[RFC PATCH 00/11] Introduce Tegra register config settings

[RFC PATCH 00/11] Introduce Tegra register config settings

[Krishna Yarlagadda]

This is a request for comments on high level design of Tegra config settings.

NVIDIA Tegra SoCs have various I/O controllers and these controllers require
specific register configurations based on:
 - Functional mode (eg. speed)
 - Interface properties (eg. signal timings)
 - Manufacturing characteristics (eg. process/package)
 - Thermal characteristics
 - Board characteristics

Some of the configurations can be provided by device specific standard DT
properties like speed of interface in I2C, rising/falling timing etc. However,
there are more device specific configurations required to tune the interface
based on execution mode or other runtime parameters. All such configurations are
defined as 'config' settings of the device. This configures a device to operate
with the optimal settings for a particular mode to improve performance,
stability or reduce power.

Add the mechanism to provide the configuration parameters from the device tree
called "config setting via Device Tree".
This series capture the device tree details, common parser code for Tegra SOC
and the usage in I/O controllers I2C, SPI.
 
 Patch 01: Documentation about the device tree binding for common config framework.
 Patch 02: Common parser of the device tree config setting node for Tegra SoC.
 Patch 03: Device tree binding documentation for config setting.
 Patch 04: Device tree binding documentation for the I2C config setting.
 Patch 05: Avoid config settings child node to be treated as I2C device.
 Patch 06: Move clock initialization code into new methods
 Patch 07: Using config settings in Tegra I2C driver for interface timing registers.
 Patch 08: Add Tegra234 I2C config settings in DT.
 Patch 09: Device tree binding documentation for the SDHCI config setting.
 Patch 10: Using config settings in Tegra SDHCI driver for tuning iteration.
 Patch 11: Add Tegra234 SDHCI config settings in DT.

Known Issues:
 - DTC warning for config 'missing or empty reg property for I2C nodes'

Krishna Yarlagadda (11):
  Documentation: Introduce config settings framework
  soc: tegra: Add config setting framework
  soc: tegra: config settings binding document
  i2c: dt-bindings: configuration settings
  i2c: core: Avoid config node enumeration
  i2c: tegra: split clock initialization code
  i2c: tegra: config settings for interface timings
  arm64: tegra: I2C interface timings
  sdhci: dt-bindings: configuration settings
  mmc: host: tegra: config settings for timing
  arm64: tegra: SDHCI timing settings

 .../bindings/i2c/nvidia,tegra20-i2c.yaml      | 104 ++++
 .../misc/nvidia,tegra-config-settings.yaml    |  50 ++
 .../bindings/mmc/nvidia,tegra20-sdhci.yaml    |  36 ++
 Documentation/misc-devices/tegra-cfg.rst      | 128 +++++
 MAINTAINERS                                   |  10 +
 arch/arm64/boot/dts/nvidia/tegra234-cfg.dtsi  | 478 ++++++++++++++++++
 .../dts/nvidia/tegra234-p3701-0000-cfg.dtsi   | 123 +++++
 .../boot/dts/nvidia/tegra234-p3701-0000.dtsi  |   1 +
 drivers/i2c/busses/i2c-tegra.c                | 257 ++++++++--
 drivers/i2c/i2c-core-of.c                     |   3 +
 drivers/mmc/host/sdhci-tegra.c                |  84 +++
 drivers/soc/tegra/Makefile                    |   1 +
 drivers/soc/tegra/tegra-cfg.c                 | 147 ++++++
 include/soc/tegra/tegra-cfg.h                 |  87 ++++
 14 files changed, 1456 insertions(+), 53 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/misc/nvidia,tegra-config-settings.yaml
 create mode 100644 Documentation/misc-devices/tegra-cfg.rst
 create mode 100644 arch/arm64/boot/dts/nvidia/tegra234-cfg.dtsi
 create mode 100644 arch/arm64/boot/dts/nvidia/tegra234-p3701-0000-cfg.dtsi
 create mode 100644 drivers/soc/tegra/tegra-cfg.c
 create mode 100644 include/soc/tegra/tegra-cfg.h

-- 
2.43.2

[RFC PATCH 01/11] Documentation: Introduce config settings framework

[Krishna Yarlagadda]

Add documentation for config settings framework utilized by Tegra SOCs.
This framework is used to configure various device registers (I2C, SPI,
etc)  with the optimal/recommended settings for a given operating mode.
For each operating mode there may be various register fields that need
to be configured and so these settings are broken down by register field.

This framework uses device-tree for specifying various register settings
for each operating mode for a given device.

Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com>
---
 Documentation/misc-devices/tegra-cfg.rst | 128 +++++++++++++++++++++++
 MAINTAINERS                              |   7 ++
 2 files changed, 135 insertions(+)
 create mode 100644 Documentation/misc-devices/tegra-cfg.rst

diff --git a/Documentation/misc-devices/tegra-cfg.rst b/Documentation/misc-devices/tegra-cfg.rst
new file mode 100644
index 000000000000..be3926ff9a3e
--- /dev/null
+++ b/Documentation/misc-devices/tegra-cfg.rst
@@ -0,0 +1,128 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+===================================
+NVIDIA Tegra Configuration Settings
+===================================
+
+Introduction
+------------
+NVIDIA Tegra SoCs have various I/O controllers and these controllers require
+specific register configurations.
+
+They could be due to changes in:
+ - Functional mode (eg. speed)
+ - Interface properties (eg. signal timings)
+ - Manufacturing characteristics (eg. process/package)
+ - Thermal characteristics
+ - Board characteristics
+
+Some of the configurations can be provided by device specific standard DT
+properties like speed of interface in I2C, rising/falling timing etc. However,
+there are more device specific configurations required to tune the interface
+based on execution mode or other runtime parameters. All such configurations are
+defined as 'config' settings of the device. This configures a device to operate
+with the optimal settings for a particular mode to improve performance,
+stability or reduce power.
+
+These configurations are either static or dynamic:
+ - Static configuration which is set once during device boot and controller
+   reset
+ - Dynamic configuration is applied based on a particular condition like bus
+   speed, controller mode, peripheral connected to controller, SoC and platform
+   characterization
+
+Static configurations are provided as common config setting and dynamic
+configurations are provided as mode/condition specific.
+
+Background
+----------
+Slew rates, tap delay and other calibration parameters for an interface
+controller, are measured through characterization. These values are dynamic
+and requires different values for same property / field.
+
+Use case
+--------
+Tegra device drivers that use these config settings include:
+ - I2C uses config settings to configure setup & hold times, clock divider
+   values.
+ - SDMMC tuning iterations per speed and CQE values can be set with this method.
+
+Device tree
+-----------
+Config settings of a controller are added under a child node
+"config" of the controller's device tree node.
+Further subnodes are created under config for each conditional setting.
+::
+
+  controller@xyz {
+    config {
+      common {
+        reg-field-a = <val-a1>;
+        reg-field-b = <val-b1>;
+        reg-field-c = <val-c1>;
+      };
+      cfg1 {
+        reg-field-a = <val-a2>;
+        reg-field-b = <val-b2>;
+        reg-field-c = <val-c2>;
+      };
+      cfg2 {
+        reg-field-a = <val-a3>;
+        reg-field-b = <val-b3>;
+        reg-field-c = <val-c3>;
+      };
+    };
+  };
+
+:
+ - "config": subnode in device node to hold configuration settings.
+ - "common": static configuration that needs to be applied on controller reset.
+   Register fields under 'common' node are applied during initialization
+   irrespective of any condition.
+ - "cfg1": conditional configuration to be applied when controller is set in
+   specific functional mode. Conditional configs may override existing settings
+   in 'common' or contain settings unique to the config.
+ - Properties defined under config must correspond to a register field of
+   device controller.
+ - Properties are device specific and added to device node.
+
+Example
+-------
+Ex::
+
+  i2c@3160000 {
+    config {
+      common {
+        nvidia,i2c-hs-sclk-high-period = <0x03>;
+        nvidia,i2c-hs-sclk-low-period = <0x08>;
+      };
+      fast {
+        nvidia,i2c-clk-divisor-fs-mode = <0x3c>;
+        nvidia,i2c-sclk-high-period = <0x02>;
+        nvidia,i2c-sclk-low-period = <0x02>;
+        nvidia,i2c-bus-free-time = <0x02>;
+        nvidia,i2c-stop-setup-time = <0x02>;
+        nvidia,i2c-start-hold-time = <0x02>;
+        nvidia,i2c-start-setup-time = <0x02>;
+      };
+      fastplus {
+        nvidia,i2c-clk-divisor-fs-mode = <0x16>;
+        nvidia,i2c-sclk-high-period = <0x02>;
+        nvidia,i2c-sclk-low-period = <0x02>;
+        nvidia,i2c-bus-free-time = <0x02>;
+        nvidia,i2c-stop-setup-time = <0x02>;
+        nvidia,i2c-start-hold-time = <0x02>;
+        nvidia,i2c-start-setup-time = <0x02>;
+      };
+      standard {
+        nvidia,i2c-clk-divisor-fs-mode = <0x4f>;
+        nvidia,i2c-sclk-high-period = <0x07>;
+        nvidia,i2c-sclk-low-period = <0x08>;
+        nvidia,i2c-bus-free-time = <0x08>;
+        nvidia,i2c-stop-setup-time = <0x08>;
+        nvidia,i2c-start-hold-time = <0x08>;
+        nvidia,i2c-start-setup-time = <0x08>;
+      };
+    };
+  };
+
diff --git a/MAINTAINERS b/MAINTAINERS
index eea74166a2d9..c788ff0506c3 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -21991,6 +21991,13 @@ S:	Maintained
 F:	Documentation/devicetree/bindings/mtd/nvidia-tegra20-nand.txt
 F:	drivers/mtd/nand/raw/tegra_nand.c
 
+TEGRA CONFIG SETTINGS DRIVER
+M:	Thierry Reding <thierry.reding@gmail.com>
+R:	Laxman Dewangan <ldewangan@nvidia.com>
+R:	Krishna Yarlagadda <kyarlagadda@nvidia.com>
+S:	Supported
+F:	Documentation/misc-devices/tegra-cfg.rst
+
 TEGRA PWM DRIVER
 M:	Thierry Reding <thierry.reding@gmail.com>
 S:	Supported
-- 
2.43.2

[RFC PATCH 02/11] soc: tegra: Add config setting framework

[Krishna Yarlagadda]

Config settings are defined as a property per field and have different
modes per device. Each mode contains multiple properties and a device
can have multiple modes.
Config framework parses device tree and provides a list of register
settings with mask per mode to be applied by the controller.
Add APIs to parse list of register config settings and to get config
from the list by name to be applied.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com>
---
 MAINTAINERS                   |   1 +
 drivers/soc/tegra/Makefile    |   1 +
 drivers/soc/tegra/tegra-cfg.c | 147 ++++++++++++++++++++++++++++++++++
 include/soc/tegra/tegra-cfg.h |  87 ++++++++++++++++++++
 4 files changed, 236 insertions(+)
 create mode 100644 drivers/soc/tegra/tegra-cfg.c
 create mode 100644 include/soc/tegra/tegra-cfg.h

diff --git a/MAINTAINERS b/MAINTAINERS
index c788ff0506c3..9eeb749ef234 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -21997,6 +21997,7 @@ R:	Laxman Dewangan <ldewangan@nvidia.com>
 R:	Krishna Yarlagadda <kyarlagadda@nvidia.com>
 S:	Supported
 F:	Documentation/misc-devices/tegra-cfg.rst
+F:	drivers/soc/tegra/tegra-cfg.c
 
