Subversion Repositories HelenOS

Rev

Rev 3386 | Go to most recent revision | Show entire file | Ignore whitespace | Details | Blame | Last modification | View Log | RSS feed

Rev 3386 Rev 4153
Line 24... Line 24...
24 
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 24 
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 25 
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 26 
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 
 */
 27 
 */
28 
 
 28 
 
29 
/** @addtogroup ia32   
 29 
/** @addtogroup ia32
30 
 * @{
 30 
 * @{
31 
 */
 31 
 */
32 
/**
 32 
/**
33 
 * @file
 33 
 * @file
34 
 * @brief   i8254 chip driver.
 34 
 * @brief i8254 chip driver.
35 
 *
 35 
 *
36 
 * Low level time functions.
 36 
 * Low level time functions.
37 
 */
 37 
 */
38 
 
 38 
 
39 
#include <arch/types.h>
 39 
#include <arch/types.h>
Line 51... Line 51...
51 
#include <arch.h>
 51 
#include <arch.h>
52 
#include <time/delay.h>
 52 
#include <time/delay.h>
53 
#include <ddi/irq.h>
 53 
#include <ddi/irq.h>
54 
#include <ddi/device.h>
 54 
#include <ddi/device.h>
55 
 
 55 
 
56 
#define CLK_PORT1   0x40
 56 
#define CLK_PORT1   ((ioport8_t *)0x40)
57 
#define CLK_PORT4   0x43
 57 
#define CLK_PORT4   ((ioport8_t *)0x43)
58 
 
 58 
 
59 
#define CLK_CONST   1193180
 59 
#define CLK_CONST   1193180
60 
#define MAGIC_NUMBER    1194
 60 
#define MAGIC_NUMBER    1194
61 
 
 61 
 
62 
static irq_t i8254_irq;
 62 
static irq_t i8254_irq;
63 
 
 63 
 
64 
static irq_ownership_t i8254_claim(void)
 64 
static irq_ownership_t i8254_claim(irq_t *irq)
65 
{
 65 
{
66 
    return IRQ_ACCEPT;
 66 
    return IRQ_ACCEPT;
67 
}
 67 
}
68 
 
 68 
 
69 
static void i8254_irq_handler(irq_t *irq, void *arg __attribute__((unused)), ...)
 69 
static void i8254_irq_handler(irq_t *irq)
70 
{
 70 
{
71 
    /*
 71 
    /*
72 
     * This IRQ is responsible for kernel preemption.
 72 
     * This IRQ is responsible for kernel preemption.
73 
     * Nevertheless, we are now holding a spinlock which prevents
 73 
     * Nevertheless, we are now holding a spinlock which prevents
74 
     * preemption. For this particular IRQ, we don't need the
 74 
     * preemption. For this particular IRQ, we don't need the
Line 92... Line 92...
92 
    i8254_normal_operation();
 92 
    i8254_normal_operation();
93 
}
 93 
}
94 
 
 94 
 
95 
void i8254_normal_operation(void)
 95 
void i8254_normal_operation(void)
96 
{
 96 
{
97 
    outb(CLK_PORT4, 0x36);
 97 
    pio_write_8(CLK_PORT4, 0x36);
98 
    pic_disable_irqs(1 << IRQ_CLK);
 98 
    pic_disable_irqs(1 << IRQ_CLK);
99 
    outb(CLK_PORT1, (CLK_CONST / HZ) & 0xf);
 99 
    pio_write_8(CLK_PORT1, (CLK_CONST / HZ) & 0xf);
100 
    outb(CLK_PORT1, (CLK_CONST / HZ) >> 8);
 100 
    pio_write_8(CLK_PORT1, (CLK_CONST / HZ) >> 8);
101 
    pic_enable_irqs(1 << IRQ_CLK);
 101 
    pic_enable_irqs(1 << IRQ_CLK);
102 
}
 102 
}
103 
 
 103 
 
104 
#define LOOPS 150000
 104 
#define LOOPS 150000
105 
#define SHIFT 11
 105 
#define SHIFT 11
Line 112... Line 112...
112 
 
