[PATCH 0/2] IO voltage domain support for rk3188 and rk3288

[PATCH 0/2] IO voltage domain support for rk3188 and rk3288

[Doug Anderson]

These two patches add support for automatically configuring the IO
voltage domains on rk3188 and rk3288 SoCs.  The first patch adds some
new notification types to the regulator code.  It's used by the second
patch which actually implements the IO voltage domain driver.

These two patches were co-developed by Heiko Stübner and Doug Anderson
(proof of concept patches were written by Heiko).  They were tested in
a private branch on an rk3288 board using rk808 instead of mainline
since rk808 support isn't finalized in mainline yet.


Heiko Stübner (2):
  regulator: core: Add REGULATOR_EVENT_PRE_VOLTAGE_CHANGE (and ABORT)
  soc/rockchip: io-domain: add driver handling io domains

 .../devicetree/bindings/arm/rockchip/io-domain.txt |  60 ++++
 drivers/regulator/core.c                           |  63 +++-
 drivers/soc/Kconfig                                |   1 +
 drivers/soc/Makefile                               |   1 +
 drivers/soc/rockchip/Kconfig                       |  10 +
 drivers/soc/rockchip/Makefile                      |   1 +
 drivers/soc/rockchip/io-domain.c                   | 333 +++++++++++++++++++++
 include/linux/regulator/consumer.h                 |  20 ++
 8 files changed, 482 insertions(+), 7 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/arm/rockchip/io-domain.txt
 create mode 100644 drivers/soc/rockchip/Kconfig
 create mode 100644 drivers/soc/rockchip/Makefile
 create mode 100644 drivers/soc/rockchip/io-domain.c

-- 
2.1.0.rc2.206.gedb03e5

[PATCH 1/2] regulator: core: Add REGULATOR_EVENT_PRE_VOLTAGE_CHANGE (and ABORT)

[Doug Anderson]

From: Heiko Stübner <heiko@sntech.de>

In some cases we need to know when a regulator is about to be changed.
Add a way for clients to be notified.  Note that for set_voltage() we
don't necessarily know what voltage we'll end up with, so we tell the
client what the range will be so they can prepare.

Signed-off-by: Heiko Stübner <heiko@sntech.de>
Signed-off-by: Doug Anderson <dianders@chromium.org>
---
 drivers/regulator/core.c           | 63 +++++++++++++++++++++++++++++++++-----
 include/linux/regulator/consumer.h | 20 ++++++++++++
 2 files changed, 76 insertions(+), 7 deletions(-)

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 7bce715..b31d706 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -102,7 +102,7 @@ static int _regulator_disable(struct regulator_dev *rdev);
 static int _regulator_get_voltage(struct regulator_dev *rdev);
 static int _regulator_get_current_limit(struct regulator_dev *rdev);
 static unsigned int _regulator_get_mode(struct regulator_dev *rdev);
-static void _notifier_call_chain(struct regulator_dev *rdev,
+static int _notifier_call_chain(struct regulator_dev *rdev,
 				  unsigned long event, void *data);
 static int _regulator_do_set_voltage(struct regulator_dev *rdev,
 				     int min_uV, int max_uV);
@@ -2406,6 +2406,55 @@ int regulator_is_supported_voltage(struct regulator *regulator,
 }
 EXPORT_SYMBOL_GPL(regulator_is_supported_voltage);
 
+static int _regulator_call_set_voltage(struct regulator_dev *rdev,
+				       int min_uV, int max_uV,
+				       unsigned *selector)
+{
+	struct pre_voltage_change_data data;
+	int ret;
+
+	data.old_uV = _regulator_get_voltage(rdev);
+	data.min_uV = min_uV;
+	data.max_uV = max_uV;
+	ret = _notifier_call_chain(rdev, REGULATOR_EVENT_PRE_VOLTAGE_CHANGE,
+				   &data);
+	if (ret & NOTIFY_STOP_MASK)
+		return -EINVAL;
+
+	ret = rdev->desc->ops->set_voltage(rdev, min_uV, max_uV, selector);
+	if (ret >= 0)
+		return ret;
+
+	_notifier_call_chain(rdev, REGULATOR_EVENT_ABORT_VOLTAGE_CHANGE,
+			     (void *)data.old_uV);
+
+	return ret;
+}
+
+static int _regulator_call_set_voltage_sel(struct regulator_dev *rdev,
+					   int uV, unsigned selector)
+{
+	struct pre_voltage_change_data data;
+	int ret;
+
+	data.old_uV = _regulator_get_voltage(rdev);
+	data.min_uV = uV;
+	data.max_uV = uV;
+	ret = _notifier_call_chain(rdev, REGULATOR_EVENT_PRE_VOLTAGE_CHANGE,
+				   &data);
+	if (ret & NOTIFY_STOP_MASK)
+		return -EINVAL;
+
+	ret = rdev->desc->ops->set_voltage_sel(rdev, selector);
+	if (ret >= 0)
+		return ret;
+
+	_notifier_call_chain(rdev, REGULATOR_EVENT_ABORT_VOLTAGE_CHANGE,
+			     (void *)data.old_uV);
+
+	return ret;
+}
+
 static int _regulator_do_set_voltage(struct regulator_dev *rdev,
 				     int min_uV, int max_uV)
 {
@@ -2433,8 +2482,8 @@ static int _regulator_do_set_voltage(struct regulator_dev *rdev,
 	}
 