 TEGRA PWM DRIVER
 M:	Thierry Reding <thierry.reding@gmail.com>
diff --git a/drivers/soc/tegra/Makefile b/drivers/soc/tegra/Makefile
index 01059619e764..8d0c8dc62c8c 100644
--- a/drivers/soc/tegra/Makefile
+++ b/drivers/soc/tegra/Makefile
@@ -8,3 +8,4 @@ obj-$(CONFIG_SOC_TEGRA_PMC) += pmc.o
 obj-$(CONFIG_SOC_TEGRA20_VOLTAGE_COUPLER) += regulators-tegra20.o
 obj-$(CONFIG_SOC_TEGRA30_VOLTAGE_COUPLER) += regulators-tegra30.o
 obj-$(CONFIG_ARCH_TEGRA_186_SOC) += ari-tegra186.o
+obj-y += tegra-cfg.o
diff --git a/drivers/soc/tegra/tegra-cfg.c b/drivers/soc/tegra/tegra-cfg.c
new file mode 100644
index 000000000000..53d181bff40a
--- /dev/null
+++ b/drivers/soc/tegra/tegra-cfg.c
@@ -0,0 +1,147 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2024 NVIDIA CORPORATION.  All rights reserved.
+ */
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/slab.h>
+
+#include <soc/tegra/tegra-cfg.h>
+
+static int tegra_cfg_update_reg_info(struct device_node *cfg_node,
+				     const struct tegra_cfg_field_desc *field,
+				     struct tegra_cfg_reg *regs,
+				     struct tegra_cfg *cfg)
+{
+	int ret;
+	unsigned int k, value = 0;
+
+	ret = of_property_read_u32(cfg_node, field->name, &value);
+	if (ret)
+		return ret;
+
+	/*
+	 * Find matching register for this field in register info. Field info
+	 * has details of register offset.
+	 */
+	for (k = 0; k < cfg->num_regs; ++k) {
+		if (regs[k].offset == field->offset)
+			break;
+	}
+
+	/* If register not found, add new at end of list */
+	if (k == cfg->num_regs) {
+		cfg->num_regs++;
+		regs[k].offset = field->offset;
+	}
+
+	/* add field value to register */
+	value = value << __ffs(field->mask);
+	regs[k].value |= value & field->mask;
+	regs[k].mask |= field->mask;
+
+	return 0;
+}
+
+/*
+ * Initialize config list. Parse config node for properties (register fields).
+ * Get list of configs and value of fields populated in tegra_cfg_desc.
+ * Consolidate field data in reg offset, mask & value format in tegra_cfg.
+ * Repeat for each config and store in tegra_cfg_list.
+ */
+static struct tegra_cfg_list *tegra_cfg_init(struct device *dev,
+					     const struct device_node *np,
+					     const struct tegra_cfg_desc *cfg_desc)
+{
+	struct device_node *np_cfg = NULL, *child;
+	struct tegra_cfg_reg *regs;
+	struct tegra_cfg_list *list;
+	struct tegra_cfg *cfg;
+	const struct tegra_cfg_field_desc *fields;
+	unsigned int count, i;
+	int ret;
+
+	if (np)
+		np_cfg = of_get_child_by_name(np, "config");
+	if (!np_cfg)
+		return ERR_PTR(-ENODEV);
+
+	count = of_get_child_count(np_cfg);
+	if (count <= 0) {
+		dev_dbg(dev, "Node %s: No child node for config settings\n",
+			np->name);
+		return ERR_PTR(-ENODEV);
+	}
+
+	list = devm_kzalloc(dev, sizeof(*list), GFP_KERNEL);
+	if (!list)
+		return ERR_PTR(-ENOMEM);
+	list->num_cfg = 0;
+	list->cfg = NULL;
+
+	/* allocate mem for all configurations */
+	list->cfg = devm_kcalloc(dev, count, sizeof(*list->cfg),
+				 GFP_KERNEL);
+	if (!list->cfg)
+		return ERR_PTR(-ENOMEM);
+
+	fields = cfg_desc->fields;
+	count = 0;
+	/*
+	 * Iterate through all configurations.
+	 */
+	for_each_available_child_of_node(np_cfg, child) {
+		cfg = &list->cfg[count];
+
+		regs = devm_kcalloc(dev, cfg_desc->num_regs,
+				    sizeof(*regs), GFP_KERNEL);
+		if (!regs)
+			return ERR_PTR(-ENOMEM);
+
+		cfg->name = child->name;
+		cfg->regs = regs;
+		cfg->num_regs = 0;
+
+		/* Look for all fields in 'child' config */
+		for (i = 0; i < cfg_desc->num_fields; i++) {
+			ret = tegra_cfg_update_reg_info(child, &fields[i],
+							regs, cfg);
+			if (ret < 0)
+				continue;
+		}
+		count++;
+	}
+
+	list->num_cfg = count;
+
+	return list;
+}
+
+struct tegra_cfg *
+tegra_cfg_get_by_name(struct device *dev,
+		      const struct tegra_cfg_list *list,
+		      const char *name)
+{
+	unsigned int i;
+
+	for (i = 0; i < list->num_cfg; ++i) {
+		if (!strcmp(list->cfg[i].name, name))
+			return &list->cfg[i];
+	}
+
+	return NULL;
+}
+EXPORT_SYMBOL(tegra_cfg_get_by_name);
+
+struct tegra_cfg_list *tegra_cfg_get(struct device *dev,
+				     const struct device_node *np,
+				     const struct tegra_cfg_desc *cfg_desc)
+{
+	return tegra_cfg_init(dev, np, cfg_desc);
+}
+EXPORT_SYMBOL(tegra_cfg_get);
diff --git a/include/soc/tegra/tegra-cfg.h b/include/soc/tegra/tegra-cfg.h
new file mode 100644
index 000000000000..ece6f63a83c1
--- /dev/null
+++ b/include/soc/tegra/tegra-cfg.h
@@ -0,0 +1,87 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2024, NVIDIA CORPORATION.  All rights reserved.
+ */
+
+#ifndef __SOC_TEGRA_CFG_H__
+#define __SOC_TEGRA_CFG_H__
+
+#include <linux/types.h>
+
+/**
+ * Config settings are a list of DT properties holding each field's recommended
+ * value. Field info is held in tegra_cfg_field and tegra_cfg_desc.
+ * Data of all fields in a single register are parsed and stored in
+ * tegra_cfg_reg. Struct tegra_cfg_list contains list of configurations
+ * and each config tegra_cfg contains register list.
+ * Client drivers provide field and register data through tegra_cfg_desc.
+ */
+
+/**
+ * Register field and DT property mapping.
+ * @name: device property name of the field.
+ * @offset: offset of register from base.
+ * @mask: mask of field within register.
+ */
+struct tegra_cfg_field_desc {
+	const char *name;
+	u32 offset;
+	u32 mask;
+};
+
+#define TEGRA_CFG_FIELD(fname, roffset, fmask)	\
+{						\
+	.name = fname,				\
+	.offset = roffset,			\
+	.mask = fmask,				\
+}
+
+/**
+ * Configuration setting from controller where it passes the total number of
+ * registers having config, and their register field names.
+ */
+struct tegra_cfg_desc {
+	unsigned int num_regs;
+	unsigned int num_fields;
+	const struct tegra_cfg_field_desc *fields;
+};
+
+/**
+ * Configuration register info generated by combining all field config settings
+ * in device tree of a register.
+ * @offset: offset of register from base.
+ * @mask: generated mask from aggregate of all field settings read from dt.
+ * @value: generated value by combining all field properties read from dt.
+ */
+struct tegra_cfg_reg {
+	u32 offset;
+	u32 mask;
+	u32 value;
+};
+
+/**
+ * Per config info of all registers.
+ */
+struct tegra_cfg {
+	const char *name;
+	unsigned int num_regs;
+	struct tegra_cfg_reg *regs;
+};
+
+/**
+ * Config settings list.
+ */
+struct tegra_cfg_list {
+	unsigned int num_cfg;
+	struct tegra_cfg *cfg;
+};
+
+struct tegra_cfg *
+tegra_cfg_get_by_name(struct device *dev,
+		      const struct tegra_cfg_list *list,
+		      const char *cfg_name);
+
+struct tegra_cfg_list *tegra_cfg_get(struct device *dev,
+				     const struct device_node *np,
+				     const struct tegra_cfg_desc *cfg_dev);
+#endif /* __SOC_TEGRA_CFG_H__ */
-- 
2.43.2

[RFC PATCH 03/11] soc: tegra: config settings binding document

[Krishna Yarlagadda]

Config framework parses device tree and provides a list of register
settings with mask per mode to be applied by the controller.

Add binding document for config settings framework. Config settings
are defined as a property per field and have different modes per device.

Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com>
---
 .../misc/nvidia,tegra-config-settings.yaml    | 50 +++++++++++++++++++
 MAINTAINERS                                   |  1 +
 2 files changed, 51 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/misc/nvidia,tegra-config-settings.yaml

diff --git a/Documentation/devicetree/bindings/misc/nvidia,tegra-config-settings.yaml b/Documentation/devicetree/bindings/misc/nvidia,tegra-config-settings.yaml
new file mode 100644
index 000000000000..e379cbd5b597
--- /dev/null
+++ b/Documentation/devicetree/bindings/misc/nvidia,tegra-config-settings.yaml
@@ -0,0 +1,50 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/misc/nvidia,tegra-config-settings.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Config properties for a device.
+
+description:
+  Config setting is the configuration based on chip/board/system
+  characterization on interface/controller settings. This is needed for
+  - making the controller internal configuration to better perform
+  - making the interface to work proper by setting drive strength, slew
+    rates etc
+  - making the low power leakage.
+  There are two types of recommended configuration settings
+  - Controller register specific for internal operation of controller.
+  - Pad control/Pinmux/pincontrol registers for interfacing.
+  These configurations can further be categorized as static and dynamic.
+  - Static config does not change until a controller is reset.
+  - Dynamic config changes based on mode or condition, controller is
+    operating in.
+
+maintainers:
+  - Thierry Reding <thierry.reding@gmail.com>
+
+patternProperties:
+  "^[a-z0-9_]*$":
+    description:
+      Config name to be applied on controller.
+    type: object
+
+additionalProperties: true
+
+examples:
+  - |
+        config {
+            common {
+                nvidia,i2c-hs-sclk-high-period = <0x03>;
+                nvidia,i2c-hs-sclk-low-period = <0x08>;
+            };
+            fast {
+                nvidia,i2c-clk-divisor-fs-mode = <0x3c>;
+                nvidia,i2c-sclk-high-period = <0x02>;
+            };
+            fastplus {
+                nvidia,i2c-clk-divisor-fs-mode = <0x4f>;
+                nvidia,i2c-sclk-high-period = <0x07>;
+            };
+        };
diff --git a/MAINTAINERS b/MAINTAINERS
index 9eeb749ef234..a8c0cfd1d5a6 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -21996,6 +21996,7 @@ M:	Thierry Reding <thierry.reding@gmail.com>
 R:	Laxman Dewangan <ldewangan@nvidia.com>
 R:	Krishna Yarlagadda <kyarlagadda@nvidia.com>
 S:	Supported
+F:	Documentation/devicetree/bindings/misc/nvidia,tegra-config-settings.yaml
 F:	Documentation/misc-devices/tegra-cfg.rst
 F:	drivers/soc/tegra/tegra-cfg.c
 
-- 
2.43.2

[RFC PATCH 04/11] i2c: dt-bindings: configuration settings

[Krishna Yarlagadda]

I2C interface timing registers are configured using config setting
framework. Document available properties for Tegra I2C controllers.

Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com>
---
 .../bindings/i2c/nvidia,tegra20-i2c.yaml      | 104 ++++++++++++++++++
 1 file changed, 104 insertions(+)

diff --git a/Documentation/devicetree/bindings/i2c/nvidia,tegra20-i2c.yaml b/Documentation/devicetree/bindings/i2c/nvidia,tegra20-i2c.yaml
index 424a4fc218b6..3b22e75e5aa0 100644
--- a/Documentation/devicetree/bindings/i2c/nvidia,tegra20-i2c.yaml
+++ b/Documentation/devicetree/bindings/i2c/nvidia,tegra20-i2c.yaml
@@ -119,6 +119,96 @@ properties:
       - const: rx
       - const: tx
 
+  config:
+    description: Config settings for I2C devices enlisted with I2C controller.
+      Config setting is the configuration based on chip/board/system
+      characterization on interface/controller settings. This is needed for
+      - making the controller internal configuration to better perform
+      - making the interface to work proper by setting drive strength, slew
+        rates etc
+      - making the low power leakage.
+      There are two types of recommended configuration settings
+      - Controller register specific for internal operation of controller.
+      - Pad control/Pinmux/pincontrol registers for interfacing.
+      These configurations can further be categorized as static and dynamic.
+      - Static config does not change until a controller is reset.
+      - Dynamic config changes based on mode or condition, controller is
+        operating in.
+      I2C has configuration based on clock speed and has below modes.
+      - common is set on all speeds and can be overridden by speed mode.
+      - high is set when clock mode is high speed.
+      - fastplus is set when clock mode is fast plus.
+      - fast is set when clock mode is fast mode.
+      - standard is set when clock mode is standard mode.
+    $ref: /schemas/misc/nvidia,tegra-config-settings.yaml
+    unevaluatedProperties: false
+    properties:
+      nvidia,i2c-clk-divisor-hs-mode:
+        description: I2C clock divisor for HS mode.
+        $ref: /schemas/types.yaml#/definitions/uint32
+        minimum: 0
+        maximum: 0xffff
+      nvidia,i2c-clk-divisor-fs-mode:
+        description: I2C clock divisor for FS mode.
+        $ref: /schemas/types.yaml#/definitions/uint32
+        minimum: 0
+        maximum: 0xffff
+      nvidia,i2c-hs-sclk-high-period:
+        description: I2C high speed sclk high period.
+        $ref: /schemas/types.yaml#/definitions/uint32
+        minimum: 0
+        maximum: 0xffff
+      nvidia,i2c-hs-sclk-low-period:
+        description: I2C high speed sclk low period.
+        $ref: /schemas/types.yaml#/definitions/uint32
+        minimum: 0
+        maximum: 0xffff
+      nvidia,i2c-hs-stop-setup-time:
+        description: I2C high speed stop setup time.
+        $ref: /schemas/types.yaml#/definitions/uint32
+        minimum: 0
+        maximum: 0xffff
+      nvidia,i2c-hs-start-hold-time:
+        description: I2C high speed start hold time.
+        $ref: /schemas/types.yaml#/definitions/uint32
+        minimum: 0
+        maximum: 0xffff
+      nvidia,i2c-hs-start-setup-time:
+        description: I2C high speed start setup time.
+        $ref: /schemas/types.yaml#/definitions/uint32
+        minimum: 0
+        maximum: 0xffff
+      nvidia,i2c-sclk-high-period:
+        description: I2C sclk high period.
+        $ref: /schemas/types.yaml#/definitions/uint32
+        minimum: 0
+        maximum: 0xffff
+      nvidia,i2c-sclk-low-period:
+        description: I2C sclk low period.
+        $ref: /schemas/types.yaml#/definitions/uint32
+        minimum: 0
+        maximum: 0xffff
+      nvidia,i2c-bus-free-time:
+        description: I2C bus free time.
+        $ref: /schemas/types.yaml#/definitions/uint32
+        minimum: 0
+        maximum: 0xffff
+      nvidia,i2c-stop-setup-time:
+        description: I2C stop setup time.
+        $ref: /schemas/types.yaml#/definitions/uint32
+        minimum: 0
+        maximum: 0xffff
+      nvidia,i2c-start-hold-time:
+        description: I2C start hold time.
+        $ref: /schemas/types.yaml#/definitions/uint32
+        minimum: 0
+        maximum: 0xffff
+      nvidia,i2c-start-setup-time:
+        description: I2C start setup time.
+        $ref: /schemas/types.yaml#/definitions/uint32
+        minimum: 0
+        maximum: 0xffff
+
 allOf:
   - $ref: /schemas/i2c/i2c-controller.yaml
   - if:
@@ -189,4 +279,18 @@ examples:
 
