On 10/5/20 9:56 PM, Luc Michel wrote:
> The clock multiplexers are the last clock stage in the CPRMAN. Each mux
> outputs one clock signal that goes out of the CPRMAN to the SoC
> peripherals.
>
> Each mux has at most 10 sources. The sources 0 to 3 are common to all
> muxes. They are:
> 0. ground (no clock signal)
> 1. the main oscillator (xosc)
> 2. "test debug 0" clock
> 3. "test debug 1" clock
>
> Test debug 0 and 1 are actual clock muxes that can be used as sources to
> other muxes (for debug purpose).
>
> Sources 4 to 9 are mux specific and can be unpopulated (grounded). Those
> sources are fed by the PLL channels outputs.
>
> One corner case exists for DSI0E and DSI0P muxes. They have their source
> number 4 connected to an intermediate multiplexer that can select
> between PLLA-DSI0 and PLLD-DSI0 channel. This multiplexer is called
> DSI0HSCK and is not a clock mux as such. It is really a simple mux from
> the hardware point of view (see https://elinux.org/The_Undocumented_Pi).
> This mux is not implemented in this commit.
>
> Note that there is some muxes for which sources are unknown (because of
> a lack of documentation). For those cases all the sources are connected
> to ground in this implementation.
>
> Each clock mux output is exported by the CPRMAN at the qdev level,
> adding the suffix '-out' to the mux name to form the output clock name.
> (E.g. the 'uart' mux sees its output exported as 'uart-out' at the
> CPRMAN level.)
>
> Tested-by: Philippe Mathieu-Daudé <f4...@amsat.org>
> Signed-off-by: Luc Michel <l...@lmichel.fr>
> ---
> include/hw/misc/bcm2835_cprman.h | 84 ++++
> include/hw/misc/bcm2835_cprman_internals.h | 421 +++++++++++++++++++++
> hw/misc/bcm2835_cprman.c | 150 ++++++++
> 3 files changed, 655 insertions(+)
[...]
> +#define FILL_CLOCK_MUX_INIT_INFO(clock_, kind_) \
> + .cm_offset = R_CM_ ## clock_ ## CTL, \
> + FILL_CLOCK_MUX_SRC_MAPPING_INIT_INFO(kind_)
> +
> +static ClockMuxInitInfo CLOCK_MUX_INIT_INFO[] = {
> + [CPRMAN_CLOCK_GNRIC] = {
> + .name = "gnric",
> + FILL_CLOCK_MUX_INIT_INFO(GNRIC, unknown),
> + },
[...]
> +static inline void update_mux_from_cm(BCM2835CprmanState *s, size_t idx)
> +{
> + size_t i;
> +
> + for (i = 0; i < CPRMAN_NUM_CLOCK_MUX; i++) {
> + if ((CLOCK_MUX_INIT_INFO[i].cm_offset == idx) ||
> + (CLOCK_MUX_INIT_INFO[i].cm_offset == idx + 4)) {
Maybe add a /* Matches DIV or CTL */ comment. Anyway
FILL_CLOCK_MUX_INIT_INFO() only uses CTL, not DIV, so
+4 check is not necessary.
Otherwise:
Reviewed-by: Philippe Mathieu-Daudé <f4...@amsat.org>
> + clock_mux_update(&s->clock_muxes[i]);
> + return;
> + }
> + }
> +}
> +
> #define CASE_PLL_A2W_REGS(pll_) \
> case R_A2W_ ## pll_ ## _CTRL: \
> case R_A2W_ ## pll_ ## _ANA0: \
> case R_A2W_ ## pll_ ## _ANA1: \
> case R_A2W_ ## pll_ ## _ANA2: \
> @@ -363,10 +438,19 @@ static void cprman_write(void *opaque, hwaddr offset,
> case R_A2W_PLLH_RCAL:
> case R_A2W_PLLH_PIX:
> case R_A2W_PLLB_ARM:
> update_channel_from_a2w(s, idx);
> break;
> +
> + case R_CM_GNRICCTL ... R_CM_SMIDIV:
> + case R_CM_TCNTCNT ... R_CM_VECDIV:
> + case R_CM_PULSECTL ... R_CM_PULSEDIV:
> + case R_CM_SDCCTL ... R_CM_ARMCTL:
> + case R_CM_AVEOCTL ... R_CM_EMMCDIV:
> + case R_CM_EMMC2CTL ... R_CM_EMMC2DIV:
> + update_mux_from_cm(s, idx);
> + break;
> }
> }
[...]
