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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/mips/momentum/ocelot_c/uart-irq.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/mips/momentum/ocelot_c/uart-irq.c')
-rw-r--r--arch/mips/momentum/ocelot_c/uart-irq.c147
1 files changed, 147 insertions, 0 deletions
diff --git a/arch/mips/momentum/ocelot_c/uart-irq.c b/arch/mips/momentum/ocelot_c/uart-irq.c
new file mode 100644
index 000000000000..ebe1507b17df
--- /dev/null
+++ b/arch/mips/momentum/ocelot_c/uart-irq.c
@@ -0,0 +1,147 @@
1/*
2 * Copyright 2002 Momentum Computer
3 * Author: mdharm@momenco.com
4 *
5 * arch/mips/momentum/ocelot_c/uart-irq.c
6 * Interrupt routines for UARTs. Interrupt numbers are assigned from
7 * 80 to 81 (2 interrupt sources).
8 *
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public License as published by the
11 * Free Software Foundation; either version 2 of the License, or (at your
12 * option) any later version.
13 */
14
15#include <linux/module.h>
16#include <linux/interrupt.h>
17#include <linux/irq.h>
18#include <linux/kernel.h>
19#include <asm/ptrace.h>
20#include <linux/sched.h>
21#include <linux/kernel_stat.h>
22#include <asm/io.h>
23#include <asm/irq.h>
24#include "ocelot_c_fpga.h"
25
26static inline int ls1bit8(unsigned int x)
27{
28 int b = 7, s;
29
30 s = 4; if (((unsigned char)(x << 4)) == 0) s = 0; b -= s; x <<= s;
31 s = 2; if (((unsigned char)(x << 2)) == 0) s = 0; b -= s; x <<= s;
32 s = 1; if (((unsigned char)(x << 1)) == 0) s = 0; b -= s;
33
34 return b;
35}
36
37/* mask off an interrupt -- 0 is enable, 1 is disable */
38static inline void mask_uart_irq(unsigned int irq)
39{
40 uint8_t value;
41
42 value = OCELOT_FPGA_READ(UART_INTMASK);
43 value |= 1 << (irq - 74);
44 OCELOT_FPGA_WRITE(value, UART_INTMASK);
45
46 /* read the value back to assure that it's really been written */
47 value = OCELOT_FPGA_READ(UART_INTMASK);
48}
49
50/* unmask an interrupt -- 0 is enable, 1 is disable */
51static inline void unmask_uart_irq(unsigned int irq)
52{
53 uint8_t value;
54
55 value = OCELOT_FPGA_READ(UART_INTMASK);
56 value &= ~(1 << (irq - 74));
57 OCELOT_FPGA_WRITE(value, UART_INTMASK);
58
59 /* read the value back to assure that it's really been written */
60 value = OCELOT_FPGA_READ(UART_INTMASK);
61}
62
63/*
64 * Enables the IRQ in the FPGA
65 */
66static void enable_uart_irq(unsigned int irq)
67{
68 unmask_uart_irq(irq);
69}
70
71/*
72 * Initialize the IRQ in the FPGA
73 */
74static unsigned int startup_uart_irq(unsigned int irq)
75{
76 unmask_uart_irq(irq);
77 return 0;
78}
79
80/*
81 * Disables the IRQ in the FPGA
82 */
83static void disable_uart_irq(unsigned int irq)
84{
85 mask_uart_irq(irq);
86}
87
88/*
89 * Masks and ACKs an IRQ
90 */
91static void mask_and_ack_uart_irq(unsigned int irq)
92{
93 mask_uart_irq(irq);
94}
95
96/*
97 * End IRQ processing
98 */
99static void end_uart_irq(unsigned int irq)
100{
101 if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)))
102 unmask_uart_irq(irq);
103}
104
105/*
106 * Interrupt handler for interrupts coming from the FPGA chip.
107 */
108void ll_uart_irq(struct pt_regs *regs)
109{
110 unsigned int irq_src, irq_mask;
111
112 /* read the interrupt status registers */
113 irq_src = OCELOT_FPGA_READ(UART_INTSTAT);
114 irq_mask = OCELOT_FPGA_READ(UART_INTMASK);
115
116 /* mask for just the interrupts we want */
117 irq_src &= ~irq_mask;
118
119 do_IRQ(ls1bit8(irq_src) + 74, regs);
120}
121
122#define shutdown_uart_irq disable_uart_irq
123
124struct hw_interrupt_type uart_irq_type = {
125 "UART/FPGA",
126 startup_uart_irq,
127 shutdown_uart_irq,
128 enable_uart_irq,
129 disable_uart_irq,
130 mask_and_ack_uart_irq,
131 end_uart_irq,
132 NULL
133};
134
135void uart_irq_init(void)
136{
137 /* Reset irq handlers pointers to NULL */
138 irq_desc[80].status = IRQ_DISABLED;
139 irq_desc[80].action = 0;
140 irq_desc[80].depth = 2;
141 irq_desc[80].handler = &uart_irq_type;
142
143 irq_desc[81].status = IRQ_DISABLED;
144 irq_desc[81].action = 0;
145 irq_desc[81].depth = 2;
146 irq_desc[81].handler = &uart_irq_type;
147}