1/*
2 *  linux/arch/arm/mach-omap1/ams-delta-fiq-handler.S
3 *
4 *  Based on  linux/arch/arm/lib/floppydma.S
5 *  Renamed and modified to work with 2.6 kernel by Matt Callow
6 *  Copyright (C) 1995, 1996 Russell King
7 *  Copyright (C) 2004 Pete Trapps
8 *  Copyright (C) 2006 Matt Callow
9 *  Copyright (C) 2010 Janusz Krzysztofik
10 *
11 * This program is free software; you can redistribute it and/or modify it
12 * under the terms of the GNU General Public License version 2
13 * as published by the Free Software Foundation.
14 */
15
16#include <linux/linkage.h>
17#include <asm/assembler.h>
18
19#include <mach/board-ams-delta.h>
20
21#include <mach/irqs.h>
22#include <mach/ams-delta-fiq.h>
23
24#include "iomap.h"
25
26/*
27 * GPIO related definitions, copied from arch/arm/plat-omap/gpio.c.
28 * Unfortunately, those were not placed in a separate header file.
29 */
30#define OMAP1510_GPIO_BASE		0xFFFCE000
31#define OMAP1510_GPIO_DATA_INPUT	0x00
32#define OMAP1510_GPIO_DATA_OUTPUT	0x04
33#define OMAP1510_GPIO_DIR_CONTROL	0x08
34#define OMAP1510_GPIO_INT_CONTROL	0x0c
35#define OMAP1510_GPIO_INT_MASK		0x10
36#define OMAP1510_GPIO_INT_STATUS	0x14
37#define OMAP1510_GPIO_PIN_CONTROL	0x18
38
39/* GPIO register bitmasks */
40#define KEYBRD_DATA_MASK		(0x1 << AMS_DELTA_GPIO_PIN_KEYBRD_DATA)
41#define KEYBRD_CLK_MASK			(0x1 << AMS_DELTA_GPIO_PIN_KEYBRD_CLK)
42#define MODEM_IRQ_MASK			(0x1 << AMS_DELTA_GPIO_PIN_MODEM_IRQ)
43#define HOOK_SWITCH_MASK		(0x1 << AMS_DELTA_GPIO_PIN_HOOK_SWITCH)
44#define OTHERS_MASK			(MODEM_IRQ_MASK | HOOK_SWITCH_MASK)
45
46/* IRQ handler register bitmasks */
47#define DEFERRED_FIQ_MASK		(0x1 << (INT_DEFERRED_FIQ % IH2_BASE))
48#define GPIO_BANK1_MASK  		(0x1 << INT_GPIO_BANK1)
49
50/* Driver buffer byte offsets */
51#define BUF_MASK			(FIQ_MASK * 4)
52#define BUF_STATE			(FIQ_STATE * 4)
53#define BUF_KEYS_CNT			(FIQ_KEYS_CNT * 4)
54#define BUF_TAIL_OFFSET			(FIQ_TAIL_OFFSET * 4)
55#define BUF_HEAD_OFFSET			(FIQ_HEAD_OFFSET * 4)
56#define BUF_BUF_LEN			(FIQ_BUF_LEN * 4)
57#define BUF_KEY				(FIQ_KEY * 4)
58#define BUF_MISSED_KEYS			(FIQ_MISSED_KEYS * 4)
59#define BUF_BUFFER_START		(FIQ_BUFFER_START * 4)
60#define BUF_GPIO_INT_MASK		(FIQ_GPIO_INT_MASK * 4)
61#define BUF_KEYS_HICNT			(FIQ_KEYS_HICNT * 4)
62#define BUF_IRQ_PEND			(FIQ_IRQ_PEND * 4)
63#define BUF_SIR_CODE_L1			(FIQ_SIR_CODE_L1 * 4)
64#define BUF_SIR_CODE_L2			(IRQ_SIR_CODE_L2 * 4)
65#define BUF_CNT_INT_00			(FIQ_CNT_INT_00 * 4)
66#define BUF_CNT_INT_KEY			(FIQ_CNT_INT_KEY * 4)
67#define BUF_CNT_INT_MDM			(FIQ_CNT_INT_MDM * 4)
68#define BUF_CNT_INT_03			(FIQ_CNT_INT_03 * 4)
69#define BUF_CNT_INT_HSW			(FIQ_CNT_INT_HSW * 4)
70#define BUF_CNT_INT_05			(FIQ_CNT_INT_05 * 4)
71#define BUF_CNT_INT_06			(FIQ_CNT_INT_06 * 4)
72#define BUF_CNT_INT_07			(FIQ_CNT_INT_07 * 4)
73#define BUF_CNT_INT_08			(FIQ_CNT_INT_08 * 4)
74#define BUF_CNT_INT_09			(FIQ_CNT_INT_09 * 4)
75#define BUF_CNT_INT_10			(FIQ_CNT_INT_10 * 4)
76#define BUF_CNT_INT_11			(FIQ_CNT_INT_11 * 4)
77#define BUF_CNT_INT_12			(FIQ_CNT_INT_12 * 4)
78#define BUF_CNT_INT_13			(FIQ_CNT_INT_13 * 4)
79#define BUF_CNT_INT_14			(FIQ_CNT_INT_14 * 4)
80#define BUF_CNT_INT_15			(FIQ_CNT_INT_15 * 4)
81#define BUF_CIRC_BUFF			(FIQ_CIRC_BUFF * 4)
82
83
84/*
85 * Register usage
86 * r8  - temporary
87 * r9  - the driver buffer
88 * r10 - temporary
89 * r11 - interrupts mask
90 * r12 - base pointers
91 * r13 - interrupts status
92 */
93
94	.text
95
96	.global qwerty_fiqin_end
97
98ENTRY(qwerty_fiqin_start)
99	@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
100	@ FIQ intrrupt handler
101	ldr r12, omap_ih1_base			@ set pointer to level1 handler
102
103	ldr r11, [r12, #IRQ_MIR_REG_OFFSET]	@ fetch interrupts mask
104
105	ldr r13, [r12, #IRQ_ITR_REG_OFFSET]	@ fetch interrupts status
106	bics r13, r13, r11			@ clear masked - any left?
