[PATCH v2 00/12] i2c: designeware: Add Baikal-T1 System I2C support

[PATCH v2 00/12] i2c: designeware: Add Baikal-T1 System I2C support

[Serge Semin]

Initially this has been a small patchset which embedded the Baikal-T1
System I2C support into the DW APB I2C driver as is by using a simplest
way. After a short discussion with Andy we decided to implement what he
suggested (introduce regmap-based accessors and create a glue driver) and
even more than that to provide some cleanups of the code. So here is what
this patchset consists of.

First of all we've found out that current implementation of scripts/dtc
didn't support i2c dt nodes with 10bit and slave flags set in the
reg property. You'll see an error if you try to dt_binding_check it.
So the very first patch fixes the problem by adding these flags support
into the check_i2c_bus_reg() method.

Traditionally we converted the plain text-based DT binding to the DT schema
and added Baikal-T1 System I2C device support there. This required to mark
the reg property redundant for Baikal-T1 I2C since its reg-space is
indirectly accessed by means of the System Controller cmd/read/write
registers.

Then as Andy suggested we replaced the Synopsys DW APB I2C common driver
registers IO accessors into the regmap API methods. This doesn't change
the code logic much, though in two places we managed to replace some bulky
peaces of code with a ready-to-use regmap methods.

Additionally before adding the glue layer API we initiated a set of cleanups:
- Define components of the multi-object drivers (like i2c-designware-core.o
  and i2c-designware-paltform.o) with using `-y` suffixed makefile
  variables instead of `-objs` suffixed one. This is encouraged by
  Documentation/kbuild/makefiles.rst text since `-objs` is supposed to be used
  to build host programs.
- Make DW I2C slave driver depended on the DW I2C core code instead of the
  platform one, which it really is.
- Move Intel Baytrail semaphore feature to the platform if-clause of the
  kernel config.

After this we finally can introduce the glue layer API for the DW APB I2C
platform driver. So there are three methods exported from the driver:
i2c_dw_plat_setup(), i2c_dw_plat_clear(), &i2c_dw_plat_dev_pm_ops to
setup, cleanup and add PM operations to the glue driven I2C device. Before
setting the platform DW I2C device up the glue probe code is supposed to
create an instance of DW I2C device generic object and pre-initialize
its `struct device` pointer together with optional platform-specific
flags. In addition to that we converted the MSCC Ocelot SoC I2C specific
code into the glue layer seeing it's really too specific and, which is more
important, isn't that complicated so we could unpin it without much of
worrying to break something.

Meanwhile we discovered that MODEL_CHERRYTRAIL and MODEL_MASK actually
were no longer used in the code. MODEL_MSCC flag has been discarded since
the MSCC Ocelot I2C code conversion to the glue driver. So now we can get
rid of all the MODEL-specific flags.

Finally we introduced a glue driver with Baikal-T1 System I2C device
support. The driver probe tries to find a syscon regmap, creates the DW
APB I2C regmap based on it and passes it further to the DW I2C device
descriptor. Then it does normal DW APB I2C platform setup by calling a
generic setup method. Cleanup is straightforward. It's just calling a
generic DW APB I2C clean method.

This patchset is rebased and tested on the mainline Linux kernel 5.6-rc4:
base-commit: 0e698dfa2822 ("Linux 5.7-rc4")
tag: v5.7-rc4

Note new vendor prefix for Baikal-T1 System I2C device will be added in
the framework of the next patchset:
https://lkml.org/lkml/2020/5/6/1047

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Maxim Kaurkin <Maxim.Kaurkin@baikalelectronics.ru>
Cc: Pavel Parkhomenko <Pavel.Parkhomenko@baikalelectronics.ru>
Cc: Ramil Zaripov <Ramil.Zaripov@baikalelectronics.ru>
Cc: Ekaterina Skachko <Ekaterina.Skachko@baikalelectronics.ru>
Cc: Vadim Vlasov <V.Vlasov@baikalelectronics.ru>
Cc: Alexey Kolotnikov <Alexey.Kolotnikov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Wolfram Sang <wsa@the-dreams.de>
Cc: linux-mips@vger.kernel.org
Cc: linux-i2c@vger.kernel.org
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org

---

Changelog v2:
- Fix the SoB tags.
- Use a shorter summary describing the bindings convertion patch.
- Patch "i2c: designware: Detect the FIFO size in the common code" has
  been acked by Jarkko and applied by Wolfram to for-next so drop it from
  the set.
- Patch "i2c: designware: Discard i2c_dw_read_comp_param() function" has
  been acked by Jarkko and applied by Wolfram to for-next so drop it from
  the set.
- Make sure that "mscc,ocelot-i2c" compatible node may have up to two
  registers space defined in the DT node, while normal DW I2C controller
  will have only one registers space.
- Add "mscc,ocelot-i2c" DT schema example to test the previous fix.
- Declare "unevaluatedProperties" property instead of
  "additionalProperties" one in the DT schema.
- Due to the previous fix we can now discard the dummy boolean properties
  declaration, since the proper type evaluation will be performed by the
  generic i2c-controller.yaml schema.
- Refactor the DW I2C APB driver related series to address the Andies
  notes.
- Convert DW APB I2C driver to using regmap instead of handwritten
  accessors.
- Use `-y` to build multi-object DW APB drivers.
- Fix DW APB I2C slave code dependency. It should depend on
  I2C_DESIGNWARE_CORE instead I2C_DESIGNWARE_PLATFORM.
- Move Baytrail semaphore config to the platform if-clause.
- Introduce a glue-layer platform driver API.
- Unpin Microsemi Ocelot I2C code into a glue driver.
- Remove MODEL_CHERRYTRAIL and MODEL_MASK as no longer needed.
- Add support for custom regmap passed from glue driver.
- Add Baikal-T1 System I2C support in a dedicated glue layer driver.

Serge Semin (12):
  scripts/dtc: check: Add 10bit/slave i2c reg flags support
  dt-bindings: i2c: Convert DW I2C binding to DT schema
  dt-bindings: i2c: dw: Add Baikal-T1 SoC I2C controller
  i2c: designware: Convert driver to using regmap API
  i2c: designware: Use `-y` to build multi-object modules
  i2c: designware: slave: Set DW I2C core module dependency
  i2c: designware: Move Baytrail sem config to the platform if-clause
  i2c: designware: Introduce platform drivers glue layer interface
  i2c: designware: Unpin Microsemi Ocelot I2C into a glue driver
  i2c: designware: Discard Cherry Trail model flag
  i2c: designware: Use provided regmap instead of reg resource
  i2c: designware: Add Baikal-T1 System I2C glue driver

 .../bindings/i2c/i2c-designware.txt           |  73 -------
 .../bindings/i2c/snps,designware-i2c.yaml     | 164 ++++++++++++++++
 drivers/i2c/busses/Kconfig                    |  56 ++++--
 drivers/i2c/busses/Makefile                   |  19 +-
 drivers/i2c/busses/i2c-designware-bt1.c       | 129 +++++++++++++
 drivers/i2c/busses/i2c-designware-common.c    | 178 +++++++++++++-----
 drivers/i2c/busses/i2c-designware-core.h      |  26 ++-
 drivers/i2c/busses/i2c-designware-master.c    | 125 ++++++------
 drivers/i2c/busses/i2c-designware-mscc.c      |  83 ++++++++
 drivers/i2c/busses/i2c-designware-pcidrv.c    |   1 -
 drivers/i2c/busses/i2c-designware-platdrv.c   | 132 ++++++-------
 drivers/i2c/busses/i2c-designware-platdrv.h   |  16 ++
 drivers/i2c/busses/i2c-designware-slave.c     |  77 ++++----
 scripts/dtc/checks.c                          |  13 +-
 14 files changed, 759 insertions(+), 333 deletions(-)
 delete mode 100644 Documentation/devicetree/bindings/i2c/i2c-designware.txt
 create mode 100644 Documentation/devicetree/bindings/i2c/snps,designware-i2c.yaml
 create mode 100644 drivers/i2c/busses/i2c-designware-bt1.c
 create mode 100644 drivers/i2c/busses/i2c-designware-mscc.c
 create mode 100644 drivers/i2c/busses/i2c-designware-platdrv.h

-- 
2.25.1

[PATCH v2 01/12] scripts/dtc: check: Add 10bit/slave i2c reg flags support

[Serge Semin]

Recently the I2C-controllers slave interface support was added to the
kernel I2C subsystem. In this case Linux can be used as, for example,
a I2C EEPROM machine. See [1] for details. Other than instantiating
the EEPROM-slave device from user-space there is a way to declare the
device in dts. In this case firstly the I2C bus controller must support
the slave interface. Secondly I2C-slave sub-node of that controller
must have "reg"-property with flag I2C_OWN_SLAVE_ADDRESS set (flag is
declared in [2]). That flag is declared as (1 << 30), which when set
makes dtc unhappy about too big address set for a I2C-slave:

Warning (i2c_bus_reg): /example-2/i2c@1120000/eeprom@64: I2C bus unit address format error, expected "40000064"
Warning (i2c_bus_reg): /example-2/i2c@1120000/eeprom@64:reg: I2C address must be less than 10-bits, got "0x40000064"

Similar problem would have happened if we had set the 10-bit address
flag I2C_TEN_BIT_ADDRESS in the "reg"-property.

In order to fix the problem we suggest to alter the I2C-bus reg-check
algorithm, so one would be aware of the upper bits set. Normally if no
flag specified, the 7-bit address is expected in the "reg"-property.
If I2C_TEN_BIT_ADDRESS is set, then the 10-bit address check will be
performed. The I2C_OWN_SLAVE_ADDRESS flag will be just ignored.

[1] Documentation/i2c/slave-interface.rst
[2] include/dt-bindings/i2c/i2c.h

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Wolfram Sang <wsa@the-dreams.de>
Cc: linux-mips@vger.kernel.org
Cc: linux-i2c@vger.kernel.org
---
 scripts/dtc/checks.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/scripts/dtc/checks.c b/scripts/dtc/checks.c
index 4b3c486f1399..6321fc5b7404 100644
--- a/scripts/dtc/checks.c
+++ b/scripts/dtc/checks.c
@@ -1028,6 +1028,7 @@ static void check_i2c_bus_reg(struct check *c, struct dt_info *dti, struct node
 	const char *unitname = get_unitname(node);
 	char unit_addr[17];
 	uint32_t reg = 0;
+	uint32_t addr;
 	int len;
 	cell_t *cells = NULL;
 
@@ -1044,17 +1045,21 @@ static void check_i2c_bus_reg(struct check *c, struct dt_info *dti, struct node
 	}
 
 	reg = fdt32_to_cpu(*cells);
-	snprintf(unit_addr, sizeof(unit_addr), "%x", reg);
+	addr = reg & 0x3FFFFFFFU;
+	snprintf(unit_addr, sizeof(unit_addr), "%x", addr);
 	if (!streq(unitname, unit_addr))
 		FAIL(c, dti, node, "I2C bus unit address format error, expected \"%s\"",
 		     unit_addr);
 
 	for (len = prop->val.len; len > 0; len -= 4) {
 		reg = fdt32_to_cpu(*(cells++));
-		if (reg > 0x3ff)
+		addr = reg & 0x3FFFFFFFU;
+		if ((reg & (1 << 31)) && addr > 0x3ff)
 			FAIL_PROP(c, dti, node, prop, "I2C address must be less than 10-bits, got \"0x%x\"",
-				  reg);
-
+				  addr);
+		else if (!(reg & (1 << 31)) && addr > 0x7f)
+			FAIL_PROP(c, dti, node, prop, "I2C address must be less than 7-bits, got \"0x%x\"",
+				  addr);
 	}
 }
 WARNING(i2c_bus_reg, check_i2c_bus_reg, NULL, &reg_format, &i2c_bus_bridge);
-- 
2.25.1

[PATCH v2 02/12] dt-bindings: i2c: Convert DW I2C binding to DT schema

[Serge Semin]

Modern device tree bindings are supposed to be created as YAML-files
in accordance with dt-schema. This commit replaces Synopsys DW I2C
legacy bare text bindings with YAML file. As before the bindings file
states that the corresponding dts node is supposed to be compatible
either with generic DW I2C controller or with Microsemi Ocelot SoC I2C
one, to have registers, interrupts and clocks properties. In addition
the node may have clock-frequency, i2c-sda-hold-time-ns,
i2c-scl-falling-time-ns and i2c-sda-falling-time-ns optional properties.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Wolfram Sang <wsa@the-dreams.de>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: linux-mips@vger.kernel.org

---

Changelog v2:
- Make sure that "mscc,ocelot-i2c" compatible node may have up to two
  registers space defined, while normal DW I2C controller will have only
  one registers space.
- Add "mscc,ocelot-i2c" example to test the previous fix.
- Declare "unevaluatedProperties" property instead of
  "additionalProperties" one.
- Due to the previous fix we can now discard the dummy boolean properties
  definitions, since the proper type evaluation will be performed by the
  generic i2c-controller.yaml schema.
---
 .../bindings/i2c/i2c-designware.txt           |  73 ---------
 .../bindings/i2c/snps,designware-i2c.yaml     | 154 ++++++++++++++++++
 2 files changed, 154 insertions(+), 73 deletions(-)
 delete mode 100644 Documentation/devicetree/bindings/i2c/i2c-designware.txt
 create mode 100644 Documentation/devicetree/bindings/i2c/snps,designware-i2c.yaml

diff --git a/Documentation/devicetree/bindings/i2c/i2c-designware.txt b/Documentation/devicetree/bindings/i2c/i2c-designware.txt
deleted file mode 100644
index 08be4d3846e5..000000000000
--- a/Documentation/devicetree/bindings/i2c/i2c-designware.txt
+++ /dev/null
@@ -1,73 +0,0 @@
-* Synopsys DesignWare I2C
-
-Required properties :
-
- - compatible : should be "snps,designware-i2c"
-                or "mscc,ocelot-i2c" with "snps,designware-i2c" for fallback
- - reg : Offset and length of the register set for the device
- - interrupts : <IRQ> where IRQ is the interrupt number.
- - clocks : phandles for the clocks, see the description of clock-names below.
-   The phandle for the "ic_clk" clock is required. The phandle for the "pclk"
-   clock is optional. If a single clock is specified but no clock-name, it is
-   the "ic_clk" clock. If both clocks are listed, the "ic_clk" must be first.
-
-Recommended properties :
-
- - clock-frequency : desired I2C bus clock frequency in Hz.
-
-Optional properties :
-
- - clock-names : Contains the names of the clocks:
-    "ic_clk", for the core clock used to generate the external I2C clock.
-    "pclk", the interface clock, required for register access.
-
- - reg : for "mscc,ocelot-i2c", a second register set to configure the SDA hold
-   time, named ICPU_CFG:TWI_DELAY in the datasheet.
-
- - i2c-sda-hold-time-ns : should contain the SDA hold time in nanoseconds.
-   This option is only supported in hardware blocks version 1.11a or newer and
-   on Microsemi SoCs ("mscc,ocelot-i2c" compatible).
-
- - i2c-scl-falling-time-ns : should contain the SCL falling time in nanoseconds.
-   This value which is by default 300ns is used to compute the tLOW period.
-
- - i2c-sda-falling-time-ns : should contain the SDA falling time in nanoseconds.
-   This value which is by default 300ns is used to compute the tHIGH period.
-
-Examples :
-
-	i2c@f0000 {
-		#address-cells = <1>;
-		#size-cells = <0>;
-		compatible = "snps,designware-i2c";
-		reg = <0xf0000 0x1000>;
-		interrupts = <11>;
-		clock-frequency = <400000>;
-	};
-
-	i2c@1120000 {
-		#address-cells = <1>;
-		#size-cells = <0>;
-		compatible = "snps,designware-i2c";
-		reg = <0x1120000 0x1000>;
-		interrupt-parent = <&ictl>;
-		interrupts = <12 1>;
-		clock-frequency = <400000>;
-		i2c-sda-hold-time-ns = <300>;
-		i2c-sda-falling-time-ns = <300>;
-		i2c-scl-falling-time-ns = <300>;
-	};
-
-	i2c@1120000 {
-		#address-cells = <1>;
-		#size-cells = <0>;
-		reg = <0x2000 0x100>;
-		clock-frequency = <400000>;
-		clocks = <&i2cclk>;
-		interrupts = <0>;
-
-		eeprom@64 {
-			compatible = "linux,slave-24c02";
-			reg = <0x40000064>;
-		};
-	};
diff --git a/Documentation/devicetree/bindings/i2c/snps,designware-i2c.yaml b/Documentation/devicetree/bindings/i2c/snps,designware-i2c.yaml
new file mode 100644
index 000000000000..8d4e5fccbd1c
--- /dev/null
+++ b/Documentation/devicetree/bindings/i2c/snps,designware-i2c.yaml
@@ -0,0 +1,154 @@
+# SPDX-License-Identifier: GPL-2.0-only
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/i2c/snps,designware-i2c.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Synopsys DesignWare APB I2C Controller
+
+maintainers:
+  - Jarkko Nikula <jarkko.nikula@linux.intel.com>
+
+allOf:
+  - $ref: /schemas/i2c/i2c-controller.yaml#
+  - if:
+      properties:
+        compatible:
+          not:
+            contains:
+              const: mscc,ocelot-i2c
+    then:
+      properties:
+        reg:
+          maxItems: 1
+
+properties:
+  compatible:
+    oneOf:
+      - description: Generic Synopsys DesignWare I2C controller
+        const: snps,designware-i2c
+      - description: Microsemi Ocelot SoCs I2C controller
+        items:
+          - const: mscc,ocelot-i2c
+          - const: snps,designware-i2c
+
+  reg:
+    minItems: 1
+    items:
+      - description: DW APB I2C controller memory mapped registers
+      - description: |
+          ICPU_CFG:TWI_DELAY registers to setup the SDA hold time.
+          This registers are specific to the Ocelot I2C-controller.
+
+  interrupts:
+    maxItems: 1
+
+  clocks:
+    minItems: 1
+    items:
+      - description: I2C controller reference clock source
+      - description: APB interface clock source
+
+  clock-names:
+    minItems: 1
+    items:
+      - const: ref
+      - const: pclk
+
+  resets:
+    maxItems: 1
+
+  clock-frequency:
+    description: Desired I2C bus clock frequency in Hz
+    enum: [100000, 400000, 1000000, 3400000]
+    default: 400000
+
+  i2c-sda-hold-time-ns:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: |
+      The property should contain the SDA hold time in nanoseconds. This option
+      is only supported in hardware blocks version 1.11a or newer or on
+      Microsemi SoCs.
+
+  i2c-scl-falling-time-ns:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: |
+      The property should contain the SCL falling time in nanoseconds.
+      This value is used to compute the tLOW period.
+    default: 300
+
+  i2c-sda-falling-time-ns:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description: |
+      The property should contain the SDA falling time in nanoseconds.
+      This value is used to compute the tHIGH period.
+    default: 300
+
+  dmas:
+    items:
+      - description: TX DMA Channel
+      - description: RX DMA Channel
+
+  dma-names:
+    items:
+      - const: tx
+      - const: rx
+
+unevaluatedProperties: false
+
+required:
+  - compatible
+  - reg
+  - "#address-cells"
+  - "#size-cells"
+  - interrupts
+
+examples:
+  - |
+    i2c@f0000 {
+      compatible = "snps,designware-i2c";
+      reg = <0xf0000 0x1000>;
+      #address-cells = <1>;
+      #size-cells = <0>;
+      interrupts = <11>;
+      clock-frequency = <400000>;
+    };
+  - |
+    i2c@1120000 {
+      compatible = "snps,designware-i2c";
+      reg = <0x1120000 0x1000>;
+      #address-cells = <1>;
+      #size-cells = <0>;
+      interrupts = <12 1>;
+      clock-frequency = <400000>;
+      i2c-sda-hold-time-ns = <300>;
+      i2c-sda-falling-time-ns = <300>;
+      i2c-scl-falling-time-ns = <300>;
+    };
+  - |
+    i2c@2000 {
+      compatible = "snps,designware-i2c";
+      reg = <0x2000 0x100>;
+      #address-cells = <1>;
+      #size-cells = <0>;
+      clock-frequency = <400000>;
+      clocks = <&i2cclk>;
+      interrupts = <0>;
+
+      eeprom@64 {
+        compatible = "linux,slave-24c02";
+        reg = <0x40000064>;
+      };
+    };
+  - |
+    i2c@100400 {
+      compatible = "mscc,ocelot-i2c", "snps,designware-i2c";
+      reg = <0x100400 0x100>, <0x198 0x8>;
+      pinctrl-0 = <&i2c_pins>;
+      pinctrl-names = "default";
+      #address-cells = <1>;
+      #size-cells = <0>;
+      interrupts = <8>;
+      clocks = <&ahb_clk>;
+    };
+...
-- 
2.25.1

[PATCH v2 03/12] dt-bindings: i2c: dw: Add Baikal-T1 SoC I2C controller

[Serge Semin]

Add the "baikal,bt1-sys-i2c" compatible string to the DW I2C binding and
make sure the reg property isn't required in this case because the
controller is embedded into the Baikal-T1 System Controller. The rest of
the DW APB I2C properties are compatible and can be freely used to describe
the Baikal-T1 I2C controller dts-node.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Wolfram Sang <wsa@the-dreams.de>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: linux-mips@vger.kernel.org

---

Rob, I had to remove your acked-by tag because of the changes introduced
in v2 of the patch.

