altos/lpc: Add beep driver

Hardwired to our current beeper pin

Signed-off-by: Keith Packard <keithp@keithp.com>

diff --git a/src/lpc/ao_beep_lpc.c b/src/lpc/ao_beep_lpc.c
new file mode 100644 (file)
index 0000000..281f981
--- /dev/null
+++ b/src/lpc/ao_beep_lpc.c
@@ -0,0 +1,83 @@
+/*
+ * Copyright © 2013 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"
+
+void
+ao_beep(uint8_t beep)
+{
+       if (beep == 0) {
+               lpc_ct32b1.tcr = ((0 << LPC_CT32B_TCR_CEN) |
+                                 (1 << LPC_CT32B_TCR_CRST));
+               lpc_scb.sysahbclkctrl &= ~(1 << LPC_SCB_SYSAHBCLKCTRL_CT32B1);
+       } else {
+               lpc_scb.sysahbclkctrl |= (1 << LPC_SCB_SYSAHBCLKCTRL_CT32B1);
+
+               /* Set prescaler to match cc1111 clocks
+                */
+               lpc_ct32b1.pc = AO_LPC_CLKOUT / 750000 - 1;
+
+               /* Write the desired data in the match registers */
+
+               /* Reset after two time units */
+               lpc_ct32b1.mr[0] = beep << 1;
+
+               /* Flip output after one time unit */
+               lpc_ct32b1.mr[1] = beep;
+
+               /* Reset on match 0 */
+               lpc_ct32b1.mcr = (1 << LPC_CT32B_MCR_MR0R);
+
+               /* PWM on match 1 */
+               lpc_ct32b1.pwmc = (1 << LPC_CT32B_PWMC_PWMEN1);
+               
+               /* timer mode */
+               lpc_ct32b1.ctcr = 0;
+
+               /* And turn the timer on */
+               lpc_ct32b1.tcr = ((1 << LPC_CT32B_TCR_CEN) |
+                                 (1 << LPC_CT32B_TCR_CRST));
+       }
+}
+
+void
+ao_beep_for(uint8_t beep, uint16_t ticks) __reentrant
+{
+       ao_beep(beep);
+       ao_delay(ticks);
+       ao_beep(0);
+}
+
+void
+ao_beep_init(void)
+{
+       /* Our beeper is on c32b1_mat1
+        * which is on pin pio0_14
+        */
+
+       lpc_ioconf.pio0_14 = ((LPC_IOCONF_FUNC_PIO0_14_CT32B1_MAT1 << LPC_IOCONF_FUNC) |
+                             (LPC_IOCONF_MODE_INACTIVE << LPC_IOCONF_MODE) |
+                             (0 << LPC_IOCONF_HYS) |
+                             (0 << LPC_IOCONF_INV) |
+                             (0 << LPC_IOCONF_OD));
+
+       lpc_scb.sysahbclkctrl |= (1 << LPC_SCB_SYSAHBCLKCTRL_CT32B1);
+
+       /* Disable the counter and reset the value */
+       lpc_ct32b1.tcr = ((0 << LPC_CT32B_TCR_CEN) |
+                         (1 << LPC_CT32B_TCR_CRST));
+}