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authorStuart Yoder <stuart.yoder@freescale.com>2011-01-19 17:30:14 -0500
committerKumar Gala <galak@kernel.crashing.org>2011-03-15 15:09:00 -0400
commit52052875549f6ecd6520279ee0f94e4721d80077 (patch)
treea24dbb56a907f4d682557000e0ee71b5e61065e9 /Documentation
parent6820fead714d57012428c96266e86105e39075e0 (diff)
powerpc/fsl: define binding for fsl mpic interrupt controllers
Define the binding for compatible = "fsl,mpic", including the definition of 4-cell interrupt specifiers. The 3rd and 4th cells are needed to define additional types of interrupt source outside the "normal" external and internal interrupts in FSL SoCs. Define error interrupt, IPIs, and PIC timer sources. Signed-off-by: Stuart Yoder <stuart.yoder@freescale.com> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/devicetree/bindings/powerpc/fsl/mpic.txt253
1 files changed, 211 insertions, 42 deletions
diff --git a/Documentation/devicetree/bindings/powerpc/fsl/mpic.txt b/Documentation/devicetree/bindings/powerpc/fsl/mpic.txt
index 71e39cf3215b..8aa10f45ebe6 100644
--- a/Documentation/devicetree/bindings/powerpc/fsl/mpic.txt
+++ b/Documentation/devicetree/bindings/powerpc/fsl/mpic.txt
@@ -1,42 +1,211 @@
1* OpenPIC and its interrupt numbers on Freescale's e500/e600 cores 1=====================================================================
2 2Freescale MPIC Interrupt Controller Node
3The OpenPIC specification does not specify which interrupt source has to 3Copyright (C) 2010,2011 Freescale Semiconductor Inc.
4become which interrupt number. This is up to the software implementation 4=====================================================================
5of the interrupt controller. The only requirement is that every 5
6interrupt source has to have an unique interrupt number / vector number. 6The Freescale MPIC interrupt controller is found on all PowerQUICC
7To accomplish this the current implementation assigns the number zero to 7and QorIQ processors and is compatible with the Open PIC. The
8the first source, the number one to the second source and so on until 8notable difference from Open PIC binding is the addition of 2
9all interrupt sources have their unique number. 9additional cells in the interrupt specifier defining interrupt type
10Usually the assigned vector number equals the interrupt number mentioned 10information.
11in the documentation for a given core / CPU. This is however not true 11
12for the e500 cores (MPC85XX CPUs) where the documentation distinguishes 12PROPERTIES
13between internal and external interrupt sources and starts counting at 13
14zero for both of them. 14 - compatible
15 15 Usage: required
16So what to write for external interrupt source X or internal interrupt 16 Value type: <string>
17source Y into the device tree? Here is an example: 17 Definition: Shall include "fsl,mpic". Freescale MPIC
18 18 controllers compatible with this binding have Block
19The memory map for the interrupt controller in the MPC8544[0] shows, 19 Revision Registers BRR1 and BRR2 at offset 0x0 and
20that the first interrupt source starts at 0x5_0000 (PIC Register Address 20 0x10 in the MPIC.
21Map-Interrupt Source Configuration Registers). This source becomes the 21
22number zero therefore: 22 - reg
23 External interrupt 0 = interrupt number 0 23 Usage: required
24 External interrupt 1 = interrupt number 1 24 Value type: <prop-encoded-array>
25 External interrupt 2 = interrupt number 2 25 Definition: A standard property. Specifies the physical
26 ... 26 offset and length of the device's registers within the
27Every interrupt number allocates 0x20 bytes register space. So to get 27 CCSR address space.
28its number it is sufficient to shift the lower 16bits to right by five. 28
29So for the external interrupt 10 we have: 29 - interrupt-controller
30 0x0140 >> 5 = 10 30 Usage: required
31 31 Value type: <empty>
32After the external sources, the internal sources follow. The in core I2C 32 Definition: Specifies that this node is an interrupt
33controller on the MPC8544 for instance has the internal source number 33 controller
3427. Oo obtain its interrupt number we take the lower 16bits of its memory 34
35address (0x5_0560) and shift it right: 35 - #interrupt-cells
36 0x0560 >> 5 = 43 36 Usage: required
37 37 Value type: <u32>
38Therefore the I2C device node for the MPC8544 CPU has to have the 38 Definition: Shall be 2 or 4. A value of 2 means that interrupt
39interrupt number 43 specified in the device tree. 39 specifiers do not contain the interrupt-type or type-specific
40 40 information cells.
41[0] MPC8544E PowerQUICCTM III, Integrated Host Processor Family Reference Manual 41
42 MPC8544ERM Rev. 1 10/2007 42 - #address-cells
43 Usage: required
44 Value type: <u32>
45 Definition: Shall be 0.
46
47 - pic-no-reset
48 Usage: optional
49 Value type: <empty>
50 Definition: The presence of this property specifies that the
51 MPIC must not be reset by the client program, and that
52 the boot program has initialized all interrupt source
53 configuration registers to a sane state-- masked or
54 directed at other cores. This ensures that the client
55 program will not receive interrupts for sources not belonging
56 to the client. The presence of this property also mandates
57 that any initialization related to interrupt sources shall
58 be limited to sources explicitly referenced in the device tree.
