[PATCH v2 0/4] PM / OPP: Introduce ti-opp-supply driver

[PATCH v2 0/4] PM / OPP: Introduce ti-opp-supply driver

[Dave Gerlach]

Hi,
This is v2 of the series to introduce the ti-opp-supply driver which makes
use of the OPP core to enable multiple regulator DVFS and AVS Class0 for
TI DRA7 and AM57 platforms. Version 1 of this series can be found here [1].

Very few changes since v1, just added Viresh's acks to patches 1 and 2 and
added SPDX license to the ti-opp-supply driver in patch 4.

Pushed updated branch here just in case [2].

Regards,
Dave

[1] https://www.spinics.net/lists/devicetree/msg205957.html
[2] https://github.com/dgerlach/linux-pm/tree/upstream/v4.15/ti-multireg-support-v2

Dave Gerlach (4):
  cpufreq: ti-cpufreq: Convert to module_platform_driver
  cpufreq: ti-cpufreq: Add support for multiple regulators
  dt-bindings: opp: Introduce ti-opp-supply bindings
  PM / OPP: Add ti-opp-supply driver

 .../bindings/opp/ti-omap5-opp-supply.txt           |  63 +++
 drivers/cpufreq/ti-cpufreq.c                       |  51 ++-
 drivers/opp/Makefile                               |   1 +
 drivers/opp/ti-opp-supply.c                        | 425 +++++++++++++++++++++
 4 files changed, 534 insertions(+), 6 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/opp/ti-omap5-opp-supply.txt
 create mode 100644 drivers/opp/ti-opp-supply.c

-- 
2.15.1

[PATCH v2 1/4] cpufreq: ti-cpufreq: Convert to module_platform_driver

[Dave Gerlach]

ti-cpufreq will be responsible for calling dev_pm_opp_set_regulators on
platforms that require AVS and ABB regulator support so we must be
able to defer probe if regulators are not yet available, so change
ti-cpufreq to be a module_platform_driver to allow for probe defer.

Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
---
 drivers/cpufreq/ti-cpufreq.c | 23 +++++++++++++++++++++--
 1 file changed, 21 insertions(+), 2 deletions(-)

diff --git a/drivers/cpufreq/ti-cpufreq.c b/drivers/cpufreq/ti-cpufreq.c
index 923317f03b4b..b1c230a1e2aa 100644
--- a/drivers/cpufreq/ti-cpufreq.c
+++ b/drivers/cpufreq/ti-cpufreq.c
@@ -17,6 +17,7 @@
 #include <linux/cpu.h>
 #include <linux/io.h>
 #include <linux/mfd/syscon.h>
+#include <linux/module.h>
 #include <linux/init.h>
 #include <linux/of.h>
 #include <linux/of_platform.h>
@@ -195,7 +196,7 @@ static const struct of_device_id ti_cpufreq_of_match[] = {
 	{},
 };
 
-static int ti_cpufreq_init(void)
+static int ti_cpufreq_probe(struct platform_device *pdev)
 {
 	u32 version[VERSION_COUNT];
 	struct device_node *np;
@@ -269,4 +270,22 @@ static int ti_cpufreq_init(void)
 
 	return ret;
 }
-device_initcall(ti_cpufreq_init);
+
+static int ti_cpufreq_init(void)
+{
+	platform_device_register_simple("ti-cpufreq", -1, NULL, 0);
+	return 0;
+}
+module_init(ti_cpufreq_init);
+
+static struct platform_driver ti_cpufreq_driver = {
+	.probe = ti_cpufreq_probe,
+	.driver = {
+		.name = "ti-cpufreq",
+	},
+};
+module_platform_driver(ti_cpufreq_driver);
+
+MODULE_DESCRIPTION("TI CPUFreq/OPP hw-supported driver");
+MODULE_AUTHOR("Dave Gerlach <d-gerlach@ti.com>");
+MODULE_LICENSE("GPL v2");
-- 
2.15.1

[PATCH v2 2/4] cpufreq: ti-cpufreq: Add support for multiple regulators

[Dave Gerlach]

Some platforms, like those in the DRA7 and AM57 families, require the
scaling of multiple regulators in order to properly support higher OPPs.
Let the ti-cpufreq driver determine when this is required and pass the
appropriate regulator names to the OPP core so that they can be properly
managed.

Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
---
 drivers/cpufreq/ti-cpufreq.c | 28 ++++++++++++++++++++++++----
 1 file changed, 24 insertions(+), 4 deletions(-)

diff --git a/drivers/cpufreq/ti-cpufreq.c b/drivers/cpufreq/ti-cpufreq.c
index b1c230a1e2aa..a099b7bf74cd 100644
--- a/drivers/cpufreq/ti-cpufreq.c
+++ b/drivers/cpufreq/ti-cpufreq.c
@@ -51,6 +51,7 @@ struct ti_cpufreq_soc_data {
 	unsigned long efuse_mask;
 	unsigned long efuse_shift;
 	unsigned long rev_offset;
+	bool multi_regulator;
 };
 
 struct ti_cpufreq_data {
@@ -58,6 +59,7 @@ struct ti_cpufreq_data {
 	struct device_node *opp_node;
 	struct regmap *syscon;
 	const struct ti_cpufreq_soc_data *soc_data;
+	struct opp_table *opp_table;
 };
 