Changelog v2:
- Make the reg property being optional if it's Baikal-T1 System I2C DT
  node.
---
 .../devicetree/bindings/i2c/snps,designware-i2c.yaml | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/i2c/snps,designware-i2c.yaml b/Documentation/devicetree/bindings/i2c/snps,designware-i2c.yaml
index 8d4e5fccbd1c..579964098eb9 100644
--- a/Documentation/devicetree/bindings/i2c/snps,designware-i2c.yaml
+++ b/Documentation/devicetree/bindings/i2c/snps,designware-i2c.yaml
@@ -21,6 +21,15 @@ allOf:
       properties:
         reg:
           maxItems: 1
+  - if:
+      properties:
+        compatible:
+          not:
+            contains:
+              const: baikal,bt1-sys-i2c
+    then:
+      required:
+        - reg
 
 properties:
   compatible:
@@ -31,6 +40,8 @@ properties:
         items:
           - const: mscc,ocelot-i2c
           - const: snps,designware-i2c
+      - description: Baikal-T1 SoC System I2C controller
+        const: baikal,bt1-sys-i2c
 
   reg:
     minItems: 1
@@ -98,7 +109,6 @@ unevaluatedProperties: false
 
 required:
   - compatible
-  - reg
   - "#address-cells"
   - "#size-cells"
   - interrupts
-- 
2.25.1

[PATCH v2 04/12] i2c: designware: Convert driver to using regmap API

[Serge Semin]

Seeing the DW I2C driver is using flags-based accessors with two
conditional clauses it would be better to replace them with the regmap
API IO methods and to initialize the regmap object with read/write
callbacks specific to the controller registers map implementation. This
will be also handy for the drivers with non-standard registers mapping
(like an embedded into the Baikal-T1 System Controller DW I2C block, which
glue-driver is a part of this series).

As before the driver tries to detect the mapping setup at probe stage and
creates a regmap object accordingly, which will be used by the rest of the
code to correctly access the controller registers. In two places it was
appropriate to convert the hand-written read-modify-write and
read-poll-loop design patterns to the corresponding regmap API
ready-to-use methods.

Note the regmap IO methods return value is checked only at the probe
stage. The rest of the code won't do this because basically we have
MMIO-based regmap so non of the read/write methods can fail (this also
won't be needed for the Baikal-T1-specific I2C controller).

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Wolfram Sang <wsa@the-dreams.de>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: devicetree@vger.kernel.org
Cc: linux-mips@vger.kernel.org
---
 drivers/i2c/busses/Kconfig                 |   1 +
 drivers/i2c/busses/i2c-designware-common.c | 171 +++++++++++++++------
 drivers/i2c/busses/i2c-designware-core.h   |  18 +--
 drivers/i2c/busses/i2c-designware-master.c | 125 ++++++++-------
 drivers/i2c/busses/i2c-designware-slave.c  |  77 +++++-----
 5 files changed, 239 insertions(+), 153 deletions(-)

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 2ddca08f8a76..14368c46cb63 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -526,6 +526,7 @@ config I2C_DAVINCI
 
 config I2C_DESIGNWARE_CORE
 	tristate
+	select REGMAP
 
 config I2C_DESIGNWARE_PLATFORM
 	tristate "Synopsys DesignWare Platform"
diff --git a/drivers/i2c/busses/i2c-designware-common.c b/drivers/i2c/busses/i2c-designware-common.c
index c70c6fc09ee3..35c5ad7e274e 100644
--- a/drivers/i2c/busses/i2c-designware-common.c
+++ b/drivers/i2c/busses/i2c-designware-common.c
@@ -15,6 +15,7 @@
 #include <linux/err.h>
 #include <linux/i2c.h>
 #include <linux/interrupt.h>
+#include <linux/regmap.h>
 #include <linux/io.h>
 #include <linux/module.h>
 #include <linux/pm_runtime.h>
@@ -53,44 +54,82 @@ static char *abort_sources[] = {
 		"incorrect slave-transmitter mode configuration",
 };
 
-u32 dw_readl(struct dw_i2c_dev *dev, int offset)
+static int dw_reg_read(void *context, unsigned int reg, unsigned int *val)
 {
-	u32 value;
+	struct dw_i2c_dev *dev = context;
 
-	if (dev->flags & ACCESS_16BIT)
-		value = readw_relaxed(dev->base + offset) |
-			(readw_relaxed(dev->base + offset + 2) << 16);
-	else
-		value = readl_relaxed(dev->base + offset);
+	*val = readl_relaxed(dev->base + reg);
 
-	if (dev->flags & ACCESS_SWAP)
-		return swab32(value);
-	else
-		return value;
+	return 0;
 }
 
-void dw_writel(struct dw_i2c_dev *dev, u32 b, int offset)
+static int dw_reg_write(void *context, unsigned int reg, unsigned int val)
 {
-	if (dev->flags & ACCESS_SWAP)
-		b = swab32(b);
-
-	if (dev->flags & ACCESS_16BIT) {
-		writew_relaxed((u16)b, dev->base + offset);
-		writew_relaxed((u16)(b >> 16), dev->base + offset + 2);
-	} else {
-		writel_relaxed(b, dev->base + offset);
-	}
+	struct dw_i2c_dev *dev = context;
+
+	writel_relaxed(val, dev->base + reg);
+
+	return 0;
+}
+
+static int dw_reg_read_swab(void *context, unsigned int reg, unsigned int *val)
+{
+	struct dw_i2c_dev *dev = context;
+
+	*val = swab32(readl_relaxed(dev->base + reg));
+
+	return 0;
+}
+
+static int dw_reg_write_swab(void *context, unsigned int reg, unsigned int val)
+{
+	struct dw_i2c_dev *dev = context;
+
+	writel_relaxed(swab32(val), dev->base + reg);
+
+	return 0;
+}
+
+static int dw_reg_read_word(void *context, unsigned int reg, unsigned int *val)
+{
+	struct dw_i2c_dev *dev = context;
+
+	*val = readw_relaxed(dev->base + reg) |
+		(readw_relaxed(dev->base + reg + 2) << 16);
+
+	return 0;
+}
+
+static int dw_reg_write_word(void *context, unsigned int reg, unsigned int val)
+{
+	struct dw_i2c_dev *dev = context;
+
+	writew_relaxed((u16)val, dev->base + reg);
+	writew_relaxed((u16)(val >> 16), dev->base + reg + 2);
+
+	return 0;
 }
 
 /**
- * i2c_dw_set_reg_access() - Set register access flags
+ * i2c_dw_init_regmap() - Initialize registers map
  * @dev: device private data
+ * @base: Registers map base address
  *
- * Autodetects needed register access mode and sets access flags accordingly.
- * This must be called before doing any other register access.
+ * Autodetects needed register access mode and creates the regmap with
+ * corresponding read/write callbacks. This must be called before doing any
+ * other register access.
  */
-int i2c_dw_set_reg_access(struct dw_i2c_dev *dev)
+int i2c_dw_init_regmap(struct dw_i2c_dev *dev)
 {
+	struct regmap_config map_cfg = {
+		.reg_bits = 32,
+		.val_bits = 32,
+		.reg_stride = 4,
+		.disable_locking = true,
+		.reg_read = dw_reg_read,
+		.reg_write = dw_reg_write,
+		.max_register = DW_IC_COMP_TYPE
+	};
 	u32 reg;
 	int ret;
 
@@ -98,21 +137,33 @@ int i2c_dw_set_reg_access(struct dw_i2c_dev *dev)
 	if (ret)
 		return ret;
 
-	reg = dw_readl(dev, DW_IC_COMP_TYPE);
+	reg = readl(dev->base + DW_IC_COMP_TYPE);
 	i2c_dw_release_lock(dev);
 
 	if (reg == swab32(DW_IC_COMP_TYPE_VALUE)) {
-		/* Configure register endianness access */
-		dev->flags |= ACCESS_SWAP;
+		map_cfg.reg_read = dw_reg_read_swab;
+		map_cfg.reg_write = dw_reg_write_swab;
 	} else if (reg == (DW_IC_COMP_TYPE_VALUE & 0x0000ffff)) {
-		/* Configure register access mode 16bit */
-		dev->flags |= ACCESS_16BIT;
+		map_cfg.reg_read = dw_reg_read_word;
+		map_cfg.reg_write = dw_reg_write_word;
 	} else if (reg != DW_IC_COMP_TYPE_VALUE) {
 		dev_err(dev->dev,
 			"Unknown Synopsys component type: 0x%08x\n", reg);
 		return -ENODEV;
 	}
 
+	/*
+	 * Note we'll check the return value of the regmap IO accessors only
+	 * at the probe stage. The rest of the code won't do this because
+	 * basically we have MMIO-based regmap so non of the read/write methods
+	 * can fail.
+	 */
+	dev->map = devm_regmap_init(dev->dev, NULL, dev, &map_cfg);
+	if (IS_ERR(dev->map)) {
+		dev_err(dev->dev, "Failed to init the registers map\n");
+		return PTR_ERR(dev->map);
+	}
+
 	return 0;
 }
 
@@ -181,11 +232,17 @@ int i2c_dw_set_sda_hold(struct dw_i2c_dev *dev)
 		return ret;
 
 	/* Configure SDA Hold Time if required */
-	reg = dw_readl(dev, DW_IC_COMP_VERSION);
+	ret = regmap_read(dev->map, DW_IC_COMP_VERSION, &reg);
+	if (ret)
+		goto err_release_lock;
+
 	if (reg >= DW_IC_SDA_HOLD_MIN_VERS) {
 		if (!dev->sda_hold_time) {
 			/* Keep previous hold time setting if no one set it */
-			dev->sda_hold_time = dw_readl(dev, DW_IC_SDA_HOLD);
+			ret = regmap_read(dev->map, DW_IC_SDA_HOLD,
+					  &dev->sda_hold_time);
+			if (ret)
+				goto err_release_lock;
 		}
 
 		/*
@@ -209,14 +266,16 @@ int i2c_dw_set_sda_hold(struct dw_i2c_dev *dev)
 		dev->sda_hold_time = 0;
 	}
 
+err_release_lock:
 	i2c_dw_release_lock(dev);
 
-	return 0;
+	return ret;
 }
 
 void __i2c_dw_disable(struct dw_i2c_dev *dev)
 {
 	int timeout = 100;
+	u32 status;
 
 	do {
 		__i2c_dw_disable_nowait(dev);
@@ -224,7 +283,8 @@ void __i2c_dw_disable(struct dw_i2c_dev *dev)
 		 * The enable status register may be unimplemented, but
 		 * in that case this test reads zero and exits the loop.
 		 */
-		if ((dw_readl(dev, DW_IC_ENABLE_STATUS) & 1) == 0)
+		regmap_read(dev->map, DW_IC_ENABLE_STATUS, &status);
+		if ((status & 1) == 0)
 			return;
 
 		/*
@@ -303,22 +363,23 @@ void i2c_dw_release_lock(struct dw_i2c_dev *dev)
  */
 int i2c_dw_wait_bus_not_busy(struct dw_i2c_dev *dev)
 {
-	int timeout = TIMEOUT;
+	u32 status;
+	int ret;
 
-	while (dw_readl(dev, DW_IC_STATUS) & DW_IC_STATUS_ACTIVITY) {
-		if (timeout <= 0) {
-			dev_warn(dev->dev, "timeout waiting for bus ready\n");
-			i2c_recover_bus(&dev->adapter);
+	ret = regmap_read_poll_timeout(dev->map, DW_IC_STATUS, status,
+				       !(status & DW_IC_STATUS_ACTIVITY),
+				       1100, 20000);
+	if (ret) {
+		dev_warn(dev->dev, "timeout waiting for bus ready\n");
 
-			if (dw_readl(dev, DW_IC_STATUS) & DW_IC_STATUS_ACTIVITY)
-				return -ETIMEDOUT;
-			return 0;
-		}
-		timeout--;
-		usleep_range(1000, 1100);
+		i2c_recover_bus(&dev->adapter);
+
+		regmap_read(dev->map, DW_IC_STATUS, &status);
+		if (!(status & DW_IC_STATUS_ACTIVITY))
+			ret = 0;
 	}
 
-	return 0;
+	return ret;
 }
 
 int i2c_dw_handle_tx_abort(struct dw_i2c_dev *dev)
@@ -344,15 +405,19 @@ int i2c_dw_handle_tx_abort(struct dw_i2c_dev *dev)
 		return -EIO;
 }
 
-void i2c_dw_set_fifo_size(struct dw_i2c_dev *dev)
+int i2c_dw_set_fifo_size(struct dw_i2c_dev *dev)
 {
 	u32 param, tx_fifo_depth, rx_fifo_depth;
+	int ret;
 
 	/*
 	 * Try to detect the FIFO depth if not set by interface driver,
 	 * the depth could be from 2 to 256 from HW spec.
 	 */
-	param = dw_readl(dev, DW_IC_COMP_PARAM_1);
+	ret = regmap_read(dev->map, DW_IC_COMP_PARAM_1, &param);
+	if (ret)
+		return ret;
+
 	tx_fifo_depth = ((param >> 16) & 0xff) + 1;
 	rx_fifo_depth = ((param >> 8)  & 0xff) + 1;
 	if (!dev->tx_fifo_depth) {
@@ -364,6 +429,8 @@ void i2c_dw_set_fifo_size(struct dw_i2c_dev *dev)
 		dev->rx_fifo_depth = min_t(u32, dev->rx_fifo_depth,
 				rx_fifo_depth);
 	}
+
+	return 0;
 }
 
 u32 i2c_dw_func(struct i2c_adapter *adap)
@@ -375,17 +442,19 @@ u32 i2c_dw_func(struct i2c_adapter *adap)
 
 void i2c_dw_disable(struct dw_i2c_dev *dev)
 {
+	u32 dummy;
+
 	/* Disable controller */
 	__i2c_dw_disable(dev);
 
 	/* Disable all interrupts */
-	dw_writel(dev, 0, DW_IC_INTR_MASK);
-	dw_readl(dev, DW_IC_CLR_INTR);
+	regmap_write(dev->map, DW_IC_INTR_MASK, 0);
+	regmap_read(dev->map, DW_IC_CLR_INTR, &dummy);
 }
 
 void i2c_dw_disable_int(struct dw_i2c_dev *dev)
 {
-	dw_writel(dev, 0, DW_IC_INTR_MASK);
+	regmap_write(dev->map, DW_IC_INTR_MASK, 0);
 }
 
 MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter core");
diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h
index b220ad64c38d..b5b981c1bb0d 100644
--- a/drivers/i2c/busses/i2c-designware-core.h
+++ b/drivers/i2c/busses/i2c-designware-core.h
@@ -10,6 +10,7 @@
  */
 
 #include <linux/i2c.h>
+#include <linux/regmap.h>
 
 #define DW_IC_DEFAULT_FUNCTIONALITY (I2C_FUNC_I2C |			\
 					I2C_FUNC_SMBUS_BYTE |		\
@@ -120,8 +121,6 @@
 #define STATUS_WRITE_IN_PROGRESS	0x1
 #define STATUS_READ_IN_PROGRESS		0x2
 
-#define TIMEOUT			20 /* ms */
-
 /*
  * operation modes
  */
@@ -174,7 +173,9 @@
 /**
  * struct dw_i2c_dev - private i2c-designware data
  * @dev: driver model device node
+ * @map: IO registers map
  * @base: IO registers pointer
+ * @ext: Extended IO registers pointer
  * @cmd_complete: tx completion indicator
  * @clk: input reference clock
  * @pclk: clock required to access the registers
@@ -224,6 +225,7 @@
  */
 struct dw_i2c_dev {
 	struct device		*dev;
+	struct regmap		*map;
 	void __iomem		*base;
 	void __iomem		*ext;
 	struct completion	cmd_complete;
@@ -276,8 +278,6 @@ struct dw_i2c_dev {
 	bool			suspended;
 };
 
-#define ACCESS_SWAP		0x00000001
-#define ACCESS_16BIT		0x00000002
 #define ACCESS_INTR_MASK	0x00000004
 #define ACCESS_NO_IRQ_SUSPEND	0x00000008
 
@@ -285,9 +285,7 @@ struct dw_i2c_dev {
 #define MODEL_MSCC_OCELOT	0x00000200
 #define MODEL_MASK		0x00000f00
 
-u32 dw_readl(struct dw_i2c_dev *dev, int offset);
-void dw_writel(struct dw_i2c_dev *dev, u32 b, int offset);
-int i2c_dw_set_reg_access(struct dw_i2c_dev *dev);
+int i2c_dw_init_regmap(struct dw_i2c_dev *dev);
 u32 i2c_dw_scl_hcnt(u32 ic_clk, u32 tSYMBOL, u32 tf, int cond, int offset);
 u32 i2c_dw_scl_lcnt(u32 ic_clk, u32 tLOW, u32 tf, int offset);
 int i2c_dw_set_sda_hold(struct dw_i2c_dev *dev);
@@ -297,19 +295,19 @@ int i2c_dw_acquire_lock(struct dw_i2c_dev *dev);
 void i2c_dw_release_lock(struct dw_i2c_dev *dev);
 int i2c_dw_wait_bus_not_busy(struct dw_i2c_dev *dev);
 int i2c_dw_handle_tx_abort(struct dw_i2c_dev *dev);
-void i2c_dw_set_fifo_size(struct dw_i2c_dev *dev);
+int i2c_dw_set_fifo_size(struct dw_i2c_dev *dev);
 u32 i2c_dw_func(struct i2c_adapter *adap);
 void i2c_dw_disable(struct dw_i2c_dev *dev);
 void i2c_dw_disable_int(struct dw_i2c_dev *dev);
 
 static inline void __i2c_dw_enable(struct dw_i2c_dev *dev)
 {
-	dw_writel(dev, 1, DW_IC_ENABLE);
+	regmap_write(dev->map, DW_IC_ENABLE, 1);
 }
 
 static inline void __i2c_dw_disable_nowait(struct dw_i2c_dev *dev)
 {
-	dw_writel(dev, 0, DW_IC_ENABLE);
+	regmap_write(dev->map, DW_IC_ENABLE, 0);
 }
 
 void __i2c_dw_disable(struct dw_i2c_dev *dev);
diff --git a/drivers/i2c/busses/i2c-designware-master.c b/drivers/i2c/busses/i2c-designware-master.c
index 3a58eef20936..f78cb0d08b4b 100644
--- a/drivers/i2c/busses/i2c-designware-master.c
+++ b/drivers/i2c/busses/i2c-designware-master.c
@@ -15,6 +15,7 @@
 #include <linux/gpio/consumer.h>
 #include <linux/i2c.h>
 #include <linux/interrupt.h>
+#include <linux/regmap.h>
 #include <linux/io.h>
 #include <linux/module.h>
 #include <linux/pm_runtime.h>
@@ -25,11 +26,11 @@
 static void i2c_dw_configure_fifo_master(struct dw_i2c_dev *dev)
 {
 	/* Configure Tx/Rx FIFO threshold levels */
-	dw_writel(dev, dev->tx_fifo_depth / 2, DW_IC_TX_TL);
-	dw_writel(dev, 0, DW_IC_RX_TL);
+	regmap_write(dev->map, DW_IC_TX_TL, dev->tx_fifo_depth / 2);
+	regmap_write(dev->map, DW_IC_RX_TL, 0);
 
 	/* Configure the I2C master */
-	dw_writel(dev, dev->master_cfg, DW_IC_CON);
+	regmap_write(dev->map, DW_IC_CON, dev->master_cfg);
 }
 
 static int i2c_dw_set_timings_master(struct dw_i2c_dev *dev)
@@ -44,8 +45,11 @@ static int i2c_dw_set_timings_master(struct dw_i2c_dev *dev)
 	ret = i2c_dw_acquire_lock(dev);
 	if (ret)
 		return ret;
-	comp_param1 = dw_readl(dev, DW_IC_COMP_PARAM_1);
+
+	ret = regmap_read(dev->map, DW_IC_COMP_PARAM_1, &comp_param1);
 	i2c_dw_release_lock(dev);
+	if (ret)
+		return ret;
 
 	/* Set standard and fast speed dividers for high/low periods */
 	sda_falling_time = t->sda_fall_ns ?: 300; /* ns */
@@ -162,22 +166,22 @@ static int i2c_dw_init_master(struct dw_i2c_dev *dev)
 	__i2c_dw_disable(dev);
 
