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* [PATCHv5 1/3] arm: socfpga: dts: Add a syscon binding for sys-mgr
@ 2013-08-23 15:44 dinguyen at altera.com
  2013-08-23 15:44 ` [PATCHv5 2/3] ARM: socfpga: dts: Add support for SD/MMC dinguyen at altera.com
  2013-08-23 15:44 ` [PATCHv5 3/3] mmc: dw_mmc: Use phandle to get SDR timing values from sys-mgr dinguyen at altera.com
  0 siblings, 2 replies; 8+ messages in thread
From: dinguyen at altera.com @ 2013-08-23 15:44 UTC (permalink / raw)
  To: linux-arm-kernel

From: Dinh Nguyen <dinguyen@altera.com>

The system manager block in SOCFPGA contains registers that control other
IPs in the SoC. Using the mfd/syscon driver is the best mechanism to
link the system manager to the other IPs.

Signed-off-by: Dinh Nguyen <dinguyen@altera.com>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: devicetree at vger.kernel.org
CC: linux-arm-kernel at lists.infradead.org
---
 arch/arm/boot/dts/socfpga.dtsi |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm/boot/dts/socfpga.dtsi b/arch/arm/boot/dts/socfpga.dtsi
index bee62a2..c31c8e9 100644
--- a/arch/arm/boot/dts/socfpga.dtsi
+++ b/arch/arm/boot/dts/socfpga.dtsi
@@ -520,8 +520,8 @@
 				reg = <0xffd05000 0x1000>;
 			};
 
-		sysmgr at ffd08000 {
-				compatible = "altr,sys-mgr";
+		system_mgr: sysmgr at ffd08000 {
+				compatible = "altr,sys-mgr", "syscon";
 				reg = <0xffd08000 0x4000>;
 			};
 	};
-- 
1.7.9.5

^ permalink raw reply related	[flat|nested] 8+ messages in thread

* [PATCHv5 2/3] ARM: socfpga: dts: Add support for SD/MMC
  2013-08-23 15:44 [PATCHv5 1/3] arm: socfpga: dts: Add a syscon binding for sys-mgr dinguyen at altera.com
@ 2013-08-23 15:44 ` dinguyen at altera.com
  2013-08-23 22:29   ` Stephen Warren
  2013-08-27 15:31   ` Steffen Trumtrar
  2013-08-23 15:44 ` [PATCHv5 3/3] mmc: dw_mmc: Use phandle to get SDR timing values from sys-mgr dinguyen at altera.com
  1 sibling, 2 replies; 8+ messages in thread
From: dinguyen at altera.com @ 2013-08-23 15:44 UTC (permalink / raw)
  To: linux-arm-kernel

From: Dinh Nguyen <dinguyen@altera.com>

Add bindings for SD/MMC for SOCFPGA.

Signed-off-by: Dinh Nguyen <dinguyen@altera.com>
Cc: Jaehoon Chung <jh80.chung@samsung.com>
Cc: Seungwon Jeon <tgih.jun@samsung.com>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: devicetree at vger.kernel.org
Cc: linux-mmc at vger.kernel.org
CC: linux-arm-kernel at lists.infradead.org

v5:
- Add "altr,ciu-clk-offset" that represents the necessary offset
  and shift values in the sysmgr phandle. This is used to set
  the correct CIU clock values.

v4:
- Add a complete binding example in documentations
- Add a phandle entry for "altr,sysmgr" which links the system
  manager to the SD/MMC IP block that controls the SDR timings.
- Split up patches
        1/3 - Add syscon binding to sys-mgr node
        2/3 - DTS bindings and documentation for SD/MMC on SOCFPGA
        3/3 - Driver changes to use the bindings

v3:
- Explicitly reference synopsis-dw-mshc.txt for base bindings
- Remove "dw-mshc-ciu-div" as driver can get clock information dts "ciu" entry
- Fixed indentation issue

v2:
- Remove bus-width and extra line in documentation
- Merge bindings example into a single node in documentation
---
 .../devicetree/bindings/mmc/socfpga-dw-mshc.txt    |   63 ++++++++++++++++++++
 arch/arm/boot/dts/socfpga.dtsi                     |   11 ++++
 arch/arm/boot/dts/socfpga_cyclone5.dts             |   14 +++++
 arch/arm/boot/dts/socfpga_vt.dts                   |   14 +++++
 4 files changed, 102 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mmc/socfpga-dw-mshc.txt

