libertas: implement if_sdio runtime power management

The SDIO card is now fully powered down when the network interface is
brought down.
Signed-off-by: Daniel Drake <dsd@laptop.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/libertas/if_sdio.c

@@ -39,6 +39,7 @@
 #include <linux/mmc/sdio_ids.h>
 #include <linux/mmc/sdio.h>
 #include <linux/mmc/host.h>
+#include <linux/pm_runtime.h>
 
 #include "host.h"
 #include "decl.h"
@@ -47,6 +48,8 @@
 #include "cmd.h"
 #include "if_sdio.h"
 
+static void if_sdio_interrupt(struct sdio_func *func);
+
 /* The if_sdio_remove() callback function is called when
  * user removes this module from kernel space or ejects
  * the card from the slot. The driver handles these 2 cases
@@ -757,6 +760,136 @@ static int if_sdio_prog_firmware(struct if_sdio_card *card)
 	return ret;
 }
 
+/********************************************************************/
+/* Power management                                                 */
+/********************************************************************/
+
+static int if_sdio_power_on(struct if_sdio_card *card)
+{
+	struct sdio_func *func = card->func;
+	struct lbs_private *priv = card->priv;
+	struct mmc_host *host = func->card->host;
+	int ret;
+
+	sdio_claim_host(func);
+
+	ret = sdio_enable_func(func);
+	if (ret)
+		goto release;
+
+	/* For 1-bit transfers to the 8686 model, we need to enable the
+	 * interrupt flag in the CCCR register. Set the MMC_QUIRK_LENIENT_FN0
+	 * bit to allow access to non-vendor registers. */
+	if ((card->model == MODEL_8686) &&
+	    (host->caps & MMC_CAP_SDIO_IRQ) &&
+	    (host->ios.bus_width == MMC_BUS_WIDTH_1)) {
+		u8 reg;
+
+		func->card->quirks |= MMC_QUIRK_LENIENT_FN0;
+		reg = sdio_f0_readb(func, SDIO_CCCR_IF, &ret);
+		if (ret)
+			goto disable;
+
+		reg |= SDIO_BUS_ECSI;
+		sdio_f0_writeb(func, reg, SDIO_CCCR_IF, &ret);
+		if (ret)
+			goto disable;
+	}
+
+	card->ioport = sdio_readb(func, IF_SDIO_IOPORT, &ret);
+	if (ret)
+		goto disable;
+
+	card->ioport |= sdio_readb(func, IF_SDIO_IOPORT + 1, &ret) << 8;
+	if (ret)
+		goto disable;
+
+	card->ioport |= sdio_readb(func, IF_SDIO_IOPORT + 2, &ret) << 16;
+	if (ret)
+		goto disable;
+
+	sdio_release_host(func);
+	ret = if_sdio_prog_firmware(card);
+	sdio_claim_host(func);
+	if (ret)
+		goto disable;
+
+	/*
+	 * Get rx_unit if the chip is SD8688 or newer.
+	 * SD8385 & SD8686 do not have rx_unit.
+	 */
+	if ((card->model != MODEL_8385)
+			&& (card->model != MODEL_8686))
+		card->rx_unit = if_sdio_read_rx_unit(card);
+	else
+		card->rx_unit = 0;
+
+	/*
+	 * Set up the interrupt handler late.
+	 *
+	 * If we set it up earlier, the (buggy) hardware generates a spurious
+	 * interrupt, even before the interrupt has been enabled, with
+	 * CCCR_INTx = 0.
+	 *
+	 * We register the interrupt handler late so that we can handle any
+	 * spurious interrupts, and also to avoid generation of that known
+	 * spurious interrupt in the first place.
+	 */
+	ret = sdio_claim_irq(func, if_sdio_interrupt);
+	if (ret)
+		goto disable;
+
+	/*
+	 * Enable interrupts now that everything is set up
+	 */
+	sdio_writeb(func, 0x0f, IF_SDIO_H_INT_MASK, &ret);
+	if (ret)
+		goto release_irq;
+
+	sdio_release_host(func);
+
+	/*
+	 * FUNC_INIT is required for SD8688 WLAN/BT multiple functions
+	 */
+	if (card->model == MODEL_8688) {
+		struct cmd_header cmd;
+
+		memset(&cmd, 0, sizeof(cmd));
+
+		lbs_deb_sdio("send function INIT command\n");
+		if (__lbs_cmd(priv, CMD_FUNC_INIT, &cmd, sizeof(cmd),
+				lbs_cmd_copyback, (unsigned long) &cmd))
+			netdev_alert(priv->dev, "CMD_FUNC_INIT cmd failed\n");
+	}
+
+	priv->fw_ready = 1;
+
+	return 0;
+
+release_irq:
+	sdio_release_irq(func);
+disable:
+	sdio_disable_func(func);
+release:
+	sdio_release_host(func);
+	return ret;
+}
+
+static int if_sdio_power_off(struct if_sdio_card *card)
+{
+	struct sdio_func *func = card->func;
+	struct lbs_private *priv = card->priv;
+
+	priv->fw_ready = 0;
+
+	sdio_claim_host(func);
+	sdio_release_irq(func);
+	sdio_disable_func(func);
+	sdio_release_host(func);
+	return 0;
+}
+
+
 /*******************************************************************/
 /* Libertas callbacks                                              */
 /*******************************************************************/
@@ -923,6 +1056,32 @@ static void if_sdio_reset_card(struct lbs_private *priv)
 	schedule_work(&card_reset_work);
 }
 
