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1da177e4 | 1 | /* |
7c38cf02 | 2 | * linux/arch/arm/mach-omap1/fpga.c |
1da177e4 LT |
3 | * |
4 | * Interrupt handler for OMAP-1510 Innovator FPGA | |
5 | * | |
6 | * Copyright (C) 2001 RidgeRun, Inc. | |
7 | * Author: Greg Lonnon <glonnon@ridgerun.com> | |
8 | * | |
9 | * Copyright (C) 2002 MontaVista Software, Inc. | |
10 | * | |
11 | * Separated FPGA interrupts from innovator1510.c and cleaned up for 2.6 | |
12 | * Copyright (C) 2004 Nokia Corporation by Tony Lindrgen <tony@atomide.com> | |
13 | * | |
14 | * This program is free software; you can redistribute it and/or modify | |
15 | * it under the terms of the GNU General Public License version 2 as | |
16 | * published by the Free Software Foundation. | |
17 | */ | |
18 | ||
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19 | #include <linux/types.h> |
20 | #include <linux/init.h> | |
21 | #include <linux/kernel.h> | |
22 | #include <linux/device.h> | |
23 | #include <linux/errno.h> | |
24 | ||
25 | #include <asm/hardware.h> | |
26 | #include <asm/io.h> | |
27 | #include <asm/irq.h> | |
28 | #include <asm/mach/irq.h> | |
29 | ||
30 | #include <asm/arch/fpga.h> | |
31 | #include <asm/arch/gpio.h> | |
32 | ||
33 | static void fpga_mask_irq(unsigned int irq) | |
34 | { | |
35 | irq -= OMAP1510_IH_FPGA_BASE; | |
36 | ||
37 | if (irq < 8) | |
38 | __raw_writeb((__raw_readb(OMAP1510_FPGA_IMR_LO) | |
39 | & ~(1 << irq)), OMAP1510_FPGA_IMR_LO); | |
40 | else if (irq < 16) | |
41 | __raw_writeb((__raw_readb(OMAP1510_FPGA_IMR_HI) | |
42 | & ~(1 << (irq - 8))), OMAP1510_FPGA_IMR_HI); | |
43 | else | |
44 | __raw_writeb((__raw_readb(INNOVATOR_FPGA_IMR2) | |
45 | & ~(1 << (irq - 16))), INNOVATOR_FPGA_IMR2); | |
46 | } | |
47 | ||
48 | ||
49 | static inline u32 get_fpga_unmasked_irqs(void) | |
50 | { | |
51 | return | |
52 | ((__raw_readb(OMAP1510_FPGA_ISR_LO) & | |
53 | __raw_readb(OMAP1510_FPGA_IMR_LO))) | | |
54 | ((__raw_readb(OMAP1510_FPGA_ISR_HI) & | |
55 | __raw_readb(OMAP1510_FPGA_IMR_HI)) << 8) | | |
56 | ((__raw_readb(INNOVATOR_FPGA_ISR2) & | |
57 | __raw_readb(INNOVATOR_FPGA_IMR2)) << 16); | |
58 | } | |
59 | ||
60 | ||
61 | static void fpga_ack_irq(unsigned int irq) | |
62 | { | |
63 | /* Don't need to explicitly ACK FPGA interrupts */ | |
64 | } | |
65 | ||
66 | static void fpga_unmask_irq(unsigned int irq) | |
67 | { | |
68 | irq -= OMAP1510_IH_FPGA_BASE; | |
69 | ||
70 | if (irq < 8) | |
71 | __raw_writeb((__raw_readb(OMAP1510_FPGA_IMR_LO) | (1 << irq)), | |
72 | OMAP1510_FPGA_IMR_LO); | |
73 | else if (irq < 16) | |
74 | __raw_writeb((__raw_readb(OMAP1510_FPGA_IMR_HI) | |
75 | | (1 << (irq - 8))), OMAP1510_FPGA_IMR_HI); | |
76 | else | |
77 | __raw_writeb((__raw_readb(INNOVATOR_FPGA_IMR2) | |
78 | | (1 << (irq - 16))), INNOVATOR_FPGA_IMR2); | |
79 | } | |
80 | ||
81 | static void fpga_mask_ack_irq(unsigned int irq) | |
82 | { | |
83 | fpga_mask_irq(irq); | |
84 | fpga_ack_irq(irq); | |
85 | } | |
86 | ||
87 | void innovator_fpga_IRQ_demux(unsigned int irq, struct irqdesc *desc, | |
88 | struct pt_regs *regs) | |
89 | { | |
90 | struct irqdesc *d; | |
91 | u32 stat; | |
92 | int fpga_irq; | |
93 | ||
94 | stat = get_fpga_unmasked_irqs(); | |
95 | ||
96 | if (!stat) | |
97 | return; | |
98 | ||
99 | for (fpga_irq = OMAP1510_IH_FPGA_BASE; | |
100 | (fpga_irq < (OMAP1510_IH_FPGA_BASE + NR_FPGA_IRQS)) && stat; | |
101 | fpga_irq++, stat >>= 1) { | |
102 | if (stat & 1) { | |
103 | d = irq_desc + fpga_irq; | |
664399e1 | 104 | desc_handle_irq(fpga_irq, d, regs); |
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105 | } |
106 | } | |