diff --git a/Documentation/devicetree/bindings/mmc/socfpga-dw-mshc.txt b/Documentation/devicetree/bindings/mmc/socfpga-dw-mshc.txt
new file mode 100644
index 0000000..70893a4
--- /dev/null
+++ b/Documentation/devicetree/bindings/mmc/socfpga-dw-mshc.txt
@@ -0,0 +1,63 @@
+* Altera SOCFPGA specific extensions to the Synopsis Designware Mobile
+  Storage Host Controller
+
+The Synopsis designware mobile storage host controller is used to interface
+a SoC with storage medium such as eMMC or SD/MMC cards. This file documents
+differences between the core Synopsis dw mshc controller properties described
+by synopsis-dw-mshc.txt and the properties used by the SOCFPGA specific
+extensions to the Synopsis Designware Mobile Storage Host Controller.
+
+Required Properties:
+
+* compatible: should be
+	- "altr,socfpga-dw-mshc": for controllers with Altera SOCFPGA
+	  specific extensions.
+
+* altr,dw-mshc-sdr-timing: Specifies the value of CIU clock phase shift value
+  in transmit mode and CIU clock phase shift value in receive mode for single
+  data rate mode operation. Refer to notes below for the order of the cells and the
+  valid values.
+
+  Notes for the sdr-timing values:
+
+    The order of the cells should be
+      - First Cell: CIU clock phase shift value for RX mode, smplsel bits in
+	the system manager SDMMC control group.
+      - Second Cell: CIU clock phase shift value for TX mode, drvsel bits in
+	the system manager SDMMC control group.
+
+    Valid values for SDR CIU clock timing for SOCFPGA:
+      - valid value for tx phase shift and rx phase shift is 0 to 7.
+
+* altr,sysmgr: Should be the phandle to the system_mgr node. As this is where
+		this where the register that controls the CIU clock phases
+		reside.
+
+* altr,ciu-clk-offset: The order of the cells should be:
+	- First Cell: Offset of the register in the system_mgr node that controls
+		the smpsel bits.
+	- Second Cell: Shift value of the drvsel bits.
+	- Third Cell: Shift value of the smpsel bits.
+
+Example:
+	dwmmc0 at ff704000 {
+		compatible = "altr,socfpga-dw-mshc", "snps,dw-mshc";
+		reg = <0xff704000 0x1000>;
+		interrupts = <0 139 4>;
+		fifo-depth = <0x400>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+		clocks = <&l4_mp_clk>, <&sdmmc_clk>;
+		clock-names = "biu", "ciu";
+		num-slots = <1>;
+		supports-highspeed;
+		broken-cd;
+		altr,sysmgr = <&system_mgr>;
+		altr,ciu-clk-offset = <0x108 0 3>;
+		altr,dw-mshc-sdr-timing = <0 3>;
+
+		slot at 0 {
+			reg = <0>;
+			bus-width = <4>;
+		};
+	};
diff --git a/arch/arm/boot/dts/socfpga.dtsi b/arch/arm/boot/dts/socfpga.dtsi
index c31c8e9..9706767 100644
--- a/arch/arm/boot/dts/socfpga.dtsi
+++ b/arch/arm/boot/dts/socfpga.dtsi
@@ -468,6 +468,17 @@
 			cache-level = <2>;
 		};
 
+		mmc: dwmmc0 at ff704000 {
+			compatible = "altr,socfpga-dw-mshc";
+			reg = <0xff704000 0x1000>;
+			interrupts = <0 139 4>;
+			fifo-depth = <0x400>;
+			#address-cells = <1>;
+			#size-cells = <0>;
+			clocks = <&l4_mp_clk>, <&sdmmc_clk>;
+			clock-names = "biu", "ciu";
+		};
+
 		/* Local timer */
 		timer at fffec600 {
 			compatible = "arm,cortex-a9-twd-timer";
diff --git a/arch/arm/boot/dts/socfpga_cyclone5.dts b/arch/arm/boot/dts/socfpga_cyclone5.dts
index 973999d..c5861b1 100644
--- a/arch/arm/boot/dts/socfpga_cyclone5.dts
+++ b/arch/arm/boot/dts/socfpga_cyclone5.dts
@@ -54,6 +54,20 @@
 			status = "okay";
 		};
 
+		dwmmc0 at ff704000 {
+			num-slots = <1>;
+			supports-highspeed;
+			broken-cd;
+			altr,sysmgr = <&system_mgr>;
+			altr,ciu-clk-offset = <0x108 0 3>;
+			altr,dw-mshc-sdr-timing = <0 3>;
+
+			slot at 0 {
+				reg = <0>;
+				bus-width = <4>;
+			};
+		};
+
 		timer0 at ffc08000 {
 			clock-frequency = <100000000>;
 		};
diff --git a/arch/arm/boot/dts/socfpga_vt.dts b/arch/arm/boot/dts/socfpga_vt.dts
index d1ec0ca..250991c 100644
--- a/arch/arm/boot/dts/socfpga_vt.dts
+++ b/arch/arm/boot/dts/socfpga_vt.dts
@@ -46,6 +46,20 @@
 			status = "okay";
 		};
 
