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From: Serge Semin <Sergey.Semin@baikalelectronics.ru>
To: Rob Herring <robh+dt@kernel.org>,
	Giuseppe Cavallaro <peppe.cavallaro@st.com>,
	Alexandre Torgue <alexandre.torgue@st.com>,
	Jose Abreu <joabreu@synopsys.com>,
	"David S. Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>, Johan Hovold <johan@kernel.org>,
	Maxime Ripard <mripard@kernel.org>,
	Joao Pinto <jpinto@synopsys.com>, Lars Persson <larper@axis.com>,
	Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Serge Semin <Sergey.Semin@baikalelectronics.ru>,
	Serge Semin <fancer.lancer@gmail.com>,
	Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>,
	Pavel Parkhomenko <Pavel.Parkhomenko@baikalelectronics.ru>,
	Vyacheslav Mitrofanov 
	<Vyacheslav.Mitrofanov@baikalelectronics.ru>,
	<netdev@vger.kernel.org>,
	<linux-stm32@st-md-mailman.stormreply.com>,
	<linux-arm-kernel@lists.infradead.org>,
	<devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: [PATCH 24/25] net: stmmac: Use pclk to set MDC clock frequency
Date: Mon, 14 Dec 2020 12:16:14 +0300	[thread overview]
Message-ID: <20201214091616.13545-25-Sergey.Semin@baikalelectronics.ru> (raw)
In-Reply-To: <20201214091616.13545-1-Sergey.Semin@baikalelectronics.ru>

In accordance with [1] the MDC clock frequency is supposed to be selected
with respect to the CSR clock frequency. CSR clock can be either tied to
the DW MAC system clock (GMAC main clock) or supplied via a dedicated
clk_csr_i signal. Current MDC clock selection procedure handles the former
case while having no support of the later one. That's wrong for the
devices which have separate system and CSR clocks. Let's fix it by first
trying to get the synchro-signal rate from the "pclk" clock, if it hasn't
been specified then fall-back to the "stmmaceth" clock.

[1] DesignWare Cores Ethernet MAC Universal Databook, Revision 3.73a,
    October 2013, p. 424.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 7f4d54d2fc72..719b00fd2a70 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -206,7 +206,12 @@ static void stmmac_clk_csr_set(struct stmmac_priv *priv)
 {
 	u32 clk_rate;
 
-	clk_rate = clk_get_rate(priv->plat->stmmac_clk);
+	/* If APB clock has been specified then it is supposed to be used
+	 * to select the CSR mode. Otherwise the application clock is the
+	 * source of the periodic signal for the CSR interface.
+	 */
+	clk_rate = clk_get_rate(priv->plat->pclk) ?:
+		   clk_get_rate(priv->plat->stmmac_clk);
 
 	/* Platform provided default clk_csr would be assumed valid
 	 * for all other cases except for the below mentioned ones.
-- 
2.29.2


  parent reply	other threads:[~2020-12-14  9:20 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-12-14  9:15 [PATCH 00/25] net: stmmac: Fix clocks/reset-related procedures Serge Semin
2020-12-14  9:15 ` [PATCH 01/25] dt-bindings: net: dwmac: Validate PBL for all IP-cores Serge Semin
2020-12-15 17:14   ` Rob Herring
2020-12-14  9:15 ` [PATCH 02/25] dt-bindings: net: dwmac: Extend number of PBL values Serge Semin
2020-12-15 17:14   ` Rob Herring
2020-12-14  9:15 ` [PATCH 03/25] dt-bindings: net: dwmac: Fix the TSO property declaration Serge Semin
2020-12-15 17:22   ` Rob Herring
2020-12-16  8:59     ` Serge Semin
2020-12-14  9:15 ` [PATCH 04/25] dt-bindings: net: dwmac: Refactor snps,*-config properties Serge Semin
2020-12-14 14:30   ` Rob Herring
2020-12-15  8:54     ` Serge Semin
2020-12-15 14:08       ` Rob Herring
2020-12-16  6:24         ` Serge Semin
2020-12-14  9:15 ` [PATCH 05/25] dt-bindings: net: dwmac: Elaborate stmmaceth/pclk description Serge Semin
2020-12-15 17:30   ` Rob Herring
2020-12-14  9:15 ` [PATCH 06/25] dt-bindings: net: dwmac: Add Tx/Rx clock sources Serge Semin
2020-12-15 17:32   ` Rob Herring
2020-12-16  6:02     ` Serge Semin
2020-12-15 17:32   ` Rob Herring
2020-12-14  9:15 ` [PATCH 07/25] dt-bindings: net: dwmac: Detach Generic DW MAC bindings Serge Semin
2020-12-15 17:50   ` Rob Herring
2020-12-16  9:10     ` Serge Semin
2020-12-14  9:15 ` [PATCH 08/25] net: stmmac: Add snps,*-config sub-nodes support Serge Semin
2020-12-14  9:15 ` [PATCH 09/25] net: stmmac: dwmac-rk: Cleanup STMMAC DT-config in remove cb Serge Semin
2020-12-14  9:16 ` [PATCH 10/25] net: stmmac: dwmac-sti: " Serge Semin
2020-12-14  9:16 ` [PATCH 11/25] net: stmmac: dwmac-stm32: " Serge Semin
2020-12-14  9:16 ` [PATCH 12/25] net: stmmac: Directly call reverse methods in stmmac_probe_config_dt() Serge Semin
2020-12-14  9:16 ` [PATCH 13/25] net: stmmac: Fix clocks left enabled on glue-probes failure Serge Semin
2020-12-14  9:16 ` [PATCH 14/25] net: stmmac: Use optional clock request method to get stmmaceth Serge Semin
2020-12-14  9:16 ` [PATCH 15/25] net: stmmac: Use optional clock request method to get pclk Serge Semin
2020-12-14  9:16 ` [PATCH 16/25] net: stmmac: Use optional clock request method to get ptp_clk Serge Semin
2020-12-14  9:16 ` [PATCH 17/25] net: stmmac: Use optional reset control API to work with stmmaceth Serge Semin
2020-12-14  9:16 ` [PATCH 18/25] net: stmmac: dwc-qos: Cleanup STMMAC platform data clock pointers Serge Semin
2020-12-14  9:16 ` [PATCH 19/25] net: stmmac: dwc-qos: Use dev_err_probe() for probe errors handling Serge Semin
2020-12-14  9:16 ` [PATCH 20/25] net: stmmac: Add Tx/Rx platform clocks support Serge Semin
2020-12-14  9:16 ` [PATCH 21/25] net: stmmac: dwc-qos: Discard Tx/Rx clocks request Serge Semin
2020-12-14  9:16 ` [PATCH 22/25] net: stmmac: dwmac-imx: Discard Tx clock request Serge Semin
2020-12-14  9:16 ` [PATCH 23/25] net: stmmac: Call stmmaceth clock as system clock in warn-message Serge Semin
2020-12-14  9:16 ` Serge Semin [this message]
2020-12-14  9:16 ` [PATCH 25/25] net: stmmac: dwc-qos: Save master/slave clocks in the plat-data Serge Semin

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