powerpc/pmac: Convert windfarm_smu_sat to new i2c probing

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>

1 files changed, 47 insertions, 79 deletions

diff --git a/drivers/macintosh/windfarm_smu_sat.c b/drivers/macintosh/windfarm_smu_sat.c
index 65a8ff3e1f8e..72dfe191235b 100644
--- a/drivers/macintosh/windfarm_smu_sat.c
+++ b/drivers/macintosh/windfarm_smu_sat.c
@@ -20,7 +20,7 @@
 
 #include "windfarm.h"
 
-#define VERSION "0.2"
+#define VERSION "1.0"
 
 #define DEBUG
 
@@ -34,11 +34,12 @@
 #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");