 	/* Write standard speed timing parameters */
-	dw_writel(dev, dev->ss_hcnt, DW_IC_SS_SCL_HCNT);
-	dw_writel(dev, dev->ss_lcnt, DW_IC_SS_SCL_LCNT);
+	regmap_write(dev->map, DW_IC_SS_SCL_HCNT, dev->ss_hcnt);
+	regmap_write(dev->map, DW_IC_SS_SCL_LCNT, dev->ss_lcnt);
 
 	/* Write fast mode/fast mode plus timing parameters */
-	dw_writel(dev, dev->fs_hcnt, DW_IC_FS_SCL_HCNT);
-	dw_writel(dev, dev->fs_lcnt, DW_IC_FS_SCL_LCNT);
+	regmap_write(dev->map, DW_IC_FS_SCL_HCNT, dev->fs_hcnt);
+	regmap_write(dev->map, DW_IC_FS_SCL_LCNT, dev->fs_lcnt);
 
 	/* Write high speed timing parameters if supported */
 	if (dev->hs_hcnt && dev->hs_lcnt) {
-		dw_writel(dev, dev->hs_hcnt, DW_IC_HS_SCL_HCNT);
-		dw_writel(dev, dev->hs_lcnt, DW_IC_HS_SCL_LCNT);
+		regmap_write(dev->map, DW_IC_HS_SCL_HCNT, dev->hs_hcnt);
+		regmap_write(dev->map, DW_IC_HS_SCL_LCNT, dev->hs_lcnt);
 	}
 
 	/* Write SDA hold time if supported */
 	if (dev->sda_hold_time)
-		dw_writel(dev, dev->sda_hold_time, DW_IC_SDA_HOLD);
+		regmap_write(dev->map, DW_IC_SDA_HOLD, dev->sda_hold_time);
 
 	i2c_dw_configure_fifo_master(dev);
 	i2c_dw_release_lock(dev);
@@ -188,15 +192,15 @@ static int i2c_dw_init_master(struct dw_i2c_dev *dev)
 static void i2c_dw_xfer_init(struct dw_i2c_dev *dev)
 {
 	struct i2c_msg *msgs = dev->msgs;
-	u32 ic_con, ic_tar = 0;
+	u32 ic_con = 0, ic_tar = 0;
+	u32 dummy;
 
 	/* Disable the adapter */
 	__i2c_dw_disable(dev);
 
 	/* If the slave address is ten bit address, enable 10BITADDR */
-	ic_con = dw_readl(dev, DW_IC_CON);
 	if (msgs[dev->msg_write_idx].flags & I2C_M_TEN) {
-		ic_con |= DW_IC_CON_10BITADDR_MASTER;
+		ic_con = DW_IC_CON_10BITADDR_MASTER;
 		/*
 		 * If I2C_DYNAMIC_TAR_UPDATE is set, the 10-bit addressing
 		 * mode has to be enabled via bit 12 of IC_TAR register.
@@ -204,17 +208,17 @@ static void i2c_dw_xfer_init(struct dw_i2c_dev *dev)
 		 * detected from registers.
 		 */
 		ic_tar = DW_IC_TAR_10BITADDR_MASTER;
-	} else {
-		ic_con &= ~DW_IC_CON_10BITADDR_MASTER;
 	}
 
-	dw_writel(dev, ic_con, DW_IC_CON);
+	regmap_update_bits(dev->map, DW_IC_CON, DW_IC_CON_10BITADDR_MASTER,
+			   ic_con);
 
 	/*
 	 * Set the slave (target) address and enable 10-bit addressing mode
 	 * if applicable.
 	 */
-	dw_writel(dev, msgs[dev->msg_write_idx].addr | ic_tar, DW_IC_TAR);
+	regmap_write(dev->map, DW_IC_TAR,
+		     msgs[dev->msg_write_idx].addr | ic_tar);
 
 	/* Enforce disabled interrupts (due to HW issues) */
 	i2c_dw_disable_int(dev);
@@ -223,11 +227,11 @@ static void i2c_dw_xfer_init(struct dw_i2c_dev *dev)
 	__i2c_dw_enable(dev);
 
 	/* Dummy read to avoid the register getting stuck on Bay Trail */
-	dw_readl(dev, DW_IC_ENABLE_STATUS);
+	regmap_read(dev->map, DW_IC_ENABLE_STATUS, &dummy);
 
 	/* Clear and enable interrupts */
-	dw_readl(dev, DW_IC_CLR_INTR);
-	dw_writel(dev, DW_IC_INTR_MASTER_MASK, DW_IC_INTR_MASK);
+	regmap_read(dev->map, DW_IC_CLR_INTR, &dummy);
+	regmap_write(dev->map, DW_IC_INTR_MASK, DW_IC_INTR_MASTER_MASK);
 }
 
 /*
@@ -246,6 +250,7 @@ i2c_dw_xfer_msg(struct dw_i2c_dev *dev)
 	u32 buf_len = dev->tx_buf_len;
 	u8 *buf = dev->tx_buf;
 	bool need_restart = false;
+	unsigned int flr;
 
 	intr_mask = DW_IC_INTR_MASTER_MASK;
 
@@ -278,8 +283,11 @@ i2c_dw_xfer_msg(struct dw_i2c_dev *dev)
 				need_restart = true;
 		}
 
-		tx_limit = dev->tx_fifo_depth - dw_readl(dev, DW_IC_TXFLR);
-		rx_limit = dev->rx_fifo_depth - dw_readl(dev, DW_IC_RXFLR);
+		regmap_read(dev->map, DW_IC_TXFLR, &flr);
+		tx_limit = dev->tx_fifo_depth - flr;
+
+		regmap_read(dev->map, DW_IC_RXFLR, &flr);
+		rx_limit = dev->rx_fifo_depth - flr;
 
 		while (buf_len > 0 && tx_limit > 0 && rx_limit > 0) {
 			u32 cmd = 0;
@@ -312,11 +320,14 @@ i2c_dw_xfer_msg(struct dw_i2c_dev *dev)
 				if (dev->rx_outstanding >= dev->rx_fifo_depth)
 					break;
 
-				dw_writel(dev, cmd | 0x100, DW_IC_DATA_CMD);
+				regmap_write(dev->map, DW_IC_DATA_CMD,
+					     cmd | 0x100);
 				rx_limit--;
 				dev->rx_outstanding++;
-			} else
-				dw_writel(dev, cmd | *buf++, DW_IC_DATA_CMD);
+			} else {
+				regmap_write(dev->map, DW_IC_DATA_CMD,
+					     cmd | *buf++);
+			}
 			tx_limit--; buf_len--;
 		}
 
@@ -346,7 +357,7 @@ i2c_dw_xfer_msg(struct dw_i2c_dev *dev)
 	if (dev->msg_err)
 		intr_mask = 0;
 
-	dw_writel(dev, intr_mask,  DW_IC_INTR_MASK);
+	regmap_write(dev->map,  DW_IC_INTR_MASK, intr_mask);
 }
 
 static u8
@@ -374,7 +385,7 @@ i2c_dw_read(struct dw_i2c_dev *dev)
 	int rx_valid;
 
 	for (; dev->msg_read_idx < dev->msgs_num; dev->msg_read_idx++) {
-		u32 len;
+		u32 len, tmp;
 		u8 *buf;
 
 		if (!(msgs[dev->msg_read_idx].flags & I2C_M_RD))
@@ -388,18 +399,18 @@ i2c_dw_read(struct dw_i2c_dev *dev)
 			buf = dev->rx_buf;
 		}
 
-		rx_valid = dw_readl(dev, DW_IC_RXFLR);
+		regmap_read(dev->map, DW_IC_RXFLR, &rx_valid);
 
 		for (; len > 0 && rx_valid > 0; len--, rx_valid--) {
 			u32 flags = msgs[dev->msg_read_idx].flags;
 
-			*buf = dw_readl(dev, DW_IC_DATA_CMD);
+			regmap_read(dev->map, DW_IC_DATA_CMD, &tmp);
 			/* Ensure length byte is a valid value */
 			if (flags & I2C_M_RECV_LEN &&
-				*buf <= I2C_SMBUS_BLOCK_MAX && *buf > 0) {
-				len = i2c_dw_recv_len(dev, *buf);
+			    tmp <= I2C_SMBUS_BLOCK_MAX && tmp > 0) {
+				len = i2c_dw_recv_len(dev, tmp);
 			}
-			buf++;
+			*buf++ = tmp;
 			dev->rx_outstanding--;
 		}
 
@@ -517,7 +528,7 @@ static const struct i2c_adapter_quirks i2c_dw_quirks = {
 
 static u32 i2c_dw_read_clear_intrbits(struct dw_i2c_dev *dev)
 {
-	u32 stat;
+	u32 stat, dummy;
 
 	/*
 	 * The IC_INTR_STAT register just indicates "enabled" interrupts.
@@ -525,47 +536,47 @@ static u32 i2c_dw_read_clear_intrbits(struct dw_i2c_dev *dev)
 	 * in the IC_RAW_INTR_STAT register.
 	 *
 	 * That is,
-	 *   stat = dw_readl(IC_INTR_STAT);
+	 *   stat = readl(IC_INTR_STAT);
 	 * equals to,
-	 *   stat = dw_readl(IC_RAW_INTR_STAT) & dw_readl(IC_INTR_MASK);
+	 *   stat = readl(IC_RAW_INTR_STAT) & readl(IC_INTR_MASK);
 	 *
 	 * The raw version might be useful for debugging purposes.
 	 */
-	stat = dw_readl(dev, DW_IC_INTR_STAT);
+	regmap_read(dev->map, DW_IC_INTR_STAT, &stat);
 
 	/*
 	 * Do not use the IC_CLR_INTR register to clear interrupts, or
 	 * you'll miss some interrupts, triggered during the period from
-	 * dw_readl(IC_INTR_STAT) to dw_readl(IC_CLR_INTR).
+	 * readl(IC_INTR_STAT) to readl(IC_CLR_INTR).
 	 *
 	 * Instead, use the separately-prepared IC_CLR_* registers.
 	 */
 	if (stat & DW_IC_INTR_RX_UNDER)
-		dw_readl(dev, DW_IC_CLR_RX_UNDER);
+		regmap_read(dev->map, DW_IC_CLR_RX_UNDER, &dummy);
 	if (stat & DW_IC_INTR_RX_OVER)
-		dw_readl(dev, DW_IC_CLR_RX_OVER);
+		regmap_read(dev->map, DW_IC_CLR_RX_OVER, &dummy);
 	if (stat & DW_IC_INTR_TX_OVER)
-		dw_readl(dev, DW_IC_CLR_TX_OVER);
+		regmap_read(dev->map, DW_IC_CLR_TX_OVER, &dummy);
 	if (stat & DW_IC_INTR_RD_REQ)
-		dw_readl(dev, DW_IC_CLR_RD_REQ);
+		regmap_read(dev->map, DW_IC_CLR_RD_REQ, &dummy);
 	if (stat & DW_IC_INTR_TX_ABRT) {
 		/*
 		 * The IC_TX_ABRT_SOURCE register is cleared whenever
 		 * the IC_CLR_TX_ABRT is read.  Preserve it beforehand.
 		 */
-		dev->abort_source = dw_readl(dev, DW_IC_TX_ABRT_SOURCE);
-		dw_readl(dev, DW_IC_CLR_TX_ABRT);
+		regmap_read(dev->map, DW_IC_TX_ABRT_SOURCE, &dev->abort_source);
+		regmap_read(dev->map, DW_IC_CLR_TX_ABRT, &dummy);
 	}
 	if (stat & DW_IC_INTR_RX_DONE)
-		dw_readl(dev, DW_IC_CLR_RX_DONE);
+		regmap_read(dev->map, DW_IC_CLR_RX_DONE, &dummy);
 	if (stat & DW_IC_INTR_ACTIVITY)
-		dw_readl(dev, DW_IC_CLR_ACTIVITY);
+		regmap_read(dev->map, DW_IC_CLR_ACTIVITY, &dummy);
 	if (stat & DW_IC_INTR_STOP_DET)
-		dw_readl(dev, DW_IC_CLR_STOP_DET);
+		regmap_read(dev->map, DW_IC_CLR_STOP_DET, &dummy);
 	if (stat & DW_IC_INTR_START_DET)
-		dw_readl(dev, DW_IC_CLR_START_DET);
+		regmap_read(dev->map, DW_IC_CLR_START_DET, &dummy);
 	if (stat & DW_IC_INTR_GEN_CALL)
-		dw_readl(dev, DW_IC_CLR_GEN_CALL);
+		regmap_read(dev->map, DW_IC_CLR_GEN_CALL, &dummy);
 
 	return stat;
 }
@@ -587,7 +598,7 @@ static int i2c_dw_irq_handler_master(struct dw_i2c_dev *dev)
 		 * Anytime TX_ABRT is set, the contents of the tx/rx
 		 * buffers are flushed. Make sure to skip them.
 		 */
-		dw_writel(dev, 0, DW_IC_INTR_MASK);
+		regmap_write(dev->map, DW_IC_INTR_MASK, 0);
 		goto tx_aborted;
 	}
 
@@ -608,9 +619,9 @@ static int i2c_dw_irq_handler_master(struct dw_i2c_dev *dev)
 		complete(&dev->cmd_complete);
 	else if (unlikely(dev->flags & ACCESS_INTR_MASK)) {
 		/* Workaround to trigger pending interrupt */
-		stat = dw_readl(dev, DW_IC_INTR_MASK);
+		regmap_read(dev->map, DW_IC_INTR_MASK, &stat);
 		i2c_dw_disable_int(dev);
-		dw_writel(dev, stat, DW_IC_INTR_MASK);
+		regmap_write(dev->map, DW_IC_INTR_MASK, stat);
 	}
 
 	return 0;
@@ -621,8 +632,8 @@ static irqreturn_t i2c_dw_isr(int this_irq, void *dev_id)
 	struct dw_i2c_dev *dev = dev_id;
 	u32 stat, enabled;
 
-	enabled = dw_readl(dev, DW_IC_ENABLE);
-	stat = dw_readl(dev, DW_IC_RAW_INTR_STAT);
+	regmap_read(dev->map, DW_IC_ENABLE, &enabled);
+	regmap_read(dev->map, DW_IC_RAW_INTR_STAT, &stat);
 	dev_dbg(dev->dev, "enabled=%#x stat=%#x\n", enabled, stat);
 	if (!enabled || !(stat & ~DW_IC_INTR_ACTIVITY))
 		return IRQ_NONE;
@@ -690,7 +701,7 @@ int i2c_dw_probe(struct dw_i2c_dev *dev)
 	dev->disable = i2c_dw_disable;
 	dev->disable_int = i2c_dw_disable_int;
 
-	ret = i2c_dw_set_reg_access(dev);
+	ret = i2c_dw_init_regmap(dev);
 	if (ret)
 		return ret;
 
@@ -698,7 +709,9 @@ int i2c_dw_probe(struct dw_i2c_dev *dev)
 	if (ret)
 		return ret;
 
-	i2c_dw_set_fifo_size(dev);
+	ret = i2c_dw_set_fifo_size(dev);
+	if (ret)
+		return ret;
 
 	ret = dev->init(dev);
 	if (ret)
diff --git a/drivers/i2c/busses/i2c-designware-slave.c b/drivers/i2c/busses/i2c-designware-slave.c
index f5ecf76c0d02..9f8aef7a69b2 100644
--- a/drivers/i2c/busses/i2c-designware-slave.c
+++ b/drivers/i2c/busses/i2c-designware-slave.c
@@ -11,6 +11,7 @@
 #include <linux/errno.h>
 #include <linux/i2c.h>
 #include <linux/interrupt.h>
+#include <linux/regmap.h>
 #include <linux/io.h>
 #include <linux/module.h>
 #include <linux/pm_runtime.h>
@@ -20,12 +21,12 @@
 static void i2c_dw_configure_fifo_slave(struct dw_i2c_dev *dev)
 {
 	/* Configure Tx/Rx FIFO threshold levels. */
-	dw_writel(dev, 0, DW_IC_TX_TL);
-	dw_writel(dev, 0, DW_IC_RX_TL);
+	regmap_write(dev->map, DW_IC_TX_TL, 0);
+	regmap_write(dev->map, DW_IC_RX_TL, 0);
 
 	/* Configure the I2C slave. */
-	dw_writel(dev, dev->slave_cfg, DW_IC_CON);
-	dw_writel(dev, DW_IC_INTR_SLAVE_MASK, DW_IC_INTR_MASK);
+	regmap_write(dev->map, DW_IC_CON, dev->slave_cfg);
+	regmap_write(dev->map, DW_IC_INTR_MASK, DW_IC_INTR_SLAVE_MASK);
 }
 
 /**
@@ -49,7 +50,7 @@ static int i2c_dw_init_slave(struct dw_i2c_dev *dev)
 
 	/* Write SDA hold time if supported */
 	if (dev->sda_hold_time)
-		dw_writel(dev, dev->sda_hold_time, DW_IC_SDA_HOLD);
+		regmap_write(dev->map, DW_IC_SDA_HOLD, dev->sda_hold_time);
 
 	i2c_dw_configure_fifo_slave(dev);
 	i2c_dw_release_lock(dev);
@@ -72,7 +73,7 @@ static int i2c_dw_reg_slave(struct i2c_client *slave)
 	 * the address to which the DW_apb_i2c responds.
 	 */
 	__i2c_dw_disable_nowait(dev);
-	dw_writel(dev, slave->addr, DW_IC_SAR);
+	regmap_write(dev->map, DW_IC_SAR, slave->addr);
 	dev->slave = slave;
 
 	__i2c_dw_enable(dev);
@@ -103,7 +104,7 @@ static int i2c_dw_unreg_slave(struct i2c_client *slave)
 
 static u32 i2c_dw_read_clear_intrbits_slave(struct dw_i2c_dev *dev)
 {
-	u32 stat;
+	u32 stat, dummy;
 
 	/*
 	 * The IC_INTR_STAT register just indicates "enabled" interrupts.
@@ -111,39 +112,39 @@ static u32 i2c_dw_read_clear_intrbits_slave(struct dw_i2c_dev *dev)
 	 * in the IC_RAW_INTR_STAT register.
 	 *
 	 * That is,
-	 *   stat = dw_readl(IC_INTR_STAT);
+	 *   stat = readl(IC_INTR_STAT);
 	 * equals to,
-	 *   stat = dw_readl(IC_RAW_INTR_STAT) & dw_readl(IC_INTR_MASK);
+	 *   stat = readl(IC_RAW_INTR_STAT) & readl(IC_INTR_MASK);
 	 *
 	 * The raw version might be useful for debugging purposes.
 	 */
-	stat = dw_readl(dev, DW_IC_INTR_STAT);
+	regmap_read(dev->map, DW_IC_INTR_STAT, &stat);
 
 	/*
 	 * Do not use the IC_CLR_INTR register to clear interrupts, or
 	 * you'll miss some interrupts, triggered during the period from
-	 * dw_readl(IC_INTR_STAT) to dw_readl(IC_CLR_INTR).
+	 * readl(IC_INTR_STAT) to readl(IC_CLR_INTR).
 	 *
 	 * Instead, use the separately-prepared IC_CLR_* registers.
 	 */
 	if (stat & DW_IC_INTR_TX_ABRT)
-		dw_readl(dev, DW_IC_CLR_TX_ABRT);
+		regmap_read(dev->map, DW_IC_CLR_TX_ABRT, &dummy);
 	if (stat & DW_IC_INTR_RX_UNDER)
-		dw_readl(dev, DW_IC_CLR_RX_UNDER);
+		regmap_read(dev->map, DW_IC_CLR_RX_UNDER, &dummy);
 	if (stat & DW_IC_INTR_RX_OVER)
-		dw_readl(dev, DW_IC_CLR_RX_OVER);
+		regmap_read(dev->map, DW_IC_CLR_RX_OVER, &dummy);
 	if (stat & DW_IC_INTR_TX_OVER)
-		dw_readl(dev, DW_IC_CLR_TX_OVER);
+		regmap_read(dev->map, DW_IC_CLR_TX_OVER, &dummy);
 	if (stat & DW_IC_INTR_RX_DONE)
-		dw_readl(dev, DW_IC_CLR_RX_DONE);
+		regmap_read(dev->map, DW_IC_CLR_RX_DONE, &dummy);
 	if (stat & DW_IC_INTR_ACTIVITY)
-		dw_readl(dev, DW_IC_CLR_ACTIVITY);
+		regmap_read(dev->map, DW_IC_CLR_ACTIVITY, &dummy);
 	if (stat & DW_IC_INTR_STOP_DET)
-		dw_readl(dev, DW_IC_CLR_STOP_DET);
+		regmap_read(dev->map, DW_IC_CLR_STOP_DET, &dummy);
 	if (stat & DW_IC_INTR_START_DET)
-		dw_readl(dev, DW_IC_CLR_START_DET);
+		regmap_read(dev->map, DW_IC_CLR_START_DET, &dummy);
 	if (stat & DW_IC_INTR_GEN_CALL)
-		dw_readl(dev, DW_IC_CLR_GEN_CALL);
+		regmap_read(dev->map, DW_IC_CLR_GEN_CALL, &dummy);
 
 	return stat;
 }
@@ -155,14 +156,14 @@ static u32 i2c_dw_read_clear_intrbits_slave(struct dw_i2c_dev *dev)
 
 static int i2c_dw_irq_handler_slave(struct dw_i2c_dev *dev)
 {
-	u32 raw_stat, stat, enabled;
-	u8 val, slave_activity;
+	u32 raw_stat, stat, enabled, tmp;
+	u8 val = 0, slave_activity;
 
