tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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>
+85
-1
+27
-1
Documentation/devicetree/bindings/bus/imx-weim.txt
+27
-1
Documentation/devicetree/bindings/bus/imx-weim.txt
···
8
8
9
9
Required properties:
10
10
11
-
- compatible: Should be set to "fsl,<soc>-weim"
11
+
- compatible: Should contain one of the following:
12
+
"fsl,imx1-weim"
13
+
"fsl,imx27-weim"
14
+
"fsl,imx51-weim"
15
+
"fsl,imx50-weim"
16
+
"fsl,imx6q-weim"
12
17
- reg: A resource specifier for the register space
13
18
(see the example below)
14
19
- clocks: the clock, see the example below.
···
23
18
integer values for each chip-select line in use:
24
19
25
20
<cs-number> 0 <physical address of mapping> <size>
21
+
22
+
Optional properties:
23
+
24
+
- fsl,weim-cs-gpr: For "fsl,imx50-weim" and "fsl,imx6q-weim" type of
25
+
devices, it should be the phandle to the system General
26
+
Purpose Register controller that contains WEIM CS GPR
27
+
register, e.g. IOMUXC_GPR1 on i.MX6Q. IOMUXC_GPR1[11:0]
28
+
should be set up as one of the following 4 possible
29
+
values depending on the CS space configuration.
30
+
31
+
IOMUXC_GPR1[11:0] CS0 CS1 CS2 CS3
32
+
---------------------------------------------
33
+
05 128M 0M 0M 0M
34
+
033 64M 64M 0M 0M
35
+
0113 64M 32M 32M 0M
36
+
01111 32M 32M 32M 32M
37
+
38
+
In case that the property is absent, the reset value or
39
+
what bootloader sets up in IOMUXC_GPR1[11:0] will be
40
+
used.
26
41
27
42
Timing property for child nodes. It is mandatory, not optional.
28
43
···
68
43
#address-cells = <2>;
69
44
#size-cells = <1>;
70
45
ranges = <0 0 0x08000000 0x08000000>;
46
+
fsl,weim-cs-gpr = <&gpr>;
71
47
72
48
nor@0,0 {
73
49
compatible = "cfi-flash";
+58
drivers/bus/imx-weim.c
+58
drivers/bus/imx-weim.c
···
11
11
#include <linux/clk.h>
12
12
#include <linux/io.h>
13
13
#include <linux/of_device.h>
14
+
#include <linux/mfd/syscon.h>
15
+
#include <linux/mfd/syscon/imx6q-iomuxc-gpr.h>
16
+
#include <linux/regmap.h>
14
17
15
18
struct imx_weim_devtype {
16
19
unsigned int cs_count;
···
59
56
};
60
57
MODULE_DEVICE_TABLE(of, weim_id_table);
61
58
59
+
static int __init imx_weim_gpr_setup(struct platform_device *pdev)
60
+
{
61
+
struct device_node *np = pdev->dev.of_node;
62
+
struct property *prop;
63
+
const __be32 *p;
64
+
struct regmap *gpr;
65
+
u32 gprvals[4] = {
66
+
05, /* CS0(128M) CS1(0M) CS2(0M) CS3(0M) */
67
+
033, /* CS0(64M) CS1(64M) CS2(0M) CS3(0M) */
68
+
0113, /* CS0(64M) CS1(32M) CS2(32M) CS3(0M) */
69
+
01111, /* CS0(32M) CS1(32M) CS2(32M) CS3(32M) */
70
+
};
71
+
u32 gprval = 0;
72
+
u32 val;
73
+
int cs = 0;
74
+
int i = 0;
75
+
76
+
gpr = syscon_regmap_lookup_by_phandle(np, "fsl,weim-cs-gpr");
77
+
if (IS_ERR(gpr)) {
78
+
dev_dbg(&pdev->dev, "failed to find weim-cs-gpr\n");
79
+
return 0;
80
+
}
81
+
82
+
of_property_for_each_u32(np, "ranges", prop, p, val) {
83
+
if (i % 4 == 0) {
84
+
cs = val;
85
+
} else if (i % 4 == 3 && val) {
86
+
val = (val / SZ_32M) | 1;
87
+
gprval |= val << cs * 3;
88
+
}
89
+
i++;
90
+
}
91
+
92
+
if (i == 0 || i % 4)
93
+
goto err;
94
+
95
+
for (i = 0; i < ARRAY_SIZE(gprvals); i++) {
96
+
if (gprval == gprvals[i]) {
97
+
/* Found it. Set up IOMUXC_GPR1[11:0] with it. */
98
+
regmap_update_bits(gpr, IOMUXC_GPR1, 0xfff, gprval);
99
+
return 0;
100
+
}
101
+
}
102
+
103
+
err:
104
+
dev_err(&pdev->dev, "Invalid 'ranges' configuration\n");
105
+
return -EINVAL;
106
+
}
107
+
62
108
/* Parse and set the timing for this device. */
63
109
static int __init weim_timing_setup(struct device_node *np, void __iomem *base,
64
110
const struct imx_weim_devtype *devtype)
···
143
91
const struct imx_weim_devtype *devtype = of_id->data;
144
92
struct device_node *child;
145
93
int ret;
94
+
95
+
if (devtype == &imx50_weim_devtype) {
96
+
ret = imx_weim_gpr_setup(pdev);
97
+
if (ret)
98
+
return ret;
99
+
}
146
100
147
101
for_each_child_of_node(pdev->dev.of_node, child) {
148
102
if (!child->name)