Am 12.09.19 um 20:52 schrieb Eric Anholt:
> Matthias Brugger <matthias.bgg@xxxxxxxxx> writes:
>
>> On 13/08/2019 18:20, Stefan Wahren wrote:
>>> The new BCM2711 supports an additional clock for the emmc2 block.
>>> So add a new compatible and register this clock only for BCM2711.
>>>
>>> Signed-off-by: Stefan Wahren <wahrenst@xxxxxxx>
>>> Reviewed-by: Matthias Brugger <mbrugger@xxxxxxxx>
>>> Acked-by: Eric Anholt <eric@xxxxxxxxxx>
>>> ---
>>> drivers/clk/bcm/clk-bcm2835.c | 20 +++++++++++++++++++-
>>> 1 file changed, 19 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/clk/bcm/clk-bcm2835.c b/drivers/clk/bcm/clk-bcm2835.c
>>> index 21cd952..fdf672a 100644
>>> --- a/drivers/clk/bcm/clk-bcm2835.c
>>> +++ b/drivers/clk/bcm/clk-bcm2835.c
>>> @@ -114,6 +114,8 @@
>>> #define CM_AVEODIV 0x1bc
>>> #define CM_EMMCCTL 0x1c0
>>> #define CM_EMMCDIV 0x1c4
>>> +#define CM_EMMC2CTL 0x1d0
>>> +#define CM_EMMC2DIV 0x1d4
>>>
>>> /* General bits for the CM_*CTL regs */
>>> # define CM_ENABLE BIT(4)
>>> @@ -290,7 +292,8 @@
>>> #define BCM2835_MAX_FB_RATE 1750000000u
>>>
>>> #define SOC_BCM2835 BIT(0)
>>> -#define SOC_ALL (SOC_BCM2835)
>>> +#define SOC_BCM2711 BIT(1)
>>> +#define SOC_ALL (SOC_BCM2835 | SOC_BCM2711)
>>>
>>> /*
>>> * Names of clocks used within the driver that need to be replaced
>>> @@ -2003,6 +2006,16 @@ static const struct bcm2835_clk_desc clk_desc_array[] = {
>>> .frac_bits = 8,
>>> .tcnt_mux = 39),
>>>
>>> + /* EMMC2 clock (only available for BCM2711) */
>>> + [BCM2711_CLOCK_EMMC2] = REGISTER_PER_CLK(
>>> + SOC_BCM2711,
>>> + .name = "emmc2",
>>> + .ctl_reg = CM_EMMC2CTL,
>>> + .div_reg = CM_EMMC2DIV,
>>> + .int_bits = 4,
>>> + .frac_bits = 8,
>>> + .tcnt_mux = 42),
>>> +
>>> /* General purpose (GPIO) clocks */
>>> [BCM2835_CLOCK_GP0] = REGISTER_PER_CLK(
>>> SOC_ALL,
>>> @@ -2238,8 +2251,13 @@ static const struct cprman_plat_data cprman_bcm2835_plat_data = {
>>> .soc = SOC_BCM2835,
>>> };
>>>
>>> +static const struct cprman_plat_data cprman_bcm2711_plat_data = {
>>> + .soc = SOC_BCM2711,
>>> +};
>>> +
>>> static const struct of_device_id bcm2835_clk_of_match[] = {
>>> { .compatible = "brcm,bcm2835-cprman", .data = &cprman_bcm2835_plat_data },
>>> + { .compatible = "brcm,bcm2711-cprman", .data = &cprman_bcm2711_plat_data },
>> Because the RPi4 FW uses bcm2838-cprman as compatible, we will need to add this
>> here as well.
> Upstream has not committed to backwards compat with Pi's firmware. That
> makes the ABI requirement we get held to for upstream's DT absurd, but
> that's the state of things.
We also learned from past, that's not possible to keep things downstream
compatible. As soon as a binding is not accepted, this wont work
anymore. A lot of the downstream stuff is hacky.
For example yesterday, i learned that the thermal node is broken
(register is part of ring oscillator block). So do we really want to be
compatible with a hack? I would say: No