         #address-cells = <1>;
         #size-cells = <0>;
+        config {
+            common {
+                nvidia,i2c-hs-sclk-high-period = <0x03>;
+                nvidia,i2c-hs-sclk-low-period = <0x08>;
+            };
+            fast {
+                nvidia,i2c-clk-divisor-fs-mode = <0x3c>;
+                nvidia,i2c-sclk-high-period = <0x02>;
+            };
+            fastplus {
+                nvidia,i2c-clk-divisor-fs-mode = <0x4f>;
+                nvidia,i2c-sclk-high-period = <0x07>;
+            };
+        };
     };
-- 
2.43.2

[RFC PATCH 05/11] i2c: core: Avoid config node enumeration

[Krishna Yarlagadda]

Add "config" as a common node to add device configuration settings and
other data. This child node should not be treated as a device.
Skip "config" child node during i2c device registration.

Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com>
---
 drivers/i2c/i2c-core-of.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/i2c/i2c-core-of.c b/drivers/i2c/i2c-core-of.c
index a6c407d36800..f50206c6c4d6 100644
--- a/drivers/i2c/i2c-core-of.c
+++ b/drivers/i2c/i2c-core-of.c
@@ -98,6 +98,9 @@ void of_i2c_register_devices(struct i2c_adapter *adap)
 		bus = of_node_get(adap->dev.of_node);
 
 	for_each_available_child_of_node(bus, node) {
+		if (!strcmp(node->name, "config"))
+			continue;
+
 		if (of_node_test_and_set_flag(node, OF_POPULATED))
 			continue;
 
-- 
2.43.2

[RFC PATCH 06/11] i2c: tegra: split clock initialization code

[Krishna Yarlagadda]

Add new methods for setting clock parameters and setting
clock divisor.

Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com>
---
 drivers/i2c/busses/i2c-tegra.c | 127 ++++++++++++++++++++-------------
 1 file changed, 77 insertions(+), 50 deletions(-)

diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index 85b31edc558d..b3dc2603db35 100644
--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c
@@ -604,12 +604,83 @@ static int tegra_i2c_wait_for_config_load(struct tegra_i2c_dev *i2c_dev)
 	return 0;
 }
 
+static void tegra_i2c_set_clk_params(struct tegra_i2c_dev *i2c_dev)
+{
+	u32 val, clk_divisor, tsu_thd, tlow, thigh, non_hs_mode;
+
+	switch (i2c_dev->timings.bus_freq_hz) {
+	case I2C_MAX_STANDARD_MODE_FREQ + 1 ... I2C_MAX_FAST_MODE_PLUS_FREQ:
+	default:
+		tlow = i2c_dev->hw->tlow_fast_fastplus_mode;
+		thigh = i2c_dev->hw->thigh_fast_fastplus_mode;
+		tsu_thd = i2c_dev->hw->setup_hold_time_fast_fast_plus_mode;
+
+		if (i2c_dev->timings.bus_freq_hz > I2C_MAX_FAST_MODE_FREQ)
+			non_hs_mode = i2c_dev->hw->clk_divisor_fast_plus_mode;
+		else
+			non_hs_mode = i2c_dev->hw->clk_divisor_fast_mode;
+		break;
+
+	case 0 ... I2C_MAX_STANDARD_MODE_FREQ:
+		tlow = i2c_dev->hw->tlow_std_mode;
+		thigh = i2c_dev->hw->thigh_std_mode;
+		tsu_thd = i2c_dev->hw->setup_hold_time_std_mode;
+		non_hs_mode = i2c_dev->hw->clk_divisor_std_mode;
+		break;
+	}
+
+	/* make sure clock divisor programmed correctly */
+	clk_divisor = FIELD_PREP(I2C_CLK_DIVISOR_HSMODE,
+				 i2c_dev->hw->clk_divisor_hs_mode) |
+		      FIELD_PREP(I2C_CLK_DIVISOR_STD_FAST_MODE, non_hs_mode);
+	i2c_writel(i2c_dev, clk_divisor, I2C_CLK_DIVISOR);
+
+	if (i2c_dev->hw->has_interface_timing_reg) {
+		val = FIELD_PREP(I2C_INTERFACE_TIMING_THIGH, thigh) |
+		      FIELD_PREP(I2C_INTERFACE_TIMING_TLOW, tlow);
+		i2c_writel(i2c_dev, val, I2C_INTERFACE_TIMING_0);
+	}
+
+	/*
+	 * Configure setup and hold times only when tsu_thd is non-zero.
+	 * Otherwise, preserve the chip default values.
+	 */
+	if (i2c_dev->hw->has_interface_timing_reg && tsu_thd)
+		i2c_writel(i2c_dev, tsu_thd, I2C_INTERFACE_TIMING_1);
+}
+
+static int tegra_i2c_set_div_clk(struct tegra_i2c_dev *i2c_dev)
+{
+	u32 clk_multiplier, tlow, thigh, non_hs_mode;
+	u32 timing, clk_divisor;
+	int err;
+
+	timing = i2c_readl(i2c_dev, I2C_INTERFACE_TIMING_0);
+
+	tlow = FIELD_GET(I2C_INTERFACE_TIMING_TLOW, timing);
+	thigh = FIELD_GET(I2C_INTERFACE_TIMING_THIGH, timing);
+
+	clk_divisor = i2c_readl(i2c_dev, I2C_CLK_DIVISOR);
+
+	non_hs_mode = FIELD_GET(I2C_CLK_DIVISOR_STD_FAST_MODE, clk_divisor);
+
+	clk_multiplier = (thigh + tlow + 2) * (non_hs_mode + 1);
+
+	err = clk_set_rate(i2c_dev->div_clk,
+			   i2c_dev->timings.bus_freq_hz * clk_multiplier);
+	if (err) {
+		dev_err(i2c_dev->dev, "failed to set div_clk rate: %d\n", err);
+		return err;
+	}
+
+	return 0;
+}
+
 static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev)
 {
-	u32 val, clk_divisor, clk_multiplier, tsu_thd, tlow, thigh, non_hs_mode;
+	u32 val;
+	int err;
 	acpi_handle handle = ACPI_HANDLE(i2c_dev->dev);
-	struct i2c_timings *t = &i2c_dev->timings;
-	int err;
 
 	/*
 	 * The reset shouldn't ever fail in practice. The failure will be a
@@ -641,54 +712,10 @@ static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev)
 	if (IS_VI(i2c_dev))
 		tegra_i2c_vi_init(i2c_dev);
 
-	switch (t->bus_freq_hz) {
-	case I2C_MAX_STANDARD_MODE_FREQ + 1 ... I2C_MAX_FAST_MODE_PLUS_FREQ:
-	default:
-		tlow = i2c_dev->hw->tlow_fast_fastplus_mode;
-		thigh = i2c_dev->hw->thigh_fast_fastplus_mode;
-		tsu_thd = i2c_dev->hw->setup_hold_time_fast_fast_plus_mode;
-
-		if (t->bus_freq_hz > I2C_MAX_FAST_MODE_FREQ)
-			non_hs_mode = i2c_dev->hw->clk_divisor_fast_plus_mode;
-		else
-			non_hs_mode = i2c_dev->hw->clk_divisor_fast_mode;
-		break;
-
-	case 0 ... I2C_MAX_STANDARD_MODE_FREQ:
-		tlow = i2c_dev->hw->tlow_std_mode;
-		thigh = i2c_dev->hw->thigh_std_mode;
-		tsu_thd = i2c_dev->hw->setup_hold_time_std_mode;
-		non_hs_mode = i2c_dev->hw->clk_divisor_std_mode;
-		break;
-	}
-
-	/* make sure clock divisor programmed correctly */
-	clk_divisor = FIELD_PREP(I2C_CLK_DIVISOR_HSMODE,
-				 i2c_dev->hw->clk_divisor_hs_mode) |
-		      FIELD_PREP(I2C_CLK_DIVISOR_STD_FAST_MODE, non_hs_mode);
-	i2c_writel(i2c_dev, clk_divisor, I2C_CLK_DIVISOR);
-
-	if (i2c_dev->hw->has_interface_timing_reg) {
-		val = FIELD_PREP(I2C_INTERFACE_TIMING_THIGH, thigh) |
-		      FIELD_PREP(I2C_INTERFACE_TIMING_TLOW, tlow);
-		i2c_writel(i2c_dev, val, I2C_INTERFACE_TIMING_0);
-	}
-
-	/*
-	 * Configure setup and hold times only when tsu_thd is non-zero.
-	 * Otherwise, preserve the chip default values.
-	 */
-	if (i2c_dev->hw->has_interface_timing_reg && tsu_thd)
-		i2c_writel(i2c_dev, tsu_thd, I2C_INTERFACE_TIMING_1);
-
-	clk_multiplier = (tlow + thigh + 2) * (non_hs_mode + 1);
-
-	err = clk_set_rate(i2c_dev->div_clk,
-			   t->bus_freq_hz * clk_multiplier);
-	if (err) {
-		dev_err(i2c_dev->dev, "failed to set div-clk rate: %d\n", err);
+	tegra_i2c_set_clk_params(i2c_dev);
+	err = tegra_i2c_set_div_clk(i2c_dev);
+	if (err)
 		return err;
-	}
 
 	if (!IS_DVC(i2c_dev) && !IS_VI(i2c_dev)) {
 		u32 sl_cfg = i2c_readl(i2c_dev, I2C_SL_CNFG);
-- 
2.43.2

[RFC PATCH 07/11] i2c: tegra: config settings for interface timings

[Krishna Yarlagadda]

Use config settings framework to initialize Tegra I2C interface
timing registers and clock divisor based on I2C speed modes.

Each speed mode uses predefined configuration for interface timing
and clock registers.