 static unsigned long amx3_efuse_xlate(struct ti_cpufreq_data *opp_data,
@@ -96,6 +98,7 @@ static struct ti_cpufreq_soc_data am3x_soc_data = {
 	.efuse_offset = 0x07fc,
 	.efuse_mask = 0x1fff,
 	.rev_offset = 0x600,
+	.multi_regulator = false,
 };
 
 static struct ti_cpufreq_soc_data am4x_soc_data = {
@@ -104,6 +107,7 @@ static struct ti_cpufreq_soc_data am4x_soc_data = {
 	.efuse_offset = 0x0610,
 	.efuse_mask = 0x3f,
 	.rev_offset = 0x600,
+	.multi_regulator = false,
 };
 
 static struct ti_cpufreq_soc_data dra7_soc_data = {
@@ -112,6 +116,7 @@ static struct ti_cpufreq_soc_data dra7_soc_data = {
 	.efuse_mask = 0xf80000,
 	.efuse_shift = 19,
 	.rev_offset = 0x204,
+	.multi_regulator = true,
 };
 
 /**
@@ -201,7 +206,9 @@ static int ti_cpufreq_probe(struct platform_device *pdev)
 	u32 version[VERSION_COUNT];
 	struct device_node *np;
 	const struct of_device_id *match;
+	struct opp_table *ti_opp_table;
 	struct ti_cpufreq_data *opp_data;
+	const char * const reg_names[] = {"vdd", "vbb"};
 	int ret;
 
 	np = of_find_node_by_path("/");
@@ -248,16 +255,29 @@ static int ti_cpufreq_probe(struct platform_device *pdev)
 	if (ret)
 		goto fail_put_node;
 
-	ret = PTR_ERR_OR_ZERO(dev_pm_opp_set_supported_hw(opp_data->cpu_dev,
-							  version, VERSION_COUNT));
-	if (ret) {
+	ti_opp_table = dev_pm_opp_set_supported_hw(opp_data->cpu_dev,
+						   version, VERSION_COUNT);
+	if (IS_ERR(ti_opp_table)) {
 		dev_err(opp_data->cpu_dev,
 			"Failed to set supported hardware\n");
+		ret = PTR_ERR(ti_opp_table);
 		goto fail_put_node;
 	}
 
-	of_node_put(opp_data->opp_node);
+	opp_data->opp_table = ti_opp_table;
+
+	if (opp_data->soc_data->multi_regulator) {
+		ti_opp_table = dev_pm_opp_set_regulators(opp_data->cpu_dev,
+							 reg_names,
+							 ARRAY_SIZE(reg_names));
+		if (IS_ERR(ti_opp_table)) {
+			dev_pm_opp_put_supported_hw(opp_data->opp_table);
+			ret =  PTR_ERR(ti_opp_table);
+			goto fail_put_node;
+		}
+	}
 
+	of_node_put(opp_data->opp_node);
 register_cpufreq_dt:
 	platform_device_register_simple("cpufreq-dt", -1, NULL, 0);
 
-- 
2.15.1

[PATCH v2 3/4] dt-bindings: opp: Introduce ti-opp-supply bindings

[Dave Gerlach]

Document the devicetree bindings that describe Texas Instruments
opp-supply which allow a platform to describe multiple regulators and
additional information, such as registers containing data needed to
program aforementioned regulators.

Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
---
 .../bindings/opp/ti-omap5-opp-supply.txt           | 63 ++++++++++++++++++++++
 1 file changed, 63 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/opp/ti-omap5-opp-supply.txt

diff --git a/Documentation/devicetree/bindings/opp/ti-omap5-opp-supply.txt b/Documentation/devicetree/bindings/opp/ti-omap5-opp-supply.txt
new file mode 100644
index 000000000000..832346e489a3
--- /dev/null
+++ b/Documentation/devicetree/bindings/opp/ti-omap5-opp-supply.txt
@@ -0,0 +1,63 @@
+Texas Instruments OMAP compatible OPP supply description
+
+OMAP5, DRA7, and AM57 family of SoCs have Class0 AVS eFuse registers which
+contain data that can be used to adjust voltages programmed for some of their
+supplies for more efficient operation. This binding provides the information
+needed to read these values and use them to program the main regulator during
+an OPP transitions.
+
+Also, some supplies may have an associated vbb-supply which is an Adaptive Body
+Bias regulator which much be transitioned in a specific sequence with regards
+to the vdd-supply and clk when making an OPP transition. By supplying two
+regulators to the device that will undergo OPP transitions we can make use
+of the multi regulator binding that is part of the OPP core described here [1]
+to describe both regulators needed by the platform.
+
+[1] Documentation/devicetree/bindings/opp/opp.txt
+
+Required Properties for Device Node:
+- vdd-supply: phandle to regulator controlling VDD supply
+- vbb-supply: phandle to regulator controlling Body Bias supply
+	      (Usually Adaptive Body Bias regulator)
+
+Required Properties for opp-supply node:
+- compatible: Should be one of:
+	"ti,omap-opp-supply" - basic OPP supply controlling VDD and VBB
+	"ti,omap5-opp-supply" - OMAP5+ optimized voltages in efuse(class0)VDD
+			    along with VBB
+	"ti,omap5-core-opp-supply" - OMAP5+ optimized voltages in efuse(class0) VDD
+			    but no VBB.
+- reg: Address and length of the efuse register set for the device (mandatory
+	only for "ti,omap5-opp-supply")
+- ti,efuse-settings: An array of u32 tuple items providing information about
+	optimized efuse configuration. Each item consists of the following:
+	volt: voltage in uV - reference voltage (OPP voltage)
+	efuse_offseet: efuse offset from reg where the optimized voltage is stored.
+- ti,absolute-max-voltage-uv: absolute maximum voltage for the OPP supply.
+
+Example:
+
+/* Device Node (CPU)  */
+cpus {
+	cpu0: cpu at 0 {
+		device_type = "cpu";
+
+		...
+
+		vdd-supply = <&vcc>;
+		vbb-supply = <&abb_mpu>;
+	};
+};
+
+/* OMAP OPP Supply with Class0 registers */
+opp_supply_mpu: opp_supply at 4a003b20 {
+	compatible = "ti,omap5-opp-supply";
+	reg = <0x4a003b20 0x8>;
+	ti,efuse-settings = <
+	/* uV   offset */
+	1060000 0x0
+	1160000 0x4
+	1210000 0x8
+	>;
+	ti,absolute-max-voltage-uv = <1500000>;
+};
-- 
2.15.1