+		dwmmc0 at ff704000 {
+			num-slots = <1>;
+			supports-highspeed;
+			broken-cd;
+			altr,sysmgr = <&system_mgr>;
+			altr,ciu-clk-offset = <0x108 0 3>;
+			altr,dw-mshc-sdr-timing = <0 3>;
+
+			slot at 0 {
+				reg = <0>;
+				bus-width = <4>;
+			};
+		};
+
 		timer0 at ffc08000 {
 			clock-frequency = <7000000>;
 		};
-- 
1.7.9.5

^ permalink raw reply related	[flat|nested] 8+ messages in thread

* [PATCHv5 3/3] mmc: dw_mmc: Use phandle to get SDR timing values from sys-mgr
  2013-08-23 15:44 [PATCHv5 1/3] arm: socfpga: dts: Add a syscon binding for sys-mgr dinguyen at altera.com
  2013-08-23 15:44 ` [PATCHv5 2/3] ARM: socfpga: dts: Add support for SD/MMC dinguyen at altera.com
@ 2013-08-23 15:44 ` dinguyen at altera.com
  2013-08-29 11:56   ` Seungwon Jeon
  1 sibling, 1 reply; 8+ messages in thread
From: dinguyen at altera.com @ 2013-08-23 15:44 UTC (permalink / raw)
  To: linux-arm-kernel

From: Dinh Nguyen <dinguyen@altera.com>

Update the driver to get the system manager node from a phandle. Also, the
driver can get the correct clock value from the common clock API, thus the
"altr,dw-mshc-ciu-div" binding is not needed at all.

Signed-off-by: Dinh Nguyen <dinguyen@altera.com>
Cc: Jaehoon Chung <jh80.chung@samsung.com>
Cc: Seungwon Jeon <tgih.jun@samsung.com>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Chris Ball <cjb@laptop.org>
Cc: devicetree at vger.kernel.org
Cc: linux-mmc at vger.kernel.org
CC: linux-arm-kernel at lists.infradead.org

v2:
- Use "altr,ciu-clk-offset" to get the correct CIU clock values to be
  set in the system manager.
---
 drivers/mmc/host/dw_mmc-socfpga.c |   33 +++++++++++++++------------------
 1 file changed, 15 insertions(+), 18 deletions(-)

diff --git a/drivers/mmc/host/dw_mmc-socfpga.c b/drivers/mmc/host/dw_mmc-socfpga.c
index 14b5961..cfd67e1 100644
--- a/drivers/mmc/host/dw_mmc-socfpga.c
+++ b/drivers/mmc/host/dw_mmc-socfpga.c
@@ -24,21 +24,20 @@
 #include "dw_mmc.h"
 #include "dw_mmc-pltfm.h"
 
-#define SYSMGR_SDMMCGRP_CTRL_OFFSET		0x108
-#define DRV_CLK_PHASE_SHIFT_SEL_MASK	0x7
-#define SYSMGR_SDMMC_CTRL_SET(smplsel, drvsel)          \
-	((((smplsel) & 0x7) << 3) | (((drvsel) & 0x7) << 0))
+#define DRV_CLK_PHASE_SHIFT_SEL_MASK   0x7
 
 /* SOCFPGA implementation specific driver private data */
 struct dw_mci_socfpga_priv_data {
-	u8	ciu_div; /* card interface unit divisor */
 	u32	hs_timing; /* bitmask for CIU clock phase shift */
 	struct regmap   *sysreg; /* regmap for system manager register */
+	/* Offset for the ciu clock setting register inside the system manager.*/
+	u32     ciu_clk_offset;
 };
 
 static int dw_mci_socfpga_priv_init(struct dw_mci *host)
 {
 	struct dw_mci_socfpga_priv_data *priv;
+	struct device_node *np = host->dev->of_node;
 
 	priv = devm_kzalloc(host->dev, sizeof(*priv), GFP_KERNEL);
 	if (!priv) {
@@ -46,9 +45,9 @@ static int dw_mci_socfpga_priv_init(struct dw_mci *host)
 		return -ENOMEM;
 	}
 