-	stat = dw_readl(dev, DW_IC_INTR_STAT);
-	enabled = dw_readl(dev, DW_IC_ENABLE);
-	raw_stat = dw_readl(dev, DW_IC_RAW_INTR_STAT);
-	slave_activity = ((dw_readl(dev, DW_IC_STATUS) &
-		DW_IC_STATUS_SLAVE_ACTIVITY) >> 6);
+	regmap_read(dev->map, DW_IC_INTR_STAT, &stat);
+	regmap_read(dev->map, DW_IC_ENABLE, &enabled);
+	regmap_read(dev->map, DW_IC_RAW_INTR_STAT, &raw_stat);
+	regmap_read(dev->map, DW_IC_STATUS, &tmp);
+	slave_activity = ((tmp & DW_IC_STATUS_SLAVE_ACTIVITY) >> 6);
 
 	if (!enabled || !(raw_stat & ~DW_IC_INTR_ACTIVITY) || !dev->slave)
 		return 0;
@@ -177,7 +178,8 @@ static int i2c_dw_irq_handler_slave(struct dw_i2c_dev *dev)
 	if (stat & DW_IC_INTR_RD_REQ) {
 		if (slave_activity) {
 			if (stat & DW_IC_INTR_RX_FULL) {
-				val = dw_readl(dev, DW_IC_DATA_CMD);
+				regmap_read(dev->map, DW_IC_DATA_CMD, &tmp);
+				val = tmp;
 
 				if (!i2c_slave_event(dev->slave,
 						     I2C_SLAVE_WRITE_RECEIVED,
@@ -185,24 +187,24 @@ static int i2c_dw_irq_handler_slave(struct dw_i2c_dev *dev)
 					dev_vdbg(dev->dev, "Byte %X acked!",
 						 val);
 				}
-				dw_readl(dev, DW_IC_CLR_RD_REQ);
+				regmap_read(dev->map, DW_IC_CLR_RD_REQ, &tmp);
 				stat = i2c_dw_read_clear_intrbits_slave(dev);
 			} else {
-				dw_readl(dev, DW_IC_CLR_RD_REQ);
-				dw_readl(dev, DW_IC_CLR_RX_UNDER);
+				regmap_read(dev->map, DW_IC_CLR_RD_REQ, &tmp);
+				regmap_read(dev->map, DW_IC_CLR_RX_UNDER, &tmp);
 				stat = i2c_dw_read_clear_intrbits_slave(dev);
 			}
 			if (!i2c_slave_event(dev->slave,
 					     I2C_SLAVE_READ_REQUESTED,
 					     &val))
-				dw_writel(dev, val, DW_IC_DATA_CMD);
+				regmap_write(dev->map, DW_IC_DATA_CMD, val);
 		}
 	}
 
 	if (stat & DW_IC_INTR_RX_DONE) {
 		if (!i2c_slave_event(dev->slave, I2C_SLAVE_READ_PROCESSED,
 				     &val))
-			dw_readl(dev, DW_IC_CLR_RX_DONE);
+			regmap_read(dev->map, DW_IC_CLR_RX_DONE, &tmp);
 
 		i2c_slave_event(dev->slave, I2C_SLAVE_STOP, &val);
 		stat = i2c_dw_read_clear_intrbits_slave(dev);
@@ -210,7 +212,8 @@ static int i2c_dw_irq_handler_slave(struct dw_i2c_dev *dev)
 	}
 
 	if (stat & DW_IC_INTR_RX_FULL) {
-		val = dw_readl(dev, DW_IC_DATA_CMD);
+		regmap_read(dev->map, DW_IC_DATA_CMD, &tmp);
+		val = tmp;
 		if (!i2c_slave_event(dev->slave, I2C_SLAVE_WRITE_RECEIVED,
 				     &val))
 			dev_vdbg(dev->dev, "Byte %X acked!", val);
@@ -252,7 +255,7 @@ int i2c_dw_probe_slave(struct dw_i2c_dev *dev)
 	dev->disable = i2c_dw_disable;
 	dev->disable_int = i2c_dw_disable_int;
 
-	ret = i2c_dw_set_reg_access(dev);
+	ret = i2c_dw_init_regmap(dev);
 	if (ret)
 		return ret;
 
@@ -260,7 +263,9 @@ int i2c_dw_probe_slave(struct dw_i2c_dev *dev)
 	if (ret)
 		return ret;
 
-	i2c_dw_set_fifo_size(dev);
+	ret = i2c_dw_set_fifo_size(dev);
+	if (ret)
+		return ret;
 
 	ret = dev->init(dev);
 	if (ret)
-- 
2.25.1

[PATCH v2 05/12] i2c: designware: Use `-y` to build multi-object modules

[Serge Semin]

Since commit 4f8272802739 ("Documentation: update kbuild loadable modules
goals & examples") `-objs` is fitted for building host programs, lets
change DW I2C core, platform and PCI driver kbuild directives to using
`-y`, which more straightforward for device drivers. By doing so we can
discard the ifeq construction in favor to the more natural and less bulky
`<module>-$(CONFIG_X) += x.o`

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Wolfram Sang <wsa@the-dreams.de>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: linux-mips@vger.kernel.org
Cc: devicetree@vger.kernel.org
---
 drivers/i2c/busses/Makefile | 17 ++++++++---------
 1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 25d60889713c..c6813d7b2780 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -48,16 +48,15 @@ obj-$(CONFIG_I2C_CADENCE)	+= i2c-cadence.o
 obj-$(CONFIG_I2C_CBUS_GPIO)	+= i2c-cbus-gpio.o
 obj-$(CONFIG_I2C_CPM)		+= i2c-cpm.o
 obj-$(CONFIG_I2C_DAVINCI)	+= i2c-davinci.o
-obj-$(CONFIG_I2C_DESIGNWARE_CORE)	+= i2c-designware-core.o
-i2c-designware-core-objs := i2c-designware-common.o i2c-designware-master.o
-ifeq ($(CONFIG_I2C_DESIGNWARE_SLAVE),y)
-i2c-designware-core-objs += i2c-designware-slave.o
-endif
-obj-$(CONFIG_I2C_DESIGNWARE_PLATFORM)	+= i2c-designware-platform.o
-i2c-designware-platform-objs := i2c-designware-platdrv.o
+obj-$(CONFIG_I2C_DESIGNWARE_CORE)			+= i2c-designware-core.o
+i2c-designware-core-y					:= i2c-designware-common.o
+i2c-designware-core-y					+= i2c-designware-master.o
+i2c-designware-core-$(CONFIG_I2C_DESIGNWARE_SLAVE) 	+= i2c-designware-slave.o
+obj-$(CONFIG_I2C_DESIGNWARE_PLATFORM)			+= i2c-designware-platform.o
+i2c-designware-platform-y 				:= i2c-designware-platdrv.o
 i2c-designware-platform-$(CONFIG_I2C_DESIGNWARE_BAYTRAIL) += i2c-designware-baytrail.o
-obj-$(CONFIG_I2C_DESIGNWARE_PCI)	+= i2c-designware-pci.o
-i2c-designware-pci-objs := i2c-designware-pcidrv.o
+obj-$(CONFIG_I2C_DESIGNWARE_PCI)			+= i2c-designware-pci.o
+i2c-designware-pci-y					:= i2c-designware-pcidrv.o
 obj-$(CONFIG_I2C_DIGICOLOR)	+= i2c-digicolor.o
 obj-$(CONFIG_I2C_EFM32)		+= i2c-efm32.o
 obj-$(CONFIG_I2C_EG20T)		+= i2c-eg20t.o
-- 
2.25.1

[PATCH v2 06/12] i2c: designware: slave: Set DW I2C core module dependency

[Serge Semin]

DW APB I2C slave code in fact depends on the DW I2C driver core, but not
on the platform code. Yes, the I2C slave interface is currently supported
by the platform version of the IP core, but it doesn't make it dependent
on it. So make sure the DW APB I2C slave config is only available if the
I2C_DESIGNWARE_CORE config is enabled.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Wolfram Sang <wsa@the-dreams.de>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: linux-mips@vger.kernel.org
Cc: devicetree@vger.kernel.org
---
 drivers/i2c/busses/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 14368c46cb63..368aa64e9266 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -541,8 +541,8 @@ config I2C_DESIGNWARE_PLATFORM
 
 config I2C_DESIGNWARE_SLAVE
 	bool "Synopsys DesignWare Slave"
+	depends on I2C_DESIGNWARE_CORE
 	select I2C_SLAVE
-	depends on I2C_DESIGNWARE_PLATFORM
 	help
 	  If you say yes to this option, support will be included for the
 	  Synopsys DesignWare I2C slave adapter.
-- 
2.25.1

[PATCH v2 07/12] i2c: designware: Move Baytrail sem config to the platform if-clause

[Serge Semin]

Currently Intel Baytrail I2C semaphore is a feature of the DW APB I2C
platform driver. It's a bit confusing to see it's config in the menu at
some separated place with no reference to the platform code. Lets move the
config definition under the if-I2C_DESIGNWARE_PLATFORM clause. By doing so
the config menu will display the feature right below the DW I2C platform
driver item and will indent it to the right so signifying its belonging.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Wolfram Sang <wsa@the-dreams.de>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: linux-mips@vger.kernel.org
Cc: devicetree@vger.kernel.org
---
 drivers/i2c/busses/Kconfig | 30 +++++++++++++++++-------------
 1 file changed, 17 insertions(+), 13 deletions(-)

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 368aa64e9266..ed6927c4c540 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -530,8 +530,8 @@ config I2C_DESIGNWARE_CORE
 
 config I2C_DESIGNWARE_PLATFORM
 	tristate "Synopsys DesignWare Platform"
-	select I2C_DESIGNWARE_CORE
 	depends on (ACPI && COMMON_CLK) || !ACPI
+	select I2C_DESIGNWARE_CORE
 	help
 	  If you say yes to this option, support will be included for the
 	  Synopsys DesignWare I2C adapter.
@@ -539,6 +539,22 @@ config I2C_DESIGNWARE_PLATFORM
 	  This driver can also be built as a module.  If so, the module
 	  will be called i2c-designware-platform.
 
+if I2C_DESIGNWARE_PLATFORM
+
+config I2C_DESIGNWARE_BAYTRAIL
+	bool "Intel Baytrail I2C semaphore support"
+	depends on ACPI
+	depends on (I2C_DESIGNWARE_PLATFORM=m && IOSF_MBI) || \
+		   (I2C_DESIGNWARE_PLATFORM=y && IOSF_MBI=y)
+	help
+	  This driver enables managed host access to the PMIC I2C bus on select
+	  Intel BayTrail platforms using the X-Powers AXP288 PMIC. It allows
+	  the host to request uninterrupted access to the PMIC's I2C bus from
+	  the platform firmware controlling it. You should say Y if running on
+	  a BayTrail system using the AXP288.
+
+endif # I2C_DESIGNWARE_PLATFORM
+
 config I2C_DESIGNWARE_SLAVE
 	bool "Synopsys DesignWare Slave"
 	depends on I2C_DESIGNWARE_CORE
@@ -561,18 +577,6 @@ config I2C_DESIGNWARE_PCI
 	  This driver can also be built as a module.  If so, the module
 	  will be called i2c-designware-pci.
 
-config I2C_DESIGNWARE_BAYTRAIL
-	bool "Intel Baytrail I2C semaphore support"
-	depends on ACPI
-	depends on (I2C_DESIGNWARE_PLATFORM=m && IOSF_MBI) || \
-		   (I2C_DESIGNWARE_PLATFORM=y && IOSF_MBI=y)
-	help
-	  This driver enables managed host access to the PMIC I2C bus on select
-	  Intel BayTrail platforms using the X-Powers AXP288 PMIC. It allows
-	  the host to request uninterrupted access to the PMIC's I2C bus from
-	  the platform firmware controlling it. You should say Y if running on
-	  a BayTrail system using the AXP288.
-
 config I2C_DIGICOLOR
 	tristate "Conexant Digicolor I2C driver"
 	depends on ARCH_DIGICOLOR || COMPILE_TEST
-- 
2.25.1

[PATCH v2 08/12] i2c: designware: Introduce platform drivers glue layer interface

[Serge Semin]

Seeing the DW I2C platform driver is getting overcomplicated with a lot of
vendor-specific configs let's introduce a glue-layer interface so new
platforms which equipped with Synopsys Designware APB I2C IP-core would
be able to handle their peculiarities in the dedicated objects.

The generic platform setups and cleanups can now be performed by means of
two new functions exported from the Dw I2C platform driver:

int i2c_dw_plat_setup(struct dw_i2c_dev *dev);
int i2c_dw_plat_clear(struct dw_i2c_dev *dev);

They also install and remove the I2C controller respectively. In addition
if device supports the PM interface a glue driver can use the generic
platform PM callbacks collected into the PM dev ops structure:

const struct dev_pm_ops i2c_dw_plat_dev_pm_ops;

Before setting the platform DW I2C device up the glue probe code is
supposed to create an instance of `struct dw_i2c_dev` and pre-initialize
its `struct device` pointer together with optional platform-specific
flags. Currently the ACCESS_NO_IRQ_SUSPEND and ACCESS_INTR_MASK flags are
supported.

Note we moved the platform driver private data setup to the generic
platform probe method. By doing so the driver data pointer will be free
to be used by the glue-layer driver.

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: linux-mips@vger.kernel.org
Cc: devicetree@vger.kernel.org
---
 drivers/i2c/busses/i2c-designware-core.h    |  4 +
 drivers/i2c/busses/i2c-designware-platdrv.c | 84 +++++++++++++--------
 drivers/i2c/busses/i2c-designware-platdrv.h | 16 ++++
 3 files changed, 71 insertions(+), 33 deletions(-)
 create mode 100644 drivers/i2c/busses/i2c-designware-platdrv.h

diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h
index b5b981c1bb0d..10606266b30c 100644
--- a/drivers/i2c/busses/i2c-designware-core.h
+++ b/drivers/i2c/busses/i2c-designware-core.h
@@ -8,6 +8,8 @@
  * Copyright (C) 2007 MontaVista Software Inc.
  * Copyright (C) 2009 Provigent Ltd.
  */
+#ifndef __I2C_DESIGNWARE_CORE_H__
+#define __I2C_DESIGNWARE_CORE_H__
 
 #include <linux/i2c.h>
 #include <linux/regmap.h>
@@ -324,3 +326,5 @@ extern int i2c_dw_probe_lock_support(struct dw_i2c_dev *dev);
 #else
 static inline int i2c_dw_probe_lock_support(struct dw_i2c_dev *dev) { return 0; }
 #endif
+
+#endif /* __I2C_DESIGNWARE_CORE_H__ */
diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
index 5536673060cc..274953155569 100644
--- a/drivers/i2c/busses/i2c-designware-platdrv.c
+++ b/drivers/i2c/busses/i2c-designware-platdrv.c
@@ -32,6 +32,7 @@
 #include <linux/suspend.h>
 
 #include "i2c-designware-core.h"
+#include "i2c-designware-platdrv.h"
 
 static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev)
 {
@@ -80,9 +81,9 @@ static void dw_i2c_acpi_params(struct platform_device *pdev, char method[],
 	kfree(buf.pointer);
 }
 
-static int dw_i2c_acpi_configure(struct platform_device *pdev)
+static int dw_i2c_acpi_configure(struct dw_i2c_dev *dev)
 {
-	struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
+	struct platform_device *pdev = to_platform_device(dev->dev);
 	struct i2c_timings *t = &dev->timings;
 	u32 ss_ht = 0, fp_ht = 0, hs_ht = 0, fs_ht = 0;
 
@@ -135,7 +136,7 @@ static const struct acpi_device_id dw_i2c_acpi_match[] = {
 };
 MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match);
 #else
-static inline int dw_i2c_acpi_configure(struct platform_device *pdev)
+static inline int dw_i2c_acpi_configure(struct dw_i2c_dev *dev)
 {
 	return -ENODEV;
 }
@@ -154,9 +155,9 @@ static int mscc_twi_set_sda_hold_time(struct dw_i2c_dev *dev)
 	return 0;
 }
 
-static int dw_i2c_of_configure(struct platform_device *pdev)
+static int dw_i2c_of_configure(struct dw_i2c_dev *dev)
 {
-	struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
+	struct platform_device *pdev = to_platform_device(dev->dev);
 	struct resource *mem;
 
 	switch (dev->flags & MODEL_MASK) {
@@ -180,7 +181,7 @@ static const struct of_device_id dw_i2c_of_match[] = {
 };
 MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
 #else
-static inline int dw_i2c_of_configure(struct platform_device *pdev)
+static inline int dw_i2c_of_configure(struct dw_i2c_dev *dev)
 {
 	return -ENODEV;
 }
@@ -234,33 +235,25 @@ static const u32 supported_speeds[] = {
 	I2C_MAX_STANDARD_MODE_FREQ,
 };
 
-static int dw_i2c_plat_probe(struct platform_device *pdev)
+int i2c_dw_plat_setup(struct dw_i2c_dev *dev)
 {
+	struct platform_device *pdev = to_platform_device(dev->dev);
 	struct dw_i2c_platform_data *pdata = dev_get_platdata(&pdev->dev);
 	struct i2c_adapter *adap;
-	struct dw_i2c_dev *dev;
 	struct i2c_timings *t;
 	u32 acpi_speed;
 	struct resource *mem;
-	int i, irq, ret;
+	int i, ret;
 
-	irq = platform_get_irq(pdev, 0);
-	if (irq < 0)
-		return irq;
-
-	dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL);
-	if (!dev)
-		return -ENOMEM;
+	dev->irq = platform_get_irq(pdev, 0);
+	if (dev->irq < 0)
+		return dev->irq;
 
 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	dev->base = devm_ioremap_resource(&pdev->dev, mem);
 	if (IS_ERR(dev->base))
 		return PTR_ERR(dev->base);
 
-	dev->dev = &pdev->dev;
-	dev->irq = irq;
-	platform_set_drvdata(pdev, dev);
-
 	dev->rst = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL);
 	if (IS_ERR(dev->rst))
 		return PTR_ERR(dev->rst);
@@ -295,13 +288,11 @@ static int dw_i2c_plat_probe(struct platform_device *pdev)
 	else
 		t->bus_freq_hz = I2C_MAX_FAST_MODE_FREQ;
 
-	dev->flags |= (uintptr_t)device_get_match_data(&pdev->dev);
-
 	if (pdev->dev.of_node)
-		dw_i2c_of_configure(pdev);
+		dw_i2c_of_configure(dev);
 
 	if (has_acpi_companion(&pdev->dev))
-		dw_i2c_acpi_configure(pdev);
+		dw_i2c_acpi_configure(dev);
 
 	/*
 	 * Only standard mode at 100kHz, fast mode at 400kHz,
@@ -393,10 +384,11 @@ static int dw_i2c_plat_probe(struct platform_device *pdev)
 	reset_control_assert(dev->rst);
 	return ret;
 }
+EXPORT_SYMBOL_GPL(i2c_dw_plat_setup);
 
-static int dw_i2c_plat_remove(struct platform_device *pdev)
+int i2c_dw_plat_clear(struct dw_i2c_dev *dev)
 {
-	struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
+	struct platform_device *pdev = to_platform_device(dev->dev);
 
 	pm_runtime_get_sync(&pdev->dev);
 
@@ -412,6 +404,29 @@ static int dw_i2c_plat_remove(struct platform_device *pdev)
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(i2c_dw_plat_clear);
+
+static int dw_i2c_plat_probe(struct platform_device *pdev)
+{
+	struct dw_i2c_dev *dev;
+
+	dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
+	if (!dev)
+		return -ENOMEM;
+
+	dev->dev = &pdev->dev;
+	dev->flags |= (uintptr_t)device_get_match_data(dev->dev);
+	platform_set_drvdata(pdev, dev);
+
+	return i2c_dw_plat_setup(dev);
+}
+
+static int dw_i2c_plat_remove(struct platform_device *pdev)
+{
+	struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
+
+	return i2c_dw_plat_clear(dev);
+}
 
 #ifdef CONFIG_PM_SLEEP
 static int dw_i2c_plat_prepare(struct device *dev)
@@ -470,17 +485,20 @@ static int dw_i2c_plat_resume(struct device *dev)
 	return 0;
 }
 
-static const struct dev_pm_ops dw_i2c_dev_pm_ops = {
+#else
+
+#define dw_i2c_plat_prepare	NULL
+#define dw_i2c_plat_complete	NULL
+
+#endif
+
+const struct dev_pm_ops i2c_dw_plat_dev_pm_ops = {
 	.prepare = dw_i2c_plat_prepare,
 	.complete = dw_i2c_plat_complete,
 	SET_LATE_SYSTEM_SLEEP_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume)
 	SET_RUNTIME_PM_OPS(dw_i2c_plat_suspend, dw_i2c_plat_resume, NULL)
 };
-
-#define DW_I2C_DEV_PMOPS (&dw_i2c_dev_pm_ops)
-#else
-#define DW_I2C_DEV_PMOPS NULL
-#endif
+EXPORT_SYMBOL_GPL(i2c_dw_plat_dev_pm_ops);
 
 /* Work with hotplug and coldplug */
 MODULE_ALIAS("platform:i2c_designware");
@@ -492,7 +510,7 @@ static struct platform_driver dw_i2c_driver = {
 		.name	= "i2c_designware",
 		.of_match_table = of_match_ptr(dw_i2c_of_match),
 		.acpi_match_table = ACPI_PTR(dw_i2c_acpi_match),
-		.pm	= DW_I2C_DEV_PMOPS,
+		.pm	= &i2c_dw_plat_dev_pm_ops,
 	},
 };
 
diff --git a/drivers/i2c/busses/i2c-designware-platdrv.h b/drivers/i2c/busses/i2c-designware-platdrv.h
new file mode 100644
index 000000000000..8916c4f61d7f
--- /dev/null
+++ b/drivers/i2c/busses/i2c-designware-platdrv.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Synopsys DesignWare I2C adapter driver.
+ */
+#ifndef __I2C_DESIGNWARE_PLATDRV_H__
+#define __I2C_DESIGNWARE_PLATDRV_H__
+
+#include <linux/pm.h>
+
+#include "i2c-designware-core.h"
+
+extern int i2c_dw_plat_setup(struct dw_i2c_dev *dev);
+extern int i2c_dw_plat_clear(struct dw_i2c_dev *dev);
+extern const struct dev_pm_ops i2c_dw_plat_dev_pm_ops;
+
+#endif /* __I2C_DESIGNWARE_PLATDRV_H__ */
-- 
2.25.1

[PATCH v2 09/12] i2c: designware: Unpin Microsemi Ocelot I2C into a glue driver

[Serge Semin]

Since glue-layer drivers design is now supported by the DW APB I2C
platform code lets unpin MSCC Ocelot I2C driver at least. It won't be that
hard because the only difference between this controller and vanilly core
is in what the former sets the sda hold time in a dedicated configure
registers space.

