From: Marek Vasut <marex@denx.de> To: linux-arm-kernel@lists.infradead.org Cc: Marek Vasut <marex@denx.de>, Alexandre Torgue <alexandre.torgue@foss.st.com>, Christophe Roullier <christophe.roullier@foss.st.com>, Gabriel Fernandez <gabriel.fernandez@foss.st.com>, Patrice Chotard <patrice.chotard@foss.st.com>, Patrick Delaunay <patrick.delaunay@foss.st.com>, Stephen Boyd <swboyd@chromium.org>, linux-clk@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com Subject: [PATCH 7/7] ARM: dts: stm32: Switch DWMAC RMII clock to MCO2 on DHCOM Date: Thu, 8 Apr 2021 20:57:31 +0200 [thread overview] Message-ID: <20210408185731.135511-8-marex@denx.de> (raw) In-Reply-To: <20210408185731.135511-1-marex@denx.de> The DHCOM SoM has two options for supplying ETHRX clock to the DWMAC block and PHY. Either (1) ETHCK_K generates 50 MHz clock on ETH_CLK pad for the PHY and the same 50 MHz clock are fed back to ETHRX via internal eth_clk_fb clock connection OR (2) ETH_CLK is not used at all, MCO2 generates 50 MHz clock on MCO2 output pad for the PHY and the same MCO2 clock are fed back into ETHRX via ETH_RX_CLK input pad using external pad-to-pad connection. Option (1) has two downsides. ETHCK_K is supplied directly from either PLL3_Q or PLL4_P, hence the PLL output is limited to exactly 50 MHz and since the same PLL output is also used to supply SDMMC blocks, the performance of SD and eMMC access is affected. The second downside is that using this option, the EMI of the SoM is higher. Option (2) solves both of those problems, so implement it here. In this case, the PLL4_P is no longer limited and can be operated faster, at 100 MHz, which improves SDMMC performance (read performance is improved from ~41 MiB/s to ~57 MiB/s with dd if=/dev/mmcblk1 of=/dev/null bs=64M count=1). The EMI interference also decreases. 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 --- arch/arm/boot/dts/stm32mp15xx-dhcom-som.dtsi | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-) diff --git a/arch/arm/boot/dts/stm32mp15xx-dhcom-som.dtsi b/arch/arm/boot/dts/stm32mp15xx-dhcom-som.dtsi index 272a1a67a9ad..4c7c06a7aea0 100644 --- a/arch/arm/boot/dts/stm32mp15xx-dhcom-som.dtsi +++ b/arch/arm/boot/dts/stm32mp15xx-dhcom-som.dtsi @@ -114,15 +114,29 @@ &dts { status = "okay"; }; +&rcc { + /* Connect MCO2 output to ETH_RX_CLK input via pad-pad connection */ + clocks = <&rcc CK_MCO2>; + clock-names = "ETH_RX_CLK/ETH_REF_CLK"; + + /* + * Set PLL4P output to 100 MHz to supply SDMMC with faster clock, + * set MCO2 output to 50 MHz to supply ETHRX clock with PLL4P/2, + * so that MCO2 behaves as a divider for the ETHRX clock here. + */ + assigned-clocks = <&rcc CK_MCO2>, <&rcc PLL4_P>; + assigned-clock-parents = <&rcc PLL4_P>; + assigned-clock-rates = <50000000>, <100000000>; +}; + ðernet0 { status = "okay"; - pinctrl-0 = <ðernet0_rmii_pins_a>; - pinctrl-1 = <ðernet0_rmii_sleep_pins_a>; + pinctrl-0 = <ðernet0_rmii_pins_b &mco2_pins_a>; + pinctrl-1 = <ðernet0_rmii_sleep_pins_b &mco2_sleep_pins_a>; pinctrl-names = "default", "sleep"; phy-mode = "rmii"; max-speed = <100>; phy-handle = <&phy0>; - st,eth-ref-clk-sel; phy-reset-gpios = <&gpioh 3 GPIO_ACTIVE_LOW>; mdio0 { -- 2.30.2
