hwmon: (ucd9000) Add gpio and debugfs interfaces

From: Christopher Bostic <[email protected]>

Add a struct gpio_chip and define some methods so that this device's I/O can be accessed via /sys/class/gpio.

Signed-off-by Christopher Bostic <[email protected]>

Signed-off-by Andrew Jeffery <[email protected]>

Signed-off-by Eddie James <[email protected]>

---
 drivers/hwmon/pmbus/ucd9000.c | 201 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 201 insertions(+)

drivers/hwmon/pmbus/ucd9000.c +201 -0

index b74dbec..a34ffc4 100644
@@ -27,6 +27,7 @@
 #include <linux/slab.h>
 #include <linux/i2c.h>
 #include <linux/pmbus.h>
+#include <linux/gpio.h>
 #include "pmbus.h"
 
 enum chips { ucd9000, ucd90120, ucd90124, ucd90160, ucd9090, ucd90910 };

@@ -35,8 +36,18 @@
 #define UCD9000_NUM_PAGES		0xd6
 #define UCD9000_FAN_CONFIG_INDEX	0xe7
 #define UCD9000_FAN_CONFIG		0xe8
+#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_OUT_VALUE	BIT(2)
+#define UCD9000_GPIO_CONFIG_STATUS	BIT(3)
+#define UCD9000_GPIO_INPUT		0
+#define UCD9000_GPIO_OUTPUT		1
+
 #define UCD9000_MON_TYPE(x)	(((x) >> 5) & 0x07)
 #define UCD9000_MON_PAGE(x)	((x) & 0x0f)
 

@@ -47,9 +58,15 @@
 
 #define UCD9000_NUM_FAN		4
 
+#define UCD9000_GPIO_NAME_LEN	16
+#define UCD9090_NUM_GPIOS	23
+#define UCD901XX_NUM_GPIOS	26
+#define UCD90910_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)
 

@@ -149,6 +166,188 @@ static int ucd9000_read_byte_data(struct i2c_client *client, int page, int reg)
 };
 MODULE_DEVICE_TABLE(of, ucd9000_of_match);
 