[PATCH v2 3/4] dt-bindings: opp: Introduce ti-opp-supply bindings

[Rafael J. Wysocki]

On Fri, Dec 15, 2017 at 5:25 AM, Dave Gerlach <d-gerlach@ti.com> wrote:
> Document the devicetree bindings that describe Texas Instruments
> opp-supply which allow a platform to describe multiple regulators and
> additional information, such as registers containing data needed to
> program aforementioned regulators.
>
> Signed-off-by: Dave Gerlach <d-gerlach@ti.com>

I need an ACK from Rob on this one.

> ---
>  .../bindings/opp/ti-omap5-opp-supply.txt           | 63 ++++++++++++++++++++++
>  1 file changed, 63 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/opp/ti-omap5-opp-supply.txt
>
> diff --git a/Documentation/devicetree/bindings/opp/ti-omap5-opp-supply.txt b/Documentation/devicetree/bindings/opp/ti-omap5-opp-supply.txt
> new file mode 100644
> index 000000000000..832346e489a3
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/opp/ti-omap5-opp-supply.txt
> @@ -0,0 +1,63 @@
> +Texas Instruments OMAP compatible OPP supply description
> +
> +OMAP5, DRA7, and AM57 family of SoCs have Class0 AVS eFuse registers which
> +contain data that can be used to adjust voltages programmed for some of their
> +supplies for more efficient operation. This binding provides the information
> +needed to read these values and use them to program the main regulator during
> +an OPP transitions.
> +
> +Also, some supplies may have an associated vbb-supply which is an Adaptive Body
> +Bias regulator which much be transitioned in a specific sequence with regards
> +to the vdd-supply and clk when making an OPP transition. By supplying two
> +regulators to the device that will undergo OPP transitions we can make use
> +of the multi regulator binding that is part of the OPP core described here [1]
> +to describe both regulators needed by the platform.
> +
> +[1] Documentation/devicetree/bindings/opp/opp.txt
> +
> +Required Properties for Device Node:
> +- vdd-supply: phandle to regulator controlling VDD supply
> +- vbb-supply: phandle to regulator controlling Body Bias supply
> +             (Usually Adaptive Body Bias regulator)
> +
> +Required Properties for opp-supply node:
> +- compatible: Should be one of:
> +       "ti,omap-opp-supply" - basic OPP supply controlling VDD and VBB
> +       "ti,omap5-opp-supply" - OMAP5+ optimized voltages in efuse(class0)VDD
> +                           along with VBB
> +       "ti,omap5-core-opp-supply" - OMAP5+ optimized voltages in efuse(class0) VDD
> +                           but no VBB.
> +- reg: Address and length of the efuse register set for the device (mandatory
> +       only for "ti,omap5-opp-supply")
> +- ti,efuse-settings: An array of u32 tuple items providing information about
> +       optimized efuse configuration. Each item consists of the following:
> +       volt: voltage in uV - reference voltage (OPP voltage)
> +       efuse_offseet: efuse offset from reg where the optimized voltage is stored.
> +- ti,absolute-max-voltage-uv: absolute maximum voltage for the OPP supply.
> +
> +Example:
> +
> +/* Device Node (CPU)  */
> +cpus {
> +       cpu0: cpu at 0 {
> +               device_type = "cpu";
> +
> +               ...
> +
> +               vdd-supply = <&vcc>;
> +               vbb-supply = <&abb_mpu>;
> +       };
> +};
> +
> +/* OMAP OPP Supply with Class0 registers */
> +opp_supply_mpu: opp_supply at 4a003b20 {
> +       compatible = "ti,omap5-opp-supply";
> +       reg = <0x4a003b20 0x8>;
> +       ti,efuse-settings = <
> +       /* uV   offset */
> +       1060000 0x0
> +       1160000 0x4
> +       1210000 0x8
> +       >;
> +       ti,absolute-max-voltage-uv = <1500000>;
> +};
> --
> 2.15.1
>