Signed-off-by: Akhil R <akhilrajeev@nvidia.com>
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com>
---
 drivers/i2c/busses/i2c-tegra.c | 134 +++++++++++++++++++++++++++++++--
 1 file changed, 129 insertions(+), 5 deletions(-)

diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
index b3dc2603db35..263fd64e440f 100644
--- a/drivers/i2c/busses/i2c-tegra.c
+++ b/drivers/i2c/busses/i2c-tegra.c
@@ -28,6 +28,8 @@
 #include <linux/pm_runtime.h>
 #include <linux/reset.h>
 
+#include <soc/tegra/tegra-cfg.h>
+
 #define BYTES_PER_FIFO_WORD 4
 
 #define I2C_CNFG				0x000
@@ -108,8 +110,9 @@
 #define I2C_MST_CORE_CLKEN_OVR			BIT(0)
 
 #define I2C_INTERFACE_TIMING_0			0x094
-#define  I2C_INTERFACE_TIMING_THIGH		GENMASK(13, 8)
-#define  I2C_INTERFACE_TIMING_TLOW		GENMASK(5, 0)
+#define  I2C_INTERFACE_TIMING_THIGH		GENMASK(15, 8)
+#define  I2C_INTERFACE_TIMING_TLOW		GENMASK(7, 0)
+
 #define I2C_INTERFACE_TIMING_1			0x098
 #define  I2C_INTERFACE_TIMING_TBUF		GENMASK(29, 24)
 #define  I2C_INTERFACE_TIMING_TSU_STO		GENMASK(21, 16)
@@ -117,8 +120,9 @@
 #define  I2C_INTERFACE_TIMING_TSU_STA		GENMASK(5, 0)
 
 #define I2C_HS_INTERFACE_TIMING_0		0x09c
-#define  I2C_HS_INTERFACE_TIMING_THIGH		GENMASK(13, 8)
-#define  I2C_HS_INTERFACE_TIMING_TLOW		GENMASK(5, 0)
+#define  I2C_HS_INTERFACE_TIMING_THIGH		GENMASK(15, 8)
+#define  I2C_HS_INTERFACE_TIMING_TLOW		GENMASK(7, 0)
+
 #define I2C_HS_INTERFACE_TIMING_1		0x0a0
 #define  I2C_HS_INTERFACE_TIMING_TSU_STO	GENMASK(21, 16)
 #define  I2C_HS_INTERFACE_TIMING_THD_STA	GENMASK(13, 8)
@@ -226,6 +230,49 @@ struct tegra_i2c_hw_feature {
 	bool has_interface_timing_reg;
 };
 
+/**
+ * I2C register config fields.
+ */
+static const struct tegra_cfg_field_desc i2c_cfg_fields[] = {
+	TEGRA_CFG_FIELD("nvidia,i2c-clk-divisor-fs-mode",
+			I2C_CLK_DIVISOR, I2C_CLK_DIVISOR_STD_FAST_MODE),
+	TEGRA_CFG_FIELD("nvidia,i2c-clk-divisor-hs-mode",
+			I2C_CLK_DIVISOR, I2C_CLK_DIVISOR_HSMODE),
+	TEGRA_CFG_FIELD("nvidia,i2c-hs-sclk-high-period",
+			I2C_HS_INTERFACE_TIMING_0,
+			I2C_HS_INTERFACE_TIMING_THIGH),
+	TEGRA_CFG_FIELD("nvidia,i2c-hs-sclk-low-period",
+			I2C_HS_INTERFACE_TIMING_0,
+			I2C_HS_INTERFACE_TIMING_TLOW),
+	TEGRA_CFG_FIELD("nvidia,i2c-hs-stop-setup-time",
+			I2C_HS_INTERFACE_TIMING_1,
+			I2C_HS_INTERFACE_TIMING_TSU_STO),
+	TEGRA_CFG_FIELD("nvidia,i2c-hs-start-hold-time",
+			I2C_HS_INTERFACE_TIMING_1,
+			I2C_HS_INTERFACE_TIMING_THD_STA),
+	TEGRA_CFG_FIELD("nvidia,i2c-hs-start-setup-time",
+			I2C_HS_INTERFACE_TIMING_1,
+			I2C_HS_INTERFACE_TIMING_TSU_STA),
+	TEGRA_CFG_FIELD("nvidia,i2c-sclk-high-period",
+			I2C_INTERFACE_TIMING_0, I2C_INTERFACE_TIMING_THIGH),
+	TEGRA_CFG_FIELD("nvidia,i2c-sclk-low-period",
+			I2C_INTERFACE_TIMING_0, I2C_INTERFACE_TIMING_TLOW),
+	TEGRA_CFG_FIELD("nvidia,i2c-bus-free-time",
+			I2C_INTERFACE_TIMING_1, I2C_INTERFACE_TIMING_TBUF),
+	TEGRA_CFG_FIELD("nvidia,i2c-stop-setup-time",
+			I2C_INTERFACE_TIMING_1, I2C_INTERFACE_TIMING_TSU_STO),
+	TEGRA_CFG_FIELD("nvidia,i2c-start-hold-time",
+			I2C_INTERFACE_TIMING_1, I2C_INTERFACE_TIMING_THD_STA),
+	TEGRA_CFG_FIELD("nvidia,i2c-start-setup-time",
+			I2C_INTERFACE_TIMING_1, I2C_INTERFACE_TIMING_TSU_STA),
+};
+
+static struct tegra_cfg_desc i2c_cfg_desc = {
+	.num_regs = 0,
+	.num_fields = ARRAY_SIZE(i2c_cfg_fields),
+	.fields = i2c_cfg_fields,
+};
+
 /**
  * struct tegra_i2c_dev - per device I2C context
  * @dev: device reference for power management
@@ -288,6 +335,8 @@ struct tegra_i2c_dev {
 	dma_addr_t dma_phys;
 	void *dma_buf;
 
+	struct tegra_cfg_list *list;
+
 	bool multimaster_mode;
 	bool atomic_mode;
 	bool dma_mode;
@@ -340,6 +389,16 @@ static u32 i2c_readl(struct tegra_i2c_dev *i2c_dev, unsigned int reg)
 	return readl_relaxed(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg));
 }
 
+static void i2c_update(struct tegra_i2c_dev *i2c_dev, u32 mask,
+		       u32 val, unsigned int reg)
+{
+	u32 rval;
+
+	rval = i2c_readl(i2c_dev, reg);
+	rval = (rval & ~mask) | val;
+	i2c_writel(i2c_dev, rval, reg);
+}
+
 static void i2c_writesl(struct tegra_i2c_dev *i2c_dev, void *data,
 			unsigned int reg, unsigned int len)
 {
@@ -604,6 +663,48 @@ static int tegra_i2c_wait_for_config_load(struct tegra_i2c_dev *i2c_dev)
 	return 0;
 }
 
+static void tegra_i2c_write_cfg_settings(struct tegra_i2c_dev *i2c_dev,
+					 const char *name)
+{
+	struct tegra_cfg_reg *regs;
+	struct tegra_cfg *cfg;
+	unsigned int i;
+
+	cfg = tegra_cfg_get_by_name(i2c_dev->dev, i2c_dev->list, name);
+	if (!cfg)
+		return;
+
+	regs = cfg->regs;
+	for (i = 0; i < cfg->num_regs; i++) {
+		i2c_update(i2c_dev, regs[i].mask, regs[i].value,
+			   regs[i].offset);
+	}
+}
+
+static void tegra_i2c_config_cfg_settings(struct tegra_i2c_dev *i2c_dev)
+{
+	const char *name;
+
+	switch (i2c_dev->timings.bus_freq_hz) {
+	case I2C_MAX_FAST_MODE_PLUS_FREQ + 1 ... I2C_MAX_HIGH_SPEED_MODE_FREQ:
+		name = "high";
+		break;
+	case I2C_MAX_FAST_MODE_FREQ + 1 ... I2C_MAX_FAST_MODE_PLUS_FREQ:
+		name = "fastplus";
+		break;
+	case I2C_MAX_STANDARD_MODE_FREQ + 1 ... I2C_MAX_FAST_MODE_FREQ:
+		name = "fast";
+		break;
+	case 0 ... I2C_MAX_STANDARD_MODE_FREQ:
+	default:
+		name = "standard";
+		break;
+	}
+
+	tegra_i2c_write_cfg_settings(i2c_dev, "common");
+	tegra_i2c_write_cfg_settings(i2c_dev, name);
+}
+
 static void tegra_i2c_set_clk_params(struct tegra_i2c_dev *i2c_dev)
 {
 	u32 val, clk_divisor, tsu_thd, tlow, thigh, non_hs_mode;
@@ -712,7 +813,11 @@ static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev)
 	if (IS_VI(i2c_dev))
 		tegra_i2c_vi_init(i2c_dev);
 
-	tegra_i2c_set_clk_params(i2c_dev);
+	if (i2c_dev->list)
+		tegra_i2c_config_cfg_settings(i2c_dev);
+	else
+		tegra_i2c_set_clk_params(i2c_dev);
+
 	err = tegra_i2c_set_div_clk(i2c_dev);
 	if (err)
 		return err;
@@ -1772,6 +1877,8 @@ static int tegra_i2c_probe(struct platform_device *pdev)
 	struct tegra_i2c_dev *i2c_dev;
 	struct resource *res;
 	int err;
+	const struct tegra_cfg_field_desc *fields;
+	unsigned int count = 0, i, j;
 
 	i2c_dev = devm_kzalloc(&pdev->dev, sizeof(*i2c_dev), GFP_KERNEL);
 	if (!i2c_dev)
@@ -1808,6 +1915,23 @@ static int tegra_i2c_probe(struct platform_device *pdev)
 	if (err)
 		return err;
 
+	fields = i2c_cfg_fields;
+
+	for (i = 0; i < i2c_cfg_desc.num_fields; i++) {
+		for (j = 0; j < i; j++)
+			if (fields[i].offset == fields[j].offset)
+				break;
+		if (i == j)
+			count++;
+	}
+	i2c_cfg_desc.num_regs = count;
+
+	i2c_dev->list = tegra_cfg_get(i2c_dev->dev, NULL, &i2c_cfg_desc);
+	if (IS_ERR_OR_NULL(i2c_dev->list)) {
+		dev_dbg(&pdev->dev, "Config setting not available\n");
+		i2c_dev->list = NULL;
+	}
+
 	tegra_i2c_parse_dt(i2c_dev);
 
 	err = tegra_i2c_init_reset(i2c_dev);
-- 
2.43.2

[RFC PATCH 08/11] arm64: tegra: I2C interface timings

[Krishna Yarlagadda]

Set I2C interface timing registers through config settings for
Tegra234 chip and P3701 board.

Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com>
---
 MAINTAINERS                                   |   1 +
 arch/arm64/boot/dts/nvidia/tegra234-cfg.dtsi  | 446 ++++++++++++++++++
 .../dts/nvidia/tegra234-p3701-0000-cfg.dtsi   | 123 +++++
 .../boot/dts/nvidia/tegra234-p3701-0000.dtsi  |   1 +
 4 files changed, 571 insertions(+)
 create mode 100644 arch/arm64/boot/dts/nvidia/tegra234-cfg.dtsi
 create mode 100644 arch/arm64/boot/dts/nvidia/tegra234-p3701-0000-cfg.dtsi

