net/smsc911x: Add regulator support

Add some basic regulator support for the power pins, as needed
by the ST-Ericsson Snowball platform that powers up the SMSC911
chip using an external regulator.

Platforms that use regulators and the smsc911x and have no defined
regulator for the smsc911x and claim complete regulator
constraints with no dummy regulators will need to provide it, for
example using a fixed voltage regulator. It appears that this may
affect (apart from Ux500 Snowball) possibly these archs/machines
that from some grep:s appear to define both CONFIG_SMSC911X and
CONFIG_REGULATOR:

- ARM Freescale mx3 and OMAP 2 plus, Raumfeld machines
- Blackfin
- Super-H

Cc: Paul Mundt <lethal@linux-sh.org>
Cc: linux-sh@vger.kernel.org
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Tony Lindgren <tony@atomide.com>
Cc: linux-omap@vger.kernel.org
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: uclinux-dist-devel@blackfin.uclinux.org
Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Robert Marklund <robert.marklund@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/smsc/smsc911x.c

@@ -44,6 +44,7 @@
 #include <linux/module.h>
 #include <linux/netdevice.h>
 #include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
 #include <linux/sched.h>
 #include <linux/timer.h>
 #include <linux/bug.h>
@@ -88,6 +89,8 @@ struct smsc911x_ops {
 				unsigned int *buf, unsigned int wordcount);
 };
 
+#define SMSC911X_NUM_SUPPLIES 2
+
 struct smsc911x_data {
 	void __iomem *ioaddr;
 
@@ -138,6 +141,9 @@ struct smsc911x_data {
 
 	/* register access functions */
 	const struct smsc911x_ops *ops;
+
+	/* regulators */
+	struct regulator_bulk_data supplies[SMSC911X_NUM_SUPPLIES];
 };
 
 /* Easy access to information */
@@ -362,6 +368,76 @@ smsc911x_rx_readfifo_shift(struct smsc911x_data *pdata, unsigned int *buf,
 	spin_unlock_irqrestore(&pdata->dev_lock, flags);
 }
 
+/*
+ * enable resources, currently just regulators.
+ */
+static int smsc911x_enable_resources(struct platform_device *pdev)
+{
+	struct net_device *ndev = platform_get_drvdata(pdev);
+	struct smsc911x_data *pdata = netdev_priv(ndev);
+	int ret = 0;
+
+	ret = regulator_bulk_enable(ARRAY_SIZE(pdata->supplies),
+			pdata->supplies);
+	if (ret)
+		netdev_err(ndev, "failed to enable regulators %d\n",
+				ret);
+	return ret;
+}
+
+/*
+ * disable resources, currently just regulators.
+ */
+static int smsc911x_disable_resources(struct platform_device *pdev)
+{
+	struct net_device *ndev = platform_get_drvdata(pdev);
+	struct smsc911x_data *pdata = netdev_priv(ndev);
+	int ret = 0;
+
+	ret = regulator_bulk_disable(ARRAY_SIZE(pdata->supplies),
+			pdata->supplies);
+	return ret;
+}
+
+/*
+ * Request resources, currently just regulators.
+ *
+ * The SMSC911x has two power pins: vddvario and vdd33a, in designs where
+ * these are not always-on we need to request regulators to be turned on
+ * before we can try to access the device registers.
+ */
+static int smsc911x_request_resources(struct platform_device *pdev)
+{
+	struct net_device *ndev = platform_get_drvdata(pdev);
+	struct smsc911x_data *pdata = netdev_priv(ndev);
+	int ret = 0;
+
+	/* Request regulators */
+	pdata->supplies[0].supply = "vdd33a";
+	pdata->supplies[1].supply = "vddvario";
+	ret = regulator_bulk_get(&pdev->dev,
+			ARRAY_SIZE(pdata->supplies),
+			pdata->supplies);
+	if (ret)
+		netdev_err(ndev, "couldn't get regulators %d\n",
+				ret);
+	return ret;
+}
+
+/*
+ * Free resources, currently just regulators.
+ *
+ */
+static void smsc911x_free_resources(struct platform_device *pdev)
+{
+	struct net_device *ndev = platform_get_drvdata(pdev);
+	struct smsc911x_data *pdata = netdev_priv(ndev);
+
+	/* Free regulators */
+	regulator_bulk_free(ARRAY_SIZE(pdata->supplies),
+			pdata->supplies);
+}
+
 /* waits for MAC not busy, with timeout.  Only called by smsc911x_mac_read
  * and smsc911x_mac_write, so assumes mac_lock is held */
 static int smsc911x_mac_complete(struct smsc911x_data *pdata)
@@ -2092,6 +2168,9 @@ static int __devexit smsc911x_drv_remove(struct platform_device *pdev)
 