Note I enabled the new driver by default for the MSCC Ocelot platform so
one would be automatically built and we wouldn't need to alter the in- and
out-of-source tree platform configs.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Wolfram Sang <wsa@the-dreams.de>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: linux-mips@vger.kernel.org
Cc: devicetree@vger.kernel.org
---
 drivers/i2c/busses/Kconfig                  | 12 +++
 drivers/i2c/busses/Makefile                 |  1 +
 drivers/i2c/busses/i2c-designware-core.h    |  3 -
 drivers/i2c/busses/i2c-designware-mscc.c    | 83 +++++++++++++++++++++
 drivers/i2c/busses/i2c-designware-platdrv.c | 40 ----------
 5 files changed, 96 insertions(+), 43 deletions(-)
 create mode 100644 drivers/i2c/busses/i2c-designware-mscc.c

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index ed6927c4c540..2f047cf07fee 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -566,6 +566,18 @@ config I2C_DESIGNWARE_SLAVE
 	  This is not a standalone module, this module compiles together with
 	  i2c-designware-core.
 
+config I2C_DESIGNWARE_MSCC
+	tristate "Microsemi Ocelot I2C"
+	depends on MSCC_OCELOT
+	select I2C_DESIGNWARE_PLATFORM
+	default y
+	help
+	  This driver supports the Microsemi Ocelot SoC version of the Synopsys
+	  Designware I2C IP-core.
+
+	  The driver can also be built as a module. If so, the module will be
+	  called i2c-designware-mscc.
+
 config I2C_DESIGNWARE_PCI
 	tristate "Synopsys DesignWare PCI"
 	depends on PCI
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index c6813d7b2780..480a9fe4fb64 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -55,6 +55,7 @@ i2c-designware-core-$(CONFIG_I2C_DESIGNWARE_SLAVE) 	+= i2c-designware-slave.o
 obj-$(CONFIG_I2C_DESIGNWARE_PLATFORM)			+= i2c-designware-platform.o
 i2c-designware-platform-y 				:= i2c-designware-platdrv.o
 i2c-designware-platform-$(CONFIG_I2C_DESIGNWARE_BAYTRAIL) += i2c-designware-baytrail.o
+obj-$(CONFIG_I2C_DESIGNWARE_MSCC)			+= i2c-designware-mscc.o
 obj-$(CONFIG_I2C_DESIGNWARE_PCI)			+= i2c-designware-pci.o
 i2c-designware-pci-y					:= i2c-designware-pcidrv.o
 obj-$(CONFIG_I2C_DIGICOLOR)	+= i2c-digicolor.o
diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h
index 10606266b30c..64544777a1fa 100644
--- a/drivers/i2c/busses/i2c-designware-core.h
+++ b/drivers/i2c/busses/i2c-designware-core.h
@@ -177,7 +177,6 @@
  * @dev: driver model device node
  * @map: IO registers map
  * @base: IO registers pointer
- * @ext: Extended IO registers pointer
  * @cmd_complete: tx completion indicator
  * @clk: input reference clock
  * @pclk: clock required to access the registers
@@ -229,7 +228,6 @@ struct dw_i2c_dev {
 	struct device		*dev;
 	struct regmap		*map;
 	void __iomem		*base;
-	void __iomem		*ext;
 	struct completion	cmd_complete;
 	struct clk		*clk;
 	struct clk		*pclk;
@@ -284,7 +282,6 @@ struct dw_i2c_dev {
 #define ACCESS_NO_IRQ_SUSPEND	0x00000008
 
 #define MODEL_CHERRYTRAIL	0x00000100
-#define MODEL_MSCC_OCELOT	0x00000200
 #define MODEL_MASK		0x00000f00
 
 int i2c_dw_init_regmap(struct dw_i2c_dev *dev);
diff --git a/drivers/i2c/busses/i2c-designware-mscc.c b/drivers/i2c/busses/i2c-designware-mscc.c
new file mode 100644
index 000000000000..0649e3d1fefc
--- /dev/null
+++ b/drivers/i2c/busses/i2c-designware-mscc.c
@@ -0,0 +1,83 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Microsemi Ocelot I2C Controller.
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+
+#include "i2c-designware-core.h"
+#include "i2c-designware-platdrv.h"
+
+#define MSCC_ICPU_CFG_TWI_DELAY		0x0
+#define MSCC_ICPU_CFG_TWI_DELAY_ENABLE	BIT(0)
+#define MSCC_ICPU_CFG_TWI_SPIKE_FILTER	0x4
+
+struct mscc_i2c_dev {
+	struct dw_i2c_dev	dev;
+	void __iomem		*ext;
+};
+#define to_mscc_device(_dev)	container_of((_dev), struct mscc_i2c_dev, dev)
+
+static int mscc_twi_set_sda_hold_time(struct dw_i2c_dev *dev)
+{
+	struct mscc_i2c_dev *mscc = to_mscc_device(dev);
+
+	writel((dev->sda_hold_time << 1) | MSCC_ICPU_CFG_TWI_DELAY_ENABLE,
+	       mscc->ext + MSCC_ICPU_CFG_TWI_DELAY);
+
+	return 0;
+}
+
+static int mscc_i2c_plat_probe(struct platform_device *pdev)
+{
+	struct mscc_i2c_dev *mscc;
+	struct resource *mem;
+
+	mscc = devm_kzalloc(&pdev->dev, sizeof(*mscc), GFP_KERNEL);
+	if (!mscc)
+		return -ENOMEM;
+
+	mem = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	mscc->ext = devm_ioremap_resource(&pdev->dev, mem);
+	if (!IS_ERR(mscc->ext))
+		mscc->dev.set_sda_hold_time = mscc_twi_set_sda_hold_time;
+
+	mscc->dev.dev = &pdev->dev;
+	platform_set_drvdata(pdev, mscc);
+
+	return i2c_dw_plat_setup(&mscc->dev);
+}
+
+static int mscc_i2c_plat_remove(struct platform_device *pdev)
+{
+	struct mscc_i2c_dev *mscc = platform_get_drvdata(pdev);
+
+	return i2c_dw_plat_clear(&mscc->dev);
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id mscc_i2c_of_match[] = {
+	{ .compatible = "mscc,ocelot-i2c" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, mscc_i2c_of_match);
+#endif
+
+static struct platform_driver mscc_i2c_driver = {
+	.probe = mscc_i2c_plat_probe,
+	.remove = mscc_i2c_plat_remove,
+	.driver		= {
+		.name	= "i2c_ocelot",
+		.of_match_table = of_match_ptr(mscc_i2c_of_match),
+		.pm	= &i2c_dw_plat_dev_pm_ops,
+	},
+};
+module_platform_driver(mscc_i2c_driver);
+
+MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@bootlin.com>");
+MODULE_DESCRIPTION("Microsemi Ocelot I2C Controller");
+MODULE_LICENSE("GPL");
diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
index 274953155569..1f56865bb6ca 100644
--- a/drivers/i2c/busses/i2c-designware-platdrv.c
+++ b/drivers/i2c/busses/i2c-designware-platdrv.c
@@ -143,48 +143,11 @@ static inline int dw_i2c_acpi_configure(struct dw_i2c_dev *dev)
 #endif
 
 #ifdef CONFIG_OF
-#define MSCC_ICPU_CFG_TWI_DELAY		0x0
-#define MSCC_ICPU_CFG_TWI_DELAY_ENABLE	BIT(0)
-#define MSCC_ICPU_CFG_TWI_SPIKE_FILTER	0x4
-
-static int mscc_twi_set_sda_hold_time(struct dw_i2c_dev *dev)
-{
-	writel((dev->sda_hold_time << 1) | MSCC_ICPU_CFG_TWI_DELAY_ENABLE,
-	       dev->ext + MSCC_ICPU_CFG_TWI_DELAY);
-
-	return 0;
-}
-
-static int dw_i2c_of_configure(struct dw_i2c_dev *dev)
-{
-	struct platform_device *pdev = to_platform_device(dev->dev);
-	struct resource *mem;
-
-	switch (dev->flags & MODEL_MASK) {
-	case MODEL_MSCC_OCELOT:
-		mem = platform_get_resource(pdev, IORESOURCE_MEM, 1);
-		dev->ext = devm_ioremap_resource(&pdev->dev, mem);
-		if (!IS_ERR(dev->ext))
-			dev->set_sda_hold_time = mscc_twi_set_sda_hold_time;
-		break;
-	default:
-		break;
-	}
-
-	return 0;
-}
-
 static const struct of_device_id dw_i2c_of_match[] = {
 	{ .compatible = "snps,designware-i2c", },
-	{ .compatible = "mscc,ocelot-i2c", .data = (void *)MODEL_MSCC_OCELOT },
 	{},
 };
 MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
-#else
-static inline int dw_i2c_of_configure(struct dw_i2c_dev *dev)
-{
-	return -ENODEV;
-}
 #endif
 
 static void i2c_dw_configure_master(struct dw_i2c_dev *dev)
@@ -288,9 +251,6 @@ int i2c_dw_plat_setup(struct dw_i2c_dev *dev)
 	else
 		t->bus_freq_hz = I2C_MAX_FAST_MODE_FREQ;
 
-	if (pdev->dev.of_node)
-		dw_i2c_of_configure(dev);
-
 	if (has_acpi_companion(&pdev->dev))
 		dw_i2c_acpi_configure(dev);
 
-- 
2.25.1

[PATCH v2 10/12] i2c: designware: Discard Cherry Trail model flag

[Serge Semin]

A PM workaround activated by the flag MODEL_CHERRYTRAIL has been removed
since commit 9cbeeca05049 ("i2c: designware: Remove Cherry Trail PMIC I2C
bus pm_disabled workaround"), but the flag most likely by mistake has been
left in the Dw I2C drivers. Lets remove it.

By doing so we get rid from the last DW APB I2C IP-core model flag, so we
can remove the MODEL_MASK macro too.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: linux-mips@vger.kernel.org
Cc: devicetree@vger.kernel.org
---
 drivers/i2c/busses/i2c-designware-core.h    | 3 ---
 drivers/i2c/busses/i2c-designware-pcidrv.c  | 1 -
 drivers/i2c/busses/i2c-designware-platdrv.c | 2 +-
 3 files changed, 1 insertion(+), 5 deletions(-)

diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h
index 64544777a1fa..5a1f6b623a9a 100644
--- a/drivers/i2c/busses/i2c-designware-core.h
+++ b/drivers/i2c/busses/i2c-designware-core.h
@@ -281,9 +281,6 @@ struct dw_i2c_dev {
 #define ACCESS_INTR_MASK	0x00000004
 #define ACCESS_NO_IRQ_SUSPEND	0x00000008
 
-#define MODEL_CHERRYTRAIL	0x00000100
-#define MODEL_MASK		0x00000f00
-
 int i2c_dw_init_regmap(struct dw_i2c_dev *dev);
 u32 i2c_dw_scl_hcnt(u32 ic_clk, u32 tSYMBOL, u32 tf, int cond, int offset);
 u32 i2c_dw_scl_lcnt(u32 ic_clk, u32 tLOW, u32 tf, int offset);
diff --git a/drivers/i2c/busses/i2c-designware-pcidrv.c b/drivers/i2c/busses/i2c-designware-pcidrv.c
index 7a0b65b5b5b5..76357b575aa5 100644
--- a/drivers/i2c/busses/i2c-designware-pcidrv.c
+++ b/drivers/i2c/busses/i2c-designware-pcidrv.c
@@ -166,7 +166,6 @@ static struct dw_pci_controller dw_pci_controllers[] = {
 		.tx_fifo_depth = 32,
 		.rx_fifo_depth = 32,
 		.functionality = I2C_FUNC_10BIT_ADDR,
-		.flags = MODEL_CHERRYTRAIL,
 		.scl_sda_cfg = &byt_config,
 	},
 	[elkhartlake] = {
diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
index 1f56865bb6ca..f577e2a92a4f 100644
--- a/drivers/i2c/busses/i2c-designware-platdrv.c
+++ b/drivers/i2c/busses/i2c-designware-platdrv.c
@@ -124,7 +124,7 @@ static const struct acpi_device_id dw_i2c_acpi_match[] = {
 	{ "INT3432", 0 },
 	{ "INT3433", 0 },
 	{ "80860F41", ACCESS_NO_IRQ_SUSPEND },
-	{ "808622C1", ACCESS_NO_IRQ_SUSPEND | MODEL_CHERRYTRAIL },
+	{ "808622C1", ACCESS_NO_IRQ_SUSPEND },
 	{ "AMD0010", ACCESS_INTR_MASK },
 	{ "AMDI0010", ACCESS_INTR_MASK },
 	{ "AMDI0510", 0 },
-- 
2.25.1

[PATCH v2 11/12] i2c: designware: Use provided regmap instead of reg resource

[Serge Semin]

This is a preparation patch before adding a glue platform driver for the
Baikal-T1 I2C controller. Since the i2c controller registers are indirectly
accessed by means of the Baikal-T1 System Controller registers we need to
have a way to disable the default registers mapping setup procedure and
make the DW I2C core/platform code to use a provided by a glue driver
regmap.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: linux-mips@vger.kernel.org
Cc: devicetree@vger.kernel.org
---
 drivers/i2c/busses/i2c-designware-common.c  |  7 +++++++
 drivers/i2c/busses/i2c-designware-platdrv.c | 14 ++++++++++----
 2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/drivers/i2c/busses/i2c-designware-common.c b/drivers/i2c/busses/i2c-designware-common.c
index 35c5ad7e274e..141ea0651a8f 100644
--- a/drivers/i2c/busses/i2c-designware-common.c
+++ b/drivers/i2c/busses/i2c-designware-common.c
@@ -133,6 +133,13 @@ int i2c_dw_init_regmap(struct dw_i2c_dev *dev)
 	u32 reg;
 	int ret;
 
+	/*
+	 * Skip detecting the registers map configuration if the regmap has
+	 * already been provided by a higher code.
+	 */
+	if (dev->map)
+		return 0;
+
 	ret = i2c_dw_acquire_lock(dev);
 	if (ret)
 		return ret;
diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
index f577e2a92a4f..9d131a64ea81 100644
--- a/drivers/i2c/busses/i2c-designware-platdrv.c
+++ b/drivers/i2c/busses/i2c-designware-platdrv.c
@@ -212,10 +212,16 @@ int i2c_dw_plat_setup(struct dw_i2c_dev *dev)
 	if (dev->irq < 0)
 		return dev->irq;
 
-	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	dev->base = devm_ioremap_resource(&pdev->dev, mem);
-	if (IS_ERR(dev->base))
-		return PTR_ERR(dev->base);
+	/*
+	 * Don't try to get the controller registers MMIO space if regmap has
+	 * been provided by a higher level code.
+	 */
+	if (!dev->map) {
+		mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+		dev->base = devm_ioremap_resource(&pdev->dev, mem);
+		if (IS_ERR(dev->base))
+			return PTR_ERR(dev->base);
+	}
 
 	dev->rst = devm_reset_control_get_optional_exclusive(&pdev->dev, NULL);
 	if (IS_ERR(dev->rst))
-- 
2.25.1

[PATCH v2 12/12] i2c: designware: Add Baikal-T1 System I2C glue driver

[Serge Semin]

Baikal-T1 System Controller is equipped with a dedicated I2C Controller
which functionality is based on the DW APB I2C IP-core, the only
difference in a way it' registers are accessed. There are three access
register provided in the System Controller registers map, which
indirectly address the normal DW APB I2C registers space.
So in order to have the Baikal-T1 System I2C Controller supported by the
common DW APB I2C driver we created a dedicated glue driver, which
retrieves the syscon regmap from the parental dt node and creates a
new regmap based on it. The new regmap is then passed to the generic DW I2C
platform driver initializer.

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Wolfram Sang <wsa@the-dreams.de>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: linux-mips@vger.kernel.org
Cc: devicetree@vger.kernel.org
---
 drivers/i2c/busses/Kconfig              |  11 ++
 drivers/i2c/busses/Makefile             |   1 +
 drivers/i2c/busses/i2c-designware-bt1.c | 129 ++++++++++++++++++++++++
 3 files changed, 141 insertions(+)
 create mode 100644 drivers/i2c/busses/i2c-designware-bt1.c

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 2f047cf07fee..d4a5d78cc181 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -578,6 +578,17 @@ config I2C_DESIGNWARE_MSCC
 	  The driver can also be built as a module. If so, the module will be
 	  called i2c-designware-mscc.
 
