[PATCH 1/5] clk: stm32mp1: Split ETHCK_K into separate MUX and GATE clock

[gabriel.fernandez at foss.st.com]

Hi Marek,

The split between ETHCK_K gate, ETHPTPDIV and ck_ker_eth is fine for me.
It's reflected much better the clock ethernet distribution.
However the initial code should have let the ethck gate disable if ethck 
is not used.

You can add
Acked-by: Gabriel Fernandez <gabriel.fernandez at foss.st.com>

On 1/18/22 9:29 PM, Marek Vasut wrote:
> The ETHCK_K are modeled as composite clock of MUX and GATE, however per
> STM32MP1 Reference Manual RM0436 Rev 3, Page 574, Figure 83. Peripheral
> clock distribution for Ethernet, ETHPTPDIV divider is attached past the
> ETHCK_K mux, and ETH_CLK/eth_clk_fb clock are output past ETHCKEN gate.
> Therefore, in case ETH_CLK/eth_clk_fb are not in use AND PTP clock are
> in use, ETHCKEN gate can be turned off. Current driver does not permit
> that, fix it.
> 
> This patch converts ETHCK_K from composite clock into a ETHCKEN gate,
> ETHPTP_K from composite clock into ETHPTPDIV divider, and adds another
> NO_ID clock "ck_ker_eth" which models the ETHSRC mux and is parent clock
> to both ETHCK_K and ETHPTP_K. Therefore, all references to ETHCK_K and
> ETHPTP_K remain functional as before.
> 
> [1] STM32MP1 Reference Manual RM0436 Rev 3, Page 574,
>      Figure 83. Peripheral clock distribution for Ethernet
>      https://www.st.com/resource/en/reference_manual/dm00327659-stm32mp157-advanced-armbased-32bit-mpus-stmicroelectronics.pdf
> 
> Signed-off-by: Marek Vasut <marex at denx.de>
> Cc: Alexandre Torgue <alexandre.torgue at foss.st.com>
> Cc: Christophe Roullier <christophe.roullier at foss.st.com>
> Cc: Gabriel Fernandez <gabriel.fernandez at foss.st.com>
> Cc: Patrice Chotard <patrice.chotard at foss.st.com>
> Cc: Patrick Delaunay <patrick.delaunay at foss.st.com>
> Cc: Stephen Boyd <sboyd at kernel.org>
> Cc: linux-clk at vger.kernel.org
> Cc: linux-stm32 at st-md-mailman.stormreply.com
> To: linux-arm-kernel at lists.infradead.org
> ---
>   drivers/clk/clk-stm32mp1.c | 10 +++++++---
>   1 file changed, 7 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/clk/clk-stm32mp1.c b/drivers/clk/clk-stm32mp1.c
> index 863274aa50e38..23a34ab459a3b 100644
> --- a/drivers/clk/clk-stm32mp1.c
> +++ b/drivers/clk/clk-stm32mp1.c
> @@ -2008,7 +2008,6 @@ static const struct clock_config stm32mp1_clock_cfg[] = {
>   	KCLK(DSI_K, "dsi_k", dsi_src, 0, G_DSI, M_DSI),
>   	KCLK(ADFSDM_K, "adfsdm_k", sai_src, 0, G_ADFSDM, M_SAI1),
>   	KCLK(USBO_K, "usbo_k", usbo_src, 0, G_USBO, M_USBO),
> -	KCLK(ETHCK_K, "ethck_k", eth_src, 0, G_ETHCK, M_ETHCK),
>   
>   	/* Particulary Kernel Clocks (no mux or no gate) */
>   	MGATE_MP1(DFSDM_K, "dfsdm_k", "ck_mcu", 0, G_DFSDM),
> @@ -2017,11 +2016,16 @@ static const struct clock_config stm32mp1_clock_cfg[] = {
>   	MGATE_MP1(GPU_K, "gpu_k", "pll2_q", 0, G_GPU),
>   	MGATE_MP1(DAC12_K, "dac12_k", "ck_lsi", 0, G_DAC12),
>   
> -	COMPOSITE(ETHPTP_K, "ethptp_k", eth_src, CLK_OPS_PARENT_ENABLE |
> +	COMPOSITE(NO_ID, "ck_ker_eth", eth_src, CLK_OPS_PARENT_ENABLE |
>   		  CLK_SET_RATE_NO_REPARENT,
>   		  _NO_GATE,
>   		  _MMUX(M_ETHCK),
> -		  _DIV(RCC_ETHCKSELR, 4, 4, 0, NULL)),
> +		  _NO_DIV),
> +
> +	MGATE_MP1(ETHCK_K, "ethck_k", "ck_ker_eth", 0, G_ETHCK),
> +
> +	DIV(ETHPTP_K, "ethptp_k", "ck_ker_eth", CLK_OPS_PARENT_ENABLE |
> +	    CLK_SET_RATE_NO_REPARENT, RCC_ETHCKSELR, 4, 4, 0),
>   
>   	/* RTC clock */
>   	COMPOSITE(RTC, "ck_rtc", rtc_src, CLK_OPS_PARENT_ENABLE,
>