[PATCH linux dev-4.10 v8 1/2] hwmon: (ucd9000) Add gpio chip interface
Christopher Bostic
cbostic at linux.vnet.ibm.com
Fri Sep 8 04:38:00 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.
Present requirements only call for retrieving current state of pin
values and their direction. No requirement at this time to switch
modes between output and input within the device driver.
Signed-off-by: Christopher Bostic <cbostic at linux.vnet.ibm.com>
---
v8 - Remove redundant ! ops for gpio get_direction method
v7 - Reorder this patch from #2 in series to #1
v6 - Break out sysfs clear logged faults into separate patch
- Fix logic bug that was bitwise inverting instead of !
- Add further comments about assumptions related to pin mux.
v5 - Clean up remaining branch return statements to !! non
branching method.
- Clean up white space issues.
- Add return codes to error messages.
- Add comments describing assumptions of ucd90160 type.
- Define gpio direction set methods.
- Add unique id for each ucd9000 in system for gpio chip.
v4 - Change status check from branch to a !! non branching method
- Remove usage comments on libgpiod for the struct gpio_chip
methods.
- Clean up some text formatting.
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 | 206 ++++++++++++++++++++++++++++++++++++++++++
1 file changed, 206 insertions(+)
diff --git a/drivers/hwmon/pmbus/ucd9000.c b/drivers/hwmon/pmbus/ucd9000.c
index 3e3aa95..8c0d3d3 100644
--- a/drivers/hwmon/pmbus/ucd9000.c
+++ b/drivers/hwmon/pmbus/ucd9000.c
@@ -26,6 +26,7 @@
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/i2c/pmbus.h>
+#include <linux/gpio.h>
#include "pmbus.h"
enum chips { ucd9000, ucd90120, ucd90124, ucd90160, ucd9090, ucd90910 };
@@ -34,8 +35,18 @@
#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)
@@ -46,9 +57,13 @@
#define UCD9000_NUM_FAN 4
+#define UCD9000_GPIO_NAME_LEN 16
+#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 +134,166 @@ 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 select GPIO %d: %d\n", offset,
+ ret);
+
+ 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 %d config: %d\n",
+ offset, ret);
+
+ 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_err(&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_err(&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_err(&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) {
+ dev_err(&client->dev, "failed to read GPIO %d config: %d\n",
+ offset, ret);
+
+ 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) {
+ dev_err(&client->dev, "failed to read GPIO %d config: %d\n",
+ offset, ret);
+
+ 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) {
+ dev_err(&client->dev, "Failed to write GPIO %d config: %d\n",
+ offset, ret);
+
+ 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 int ucd9000_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
@@ -227,6 +402,37 @@ static int ucd9000_probe(struct i2c_client *client,
| PMBUS_HAVE_FAN34 | PMBUS_HAVE_STATUS_FAN34;
}
+ /*
+ * Note:
+ *
+ * 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 = (const char *)&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 = 1;
+ data->gpio.base = -1;
+
+ /*
+ * TODO: set ngpio for ucd9000 devs that aren't 90160 type
+ */
+ 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, "Could not add gpiochip: %d\n", ret);
+ return ret;
+ }
+
return pmbus_do_probe(client, mid, info);
}
--
1.8.2.2
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