pcmcia: add new CIS access helpers

As a replacement to pcmcia_get_{first,next}_tuple() and
pcmcia_get_tuple_data(), three new -- and easier to use --
functions are added:

- pcmcia_get_tuple() to get the very first CIS entry of one
  type.

- pcmcia_loop_tuple() to loop over all CIS entries of one type.

- pcmcia_get_mac_from_cis() to read out the hardware MAC address
  from CISTPL_FUNCE.

Only a handful of drivers need these functions anyway, as most
CIS access is already handled by pcmcia_loop_config(), which
now shares the same backed (pccard_loop_tuple()) with
pcmcia_loop_tuple().

A pcmcia_get_mac_from_cis() bug noted by Komuro
<komurojun-mbn@nifty.com> has been fixed in this revision.

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
diff --git a/drivers/pcmcia/pcmcia_resource.c b/drivers/pcmcia/pcmcia_resource.c
index d919e96..0bfb05a 100644
--- a/drivers/pcmcia/pcmcia_resource.c
+++ b/drivers/pcmcia/pcmcia_resource.c
@@ -20,6 +20,7 @@
 #include <linux/delay.h>
 #include <linux/pci.h>
 #include <linux/device.h>
+#include <linux/netdevice.h>
 
 #include <pcmcia/cs_types.h>
 #include <pcmcia/ss.h>
@@ -885,13 +886,40 @@
 
 
 struct pcmcia_cfg_mem {
-	tuple_t tuple;
+	struct pcmcia_device *p_dev;
+	void *priv_data;
+	int (*conf_check) (struct pcmcia_device *p_dev,
+			   cistpl_cftable_entry_t *cfg,
+			   cistpl_cftable_entry_t *dflt,
+			   unsigned int vcc,
+			   void *priv_data);
 	cisparse_t parse;
-	u8 buf[256];
 	cistpl_cftable_entry_t dflt;
 };
 
 /**
+ * pcmcia_do_loop_config() - internal helper for pcmcia_loop_config()
+ *
+ * pcmcia_do_loop_config() is the internal callback for the call from
+ * pcmcia_loop_config() to pccard_loop_tuple(). Data is transferred
+ * by a struct pcmcia_cfg_mem.
+ */
+static int pcmcia_do_loop_config(tuple_t *tuple, cisparse_t *parse, void *priv)
+{
+	cistpl_cftable_entry_t *cfg = &parse->cftable_entry;
+	struct pcmcia_cfg_mem *cfg_mem = priv;
+
+	/* default values */
+	cfg_mem->p_dev->conf.ConfigIndex = cfg->index;
+	if (cfg->flags & CISTPL_CFTABLE_DEFAULT)
+		cfg_mem->dflt = *cfg;
+
+	return cfg_mem->conf_check(cfg_mem->p_dev, cfg, &cfg_mem->dflt,
+				   cfg_mem->p_dev->socket->socket.Vcc,
+				   cfg_mem->priv_data);
+}
+
+/**
  * pcmcia_loop_config() - loop over configuration options
  * @p_dev:	the struct pcmcia_device which we need to loop for.
  * @conf_check:	function to call for each configuration option.
@@ -913,48 +941,173 @@
 		       void *priv_data)
 {
 	struct pcmcia_cfg_mem *cfg_mem;
-
-	tuple_t *tuple;
 	int ret;
-	unsigned int vcc;
 
 	cfg_mem = kzalloc(sizeof(struct pcmcia_cfg_mem), GFP_KERNEL);
 	if (cfg_mem == NULL)
 		return -ENOMEM;
 
-	/* get the current Vcc setting */
-	vcc = p_dev->socket->socket.Vcc;
+	cfg_mem->p_dev = p_dev;
+	cfg_mem->conf_check = conf_check;
+	cfg_mem->priv_data = priv_data;
 