[PATCH v2 3/4] dt-bindings: opp: Introduce ti-opp-supply bindings

[Rafael J. Wysocki]

On Fri, Dec 15, 2017 at 3:29 PM, Rafael J. Wysocki <rafael@kernel.org> wrote:
> On Fri, Dec 15, 2017 at 5:25 AM, Dave Gerlach <d-gerlach@ti.com> wrote:
>> Document the devicetree bindings that describe Texas Instruments
>> opp-supply which allow a platform to describe multiple regulators and
>> additional information, such as registers containing data needed to
>> program aforementioned regulators.
>>
>> Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
>
> I need an ACK from Rob on this one.

Actually, how this (and the next patch) is related to the [1-2/4]?

[PATCH v2 3/4] dt-bindings: opp: Introduce ti-opp-supply bindings

[Dave Gerlach]

Rafael,
On 12/16/2017 04:52 AM, Rafael J. Wysocki wrote:
> On Fri, Dec 15, 2017 at 3:29 PM, Rafael J. Wysocki <rafael@kernel.org> wrote:
>> On Fri, Dec 15, 2017 at 5:25 AM, Dave Gerlach <d-gerlach@ti.com> wrote:
>>> Document the devicetree bindings that describe Texas Instruments
>>> opp-supply which allow a platform to describe multiple regulators and
>>> additional information, such as registers containing data needed to
>>> program aforementioned regulators.
>>>
>>> Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
>>
>> I need an ACK from Rob on this one.
> 
> Actually, how this (and the next patch) is related to the [1-2/4]?
> 

The main goal of this series is to add support for scaling the multiple
regulators needed for the CPU on these TI platforms. The OPP core supports
multiple regulators but only to the point that it can associate a list of
regulators to a device. It still by default only scales the normal vdd regulator
when doing a rate transition. Because of this, we must define our own method of
doing rate transitions to take the references to our regulators held in the OPP
core and scale them in the proper sequence depending on what the platform needs.

So to describe the purpose of each patch and their relation to each other:

Patch 1: We must be able to defer the ti-cpufreq driver now that we look for
regulators during probe as they likely won't be ready when we probe.

Patch 2: Tell the OPP core about regulators needed for TI CPUFreq operation
using the OPP core. This doesn't actually do anything besides place them in a
list at this point because the OPP core can't know how TI platforms needs them
scaled in relation to each other. Placing the regulator definition in ti-cpufreq
driver ensures they are registered with opp core before cpufreq-dt probes (which
is triggered at the end of ti-cpufreq probe) and actually makes the opp core get
the regulators.

Patch 3: Binding doc for patch 4 driver.

Patch 4: TI OPP supply driver which understands how to actually make use of the
two regulators that the OPP core now has a reference to. This overrides the
standard opp_set_rate function to let us scale frequency and voltage as needed
for TI platforms.

Regards,
Dave

[PATCH v2 3/4] dt-bindings: opp: Introduce ti-opp-supply bindings

[Rafael J. Wysocki]

On Mon, Dec 18, 2017 at 8:25 PM, Dave Gerlach <d-gerlach@ti.com> wrote:
> Rafael,
> On 12/16/2017 04:52 AM, Rafael J. Wysocki wrote:
>> On Fri, Dec 15, 2017 at 3:29 PM, Rafael J. Wysocki <rafael@kernel.org> wrote:
>>> On Fri, Dec 15, 2017 at 5:25 AM, Dave Gerlach <d-gerlach@ti.com> wrote:
>>>> Document the devicetree bindings that describe Texas Instruments
>>>> opp-supply which allow a platform to describe multiple regulators and
>>>> additional information, such as registers containing data needed to
>>>> program aforementioned regulators.
>>>>
>>>> Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
>>>
>>> I need an ACK from Rob on this one.
>>
>> Actually, how this (and the next patch) is related to the [1-2/4]?
>>
>
> The main goal of this series is to add support for scaling the multiple
> regulators needed for the CPU on these TI platforms. The OPP core supports
> multiple regulators but only to the point that it can associate a list of
> regulators to a device. It still by default only scales the normal vdd regulator
> when doing a rate transition. Because of this, we must define our own method of
> doing rate transitions to take the references to our regulators held in the OPP
> core and scale them in the proper sequence depending on what the platform needs.
>
> So to describe the purpose of each patch and their relation to each other:
>
> Patch 1: We must be able to defer the ti-cpufreq driver now that we look for
> regulators during probe as they likely won't be ready when we probe.
>
> Patch 2: Tell the OPP core about regulators needed for TI CPUFreq operation
> using the OPP core. This doesn't actually do anything besides place them in a
> list at this point because the OPP core can't know how TI platforms needs them
> scaled in relation to each other. Placing the regulator definition in ti-cpufreq
> driver ensures they are registered with opp core before cpufreq-dt probes (which
> is triggered at the end of ti-cpufreq probe) and actually makes the opp core get
> the regulators.
>
> Patch 3: Binding doc for patch 4 driver.
>
> Patch 4: TI OPP supply driver which understands how to actually make use of the
> two regulators that the OPP core now has a reference to. This overrides the
> standard opp_set_rate function to let us scale frequency and voltage as needed
> for TI platforms.