WARNING: multiple messages have this Message-ID (diff)
From: Marek Vasut <marex@denx.de> To: linux-arm-kernel@lists.infradead.org Cc: Marek Vasut <marex@denx.de>, Alexandre Torgue <alexandre.torgue@foss.st.com>, Christophe Roullier <christophe.roullier@foss.st.com>, Gabriel Fernandez <gabriel.fernandez@foss.st.com>, Patrice Chotard <patrice.chotard@foss.st.com>, Patrick Delaunay <patrick.delaunay@foss.st.com>, Stephen Boyd <swboyd@chromium.org>, linux-clk@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com Subject: [PATCH 7/7] ARM: dts: stm32: Switch DWMAC RMII clock to MCO2 on DHCOM Date: Thu, 8 Apr 2021 20:57:31 +0200 [thread overview] Message-ID: <20210408185731.135511-8-marex@denx.de> (raw) In-Reply-To: <20210408185731.135511-1-marex@denx.de> The DHCOM SoM has two options for supplying ETHRX clock to the DWMAC block and PHY. Either (1) ETHCK_K generates 50 MHz clock on ETH_CLK pad for the PHY and the same 50 MHz clock are fed back to ETHRX via internal eth_clk_fb clock connection OR (2) ETH_CLK is not used at all, MCO2 generates 50 MHz clock on MCO2 output pad for the PHY and the same MCO2 clock are fed back into ETHRX via ETH_RX_CLK input pad using external pad-to-pad connection. Option (1) has two downsides. ETHCK_K is supplied directly from either PLL3_Q or PLL4_P, hence the PLL output is limited to exactly 50 MHz and since the same PLL output is also used to supply SDMMC blocks, the performance of SD and eMMC access is affected. The second downside is that using this option, the EMI of the SoM is higher. Option (2) solves both of those problems, so implement it here. In this case, the PLL4_P is no longer limited and can be operated faster, at 100 MHz, which improves SDMMC performance (read performance is improved from ~41 MiB/s to ~57 MiB/s with dd if=/dev/mmcblk1 of=/dev/null bs=64M count=1). The EMI interference also decreases. 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 --- arch/arm/boot/dts/stm32mp15xx-dhcom-som.dtsi | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-) diff --git a/arch/arm/boot/dts/stm32mp15xx-dhcom-som.dtsi b/arch/arm/boot/dts/stm32mp15xx-dhcom-som.dtsi index 272a1a67a9ad..4c7c06a7aea0 100644 --- a/arch/arm/boot/dts/stm32mp15xx-dhcom-som.dtsi +++ b/arch/arm/boot/dts/stm32mp15xx-dhcom-som.dtsi @@ -114,15 +114,29 @@ &dts { status = "okay"; }; +&rcc { + /* Connect MCO2 output to ETH_RX_CLK input via pad-pad connection */ + clocks = <&rcc CK_MCO2>; + clock-names = "ETH_RX_CLK/ETH_REF_CLK"; + + /* + * Set PLL4P output to 100 MHz to supply SDMMC with faster clock, + * set MCO2 output to 50 MHz to supply ETHRX clock with PLL4P/2, + * so that MCO2 behaves as a divider for the ETHRX clock here. + */ + assigned-clocks = <&rcc CK_MCO2>, <&rcc PLL4_P>; + assigned-clock-parents = <&rcc PLL4_P>; + assigned-clock-rates = <50000000>, <100000000>; +}; + ðernet0 { status = "okay"; - pinctrl-0 = <ðernet0_rmii_pins_a>; - pinctrl-1 = <ðernet0_rmii_sleep_pins_a>; + pinctrl-0 = <ðernet0_rmii_pins_b &mco2_pins_a>; + pinctrl-1 = <ðernet0_rmii_sleep_pins_b &mco2_sleep_pins_a>; pinctrl-names = "default", "sleep"; phy-mode = "rmii"; max-speed = <100>; phy-handle = <&phy0>; - st,eth-ref-clk-sel; phy-reset-gpios = <&gpioh 3 GPIO_ACTIVE_LOW>; mdio0 { -- 2.30.2 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2021-04-08 18:57 UTC|newest] Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-04-08 18:57 [PATCH 0/7] ARM: dts: stm32: clk: Switch ETHRX clock parent from ETHCK_K to MCO2 on DHCOM SoM Marek Vasut 2021-04-08 18:57 ` Marek Vasut 2021-04-08 18:57 ` [PATCH 1/7] clk: stm32mp1: Split ETHCK_K into separate MUX and GATE clock Marek Vasut 2021-04-08 18:57 ` Marek Vasut 2021-04-14 13:03 ` gabriel.fernandez 2021-04-14 13:03 ` gabriel.fernandez 2021-04-14 14:04 ` Marek Vasut 2021-04-14 14:04 ` Marek Vasut 2021-04-16 6:44 ` gabriel.fernandez 2021-04-16 6:44 ` gabriel.fernandez 2021-04-16 13:47 ` Marek Vasut 2021-04-16 13:47 ` Marek Vasut 2021-04-16 15:23 ` Alexandre TORGUE 2021-04-16 15:23 ` Alexandre TORGUE 2021-04-16 15:31 ` Marek Vasut 2021-04-16 15:31 ` Marek Vasut 2021-04-19 7:46 ` gabriel.fernandez 2021-04-19 7:46 ` gabriel.fernandez 2022-01-18 22:11 ` Marek Vasut 2022-01-18 22:11 ` Marek Vasut 2021-04-08 18:57 ` [PATCH 2/7] clk: stm32mp1: The dev is always NULL, replace it with np Marek Vasut 2021-04-08 18:57 ` Marek Vasut 2021-04-16 6:44 ` gabriel.fernandez 2021-04-16 6:44 ` gabriel.fernandez 2021-04-16 13:39 ` Marek Vasut 2021-04-16 13:39 ` Marek Vasut 2021-04-16 14:39 ` Alexandre TORGUE 2021-04-16 14:39 ` Alexandre TORGUE 2021-04-16 14:54 ` Marek Vasut 2021-04-16 14:54 ` Marek Vasut 2021-04-16 15:01 ` Alexandre TORGUE 2021-04-16 15:01 ` Alexandre TORGUE 2021-04-08 18:57 ` [PATCH 3/7] clk: stm32mp1: Register clock with device_node pointer Marek Vasut 2021-04-08 18:57 ` Marek Vasut 2021-04-08 18:57 ` [PATCH 4/7] clk: stm32mp1: Add parent_data to ETHRX clock Marek Vasut 2021-04-08 18:57 ` Marek Vasut 2021-04-08 18:57 ` [PATCH 5/7] ARM: dts: stm32: Add alternate pinmux for ethernet0 pins Marek Vasut 2021-04-08 18:57 ` Marek Vasut 2021-04-08 18:57 ` [PATCH 6/7] ARM: dts: stm32: Add alternate pinmux for mco2 pins Marek Vasut 2021-04-08 18:57 ` Marek Vasut 2021-04-08 18:57 ` Marek Vasut [this message] 2021-04-08 18:57 ` [PATCH 7/7] ARM: dts: stm32: Switch DWMAC RMII clock to MCO2 on DHCOM Marek Vasut 2021-04-08 20:32 ` [PATCH 0/7] ARM: dts: stm32: clk: Switch ETHRX clock parent from ETHCK_K to MCO2 on DHCOM SoM Stephen Boyd 2021-04-08 20:32 ` Stephen Boyd 2021-04-12 8:09 ` Alexandre TORGUE 2021-04-12 8:09 ` Alexandre TORGUE 2021-04-12 18:44 ` Marek Vasut 2021-04-12 18:44 ` Marek Vasut 2021-04-13 7:48 ` Alexandre TORGUE 2021-04-13 7:48 ` Alexandre TORGUE 2021-04-13 12:05 ` Marek Vasut 2021-04-13 12:05 ` Marek Vasut
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