i2c: at91: extend for sama5d2 support ...

Port over the Linux v5.8-rc4 bits to support i2c on the sama5d2.
This has been tested by reading the i2c EEPROM on the sama5d27-som1-ek.

Signed-off-by: Ahmad Fatoum <a.fatoum@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>

driver: Fix return check of dev_request_mem_region ...

dev_request_mem_region returns an ERR_PTR, fix places which check for a
NULL pointer instead. This patch has been generated with this semantic
patch, written by me and improved by Andrey Smirnov:

// <smpl>
@@
expression e;
expression e1;
@@
e = dev_request_mem_region(...);
...
-if (!e)
-	return e1;
+if (IS_ERR(e))
+	return PTR_ERR(e);

@ rule1 @
expression e;
@@
e = dev_request_mem_region(...);

@@
expression rule1.e;
identifier ret, label;
constant errno;
@@
if (!e) {
	...
(
-	ret = -errno;
+	ret = PTR_ERR(e);
	...
	goto label;
|
-	return -errno;
+	return PTR_ERR(e);
)
}

@depends on rule1@
expression rule1.e;
@@
-	if (e == NULL)
+	if (IS_ERR(e))
{
...
}
// </smpl>

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>

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: at91: fix invalid length check ...

Signed-off-by: Lucas Stach <dev@lynxeye.de>
Acked-by: Bo Shen <voice.shen@atmel.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

I2C: at91: fix the method for interrupt ...

As the i2c-at91 driver won't work in the interrupt mode,
so need to poll the interrupts.

Signed-off-by: Bo Shen <voice.shen@atmel.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

i2c: at91: add support of device tree ...

Signed-off-by: Raphaël Poggi <poggi.raph@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

i2c: at91: add at91sam9x5 config ...

Signed-off-by: Raphaël Poggi <poggi.raph@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

i2c: at91: fix coding style issue ...

Signed-off-by: Raphaël Poggi <poggi.raph@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

i2c: add Atmel AT91 driver ...

Signed-off-by: Raphaël Poggi <poggi.raph@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>