 	if (rdev->desc->ops->set_voltage) {
-		ret = rdev->desc->ops->set_voltage(rdev, min_uV, max_uV,
-						   &selector);
+		ret = _regulator_call_set_voltage(rdev, min_uV, max_uV,
+						  &selector);
 
 		if (ret >= 0) {
 			if (rdev->desc->ops->list_voltage)
@@ -2469,8 +2518,8 @@ static int _regulator_do_set_voltage(struct regulator_dev *rdev,
 				if (old_selector == selector)
 					ret = 0;
 				else
-					ret = rdev->desc->ops->set_voltage_sel(
-								rdev, ret);
+					ret = _regulator_call_set_voltage_sel(
+						rdev, best_val, selector);
 			} else {
 				ret = -EINVAL;
 			}
@@ -3116,11 +3165,11 @@ EXPORT_SYMBOL_GPL(regulator_unregister_notifier);
 /* notify regulator consumers and downstream regulator consumers.
  * Note mutex must be held by caller.
  */
-static void _notifier_call_chain(struct regulator_dev *rdev,
+static int _notifier_call_chain(struct regulator_dev *rdev,
 				  unsigned long event, void *data)
 {
 	/* call rdev chain first */
-	blocking_notifier_call_chain(&rdev->notifier, event, data);
+	return blocking_notifier_call_chain(&rdev->notifier, event, data);
 }
 
 /**
diff --git a/include/linux/regulator/consumer.h b/include/linux/regulator/consumer.h
index f8a8733..d347c80 100644
--- a/include/linux/regulator/consumer.h
+++ b/include/linux/regulator/consumer.h
@@ -93,7 +93,12 @@ struct regmap;
  * OVER_TEMP      Regulator over temp.
  * FORCE_DISABLE  Regulator forcibly shut down by software.
  * VOLTAGE_CHANGE Regulator voltage changed.
+ *                Data passed is old voltage cast to (void *).
  * DISABLE        Regulator was disabled.
+ * PRE_VOLTAGE_CHANGE   Regulator is about to have voltage changed.
+ *                      Data passed is "struct pre_voltage_change_data"
+ * ABORT_VOLTAGE_CHANGE Regulator voltage change failed for some reason.
+ *                      Data passed is old voltage cast to (void *).
  *
  * NOTE: These events can be OR'ed together when passed into handler.
  */
@@ -106,6 +111,21 @@ struct regmap;
 #define REGULATOR_EVENT_FORCE_DISABLE		0x20
 #define REGULATOR_EVENT_VOLTAGE_CHANGE		0x40
 #define REGULATOR_EVENT_DISABLE 		0x80
+#define REGULATOR_EVENT_PRE_VOLTAGE_CHANGE	0x100
+#define REGULATOR_EVENT_ABORT_VOLTAGE_CHANGE	0x200
+
+/**
+ * struct pre_voltage_change_data - Data sent with PRE_VOLTAGE_CHANGE event
+ *
+ * @old_uV: Current voltage before change.
+ * @min_uV: Min voltage we'll change to.
+ * @max_uV: Max voltage we'll change to.
+ */
+struct pre_voltage_change_data {
+	unsigned long old_uV;
+	unsigned long min_uV;
+	unsigned long max_uV;
+};
 
 struct regulator;
 
-- 
2.1.0.rc2.206.gedb03e5

[PATCH 2/2] soc/rockchip: io-domain: add driver handling io domains

[Doug Anderson]

From: Heiko Stübner <heiko@sntech.de>

IO domain voltages on some Rockchip SoCs are variable but need to be
kept in sync between the regulators and a special register.

Signed-off-by: Heiko Stübner <heiko@sntech.de>
Signed-off-by: Doug Anderson <dianders@chromium.org>
---
 .../devicetree/bindings/arm/rockchip/io-domain.txt |  60 ++++
 drivers/soc/Kconfig                                |   1 +
 drivers/soc/Makefile                               |   1 +
 drivers/soc/rockchip/Kconfig                       |  10 +
 drivers/soc/rockchip/Makefile                      |   1 +
 drivers/soc/rockchip/io-domain.c                   | 333 +++++++++++++++++++++
 6 files changed, 406 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/arm/rockchip/io-domain.txt
 create mode 100644 drivers/soc/rockchip/Kconfig
 create mode 100644 drivers/soc/rockchip/Makefile
 create mode 100644 drivers/soc/rockchip/io-domain.c