59
60INTERRUPT SPECIFIER DEFINITION
61
62 Interrupt specifiers consists of 4 cells encoded as
63 follows:
64
65 <1st-cell> interrupt-number
66
67 Identifies the interrupt source. The meaning
68 depends on the type of interrupt.
69
70 Note: If the interrupt-type cell is undefined
71 (i.e. #interrupt-cells = 2), this cell
72 should be interpreted the same as for
73 interrupt-type 0-- i.e. an external or
74 normal SoC device interrupt.
75
76 <2nd-cell> level-sense information, encoded as follows:
77 0 = low-to-high edge triggered
78 1 = active low level-sensitive
79 2 = active high level-sensitive
80 3 = high-to-low edge triggered
81
82 <3rd-cell> interrupt-type
83
84 The following types are supported:
85
86 0 = external or normal SoC device interrupt
87
88 The interrupt-number cell contains
89 the SoC device interrupt number. The
90 type-specific cell is undefined. The
91 interrupt-number is derived from the
92 MPIC a block of registers referred to as
93 the "Interrupt Source Configuration Registers".
94 Each source has 32-bytes of registers
95 (vector/priority and destination) in this
96 region. So interrupt 0 is at offset 0x0,
97 interrupt 1 is at offset 0x20, and so on.
98
99 1 = error interrupt
100
101 The interrupt-number cell contains
102 the SoC device interrupt number for
103 the error interrupt. The type-specific
104 cell identifies the specific error
105 interrupt number.
106
107 2 = MPIC inter-processor interrupt (IPI)
108
109 The interrupt-number cell identifies
110 the MPIC IPI number. The type-specific
111 cell is undefined.
112
113 3 = MPIC timer interrupt
114
115 The interrupt-number cell identifies
116 the MPIC timer number. The type-specific
117 cell is undefined.
118
119 <4th-cell> type-specific information
120
121 The type-specific cell is encoded as follows:
122
123 - For interrupt-type 1 (error interrupt),
124 the type-specific cell contains the
125 bit number of the error interrupt in the
126 Error Interrupt Summary Register.
127
128EXAMPLE 1
129 /*
130 * mpic interrupt controller with 4 cells per specifier
131 */
132 mpic: pic@40000 {
133 compatible = "fsl,mpic";
134 interrupt-controller;
135 #interrupt-cells = <4>;
136 #address-cells = <0>;
137 reg = <0x40000 0x40000>;
138 };
139
140EXAMPLE 2
141 /*
142 * The MPC8544 I2C controller node has an internal
143 * interrupt number of 27. As per the reference manual
144 * this corresponds to interrupt source configuration
145 * registers at 0x5_0560.
146 *
147 * The interrupt source configuration registers begin
148 * at 0x5_0000.
149 *
150 * To compute the interrupt specifier interrupt number
151 *
152 * 0x560 >> 5 = 43
153 *
154 * The interrupt source configuration registers begin
155 * at 0x5_0000, and so the i2c vector/priority registers
156 * are at 0x5_0560.
157 */
158 i2c@3000 {
159 #address-cells = <1>;
160 #size-cells = <0>;
161 cell-index = <0>;
162 compatible = "fsl-i2c";
163 reg = <0x3000 0x100>;
164 interrupts = <43 2>;
165 interrupt-parent = <&mpic>;
166 dfsrr;
167 };
168
169
170EXAMPLE 3
171 /*
172 * Definition of a node defining the 4
173 * MPIC IPI interrupts. Note the interrupt
174 * type of 2.
175 */
176 ipi@410a0 {
177 compatible = "fsl,mpic-ipi";
178 reg = <0x40040 0x10>;
179 interrupts = <0 0 2 0
180 1 0 2 0
181 2 0 2 0
182 3 0 2 0>;
183 };
184
185EXAMPLE 4
186 /*
187 * Definition of a node defining the MPIC
188 * global timers. Note the interrupt
189 * type of 3.
190 */
191 timer0: timer@41100 {
192 compatible = "fsl,mpic-global-timer";
193 reg = <0x41100 0x100>;
194 interrupts = <0 0 3 0
195 1 0 3 0
196 2 0 3 0
197 3 0 3 0>;
198 };
199
200EXAMPLE 5
201 /*
202 * Definition of an error interrupt (interupt type 1).
203 * SoC interrupt number is 16 and the specific error
204 * interrupt bit in the error interrupt summary register
205 * is 23.
206 */
207 memory-controller@8000 {
208 compatible = "fsl,p4080-memory-controller";
209 reg = <0x8000 0x1000>;
210 interrupts = <16 2 1 23>;
211 };