-	priv->sysreg = syscon_regmap_lookup_by_compatible("altr,sys-mgr");
+	priv->sysreg = syscon_regmap_lookup_by_phandle(np, "altr,sysmgr");
 	if (IS_ERR(priv->sysreg)) {
-		dev_err(host->dev, "regmap for altr,sys-mgr lookup failed.\n");
+		dev_err(host->dev, "No sysmgr phandle specified!\n");
 		return PTR_ERR(priv->sysreg);
 	}
 	host->priv = priv;
@@ -61,11 +60,8 @@ static int dw_mci_socfpga_setup_clock(struct dw_mci *host)
 	struct dw_mci_socfpga_priv_data *priv = host->priv;
 
 	clk_disable_unprepare(host->ciu_clk);
-	regmap_write(priv->sysreg, SYSMGR_SDMMCGRP_CTRL_OFFSET,
-		priv->hs_timing);
+	regmap_write(priv->sysreg, priv->ciu_clk_offset, priv->hs_timing);
 	clk_prepare_enable(host->ciu_clk);
-
-	host->bus_hz /= (priv->ciu_div + 1);
 	return 0;
 }
 
@@ -82,20 +78,21 @@ static int dw_mci_socfpga_parse_dt(struct dw_mci *host)
 	struct dw_mci_socfpga_priv_data *priv = host->priv;
 	struct device_node *np = host->dev->of_node;
 	u32 timing[2];
-	u32 div = 0;
+	u32 offset[3];
 	int ret;
 
-	ret = of_property_read_u32(np, "altr,dw-mshc-ciu-div", &div);
-	if (ret)
-		dev_info(host->dev, "No dw-mshc-ciu-div specified, assuming 1");
-	priv->ciu_div = div;
-
 	ret = of_property_read_u32_array(np,
 			"altr,dw-mshc-sdr-timing", timing, 2);
 	if (ret)
 		return ret;
 
-	priv->hs_timing = SYSMGR_SDMMC_CTRL_SET(timing[0], timing[1]);
+	ret = of_property_read_u32_array(np, "altr,ciu-clk-offset", offset, 3);
+	if (ret)
+		return ret;
+
+	priv->ciu_clk_offset = offset[0];
+	priv->hs_timing =
+		((((timing[0]) & 0x7) << offset[2]) | (((timing[1]) & 0x7) << offset[1]));
 	return 0;
 }
 
-- 
1.7.9.5

^ permalink raw reply related	[flat|nested] 8+ messages in thread

* [PATCHv5 2/3] ARM: socfpga: dts: Add support for SD/MMC
  2013-08-23 15:44 ` [PATCHv5 2/3] ARM: socfpga: dts: Add support for SD/MMC dinguyen at altera.com
@ 2013-08-23 22:29   ` Stephen Warren
  2013-08-23 23:01     ` Dinh Nguyen
  2013-08-27 15:31   ` Steffen Trumtrar
  1 sibling, 1 reply; 8+ messages in thread
From: Stephen Warren @ 2013-08-23 22:29 UTC (permalink / raw)
  To: linux-arm-kernel

On 08/23/2013 09:44 AM, dinguyen at altera.com wrote:
> From: Dinh Nguyen <dinguyen@altera.com>
> 
> Add bindings for SD/MMC for SOCFPGA.

> diff --git a/Documentation/devicetree/bindings/mmc/socfpga-dw-mshc.txt b/Documentation/devicetree/bindings/mmc/socfpga-dw-mshc.txt

> +* altr,sysmgr: Should be the phandle to the system_mgr node. As this is where
> +		this where the register that controls the CIU clock phases
> +		reside.
> +
> +* altr,ciu-clk-offset: The order of the cells should be:
> +	- First Cell: Offset of the register in the system_mgr node that controls
> +		the smpsel bits.
> +	- Second Cell: Shift value of the drvsel bits.
> +	- Third Cell: Shift value of the smpsel bits.

This almost solves the issues I was thinking of. A few more thoughts though:

* What if the sysmgr node has multiple reg entries. Is the offset cell
in altr,ciu-clk-offset an offset from the first reg entry, or across all
reg entries? It might be better to specify this as a reg index plus
offset, or allow the sysmgr node to define the format (#sysmgr-cells
perhaps).

* What if the drvsel and smpsel bits are in different registers, even
different sysmgr blocks? Wouldn't it be better to have 2 separate
properties, each one defining the location of one bit-field?

* bikeshed: altr,ciu-clk-offset isn't a great name; the value is more
than just an offset.

Putting those together, I might expect the following properties:

sysmgr: sysmgr {
    /* binding for sysmgr node must specify what those 3 cells are */
    #sysmgr-cells = <3>;
}

dwmmc {
    altr,drvsel-reg-field = <
        &sysmgr /* sysmgr phandle */
        0 /* reg index */
        0 /* reg offset */
        0 /* field bit position */
        3 /* field bit size */>;
    altr,smpsel-reg-field = <
        &sysmgr /* sysmgr phandle */
        0 /* reg index */
        0 /* reg offset */
        3 /* field bit position */
        3 /* field bit size */>;
};

That would allow the whole sysmgr concept to be completely generic.

But, this is a bit like representing raw register I/O in DT, which has
been frowned upon in the past.

