i2c: mv64xxx: fix indentation ...

The patch fixes this compiler's warning:

    drivers/i2c/busses/i2c-mv64xxx.c: In function ‘mv64xxx_i2c_fsm’:
    drivers/i2c/busses/i2c-mv64xxx.c:303:3: warning: this ‘if’ clause does
    not guard... [-Wmisleading-indentation]
       if (drv_data->bytes_left == 1)
       ^~
    drivers/i2c/busses/i2c-mv64xxx.c:305:4: note: ...this statement, but the
    latter is misleadingly indented as if it is guarded by the ‘if’
        udelay(2);
        ^~~~~~

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Cc: Bastian Stender <bst@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

i2c: mv64xxx: simplify mv64xxx_i2c_wait_for_completion ...

Two nested while loops are not necessary here, so integrate the read,
i2c_fsm and i2c_do_action calls into mv64xxx_i2c_wait_for_completion()
and remove the obsolete interrupt remains.

Signed-off-by: Bastian Stender <bst@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

i2c: mv64xxx: add software delays ...

As stated in Marvell's Functional Specifications in MV-S107021-U0 Rev. A
on page 420 ff. software delays are needed. "SW delay represent a delay
of at least 2 internal clock cycles". These delays are hereby
implemented.

The original kernel driver compensates the needed software delays with
the time the interrupts take.

Signed-off-by: Bastian Stender <bst@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

driver: replace dev_request_mem_region with dev_request_mem_resource ...

dev_request_mem_region doesn't work properly one some SoCs on which
PTR_ERR() values clash with valid return values from dev_request_mem_region.
Replace them with dev_request_mem_resource where possible.

This patch has been generated with the following semantic patch:

// <smpl>
@@
expression d;
expression n;
expression io;
identifier func;
@@
func(...) {
+struct resource *iores;
<+...
-io = dev_request_mem_region(d, n);
-if (IS_ERR(io)) {
+iores = dev_request_mem_resource(d, n);
+if (IS_ERR(iores)) {
...
-	return PTR_ERR(io);
-}
+	return PTR_ERR(iores);
+}
+io = IOMEM(iores->start);
...+>
}

@@
expression d;
expression n;
expression io;
identifier func;
@@
func(...) {
+struct resource *iores;
<+...
-io = dev_request_mem_region(d, n);
-if (IS_ERR(io)) {
+iores = dev_request_mem_resource(d, n);
+if (IS_ERR(iores))
-	return PTR_ERR(io);
-}
+	return PTR_ERR(iores);
+io = IOMEM(iores->start);
...+>
}

@@
expression d;
expression n;
expression io;
identifier func;
@@
func(...) {
+struct resource *iores;
<+...
-io = dev_request_mem_region(d, n);
-if (IS_ERR(io)) {
-	ret = PTR_ERR(io);
+iores = dev_request_mem_resource(d, n);
+if (IS_ERR(iores)) {
+	ret = PTR_ERR(iores);
...
}
+io = IOMEM(iores->start);
...+>
}

@@
expression d;
expression n;
expression io;
identifier func;
@@
func(...) {
+struct resource *iores;
<+...
-io = dev_request_mem_region(d, n);
+iores = dev_request_mem_resource(d, n);
+if (IS_ERR(iores))
+	return PTR_ERR(iores);
+io = IOMEM(iores->start);
...+>
}

@@
identifier func;
@@
func(...) {
<+...
struct resource *iores;
-struct resource *iores;
...+>
}
// </smpl>

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Merge branch 'for-next/of-device-id'

of: use 'const void *' for struct of_device_id.data ...

Since 2011 barebox' of_device_id struct uses unsigned long type for data field:

    struct of_device_id {
            char *compatible;
            unsigned long data;
    };

Almost always struct of_device_id.data field are used as pointer
and need 'unsigned long' casting.

E.g. see 'git grep -A 4 of_device_id drivers/' output:

    drivers/ata/sata-imx.c:static __maybe_unused struct of_device_id imx_sata_dt_ids[] = {
    drivers/ata/sata-imx.c- {
    drivers/ata/sata-imx.c-         .compatible = "fsl,imx6q-ahci",
    drivers/ata/sata-imx.c-         .data = (unsigned long)&data_imx6,
    drivers/ata/sata-imx.c- }, {

Here is of_device_id struct in linux kernel v4.0:

    struct of_device_id {
            char name[32];
            char type[32];
            char compatible[128];
            const void *data;
    };

Changing of_device_id.data type to 'const void *data' will increase
barebox' linux kernel compatibility and decrease number of 'unsigned
long' casts.

Part of the patch was done using the 'coccinelle' tool with the
following semantic patch:

    @rule1@
    identifier dev;
    identifier type;
    identifier func;
    @@
    func(...) {
    <...
    - dev_get_drvdata(dev, (unsigned long *)&type)
    + dev_get_drvdata(dev, (const void **)&type)
    ...>
    }
    @rule2@
    identifier dev;
    identifier type;
    identifier func;
    identifier data;
    @@
    func(...) {
    <...
    - dev_get_drvdata(dev, (unsigned long *)&type->data)
    + dev_get_drvdata(dev, (const void **)&type->data)
    ...>
    }

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

i2c: mv64xxx: continue probe when clock-frequency is missing ...

Based on this linux kernel commit:

    commit 0ce4bc1
    Author: Chen-Yu Tsai <wens@csie.org>
    Date:   Mon Sep 1 22:28:13 2014 +0800

        i2c: mv64xxx: continue probe when clock-frequency is missing

        The "clock-frequency" DT property is listed as optional, However,
        the current code stores the return value of of_property_read_u32 in
        the return code of mv64xxx_of_config, but then forgets to clear it
        after setting the default value of "clock-frequency". It is then
        passed out to the main probe function, resulting in a probe failure
        when "clock-frequency" is missing.

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

i2c: add Marvell 64xxx driver ...

This driver is also used for Allwinner SoCs I2C controllers.

Ported from linux-3.15.

The most notable barebox driver version changes:

  * drop platform device stuff;
  * drop "allwinner,sun*" stuff;
  * drop message offloading support;
  * add reg-io-width devicetree parameter to use driver
    with byte-oriented controller versions.

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Acked-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
On Armada XP:
Tested-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>