| Message ID | 68d9f677-3dd7-24b3-141a-f1d49bd6bb5d@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
On Thu, Dec 07, 2017 at 04:19:45PM -0600, Eddie James wrote: > > > On 12/07/2017 02:53 PM, Guenter Roeck wrote: > >On Thu, Dec 07, 2017 at 01:50:38PM -0600, Eddie James wrote: > >>From: "Edward A. James" <eajames@us.ibm.com> > >> > >>Add debugfs entries for additional power supply data, including part > >>number, serial number, FRU number, firmware revision, ccin, and the > >>input history of the power supply. The input history is 10 minutes of > >>input power data in the form of twenty 30-second packets. Each packet > >>contains average and maximum power for that 30 second period. > >> > >>Signed-off-by: Edward A. James <eajames@us.ibm.com> > >>--- > >> drivers/hwmon/pmbus/ibm-cffps.c | 199 +++++++++++++++++++++++++++++++++++++++- > >> 1 file changed, 198 insertions(+), 1 deletion(-) > >> > >>diff --git a/drivers/hwmon/pmbus/ibm-cffps.c b/drivers/hwmon/pmbus/ibm-cffps.c > >>index cb56da6..6d19399 100644 > >>--- a/drivers/hwmon/pmbus/ibm-cffps.c > >>+++ b/drivers/hwmon/pmbus/ibm-cffps.c > >>@@ -8,12 +8,26 @@ > >> */ > >> #include <linux/bitops.h> > >>+#include <linux/debugfs.h> > >> #include <linux/device.h> > >>+#include <linux/fs.h> > >> #include <linux/i2c.h> > >>+#include <linux/jiffies.h> > >> #include <linux/module.h> > >>+#include <linux/mutex.h> > >> #include "pmbus.h" > >>+#define CFFPS_FRU_CMD 0x9A > >>+#define CFFPS_PN_CMD 0x9B > >>+#define CFFPS_SN_CMD 0x9E > >>+#define CFFPS_CCIN_CMD 0xBD > >>+#define CFFPS_FW_CMD_START 0xFA > >>+#define CFFPS_FW_NUM_BYTES 4 > >>+ > >>+#define CFFPS_INPUT_HISTORY_CMD 0xD6 > >>+#define CFFPS_INPUT_HISTORY_SIZE 100 > >>+ > >> /* STATUS_MFR_SPECIFIC bits */ > >> #define CFFPS_MFR_FAN_FAULT BIT(0) > >> #define CFFPS_MFR_THERMAL_FAULT BIT(1) > >>@@ -24,6 +38,144 @@ > >> #define CFFPS_MFR_VAUX_FAULT BIT(6) > >> #define CFFPS_MFR_CURRENT_SHARE_WARNING BIT(7) > >>+enum { > >>+ CFFPS_DEBUGFS_INPUT_HISTORY = 0, > >>+ CFFPS_DEBUGFS_FRU, > >>+ CFFPS_DEBUGFS_PN, > >>+ CFFPS_DEBUGFS_SN, > >>+ CFFPS_DEBUGFS_CCIN, > >>+ CFFPS_DEBUGFS_FW, > >>+ CFFPS_DEBUGFS_NUM_ENTRIES > >>+}; > >>+ > >>+struct ibm_cffps_input_history { > >>+ struct mutex update_lock; > >>+ unsigned long last_update; > >>+ > >>+ u8 byte_count; > >>+ u8 data[CFFPS_INPUT_HISTORY_SIZE]; > >>+}; > >>+ > >>+struct ibm_cffps { > >>+ struct i2c_client *client; > >>+ > >>+ struct ibm_cffps_input_history input_history; > >>+ > >>+ int debugfs_entries[CFFPS_DEBUGFS_NUM_ENTRIES]; > >>+}; > >>+ > >>+#define to_psu(x, y) container_of((x), struct ibm_cffps, debugfs_entries[(y)]) > >>+ > >>+static ssize_t ibm_cffps_read_input_history(struct ibm_cffps *psu, > >>+ char __user *buf, size_t count, > >>+ loff_t *ppos) > >>+{ > >>+ int rc; > >>+ u8 msgbuf0[1] = { CFFPS_INPUT_HISTORY_CMD }; > >>+ u8 msgbuf1[CFFPS_INPUT_HISTORY_SIZE + 1] = { 0 }; > >>+ struct i2c_msg msg[2] = { > >>+ { > >>+ .addr = psu->client->addr, > >>+ .flags = psu->client->flags, > >>+ .len = 1, > >>+ .buf = msgbuf0, > >>+ }, { > >>+ .addr = psu->client->addr, > >>+ .flags = psu->client->flags | I2C_M_RD, > >>+ .len = CFFPS_INPUT_HISTORY_SIZE + 1, > >>+ .buf = msgbuf1, > >>+ }, > >>+ }; > >>+ > >>+ if (!*ppos) { > >>+ mutex_lock(&psu->input_history.update_lock); > >>+ if (time_after(jiffies, psu->input_history.last_update + HZ)) { > >>+ /* > >>+ * Use a raw i2c transfer, since we need more bytes > >>+ * than Linux I2C supports through smbus xfr (only 32). > >>+ */ > >>+ rc = i2c_transfer(psu->client->adapter, msg, 2); > >>+ if (rc < 0) { > >>+ mutex_unlock(&psu->input_history.update_lock); > >>+ return rc; > >>+ } > >>+ > >>+ psu->input_history.byte_count = msgbuf1[0]; > >>+ memcpy(psu->input_history.data, &msgbuf1[1], > >>+ CFFPS_INPUT_HISTORY_SIZE); > >>+ psu->input_history.last_update = jiffies; > >>+ } > >>+ > >>+ mutex_unlock(&psu->input_history.update_lock); > >>+ } > >>+ > >>+ return simple_read_from_buffer(buf, count, ppos, > >>+ psu->input_history.data, > >>+ psu->input_history.byte_count); > >>+} > >>+ > >>+static ssize_t ibm_cffps_debugfs_op(struct