[PATCH 4/8] mfd: Add TWL6030 power driver, with minimal support for power off

[Paul Kocialkowski <contact@paulk.fr>]

This adds a TWL6030 power driver, that currently only supports powering off the
device when the TWL is used as system power controller.

This driver might be extended to support more power-related features of the
TWL6030.

Signed-off-by: Paul Kocialkowski <contact@paulk.fr>
---
 .../devicetree/bindings/mfd/twl6030-power.txt      |  31 +++++++
 drivers/mfd/Kconfig                                |  10 ++
 drivers/mfd/Makefile                               |   5 +-
 drivers/mfd/twl-core.c                             |   8 ++
 drivers/mfd/twl6030-power.c                        | 102 +++++++++++++++++++++
 5 files changed, 154 insertions(+), 2 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/mfd/twl6030-power.txt
 create mode 100644 drivers/mfd/twl6030-power.c

diff --git a/Documentation/devicetree/bindings/mfd/twl6030-power.txt b/Documentation/devicetree/bindings/mfd/twl6030-power.txt
new file mode 100644
index 0000000..97600e7
--- /dev/null
+++ b/Documentation/devicetree/bindings/mfd/twl6030-power.txt
@@ -0,0 +1,31 @@
+Texas Instruments TWL family (twl6030) reset and power management module
+
+For now, the binding only supports the complete shutdown of the system after
+poweroff.
+
+Required properties:
+- compatible : must be
+	"ti,twl6030-power"
+
+Optional properties:
+
+- ti,system-power-controller: This indicates that TWL6030 is the
+  power supply master of the system. With this flag, the chip will
+  initiate an ACTIVE-to-OFF or SLEEP-to-OFF transition when the
+  system poweroffs.
+
+Example:
+&i2c1 {
+	clock-frequency = <2600000>;
+
+	twl: twl@48 {
+		reg = <0x48>;
+		interrupts = <7>; /* SYS_NIRQ cascaded to intc */
+		interrupt-parent = <&intc>;
+
+		twl_power: power {
+			compatible = "ti,twl6030-power";
+			ti,system-power-controller;
+		};
+	};
+};
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 28bfe3d..a0a8012 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -1301,6 +1301,16 @@ config MFD_TWL4030_AUDIO
 	select MFD_CORE
 	default n
 
+config TWL6030_POWER
+	bool "TI TWL6030 power resources"
+	depends on TWL_CORE && ARM
+	help
+	  Say yes here if you want to use the power resources on the
+	  TWL6030 family chips.
+
+	  When used as system power controller, this driver allows turning off
+	  the main power supply.
+
 config TWL6040_CORE
 	bool "TI TWL6040 audio codec"
 	depends on I2C=y
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 7daeab5..5aa16c8 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -81,9 +81,10 @@ obj-$(CONFIG_MFD_TPS65912_SPI)  += tps65912-spi.o
 obj-$(CONFIG_MFD_TPS80031)	+= tps80031.o
 obj-$(CONFIG_MENELAUS)		+= menelaus.o
 
-obj-$(CONFIG_TWL_CORE)	+= twl-core.o twl4030-irq.o twl6030-irq.o
-obj-$(CONFIG_TWL4030_POWER)    += twl4030-power.o
+obj-$(CONFIG_TWL_CORE)		+= twl-core.o twl4030-irq.o twl6030-irq.o
+obj-$(CONFIG_TWL4030_POWER)	+= twl4030-power.o
 obj-$(CONFIG_MFD_TWL4030_AUDIO)	+= twl4030-audio.o
+obj-$(CONFIG_TWL6030_POWER)	+= twl6030-power.o
 obj-$(CONFIG_TWL6040_CORE)	+= twl6040.o
 
 obj-$(CONFIG_MFD_MX25_TSADC)	+= fsl-imx25-tsadc.o
diff --git a/drivers/mfd/twl-core.c b/drivers/mfd/twl-core.c
index dae52f7..74372bc 100644
--- a/drivers/mfd/twl-core.c
+++ b/drivers/mfd/twl-core.c
@@ -972,6 +972,14 @@ add_children(struct twl_platform_data *pdata, unsigned irq_base,
 			return PTR_ERR(child);
 	}
 