diff --git a/Documentation/devicetree/bindings/arm/rockchip/io-domain.txt b/Documentation/devicetree/bindings/arm/rockchip/io-domain.txt
new file mode 100644
index 0000000..20b4965
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/rockchip/io-domain.txt
@@ -0,0 +1,60 @@
+Rockchip SRAM for IO Voltage Domains:
+-------------------------------------
+
+IO domain voltages on some Rockchip SoCs are variable but need to be
+kept in sync between the regulators and a special register.
+
+We can specify which regulator is associated with which IO Voltage
+Domain and then we can automatically adjust the register to match
+what's actually being provided on the rails.
+
+Required properties:
+- compatible: should be one of:
+  - "rockchip,rk3188-iodomain" for rk3188
+  - "rockchip,rk3288-iodomain" for rk3288
+
+You specify supplies using the standard regulator bindings by including
+a phandle the the relevant regulator.  All specified supplies must be able
+to report their voltage.  The IO Voltage Domain for any non-specified
+supplies will be not be touched.
+
+Possible supplies for rk3188:
+- ap0-supply:    The supply connected to AP0_VCC.
+- ap1-supply:    The supply connected to AP1_VCC.
+- cif-supply:    The supply connected to CIF_VCC.
+- flash-supply:  The supply connected to FLASH_VCC.
+- lcdc0-supply:  The supply connected to LCD0_VCC.
+- lcdc1-supply:  The supply connected to LCD1_VCC.
+- vccio0-supply: The supply connected to VCCIO0.
+- vccio1-supply: The supply connected to VCCIO1.
+                 Sometimes also labeled VCCIO1 and VCCIO2.
+
+Possible supplies for rk3288:
+- audio-supply:  The supply connected to APIO4_VDD.
+- bb-supply:     The supply connected to APIO5_VDD.
+- dvp-supply:    The supply connected to DVPIO_VDD.
+- flash0-supply: The supply connected to FLASH0_VDD.  Typically for eMMC
+- flash1-supply: The supply connected to FLASH1_VDD.  Also known as SDIO1.
+- gpio30-supply: The supply connected to APIO1_VDD.
+- gpio1830       The supply connected to APIO2_VDD.
+- lcdc-supply:   The supply connected to LCDC_VDD.
+- sdcard-supply: The supply connected to SDMMC0_VDD.
+- wifi-supply:   The supply connected to APIO3_VDD.  Also known as SDIO0.
+
+
+Example:
+
+	io-domains {
+		compatible = "rockchip,rk3288-iodomain";
+		rockchip,grf = <&grf>;
+
+		audio-supply = <&vcc18_codec>;
+		bb-supply = <&vcc33_io>;
+		dvp-supply = <&vcc_18>;
+		flash0-supply = <&vcc18_flashio>;
+		gpio1830-supply = <&vcc33_io>;
+		gpio30-supply = <&vcc33_pmuio>;
+		lcdc-supply = <&vcc33_lcd>;
+		sdcard-supply = <&vccio_sd>;
+		wifi-supply = <&vcc18_wl>;
+	};
diff --git a/drivers/soc/Kconfig b/drivers/soc/Kconfig
index c854385..443d946 100644
--- a/drivers/soc/Kconfig
+++ b/drivers/soc/Kconfig
@@ -1,5 +1,6 @@
 menu "SOC (System On Chip) specific Drivers"
 
 source "drivers/soc/qcom/Kconfig"
+source "drivers/soc/rockchip/Kconfig"
 
 endmenu
diff --git a/drivers/soc/Makefile b/drivers/soc/Makefile
index 3b1b95d..52808bf 100644
--- a/drivers/soc/Makefile
+++ b/drivers/soc/Makefile
@@ -3,4 +3,5 @@
 #
 