+config I2C_DESIGNWARE_BT1
+	tristate "Baikal-T1 System I2C"
+	depends on (MIPS_BAIKAL_T1 && OF) || COMPILE_TEST
+	select I2C_DESIGNWARE_PLATFORM
+	help
+	  This driver supports the Baikal-T1 SoC version of the Synopsys
+	  Designware I2C IP-core.
+
+	  The driver can also be built as a module. If so, the module will be
+	  called i2c-designware-bt1.
+
 config I2C_DESIGNWARE_PCI
 	tristate "Synopsys DesignWare PCI"
 	depends on PCI
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 480a9fe4fb64..7b044d4e299a 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -56,6 +56,7 @@ obj-$(CONFIG_I2C_DESIGNWARE_PLATFORM)			+= i2c-designware-platform.o
 i2c-designware-platform-y 				:= i2c-designware-platdrv.o
 i2c-designware-platform-$(CONFIG_I2C_DESIGNWARE_BAYTRAIL) += i2c-designware-baytrail.o
 obj-$(CONFIG_I2C_DESIGNWARE_MSCC)			+= i2c-designware-mscc.o
+obj-$(CONFIG_I2C_DESIGNWARE_BT1)			+= i2c-designware-bt1.o
 obj-$(CONFIG_I2C_DESIGNWARE_PCI)			+= i2c-designware-pci.o
 i2c-designware-pci-y					:= i2c-designware-pcidrv.o
 obj-$(CONFIG_I2C_DIGICOLOR)	+= i2c-digicolor.o
diff --git a/drivers/i2c/busses/i2c-designware-bt1.c b/drivers/i2c/busses/i2c-designware-bt1.c
new file mode 100644
index 000000000000..ed157d1c3b81
--- /dev/null
+++ b/drivers/i2c/busses/i2c-designware-bt1.c
@@ -0,0 +1,129 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2020 BAIKAL ELECTRONICS, JSC
+ *
+ * Authors:
+ *   Serge Semin <Sergey.Semin@baikalelectronics.ru>
+ *
+ * Baikal-T1 System I2C driver
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/platform_device.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+
+#include "i2c-designware-core.h"
+#include "i2c-designware-platdrv.h"
+
+/*
+ * Access registers to the normal I2C regspace.
+ */
+#define BT1_I2C_CTL			0x100
+#define BT1_I2C_CTL_ADDR_MASK		GENMASK(7, 0)
+#define BT1_I2C_CTL_WR			BIT(8)
+#define BT1_I2C_CTL_GO			BIT(31)
+#define BT1_I2C_DI			0x104
+#define BT1_I2C_DO			0x108
+
+struct bt1_i2c_dev {
+	struct dw_i2c_dev dev;
+	struct regmap *sys_regs;
+};
+
+static int bt1_i2c_read(void *context, unsigned int reg, unsigned int *val)
+{
+	struct bt1_i2c_dev *bt1 = context;
+	int ret;
+
+	/*
+	 * Note these methods shouldn't ever fail because the system controller
+	 * registers are memory mapped. We check the return value just in case.
+	 */
+	ret = regmap_write(bt1->sys_regs, BT1_I2C_CTL,
+			   BT1_I2C_CTL_GO | (reg & BT1_I2C_CTL_ADDR_MASK));
+	if (ret)
+		return ret;
+
+	return regmap_read(bt1->sys_regs, BT1_I2C_DO, val);
+}
+
+static int bt1_i2c_write(void *context, unsigned int reg, unsigned int val)
+{
+	struct bt1_i2c_dev *bt1 = context;
+	int ret;
+
+	ret = regmap_write(bt1->sys_regs, BT1_I2C_DI, val);
+	if (ret)
+		return ret;
+
+	return regmap_write(bt1->sys_regs, BT1_I2C_CTL,
+		BT1_I2C_CTL_GO | BT1_I2C_CTL_WR | (reg & BT1_I2C_CTL_ADDR_MASK));
+}
+
+static struct regmap_config bt1_i2c_cfg = {
+	.reg_bits = 32,
+	.val_bits = 32,
+	.reg_stride = 4,
+	.fast_io = true,
+	.reg_read = bt1_i2c_read,
+	.reg_write = bt1_i2c_write,
+	.max_register = DW_IC_COMP_TYPE
+};
+
+static int bt1_i2c_plat_probe(struct platform_device *pdev)
+{
+	struct bt1_i2c_dev *bt1;
+
+	bt1 = devm_kzalloc(&pdev->dev, sizeof(*bt1), GFP_KERNEL);
+	if (!bt1)
+		return -ENOMEM;
+
+	bt1->sys_regs = syscon_node_to_regmap(pdev->dev.of_node->parent);
+	if (IS_ERR(bt1->sys_regs)) {
+		dev_err(&pdev->dev, "Couldn't get BT1 I2C register map\n");
+		return PTR_ERR(bt1->sys_regs);
+	}
+
+	bt1->dev.map = devm_regmap_init(&pdev->dev, NULL, bt1, &bt1_i2c_cfg);
+	if (IS_ERR(bt1->dev.map)) {
+		dev_err(&pdev->dev, "Failed to init the registers map\n");
+		return PTR_ERR(bt1->dev.map);
+	}
+
+	bt1->dev.dev = &pdev->dev;
+	platform_set_drvdata(pdev, bt1);
+
+	return i2c_dw_plat_setup(&bt1->dev);
+}
+
+static int bt1_i2c_plat_remove(struct platform_device *pdev)
+{
+	struct bt1_i2c_dev *bt1 = platform_get_drvdata(pdev);
+
+	return i2c_dw_plat_clear(&bt1->dev);
+}
+
+static const struct of_device_id bt1_i2c_of_match[] = {
+	{ .compatible = "baikal,bt1-sys-i2c" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, bt1_i2c_of_match);
+
+static struct platform_driver bt1_i2c_driver = {
+	.probe = bt1_i2c_plat_probe,
+	.remove = bt1_i2c_plat_remove,
+	.driver		= {
+		.name	= "bt1-sys-i2c",
+		.of_match_table = bt1_i2c_of_match,
+		.pm	= &i2c_dw_plat_dev_pm_ops,
+	},
+};
+module_platform_driver(bt1_i2c_driver);
+
+MODULE_AUTHOR("Serge Semin <Sergey.Semin@baikalelectronics.ru>");
+MODULE_DESCRIPTION("Baikal-T1 System I2C Controller");
+MODULE_LICENSE("GPL v2");
-- 
2.25.1

Re: [PATCH v2 02/12] dt-bindings: i2c: Convert DW I2C binding to DT schema

[Rob Herring]

On Sun, May 10, 2020 at 12:50:08PM +0300, Serge Semin wrote:
> Modern device tree bindings are supposed to be created as YAML-files
> in accordance with dt-schema. This commit replaces Synopsys DW I2C
> legacy bare text bindings with YAML file. As before the bindings file
> states that the corresponding dts node is supposed to be compatible
> either with generic DW I2C controller or with Microsemi Ocelot SoC I2C
> one, to have registers, interrupts and clocks properties. In addition
> the node may have clock-frequency, i2c-sda-hold-time-ns,
> i2c-scl-falling-time-ns and i2c-sda-falling-time-ns optional properties.
> 
> Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
> Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
> Cc: Paul Burton <paulburton@kernel.org>
> Cc: Ralf Baechle <ralf@linux-mips.org>
> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
> Cc: Wolfram Sang <wsa@the-dreams.de>
> Cc: Frank Rowand <frowand.list@gmail.com>
> Cc: linux-mips@vger.kernel.org
> 
> ---
> 
> Changelog v2:
> - Make sure that "mscc,ocelot-i2c" compatible node may have up to two
>   registers space defined, while normal DW I2C controller will have only
>   one registers space.
> - Add "mscc,ocelot-i2c" example to test the previous fix.
> - Declare "unevaluatedProperties" property instead of
>   "additionalProperties" one.
> - Due to the previous fix we can now discard the dummy boolean properties
>   definitions, since the proper type evaluation will be performed by the
>   generic i2c-controller.yaml schema.
> ---
>  .../bindings/i2c/i2c-designware.txt           |  73 ---------
>  .../bindings/i2c/snps,designware-i2c.yaml     | 154 ++++++++++++++++++
>  2 files changed, 154 insertions(+), 73 deletions(-)
>  delete mode 100644 Documentation/devicetree/bindings/i2c/i2c-designware.txt
>  create mode 100644 Documentation/devicetree/bindings/i2c/snps,designware-i2c.yaml
> 
> diff --git a/Documentation/devicetree/bindings/i2c/i2c-designware.txt b/Documentation/devicetree/bindings/i2c/i2c-designware.txt
> deleted file mode 100644
> index 08be4d3846e5..000000000000
> --- a/Documentation/devicetree/bindings/i2c/i2c-designware.txt
> +++ /dev/null
> @@ -1,73 +0,0 @@
> -* Synopsys DesignWare I2C
> -
> -Required properties :
> -
> - - compatible : should be "snps,designware-i2c"
> -                or "mscc,ocelot-i2c" with "snps,designware-i2c" for fallback
> - - reg : Offset and length of the register set for the device
> - - interrupts : <IRQ> where IRQ is the interrupt number.
> - - clocks : phandles for the clocks, see the description of clock-names below.
> -   The phandle for the "ic_clk" clock is required. The phandle for the "pclk"
> -   clock is optional. If a single clock is specified but no clock-name, it is
> -   the "ic_clk" clock. If both clocks are listed, the "ic_clk" must be first.
> -
> -Recommended properties :
> -
> - - clock-frequency : desired I2C bus clock frequency in Hz.
> -
> -Optional properties :
> -
> - - clock-names : Contains the names of the clocks:
> -    "ic_clk", for the core clock used to generate the external I2C clock.
> -    "pclk", the interface clock, required for register access.
> -
> - - reg : for "mscc,ocelot-i2c", a second register set to configure the SDA hold
> -   time, named ICPU_CFG:TWI_DELAY in the datasheet.
> -
> - - i2c-sda-hold-time-ns : should contain the SDA hold time in nanoseconds.
> -   This option is only supported in hardware blocks version 1.11a or newer and
> -   on Microsemi SoCs ("mscc,ocelot-i2c" compatible).
> -
> - - i2c-scl-falling-time-ns : should contain the SCL falling time in nanoseconds.
> -   This value which is by default 300ns is used to compute the tLOW period.
> -
> - - i2c-sda-falling-time-ns : should contain the SDA falling time in nanoseconds.
> -   This value which is by default 300ns is used to compute the tHIGH period.
> -
> -Examples :
> -
> -	i2c@f0000 {
> -		#address-cells = <1>;
> -		#size-cells = <0>;
> -		compatible = "snps,designware-i2c";
> -		reg = <0xf0000 0x1000>;
> -		interrupts = <11>;
> -		clock-frequency = <400000>;
> -	};
> -
> -	i2c@1120000 {
> -		#address-cells = <1>;
> -		#size-cells = <0>;
> -		compatible = "snps,designware-i2c";
> -		reg = <0x1120000 0x1000>;
> -		interrupt-parent = <&ictl>;
> -		interrupts = <12 1>;
> -		clock-frequency = <400000>;
> -		i2c-sda-hold-time-ns = <300>;
> -		i2c-sda-falling-time-ns = <300>;
> -		i2c-scl-falling-time-ns = <300>;
> -	};
> -
> -	i2c@1120000 {
> -		#address-cells = <1>;
> -		#size-cells = <0>;
> -		reg = <0x2000 0x100>;
> -		clock-frequency = <400000>;
> -		clocks = <&i2cclk>;
> -		interrupts = <0>;
> -
> -		eeprom@64 {
> -			compatible = "linux,slave-24c02";
> -			reg = <0x40000064>;
> -		};
> -	};
> diff --git a/Documentation/devicetree/bindings/i2c/snps,designware-i2c.yaml b/Documentation/devicetree/bindings/i2c/snps,designware-i2c.yaml
> new file mode 100644
> index 000000000000..8d4e5fccbd1c
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/i2c/snps,designware-i2c.yaml
> @@ -0,0 +1,154 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/i2c/snps,designware-i2c.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Synopsys DesignWare APB I2C Controller
> +
> +maintainers:
> +  - Jarkko Nikula <jarkko.nikula@linux.intel.com>
> +
> +allOf:
> +  - $ref: /schemas/i2c/i2c-controller.yaml#
> +  - if:
> +      properties:
> +        compatible:
> +          not:
> +            contains:
> +              const: mscc,ocelot-i2c
> +    then:
> +      properties:
> +        reg:
> +          maxItems: 1
> +
> +properties:
> +  compatible:
> +    oneOf:
> +      - description: Generic Synopsys DesignWare I2C controller
> +        const: snps,designware-i2c
> +      - description: Microsemi Ocelot SoCs I2C controller
> +        items:
> +          - const: mscc,ocelot-i2c
> +          - const: snps,designware-i2c
> +
> +  reg:
> +    minItems: 1
> +    items:
> +      - description: DW APB I2C controller memory mapped registers
> +      - description: |
> +          ICPU_CFG:TWI_DELAY registers to setup the SDA hold time.
> +          This registers are specific to the Ocelot I2C-controller.
> +
> +  interrupts:
> +    maxItems: 1
> +
> +  clocks:
> +    minItems: 1
> +    items:
> +      - description: I2C controller reference clock source
> +      - description: APB interface clock source
> +
> +  clock-names:
> +    minItems: 1
> +    items:
> +      - const: ref
> +      - const: pclk
> +
> +  resets:
> +    maxItems: 1
> +
> +  clock-frequency:
> +    description: Desired I2C bus clock frequency in Hz
> +    enum: [100000, 400000, 1000000, 3400000]
> +    default: 400000
> +
> +  i2c-sda-hold-time-ns:
> +    $ref: /schemas/types.yaml#/definitions/uint32

Don't need a type ref as properties with a unit-suffix already have one.

> +    description: |
> +      The property should contain the SDA hold time in nanoseconds. This option
> +      is only supported in hardware blocks version 1.11a or newer or on
> +      Microsemi SoCs.
> +
> +  i2c-scl-falling-time-ns:
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    description: |
> +      The property should contain the SCL falling time in nanoseconds.
> +      This value is used to compute the tLOW period.
> +    default: 300
> +
> +  i2c-sda-falling-time-ns:
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    description: |
> +      The property should contain the SDA falling time in nanoseconds.
> +      This value is used to compute the tHIGH period.
> +    default: 300
> +
> +  dmas:
> +    items:
> +      - description: TX DMA Channel
> +      - description: RX DMA Channel
> +
> +  dma-names:
> +    items:
> +      - const: tx
> +      - const: rx
> +
> +unevaluatedProperties: false
> +
> +required:
> +  - compatible
> +  - reg
> +  - "#address-cells"
> +  - "#size-cells"
> +  - interrupts
> +
> +examples:
> +  - |
> +    i2c@f0000 {
> +      compatible = "snps,designware-i2c";
> +      reg = <0xf0000 0x1000>;
> +      #address-cells = <1>;
> +      #size-cells = <0>;
> +      interrupts = <11>;
> +      clock-frequency = <400000>;
> +    };
> +  - |
> +    i2c@1120000 {
> +      compatible = "snps,designware-i2c";
> +      reg = <0x1120000 0x1000>;
> +      #address-cells = <1>;
> +      #size-cells = <0>;
> +      interrupts = <12 1>;
> +      clock-frequency = <400000>;
> +      i2c-sda-hold-time-ns = <300>;
> +      i2c-sda-falling-time-ns = <300>;
> +      i2c-scl-falling-time-ns = <300>;
> +    };
> +  - |
> +    i2c@2000 {
> +      compatible = "snps,designware-i2c";
> +      reg = <0x2000 0x100>;
> +      #address-cells = <1>;
> +      #size-cells = <0>;
> +      clock-frequency = <400000>;
> +      clocks = <&i2cclk>;
> +      interrupts = <0>;
> +
> +      eeprom@64 {
> +        compatible = "linux,slave-24c02";
> +        reg = <0x40000064>;

This causes 'make dt_binding_check' to fail. The unit-address should be 
'40000064'. However, there's a bug in dtc not liking the high bits set 
either. There's a fix pending, but I'd just fix the example here to 
avoid the issue. 

> +      };
> +    };
> +  - |
> +    i2c@100400 {
> +      compatible = "mscc,ocelot-i2c", "snps,designware-i2c";
> +      reg = <0x100400 0x100>, <0x198 0x8>;
> +      pinctrl-0 = <&i2c_pins>;
> +      pinctrl-names = "default";
> +      #address-cells = <1>;
> +      #size-cells = <0>;
> +      interrupts = <8>;
> +      clocks = <&ahb_clk>;
> +    };
> +...
> -- 
> 2.25.1
> 

Re: [PATCH v2 02/12] dt-bindings: i2c: Convert DW I2C binding to DT schema

[Serge Semin]

On Mon, May 11, 2020 at 11:09:24AM -0500, Rob Herring wrote:
> On Sun, May 10, 2020 at 12:50:08PM +0300, Serge Semin wrote:
> > Modern device tree bindings are supposed to be created as YAML-files
> > in accordance with dt-schema. This commit replaces Synopsys DW I2C
> > legacy bare text bindings with YAML file. As before the bindings file
> > states that the corresponding dts node is supposed to be compatible
> > either with generic DW I2C controller or with Microsemi Ocelot SoC I2C
> > one, to have registers, interrupts and clocks properties. In addition
> > the node may have clock-frequency, i2c-sda-hold-time-ns,
> > i2c-scl-falling-time-ns and i2c-sda-falling-time-ns optional properties.
> > 
> > Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
> > Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
> > Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
> > Cc: Paul Burton <paulburton@kernel.org>
> > Cc: Ralf Baechle <ralf@linux-mips.org>
> > Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> > Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
> > Cc: Wolfram Sang <wsa@the-dreams.de>
> > Cc: Frank Rowand <frowand.list@gmail.com>
> > Cc: linux-mips@vger.kernel.org
> > 
> > ---
> > 
> > Changelog v2:
> > - Make sure that "mscc,ocelot-i2c" compatible node may have up to two
> >   registers space defined, while normal DW I2C controller will have only
> >   one registers space.
> > - Add "mscc,ocelot-i2c" example to test the previous fix.
> > - Declare "unevaluatedProperties" property instead of
> >   "additionalProperties" one.
> > - Due to the previous fix we can now discard the dummy boolean properties
> >   definitions, since the proper type evaluation will be performed by the
> >   generic i2c-controller.yaml schema.
> > ---
> >  .../bindings/i2c/i2c-designware.txt           |  73 ---------
> >  .../bindings/i2c/snps,designware-i2c.yaml     | 154 ++++++++++++++++++
> >  2 files changed, 154 insertions(+), 73 deletions(-)
> >  delete mode 100644 Documentation/devicetree/bindings/i2c/i2c-designware.txt
> >  create mode 100644 Documentation/devicetree/bindings/i2c/snps,designware-i2c.yaml
> > 
> > diff --git a/Documentation/devicetree/bindings/i2c/i2c-designware.txt b/Documentation/devicetree/bindings/i2c/i2c-designware.txt
> > deleted file mode 100644
> > index 08be4d3846e5..000000000000
> > --- a/Documentation/devicetree/bindings/i2c/i2c-designware.txt
> > +++ /dev/null
> > @@ -1,73 +0,0 @@
> > -* Synopsys DesignWare I2C
> > -
> > -Required properties :
> > -
> > - - compatible : should be "snps,designware-i2c"
> > -                or "mscc,ocelot-i2c" with "snps,designware-i2c" for fallback
> > - - reg : Offset and length of the register set for the device
> > - - interrupts : <IRQ> where IRQ is the interrupt number.
> > - - clocks : phandles for the clocks, see the description of clock-names below.
> > -   The phandle for the "ic_clk" clock is required. The phandle for the "pclk"
> > -   clock is optional. If a single clock is specified but no clock-name, it is
> > -   the "ic_clk" clock. If both clocks are listed, the "ic_clk" must be first.
> > -
> > -Recommended properties :
> > -
> > - - clock-frequency : desired I2C bus clock frequency in Hz.
> > -
> > -Optional properties :
> > -
> > - - clock-names : Contains the names of the clocks:
> > -    "ic_clk", for the core clock used to generate the external I2C clock.
> > -    "pclk", the interface clock, required for register access.
> > -
> > - - reg : for "mscc,ocelot-i2c", a second register set to configure the SDA hold
> > -   time, named ICPU_CFG:TWI_DELAY in the datasheet.
> > -
> > - - i2c-sda-hold-time-ns : should contain the SDA hold time in nanoseconds.
> > -   This option is only supported in hardware blocks version 1.11a or newer and
> > -   on Microsemi SoCs ("mscc,ocelot-i2c" compatible).
> > -
> > - - i2c-scl-falling-time-ns : should contain the SCL falling time in nanoseconds.
> > -   This value which is by default 300ns is used to compute the tLOW period.
> > -
> > - - i2c-sda-falling-time-ns : should contain the SDA falling time in nanoseconds.
> > -   This value which is by default 300ns is used to compute the tHIGH period.
> > -
> > -Examples :
> > -
> > -	i2c@f0000 {
> > -		#address-cells = <1>;
> > -		#size-cells = <0>;
> > -		compatible = "snps,designware-i2c";
> > -		reg = <0xf0000 0x1000>;
> > -		interrupts = <11>;
> > -		clock-frequency = <400000>;
> > -	};
> > -
> > -	i2c@1120000 {
> > -		#address-cells = <1>;
> > -		#size-cells = <0>;
> > -		compatible = "snps,designware-i2c";
> > -		reg = <0x1120000 0x1000>;
> > -		interrupt-parent = <&ictl>;
> > -		interrupts = <12 1>;
> > -		clock-frequency = <400000>;
> > -		i2c-sda-hold-time-ns = <300>;
> > -		i2c-sda-falling-time-ns = <300>;
> > -		i2c-scl-falling-time-ns = <300>;
> > -	};
> > -
> > -	i2c@1120000 {
> > -		#address-cells = <1>;
> > -		#size-cells = <0>;
> > -		reg = <0x2000 0x100>;
> > -		clock-frequency = <400000>;
> > -		clocks = <&i2cclk>;
> > -		interrupts = <0>;
> > -
> > -		eeprom@64 {
> > -			compatible = "linux,slave-24c02";
> > -			reg = <0x40000064>;
> > -		};
> > -	};
> > diff --git a/Documentation/devicetree/bindings/i2c/snps,designware-i2c.yaml b/Documentation/devicetree/bindings/i2c/snps,designware-i2c.yaml
> > new file mode 100644
> > index 000000000000..8d4e5fccbd1c
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/i2c/snps,designware-i2c.yaml
> > @@ -0,0 +1,154 @@
> > +# SPDX-License-Identifier: GPL-2.0-only
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/i2c/snps,designware-i2c.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: Synopsys DesignWare APB I2C Controller
> > +
> > +maintainers:
> > +  - Jarkko Nikula <jarkko.nikula@linux.intel.com>
> > +
> > +allOf:
> > +  - $ref: /schemas/i2c/i2c-controller.yaml#
> > +  - if:
> > +      properties:
> > +        compatible:
> > +          not:
> > +            contains:
> > +              const: mscc,ocelot-i2c
> > +    then:
> > +      properties:
> > +        reg:
> > +          maxItems: 1
> > +
> > +properties:
> > +  compatible:
> > +    oneOf:
> > +      - description: Generic Synopsys DesignWare I2C controller
> > +        const: snps,designware-i2c
> > +      - description: Microsemi Ocelot SoCs I2C controller
> > +        items:
> > +          - const: mscc,ocelot-i2c
> > +          - const: snps,designware-i2c
> > +
> > +  reg:
> > +    minItems: 1
> > +    items:
> > +      - description: DW APB I2C controller memory mapped registers
> > +      - description: |
> > +          ICPU_CFG:TWI_DELAY registers to setup the SDA hold time.
> > +          This registers are specific to the Ocelot I2C-controller.
> > +
> > +  interrupts:
> > +    maxItems: 1
> > +
> > +  clocks:
> > +    minItems: 1
> > +    items:
> > +      - description: I2C controller reference clock source
> > +      - description: APB interface clock source
> > +
> > +  clock-names:
> > +    minItems: 1
> > +    items:
> > +      - const: ref
> > +      - const: pclk
> > +
> > +  resets:
> > +    maxItems: 1
> > +
> > +  clock-frequency:
> > +    description: Desired I2C bus clock frequency in Hz
> > +    enum: [100000, 400000, 1000000, 3400000]
> > +    default: 400000
> > +
> > +  i2c-sda-hold-time-ns:
> > +    $ref: /schemas/types.yaml#/definitions/uint32
> 
> Don't need a type ref as properties with a unit-suffix already have one.