Thanks for the explanation, I've applied the series.

[PATCH v2 3/4] dt-bindings: opp: Introduce ti-opp-supply bindings

[Rob Herring]

On Thu, Dec 14, 2017 at 10:25:27PM -0600, Dave Gerlach wrote:
> Document the devicetree bindings that describe Texas Instruments
> opp-supply which allow a platform to describe multiple regulators and
> additional information, such as registers containing data needed to
> program aforementioned regulators.
> 
> Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
> ---
>  .../bindings/opp/ti-omap5-opp-supply.txt           | 63 ++++++++++++++++++++++
>  1 file changed, 63 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/opp/ti-omap5-opp-supply.txt

Acked-by: Rob Herring <robh@kernel.org>

[PATCH v2 4/4] PM / OPP: Add ti-opp-supply driver

[Dave Gerlach]

Introduce a ti-opp-supply driver that will use new multiple regulator
support that is part of the OPP core This is needed on TI platforms like
DRA7/AM57 in order to control both CPU regulator and Adaptive Body Bias
(ABB) regulator. These regulators must be scaled in sequence during an
OPP transition depending on whether or not the frequency is being scaled
up or down.

This driver also implements AVS Class0 for these parts by looking up the
required values from registers in the SoC and programming adjusted
optimal voltage values for each OPP.

Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
---
 drivers/opp/Makefile        |   1 +
 drivers/opp/ti-opp-supply.c | 425 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 426 insertions(+)
 create mode 100644 drivers/opp/ti-opp-supply.c