107 | } | |
108 | ||
38c677cb DB |
109 | static struct irq_chip omap_fpga_irq_ack = { |
110 | .name = "FPGA-ack", | |
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111 | .ack = fpga_mask_ack_irq, |
112 | .mask = fpga_mask_irq, | |
113 | .unmask = fpga_unmask_irq, | |
114 | }; | |
115 | ||
116 | ||
38c677cb DB |
117 | static struct irq_chip omap_fpga_irq = { |
118 | .name = "FPGA", | |
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119 | .ack = fpga_ack_irq, |
120 | .mask = fpga_mask_irq, | |
121 | .unmask = fpga_unmask_irq, | |
122 | }; | |
123 | ||
124 | /* | |
125 | * All of the FPGA interrupt request inputs except for the touchscreen are | |
126 | * edge-sensitive; the touchscreen is level-sensitive. The edge-sensitive | |
127 | * interrupts are acknowledged as a side-effect of reading the interrupt | |
128 | * status register from the FPGA. The edge-sensitive interrupt inputs | |
129 | * cause a problem with level interrupt requests, such as Ethernet. The | |
130 | * problem occurs when a level interrupt request is asserted while its | |
131 | * interrupt input is masked in the FPGA, which results in a missed | |
132 | * interrupt. | |
133 | * | |
134 | * In an attempt to workaround the problem with missed interrupts, the | |
135 | * mask_ack routine for all of the FPGA interrupts has been changed from | |
136 | * fpga_mask_ack_irq() to fpga_ack_irq() so that the specific FPGA interrupt | |
137 | * being serviced is left unmasked. We can do this because the FPGA cascade | |
52e405ea | 138 | * interrupt is installed with the IRQF_DISABLED flag, which leaves all |
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139 | * interrupts masked at the CPU while an FPGA interrupt handler executes. |
140 | * | |
141 | * Limited testing indicates that this workaround appears to be effective | |
142 | * for the smc9194 Ethernet driver used on the Innovator. It should work | |
143 | * on other FPGA interrupts as well, but any drivers that explicitly mask | |
144 | * interrupts at the interrupt controller via disable_irq/enable_irq | |
145 | * could pose a problem. | |
146 | */ | |
147 | void omap1510_fpga_init_irq(void) | |
148 | { | |
149 | int i; | |
150 | ||
151 | __raw_writeb(0, OMAP1510_FPGA_IMR_LO); | |
152 | __raw_writeb(0, OMAP1510_FPGA_IMR_HI); | |
153 | __raw_writeb(0, INNOVATOR_FPGA_IMR2); | |
154 | ||
155 | for (i = OMAP1510_IH_FPGA_BASE; i < (OMAP1510_IH_FPGA_BASE + NR_FPGA_IRQS); i++) { | |
156 | ||
157 | if (i == OMAP1510_INT_FPGA_TS) { | |
158 | /* | |
159 | * The touchscreen interrupt is level-sensitive, so | |
160 | * we'll use the regular mask_ack routine for it. | |
161 | */ | |
162 | set_irq_chip(i, &omap_fpga_irq_ack); | |
163 | } | |
164 | else { | |
165 | /* | |
166 | * All FPGA interrupts except the touchscreen are | |
167 | * edge-sensitive, so we won't mask them. | |
168 | */ | |
169 | set_irq_chip(i, &omap_fpga_irq); | |
170 | } | |
171 | ||
172 | set_irq_handler(i, do_edge_IRQ); | |
173 | set_irq_flags(i, IRQF_VALID); | |
174 | } | |
175 | ||
176 | /* | |
177 | * The FPGA interrupt line is connected to GPIO13. Claim this pin for | |
178 | * the ARM. | |
179 | * | |
180 | * NOTE: For general GPIO/MPUIO access and interrupts, please see | |
181 | * gpio.[ch] | |
182 | */ | |
183 | omap_request_gpio(13); | |
184 | omap_set_gpio_direction(13, 1); | |
7c38cf02 | 185 | set_irq_type(OMAP_GPIO_IRQ(13), IRQT_RISING); |
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186 | set_irq_chained_handler(OMAP1510_INT_FPGA, innovator_fpga_IRQ_demux); |
187 | } | |
188 | ||
189 | EXPORT_SYMBOL(omap1510_fpga_init_irq); |