drivers/hwmon/pmbus/tps53679.c | 128 +++++++++++++++++++++++++++----
3 files changed, 134 insertions(+), 19 deletions(-)
diff --git a/Documentation/hwmon/tps53679.rst b/Documentation/hwmon/tps53679.rst
index 2280e043c4de9..3d584197b3a03 100644
--- a/Documentation/hwmon/tps53679.rst
+++ b/Documentation/hwmon/tps53679.rst
@@ -75,6 +75,14 @@ Supported chips:
Datasheet: Available under NDA
+ * Texas Instruments TPS536C7
+
+ Prefix: 'tps536c7'
+
+ Addresses scanned: -
+
+ Datasheet: https://www.ti.com/lit/gpn/TPS536C7
+
Authors:
Vadim Pasternak <vadimp@mellanox.com>
@@ -85,7 +93,12 @@ Description
-----------
Chips in this series are multi-phase step-down converters with one or two
-output channels and up to 8 phases per channel.
+output channels and up to 12 phases in total, depending on the device.
+
+For TPS536C7 only aggregate per-channel telemetry is exposed; the
+individual per-phase output currents the hardware can report are not.
+Attributes for the second output channel are present only when channel B
+is configured.
Usage Notes
@@ -124,7 +137,7 @@ in1_crit_alarm Input voltage critical high alarm.
in[N]_label "vout[1-2]"
- TPS53647, TPS53667: N=2
- - TPS53622, TPS53659, TPS53679, TPS53688: N=2,3
+ - TPS53622, TPS53659, TPS53679, TPS53688, TPS536C7: N=2,3
in[N]_input Measured output voltage.
@@ -151,7 +164,7 @@ in[N]_crit_alarm Output voltage critical high alarm.
temp[N]_input Measured temperature.
- TPS53647, TPS53667: N=1
- - TPS53622, TPS53659, TPS53679, TPS53681, TPS53688: N=1,2
+ - TPS53622, TPS53659, TPS53679, TPS53681, TPS53688, TPS536C7: N=1,2
temp[N]_max Maximum temperature.
@@ -168,7 +181,7 @@ power1_input Measured input power.
power[N]_label "pout[1-2]".
- TPS53647, TPS53667: N=2
- - TPS53622, TPS53659, TPS53676, TPS53679, TPS53681, TPS53688: N=2,3
+ - TPS53622, TPS53659, TPS53676, TPS53679, TPS53681, TPS53688, TPS536C7: N=2,3
power[N]_input Measured output power.
@@ -191,7 +204,7 @@ curr[N]_label "iout[1-2]" or "iout1.[0-5]".
telemetry supported on TPS53676 and TPS53681 only.
- TPS53647, TPS53667: N=2
- - TPS53622, TPS53659, TPS53679, TPS53688: N=2,3
+ - TPS53622, TPS53659, TPS53679, TPS53688, TPS536C7: N=2,3
- TPS53676: N=2-8
- TPS53681: N=2-9
diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
index bcfdc4ce4c100..b6658ff242ef9 100644
--- a/drivers/hwmon/pmbus/Kconfig
+++ b/drivers/hwmon/pmbus/Kconfig
@@ -794,7 +794,7 @@ config SENSORS_TPS53679
help
If you say yes here you get hardware monitoring support for TI
TPS53622, TPS53647, TPS53659, TPS53667, TPS53676, TPS53679, TPS53681,
- TPS53685, and TPS53688.
+ TPS53685, TPS53688, and TPS536C7.
This driver can also be built as a module. If so, the module will
be called tps53679.
diff --git a/drivers/hwmon/pmbus/tps53679.c b/drivers/hwmon/pmbus/tps53679.c
index 680339a6b90fe..98a68211a2bbf 100644
--- a/drivers/hwmon/pmbus/tps53679.c
+++ b/drivers/hwmon/pmbus/tps53679.c
@@ -17,13 +17,20 @@
enum chips {
tps53622, tps53647, tps53659, tps53667, tps53676, tps53679, tps53681,
- tps53685, tps53688
+ tps53685, tps53688, tps536c7
};
#define TPS53647_PAGE_NUM 1
-#define TPS53676_USER_DATA_03 0xb3
+#define TPS536XX_PHASE_CONFIG 0xb3
#define TPS53676_MAX_PHASES 7
+#define TPS536C7_MAX_PHASES 12
+
+#define TPS536XX_PHASE_ENABLE BIT(7)
+#define TPS536XX_PHASE_PAGE BIT(4)
+
+#define TPS53676_DEVICE_ID "TI\x53\x67\x60\x00"
+#define TPS536C7_DEVICE_ID "TI\x53\x6c\x70\x00"
#define TPS53679_PROT_VR12_5MV 0x01 /* VR12.0 mode, 5-mV DAC */
#define TPS53679_PROT_VR12_5_10MV 0x02 /* VR12.5 mode, 10-mV DAC */
@@ -166,34 +173,72 @@ static int tps53681_identify(struct i2c_client *client,
TPS53681_DEVICE_ID);
}
-static int tps53676_identify(struct i2c_client *client,
- struct pmbus_driver_info *info)
+static int tps536xx_read_block(struct i2c_client *client, u8 reg, u8 *buf,
+ bool retry_without_pec)
+{
+ int ret = i2c_smbus_read_block_data(client, reg, buf);
+
+ /*
+ * Some TPS536C7 samples return an invalid PEC on the device-ID and
+ * phase-configuration block reads. Retry once without PEC; ordinary
+ * telemetry keeps using PEC.
