The on-board uC on the SMARC-sAM67 board is compatible with the older
CPLD implementation on the SMARC-sAL28 board, but has different sensors,
namely two voltage sensors and one temperature sensor. Add support for it.
Signed-off-by: Michael Walle <mwalle@kernel.org>
---
drivers/hwmon/sl28cpld-hwmon.c | 76 ++++++++++++++++++++++++++++++++--
1 file changed, 73 insertions(+), 3 deletions(-)
diff --git a/drivers/hwmon/sl28cpld-hwmon.c b/drivers/hwmon/sl28cpld-hwmon.c
index 454cc844fb9d..670308d9b72f 100644
--- a/drivers/hwmon/sl28cpld-hwmon.c
+++ b/drivers/hwmon/sl28cpld-hwmon.c
@@ -18,6 +18,9 @@
#define FAN_SCALE_X8 BIT(7)
#define FAN_VALUE_MASK GENMASK(6, 0)
+#define SA67MCU_VOLTAGE(n) (0x00 + ((n) * 2))
+#define SA67MCU_TEMP(n) (0x04 + ((n) * 2))
+
struct sl28cpld_hwmon {
struct regmap *regmap;
u32 offset;
@@ -75,8 +78,71 @@ static const struct hwmon_chip_info sl28cpld_hwmon_chip_info = {
.info = sl28cpld_hwmon_info,
};
+static int sa67mcu_hwmon_read(struct device *dev,
+ enum hwmon_sensor_types type, u32 attr,
+ int channel, long *input)
+{
+ struct sl28cpld_hwmon *hwmon = dev_get_drvdata(dev);
+ unsigned int offset;
+ u8 reg[2];
+ int ret;
+
+ switch (type) {
+ case hwmon_in:
+ switch (attr) {
+ case hwmon_in_input:
+ offset = hwmon->offset + SA67MCU_VOLTAGE(channel);
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
+ break;
+ case hwmon_temp:
+ switch (attr) {
+ case hwmon_temp_input:
+ offset = hwmon->offset + SA67MCU_TEMP(channel);
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ /* Reading the low byte will capture the value */
+ ret = regmap_bulk_read(hwmon->regmap, offset, reg, ARRAY_SIZE(reg));
+ if (ret)
+ return ret;
+
+ *input = reg[1] << 8 | reg[0];
+
+ /* Temperatures are s16 and in 0.1degC steps. */
+ if (type == hwmon_temp)
+ *input = sign_extend32(*input, 15) * 100;
+
+ return 0;
+}
+
+static const struct hwmon_channel_info * const sa67mcu_hwmon_info[] = {
+ HWMON_CHANNEL_INFO(in, HWMON_I_INPUT, HWMON_I_INPUT),
+ HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT),
+ NULL
+};
+
+static const struct hwmon_ops sa67mcu_hwmon_ops = {
+ .visible = 0444,
+ .read = sa67mcu_hwmon_read,
+};
+
+static const struct hwmon_chip_info sa67mcu_hwmon_chip_info = {
+ .ops = &sa67mcu_hwmon_ops,
+ .info = sa67mcu_hwmon_info,
+};
+
static int sl28cpld_hwmon_probe(struct platform_device *pdev)
{
+ const struct hwmon_chip_info *chip_info;
struct sl28cpld_hwmon *hwmon;
struct device *hwmon_dev;
int ret;
@@ -84,6 +150,10 @@ static int sl28cpld_hwmon_probe(struct platform_device *pdev)
if (!pdev->dev.parent)
return -ENODEV;
+ chip_info = device_get_match_data(&pdev->dev);
+ if (!chip_info)
+ return -EINVAL;
+
hwmon = devm_kzalloc(&pdev->dev, sizeof(*hwmon), GFP_KERNEL);
if (!hwmon)
return -ENOMEM;
@@ -97,8 +167,7 @@ static int sl28cpld_hwmon_probe(struct platform_device *pdev)
return -EINVAL;
hwmon_dev = devm_hwmon_device_register_with_info(&pdev->dev,
- "sl28cpld_hwmon", hwmon,
- &sl28cpld_hwmon_chip_info, NULL);
+ "sl28cpld_hwmon", hwmon, chip_info, NULL);
if (IS_ERR(hwmon_dev))
dev_err(&pdev->dev, "failed to register as hwmon device");