diff --git a/MAINTAINERS b/MAINTAINERS
index a8c0cfd1d5a6..27ca5bd9203e 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -21996,6 +21996,7 @@ M:	Thierry Reding <thierry.reding@gmail.com>
 R:	Laxman Dewangan <ldewangan@nvidia.com>
 R:	Krishna Yarlagadda <kyarlagadda@nvidia.com>
 S:	Supported
+F:	arch/arm64/boot/dts/nvidia/tegra234*cfg.dtsi
 F:	Documentation/devicetree/bindings/misc/nvidia,tegra-config-settings.yaml
 F:	Documentation/misc-devices/tegra-cfg.rst
 F:	drivers/soc/tegra/tegra-cfg.c
diff --git a/arch/arm64/boot/dts/nvidia/tegra234-cfg.dtsi b/arch/arm64/boot/dts/nvidia/tegra234-cfg.dtsi
new file mode 100644
index 000000000000..832538e45797
--- /dev/null
+++ b/arch/arm64/boot/dts/nvidia/tegra234-cfg.dtsi
@@ -0,0 +1,446 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+/ {
+	bus@0 {
+		i2c@3160000 {
+			config {
+
+				common {
+					nvidia,i2c-hs-sclk-high-period = <0x03>;
+					nvidia,i2c-hs-sclk-low-period = <0x08>;
+				};
+
+				fast {
+					nvidia,i2c-clk-divisor-fs-mode = <0x3c>;
+					nvidia,i2c-sclk-high-period = <0x02>;
+					nvidia,i2c-sclk-low-period = <0x02>;
+					nvidia,i2c-bus-free-time = <0x02>;
+					nvidia,i2c-stop-setup-time = <0x02>;
+					nvidia,i2c-start-hold-time = <0x02>;
+					nvidia,i2c-start-setup-time = <0x02>;
+				};
+
+				fastplus {
+					nvidia,i2c-clk-divisor-fs-mode = <0x16>;
+					nvidia,i2c-sclk-high-period = <0x02>;
+					nvidia,i2c-sclk-low-period = <0x02>;
+					nvidia,i2c-bus-free-time = <0x02>;
+					nvidia,i2c-stop-setup-time = <0x02>;
+					nvidia,i2c-start-hold-time = <0x02>;
+					nvidia,i2c-start-setup-time = <0x02>;
+				};
+
+				high {
+					nvidia,i2c-clk-divisor-fs-mode = <0x16>;
+					nvidia,i2c-clk-divisor-hs-mode = <0x02>;
+					nvidia,i2c-sclk-high-period = <0x02>;
+					nvidia,i2c-sclk-low-period = <0x02>;
+					nvidia,i2c-bus-free-time = <0x02>;
+					nvidia,i2c-stop-setup-time = <0x02>;
+					nvidia,i2c-start-hold-time = <0x02>;
+					nvidia,i2c-start-setup-time = <0x02>;
+					nvidia,i2c-hs-stop-setup-time = <0x09>;
+					nvidia,i2c-hs-start-hold-time = <0x09>;
+					nvidia,i2c-hs-start-setup-time = <0x09>;
+				};
+
+				standard {
+					nvidia,i2c-clk-divisor-fs-mode = <0x4f>;
+					nvidia,i2c-sclk-high-period = <0x07>;
+					nvidia,i2c-sclk-low-period = <0x08>;
+					nvidia,i2c-bus-free-time = <0x08>;
+					nvidia,i2c-stop-setup-time = <0x08>;
+					nvidia,i2c-start-hold-time = <0x08>;
+					nvidia,i2c-start-setup-time = <0x08>;
+				};
+
+			};
+		};
+
+		i2c@3180000 {
+			config {
+
+				common {
+					nvidia,i2c-hs-sclk-high-period = <0x03>;
+					nvidia,i2c-hs-sclk-low-period = <0x08>;
+				};
+
+				fast {
+					nvidia,i2c-clk-divisor-fs-mode = <0x3c>;
+					nvidia,i2c-sclk-high-period = <0x02>;
+					nvidia,i2c-sclk-low-period = <0x02>;
+					nvidia,i2c-bus-free-time = <0x02>;
+					nvidia,i2c-stop-setup-time = <0x02>;
+					nvidia,i2c-start-hold-time = <0x02>;
+					nvidia,i2c-start-setup-time = <0x02>;
+				};
+
+				fastplus {
+					nvidia,i2c-clk-divisor-fs-mode = <0x16>;
+					nvidia,i2c-sclk-high-period = <0x02>;
+					nvidia,i2c-sclk-low-period = <0x02>;
+					nvidia,i2c-bus-free-time = <0x02>;
+					nvidia,i2c-stop-setup-time = <0x02>;
+					nvidia,i2c-start-hold-time = <0x02>;
+					nvidia,i2c-start-setup-time = <0x02>;
+				};
+
+				high {
+					nvidia,i2c-clk-divisor-fs-mode = <0x16>;
+					nvidia,i2c-clk-divisor-hs-mode = <0x02>;
+					nvidia,i2c-sclk-high-period = <0x02>;
+					nvidia,i2c-sclk-low-period = <0x02>;
+					nvidia,i2c-bus-free-time = <0x02>;
+					nvidia,i2c-stop-setup-time = <0x02>;
+					nvidia,i2c-start-hold-time = <0x02>;
+					nvidia,i2c-start-setup-time = <0x02>;
+					nvidia,i2c-hs-stop-setup-time = <0x09>;
+					nvidia,i2c-hs-start-hold-time = <0x09>;
+					nvidia,i2c-hs-start-setup-time = <0x09>;
+				};
+
+				standard {
+					nvidia,i2c-clk-divisor-fs-mode = <0x4f>;
+					nvidia,i2c-sclk-high-period = <0x07>;
+					nvidia,i2c-sclk-low-period = <0x08>;
+					nvidia,i2c-bus-free-time = <0x08>;
+					nvidia,i2c-stop-setup-time = <0x08>;
+					nvidia,i2c-start-hold-time = <0x08>;
+					nvidia,i2c-start-setup-time = <0x08>;
+				};
+
+			};
+		};
+
+		i2c@3190000 {
+			config {
+
+				common {
+					nvidia,i2c-hs-sclk-high-period = <0x03>;
+					nvidia,i2c-hs-sclk-low-period = <0x08>;
+				};
+
+				fast {
+					nvidia,i2c-clk-divisor-fs-mode = <0x3c>;
+					nvidia,i2c-sclk-high-period = <0x02>;
+					nvidia,i2c-sclk-low-period = <0x02>;
+					nvidia,i2c-bus-free-time = <0x02>;
+					nvidia,i2c-stop-setup-time = <0x02>;
+					nvidia,i2c-start-hold-time = <0x02>;
+					nvidia,i2c-start-setup-time = <0x02>;
+				};
+
+				fastplus {
+					nvidia,i2c-clk-divisor-fs-mode = <0x16>;
+					nvidia,i2c-sclk-high-period = <0x02>;
+					nvidia,i2c-sclk-low-period = <0x02>;
+					nvidia,i2c-bus-free-time = <0x02>;
+					nvidia,i2c-stop-setup-time = <0x02>;
+					nvidia,i2c-start-hold-time = <0x02>;
+					nvidia,i2c-start-setup-time = <0x02>;
+				};
+
+				high {
+					nvidia,i2c-clk-divisor-fs-mode = <0x16>;
+					nvidia,i2c-clk-divisor-hs-mode = <0x02>;
+					nvidia,i2c-sclk-high-period = <0x02>;
+					nvidia,i2c-sclk-low-period = <0x02>;
+					nvidia,i2c-bus-free-time = <0x02>;
+					nvidia,i2c-stop-setup-time = <0x02>;
+					nvidia,i2c-start-hold-time = <0x02>;
+					nvidia,i2c-start-setup-time = <0x02>;
+					nvidia,i2c-hs-stop-setup-time = <0x09>;
+					nvidia,i2c-hs-start-hold-time = <0x09>;
+					nvidia,i2c-hs-start-setup-time = <0x09>;
+				};
+
+				standard {
+					nvidia,i2c-clk-divisor-fs-mode = <0x4f>;
+					nvidia,i2c-sclk-high-period = <0x07>;
+					nvidia,i2c-sclk-low-period = <0x08>;
+					nvidia,i2c-bus-free-time = <0x08>;
+					nvidia,i2c-stop-setup-time = <0x08>;
+					nvidia,i2c-start-hold-time = <0x08>;
+					nvidia,i2c-start-setup-time = <0x08>;
+				};
+
+			};
+		};
+
+		i2c@31b0000 {
+			config {
+
+				common {
+					nvidia,i2c-hs-sclk-high-period = <0x03>;
+					nvidia,i2c-hs-sclk-low-period = <0x08>;
+				};
+
+				fast {
+					nvidia,i2c-clk-divisor-fs-mode = <0x3c>;
+					nvidia,i2c-sclk-high-period = <0x02>;
+					nvidia,i2c-sclk-low-period = <0x02>;
+					nvidia,i2c-bus-free-time = <0x02>;
+					nvidia,i2c-stop-setup-time = <0x02>;
+					nvidia,i2c-start-hold-time = <0x02>;
+					nvidia,i2c-start-setup-time = <0x02>;
+				};
+
+				fastplus {
+					nvidia,i2c-clk-divisor-fs-mode = <0x16>;
+					nvidia,i2c-sclk-high-period = <0x02>;
+					nvidia,i2c-sclk-low-period = <0x02>;
+					nvidia,i2c-bus-free-time = <0x02>;
+					nvidia,i2c-stop-setup-time = <0x02>;
+					nvidia,i2c-start-hold-time = <0x02>;
+					nvidia,i2c-start-setup-time = <0x02>;
+				};
+
+				high {
+					nvidia,i2c-clk-divisor-fs-mode = <0x16>;
+					nvidia,i2c-clk-divisor-hs-mode = <0x02>;
+					nvidia,i2c-sclk-high-period = <0x02>;
+					nvidia,i2c-sclk-low-period = <0x02>;
+					nvidia,i2c-bus-free-time = <0x02>;
+					nvidia,i2c-stop-setup-time = <0x02>;
+					nvidia,i2c-start-hold-time = <0x02>;
+					nvidia,i2c-start-setup-time = <0x02>;
+					nvidia,i2c-hs-stop-setup-time = <0x09>;
+					nvidia,i2c-hs-start-hold-time = <0x09>;
+					nvidia,i2c-hs-start-setup-time = <0x09>;
+				};
+
+				standard {
+					nvidia,i2c-clk-divisor-fs-mode = <0x4f>;
+					nvidia,i2c-sclk-high-period = <0x07>;
+					nvidia,i2c-sclk-low-period = <0x08>;
+					nvidia,i2c-bus-free-time = <0x08>;
+					nvidia,i2c-stop-setup-time = <0x08>;
+					nvidia,i2c-start-hold-time = <0x08>;
+					nvidia,i2c-start-setup-time = <0x08>;
+				};
+
+			};
+		};
+
+		i2c@31c0000 {
+			config {
+
+				common {
+					nvidia,i2c-hs-sclk-high-period = <0x03>;
+					nvidia,i2c-hs-sclk-low-period = <0x08>;
+				};
+
+				fast {
+					nvidia,i2c-clk-divisor-fs-mode = <0x3c>;
+					nvidia,i2c-sclk-high-period = <0x02>;
+					nvidia,i2c-sclk-low-period = <0x02>;
+					nvidia,i2c-bus-free-time = <0x02>;
+					nvidia,i2c-stop-setup-time = <0x02>;
+					nvidia,i2c-start-hold-time = <0x02>;
+					nvidia,i2c-start-setup-time = <0x02>;
+				};
+
+				fastplus {
+					nvidia,i2c-clk-divisor-fs-mode = <0x16>;
+					nvidia,i2c-sclk-high-period = <0x02>;
+					nvidia,i2c-sclk-low-period = <0x02>;
+					nvidia,i2c-bus-free-time = <0x02>;
+					nvidia,i2c-stop-setup-time = <0x02>;
+					nvidia,i2c-start-hold-time = <0x02>;
+					nvidia,i2c-start-setup-time = <0x02>;
+				};
+
+				high {
+					nvidia,i2c-clk-divisor-fs-mode = <0x16>;
+					nvidia,i2c-clk-divisor-hs-mode = <0x02>;
+					nvidia,i2c-sclk-high-period = <0x02>;
+					nvidia,i2c-sclk-low-period = <0x02>;
+					nvidia,i2c-bus-free-time = <0x02>;
+					nvidia,i2c-stop-setup-time = <0x02>;
+					nvidia,i2c-start-hold-time = <0x02>;
+					nvidia,i2c-start-setup-time = <0x02>;
+					nvidia,i2c-hs-stop-setup-time = <0x09>;
+					nvidia,i2c-hs-start-hold-time = <0x09>;
+					nvidia,i2c-hs-start-setup-time = <0x09>;
+				};
+
+				standard {
+					nvidia,i2c-clk-divisor-fs-mode = <0x4f>;
+					nvidia,i2c-sclk-high-period = <0x07>;
+					nvidia,i2c-sclk-low-period = <0x08>;
+					nvidia,i2c-bus-free-time = <0x08>;
+					nvidia,i2c-stop-setup-time = <0x08>;
+					nvidia,i2c-start-hold-time = <0x08>;
+					nvidia,i2c-start-setup-time = <0x08>;
+				};
+
+			};
+		};
+
+		i2c@31e0000 {
+			config {
+
+				common {
+					nvidia,i2c-hs-sclk-high-period = <0x03>;
+					nvidia,i2c-hs-sclk-low-period = <0x08>;
+				};
+
+				fast {
+					nvidia,i2c-clk-divisor-fs-mode = <0x3c>;
+					nvidia,i2c-sclk-high-period = <0x02>;
+					nvidia,i2c-sclk-low-period = <0x02>;
+					nvidia,i2c-bus-free-time = <0x02>;
+					nvidia,i2c-stop-setup-time = <0x02>;
+					nvidia,i2c-start-hold-time = <0x02>;
+					nvidia,i2c-start-setup-time = <0x02>;
+				};
+
+				fastplus {
+					nvidia,i2c-clk-divisor-fs-mode = <0x16>;
+					nvidia,i2c-sclk-high-period = <0x02>;
+					nvidia,i2c-sclk-low-period = <0x02>;
+					nvidia,i2c-bus-free-time = <0x02>;
+					nvidia,i2c-stop-setup-time = <0x02>;
+					nvidia,i2c-start-hold-time = <0x02>;
+					nvidia,i2c-start-setup-time = <0x02>;
+				};
+
+				high {
+					nvidia,i2c-clk-divisor-fs-mode = <0x16>;
+					nvidia,i2c-clk-divisor-hs-mode = <0x02>;
+					nvidia,i2c-sclk-high-period = <0x02>;
+					nvidia,i2c-sclk-low-period = <0x02>;
+					nvidia,i2c-bus-free-time = <0x02>;
+					nvidia,i2c-stop-setup-time = <0x02>;
+					nvidia,i2c-start-hold-time = <0x02>;
+					nvidia,i2c-start-setup-time = <0x02>;
+					nvidia,i2c-hs-stop-setup-time = <0x09>;
+					nvidia,i2c-hs-start-hold-time = <0x09>;
+					nvidia,i2c-hs-start-setup-time = <0x09>;
+				};
+
+				standard {
+					nvidia,i2c-clk-divisor-fs-mode = <0x4f>;
+					nvidia,i2c-sclk-high-period = <0x07>;
+					nvidia,i2c-sclk-low-period = <0x08>;
+					nvidia,i2c-bus-free-time = <0x08>;
+					nvidia,i2c-stop-setup-time = <0x08>;
+					nvidia,i2c-start-hold-time = <0x08>;
+					nvidia,i2c-start-setup-time = <0x08>;
+				};
+
+			};
+		};
+
+		i2c@c240000 {
+			config {
+
+				common {
+					nvidia,i2c-hs-sclk-high-period = <0x03>;
+					nvidia,i2c-hs-sclk-low-period = <0x08>;
+				};
+
+				fast {
+					nvidia,i2c-clk-divisor-fs-mode = <0x3c>;
+					nvidia,i2c-sclk-high-period = <0x02>;
+					nvidia,i2c-sclk-low-period = <0x02>;
+					nvidia,i2c-bus-free-time = <0x02>;
+					nvidia,i2c-stop-setup-time = <0x02>;
+					nvidia,i2c-start-hold-time = <0x02>;
+					nvidia,i2c-start-setup-time = <0x02>;
+				};
+
+				fastplus {
+					nvidia,i2c-clk-divisor-fs-mode = <0x16>;
+					nvidia,i2c-sclk-high-period = <0x02>;
+					nvidia,i2c-sclk-low-period = <0x02>;
+					nvidia,i2c-bus-free-time = <0x02>;
+					nvidia,i2c-stop-setup-time = <0x02>;
+					nvidia,i2c-start-hold-time = <0x02>;
+					nvidia,i2c-start-setup-time = <0x02>;
+				};
+
+				high {
+					nvidia,i2c-clk-divisor-fs-mode = <0x16>;
+					nvidia,i2c-clk-divisor-hs-mode = <0x02>;
+					nvidia,i2c-sclk-high-period = <0x02>;
+					nvidia,i2c-sclk-low-period = <0x02>;
+					nvidia,i2c-bus-free-time = <0x02>;
+					nvidia,i2c-stop-setup-time = <0x02>;
+					nvidia,i2c-start-hold-time = <0x02>;
+					nvidia,i2c-start-setup-time = <0x02>;
+					nvidia,i2c-hs-stop-setup-time = <0x09>;
+					nvidia,i2c-hs-start-hold-time = <0x09>;
+					nvidia,i2c-hs-start-setup-time = <0x09>;
+				};
+
+				standard {
+					nvidia,i2c-clk-divisor-fs-mode = <0x4f>;
+					nvidia,i2c-sclk-high-period = <0x07>;
+					nvidia,i2c-sclk-low-period = <0x08>;
+					nvidia,i2c-bus-free-time = <0x08>;
+					nvidia,i2c-stop-setup-time = <0x08>;
+					nvidia,i2c-start-hold-time = <0x08>;
+					nvidia,i2c-start-setup-time = <0x08>;
+				};
+
+			};
+		};
+
+		i2c@c250000 {
+			config {
+
+				common {
+					nvidia,i2c-hs-sclk-high-period = <0x03>;
+					nvidia,i2c-hs-sclk-low-period = <0x08>;
+				};
+
+				fast {
+					nvidia,i2c-clk-divisor-fs-mode = <0x3c>;
+					nvidia,i2c-sclk-high-period = <0x02>;
+					nvidia,i2c-sclk-low-period = <0x02>;
+					nvidia,i2c-bus-free-time = <0x02>;
+					nvidia,i2c-stop-setup-time = <0x02>;
+					nvidia,i2c-start-hold-time = <0x02>;
+					nvidia,i2c-start-setup-time = <0x02>;
+				};
+
+				fastplus {
+					nvidia,i2c-clk-divisor-fs-mode = <0x16>;
+					nvidia,i2c-sclk-high-period = <0x02>;
+					nvidia,i2c-sclk-low-period = <0x02>;
+					nvidia,i2c-bus-free-time = <0x02>;
+					nvidia,i2c-stop-setup-time = <0x02>;
+					nvidia,i2c-start-hold-time = <0x02>;
+					nvidia,i2c-start-setup-time = <0x02>;
+				};
+
+				high {
+					nvidia,i2c-clk-divisor-fs-mode = <0x16>;
+					nvidia,i2c-clk-divisor-hs-mode = <0x02>;
+					nvidia,i2c-sclk-high-period = <0x02>;
+					nvidia,i2c-sclk-low-period = <0x02>;
+					nvidia,i2c-bus-free-time = <0x02>;
+					nvidia,i2c-stop-setup-time = <0x02>;
+					nvidia,i2c-start-hold-time = <0x02>;
+					nvidia,i2c-start-setup-time = <0x02>;
+					nvidia,i2c-hs-stop-setup-time = <0x09>;
+					nvidia,i2c-hs-start-hold-time = <0x09>;
+					nvidia,i2c-hs-start-setup-time = <0x09>;
+				};
+
+				standard {
+					nvidia,i2c-clk-divisor-fs-mode = <0x4f>;
+					nvidia,i2c-sclk-high-period = <0x07>;
+					nvidia,i2c-sclk-low-period = <0x08>;
+					nvidia,i2c-bus-free-time = <0x08>;
+					nvidia,i2c-stop-setup-time = <0x08>;
+					nvidia,i2c-start-hold-time = <0x08>;
+					nvidia,i2c-start-setup-time = <0x08>;
+				};
+
+			};
+		};
+
+	};
+};
diff --git a/arch/arm64/boot/dts/nvidia/tegra234-p3701-0000-cfg.dtsi b/arch/arm64/boot/dts/nvidia/tegra234-p3701-0000-cfg.dtsi
new file mode 100644
index 000000000000..3eb13c06d34d
--- /dev/null
+++ b/arch/arm64/boot/dts/nvidia/tegra234-p3701-0000-cfg.dtsi
@@ -0,0 +1,123 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include "tegra234-cfg.dtsi"
+
+/ {
+	bus@0 {
+		i2c@3160000 {
+			config {
+				fast {
+					nvidia,i2c-clk-divisor-fs-mode = <0x3c>;
+					nvidia,i2c-sclk-high-period = <0x02>;
+					nvidia,i2c-sclk-low-period = <0x02>;
+					nvidia,i2c-bus-free-time = <0x02>;
+					nvidia,i2c-stop-setup-time = <0x02>;
+					nvidia,i2c-start-hold-time = <0x02>;
+					nvidia,i2c-start-setup-time = <0x02>;
+				};
+				fastplus {
+					nvidia,i2c-clk-divisor-fs-mode = <0x16>;
+					nvidia,i2c-sclk-high-period = <0x02>;
+					nvidia,i2c-sclk-low-period = <0x02>;
+					nvidia,i2c-bus-free-time = <0x02>;
+					nvidia,i2c-stop-setup-time = <0x02>;
+					nvidia,i2c-start-hold-time = <0x02>;
+					nvidia,i2c-start-setup-time = <0x02>;
+				};
+			};
+		};
+
+		i2c@3180000 {
+			config {
+				fastplus {
+					nvidia,i2c-clk-divisor-fs-mode = <0x16>;
+					nvidia,i2c-sclk-high-period = <0x02>;
+					nvidia,i2c-sclk-low-period = <0x02>;
+					nvidia,i2c-bus-free-time = <0x02>;
+					nvidia,i2c-stop-setup-time = <0x02>;
+					nvidia,i2c-start-hold-time = <0x02>;
+					nvidia,i2c-start-setup-time = <0x02>;
+				};
+				standard {
+					nvidia,i2c-clk-divisor-fs-mode = <0x4f>;
+					nvidia,i2c-sclk-high-period = <0x07>;
+					nvidia,i2c-sclk-low-period = <0x08>;
+					nvidia,i2c-bus-free-time = <0x08>;
+					nvidia,i2c-stop-setup-time = <0x08>;
+					nvidia,i2c-start-hold-time = <0x08>;
+					nvidia,i2c-start-setup-time = <0x08>;
+				};
+			};
+		};
+
+		i2c@3190000 {
+			config {
+				fast {
+					nvidia,i2c-clk-divisor-fs-mode = <0x3c>;
+					nvidia,i2c-sclk-high-period = <0x02>;
+					nvidia,i2c-sclk-low-period = <0x02>;
+					nvidia,i2c-bus-free-time = <0x02>;
+					nvidia,i2c-stop-setup-time = <0x02>;
+					nvidia,i2c-start-hold-time = <0x02>;
+					nvidia,i2c-start-setup-time = <0x02>;
+				};
+			};
+		};
+
+		i2c@31c0000 {
+			config {
+				fast {
+					nvidia,i2c-clk-divisor-fs-mode = <0x3c>;
+					nvidia,i2c-sclk-high-period = <0x02>;
+					nvidia,i2c-sclk-low-period = <0x02>;
+					nvidia,i2c-bus-free-time = <0x02>;
+					nvidia,i2c-stop-setup-time = <0x02>;
+					nvidia,i2c-start-hold-time = <0x02>;
+					nvidia,i2c-start-setup-time = <0x02>;
+				};
+			};
+		};
+
+		i2c@31e0000 {
+			config {
+				fast {
+					nvidia,i2c-clk-divisor-fs-mode = <0x3c>;
+					nvidia,i2c-sclk-high-period = <0x02>;
+					nvidia,i2c-sclk-low-period = <0x02>;
+					nvidia,i2c-bus-free-time = <0x02>;
+					nvidia,i2c-stop-setup-time = <0x02>;
+					nvidia,i2c-start-hold-time = <0x02>;
+					nvidia,i2c-start-setup-time = <0x02>;
+				};
+			};
+		};
+
+		i2c@c240000 {
+			config {
+				fastplus {
+					nvidia,i2c-clk-divisor-fs-mode = <0x16>;
+					nvidia,i2c-sclk-high-period = <0x02>;
+					nvidia,i2c-sclk-low-period = <0x02>;
+					nvidia,i2c-bus-free-time = <0x02>;
+					nvidia,i2c-stop-setup-time = <0x02>;
+					nvidia,i2c-start-hold-time = <0x02>;
+					nvidia,i2c-start-setup-time = <0x02>;
+				};
+			};
+		};
+
+		i2c@c250000 {
+			config {
+				fastplus {
+					nvidia,i2c-clk-divisor-fs-mode = <0x16>;
+					nvidia,i2c-sclk-high-period = <0x02>;
+					nvidia,i2c-sclk-low-period = <0x02>;
+					nvidia,i2c-bus-free-time = <0x02>;
+					nvidia,i2c-stop-setup-time = <0x02>;
+					nvidia,i2c-start-hold-time = <0x02>;
+					nvidia,i2c-start-setup-time = <0x02>;
+				};
+			};
+		};
+	};
+};
diff --git a/arch/arm64/boot/dts/nvidia/tegra234-p3701-0000.dtsi b/arch/arm64/boot/dts/nvidia/tegra234-p3701-0000.dtsi
index cb792041fc62..71506c51a5ea 100644
--- a/arch/arm64/boot/dts/nvidia/tegra234-p3701-0000.dtsi
+++ b/arch/arm64/boot/dts/nvidia/tegra234-p3701-0000.dtsi
@@ -2,6 +2,7 @@
 
