altos/lpc: Get USB working

[fw/altos] / src / lpc / ao_timer_lpc.c

diff --git a/src/lpc/ao_timer_lpc.c b/src/lpc/ao_timer_lpc.c
index 51e82525383fb381c7ba795f82197d338216b911..51835baaa76310f94ec1381541db33e65987f210 100644 (file)
--- a/src/lpc/ao_timer_lpc.c
+++ b/src/lpc/ao_timer_lpc.c
@@ -78,6 +78,14 @@ ao_timer_init(void)
 
 #define AO_LPC_FCCO_MIN        156000000
 
+static void
+ao_clock_delay(void)
+{
+       uint32_t        i;
+       for (i = 0; i < 200; i++)
+               ao_arch_nop();
+}
+
 void
 ao_clock_init(void)
 {
@@ -94,11 +102,15 @@ ao_clock_init(void)
                                 
        /* Turn the IRC clock back on */
        lpc_scb.pdruncfg &= ~(1 << LPC_SCB_PDRUNCFG_IRC_PD);
+       ao_clock_delay();
        
        /* Switch to the IRC clock */
        lpc_scb.mainclksel = LPC_SCB_MAINCLKSEL_SEL_IRC << LPC_SCB_MAINCLKSEL_SEL;
+       lpc_scb.mainclkuen = (1 << LPC_SCB_MAINCLKUEN_ENA);
        lpc_scb.mainclkuen = (0 << LPC_SCB_MAINCLKUEN_ENA);
        lpc_scb.mainclkuen = (1 << LPC_SCB_MAINCLKUEN_ENA);
+       while (!(lpc_scb.mainclkuen & (1 << LPC_SCB_MAINCLKUEN_ENA)))
+               ;
        
        /* Find a PLL post divider ratio that gets the FCCO in range */
        for (p = 0; p < 4; p++)
@@ -110,14 +122,15 @@ ao_clock_init(void)
 
        /* Power down the PLL before touching the registers */
        lpc_scb.pdruncfg |= (1 << LPC_SCB_PDRUNCFG_SYSPLL_PD);
+       ao_clock_delay();
 
        /* Set PLL divider values */
        lpc_scb.syspllctrl = ((AO_LPC_M << LPC_SCB_SYSPLLCTRL_MSEL) |
                              (p << LPC_SCB_SYSPLLCTRL_PSEL));
 
-
        /* Turn off the external crystal clock */
        lpc_scb.pdruncfg |= (1 << LPC_SCB_PDRUNCFG_SYSOSC_PD);
+       ao_clock_delay();
 
        /* Configure the crystal clock */
        lpc_scb.sysoscctrl = ((0 << LPC_SCB_SYSOSCCTRL_BYPASS) |                           /* using a crystal */
@@ -125,12 +138,16 @@ ao_clock_init(void)
 
        /* Turn on the external crystal clock */
        lpc_scb.pdruncfg &= ~(1 << LPC_SCB_PDRUNCFG_SYSOSC_PD);
+       ao_clock_delay();
 
        /* Select crystal as PLL input */
 
        lpc_scb.syspllclksel = (LPC_SCB_SYSPLLCLKSEL_SEL_SYSOSC << LPC_SCB_SYSPLLCLKSEL_SEL);
-       lpc_scb.syspllclkuen = 0;
        lpc_scb.syspllclkuen = (1 << LPC_SCB_SYSPLLCLKUEN_ENA);
+       lpc_scb.syspllclkuen = (0 << LPC_SCB_SYSPLLCLKUEN_ENA);
+       lpc_scb.syspllclkuen = (1 << LPC_SCB_SYSPLLCLKUEN_ENA);
+       while (!(lpc_scb.syspllclkuen & (1 << LPC_SCB_SYSPLLCLKUEN_ENA)))
+               ;
        
        /* Turn on the PLL */
        lpc_scb.pdruncfg &= ~(1 << LPC_SCB_PDRUNCFG_SYSPLL_PD);
@@ -145,17 +162,15 @@ ao_clock_init(void)
 
        /* Switch to the PLL */
        lpc_scb.mainclksel = LPC_SCB_MAINCLKSEL_SEL_PLL_OUTPUT << LPC_SCB_MAINCLKSEL_SEL;
-       lpc_scb.mainclkuen = 0 << LPC_SCB_MAINCLKUEN_ENA;
-       lpc_scb.mainclkuen = 1 << LPC_SCB_MAINCLKUEN_ENA;
+       lpc_scb.mainclkuen = (1 << LPC_SCB_MAINCLKUEN_ENA);
+       lpc_scb.mainclkuen = (0 << LPC_SCB_MAINCLKUEN_ENA);
+       lpc_scb.mainclkuen = (1 << LPC_SCB_MAINCLKUEN_ENA);
+       while (!(lpc_scb.mainclkuen & (1 << LPC_SCB_MAINCLKUEN_ENA)))
+               ;
 
        /* Set system clock divider */
        lpc_scb.sysahbclkdiv = AO_LPC_CLKOUT / AO_LPC_SYSCLK;
 
-       /* Set USB clock source */
-       lpc_scb.usbclksel = (LPC_SCB_USBCLKSEL_SEL_MAIN_CLOCK << LPC_SCB_USBCLKSEL_SEL);
-       lpc_scb.usbclkuen = (0 << LPC_SCB_USBCLKUEN_ENA);
-       lpc_scb.usbclkuen = (1 << LPC_SCB_USBCLKUEN_ENA);
-
        /* Shut down perhipheral clocks (enabled as needed) */
        lpc_scb.ssp0clkdiv = 0;
        lpc_scb.uartclkdiv = 0;