+static int if_sdio_power_save(struct lbs_private *priv)
+{
+	struct if_sdio_card *card = priv->card;
+	int ret;
+
+	flush_workqueue(card->workqueue);
+
+	ret = if_sdio_power_off(card);
+
+	/* Let runtime PM know the card is powered off */
+	pm_runtime_put_sync(&card->func->dev);
+
+	return ret;
+}
+
+static int if_sdio_power_restore(struct lbs_private *priv)
+{
+	struct if_sdio_card *card = priv->card;
+
+	/* Make sure the card will not be powered off by runtime PM */
+	pm_runtime_get_sync(&card->func->dev);
+
+	return if_sdio_power_on(card);
+}
+
+
 /*******************************************************************/
 /* SDIO callbacks                                                  */
 /*******************************************************************/
@@ -976,7 +1135,6 @@ static int if_sdio_probe(struct sdio_func *func,
 	int ret, i;
 	unsigned int model;
 	struct if_sdio_packet *packet;
-	struct mmc_host *host = func->card->host;
 
 	lbs_deb_enter(LBS_DEB_SDIO);
 
@@ -1033,45 +1191,6 @@ static int if_sdio_probe(struct sdio_func *func,
 		goto free;
 	}
 
-	sdio_claim_host(func);
-
-	ret = sdio_enable_func(func);
-	if (ret)
-		goto release;
-
-	/* For 1-bit transfers to the 8686 model, we need to enable the
-	 * interrupt flag in the CCCR register. Set the MMC_QUIRK_LENIENT_FN0
-	 * bit to allow access to non-vendor registers. */
-	if ((card->model == MODEL_8686) &&
-	    (host->caps & MMC_CAP_SDIO_IRQ) &&
-	    (host->ios.bus_width == MMC_BUS_WIDTH_1)) {
-		u8 reg;
-
-		func->card->quirks |= MMC_QUIRK_LENIENT_FN0;
-		reg = sdio_f0_readb(func, SDIO_CCCR_IF, &ret);
-		if (ret)
-			goto release_int;
-
-		reg |= SDIO_BUS_ECSI;
-		sdio_f0_writeb(func, reg, SDIO_CCCR_IF, &ret);
-		if (ret)
-			goto release_int;
-	}
-
-	card->ioport = sdio_readb(func, IF_SDIO_IOPORT, &ret);
-	if (ret)
-		goto release_int;
-
-	card->ioport |= sdio_readb(func, IF_SDIO_IOPORT + 1, &ret) << 8;
-	if (ret)
-		goto release_int;
-
-	card->ioport |= sdio_readb(func, IF_SDIO_IOPORT + 2, &ret) << 16;
-	if (ret)
-		goto release_int;
-
-	sdio_release_host(func);
-
 	sdio_set_drvdata(func, card);
 
 	lbs_deb_sdio("class = 0x%X, vendor = 0x%X, "
@@ -1079,14 +1198,11 @@ static int if_sdio_probe(struct sdio_func *func,
 			func->class, func->vendor, func->device,
 			model, (unsigned)card->ioport);
 
