From 298e54856b5f8809b43f24407caa4a6be60822f3 Mon Sep 17 00:00:00 2001 From: Keith Packard Date: Mon, 17 Jun 2013 14:00:11 -0700 Subject: [PATCH] altos/lpc: Get the IRC turned off after boot time This involved carefully moving the USB away from the IRC before turning it off. Signed-off-by: Keith Packard --- src/lpc/ao_timer_lpc.c | 17 ++++++++++++++--- src/lpc/ao_usb_lpc.c | 10 +++++++--- 2 files changed, 21 insertions(+), 6 deletions(-) diff --git a/src/lpc/ao_timer_lpc.c b/src/lpc/ao_timer_lpc.c index 62235d1e..c0de90a3 100644 --- a/src/lpc/ao_timer_lpc.c +++ b/src/lpc/ao_timer_lpc.c @@ -106,12 +106,18 @@ ao_clock_init(void) /* 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))) ; + /* Switch USB to the main clock */ + 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); + while (!(lpc_scb.usbclkuen & (1 << LPC_SCB_USBCLKUEN_ENA))) + ; + /* Find a PLL post divider ratio that gets the FCCO in range */ for (p = 0; p < 4; p++) if (AO_LPC_CLKOUT << (1 + p) >= AO_LPC_FCCO_MIN) @@ -178,7 +184,13 @@ ao_clock_init(void) lpc_scb.usbclkdiv = 0; lpc_scb.clkoutdiv = 0; -#if 0 + /* Switch USB PLL source to system osc so we can power down the IRC */ + lpc_scb.usbpllclksel = (LPC_SCB_USBPLLCLKSEL_SEL_SYSOSC << LPC_SCB_USBPLLCLKSEL_SEL); + lpc_scb.usbpllclkuen = (0 << LPC_SCB_USBPLLCLKUEN_ENA); + lpc_scb.usbpllclkuen = (1 << LPC_SCB_USBPLLCLKUEN_ENA); + while (!(lpc_scb.usbpllclkuen & (1 << LPC_SCB_USBPLLCLKUEN_ENA))) + ; + /* Power down everything we don't need */ lpc_scb.pdruncfg = ((1 << LPC_SCB_PDRUNCFG_IRCOUT_PD) | (1 << LPC_SCB_PDRUNCFG_IRC_PD) | @@ -189,5 +201,4 @@ ao_clock_init(void) (1 << LPC_SCB_PDRUNCFG_USBPAD_PD) | (1 << 11) | (7 << 13)); -#endif } diff --git a/src/lpc/ao_usb_lpc.c b/src/lpc/ao_usb_lpc.c index aac0df04..e574f1e2 100644 --- a/src/lpc/ao_usb_lpc.c +++ b/src/lpc/ao_usb_lpc.c @@ -834,8 +834,9 @@ ao_usb_disable(void) /* Turn off USB clock */ lpc_scb.usbclkdiv = 0; - /* Disable USB PHY */ - lpc_scb.pdruncfg |= (1 << LPC_SCB_PDRUNCFG_USBPAD_PD); + /* Disable USB PHY and PLL */ + lpc_scb.pdruncfg |= ((1 << LPC_SCB_PDRUNCFG_USBPAD_PD) | + (1 << LPC_SCB_PDRUNCFG_USBPLL_PD)); /* Disable USB registers and RAM */ lpc_scb.sysahbclkctrl &= ~((1 << LPC_SCB_SYSAHBCLKCTRL_USB) | @@ -877,7 +878,6 @@ ao_usb_enable(void) lpc_scb.pdruncfg &= ~(1 << LPC_SCB_PDRUNCFG_USBPLL_PD); lpc_scb.usbpllclksel = (LPC_SCB_SYSPLLCLKSEL_SEL_SYSOSC << LPC_SCB_SYSPLLCLKSEL_SEL); - lpc_scb.usbpllclkuen = (1 << LPC_SCB_USBPLLCLKUEN_ENA); lpc_scb.usbpllclkuen = (0 << LPC_SCB_USBPLLCLKUEN_ENA); lpc_scb.usbpllclkuen = (1 << LPC_SCB_USBPLLCLKUEN_ENA); while (!(lpc_scb.usbpllclkuen & (1 << LPC_SCB_USBPLLCLKUEN_ENA))) @@ -887,6 +887,10 @@ ao_usb_enable(void) ; lpc_scb.usbclksel = 0; + lpc_scb.usbclkuen = (0 << LPC_SCB_USBCLKUEN_ENA); + lpc_scb.usbclkuen = (1 << LPC_SCB_USBCLKUEN_ENA); + while (!(lpc_scb.usbclkuen & (1 << LPC_SCB_USBCLKUEN_ENA))) + ; /* Turn on USB clock, use 48MHz clock unchanged */ lpc_scb.usbclkdiv = 1; -- 2.30.2