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From: Douglas Anderson <dianders@chromium.org>
To: ulf.hansson@linaro.org, kishon@ti.com,
	Heiko Stuebner <heiko@sntech.de>,
	robh+dt@kernel.org
Cc: shawn.lin@rock-chips.com, xzy.xu@rock-chips.com,
	briannorris@chromium.org, adrian.hunter@intel.com,
	linux-rockchip@lists.infradead.org, linux-mmc@vger.kernel.org,
	devicetree@vger.kernel.org,
	Douglas Anderson <dianders@chromium.org>,
	pawel.moll@arm.com, mark.rutland@arm.com,
	ijc+devicetree@hellion.org.uk, galak@codeaurora.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH 03/11] Documentation: mmc: sdhci-of-arasan: Add soc-ctl-syscon for corecfg regs
Date: Tue,  7 Jun 2016 15:44:36 -0700	[thread overview]
Message-ID: <1465339484-969-4-git-send-email-dianders@chromium.org> (raw)
In-Reply-To: <1465339484-969-1-git-send-email-dianders@chromium.org>

As can be seen in Arasan's datasheet [1] there are several "corecfg"
settings in their SDHCI IP Block that are supposed to be controlled by
software.  Although the datasheet referenced is a bit vague about how to
access corecfg, in Figure 5 you can see that for Arasan's PHY (a
separate component than their SDHCI component) they describe the
"phyctrl" registers as being "FROM SOC CTL REG", implying that it's up
to the licensee of the Arasan IP block to implement these registers.  It
seems sane to assume that the "corecfg" registers in their SDHCI IP
block works in a similar way for all licensees of the IP Block.

Device tree has a model that allows a device to get a reference to
random registers located elsewhere in the SoC: sysctl.  Let's leverage
this model and allow adding a sysctl reference to access the control
registers for the Arasan SDHCI PHYs.

Having a reference to the control registers doesn't do much for us on
its own since the Arasan spec doesn't specify how these corecfg values
are laid out in memory.  In the SDHCI driver we'll need a map detailing
where each corecfg can be found in each implementation.  This map can be
found using the primary compatible string of the SDHCI device.  In that
spirit, document that existing rk3399 device trees already have a
specific compatible string, though up to now they've always been relying
on the driver supporting the generic.

Note that since existing devices seem to work fairly well as-is, we'll
list the syscon reference as "optional", but it's likely that we'll run
into much fewer problems if we can actually set the proper values in the
syscon, so it is strongly suggested that any SoCs where we have a map to
set the corecfg also include a reference to the syscon.

[1]: https://arasan.com/wp-content/media/eMMC-5-1-Total-Solution_Rev-1-3.pdf

Signed-off-by: Douglas Anderson <dianders@chromium.org>
---
 .../devicetree/bindings/mmc/arasan,sdhci.txt       | 27 ++++++++++++++++++++--
 1 file changed, 25 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/mmc/arasan,sdhci.txt b/Documentation/devicetree/bindings/mmc/arasan,sdhci.txt
index 31b35c3a5e47..b67e623ca1ff 100644
--- a/Documentation/devicetree/bindings/mmc/arasan,sdhci.txt
+++ b/Documentation/devicetree/bindings/mmc/arasan,sdhci.txt
@@ -9,8 +9,12 @@ Device Tree Bindings for the Arasan SDHCI Controller
   [4] Documentation/devicetree/bindings/phy/phy-bindings.txt
 
 Required Properties:
-  - compatible: Compatibility string. Must be 'arasan,sdhci-8.9a' or
-                'arasan,sdhci-4.9a' or 'arasan,sdhci-5.1'
+  - compatible: Compatibility string.  One of:
+    - "arasan,sdhci-8.9a"
+    - "arasan,sdhci-4.9a"
+    - "arasan,sdhci-5.1"
+    - "rockchip,rk3399-sdhci-5.1", "arasan,sdhci-5.1": The PHY in rk3399.
+      For this device it is strongly suggested to include arasan,soc-ctl-syscon.
   - reg: From mmc bindings: Register location and length.
   - clocks: From clock bindings: Handles to clock inputs.
   - clock-names: From clock bindings: Tuple including "clk_xin" and "clk_ahb"
@@ -22,6 +26,11 @@ Required Properties for "arasan,sdhci-5.1":
   - phys: From PHY bindings: Phandle for the Generic PHY for arasan.
   - phy-names:  MUST be "phy_arasan".
 
