[PATCH v3 1/2] hwmon: (pmbus) add a function to check the presence of a block register

[PATCH v3 1/2] hwmon: (pmbus) add a function to check the presence of a block register

[Adam Wujek]

Other functions (like pmbus_check_byte_register) cannot be used to check
the presence of a block register, because it will generate error when PEC
is used.

Signed-off-by: Adam Wujek <dev_public@wujek.eu>
---
Notes:
  Changes in v2:
    - Use Phase 0xff when setting the page
  Changes in v3:
    - remove not needed initialization of a buffer
    - add checking the flag PMBUS_READ_STATUS_AFTER_FAILED_CHECK

 drivers/hwmon/pmbus/pmbus_core.c | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
index acf78d0829d9..a1c70877ae68 100644
--- a/drivers/hwmon/pmbus/pmbus_core.c
+++ b/drivers/hwmon/pmbus/pmbus_core.c
@@ -421,6 +421,18 @@ static int _pmbus_read_byte_data(struct i2c_client *client, int page, int reg)
 	return pmbus_read_byte_data(client, page, reg);
 }

+static int pmbus_read_block_data(struct i2c_client *client, int page, u8 reg,
+				 char *data_buf)
+{
+	int rv;
+
+	rv = pmbus_set_page(client, page, 0xff);
+	if (rv < 0)
+		return rv;
+
+	return i2c_smbus_read_block_data(client, reg, data_buf);
+}
+
 static struct pmbus_sensor *pmbus_find_sensor(struct pmbus_data *data, int page,
 					      int reg)
 {
@@ -558,6 +570,22 @@ bool pmbus_check_word_register(struct i2c_client *client, int page, int reg)
 }
 EXPORT_SYMBOL_NS_GPL(pmbus_check_word_register, PMBUS);

+static bool pmbus_check_block_register(struct i2c_client *client, int page,
+				       int reg)
+{
+	int rv;
+	struct pmbus_data *data = i2c_get_clientdata(client);
+	char data_buf[I2C_SMBUS_BLOCK_MAX + 2];
+
+	rv = pmbus_read_block_data(client, page, reg, data_buf);
+	if (rv >= 0 && !(data->flags & PMBUS_SKIP_STATUS_CHECK))
+		rv = pmbus_check_status_cml(client);
+	if (rv < 0 && (data->flags & PMBUS_READ_STATUS_AFTER_FAILED_CHECK))
+		data->read_status(client, -1);
+	pmbus_clear_fault_page(client, -1);
+	return rv >= 0;
+}
+
 const struct pmbus_driver_info *pmbus_get_driver_info(struct i2c_client *client)
 {
 	struct pmbus_data *data = i2c_get_clientdata(client);
--
2.17.1

[PATCH v3 2/2] hwmon: (pmbus) add MFR_* registers to debugfs

[Adam Wujek]

Add registers to debugfs:
PMBUS_MFR_ID
PMBUS_MFR_MODEL
PMBUS_MFR_REVISION
PMBUS_MFR_LOCATION
PMBUS_MFR_DATE
PMBUS_MFR_SERIAL

To reduce the number of debugfs entries, only values from page 0 are
reported. It is assumed that values of these registers are the same for
all pages. Please note that the PMBUS standard allows added registers to
be page-specific.

Signed-off-by: Adam Wujek <dev_public@wujek.eu>
---
  - This is a reworked patch to report the registers only once (for page 0)
  Changes in v2:
    - no changes
  Changes in v3:
    - Change last paragraph od the commit message
    - fix formating in the comment
 drivers/hwmon/pmbus/pmbus_core.c | 99 +++++++++++++++++++++++++++++++-
 1 file changed, 97 insertions(+), 2 deletions(-)

diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c
index a1c70877ae68..9c55b0cf1511 100644
--- a/drivers/hwmon/pmbus/pmbus_core.c
+++ b/drivers/hwmon/pmbus/pmbus_core.c
@@ -2659,6 +2659,34 @@ static int pmbus_debugfs_get_status(void *data, u64 *val)
 DEFINE_DEBUGFS_ATTRIBUTE(pmbus_debugfs_ops_status, pmbus_debugfs_get_status,
 			 NULL, "0x%04llx\n");

