Re: [PATCH 1/7] clk: stm32mp1: Split ETHCK_K into separate MUX and GATE clock

["gabriel.fernandez@foss.st.com" <gabriel.fernandez@foss.st.com>]

Hi Marek,

Thanks for the patchset

On 4/8/21 8:57 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.

I don"t understand, it's already the case.

ETHCK_K it's a composite with a MUX and a GATE.

ETHPTP_K (ETHPTPDIV) it's a composite with the same MUX and a DIV (no gate)

If you use only ETHPTPDIV,  ETHCKEN gate can be turned off.

  

> 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@denx.de>
> Cc: Alexandre Torgue<alexandre.torgue@foss.st.com>
> Cc: Christophe Roullier<christophe.roullier@foss.st.com>
> Cc: Gabriel Fernandez<gabriel.fernandez@foss.st.com>
> Cc: Patrice Chotard<patrice.chotard@foss.st.com>
> Cc: Patrick Delaunay<patrick.delaunay@foss.st.com>
> Cc: Stephen Boyd<swboyd@chromium.org>
> Cc:linux-clk@vger.kernel.org
> Cc:linux-stm32@st-md-mailman.stormreply.com
> To:linux-arm-kernel@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 a875649df8b8..a7c7f544ee5d 100644
> --- a/drivers/clk/clk-stm32mp1.c
> +++ b/drivers/clk/clk-stm32mp1.c
> @@ -1949,7 +1949,6 @@ 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),
> @@ -1958,11 +1957,16 @@ 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),
assigned parent with ETHCK_K will not work
> +
> +	DIV(ETHPTP_K, "ethptp_k", "ck_ker_eth", CLK_OPS_PARENT_ENABLE |

CLK_OPS_PARENT_ENABLE flags not useful with a divider.

best regards

Gabriel

> +	    CLK_SET_RATE_NO_REPARENT, RCC_ETHCKSELR, 4, 4, 0),
>   
>   	/* RTC clock */
>   	DIV(NO_ID, "ck_hse_rtc", "ck_hse", 0, RCC_RTCDIVR, 0, 6, 0),

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