107	beq exit				@ none - spurious FIQ? exit
108
109	ldr r10, [r12, #IRQ_SIR_FIQ_REG_OFFSET]	@ get requested interrupt number
110
111	mov r8, #2				@ reset FIQ agreement
112	str r8, [r12, #IRQ_CONTROL_REG_OFFSET]
113
114	cmp r10, #INT_GPIO_BANK1		@ is it GPIO bank interrupt?
115	beq gpio				@ yes - process it
116
117	mov r8, #1
118	orr r8, r11, r8, lsl r10		@ mask spurious interrupt
119	str r8, [r12, #IRQ_MIR_REG_OFFSET]
120exit:
121	subs	pc, lr, #4			@ return from FIQ
122	@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
123
124
125	@@@@@@@@@@@@@@@@@@@@@@@@@@@
126gpio:	@ GPIO bank interrupt handler
127	ldr r12, omap1510_gpio_base		@ set base pointer to GPIO bank
128
129	ldr r11, [r12, #OMAP1510_GPIO_INT_MASK]	@ fetch GPIO interrupts mask
130restart:
131	ldr r13, [r12, #OMAP1510_GPIO_INT_STATUS]	@ fetch status bits
132	bics r13, r13, r11			@ clear masked - any left?
133	beq exit				@ no - spurious interrupt? exit
134
135	orr r11, r11, r13			@ mask all requested interrupts
136	str r11, [r12, #OMAP1510_GPIO_INT_MASK]
137
138	ands r10, r13, #KEYBRD_CLK_MASK		@ extract keyboard status - set?
139	beq hksw				@ no - try next source
140
141
142	@@@@@@@@@@@@@@@@@@@@@@
143	@ Keyboard clock FIQ mode interrupt handler
144	@ r10 now contains KEYBRD_CLK_MASK, use it
145	str r10, [r12, #OMAP1510_GPIO_INT_STATUS]	@ ack the interrupt
146	bic r11, r11, r10				@ unmask it
147	str r11, [r12, #OMAP1510_GPIO_INT_MASK]
148
149	@ Process keyboard data
150	ldr r8, [r12, #OMAP1510_GPIO_DATA_INPUT]	@ fetch GPIO input
151
152	ldr r10, [r9, #BUF_STATE]		@ fetch kbd interface state
153	cmp r10, #0				@ are we expecting start bit?
154	bne data				@ no - go to data processing
155
156	ands r8, r8, #KEYBRD_DATA_MASK		@ check start bit - detected?
157	beq hksw				@ no - try next source
158
159	@ r8 contains KEYBRD_DATA_MASK, use it
160	str r8, [r9, #BUF_STATE]		@ enter data processing state
161	@ r10 already contains 0, reuse it
162	str r10, [r9, #BUF_KEY]			@ clear keycode
163	mov r10, #2				@ reset input bit mask
164	str r10, [r9, #BUF_MASK]
165
166	@ Mask other GPIO line interrupts till key done
167	str r11, [r9, #BUF_GPIO_INT_MASK]	@ save mask for later restore
168	mvn r11, #KEYBRD_CLK_MASK		@ prepare all except kbd mask
169	str r11, [r12, #OMAP1510_GPIO_INT_MASK]	@ store into the mask register
170
171	b restart				@ restart
172
173data:	ldr r10, [r9, #BUF_MASK]		@ fetch current input bit mask
174
175	@ r8 still contains GPIO input bits
176	ands r8, r8, #KEYBRD_DATA_MASK		@ is keyboard data line low?