 obj-$(CONFIG_ARCH_QCOM)		+= qcom/
+obj-$(CONFIG_ARCH_ROCKCHIP)	+= rockchip/
 obj-$(CONFIG_ARCH_TEGRA)	+= tegra/
diff --git a/drivers/soc/rockchip/Kconfig b/drivers/soc/rockchip/Kconfig
new file mode 100644
index 0000000..d25cb53
--- /dev/null
+++ b/drivers/soc/rockchip/Kconfig
@@ -0,0 +1,10 @@
+#
+# Rockchip Soc drivers
+#
+config ROCKCHIP_IODOMAIN
+        tristate "Rockchip IO domain support"
+        depends on ARCH_ROCKCHIP && OF
+        help
+          Say y here to enable support io domains on Rockchip SoCs. It is
+          necessary for the io domain setting of the SoC to match the
+          voltage supplied by the regulators.
diff --git a/drivers/soc/rockchip/Makefile b/drivers/soc/rockchip/Makefile
new file mode 100644
index 0000000..dbf6da9
--- /dev/null
+++ b/drivers/soc/rockchip/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_ROCKCHIP_IODOMAIN)	+=	io-domain.o
diff --git a/drivers/soc/rockchip/io-domain.c b/drivers/soc/rockchip/io-domain.c
new file mode 100644
index 0000000..f4e0ebc
--- /dev/null
+++ b/drivers/soc/rockchip/io-domain.c
@@ -0,0 +1,333 @@
+/*
+ * Rockchip IO Voltage Domain driver
+ *
+ * Copyright 2014 MundoReader S.L.
+ * Copyright 2014 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/mfd/syscon.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+
+#define MAX_SUPPLIES		16
+
+#define MAX_VOLTAGE_1_8		1980000
+#define MAX_VOLTAGE_3_3		3600000
+
+struct rockchip_iodomain;
+
+/**
+ * @supplies: voltage settings matching the register bits.
+ */
+struct rockchip_iodomain_soc_data {
+	int grf_offset;
+	const char *supply_names[MAX_SUPPLIES];
+	void (*init)(struct rockchip_iodomain *iod);
+};
+
+struct rockchip_iodomain_supply {
+	struct rockchip_iodomain *iod;
+	struct regulator *reg;
+	struct notifier_block nb;
+	int idx;
+};
+
+struct rockchip_iodomain {
+	struct device *dev;
+	struct regmap *grf;
+	struct rockchip_iodomain_soc_data *soc_data;
+	struct rockchip_iodomain_supply supplies[MAX_SUPPLIES];
+};
+
+static int rockchip_iodomain_write(struct rockchip_iodomain_supply *supply,
+				   int uV)
+{
+	struct rockchip_iodomain *iod = supply->iod;
+	u32 val;
+	int ret;
+
+	/* set value bit */
+	val = (uV > MAX_VOLTAGE_1_8) ? 0 : 1;
+	val <<= supply->idx;
+
+	/* apply hiword-mask */
+	val |= (BIT(supply->idx) << 16);
+
+	ret = regmap_write(iod->grf, iod->soc_data->grf_offset, val);
+	if (ret)
+		dev_err(iod->dev, "Couldn't write to GRF\n");
+
+	return ret;
+}
+
+static int rockchip_iodomain_notify(struct notifier_block *nb,
+				    unsigned long event,
+				    void *data)
+{
+	struct rockchip_iodomain_supply *supply =
+			container_of(nb, struct rockchip_iodomain_supply, nb);
+	int uV;
+	int ret;
+
+	/*
+	 * According to Rockchip it's important to keep the SoC IO domain
+	 * higher than (or equal to) the external voltage.  That means we need
+	 * to change it before external voltage changes happen in the case
+	 * of an increase.
+	 */
+	if (event & REGULATOR_EVENT_PRE_VOLTAGE_CHANGE) {
+		struct pre_voltage_change_data *pvc_data = data;
+
+		uV = max_t(unsigned long, pvc_data->old_uV, pvc_data->max_uV);
+	} else if (event & (REGULATOR_EVENT_VOLTAGE_CHANGE |
+			    REGULATOR_EVENT_ABORT_VOLTAGE_CHANGE)) {
+		uV = (unsigned long)data;
+	} else {
+		return NOTIFY_OK;
+	}
+
+	dev_dbg(supply->iod->dev, "Setting to %d\n", uV);
+
+	if (uV > MAX_VOLTAGE_3_3) {
+		dev_err(supply->iod->dev, "Voltage too high: %d\n", uV);
+
+		if (event == REGULATOR_EVENT_PRE_VOLTAGE_CHANGE)
+			return NOTIFY_BAD;
+	}
+
+	ret = rockchip_iodomain_write(supply, uV);
+	if (ret && event == REGULATOR_EVENT_PRE_VOLTAGE_CHANGE)
+		return NOTIFY_BAD;
+
+	dev_info(supply->iod->dev, "Setting to %d done\n", uV);
+	return NOTIFY_OK;
+}
+
+#define RK3288_SOC_CON2			0x24c
+#define RK3288_SOC_CON2_FLASH0		BIT(7)
+#define RK3288_SOC_FLASH_SUPPLY_NUM	2
+
+static void rk3288_iodomain_init(struct rockchip_iodomain *iod)
+{
+	int ret;
+	u32 val;
+
+	/* if no flash supply we should leave things alone */
+	if (!iod->supplies[RK3288_SOC_FLASH_SUPPLY_NUM].reg)
+		return;
+
+	/*
+	 * set flash0 iodomain to also use this framework
+	 * instead of a special gpio.
+	 */
+	val = RK3288_SOC_CON2_FLASH0 | (RK3288_SOC_CON2_FLASH0 << 16);
+	ret = regmap_write(iod->grf, RK3288_SOC_CON2, val);
+	if (ret < 0)
+		dev_warn(iod->dev, "couldn't update flash0 ctrl\n");
+}
+
+/*
+ * On the rk3188 the io-domains are handled by a shared register with the