file *file, char __user *buf, > >>+ size_t count, loff_t *ppos) > >>+{ > >>+ u8 cmd; > >>+ int i, rc; > >>+ int *idxp = file->private_data; > >>+ int idx = *idxp; > >>+ struct ibm_cffps *psu = to_psu(idxp, idx); > >>+ char data[I2C_SMBUS_BLOCK_MAX] = { 0 }; > >>+ > >>+ switch (idx) { > >>+ case CFFPS_DEBUGFS_INPUT_HISTORY: > >>+ return ibm_cffps_read_input_history(psu, buf, count, ppos); > >>+ case CFFPS_DEBUGFS_FRU: > >>+ cmd = CFFPS_FRU_CMD; > >>+ break; > >>+ case CFFPS_DEBUGFS_PN: > >>+ cmd = CFFPS_PN_CMD; > >>+ break; > >>+ case CFFPS_DEBUGFS_SN: > >>+ cmd = CFFPS_SN_CMD; > >>+ break; > >>+ case CFFPS_DEBUGFS_CCIN: > >>+ rc = i2c_smbus_read_word_data(psu->client, CFFPS_CCIN_CMD); > >>+ if (rc < 0) > >>+ return rc; > >>+ > >>+ rc = snprintf(data, 5, "%04X", rc); > >>+ goto done; > >>+ case CFFPS_DEBUGFS_FW: > >>+ for (i = 0; i < CFFPS_FW_NUM_BYTES; ++i) { > >>+ rc = i2c_smbus_read_byte_data(psu->client, > >>+ CFFPS_FW_CMD_START + i); > >>+ if (rc < 0) > >>+ return rc; > >>+ > >>+ snprintf(&data[i * 2], 3, "%02X", rc); > >>+ } > >>+ > >>+ rc = i * 2; > >>+ goto done; > >>+ default: > >>+ return -EINVAL; > >>+ } > >>+ > >>+ rc = i2c_smbus_read_block_data(psu->client, cmd, data); > >>+ if (rc < 0) > >>+ return rc; > >>+ > >>+done: > >>+ data[rc] = '\n'; > >>+ rc += 2; > >>+ > >>+ return simple_read_from_buffer(buf, count, ppos, data, rc); > >>+} > >>+ > >>+static const struct file_operations ibm_cffps_fops = { > >>+ .llseek = noop_llseek, > >>+ .read = ibm_cffps_debugfs_op, > >>+ .open = simple_open, > >>+}; > >>+ > >> static int ibm_cffps_read_byte_data(struct i2c_client *client, int page, > >> int reg) > >> { > >>@@ -119,7 +271,52 @@ static int ibm_cffps_read_word_data(struct i2c_client *client, int page, > >> static int ibm_cffps_probe(struct i2c_client *client, > >> const struct i2c_device_id *id) > >> { > >>- return pmbus_do_probe(client, id, &ibm_cffps_info); > >>+ int i, rc; > >>+ struct dentry *debugfs; > >>+ struct ibm_cffps *psu; > >>+ > >>+ rc = pmbus_do_probe(client, id, &ibm_cffps_info); > >>+ if (rc) > >>+ return rc; > >>+ > >>+ /* Don't fail the probe if we can't create debugfs */ > >>+ psu = devm_kzalloc(&client->dev, sizeof(*psu), GFP_KERNEL); > >>+ if (!psu) > >>+ return 0; > >>+ > >>+ psu->client = client; > >>+ mutex_init(&psu->input_history.update_lock); > >>+ if (jiffies > HZ) > >>+ /* time_after wouldn't succeed with last_update = 0 in test */ > >... but you are setting it to 'jiffies' elsewhere, so it can still end up > >being 0 at some point, especially since 'jiffies' starts with a large number > >and wraps a few minutes after boot. Not sure I understand the problem, > >actually. Can you elaborate ? > > Yea, not sure I understand it either, but basically, if we don't set > last_update to jiffies - HZ or similar at start up, the check above for > time_after(jiffies, last_upate + HZ) doesn't succeed soon after the boot. > This doesn't make any sense to me, unless time_after is broken, but setting > last_update to something relative to jiffies during probe fixes it. > That is easy; just set it unconditionally to jiffies - HZ. The 'jiffies > HZ' check is wrong; if jiffies happens to be < HZ, you'd still want to set the value to jiffies - HZ (and it will be somewhere between ULONG_MAX-HZ+1 .. ULONG_MAX). Problem is that jiffies doesn't start with 0 but with something large. That is why drivers typically have a 'valid' flag in addition to the jiffies check. Thanks, Guenter -- To unsubscribe from this list: send the line "unsubscribe linux-hwmon" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/hwmon/pmbus/ibm-cffps.c b/drivers/hwmon/pmbus/ibm-cffps.c index 6d19399..e5cb52a 100644 --- a/drivers/hwmon/pmbus/ibm-cffps.c +++ b/drivers/hwmon/pmbus/ibm-cffps.c @@ -90,6 +90,7 @@ static ssize_t ibm_cffps_read_input_history(struct ibm_cffps *psu, if (!*ppos) { mutex_lock(&psu->input_history.update_lock); if (time_after(jiffies, psu->input_history.last_update + HZ)) { +printk("succeeded time_after with jiffies[%d] last_update[%d]\n", jiffies, psu->input_history.last_update); /*