Ok. Seeing "-ns" suffixed properties have uint32-array type I'll have to add the
restriction "maxItems: 1" here then.

> 
> > +    description: |
> > +      The property should contain the SDA hold time in nanoseconds. This option
> > +      is only supported in hardware blocks version 1.11a or newer or on
> > +      Microsemi SoCs.
> > +
> > +  i2c-scl-falling-time-ns:
> > +    $ref: /schemas/types.yaml#/definitions/uint32
> > +    description: |
> > +      The property should contain the SCL falling time in nanoseconds.
> > +      This value is used to compute the tLOW period.
> > +    default: 300
> > +
> > +  i2c-sda-falling-time-ns:
> > +    $ref: /schemas/types.yaml#/definitions/uint32
> > +    description: |
> > +      The property should contain the SDA falling time in nanoseconds.
> > +      This value is used to compute the tHIGH period.
> > +    default: 300
> > +
> > +  dmas:
> > +    items:
> > +      - description: TX DMA Channel
> > +      - description: RX DMA Channel
> > +
> > +  dma-names:
> > +    items:
> > +      - const: tx
> > +      - const: rx
> > +
> > +unevaluatedProperties: false
> > +
> > +required:
> > +  - compatible
> > +  - reg
> > +  - "#address-cells"
> > +  - "#size-cells"
> > +  - interrupts
> > +
> > +examples:
> > +  - |
> > +    i2c@f0000 {
> > +      compatible = "snps,designware-i2c";
> > +      reg = <0xf0000 0x1000>;
> > +      #address-cells = <1>;
> > +      #size-cells = <0>;
> > +      interrupts = <11>;
> > +      clock-frequency = <400000>;
> > +    };
> > +  - |
> > +    i2c@1120000 {
> > +      compatible = "snps,designware-i2c";
> > +      reg = <0x1120000 0x1000>;
> > +      #address-cells = <1>;
> > +      #size-cells = <0>;
> > +      interrupts = <12 1>;
> > +      clock-frequency = <400000>;
> > +      i2c-sda-hold-time-ns = <300>;
> > +      i2c-sda-falling-time-ns = <300>;
> > +      i2c-scl-falling-time-ns = <300>;
> > +    };
> > +  - |
> > +    i2c@2000 {
> > +      compatible = "snps,designware-i2c";
> > +      reg = <0x2000 0x100>;
> > +      #address-cells = <1>;
> > +      #size-cells = <0>;
> > +      clock-frequency = <400000>;
> > +      clocks = <&i2cclk>;
> > +      interrupts = <0>;
> > +
> > +      eeprom@64 {
> > +        compatible = "linux,slave-24c02";
> > +        reg = <0x40000064>;
> 
> This causes 'make dt_binding_check' to fail. The unit-address should be 
> '40000064'. However, there's a bug in dtc not liking the high bits set 
> either. There's a fix pending, but I'd just fix the example here to 
> avoid the issue. 

Do you mean a fix suggested in this patchset or someplace else? I've submitted
it before this patch so to solve the problem you've discovered.

Regarding the example. Do you suggest to completely remove the eeprom
sub-node? I am asking because without proper reg flags setting the i2c-slave
mode example would be just wrong.

-Sergey

> 
> > +      };
> > +    };
> > +  - |
> > +    i2c@100400 {
> > +      compatible = "mscc,ocelot-i2c", "snps,designware-i2c";
> > +      reg = <0x100400 0x100>, <0x198 0x8>;
> > +      pinctrl-0 = <&i2c_pins>;
> > +      pinctrl-names = "default";
> > +      #address-cells = <1>;
> > +      #size-cells = <0>;
> > +      interrupts = <8>;
> > +      clocks = <&ahb_clk>;
> > +    };
> > +...
> > -- 
> > 2.25.1
> > 

Re: [PATCH v2 03/12] dt-bindings: i2c: dw: Add Baikal-T1 SoC I2C controller

[Rob Herring]

On Sun, May 10, 2020 at 12:50:09PM +0300, Serge Semin wrote:
> Add the "baikal,bt1-sys-i2c" compatible string to the DW I2C binding and
> make sure the reg property isn't required in this case because the
> controller is embedded into the Baikal-T1 System Controller. The rest of
> the DW APB I2C properties are compatible and can be freely used to describe
> the Baikal-T1 I2C controller dts-node.

Is there not a sub-range of the system controller with the I2C 
registers? I'd assume there is, so you can still have 'reg' even if 
Linux doesn't use it (currently).

> 
> Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
> Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
> Cc: Paul Burton <paulburton@kernel.org>
> Cc: Ralf Baechle <ralf@linux-mips.org>
> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
> Cc: Wolfram Sang <wsa@the-dreams.de>
> Cc: Frank Rowand <frowand.list@gmail.com>
> Cc: linux-mips@vger.kernel.org
> 
> ---
> 
> Rob, I had to remove your acked-by tag because of the changes introduced
> in v2 of the patch.
> 
> Changelog v2:
> - Make the reg property being optional if it's Baikal-T1 System I2C DT
>   node.
> ---
>  .../devicetree/bindings/i2c/snps,designware-i2c.yaml | 12 +++++++++++-
>  1 file changed, 11 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/devicetree/bindings/i2c/snps,designware-i2c.yaml b/Documentation/devicetree/bindings/i2c/snps,designware-i2c.yaml
> index 8d4e5fccbd1c..579964098eb9 100644
> --- a/Documentation/devicetree/bindings/i2c/snps,designware-i2c.yaml
> +++ b/Documentation/devicetree/bindings/i2c/snps,designware-i2c.yaml
> @@ -21,6 +21,15 @@ allOf:
>        properties:
>          reg:
>            maxItems: 1
> +  - if:
> +      properties:
> +        compatible:
> +          not:
> +            contains:
> +              const: baikal,bt1-sys-i2c
> +    then:
> +      required:
> +        - reg
>  
>  properties:
>    compatible:
> @@ -31,6 +40,8 @@ properties:
>          items:
>            - const: mscc,ocelot-i2c
>            - const: snps,designware-i2c
> +      - description: Baikal-T1 SoC System I2C controller
> +        const: baikal,bt1-sys-i2c
>  
>    reg:
>      minItems: 1
> @@ -98,7 +109,6 @@ unevaluatedProperties: false
>  
>  required:
>    - compatible
> -  - reg
>    - "#address-cells"
>    - "#size-cells"
>    - interrupts
> -- 
> 2.25.1
> 

Re: [PATCH v2 03/12] dt-bindings: i2c: dw: Add Baikal-T1 SoC I2C controller

[Serge Semin]

On Mon, May 18, 2020 at 02:33:19PM -0600, Rob Herring wrote:
> On Sun, May 10, 2020 at 12:50:09PM +0300, Serge Semin wrote:
> > Add the "baikal,bt1-sys-i2c" compatible string to the DW I2C binding and
> > make sure the reg property isn't required in this case because the
> > controller is embedded into the Baikal-T1 System Controller. The rest of
> > the DW APB I2C properties are compatible and can be freely used to describe
> > the Baikal-T1 I2C controller dts-node.
> 
> Is there not a sub-range of the system controller with the I2C 
> registers? I'd assume there is, so you can still have 'reg' even if 
> Linux doesn't use it (currently).

Yes, there is a range. It's just three access registers. Is it wrong to make the
reg property being optional in this case since it can be accessed over syscon
regmap? Do you suggest to get back the reg property being required for our
device?

-Sergey

> 
> > 
> > Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
> > Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
> > Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
> > Cc: Paul Burton <paulburton@kernel.org>
> > Cc: Ralf Baechle <ralf@linux-mips.org>
> > Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> > Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
> > Cc: Wolfram Sang <wsa@the-dreams.de>
> > Cc: Frank Rowand <frowand.list@gmail.com>
> > Cc: linux-mips@vger.kernel.org
> > 
> > ---
> > 
> > Rob, I had to remove your acked-by tag because of the changes introduced
> > in v2 of the patch.
> > 
> > Changelog v2:
> > - Make the reg property being optional if it's Baikal-T1 System I2C DT
> >   node.
> > ---
> >  .../devicetree/bindings/i2c/snps,designware-i2c.yaml | 12 +++++++++++-
> >  1 file changed, 11 insertions(+), 1 deletion(-)
> > 
> > diff --git a/Documentation/devicetree/bindings/i2c/snps,designware-i2c.yaml b/Documentation/devicetree/bindings/i2c/snps,designware-i2c.yaml
> > index 8d4e5fccbd1c..579964098eb9 100644
> > --- a/Documentation/devicetree/bindings/i2c/snps,designware-i2c.yaml
> > +++ b/Documentation/devicetree/bindings/i2c/snps,designware-i2c.yaml
> > @@ -21,6 +21,15 @@ allOf:
> >        properties:
> >          reg:
> >            maxItems: 1
> > +  - if:
> > +      properties:
> > +        compatible:
> > +          not:
> > +            contains:
> > +              const: baikal,bt1-sys-i2c
> > +    then:
> > +      required:
> > +        - reg
> >  
> >  properties:
> >    compatible:
> > @@ -31,6 +40,8 @@ properties:
> >          items:
> >            - const: mscc,ocelot-i2c
> >            - const: snps,designware-i2c
> > +      - description: Baikal-T1 SoC System I2C controller
> > +        const: baikal,bt1-sys-i2c
> >  
> >    reg:
> >      minItems: 1
> > @@ -98,7 +109,6 @@ unevaluatedProperties: false
> >  
> >  required:
> >    - compatible
> > -  - reg
> >    - "#address-cells"
> >    - "#size-cells"
> >    - interrupts
> > -- 
> > 2.25.1
> > 

Re: [PATCH v2 06/12] i2c: designware: slave: Set DW I2C core module dependency

[Jarkko Nikula]

On 5/10/20 12:50 PM, Serge Semin wrote:
> DW APB I2C slave code in fact depends on the DW I2C driver core, but not
> on the platform code. Yes, the I2C slave interface is currently supported
> by the platform version of the IP core, but it doesn't make it dependent
> on it. So make sure the DW APB I2C slave config is only available if the
> I2C_DESIGNWARE_CORE config is enabled.
> 
> Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
> Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
> Cc: Paul Burton <paulburton@kernel.org>
> Cc: Ralf Baechle <ralf@linux-mips.org>
> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
> Cc: Wolfram Sang <wsa@the-dreams.de>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: Frank Rowand <frowand.list@gmail.com>
> Cc: linux-mips@vger.kernel.org
> Cc: devicetree@vger.kernel.org
> ---
>   drivers/i2c/busses/Kconfig | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>

Re: [PATCH v2 05/12] i2c: designware: Use `-y` to build multi-object modules

[Jarkko Nikula]

On 5/10/20 12:50 PM, Serge Semin wrote:
> Since commit 4f8272802739 ("Documentation: update kbuild loadable modules
> goals & examples") `-objs` is fitted for building host programs, lets
> change DW I2C core, platform and PCI driver kbuild directives to using
> `-y`, which more straightforward for device drivers. By doing so we can
> discard the ifeq construction in favor to the more natural and less bulky
> `<module>-$(CONFIG_X) += x.o`
> 
> Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
> Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
> Cc: Paul Burton <paulburton@kernel.org>
> Cc: Ralf Baechle <ralf@linux-mips.org>
> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
> Cc: Wolfram Sang <wsa@the-dreams.de>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: Frank Rowand <frowand.list@gmail.com>
> Cc: linux-mips@vger.kernel.org
> Cc: devicetree@vger.kernel.org
> ---
>   drivers/i2c/busses/Makefile | 17 ++++++++---------
>   1 file changed, 8 insertions(+), 9 deletions(-)
> 
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>

Re: [PATCH v2 04/12] i2c: designware: Convert driver to using regmap API

[Jarkko Nikula]

On 5/10/20 12:50 PM, Serge Semin wrote:
> Seeing the DW I2C driver is using flags-based accessors with two
> conditional clauses it would be better to replace them with the regmap
> API IO methods and to initialize the regmap object with read/write
> callbacks specific to the controller registers map implementation. This
> will be also handy for the drivers with non-standard registers mapping
> (like an embedded into the Baikal-T1 System Controller DW I2C block, which
> glue-driver is a part of this series).
> 
> As before the driver tries to detect the mapping setup at probe stage and
> creates a regmap object accordingly, which will be used by the rest of the
> code to correctly access the controller registers. In two places it was
> appropriate to convert the hand-written read-modify-write and
> read-poll-loop design patterns to the corresponding regmap API
> ready-to-use methods.
> 
> Note the regmap IO methods return value is checked only at the probe
> stage. The rest of the code won't do this because basically we have
> MMIO-based regmap so non of the read/write methods can fail (this also
> won't be needed for the Baikal-T1-specific I2C controller).
> 
> Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
> Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
> Cc: Paul Burton <paulburton@kernel.org>
> Cc: Ralf Baechle <ralf@linux-mips.org>
> Cc: Wolfram Sang <wsa@the-dreams.de>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: Frank Rowand <frowand.list@gmail.com>
> Cc: devicetree@vger.kernel.org
> Cc: linux-mips@vger.kernel.org
> ---
>   drivers/i2c/busses/Kconfig                 |   1 +
>   drivers/i2c/busses/i2c-designware-common.c | 171 +++++++++++++++------
>   drivers/i2c/busses/i2c-designware-core.h   |  18 +--
>   drivers/i2c/busses/i2c-designware-master.c | 125 ++++++++-------
>   drivers/i2c/busses/i2c-designware-slave.c  |  77 +++++-----
>   5 files changed, 239 insertions(+), 153 deletions(-)
> 
Looking at patches 4/12-12/12 I think it would be good to move fixes and 
less invasive patches before this. Like

i2c: designware: slave: Set DW I2C core module dependency
i2c: designware: Use `-y` to build multi-object modules
i2c: designware: Move Baytrail sem config to the platform if-clause

That said, you may add:

Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>

Re: [PATCH v2 07/12] i2c: designware: Move Baytrail sem config to the platform if-clause

[Jarkko Nikula]

On 5/10/20 12:50 PM, Serge Semin wrote:
> Currently Intel Baytrail I2C semaphore is a feature of the DW APB I2C
> platform driver. It's a bit confusing to see it's config in the menu at
> some separated place with no reference to the platform code. Lets move the
> config definition under the if-I2C_DESIGNWARE_PLATFORM clause. By doing so
> the config menu will display the feature right below the DW I2C platform
> driver item and will indent it to the right so signifying its belonging.
> 
> Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
> Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
> Cc: Paul Burton <paulburton@kernel.org>
> Cc: Ralf Baechle <ralf@linux-mips.org>
> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
> Cc: Wolfram Sang <wsa@the-dreams.de>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: Frank Rowand <frowand.list@gmail.com>
> Cc: linux-mips@vger.kernel.org
> Cc: devicetree@vger.kernel.org
> ---
>   drivers/i2c/busses/Kconfig | 30 +++++++++++++++++-------------
>   1 file changed, 17 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
> index 368aa64e9266..ed6927c4c540 100644
> --- a/drivers/i2c/busses/Kconfig
> +++ b/drivers/i2c/busses/Kconfig
> @@ -530,8 +530,8 @@ config I2C_DESIGNWARE_CORE
>   
>   config I2C_DESIGNWARE_PLATFORM
>   	tristate "Synopsys DesignWare Platform"
> -	select I2C_DESIGNWARE_CORE
>   	depends on (ACPI && COMMON_CLK) || !ACPI
> +	select I2C_DESIGNWARE_CORE
>   	help
>   	  If you say yes to this option, support will be included for the
>   	  Synopsys DesignWare I2C adapter.
> @@ -539,6 +539,22 @@ config I2C_DESIGNWARE_PLATFORM
>   	  This driver can also be built as a module.  If so, the module
>   	  will be called i2c-designware-platform.
>   
> +if I2C_DESIGNWARE_PLATFORM
> +
> +config I2C_DESIGNWARE_BAYTRAIL
> +	bool "Intel Baytrail I2C semaphore support"
> +	depends on ACPI
> +	depends on (I2C_DESIGNWARE_PLATFORM=m && IOSF_MBI) || \
> +		   (I2C_DESIGNWARE_PLATFORM=y && IOSF_MBI=y)
> +	help
> +	  This driver enables managed host access to the PMIC I2C bus on select
> +	  Intel BayTrail platforms using the X-Powers AXP288 PMIC. It allows
> +	  the host to request uninterrupted access to the PMIC's I2C bus from
> +	  the platform firmware controlling it. You should say Y if running on
> +	  a BayTrail system using the AXP288.
> +
> +endif # I2C_DESIGNWARE_PLATFORM
> +

Is the added "if I2C_DESIGNWARE_PLATFORM" needed here? Should the 
"depends on" be enough?

Jarkko

Re: [PATCH v2 10/12] i2c: designware: Discard Cherry Trail model flag

[Jarkko Nikula]

On 5/10/20 12:50 PM, Serge Semin wrote:
> A PM workaround activated by the flag MODEL_CHERRYTRAIL has been removed
> since commit 9cbeeca05049 ("i2c: designware: Remove Cherry Trail PMIC I2C
> bus pm_disabled workaround"), but the flag most likely by mistake has been
> left in the Dw I2C drivers. Lets remove it.
> 
> By doing so we get rid from the last DW APB I2C IP-core model flag, so we
> can remove the MODEL_MASK macro too.
> 
> Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
> Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
> Cc: Paul Burton <paulburton@kernel.org>
> Cc: Ralf Baechle <ralf@linux-mips.org>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: Frank Rowand <frowand.list@gmail.com>
> Cc: linux-mips@vger.kernel.org
> Cc: devicetree@vger.kernel.org
> ---
>   drivers/i2c/busses/i2c-designware-core.h    | 3 ---
>   drivers/i2c/busses/i2c-designware-pcidrv.c  | 1 -
>   drivers/i2c/busses/i2c-designware-platdrv.c | 2 +-
>   3 files changed, 1 insertion(+), 5 deletions(-)
> 
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>

Re: [PATCH v2 08/12] i2c: designware: Introduce platform drivers glue layer interface

[Jarkko Nikula]

Hi

On 5/10/20 12:50 PM, Serge Semin wrote:
> Seeing the DW I2C platform driver is getting overcomplicated with a lot of
> vendor-specific configs let's introduce a glue-layer interface so new
> platforms which equipped with Synopsys Designware APB I2C IP-core would
> be able to handle their peculiarities in the dedicated objects.
> 
Comment to this patch and patches 9/12 and 12/12:

Currently i2c-designware-platdrv.c is about 500 lines of code so I don't 
think it's too overcomplicated. But I feel we have already too many 
Kconfig options and source modules for i2c-designware and obviously 
would like to push back a little from adding more.

I don't think i2c-designware-platdrv.c becomes yet too complicated if 
Baikal related code is added there, perhaps under #ifdef CONFIG_OF like 
MSCC Ocelot code is currently.