+ * lower 8 bits being still being continuing drive-strength settings.
+ */
+static const struct rockchip_iodomain_soc_data soc_data_rk3188 = {
+	.grf_offset = 0x104,
+	.supply_names = {
+		NULL,
+		NULL,
+		NULL,
+		NULL,
+		NULL,
+		NULL,
+		NULL,
+		NULL,
+		"ap0",
+		"ap1",
+		"cif",
+		"flash",
+		"vccio0",
+		"vccio1",
+		"lcdc0",
+		"lcdc1",
+	},
+};
+
+static const struct rockchip_iodomain_soc_data soc_data_rk3288 = {
+	.grf_offset = 0x380,
+	.supply_names = {
+		"lcdc",		/* LCDC_VDD */
+		"dvp",		/* DVPIO_VDD */
+		"flash0",	/* FLASH0_VDD (emmc) */
+		"flash1",	/* FLASH1_VDD (sdio1) */
+		"wifi",		/* APIO3_VDD  (sdio0) */
+		"bb",		/* APIO5_VDD */
+		"audio",	/* APIO4_VDD */
+		"sdcard",	/* SDMMC0_VDD (sdmmc) */
+		"gpio30",	/* APIO1_VDD */
+		"gpio1830",	/* APIO2_VDD */
+	},
+	.init = rk3288_iodomain_init,
+};
+
+static const struct of_device_id rockchip_iodomain_match[] = {
+	{
+		.compatible = "rockchip,rk3188-iodomain",
+		.data = (void *)&soc_data_rk3188
+	},
+	{
+		.compatible = "rockchip,rk3288-iodomain",
+		.data = (void *)&soc_data_rk3288
+	},
+	{ /* sentinel */ },
+};
+
+static int rockchip_iodomain_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	const struct of_device_id *match;
+	struct rockchip_iodomain *iod;
+	int i, ret;
+
+	if (!np)
+		return -ENODEV;
+
+	iod = devm_kzalloc(&pdev->dev, sizeof(*iod), GFP_KERNEL);
+	if (!iod)
+		return -ENOMEM;
+
+	iod->dev = &pdev->dev;
+	platform_set_drvdata(pdev, iod);
+
+	match = of_match_node(rockchip_iodomain_match, np);
+	iod->soc_data = (struct rockchip_iodomain_soc_data *)match->data;
+
+	iod->grf = syscon_regmap_lookup_by_phandle(np, "rockchip,grf");
+	if (IS_ERR(iod->grf)) {
+		dev_err(&pdev->dev, "couldn't find grf regmap\n");
+		return PTR_ERR(iod->grf);
+	}
+
+	for (i = 0; i < MAX_SUPPLIES; i++) {
+		const char *supply_name = iod->soc_data->supply_names[i];
+		struct rockchip_iodomain_supply *supply = &iod->supplies[i];
+		struct regulator *reg;
+		int uV;
+
+		if (!supply_name)
+			continue;
+
+		reg = devm_regulator_get_optional(iod->dev, supply_name);
+		if (IS_ERR(reg)) {
+			ret = PTR_ERR(reg);
+
+			/* If a supply wasn't specified, that's OK */
+			if (ret == -ENODEV)
+				continue;
+			else if (ret != -EPROBE_DEFER)
+				dev_err(iod->dev, "couldn't get regulator %s\n",
+					supply_name);
+			goto unreg_notify;
+		}
+
+		/* set initial correct value */
+		uV = regulator_get_voltage(reg);
+
+		/* must be a regulator we can get the voltage of */
+		if (uV < 0) {
+			dev_err(iod->dev, "Can't determine voltage: %s\n",
+				supply_name);
+			goto unreg_notify;
+		}
+
+		if (uV > MAX_VOLTAGE_3_3) {
+			dev_crit(iod->dev,
+				 "%d uV is too high. May damage SoC!\n",
+				 uV);
+			ret = -EINVAL;
+			goto unreg_notify;
+		}
+
+		/* setup our supply */
+		supply->idx = i;
+		supply->iod = iod;
+		supply->reg = reg;
+		supply->nb.notifier_call = rockchip_iodomain_notify;
+
+		ret = rockchip_iodomain_write(supply, uV);
+		if (ret) {
+			supply->reg = NULL;
+			goto unreg_notify;
+		}
+
+		/* register regulator notifier */
+		ret = regulator_register_notifier(reg, &supply->nb);
+		if (ret) {
+			dev_err(&pdev->dev,
+				"regulator notifier request failed\n");
+			supply->reg = NULL;
+			goto unreg_notify;
+		}
+	}
+
+	if (iod->soc_data->init)
+		iod->soc_data->init(iod);
+
+	return 0;
+
+unreg_notify:
+	for (i = MAX_SUPPLIES - 1; i >= 0; i--) {
+		struct rockchip_iodomain_supply *io_supply = &iod->supplies[i];
+
+		if (io_supply->reg)
+			regulator_unregister_notifier(io_supply->reg,
+						      &io_supply->nb);
+	}
+
+	return ret;
+}
+
+static int rockchip_iodomain_remove(struct platform_device *pdev)
+{
+	struct rockchip_iodomain *iod = platform_get_drvdata(pdev);
+	int i;
+
+	for (i = MAX_SUPPLIES - 1; i >= 0; i--) {
+		struct rockchip_iodomain_supply *io_supply = &iod->supplies[i];
+
+		if (io_supply->reg)
+			regulator_unregister_notifier(io_supply->reg,
+						      &io_supply->nb);
+	}
+
+	return 0;
+}
+
+static struct platform_driver rockchip_iodomain_driver = {
+	.probe   = rockchip_iodomain_probe,
+	.remove  = rockchip_iodomain_remove,
+	.driver  = {
+		.name  = "rockchip-iodomain",
+		.of_match_table = rockchip_iodomain_match,
+	},
+};
+
+module_platform_driver(rockchip_iodomain_driver);
+
+MODULE_DESCRIPTION("Rockchip IO-domain driver");
+MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
+MODULE_AUTHOR("Doug Anderson <dianders@chromium.org>");
+MODULE_LICENSE("GPL v2");
-- 
2.1.0.rc2.206.gedb03e5