diff --git a/drivers/opp/Makefile b/drivers/opp/Makefile
index e70ceb406fe9..6ce6aefacc81 100644
--- a/drivers/opp/Makefile
+++ b/drivers/opp/Makefile
@@ -2,3 +2,4 @@ ccflags-$(CONFIG_DEBUG_DRIVER)	:= -DDEBUG
 obj-y				+= core.o cpu.o
 obj-$(CONFIG_OF)		+= of.o
 obj-$(CONFIG_DEBUG_FS)		+= debugfs.o
+obj-$(CONFIG_ARM_TI_CPUFREQ)	+= ti-opp-supply.o
diff --git a/drivers/opp/ti-opp-supply.c b/drivers/opp/ti-opp-supply.c
new file mode 100644
index 000000000000..44dae3e51aac
--- /dev/null
+++ b/drivers/opp/ti-opp-supply.c
@@ -0,0 +1,425 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2016-2017 Texas Instruments Incorporated - http://www.ti.com/
+ *	Nishanth Menon <nm@ti.com>
+ *	Dave Gerlach <d-gerlach@ti.com>
+ *
+ * TI OPP supply driver that provides override into the regulator control
+ * for generic opp core to handle devices with ABB regulator and/or
+ * SmartReflex Class0.
+ */
+#include <linux/clk.h>
+#include <linux/cpufreq.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/notifier.h>
+#include <linux/of_device.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm_opp.h>
+#include <linux/regulator/consumer.h>
+#include <linux/slab.h>
+
+/**
+ * struct ti_opp_supply_optimum_voltage_table - optimized voltage table
+ * @reference_uv:	reference voltage (usually Nominal voltage)
+ * @optimized_uv:	Optimized voltage from efuse
+ */
+struct ti_opp_supply_optimum_voltage_table {
+	unsigned int reference_uv;
+	unsigned int optimized_uv;
+};
+
+/**
+ * struct ti_opp_supply_data - OMAP specific opp supply data
+ * @vdd_table:	Optimized voltage mapping table
+ * @num_vdd_table: number of entries in vdd_table
+ * @vdd_absolute_max_voltage_uv: absolute maximum voltage in UV for the supply
+ */
+struct ti_opp_supply_data {
+	struct ti_opp_supply_optimum_voltage_table *vdd_table;
+	u32 num_vdd_table;
+	u32 vdd_absolute_max_voltage_uv;
+};
+
+static struct ti_opp_supply_data opp_data;
+
+/**
+ * struct ti_opp_supply_of_data - device tree match data
+ * @flags:	specific type of opp supply
+ * @efuse_voltage_mask: mask required for efuse register representing voltage
+ * @efuse_voltage_uv: Are the efuse entries in micro-volts? if not, assume
+ *		milli-volts.
+ */
+struct ti_opp_supply_of_data {
+#define OPPDM_EFUSE_CLASS0_OPTIMIZED_VOLTAGE	BIT(1)
+#define OPPDM_HAS_NO_ABB			BIT(2)
+	const u8 flags;
+	const u32 efuse_voltage_mask;
+	const bool efuse_voltage_uv;
+};
+
+/**
+ * _store_optimized_voltages() - store optimized voltages
+ * @dev:	ti opp supply device for which we need to store info
+ * @data:	data specific to the device
+ *
+ * Picks up efuse based optimized voltages for VDD unique per device and
+ * stores it in internal data structure for use during transition requests.
+ *
+ * Return: If successful, 0, else appropriate error value.
+ */
+static int _store_optimized_voltages(struct device *dev,
+				     struct ti_opp_supply_data *data)
+{
+	void __iomem *base;
+	struct property *prop;
+	struct resource *res;
+	const __be32 *val;
+	int proplen, i;
+	int ret = 0;
+	struct ti_opp_supply_optimum_voltage_table *table;
+	const struct ti_opp_supply_of_data *of_data = dev_get_drvdata(dev);
+
+	/* pick up Efuse based voltages */
+	res = platform_get_resource(to_platform_device(dev), IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(dev, "Unable to get IO resource\n");
+		ret = -ENODEV;
+		goto out_map;
+	}
+
+	base = ioremap_nocache(res->start, resource_size(res));
+	if (!base) {
+		dev_err(dev, "Unable to map Efuse registers\n");
+		ret = -ENOMEM;
+		goto out_map;
+	}
+
+	/* Fetch efuse-settings. */
+	prop = of_find_property(dev->of_node, "ti,efuse-settings", NULL);
+	if (!prop) {
+		dev_err(dev, "No 'ti,efuse-settings' property found\n");
+		ret = -EINVAL;
+		goto out;
+	}
+
+	proplen = prop->length / sizeof(int);
+	data->num_vdd_table = proplen / 2;
+	/* Verify for corrupted OPP entries in dt */
+	if (data->num_vdd_table * 2 * sizeof(int) != prop->length) {
+		dev_err(dev, "Invalid 'ti,efuse-settings'\n");
+		ret = -EINVAL;
+		goto out;
+	}
+
+	ret = of_property_read_u32(dev->of_node, "ti,absolute-max-voltage-uv",
+				   &data->vdd_absolute_max_voltage_uv);
+	if (ret) {
+		dev_err(dev, "ti,absolute-max-voltage-uv is missing\n");
+		ret = -EINVAL;
+		goto out;
+	}
+
+	table = kzalloc(sizeof(*data->vdd_table) *
+				  data->num_vdd_table, GFP_KERNEL);
+	if (!table) {
+		ret = -ENOMEM;
+		goto out;
+	}
+	data->vdd_table = table;
+
+	val = prop->value;
+	for (i = 0; i < data->num_vdd_table; i++, table++) {
+		u32 efuse_offset;
+		u32 tmp;
+
+		table->reference_uv = be32_to_cpup(val++);
+		efuse_offset = be32_to_cpup(val++);
+
+		tmp = readl(base + efuse_offset);
+		tmp &= of_data->efuse_voltage_mask;
+		tmp >>= __ffs(of_data->efuse_voltage_mask);
+
+		table->optimized_uv = of_data->efuse_voltage_uv ? tmp :
+					tmp * 1000;
+
+		dev_dbg(dev, "[%d] efuse=0x%08x volt_table=%d vset=%d\n",
+			i, efuse_offset, table->reference_uv,
+			table->optimized_uv);
+
+		/*
+		 * Some older samples might not have optimized efuse
+		 * Use reference voltage for those - just add debug message
+		 * for them.
+		 */
+		if (!table->optimized_uv) {
+			dev_dbg(dev, "[%d] efuse=0x%08x volt_table=%d:vset0\n",
+				i, efuse_offset, table->reference_uv);
+			table->optimized_uv = table->reference_uv;
+		}
+	}
+out:
+	iounmap(base);
+out_map:
+	return ret;
+}
+
+/**
+ * _free_optimized_voltages() - free resources for optvoltages
+ * @dev:	device for which we need to free info
+ * @data:	data specific to the device
+ */
+static void _free_optimized_voltages(struct device *dev,
+				     struct ti_opp_supply_data *data)
+{
+	kfree(data->vdd_table);
+	data->vdd_table = NULL;
+	data->num_vdd_table = 0;
+}
+
+/**
+ * _get_optimal_vdd_voltage() - Finds optimal voltage for the supply
+ * @dev:	device for which we need to find info
+ * @data:	data specific to the device
+ * @reference_uv:	reference voltage (OPP voltage) for which we need value
+ *
+ * Return: if a match is found, return optimized voltage, else return
+ * reference_uv, also return reference_uv if no optimization is needed.
+ */
+static int _get_optimal_vdd_voltage(struct device *dev,
+				    struct ti_opp_supply_data *data,
+				    int reference_uv)
+{
+	int i;
+	struct ti_opp_supply_optimum_voltage_table *table;
+
+	if (!data->num_vdd_table)
+		return reference_uv;
+
+	table = data->vdd_table;
+	if (!table)
+		return -EINVAL;
+
+	/* Find a exact match - this list is usually very small */
