[PATCH linux dev-4.10 v3 1/2] hwmon: (ucd9000) Add gpio chip interface and clear logged faults
Christopher Bostic
cbostic at linux.vnet.ibm.com
Fri Aug 18 11:35:25 AEST 2017
Add a struct gpio_chip and define some methods so that this device's
I/O can be accessed via /sys/class/gpio.
Add capability to clear logged faults via sysfs.
Signed-off-by: Christopher Bostic <cbostic at linux.vnet.ibm.com>
---
v3 - Correct bug in gpio_chip get method. Wasn't retrieving
gpio config information correctly.
- Remove old debugfs flag from previous pmbus core changes.
- Remove all sysfs files for mfr_status command.
- Add comments on direct i2c_smbus calls to clarify that no page
set is required.
v2 - Remove clear_faults file - redundant since all other sysfs
core accesses result in an automatic clear fault.
- Removed local status_word and status_vout register dumps and
use the new pmbus core status facilities instead.
- Rename gpi<x>_fault to gpi<x>_alarm to better match core naming
conventions.
- Add full register dump for mfr_status.
- Add gpio chip to device structure and use gpio interfaces.
---
drivers/hwmon/pmbus/ucd9000.c | 136 +++++++++++++++++++++++++++++++++++++++++-
1 file changed, 134 insertions(+), 2 deletions(-)
diff --git a/drivers/hwmon/pmbus/ucd9000.c b/drivers/hwmon/pmbus/ucd9000.c
index 3e3aa95..af44c1e 100644
--- a/drivers/hwmon/pmbus/ucd9000.c
+++ b/drivers/hwmon/pmbus/ucd9000.c
@@ -26,6 +26,9 @@
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/i2c/pmbus.h>
+#include <linux/sysfs.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/gpio.h>
#include "pmbus.h"
enum chips { ucd9000, ucd90120, ucd90124, ucd90160, ucd9090, ucd90910 };
@@ -34,8 +37,16 @@
#define UCD9000_NUM_PAGES 0xd6
#define UCD9000_FAN_CONFIG_INDEX 0xe7
#define UCD9000_FAN_CONFIG 0xe8
+#define UCD9000_LOGGED_FAULTS 0xea
+#define UCD9000_GPIO_SELECT 0xfa
+#define UCD9000_GPIO_CONFIG 0xfb
#define UCD9000_DEVICE_ID 0xfd
+/* GPIO CONFIG bits */
+#define UCD9000_GPIO_CONFIG_ENABLE BIT(0)
+#define UCD9000_GPIO_CONFIG_OUT_ENABLE BIT(1)
+#define UCD9000_GPIO_CONFIG_STATUS BIT(3)
+
#define UCD9000_MON_TYPE(x) (((x) >> 5) & 0x07)
#define UCD9000_MON_PAGE(x) ((x) & 0x0f)
@@ -46,9 +57,12 @@
#define UCD9000_NUM_FAN 4
+#define UCD90160_NUM_GPIOS 26
+
struct ucd9000_data {
u8 fan_data[UCD9000_NUM_FAN][I2C_SMBUS_BLOCK_MAX];
struct pmbus_driver_info info;
+ struct gpio_chip gpio;
};
#define to_ucd9000_data(_info) container_of(_info, struct ucd9000_data, info)
@@ -119,6 +133,92 @@ static int ucd9000_read_byte_data(struct i2c_client *client, int page, int reg)
};
MODULE_DEVICE_TABLE(i2c, ucd9000_id);
+static int ucd9000_gpio_read_config(struct i2c_client *client,
+ unsigned int offset)
+{
+ int ret;
+
+ /* No page set required */
+ ret = i2c_smbus_write_byte_data(client, UCD9000_GPIO_SELECT, offset);
+ if (ret < 0) {
+ dev_err(&client->dev,
+ "Failed to read pin ID %d\n", offset);
+ return ret;
+ }
+
+ return i2c_smbus_read_byte_data(client, UCD9000_GPIO_CONFIG);
+}
+
+static int ucd9000_gpio_get(struct gpio_chip *gc, unsigned int offset)
+{
+ struct i2c_client *client = gpiochip_get_data(gc);
+ int ret;
+
+ ret = ucd9000_gpio_read_config(client, offset);
+ if (ret < 0) {
+ dev_err(&client->dev,
+ "failed to read GPIO config\n");
+ return ret;
+ }
+
+ return ret & UCD9000_GPIO_CONFIG_STATUS ? 1 : 0;
+}
+
+static int ucd9000_gpio_get_direction(struct gpio_chip *gc,
+ unsigned int offset)
+{
+ struct i2c_client *client = gpiochip_get_data(gc);
+ int ret;
+
+ ret = ucd9000_gpio_read_config(client, offset);
+ if (ret < 0) {
+ dev_err(&client->dev,
+ "failed to read GPIO config\n");
+ return ret;
+ }
+
+ return ret & UCD9000_GPIO_CONFIG_OUT_ENABLE ? 0 : 1;
+}
+
+/*
+ * Defined so that libgpiod tool can access pin states. No plan to actually
+ * change pin direction within this driver.
