bcm2835-pm: Move bcm2835-watchdog's DT probe to an MFD.

The PM block that the wdt driver was binding to actually has multiple
features we want to expose (power domains, reset, watchdog).  Move the
DT attachment to a MFD driver and make WDT probe against MFD.

Signed-off-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>

3 files changed, 74 insertions, 17 deletions

diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 12980a4ad460..ee6fb6af655e 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -10,6 +10,7 @@ obj-$(CONFIG_MFD_88PM805)	+= 88pm805.o 88pm80x.o
 obj-$(CONFIG_MFD_ACT8945A)	+= act8945a.o
 obj-$(CONFIG_MFD_SM501)		+= sm501.o
 obj-$(CONFIG_MFD_ASIC3)		+= asic3.o tmio_core.o
+obj-$(CONFIG_ARCH_BCM2835)	+= bcm2835-pm.o
 obj-$(CONFIG_MFD_BCM590XX)	+= bcm590xx.o
 obj-$(CONFIG_MFD_BD9571MWV)	+= bd9571mwv.o
 cros_ec_core-objs		:= cros_ec.o
diff --git a/drivers/mfd/bcm2835-pm.c b/drivers/mfd/bcm2835-pm.c
new file mode 100644
index 000000000000..53839e6a81e7
--- /dev/null
+++ b/drivers/mfd/bcm2835-pm.c
@@ -0,0 +1,64 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * PM MFD driver for Broadcom BCM2835
+ *
+ * This driver binds to the PM block and creates the MFD device for
+ * the WDT driver.
+ */
+
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/mfd/bcm2835-pm.h>
+#include <linux/mfd/core.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/types.h>
+#include <linux/watchdog.h>
+
+static const struct mfd_cell bcm2835_pm_devs[] = {
+	{ .name = "bcm2835-wdt" },
+};
+
+static int bcm2835_pm_probe(struct platform_device *pdev)
+{
+	struct resource *res;
+	struct device *dev = &pdev->dev;
+	struct bcm2835_pm *pm;
+
+	pm = devm_kzalloc(dev, sizeof(*pm), GFP_KERNEL);
+	if (!pm)
+		return -ENOMEM;
+	platform_set_drvdata(pdev, pm);
+
+	pm->dev = dev;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	pm->base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(pm->base))
+		return PTR_ERR(pm->base);
+
+	return devm_mfd_add_devices(dev, -1,
+				    bcm2835_pm_devs, ARRAY_SIZE(bcm2835_pm_devs),
+				    NULL, 0, NULL);
+}
+
+static const struct of_device_id bcm2835_pm_of_match[] = {
+	{ .compatible = "brcm,bcm2835-pm-wdt", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, bcm2835_pm_of_match);
+
+static struct platform_driver bcm2835_pm_driver = {
+	.probe		= bcm2835_pm_probe,
+	.driver = {
+		.name =	"bcm2835-pm",
+		.of_match_table = bcm2835_pm_of_match,
+	},
+};
+module_platform_driver(bcm2835_pm_driver);
+
+MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
+MODULE_DESCRIPTION("Driver for Broadcom BCM2835 PM MFD");
+MODULE_LICENSE("GPL");
diff --git a/drivers/watchdog/bcm2835_wdt.c b/drivers/watchdog/bcm2835_wdt.c
index ed05514cc2dc..1834524ae373 100644
--- a/drivers/watchdog/bcm2835_wdt.c
+++ b/drivers/watchdog/bcm2835_wdt.c
@@ -12,6 +12,7 @@
 
 #include <linux/delay.h>
 #include <linux/types.h>
+#include <linux/mfd/bcm2835-pm.h>
 #include <linux/module.h>
 #include <linux/io.h>
 #include <linux/watchdog.h>
@@ -47,6 +48,8 @@ struct bcm2835_wdt {
 	spinlock_t		lock;
 };
 
+static struct bcm2835_wdt *bcm2835_power_off_wdt;
+
 static unsigned int heartbeat;
 static bool nowayout = WATCHDOG_NOWAYOUT;
 
@@ -148,10 +151,7 @@ static struct watchdog_device bcm2835_wdt_wdd = {
  */
 static void bcm2835_power_off(void)
 {
-	struct device_node *np =
-		of_find_compatible_node(NULL, NULL, "brcm,bcm2835-pm-wdt");
-	struct platform_device *pdev = of_find_device_by_node(np);
-	struct bcm2835_wdt *wdt = platform_get_drvdata(pdev);
+	struct bcm2835_wdt *wdt = bcm2835_power_off_wdt;
 	u32 val;
 
 	/*
@@ -169,7 +169,7 @@ static void bcm2835_power_off(void)
 
 static int bcm2835_wdt_probe(struct platform_device *pdev)
 {
-	struct resource *res;
+	struct bcm2835_pm *pm = dev_get_drvdata(pdev->dev.parent);
 	struct device *dev = &pdev->dev;
 	struct bcm2835_wdt *wdt;
 	int err;
@@ -181,10 +181,7 @@ static int bcm2835_wdt_probe(struct platform_device *pdev)
 
 	spin_lock_init(&wdt->lock);
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	wdt->base = devm_ioremap_resource(dev, res);
-	if (IS_ERR(wdt->base))
-		return PTR_ERR(wdt->base);
+	wdt->base = pm->base;
 
 	watchdog_set_drvdata(&bcm2835_wdt_wdd, wdt);
 	watchdog_init_timeout(&bcm2835_wdt_wdd, heartbeat, dev);
@@ -211,8 +208,10 @@ static int bcm2835_wdt_probe(struct platform_device *pdev)
 		return err;
 	}
 
-	if (pm_power_off == NULL)
+	if (pm_power_off == NULL) {
 		pm_power_off = bcm2835_power_off;
+		bcm2835_power_off_wdt = wdt;
+	}
 
 	dev_info(dev, "Broadcom BCM2835 watchdog timer");
 	return 0;
@@ -226,18 +225,11 @@ static int bcm2835_wdt_remove(struct platform_device *pdev)
 	return 0;
 }
 
-static const struct of_device_id bcm2835_wdt_of_match[] = {
-	{ .compatible = "brcm,bcm2835-pm-wdt", },
-	{},
-};
-MODULE_DEVICE_TABLE(of, bcm2835_wdt_of_match);
-
 static struct platform_driver bcm2835_wdt_driver = {
 	.probe		= bcm2835_wdt_probe,
 	.remove		= bcm2835_wdt_remove,
 	.driver = {
 		.name =		"bcm2835-wdt",
-		.of_match_table = bcm2835_wdt_of_match,
 	},
 };
 module_platform_driver(bcm2835_wdt_driver);