Finally, what if the values for drvsel, smpsel are different in
different sysmgr implementations? Do you need a property that defines
that values?

Another option might be to define a semantic API between the two, such
that you only need a sysmgr=<&sysmgr> property, yet the driver for the
sysmgr node exposes a function sysmgr_set_dwmmc_drvsel_smpsel(struct
device_node *sysmgr_node, uint drvsel, uint smpsel); Now, the sysmgr
driver would have to implement that on any SoC that supported a dwmmc.

^ permalink raw reply	[flat|nested] 8+ messages in thread

* [PATCHv5 2/3] ARM: socfpga: dts: Add support for SD/MMC
  2013-08-23 22:29   ` Stephen Warren
@ 2013-08-23 23:01     ` Dinh Nguyen
  2013-08-26 16:44       ` Stephen Warren
  0 siblings, 1 reply; 8+ messages in thread
From: Dinh Nguyen @ 2013-08-23 23:01 UTC (permalink / raw)
  To: linux-arm-kernel

On Fri, 2013-08-23 at 16:29 -0600, Stephen Warren wrote:
> On 08/23/2013 09:44 AM, dinguyen at altera.com wrote:
> > From: Dinh Nguyen <dinguyen@altera.com>
> > 
> > Add bindings for SD/MMC for SOCFPGA.
> 
> > diff --git a/Documentation/devicetree/bindings/mmc/socfpga-dw-mshc.txt b/Documentation/devicetree/bindings/mmc/socfpga-dw-mshc.txt
> 
> > +* altr,sysmgr: Should be the phandle to the system_mgr node. As this is where
> > +		this where the register that controls the CIU clock phases
> > +		reside.
> > +
> > +* altr,ciu-clk-offset: The order of the cells should be:
> > +	- First Cell: Offset of the register in the system_mgr node that controls
> > +		the smpsel bits.
> > +	- Second Cell: Shift value of the drvsel bits.
> > +	- Third Cell: Shift value of the smpsel bits.
> 
> This almost solves the issues I was thinking of. A few more thoughts though:
> 
> * What if the sysmgr node has multiple reg entries. Is the offset cell
> in altr,ciu-clk-offset an offset from the first reg entry, or across all
> reg entries? It might be better to specify this as a reg index plus
> offset, or allow the sysmgr node to define the format (#sysmgr-cells
> perhaps).
> 
> * What if the drvsel and smpsel bits are in different registers, even
> different sysmgr blocks? Wouldn't it be better to have 2 separate
> properties, each one defining the location of one bit-field?
> 
> * bikeshed: altr,ciu-clk-offset isn't a great name; the value is more
> than just an offset.
> 
> Putting those together, I might expect the following properties:
> 
> sysmgr: sysmgr {
>     /* binding for sysmgr node must specify what those 3 cells are */
>     #sysmgr-cells = <3>;
> }
> 
> dwmmc {
>     altr,drvsel-reg-field = <
>         &sysmgr /* sysmgr phandle */
>         0 /* reg index */
>         0 /* reg offset */
>         0 /* field bit position */
>         3 /* field bit size */>;
>     altr,smpsel-reg-field = <
>         &sysmgr /* sysmgr phandle */
>         0 /* reg index */
>         0 /* reg offset */
>         3 /* field bit position */
>         3 /* field bit size */>;
> };
> 
> That would allow the whole sysmgr concept to be completely generic.
> 
> But, this is a bit like representing raw register I/O in DT, which has
> been frowned upon in the past.
> 
> Finally, what if the values for drvsel, smpsel are different in
> different sysmgr implementations? Do you need a property that defines
> that values?
> 
> Another option might be to define a semantic API between the two, such
> that you only need a sysmgr=<&sysmgr> property, yet the driver for the
> sysmgr node exposes a function sysmgr_set_dwmmc_drvsel_smpsel(struct
> device_node *sysmgr_node, uint drvsel, uint smpsel); Now, the sysmgr
> driver would have to implement that on any SoC that supported a dwmmc.

I was trying to avoid adding a driver for the sysmgr, as it really does
not represent any type of device. It is a merely a register region with
miscellaneous registers that controls other IPs in the SOC.

I'm thinking perhaps I can set this register in the arch specific file,
then the SD/MMC driver would not need to bother with it at all?