+	for (i = 0; i < data->num_vdd_table; i++, table++)
+		if (table->reference_uv == reference_uv)
+			return table->optimized_uv;
+
+	/* IF things are screwed up, we'd make a mess on console.. ratelimit */
+	dev_err_ratelimited(dev, "%s: Failed optimized voltage match for %d\n",
+			    __func__, reference_uv);
+	return reference_uv;
+}
+
+static int _opp_set_voltage(struct device *dev,
+			    struct dev_pm_opp_supply *supply,
+			    int new_target_uv, struct regulator *reg,
+			    char *reg_name)
+{
+	int ret;
+	unsigned long vdd_uv, uv_max;
+
+	if (new_target_uv)
+		vdd_uv = new_target_uv;
+	else
+		vdd_uv = supply->u_volt;
+
+	/*
+	 * If we do have an absolute max voltage specified, then we should
+	 * use that voltage instead to allow for cases where the voltage rails
+	 * are ganged (example if we set the max for an opp as 1.12v, and
+	 * the absolute max is 1.5v, for another rail to get 1.25v, it cannot
+	 * be achieved if the regulator is constrainted to max of 1.12v, even
+	 * if it can function at 1.25v
+	 */
+	if (opp_data.vdd_absolute_max_voltage_uv)
+		uv_max = opp_data.vdd_absolute_max_voltage_uv;
+	else
+		uv_max = supply->u_volt_max;
+
+	if (vdd_uv > uv_max ||
+	    vdd_uv < supply->u_volt_min ||
+	    supply->u_volt_min > uv_max) {
+		dev_warn(dev,
+			 "Invalid range voltages [Min:%lu target:%lu Max:%lu]\n",
+			 supply->u_volt_min, vdd_uv, uv_max);
+		return -EINVAL;
+	}
+
+	dev_dbg(dev, "%s scaling to %luuV[min %luuV max %luuV]\n", reg_name,
+		vdd_uv, supply->u_volt_min,
+		uv_max);
+
+	ret = regulator_set_voltage_triplet(reg,
+					    supply->u_volt_min,
+					    vdd_uv,
+					    uv_max);
+	if (ret) {
+		dev_err(dev, "%s failed for %luuV[min %luuV max %luuV]\n",
+			reg_name, vdd_uv, supply->u_volt_min,
+			uv_max);
+		return ret;
+	}
+
+	return 0;
+}
+
+/**
+ * ti_opp_supply_set_opp() - do the opp supply transition
+ * @data:	information on regulators and new and old opps provided by
+ *		opp core to use in transition
+ *
+ * Return: If successful, 0, else appropriate error value.
+ */
+int ti_opp_supply_set_opp(struct dev_pm_set_opp_data *data)
+{
+	struct dev_pm_opp_supply *old_supply_vdd = &data->old_opp.supplies[0];
+	struct dev_pm_opp_supply *old_supply_vbb = &data->old_opp.supplies[1];
+	struct dev_pm_opp_supply *new_supply_vdd = &data->new_opp.supplies[0];
+	struct dev_pm_opp_supply *new_supply_vbb = &data->new_opp.supplies[1];
+	struct device *dev = data->dev;
+	unsigned long old_freq = data->old_opp.rate, freq = data->new_opp.rate;
+	struct clk *clk = data->clk;
+	struct regulator *vdd_reg = data->regulators[0];
+	struct regulator *vbb_reg = data->regulators[1];
+	int vdd_uv;
+	int ret;
+
+	vdd_uv = _get_optimal_vdd_voltage(dev, &opp_data,
+					  new_supply_vbb->u_volt);
+
+	/* Scaling up? Scale voltage before frequency */
+	if (freq > old_freq) {
+		ret = _opp_set_voltage(dev, new_supply_vdd, vdd_uv, vdd_reg,
+				       "vdd");
+		if (ret)
+			goto restore_voltage;
+
+		ret = _opp_set_voltage(dev, new_supply_vbb, 0, vbb_reg, "vbb");
+		if (ret)
+			goto restore_voltage;
+	}
+
+	/* Change frequency */
+	dev_dbg(dev, "%s: switching OPP: %lu Hz --> %lu Hz\n",
+		__func__, old_freq, freq);
+
+	ret = clk_set_rate(clk, freq);
+	if (ret) {
+		dev_err(dev, "%s: failed to set clock rate: %d\n", __func__,
+			ret);
+		goto restore_voltage;
+	}
+
+	/* Scaling down? Scale voltage after frequency */
+	if (freq < old_freq) {
+		ret = _opp_set_voltage(dev, new_supply_vbb, 0, vbb_reg, "vbb");
+		if (ret)
+			goto restore_freq;
+
+		ret = _opp_set_voltage(dev, new_supply_vdd, vdd_uv, vdd_reg,
+				       "vdd");
+		if (ret)
+			goto restore_freq;
+	}
+
+	return 0;
+
+restore_freq:
+	ret = clk_set_rate(clk, old_freq);
+	if (ret)
+		dev_err(dev, "%s: failed to restore old-freq (%lu Hz)\n",
+			__func__, old_freq);
+restore_voltage:
+	/* This shouldn't harm even if the voltages weren't updated earlier */
+	if (old_supply_vdd->u_volt) {
+		ret = _opp_set_voltage(dev, old_supply_vbb, 0, vbb_reg, "vbb");
+		if (ret)
+			return ret;
+
+		ret = _opp_set_voltage(dev, old_supply_vdd, 0, vdd_reg,
+				       "vdd");
+		if (ret)
+			return ret;
+	}
+
+	return ret;
+}
+
+static const struct ti_opp_supply_of_data omap_generic_of_data = {
+};
+
+static const struct ti_opp_supply_of_data omap_omap5_of_data = {
+	.flags = OPPDM_EFUSE_CLASS0_OPTIMIZED_VOLTAGE,
+	.efuse_voltage_mask = 0xFFF,
+	.efuse_voltage_uv = false,
+};
+
+static const struct ti_opp_supply_of_data omap_omap5core_of_data = {
+	.flags = OPPDM_EFUSE_CLASS0_OPTIMIZED_VOLTAGE | OPPDM_HAS_NO_ABB,
+	.efuse_voltage_mask = 0xFFF,
+	.efuse_voltage_uv = false,
+};
+
+static const struct of_device_id ti_opp_supply_of_match[] = {
+	{.compatible = "ti,omap-opp-supply", .data = &omap_generic_of_data},
+	{.compatible = "ti,omap5-opp-supply", .data = &omap_omap5_of_data},
+	{.compatible = "ti,omap5-core-opp-supply",
+	 .data = &omap_omap5core_of_data},
+	{},
+};
+MODULE_DEVICE_TABLE(of, ti_opp_supply_of_match);
+
+static int ti_opp_supply_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device *cpu_dev = get_cpu_device(0);
+	const struct of_device_id *match;
+	const struct ti_opp_supply_of_data *of_data;
+	int ret = 0;
+
+	match = of_match_device(ti_opp_supply_of_match, dev);
+	if (!match) {
+		/* We do not expect this to happen */
+		dev_err(dev, "%s: Unable to match device\n", __func__);
+		return -ENODEV;
+	}
+	if (!match->data) {
+		/* Again, unlikely.. but mistakes do happen */
+		dev_err(dev, "%s: Bad data in match\n", __func__);
+		return -EINVAL;
+	}
+	of_data = match->data;
+
+	dev_set_drvdata(dev, (void *)of_data);
+
+	/* If we need optimized voltage */
+	if (of_data->flags & OPPDM_EFUSE_CLASS0_OPTIMIZED_VOLTAGE) {
+		ret = _store_optimized_voltages(dev, &opp_data);
+		if (ret)
+			return ret;
+	}
+
+	ret = PTR_ERR_OR_ZERO(dev_pm_opp_register_set_opp_helper(cpu_dev,
+								 ti_opp_supply_set_opp));
+	if (ret)
+		_free_optimized_voltages(dev, &opp_data);
+
+	return ret;
+}
+
+static struct platform_driver ti_opp_supply_driver = {
+	.probe = ti_opp_supply_probe,
+	.driver = {
+		   .name = "ti_opp_supply",
+		   .owner = THIS_MODULE,
+		   .of_match_table = of_match_ptr(ti_opp_supply_of_match),
+		   },
+};
+module_platform_driver(ti_opp_supply_driver);
+
+MODULE_DESCRIPTION("Texas Instruments OMAP OPP Supply driver");
+MODULE_AUTHOR("Texas Instruments Inc.");
+MODULE_LICENSE("GPL v2");
-- 
2.15.1

