it8587e, it5570e: Implement logging to parport

Implement configuring the keyboard controller as a parallel host device
and writing to the parallel port. This allows the EC to send log
messages over the port.

src/ec/it5570e/include/ec/parallel.h

@@ -0,0 +1,9 @@
+#ifndef _EC_PARALLEL_H
+#define _EC_PARALLEL_H
+
+#include <stdint.h>
+
+void parport_init(void);
+int parport_write(uint8_t * data, int length);
+
+#endif // _EC_PARALLEL_H

src/ec/it5570e/parallel.c

@@ -0,0 +1,122 @@
+#include <arch/delay.h>
+#include <arch/time.h>
+#include <ec/kbscan.h>
+#include <ec/parallel.h>
+
+#include <stdbool.h>
+
+/*
+ * nWRITE   = KSI[0]
+ * nDATASTB = KSI[1]
+ * nRESET   = KSI[2]
+ * nADDRSTB = KSI[3]
+ *
+ * AD[8:1]  = KSOL[7:0]
+ * nINTR    = KSOH[0]
+ * nWAIT    = KSOH[1]
+ */
+
+#define CTL_WRITE   (1 << 0)
+#define CTL_DATA    (1 << 1)
+#define CTL_RESET   (1 << 2)
+#define CTL_ADDR    (1 << 3)
+
+#define STS_WAIT    (1 << 1)
+
+// Maximum peripheral response time in ms
+#define PARPORT_TIMEOUT 35
+
+void parport_init(void) {
+    // XXX: Needed? Pull-ups, open-drain are always disabled in GPIO mode
+    KSOCTRL = 0;
+    // XXX: Needed? OVRPPK is for KBS mode, pull-ups are always disabled in GPIO mode
+    KSICTRLR = (1 << 4);
+
+    // Set all outputs to GPIO mode, low, and inputs
+    KSOL = 0;
+    KSOLGCTRL = 0xFF;
+    KSOLGOEN = 0;
+    KSOH1 = 0;
+    KSOHGCTRL = 0xFF;
+    KSOHGOEN = 0;
+    KSOH2 = 0;
+
+    // Set control lines as outputs, low
+    KSIGCTRL = 0xFF;
+    KSIGOEN = 0x0F;
+    KSIGDAT = 0;
+
+    // Assert nRESET
+    KSIGDAT &= ~CTL_RESET;
+
+    // Deassert nWRITE, nDATASTB, nADDRSTB
+    KSIGDAT |= CTL_WRITE | CTL_DATA | CTL_ADDR;
+
+    // Set nWAIT high
+    KSOH1 |= STS_WAIT;
+
+    // Pull up data lines
+    KSOL = 0xFF;
+
+    // Deassert nRESET
+    KSIGDAT |= CTL_RESET;
+}
+
+bool parport_wait_peripheral(uint8_t mask, uint8_t value) {
+    uint32_t start = time_get();
+
+    while (time_get() < start + PARPORT_TIMEOUT) {
+        if ((KSOHGDMRR & mask) == value) {
+            return true;
+        }
+    }
+
+    return false;
+}
+
+int parport_write(uint8_t * data, int length) {
+    // Assert nWRITE
+    KSIGDAT &= ~CTL_WRITE;
+
+    // Set data lines as outputs
+    KSOLGOEN = 0xFF;
+
+    int i;
+    for (i = 0; i < length; i++) {
+        // Wait for peripheral to indicate it's ready for next cycle
+        if (!parport_wait_peripheral(STS_WAIT, 0)) {
+            break;
+        }
+
+        // Write data to port
+        KSOL = data[i];
+
+        // Assert nDATASTB
+        KSIGDAT &= ~CTL_DATA;
+        delay_us(1);
+
+        // Wait for peripheral to indicate it's ready
+        if (!parport_wait_peripheral(STS_WAIT, STS_WAIT)) {
+            KSIGDAT |= CTL_DATA;
+            break;
+        }
+
+        // Deassert nDATASTB
+        KSIGDAT |= CTL_DATA;
+        delay_us(1);
+
+        // XXX: Arduino takes a while to read?
+        delay_us(5);
+
+        // Reset data lines to high
+        KSOL = 0xFF;
+    }
+
+    // Set data lines back to inputs
+    KSOLGOEN = 0;
+
+    // Deassert nWRITE
+    KSIGDAT |= CTL_WRITE;
+
+    return i;
+}