Thanks,
Dinh
> 
> 

^ permalink raw reply	[flat|nested] 8+ messages in thread

* [PATCHv5 2/3] ARM: socfpga: dts: Add support for SD/MMC
  2013-08-23 23:01     ` Dinh Nguyen
@ 2013-08-26 16:44       ` Stephen Warren
  0 siblings, 0 replies; 8+ messages in thread
From: Stephen Warren @ 2013-08-26 16:44 UTC (permalink / raw)
  To: linux-arm-kernel

On 08/23/2013 05:01 PM, Dinh Nguyen wrote:
> On Fri, 2013-08-23 at 16:29 -0600, Stephen Warren wrote:
>> On 08/23/2013 09:44 AM, dinguyen at altera.com wrote:
>>> From: Dinh Nguyen <dinguyen@altera.com>
>>>
>>> Add bindings for SD/MMC for SOCFPGA.
>>
>>> diff --git a/Documentation/devicetree/bindings/mmc/socfpga-dw-mshc.txt b/Documentation/devicetree/bindings/mmc/socfpga-dw-mshc.txt
>>
>>> +* altr,sysmgr: Should be the phandle to the system_mgr node. As this is where
>>> +		this where the register that controls the CIU clock phases
>>> +		reside.
>>> +
>>> +* altr,ciu-clk-offset: The order of the cells should be:
>>> +	- First Cell: Offset of the register in the system_mgr node that controls
>>> +		the smpsel bits.
>>> +	- Second Cell: Shift value of the drvsel bits.
>>> +	- Third Cell: Shift value of the smpsel bits.
>>
>> This almost solves the issues I was thinking of. A few more thoughts though:
>>
>> * What if the sysmgr node has multiple reg entries. Is the offset cell
>> in altr,ciu-clk-offset an offset from the first reg entry, or across all
>> reg entries? It might be better to specify this as a reg index plus
>> offset, or allow the sysmgr node to define the format (#sysmgr-cells
>> perhaps).
>>
>> * What if the drvsel and smpsel bits are in different registers, even
>> different sysmgr blocks? Wouldn't it be better to have 2 separate
>> properties, each one defining the location of one bit-field?
>>
>> * bikeshed: altr,ciu-clk-offset isn't a great name; the value is more
>> than just an offset.
>>
>> Putting those together, I might expect the following properties:
>>
>> sysmgr: sysmgr {
>>     /* binding for sysmgr node must specify what those 3 cells are */
>>     #sysmgr-cells = <3>;
>> }
>>
>> dwmmc {
>>     altr,drvsel-reg-field = <
>>         &sysmgr /* sysmgr phandle */
>>         0 /* reg index */
>>         0 /* reg offset */
>>         0 /* field bit position */
>>         3 /* field bit size */>;
>>     altr,smpsel-reg-field = <
>>         &sysmgr /* sysmgr phandle */
>>         0 /* reg index */
>>         0 /* reg offset */
>>         3 /* field bit position */
>>         3 /* field bit size */>;
>> };
>>
>> That would allow the whole sysmgr concept to be completely generic.
>>
>> But, this is a bit like representing raw register I/O in DT, which has
>> been frowned upon in the past.
>>
>> Finally, what if the values for drvsel, smpsel are different in
>> different sysmgr implementations? Do you need a property that defines
>> that values?
>>
>> Another option might be to define a semantic API between the two, such
>> that you only need a sysmgr=<&sysmgr> property, yet the driver for the
>> sysmgr node exposes a function sysmgr_set_dwmmc_drvsel_smpsel(struct
>> device_node *sysmgr_node, uint drvsel, uint smpsel); Now, the sysmgr
>> driver would have to implement that on any SoC that supported a dwmmc.
> 
> I was trying to avoid adding a driver for the sysmgr, as it really does
> not represent any type of device. It is a merely a register region with
> miscellaneous registers that controls other IPs in the SOC.
> 
> I'm thinking perhaps I can set this register in the arch specific file,
> then the SD/MMC driver would not need to bother with it at all?

The problem with hard-coding this in the MMC driver is that it makes the
MMC driver depend on information outside the MMC HW block. If you do
that, you may as well just write the "syscon" registers directly in the
MMC driver.

^ permalink raw reply	[flat|nested] 8+ messages in thread

* [PATCHv5 2/3] ARM: socfpga: dts: Add support for SD/MMC
  2013-08-23 15:44 ` [PATCHv5 2/3] ARM: socfpga: dts: Add support for SD/MMC dinguyen at altera.com
  2013-08-23 22:29   ` Stephen Warren
@ 2013-08-27 15:31   ` Steffen Trumtrar
  1 sibling, 0 replies; 8+ messages in thread
From: Steffen Trumtrar @ 2013-08-27 15:31 UTC (permalink / raw)
  To: linux-arm-kernel

Hi!

