pcmcia: Documentation update

Fill in missing descriptions and update some others for functions in
pcmcia_resource.c.

Tested-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>

1 files changed, 89 insertions, 22 deletions

diff --git a/drivers/pcmcia/pcmcia_resource.c b/drivers/pcmcia/pcmcia_resource.c
index 28de5e6e164c..3194d515c023 100644
--- a/drivers/pcmcia/pcmcia_resource.c
+++ b/drivers/pcmcia/pcmcia_resource.c
@@ -6,7 +6,7 @@
  * are Copyright (C) 1999 David A. Hinds.  All Rights Reserved.
  *
  * Copyright (C) 1999        David A. Hinds
- * Copyright (C) 2004-2005   Dominik Brodowski
+ * Copyright (C) 2004-2010   Dominik Brodowski
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
@@ -55,6 +55,12 @@ struct resource *pcmcia_find_mem_region(u_long base, u_long num, u_long align,
 }
 
 
+/**
+ * release_io_space() - release IO ports allocated with alloc_io_space()
+ * @s: pcmcia socket
+ * @res: resource to release
+ *
+ */
 static void release_io_space(struct pcmcia_socket *s, struct resource *res)
 {
         resource_size_t num = resource_size(res);
@@ -80,9 +86,14 @@ static void release_io_space(struct pcmcia_socket *s, struct resource *res)
                         }
                 }
         }
-} /* release_io_space */
+}
+
 
-/** alloc_io_space
+/**
+ * alloc_io_space() - allocate IO ports for use by a PCMCIA device
+ * @s: pcmcia socket
+ * @res: resource to allocate (begin: begin, end: size)
+ * @lines: number of IO lines decoded by the PCMCIA card
  *
  * Special stuff for managing IO windows, because they are scarce
  */
@@ -134,7 +145,7 @@ static int alloc_io_space(struct pcmcia_socket *s, struct resource *res,
         }
         dev_dbg(&s->dev, "alloc_io_space request result %d: %pR\n", ret, res);
         return ret;
-} /* alloc_io_space */
+}
 
 
 /**
@@ -174,7 +185,7 @@ static int pcmcia_access_config(struct pcmcia_device *p_dev,
         mutex_unlock(&s->ops_mutex);
 
         return ret;
-} /* pcmcia_access_config */
+}
 
 
 /**
@@ -203,6 +214,16 @@ int pcmcia_write_config_byte(struct pcmcia_device *p_dev, off_t where, u8 val)
 EXPORT_SYMBOL(pcmcia_write_config_byte);
 
 
+/**
+ * pcmcia_map_mem_page() - modify iomem window to point to a different offset
+ * @p_dev: pcmcia device
+ * @res: iomem resource already enabled by pcmcia_request_window()
+ * @offset: card_offset to map
+ *
+ * pcmcia_map_mem_page() modifies what can be read and written by accessing
+ * an iomem range previously enabled by pcmcia_request_window(), by setting
+ * the card_offset value to @offset.
+ */
 int pcmcia_map_mem_page(struct pcmcia_device *p_dev, struct resource *res,
                         unsigned int offset)
 {
@@ -221,12 +242,13 @@ int pcmcia_map_mem_page(struct pcmcia_device *p_dev, struct resource *res,
                 dev_warn(&p_dev->dev, "failed to set_mem_map\n");
         mutex_unlock(&s->ops_mutex);
         return ret;
-} /* pcmcia_map_mem_page */
+}
 EXPORT_SYMBOL(pcmcia_map_mem_page);
 
 
 /**
  * pcmcia_fixup_iowidth() - reduce io width to 8bit
+ * @p_dev: pcmcia device
  *
  * pcmcia_fixup_iowidth() allows a PCMCIA device driver to reduce the
  * IO width to 8bit after having called pcmcia_enable_device()
@@ -275,6 +297,8 @@ EXPORT_SYMBOL(pcmcia_fixup_iowidth);
 