[PATCH v2 0/4] PM / OPP: Introduce ti-opp-supply driver

[Viresh Kumar]

On 14-12-17, 22:25, Dave Gerlach wrote:
> Hi,
> This is v2 of the series to introduce the ti-opp-supply driver which makes
> use of the OPP core to enable multiple regulator DVFS and AVS Class0 for
> TI DRA7 and AM57 platforms. Version 1 of this series can be found here [1].
> 
> Very few changes since v1, just added Viresh's acks to patches 1 and 2 and
> added SPDX license to the ti-opp-supply driver in patch 4.
> 
> Pushed updated branch here just in case [2].
> 
> Regards,
> Dave
> 
> [1] https://www.spinics.net/lists/devicetree/msg205957.html
> [2] https://github.com/dgerlach/linux-pm/tree/upstream/v4.15/ti-multireg-support-v2
> 
> Dave Gerlach (4):
>   cpufreq: ti-cpufreq: Convert to module_platform_driver
>   cpufreq: ti-cpufreq: Add support for multiple regulators
>   dt-bindings: opp: Introduce ti-opp-supply bindings
>   PM / OPP: Add ti-opp-supply driver
> 
>  .../bindings/opp/ti-omap5-opp-supply.txt           |  63 +++
>  drivers/cpufreq/ti-cpufreq.c                       |  51 ++-
>  drivers/opp/Makefile                               |   1 +
>  drivers/opp/ti-opp-supply.c                        | 425 +++++++++++++++++++++
>  4 files changed, 534 insertions(+), 6 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/opp/ti-omap5-opp-supply.txt
>  create mode 100644 drivers/opp/ti-opp-supply.c

Acked-by: Viresh Kumar <viresh.kumar@linaro.org>

-- 
viresh

[PATCH v2 0/4] PM / OPP: Introduce ti-opp-supply driver

[Tony Lindgren]

* Dave Gerlach <d-gerlach@ti.com> [171215 04:28]:
> Hi,
> This is v2 of the series to introduce the ti-opp-supply driver which makes
> use of the OPP core to enable multiple regulator DVFS and AVS Class0 for
> TI DRA7 and AM57 platforms. Version 1 of this series can be found here [1].

Good to see this :) For the whole series:

Acked-by: Tony Lindgren <tony@atomide.com>