@@ -106,7 +175,8 @@ static int sl28cpld_hwmon_probe(struct platform_device *pdev)
}
static const struct of_device_id sl28cpld_hwmon_of_match[] = {
- { .compatible = "kontron,sl28cpld-fan" },
+ { .compatible = "kontron,sl28cpld-fan", .data = &sl28cpld_hwmon_chip_info },
+ { .compatible = "kontron,sa67mcu-hwmon", .data = &sa67mcu_hwmon_chip_info },
{}
};
MODULE_DEVICE_TABLE(of, sl28cpld_hwmon_of_match);
--
2.39.5On 8/22/25 06:15, Michael Walle wrote:
> The on-board uC on the SMARC-sAM67 board is compatible with the older
> CPLD implementation on the SMARC-sAL28 board, but has different sensors,
> namely two voltage sensors and one temperature sensor. Add support for it.
>
> Signed-off-by: Michael Walle <mwalle@kernel.org>
> ---
> drivers/hwmon/sl28cpld-hwmon.c | 76 ++++++++++++++++++++++++++++++++--
Documentation/hwmon/sl28cpld.rst would have to be updated as well.
...
> static const struct of_device_id sl28cpld_hwmon_of_match[] = {
> - { .compatible = "kontron,sl28cpld-fan" },
> + { .compatible = "kontron,sl28cpld-fan", .data = &sl28cpld_hwmon_chip_info },
> + { .compatible = "kontron,sa67mcu-hwmon", .data = &sa67mcu_hwmon_chip_info },
Effectively this means that the two chips have completely different functionality.
One reports fan speeds, the other reports voltages and current.
This should be a separate driver.
Guenter
Hi Guenter,
> > static const struct of_device_id sl28cpld_hwmon_of_match[] = {
> > - { .compatible = "kontron,sl28cpld-fan" },
> > + { .compatible = "kontron,sl28cpld-fan", .data = &sl28cpld_hwmon_chip_info },
> > + { .compatible = "kontron,sa67mcu-hwmon", .data = &sa67mcu_hwmon_chip_info },
>
> Effectively this means that the two chips have completely different functionality.
> One reports fan speeds, the other reports voltages and current.
> This should be a separate driver.
Fair enough. I wasn't sure, the reason why I've chosen to add it to
the sl28cpld driver was that I don't want to clutter the directory
with many small board specific drivers. They all have the simple-mfd
parent driver in common. In the end it's up to you of course, so
separate driver?
-michael
On 9/8/25 00:04, Michael Walle wrote:
> Hi Guenter,
>
>>> static const struct of_device_id sl28cpld_hwmon_of_match[] = {
>>> - { .compatible = "kontron,sl28cpld-fan" },
>>> + { .compatible = "kontron,sl28cpld-fan", .data = &sl28cpld_hwmon_chip_info },
>>> + { .compatible = "kontron,sa67mcu-hwmon", .data = &sa67mcu_hwmon_chip_info },
>>
>> Effectively this means that the two chips have completely different functionality.
>> One reports fan speeds, the other reports voltages and current.
>> This should be a separate driver.
>
> Fair enough. I wasn't sure, the reason why I've chosen to add it to
> the sl28cpld driver was that I don't want to clutter the directory
> with many small board specific drivers. They all have the simple-mfd
> parent driver in common. In the end it's up to you of course, so
> separate driver?
>
Yes, please. The parent is irrelevant. Functionality isn't.
Thanks,
Guenter
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