+	if (IS_ENABLED(CONFIG_TWL6030_POWER) && pdata->power) {
+		child = add_child(TWL_MODULE_PM_MASTER, "twl6030_power",
+				  pdata->power, sizeof(*pdata->power), false,
+				  0, 0);
+		if (IS_ERR(child))
+			return PTR_ERR(child);
+	}
+
 	return 0;
 }
 
diff --git a/drivers/mfd/twl6030-power.c b/drivers/mfd/twl6030-power.c
new file mode 100644
index 0000000..a0bb6d8
--- /dev/null
+++ b/drivers/mfd/twl6030-power.c
@@ -0,0 +1,102 @@
+/*
+ * TWL6030 power
+ *
+ * Copyright (C) 2016 Paul Kocialkowski <contact@paulk.fr>
+ *
+ * This file is subject to the terms and conditions of the GNU General
+ * Public License. See the file "COPYING" in the main directory of this
+ * archive for more details.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <linux/module.h>
+#include <linux/pm.h>
+#include <linux/i2c/twl.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+
+#define TWL6030_PHOENIX_DEV_ON		0x25
+
+#define TWL6030_PHOENIX_APP_DEVOFF	(1 << 0)
+#define TWL6030_PHOENIX_CON_DEVOFF	(1 << 1)
+#define TWL6030_PHOENIX_MOD_DEVOFF	(1 << 2)
+
+void twl6030_power_off(void)
+{
+	int err;
+
+	err = twl_i2c_write_u8(TWL6030_MODULE_ID0, TWL6030_PHOENIX_APP_DEVOFF |
+		TWL6030_PHOENIX_CON_DEVOFF | TWL6030_PHOENIX_MOD_DEVOFF,
+		TWL6030_PHOENIX_DEV_ON);
+	if (err)
+		pr_err("TWL6030 Unable to power off\n");
+}
+
+static bool twl6030_power_use_poweroff(const struct twl_power_data *pdata,
+	struct device_node *node)
+{
+	if (pdata && pdata->use_poweroff)
+		return true;
+
+	if (of_property_read_bool(node, "ti,system-power-controller"))
+		return true;
+
+	return false;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id twl6030_power_of_match[] = {
+	{
+		.compatible = "ti,twl6030-power",
+	},
+	{ },
+};
+
+MODULE_DEVICE_TABLE(of, twl6030_power_of_match);
+#endif	/* CONFIG_OF */
+
+static int twl6030_power_probe(struct platform_device *pdev)
+{
+	const struct twl_power_data *pdata = dev_get_platdata(&pdev->dev);
+	struct device_node *node = pdev->dev.of_node;
+
+	if (!pdata && !node) {
+		dev_err(&pdev->dev, "Platform data is missing\n");
+		return -EINVAL;
+	}
+
+	/* Board has to be wired properly to use this feature */
+	if (twl6030_power_use_poweroff(pdata, node) && !pm_power_off)
+		pm_power_off = twl6030_power_off;
+
+	return 0;
+}
+
+static int twl6030_power_remove(struct platform_device *pdev)
+{
+	return 0;
+}
+
+static struct platform_driver twl6030_power_driver = {
+	.driver = {
+		.name	= "twl6030_power",
+		.of_match_table = of_match_ptr(twl6030_power_of_match),
+	},
+	.probe		= twl6030_power_probe,
+	.remove		= twl6030_power_remove,
+};
+
+module_platform_driver(twl6030_power_driver);
+
+MODULE_AUTHOR("Paul Kocialkowski <contact@paulk.fr>");
+MODULE_DESCRIPTION("Power management for TWL6030");
+MODULE_LICENSE("GPL");
-- 
2.7.4