 #include "tegra234.dtsi"
 #include "tegra234-p3701.dtsi"
+#include "tegra234-p3701-0000-cfg.dtsi"
 
 / {
 	model = "NVIDIA Jetson AGX Orin";
-- 
2.43.2

[RFC PATCH 09/11] sdhci: dt-bindings: configuration settings

[Krishna Yarlagadda]

SDHCI vendor tuning registers are configured using config setting
framework. Document available config for Tegra SDHCI controllers.

Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com>
---
 .../bindings/mmc/nvidia,tegra20-sdhci.yaml    | 36 +++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.yaml b/Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.yaml
index 72987f0326a1..002bc1ffc156 100644
--- a/Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.yaml
+++ b/Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.yaml
@@ -177,6 +177,37 @@ properties:
       operates at a 1.8 V fixed I/O voltage.
     $ref: /schemas/types.yaml#/definitions/flag
 
+  config:
+    description: Config settings for SDHCI devices.
+      Config setting is the configuration based on chip/board/system
+      characterization on interface/controller settings. This is needed for
+      - making the controller internal configuration to better perform
+      - making the interface to work proper by setting drive strength, slew
+        rates etc
+      - making the low power leakage.
+      SDHCI has configuration based on device speed modes.
+      - common is set on all speeds and can be overridden by speed mode.
+      - List of speed modes and their config name
+        "default", /* MMC_TIMING_LEGACY */
+        "sd-mmc-highspeed", /* MMC_TIMING_MMC_HS */
+        "sd-mmc-highspeed", /* MMC_TIMING_SD_HS */
+        "uhs-sdr12", /* MMC_TIMING_UHS_SDR12 */
+        "uhs-sdr25", /* MMC_TIMING_UHS_SDR25 */
+        "uhs-sdr50", /* MMC_TIMING_UHS_SDR50 */
+        "uhs-sdr104", /* MMC_TIMING_UHS_SDR104 */
+        "uhs-ddr52", /* MMC_TIMING_UHS_DDR50 */
+        "uhs-ddr52", /* MMC_TIMING_MMC_DDR52 */
+        "mmc-hs200", /* MMC_TIMING_MMC_HS200 */
+        "mmc-hs400", /* MMC_TIMING_MMC_HS400 */
+    type: object
+    unevaluatedProperties: true
+    properties:
+      nvidia,num-tuning-iter:
+        description: Specify DQS trim value for HS400 timing.
+        $ref: /schemas/types.yaml#/definitions/uint32
+        minimum: 0
+        maximum: 0xffff
+
 required:
   - compatible
   - reg
@@ -278,6 +309,11 @@ examples:
         wp-gpios = <&gpio 57 0>; /* gpio PH1 */
         power-gpios = <&gpio 155 0>; /* gpio PT3 */
         bus-width = <8>;
+        config {
+            mmc-hs200 {
+                nvidia,num-tuning-iter = <0x2>;
+            };
+        };
     };
 
   - |
-- 
2.43.2

[RFC PATCH 10/11] mmc: host: tegra: config settings for timing

[Krishna Yarlagadda]

