Re: [PATCH v2 3/4] hwmon: (pmbus/core): Add interrupt support
From: Naresh Solanki
Date: Tue Feb 14 2023 - 09:11:32 EST
Hi
On 11-02-2023 09:07 pm, Guenter Roeck wrote:
On Tue, Feb 07, 2023 at 01:02:40PM +0100, Naresh Solanki wrote:
From: Patrick Rudolph <patrick.rudolph@xxxxxxxxxxxxx>
Implement PMBUS irq handler.
Signed-off-by: Patrick Rudolph <patrick.rudolph@xxxxxxxxxxxxx>
Signed-off-by: Naresh Solanki <Naresh.Solanki@xxxxxxxxxxxxx>
---
drivers/hwmon/pmbus/pmbus.h | 2 +-
drivers/hwmon/pmbus/pmbus_core.c | 85 ++++++++++++++++++++++++++++++++
2 files changed, 86 insertions(+), 1 deletion(-)
diff --git a/drivers/hwmon/pmbus/pmbus.h b/drivers/hwmon/pmbus/pmbus.h
index 713ea7915425..11e84e141126 100644
--- a/drivers/hwmon/pmbus/pmbus.h
+++ b/drivers/hwmon/pmbus/pmbus.h
@@ -26,7 +26,7 @@ enum pmbus_regs {
PMBUS_CAPABILITY = 0x19,
PMBUS_QUERY = 0x1A,
-
+ PMBUS_SMBALERT_MASK = 0x1B,
PMBUS_VOUT_MODE = 0x20,
PMBUS_VOUT_COMMAND = 0x21,
PMBUS_VOUT_TRIM = 0x22,
diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
index 5ccae8126a56..d5403baad60a 100644
--- a/drivers/hwmon/pmbus/pmbus_core.c
+++ b/drivers/hwmon/pmbus/pmbus_core.c
@@ -3093,6 +3093,85 @@ static int pmbus_regulator_register(struct pmbus_data *data)
}
#endif
+static int pmbus_write_smbalert_mask(struct i2c_client *client, u8 page, u8 reg, u8 val)
+{
+ int err;
+
+ err = pmbus_check_word_register(client, page, reg | (val << 8));
+ if (err)
+ return err;
I am not convinced that this is necessary. The next command will return an
error anyway if the register or the specific mask is not supported, so what
is the point ?
Sure. will remove.
+
+ return pmbus_write_word_data(client, page, PMBUS_SMBALERT_MASK, reg | (val << 8));
+}
+
+static irqreturn_t pmbus_fault_handler(int irq, void *pdata)
+{
+ struct pmbus_data *data = pdata;
+ struct i2c_client *client = to_i2c_client(data->dev);
+ int i, status;
+
+ mutex_lock(&data->update_lock);
+ for (i = 0; i < data->info->pages; i++) {
+ status = pmbus_read_status_word(client, i);
+ if (status < 0) {
+ mutex_unlock(&data->update_lock);
+ return status;
+ }
+
+ if (status & ~(PB_STATUS_OFF | PB_STATUS_BUSY | PB_STATUS_POWER_GOOD_N))
+ pmbus_clear_fault_page(client, i);
+ }
+ mutex_unlock(&data->update_lock);
+
+ return IRQ_HANDLED;
+}
+
+static int pmbus_irq_setup(struct i2c_client *client, struct pmbus_data *data)
+{
+ struct device *dev = &client->dev;
+ const struct pmbus_status_category *cat;
+ const struct pmbus_status_assoc *bit;
+ int i, j, err, ret, func;
+ u8 mask;
+ u8 misc_status[] = {PMBUS_STATUS_CML, PMBUS_STATUS_OTHER, PMBUS_STATUS_MFR_SPECIFIC,
+ PMBUS_STATUS_FAN_12, PMBUS_STATUS_FAN_34};
static const u8 ...
Done
+
+ for (i = 0; i < data->info->pages; i++) {
+ func = data->info->func[i];
+
+ for (j = 0; j < ARRAY_SIZE(pmbus_status_flag_map); j++) {
+ cat = &pmbus_status_flag_map[j];
+ if (!(func & cat->func))
+ continue;
+ mask = 0;
+ for (bit = cat->bits; bit->pflag; bit++)
+ mask |= bit->pflag;
+
+ err = pmbus_write_smbalert_mask(client, i, cat->reg, ~mask);
+ if (err)
+ dev_err_once(dev, "Failed to set smbalert for reg 0x%02x\n",
+ cat->reg);
dev_err implies an error. This is ignored and thus not an error. On top of that,
not all chips support PMBUS_SMBALERT_MASK. All of those would see this message.
We can't have that. At best make it a dev_dbg.
Sure. Will make it dev_dbg_once.
+ }
+
+ for (j = 0; j < ARRAY_SIZE(misc_status); j++) {
+ err = pmbus_write_smbalert_mask(client, i, misc_status[j], 0xff);
+ if (err)
+ dev_err_once(dev, "Failed to set smbalert for reg 0x%02x\n",
+ misc_status[j]);
We definitely can't have a message here; that would fire for almost
every chip.
Sure. Will remove printing of error here.
+ }
+ }
+
+ /* Register notifiers - can fail if IRQ is not given */
If there is no irq, what is the point of executing this code in the first
place ? No, wait, in that case the function isn't called in the first place.
I think the comment doesn't add any value and is just confusing.
Will clean this comment.
+ ret = devm_request_threaded_irq(dev, client->irq, NULL, pmbus_fault_handler, 0,
+ "pmbus-irq", data);
+ if (ret) {
Why both "err" and "ret" ?
Will replace ret with err.
+ dev_warn(dev, "IRQ disabled %d\n", ret);
The calling code aborts, so this should be dev_err() and say something
better than "IRQ disabled"; It should be something like "failed to
request irq".
Sure. Will update to "failed to request an irq"
+ return ret;
+ }
+
+ return 0;
+}
+
static struct dentry *pmbus_debugfs_dir; /* pmbus debugfs directory */
#if IS_ENABLED(CONFIG_DEBUG_FS)
@@ -3455,6 +3534,12 @@ int pmbus_do_probe(struct i2c_client *client, struct pmbus_driver_info *info)
if (ret)
return ret;
+ if (client->irq > 0) {
+ ret = pmbus_irq_setup(client, data);
+ if (ret)
+ return ret;
+ }
+
I think it would be better to have the check in pmbus_irq_setup():
pmbus_irq_setup()
{
if (!client->irq)
return 0;
...
}
and here
ret = pmbus_irq_setup(client, data);
if (ret)
return ret;
Sure
ret = pmbus_init_debugfs(client, data);
if (ret)
dev_warn(dev, "Failed to register debugfs\n");