177	ldreq r8, [r9, #BUF_KEY]		@ yes - fetch collected so far,
178	orreq r8, r8, r10			@ set 1 at current mask position
179	streq r8, [r9, #BUF_KEY]		@ and save back
180
181	mov r10, r10, lsl #1			@ shift mask left
182	bics r10, r10, #0x800			@ have we got all the bits?
183	strne r10, [r9, #BUF_MASK]		@ not yet - store the mask
184	bne restart				@ and restart
185
186	@ r10 already contains 0, reuse it
187	str r10, [r9, #BUF_STATE]		@ reset state to start
188
189	@ Key done - restore interrupt mask
190	ldr r10, [r9, #BUF_GPIO_INT_MASK]	@ fetch saved mask
191	and r11, r11, r10			@ unmask all saved as unmasked
192	str r11, [r12, #OMAP1510_GPIO_INT_MASK]	@ restore into the mask register
193
194	@ Try appending the keycode to the circular buffer
195	ldr r10, [r9, #BUF_KEYS_CNT]		@ get saved keystrokes count
196	ldr r8, [r9, #BUF_BUF_LEN]		@ get buffer size
197	cmp r10, r8				@ is buffer full?
198	beq hksw				@ yes - key lost, next source
199
200	add r10, r10, #1			@ incremet keystrokes counter
201	str r10, [r9, #BUF_KEYS_CNT]
202
203	ldr r10, [r9, #BUF_TAIL_OFFSET]		@ get buffer tail offset
204	@ r8 already contains buffer size
205	cmp r10, r8				@ end of buffer?
206	moveq r10, #0				@ yes - rewind to buffer start
207
208	ldr r12, [r9, #BUF_BUFFER_START]	@ get buffer start address
209	add r12, r12, r10, LSL #2		@ calculate buffer tail address
210	ldr r8, [r9, #BUF_KEY]			@ get last keycode
211	str r8, [r12]				@ append it to the buffer tail
212
213	add r10, r10, #1			@ increment buffer tail offset
214	str r10, [r9, #BUF_TAIL_OFFSET]
215
216	ldr r10, [r9, #BUF_CNT_INT_KEY]		@ increment interrupts counter
217	add r10, r10, #1
218	str r10, [r9, #BUF_CNT_INT_KEY]
219	@@@@@@@@@@@@@@@@@@@@@@@@
220
221
222hksw:	@Is hook switch interrupt requested?
223	tst r13, #HOOK_SWITCH_MASK 		@ is hook switch status bit set?
224	beq mdm					@ no - try next source
225
226
227	@@@@@@@@@@@@@@@@@@@@@@@@
228	@ Hook switch interrupt FIQ mode simple handler
229
230	@ Don't toggle active edge, the switch always bounces
231
232	@ Increment hook switch interrupt counter
233	ldr r10, [r9, #BUF_CNT_INT_HSW]
234	add r10, r10, #1
235	str r10, [r9, #BUF_CNT_INT_HSW]
236	@@@@@@@@@@@@@@@@@@@@@@@@
237
238
239mdm:	@Is it a modem interrupt?
240	tst r13, #MODEM_IRQ_MASK 		@ is modem status bit set?
241	beq irq					@ no - check for next interrupt
242
243
244	@@@@@@@@@@@@@@@@@@@@@@@@
245	@ Modem FIQ mode interrupt handler stub
246
247	@ Increment modem interrupt counter
248	ldr r10, [r9, #BUF_CNT_INT_MDM]
249	add r10, r10, #1
250	str r10, [r9, #BUF_CNT_INT_MDM]
251	@@@@@@@@@@@@@@@@@@@@@@@@
252
253
254irq:	@ Place deferred_fiq interrupt request
255	ldr r12, deferred_fiq_ih_base		@ set pointer to IRQ handler
256	mov r10, #DEFERRED_FIQ_MASK		@ set deferred_fiq bit
257	str r10, [r12, #IRQ_ISR_REG_OFFSET] 	@ place it in the ISR register
258
259	ldr r12, omap1510_gpio_base		@ set pointer back to GPIO bank
260	b restart				@ check for next GPIO interrupt
261	@@@@@@@@@@@@@@@@@@@@@@@@@@@
262
263
264/*
265 * Virtual addresses for IO
266 */
267omap_ih1_base:
268	.word OMAP1_IO_ADDRESS(OMAP_IH1_BASE)
269deferred_fiq_ih_base:
270	.word OMAP1_IO_ADDRESS(DEFERRED_FIQ_IH_BASE)
271omap1510_gpio_base:
272	.word OMAP1_IO_ADDRESS(OMAP1510_GPIO_BASE)
273qwerty_fiqin_end:
274
275/*
276 * Check the size of the FIQ,
277 * it cannot go beyond 0xffff0200, and is copied to 0xffff001c
278 */
279.if (qwerty_fiqin_end - qwerty_fiqin_start) > (0x200 - 0x1c)
280	.err
281.endif
282