Use config settings framework to initialize Tegra SDHCI
timing registers

Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com>
Signed-off-by: Prathamesh Shete <pshete@nvidia.com>
---
 drivers/mmc/host/sdhci-tegra.c | 84 ++++++++++++++++++++++++++++++++++
 1 file changed, 84 insertions(+)

diff --git a/drivers/mmc/host/sdhci-tegra.c b/drivers/mmc/host/sdhci-tegra.c
index 1ad0a6b3a2eb..87fe85991617 100644
--- a/drivers/mmc/host/sdhci-tegra.c
+++ b/drivers/mmc/host/sdhci-tegra.c
@@ -28,6 +28,7 @@
 #include <linux/reset.h>
 
 #include <soc/tegra/common.h>
+#include <soc/tegra/tegra-cfg.h>
 
 #include "sdhci-cqhci.h"
 #include "sdhci-pltfm.h"
@@ -64,6 +65,7 @@
 #define SDHCI_TEGRA_DLLCAL_STA_ACTIVE			BIT(31)
 
 #define SDHCI_VNDR_TUN_CTRL0_0				0x1c0
+#define SDHCI_VNDR_TUN_CTRL0_CMD_CRC_ERR_EN		BIT(28)
 #define SDHCI_VNDR_TUN_CTRL0_TUN_HW_TAP			0x20000
 #define SDHCI_VNDR_TUN_CTRL0_START_TAP_VAL_MASK		0x03fc0000
 #define SDHCI_VNDR_TUN_CTRL0_START_TAP_VAL_SHIFT	18
@@ -74,6 +76,7 @@
 #define TRIES_128					2
 #define TRIES_256					4
 #define SDHCI_VNDR_TUN_CTRL0_TUN_WORD_SEL_MASK		0x7
+#define SDHCI_VNDR_TUN_CTRL0_DIV_N_MASK			GENMASK(5, 3)
 
 #define SDHCI_TEGRA_VNDR_TUN_CTRL1_0			0x1c4
 #define SDHCI_TEGRA_VNDR_TUN_STATUS0			0x1C8
@@ -134,6 +137,20 @@
 					 SDHCI_TRNS_BLK_CNT_EN | \
 					 SDHCI_TRNS_DMA)
 
+static const char * const cfg_device_states[] = {
+	"default",		/* MMC_TIMING_LEGACY */
+	"sd-mmc-highspeed",	/* MMC_TIMING_MMC_HS */
+	"sd-mmc-highspeed",	/* MMC_TIMING_SD_HS */
+	"uhs-sdr12",		/* MMC_TIMING_UHS_SDR12 */
+	"uhs-sdr25",		/* MMC_TIMING_UHS_SDR25 */
+	"uhs-sdr50",		/* MMC_TIMING_UHS_SDR50 */
+	"uhs-sdr104",		/* MMC_TIMING_UHS_SDR104 */
+	"uhs-ddr52",		/* MMC_TIMING_UHS_DDR50 */
+	"uhs-ddr52",		/* MMC_TIMING_MMC_DDR52 */
+	"mmc-hs200",		/* MMC_TIMING_MMC_HS200 */
+	"mmc-hs400",		/* MMC_TIMING_MMC_HS400 */
+};
+
 struct sdhci_tegra_soc_data {
 	const struct sdhci_pltfm_data *pdata;
 	u64 dma_mask;
@@ -158,6 +175,18 @@ struct sdhci_tegra_autocal_offsets {
 	u32 pull_down_hs400;
 };
 
+static const struct tegra_cfg_field_desc sdhci_cfg_fields[] = {
+	TEGRA_CFG_FIELD("nvidia,num-tuning-iter",
+			SDHCI_VNDR_TUN_CTRL0_0,
+			SDHCI_VNDR_TUN_CTRL0_TUN_ITER_MASK),
+};
+
+static struct tegra_cfg_desc sdhci_cfg_desc = {
+	.num_regs = 0,
+	.num_fields = ARRAY_SIZE(sdhci_cfg_fields),
+	.fields = sdhci_cfg_fields,
+};
+
 struct sdhci_tegra {
 	const struct sdhci_tegra_soc_data *soc_data;
 	struct gpio_desc *power_gpio;
@@ -183,6 +212,7 @@ struct sdhci_tegra {
 	unsigned long curr_clk_rate;
 	u8 tuned_tap_delay;
 	u32 stream_id;
+	struct tegra_cfg_list *list;
 };
 
 static u16 tegra_sdhci_readw(struct sdhci_host *host, int reg)
@@ -362,6 +392,30 @@ static void tegra_sdhci_set_tap(struct sdhci_host *host, unsigned int tap)
 	}
 }
 
+static void tegra_sdhci_write_cfg_settings(struct sdhci_host *host,
+					   const char *name)
+{
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct sdhci_tegra *tegra_host = sdhci_pltfm_priv(pltfm_host);
+	struct tegra_cfg_reg *regs;
+	struct tegra_cfg *cfg;
+	unsigned int i;
+	u32 val;
+
+	cfg = tegra_cfg_get_by_name(mmc_dev(host->mmc),
+				    tegra_host->list, name);
+	if (!cfg)
+		return;
+
+	regs = cfg->regs;
+	for (i = 0; i < cfg->num_regs; ++i) {
+		val = sdhci_readl(host, regs[i].offset);
+		val &= ~regs[i].mask;
+		val |= regs[i].value;
+		sdhci_writel(host, val, regs[i].offset);
+	}
+}
+
 static void tegra_sdhci_reset(struct sdhci_host *host, u8 mask)
 {
 	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
@@ -374,6 +428,8 @@ static void tegra_sdhci_reset(struct sdhci_host *host, u8 mask)
 	if (!(mask & SDHCI_RESET_ALL))
 		return;
 
+	tegra_sdhci_write_cfg_settings(host, "common");
+
 	tegra_sdhci_set_tap(host, tegra_host->default_tap);
 
 	misc_ctrl = sdhci_readl(host, SDHCI_TEGRA_VENDOR_MISC_CTRL);
@@ -1011,6 +1067,7 @@ static void tegra_sdhci_set_uhs_signaling(struct sdhci_host *host,
 	bool set_default_tap = false;
 	bool set_dqs_trim = false;
 	bool do_hs400_dll_cal = false;
+	bool set_config = false;
 	u8 iter = TRIES_256;
 	u32 val;
 
@@ -1027,6 +1084,7 @@ static void tegra_sdhci_set_uhs_signaling(struct sdhci_host *host,
 		set_dqs_trim = true;
 		do_hs400_dll_cal = true;
 		iter = TRIES_128;
+		set_config = true;
 		break;
 	case MMC_TIMING_MMC_DDR52:
 	case MMC_TIMING_UHS_DDR50:
@@ -1059,6 +1117,9 @@ static void tegra_sdhci_set_uhs_signaling(struct sdhci_host *host,
 	else
 		tegra_sdhci_set_tap(host, tegra_host->default_tap);
 
+	if (set_config)
+		tegra_sdhci_write_cfg_settings(host,
+					       cfg_device_states[timing]);
 	if (set_dqs_trim)
 		tegra_sdhci_set_dqs_trim(host, tegra_host->dqs_trim);
 
@@ -1129,6 +1190,29 @@ static int sdhci_tegra_start_signal_voltage_switch(struct mmc_host *mmc,
 static int tegra_sdhci_init_pinctrl_info(struct device *dev,
 					 struct sdhci_tegra *tegra_host)
 {
+	unsigned int i, j, count;
+	const struct tegra_cfg_field_desc *fields;
+
+	count = 0;
+	fields = sdhci_cfg_fields;
+
+	for (i = 0; i < sdhci_cfg_desc.num_fields; i++) {
+		for (j = 0; j < i; j++)
+			if (fields[i].offset == fields[j].offset)
+				break;
+
+		if (i == j)
+			count++;
+	}
+
+	sdhci_cfg_desc.num_regs = count;
+	tegra_host->list = tegra_cfg_get(dev, NULL, &sdhci_cfg_desc);
+	if (IS_ERR(tegra_host->list)) {
+		dev_dbg(dev, "Config setting not available, err: %ld\n",
+			PTR_ERR(tegra_host->list));
+		tegra_host->list = NULL;
+	}
+
 	tegra_host->pinctrl_sdmmc = devm_pinctrl_get(dev);
 	if (IS_ERR(tegra_host->pinctrl_sdmmc)) {
 		dev_dbg(dev, "No pinctrl info, err: %ld\n",
-- 
2.43.2

[RFC PATCH 11/11] arm64: tegra: SDHCI timing settings

[Krishna Yarlagadda]

Set SDHCI timing registers through config settings for
Tegra234 chip and P3701 board.

Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com>
---
 arch/arm64/boot/dts/nvidia/tegra234-cfg.dtsi | 32 ++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/arch/arm64/boot/dts/nvidia/tegra234-cfg.dtsi b/arch/arm64/boot/dts/nvidia/tegra234-cfg.dtsi
index 832538e45797..f9a92853b04a 100644
--- a/arch/arm64/boot/dts/nvidia/tegra234-cfg.dtsi
+++ b/arch/arm64/boot/dts/nvidia/tegra234-cfg.dtsi
@@ -442,5 +442,37 @@ standard {
 			};
 		};
 
+		mmc@3400000 {
+			config {
+
+				mmc-hs200 {
+					nvidia,num-tuning-iter = <0x2>;
+				};
+
+				uhs-sdr104 {
+					nvidia,num-tuning-iter = <0x2>;
+				};
+
+				uhs-sdr50 {
+					nvidia,num-tuning-iter = <0x4>;
+				};
+
+			};
+		};
+
+		mmc@3460000 {
+			config {
+
+				mmc-hs200 {
+					nvidia,num-tuning-iter = <0x2>;
+				};
+
+				mmc-hs400 {
+					nvidia,num-tuning-iter = <0x2>;
+				};
+
+			};
+		};
+
 	};
 };
-- 
2.43.2

Re: [RFC PATCH 03/11] soc: tegra: config settings binding document

[Krzysztof Kozlowski]

On 07/05/2024 00:51, Krishna Yarlagadda wrote:
> Config framework parses device tree and provides a list of register
> settings with mask per mode to be applied by the controller.
> 
> Add binding document for config settings framework. Config settings
> are defined as a property per field and have different modes per device.

Please use subject prefixes matching the subsystem. You can get them for
example with `git log --oneline -- DIRECTORY_OR_FILE` on the directory
your patch is touching. For bindings, the preferred subjects are
explained here:
https://www.kernel.org/doc/html/latest/devicetree/bindings/submitting-patches.html#i-for-patch-submitters

> 
> Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com>
> ---
>  .../misc/nvidia,tegra-config-settings.yaml    | 50 +++++++++++++++++++
>  MAINTAINERS                                   |  1 +
>  2 files changed, 51 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/misc/nvidia,tegra-config-settings.yaml
> 
> diff --git a/Documentation/devicetree/bindings/misc/nvidia,tegra-config-settings.yaml b/Documentation/devicetree/bindings/misc/nvidia,tegra-config-settings.yaml
> new file mode 100644
> index 000000000000..e379cbd5b597
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/misc/nvidia,tegra-config-settings.yaml
> @@ -0,0 +1,50 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/misc/nvidia,tegra-config-settings.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Config properties for a device.

No full stop, that's a title.

> +
> +description:
> +  Config setting is the configuration based on chip/board/system
> +  characterization on interface/controller settings. This is needed for
> +  - making the controller internal configuration to better perform
> +  - making the interface to work proper by setting drive strength, slew
> +    rates etc
> +  - making the low power leakage.
> +  There are two types of recommended configuration settings
> +  - Controller register specific for internal operation of controller.
> +  - Pad control/Pinmux/pincontrol registers for interfacing.
> +  These configurations can further be categorized as static and dynamic.
> +  - Static config does not change until a controller is reset.
> +  - Dynamic config changes based on mode or condition, controller is
> +    operating in.
> +
> +maintainers:
> +  - Thierry Reding <thierry.reding@gmail.com>
> +
> +patternProperties:
> +  "^[a-z0-9_]*$":
> +    description:
> +      Config name to be applied on controller.
> +    type: object

Nope, this means nothing. Sorry, describe hardware, do not create some
fake nodes.

> +
> +additionalProperties: true
> +
> +examples:
> +  - |
> +        config {

Messed indentation.

> +            common {
> +                nvidia,i2c-hs-sclk-high-period = <0x03>;
> +                nvidia,i2c-hs-sclk-low-period = <0x08>;
> +            };


Best regards,
Krzysztof

Re: [RFC PATCH 04/11] i2c: dt-bindings: configuration settings

[Krzysztof Kozlowski]

On 07/05/2024 00:51, Krishna Yarlagadda wrote:
> I2C interface timing registers are configured using config setting
> framework. Document available properties for Tegra I2C controllers.
> 
> Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com>
> ---
>  .../bindings/i2c/nvidia,tegra20-i2c.yaml      | 104 ++++++++++++++++++
>  1 file changed, 104 insertions(+)
> 

You called it RFC, so not ready for review, thus just few remarks.

