X-Git-Url: https://git.gag.com/?p=fw%2Faltos;a=blobdiff_plain;f=src%2Flpc%2Fao_fast_timer_lpc.c;fp=src%2Flpc%2Fao_fast_timer_lpc.c;h=c4f26fc40af8ef41a0f3189f2b17a2d9685b796f;hp=0000000000000000000000000000000000000000;hb=b31c6fd153825ae5ad0fcea7189472af1a9cffff;hpb=a86d98b708d84c6e0b85cb950e3f1ee16cfc56f5

diff --git a/src/lpc/ao_fast_timer_lpc.c b/src/lpc/ao_fast_timer_lpc.c
new file mode 100644
index 00000000..c4f26fc4
--- /dev/null
+++ b/src/lpc/ao_fast_timer_lpc.c
@@ -0,0 +1,110 @@
+/*
+ * Copyright © 2016 Keith Packard <keithp@keithp.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ */
+
+#include <ao.h>
+#include <ao_fast_timer.h>
+
+static void (*ao_fast_timer_callback[AO_FAST_TIMER_MAX])(void);
+static uint8_t ao_fast_timer_count;
+static uint8_t ao_fast_timer_users;
+
+static void
+ao_fast_timer_enable(void)
+{
+	lpc_ct16b0.tcr = ((1 << LPC_CT16B_TCR_CEN) |
+			  (1 << LPC_CT16B_TCR_CRST));
+}
+
+static void
+ao_fast_timer_disable(void)
+{
+	lpc_ct16b0.tcr = ((0 << LPC_CT16B_TCR_CEN) |
+			  (0 << LPC_CT16B_TCR_CRST));
+}
+
+void
+ao_fast_timer_on(void (*callback)(void))
+{
+	ao_fast_timer_callback[ao_fast_timer_count] = callback;
+	if (!ao_fast_timer_count++)
+		ao_fast_timer_enable();
+}
+
+void
+ao_fast_timer_off(void (*callback)(void))
+{
+	uint8_t	n;
+
+	for (n = 0; n < ao_fast_timer_count; n++)
+		if (ao_fast_timer_callback[n] == callback) {
+			for (; n < ao_fast_timer_count-1; n++) {
+				ao_fast_timer_callback[n] = ao_fast_timer_callback[n+1];
+			}
+			if (!--ao_fast_timer_count)
+				ao_fast_timer_disable();
+			break;
+		}
+}
+
+void lpc_ct16b0_isr(void)
+{
+	uint32_t	v = lpc_ct16b0.ir;
+	int		i;
+
+	lpc_ct16b0.ir = v;
+	if (v & (1 << LPC_CT16B_IR_MR0INT)) {
+		for (i = 0; i < ao_fast_timer_count; i++)
+			(*ao_fast_timer_callback[i])();
+	}
+}
+
+#ifndef FAST_TIMER_FREQ
+#define FAST_TIMER_FREQ	10000
+#endif
+
+#define TIMER_FAST	(AO_LPC_SYSCLK / FAST_TIMER_FREQ)
+
+void
+ao_fast_timer_init(void)
+{
+	if (!ao_fast_timer_users) {
+
+		lpc_nvic_set_enable(LPC_ISR_CT16B0_POS);
+		lpc_nvic_set_priority(LPC_ISR_CT16B0_POS, AO_LPC_NVIC_CLOCK_PRIORITY);
+		/* Turn on 16-bit timer CT16B0 */
+
+		lpc_scb.sysahbclkctrl |= 1 << LPC_SCB_SYSAHBCLKCTRL_CT16B0;
+
+		/* Disable timer */
+		lpc_ct16b0.tcr = 0;
+
+		/* scale factor 1 */
+		lpc_ct16b0.pr = 0;
+		lpc_ct16b0.pc = 0;
+
+		lpc_ct16b0.mcr = ((1 << LPC_CT16B_MCR_MR0I) |
+				  (1 << LPC_CT16B_MCR_MR0R));
+
+		lpc_ct16b0.mr[0] = TIMER_FAST;
+
+		ao_fast_timer_disable();
+	}
+	if (ao_fast_timer_users == AO_FAST_TIMER_MAX)
+		ao_panic(AO_PANIC_FAST_TIMER);
+	ao_fast_timer_users++;
+}
+