On Fri, Aug 23, 2013 at 10:44:45AM -0500, dinguyen at altera.com wrote:
> From: Dinh Nguyen <dinguyen@altera.com>
> 
> Add bindings for SD/MMC for SOCFPGA.
> 
> Signed-off-by: Dinh Nguyen <dinguyen@altera.com>
> Cc: Jaehoon Chung <jh80.chung@samsung.com>
> Cc: Seungwon Jeon <tgih.jun@samsung.com>
> Cc: Rob Herring <rob.herring@calxeda.com>
> Cc: Pawel Moll <pawel.moll@arm.com>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: Stephen Warren <swarren@wwwdotorg.org>
> Cc: Ian Campbell <ian.campbell@citrix.com>
> Cc: devicetree at vger.kernel.org
> Cc: linux-mmc at vger.kernel.org
> CC: linux-arm-kernel at lists.infradead.org
> 
> v5:
> - Add "altr,ciu-clk-offset" that represents the necessary offset
>   and shift values in the sysmgr phandle. This is used to set
>   the correct CIU clock values.
> 
> v4:
> - Add a complete binding example in documentations
> - Add a phandle entry for "altr,sysmgr" which links the system
>   manager to the SD/MMC IP block that controls the SDR timings.
> - Split up patches
>         1/3 - Add syscon binding to sys-mgr node
>         2/3 - DTS bindings and documentation for SD/MMC on SOCFPGA
>         3/3 - Driver changes to use the bindings
> 
> v3:
> - Explicitly reference synopsis-dw-mshc.txt for base bindings
> - Remove "dw-mshc-ciu-div" as driver can get clock information dts "ciu" entry
> - Fixed indentation issue
> 
> v2:
> - Remove bus-width and extra line in documentation
> - Merge bindings example into a single node in documentation
> ---

You should put your changelogs here and not above the ---
AFAIK nobody cares for the development history of a patch once it is applied.

>  .../devicetree/bindings/mmc/socfpga-dw-mshc.txt    |   63 ++++++++++++++++++++
>  arch/arm/boot/dts/socfpga.dtsi                     |   11 ++++
>  arch/arm/boot/dts/socfpga_cyclone5.dts             |   14 +++++
>  arch/arm/boot/dts/socfpga_vt.dts                   |   14 +++++
>  4 files changed, 102 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/mmc/socfpga-dw-mshc.txt
> 

Regards,
Steffen

-- 
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^ permalink raw reply	[flat|nested] 8+ messages in thread

* [PATCHv5 3/3] mmc: dw_mmc: Use phandle to get SDR timing values from sys-mgr
  2013-08-23 15:44 ` [PATCHv5 3/3] mmc: dw_mmc: Use phandle to get SDR timing values from sys-mgr dinguyen at altera.com
@ 2013-08-29 11:56   ` Seungwon Jeon
  0 siblings, 0 replies; 8+ messages in thread
From: Seungwon Jeon @ 2013-08-29 11:56 UTC (permalink / raw)
  To: linux-arm-kernel