Please use subject prefixes matching the subsystem. You can get them for
example with `git log --oneline -- DIRECTORY_OR_FILE` on the directory
your patch is touching. For bindings, the preferred subjects are
explained here:
https://www.kernel.org/doc/html/latest/devicetree/bindings/submitting-patches.html#i-for-patch-submitters


> diff --git a/Documentation/devicetree/bindings/i2c/nvidia,tegra20-i2c.yaml b/Documentation/devicetree/bindings/i2c/nvidia,tegra20-i2c.yaml
> index 424a4fc218b6..3b22e75e5aa0 100644
> --- a/Documentation/devicetree/bindings/i2c/nvidia,tegra20-i2c.yaml
> +++ b/Documentation/devicetree/bindings/i2c/nvidia,tegra20-i2c.yaml
> @@ -119,6 +119,96 @@ properties:
>        - const: rx
>        - const: tx
>  
> +  config:
> +    description: Config settings for I2C devices enlisted with I2C controller.
> +      Config setting is the configuration based on chip/board/system
> +      characterization on interface/controller settings. This is needed for
> +      - making the controller internal configuration to better perform
> +      - making the interface to work proper by setting drive strength, slew
> +        rates etc
> +      - making the low power leakage.
> +      There are two types of recommended configuration settings
> +      - Controller register specific for internal operation of controller.
> +      - Pad control/Pinmux/pincontrol registers for interfacing.
> +      These configurations can further be categorized as static and dynamic.
> +      - Static config does not change until a controller is reset.
> +      - Dynamic config changes based on mode or condition, controller is
> +        operating in.
> +      I2C has configuration based on clock speed and has below modes.
> +      - common is set on all speeds and can be overridden by speed mode.
> +      - high is set when clock mode is high speed.
> +      - fastplus is set when clock mode is fast plus.
> +      - fast is set when clock mode is fast mode.
> +      - standard is set when clock mode is standard mode.
> +    $ref: /schemas/misc/nvidia,tegra-config-settings.yaml
> +    unevaluatedProperties: false
> +    properties:
> +      nvidia,i2c-clk-divisor-hs-mode:
> +        description: I2C clock divisor for HS mode.

So you decided to implement clocks in DT? No.

> +        $ref: /schemas/types.yaml#/definitions/uint32
> +        minimum: 0
> +        maximum: 0xffff

Anyway divisors, clock rates and everything is human-readable so in
decimal, not hex.

There are also several issues further, like using wrong units (time has
a unit), but since this is RFC, I will just NAK.

Best regards,
Krzysztof

Re: [RFC PATCH 05/11] i2c: core: Avoid config node enumeration

[Krzysztof Kozlowski]

On 07/05/2024 00:51, Krishna Yarlagadda wrote:
> Add "config" as a common node to add device configuration settings and
> other data. This child node should not be treated as a device.
> Skip "config" child node during i2c device registration.
> 
> Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com>
> ---
>  drivers/i2c/i2c-core-of.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/i2c/i2c-core-of.c b/drivers/i2c/i2c-core-of.c
> index a6c407d36800..f50206c6c4d6 100644
> --- a/drivers/i2c/i2c-core-of.c
> +++ b/drivers/i2c/i2c-core-of.c
> @@ -98,6 +98,9 @@ void of_i2c_register_devices(struct i2c_adapter *adap)
>  		bus = of_node_get(adap->dev.of_node);
>  
>  	for_each_available_child_of_node(bus, node) {
> +		if (!strcmp(node->name, "config"))
> +			continue;

NAK

All children are devices (they have unit addresses). Do not introduce
some another, parallel addressing.

Best regards,
Krzysztof

Re: [RFC PATCH 09/11] sdhci: dt-bindings: configuration settings

[Krzysztof Kozlowski]

On 07/05/2024 00:51, Krishna Yarlagadda wrote:
> SDHCI vendor tuning registers are configured using config setting
> framework. Document available config for Tegra SDHCI controllers.
> 
> Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com>
> ---
>  .../bindings/mmc/nvidia,tegra20-sdhci.yaml    | 36 +++++++++++++++++++
>  1 file changed, 36 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.yaml b/Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.yaml
> index 72987f0326a1..002bc1ffc156 100644
> --- a/Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.yaml
> +++ b/Documentation/devicetree/bindings/mmc/nvidia,tegra20-sdhci.yaml
> @@ -177,6 +177,37 @@ properties:
>        operates at a 1.8 V fixed I/O voltage.
>      $ref: /schemas/types.yaml#/definitions/flag
>  
> +  config:

No. This node does not re


> +    description: Config settings for SDHCI devices.
> +      Config setting is the configuration based on chip/board/system
> +      characterization on interface/controller settings. This is needed for
> +      - making the controller internal configuration to better perform
> +      - making the interface to work proper by setting drive strength, slew
> +        rates etc
> +      - making the low power leakage.
> +      SDHCI has configuration based on device speed modes.
> +      - common is set on all speeds and can be overridden by speed mode.
> +      - List of speed modes and their config name
> +        "default", /* MMC_TIMING_LEGACY */
> +        "sd-mmc-highspeed", /* MMC_TIMING_MMC_HS */
> +        "sd-mmc-highspeed", /* MMC_TIMING_SD_HS */
> +        "uhs-sdr12", /* MMC_TIMING_UHS_SDR12 */
> +        "uhs-sdr25", /* MMC_TIMING_UHS_SDR25 */
> +        "uhs-sdr50", /* MMC_TIMING_UHS_SDR50 */
> +        "uhs-sdr104", /* MMC_TIMING_UHS_SDR104 */
> +        "uhs-ddr52", /* MMC_TIMING_UHS_DDR50 */
> +        "uhs-ddr52", /* MMC_TIMING_MMC_DDR52 */
> +        "mmc-hs200", /* MMC_TIMING_MMC_HS200 */
> +        "mmc-hs400", /* MMC_TIMING_MMC_HS400 */
> +    type: object
> +    unevaluatedProperties: true

NAK.

> +    properties:
> +      nvidia,num-tuning-iter:
> +        description: Specify DQS trim value for HS400 timing.
> +        $ref: /schemas/types.yaml#/definitions/uint32
> +        minimum: 0
> +        maximum: 0xffff

"iterations" is decimal value. How it can be 0? 0 tries to time?


Best regards,
Krzysztof

Re: [RFC PATCH 00/11] Introduce Tegra register config settings

[Krzysztof Kozlowski]

On 07/05/2024 00:51, Krishna Yarlagadda wrote:
>  
>  Patch 01: Documentation about the device tree binding for common config framework.
>  Patch 02: Common parser of the device tree config setting node for Tegra SoC.
>  Patch 03: Device tree binding documentation for config setting.
>  Patch 04: Device tree binding documentation for the I2C config setting.
>  Patch 05: Avoid config settings child node to be treated as I2C device.
>  Patch 06: Move clock initialization code into new methods
>  Patch 07: Using config settings in Tegra I2C driver for interface timing registers.
>  Patch 08: Add Tegra234 I2C config settings in DT.
>  Patch 09: Device tree binding documentation for the SDHCI config setting.
>  Patch 10: Using config settings in Tegra SDHCI driver for tuning iteration.
>  Patch 11: Add Tegra234 SDHCI config settings in DT.
> 
> Known Issues:
>  - DTC warning for config 'missing or empty reg property for I2C nodes'

Which should stop you from sending buggy code, till you fix it.

Best regards,
Krzysztof

Re: [RFC PATCH 04/11] i2c: dt-bindings: configuration settings

[Rob Herring (Arm)]

On Tue, 07 May 2024 04:21:32 +0530, Krishna Yarlagadda wrote:
> I2C interface timing registers are configured using config setting
> framework. Document available properties for Tegra I2C controllers.
> 
> Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com>
> ---
>  .../bindings/i2c/nvidia,tegra20-i2c.yaml      | 104 ++++++++++++++++++
>  1 file changed, 104 insertions(+)
> 

My bot found errors running 'make dt_binding_check' on your patch:

yamllint warnings/errors:

dtschema/dtc warnings/errors:
Documentation/devicetree/bindings/i2c/nvidia,tegra20-i2c.example.dts:37.20-50.15: Warning (i2c_bus_reg): /example-0/i2c@7000c000/config: missing or empty reg property

doc reference errors (make refcheckdocs):

See https://patchwork.ozlabs.org/project/devicetree-bindings/patch/20240506225139.57647-5-kyarlagadda@nvidia.com

The base for the series is generally the latest rc1. A different dependency
should be noted in *this* patch.

If you already ran 'make dt_binding_check' and didn't see the above
error(s), then make sure 'yamllint' is installed and dt-schema is up to
date:

pip3 install dtschema --upgrade

Please check and re-submit after running the above command yourself. Note
that DT_SCHEMA_FILES can be set to your schema file to speed up checking
your schema. However, it must be unset to test all examples with your schema.

Re: [RFC PATCH 00/11] Introduce Tegra register config settings

[Thierry Reding]

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On Tue May 7, 2024 at 8:38 AM CEST, Krzysztof Kozlowski wrote:
> On 07/05/2024 00:51, Krishna Yarlagadda wrote:
> >  
> >  Patch 01: Documentation about the device tree binding for common config framework.
> >  Patch 02: Common parser of the device tree config setting node for Tegra SoC.
> >  Patch 03: Device tree binding documentation for config setting.
> >  Patch 04: Device tree binding documentation for the I2C config setting.
> >  Patch 05: Avoid config settings child node to be treated as I2C device.
> >  Patch 06: Move clock initialization code into new methods
> >  Patch 07: Using config settings in Tegra I2C driver for interface timing registers.
> >  Patch 08: Add Tegra234 I2C config settings in DT.
> >  Patch 09: Device tree binding documentation for the SDHCI config setting.
> >  Patch 10: Using config settings in Tegra SDHCI driver for tuning iteration.
> >  Patch 11: Add Tegra234 SDHCI config settings in DT.
> > 
> > Known Issues:
> >  - DTC warning for config 'missing or empty reg property for I2C nodes'
>
> Which should stop you from sending buggy code, till you fix it.

Okay, so this RFC series was meant to solicit comments on the general
approach of this. Fixing this known issue is fairly complicated and
involves patching DTC, which we would be prepared to do if this was
generally deemed acceptable, but doesn't seem like a worthwhile
undertaking until we know we can move ahead with this.

So rather than categorically NAKing something that was sent out as a
proposal looking for feedback on how to improve and turn this into
something acceptable, it'd be great to get constructive feedback on how
we can get there.

Thierry

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Re: [RFC PATCH 03/11] soc: tegra: config settings binding document

[Thierry Reding]

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On Tue May 7, 2024 at 8:32 AM CEST, Krzysztof Kozlowski wrote:
> On 07/05/2024 00:51, Krishna Yarlagadda wrote:
> > Config framework parses device tree and provides a list of register
> > settings with mask per mode to be applied by the controller.
> > 
> > Add binding document for config settings framework. Config settings
> > are defined as a property per field and have different modes per device.
>
> Please use subject prefixes matching the subsystem. You can get them for
> example with `git log --oneline -- DIRECTORY_OR_FILE` on the directory
> your patch is touching. For bindings, the preferred subjects are
> explained here:
> https://www.kernel.org/doc/html/latest/devicetree/bindings/submitting-patches.html#i-for-patch-submitters
>
> > 
> > Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com>
> > ---
> >  .../misc/nvidia,tegra-config-settings.yaml    | 50 +++++++++++++++++++
> >  MAINTAINERS                                   |  1 +
> >  2 files changed, 51 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/misc/nvidia,tegra-config-settings.yaml
> > 
> > diff --git a/Documentation/devicetree/bindings/misc/nvidia,tegra-config-settings.yaml b/Documentation/devicetree/bindings/misc/nvidia,tegra-config-settings.yaml
> > new file mode 100644
> > index 000000000000..e379cbd5b597
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/misc/nvidia,tegra-config-settings.yaml
> > @@ -0,0 +1,50 @@
> > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/misc/nvidia,tegra-config-settings.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Config properties for a device.
>
> No full stop, that's a title.
>
> > +
> > +description:
> > +  Config setting is the configuration based on chip/board/system
> > +  characterization on interface/controller settings. This is needed for
> > +  - making the controller internal configuration to better perform
> > +  - making the interface to work proper by setting drive strength, slew
> > +    rates etc
> > +  - making the low power leakage.
> > +  There are two types of recommended configuration settings
> > +  - Controller register specific for internal operation of controller.
> > +  - Pad control/Pinmux/pincontrol registers for interfacing.
> > +  These configurations can further be categorized as static and dynamic.
> > +  - Static config does not change until a controller is reset.
> > +  - Dynamic config changes based on mode or condition, controller is
> > +    operating in.
> > +
> > +maintainers:
> > +  - Thierry Reding <thierry.reding@gmail.com>
> > +
> > +patternProperties:
> > +  "^[a-z0-9_]*$":
> > +    description:
> > +      Config name to be applied on controller.
> > +    type: object
>
> Nope, this means nothing. Sorry, describe hardware, do not create some
> fake nodes.

We're trying to solve a real problem here, though. In order for the
hardware to operate properly we need certain parameters to be programmed
into the hardware.

If this is not acceptable, do you have a suggestion on where else to put
this information?

Thierry

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