From: Christopher Bostic <cbos...@linux.vnet.ibm.com>

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 <cbos...@linux.vnet.ibm.com>
Signed-off-by: Andrew Jeffery <and...@aj.id.au>
Signed-off-by: Eddie James <eaja...@linux.vnet.ibm.com>
---
 drivers/hwmon/pmbus/ucd9000.c | 201 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 201 insertions(+)

diff --git a/drivers/hwmon/pmbus/ucd9000.c b/drivers/hwmon/pmbus/ucd9000.c
index b74dbec..023fb9e 100644
--- a/drivers/hwmon/pmbus/ucd9000.c
+++ b/drivers/hwmon/pmbus/ucd9000.c
@@ -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 +166,146 @@ 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 int ucd9000_probe(struct i2c_client *client,
                         const struct i2c_device_id *id)
 {
@@ -263,6 +420,50 @@ 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;
+
+       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:
+               break;
+       }
+
+       data->gpio.parent = &client->dev;
+       data->gpio.owner = THIS_MODULE;
+       data->gpio.of_node = client->dev.of_node;
+
+       if (data->gpio.ngpio) {
+               ret = devm_gpiochip_add_data(&client->dev, &data->gpio,
+                                            client);
+               if (ret)
+                       dev_warn(&client->dev, "Could not add gpiochip: %d\n",
+                                ret);
+       }
+
        return pmbus_do_probe(client, mid, info);
 }
 
-- 
1.8.3.1

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