-- 
Jarkko

Re: [PATCH v2 04/12] i2c: designware: Convert driver to using regmap API

[Serge Semin]

On Wed, May 20, 2020 at 03:16:07PM +0300, Jarkko Nikula wrote:
> On 5/10/20 12:50 PM, Serge Semin wrote:
> > Seeing the DW I2C driver is using flags-based accessors with two
> > conditional clauses it would be better to replace them with the regmap
> > API IO methods and to initialize the regmap object with read/write
> > callbacks specific to the controller registers map implementation. This
> > will be also handy for the drivers with non-standard registers mapping
> > (like an embedded into the Baikal-T1 System Controller DW I2C block, which
> > glue-driver is a part of this series).
> > 
> > As before the driver tries to detect the mapping setup at probe stage and
> > creates a regmap object accordingly, which will be used by the rest of the
> > code to correctly access the controller registers. In two places it was
> > appropriate to convert the hand-written read-modify-write and
> > read-poll-loop design patterns to the corresponding regmap API
> > ready-to-use methods.
> > 
> > Note the regmap IO methods return value is checked only at the probe
> > stage. The rest of the code won't do this because basically we have
> > MMIO-based regmap so non of the read/write methods can fail (this also
> > won't be needed for the Baikal-T1-specific I2C controller).
> > 
> > Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> > Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
> > Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
> > Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
> > Cc: Paul Burton <paulburton@kernel.org>
> > Cc: Ralf Baechle <ralf@linux-mips.org>
> > Cc: Wolfram Sang <wsa@the-dreams.de>
> > Cc: Rob Herring <robh+dt@kernel.org>
> > Cc: Frank Rowand <frowand.list@gmail.com>
> > Cc: devicetree@vger.kernel.org
> > Cc: linux-mips@vger.kernel.org
> > ---
> >   drivers/i2c/busses/Kconfig                 |   1 +
> >   drivers/i2c/busses/i2c-designware-common.c | 171 +++++++++++++++------
> >   drivers/i2c/busses/i2c-designware-core.h   |  18 +--
> >   drivers/i2c/busses/i2c-designware-master.c | 125 ++++++++-------
> >   drivers/i2c/busses/i2c-designware-slave.c  |  77 +++++-----
> >   5 files changed, 239 insertions(+), 153 deletions(-)
> > 
> Looking at patches 4/12-12/12 I think it would be good to move fixes and
> less invasive patches before this. Like
> 
> i2c: designware: slave: Set DW I2C core module dependency
> i2c: designware: Use `-y` to build multi-object modules
> i2c: designware: Move Baytrail sem config to the platform if-clause
> 
> That said, you may add:
> 
> Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
> Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>

Ok. I'll move those three patches to be before this one in v3. Thanks.

-Sergey

Re: [PATCH v2 07/12] i2c: designware: Move Baytrail sem config to the platform if-clause

[Serge Semin]

On Wed, May 20, 2020 at 03:16:14PM +0300, Jarkko Nikula wrote:
> On 5/10/20 12:50 PM, Serge Semin wrote:
> > Currently Intel Baytrail I2C semaphore is a feature of the DW APB I2C
> > platform driver. It's a bit confusing to see it's config in the menu at
> > some separated place with no reference to the platform code. Lets move the
> > config definition under the if-I2C_DESIGNWARE_PLATFORM clause. By doing so
> > the config menu will display the feature right below the DW I2C platform
> > driver item and will indent it to the right so signifying its belonging.
> > 
> > Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
> > Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
> > Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
> > Cc: Paul Burton <paulburton@kernel.org>
> > Cc: Ralf Baechle <ralf@linux-mips.org>
> > Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> > Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
> > Cc: Wolfram Sang <wsa@the-dreams.de>
> > Cc: Rob Herring <robh+dt@kernel.org>
> > Cc: Frank Rowand <frowand.list@gmail.com>
> > Cc: linux-mips@vger.kernel.org
> > Cc: devicetree@vger.kernel.org
> > ---
> >   drivers/i2c/busses/Kconfig | 30 +++++++++++++++++-------------
> >   1 file changed, 17 insertions(+), 13 deletions(-)
> > 
> > diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
> > index 368aa64e9266..ed6927c4c540 100644
> > --- a/drivers/i2c/busses/Kconfig
> > +++ b/drivers/i2c/busses/Kconfig
> > @@ -530,8 +530,8 @@ config I2C_DESIGNWARE_CORE
> >   config I2C_DESIGNWARE_PLATFORM
> >   	tristate "Synopsys DesignWare Platform"
> > -	select I2C_DESIGNWARE_CORE
> >   	depends on (ACPI && COMMON_CLK) || !ACPI
> > +	select I2C_DESIGNWARE_CORE
> >   	help
> >   	  If you say yes to this option, support will be included for the
> >   	  Synopsys DesignWare I2C adapter.
> > @@ -539,6 +539,22 @@ config I2C_DESIGNWARE_PLATFORM
> >   	  This driver can also be built as a module.  If so, the module
> >   	  will be called i2c-designware-platform.
> > +if I2C_DESIGNWARE_PLATFORM
> > +
> > +config I2C_DESIGNWARE_BAYTRAIL
> > +	bool "Intel Baytrail I2C semaphore support"
> > +	depends on ACPI
> > +	depends on (I2C_DESIGNWARE_PLATFORM=m && IOSF_MBI) || \
> > +		   (I2C_DESIGNWARE_PLATFORM=y && IOSF_MBI=y)
> > +	help
> > +	  This driver enables managed host access to the PMIC I2C bus on select
> > +	  Intel BayTrail platforms using the X-Powers AXP288 PMIC. It allows
> > +	  the host to request uninterrupted access to the PMIC's I2C bus from
> > +	  the platform firmware controlling it. You should say Y if running on
> > +	  a BayTrail system using the AXP288.
> > +
> > +endif # I2C_DESIGNWARE_PLATFORM
> > +
> 
> Is the added "if I2C_DESIGNWARE_PLATFORM" needed here? Should the "depends
> on" be enough?

The idea was to add if-endif clause here for features possibly added sometime
in future. But using normal "depends on I2C_DESIGNWARE_PLATFORM" shall make
the config depicted as an indented sub-config as well. Would you like me to
remove the if-clause and use the depends on operator instead?

-Sergey

> 
> Jarkko

Re: [PATCH v2 08/12] i2c: designware: Introduce platform drivers glue layer interface

[Serge Semin]

On Wed, May 20, 2020 at 03:46:11PM +0300, Jarkko Nikula wrote:
> Hi
> 
> On 5/10/20 12:50 PM, Serge Semin wrote:
> > Seeing the DW I2C platform driver is getting overcomplicated with a lot of
> > vendor-specific configs let's introduce a glue-layer interface so new
> > platforms which equipped with Synopsys Designware APB I2C IP-core would
> > be able to handle their peculiarities in the dedicated objects.
> > 
> Comment to this patch and patches 9/12 and 12/12:
> 
> Currently i2c-designware-platdrv.c is about 500 lines of code so I don't
> think it's too overcomplicated. But I feel we have already too many Kconfig
> options and source modules for i2c-designware and obviously would like to
> push back a little from adding more.
> 
> I don't think i2c-designware-platdrv.c becomes yet too complicated if Baikal
> related code is added there, perhaps under #ifdef CONFIG_OF like MSCC Ocelot
> code is currently.

Well, it's up to you to decide, what solution is more suitable for you to
maintain. My idea of detaching the MSCC and Baikal-T1 code to the dedicated
source files was to eventually move the whole i2c-designware-* set of files
into a dedicated directory drivers/i2c/buses/dw as it's done for some others
Synopsys DesignWare controllers: drivers/pci/controller/dwc/, drivers/usb/dwc2,
drivers/usb/dwc3, drivers/net/ethernet/synopsys/ . If you think, that it's too
early for Dw I2C code to live in a dedicated directory, fine with me. I can
merge the MSCC and Baikal-T1 code back into the i2c-designware-platdrv.c .
So what's your final word in this matter?

-Sergey

> 
> -- 
> Jarkko

Re: [PATCH v2 07/12] i2c: designware: Move Baytrail sem config to the platform if-clause

[Jarkko Nikula]

On 5/21/20 5:22 AM, Serge Semin wrote:
> On Wed, May 20, 2020 at 03:16:14PM +0300, Jarkko Nikula wrote:
>> On 5/10/20 12:50 PM, Serge Semin wrote:
>>> Currently Intel Baytrail I2C semaphore is a feature of the DW APB I2C
>>> platform driver. It's a bit confusing to see it's config in the menu at
>>> some separated place with no reference to the platform code. Lets move the
>>> config definition under the if-I2C_DESIGNWARE_PLATFORM clause. By doing so
>>> the config menu will display the feature right below the DW I2C platform
>>> driver item and will indent it to the right so signifying its belonging.
>>>
>>> Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
>>> Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
>>> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
>>> Cc: Paul Burton <paulburton@kernel.org>
>>> Cc: Ralf Baechle <ralf@linux-mips.org>
>>> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
>>> Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
>>> Cc: Wolfram Sang <wsa@the-dreams.de>
>>> Cc: Rob Herring <robh+dt@kernel.org>
>>> Cc: Frank Rowand <frowand.list@gmail.com>
>>> Cc: linux-mips@vger.kernel.org
>>> Cc: devicetree@vger.kernel.org
>>> ---
>>>    drivers/i2c/busses/Kconfig | 30 +++++++++++++++++-------------
>>>    1 file changed, 17 insertions(+), 13 deletions(-)
>>>
>>> diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
>>> index 368aa64e9266..ed6927c4c540 100644
>>> --- a/drivers/i2c/busses/Kconfig
>>> +++ b/drivers/i2c/busses/Kconfig
>>> @@ -530,8 +530,8 @@ config I2C_DESIGNWARE_CORE
>>>    config I2C_DESIGNWARE_PLATFORM
>>>    	tristate "Synopsys DesignWare Platform"
>>> -	select I2C_DESIGNWARE_CORE
>>>    	depends on (ACPI && COMMON_CLK) || !ACPI
>>> +	select I2C_DESIGNWARE_CORE
>>>    	help
>>>    	  If you say yes to this option, support will be included for the
>>>    	  Synopsys DesignWare I2C adapter.
>>> @@ -539,6 +539,22 @@ config I2C_DESIGNWARE_PLATFORM
>>>    	  This driver can also be built as a module.  If so, the module
>>>    	  will be called i2c-designware-platform.
>>> +if I2C_DESIGNWARE_PLATFORM
>>> +
>>> +config I2C_DESIGNWARE_BAYTRAIL
>>> +	bool "Intel Baytrail I2C semaphore support"
>>> +	depends on ACPI
>>> +	depends on (I2C_DESIGNWARE_PLATFORM=m && IOSF_MBI) || \
>>> +		   (I2C_DESIGNWARE_PLATFORM=y && IOSF_MBI=y)
>>> +	help
>>> +	  This driver enables managed host access to the PMIC I2C bus on select
>>> +	  Intel BayTrail platforms using the X-Powers AXP288 PMIC. It allows
>>> +	  the host to request uninterrupted access to the PMIC's I2C bus from
>>> +	  the platform firmware controlling it. You should say Y if running on
>>> +	  a BayTrail system using the AXP288.
>>> +
>>> +endif # I2C_DESIGNWARE_PLATFORM
>>> +
>>
>> Is the added "if I2C_DESIGNWARE_PLATFORM" needed here? Should the "depends
>> on" be enough?
> 
> The idea was to add if-endif clause here for features possibly added sometime
> in future. But using normal "depends on I2C_DESIGNWARE_PLATFORM" shall make
> the config depicted as an indented sub-config as well. Would you like me to
> remove the if-clause and use the depends on operator instead?
> 
Yes, please remove it from this patch. Keeps this patch simpler and if 
some future feature needs it then that patch(set) is the right place to 
add it.

Jarkko

Re: [PATCH v2 08/12] i2c: designware: Introduce platform drivers glue layer interface

[Jarkko Nikula]

Hi

On 5/21/20 5:37 AM, Serge Semin wrote:
> On Wed, May 20, 2020 at 03:46:11PM +0300, Jarkko Nikula wrote:
>> Hi
>>
>> On 5/10/20 12:50 PM, Serge Semin wrote:
>>> Seeing the DW I2C platform driver is getting overcomplicated with a lot of
>>> vendor-specific configs let's introduce a glue-layer interface so new
>>> platforms which equipped with Synopsys Designware APB I2C IP-core would
>>> be able to handle their peculiarities in the dedicated objects.
>>>
>> Comment to this patch and patches 9/12 and 12/12:
>>
>> Currently i2c-designware-platdrv.c is about 500 lines of code so I don't
>> think it's too overcomplicated. But I feel we have already too many Kconfig
>> options and source modules for i2c-designware and obviously would like to
>> push back a little from adding more.
>>
>> I don't think i2c-designware-platdrv.c becomes yet too complicated if Baikal
>> related code is added there, perhaps under #ifdef CONFIG_OF like MSCC Ocelot
>> code is currently.
> 
> Well, it's up to you to decide, what solution is more suitable for you to
> maintain. My idea of detaching the MSCC and Baikal-T1 code to the dedicated
> source files was to eventually move the whole i2c-designware-* set of files
> into a dedicated directory drivers/i2c/buses/dw as it's done for some others
> Synopsys DesignWare controllers: drivers/pci/controller/dwc/, drivers/usb/dwc2,
> drivers/usb/dwc3, drivers/net/ethernet/synopsys/ . If you think, that it's too
> early for Dw I2C code to live in a dedicated directory, fine with me. I can
> merge the MSCC and Baikal-T1 code back into the i2c-designware-platdrv.c .
> So what's your final word in this matter?
> 
I think sub directory decision under each subsystem is more subsystem 
rather than vendor/driver specific. Good point anyway.

For this patchset I'd like more if changes are done to 
i2c-designware-platdrv.c since it's not too complicated yet :-)

If it starts to look too messy in the future then it's time split I think.

Jarkko

Re: [PATCH v2 08/12] i2c: designware: Introduce platform drivers glue layer interface

[Andy Shevchenko]

On Mon, May 25, 2020 at 04:16:05PM +0300, Jarkko Nikula wrote:
> On 5/21/20 5:37 AM, Serge Semin wrote:

> For this patchset I'd like more if changes are done to
> i2c-designware-platdrv.c since it's not too complicated yet :-)

And after moving ACPI stuff to common code, the one has even been shrunk significantly.

> If it starts to look too messy in the future then it's time split I think.

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v2 07/12] i2c: designware: Move Baytrail sem config to the platform if-clause

[Serge Semin]

On Mon, May 25, 2020 at 04:01:26PM +0300, Jarkko Nikula wrote:
> On 5/21/20 5:22 AM, Serge Semin wrote:
> > On Wed, May 20, 2020 at 03:16:14PM +0300, Jarkko Nikula wrote:
> > > On 5/10/20 12:50 PM, Serge Semin wrote:
> > > > Currently Intel Baytrail I2C semaphore is a feature of the DW APB I2C
> > > > platform driver. It's a bit confusing to see it's config in the menu at
> > > > some separated place with no reference to the platform code. Lets move the
> > > > config definition under the if-I2C_DESIGNWARE_PLATFORM clause. By doing so
> > > > the config menu will display the feature right below the DW I2C platform
> > > > driver item and will indent it to the right so signifying its belonging.
> > > > 
> > > > Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
> > > > Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
> > > > Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
> > > > Cc: Paul Burton <paulburton@kernel.org>
> > > > Cc: Ralf Baechle <ralf@linux-mips.org>
> > > > Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> > > > Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
> > > > Cc: Wolfram Sang <wsa@the-dreams.de>
> > > > Cc: Rob Herring <robh+dt@kernel.org>
> > > > Cc: Frank Rowand <frowand.list@gmail.com>
> > > > Cc: linux-mips@vger.kernel.org
> > > > Cc: devicetree@vger.kernel.org
> > > > ---
> > > >    drivers/i2c/busses/Kconfig | 30 +++++++++++++++++-------------
> > > >    1 file changed, 17 insertions(+), 13 deletions(-)
> > > > 
> > > > diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
> > > > index 368aa64e9266..ed6927c4c540 100644
> > > > --- a/drivers/i2c/busses/Kconfig
> > > > +++ b/drivers/i2c/busses/Kconfig
> > > > @@ -530,8 +530,8 @@ config I2C_DESIGNWARE_CORE
> > > >    config I2C_DESIGNWARE_PLATFORM
> > > >    	tristate "Synopsys DesignWare Platform"
> > > > -	select I2C_DESIGNWARE_CORE
> > > >    	depends on (ACPI && COMMON_CLK) || !ACPI
> > > > +	select I2C_DESIGNWARE_CORE
> > > >    	help
> > > >    	  If you say yes to this option, support will be included for the
> > > >    	  Synopsys DesignWare I2C adapter.
> > > > @@ -539,6 +539,22 @@ config I2C_DESIGNWARE_PLATFORM
> > > >    	  This driver can also be built as a module.  If so, the module
> > > >    	  will be called i2c-designware-platform.
> > > > +if I2C_DESIGNWARE_PLATFORM
> > > > +
> > > > +config I2C_DESIGNWARE_BAYTRAIL
> > > > +	bool "Intel Baytrail I2C semaphore support"
> > > > +	depends on ACPI
> > > > +	depends on (I2C_DESIGNWARE_PLATFORM=m && IOSF_MBI) || \
> > > > +		   (I2C_DESIGNWARE_PLATFORM=y && IOSF_MBI=y)
> > > > +	help
> > > > +	  This driver enables managed host access to the PMIC I2C bus on select
> > > > +	  Intel BayTrail platforms using the X-Powers AXP288 PMIC. It allows
> > > > +	  the host to request uninterrupted access to the PMIC's I2C bus from
> > > > +	  the platform firmware controlling it. You should say Y if running on
> > > > +	  a BayTrail system using the AXP288.
> > > > +
> > > > +endif # I2C_DESIGNWARE_PLATFORM
> > > > +
> > > 
> > > Is the added "if I2C_DESIGNWARE_PLATFORM" needed here? Should the "depends
> > > on" be enough?
> > 
> > The idea was to add if-endif clause here for features possibly added sometime
> > in future. But using normal "depends on I2C_DESIGNWARE_PLATFORM" shall make
> > the config depicted as an indented sub-config as well. Would you like me to
> > remove the if-clause and use the depends on operator instead?
> > 
> Yes, please remove it from this patch. Keeps this patch simpler and if some
> future feature needs it then that patch(set) is the right place to add it.

Agreed. I'll do this in v3.

-Sergey

> 
> Jarkko

Re: [PATCH v2 08/12] i2c: designware: Introduce platform drivers glue layer interface

[Serge Semin]

On Mon, May 25, 2020 at 04:16:05PM +0300, Jarkko Nikula wrote:
> Hi
> 
> On 5/21/20 5:37 AM, Serge Semin wrote:
> > On Wed, May 20, 2020 at 03:46:11PM +0300, Jarkko Nikula wrote:
> > > Hi
> > > 
> > > On 5/10/20 12:50 PM, Serge Semin wrote:
> > > > Seeing the DW I2C platform driver is getting overcomplicated with a lot of
> > > > vendor-specific configs let's introduce a glue-layer interface so new
> > > > platforms which equipped with Synopsys Designware APB I2C IP-core would
> > > > be able to handle their peculiarities in the dedicated objects.
> > > > 
> > > Comment to this patch and patches 9/12 and 12/12:
> > > 
> > > Currently i2c-designware-platdrv.c is about 500 lines of code so I don't
> > > think it's too overcomplicated. But I feel we have already too many Kconfig
> > > options and source modules for i2c-designware and obviously would like to
> > > push back a little from adding more.
> > > 
> > > I don't think i2c-designware-platdrv.c becomes yet too complicated if Baikal
> > > related code is added there, perhaps under #ifdef CONFIG_OF like MSCC Ocelot
> > > code is currently.
> > 
> > Well, it's up to you to decide, what solution is more suitable for you to
> > maintain. My idea of detaching the MSCC and Baikal-T1 code to the dedicated
> > source files was to eventually move the whole i2c-designware-* set of files
> > into a dedicated directory drivers/i2c/buses/dw as it's done for some others
> > Synopsys DesignWare controllers: drivers/pci/controller/dwc/, drivers/usb/dwc2,
> > drivers/usb/dwc3, drivers/net/ethernet/synopsys/ . If you think, that it's too
> > early for Dw I2C code to live in a dedicated directory, fine with me. I can
> > merge the MSCC and Baikal-T1 code back into the i2c-designware-platdrv.c .
> > So what's your final word in this matter?
> > 
> I think sub directory decision under each subsystem is more subsystem rather
> than vendor/driver specific. Good point anyway.
> 
> For this patchset I'd like more if changes are done to
> i2c-designware-platdrv.c since it's not too complicated yet :-)
> 
> If it starts to look too messy in the future then it's time split I think.

Ok. I'll merge the MSCC back and add Baikal-T1 System I2C support into the
DW I2C platform driver.

-Sergey

> 
> Jarkko