[PATCH 2/2] soc/rockchip: io-domain: add driver handling io domains

[Doug Anderson]

From: Heiko Stübner <heiko@sntech.de>

IO domain voltages on some Rockchip SoCs are variable but need to be
kept in sync between the regulators and a special register.

Signed-off-by: Heiko Stübner <heiko@sntech.de>
Signed-off-by: Doug Anderson <dianders@chromium.org>
---
 .../devicetree/bindings/arm/rockchip/io-domain.txt |  60 ++++
 drivers/soc/Kconfig                                |   1 +
 drivers/soc/Makefile                               |   1 +
 drivers/soc/rockchip/Kconfig                       |  10 +
 drivers/soc/rockchip/Makefile                      |   1 +
 drivers/soc/rockchip/io-domain.c                   | 333 +++++++++++++++++++++
 6 files changed, 406 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/arm/rockchip/io-domain.txt
 create mode 100644 drivers/soc/rockchip/Kconfig
 create mode 100644 drivers/soc/rockchip/Makefile
 create mode 100644 drivers/soc/rockchip/io-domain.c

diff --git a/Documentation/devicetree/bindings/arm/rockchip/io-domain.txt b/Documentation/devicetree/bindings/arm/rockchip/io-domain.txt
new file mode 100644
index 0000000..20b4965
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/rockchip/io-domain.txt
@@ -0,0 +1,60 @@
+Rockchip SRAM for IO Voltage Domains:
+-------------------------------------
+
+IO domain voltages on some Rockchip SoCs are variable but need to be
+kept in sync between the regulators and a special register.
+
+We can specify which regulator is associated with which IO Voltage
+Domain and then we can automatically adjust the register to match
+what's actually being provided on the rails.
+
+Required properties:
+- compatible: should be one of:
+  - "rockchip,rk3188-iodomain" for rk3188
+  - "rockchip,rk3288-iodomain" for rk3288
+
+You specify supplies using the standard regulator bindings by including
+a phandle the the relevant regulator.  All specified supplies must be able
+to report their voltage.  The IO Voltage Domain for any non-specified
+supplies will be not be touched.
+
+Possible supplies for rk3188:
+- ap0-supply:    The supply connected to AP0_VCC.
+- ap1-supply:    The supply connected to AP1_VCC.
+- cif-supply:    The supply connected to CIF_VCC.
+- flash-supply:  The supply connected to FLASH_VCC.
+- lcdc0-supply:  The supply connected to LCD0_VCC.
+- lcdc1-supply:  The supply connected to LCD1_VCC.
+- vccio0-supply: The supply connected to VCCIO0.
+- vccio1-supply: The supply connected to VCCIO1.
+                 Sometimes also labeled VCCIO1 and VCCIO2.
+
+Possible supplies for rk3288:
+- audio-supply:  The supply connected to APIO4_VDD.
+- bb-supply:     The supply connected to APIO5_VDD.
+- dvp-supply:    The supply connected to DVPIO_VDD.
+- flash0-supply: The supply connected to FLASH0_VDD.  Typically for eMMC
+- flash1-supply: The supply connected to FLASH1_VDD.  Also known as SDIO1.
+- gpio30-supply: The supply connected to APIO1_VDD.
+- gpio1830       The supply connected to APIO2_VDD.
+- lcdc-supply:   The supply connected to LCDC_VDD.
+- sdcard-supply: The supply connected to SDMMC0_VDD.
+- wifi-supply:   The supply connected to APIO3_VDD.  Also known as SDIO0.
+
+
+Example:
+
+	io-domains {
+		compatible = "rockchip,rk3288-iodomain";
+		rockchip,grf = <&grf>;
+
+		audio-supply = <&vcc18_codec>;
+		bb-supply = <&vcc33_io>;
+		dvp-supply = <&vcc_18>;
+		flash0-supply = <&vcc18_flashio>;
+		gpio1830-supply = <&vcc33_io>;
+		gpio30-supply = <&vcc33_pmuio>;
+		lcdc-supply = <&vcc33_lcd>;
+		sdcard-supply = <&vccio_sd>;
+		wifi-supply = <&vcc18_wl>;
+	};
diff --git a/drivers/soc/Kconfig b/drivers/soc/Kconfig
index c854385..443d946 100644
--- a/drivers/soc/Kconfig
+++ b/drivers/soc/Kconfig
@@ -1,5 +1,6 @@
 menu "SOC (System On Chip) specific Drivers"
 
 source "drivers/soc/qcom/Kconfig"
+source "drivers/soc/rockchip/Kconfig"
 
 endmenu
diff --git a/drivers/soc/Makefile b/drivers/soc/Makefile
index 3b1b95d..52808bf 100644
--- a/drivers/soc/Makefile
+++ b/drivers/soc/Makefile
@@ -3,4 +3,5 @@
 #
 