-	tuple = &cfg_mem->tuple;
-	tuple->TupleData = cfg_mem->buf;
-	tuple->TupleDataMax = 255;
-	tuple->TupleOffset = 0;
-	tuple->DesiredTuple = CISTPL_CFTABLE_ENTRY;
-	tuple->Attributes = 0;
+	ret = pccard_loop_tuple(p_dev->socket, p_dev->func,
+				CISTPL_CFTABLE_ENTRY, &cfg_mem->parse,
+				cfg_mem, pcmcia_do_loop_config);
 
-	ret = pcmcia_get_first_tuple(p_dev, tuple);
-	while (!ret) {
-		cistpl_cftable_entry_t *cfg = &cfg_mem->parse.cftable_entry;
-
-		if (pcmcia_get_tuple_data(p_dev, tuple))
-			goto next_entry;
-
-		if (pcmcia_parse_tuple(tuple, &cfg_mem->parse))
-			goto next_entry;
-
-		/* default values */
-		p_dev->conf.ConfigIndex = cfg->index;
-		if (cfg->flags & CISTPL_CFTABLE_DEFAULT)
-			cfg_mem->dflt = *cfg;
-
-		ret = conf_check(p_dev, cfg, &cfg_mem->dflt, vcc, priv_data);
-		if (!ret)
-			break;
-
-next_entry:
-		ret = pcmcia_get_next_tuple(p_dev, tuple);
-	}
-
+	kfree(cfg_mem);
 	return ret;
 }
 EXPORT_SYMBOL(pcmcia_loop_config);
+
+
+struct pcmcia_loop_mem {
+	struct pcmcia_device *p_dev;
+	void *priv_data;
+	int (*loop_tuple) (struct pcmcia_device *p_dev,
+			   tuple_t *tuple,
+			   void *priv_data);
+};
+
+/**
+ * pcmcia_do_loop_tuple() - internal helper for pcmcia_loop_config()
+ *
+ * pcmcia_do_loop_tuple() is the internal callback for the call from
+ * pcmcia_loop_tuple() to pccard_loop_tuple(). Data is transferred
+ * by a struct pcmcia_cfg_mem.
+ */
+static int pcmcia_do_loop_tuple(tuple_t *tuple, cisparse_t *parse, void *priv)
+{
+	struct pcmcia_loop_mem *loop = priv;
+
+	return loop->loop_tuple(loop->p_dev, tuple, loop->priv_data);
+};
+
+/**
+ * pcmcia_loop_tuple() - loop over tuples in the CIS
+ * @p_dev:	the struct pcmcia_device which we need to loop for.
+ * @code:	which CIS code shall we look for?
+ * @priv_data:	private data to be passed to the loop_tuple function.
+ * @loop_tuple:	function to call for each CIS entry of type @function. IT
+ *		gets passed the raw tuple and @priv_data.
+ *
+ * pcmcia_loop_tuple() loops over all CIS entries of type @function, and
+ * calls the @loop_tuple function for each entry. If the call to @loop_tuple
+ * returns 0, the loop exits. Returns 0 on success or errorcode otherwise.
+ */
+int pcmcia_loop_tuple(struct pcmcia_device *p_dev, cisdata_t code,
+		      int (*loop_tuple) (struct pcmcia_device *p_dev,
+					 tuple_t *tuple,
+					 void *priv_data),
+		      void *priv_data)
+{
+	struct pcmcia_loop_mem loop = {
+		.p_dev = p_dev,
+		.loop_tuple = loop_tuple,
+		.priv_data = priv_data};
+
+	return pccard_loop_tuple(p_dev->socket, p_dev->func, code, NULL,
+				 &loop, pcmcia_do_loop_tuple);
+};
+EXPORT_SYMBOL(pcmcia_loop_tuple);
+
+
+struct pcmcia_loop_get {
+	size_t len;
+	cisdata_t **buf;
+};
+
+/**
+ * pcmcia_do_get_tuple() - internal helper for pcmcia_get_tuple()
+ *
+ * pcmcia_do_get_tuple() is the internal callback for the call from