src/ec/it8587e/include/ec/parallel.h

@@ -0,0 +1,9 @@
+#ifndef _EC_PARALLEL_H
+#define _EC_PARALLEL_H
+
+#include <stdint.h>
+
+void parport_init(void);
+int parport_write(uint8_t * data, int length);
+
+#endif // _EC_PARALLEL_H

src/ec/it8587e/parallel.c

@@ -0,0 +1,122 @@
+#include <arch/delay.h>
+#include <arch/time.h>
+#include <ec/kbscan.h>
+#include <ec/parallel.h>
+
+#include <stdbool.h>
+
+/*
+ * nWRITE   = KSI[0]
+ * nDATASTB = KSI[1]
+ * nRESET   = KSI[2]
+ * nADDRSTB = KSI[3]
+ *
+ * AD[8:1]  = KSOL[7:0]
+ * nINTR    = KSOH[0]
+ * nWAIT    = KSOH[1]
+ */
+
+#define CTL_WRITE   (1 << 0)
+#define CTL_DATA    (1 << 1)
+#define CTL_RESET   (1 << 2)
+#define CTL_ADDR    (1 << 3)
+
+#define STS_WAIT    (1 << 1)
+
+// Maximum peripheral response time in ms
+#define PARPORT_TIMEOUT 35
+
+void parport_init(void) {
+    // XXX: Needed? Pull-ups, open-drain are always disabled in GPIO mode
+    KSOCTRL = 0;
+    // XXX: Needed? OVRPPK is for KBS mode, pull-ups are always disabled in GPIO mode
+    KSICTRLR = (1 << 4);
+
+    // Set all outputs to GPIO mode, low, and inputs
+    KSOL = 0;
+    KSOLGCTRL = 0xFF;
+    KSOLGOEN = 0;
+    KSOH1 = 0;
+    KSOHGCTRL = 0xFF;
+    KSOHGOEN = 0;
+    KSOH2 = 0;
+
+    // Set control lines as outputs, low
+    KSIGCTRL = 0xFF;
+    KSIGOEN = 0x0F;
+    KSIGDAT = 0;
+
+    // Assert nRESET
+    KSIGDAT &= ~CTL_RESET;
+
+    // Deassert nWRITE, nDATASTB, nADDRSTB
+    KSIGDAT |= CTL_WRITE | CTL_DATA | CTL_ADDR;
+
+    // Set nWAIT high
+    KSOH1 |= STS_WAIT;
+
+    // Pull up data lines
+    KSOL = 0xFF;
+
+    // Deassert nRESET
+    KSIGDAT |= CTL_RESET;
+}
+
+bool parport_wait_peripheral(uint8_t mask, uint8_t value) {
+    uint32_t start = time_get();
+
+    while (time_get() < start + PARPORT_TIMEOUT) {
+        if ((KSOHGDMRR & mask) == value) {
+            return true;
+        }
+    }
+
+    return false;
+}
+
+int parport_write(uint8_t * data, int length) {
+    // Assert nWRITE
+    KSIGDAT &= ~CTL_WRITE;
+
+    // Set data lines as outputs
+    KSOLGOEN = 0xFF;
+
+    int i;
+    for (i = 0; i < length; i++) {
+        // Wait for peripheral to indicate it's ready for next cycle
+        if (!parport_wait_peripheral(STS_WAIT, 0)) {
+            break;
+        }
+
+        // Write data to port
+        KSOL = data[i];
+
+        // Assert nDATASTB
+        KSIGDAT &= ~CTL_DATA;
+        delay_us(1);
+
+        // Wait for peripheral to indicate it's ready
+        if (!parport_wait_peripheral(STS_WAIT, STS_WAIT)) {
+            KSIGDAT |= CTL_DATA;
+            break;
+        }
+
+        // Deassert nDATASTB
+        KSIGDAT |= CTL_DATA;
+        delay_us(1);
+
+        // XXX: Arduino takes a while to read?
+        delay_us(5);
+
+        // Reset data lines to high
+        KSOL = 0xFF;
+    }
+
+    // Set data lines back to inputs
+    KSOLGOEN = 0;
+
+    // Deassert nWRITE
+    KSIGDAT |= CTL_WRITE;
+
+    return i;
+}