 obj-$(CONFIG_ARCH_QCOM)		+= qcom/
+obj-$(CONFIG_ARCH_ROCKCHIP)	+= rockchip/
 obj-$(CONFIG_ARCH_TEGRA)	+= tegra/
diff --git a/drivers/soc/rockchip/Kconfig b/drivers/soc/rockchip/Kconfig
new file mode 100644
index 0000000..d25cb53
--- /dev/null
+++ b/drivers/soc/rockchip/Kconfig
@@ -0,0 +1,10 @@
+#
+# Rockchip Soc drivers
+#
+config ROCKCHIP_IODOMAIN
+        tristate "Rockchip IO domain support"
+        depends on ARCH_ROCKCHIP && OF
+        help
+          Say y here to enable support io domains on Rockchip SoCs. It is
+          necessary for the io domain setting of the SoC to match the
+          voltage supplied by the regulators.
diff --git a/drivers/soc/rockchip/Makefile b/drivers/soc/rockchip/Makefile
new file mode 100644
index 0000000..dbf6da9
--- /dev/null
+++ b/drivers/soc/rockchip/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_ROCKCHIP_IODOMAIN)	+=	io-domain.o
diff --git a/drivers/soc/rockchip/io-domain.c b/drivers/soc/rockchip/io-domain.c
new file mode 100644
index 0000000..f4e0ebc
--- /dev/null
+++ b/drivers/soc/rockchip/io-domain.c
@@ -0,0 +1,333 @@
+/*
+ * Rockchip IO Voltage Domain driver
+ *
+ * Copyright 2014 MundoReader S.L.
+ * Copyright 2014 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/mfd/syscon.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+
+#define MAX_SUPPLIES		16
+
+#define MAX_VOLTAGE_1_8		1980000
+#define MAX_VOLTAGE_3_3		3600000
+
+struct rockchip_iodomain;
+
+/**
+ * @supplies: voltage settings matching the register bits.
+ */
+struct rockchip_iodomain_soc_data {
+	int grf_offset;
+	const char *supply_names[MAX_SUPPLIES];
+	void (*init)(struct rockchip_iodomain *iod);
+};
+
+struct rockchip_iodomain_supply {
+	struct rockchip_iodomain *iod;
+	struct regulator *reg;
+	struct notifier_block nb;
+	int idx;
+};
+
+struct rockchip_iodomain {
+	struct device *dev;
+	struct regmap *grf;
+	struct rockchip_iodomain_soc_data *soc_data;
+	struct rockchip_iodomain_supply supplies[MAX_SUPPLIES];
+};
+
+static int rockchip_iodomain_write(struct rockchip_iodomain_supply *supply,
+				   int uV)
+{
+	struct rockchip_iodomain *iod = supply->iod;
+	u32 val;
+	int ret;
+
+	/* set value bit */
+	val = (uV > MAX_VOLTAGE_1_8) ? 0 : 1;
+	val <<= supply->idx;
+
+	/* apply hiword-mask */
+	val |= (BIT(supply->idx) << 16);
+
+	ret = regmap_write(iod->grf, iod->soc_data->grf_offset, val);
+	if (ret)
+		dev_err(iod->dev, "Couldn't write to GRF\n");
+
+	return ret;
+}
+
+static int rockchip_iodomain_notify(struct notifier_block *nb,
+				    unsigned long event,
+				    void *data)
+{
+	struct rockchip_iodomain_supply *supply =
+			container_of(nb, struct rockchip_iodomain_supply, nb);
+	int uV;
+	int ret;
+
+	/*
+	 * According to Rockchip it's important to keep the SoC IO domain
+	 * higher than (or equal to) the external voltage.  That means we need
+	 * to change it before external voltage changes happen in the case
+	 * of an increase.
+	 */
+	if (event & REGULATOR_EVENT_PRE_VOLTAGE_CHANGE) {
+		struct pre_voltage_change_data *pvc_data = data;
+
+		uV = max_t(unsigned long, pvc_data->old_uV, pvc_data->max_uV);
+	} else if (event & (REGULATOR_EVENT_VOLTAGE_CHANGE |
+			    REGULATOR_EVENT_ABORT_VOLTAGE_CHANGE)) {
+		uV = (unsigned long)data;
+	} else {
+		return NOTIFY_OK;
+	}
+
+	dev_dbg(supply->iod->dev, "Setting to %d\n", uV);
+
+	if (uV > MAX_VOLTAGE_3_3) {
+		dev_err(supply->iod->dev, "Voltage too high: %d\n", uV);
+
+		if (event == REGULATOR_EVENT_PRE_VOLTAGE_CHANGE)
+			return NOTIFY_BAD;
+	}
+
+	ret = rockchip_iodomain_write(supply, uV);
+	if (ret && event == REGULATOR_EVENT_PRE_VOLTAGE_CHANGE)
+		return NOTIFY_BAD;
+
+	dev_info(supply->iod->dev, "Setting to %d done\n", uV);
+	return NOTIFY_OK;
+}
+
+#define RK3288_SOC_CON2			0x24c
+#define RK3288_SOC_CON2_FLASH0		BIT(7)
+#define RK3288_SOC_FLASH_SUPPLY_NUM	2
+
+static void rk3288_iodomain_init(struct rockchip_iodomain *iod)
+{
+	int ret;
+	u32 val;
+
+	/* if no flash supply we should leave things alone */
+	if (!iod->supplies[RK3288_SOC_FLASH_SUPPLY_NUM].reg)
+		return;
+
+	/*
+	 * set flash0 iodomain to also use this framework
+	 * instead of a special gpio.
+	 */
+	val = RK3288_SOC_CON2_FLASH0 | (RK3288_SOC_CON2_FLASH0 << 16);
+	ret = regmap_write(iod->grf, RK3288_SOC_CON2, val);
+	if (ret < 0)
+		dev_warn(iod->dev, "couldn't update flash0 ctrl\n");
+}
+
+/*
+ * On the rk3188 the io-domains are handled by a shared register with the