+ * pcmcia_get_tuple() to pcmcia_loop_tuple(). As we're only interested in
+ * the first tuple, return 0 unconditionally. Create a memory buffer large
+ * enough to hold the content of the tuple, and fill it with the tuple data.
+ * The caller is responsible to free the buffer.
+ */
+static int pcmcia_do_get_tuple(struct pcmcia_device *p_dev, tuple_t *tuple,
+			       void *priv)
+{
+	struct pcmcia_loop_get *get = priv;
+
+	*get->buf = kzalloc(tuple->TupleDataLen, GFP_KERNEL);
+	if (*get->buf) {
+		get->len = tuple->TupleDataLen;
+		memcpy(*get->buf, tuple->TupleData, tuple->TupleDataLen);
+	}
+	return 0;
+};
+
+/**
+ * pcmcia_get_tuple() - get first tuple from CIS
+ * @p_dev:	the struct pcmcia_device which we need to loop for.
+ * @code:	which CIS code shall we look for?
+ * @buf:        pointer to store the buffer to.
+ *
+ * pcmcia_get_tuple() gets the content of the first CIS entry of type @code.
+ * It returns the buffer length (or zero). The caller is responsible to free
+ * the buffer passed in @buf.
+ */
+size_t pcmcia_get_tuple(struct pcmcia_device *p_dev, cisdata_t code,
+			unsigned char **buf)
+{
+	struct pcmcia_loop_get get = {
+		.len = 0,
+		.buf = buf,
+	};
+
+	*get.buf = NULL;
+	pcmcia_loop_tuple(p_dev, code, pcmcia_do_get_tuple, &get);
+
+	return get.len;
+};
+EXPORT_SYMBOL(pcmcia_get_tuple);
+
+
+/**
+ * pcmcia_do_get_mac() - internal helper for pcmcia_get_mac_from_cis()
+ *
+ * pcmcia_do_get_mac() is the internal callback for the call from
+ * pcmcia_get_mac_from_cis() to pcmcia_loop_tuple(). We check whether the
+ * tuple contains a proper LAN_NODE_ID of length 6, and copy the data
+ * to struct net_device->dev_addr[i].
+ */
+static int pcmcia_do_get_mac(struct pcmcia_device *p_dev, tuple_t *tuple,
+			     void *priv)
+{
+	struct net_device *dev = priv;
+	int i;
+
+	if (tuple->TupleData[0] != CISTPL_FUNCE_LAN_NODE_ID)
+		return -EINVAL;
+	if (tuple->TupleDataLen < ETH_ALEN + 2) {
+		dev_warn(&p_dev->dev, "Invalid CIS tuple length for "
+			"LAN_NODE_ID\n");
+		return -EINVAL;
+	}
+
+	if (tuple->TupleData[1] != ETH_ALEN) {
+		dev_warn(&p_dev->dev, "Invalid header for LAN_NODE_ID\n");
+		return -EINVAL;
+	}
+	for (i = 0; i < 6; i++)
+		dev->dev_addr[i] = tuple->TupleData[i+2];
+	return 0;
+};
+
+/**
+ * pcmcia_get_mac_from_cis() - read out MAC address from CISTPL_FUNCE
+ * @p_dev:	the struct pcmcia_device for which we want the address.
+ * @dev:	a properly prepared struct net_device to store the info to.
+ *
+ * pcmcia_get_mac_from_cis() reads out the hardware MAC address from
+ * CISTPL_FUNCE and stores it into struct net_device *dev->dev_addr which
+ * must be set up properly by the driver (see examples!).
+ */
+int pcmcia_get_mac_from_cis(struct pcmcia_device *p_dev, struct net_device *dev)
+{
+	return pcmcia_loop_tuple(p_dev, CISTPL_FUNCE, pcmcia_do_get_mac, dev);
+};
+EXPORT_SYMBOL(pcmcia_get_mac_from_cis);
+