 /**
  * pcmcia_fixup_vpp() - set Vpp to a new voltage level
+ * @p_dev: pcmcia device
+ * @new_vpp: new Vpp voltage
  *
  * pcmcia_fixup_vpp() allows a PCMCIA device driver to set Vpp to
  * a new voltage level between calls to pcmcia_enable_device()
@@ -312,6 +336,17 @@ unlock:
 EXPORT_SYMBOL(pcmcia_fixup_vpp);
 
 
+/**
+ * pcmcia_release_configuration() - physically disable a PCMCIA device
+ * @p_dev: pcmcia device
+ *
+ * pcmcia_release_configuration() is the 1:1 counterpart to
+ * pcmcia_enable_device(): If a PCMCIA device is no longer used by any
+ * driver, the Vpp voltage is set to 0, IRQs will no longer be generated,
+ * and I/O ranges will be disabled. As pcmcia_release_io() and
+ * pcmcia_release_window() still need to be called, device drivers are
+ * expected to call pcmcia_disable_device() instead.
+ */
 int pcmcia_release_configuration(struct pcmcia_device *p_dev)
 {
         pccard_io_map io = { 0, 0, 0, 0, 1 };
@@ -324,7 +359,7 @@ int pcmcia_release_configuration(struct pcmcia_device *p_dev)
         if (p_dev->_locked) {
                 p_dev->_locked = 0;
                 if (--(s->lock_count) == 0) {
-                        s->socket.flags = SS_OUTPUT_ENA;   /* Is this correct? */
+                        s->socket.flags = SS_OUTPUT_ENA; /* Is this correct? */
                         s->socket.Vpp = 0;
                         s->socket.io_irq = 0;
                         s->ops->set_socket(s, &s->socket);
@@ -346,16 +381,18 @@ int pcmcia_release_configuration(struct pcmcia_device *p_dev)
         mutex_unlock(&s->ops_mutex);
 
         return 0;
-} /* pcmcia_release_configuration */
+}
 
 
-/** pcmcia_release_io
+/**
+ * pcmcia_release_io() - release I/O allocated by a PCMCIA device
+ * @p_dev: pcmcia device
  *
- * Release_io() releases the I/O ranges allocated by a client.  This
- * may be invoked some time after a card ejection has already dumped
- * the actual socket configuration, so if the client is "stale", we
- * don't bother checking the port ranges against the current socket
- * values.
+ * pcmcia_release_io() releases the I/O ranges allocated by a PCMCIA
+ * device.  This may be invoked some time after a card ejection has
+ * already dumped the actual socket configuration, so if the client is
+ * "stale", we don't bother checking the port ranges against the
+ * current socket values.
  */
 static int pcmcia_release_io(struct pcmcia_device *p_dev)
 {
@@ -383,10 +420,13 @@ out:
         return ret;
 } /* pcmcia_release_io */
 
+
 /**
  * pcmcia_release_window() - release reserved iomem for PCMCIA devices
+ * @p_dev: pcmcia device
+ * @res: iomem resource to release
  *
- * pcmcia_release_window() releases struct resource *res which was
+ * pcmcia_release_window() releases &struct resource *res which was
  * previously reserved by calling pcmcia_request_window().
  */
 int pcmcia_release_window(struct pcmcia_device *p_dev, struct resource *res)
@@ -431,9 +471,15 @@ int pcmcia_release_window(struct pcmcia_device *p_dev, struct resource *res)
 } /* pcmcia_release_window */
 EXPORT_SYMBOL(pcmcia_release_window);
 
+
 /**
  * pcmcia_enable_device() - set up and activate a PCMCIA device
+ * @p_dev: the associated PCMCIA device
  *
+ * pcmcia_enable_device() physically enables a PCMCIA device. It parses
+ * the flags passed to in @flags and stored in @p_dev->flags and sets up
+ * the Vpp voltage, enables the speaker line, I/O ports and store proper
+ * values to configuration registers.
  */
 int pcmcia_enable_device(struct pcmcia_device *p_dev)
 {
@@ -565,8 +611,9 @@ EXPORT_SYMBOL(pcmcia_enable_device);
 