+ * lower 8 bits being still being continuing drive-strength settings.
+ */
+static const struct rockchip_iodomain_soc_data soc_data_rk3188 = {
+	.grf_offset = 0x104,
+	.supply_names = {
+		NULL,
+		NULL,
+		NULL,
+		NULL,
+		NULL,
+		NULL,
+		NULL,
+		NULL,
+		"ap0",
+		"ap1",
+		"cif",
+		"flash",
+		"vccio0",
+		"vccio1",
+		"lcdc0",
+		"lcdc1",
+	},
+};
+
+static const struct rockchip_iodomain_soc_data soc_data_rk3288 = {
+	.grf_offset = 0x380,
+	.supply_names = {
+		"lcdc",		/* LCDC_VDD */
+		"dvp",		/* DVPIO_VDD */
+		"flash0",	/* FLASH0_VDD (emmc) */
+		"flash1",	/* FLASH1_VDD (sdio1) */
+		"wifi",		/* APIO3_VDD  (sdio0) */
+		"bb",		/* APIO5_VDD */
+		"audio",	/* APIO4_VDD */
+		"sdcard",	/* SDMMC0_VDD (sdmmc) */
+		"gpio30",	/* APIO1_VDD */
+		"gpio1830",	/* APIO2_VDD */
+	},
+	.init = rk3288_iodomain_init,
+};
+
+static const struct of_device_id rockchip_iodomain_match[] = {
+	{
+		.compatible = "rockchip,rk3188-iodomain",
+		.data = (void *)&soc_data_rk3188
+	},
+	{
+		.compatible = "rockchip,rk3288-iodomain",
+		.data = (void *)&soc_data_rk3288
+	},
+	{ /* sentinel */ },
+};
+
+static int rockchip_iodomain_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	const struct of_device_id *match;
+	struct rockchip_iodomain *iod;
+	int i, ret;
+
+	if (!np)
+		return -ENODEV;
+
+	iod = devm_kzalloc(&pdev->dev, sizeof(*iod), GFP_KERNEL);
+	if (!iod)
+		return -ENOMEM;
+
+	iod->dev = &pdev->dev;
+	platform_set_drvdata(pdev, iod);
+
+	match = of_match_node(rockchip_iodomain_match, np);
+	iod->soc_data = (struct rockchip_iodomain_soc_data *)match->data;
+
+	iod->grf = syscon_regmap_lookup_by_phandle(np, "rockchip,grf");
+	if (IS_ERR(iod->grf)) {
+		dev_err(&pdev->dev, "couldn't find grf regmap\n");
+		return PTR_ERR(iod->grf);
+	}
+
+	for (i = 0; i < MAX_SUPPLIES; i++) {
+		const char *supply_name = iod->soc_data->supply_names[i];
+		struct rockchip_iodomain_supply *supply = &iod->supplies[i];
+		struct regulator *reg;
+		int uV;
+
+		if (!supply_name)
+			continue;
+
+		reg = devm_regulator_get_optional(iod->dev, supply_name);
+		if (IS_ERR(reg)) {
+			ret = PTR_ERR(reg);
+
+			/* If a supply wasn't specified, that's OK */
+			if (ret == -ENODEV)
+				continue;
+			else if (ret != -EPROBE_DEFER)
+				dev_err(iod->dev, "couldn't get regulator %s\n",
+					supply_name);
+			goto unreg_notify;
+		}
+
+		/* set initial correct value */
+		uV = regulator_get_voltage(reg);
+
+		/* must be a regulator we can get the voltage of */
+		if (uV < 0) {
+			dev_err(iod->dev, "Can't determine voltage: %s\n",
+				supply_name);
+			goto unreg_notify;
+		}
+
+		if (uV > MAX_VOLTAGE_3_3) {
+			dev_crit(iod->dev,
+				 "%d uV is too high. May damage SoC!\n",
+				 uV);
+			ret = -EINVAL;
+			goto unreg_notify;
+		}
+
+		/* setup our supply */
+		supply->idx = i;
+		supply->iod = iod;
+		supply->reg = reg;
+		supply->nb.notifier_call = rockchip_iodomain_notify;
+
+		ret = rockchip_iodomain_write(supply, uV);
+		if (ret) {
+			supply->reg = NULL;
+			goto unreg_notify;
+		}
+
+		/* register regulator notifier */
+		ret = regulator_register_notifier(reg, &supply->nb);
+		if (ret) {
+			dev_err(&pdev->dev,
+				"regulator notifier request failed\n");
+			supply->reg = NULL;
+			goto unreg_notify;
+		}
+	}
+
+	if (iod->soc_data->init)
+		iod->soc_data->init(iod);
+
+	return 0;
+
+unreg_notify:
+	for (i = MAX_SUPPLIES - 1; i >= 0; i--) {
+		struct rockchip_iodomain_supply *io_supply = &iod->supplies[i];
+
+		if (io_supply->reg)
+			regulator_unregister_notifier(io_supply->reg,
+						      &io_supply->nb);
+	}
+
+	return ret;
+}
+
+static int rockchip_iodomain_remove(struct platform_device *pdev)
+{
+	struct rockchip_iodomain *iod = platform_get_drvdata(pdev);
+	int i;
+
+	for (i = MAX_SUPPLIES - 1; i >= 0; i--) {
+		struct rockchip_iodomain_supply *io_supply = &iod->supplies[i];
+
+		if (io_supply->reg)
+			regulator_unregister_notifier(io_supply->reg,
+						      &io_supply->nb);
+	}
+
+	return 0;
+}
+
+static struct platform_driver rockchip_iodomain_driver = {
+	.probe   = rockchip_iodomain_probe,
+	.remove  = rockchip_iodomain_remove,
+	.driver  = {
+		.name  = "rockchip-iodomain",
+		.of_match_table = rockchip_iodomain_match,
+	},
+};
+
+module_platform_driver(rockchip_iodomain_driver);
+
+MODULE_DESCRIPTION("Rockchip IO-domain driver");
+MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
+MODULE_AUTHOR("Doug Anderson <dianders@chromium.org>");
+MODULE_LICENSE("GPL v2");
-- 
2.1.0.rc2.206.gedb03e5