powerpc/pmac: Convert windfarm_smu_sat to new i2c probing
Benjamin Herrenschmidt [Wed, 18 Apr 2012 22:16:46 +0000 (22:16 +0000)]
This simplifies the driver to stop using the deprecated attach interface.

While at it we also implement teardown properly and fix the refcounting
by using a kref.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

drivers/macintosh/windfarm_smu_sat.c

index 65a8ff3..72dfe19 100644 (file)
@@ -20,7 +20,7 @@
 
 #include "windfarm.h"
 
-#define VERSION "0.2"
+#define VERSION "1.0"
 
 #define DEBUG
 
 #define MAX_AGE                msecs_to_jiffies(800)
 
 struct wf_sat {
+       struct kref             ref;
        int                     nr;
-       atomic_t                refcnt;
        struct mutex            mutex;
        unsigned long           last_read; /* jiffies when cache last updated */
        u8                      cache[16];
+       struct list_head        sensors;
        struct i2c_client       *i2c;
        struct device_node      *node;
 };
@@ -46,11 +47,12 @@ struct wf_sat {
 static struct wf_sat *sats[2];
 
 struct wf_sat_sensor {
-       int             index;
-       int             index2;         /* used for power sensors */
-       int             shift;
-       struct wf_sat   *sat;
-       struct wf_sensor sens;
+       struct list_head        link;
+       int                     index;
+       int                     index2;         /* used for power sensors */
+       int                     shift;
+       struct wf_sat           *sat;
+       struct wf_sensor        sens;
 };
 
 #define wf_to_sat(c)   container_of(c, struct wf_sat_sensor, sens)
@@ -142,7 +144,7 @@ static int wf_sat_read_cache(struct wf_sat *sat)
        return 0;
 }
 
-static int wf_sat_get(struct wf_sensor *sr, s32 *value)
+static int wf_sat_sensor_get(struct wf_sensor *sr, s32 *value)
 {
        struct wf_sat_sensor *sens = wf_to_sat(sr);
        struct wf_sat *sat = sens->sat;
@@ -175,58 +177,30 @@ static int wf_sat_get(struct wf_sensor *sr, s32 *value)
        return err;
 }
 
-static void wf_sat_release(struct wf_sensor *sr)
+static void wf_sat_release(struct kref *ref)
+{
+       struct wf_sat *sat = container_of(ref, struct wf_sat, ref);
+
+       if (sat->nr >= 0)
+               sats[sat->nr] = NULL;
+       kfree(sat);
+}
+
+static void wf_sat_sensor_release(struct wf_sensor *sr)
 {
        struct wf_sat_sensor *sens = wf_to_sat(sr);
        struct wf_sat *sat = sens->sat;
 
-       if (atomic_dec_and_test(&sat->refcnt)) {
-               if (sat->nr >= 0)
-                       sats[sat->nr] = NULL;
-               kfree(sat);
-       }
        kfree(sens);
+       kref_put(&sat->ref, wf_sat_release);
 }
 
 static struct wf_sensor_ops wf_sat_ops = {
-       .get_value      = wf_sat_get,
-       .release        = wf_sat_release,
+       .get_value      = wf_sat_sensor_get,
+       .release        = wf_sat_sensor_release,
        .owner          = THIS_MODULE,
 };
 
-static struct i2c_driver wf_sat_driver;
-
-static void wf_sat_create(struct i2c_adapter *adapter, struct device_node *dev)
-{
-       struct i2c_board_info info;
-       struct i2c_client *client;
-       const u32 *reg;
-       u8 addr;
-
-       reg = of_get_property(dev, "reg", NULL);
-       if (reg == NULL)
-               return;
-       addr = *reg;
-       DBG(KERN_DEBUG "wf_sat: creating sat at address %x\n", addr);
-
-       memset(&info, 0, sizeof(struct i2c_board_info));
-       info.addr = (addr >> 1) & 0x7f;
-       info.platform_data = dev;
-       strlcpy(info.type, "wf_sat", I2C_NAME_SIZE);
-
-       client = i2c_new_device(adapter, &info);
-       if (client == NULL) {
-               printk(KERN_ERR "windfarm: failed to attach smu-sat to i2c\n");
-               return;
-       }
-
-       /*
-        * Let i2c-core delete that device on driver removal.
-        * This is safe because i2c-core holds the core_lock mutex for us.
-        */
-       list_add_tail(&client->detected, &wf_sat_driver.clients);
-}
-
 static int wf_sat_probe(struct i2c_client *client,
                        const struct i2c_device_id *id)
 {
@@ -246,9 +220,10 @@ static int wf_sat_probe(struct i2c_client *client,
                return -ENOMEM;
        sat->nr = -1;
        sat->node = of_node_get(dev);
-       atomic_set(&sat->refcnt, 0);
+       kref_init(&sat->ref);
        mutex_init(&sat->mutex);
        sat->i2c = client;
+       INIT_LIST_HEAD(&sat->sensors);
        i2c_set_clientdata(client, sat);
 
