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Subject[PATCH v4 2/2] hwmon: (ucd9000) Add debugfs attributes to provide mfr_status
Date
From: Christopher Bostic <cbostic@linux.vnet.ibm.com>

Expose the gpiN_fault fields of mfr_status as individual debugfs
attributes. This provides a way for users to be easily notified of gpi
faults. Also provide the whole mfr_status register in debugfs.

Signed-off-by: Christopher Bostic <cbostic@linux.vnet.ibm.com>
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Eddie James <eajames@linux.vnet.ibm.com>
---
drivers/hwmon/pmbus/ucd9000.c | 153 +++++++++++++++++++++++++++++++++++++++++-
1 file changed, 152 insertions(+), 1 deletion(-)

diff --git a/drivers/hwmon/pmbus/ucd9000.c b/drivers/hwmon/pmbus/ucd9000.c
index a34ffc4..f03c404 100644
--- a/drivers/hwmon/pmbus/ucd9000.c
+++ b/drivers/hwmon/pmbus/ucd9000.c
@@ -19,6 +19,7 @@
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

+#include <linux/debugfs.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of_device.h>
@@ -36,6 +37,7 @@
#define UCD9000_NUM_PAGES 0xd6
#define UCD9000_FAN_CONFIG_INDEX 0xe7
#define UCD9000_FAN_CONFIG 0xe8
+#define UCD9000_MFR_STATUS 0xf3
#define UCD9000_GPIO_SELECT 0xfa
#define UCD9000_GPIO_CONFIG 0xfb
#define UCD9000_DEVICE_ID 0xfd
@@ -63,13 +65,22 @@
#define UCD901XX_NUM_GPIOS 26
#define UCD90910_NUM_GPIOS 26

+#define UCD9000_DEBUGFS_NAME_LEN 24
+#define UCD9000_GPI_COUNT 8
+
struct ucd9000_data {
u8 fan_data[UCD9000_NUM_FAN][I2C_SMBUS_BLOCK_MAX];
struct pmbus_driver_info info;
struct gpio_chip gpio;
+ struct dentry *debugfs;
};
#define to_ucd9000_data(_info) container_of(_info, struct ucd9000_data, info)

+struct ucd9000_debugfs_entry {
+ struct i2c_client *client;
+ u8 index;
+};
+
static int ucd9000_get_fan_config(struct i2c_client *client, int fan)
{
int fan_config = 0;
@@ -306,6 +317,137 @@ static int ucd9000_gpio_direction_output(struct gpio_chip *gc,
val);
}

