63 lines
1.3 KiB
C
63 lines
1.3 KiB
C
struct Lpc {
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u16 data_port;
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u16 cmd_port;
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};
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static struct Lpc lpc_new(void) {
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struct Lpc lpc = {
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.data_port = 0x62,
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.cmd_port = 0x66,
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};
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return lpc;
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}
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static u8 lpc_sts(struct Lpc * lpc) {
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return inb(lpc->cmd_port);
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}
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static bool lpc_can_read(struct Lpc * lpc) {
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return (lpc_sts(lpc) & 1) == 1;
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}
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static int lpc_wait_read(struct Lpc * lpc, int timeout) {
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while (! lpc_can_read(lpc) && timeout > 0) {
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timeout -= 1;
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}
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return timeout;
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}
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static bool lpc_can_write(struct Lpc * lpc) {
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return (lpc_sts(lpc) & 2) == 0;
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}
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static int lpc_wait_write(struct Lpc * lpc, int timeout) {
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while (! lpc_can_write(lpc) && timeout > 0) {
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timeout -= 1;
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}
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return timeout;
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}
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static int lpc_cmd(struct Lpc * lpc, u8 data, int timeout) {
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timeout = lpc_wait_write(lpc, timeout);
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if (timeout > 0) {
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outb(lpc->cmd_port, data);
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}
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return timeout;
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}
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static int lpc_read(struct Lpc * lpc, u8 * data, int timeout) {
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timeout = lpc_wait_read(lpc, timeout);
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if (timeout > 0) {
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*data = inb(lpc->data_port);
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}
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return timeout;
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}
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static int lpc_write(struct Lpc * lpc, u8 data, int timeout) {
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timeout = lpc_wait_write(lpc, timeout);
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if (timeout > 0) {
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outb(lpc->data_port, data);
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}
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return timeout;
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}
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