+ */
+ if (ret == -EBADMSG && retry_without_pec &&
+ (client->flags & I2C_CLIENT_PEC)) {
+ client->flags &= ~I2C_CLIENT_PEC;
+ ret = i2c_smbus_read_block_data(client, reg, buf);
+ client->flags |= I2C_CLIENT_PEC;
+ }
+ return ret;
+}
+
+static int tps536xx_read_phases(struct i2c_client *client,
+ const char *device_id, int max_phases,
+ bool retry_without_pec, int *phases_a,
+ int *phases_b)
{
u8 buf[I2C_SMBUS_BLOCK_MAX];
- int phases_a = 0, phases_b = 0;
int i, ret;
- ret = i2c_smbus_read_block_data(client, PMBUS_IC_DEVICE_ID, buf);
+ ret = tps536xx_read_block(client, PMBUS_IC_DEVICE_ID, buf,
+ retry_without_pec);
if (ret < 0)
return ret;
- if (ret != 6 || memcmp(buf, "TI\x53\x67\x60\x00", 6)) {
+ if (ret != 6 || memcmp(buf, device_id, 6)) {
dev_err(&client->dev, "Unexpected device ID: %*ph\n", ret, buf);
return -ENODEV;
}
- ret = i2c_smbus_read_block_data(client, TPS53676_USER_DATA_03, buf);
+ ret = tps536xx_read_block(client, TPS536XX_PHASE_CONFIG, buf,
+ retry_without_pec);
if (ret < 0)
return ret;
if (ret != 24)
return -EIO;
- for (i = 0; i < 2 * TPS53676_MAX_PHASES; i += 2) {
- if (buf[i + 1] & 0x80) {
- if (buf[i] & BIT(4))
- phases_b++;
+
+ *phases_a = 0;
+ *phases_b = 0;
+ for (i = 0; i < 2 * max_phases; i += 2) {
+ if (buf[i + 1] & TPS536XX_PHASE_ENABLE) {
+ if (buf[i] & TPS536XX_PHASE_PAGE)
+ (*phases_b)++;
else
- phases_a++;
+ (*phases_a)++;
}
}
+ return 0;
+}
+
+static int tps53676_identify(struct i2c_client *client,
+ struct pmbus_driver_info *info)
+{
+ int phases_a, phases_b, ret;
+
+ ret = tps536xx_read_phases(client, TPS53676_DEVICE_ID,
+ TPS53676_MAX_PHASES, false,
+ &phases_a, &phases_b);
+ if (ret)
+ return ret;
info->format[PSC_VOLTAGE_OUT] = linear;
info->pages = 1;
@@ -205,6 +250,58 @@ static int tps53676_identify(struct i2c_client *client,
return 0;
}
+static int tps536c7_identify(struct i2c_client *client,
+ struct pmbus_driver_info *info)
+{
+ int phases_a, phases_b, page, ret;
+
+ ret = tps536xx_read_phases(client, TPS536C7_DEVICE_ID,
+ TPS536C7_MAX_PHASES, true,
+ &phases_a, &phases_b);
+ if (ret)
+ return ret;
+ if (!phases_a) {
+ dev_err(&client->dev,
+ "TPS536C7 without channel A is not supported\n");
+ return -EOPNOTSUPP;
+ }
+
+ info->format[PSC_VOLTAGE_OUT] = linear;
+ /*
+ * TPS536C7 can place up to 12 phases on channel A, which exceeds
+ * PMBUS_PHASES. Report aggregate per-channel telemetry only and do
+ * not populate info->phases[].
+ */
+ info->pages = phases_b ? 2 : 1;
+
+ /*
+ * With info->phases[] left unset the PMBus core never programs the
+ * PHASE selector, so make sure each page reports the aggregate
+ * current (PHASE = 0xff) rather than whatever a previous boot left.
+ */
+ for (page = 0; page < info->pages; page++) {
+ ret = pmbus_read_byte_data(client, page, PMBUS_PHASE);
+ if (ret < 0)
+ return ret;
+ if (ret == 0xff)
+ continue;
+ ret = pmbus_write_byte_data(client, page, PMBUS_PHASE, 0xff);
+ if (ret < 0)
+ return ret;
+ /* PHASE may be write-protected; confirm it actually changed. */
+ ret = pmbus_read_byte_data(client, page, PMBUS_PHASE);
+ if (ret < 0)
+ return ret;
+ if (ret != 0xff) {
+ dev_err(&client->dev,
+ "failed to select aggregate PHASE on page %d\n",
+ page);
+ return -EIO;
+ }
+ }
+ return 0;
+}
+
static int tps53681_read_word_data(struct i2c_client *client, int page,
int phase, int reg)
{
@@ -286,6 +383,9 @@ static int tps53679_probe(struct i2c_client *client)
info->pages = TPS53679_PAGE_NUM;
info->identify = tps53685_identify;
break;
+ case tps536c7:
+ info->identify = tps536c7_identify;
+ break;
default:
return -ENODEV;
}
@@ -304,6 +404,7 @@ static const struct i2c_device_id tps53679_id[] = {
{ .name = "tps53681", .driver_data = tps53681 },
{ .name = "tps53685", .driver_data = tps53685 },
{ .name = "tps53688", .driver_data = tps53688 },
+ { .name = "tps536c7", .driver_data = tps536c7 },
{ }
};
@@ -319,6 +420,7 @@ static const struct of_device_id __maybe_unused tps53679_of_match[] = {
{.compatible = "ti,tps53681", .data = (void *)tps53681},
{.compatible = "ti,tps53685", .data = (void *)tps53685},
{.compatible = "ti,tps53688", .data = (void *)tps53688},
+ {.compatible = "ti,tps536c7", .data = (void *)tps536c7},
{}
};
MODULE_DEVICE_TABLE(of, tps53679_of_match);
--
2.34.1
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