+static ssize_t pmbus_debugfs_mfr_read(struct file *file, char __user *buf,
+				       size_t count, loff_t *ppos)
+{
+	int rc;
+	struct pmbus_debugfs_entry *entry = file->private_data;
+	char data[I2C_SMBUS_BLOCK_MAX + 2] = { 0 };
+
+	rc = pmbus_read_block_data(entry->client, entry->page, entry->reg,
+				   data);
+	if (rc < 0)
+		return rc;
+
+	/* Add newline at the end of a read data */
+	data[rc] = '\n';
+
+	/* Include newline into the length */
+	rc += 1;
+
+	return simple_read_from_buffer(buf, count, ppos, data, rc);
+}
+
+static const struct file_operations pmbus_debugfs_ops_mfr = {
+	.llseek = noop_llseek,
+	.read = pmbus_debugfs_mfr_read,
+	.write = NULL,
+	.open = simple_open,
+};
+
 static int pmbus_debugfs_get_pec(void *data, u64 *val)
 {
 	struct i2c_client *client = data;
@@ -2723,9 +2751,13 @@ static int pmbus_init_debugfs(struct i2c_client *client,
 		return -ENODEV;
 	}

-	/* Allocate the max possible entries we need. */
+	/*
+	 * Allocate the max possible entries we need.
+	 * 6 entries device-specific
+	 * 10 entries page-specific
+	 */
 	entries = devm_kcalloc(data->dev,
-			       data->info->pages * 10, sizeof(*entries),
+			       6 + data->info->pages * 10, sizeof(*entries),
 			       GFP_KERNEL);
 	if (!entries)
 		return -ENOMEM;
@@ -2733,6 +2765,69 @@ static int pmbus_init_debugfs(struct i2c_client *client,
 	debugfs_create_file("pec", 0664, data->debugfs, client,
 			    &pmbus_debugfs_ops_pec);

+	/*
+	 * Add device-specific entries.
+	 * Please note that the PMBUS standard allows all registers to be
+	 * page-specific.
+	 * To reduce the number of debugfs entries for devices with many pages
+	 * assume that values of the following registers are the same for all
+	 * pages and report values only for page 0.
+	 */
+	if (pmbus_check_block_register(client, 0, PMBUS_MFR_ID)) {
+		entries[idx].client = client;
+		entries[idx].page = 0;
+		entries[idx].reg = PMBUS_MFR_ID;
+		debugfs_create_file("mfr_id", 0444, data->debugfs,
+				    &entries[idx++],
+				    &pmbus_debugfs_ops_mfr);
+	}
+
+	if (pmbus_check_block_register(client, 0, PMBUS_MFR_MODEL)) {
+		entries[idx].client = client;
+		entries[idx].page = 0;
+		entries[idx].reg = PMBUS_MFR_MODEL;
+		debugfs_create_file("mfr_model", 0444, data->debugfs,
+				    &entries[idx++],
+				    &pmbus_debugfs_ops_mfr);
+	}
+
+	if (pmbus_check_block_register(client, 0, PMBUS_MFR_REVISION)) {
+		entries[idx].client = client;
+		entries[idx].page = 0;
+		entries[idx].reg = PMBUS_MFR_REVISION;
+		debugfs_create_file("mfr_revision", 0444, data->debugfs,
+				    &entries[idx++],
+				    &pmbus_debugfs_ops_mfr);
+	}
+
+	if (pmbus_check_block_register(client, 0, PMBUS_MFR_LOCATION)) {
+		entries[idx].client = client;
+		entries[idx].page = 0;
+		entries[idx].reg = PMBUS_MFR_LOCATION;
+		debugfs_create_file("mfr_location", 0444, data->debugfs,
+				    &entries[idx++],
+				    &pmbus_debugfs_ops_mfr);
+	}
+
+	if (pmbus_check_block_register(client, 0, PMBUS_MFR_DATE)) {
+		entries[idx].client = client;
+		entries[idx].page = 0;
+		entries[idx].reg = PMBUS_MFR_DATE;
+		debugfs_create_file("mfr_date", 0444, data->debugfs,
+				    &entries[idx++],
+				    &pmbus_debugfs_ops_mfr);
+	}
+
+	if (pmbus_check_block_register(client, 0, PMBUS_MFR_SERIAL)) {
+		entries[idx].client = client;
+		entries[idx].page = 0;
+		entries[idx].reg = PMBUS_MFR_SERIAL;
+		debugfs_create_file("mfr_serial", 0444, data->debugfs,
+				    &entries[idx++],
+				    &pmbus_debugfs_ops_mfr);
+	}
+
+	/* Add page specific entries */
 	for (i = 0; i < data->info->pages; ++i) {
 		/* Check accessibility of status register if it's not page 0 */
 		if (!i || pmbus_check_status_register(client, i)) {
--
2.17.1