bus: imx-weim: support CS GPR configuration

For imx50-weim and imx6q-weim type of devices, there might a WEIM CS
space configuration register in General Purpose Register controller,
e.g. IOMUXC_GPR1 on i.MX6Q.

Depending on which configuration of the following 4 is chosen for given
system, IOMUXC_GPR1[11:0] should be set up as 05, 033, 0113 or 01111
correspondingly.

	CS0(128M) CS1(0M)  CS2(0M)  CS3(0M)
	CS0(64M)  CS1(64M) CS2(0M)  CS3(0M)
	CS0(64M)  CS1(32M) CS2(32M) CS3(0M)
	CS0(32M)  CS1(32M) CS2(32M) CS3(32M)

The patch creates a function for such type of devices, which scans
'ranges' property of WEIM node and build the GPR value incrementally.
Thus the WEIM CS GPR can be set up automatically at boot time.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Reviewed-by: Philippe De Muyter <phdm@macqel.be>
Tested-by: Philippe De Muyter <phdm@macqel.be>
This commit is contained in:
Shawn Guo 2014-02-11 09:52:09 +08:00
parent 7899d7d578
commit 8d9ee21e98
2 changed files with 85 additions and 1 deletions

View file

@ -8,7 +8,12 @@ The actual devices are instantiated from the child nodes of a WEIM node.
Required properties:
- compatible: Should be set to "fsl,<soc>-weim"
- compatible: Should contain one of the following:
"fsl,imx1-weim"
"fsl,imx27-weim"
"fsl,imx51-weim"
"fsl,imx50-weim"
"fsl,imx6q-weim"
- reg: A resource specifier for the register space
(see the example below)
- clocks: the clock, see the example below.
@ -19,6 +24,26 @@ Required properties:
<cs-number> 0 <physical address of mapping> <size>
Optional properties:
- fsl,weim-cs-gpr: For "fsl,imx50-weim" and "fsl,imx6q-weim" type of
devices, it should be the phandle to the system General
Purpose Register controller that contains WEIM CS GPR
register, e.g. IOMUXC_GPR1 on i.MX6Q. IOMUXC_GPR1[11:0]
should be set up as one of the following 4 possible
values depending on the CS space configuration.
IOMUXC_GPR1[11:0] CS0 CS1 CS2 CS3
---------------------------------------------
05 128M 0M 0M 0M
033 64M 64M 0M 0M
0113 64M 32M 32M 0M
01111 32M 32M 32M 32M
In case that the property is absent, the reset value or
what bootloader sets up in IOMUXC_GPR1[11:0] will be
used.
Timing property for child nodes. It is mandatory, not optional.
- fsl,weim-cs-timing: The timing array, contains timing values for the
@ -43,6 +68,7 @@ Example for an imx6q-sabreauto board, the NOR flash connected to the WEIM:
#address-cells = <2>;
#size-cells = <1>;
ranges = <0 0 0x08000000 0x08000000>;
fsl,weim-cs-gpr = <&gpr>;
nor@0,0 {
compatible = "cfi-flash";

View file

@ -11,6 +11,9 @@
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/of_device.h>
#include <linux/mfd/syscon.h>
#include <linux/mfd/syscon/imx6q-iomuxc-gpr.h>
#include <linux/regmap.h>
struct imx_weim_devtype {
unsigned int cs_count;
@ -56,6 +59,55 @@ static const struct of_device_id weim_id_table[] = {
};
MODULE_DEVICE_TABLE(of, weim_id_table);
static int __init imx_weim_gpr_setup(struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
struct property *prop;
const __be32 *p;
struct regmap *gpr;
u32 gprvals[4] = {
05, /* CS0(128M) CS1(0M) CS2(0M) CS3(0M) */
033, /* CS0(64M) CS1(64M) CS2(0M) CS3(0M) */
0113, /* CS0(64M) CS1(32M) CS2(32M) CS3(0M) */
01111, /* CS0(32M) CS1(32M) CS2(32M) CS3(32M) */
};
u32 gprval = 0;
u32 val;
int cs = 0;
int i = 0;
gpr = syscon_regmap_lookup_by_phandle(np, "fsl,weim-cs-gpr");
if (IS_ERR(gpr)) {
dev_dbg(&pdev->dev, "failed to find weim-cs-gpr\n");
return 0;
}
of_property_for_each_u32(np, "ranges", prop, p, val) {
if (i % 4 == 0) {
cs = val;
} else if (i % 4 == 3 && val) {
val = (val / SZ_32M) | 1;
gprval |= val << cs * 3;
}
i++;
}
if (i == 0 || i % 4)
goto err;
for (i = 0; i < ARRAY_SIZE(gprvals); i++) {
if (gprval == gprvals[i]) {
/* Found it. Set up IOMUXC_GPR1[11:0] with it. */
regmap_update_bits(gpr, IOMUXC_GPR1, 0xfff, gprval);
return 0;
}
}
err:
dev_err(&pdev->dev, "Invalid 'ranges' configuration\n");
return -EINVAL;
}
/* Parse and set the timing for this device. */
static int __init weim_timing_setup(struct device_node *np, void __iomem *base,
const struct imx_weim_devtype *devtype)
@ -92,6 +144,12 @@ static int __init weim_parse_dt(struct platform_device *pdev,
struct device_node *child;
int ret;
if (devtype == &imx50_weim_devtype) {
ret = imx_weim_gpr_setup(pdev);
if (ret)
return ret;
}
for_each_child_of_node(pdev->dev.of_node, child) {
if (!child->name)
continue;