+ */
+static int ucd9000_gpio_direction_input(struct gpio_chip *gc,
+ unsigned int offset)
+{
+ return 0;
+}
+
+static ssize_t ucd9000_clear_logged_faults(struct device *dev,
+ struct device_attribute *attr, const char *buf,
+ size_t count)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ int ret;
+
+ /* No page set required */
+ ret = i2c_smbus_write_byte_data(client, UCD9000_LOGGED_FAULTS, 0);
+ if (ret) {
+ dev_err(&client->dev, "Failed to clear logged faults\n");
+ return ret;
+ }
+
+ return count;
+}
+
+static DEVICE_ATTR(clear_logged_faults, 0200, NULL,
+ ucd9000_clear_logged_faults);
+
+static struct attribute *ucd9000_attributes[] = {
+ &dev_attr_clear_logged_faults.attr,
+ NULL
+};
+
+static const struct attribute_group ucd9000_attr_group = {
+ .attrs = ucd9000_attributes,
+};
+
static int ucd9000_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
@@ -227,7 +327,39 @@ static int ucd9000_probe(struct i2c_client *client,
| PMBUS_HAVE_FAN34 | PMBUS_HAVE_STATUS_FAN34;
}
- return pmbus_do_probe(client, mid, info);
+ data->gpio.label = "gpio-ucd9000";
+ data->gpio.get_direction = ucd9000_gpio_get_direction;
+ data->gpio.direction_input = ucd9000_gpio_direction_input;
+ data->gpio.get = ucd9000_gpio_get;
+ data->gpio.can_sleep = 1;
+ data->gpio.base = -1;
+ if (mid->driver_data == ucd90160)
+ data->gpio.ngpio = UCD90160_NUM_GPIOS;
+ data->gpio.parent = &client->dev;
+ data->gpio.owner = THIS_MODULE;
+
+ ret = devm_gpiochip_add_data(&client->dev, &data->gpio, client);
+ if (ret) {
+ data->gpio.parent = NULL;
+ dev_warn(&client->dev, "Count not add gpiochip\n");
+ return ret;
+ }
+
+ dev_info(&client->dev, "gpios %i...%i\n", data->gpio.base,
+ data->gpio.base + data->gpio.ngpio - 1);
+
+ ret = sysfs_create_group(&client->dev.kobj,
+ &ucd9000_attr_group);
+ if (ret < 0)
+ return ret;
+
+ return pmbus_do_probe(client, mid, info);
+}
+
+static int ucd9000_remove(struct i2c_client *client)
+{
+ sysfs_remove_group(&client->dev.kobj, &ucd9000_attr_group);
+ return pmbus_do_remove(client);
}
/* This is the driver that will be inserted */
@@ -236,7 +368,7 @@ static int ucd9000_probe(struct i2c_client *client,
.name = "ucd9000",
},
.probe = ucd9000_probe,
- .remove = pmbus_do_remove,
+ .remove = ucd9000_remove,
.id_table = ucd9000_id,
};
--
1.8.2.2
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