+#ifdef CONFIG_DEBUG_FS
+static int ucd9000_get_mfr_status(struct i2c_client *client, u8 *buffer)
+{
+ int ret = pmbus_set_page(client, 0);
+
+ if (ret < 0)
+ return ret;
+
+ /*
+ * With the ucd90120 and ucd90124 devices, this command [MFR_STATUS]
+ * is 2 bytes long (bits 0-15). With the ucd90240 this command is 5
+ * bytes long. With all other devices, it is 4 bytes long.
+ */
+ return i2c_smbus_read_block_data(client, UCD9000_MFR_STATUS, buffer);
+}
+
+static int ucd9000_debugfs_show_mfr_status_bit(void *data, u64 *val)
+{
+ struct ucd9000_debugfs_entry *entry = data;
+ struct i2c_client *client = entry->client;
+ u8 buffer[4];
+ int ret;
+
+ /*
+ * This attribute is only created for devices that return 4 bytes for
+ * status_mfr, so it's safe to call with 4-byte buffer.
+ */
+ ret = ucd9000_get_mfr_status(client, buffer);
+ if (ret < 0)
+ return ret;
+
+ /*
+ * Attribute only created for devices with gpi fault bits at bits
+ * 16-23, which is the second byte of the response.
+ */
+ *val = !!(buffer[1] & BIT(entry->index));
+
+ return 0;
+}
+DEFINE_DEBUGFS_ATTRIBUTE(ucd9000_debugfs_mfr_status_bit,
+ ucd9000_debugfs_show_mfr_status_bit, NULL, "%1lld\n");
+
+static ssize_t ucd9000_debugfs_read_mfr_status(struct file *file,
+ char __user *buf, size_t count,
+ loff_t *ppos)
+{
+ struct i2c_client *client = file->private_data;
+ u8 buffer[5] = { 0 }; /* Need max 5 bytes for any ucd9000 chip. */
+ char str[12] = { 0 }; /* Two chars per byte plus \n and \0. */
+ int i, num_bytes, num_chars = 0, rc;
+
+ num_bytes = ucd9000_get_mfr_status(client, buffer);
+ if (num_bytes < 0)
+ return num_bytes;
+
+ for (i = 0; i < num_bytes; ++i) {
+ rc = snprintf(&str[num_chars], (sizeof(str) - 1) - num_chars,
+ "%02x", buffer[i]);
+ if (rc <= 0)
+ break;
+
+ num_chars += rc;
+ }
+
+ str[num_chars] = '\n';
+
+ return simple_read_from_buffer(buf, count, ppos, str, num_chars + 2);
+}
+
+static const struct file_operations ucd9000_debugfs_show_mfr_status_fops = {
+ .llseek = noop_llseek,
+ .read = ucd9000_debugfs_read_mfr_status,
+ .open = simple_open,
+};
+
+static int ucd9000_init_debugfs(struct i2c_client *client,
+ const struct i2c_device_id *mid,
+ struct ucd9000_data *data)
+{
+ struct dentry *debugfs;
+ struct ucd9000_debugfs_entry *entries;
+ int i;
+ char name[UCD9000_DEBUGFS_NAME_LEN];
+
+ debugfs = pmbus_get_debugfs_dir(client);
+ if (!debugfs)
+ return -ENOENT;
+
+ data->debugfs = debugfs_create_dir(client->name, debugfs);
+ if (!data->debugfs)
+ return -ENOENT;
+
+ /*
+ * Of the chips this driver supports, only the UCD9090, UCD90160,
+ * and UCD90910 report GPI faults in their MFR_STATUS register, so only
+ * create the GPI fault debugfs attributes for those chips.
+ */
+ if (mid->driver_data == ucd9090 || mid->driver_data == ucd90160 ||
+ mid->driver_data == ucd90910) {
+ entries = devm_kzalloc(&client->dev,
+ sizeof(*entries) * UCD9000_GPI_COUNT,
+ GFP_KERNEL);
+ if (!entries)
+ return -ENOMEM;
+
+ for (i = 0; i < UCD9000_GPI_COUNT; i++) {
+ entries[i].client = client;
+ entries[i].index = i;
+ scnprintf(name, UCD9000_DEBUGFS_NAME_LEN,
+ "gpi%d_alarm", i + 1);
+ debugfs_create_file(name, 0444, data->debugfs,
+ &entries[i],
+ &ucd9000_debugfs_mfr_status_bit);
+ }
+ }
+
+ scnprintf(name, UCD9000_DEBUGFS_NAME_LEN, "mfr_status");
+ debugfs_create_file(name, 0444, data->debugfs, client,
+ &ucd9000_debugfs_show_mfr_status_fops);
+
+ return 0;
+}
+#else
+static int ucd9000_init_debugfs(struct i2c_client *client,
+ const struct i2c_device_id *mid,
+ struct ucd9000_data *data)
+{
+ return 0;
+}
+#endif /* CONFIG_DEBUG_FS */
+
static void ucd9000_probe_gpio(struct i2c_client *client,
const struct i2c_device_id *mid,
struct ucd9000_data *data)
@@ -464,7 +606,16 @@ static int ucd9000_probe(struct i2c_client *client,

ucd9000_probe_gpio(client, mid, data);

- return pmbus_do_probe(client, mid, info);
+ ret = pmbus_do_probe(client, mid, info);
+ if (ret)
+ return ret;
+
+ ret = ucd9000_init_debugfs(client, mid, data);
+ if (ret)
+ dev_warn(&client->dev, "Failed to register debugfs: %d\n",
+ ret);
+
+ return 0;
}

/* This is the driver that will be inserted */
--
1.8.3.1
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