+Optional Properties:
+  - arasan,soc-ctl-syscon: A phandle to a syscon device (see ../mfd/syscon.txt)
+    used to access core corecfg registers.  Offsets of registers in this
+    syscon are determined based on the main compatible string for the device.
+
 Example:
 	sdhci@e0100000 {
 		compatible = "arasan,sdhci-8.9a";
@@ -42,3 +51,17 @@ Example:
 		phys = <&emmc_phy>;
 		phy-names = "phy_arasan";
 	} ;
+
+	sdhci: sdhci@fe330000 {
+		compatible = "rockchip,rk3399-sdhci-5.1", "arasan,sdhci-5.1";
+		reg = <0x0 0xfe330000 0x0 0x10000>;
+		interrupts = <GIC_SPI 11 IRQ_TYPE_LEVEL_HIGH>;
+		clocks = <&cru SCLK_EMMC>, <&cru ACLK_EMMC>;
+		clock-names = "clk_xin", "clk_ahb";
+		arasan,soc-ctl-syscon = <&grf>;
+		assigned-clocks = <&cru SCLK_EMMC>;
+		assigned-clock-rates = <200000000>;
+		phys = <&emmc_phy>;
+		phy-names = "phy_arasan";
+		status = "disabled";
+	};
-- 
2.8.0.rc3.226.g39d4020

  parent reply	other threads:[~2016-06-07 22:48 UTC|newest]

Thread overview: 39+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-06-07 22:44 [PATCH 0/11] Changes to support 150 MHz eMMC on rk3399 Douglas Anderson
2016-06-07 22:44 ` [PATCH 01/11] phy: rockchip-emmc: Increase lock time allowance Douglas Anderson
2016-06-13  7:58   ` Shawn Lin
2016-06-13 23:07     ` Doug Anderson
2016-06-07 22:44 ` [PATCH 02/11] mmc: sdhci-of-arasan: Always power the PHY off/on when clock changes Douglas Anderson
2016-06-13  8:08   ` Shawn Lin
2016-06-13 23:06     ` Doug Anderson
2016-06-07 22:44 ` Douglas Anderson [this message]
2016-06-08 20:17   ` [PATCH 03/11] Documentation: mmc: sdhci-of-arasan: Add soc-ctl-syscon for corecfg regs Rob Herring
2016-06-13  8:18   ` Shawn Lin
2016-06-13  9:32     ` Heiko Stübner
2016-06-13 23:07     ` Doug Anderson
2016-06-07 22:44 ` [PATCH 04/11] mmc: sdhci-of-arasan: Properly set corecfg_baseclkfreq on rk3399 Douglas Anderson
2016-06-13  8:36   ` Shawn Lin
2016-06-13 23:06     ` Doug Anderson
2016-06-14  0:14       ` Shawn Lin
2016-06-14  0:43         ` Doug Anderson
2016-06-14  0:59           ` Shawn Lin
2016-06-14  2:13             ` Doug Anderson
2016-06-16  1:06               ` Shawn Lin
2016-06-07 22:44 ` [PATCH 05/11] arm64: dts: rockchip: Add soc-ctl-syscon to sdhci for rk3399 Douglas Anderson
2016-06-07 22:44 ` [PATCH 06/11] Documentation: mmc: sdhci-of-arasan: Add ability to export card clock Douglas Anderson
2016-06-08 20:19   ` Rob Herring
2016-06-08 20:52     ` Doug Anderson
2016-06-10 13:10       ` Rob Herring
2016-06-13 23:05         ` Doug Anderson
2016-06-07 22:44 ` [PATCH 07/11] " Douglas Anderson
2016-06-07 22:44 ` [PATCH 08/11] Documentation: phy: Let the rockchip eMMC PHY get an exported " Douglas Anderson
2016-06-10 13:36   ` Rob Herring
2016-06-13 23:05     ` Doug Anderson
2016-06-07 22:44 ` [PATCH 09/11] phy: rockchip-emmc: Set phyctrl_frqsel based on " Douglas Anderson
2016-06-13  8:54   ` Shawn Lin
2016-06-13 23:05     ` Doug Anderson
2016-06-14  0:24       ` Shawn Lin
2016-06-14  0:45         ` Doug Anderson
2016-06-07 22:44 ` [PATCH 10/11] phy: rockchip-emmc: Minor code cleanup in rockchip_emmc_phy_power_off() Douglas Anderson
2016-06-13  8:56   ` Shawn Lin
2016-06-13 23:05     ` Doug Anderson
2016-06-07 22:44 ` [PATCH 11/11] arm64: dts: rockchip: Provide emmcclk to PHY for rk3399 Douglas Anderson

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