-	ret = if_sdio_prog_firmware(card);
-	if (ret)
-		goto reclaim;
 
 	priv = lbs_add_card(card, &func->dev);
 	if (!priv) {
 		ret = -ENOMEM;
-		goto reclaim;
+		goto free;
 	}
 
 	card->priv = priv;
@@ -1097,62 +1213,21 @@ static int if_sdio_probe(struct sdio_func *func,
 	priv->exit_deep_sleep = if_sdio_exit_deep_sleep;
 	priv->reset_deep_sleep_wakeup = if_sdio_reset_deep_sleep_wakeup;
 	priv->reset_card = if_sdio_reset_card;
+	priv->power_save = if_sdio_power_save;
+	priv->power_restore = if_sdio_power_restore;
 
-	sdio_claim_host(func);
-
-	/*
-	 * Get rx_unit if the chip is SD8688 or newer.
-	 * SD8385 & SD8686 do not have rx_unit.
-	 */
-	if ((card->model != MODEL_8385)
-			&& (card->model != MODEL_8686))
-		card->rx_unit = if_sdio_read_rx_unit(card);
-	else
-		card->rx_unit = 0;
-
-	/*
-	 * Set up the interrupt handler late.
-	 *
-	 * If we set it up earlier, the (buggy) hardware generates a spurious
-	 * interrupt, even before the interrupt has been enabled, with
-	 * CCCR_INTx = 0.
-	 *
-	 * We register the interrupt handler late so that we can handle any
-	 * spurious interrupts, and also to avoid generation of that known
-	 * spurious interrupt in the first place.
-	 */
-	ret = sdio_claim_irq(func, if_sdio_interrupt);
-	if (ret)
-		goto disable;
-
-	/*
-	 * Enable interrupts now that everything is set up
-	 */
-	sdio_writeb(func, 0x0f, IF_SDIO_H_INT_MASK, &ret);
-	sdio_release_host(func);
+	ret = if_sdio_power_on(card);
 	if (ret)
-		goto reclaim;
-
-	priv->fw_ready = 1;
-
-	/*
-	 * FUNC_INIT is required for SD8688 WLAN/BT multiple functions
-	 */
-	if (card->model == MODEL_8688) {
-		struct cmd_header cmd;
-
-		memset(&cmd, 0, sizeof(cmd));
-
-		lbs_deb_sdio("send function INIT command\n");
-		if (__lbs_cmd(priv, CMD_FUNC_INIT, &cmd, sizeof(cmd),
-				lbs_cmd_copyback, (unsigned long) &cmd))
-			netdev_alert(priv->dev, "CMD_FUNC_INIT cmd failed\n");
-	}
+		goto err_activate_card;
 
 	ret = lbs_start_card(priv);
+	if_sdio_power_off(card);
 	if (ret)
 		goto err_activate_card;
 
+	/* Tell PM core that we don't need the card to be powered now */
+	pm_runtime_put_noidle(&func->dev);
+
 out:
 	lbs_deb_leave_args(LBS_DEB_SDIO, "ret %d", ret);
 
@@ -1161,14 +1236,6 @@ static int if_sdio_probe(struct sdio_func *func,
 err_activate_card:
 	flush_workqueue(card->workqueue);
 	lbs_remove_card(priv);
-reclaim:
-	sdio_claim_host(func);
-release_int:
-	sdio_release_irq(func);
-disable:
-	sdio_disable_func(func);
-release:
-	sdio_release_host(func);
 free:
 	destroy_workqueue(card->workqueue);
 	while (card->packets) {
@@ -1195,6 +1262,9 @@ static void if_sdio_remove(struct sdio_func *func)
 
 	card = sdio_get_drvdata(func);
 
+	/* Undo decrement done above in if_sdio_probe */
+	pm_runtime_get_noresume(&func->dev);
+
 	if (user_rmmod && (card->model == MODEL_8688)) {
 		/*
 		 * FUNC_SHUTDOWN is required for SD8688 WLAN/BT
@@ -1219,11 +1289,6 @@ static void if_sdio_remove(struct sdio_func *func)
 	flush_workqueue(card->workqueue);
 	destroy_workqueue(card->workqueue);
 
-	sdio_claim_host(func);
-	sdio_release_irq(func);
-	sdio_disable_func(func);
-	sdio_release_host(func);
-
 	while (card->packets) {
 		packet = card->packets;
 		card->packets = card->packets->next;