diff options
| -rw-r--r-- | firmware/target/arm/imx233/clkctrl-imx233.c | 32 | ||||
| -rw-r--r-- | firmware/target/arm/imx233/clkctrl-imx233.h | 2 |
2 files changed, 34 insertions, 0 deletions
diff --git a/firmware/target/arm/imx233/clkctrl-imx233.c b/firmware/target/arm/imx233/clkctrl-imx233.c index a5ca61c1c7..2f507b076a 100644 --- a/firmware/target/arm/imx233/clkctrl-imx233.c +++ b/firmware/target/arm/imx233/clkctrl-imx233.c @@ -189,6 +189,38 @@ bool imx233_clkctrl_get_bypass(enum imx233_clock_t clk) default: return false; } } + +void imx233_clkctrl_set_cpu_hbus_div(int cpu_idiv, int cpu_fdiv, int hbus_div) +{ + /* disable interrupts to avoid an IRQ being triggered at the point + * where we are slow/weird speeds, that would result in massive slow-down... */ + int oldstatus = disable_interrupt_save(IRQ_FIQ_STATUS); + /* we need to be very careful here: putting the wrong dividers could blow-up the + * frequency and result in crash, also the cpu could be running from XTAL or + * PLL at this point */ + int old_cpu_fdiv = imx233_clkctrl_get_frac_div(CLK_CPU); + int old_hbus_div = imx233_clkctrl_get_div(CLK_HBUS); + /* since HBUS is tied to cpu, we first ensure that the HBUS is safe to handle + * both old and new speed: take maximum of old and new dividers */ + if(hbus_div > old_hbus_div) + imx233_clkctrl_set_div(CLK_HBUS, hbus_div); + /* we are about to change cpu speed: we first ensure that the fractional + * divider is safe to handle both old and new integer divided frequency: take max */ + if(cpu_fdiv > old_cpu_fdiv) + imx233_clkctrl_set_frac_div(CLK_CPU, cpu_fdiv); + /* we are safe for major divider change */ + imx233_clkctrl_set_div(CLK_CPU, cpu_idiv); + /* if the final fractional divider is lower than previous one, it's time to switch */ + if(cpu_fdiv < old_cpu_fdiv) + imx233_clkctrl_set_frac_div(CLK_CPU, cpu_fdiv); + /* if we were running from XTAL, switch to PLL */ + imx233_clkctrl_set_bypass(CLK_CPU, false); + /* finally restore HBUS to its proper value */ + if(hbus_div < old_hbus_div) + imx233_clkctrl_set_div(CLK_HBUS, hbus_div); + /* we are free again */ + restore_interrupt(oldstatus); +} #endif void imx233_clkctrl_enable_usb(bool enable) diff --git a/firmware/target/arm/imx233/clkctrl-imx233.h b/firmware/target/arm/imx233/clkctrl-imx233.h index 7dc21c2b30..bca5494da8 100644 --- a/firmware/target/arm/imx233/clkctrl-imx233.h +++ b/firmware/target/arm/imx233/clkctrl-imx233.h @@ -72,6 +72,8 @@ void imx233_clkctrl_set_frac_div(enum imx233_clock_t clk, int fracdiv); int imx233_clkctrl_get_frac_div(enum imx233_clock_t clk); void imx233_clkctrl_set_bypass(enum imx233_clock_t clk, bool bypass); bool imx233_clkctrl_get_bypass(enum imx233_clock_t clk); +/* all-in-one function which handle all quirks */ +void imx233_clkctrl_set_cpu_hbus_div(int cpu_idiv, int cpu_fdiv, int hbus_div); #endif void imx233_clkctrl_enable_usb(bool enable); bool imx233_clkctrl_is_usb_enabled(void); |