On Saturday, August 24, 2013, Dinh Nguyen wrote:
> From: Dinh Nguyen <dinguyen@altera.com>
> 
> Update the driver to get the system manager node from a phandle. Also, the
> driver can get the correct clock value from the common clock API, thus the
> "altr,dw-mshc-ciu-div" binding is not needed at all.
> 
> Signed-off-by: Dinh Nguyen <dinguyen@altera.com>
> Cc: Jaehoon Chung <jh80.chung@samsung.com>
> Cc: Seungwon Jeon <tgih.jun@samsung.com>
> Cc: Rob Herring <rob.herring@calxeda.com>
> Cc: Pawel Moll <pawel.moll@arm.com>
> Cc: Mark Rutland <mark.rutland@arm.com>
> Cc: Stephen Warren <swarren@wwwdotorg.org>
> Cc: Ian Campbell <ian.campbell@citrix.com>
> Cc: Chris Ball <cjb@laptop.org>
> Cc: devicetree at vger.kernel.org
> Cc: linux-mmc at vger.kernel.org
> CC: linux-arm-kernel at lists.infradead.org
> 
> v2:
> - Use "altr,ciu-clk-offset" to get the correct CIU clock values to be
>   set in the system manager.
> ---
>  drivers/mmc/host/dw_mmc-socfpga.c |   33 +++++++++++++++------------------
>  1 file changed, 15 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/mmc/host/dw_mmc-socfpga.c b/drivers/mmc/host/dw_mmc-socfpga.c
> index 14b5961..cfd67e1 100644
> --- a/drivers/mmc/host/dw_mmc-socfpga.c
> +++ b/drivers/mmc/host/dw_mmc-socfpga.c
> @@ -24,21 +24,20 @@
>  #include "dw_mmc.h"
>  #include "dw_mmc-pltfm.h"
> 
> -#define SYSMGR_SDMMCGRP_CTRL_OFFSET		0x108
> -#define DRV_CLK_PHASE_SHIFT_SEL_MASK	0x7
> -#define SYSMGR_SDMMC_CTRL_SET(smplsel, drvsel)          \
> -	((((smplsel) & 0x7) << 3) | (((drvsel) & 0x7) << 0))
> +#define DRV_CLK_PHASE_SHIFT_SEL_MASK   0x7
> 
>  /* SOCFPGA implementation specific driver private data */
>  struct dw_mci_socfpga_priv_data {
> -	u8	ciu_div; /* card interface unit divisor */
>  	u32	hs_timing; /* bitmask for CIU clock phase shift */
>  	struct regmap   *sysreg; /* regmap for system manager register */
> +	/* Offset for the ciu clock setting register inside the system manager.*/
> +	u32     ciu_clk_offset;
>  };
> 
>  static int dw_mci_socfpga_priv_init(struct dw_mci *host)
>  {
>  	struct dw_mci_socfpga_priv_data *priv;
> +	struct device_node *np = host->dev->of_node;
> 
>  	priv = devm_kzalloc(host->dev, sizeof(*priv), GFP_KERNEL);
>  	if (!priv) {
> @@ -46,9 +45,9 @@ static int dw_mci_socfpga_priv_init(struct dw_mci *host)
>  		return -ENOMEM;
>  	}
> 
> -	priv->sysreg = syscon_regmap_lookup_by_compatible("altr,sys-mgr");
> +	priv->sysreg = syscon_regmap_lookup_by_phandle(np, "altr,sysmgr");
>  	if (IS_ERR(priv->sysreg)) {
> -		dev_err(host->dev, "regmap for altr,sys-mgr lookup failed.\n");
> +		dev_err(host->dev, "No sysmgr phandle specified!\n");
>  		return PTR_ERR(priv->sysreg);
>  	}
>  	host->priv = priv;
> @@ -61,11 +60,8 @@ static int dw_mci_socfpga_setup_clock(struct dw_mci *host)
>  	struct dw_mci_socfpga_priv_data *priv = host->priv;
> 
>  	clk_disable_unprepare(host->ciu_clk);
> -	regmap_write(priv->sysreg, SYSMGR_SDMMCGRP_CTRL_OFFSET,
> -		priv->hs_timing);
> +	regmap_write(priv->sysreg, priv->ciu_clk_offset, priv->hs_timing);
>  	clk_prepare_enable(host->ciu_clk);
> -
> -	host->bus_hz /= (priv->ciu_div + 1);
>  	return 0;
>  }
> 
> @@ -82,20 +78,21 @@ static int dw_mci_socfpga_parse_dt(struct dw_mci *host)
>  	struct dw_mci_socfpga_priv_data *priv = host->priv;
>  	struct device_node *np = host->dev->of_node;
>  	u32 timing[2];
> -	u32 div = 0;
> +	u32 offset[3];
>  	int ret;
> 
> -	ret = of_property_read_u32(np, "altr,dw-mshc-ciu-div", &div);
> -	if (ret)
> -		dev_info(host->dev, "No dw-mshc-ciu-div specified, assuming 1");
> -	priv->ciu_div = div;
> -
>  	ret = of_property_read_u32_array(np,
>  			"altr,dw-mshc-sdr-timing", timing, 2);
>  	if (ret)
>  		return ret;
> 
> -	priv->hs_timing = SYSMGR_SDMMC_CTRL_SET(timing[0], timing[1]);
> +	ret = of_property_read_u32_array(np, "altr,ciu-clk-offset", offset, 3);
> +	if (ret)
> +		return ret;
> +
> +	priv->ciu_clk_offset = offset[0];
> +	priv->hs_timing =
> +		((((timing[0]) & 0x7) << offset[2]) | (((timing[1]) & 0x7) << offset[1]));
offset should be gotten from DT?
These are variable?

Thanks,
Seungwon Jeon

>  	return 0;
>  }
> 
> --
> 1.7.9.5
> 
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
> the body of a message to majordomo at vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

^ permalink raw reply	[flat|nested] 8+ messages in thread

end of thread, other threads:[~2013-08-29 11:56 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2013-08-23 15:44 [PATCHv5 1/3] arm: socfpga: dts: Add a syscon binding for sys-mgr dinguyen at altera.com
2013-08-23 15:44 ` [PATCHv5 2/3] ARM: socfpga: dts: Add support for SD/MMC dinguyen at altera.com
2013-08-23 22:29   ` Stephen Warren
2013-08-23 23:01     ` Dinh Nguyen
2013-08-26 16:44       ` Stephen Warren
2013-08-27 15:31   ` Steffen Trumtrar
2013-08-23 15:44 ` [PATCHv5 3/3] mmc: dw_mmc: Use phandle to get SDR timing values from sys-mgr dinguyen at altera.com
2013-08-29 11:56   ` Seungwon Jeon

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