 /**
  * pcmcia_request_io() - attempt to reserve port ranges for PCMCIA devices
+ * @p_dev: the associated PCMCIA device
  *
- * pcmcia_request_io() attepts to reserve the IO port ranges specified in
+ * pcmcia_request_io() attempts to reserve the IO port ranges specified in
  * &struct pcmcia_device @p_dev->resource[0] and @p_dev->resource[1]. The
  * "start" value is the requested start of the IO port resource; "end"
  * reflects the number of ports requested. The number of IO lines requested
@@ -630,11 +677,13 @@ EXPORT_SYMBOL(pcmcia_request_io);
 
 /**
  * pcmcia_request_irq() - attempt to request a IRQ for a PCMCIA device
+ * @p_dev: the associated PCMCIA device
+ * @handler: IRQ handler to register
  *
- * pcmcia_request_irq() is a wrapper around request_irq which will allow
+ * pcmcia_request_irq() is a wrapper around request_irq() which allows
  * the PCMCIA core to clean up the registration in pcmcia_disable_device().
  * Drivers are free to use request_irq() directly, but then they need to
- * call free_irq themselfves, too. Also, only IRQF_SHARED capable IRQ
+ * call free_irq() themselfves, too. Also, only %IRQF_SHARED capable IRQ
  * handlers are allowed.
  */
 int __must_check pcmcia_request_irq(struct pcmcia_device *p_dev,
@@ -657,12 +706,14 @@ EXPORT_SYMBOL(pcmcia_request_irq);
 
 /**
  * pcmcia_request_exclusive_irq() - attempt to request an exclusive IRQ first
+ * @p_dev: the associated PCMCIA device
+ * @handler: IRQ handler to register
  *
- * pcmcia_request_exclusive_irq() is a wrapper around request_irq which
+ * pcmcia_request_exclusive_irq() is a wrapper around request_irq() which
  * attempts first to request an exclusive IRQ. If it fails, it also accepts
  * a shared IRQ, but prints out a warning. PCMCIA drivers should allow for
  * IRQ sharing and either use request_irq directly (then they need to call
- * free_irq themselves, too), or the pcmcia_request_irq() function.
+ * free_irq() themselves, too), or the pcmcia_request_irq() function.
  */
 int __must_check
 __pcmcia_request_exclusive_irq(struct pcmcia_device *p_dev,
@@ -805,10 +856,13 @@ int pcmcia_setup_irq(struct pcmcia_device *p_dev)
 
 /**
  * pcmcia_request_window() - attempt to reserve iomem for PCMCIA devices
+ * @p_dev: the associated PCMCIA device
+ * @res: &struct resource pointing to p_dev->resource[2..5]
+ * @speed: access speed
  *
  * pcmcia_request_window() attepts to reserve an iomem ranges specified in
- * struct resource *res pointing to one of the entries in
- * struct pcmcia_device *p_dev->resource[2..5]. The "start" value is the
+ * &struct resource @res pointing to one of the entries in
+ * &struct pcmcia_device @p_dev->resource[2..5]. The "start" value is the
  * requested start of the IO mem resource; "end" reflects the size
  * requested.
  */
@@ -900,6 +954,19 @@ int pcmcia_request_window(struct pcmcia_device *p_dev, struct resource *res,
 } /* pcmcia_request_window */
 EXPORT_SYMBOL(pcmcia_request_window);
 
+
+/**
+ * pcmcia_disable_device() - disable and clean up a PCMCIA device
+ * @p_dev: the associated PCMCIA device
+ *
+ * pcmcia_disable_device() is the driver-callable counterpart to
+ * pcmcia_enable_device(): If a PCMCIA device is no longer used,
+ * drivers are expected to clean up and disable the device by calling
+ * this function. Any I/O ranges (iomem and ioports) will be released,
+ * the Vpp voltage will be set to 0, and IRQs will no longer be
+ * generated -- at least if there is no other card function (of
+ * multifunction devices) being used.
+ */
 void pcmcia_disable_device(struct pcmcia_device *p_dev)
 {
         int i;