        vsens[0] = vsens[1] = -1;
@@ -310,14 +285,15 @@ static int wf_sat_probe(struct i2c_client *client,
                sens->index2 = -1;
                sens->shift = shift;
                sens->sat = sat;
-               atomic_inc(&sat->refcnt);
                sens->sens.ops = &wf_sat_ops;
                sens->sens.name = (char *) (sens + 1);
                snprintf(sens->sens.name, 16, "%s-%d", name, cpu);
 
-               if (wf_register_sensor(&sens->sens)) {
-                       atomic_dec(&sat->refcnt);
+               if (wf_register_sensor(&sens->sens))
                        kfree(sens);
+               else {
+                       list_add(&sens->link, &sat->sensors);
+                       kref_get(&sat->ref);
                }
        }
 
@@ -336,14 +312,15 @@ static int wf_sat_probe(struct i2c_client *client,
                sens->index2 = isens[core];
                sens->shift = 0;
                sens->sat = sat;
-               atomic_inc(&sat->refcnt);
                sens->sens.ops = &wf_sat_ops;
                sens->sens.name = (char *) (sens + 1);
                snprintf(sens->sens.name, 16, "cpu-power-%d", cpu);
 
-               if (wf_register_sensor(&sens->sens)) {
-                       atomic_dec(&sat->refcnt);
+               if (wf_register_sensor(&sens->sens))
                        kfree(sens);
+               else {
+                       list_add(&sens->link, &sat->sensors);
+                       kref_get(&sat->ref);
                }
        }
 
@@ -353,42 +330,35 @@ static int wf_sat_probe(struct i2c_client *client,
        return 0;
 }
 
-static int wf_sat_attach(struct i2c_adapter *adapter)
-{
-       struct device_node *busnode, *dev = NULL;
-       struct pmac_i2c_bus *bus;
-
-       bus = pmac_i2c_adapter_to_bus(adapter);
-       if (bus == NULL)
-               return -ENODEV;
-       busnode = pmac_i2c_get_bus_node(bus);
-
-       while ((dev = of_get_next_child(busnode, dev)) != NULL)
-               if (of_device_is_compatible(dev, "smu-sat"))
-                       wf_sat_create(adapter, dev);
-       return 0;
-}
-
 static int wf_sat_remove(struct i2c_client *client)
 {
        struct wf_sat *sat = i2c_get_clientdata(client);
+       struct wf_sat_sensor *sens;
 
-       /* XXX TODO */
-
+       /* release sensors */
+       while(!list_empty(&sat->sensors)) {
+               sens = list_first_entry(&sat->sensors,
+                                       struct wf_sat_sensor, link);
+               list_del(&sens->link);
+               wf_unregister_sensor(&sens->sens);
+       }
        sat->i2c = NULL;
+       i2c_set_clientdata(client, NULL);
+       kref_put(&sat->ref, wf_sat_release);
+
        return 0;
 }
 
 static const struct i2c_device_id wf_sat_id[] = {
-       { "wf_sat", 0 },
+       { "MAC,smu-sat", 0 },
        { }
 };
+MODULE_DEVICE_TABLE(i2c, wf_sat_id);
 
 static struct i2c_driver wf_sat_driver = {
        .driver = {
                .name           = "wf_smu_sat",
        },
-       .attach_adapter = wf_sat_attach,
        .probe          = wf_sat_probe,
        .remove         = wf_sat_remove,
        .id_table       = wf_sat_id,
@@ -399,15 +369,13 @@ static int __init sat_sensors_init(void)
        return i2c_add_driver(&wf_sat_driver);
 }
 
-#if 0  /* uncomment when module_exit() below is uncommented */
 static void __exit sat_sensors_exit(void)
 {
        i2c_del_driver(&wf_sat_driver);
 }
-#endif
 
 module_init(sat_sensors_init);
-/*module_exit(sat_sensors_exit); Uncomment when cleanup is implemented */
+module_exit(sat_sensors_exit);
 
 MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>");
 MODULE_DESCRIPTION("SMU satellite sensors for PowerMac thermal control");