Linux kernel & device driver programming

Cross-Referenced Linux and Device Driver Code

[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ]
Version: [ 2.6.11.8 ] [ 2.6.25 ] [ 2.6.25.8 ] [ 2.6.31.13 ] Architecture: [ i386 ]
  1 /*
  2  *  linux/arch/arm/mach-ebsa110/core.c
  3  *
  4  *  Copyright (C) 1998-2001 Russell King
  5  *
  6  * This program is free software; you can redistribute it and/or modify
  7  * it under the terms of the GNU General Public License version 2 as
  8  * published by the Free Software Foundation.
  9  *
 10  *  Extra MM routines for the EBSA-110 architecture
 11  */
 12 #include <linux/kernel.h>
 13 #include <linux/mm.h>
 14 #include <linux/interrupt.h>
 15 #include <linux/serial_8250.h>
 16 #include <linux/init.h>
 17 #include <linux/io.h>
 18 
 19 #include <mach/hardware.h>
 20 #include <asm/irq.h>
 21 #include <asm/setup.h>
 22 #include <asm/mach-types.h>
 23 #include <asm/pgtable.h>
 24 #include <asm/page.h>
 25 #include <asm/system.h>
 26 
 27 #include <asm/mach/arch.h>
 28 #include <asm/mach/irq.h>
 29 #include <asm/mach/map.h>
 30 
 31 #include <asm/mach/time.h>
 32 
 33 #define IRQ_MASK                0xfe000000      /* read */
 34 #define IRQ_MSET                0xfe000000      /* write */
 35 #define IRQ_STAT                0xff000000      /* read */
 36 #define IRQ_MCLR                0xff000000      /* write */
 37 
 38 static void ebsa110_mask_irq(unsigned int irq)
 39 {
 40         __raw_writeb(1 << irq, IRQ_MCLR);
 41 }
 42 
 43 static void ebsa110_unmask_irq(unsigned int irq)
 44 {
 45         __raw_writeb(1 << irq, IRQ_MSET);
 46 }
 47 
 48 static struct irq_chip ebsa110_irq_chip = {
 49         .ack    = ebsa110_mask_irq,
 50         .mask   = ebsa110_mask_irq,
 51         .unmask = ebsa110_unmask_irq,
 52 };
 53  
 54 static void __init ebsa110_init_irq(void)
 55 {
 56         unsigned long flags;
 57         unsigned int irq;
 58 
 59         local_irq_save(flags);
 60         __raw_writeb(0xff, IRQ_MCLR);
 61         __raw_writeb(0x55, IRQ_MSET);
 62         __raw_writeb(0x00, IRQ_MSET);
 63         if (__raw_readb(IRQ_MASK) != 0x55)
 64                 while (1);
 65         __raw_writeb(0xff, IRQ_MCLR);   /* clear all interrupt enables */
 66         local_irq_restore(flags);
 67 
 68         for (irq = 0; irq < NR_IRQS; irq++) {
 69                 set_irq_chip(irq, &ebsa110_irq_chip);
 70                 set_irq_handler(irq, handle_level_irq);
 71                 set_irq_flags(irq, IRQF_VALID | IRQF_PROBE);
 72         }
 73 }
 74 
 75 static struct map_desc ebsa110_io_desc[] __initdata = {
 76         /*
 77          * sparse external-decode ISAIO space
 78          */
 79         {       /* IRQ_STAT/IRQ_MCLR */
 80                 .virtual        = IRQ_STAT,
 81                 .pfn            = __phys_to_pfn(TRICK4_PHYS),
 82                 .length         = PGDIR_SIZE,
 83                 .type           = MT_DEVICE
 84         }, {    /* IRQ_MASK/IRQ_MSET */
 85                 .virtual        = IRQ_MASK,
 86                 .pfn            = __phys_to_pfn(TRICK3_PHYS),
 87                 .length         = PGDIR_SIZE,
 88                 .type           = MT_DEVICE
 89         }, {    /* SOFT_BASE */
 90                 .virtual        = SOFT_BASE,
 91                 .pfn            = __phys_to_pfn(TRICK1_PHYS),
 92                 .length         = PGDIR_SIZE,
 93                 .type           = MT_DEVICE
 94         }, {    /* PIT_BASE */
 95                 .virtual        = PIT_BASE,
 96                 .pfn            = __phys_to_pfn(TRICK0_PHYS),
 97                 .length         = PGDIR_SIZE,
 98                 .type           = MT_DEVICE
 99         },
100 
101         /*
102          * self-decode ISAIO space
103          */
104         {
105                 .virtual        = ISAIO_BASE,
106                 .pfn            = __phys_to_pfn(ISAIO_PHYS),
107                 .length         = ISAIO_SIZE,
108                 .type           = MT_DEVICE
109         }, {
110                 .virtual        = ISAMEM_BASE,
111                 .pfn            = __phys_to_pfn(ISAMEM_PHYS),
112                 .length         = ISAMEM_SIZE,
113                 .type           = MT_DEVICE
114         }
115 };
116 
117 static void __init ebsa110_map_io(void)
118 {
119         iotable_init(ebsa110_io_desc, ARRAY_SIZE(ebsa110_io_desc));
120 }
121 
122 
123 #define PIT_CTRL                (PIT_BASE + 0x0d)
124 #define PIT_T2                  (PIT_BASE + 0x09)
125 #define PIT_T1                  (PIT_BASE + 0x05)
126 #define PIT_T0                  (PIT_BASE + 0x01)
127 
128 /*
129  * This is the rate at which your MCLK signal toggles (in Hz)
130  * This was measured on a 10 digit frequency counter sampling
131  * over 1 second.
