ARM i.MX31: add SPI support ...

The i.MX31 SPI interface was refered by freescale as spi_ver_0_4 in one
of their older vendor extended linux releases. spi_ver_0_4 differs only
in minor aspects to spi_ver_0_7 (i.MX35) which is already supported by
barebox.
Regarding barebox, the differences boil down to the location and length
of the CHIP SELECT and BIT COUNT/BURST LENGTH elements of CONREG. The
spi_ver_0_4 variant is limited to single word bursts with a maximum of
32 bits_per_word.

Add support for the i.MX31 SPI interface to the barebox spi_ver_0_7
implementation.

Signed-off-by: Alexander Kurz <akurz@blala.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

spi: imx: Remove the use of property "fsl, spi-num-chipselects" ...

The "fsl,spi-num-chipselects" property will be marked obsolete soon.
This patch updates the driver to be ready to such changes.

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

whole tree: remove trailing whitespaces ...

Signed-off-by: Du Huanpeng <u74147@gmail.com>
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>

spi: i.MX: optimize transfers for ECSPI v2.3 ...

Instead of writing one word to the txfifo and then wait until
one is received in the rxfifo we can write while the txfifos
are not full and read as long the rxfifos contain data. This
makes transfers for the m25p80 driver around 7 times faster
here.

Unlike the last version this time we only optimize the common
case with 8 bits per word and SPI_LSB_FIRST cleared. The other
cases would require more bit shuffling of the data.

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

Revert "spi: i.MX: optimize transfers for ECSPI v2.3" ...

This does not work on the Efika MX Smartbook which uses SPI
to connect the MC13892. Needs some rework.

This reverts commit 746a553.

spi: i.MX: optimize transfers for ECSPI v2.3 ...

Instead of writing one word to the txfifo and then wait until
one is received in the rxfifo we can write until the txfifos
are not full and read as long the rxfifos contain data. This
makes transfers for the m25p80 driver around 7 times faster
here.

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

spi: i.MX: create SoC specific transfer functions ...

There are SoC specific ways to optimize transfers. Make the way free
to implement these by creating SoC specific transfer functions.

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

spi: i.MX: use start mode control bit ...

The i.MX SPI controller in version 2.3 can immediately start a transfer
when the txfifo is written to. In this mode we no longer have to trigger
the transfer with the xch bit which makes the code a bit simpler.

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

spi: i.MX: move register defines to include/ ...

The register defines will be used by the SPI xload code, so move
them to a place where the xload code can include them.

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>

spi: i.MX: Respect the value of 'cs_change' ...

Add the code to correctly handle 'cs_change' field in 'struct
spi_transfer'(base on the similar code from altera_spi.c)

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

i.MX: SPI: Respect SPI_LSB_FIRST flag in mode settings ...

Add code to support SPI transfers that have data shifted out least
significant bit first. This is useful in many cases, but specifically
it is needed for drivers/firmware/altera_serial.c to work on i.MX
platform.

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

spi: i.MX: Move to coredevice_initcall ...

SPI is often used by other devices, so make sure it's initialized
early.

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

Merge branch 'for-next/misc'

Merge branch 'for-next/imx'

SPI: i.MX: Remove redundant assignment ...

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

spi: i.MX: Optimise driver private structure ...

No need to store init() function in the driver private structure
since it called only once during startup.

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

spi: i.MX: Simplify cspi_0_0_init() ...

Use SPI module software reset to simplify cspi_0_0_init().

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

spi: i.MX: Fix direction for CS GPIOs ...

Direction for CS GPIOs (for some targets) is undefined.
This patch fixes this issue.

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

spi: imx: Use device ids ...

To let the driver work on all SoCs without the use of cpu_is_*()

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

spi: imx: Use IS_ENABLED to drop ifdefs ...

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

spi: imx: drop use of enum ...

enum imx_spi_devtype is used as index into an array of controller types.
This makes the controller type handling unnecessarily complicated. Just
drop the enum and instead of an array use different statically initialized
structs and referene them by name.

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

treewide: Add missing includes ...

A lot of files rely on include/driver.h including include/of.h (and
this including include/errno.h. include the files explicitly so we can
eventually get rid of including of.h from driver.h

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

spi: Call spi_of_register_slaves from core ...

Makes individual handling of OF spi slaves unnecessary in the bus drivers.

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

OF: gpio: convert DT based gpio handling to new OF API ...

This creates a Linux OF API compatible counterpart of of_get_named_gpio_flags.
Existing of_get_named_gpio is converted to a static inline function, which is
in the corresponding of_gpio.h include. While at it, drivers/of/gpio.c is
also renamed to drivers/of/of_gpio.c to follow the of_ prefix naming scheme.
The new include is also added to existing users of of_get_named_gpio.

Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Merge branch 'for-next/misc'

imx_spi: fix bus-num setup ...

Signed-off-by: Hubert Feurstein <h.feurstein@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Use new device_platform_driver() macro for drivers ...

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>