 112 
 
113 
    /*
 113 
    /*
114 
     * One-shot timer. Count-down from 0xffff at 1193180Hz
 114 
     * One-shot timer. Count-down from 0xffff at 1193180Hz
115 
     * MAGIC_NUMBER is the magic value for 1ms.
 115 
     * MAGIC_NUMBER is the magic value for 1ms.
116 
     */
 116 
     */
117 
    outb(CLK_PORT4, 0x30);
 117 
    pio_write_8(CLK_PORT4, 0x30);
118 
    outb(CLK_PORT1, 0xff);
 118 
    pio_write_8(CLK_PORT1, 0xff);
119 
    outb(CLK_PORT1, 0xff);
 119 
    pio_write_8(CLK_PORT1, 0xff);
120 
 
 120 
 
121 
    do {
 121 
    do {
122 
        /* will read both status and count */
 122 
        /* will read both status and count */
123 
        outb(CLK_PORT4, 0xc2);
 123 
        pio_write_8(CLK_PORT4, 0xc2);
124 
        not_ok = (uint8_t) ((inb(CLK_PORT1) >> 6) & 1);
 124 
        not_ok = (uint8_t) ((pio_read_8(CLK_PORT1) >> 6) & 1);
125 
        t1 = inb(CLK_PORT1);
 125 
        t1 = pio_read_8(CLK_PORT1);
126 
        t1 |= inb(CLK_PORT1) << 8;
 126 
        t1 |= pio_read_8(CLK_PORT1) << 8;
127 
    } while (not_ok);
 127 
    } while (not_ok);
128 
 
 128 
 
129 
    asm_delay_loop(LOOPS);
 129 
    asm_delay_loop(LOOPS);
130 
 
 130 
 
131 
    outb(CLK_PORT4, 0xd2);
 131 
    pio_write_8(CLK_PORT4, 0xd2);
132 
    t2 = inb(CLK_PORT1);
 132 
    t2 = pio_read_8(CLK_PORT1);
133 
    t2 |= inb(CLK_PORT1) << 8;
 133 
    t2 |= pio_read_8(CLK_PORT1) << 8;
134 
 
 134 
 
135 
    /*
 135 
    /*
136 
     * We want to determine the overhead of the calibrating mechanism.
 136 
     * We want to determine the overhead of the calibrating mechanism.
137 
     */
 137 
     */
138 
    outb(CLK_PORT4, 0xd2);
 138 
    pio_write_8(CLK_PORT4, 0xd2);
139 
    o1 = inb(CLK_PORT1);
 139 
    o1 = pio_read_8(CLK_PORT1);
140 
    o1 |= inb(CLK_PORT1) << 8;
 140 
    o1 |= pio_read_8(CLK_PORT1) << 8;
141 
 
 141 
 
142 
    asm_fake_loop(LOOPS);
 142 
    asm_fake_loop(LOOPS);
143 
 
 143 
 
144 
    outb(CLK_PORT4, 0xd2);
 144 
    pio_write_8(CLK_PORT4, 0xd2);
145 
    o2 = inb(CLK_PORT1);
 145 
    o2 = pio_read_8(CLK_PORT1);
146 
    o2 |= inb(CLK_PORT1) << 8;
 146 
    o2 |= pio_read_8(CLK_PORT1) << 8;
147 
 
 147 
 
148 
    CPU->delay_loop_const =
 148 
    CPU->delay_loop_const =
149 
        ((MAGIC_NUMBER * LOOPS) / 1000) / ((t1 - t2) - (o1 - o2)) +
 149 
        ((MAGIC_NUMBER * LOOPS) / 1000) / ((t1 - t2) - (o1 - o2)) +
150 
        (((MAGIC_NUMBER * LOOPS) / 1000) % ((t1 - t2) - (o1 - o2)) ? 1 : 0);
 150 
        (((MAGIC_NUMBER * LOOPS) / 1000) % ((t1 - t2) - (o1 - o2)) ? 1 : 0);
151 
 
 151