+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)
+		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)
+		return ret;
+
+	return !!(ret & UCD9000_GPIO_CONFIG_STATUS);
+}
+
+static void ucd9000_gpio_set(struct gpio_chip *gc, unsigned int offset,
+			     int value)
+{
+	struct i2c_client *client = gpiochip_get_data(gc);
+	int ret;
+
+	ret = ucd9000_gpio_read_config(client, offset);
+	if (ret < 0) {
+		dev_dbg(&client->dev, "failed to read GPIO %d config: %d\n",
+			offset, ret);
+		return;
+	}
+
+	if (value) {
+		if (ret & UCD9000_GPIO_CONFIG_STATUS)
+			return;
+
+		ret |= UCD9000_GPIO_CONFIG_STATUS;
+	} else {
+		if (!(ret & UCD9000_GPIO_CONFIG_STATUS))
+			return;
+
+		ret &= ~UCD9000_GPIO_CONFIG_STATUS;
+	}
+
+	ret |= UCD9000_GPIO_CONFIG_ENABLE;
+
+	/* Page set not required */
+	ret = i2c_smbus_write_byte_data(client, UCD9000_GPIO_CONFIG, ret);
+	if (ret < 0) {
+		dev_dbg(&client->dev, "Failed to write GPIO %d config: %d\n",
+			offset, ret);
+		return;
+	}
+
+	ret &= ~UCD9000_GPIO_CONFIG_ENABLE;
+
+	ret = i2c_smbus_write_byte_data(client, UCD9000_GPIO_CONFIG, ret);
+	if (ret < 0)
+		dev_dbg(&client->dev, "Failed to write GPIO %d config: %d\n",
+			offset, ret);
+}
+
+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)
+		return ret;
+
+	return !(ret & UCD9000_GPIO_CONFIG_OUT_ENABLE);
+}
+
+static int ucd9000_gpio_set_direction(struct gpio_chip *gc,
+				      unsigned int offset, bool direction_out,
+				      int requested_out)
+{
+	struct i2c_client *client = gpiochip_get_data(gc);
+	int ret, config, out_val;
+
+	ret = ucd9000_gpio_read_config(client, offset);
+	if (ret < 0)
+		return ret;
+
+	if (direction_out) {
+		out_val = requested_out ? UCD9000_GPIO_CONFIG_OUT_VALUE : 0;
+
+		if (ret & UCD9000_GPIO_CONFIG_OUT_ENABLE) {
+			if ((ret & UCD9000_GPIO_CONFIG_OUT_VALUE) == out_val)
+				return 0;
+		} else {
+			ret |= UCD9000_GPIO_CONFIG_OUT_ENABLE;
+		}
+
+		if (out_val)
+			ret |= UCD9000_GPIO_CONFIG_OUT_VALUE;
+		else
+			ret &= ~UCD9000_GPIO_CONFIG_OUT_VALUE;
+
+	} else {
+		if (!(ret & UCD9000_GPIO_CONFIG_OUT_ENABLE))
+			return 0;
+
+		ret &= ~UCD9000_GPIO_CONFIG_OUT_ENABLE;
+	}
+
+	ret |= UCD9000_GPIO_CONFIG_ENABLE;
+	config = ret;
+
+	/* Page set not required */
+	ret = i2c_smbus_write_byte_data(client, UCD9000_GPIO_CONFIG, config);
+	if (ret < 0)
+		return ret;
+
+	config &= ~UCD9000_GPIO_CONFIG_ENABLE;
+
+	return i2c_smbus_write_byte_data(client, UCD9000_GPIO_CONFIG, config);
+}
+
+static int ucd9000_gpio_direction_input(struct gpio_chip *gc,
+					unsigned int offset)
+{
+	return ucd9000_gpio_set_direction(gc, offset, UCD9000_GPIO_INPUT, 0);
+}
+
+static int ucd9000_gpio_direction_output(struct gpio_chip *gc,
+					 unsigned int offset, int val)
+{
+	return ucd9000_gpio_set_direction(gc, offset, UCD9000_GPIO_OUTPUT,
+					  val);
+}
+
+static void ucd9000_probe_gpio(struct i2c_client *client,
+			       const struct i2c_device_id *mid,
+			       struct ucd9000_data *data)
+{
+	int rc;
+
+	switch (mid->driver_data) {
+	case ucd9090:
+		data->gpio.ngpio = UCD9090_NUM_GPIOS;
+		break;
+	case ucd90120:
+	case ucd90124:
+	case ucd90160:
+		data->gpio.ngpio = UCD901XX_NUM_GPIOS;
+		break;
+	case ucd90910:
+		data->gpio.ngpio = UCD90910_NUM_GPIOS;
+		break;
+	default:
+		return; /* GPIO support is optional. */
+	}
+
+	/*
+	 * Pinmux support has not been added to the new gpio_chip.
+	 * This support should be added when possible given the mux
+	 * behavior of these IO devices.
+	 */
+	data->gpio.label = client->name;
+	data->gpio.get_direction = ucd9000_gpio_get_direction;
+	data->gpio.direction_input = ucd9000_gpio_direction_input;
+	data->gpio.direction_output = ucd9000_gpio_direction_output;
+	data->gpio.get = ucd9000_gpio_get;
+	data->gpio.set = ucd9000_gpio_set;
+	data->gpio.can_sleep = true;
+	data->gpio.base = -1;
+	data->gpio.parent = &client->dev;
+
+	rc = devm_gpiochip_add_data(&client->dev, &data->gpio, client);
+	if (rc)
+		dev_warn(&client->dev, "Could not add gpiochip: %d\n", rc);
+}
+
 static int ucd9000_probe(struct i2c_client *client,
 			 const struct i2c_device_id *id)
 {

@@ -263,6 +462,8 @@ static int ucd9000_probe(struct i2c_client *client,
 		  | PMBUS_HAVE_FAN34 | PMBUS_HAVE_STATUS_FAN34;
 	}
 
+	ucd9000_probe_gpio(client, mid, data);
+
 	return pmbus_do_probe(client, mid, info);
 }
 

Signature · 1 line

1.8.3.1

From: Christopher Bostic <[email protected]>

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 <[email protected]>

Signed-off-by Andrew Jeffery <[email protected]>

Signed-off-by Eddie James <[email protected]>

---
 drivers/hwmon/pmbus/ucd9000.c | 153 +++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 152 insertions(+), 1 deletion(-)

drivers/hwmon/pmbus/ucd9000.c +14 -0

index a34ffc4..f03c404 100644
@@ -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)
+{

drivers/hwmon/pmbus/ucd9000.c +42 -0

+	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;
+

drivers/hwmon/pmbus/ucd9000.c +76 -1

+
+	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 */

Signature · 1 line

1.8.3.1