 	iounmap(pdata->ioaddr);
 
+	(void)smsc911x_disable_resources(pdev);
+	smsc911x_free_resources(pdev);
+
 	free_netdev(dev);
 
 	return 0;
@@ -2218,10 +2297,20 @@ static int __devinit smsc911x_drv_probe(struct platform_device *pdev)
 	pdata->dev = dev;
 	pdata->msg_enable = ((1 << debug) - 1);
 
+	platform_set_drvdata(pdev, dev);
+
+	retval = smsc911x_request_resources(pdev);
+	if (retval)
+		goto out_return_resources;
+
+	retval = smsc911x_enable_resources(pdev);
+	if (retval)
+		goto out_disable_resources;
+
 	if (pdata->ioaddr == NULL) {
 		SMSC_WARN(pdata, probe, "Error smsc911x base address invalid");
 		retval = -ENOMEM;
-		goto out_free_netdev_2;
+		goto out_disable_resources;
 	}
 
 	retval = smsc911x_probe_config_dt(&pdata->config, np);
@@ -2233,7 +2322,7 @@ static int __devinit smsc911x_drv_probe(struct platform_device *pdev)
 
 	if (retval) {
 		SMSC_WARN(pdata, probe, "Error smsc911x config not found");
-		goto out_unmap_io_3;
+		goto out_disable_resources;
 	}
 
 	/* assume standard, non-shifted, access to HW registers */
@@ -2244,7 +2333,7 @@ static int __devinit smsc911x_drv_probe(struct platform_device *pdev)
 
 	retval = smsc911x_init(dev);
 	if (retval < 0)
-		goto out_unmap_io_3;
+		goto out_disable_resources;
 
 	/* configure irq polarity and type before connecting isr */
 	if (pdata->config.irq_polarity == SMSC911X_IRQ_POLARITY_ACTIVE_HIGH)
@@ -2264,15 +2353,13 @@ static int __devinit smsc911x_drv_probe(struct platform_device *pdev)
 	if (retval) {
 		SMSC_WARN(pdata, probe,
 			  "Unable to claim requested irq: %d", dev->irq);
-		goto out_unmap_io_3;
+		goto out_free_irq;
 	}
 
-	platform_set_drvdata(pdev, dev);
-
 	retval = register_netdev(dev);
 	if (retval) {
 		SMSC_WARN(pdata, probe, "Error %i registering device", retval);
-		goto out_unset_drvdata_4;
+		goto out_free_irq;
 	} else {
 		SMSC_TRACE(pdata, probe,
 			   "Network interface: \"%s\"", dev->name);
@@ -2321,12 +2408,14 @@ static int __devinit smsc911x_drv_probe(struct platform_device *pdev)
 
 out_unregister_netdev_5:
 	unregister_netdev(dev);
-out_unset_drvdata_4:
-	platform_set_drvdata(pdev, NULL);
+out_free_irq:
 	free_irq(dev->irq, dev);
-out_unmap_io_3:
+out_disable_resources:
+	(void)smsc911x_disable_resources(pdev);
+out_return_resources:
+	smsc911x_free_resources(pdev);
+	platform_set_drvdata(pdev, NULL);
 	iounmap(pdata->ioaddr);
-out_free_netdev_2:
 	free_netdev(dev);
 out_release_io_1:
 	release_mem_region(res->start, resource_size(res));