MFD: ucb1x00-core: add handling for ucb1x00 reset

Provide a way to handle the software controlled ucb1x00 reset signal
from the ucb1x00-core driver without having to code platform specifics
into these drivers.

Acked-by: Jochen Friedrich <jochen@scram.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

2 files changed, 20 insertions, 4 deletions

diff --git a/drivers/mfd/ucb1x00-core.c b/drivers/mfd/ucb1x00-core.c
index cc1c0dce7bd9..42eee633b864 100644
--- a/drivers/mfd/ucb1x00-core.c
+++ b/drivers/mfd/ucb1x00-core.c
@@ -530,13 +530,17 @@ static struct class ucb1x00_class = {
 
 static int ucb1x00_probe(struct mcp *mcp)
 {
-        struct ucb1x00 *ucb;
+        struct ucb1x00_plat_data *pdata = mcp->attached_device.platform_data;
         struct ucb1x00_driver *drv;
-        struct ucb1x00_plat_data *pdata;
+        struct ucb1x00 *ucb;
         unsigned int id;
         int ret = -ENODEV;
         int temp;
 
+        /* Tell the platform to deassert the UCB1x00 reset */
+        if (pdata && pdata->reset)
+                pdata->reset(UCB_RST_PROBE);
+
         mcp_enable(mcp);
         id = mcp_reg_read(mcp, UCB_ID);
 
@@ -550,7 +554,6 @@ static int ucb1x00_probe(struct mcp *mcp)
         if (!ucb)
                 goto err_disable;
 
-        pdata = mcp->attached_device.platform_data;
         ucb->dev.class = &ucb1x00_class;
         ucb->dev.parent = &mcp->attached_device;
         dev_set_name(&ucb->dev, "ucb1x00");
@@ -606,7 +609,7 @@ static int ucb1x00_probe(struct mcp *mcp)
         }
         mutex_unlock(&ucb1x00_mutex);
 
-        goto out;
+        return ret;
 
  err_irq:
         free_irq(ucb->irq, ucb);
@@ -618,11 +621,14 @@ static int ucb1x00_probe(struct mcp *mcp)
  err_disable:
         mcp_disable(mcp);
  out:
+        if (pdata && pdata->reset)
+                pdata->reset(UCB_RST_PROBE_FAIL);
         return ret;
 }
 
 static void ucb1x00_remove(struct mcp *mcp)
 {
+        struct ucb1x00_plat_data *pdata = mcp->attached_device.platform_data;
         struct ucb1x00 *ucb = mcp_get_drvdata(mcp);
         struct list_head *l, *n;
         int ret;
@@ -643,6 +649,9 @@ static void ucb1x00_remove(struct mcp *mcp)
 
         free_irq(ucb->irq, ucb);
         device_unregister(&ucb->dev);
+
+        if (pdata && pdata->reset)
+                pdata->reset(UCB_RST_REMOVE);
 }
 
 int ucb1x00_register_driver(struct ucb1x00_driver *drv)
diff --git a/include/linux/mfd/ucb1x00.h b/include/linux/mfd/ucb1x00.h
index 731b23a656c0..fd088cc6a4ca 100644
--- a/include/linux/mfd/ucb1x00.h
+++ b/include/linux/mfd/ucb1x00.h
@@ -104,7 +104,14 @@
 #define UCB_MODE_DYN_VFLAG_ENA  (1 << 12)
 #define UCB_MODE_AUD_OFF_CAN    (1 << 13)
 
+enum ucb1x00_reset {
+        UCB_RST_PROBE,
+        UCB_RST_REMOVE,
+        UCB_RST_PROBE_FAIL,
+};
+
 struct ucb1x00_plat_data {
+        void                    (*reset)(enum ucb1x00_reset);
         int                     gpio_base;
 };