132  */
133 #define MCLK    47894000
134 
135 /*
136  * This is the rate at which the PIT timers get clocked
137  */
138 #define CLKBY7  (MCLK / 7)
139 
140 /*
141  * This is the counter value.  We tick at 200Hz on this platform.
142  */
143 #define COUNT   ((CLKBY7 + (HZ / 2)) / HZ)
144 
145 /*
146  * Get the time offset from the system PIT.  Note that if we have missed an
147  * interrupt, then the PIT counter will roll over (ie, be negative).
148  * This actually works out to be convenient.
149  */
150 static unsigned long ebsa110_gettimeoffset(void)
151 {
152         unsigned long offset, count;
153 
154         __raw_writeb(0x40, PIT_CTRL);
155         count = __raw_readb(PIT_T1);
156         count |= __raw_readb(PIT_T1) << 8;
157 
158         /*
159          * If count > COUNT, make the number negative.
160          */
161         if (count > COUNT)
162                 count |= 0xffff0000;
163 
164         offset = COUNT;
165         offset -= count;
166 
167         /*
168          * `offset' is in units of timer counts.  Convert
169          * offset to units of microseconds.
170          */
171         offset = offset * (1000000 / HZ) / COUNT;
172 
173         return offset;
174 }
175 
176 static irqreturn_t
177 ebsa110_timer_interrupt(int irq, void *dev_id)
178 {
179         u32 count;
180 
181         /* latch and read timer 1 */
182         __raw_writeb(0x40, PIT_CTRL);
183         count = __raw_readb(PIT_T1);
184         count |= __raw_readb(PIT_T1) << 8;
185 
186         count += COUNT;
187 
188         __raw_writeb(count & 0xff, PIT_T1);
189         __raw_writeb(count >> 8, PIT_T1);
190 
191         timer_tick();
192 
193         return IRQ_HANDLED;
194 }
195 
196 static struct irqaction ebsa110_timer_irq = {
197         .name           = "EBSA110 Timer Tick",
198         .flags          = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
199         .handler        = ebsa110_timer_interrupt,
200 };
201 
202 /*
203  * Set up timer interrupt.
204  */
205 static void __init ebsa110_timer_init(void)
206 {
207         /*
208          * Timer 1, mode 2, LSB/MSB
209          */
210         __raw_writeb(0x70, PIT_CTRL);
211         __raw_writeb(COUNT & 0xff, PIT_T1);
212         __raw_writeb(COUNT >> 8, PIT_T1);
213 
214         setup_irq(IRQ_EBSA110_TIMER0, &ebsa110_timer_irq);
215 }
216 
217 static struct sys_timer ebsa110_timer = {
218         .init           = ebsa110_timer_init,
219         .offset         = ebsa110_gettimeoffset,
220 };
221 
222 static struct plat_serial8250_port serial_platform_data[] = {
223         {
224                 .iobase         = 0x3f8,
225                 .irq            = 1,
226                 .uartclk        = 1843200,
227                 .regshift       = 0,
228                 .iotype         = UPIO_PORT,
229                 .flags          = UPF_BOOT_AUTOCONF | UPF_SKIP_TEST,
230         },
231         {
232                 .iobase         = 0x2f8,
233                 .irq            = 2,
234                 .uartclk        = 1843200,
235                 .regshift       = 0,
236                 .iotype         = UPIO_PORT,
237                 .flags          = UPF_BOOT_AUTOCONF | UPF_SKIP_TEST,
238         },
239         { },
240 };
241 
242 static struct platform_device serial_device = {
243         .name                   = "serial8250",
244         .id                     = PLAT8250_DEV_PLATFORM,
245         .dev                    = {
246                 .platform_data  = serial_platform_data,
247         },
248 };
249 
250 static struct resource am79c961_resources[] = {
251         {
252                 .start          = 0x220,
253                 .end            = 0x238,
254                 .flags          = IORESOURCE_IO,
255         }, {
256                 .start          = IRQ_EBSA110_ETHERNET,
257                 .end            = IRQ_EBSA110_ETHERNET,
258                 .flags          = IORESOURCE_IRQ,
259         },
260 };
261 
262 static struct platform_device am79c961_device = {
263         .name                   = "am79c961",
264         .id                     = -1,
265         .num_resources          = ARRAY_SIZE(am79c961_resources),
266         .resource               = am79c961_resources,
267 };
268 
269 static struct platform_device *ebsa110_devices[] = {
270         &serial_device,
271         &am79c961_device,
272 };
273 
274 static int __init ebsa110_init(void)
275 {
276         return platform_add_devices(ebsa110_devices, ARRAY_SIZE(ebsa110_devices));
277 }
278 
279 arch_initcall(ebsa110_init);
280 
281 MACHINE_START(EBSA110, "EBSA110")
282         /* Maintainer: Russell King */
283         .phys_io        = 0xe0000000,
284         .io_pg_offst    = ((0xe0000000) >> 18) & 0xfffc,
285         .boot_params    = 0x00000400,
286         .reserve_lp0    = 1,
287         .reserve_lp2    = 1,
288         .soft_reboot    = 1,
289         .map_io         = ebsa110_map_io,
290         .init_irq       = ebsa110_init_irq,
291         .timer          = &ebsa110_timer,
292 MACHINE_END
293 
  This page was automatically generated by the LXR engine.